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Sample records for anti-apoptotic protein bcl-2

  1. Withaferin A Suppresses Anti-apoptotic BCL2, Bcl-xL, XIAP and ...

    African Journals Online (AJOL)

    apoptotic ... Quantitative real-time polymerase chain reaction (qPCR) was performed using Taq PCR Master ... Keywords: Anti-apoptotic genes, Cervical cancer, Apoptosis, Cell viability, BCL2, .... polyclonal anti-rabbit immunoglobulin HRP-linked.

  2. B cell lymphoma-2 (BCL-2) homology domain 3 (BH3) mimetics demonstrate differential activities dependent upon the functional repertoire of pro- and anti-apoptotic BCL-2 family proteins.

    Science.gov (United States)

    Renault, Thibaud T; Elkholi, Rana; Bharti, Archana; Chipuk, Jerry E

    2014-09-19

    The B cell lymphoma-2 (BCL-2) family is the key mediator of cellular sensitivity to apoptosis during pharmacological interventions for numerous human pathologies, including cancer. There is tremendous interest to understand how the proapoptotic BCL-2 effector members (e.g. BCL-2-associated X protein, BAX) cooperate with the BCL-2 homology domain only (BH3-only) subclass (e.g. BCL-2 interacting mediator of death, BIM; BCL-2 interacting-domain death agonist, BID) to induce mitochondrial outer membrane permeabilization (MOMP) and apoptosis and whether these mechanisms may be pharmacologically exploited to enhance the killing of cancer cells. Indeed, small molecule inhibitors of the anti-apoptotic BCL-2 family members have been designed rationally. However, the success of these "BH3 mimetics" in the clinic has been limited, likely due to an incomplete understanding of how these drugs function in the presence of multiple BCL-2 family members. To increase our mechanistic understanding of how BH3 mimetics cooperate with multiple BCL-2 family members in vitro, we directly compared the activity of several BH3-mimetic compounds (i.e. ABT-263, ABT-737, GX15-070, HA14.1, TW-37) in biochemically defined large unilamellar vesicle model systems that faithfully recapitulate BAX-dependent mitochondrial outer membrane permeabilization. Our investigations revealed that the presence of BAX, BID, and BIM differentially regulated the ability of BH3 mimetics to derepress proapoptotic molecules from anti-apoptotic proteins. Using mitochondria loaded with fluorescent BH3 peptides and cells treated with inducers of cell death, these differences were supported. Together, these data suggest that although the presence of anti-apoptotic BCL-2 proteins primarily dictates cellular sensitivity to BH3 mimetics, additional specificity is conferred by proapoptotic BCL-2 proteins. © 2014 by The American Society for Biochemistry and Molecular Biology, Inc.

  3. Reconstitution of the anti-apoptotic Bcl-2 protein into lipid membranes and biophysical evidence for its detergent-driven association with the pro-apoptotic Bax protein.

    Directory of Open Access Journals (Sweden)

    Marcus Wallgren

    Full Text Available The anti-apoptotic B-cell CLL/lymphoma-2 (Bcl-2 protein and its counterpart, the pro-apoptotic Bcl-2-associated X protein (Bax, are key players in the regulation of the mitochondrial pathway of apoptosis. However, how they interact at the mitochondrial outer membrane (MOM and there determine whether the cell will live or be sentenced to death remains unknown. Competing models have been presented that describe how Bcl-2 inhibits the cell-killing activity of Bax, which is common in treatment-resistant tumors where Bcl-2 is overexpressed. Some studies suggest that Bcl-2 binds directly to and sequesters Bax, while others suggest an indirect process whereby Bcl-2 blocks BH3-only proteins and prevents them from activating Bax. Here we present the results of a biophysical study in which we investigated the putative interaction of solubilized full-length human Bcl-2 with Bax and the scope for incorporating the former into a native-like lipid environment. Far-UV circular dichroism (CD spectroscopy was used to detect direct Bcl-2-Bax-interactions in the presence of polyoxyethylene-(23-lauryl-ether (Brij-35 detergent at a level below its critical micelle concentration (CMC. Additional surface plasmon resonance (SPR measurements confirmed this observation and revealed a high affinity between the Bax and Bcl-2 proteins. Upon formation of this protein-protein complex, Bax also prevented the binding of antimycin A2 (a known inhibitory ligand of Bcl-2 to the Bcl-2 protein, as fluorescence spectroscopy experiments showed. In addition, Bcl-2 was able to form mixed micelles with Triton X-100 solubilized neutral phospholipids in the presence of high concentrations of Brij-35 (above its CMC. Following detergent removal, the integral membrane protein was found to have been fully reconstituted into a native-like membrane environment, as confirmed by ultracentrifugation and subsequent SDS-PAGE experiments.

  4. Interaction of a putative BH3 domain of clusterin with anti-apoptotic Bcl-2 family proteins as revealed by NMR spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Dong-Hwa; Ha, Ji-Hyang [Medical Proteomics Research Center, KRIBB, Daejeon 305-806 (Korea, Republic of); Kim, Yul [Department of Bio and Brain Engineering, KAIST, Daejeon 305-701 (Korea, Republic of); Bae, Kwang-Hee [Medical Proteomics Research Center, KRIBB, Daejeon 305-806 (Korea, Republic of); Park, Jae-Yong [Department of Physiology, Institute of Health Science, School of Medicine, Gyeongsang National University, Jinju, Gyeongnam 660-751 (Korea, Republic of); Choi, Wan Sung [Department of Anatomy and Neurobiology, Institute of Health Science, School of Medicine, Gyeongsang National University, Jinju, Gyeongnam 660-751 (Korea, Republic of); Yoon, Ho Sup [Division of Structural and Computational Biology, School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, Singapore 637511 (Singapore); Park, Sung Goo; Park, Byoung Chul [Medical Proteomics Research Center, KRIBB, Daejeon 305-806 (Korea, Republic of); Yi, Gwan-Su, E-mail: gsyi@kaist.ac.kr [Department of Bio and Brain Engineering, KAIST, Daejeon 305-701 (Korea, Republic of); Chi, Seung-Wook, E-mail: swchi@kribb.re.kr [Medical Proteomics Research Center, KRIBB, Daejeon 305-806 (Korea, Republic of)

    2011-05-20

    Highlights: {yields} Identification of a conserved BH3 motif in C-terminal coiled coil region of nCLU. {yields} The nCLU BH3 domain binds to BH3 peptide-binding grooves in both Bcl-X{sub L} and Bcl-2. {yields} A conserved binding mechanism of nCLU BH3 and the other pro-apoptotic BH3 peptides with Bcl-X{sub L}. {yields} The absolutely conserved Leu323 and Asp328 of nCLU BH3 domain are critical for binding to Bcl-X{sub L.} {yields} Molecular understanding of the pro-apoptotic function of nCLU as a novel BH3-only protein. -- Abstract: Clusterin (CLU) is a multifunctional glycoprotein that is overexpressed in prostate and breast cancers. Although CLU is known to be involved in the regulation of apoptosis and cell survival, the precise molecular mechanism underlying the pro-apoptotic function of nuclear CLU (nCLU) remains unclear. In this study, we identified a conserved BH3 motif in C-terminal coiled coil (CC2) region of nCLU by sequence analysis and characterized the molecular interaction of the putative nCLU BH3 domain with anti-apoptotic Bcl-2 family proteins by nuclear magnetic resonance (NMR) spectroscopy. The chemical shift perturbation data demonstrated that the nCLU BH3 domain binds to pro-apoptotic BH3 peptide-binding grooves in both Bcl-X{sub L} and Bcl-2. A structural model of the Bcl-X{sub L}/nCLU BH3 peptide complex reveals that the binding mode is remarkably similar to those of other Bcl-X{sub L}/BH3 peptide complexes. In addition, mutational analysis confirmed that Leu323 and Asp328 of nCLU BH3 domain, absolutely conserved in the BH3 motifs of BH3-only protein family, are critical for binding to Bcl-X{sub L}. Taken altogether, our results suggest a molecular basis for the pro-apoptotic function of nCLU by elucidating the residue specific interactions of the BH3 motif in nCLU with anti-apoptotic Bcl-2 family proteins.

  5. Molecular interactions of prodiginines with the BH3 domain of anti-apoptotic Bcl-2 family members.

    Directory of Open Access Journals (Sweden)

    Ali Hosseini

    Full Text Available Prodigiosin and obatoclax, members of the prodiginines family, are small molecules with anti-cancer properties that are currently under preclinical and clinical trials. The molecular target(s of these agents, however, is an open question. Combining experimental and computational techniques we find that prodigiosin binds to the BH3 domain in some BCL-2 protein families, which play an important role in the apoptotic programmed cell death. In particular, our results indicate a large affinity of prodigiosin for MCL-1, an anti-apoptotic member of the BCL-2 family. In melanoma cells, we demonstrate that prodigiosin activates the mitochondrial apoptotic pathway by disrupting MCL-1/BAK complexes. Computer simulations with the PELE software allow the description of the induced fit process, obtaining a detailed atomic view of the molecular interactions. These results provide new data to understand the mechanism of action of these molecules, and assist in the development of more specific inhibitors of anti-apoptotic BCL-2 proteins.

  6. The anti-apoptotic members of the Bcl-2 family are attractive tumor-associated antigens

    DEFF Research Database (Denmark)

    Straten, Per thor; Andersen, Mads Hald; Andersen, Mads Hald

    2010-01-01

    Anti-apoptotic members of the Bcl-2 family (Bcl-2, Bcl-X(L) and Mcl-2) are pivotal regulators of apoptotic cell death. They are all highly overexpressed in cancers of different origin in which they enhance the survival of the cancer cells. Consequently, they represent prime candidates for anti-ca...

  7. Inhibition of early 99mTc-MIBI uptake by Bcl-2 anti-apoptotic protein overexpression in untreated breast carcinoma

    International Nuclear Information System (INIS)

    Del Vecchio, Silvana; Zannetti, Antonella; Aloj, Luigi; Caraco, Corradina; Ciarmiello, Andrea; Salvatore, Marco

    2003-01-01

    Lack of technetium-99m methoxyisobutylisonitrile ( 99m Tc-MIBI) uptake is consistently reported to predict poor response to subsequent chemotherapy in a variety of human malignant tumours. Since 99m Tc-MIBI accumulates within mitochondria, which also play a central role in apoptosis through the integration of death signals by Bcl-2 family members, we tested whether early 99m Tc-MIBI uptake is affected by alterations of the apoptotic pathway. Forty-two breast cancer patients were intravenously injected with 740 MBq of 99m Tc-MIBI and planar images were obtained 10 min post injection with the patients in the prone lateral position. Ten carcinomas failed to accumulate 99m Tc-MIBI and could not be visualised on scintigraphic images despite being larger than 1.8 cm (MIBI negative). Thirty-two of the 42 breast carcinomas showed focal uptake of 99m Tc-MIBI (MIBI positive), and 10 min tumour-to-background ratios (T/B) varied between 1.14 and 6.93. The apoptotic index, the rate of proliferation, and the expression of the anti-apoptotic Bcl-2 protein and pro-apoptotic Bax protein were assessed in surgically excised tumours. All MIBI-negative carcinomas showed a dramatic and statistically significant reduction in the apoptotic index as compared with MIBI-positive lesions (mean±SD, 0.14±0.15 vs 1.28±0.83, P 99m Tc-MIBI in breast carcinomas is affected by alterations of apoptotic pathway. High levels of Bcl-2, despite the stabilisation of mitochondrial membrane potentials, prevent accumulation of 99m Tc-MIBI in tumour cells. In conclusion, absent or reduced early 99m Tc-MIBI uptake in large tumours may indicate a Bcl-2-mediated resistance to chemo- and radiotherapy. (orig.)

  8. Orphan Nuclear Receptor NR4A1 Binds a Novel Protein Interaction Site on Anti-apoptotic B Cell Lymphoma Gene 2 Family Proteins.

    Science.gov (United States)

    Godoi, Paulo H C; Wilkie-Grantham, Rachel P; Hishiki, Asami; Sano, Renata; Matsuzawa, Yasuko; Yanagi, Hiroko; Munte, Claudia E; Chen, Ya; Yao, Yong; Marassi, Francesca M; Kalbitzer, Hans R; Matsuzawa, Shu-Ichi; Reed, John C

    2016-07-01

    B cell lymphoma gene 2 (Bcl-2) family proteins are key regulators of programmed cell death and important targets for drug discovery. Pro-apoptotic and anti-apoptotic Bcl-2 family proteins reciprocally modulate their activities in large part through protein interactions involving a motif known as BH3 (Bcl-2 homology 3). Nur77 is an orphan member of the nuclear receptor family that lacks a BH3 domain but nevertheless binds certain anti-apoptotic Bcl-2 family proteins (Bcl-2, Bfl-1, and Bcl-B), modulating their effects on apoptosis and autophagy. We used a combination of NMR spectroscopy-based methods, mutagenesis, and functional studies to define the interaction site of a Nur77 peptide on anti-apoptotic Bcl-2 family proteins and reveal a novel interaction surface. Nur77 binds adjacent to the BH3 peptide-binding crevice, suggesting the possibility of cross-talk between these discrete binding sites. Mutagenesis of residues lining the identified interaction site on Bcl-B negated the interaction with Nur77 protein in cells and prevented Nur77-mediated modulation of apoptosis and autophagy. The findings establish a new protein interaction site with the potential to modulate the apoptosis and autophagy mechanisms governed by Bcl-2 family proteins. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

  9. Anti-Apoptotic Protein Bcl-xL Expression in the Midbrain Raphe Region Is Sensitive to Stress and Glucocorticoids.

    Science.gov (United States)

    Shishkina, Galina T; Kalinina, Tatyana S; Bulygina, Veta V; Lanshakov, Dmitry A; Babluk, Ekaterina V; Dygalo, Nikolay N

    2015-01-01

    Anti-apoptotic proteins are suggested to be important for the normal health of neurons and synapses as well as for resilience to stress. In order to determine whether stressful events may influence the expression of anti-apoptotic protein Bcl-xL in the midbrain and specifically in the midbrain serotonergic (5-HT) neurons involved in neurobehavioral responses to adverse stimuli, adult male rats were subjected to short-term or chronic forced swim stress. A short-term stress rapidly increased the midbrain bcl-xl mRNA levels and significantly elevated Bcl-xL immunoreactivity in the midbrain 5-HT cells. Stress-induced increase in glucocorticoid secretion was implicated in the observed effect. The levels of bcl-xl mRNA were decreased after stress when glucocorticoid elevation was inhibited by metyrapone (MET, 150 mg/kg), and this decrease was attenuated by glucocorticoid replacement with dexamethasone (DEX; 0.2 mg/kg). Both short-term stress and acute DEX administration, in parallel with Bcl-xL, caused a significant increase in tph2 mRNA levels and slightly enhanced tryptophan hydroxylase immunoreactivity in the midbrain. The increasing effect on the bcl-xl expression was specific to the short-term stress. Forced swim repeated daily for 2 weeks led to a decrease in bcl-xl mRNA in the midbrain without any effects on the Bcl-xL protein expression in the 5-HT neurons. In chronically stressed animals, an increase in tph2 gene expression was not associated with any changes in tryptophan hydroxylase protein levels. Our findings are the first to demonstrate that both short-term stress and acute glucocorticoid exposures induce Bcl-xL protein expression in the midbrain 5-HT neurons concomitantly with the activation of the 5-HT synthesis pathway in these neurons.

  10. Anti-Apoptotic Protein Bcl-xL Expression in the Midbrain Raphe Region Is Sensitive to Stress and Glucocorticoids.

    Directory of Open Access Journals (Sweden)

    Galina T Shishkina

    Full Text Available Anti-apoptotic proteins are suggested to be important for the normal health of neurons and synapses as well as for resilience to stress. In order to determine whether stressful events may influence the expression of anti-apoptotic protein Bcl-xL in the midbrain and specifically in the midbrain serotonergic (5-HT neurons involved in neurobehavioral responses to adverse stimuli, adult male rats were subjected to short-term or chronic forced swim stress. A short-term stress rapidly increased the midbrain bcl-xl mRNA levels and significantly elevated Bcl-xL immunoreactivity in the midbrain 5-HT cells. Stress-induced increase in glucocorticoid secretion was implicated in the observed effect. The levels of bcl-xl mRNA were decreased after stress when glucocorticoid elevation was inhibited by metyrapone (MET, 150 mg/kg, and this decrease was attenuated by glucocorticoid replacement with dexamethasone (DEX; 0.2 mg/kg. Both short-term stress and acute DEX administration, in parallel with Bcl-xL, caused a significant increase in tph2 mRNA levels and slightly enhanced tryptophan hydroxylase immunoreactivity in the midbrain. The increasing effect on the bcl-xl expression was specific to the short-term stress. Forced swim repeated daily for 2 weeks led to a decrease in bcl-xl mRNA in the midbrain without any effects on the Bcl-xL protein expression in the 5-HT neurons. In chronically stressed animals, an increase in tph2 gene expression was not associated with any changes in tryptophan hydroxylase protein levels. Our findings are the first to demonstrate that both short-term stress and acute glucocorticoid exposures induce Bcl-xL protein expression in the midbrain 5-HT neurons concomitantly with the activation of the 5-HT synthesis pathway in these neurons.

  11. Metformin combined with aspirin significantly inhibit pancreatic cancer cell growth in vitro and in vivo by suppressing anti-apoptotic proteins Mcl-1 and Bcl-2

    Science.gov (United States)

    Yue, Wen; Zheng, Xi; Lin, Yong; Yang, Chung S.; Xu, Qing; Carpizo, Darren; Huang, Huarong; DiPaola, Robert S.; Tan, Xiang-Lin

    2015-01-01

    Metformin and aspirin have been studied extensively as cancer preventive or therapeutic agents. However, the effects of their combination on pancreatic cancer cells have not been investigated. Herein, we evaluated the effects of metformin and aspirin, alone or in combination, on cell viability, migration, and apoptosis as well as the molecular changes in mTOR, STAT3 and apoptotic signaling pathways in PANC-1 and BxPC3 cells. Metformin and aspirin, at relatively low concentrations, demonstrated synergistically inhibitory effects on cell viability. Compared to the untreated control or individual drug, the combination of metformin and aspirin significantly inhibited cell migration and colony formation of both PANC-1 and BxPC-3 cells. Metformin combined with aspirin significantly inhibited the phosphorylation of mTOR and STAT3, and induced apoptosis as measured by caspase-3 and PARP cleavage. Remarkably, metformin combined with aspirin significantly downregulated the anti-apoptotic proteins Mcl-1 and Bcl-2, and upregulated the pro-apoptotic proteins Bim and Puma, as well as interrupted their interactions. The downregulation of Mcl-1 and Bcl-2 was independent of AMPK or STAT3 pathway but partially through mTOR signaling and proteasome degradation. In a PANC-1 xenograft mouse model, we demonstrated that the combination of metformin and aspirin significantly inhibited tumor growth and downregulated the protein expression of Mcl-1 and Bcl-2 in tumors. Taken together, the combination of metformin and aspirin significantly inhibited pancreatic cancer cell growth in vitro and in vivo by regulating the pro- and anti-apoptotic Bcl-2 family members, supporting the continued investigation of this two drug combination as chemopreventive or chemotherapeutic agents for pancreatic cancer. PMID:26056043

  12. A Review on Structures and Functions of Bcl-2 Family Proteins from Homo sapiens.

    Science.gov (United States)

    Sivakumar, Dakshinamurthy; Sivaraman, Thirunavukkarasu

    2016-01-01

    Cancer cells evade apoptosis, which is regulated by proteins of Bcl-2 family in the intrinsic pathways. Numerous experimental three-dimensional (3D) structures of the apoptotic proteins and the proteins bound with small chemical molecules/peptides/proteins have been reported in the literature. In this review article, the 3D structures of the Bcl-2 family proteins from Homo sapiens and as well complex structures of the anti-apoptotic proteins bound with small molecular inhibitors reported in the literature to date have been comprehensively listed out and described in detail. Moreover, the molecular mechanisms by which the Bcl-2 family proteins modulate the apoptotic processes and strategies for designing antagonists to anti-apoptotic proteins have been concisely discussed.

  13. Withaferin A Suppresses Anti-apoptotic BCL2, Bcl-xL, XIAP and ...

    African Journals Online (AJOL)

    apoptotic genes, BCL2, Bcl-xL, XIAP and Survivin), in cervical carcinoma cells. Methods: Annexin V-FITC/propidium iodide (PI) staining was used for the investigation of cell apoptosis. RNA RNeasy Kits was used to isolate RNA and Omniscript ...

  14. Protein phosphatase 2A mediates JS-K-induced apoptosis by affecting Bcl-2 family proteins in human hepatocellular carcinoma HepG2 cells.

    Science.gov (United States)

    Liu, Ling; Huang, Zile; Chen, Jingjing; Wang, Jiangang; Wang, Shuying

    2018-04-25

    Protein phosphatase 2A (PP2A) is an important enzyme within various signal transduction pathways. The present study was investigated PP2A mediates JS-K-induced apoptosis by affecting Bcl-2 family protein. JS-K showed diverse inhibitory effects in five HCC cell lines, especially HepG2 cells. JS-K caused a dose- and time-dependent reduction in cell viability and increased in levels of LDH release. Meanwhile, JS-K- induced apoptosis was characterized by mitochondrial membrane potential reduction, Hoechst 33342 + /PI + dual staining, release of cytochrome c (Cyt c), and activation of cleaved caspase-9/3. Moreover, JS-K-treatment could lead to the activation of protein phosphatase 2A-C (PP2A-C), decrease of anti-apoptotic Bcl-2 family-protein expression including p-Bcl-2 (Ser70), Bcl-2, Bcl-xL, and Mcl-1 as well as the increase of pro-apoptosis Bcl-2 family-protein including Bim, Bad, Bax, and Bak. Furthermore, JS-K caused a marked increase of intracellular NO levels while pre-treatment with Carboxy-PTIO (a NO scavenger) reduced the cytotoxicity effects and the apoptosis rate. Meanwhile, pre-treatment with Carboxy-PTIO attenuated the JS-K-induced up-regulation of PP2A, Cyt c, and cleaved-caspase-9/3 activation. The silencing PP2A-C by siRNA could abolish the activation of PP2A-C, down-regulation of anti-apoptotic Bcl-2 family-protein (p-Bcl-2, Bcl-2, Bcl-xL, and Mcl-1), increase of pro-apoptosis Bcl-2 family-protein (Bim, Bad, Bax, and Bak) and apoptotic-related protein (Cyt c, cleaved caspase-9/3) that were caused by JS-K in HepG2 cells. In addition, pre-treatment with OA (a PP2A inhibitor) also attenuated the above effects induced by JS-K. In summary, NO release from JS-K induces apoptosis through PP2A activation, which contributed to the regulation of Bcl-2 family proteins. © 2018 Wiley Periodicals, Inc.

  15. BAG1: the guardian of anti-apoptotic proteins in acute myeloid leukemia.

    Directory of Open Access Journals (Sweden)

    Sanja Aveic

    Full Text Available BCL2 associated Athano-Gene 1 (BAG1 is a multifunctional protein that has been described to be involved in different cell processes linked to cell survival. It has been reported as deregulated in diverse cancer types. Here, BAG1 protein was found highly expressed in children with acute myeloid leukemia at diagnosis, and in a cohort of leukemic cell lines. A silencing approach was used for determining BAG1's role in AML, finding that its down-regulation decreased expression of BCL2, BCL-XL, MCL1, and phospho-ERK1/2, all proteins able to sustain leukemia, without affecting the pro-apoptotic protein BAX. BAG1 down-regulation was also found to increase expression of BAG3, whose similar activity was able to compensate the loss of function of BAG1. BAG1/BAG3 co-silencing caused an enhanced cell predisposition to death in cell lines and also in primary AML cultures, affecting the same proteins. Cell death was CASPASE-3 dependent, was accompanied by PARP cleavage and documented by an increased release of pro-apoptotic molecules Smac/DIABLO and Cytochrome c. BAG1 was found to directly maintain BCL2 and to protect MCL1 from proteasomal degradation by controlling USP9X expression, which appeared to be its novel target. Finally, BAG1 was found able to affect leukemia cell fate by influencing the expression of anti-apoptotic proteins crucial for AML maintenance.

  16. Targeting anti-apoptotic Bcl-2 by AT-101 to increase radiation efficacy: data from in vitro and clinical pharmacokinetic studies in head and neck cancer

    International Nuclear Information System (INIS)

    Zerp, Shuraila F.; Stoter, T. Rianne; Hoebers, Frank J. P.; Brekel, Michiel W. M. van den; Dubbelman, Ria; Kuipers, Gitta K.; Lafleur, M. Vincent M.; Slotman, Ben J.; Verheij, Marcel

    2015-01-01

    Pro-survival Bcl-2 family members can promote cancer development and contribute to treatment resistance. Head and neck squamous cell carcinoma (HNSCC) is frequently characterized by overexpression of anti-apoptotic Bcl-2 family members. Increased levels of these anti-apoptotic proteins have been associated with radio- and chemoresistance and poor clinical outcome. Inhibition of anti-apoptotic Bcl-2 family members therefore represents an appealing strategy to overcome resistance to anti-cancer therapies. The aim of this study was to evaluate combined effects of radiation and the pan-Bcl-2 inhibitor AT-101 in HNSCC in vitro. In addition, we determined human plasma levels of AT-101 obtained from a phase I/II trial, and compared these with the effective in vitro concentrations to substantiate therapeutic opportunities. We examined the effect of AT-101, radiation and the combination on apoptosis induction and clonogenic survival in two HNSCC cell lines that express the target proteins. Apoptosis was assessed by bis-benzimide staining to detect morphological nuclear changes and/or by propidium iodide staining and flow-cytometry analysis to quantify sub-diploid apoptotic nuclei. The type of interaction between AT-101 and radiation was evaluated by calculating the Combination Index (CI) and by performing isobolographic analysis. For the pharmacokinetic analysis, plasma AT-101 levels were measured by HPLC in blood samples collected from patients enrolled in our clinical phase I/II study. These patients with locally advanced HNSCC were treated with standard cisplatin-based chemoradiotherapy and received dose-escalating oral AT-101 in a 2-weeks daily schedule every 3 weeks. In vitro results showed that AT-101 enhances radiation-induced apoptosis with CI’s below 1.0, indicating synergy. This effect was sequence-dependent. Clonogenic survival assays demonstrated a radiosensitizing effect with a DEF 37 of 1.3 at sub-apoptotic concentrations of AT-101. Pharmacokinetic analysis

  17. Xanthorrhizol induced DNA fragmentation in HepG2 cells involving Bcl-2 family proteins

    International Nuclear Information System (INIS)

    Tee, Thiam-Tsui; Cheah, Yew-Hoong; Meenakshii, Nallappan; Mohd Sharom, Mohd Yusof; Azimahtol Hawariah, Lope Pihie

    2012-01-01

    Highlights: ► We isolated xanthorrhizol, a sesquiterpenoid compound from Curcuma xanthorrhiza. ► Xanthorrhizol induced apoptosis in HepG2 cells as observed using SEM. ► Apoptosis in xanthorrhizol-treated HepG2 cells involved Bcl-2 family proteins. ► DNA fragmentation was observed in xanthorrhizol-treated HepG2 cells. ► DNA fragmentation maybe due to cleavage of PARP and DFF45/ICAD proteins. -- Abstract: Xanthorrhizol is a plant-derived pharmacologically active sesquiterpenoid compound isolated from Curcuma xanthorrhiza. Previously, we have reported that xanthorrhizol inhibited the proliferation of HepG2 human hepatoma cells by inducing apoptotic cell death via caspase activation. Here, we attempt to further elucidate the mode of action of xanthorrhizol. Apoptosis in xanthorrhizol-treated HepG2 cells as observed by scanning electron microscopy was accompanied by truncation of BID; reduction of both anti-apoptotic Bcl-2 and Bcl-X L expression; cleavage of PARP and DFF45/ICAD proteins and DNA fragmentation. Taken together, these results suggest xanthorrhizol as a potent antiproliferative agent on HepG2 cells by inducing apoptosis via Bcl-2 family members. Hence we proposed that xanthorrhizol could be used as an anti-liver cancer drug for future studies.

  18. Xanthorrhizol induced DNA fragmentation in HepG2 cells involving Bcl-2 family proteins

    Energy Technology Data Exchange (ETDEWEB)

    Tee, Thiam-Tsui, E-mail: thiamtsu@yahoo.com [School of Biosciences and Biotechnology, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor (Malaysia); Cheah, Yew-Hoong [School of Biosciences and Biotechnology, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor (Malaysia); Bioassay Unit, Herbal Medicine Research Center, Institute for Medical Research, Jalan Pahang, Kuala Lumpur (Malaysia); Meenakshii, Nallappan [Biology Department, Faculty of Science, Universiti Putra Malaysia, 43400 Serdang, Selangor (Malaysia); Mohd Sharom, Mohd Yusof; Azimahtol Hawariah, Lope Pihie [School of Biosciences and Biotechnology, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor (Malaysia)

    2012-04-20

    Highlights: Black-Right-Pointing-Pointer We isolated xanthorrhizol, a sesquiterpenoid compound from Curcuma xanthorrhiza. Black-Right-Pointing-Pointer Xanthorrhizol induced apoptosis in HepG2 cells as observed using SEM. Black-Right-Pointing-Pointer Apoptosis in xanthorrhizol-treated HepG2 cells involved Bcl-2 family proteins. Black-Right-Pointing-Pointer DNA fragmentation was observed in xanthorrhizol-treated HepG2 cells. Black-Right-Pointing-Pointer DNA fragmentation maybe due to cleavage of PARP and DFF45/ICAD proteins. -- Abstract: Xanthorrhizol is a plant-derived pharmacologically active sesquiterpenoid compound isolated from Curcuma xanthorrhiza. Previously, we have reported that xanthorrhizol inhibited the proliferation of HepG2 human hepatoma cells by inducing apoptotic cell death via caspase activation. Here, we attempt to further elucidate the mode of action of xanthorrhizol. Apoptosis in xanthorrhizol-treated HepG2 cells as observed by scanning electron microscopy was accompanied by truncation of BID; reduction of both anti-apoptotic Bcl-2 and Bcl-X{sub L} expression; cleavage of PARP and DFF45/ICAD proteins and DNA fragmentation. Taken together, these results suggest xanthorrhizol as a potent antiproliferative agent on HepG2 cells by inducing apoptosis via Bcl-2 family members. Hence we proposed that xanthorrhizol could be used as an anti-liver cancer drug for future studies.

  19. Bcl-2 family of proteins as drug targets for cancer chemotherapy: the long way of BH3 mimetics from bench to bedside.

    Science.gov (United States)

    Vela, Laura; Marzo, Isabel

    2015-08-01

    Bcl-2 proteins are key determinants in the life-death balance. In recent years, proteins in this family have been identified as drug targets in the design of new anti-tumor therapies. Advances in the knowledge of the mechanism of action of anti-apoptotic and pro-apoptotic members of the Bcl-2 family have enabled the development of the so-called 'BH3 mimetics'. These compounds act by inhibiting anti-apoptotic proteins of the family, imitating the function of the BH3-only subset of pro-apoptotic members. Combinations of BH3-mimetics with anti-tumor drugs are being evaluated in both preclinical models and clinical trials. Recent advances in these approaches will be reviewed. Copyright © 2015 Elsevier Ltd. All rights reserved.

  20. Mito-priming as a method to engineer Bcl-2 addiction.

    Science.gov (United States)

    Lopez, Jonathan; Bessou, Margaux; Riley, Joel S; Giampazolias, Evangelos; Todt, Franziska; Rochegüe, Tony; Oberst, Andrew; Green, Douglas R; Edlich, Frank; Ichim, Gabriel; Tait, Stephen W G

    2016-02-02

    Most apoptotic stimuli require mitochondrial outer membrane permeabilization (MOMP) in order to execute cell death. As such, MOMP is subject to tight control by Bcl-2 family proteins. We have developed a powerful new technique to investigate Bcl-2-mediated regulation of MOMP. This method, called mito-priming, uses co-expression of pro- and anti-apoptotic Bcl-2 proteins to engineer Bcl-2 addiction. On addition of Bcl-2 targeting BH3 mimetics, mito-primed cells undergo apoptosis in a rapid and synchronous manner. Using this method we have comprehensively surveyed the efficacy of BH3 mimetic compounds, identifying potent and specific MCL-1 inhibitors. Furthermore, by combining different pro- and anti-apoptotic Bcl-2 pairings together with CRISPR/Cas9-based genome editing, we find that tBID and PUMA can preferentially kill in a BAK-dependent manner. In summary, mito-priming represents a facile and robust means to trigger mitochondrial apoptosis.

  1. Bcl-2 protein level in blood of patients with acute myeloid leukaemia ...

    African Journals Online (AJOL)

    (AML), bcl-2 being an anti-apoptotic protein incriminated in cancer. ... resistant to apoptosis, defining this protein as a factor of bad prognosis in AML. Moreover, the determination ..... of the molecular mechanisms of physiological ... long term survival in breast cancer, Am. J. Pathol. ... Burkitt subtype at presentation, and is not.

  2. Homologous recombination control by the anti-apoptotic onco-protein Bcl-2

    International Nuclear Information System (INIS)

    Dumay, A.

    2003-12-01

    This research thesis deals with the different biological mechanisms, notably the repair and apoptosis mechanisms induced by irradiation in cells. After a presentation of the genotoxic stress and DNA repair mechanisms, the author discusses the cellular response to a DNA double-strand break, and the regulation of these response mechanisms (how a cellular response emerges: life or death). The next part deals with the apoptosis (cell death by necrosis or apoptosis), and presents the BCL-2 protein family. Results are then reported on laboratory studies of the effect of this protein family

  3. SPATA4 Counteracts Etoposide-Induced Apoptosis via Modulating Bcl-2 Family Proteins in HeLa Cells.

    Science.gov (United States)

    Jiang, Junjun; Li, Liyuan; Xie, Mingchao; Fuji, Ryosuke; Liu, Shangfeng; Yin, Xiaobei; Li, Genlin; Wang, Zhao

    2015-01-01

    Spermatogenesis associated 4 (SPATA4) is a testis-specific gene first cloned by our laboratory, and plays an important role in maintaining the physiological function of germ cells. Accumulated evidence suggests that SPATA4 might be associated with apoptosis. Here we established HeLa cells that stably expressed SPATA4 to investigate the function of SPATA4 in apoptosis. SPATA4 protected HeLa cells from etoposide-induced apoptosis through the mitochondrial apoptotic pathway, in the way that SPATA4 suppressed decrease of the mitochondrial membrane potential, the release of cytochrome c, and subsequent activation of caspase-9 and -3. We further demonstrated that SPATA4 upregulated anti-apoptotic members of Bcl-2 family proteins, Bcl-2, and downregulated the pro-apoptotic member of Bcl-2 family proteins, Bax. Knockdown of SPATA4 in HeLa/SPATA4 cells could partially rescue expression levels of bcl-2 and bax. In conclusion, SPATA4 protects HeLa cells against etoposide-induced apoptosis through the mitochondrial apoptotic pathway. Our findings provide further evidence that SPATA4 plays a role in regulating apoptosis.

  4. BH3-only proteins and BH3 mimetics induce autophagy by competitively disrupting the interaction between Beclin 1 and Bcl-2/Bcl-X(L).

    Science.gov (United States)

    Maiuri, Maria Chiara; Criollo, Alfredo; Tasdemir, Ezgi; Vicencio, José Miguel; Tajeddine, Nicolas; Hickman, John A; Geneste, Olivier; Kroemer, Guido

    2007-01-01

    Beclin 1 has recently been identified as novel BH3-only protein, meaning that it carries one Bcl-2-homology-3 (BH3) domain. As other BH3-only proteins, Beclin 1 interacts with anti-apoptotic multidomain proteins of the Bcl-2 family (in particular Bcl-2 and its homologue Bcl-X(L)) by virtue of its BH3 domain, an amphipathic alpha-helix that binds to the hydrophobic cleft of Bcl-2/Bcl-X(L). The BH3 domains of other BH3-only proteins such as Bad, as well as BH3-mimetic compounds such as ABT737, competitively disrupt the inhibitory interaction between Beclin 1 and Bcl-2/Bcl-X(L). This causes autophagy of mitochondria (mitophagy) but not of the endoplasmic reticulum (reticulophagy). Only ER-targeted (not mitochondrion-targeted) Bcl-2/Bcl-X(L) can inhibit autophagy induced by Beclin 1, and only Beclin 1-Bcl-2/Bcl-X(L) complexes present in the ER (but not those present on heavy membrane fractions enriched in mitochondria) are disrupted by ABT737. These findings suggest that the Beclin 1-Bcl-2/Bcl-X(L) complexes that normally inhibit autophagy are specifically located in the ER and point to an organelle-specific regulation of autophagy. Furthermore, these data suggest a spatial organization of autophagy and apoptosis control in which BH3-only proteins exert two independent functions. On the one hand, they can induce apoptosis, by (directly or indirectly) activating the mitochondrion-permeabilizing function of pro-apoptotic multidomain proteins from the Bcl-2 family. On the other hand, they can activate autophagy by liberating Beclin 1 from its inhibition by Bcl-2/Bcl-X(L) at the level of the endoplasmic reticulum.

  5. The sensitivity of diffuse large B-cell lymphoma cell lines to histone deacetylase inhibitor-induced apoptosis is modulated by BCL-2 family protein activity.

    Directory of Open Access Journals (Sweden)

    Ryan C Thompson

    Full Text Available BACKGROUND: Diffuse large B-cell lymphoma (DLBCL is a genetically heterogeneous disease and this variation can often be used to explain the response of individual patients to chemotherapy. One cancer therapeutic approach currently in clinical trials uses histone deacetylase inhibitors (HDACi's as monotherapy or in combination with other agents. METHODOLOGY/PRINCIPAL FINDINGS: We have used a variety of cell-based and molecular/biochemical assays to show that two pan-HDAC inhibitors, trichostatin A and vorinostat, induce apoptosis in seven of eight human DLBCL cell lines. Consistent with previous reports implicating the BCL-2 family in regulating HDACi-induced apoptosis, ectopic over-expression of anti-apoptotic proteins BCL-2 and BCL-XL or pro-apoptotic protein BIM in these cell lines conferred further resistance or sensitivity, respectively, to HDACi treatment. Additionally, BCL-2 family antgonist ABT-737 increased the sensitivity of several DLBCL cell lines to vorinostat-induced apoptosis, including one cell line (SUDHL6 that is resistant to vorinostat alone. Moreover, two variants of the HDACi-sensitive SUDHL4 cell line that have decreased sensitivity to vorinostat showed up-regulation of BCL-2 family anti-apoptotic proteins such as BCL-XL and MCL-1, as well as decreased sensitivity to ABT-737. These results suggest that the regulation and overall balance of anti- to pro-apoptotic BCL-2 family protein expression is important in defining the sensitivity of DLBCL to HDACi-induced apoptosis. However, the sensitivity of DLBCL cell lines to HDACi treatment does not correlate with expression of any individual BCL-2 family member. CONCLUSIONS/SIGNIFICANCE: These studies indicate that the sensitivity of DLBCL to treatment with HDACi's is dependent on the complex regulation of BCL-2 family members and that BCL-2 antagonists may enhance the response of a subset of DLBCL patients to HDACi treatment.

  6. Targeting MUC1-C suppresses BCL2A1 in triple-negative breast cancer.

    Science.gov (United States)

    Hiraki, Masayuki; Maeda, Takahiro; Mehrotra, Neha; Jin, Caining; Alam, Maroof; Bouillez, Audrey; Hata, Tsuyoshi; Tagde, Ashujit; Keating, Amy; Kharbanda, Surender; Singh, Harpal; Kufe, Donald

    2018-01-01

    B-cell lymphoma 2-related protein A1 (BCL2A1) is a member of the BCL-2 family of anti-apoptotic proteins that confers resistance to treatment with anti-cancer drugs; however, there are presently no agents that target BCL2A1. The MUC1-C oncoprotein is aberrantly expressed in triple-negative breast cancer (TNBC) cells, induces the epithelial-mesenchymal transition (EMT) and promotes anti-cancer drug resistance. The present study demonstrates that targeting MUC1-C genetically and pharmacologically in TNBC cells results in the downregulation of BCL2A1 expression. The results show that MUC1-C activates the BCL2A1 gene by an NF-κB p65-mediated mechanism, linking this pathway with the induction of EMT. The MCL-1 anti-apoptotic protein is also of importance for the survival of TNBC cells and is an attractive target for drug development. We found that inhibiting MCL-1 with the highly specific MS1 peptide results in the activation of the MUC1-C→NF-κB→BCL2A1 pathway. In addition, selection of TNBC cells for resistance to ABT-737, which inhibits BCL-2, BCL-xL and BCL-W but not MCL-1 or BCL2A1, is associated with the upregulation of MUC1-C and BCL2A1 expression. Targeting MUC1-C in ABT-737-resistant TNBC cells suppresses BCL2A1 and induces death, which is of potential therapeutic importance. These findings indicate that MUC1-C is a target for the treatment of TNBCs unresponsive to agents that inhibit anti-apoptotic members of the BCL-2 family.

  7. The BH3 α-Helical Mimic BH3-M6 Disrupts Bcl-XL, Bcl-2, and MCL-1 Protein-Protein Interactions with Bax, Bak, Bad, or Bim and Induces Apoptosis in a Bax- and Bim-dependent Manner*

    Science.gov (United States)

    Kazi, Aslamuzzaman; Sun, Jiazhi; Doi, Kenichiro; Sung, Shen-Shu; Takahashi, Yoshinori; Yin, Hang; Rodriguez, Johanna M.; Becerril, Jorge; Berndt, Norbert; Hamilton, Andrew D.; Wang, Hong-Gang; Sebti, Saïd M.

    2011-01-01

    A critical hallmark of cancer cell survival is evasion of apoptosis. This is commonly due to overexpression of anti-apoptotic proteins such as Bcl-2, Bcl-XL, and Mcl-1, which bind to the BH3 α-helical domain of pro-apoptotic proteins such as Bax, Bak, Bad, and Bim, and inhibit their function. We designed a BH3 α-helical mimetic BH3-M6 that binds to Bcl-XL and Mcl-1 and prevents their binding to fluorescently labeled Bak- or Bim-BH3 peptides in vitro. Using several approaches, we demonstrate that BH3-M6 is a pan-Bcl-2 antagonist that inhibits the binding of Bcl-XL, Bcl-2, and Mcl-1 to multi-domain Bax or Bak, or BH3-only Bim or Bad in cell-free systems and in intact human cancer cells, freeing up pro-apoptotic proteins to induce apoptosis. BH3-M6 disruption of these protein-protein interactions is associated with cytochrome c release from mitochondria, caspase-3 activation and PARP cleavage. Using caspase inhibitors and Bax and Bak siRNAs, we demonstrate that BH3-M6-induced apoptosis is caspase- and Bax-, but not Bak-dependent. Furthermore, BH3-M6 disrupts Bcl-XL/Bim, Bcl-2/Bim, and Mcl-1/Bim protein-protein interactions and frees up Bim to induce apoptosis in human cancer cells that depend for tumor survival on the neutralization of Bim with Bcl-XL, Bcl-2, or Mcl-1. Finally, BH3-M6 sensitizes cells to apoptosis induced by the proteasome inhibitor CEP-1612. PMID:21148306

  8. A targeted proteomics approach to the quantitative analysis of ERK/Bcl-2-mediated anti-apoptosis and multi-drug resistance in breast cancer.

    Science.gov (United States)

    Yang, Ting; Xu, Feifei; Sheng, Yuan; Zhang, Wen; Chen, Yun

    2016-10-01

    Apoptosis suppression caused by overexpression of anti-apoptotic proteins is a central factor to the acquisition of multi-drug resistance (MDR) in breast cancer. As a highly conserved anti-apoptotic protein, Bcl-2 can initiate an anti-apoptosis response via an ERK1/2-mediated pathway. However, the details therein are still far from completely understood and a quantitative description of the associated proteins in the biological context may provide more insights into this process. Following our previous attempts in the quantitative analysis of MDR mechanisms, liquid chromatography-tandem mass spectrometry (LC-MS/MS)-based targeted proteomics was continually employed here to describe ERK/Bcl-2-mediated anti-apoptosis. A targeted proteomics assay was developed and validated first for the simultaneous quantification of ERK1/2 and Bcl-2. In particular, ERK isoforms (i.e., ERK1 and ERK2) and their differential phosphorylated forms including isobaric ones were distinguished. Using this assay, differential protein levels and site-specific phosphorylation stoichiometry were observed in parental drug-sensitive MCF-7/WT cancer cells and drug-resistant MCF-7/ADR cancer cells and breast tissue samples from two groups of patients who were either suspected or diagnosed to have drug resistance. In addition, quantitative analysis of the time course of both ERK1/2 and Bcl-2 in doxorubicin (DOX)-treated MCF-7/WT cells confirmed these findings. Overall, we propose that targeted proteomics can be used generally to resolve more complex cellular events.

  9. Opposite role of Bax and BCL-2 in the anti-tumoral responses of the immune system

    International Nuclear Information System (INIS)

    Bougras, Gwenola; Cartron, Pierre-François; Gautier, Fabien; Martin, Stéphane; LeCabellec, Marité; Meflah, Khaled; Gregoire, Marc; Vallette, François M

    2004-01-01

    The relative role of anti apoptotic (i.e. Bcl-2) or pro-apoptotic (e.g. Bax) proteins in tumor progression is still not completely understood. The rat glioma cell line A15A5 was stably transfected with human Bcl-2 and Bax transgenes and the viability of theses cell lines was analyzed in vitro and in vivo. In vitro, the transfected cell lines (huBax A15A5 and huBcl-2 A15A5) exhibited different sensitivities toward apoptotic stimuli. huBax A15A5 cells were more sensitive and huBcl-2 A15A5 cells more resistant to apoptosis than mock-transfected A15A5 cells (pCMV A15A5). However, in vivo, in syngenic rat BDIX, these cell lines behaved differently, as no tumor growth was observed with huBax A15A5 cells while huBcl-2 A15A5 cells formed large tumors. The immune system appeared to be involved in the rejection of huBax A15A5 cells since i) huBax A15A5 cells were tumorogenic in nude mice, ii) an accumulation of CD8+ T-lymphocytes was observed at the site of injection of huBax A15A5 cells and iii) BDIX rats, which had received huBax A15A5 cells developed an immune protection against pCMV A15A5 and huBcl-2 A15A5 cells. We show that the expression of Bax and Bcl-2 controls the sensitivity of the cancer cells toward the immune system. This sensitization is most likely to be due to an increase in immune induced cell death and/or the amplification of an anti tumour immune response

  10. Behavior of solvent-exposed hydrophobic groove in the anti-apoptotic Bcl-XL protein: clues for its ability to bind diverse BH3 ligands from MD simulations.

    Directory of Open Access Journals (Sweden)

    Dilraj Lama

    Full Text Available Bcl-XL is a member of Bcl-2 family of proteins involved in the regulation of intrinsic pathway of apoptosis. Its overexpression in many human cancers makes it an important target for anti-cancer drugs. Bcl-XL interacts with the BH3 domain of several pro-apoptotic Bcl-2 partners. This helical bundle protein has a pronounced hydrophobic groove which acts as a binding region for the BH3 domains. Eight independent molecular dynamics simulations of the apo/holo forms of Bcl-XL were carried out to investigate the behavior of solvent-exposed hydrophobic groove. The simulations used either a twin-range cut-off or particle mesh Ewald (PME scheme to treat long-range interactions. Destabilization of the BH3 domain-containing helix H2 was observed in all four twin-range cut-off simulations. Most of the other major helices remained stable. The unwinding of H2 can be related to the ability of Bcl-XL to bind diverse BH3 ligands. The loss of helical character can also be linked to the formation of homo- or hetero-dimers in Bcl-2 proteins. Several experimental studies have suggested that exposure of BH3 domain is a crucial event before they form dimers. Thus unwinding of H2 seems to be functionally very important. The four PME simulations, however, revealed a stable helix H2. It is possible that the H2 unfolding might occur in PME simulations at longer time scales. Hydrophobic residues in the hydrophobic groove are involved in stable interactions among themselves. The solvent accessible surface areas of bulky hydrophobic residues in the groove are significantly buried by the loop LB connecting the helix H2 and subsequent helix. These observations help to understand how the hydrophobic patch in Bcl-XL remains stable in the solvent-exposed state. We suggest that both the destabilization of helix H2 and the conformational heterogeneity of loop LB are important factors for binding of diverse ligands in the hydrophobic groove of Bcl-XL.

  11. The BH3 alpha-helical mimic BH3-M6 disrupts Bcl-X(L), Bcl-2, and MCL-1 protein-protein interactions with Bax, Bak, Bad, or Bim and induces apoptosis in a Bax- and Bim-dependent manner.

    Science.gov (United States)

    Kazi, Aslamuzzaman; Sun, Jiazhi; Doi, Kenichiro; Sung, Shen-Shu; Takahashi, Yoshinori; Yin, Hang; Rodriguez, Johanna M; Becerril, Jorge; Berndt, Norbert; Hamilton, Andrew D; Wang, Hong-Gang; Sebti, Saïd M

    2011-03-18

    A critical hallmark of cancer cell survival is evasion of apoptosis. This is commonly due to overexpression of anti-apoptotic proteins such as Bcl-2, Bcl-X(L), and Mcl-1, which bind to the BH3 α-helical domain of pro-apoptotic proteins such as Bax, Bak, Bad, and Bim, and inhibit their function. We designed a BH3 α-helical mimetic BH3-M6 that binds to Bcl-X(L) and Mcl-1 and prevents their binding to fluorescently labeled Bak- or Bim-BH3 peptides in vitro. Using several approaches, we demonstrate that BH3-M6 is a pan-Bcl-2 antagonist that inhibits the binding of Bcl-X(L), Bcl-2, and Mcl-1 to multi-domain Bax or Bak, or BH3-only Bim or Bad in cell-free systems and in intact human cancer cells, freeing up pro-apoptotic proteins to induce apoptosis. BH3-M6 disruption of these protein-protein interactions is associated with cytochrome c release from mitochondria, caspase-3 activation and PARP cleavage. Using caspase inhibitors and Bax and Bak siRNAs, we demonstrate that BH3-M6-induced apoptosis is caspase- and Bax-, but not Bak-dependent. Furthermore, BH3-M6 disrupts Bcl-X(L)/Bim, Bcl-2/Bim, and Mcl-1/Bim protein-protein interactions and frees up Bim to induce apoptosis in human cancer cells that depend for tumor survival on the neutralization of Bim with Bcl-X(L), Bcl-2, or Mcl-1. Finally, BH3-M6 sensitizes cells to apoptosis induced by the proteasome inhibitor CEP-1612.

  12. Analyse bioinformatique des protéines BCL-2 et développement de la base de connaissance dédiée, BCL2DB

    OpenAIRE

    Rech de Laval , Valentine

    2013-01-01

    BCL-2 proteins play an essential role in the decision of life or death of animal cells. They control the induction of apoptosis (programmed cell death) in the mitochondrial pathway via regulators having opposite functions: anti- or pro-apoptotic. Proteins containing one or more Bcl-2 homology domains (BHl-4) are systematically classified in this family. Through bioinformatics and phylogenetic analysis, we revisited the different criteria for protein inclusion in the BCL-2 group and proposed a...

  13. Prohibitin (PHB) inhibits apoptosis in rat granulosa cells (GCs) through the extracellular signal-regulated kinase 1/2 (ERK1/2) and the Bcl family of proteins.

    Science.gov (United States)

    Chowdhury, Indrajit; Thompson, Winston E; Welch, Crystal; Thomas, Kelwyn; Matthews, Roland

    2013-12-01

    Mammalian ovarian follicular development is tightly regulated by crosstalk between cell death and survival signals, which include both endocrine and intra-ovarian regulators. Whether the follicle ultimately ovulates or undergoes atresia is dependent on the expression and actions of factors promoting follicular cell proliferation, differentiation or apoptosis. Prohibitin (PHB) is a highly conserved, ubiquitous protein that is abundantly expressed in granulosa cells (GCs) and associated with GC differentiation and apoptosis. The current study was designed to characterize the regulation of anti-apoptotic and pro-apoptotic factors in undifferentiated rat GCs (gonadotropin independent phase) governed by PHB. Microarray technology was initially employed to identify potential apoptosis-related genes, whose expression levels within GCs were altered by either staurosporine (STS) alone or STS in presence of ectopically over-expressed PHB. Next, immunoblot studies were performed to examine the expression patterns of selective Bcl-2 family members identified by the microarray analysis, which are commonly regulated in the intrinsic-apoptotic pathway. These studies were designed to measure protein levels of Bcl2 family in relation to expression of the acidic isoform (phosphorylated) PHB and the components of MEK-Erk1/2 pathway. These studies indicated that over-expression of PHB in undifferentiated GCs inhibit apoptosis which concomitantly results in an increased level of the anti-apoptotic proteins Bcl2 and Bclxl, reduced release of cytochrome c from mitochondria and inhibition of caspase-3 activity. In contrast, silencing of PHB expression resulted in change of mitochondrial morphology from the regular reticular network to a fragmented form, which enhanced sensitization of these GCs to the induction of apoptosis. Collectively, these studies have provided new insights on the PHB-mediated anti-apoptotic mechanism, which occurs in undifferentiated GCs through a PHB → Mek-Erk1/2

  14. Bcl-2 antisense therapy in B-cell malignancies.

    Science.gov (United States)

    Chanan-Khan, Asher

    2005-07-01

    Bcl-2 is an apoptosis regulating protein, overexpression of which is associated with chemotherapy resistant disease, aggressive clinical course, and poor survival in patients with B-cell lymphoproliferative disorders. Overexpression of Bcl-2 protein results in an aberrant intrinsic apoptotic pathway that confers a protective effect on malignant cells against a death signal (e.g., chemotherapy or radiotherapy). Downregulation of this oncoprotein, thus, represents a possible new way to target clinically aggressive disease. Preclinical studies have shown that this oncoprotein can be effectively decreased by Bcl-2 antisense in malignant lymphoid cells and can reverse chemotherapy resistance, as well as enhance the anti-apoptotic potential of both chemotherapeutic and biologic agents. Ongoing clinical trials are exploring the role of Bcl-2 downregulation with oblimersen (Bcl-2 antisense) in patients with non-Hodgkin's lymphoma, chronic lymphocytic leukemia and multiple myeloma. Early results from these studies are promising and support the proof of the principle. As these studies are completed and mature data emerges, the role of Bcl-2 antisense therapy in the treatment of B-cell malignancies will become clearer.

  15. Alpha-helical destabilization of the Bcl-2-BH4-domain peptide abolishes its ability to inhibit the IP3 receptor.

    Directory of Open Access Journals (Sweden)

    Giovanni Monaco

    Full Text Available The anti-apoptotic Bcl-2 protein is the founding member and namesake of the Bcl-2-protein family. It has recently been demonstrated that Bcl-2, apart from its anti-apoptotic role at mitochondrial membranes, can also directly interact with the inositol 1,4,5-trisphosphate receptor (IP3R, the primary Ca(2+-release channel in the endoplasmic reticulum (ER. Bcl-2 can thereby reduce pro-apoptotic IP3R-mediated Ca(2+ release from the ER. Moreover, the Bcl-2 homology domain 4 (Bcl-2-BH4 has been identified as essential and sufficient for this IP3R-mediated anti-apoptotic activity. In the present study, we investigated whether the reported inhibitory effect of a Bcl-2-BH4 peptide on the IP 3R1 was related to the distinctive α-helical conformation of the BH4 domain peptide. We therefore designed a peptide with two glycine "hinges" replacing residues I14 and V15, of the wild-type Bcl-2-BH4 domain (Bcl-2-BH4-IV/GG. By comparing the structural and functional properties of the Bcl-2-BH4-IV/GG peptide with its native counterpart, we found that the variant contained reduced α-helicity, neither bound nor inhibited the IP 3R1 channel, and in turn lost its anti-apoptotic effect. Similar results were obtained with other substitutions in Bcl-2-BH4 that destabilized the α-helix with concomitant loss of IP3R inhibition. These results provide new insights for the further development of Bcl-2-BH4-derived peptides as specific inhibitors of the IP3R with significant pharmacological implications.

  16. Apoptotic pathways as regulators of recombination

    International Nuclear Information System (INIS)

    Gauny, S.S.; Kronenberg, A.; Liu, W.-C.

    2003-01-01

    Apoptosis, or programmed cell death (PCD), is a fundamental process that protects organismal integrity. In earlier work, we demonstrated that over-expression of either of two anti-apoptotic members of the BCL-2 family (BCL-2 or BCL-X L could elevate the frequency of radiation-induced mutations at the autosomal TK1 locus in human TK6 lymphoblasts that express wild-type TP53. Ectopic expression of BCL-X L also elevated the frequencies of double-strand break-induced gene conversion. The purpose of this study is to determine if BCL-2 family proteins promote radiation mutagenesis indirectly through their suppression of PCD, or whether the 'pro-mutagenic' function of these proteins can be separated from their anti-apoptotic function. We developed stable transfectants of TK6 cells that express a mutated form of BCL-X L with a single amino acid substitution in the BH1 domain that is known to interfere with the ability to suppress PCD (BCL-X L gly159ala). We also developed stable transfectants of TK6 cells that express a dominant negative caspase-9 that suppresses PCD. The results to date indicate that the mutated form of BCL-X L (gly159ala) does not suppress x-ray-induced PCD in TK6 cells, but it elevates radiation-induced TK1 mutant frequencies to the same extent as high level expression of wild-type BCL-X L . These data suggest that the anti-apoptotic function of BCL-2 family proteins is not required to elevate radiation mutagenesis. Separate experiments using TK6 cells that express a dominant negative caspase-9 indicate that this protein inhibits x-ray-induced PCD but TK1 mutant frequencies are not elevated. Taken together, the results suggest there is a separate function of BCL-2 family proteins that elevates radiation-induced mutagenesis independent of the well-known anti-apoptotic effect of these proteins of importance in human carcinogenesis

  17. Immunogenicity of Bcl-2 in patients with cancer

    DEFF Research Database (Denmark)

    Andersen, Mads Hald; Svane, Inge Marie; Kvistborg, Pia

    2005-01-01

    activities in preclinical models and are currently in several clinical trials. The clinical application of immunotherapy against cancer is rapidly moving forward in multiple areas, including the adoptive transfer of anti-tumor-reactive T cells and the use of "therapeutic" vaccines. The overexpression of Bcl......-2 in cancer and the fact that immune escape by down-regulation or loss of expression of this protein would impair sustained tumor growth makes Bcl-2 a very attractive target for anticancer immunotherapy. Herein, we describe spontaneous T-cell reactivity against Bcl-2 in peripheral blood from......B-cell lymphoma 2 (Bcl-2) is a pivotal regulator of apoptotic cell death and it is overexpressed in many cancers. Consequently, the Bcl-2 protein is an attractive target for drug design, and Bcl-2-specific antisense oligonucleotides or small-molecule Bcl-2 inhibitors have shown broad anticancer...

  18. BCL2-BH4 antagonist BDA-366 suppresses human myeloma growth.

    Science.gov (United States)

    Deng, Jiusheng; Park, Dongkyoo; Wang, Mengchang; Nooka, Ajay; Deng, Qiaoya; Matulis, Shannon; Kaufman, Jonathan; Lonial, Sagar; Boise, Lawrence H; Galipeau, Jacques; Deng, Xingming

    2016-05-10

    Multiple myeloma (MM) is a heterogeneous plasma cell malignancy and remains incurable. B-cell lymphoma-2 (BCL2) protein correlates with the survival and the drug resistance of myeloma cells. BH3 mimetics have been developed to disrupt the binding between BCL2 and its pro-apoptotic BCL2 family partners for the treatment of MM, but with limited therapeutic efficacy. We recently identified a small molecule BDA-366 as a BCL2 BH4 domain antagonist, converting it from an anti-apoptotic into a pro-apoptotic molecule. In this study, we demonstrated that BDA-366 induces robust apoptosis in MM cell lines and primary MM cells by inducing BCL2 conformational change. Delivery of BDA-366 substantially suppressed the growth of human MM xenografts in NOD-scid/IL2Rγnull mice, without significant cytotoxic effects on normal hematopoietic cells or body weight. Thus, BDA-366 functions as a novel BH4-based BCL2 inhibitor and offers an entirely new tool for MM therapy.

  19. Apoptosis in differentiating C2C12 muscle cells selectively targets Bcl-2-deficient myotubes

    Science.gov (United States)

    Schoneich, Christian; Dremina, Elena; Galeva, Nadezhda; Sharov, Victor

    2014-01-01

    Muscle cell apoptosis accompanies normal muscle development and regeneration, as well as degenerative diseases and aging. C2C12 murine myoblast cells represent a common model to study muscle differentiation. Though it was already shown that myogenic differentiation of C2C12 cells is accompanied by enhanced apoptosis in a fraction of cells, either the cell population sensitive to apoptosis or regulatory mechanisms for the apoptotic response are unclear so far. In the current study we characterize apoptotic phenotypes of different types of C2C12 cells at all stages of differentiation, and report here that myotubes of differentiated C2C12 cells with low levels of anti-apoptotic Bcl-2 expression are particularly vulnerable to apoptosis even though they are displaying low levels of pro-apoptotic proteins Bax, Bak and Bad. In contrast, reserve cells exhibit higher levels of Bcl-2 and high resistance to apoptosis. The transfection of proliferating myoblasts with Bcl-2 prior to differentiation did not protect against spontaneous apoptosis accompanying differentiation of C2C12 cell but led to Bcl-2 overexpression in myotubes and to significant protection from apoptotic cell loss caused by exposure to hydrogen peroxide. Overall, our data advocate for a Bcl-2-dependent mechanism of apoptosis in differentiated muscle cells. However, downstream processes for spontaneous and hydrogen peroxide induced apoptosis are not completely similar. Apoptosis in differentiating myoblasts and myotubes is regulated not through interaction of Bcl-2 with pro-apoptotic Bcl-2 family proteins such as Bax, Bak, and Bad. PMID:24129924

  20. Hypoxia-response plasmid vector producing bcl-2 shRNA enhances the apoptotic cell death of mouse rectum carcinoma.

    Science.gov (United States)

    Fujioka, Takashi; Matsunaga, Naoya; Okazaki, Hiroyuki; Koyanagi, Satoru; Ohdo, Shigehiro

    2010-01-01

    Hypoxia-induced gene expression frequently occurs in malignant solid tumors because they often have hypoxic areas in which circulation is compromised due to structurally disorganized blood vessels. Hypoxia-response elements (HREs) are responsible for activating gene transcription in response to hypoxia. In this study, we constructed a hypoxia-response plasmid vector producing short hairpin RNA (shRNA) against B-cell leukemia/lymphoma-2 (bcl-2), an anti-apoptotic factor. The hypoxia-response promoter was made by inserting tandem repeats of HREs upstream of cytomegalovirus (CMV) promoter (HRE-CMV). HRE-CMV shbcl-2 vector consisted of bcl-2 shRNA under the control of HRE-CMV promoter. In hypoxic mouse rectum carcinoma cells (colon-26), the production of bcl-2 shRNA driven by HRE-CMV promoter was approximately 2-fold greater than that driven by CMV promoter. A single intratumoral (i.t.) injection of 40 microg HRE-CMV shbcl-2 to colon-26 tumor-bearing mice caused apoptotic cell death, and repetitive treatment with HRE-CMV shbcl-2 (40 microg/mouse, i.t.) also significantly suppressed the growth of colon-26 tumor cells implanted in mice. Apoptotic and anti-tumor effects were not observed in tumor-bearing mice treated with CMV shbcl-2. These results reveal the ability of HRE-CMV shbcl-2 vector to suppress the expression of bcl-2 in hypoxic tumor cells and suggest the usefulness of our constructed hypoxia-response plasmid vector to treat malignant tumors. [Supplementary Figures: available only at http://dx.doi.org/10.1254/jphs.10054FP].

  1. Interaction between Na-K-ATPase and Bcl-2 proteins BclXL and Bak.

    Science.gov (United States)

    Lauf, Peter K; Alqahtani, Tariq; Flues, Karin; Meller, Jaroslaw; Adragna, Norma C

    2015-01-01

    In silico analysis predicts interaction between Na-K-ATPase (NKA) and Bcl-2 protein canonical BH3- and BH1-like motifs, consistent with NKA inhibition by the benzo-phenanthridine alkaloid chelerythrine, a BH3 mimetic, in fetal human lens epithelial cells (FHLCs) (Lauf PK, Heiny J, Meller J, Lepera MA, Koikov L, Alter GM, Brown TL, Adragna NC. Cell Physiol Biochem 31: 257-276, 2013). This report establishes proof of concept: coimmunoprecipitation and immunocolocalization showed unequivocal and direct physical interaction between NKA and Bcl-2 proteins. Specifically, NKA antibodies (ABs) coimmunoprecipitated BclXL (B-cell lymphoma extra large) and BAK (Bcl-2 antagonist killer) proteins in FHLCs and A549 lung cancer cells. In contrast, both anti-Bcl-2 ABs failed to pull down NKA. Notably, the molecular mass of BAK1 proteins pulled down by NKA and BclXL ABs appeared to be some 4-kDa larger than found in input monomers. In silico analysis predicts these higher molecular mass BAK1 proteins as alternative splicing variants, encoding 42 amino acid (aa) larger proteins than the known 211-aa long canonical BAK1 protein. These BAK1 variants may constitute a pool separate from that forming mitochondrial pores by specifically interacting with NKA and BclXL proteins. We propose a NKA-Bcl-2 protein ternary complex supporting our hypothesis for a special sensor role of NKA in Bcl-2 protein control of cell survival and apoptosis. Copyright © 2015 the American Physiological Society.

  2. Inhibition of Bcl-2 potentiates AZD-2014-induced anti-head and neck squamous cell carcinoma cell activity

    International Nuclear Information System (INIS)

    Li, Yi; Cui, Jiang-Tao

    2016-01-01

    Mammalian target of rapamycin (mTOR) is a therapeutic target for head and neck squamous cell carcinoma (HNSCC). Here, we evaluated the activity of AZD-2014, a potent mTOR complex 1/2 (mTORC1/2) dual inhibitor, against HNSCC cells. We showed that AZD-2014 blocked mTORC1/2 activation in established and primary human HNSCC cells, where it was anti-proliferative and pro-apoptotic. Yet, AZD-2014 was non-cytotoxic to the human oral epithelial cells with low basal mTORC1/2 activation. In an effect to identify possible AZD-2014 resistance factors, we showed that the anti-apoptosis protein Bcl-2 was upregulated in AZD-2014-resistant SQ20B HNSCC cells. Inhibition of Bcl-2 by ABT-737 (a known Bcl-2 inhibitor) or Bcl-2 shRNA dramatically potentiated AZD-2014 lethality against HNSCC cells. On the other hand, exogenous overexpression of Bcl-2 largely attenuated AZD-2014’s activity against HNSCC cells. For the in vivo studies, we showed that oral gavage of AZD-2014 suppressed SQ20B xenograft growth in severe combined immunodeficient (SCID) mice. It also significantly improved mice survival. Importantly, AZD-2014’s anti-HNSCC activity in vivo was potentiated with co-administration of ABT-737. The preclinical results of this study suggest that AZD-2014 could be further tested as a valuable anti-HNSCC agent, either alone or in combination with Bcl-2 inhibitors. - Highlights: • AZD-2014 blocks mTORC1/2 activation in HNSCC cells. • AZD-2014 suppresses HNSCC cell proliferation. • AZD-2014 activates caspase-3 and apoptosis in HNSCC cells. • Bcl-2 is the key resistance factor of AZD-2014 in HNSCC cells. • ABT-737 sensitizes AZD-2014-induced anti-HNSCC activity in vivo.

  3. Inhibition of Bcl-2 potentiates AZD-2014-induced anti-head and neck squamous cell carcinoma cell activity

    Energy Technology Data Exchange (ETDEWEB)

    Li, Yi; Cui, Jiang-Tao, E-mail: cuijingtaopaper@126.com

    2016-09-02

    Mammalian target of rapamycin (mTOR) is a therapeutic target for head and neck squamous cell carcinoma (HNSCC). Here, we evaluated the activity of AZD-2014, a potent mTOR complex 1/2 (mTORC1/2) dual inhibitor, against HNSCC cells. We showed that AZD-2014 blocked mTORC1/2 activation in established and primary human HNSCC cells, where it was anti-proliferative and pro-apoptotic. Yet, AZD-2014 was non-cytotoxic to the human oral epithelial cells with low basal mTORC1/2 activation. In an effect to identify possible AZD-2014 resistance factors, we showed that the anti-apoptosis protein Bcl-2 was upregulated in AZD-2014-resistant SQ20B HNSCC cells. Inhibition of Bcl-2 by ABT-737 (a known Bcl-2 inhibitor) or Bcl-2 shRNA dramatically potentiated AZD-2014 lethality against HNSCC cells. On the other hand, exogenous overexpression of Bcl-2 largely attenuated AZD-2014’s activity against HNSCC cells. For the in vivo studies, we showed that oral gavage of AZD-2014 suppressed SQ20B xenograft growth in severe combined immunodeficient (SCID) mice. It also significantly improved mice survival. Importantly, AZD-2014’s anti-HNSCC activity in vivo was potentiated with co-administration of ABT-737. The preclinical results of this study suggest that AZD-2014 could be further tested as a valuable anti-HNSCC agent, either alone or in combination with Bcl-2 inhibitors. - Highlights: • AZD-2014 blocks mTORC1/2 activation in HNSCC cells. • AZD-2014 suppresses HNSCC cell proliferation. • AZD-2014 activates caspase-3 and apoptosis in HNSCC cells. • Bcl-2 is the key resistance factor of AZD-2014 in HNSCC cells. • ABT-737 sensitizes AZD-2014-induced anti-HNSCC activity in vivo.

  4. MRP- and BCL-2-mediated drug resistance in human SCLC: effects of apoptotic sphingolipids in vitro.

    Science.gov (United States)

    Khodadadian, M; Leroux, M E; Auzenne, E; Ghosh, S C; Farquhar, D; Evans, R; Spohn, W; Zou, Y; Klostergaard, J

    2009-10-01

    Multidrug-resistance-associated protein (MRP) and BCL-2 contribute to drug resistance expressed in SCLC. To establish whether MRP-mediated drug resistance affects sphingolipid (SL)-induced apoptosis in SCLC, we first examined the human SCLC cell line, UMCC-1, and its MRP over-expressing, drug-resistant subline, UMCC-1/VP. Despite significantly decreased sensitivity to doxorubicin (Dox) and to the etoposide, VP-16, the drug-selected line was essentially equally as sensitive to treatment with exogenous ceramide (Cer), sphingosine (Sp) or dimethyl-sphingosine (DMSP) as the parental line. Next, we observed that high BCL-2-expressing human H69 SCLC cells, that were approximately 160-fold more sensitive to Dox than their combined BCL-2 and MRP-over-expressing (H69AR) counterparts, were only approximately 5-fold more resistant to DMSP. Time-lapse fluorescence microscopy of either UMCC cell line treated with DMSP-Coumarin revealed comparable extents and kinetics of SL uptake, further ruling out MRP-mediated effects on drug uptake. DMSP potentiated the cytotoxic activity of VP-16 and Taxol, but not Dox, in drug-resistant UMCC-1/VP cells. However, this sensitization did not appear to involve DMSP-mediated effects on the function of MRP in drug export; nor did DMSP strongly shift the balance of pro-apoptotic Sps and anti-apoptotic Sp-1-Ps in these cells. We conclude that SL-induced apoptosis markedly overcomes or bypasses MRP-mediated drug resistance relevant to SCLC and may suggest a novel therapeutic approach to chemotherapy for these tumors.

  5. A BioDesign Approach to Obtain High Yields of Biosimilars by Anti-apoptotic Cell Engineering: a Case Study to Increase the Production Yield of Anti-TNF Alpha Producing Recombinant CHO Cells.

    Science.gov (United States)

    Gulce Iz, Sultan; Inevi, Muge Anil; Metiner, Pelin Saglam; Tamis, Duygu Ayyildiz; Kisbet, Nazli

    2018-01-01

    Recent developments in medical biotechnology have facilitated to enhance the production of monoclonal antibodies (mAbs) and recombinant proteins in mammalian cells. Human mAbs for clinical applications have focused on three areas, particularly cancer, immunological disorders, and infectious diseases. Tumor necrosis factor alpha (TNF-α), which has both proinflammatory and immunoregulatory functions, is an important target in biopharmaceutical industry. In this study, a humanized anti-TNF-α mAb producing stable CHO cell line which produces a biosimilar of Humira (adalimumab) was used. Adalimumab is a fully human anti-TNF mAb among the top-selling mAb products in recent years as a biosimilar. Products from mammalian cell bioprocesses are a derivative of cell viability and metabolism, which is mainly disrupted by cell death in bioreactors. Thus, different strategies are used to increase the product yield. Suppression of apoptosis, also called anti-apoptotic cell engineering, is the most remarkable strategy to enhance lifetime of cells for a longer production period. In fact, using anti-apoptotic cell engineering as a BioDesign approach was inspired by nature; nature gives prolonged life span to some cells like stem cells, tumor cells, and memory B and T cells, and researchers have been using this strategy for different purposes. In this study, as a biomimicry approach, anti-apoptotic cell engineering was used to increase the anti-TNF-α mAb production from the humanized anti-TNF-α mAb producing stable CHO cell line by Bcl-xL anti-apoptotic protein. It was shown that transient transfection of CHO cells by the Bcl-xL anti-apoptotic protein expressing plasmid prolonged the cell survival rate and protected cells from apoptosis. The transient expression of Bcl-xL using CHO cells enhanced the anti-TNF-α production. The production of anti-TNF-α in CHO cells was increased up to 215 mg/L with an increase of 160% after cells were transfected with Bcl-xL expressing plasmid

  6. Mechanism of effect of ionizing radiation on bcl-2 protein expression and apoptosis in mouse thymus

    International Nuclear Information System (INIS)

    Liu Jiamei; Chen Aijun; Chen Dong; Liu Shuzheng

    2002-01-01

    Objective: To study the mechanism of effect of ionizing radiation in varied doses of X-rays on bcl-2 express and apoptosis in mouse thymus. Methods: Immunohistochemistry, image analysis and transmission electron microscope were used in the study. Results: The expression of bcl-2 protein was limited within thymic medulla, decreased with 2 Gy, however, increased with 0.075 Gy after whole-body irradiation. Some typical apoptotic cells were found in thymic cortex after 2 Gy irradiation. The apoptotic cells decreased and mitotic metaphase increased after 0.075 Gy irradiation. Conclusion: The mechanism of effect of ionizing radiation on apoptosis of thymus was related with the expression of bcl-2 proteins

  7. Effects of low dose radiation on tumor apoptosis, cell cycle progression and changes of apoptosis-related protein bcl-2 in tumor-bearing mice

    International Nuclear Information System (INIS)

    Yu Hongsheng; Fei Conghe; Shen Fangzhen; Liang Jun

    2003-01-01

    Objective: To study the effect of low dose radiation (LDR) on tumor apoptosis, cell cycle progression and changes of apoptosis-related protein bcl-2 in tumor-bearing mice. Methods: Kunming stain male mice were implanted with S180 sarcoma cells in the left inguen subcutaneously as an in situ experimental animal model. Seven days after implantation, the mice were given 75 mGy whole-body γ-irradiation. At 24 and 48 h after irradiation, all mice were sacrificed to measure the tumor volume, and tumor cell apoptosis, cell cycle progression were analyzed by flow cytometry. The expression of apoptosis-related protein bcl-2 and the apoptotic rate of tumor cells were observed by immunohistochemistry and electron microscopy. Results: Tumor growth was significantly slowed down after LDR (P 1 phase and the expression of bcl-2 protein decreased at 24 h. Apoptotic rate of tumor cells increased significantly at 48 h after LDR. Conclusion: LDR could cause a G 1 -phase arrest and increase the apoptosis of tumor cells through the low level of apoptosis-related protein bcl-2 in the tumor-bearing mice. The organized immune function and anti-tumor ability are markedly increased after LDR. The study provides practical evidence of clinical application to cancer treatment

  8. Original Article: Investigation of Bcl-2 and PCNA in Hepatocellular Carcinoma: Relation to Chronic HCV

    International Nuclear Information System (INIS)

    ALENZI, F.Q.Ph.; ABBAS, M.Y.Ph.; HAMAD, A.M.; EL-SAEED, O.M.; EL-NASHAR, E.M.; AL-GHAMDI, S.S.; WYSE, R.K.H.; LOTFY, M.

    2010-01-01

    Bcl-2 family members can be functionally divided into anti-apoptotic and pro-apoptotic groups. The balance between these two groups may determine the fate of tumor cells. In hepatocellular carcinoma (HCC), this balance is often tilted towards the anti-apoptotic members in tumor cells, leading to resistance to cell death and rapid proliferation. Material and Methods: In the current study, we in-vestigated Bcl-2 and proliferating cell nuclear antigen (PCNA) immunohistochemically, using specific mono-clonal antibodies in liver tissues obtained from two patient groups. The first group included fifty patients infected with hepatitis C virus (HCV) without hepatocellular carcinoma, the other group included twenty five HCV-infected patients but with confirmed HCC. Serum Bcl-2 was assayed using enzyme immunoassay. Results: Results showed serum Bcl-2 was elevated in 82% versus 100% in HCC-free and HCC patients, respectively. Moreover, cytoplasmic staining of Bcl-2 was found in only 16% of chronic HCV patients without HCC, versus 8% in HCC patients. On the other hand, nuclear staining of PCNA was detected in 100% of HCC patients, but in none of the HCV patients without HCC. Conclusion: The results collectively suggest that in HCV-infected patients with and without HCC, apoptosis is dysregulated and proliferation activity perturbed. There may be prognostic and/or diagnostic potential in estimating Bcl-2 and PCNA proteins in these patient groups

  9. Born to be Alive: A Role for the BCL-2 Family in Melanoma Tumor Cell Survival, Apoptosis, and Treatment

    Energy Technology Data Exchange (ETDEWEB)

    Anvekar, Rina A.; Asciolla, James J.; Missert, Derek J.; Chipuk, Jerry E., E-mail: jerry.chipuk@mssm.edu [Department of Oncological Sciences, Mount Sinai School of Medicine, New York, NY (United States); Department of Dermatology, Mount Sinai School of Medicine, New York, NY (United States); The Tisch Cancer Institute, Mount Sinai Medical Center, New York, NY (United States)

    2011-10-13

    The global incidence of melanoma has dramatically increased during the recent decades, yet the advancement of primary and adjuvant therapies has not kept a similar pace. The development of melanoma is often centered on cellular signaling that hyper-activates survival pathways, while inducing a concomitant blockade to cell death. Aberrations in cell death signaling not only promote tumor survival and enhanced metastatic potential, but also create resistance to anti-tumor strategies. Chemotherapeutic agents target melanoma tumor cells by inducing a form of cell death called apoptosis, which is governed by the BCL-2 family of proteins. The BCL-2 family is comprised of anti-apoptotic proteins (e.g., BCL-2, BCL-xL, and MCL-1) and pro-apoptotic proteins (e.g., BAK, BAX, and BIM), and their coordinated regulation and function are essential for optimal responses to chemotherapeutics. Here we will discuss what is currently known about the mechanisms of BCL-2 family function with a focus on the signaling pathways that maintain melanoma tumor cell survival. Importantly, we will critically evaluate the literature regarding how chemotherapeutic strategies directly impact on BCL-2 family function and offer several suggestions for future regimens to target melanoma and enhance patient survival.

  10. Gingerol sensitizes TRAIL-induced apoptotic cell death of glioblastoma cells

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Dae-Hee, E-mail: leedneo@gmail.com [Departments of Surgery and Pharmacology and Cell Biology, School of Medicine, University of Pittsburgh, Pittsburgh, PA (United States); Kim, Dong-Wook [Department of Microbiology, Immunology, and Cancer Biology, University of VA (United States); Jung, Chang-Hwa [Division of Metabolism and Functionality Research, Korea Food Research Institute (Korea, Republic of); Lee, Yong J. [Departments of Surgery and Pharmacology and Cell Biology, School of Medicine, University of Pittsburgh, Pittsburgh, PA (United States); Park, Daeho, E-mail: daehopark@gist.ac.kr [School of Life Sciences, Gwangju Institute of Science and Technology, Gwangju 500-712 (Korea, Republic of)

    2014-09-15

    Glioblastoma multiforme (GBM) is the most lethal and aggressive astrocytoma of primary brain tumors in adults. Although there are many clinical trials to induce the cell death of glioblastoma cells, most glioblastoma cells have been reported to be resistant to TRAIL-induced apoptosis. Here, we showed that gingerol as a major component of ginger can induce TRAIL-mediated apoptosis of glioblastoma. Gingerol increased death receptor (DR) 5 levels in a p53-dependent manner. Furthermore, gingerol decreased the expression level of anti-apoptotic proteins (survivin, c-FLIP, Bcl-2, and XIAP) and increased pro-apoptotic protein, Bax and truncate Bid, by generating reactive oxygen species (ROS). We also found that the sensitizing effects of gingerol in TRAIL-induced cell death were blocked by scavenging ROS or overexpressing anti-apoptotic protein (Bcl-2). Therefore, we showed the functions of gingerol as a sensitizing agent to induce cell death of TRAIL-resistant glioblastoma cells. This study gives rise to the possibility of applying gingerol as an anti-tumor agent that can be used for the purpose of combination treatment with TRAIL in TRAIL-resistant glioblastoma tumor therapy. - Highlights: • Most GBM cells have been reported to be resistant to TRAIL-induced apoptosis. • Gingerol enhances the expression level of anti-apoptotic proteins by ROS. • Gingerol enhances TRAIL-induced apoptosis through actions on the ROS–Bcl2 pathway.

  11. Gingerol sensitizes TRAIL-induced apoptotic cell death of glioblastoma cells

    International Nuclear Information System (INIS)

    Lee, Dae-Hee; Kim, Dong-Wook; Jung, Chang-Hwa; Lee, Yong J.; Park, Daeho

    2014-01-01

    Glioblastoma multiforme (GBM) is the most lethal and aggressive astrocytoma of primary brain tumors in adults. Although there are many clinical trials to induce the cell death of glioblastoma cells, most glioblastoma cells have been reported to be resistant to TRAIL-induced apoptosis. Here, we showed that gingerol as a major component of ginger can induce TRAIL-mediated apoptosis of glioblastoma. Gingerol increased death receptor (DR) 5 levels in a p53-dependent manner. Furthermore, gingerol decreased the expression level of anti-apoptotic proteins (survivin, c-FLIP, Bcl-2, and XIAP) and increased pro-apoptotic protein, Bax and truncate Bid, by generating reactive oxygen species (ROS). We also found that the sensitizing effects of gingerol in TRAIL-induced cell death were blocked by scavenging ROS or overexpressing anti-apoptotic protein (Bcl-2). Therefore, we showed the functions of gingerol as a sensitizing agent to induce cell death of TRAIL-resistant glioblastoma cells. This study gives rise to the possibility of applying gingerol as an anti-tumor agent that can be used for the purpose of combination treatment with TRAIL in TRAIL-resistant glioblastoma tumor therapy. - Highlights: • Most GBM cells have been reported to be resistant to TRAIL-induced apoptosis. • Gingerol enhances the expression level of anti-apoptotic proteins by ROS. • Gingerol enhances TRAIL-induced apoptosis through actions on the ROS–Bcl2 pathway

  12. Prometaphase arrest-dependent phosphorylation of Bcl-2 family proteins and activation of mitochondrial apoptotic pathway are associated with 17α-estradiol-induced apoptosis in human Jurkat T cells.

    Science.gov (United States)

    Han, Cho Rong; Jun, Do Youn; Kim, Yoon Hee; Lee, Ji Young; Kim, Young Ho

    2013-10-01

    In Jurkat T cell clone (JT/Neo), G2/M arrest, apoptotic sub-G1 peak, mitochondrial membrane potential (Δψm) loss, and TUNEL-positive DNA fragmentation were induced following exposure to 17α-estradiol (17α-E2), whereas none of these events (except for G2/M arrest) were induced in Jurkat cells overexpressing Bcl-2 (JT/Bcl-2). Under these conditions, phosphorylation at Thr161 and dephosphorylation at Tyr15 of Cdk1, upregulation of cyclin B1 level, histone H1 phosphorylation, Cdc25C phosphorylation at Thr-48, Bcl-2 phosphorylation at Thr-56 and Ser-70, Mcl-1 phosphorylation, and Bim phosphorylation were detected in the presence of Bcl-2 overexpression. However, the 17α-E2-induced upregulation of Bak levels, activation of Bak, activation of caspase-3, and PARP degradation were abrogated by Bcl-2 overexpression. In the presence of the G1/S blocking agent hydroxyurea, 17α-E2 failed to induce G2/M arrest and all apoptotic events including Cdk1 activation and phosphorylation of Bcl-2, Mcl-1 and Bim. The 17α-E2-induced phosphorylation of Bcl-2 family proteins and mitochondrial apoptotic events were suppressed by a Cdk1 inhibitor but not by aurora A and aurora B kinase inhibitors. Immunofluorescence microscopic analysis showed that an aberrant bipolar microtubule array, incomplete chromosome congression at the metaphase plate, and prometaphase arrest, which was reversible, were the underlying factors for 17α-E2-induced mitotic arrest. The in vitro microtubule polymerization assay showed that 17α-E2 could directly inhibit microtubule formation. These results show that the apoptogenic activity of 17α-E2 was due to the impaired mitotic spindle assembly causing prometaphase arrest and prolonged Cdk1 activation, the phosphorylation of Bcl-2, Mcl-1 and Bim, and the activation of Bak and mitochondria-dependent caspase cascade. Copyright © 2013 Elsevier B.V. All rights reserved.

  13. Involvement of Bcl-xL degradation and mitochondrial-mediated apoptotic pathway in pyrrolizidine alkaloids-induced apoptosis in hepatocytes

    International Nuclear Information System (INIS)

    Ji Lili; Chen Ying; Liu Tianyu; Wang Zhengtao

    2008-01-01

    Pyrrolizidine alkaloids (PAs) are natural hepatotoxins with worldwide distribution in more than 6000 high plants including medicinal herbs or teas. The aim of this study is to investigate the signal pathway involved in PAs-induced hepatotoxicity. Our results showed that clivorine, isolated from Ligularia hodgsonii Hook, decreased cell viability and induced apoptosis in L-02 cells and mouse hepatocytes. Western-blot results showed that clivorine induced caspase-3/-9 activation, mitochondrial release of cytochrome c and decreased anti-apoptotic Bcl-xL in a time (8-48 h)- and concentration (1-100 μM)-dependent manner. Furthermore, inhibitors of pan-caspase, caspase-3 and caspase-9 significantly inhibited clivorine-induced apoptosis and rescued clivorine-decreased cell viability. Polyubiquitination of Bcl-xL was detected after incubation with 100 μM clivorine for 40 h in the presence of proteasome specific inhibitor MG132, indicating possible degradation of Bcl-xL protein. Furthermore, pretreatment with MG132 or calpain inhibitor I for 2 h significantly enhanced clivorine-decreased Bcl-xL level and cell viability. All the other tested PAs such as senecionine, isoline and monocrotaline decreased mouse hepatocytes viability in a concentration-dependent manner. Clivorine (10 μM) induced caspase-3 activation and decreased Bcl-xL was also confirmed in mouse hepatocytes. Meanwhile, another PA senecionine isolated from Senecio vulgaris L also induced apoptosis, caspase-3 activation and decreased Bcl-xL in mouse hepatocytes. In conclusion, our results suggest that PAs may share the same hepatotoxic signal pathway, which involves degradation of Bcl-xL protein and thus leading to the activation of mitochondrial-mediated apoptotic pathway

  14. Manganese activates the mitochondrial apoptotic pathway in rat astrocytes by modulating the expression of proteins of the Bcl-2 family.

    Science.gov (United States)

    Gonzalez, Laura E; Juknat, A Ana; Venosa, Andrea J; Verrengia, Noemi; Kotler, Mónica L

    2008-12-01

    Manganese induces the central nervous system injury leading to manganism, by mechanisms not completely understood. Chronic exposure to manganese generates oxidative stress and induces the mitochondrial permeability transition. In the present study, we characterized apoptotic cell death mechanisms associated with manganese toxicity in rat cortical astrocytes and demonstrated that (i) Mn treatment targets the mitochondria and induces mitochondrial membrane depolarization followed by cytochrome c release to the cytoplasm, (ii) Mn induces both effector caspases 3/7 and 6 as well as PARP-1 cleavage and (iii) Mn shifts the balance of cell death/survival of Bcl-2 family proteins to favor the apoptotic demise of astrocytes. Our model system using cortical rat astrocytes treated with Mn would emerge as a good tool for investigations aimed to elucidate the role of apoptosis in manganism.

  15. Zerumbone induced apoptosis in liver cancer cells via modulation of Bax/Bcl-2 ratio

    Directory of Open Access Journals (Sweden)

    Azimahtol Hawariah LP

    2007-04-01

    Full Text Available Abstract Background Zerumbone is a cytotoxic component isolated from Zingiber zerumbet Smith, a herbal plant which is also known as lempoyang. This new anticancer bioactive compound from Z. zerumbet was investigated for its activity and mechanism in human liver cancer cell lines. Results Zerumbone significantly showed an antiproliferative activity upon HepG2 cells with an IC50 of 3.45 ± 0.026 μg/ml. Zerumbone was also found to inhibit the proliferation of non-malignant Chang Liver and MDBK cell lines. However the IC50 obtained was higher compared to the IC50 for HepG2 cells (> 10 μg/ml. The extent of DNA fragmentation was evaluated by the Tdt-mediated dUTP nick end labelling assay which showed that, zerumbone significantly increased apoptosis in HepG2 cells in a time-course manner. In detail, the apoptotic process triggered by zerumbone involved the up-regulation of pro-apoptotic Bax protein and the suppression of anti-apoptotic Bcl-2 protein expression. The changes that occurred in the levels of this antagonistic proteins Bax/Bcl-2, was independent of p53 since zerumbone did not affect the levels of p53 although this protein exists in a functional form. Western blotting analysis for Bax protein was further confirmed qualitatively with an immunoassay that showed the distribution of Bax protein in zerumbone-treated cells. Conclusion Therefore, zerumbone was found to induce the apoptotic process in HepG2 cells through the up and down regulation of Bax/Bcl-2 protein independently of functional p53 activity.

  16. Epistatic mutations in PUMA BH3 drive an alternate binding mode to potently and selectively inhibit anti-apoptotic Bfl-1

    Energy Technology Data Exchange (ETDEWEB)

    Jenson, Justin M.; Ryan, Jeremy A.; Grant, Robert A.; Letai, Anthony; Keating, Amy E. (DFCI); (MIT)

    2017-06-08

    Overexpression of anti-apoptotic Bcl-2 family proteins contributes to cancer progression and confers resistance to chemotherapy. Small molecules that target Bcl-2 are used in the clinic to treat leukemia, but tight and selective inhibitors are not available for Bcl-2 paralog Bfl-1. Guided by computational analysis, we designed variants of the native BH3 motif PUMA that are > 150-fold selective for Bfl-1 binding. The designed peptides potently trigger disruption of the mitochondrial outer membrane in cells dependent on Bfl-1, but not in cells dependent on other anti-apoptotic homologs. High-resolution crystal structures show that designed peptide FS2 binds Bfl-1 in a shifted geometry, relative to PUMA and other binding partners, due to a set of epistatic mutations. FS2 modified with an electrophile reacts with a cysteine near the peptide-binding groove to augment specificity. Designed Bfl-1 binders provide reagents for cellular profiling and leads for developing enhanced and cell-permeable peptide or small-molecule inhibitors.

  17. Expression of Bcl-2 family proteins and spontaneous apoptosis in normal human testis.

    Science.gov (United States)

    Oldereid, N B; Angelis, P D; Wiger, R; Clausen, O P

    2001-05-01

    We investigated the frequency of spontaneous apoptosis and expression of the Bcl-2 family of proteins during normal spermatogenesis in man. Testicular tissue with both normal morphology and DNA content was obtained from necro-donors and fixed in Bouin's solution. A TdT-mediated dUTP end-labelling method (TUNEL) was used for the detection of apoptotic cells. Expression of apoptosis regulatory Bcl-2 family proteins and of p53 and p21(Waf1) was assessed by immunohistochemistry. Germ cell apoptosis was detected in all testes and was mainly seen in primary spermatocytes and spermatids and in a few spermatogonia. Bcl-2 and Bak were preferentially expressed in the compartments of spermatocytes and differentiating spermatids, while Bcl-x was preferentially expressed in spermatogonia. Bax showed a preferential expression in nuclei of round spermatids, whereas Bad was only seen in the acrosome region of various stages of spermatids. Mcl-1 staining was weak without a particular pattern, whereas expression of Bcl-w, p53 and p21(Waf1) proteins was not detected by immunohistochemistry. The results show that spontaneous apoptosis occurs in all male germ cell compartments in humans. Bcl-2 family proteins are distributed preferentially within distinct germ cell compartments suggesting a specific role for these proteins in the processes of differentiation and maturation during human spermatogenesis.

  18. The role of BIM-EL and BCL2-α on the efficacy of erlotinib and gefitinib in lung cancer.

    Science.gov (United States)

    Simasi, Jacinta; Oelkrug, Christopher; Schubert, Andreas; Nieber, Karen; Gillissen, Adrian

    2015-04-01

    Tyrosine kinase inhibitors (TKI), erlotinib and gefitinib are small molecule inhibitors which are used for the treatment of lung cancer. But, the development of drug resistance has been reported as one of the major setbacks in oncology. This study focused on the mechanisms leading to secondary resistance by assessing the gene expression of BCL2 family proteins which are associated with the intrinsic apoptotic signaling pathway. 8 genes were investigated in erlotinib and gefitinib treated cells by real time PCR and protein analysis by western blotting. The cells were exposed to the test drugs 48h prior to RNA or protein isolation. It was observed that BIM-EL, a pro-apoptotic protein was up-regulated in cells sensitive to the drugs but not in the resistant cells. On the other hand BCL2-α, an anti-apoptotic protein was up-regulated in the resistant cells and not in the sensitive cells. BCL2-α revealed a counter-regulation effect on BIM-EL and this effect is probably one of the causes of secondary resistance to erlotinib and gefitinib. Copyright © 2014 Elsevier B.V. All rights reserved.

  19. Thymosin beta 4 protects cardiomyocytes from oxidative stress by targeting anti-oxidative enzymes and anti-apoptotic genes.

    Directory of Open Access Journals (Sweden)

    Chuanyu Wei

    Full Text Available Thymosin beta-4 (Tβ4 is a ubiquitous protein with many properties relating to cell proliferation and differentiation that promotes wound healing and modulates inflammatory mediators. The mechanism by which Tβ4 modulates cardiac protection under oxidative stress is not known. The purpose of this study is to dissect the cardioprotective mechanism of Tβ4 on H(2O(2 induced cardiac damage.Rat neonatal cardiomyocytes with or without Tβ4 pretreatment were exposed to H(2O(2 and expression of antioxidant, apoptotic, and anti-inflammatory genes was evaluated by quantitative real-time PCR and western blotting. ROS levels were estimated by DCF-DA using fluorescent microscopy and fluorimetry. Selected antioxidant, anti-inflammatory and antiapoptotic genes were silenced by siRNA transfections in neonatal cardiomyocytes and effect of Tβ4 on H(2O(2-induced cardiac damage was evaluated.Pre-treatment of Tβ4 resulted in reduction of the intracellular ROS levels induced by H(2O(2 in cardiomyocytes. Tβ4 pretreatment also resulted in an increase in the expression of antiapoptotic proteins and reduction of Bax/BCl(2 ratio in the cardiomyocytes. Pretreatment with Tβ4 resulted in stimulating the expression of antioxidant enzymes copper/zinc SOD and catalase in cardiomyocytes at both transcription and translation levels. Tβ4 treatment resulted in the increased expression of anti-apoptotic and anti-inflammatory genes. Silencing of Cu/Zn SOD and catalase gene resulted in apoptotic cell death in the cardiomyocytes which was prevented by treatment with Tβ4.This is the first report that demonstrates the effect of Tβ4 on cardiomyocytes and its capability to selectively upregulate anti-oxidative enzymes, anti-inflammatory genes, and antiapoptotic enzymes in the neonatal cardiomyocytes thus preventing cell death thereby protecting the myocardium. Tβ4 treatment resulted in decreased oxidative stress and inflammation in the myocardium under oxidative stress.

  20. [Apoptosis-modulating effects of heat shock proteins: the influence of Hsp27 chaperone on TBA Bcl-2 family proteins in Jurkat cell line].

    Science.gov (United States)

    Riazantseva, N V; Kaĭgorodova, E V; Maroshkina, A N; Belkina, M V; Novitskiĭ, V V

    2012-01-01

    The in vitro phosphorylated and non-phosphorylated Hsp27 forms concentrations and Bcl-2 proteins affected by Hsp27 inhibition were studied in Jurkat-line tumor cells and healthy donor mononuclear lymphocytes by Western blotting technique. The Hsp27 inhibition causes the increase of intracellular Bax protein concentration and the decrease of Bcl-2 level leading to an increase of apoptotic changes in Jurkat line cells.

  1. SS-A/Ro52 promotes apoptosis by regulating Bcl-2 production

    Energy Technology Data Exchange (ETDEWEB)

    Jauharoh, Siti Nur Aisyah [Department of Clinical Pathology and Immunology, Kobe University Graduate School of Medicine, Hyogo 650-0017 (Japan); Faculty of Medicine and Health Science, Syarif Hidayatullah State Islamic University, Jakarta 15412 (Indonesia); Saegusa, Jun; Sugimoto, Takeshi [Department of Clinical Pathology and Immunology, Kobe University Graduate School of Medicine, Hyogo 650-0017 (Japan); Ardianto, Bambang [Department of Clinical Pathology and Immunology, Kobe University Graduate School of Medicine, Hyogo 650-0017 (Japan); Department of Child Health, Faculty of Medicine, Gadjah Mada University, Yogyakarta 55282 (Indonesia); Kasagi, Shimpei; Sugiyama, Daisuke; Kurimoto, Chiyo [Department of Clinical Pathology and Immunology, Kobe University Graduate School of Medicine, Hyogo 650-0017 (Japan); Tokuno, Osamu; Nakamachi, Yuji [Department of Laboratory Medicine, Kobe University Hospital, Hyogo 650-0017 (Japan); Kumagai, Shunichi [Department of Clinical Pathology and Immunology, Kobe University Graduate School of Medicine, Hyogo 650-0017 (Japan); Kawano, Seiji, E-mail: sjkawano@med.kobe-u.ac.jp [Department of Clinical Pathology and Immunology, Kobe University Graduate School of Medicine, Hyogo 650-0017 (Japan); Department of Laboratory Medicine, Kobe University Hospital, Hyogo 650-0017 (Japan)

    2012-01-06

    Highlights: Black-Right-Pointing-Pointer Ro52{sup low} HeLa cells are resistant to apoptosis upon various stimulations. Black-Right-Pointing-Pointer Ro52 is upregulated by IFN-{alpha}, etoposide, or IFN-{gamma} and anti-Fas Ab. Black-Right-Pointing-Pointer Ro52-mediated apoptosis is independent of p53. Black-Right-Pointing-Pointer Ro52 selectively regulates Bcl-2 expression. -- Abstract: SS-A/Ro52 (Ro52), an autoantigen in systemic autoimmune diseases such as systemic lupus erythematosus and Sjoegren's syndrome, has E3 ligase activity to ubiquitinate proteins that protect against viral infection. To investigate Ro52's role during stress, we transiently knocked it down in HeLa cells by siRo52 transfection. We found that Ro52{sup low} HeLa cells were significantly more resistant to apoptosis than wild-type HeLa cells when stimulated by H{sub 2}O{sub 2}- or diamide-induced oxidative stress, IFN-{alpha}, IFN-{gamma} and anti-Fas antibody, etoposide, or {gamma}-irradiation. Furthermore, Ro52-mediated apoptosis was not influenced by p53 protein level in HeLa cells. Depleting Ro52 in HeLa cells caused Bcl-2, but not other Bcl-2 family molecules, to be upregulated. Taken together, our data showed that Ro52 is a universal proapoptotic molecule, and that its proapoptotic effect does not depend on p53, but is exerted through negative regulation of the anti-apoptotic protein Bcl-2. These findings shed light on a new physiological role for Ro52 that is important to intracellular immunity.

  2. SS-A/Ro52 promotes apoptosis by regulating Bcl-2 production

    International Nuclear Information System (INIS)

    Jauharoh, Siti Nur Aisyah; Saegusa, Jun; Sugimoto, Takeshi; Ardianto, Bambang; Kasagi, Shimpei; Sugiyama, Daisuke; Kurimoto, Chiyo; Tokuno, Osamu; Nakamachi, Yuji; Kumagai, Shunichi; Kawano, Seiji

    2012-01-01

    Highlights: ► Ro52 low HeLa cells are resistant to apoptosis upon various stimulations. ► Ro52 is upregulated by IFN-α, etoposide, or IFN-γ and anti-Fas Ab. ► Ro52-mediated apoptosis is independent of p53. ► Ro52 selectively regulates Bcl-2 expression. -- Abstract: SS-A/Ro52 (Ro52), an autoantigen in systemic autoimmune diseases such as systemic lupus erythematosus and Sjögren’s syndrome, has E3 ligase activity to ubiquitinate proteins that protect against viral infection. To investigate Ro52’s role during stress, we transiently knocked it down in HeLa cells by siRo52 transfection. We found that Ro52 low HeLa cells were significantly more resistant to apoptosis than wild-type HeLa cells when stimulated by H 2 O 2 - or diamide-induced oxidative stress, IFN-α, IFN-γ and anti-Fas antibody, etoposide, or γ-irradiation. Furthermore, Ro52-mediated apoptosis was not influenced by p53 protein level in HeLa cells. Depleting Ro52 in HeLa cells caused Bcl-2, but not other Bcl-2 family molecules, to be upregulated. Taken together, our data showed that Ro52 is a universal proapoptotic molecule, and that its proapoptotic effect does not depend on p53, but is exerted through negative regulation of the anti-apoptotic protein Bcl-2. These findings shed light on a new physiological role for Ro52 that is important to intracellular immunity.

  3. Expression, purification and characterization of hepatitis B virus X protein BH3-like motif-linker-Bcl-xL fusion protein for structural studies

    Directory of Open Access Journals (Sweden)

    Hideki Kusunoki

    2017-03-01

    Full Text Available Hepatitis B virus X protein (HBx is a multifunctional protein that interacts directly with many host proteins. For example, HBx interacts with anti-apoptotic proteins, Bcl-2 and Bcl-xL, through its BH3-like motif, which leads to elevated cytosolic calcium levels, efficient viral DNA replication and the induction of apoptosis. To facilitate sample preparation and perform detailed structural characterization of the complex between HBx and Bcl-xL, we designed and purified a recombinant HBx BH3-like motif-linker-Bcl-xL fusion protein produced in E. coli. The fusion protein was characterized by size exclusion chromatography, circular dichroism and nuclear magnetic resonance experiments. Our results show that the fusion protein is a monomer in aqueous solution, forms a stable intramolecular complex, and likely retains the native conformation of the complex between Bcl-xL and the HBx BH3-like motif. Furthermore, the HBx BH3-like motif of the intramolecular complex forms an α-helix. These observations indicate that the fusion protein should facilitate structural studies aimed at understanding the interaction between HBx and Bcl-xL at the atomic level.

  4. Immunogenicity of Bcl-2 in patients with cancer

    DEFF Research Database (Denmark)

    Andersen, Mads Hald; Svane, Inge Marie; Kvistborg, Pia

    2005-01-01

    patients suffering from unrelated tumor types (ie, pancreatic cancer, breast cancer, acute myeloid leukemia [AML], and chronic lymphocytic leukemia [CLL]). Additionally, we show that these Bcl-2-reactive T cells are indeed peptide-specific, cytotoxic effector cells. Thus, Bcl-2 may serve as an important......B-cell lymphoma 2 (Bcl-2) is a pivotal regulator of apoptotic cell death and it is overexpressed in many cancers. Consequently, the Bcl-2 protein is an attractive target for drug design, and Bcl-2-specific antisense oligonucleotides or small-molecule Bcl-2 inhibitors have shown broad anticancer......-2 in cancer and the fact that immune escape by down-regulation or loss of expression of this protein would impair sustained tumor growth makes Bcl-2 a very attractive target for anticancer immunotherapy. Herein, we describe spontaneous T-cell reactivity against Bcl-2 in peripheral blood from...

  5. An Optically Pure Apogossypolone Derivative as Potent Pan-Active Inhibitor of Anti-Apoptotic Bcl-2 Family Proteins

    International Nuclear Information System (INIS)

    Wei, Jun; Stebbins, John L.; Kitada, Shinichi; Dash, Rupesh; Zhai, Dayong; Placzek, William J.; Wu, Bainan; Rega, Michele F.; Zhang, Ziming; Barile, Elisa; Yang, Li; Dahl, Russell; Fisher, Paul B.; Reed, John C.; Pellecchia, Maurizio

    2011-01-01

    Our focus in the past several years has been on the identification of novel and effective pan-Bcl-2 antagonists. We have recently reported a series of Apogossypolone (ApoG2) derivatives, resulting in the chiral compound (±) BI97D6. We report here the synthesis and evaluation on its optically pure (−) and (+) atropisomers. Compound (−) BI97D6 potently inhibits the binding of BH3 peptides to Bcl-X L , Bcl-2, Mcl-1, and Bfl-1 with IC 50 values of 76 ± 5, 31 ± 2, 25 ± 8, and 122 ± 28 nM, respectively. In a cellular assay, compound (−) BI97D6 effectively inhibits cell growth in the PC-3 human prostate cancer and H23 human lung cancer cell lines with EC 50 values of 0.22 ± 0.08 and 0.14 ± 0.02 μM, respectively. Similarly, compound (−) BI97D6 effectively induces apoptosis in the BP3 human lymphoma cell line in a dose-dependent manner. The compound also shows little cytotoxicity against bax −/− /bak −/− cells, suggesting that it kills cancers cells predominantly via a Bcl-2 pathway. Moreover, compound (−) BI97D6 displays in vivo efficacy in both a Bcl-2-transgenic mouse model and in a prostate cancer xenograft model in mice. Therefore, compound (−) BI97D6 represents a promising drug lead for the development of novel apoptosis-based therapies for cancer.

  6. Bcl-2 overexpression prevents 99mTc-MIBI uptake in breast cancer cell lines

    International Nuclear Information System (INIS)

    Aloj, Luigi; Zannetti, Antonella; Caraco, Corradina; Del Vecchio, Silvana; Salvatore, Marco

    2004-01-01

    We have previously shown a correlation between the absence of technetium-99m methoxyisobutylisonitrile ( 99m Tc-MIBI) uptake and overexpression of the anti-apoptotic protein Bcl-2 in human breast carcinoma. To establish a direct cause-effect relationship between Bcl-2 overexpression and reduced 99m Tc-MIBI uptake, MCF-7 and T47D breast cancer cell lines were stably transfected with the human Bcl-2 gene to increase intracellular protein levels and tested for 99m Tc-MIBI uptake. All clones overexpressing Bcl-2 showed a dramatic reduction of 99m Tc-MIBI uptake as compared with mock transfected control cells. Tracer uptake was promptly and partially restored by induction of apoptosis with staurosporine treatment. After 4.5 h of staurosporine treatment, a tenfold increase in 99m Tc-MIBI uptake was observed in treated as compared with untreated Bcl-2 overexpressing cells. Our findings provide a rational basis for the development of an in vivo test to detect Bcl-2 overexpression in human tumours. (orig.)

  7. Effects of Helicobacter pylori infection on the expressions of Bax and Bcl-2 in patients with chronic gastritis and gastric cancer.

    Science.gov (United States)

    Bartchewsky, Waldemar; Martini, Mariana R; Squassoni, Aline C; Alvarez, Marisa C; Ladeira, Marcelo S P; Salvatore, Daisy M F; Trevisan, Miriam A; Pedrazzoli, José; Ribeiro, Marcelo L

    2010-01-01

    The aim of the present study is to evaluate the influence of Helicobacter pylori on Bax and Bcl-2 mRNA and protein levels in patients with chronic gastritis and gastric cancer. The study included 217 patients, of which 26 were uninfected; 127 had chronic gastritis and were H. pylori-positive, and 64 had gastric cancer. Bacterial genotypes were evaluated by PCR, and the expression values were determined by quantitative real-time PCR and immunohistochemistry. Our data showed that the up-regulationary effects of H. pylori infection on the pro-apoptotic gene, Bax, were stronger than its induction of Bcl-2; this effect may increase apoptosis in patients with chronic gastritis. In patients with gastric cancer, the up-regulation of the anti-apoptotic gene, Bcl-2, counteracted the pro-apoptotic effects of Bax, leading to a deregulation of apoptosis-associated gene expression, favoring cell proliferation. Thus, the disturbance in Bax and Bcl-2 balance, induced by H. pylori, might be important in gastric cancer development.

  8. Bcl-2 family-regulated apoptosis in health and disease

    Directory of Open Access Journals (Sweden)

    Grant Dewson

    2010-04-01

    Full Text Available Grant Dewson, Ruth M KluckMolecular Genetics of Cancer Division, Walter and Eliza Hall Institute of Medical Research, Melbourne, AustraliaAbstract: Apoptotic cell death is essential for embryonic development, tissue homeostasis, and a well-functioning immune system, with aberrant apoptosis contributing to numerous disease conditions. Inadequate cell death is a major contributing factor to tumorigenesis, while excess cell death contributes to neurodegeneration and autoimmune disease. The major pathway of apoptotic cell death, the mitochondrial pathway, is controlled by the Bcl-2 family of proteins. The members of this family, more than 17 in humans, share significant sequence and structural homology, and fulfil either prosurvival or proapoptotic roles. Specific interactions between these functionally polar proteins, and their relative expression levels, govern the susceptibility of each cell to toxic insults. Here we review the current understanding on how apoptotic cell death is controlled by this important protein family. We also discuss how excessive or insufficient cell death can contribute to disease, and how targeting the Bcl-2 family offers novel therapeutic opportunities.Keywords: apoptosis, Bcl-2, cancer, cytochrome c, mitochondria

  9. Akt regulates drug-induced cell death through Bcl-w downregulation.

    Science.gov (United States)

    Garofalo, Michela; Quintavalle, Cristina; Zanca, Ciro; De Rienzo, Assunta; Romano, Giulia; Acunzo, Mario; Puca, Loredana; Incoronato, Mariarosaria; Croce, Carlo M; Condorelli, Gerolama

    2008-01-01

    Akt is a serine threonine kinase with a major role in transducing survival signals and regulating proteins involved in apoptosis. To find new interactors of Akt involved in cell survival, we performed a two-hybrid screening in yeast using human full-length Akt c-DNA as bait and a murine c-DNA library as prey. Among the 80 clones obtained, two were identified as Bcl-w. Bcl-w is a member of the Bcl-2 family that is essential for the regulation of cellular survival, and that is up-regulated in different human tumors, such as gastric and colorectal carcinomas. Direct interaction of Bcl-w with Akt was confirmed by immunoprecipitation assays. Subsequently, we addressed the function of this interaction: by interfering with the activity or amount of Akt, we have demonstrated that Akt modulates the amount of Bcl-w protein. We have found that inhibition of Akt activity may promote apoptosis through the downregulation of Bcl-w protein and the consequential reduction in interaction of Bcl-w with pro-apoptotic members of the Bcl-2 family. Our data provide evidence that Bcl-w is a new member of the Akt pathway and that Akt may induce anti-apoptotic signals at least in part through the regulation of the amount and activity of Bcl-w.

  10. Anti-ceramidase LCL385 acutely reduces BCL-2 expression in the hippocampus but is not associated with an increase of learned helplessness in rats.

    Science.gov (United States)

    Nahas, Ziad; Jiang, Yan; Zeidan, Youssef H; Bielawska, Alicja; Szulc, Zdzislaw; Devane, Lindsay; Kalivas, Peter; Hannun, Yusuf A

    2009-01-30

    Evidence from in situ studies supports the role of anti-apoptotic factors in the antidepressant responses of certain psychotropics. The availability of anti-ceramidase pro-apoptocic compound (LCL385) provides an opportunity to test in vivo the relation between hippocampal apopotosis and learned helplessness. 40 Sprague-Dawley male rodents underwent an FST after a treatment with LCL385, desipramine (DMI), or placebo (SAL) over 3 days. Behavioral responses, including immobility, swimming and climbing were counted during the 6min test. Western blot labeling was used to detect anti-apoptosis in hippocampus. DMI alone was associated with reduced immobility and increased climbing whereas LCL385 alone showed a decrease in Bcl-2/beta-actin ratio. Direct modulation of Bcl-2 expression in the hippocampus is not associated with learned helplessness in stressed rats. Three-day administration of DMI and LCL385 show divergent effects on behavioral and anti-apoptotic measures.

  11. Targeted BCL2 inhibition effectively inhibits neuroblastoma tumour growth

    NARCIS (Netherlands)

    Lamers, Fieke; Schild, Linda; den Hartog, Ilona J. M.; Ebus, Marli E.; Westerhout, Ellen M.; Ora, Ingrid; Koster, Jan; Versteeg, Rogier; Caron, Huib N.; Molenaar, Jan J.

    2012-01-01

    Genomic aberrations of key regulators of the apoptotic pathway have hardly been identified in neuroblastoma. We detected high BCL2 mRNA and protein levels in the majority of neuroblastoma tumours by Affymetrix expression profiling and Tissue Micro Array analysis. This BCL2 mRNA expression is

  12. CC genotype of anti-apoptotic gene BCL-2 (-938 C/A) is an independent prognostic marker of unfavorable clinical outcome in patients with non-small-cell lung cancer.

    Science.gov (United States)

    Javid, J; Mir, R; Mirza, M; Imtiyaz, A; Prasant, Y; Mariyam, Z; Julka, P K; Mohan, A; Lone, M; Ray, P C; Saxena, A

    2015-04-01

    B cell lymphoma 2 (BCL-2) gene is a well-known regulator of apoptosis and a key element in cancer development and progression. A regulatory (-938C>A, rs2279115) single-nucleotide polymorphism in the inhibitory P2 BCL-2 gene promoter generates significantly different BCL-2 promoter activities and has been associated with different clinical outcomes in various malignancies. The aim of the present study was to analyze the possible influence of the (-938C>A) SNP on the risk and survival of Indian patients suffering from NSCLC. A hospital-based case-control study of 155 age- and sex-matched patients diagnosed with NSCLC and 155 cancer-free controls was conducted and genotyped by performing PIRA-PCR to elucidate the putative association between clinical outcome and genotypes of BCL-2 (-938C>A, rs2279115). The association of the polymorphism with the survival of NSCLC patients was analyzed by Kaplan-Meier curves. In Indian NSCLC, patients increased risk of developing NSCLC was found to be associated with BCL-2 (-938) CC genotype, [OR 3.68 (1.92-6.79), RR 1.87 (1.35-2.57) and RD 31.03 (16.79-45.27) p 0.00006 for CC and OR 2.08 (1.18-3.66), RR 1.36 (1.08-1.71) and RD 17.74 (4.68-30.81) p 0.01 for AC genotype]. Patients homozygous for C allele exhibited a significant poor overall survival compared with patients displaying AC + CC or AC or AA genotype [median survival (months) 8 vs. 11 vs. 14 vs. 35.5 (p A) polymorphism. Genetic polymorphism in the inhibitory P2 promoter region of anti-apoptotic BCL-2 genes contributes to the risk of developing non-small-cell lung cancer in Indian population. BCL-2 (-938CC) genotype was an independent adverse prognostic factor for patients with NSCLC.

  13. Myocardial Ablation of G Protein-Coupled Receptor Kinase 2 (GRK2 Decreases Ischemia/Reperfusion Injury through an Anti-Intrinsic Apoptotic Pathway.

    Directory of Open Access Journals (Sweden)

    Qian Fan

    Full Text Available Studies from our lab have shown that decreasing myocardial G protein-coupled receptor kinase 2 (GRK2 activity and expression can prevent heart failure progression after myocardial infarction. Since GRK2 appears to also act as a pro-death kinase in myocytes, we investigated the effect of cardiomyocyte-specific GRK2 ablation on the acute response to cardiac ischemia/reperfusion (I/R injury. To do this we utilized two independent lines of GRK2 knockout (KO mice where the GRK2 gene was deleted in only cardiomyocytes either constitutively at birth or in an inducible manner that occurred in adult mice prior to I/R. These GRK2 KO mice and appropriate control mice were subjected to a sham procedure or 30 min of myocardial ischemia via coronary artery ligation followed by 24 hrs reperfusion. Echocardiography and hemodynamic measurements showed significantly improved post-I/R cardiac function in both GRK2 KO lines, which correlated with smaller infarct sizes in GRK2 KO mice compared to controls. Moreover, there was significantly less TUNEL positive myocytes, less caspase-3, and -9 but not caspase-8 activities in GRK2 KO mice compared to control mice after I/R injury. Of note, we found that lowering cardiac GRK2 expression was associated with significantly lower cytosolic cytochrome C levels in both lines of GRK2 KO mice after I/R compared to corresponding control animals. Mechanistically, the anti-apoptotic effects of lowering GRK2 expression were accompanied by increased levels of Bcl-2, Bcl-xl, and increased activation of Akt after I/R injury. These findings were reproduced in vitro in cultured cardiomyocytes and GRK2 mRNA silencing. Therefore, lowering GRK2 expression in cardiomyocytes limits I/R-induced injury and improves post-ischemia recovery by decreasing myocyte apoptosis at least partially via Akt/Bcl-2 mediated mitochondrial protection and implicates mitochondrial-dependent actions, solidifying GRK2 as a pro-death kinase in the heart.

  14. Inhibitory heterotrimeric GTP-binding proteins inhibit hydrogen peroxide-induced apoptosis by up-regulation of Bcl-2 via NF-κB in H1299 human lung cancer cells

    International Nuclear Information System (INIS)

    Seo, Mi Ran; Nam, Hyo-Jung; Kim, So-Young; Juhnn, Yong-Sung

    2009-01-01

    Inhibitory heterotrimeric GTP-binding proteins (Gi proteins) mediate a variety of signaling pathways by coupling receptors and effectors to regulate cellular proliferation, differentiation, and apoptosis. However, the role of Gi proteins in the modulation of hydrogen peroxide-induced apoptosis is not clearly understood. Thus, we investigated the effect of Gi proteins on hydrogen peroxide-induced apoptosis and the underlying mechanisms in H1299 human lung cancer cells. The stable expression of constitutively active alpha subunits of Gi1 (Gαi1QL), Gi2, or Gi3 inhibited hydrogen peroxide-induced apoptosis. The expression of Gαi1QL up-regulated Bcl-2 expression, and the knockdown of Bcl-2 with siRNA abolished the anti-apoptotic effect of Gαi1QL. Gαi1 induced the transcription of Bcl-2 by activation of NF-κB, which resulted from an increase in NF-κB p50 protein. We conclude that Gαi1 inhibits hydrogen peroxide-induced apoptosis of H1299 lung cancer cells by up-regulating the transcription of Bcl-2 through a p50-mediated NF-κB activation.

  15. XIAP impairs mitochondrial function during apoptosis by regulating the Bcl-2 family in renal cell carcinoma.

    Science.gov (United States)

    Chen, Chao; Liu, Tian Shu; Zhao, Si Cong; Yang, Wen Zheng; Chen, Zong Ping; Yan, Yong

    2018-05-01

    Efficient apoptosis requires Bcl-2 family-mediated mitochondrial outer membrane permeabilization (MOMP), which releases pro-apoptotic proteins to the cytosol, activating apoptosis and inhibiting X-linked inhibitor of apoptosis protein (XIAP). XIAP is a member of the inhibitors of apoptosis protein family whose expression is elevated in many cancer types and participates in the release of pro-apoptotic proteins. To explore the association between XIAP and the Bcl-2 family, and the influence of XIAP on mitochondria, RNA interference of XIAP was performed in Caki-1 cells and the dynamic change in the levels of related proteins was compared with the original Caki-1 cells upon induction of apoptosis. Upon knockdown of XIAP, the release of cytochrome c (Cyt-c), second mitochondria-derived activator of caspase (Smac) and apoptotic protease activating factor 1 (Apaf-1) from mitochondria proceeded normally, whereas in Caki-1 cells, the release of these pro-apoptotic proteins was significantly prolonged, and incomplete. Downregulation of XIAP through small interfering RNA resulted in an increase of apoptosis and a marked decrease in Bcl-2 and Bcl-xl levels at 3 h. Additionally, the regulation of the level of XIAP protein affected the specific ratios of Bcl-2/Bax and Bcl-xl/Bax, which play decisive roles in cell death. In the present study, it was revealed that XIAP can feed back to mitochondria, delaying Cyt-c and Apaf-1 release. Furthermore, XIAP can limit the release of its inhibitor Smac with the involvement of Bcl-2 family proteins.

  16. Anti-apoptotic peptides protect against radiation-induced cell death

    International Nuclear Information System (INIS)

    McConnell, Kevin W.; Muenzer, Jared T.; Chang, Kathy C.; Davis, Chris G.; McDunn, Jonathan E.; Coopersmith, Craig M.; Hilliard, Carolyn A.; Hotchkiss, Richard S.; Grigsby, Perry W.; Hunt, Clayton R.

    2007-01-01

    The risk of terrorist attacks utilizing either nuclear or radiological weapons has raised concerns about the current lack of effective radioprotectants. Here it is demonstrated that the BH4 peptide domain of the anti-apoptotic protein Bcl-xL can be delivered to cells by covalent attachment to the TAT peptide transduction domain (TAT-BH4) and provide protection in vitro and in vivo from radiation-induced apoptotic cell death. Isolated human lymphocytes treated with TAT-BH4 were protected against apoptosis following exposure to 15 Gy radiation. In mice exposed to 5 Gy radiation, TAT-BH4 treatment protected splenocytes and thymocytes from radiation-induced apoptotic cell death. Most importantly, in vivo radiation protection was observed in mice whether TAT-BH4 treatment was given prior to or after irradiation. Thus, by targeting steps within the apoptosis signaling pathway it is possible to develop post-exposure treatments to protect radio-sensitive tissues

  17. Endoplasmic Reticulum Stress Induces the Early Appearance of Pro-apoptotic and Anti-apoptotic Proteins in Neurons of Five Familial Alzheimer′s Disease Mice

    Directory of Open Access Journals (Sweden)

    Hui Shen

    2016-01-01

    Conclusions: These findings suggest that compared with those of age-matched WT mice, ERS-associated pro-apoptotic and anti-apoptotic proteins are upregulated in 2-month-old 5×FAD mice, consistent with intracellular Aβ aggregation in neurons.

  18. Akt regulates drug-induced cell death through Bcl-w downregulation.

    Directory of Open Access Journals (Sweden)

    Michela Garofalo

    Full Text Available Akt is a serine threonine kinase with a major role in transducing survival signals and regulating proteins involved in apoptosis. To find new interactors of Akt involved in cell survival, we performed a two-hybrid screening in yeast using human full-length Akt c-DNA as bait and a murine c-DNA library as prey. Among the 80 clones obtained, two were identified as Bcl-w. Bcl-w is a member of the Bcl-2 family that is essential for the regulation of cellular survival, and that is up-regulated in different human tumors, such as gastric and colorectal carcinomas. Direct interaction of Bcl-w with Akt was confirmed by immunoprecipitation assays. Subsequently, we addressed the function of this interaction: by interfering with the activity or amount of Akt, we have demonstrated that Akt modulates the amount of Bcl-w protein. We have found that inhibition of Akt activity may promote apoptosis through the downregulation of Bcl-w protein and the consequential reduction in interaction of Bcl-w with pro-apoptotic members of the Bcl-2 family. Our data provide evidence that Bcl-w is a new member of the Akt pathway and that Akt may induce anti-apoptotic signals at least in part through the regulation of the amount and activity of Bcl-w.

  19. Estradiol increases the Bax/Bcl-2 ratio and induces apoptosis in the anterior pituitary gland.

    Science.gov (United States)

    Zaldivar, Verónica; Magri, María Laura; Zárate, Sandra; Jaita, Gabriela; Eijo, Guadalupe; Radl, Daniela; Ferraris, Jimena; Pisera, Daniel; Seilicovich, Adriana

    2009-01-01

    Estrogens are recognized as acting as modulators of pituitary cell renewal, sensitizing cells to mitogenic and apoptotic signals, thus participating in anterior pituitary homeostasis during the estrous cycle. The balance of pro- and antiapoptotic proteins of the Bcl-2 family is known to regulate cell survival and apoptosis. In order to understand the mechanisms underlying apoptosis during the estrous cycle, we evaluated the expression of the proapoptotic protein Bax and the antiapoptotic proteins Bcl-2 and Bcl-xL in the anterior pituitary gland in cycling female rats as well as the influence of estradiol on the expression of these proteins in anterior pituitary cells of ovariectomized rats. As determined by Western blot, the expression of Bax was higher in anterior pituitary glands from rats at proestrus than at diestrus I, Bcl-2 protein levels showed no difference and Bcl-xL expression was lower, thus increasing the Bax/Bcl-2 ratio at proestrus. Assessed by annexin V binding and flow cytometry, the percentage of apoptotic anterior pituitary cells was higher in rats at proestrus than at diestrus I. Chronic estrogen treatment in ovariectomized rats enhanced the Bax/Bcl-2 ratio and induced apoptosis. Moreover, incubation of cultured anterior pituitary cells from ovariectomized rats with 17beta-estradiol for 24 h increased the Bax/Bcl-2 ratio, decreased Bcl-xL expression and induced apoptosis. Our results demonstrate that estradiol increases the ratio between proapoptotic and antiapoptotic proteins of the Bcl-2 family. This effect could participate in the sensitizing action of estrogens to proapoptotic stimuli and therefore be involved in the high apoptotic rate observed at proestrus in the anterior pituitary gland.

  20. Overexpression of the anti-apoptotic protein BAG3 in human choroidal melanoma: A case report.

    Science.gov (United States)

    Yunoki, Tatsuya; Tabuchi, Yoshiaki; Kondo, Takashi; Ishii, Yoko; Hayashi, Atsushi

    2017-06-01

    Bcl-2-associated athanogene 3 (BAG3), a co-chaperone of heat shock protein 70 (HSP70), exerts anti-apoptotic effects in various malignant tumors. However, relationships between choroidal melanoma and BAG3 are poorly studied. This study investigated the expression of BAG3 in a case of human choroidal melanoma. Funduscopy, computed tomography, and single-photon emission computed tomography with the intravenous injection of N-isopropyl-p-[ 123 I] iodoamphetamine strongly indicated choroidal melanoma in a 68-year-old woman. Accordingly, we carried out an enucleation and pathological diagnosis. Proteins and total RNA were extracted from normal retinochoroidal and tumor tissues. Proteins were also extracted from ocular nevus tissues of other patients. We examined the expression of BAG3 protein and mRNA using Western blotting and the real-time quantitative polymerase chain reaction, respectively. Immunohistochemical stains were positive for melan-A, HMB-45, and S-100. Histopathology confirmed a choroidal melanoma. The expression of BAG3 protein and mRNA in the choroidal melanoma tissue was upregulated with respect to both normal retinochoroidal tissue and ocular nevus tissues from other patients. Because BAG3 may inhibit apoptosis of choroidal melanoma and facilitate its survival, overexpression of this gene product may be a prognostic marker and therapeutic target.

  1. Borax-induced apoptosis in HepG2 cells involves p53, Bcl-2, and Bax.

    Science.gov (United States)

    Wei, Y; Yuan, F J; Zhou, W B; Wu, L; Chen, L; Wang, J J; Zhang, Y S

    2016-06-21

    Borax, a boron compound and a salt of boric acid, is known to inhibit the growth of tumor cells. HepG2 cells have been shown to be clearly susceptible to the anti-proliferative effects of borax. However, the specific mechanisms regulating this effect are poorly understood. This study aimed to investigate the pathways underlying the growth inhibition induced by borax in HepG2 cells. The effects of borax on HepG2 cell viability were characterized using MTT. Apoptosis was also verified by annexin V/propidium iodide staining. JC-1 dye and western blotting techniques were used to measure mitochondrial membrane potential and p53, Bax, and Bcl-2 protein expression, respectively. Relevant mRNA levels were measured by qRT-PCR. Borax inhibited the proliferation of HepG2 cells in a time- and dose-dependent manner in vitro. The apoptotic process triggered by borax involved the upregulation of p53 and Bax and the downregulation of Bcl-2, which was confirmed by a change in the mitochondrial membrane potential. These results elucidate a borax-induced apoptotic pathway in HepG2 cells that involves the upregulation of p53 and Bax and the downregulation of Bcl-2.

  2. Cannabinoids Regulate Bcl-2 and Cyclin D2 Expression in Pancreatic β Cells.

    Directory of Open Access Journals (Sweden)

    Jihye Kim

    Full Text Available Recent reports have shown that cannabinoid 1 receptors (CB1Rs are expressed in pancreatic β cells, where they induce cell death and cell cycle arrest by directly inhibiting insulin receptor activation. Here, we report that CB1Rs regulate the expression of the anti-apoptotic protein Bcl-2 and cell cycle regulator cyclin D2 in pancreatic β cells. Treatment of MIN6 and βTC6 cells with a synthetic CB1R agonist, WIN55,212-2, led to a decrease in the expression of Bcl-2 and cyclin D2, in turn inducing cell cycle arrest in G0/G1 phase and caspase-3-dependent apoptosis. Additionally, genetic deletion and pharmacological blockade of CB1Rs after injury in mice led to increased levels of Bcl-2 and cyclin D2 in pancreatic β cells. These findings provide evidence for the involvement of Bcl-2 and cyclin D2 mediated by CB1Rs in the regulation of β-cell survival and growth, and will serve as a basis for developing new therapeutic interventions to enhance β-cell function and growth in diabetes.

  3. Expanding the Cancer Arsenal with Targeted Therapies: Disarmament of the Antiapoptotic Bcl-2 Proteins by Small Molecules.

    Science.gov (United States)

    Yap, Jeremy L; Chen, Lijia; Lanning, Maryanna E; Fletcher, Steven

    2017-02-09

    A hallmark of cancer is the evasion of apoptosis, which is often associated with the upregulation of the antiapoptotic members of the Bcl-2 family of proteins. The prosurvival function of the antiapoptotic Bcl-2 proteins is manifested by capturing and neutralizing the proapoptotic Bcl-2 proteins via their BH3 death domains. Accordingly, strategies to antagonize the antiapoptotic Bcl-2 proteins have largely focused on the development of low-molecular-weight, synthetic BH3 mimetics ("magic bullets") to disrupt the protein-protein interactions between anti- and proapoptotic Bcl-2 proteins. In this way, apoptosis has been reactivated in malignant cells. Moreover, several such Bcl-2 family inhibitors are presently being evaluated for a range of cancers in clinical trials and show great promise as new additions to the cancer armamentarium. Indeed, the selective Bcl-2 inhibitor venetoclax (Venclexta) recently received FDA approval for the treatment of a specific subset of patients with chronic lymphocytic leukemia. This review focuses on the major developments in the field of Bcl-2 inhibitors over the past decade, with particular emphasis on binding modes and, thus, the origins of selectivity for specific Bcl-2 family members.

  4. Protective effects of melittin on transforming growth factor-β1 injury to hepatocytes via anti-apoptotic mechanism

    International Nuclear Information System (INIS)

    Lee, Woo-Ram; Park, Ji-Hyun; Kim, Kyung-Hyun; Park, Yoon-Yub; Han, Sang-Mi; Park, Kwan-kyu

    2011-01-01

    Melittin is a cationic, hemolytic peptide that is the main toxic component in the venom of the honey bee (Apis mellifera). Melittin has multiple effects, including anti-bacterial, anti-viral and anti-inflammatory, in various cell types. However, the anti-apoptotic mechanisms of melittin have not been fully elucidated in hepatocytes. Apoptosis contributes to liver inflammation and fibrosis. Knowledge of the apoptotic mechanisms is important to develop new and effective therapies for treatment of cirrhosis, portal hypertension, liver cancer, and other liver diseases. In the present study, we investigated the anti-apoptotic effect of melittin on transforming growth factor (TGF)-β1-induced apoptosis in hepatocytes. TGF-β1-treated hepatocytes were exposed to low doses (0.5 and 1 μg/mL) and high dose (2 μg/mL) of melittin. The low doses significantly protected these cells from DNA damage in TGF-β1-induced apoptosis compared to the high dose. Also, melittin suppressed TGF-β1-induced apoptotic activation of the Bcl-2 family and caspase family of proteins, which resulted in the inhibition of poly-ADP-ribose polymerase (PARP) cleavage. These results demonstrate that TGF-β1 induces hepatocyte apoptosis and that an optimal dose of melittin exerts anti-apoptotic effects against TGF-β1-induced injury to hepatocytes via the mitochondrial pathway. These results suggest that an optimal dose of melittin can serve to protect cells against TGF-β1-mediated injury. - Highlights: → We investigated the anti-apoptotic effect of melittin on TGF-β1-induced hepatocyte. → TGF-β1 induces hepatocyte apoptosis. → TGF-β1-treated hepatocytes were exposed to low doses and high dose of melittin. → Optimal dose of melittin exerts anti-apoptotic effects to hepatocytes.

  5. Virtual screening, SAR, and discovery of 5-(indole-3-yl)-2-[(2-nitrophenyl)amino] [1,3,4]-oxadiazole as a novel Bcl-2 inhibitor.

    Science.gov (United States)

    Ziedan, Noha I; Hamdy, Rania; Cavaliere, Alessandra; Kourti, Malamati; Prencipe, Filippo; Brancale, Andrea; Jones, Arwyn T; Westwell, Andrew D

    2017-07-01

    A new series of oxadiazoles were designed to act as inhibitors of the anti-apoptotic Bcl-2 protein. Virtual screening led to the discovery of new hits that interact with Bcl-2 at the BH3 binding pocket. Further study of the structure-activity relationship of the most active compound of the first series, compound 1, led to the discovery of a novel oxadiazole analogue, compound 16j, that was a more potent small-molecule inhibitor of Bcl-2. 16j had good in vitro inhibitory activity with submicromolar IC 50 values in a metastatic human breast cancer cell line (MDA-MB-231) and a human cervical cancer cell line (HeLa). The antitumour effect of 16j is concomitant with its ability to bind to Bcl-2 protein as shown by an enzyme-linked immunosorbent assay (IC 50  = 4.27 μm). Compound 16j has a great potential to develop into highly active anticancer agent. © 2017 John Wiley & Sons A/S.

  6. Post-infarct treatment with [Pyr1]apelin-13 exerts anti-remodelling and anti-apoptotic effects in rats' hearts.

    Science.gov (United States)

    Azizi, Yaser; Imani, Alireza; Fanaei, Hamed; Khamse, Safoura; Parvizi, Mohammad Reza; Faghihi, Mahdieh

    2017-01-01

    Ischaemic heart disease is the main cause of mortality in the world. After myocardial infarction (MI) cardiomyocytes apoptosis and ventricular remodelling have occurred. Apelin is a peptide that has been shown to exert cardioprotective effects. The aim of this study was to investigate the anti-apoptotic and anti-remodelling effects of [Pyr¹]apelin-13 in the rat model of post-MI. Thirty-six male Wistar rats were randomly divided into three groups: (1) sham, (2) MI, and (3) MI treated with [Pyr¹] apelin-13 (MI+Apel). MI animals were subjected to 30-min ligation of the left anterior descending coronary artery (LAD) and 14 days of reperfusion. Twenty-four hours after LAD ligation, [Pyr¹]apelin-13 (10 nmol/kg/day, i.p.) was administered for five consecutive days. Hypertrophic parameters, left ventricular (LV) remodelling, and gene expression of Apel, apelin receptor (Apelr), Bax, caspase-3 (Casp-3), and Bcl-2 by real-time polymerase chain reaction and cardiomyocytes apoptosis by TUNEL immunostaining were assessed on day 14 post-MI. Post-infarct treatment with [Pyr¹]apelin-13 improved myocardial hypertrophic and LV remodelling parameters and led to a significant increase in the expression of Apel, Apelr, and Bcl-2, and a decrease in the expression of Bax and Casp-3. Furthermore, treatment with [Pyr¹]apelin-13 decreased cardiomyocyte apoptosis. [Pyr¹]apelin-13 has anti-hypertrophic, anti-remodelling, and anti-apoptotic effects via overexpression of Apel, Apelr, and Bcl-2 and reduces gene expression of Bax and Casp-3 in the infarcted myocardium, which can in turn lead to repair myocardium.

  7. Histone deacetylase inhibitors strongly sensitise neuroblastoma cells to TRAIL-induced apoptosis by a caspases-dependent increase of the pro- to anti-apoptotic proteins ratio

    International Nuclear Information System (INIS)

    Mühlethaler-Mottet, Annick; Flahaut, Marjorie; Bourloud, Katia Balmas; Auderset, Katya; Meier, Roland; Joseph, Jean-Marc; Gross, Nicole

    2006-01-01

    Neuroblastoma (NB) is the second most common solid childhood tumour, an aggressive disease for which new therapeutic strategies are strongly needed. Tumour necrosis factor-related apoptosis-inducing ligand (TRAIL) selectively induces apoptosis in most tumour cells, but not in normal tissues and therefore represents a valuable candidate in apoptosis-inducing therapies. Caspase-8 is silenced in a subset of highly malignant NB cells, which results in full TRAIL resistance. In addition, despite constitutive caspase-8 expression, or its possible restoration by different strategies, NB cells remain weakly sensitive to TRAIL indicating a need to develop strategies to sensitise NB cells to TRAIL. Histone deacetylase inhibitors (HDACIs) are a new class of anti-cancer agent inducing apoptosis or cell cycle arrest in tumour cells with very low toxicity toward normal cells. Although HDACIs were recently shown to increase death induced by TRAIL in weakly TRAIL-sensitive tumour cells, the precise involved sensitisation mechanisms have not been fully identified. NB cell lines were treated with various doses of HDACIs and TRAIL, then cytotoxicity was analysed by MTS/PMS proliferation assays, apoptosis was measured by the Propidium staining method, caspases activity by colorimetric protease assays, and (in)activation of apoptotic proteins by immunoblotting. Sub-toxic doses of HDACIs strongly sensitised caspase-8 positive NB cell lines to TRAIL induced apoptosis in a caspases dependent manner. Combined treatments increased the activation of caspases and Bid, and the inactivation of the anti-apoptotic proteins XIAP, Bcl-x, RIP, and survivin, thereby increasing the pro- to anti-apoptotic protein ratio. It also enhanced the activation of the mitochondrial pathway. Interestingly, the kinetics of caspases activation and inactivation of anti-apoptotic proteins is accelerated by combined treatment with TRAIL and HDACIs compared to TRAIL alone. In contrast, cell surface expression of TRAIL

  8. Cellular responses to a prolonged delay in mitosis are determined by a DNA damage response controlled by Bcl-2 family proteins.

    Science.gov (United States)

    Colin, Didier J; Hain, Karolina O; Allan, Lindsey A; Clarke, Paul R

    2015-03-01

    Anti-cancer drugs that disrupt mitosis inhibit cell proliferation and induce apoptosis, although the mechanisms of these responses are poorly understood. Here, we characterize a mitotic stress response that determines cell fate in response to microtubule poisons. We show that mitotic arrest induced by these drugs produces a temporally controlled DNA damage response (DDR) characterized by the caspase-dependent formation of γH2AX foci in non-apoptotic cells. Following exit from a delayed mitosis, this initial response results in activation of DDR protein kinases, phosphorylation of the tumour suppressor p53 and a delay in subsequent cell cycle progression. We show that this response is controlled by Mcl-1, a regulator of caspase activation that becomes degraded during mitotic arrest. Chemical inhibition of Mcl-1 and the related proteins Bcl-2 and Bcl-xL by a BH3 mimetic enhances the mitotic DDR, promotes p53 activation and inhibits subsequent cell cycle progression. We also show that inhibitors of DDR protein kinases as well as BH3 mimetics promote apoptosis synergistically with taxol (paclitaxel) in a variety of cancer cell lines. Our work demonstrates the role of mitotic DNA damage responses in determining cell fate in response to microtubule poisons and BH3 mimetics, providing a rationale for anti-cancer combination chemotherapies.

  9. Peptide vaccination against multiple myeloma using peptides derived from anti-apoptotic protein

    DEFF Research Database (Denmark)

    Jørgensen, Nicolai Grønne Dahlager; Ahmad, Shamaila Munir; Abildgaard, N.

    2016-01-01

    The B-cell lymphoma-2 (Bcl-2) family of proteins play a crucial role in multiple myeloma (MM), contributing to lacking apoptosis which is a hallmark of the disease. This makes the Bcl-2 proteins interesting targets for therapeutic peptide vaccination. We report a phase I trial of therapeutic vacc...... vaccination. Vaccination against Bcl-2 was well tolerated and was able to induce immune responses in patients with relapsed MM. © Stem Cell Investigation. All rights reserved.......The B-cell lymphoma-2 (Bcl-2) family of proteins play a crucial role in multiple myeloma (MM), contributing to lacking apoptosis which is a hallmark of the disease. This makes the Bcl-2 proteins interesting targets for therapeutic peptide vaccination. We report a phase I trial of therapeutic...... vaccination with peptides from the proteins Bcl-2, Bcl-XL and Mcl-1 in patients with relapsed MM. Vaccines were given concomitant with bortezomib. Out of 7 enrolled patients, 4 received the full course of 8 vaccinations. The remaining 3 patients received fewer vaccinations due to progression, clinical...

  10. Bcl-xL knockout attenuates mitochondrial respiration and causes oxidative stress that is compensated by pentose phosphate pathway activity

    NARCIS (Netherlands)

    Pfeiffer, Annika; Schneider, Julia; Bueno, Diones; Dolga, Amalia; Voss, Timo-Daniel; Lewerenz, Jan; Wüllner, Verena; Methner, Axel

    2017-01-01

    Bcl-xL is an anti-apoptotic protein that localizes to the outer mitochondrial membrane and influences mitochondrial bioenergetics by controlling Ca2+ influx into mitochondria. Here, we analyzed the effect of mitochondrial Bcl-xL on mitochondrial shape and function in knockout (KO), wild type and

  11. Dapoxetine attenuates testosterone-induced prostatic hyperplasia in rats by the regulation of inflammatory and apoptotic proteins

    International Nuclear Information System (INIS)

    Sayed, Rabab H.; Saad, Muhammed A.; El-Sahar, Ayman E.

    2016-01-01

    Serotonin level plays a role in suppressing the pathological findings of benign prostatic hyperplasia (BPH). Thus a new selective serotonin reuptake inhibitor, dapoxetine was used to test its ability to ameliorate the pathological changes in the rat prostate. A dose response curve was constructed between the dose of dapoxetine and prostate weight as well as relative prostate weight, then a 5 mg/kg dose was used as a representative dose for dapoxetine administration. Rats were divided into four groups; the control group that received the vehicle; the BPH-induced group received daily s.c injection of 3 mg/kg testosterone propionate dissolved in olive oil for four weeks; BPH-induced group treated with finasteride 5 mg/kg/day p.o and BPH-induced group treated with dapoxetine 5 mg/kg/day p.o. Injection of testosterone increased prostate weight and relative prostate weight which were both returned back to the normal value after treatment with dapoxetine as well as finasteride. Testosterone also upregulated androgen receptor (AR) and proliferating cell nuclear antigen gene expression. Furthermore, testosterone injection elevated cyclooxygenase-II (COX II), inducible nitric oxide synthase (iNOS), B-cell lymphoma-2 (Bcl2) expression and tumor necrosis factor alpha content and reduced caspase-3 activity, Bcl-2-associated X protein (Bax) expression and Bax/Bcl2 ratio. Dapoxetine and finasteride administration reverted most of the changes made by testosterone injection. In conclusion, the current study provides an evidence for the protective effects of dapoxetine against testosterone-induced BPH in rats. This can be attributed, at least in part, to decreasing AR expression, and the anti-proliferative, anti-inflammatory and pro-apoptotic activities of dapoxetine in BPH. - Highlights: • Dapoxetine attenuates testosterone-induced prostatic hyperplasia in rats. • Dapoxetine decreased androgen receptor gene expression in rat prostate. • Dapoxetine possess anti

  12. Dapoxetine attenuates testosterone-induced prostatic hyperplasia in rats by the regulation of inflammatory and apoptotic proteins

    Energy Technology Data Exchange (ETDEWEB)

    Sayed, Rabab H., E-mail: rabab.sayed@pharma.cu.edu.eg; Saad, Muhammed A.; El-Sahar, Ayman E.

    2016-11-15

    Serotonin level plays a role in suppressing the pathological findings of benign prostatic hyperplasia (BPH). Thus a new selective serotonin reuptake inhibitor, dapoxetine was used to test its ability to ameliorate the pathological changes in the rat prostate. A dose response curve was constructed between the dose of dapoxetine and prostate weight as well as relative prostate weight, then a 5 mg/kg dose was used as a representative dose for dapoxetine administration. Rats were divided into four groups; the control group that received the vehicle; the BPH-induced group received daily s.c injection of 3 mg/kg testosterone propionate dissolved in olive oil for four weeks; BPH-induced group treated with finasteride 5 mg/kg/day p.o and BPH-induced group treated with dapoxetine 5 mg/kg/day p.o. Injection of testosterone increased prostate weight and relative prostate weight which were both returned back to the normal value after treatment with dapoxetine as well as finasteride. Testosterone also upregulated androgen receptor (AR) and proliferating cell nuclear antigen gene expression. Furthermore, testosterone injection elevated cyclooxygenase-II (COX II), inducible nitric oxide synthase (iNOS), B-cell lymphoma-2 (Bcl2) expression and tumor necrosis factor alpha content and reduced caspase-3 activity, Bcl-2-associated X protein (Bax) expression and Bax/Bcl2 ratio. Dapoxetine and finasteride administration reverted most of the changes made by testosterone injection. In conclusion, the current study provides an evidence for the protective effects of dapoxetine against testosterone-induced BPH in rats. This can be attributed, at least in part, to decreasing AR expression, and the anti-proliferative, anti-inflammatory and pro-apoptotic activities of dapoxetine in BPH. - Highlights: • Dapoxetine attenuates testosterone-induced prostatic hyperplasia in rats. • Dapoxetine decreased androgen receptor gene expression in rat prostate. • Dapoxetine possess anti

  13. Effect of Bcl-2 rs956572 polymorphism on age-related gray matter volume changes.

    Directory of Open Access Journals (Sweden)

    Mu-En Liu

    Full Text Available The anti-apoptotic protein B-cell CLL/lymphoma 2 (Bcl-2 gene is a major regulator of neural plasticity and cellular resilience. Recently, the Bcl-2 rs956572 single nucleotide polymorphism was proposed to be a functional allelic variant that modulates cellular vulnerability to apoptosis. Our cross-sectional study investigated the genetic effect of this Bcl-2 polymorphism on age-related decreases in gray matter (GM volume across the adult lifespan. Our sample comprised 330 healthy volunteers (191 male, 139 female with a mean age of 56.2±22.0 years (range: 21-92. Magnetic resonance imaging and genotyping of the Bcl-2 rs956572 were performed for each participant. The differences in regional GM volumes between G homozygotes and A-allele carriers were tested using optimized voxel-based morphometry. The association between the Bcl-2 rs956572 polymorphism and age was a predictor of regional GM volumes in the right cerebellum, bilateral lingual gyrus, right middle temporal gyrus, and right parahippocampal gyrus. We found that the volume of these five regions decreased with increasing age (all P<.001. Moreover, the downward slope was steeper among the Bcl-2 rs956572 A-allele carriers than in the G-homozygous participants. Our data provide convergent evidence for the genetic effect of the Bcl-2 functional allelic variant in brain aging. The rs956572 G-allele, which is associated with significantly higher Bcl-2 protein expression and diminished cellular sensitivity to stress-induced apoptosis, conferred a protective effect against age-related changes in brain GM volume, particularly in the cerebellum.

  14. Modafinil abrogates methamphetamine-induced neuroinflammation and apoptotic effects in the mouse striatum.

    Directory of Open Access Journals (Sweden)

    Mariana Raineri

    Full Text Available Methamphetamine is a drug of abuse that can cause neurotoxic damage in humans and animals. Modafinil, a wake-promoting compound approved for the treatment of sleeping disorders, is being prescribed off label for the treatment of methamphetamine dependence. The aim of the present study was to investigate if modafinil could counteract methamphetamine-induced neuroinflammatory processes, which occur in conjunction with degeneration of dopaminergic terminals in the mouse striatum. We evaluated the effect of a toxic methamphetamine binge in female C57BL/6 mice (4 × 5 mg/kg, i.p., 2 h apart and modafinil co-administration (2 × 90 mg/kg, i.p., 1 h before the first and fourth methamphetamine injections on glial cells (microglia and astroglia. We also evaluated the striatal expression of the pro-apoptotic BAX and anti-apoptotic Bcl-2 proteins, which are known to mediate methamphetamine-induced apoptotic effects. Modafinil by itself did not cause reactive gliosis and counteracted methamphetamine-induced microglial and astroglial activation. Modafinil also counteracted the decrease in tyrosine hydroxylase and dopamine transporter levels and prevented methamphetamine-induced increases in the pro-apoptotic BAX and decreases in the anti-apoptotic Bcl-2 protein expression. Our results indicate that modafinil can interfere with methamphetamine actions and provide protection against dopamine toxicity, cell death, and neuroinflammation in the mouse striatum.

  15. Systems analysis of apoptotic priming in ovarian cancer identifies vulnerabilities and predictors of drug response.

    Science.gov (United States)

    Zervantonakis, Ioannis K; Iavarone, Claudia; Chen, Hsing-Yu; Selfors, Laura M; Palakurthi, Sangeetha; Liu, Joyce F; Drapkin, Ronny; Matulonis, Ursula; Leverson, Joel D; Sampath, Deepak; Mills, Gordon B; Brugge, Joan S

    2017-08-28

    The lack of effective chemotherapies for high-grade serous ovarian cancers (HGS-OvCa) has motivated a search for alternative treatment strategies. Here, we present an unbiased systems-approach to interrogate a panel of 14 well-annotated HGS-OvCa patient-derived xenografts for sensitivity to PI3K and PI3K/mTOR inhibitors and uncover cell death vulnerabilities. Proteomic analysis reveals that PI3K/mTOR inhibition in HGS-OvCa patient-derived xenografts induces both pro-apoptotic and anti-apoptotic signaling responses that limit cell killing, but also primes cells for inhibitors of anti-apoptotic proteins. In-depth quantitative analysis of BCL-2 family proteins and other apoptotic regulators, together with computational modeling and selective anti-apoptotic protein inhibitors, uncovers new mechanistic details about apoptotic regulators that are predictive of drug sensitivity (BIM, caspase-3, BCL-X L ) and resistance (MCL-1, XIAP). Our systems-approach presents a strategy for systematic analysis of the mechanisms that limit effective tumor cell killing and the identification of apoptotic vulnerabilities to overcome drug resistance in ovarian and other cancers.High-grade serous ovarian cancers (HGS-OvCa) frequently develop chemotherapy resistance. Here, the authors through a systematic analysis of proteomic and drug response data of 14 HGS-OvCa PDXs demonstrate that targeting apoptosis regulators can improve response of these tumors to inhibitors of the PI3K/mTOR pathway.

  16. The anti-apoptotic activity associated with phosphatidylinositol transfer protein alpha activates the MAPK and Akt/PKB pathway.

    Science.gov (United States)

    Schenning, Martijn; Goedhart, Joachim; Gadella, Theodorus W J; Avram, Diana; Wirtz, Karel W A; Snoek, Gerry T

    2008-10-01

    The conditioned medium (CM) from mouse NIH3T3 fibroblast cells overexpressing phosphatidylinositol transfer protein alpha (PI-TPalpha; SPIalpha cells) demonstrates an increased anti-apoptotic activity compared with CM from wild type NIH3T3 (wtNIH3T3) cells. As previously shown, the anti-apoptotic activity acts by activating a G protein-coupled receptor, most probably a cannabinoid 1 (CB1)-like receptor as the activity was blocked by both pertussis toxin and rimonabant [M. Schenning, C.M. van Tiel, D. Van Manen, J.C. Stam, B.M. Gadella, K.W. Wirtz and G.T. Snoek, Phosphatidylinositol transfer protein alpha regulates growth and apoptosis of NIH3T3 cells: involvement of a cannabinoid 1-like receptor, J. Lipid Res. 45 (2004) 1555-1564]. The CB1 receptor appears to be expressed in mouse fibroblast cells, at levels in the order SPIalpha>wtNIH3T3>SPIbeta cells (i.e. wild type cells overexpressing PI-TPbeta). Upon incubation of SPIbeta cells with the PI-TPalpha-dependent anti-apoptotic factors, both the ERK/MAP kinase and the Akt/PKB pathway are activated in a CB1 receptor dependent manner as shown by Western blotting. In addition, activation of ERK2 was also shown by EYFP-ERK2 translocation to the nucleus, as visualized by confocal laser scanning microscopy. The subsequent activation of the anti-apoptotic transcription factor NF-kappaB is in line with the increased resistance towards UV-induced apoptosis. On the other hand, receptor activation by CM from SPIalpha cells was not linked to phospholipase C activation as the YFP-labelled C2-domain of protein kinase C was not translocated to the plasma membrane of SPIbeta cells as visualized by confocal laser scanning microscopy.

  17. Synergistic efficacy of a novel combination therapy controls growth of Bcl-x(L) bountiful neuroblastoma cells by increasing differentiation and apoptosis.

    Science.gov (United States)

    Mohan, Nishant; Banik, Naren L; Ray, Swapan K

    2011-11-01

    Neuroblastoma is the most prevalent extracranial solid tumor mainly in pediatric patients. We explored the efficacy of the combination of 2[(3-[2,3-dichlorophenoxy]propyl)amino]ethanol (2,3-DCPE, a small molecule inhibitor of the anti-apoptotic protein Bcl-x(L)) and N-(4-hydroxyphenyl) retinamide (4-HPR, a synthetic retinoid) in inducing differentiation and apoptosis in human malignant neuroblastoma cells. Immunofluorescence confocal microscopy and flow cytometry showed that the highest level of Bcl-x(L) expression occurred in SK-N-DZ cells followed by SH-SY5Y and IMR-32 cells. Combination of 20 μM 2,3-DCPE and 1 μM 4-HPR acted synergistically in decreasing viability of SK-N-DZ and SH-SY5Y cells. In situ methylene blue staining and protein gel blotting showed the efficacy of this combination of drugs in inducing neuronal differentiation morphologically and also biochemically with upregulation of the neuronal markers such as neurofilament protein (NFP) and neuron specific enolase (NSE) and downregulation of the differentiation inhibiting molecules such as N-Myc and Notch-1 in SK-N-DZ and SH-SY5Y cells. Annexin V-FITC/PI staining showed the synergistic action of this combination therapy in increasing apoptosis in both cell lines. Protein gel blotting manifested that combination therapy increased apoptosis with downregulation of the anti-apoptotic proteins Bcl-x(L), Bcl-2 and Mcl-1 and upregulation of the pro-apoptotic proteins Bax, p53, Puma (p53 upregulated modulator of apoptosis), and Noxa, ultimately causing activation of caspase-3. In conclusion, our results appeared highly encouraging in advocating the use of 2,3-DCPE and 4-HPR as a novel combination therapy for increasing both differentiation and apoptosis in human malignant neuroblastoma cells having Bcl-x(L) overexpression.

  18. Overexpression of B7-H3 augments anti-apoptosis of colorectal cancer cells by Jak2-STAT3.

    Science.gov (United States)

    Zhang, Ting; Jiang, Bo; Zou, Shi-Tao; Liu, Fen; Hua, Dong

    2015-02-14

    To investigate the role of the overexpression of B7-H3 in apoptosis in colorectal cancer cell lines and the underlying molecular mechanisms. SW620 cells that highly overexpressed B7-H3 (SW620-B7-H3-EGFP) and HCT8 cells stably transfected with B7-H3 shRNA (HCT8-shB7-H3) were previously constructed in our laboratory. Cells transfected with pIRES2-EGFP were used as negative controls (SW620-NC and HCT8-NC). Real-time PCR and western blotting analysis were used to detect the mRNA and protein expressions of the apoptosis regulator proteins Bcl-2, Bcl-xl and Bax. A cell proliferation assay was used to evaluate the survival rate and drug sensitivity of the cells. The effect of drug resistance was detected by a cell cycle assay. Active caspase-3 western blotting was used to reflect the anti-apoptotic ability of cells. Western blotting was also performed to determine the expression of proteins associated with the Jak2-STAT3 signaling pathway and the apoptosis regulator proteins after the treatment with AG490, a Jak2 specific inhibitor, in B7-H3 overexpressing cells. The data were analyzed by GraphPad Prism 6 using a non-paired t-test. Whether by overexpression in SW620 cells or downregulation in HCT8, B7-H3 significantly affected the expression of anti- and pro-apoptotic proteins, at both the transcriptional and translational levels, compared with the negative control (P overexpression increased the drug resistance of cells and resulted in a higher survival rate (P overexpression inhibited apoptosis in colorectal cancer cell lines (P overexpression improved Jak2 and STAT3 phosphorylation and, in turn, increased the expression of the downstream anti-apoptotic proteins B-cell CLL/lymphoma 2 (Bcl-2) and Bcl-xl, based on western blotting (P overexpressing cells with the Jak2-specific inhibitor AG490, the phosphorylation of Jak2 and STAT3, and the expression of Bcl-2 and Bcl-xl, decreased accordingly (P overexpression of B7-H3 induces resistance to apoptosis in colorectal cancer

  19. Enhanced dopaminergic differentiation of human neural stem cells by synergistic effect of Bcl-xL and reduced oxygen tension

    DEFF Research Database (Denmark)

    Krabbe, Christina; Courtois, Elise; Jensen, Pia

    2009-01-01

    Neural stem cells constitute a promising source of cells for transplantation in Parkinson's disease, but a protocol for controlled dopaminergic differentiation is not yet available. Here we investigated the effect of the anti-apoptotic protein Bcl-x(L) and oxygen tension on dopaminergic different......Neural stem cells constitute a promising source of cells for transplantation in Parkinson's disease, but a protocol for controlled dopaminergic differentiation is not yet available. Here we investigated the effect of the anti-apoptotic protein Bcl-x(L) and oxygen tension on dopaminergic...... days at 20% oxygen, hVMbcl-x(L) cultures contained proportionally more tyrosine hydroxylase(TH)-positive cells than hVM1 control cultures. This difference was significantly potentiated from 11 +/- 0.8% to 17.2 +/- 0.2% of total cells when the oxygen tension was lowered to 3%. Immunocytochemistry and Q...

  20. Bcl-2 Protein Expression in Egyptian Acute Myeloid Leukemia

    International Nuclear Information System (INIS)

    El-Shakankiry, N.; El-Sayed, Gh.M.M.; El-Maghraby, Sh.; Moneer, M.M.

    2009-01-01

    Objective: The primary cause of treatment failure in acute myeloid leukemia (AML) is the emergence of both resistant disease and early relapse. The bcl-2 gene encodes a 26-kDa protein that promotes cell survival by blocking programmed cell death (apoptosis). In the present study, bcl-2 protein expression was evaluated in newly diagnosed AML patients and correlated with the induction of remission and overall survival (OS), in an attempt to define patients who might benefit from modified therapeutic strategies. Patients and methods: Pretreatment cellular bcl-2 protein expression was measured in bone marrow samples obtained from 68 patients of newly diagnosed acute myeloid leukemia and 10 healthy controls by western blotting. Results: The mean bcl-2 protein expression was significantly higher in patients (0.68610.592) compared to controls (0.313±0.016) (p=0.002). The overall survival for patients with mean bcl-2 expression of less, and more than or equal to 0.315, was 67% and 56%, respectively, with no significant difference between the two groups 0»=0.86). Conclusion: Even though we did not observe a significant difference in overall survival between patients with high and low levels of bcl-2, modulation of this protein might still be considered as an option for enhancing the effectiveness of conventional chemotherapy.

  1. Inhibition of oxygen-glucose deprivation-induced apoptosis of human adipose-derived stem cells by genetic modification with antiapoptotic protein bcl-2.

    Science.gov (United States)

    Cui, Ziwei; Shen, Liangyun; Lin, Yue; Wang, Shuqin; Zheng, Dongfeng; Tan, Qian

    2014-08-01

    Adipose-derived stem cells (ADSCs) have become a promising tool for a wide range of cell-based therapies. However, transplanted ADSCs do not survive well under ischemic conditions. In this study we aimed to inhibit oxygen-glucose deprivation (OGD)-induced apoptosis of human ADSCs by genetic modification with antiapoptotic protein Bcl-2. After isolation and culture, the phenotypes of human ADSCs at passage 3 were analyzed by flow cytometry. Then, genetic modification of ADSCs with Bcl-2 was carried out. Bcl-2 gene transfection was verified by Western blot analysis and multipotent differentiation properties were evaluated in Bcl-2-modified ADSCs (Bcl-2-ADSCs). Apoptosis was evaluated by a TUNEL assay under ischemic conditions induced by OGD. Apoptotic nuclei were also assessed and quantified by Hoechst staining. The cultured ADSCs expressed stem cell-associated markers CD29, CD34, CD44, and CD90, but not fibroblast marker HLA-DR or hematopoietic stem cell marker CD133. The Bcl-2 gene was transferred into ADSCs efficiently, and Bcl-2-ADSCs differentiated into adipocytes, chondrocytes, and osteoblasts. In addition, Bcl-2 overexpression reduced the percentage of apoptotic Bcl-2-ADSCs by 38 % under OGD. Our results indicate that Bcl-2 overexpression through gene transfection inhibits apoptosis of ADSCs under ischemic conditions. This journal requires that authors assign a level of evidence to each submission to which Evidence-Based Medicine rankings are applicable. This excludes Review Articles, Book Reviews, and manuscripts that concern Basic Science, Animal Studies, Cadaver Studies, and Experimental Studies. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

  2. Loss in MCL-1 function sensitizes non-Hodgkin's lymphoma cell lines to the BCL-2-selective inhibitor venetoclax (ABT-199)

    International Nuclear Information System (INIS)

    Phillips, D C; Xiao, Y; Lam, L T; Litvinovich, E; Roberts-Rapp, L; Souers, A J; Leverson, J D

    2015-01-01

    As a population, non-Hodgkin's lymphoma (NHL) cell lines positive for the t(14;18) translocation and/or possessing elevated BCL2 copy number (CN; BCL2 High ) are exquisitely sensitive to navitoclax or the B-cell lymphoma protein-2 (BCL-2)-selective inhibitor venetoclax. Despite this, some BCL2 High cell lines remain resistant to either agent. Here we show that the MCL-1-specific inhibitor A-1210477 sensitizes these cell lines to navitoclax. Chemical segregation of this synergy with the BCL-2-selective inhibitor venetoclax or BCL-X L -selective inhibitor A-1155463 indicated that MCL-1 and BCL-2 are the two key anti-apoptotic targets for sensitization. Similarly, the CDK inhibitor flavopiridol downregulated MCL-1 expression and synergized with venetoclax in BCL2 High NHL cell lines to a similar extent as A-1210477. A-1210477 also synergized with navitoclax in the majority of BCL2 Low NHL cell lines. However, chemical segregation with venetoclax or A-1155463 revealed that synergy was driven by BCL-X L inhibition in this population. Collectively these data emphasize that BCL2 status is predictive of venetoclax potency in NHL not only as a single agent, but also in the adjuvant setting with anti-tumorigenic agents that inhibit MCL-1 function. These studies also potentially identify a patient population (BCL2 Low ) that could benefit from BCL-X L (navitoclax)-driven combination therapy

  3. The anti-apoptotic activity associated with phosphatidylinositol transfer protein α activates the MAPK and Akt/PKB pathway

    NARCIS (Netherlands)

    Schenning, M.; Goedhart, J.; Gadella (jr.), T.W.J.; Avram, D.; Wirtz, K.W.A.; Snoek, G.T.

    2008-01-01

    The conditioned medium (CM) from mouse NIH3T3 fibroblast cells overexpressing phosphatidylinositol transfer protein α (PI-TPα; SPIα cells) demonstrates an increased anti-apoptotic activity compared with CM from wild type NIH3T3 (wtNIH3T3) cells. As previously shown, the anti-apoptotic activity acts

  4. Apoptotic intrinsic pathway proteins predict survival in canine cutaneous mast cell tumours.

    Science.gov (United States)

    Barra, C N; Macedo, B M; Cadrobbi, K G; Pulz, L H; Huete, G C; Kleeb, S R; Xavier, J G; Catão-Dias, J L; Nishiya, A T; Fukumasu, H; Strefezzi, R F

    2018-03-01

    Mast cell tumours (MCTs) are the most frequent canine round cell neoplasms and show variable biological behaviours with high metastatic and recurrence rates. The disease is treated surgically and wide margins are recommended. Adjuvant chemotherapy and radiotherapy used in this disease cause DNA damage in neoplastic cells, which is aimed to induce apoptotic cell death. Resisting cell death is a hallmark of cancer, which contributes to the development and progression of tumours. The aim of this study was to investigate the expression of the proteins involved in the apoptotic intrinsic pathway and to evaluate their potential use as prognostic markers for canine cutaneous MCTs. Immunohistochemistry for BAX, BCL2, APAF1, Caspase-9, and Caspase-3 was performed in 50 canine cases of MCTs. High BAX expression was associated with higher mortality rate and shorter survival. BCL2 and APAF1 expressions offered additional prognostic information to the histopathological grading systems. The present results indicate that variations in the expression of apoptotic proteins are related to malignancy of cutaneous MCTs in dogs. © 2017 John Wiley & Sons Ltd.

  5. Increase of bcl-2 Protein Expression in Aggressive Basal Cell Carcinoma of Head and Neck

    OpenAIRE

    Cláudia CAZAL; Mariana Roesch ELY; Ana Paula Veras SOBRAL; Wilton Wilney Nascimento PADILHA

    2006-01-01

    Objective: The aim of this study was to verify the bcl-2 protein expression in 22 cutaneous basal cell carcinomas (BCC) of the head and neck, and to compare it with its aggressive behavior. Method: Tumors were histologically classified in non-aggressive (BCC 1) and aggressive (BCC 2) and then submitted to the immunohistochemistry technique with the streptavidin-biotin peroxidase method using the anti-bcl-2 antibody. Results: After proceeding to morphological analysis, sixteen tumors (72.7%) w...

  6. Intrinsic and extrinsic apoptotic pathways are involved in rat testis by cold water immersion-induced acute and chronic stress.

    Science.gov (United States)

    Juárez-Rojas, Adriana Lizbeth; García-Lorenzana, Mario; Aragón-Martínez, Andrés; Gómez-Quiroz, Luis Enrique; Retana-Márquez, María del Socorro

    2015-01-01

    Testicular apoptosis is activated by stress, but it is not clear which signaling pathway is activated in response to stress. The aim of this study was to investigate whether intrinsic, extrinsic, or both apoptotic signaling pathways are activated by acute and chronic stress. Adult male rats were subjected to cold water immersion-induced stress for 1, 20, 40, and 50 consecutive days. The seminiferous tubules:apoptotic cell ratio was assayed on acute (1 day) and chronic (20, 40, 50 days) stress. Apoptotic markers, including cleaved-caspase 3 and 8, the pro-apoptotic Bax and anti-apoptotic Bcl-2 proteins were also determined after acute and chronic stress induction. Additionally, epididymal sperm quality was evaluated, as well as corticosterone and testosterone levels. An increase in tubule apoptotic cell count percentage after an hour of acute stress and during chronic stress induction was observed. The apoptotic cells rate per tubule increment was only detected one hour after acute stress, but not with chronic stress. Accordingly, there was an increase in Bax, cleaved caspase-8 and caspase-3 pro-apoptotic proteins with a decrease of anti-apoptotic Bcl-2 in both acutely and chronically stressed male testes. In addition, sperm count, viability, as well as total and progressive motility were low in chronically stressed males. Finally, the levels of corticosterone increased whereas testosterone levels decreased in chronically stressed males. Activation of the extrinsic apoptotic pathway was shown by cleaved caspase-8 increase whereas the intrinsic apoptotic pathway activation was determined by the increase of Bax, along with Bcl-2 decrease, making evident a cross-talk between these two pathways with the activation of caspase-3. These results suggest that both acute and chronic stress can potentially activate the intrinsic/extrinsic apoptosis pathways in testes. Chronic stress also reduces the quality of epididymal spermatozoa, possibly due to a decrease in testosterone.

  7. Biliverdin reductase/bilirubin mediates the anti-apoptotic effect of hypoxia in pulmonary arterial smooth muscle cells through ERK1/2 pathway

    International Nuclear Information System (INIS)

    Song, Shasha; Wang, Shuang; Ma, Jun; Yao, Lan; Xing, Hao; Zhang, Lei; Liao, Lin; Zhu, Daling

    2013-01-01

    Inhibition of pulmonary arterial smooth muscle cell (PASMC) apoptosis induced by hypoxia plays an important role in pulmonary arterial remodeling leading to aggravate hypoxic pulmonary arterial hypertension. However, the mechanisms of hypoxia acting on PASMC apoptosis remain exclusive. Biliverdin reductase (BVR) has many essential biologic roles in physiological and pathological processes. Nevertheless, it is unclear whether the hypoxia-induced inhibition on PASMC apoptosis is mediated by BVR. In the present work, we found BVR majorly localized in PASMCs and was up-regulated in levels of protein and mRNA by hypoxia. Then we studied the contribution of BVR to anti-apoptotic response of hypoxia in PASMCs. Our results showed that siBVR, blocking generation of bilirubin, reversed the effect of hypoxia on enhancing cell survival and apoptotic protein (Bcl-2, procasepase-9, procasepase-3) expression, preventing nuclear shrinkage, DNA fragmentation and mitochondrial depolarization in starved PASMCs, which were recovered by exogenous bilirubin. Moreover, the inhibitory effect of bilirubin on PASMC apoptosis under hypoxic condition was blocked by the inhibitor of ERK1/2 pathway. Taken together, our data indicate that BVR contributes to the inhibitory process of hypoxia on PASMC apoptosis, which is mediated by bilirubin through ERK1/2 pathway. Highlights: • BVR expresses in PASMC and is up-regulated by hypoxia in protein and mRNA levels. • BVR/bilirubin contribute to the inhibitive process of hypoxia on PASMC apoptosis. • Bilirubin protects PASMC from apoptosis under hypoxia via ERK1/2 pathway

  8. Biliverdin reductase/bilirubin mediates the anti-apoptotic effect of hypoxia in pulmonary arterial smooth muscle cells through ERK1/2 pathway

    Energy Technology Data Exchange (ETDEWEB)

    Song, Shasha [Department of Biopharmaceutical Sciences, College of Pharmacy, Harbin Medical, University (Daqing), Daqing 163319 (China); Wang, Shuang [Department of Biopharmaceutical Sciences, College of Pharmacy, Harbin Medical, University (Daqing), Daqing 163319 (China); Biopharmaceutical Key Laboratory of Heilongjiang Province, Harbin 150081 (China); Ma, Jun; Yao, Lan; Xing, Hao; Zhang, Lei; Liao, Lin [Department of Biopharmaceutical Sciences, College of Pharmacy, Harbin Medical, University (Daqing), Daqing 163319 (China); Zhu, Daling, E-mail: dalingz@yahoo.com [Department of Biopharmaceutical Sciences, College of Pharmacy, Harbin Medical, University (Daqing), Daqing 163319 (China); Biopharmaceutical Key Laboratory of Heilongjiang Province, Harbin 150081 (China)

    2013-08-01

    Inhibition of pulmonary arterial smooth muscle cell (PASMC) apoptosis induced by hypoxia plays an important role in pulmonary arterial remodeling leading to aggravate hypoxic pulmonary arterial hypertension. However, the mechanisms of hypoxia acting on PASMC apoptosis remain exclusive. Biliverdin reductase (BVR) has many essential biologic roles in physiological and pathological processes. Nevertheless, it is unclear whether the hypoxia-induced inhibition on PASMC apoptosis is mediated by BVR. In the present work, we found BVR majorly localized in PASMCs and was up-regulated in levels of protein and mRNA by hypoxia. Then we studied the contribution of BVR to anti-apoptotic response of hypoxia in PASMCs. Our results showed that siBVR, blocking generation of bilirubin, reversed the effect of hypoxia on enhancing cell survival and apoptotic protein (Bcl-2, procasepase-9, procasepase-3) expression, preventing nuclear shrinkage, DNA fragmentation and mitochondrial depolarization in starved PASMCs, which were recovered by exogenous bilirubin. Moreover, the inhibitory effect of bilirubin on PASMC apoptosis under hypoxic condition was blocked by the inhibitor of ERK1/2 pathway. Taken together, our data indicate that BVR contributes to the inhibitory process of hypoxia on PASMC apoptosis, which is mediated by bilirubin through ERK1/2 pathway. Highlights: • BVR expresses in PASMC and is up-regulated by hypoxia in protein and mRNA levels. • BVR/bilirubin contribute to the inhibitive process of hypoxia on PASMC apoptosis. • Bilirubin protects PASMC from apoptosis under hypoxia via ERK1/2 pathway.

  9. Quercetin inhibits the invasion and mobility of murine melanoma B16-BL6 cells through inducing apoptosis via decreasing Bcl-2 expression.

    Science.gov (United States)

    Zhang, X; Xu, Q; Saiki, I

    2000-01-01

    Quercetin has been known to have anti-tumor and anti-oxidation activities. In the present study, we have investigated its in vitro anti-metastatic activity. Quercetin inhibited the invasion and mobility of murine melanoma B16-BL6 cells in a dose-dependent manner but did not affect their adhesion to either laminin, fibronectin, or type VI collagen. Moreover, quercetin significantly inhibited the proliferation of B16-BL6 cells only in the case of time incubation longer than 48 h. Quercetin dose-dependently decreased the cell rates in S and G2-M phases of cell cycle. The effect of quercetin to cause a remarkable apoptosis of B16-BL6 cells was also demonstrated by flow cytometric assay as well as DNA fragmentation with a typical 180-bp ladder band in agarose electrophoresis and a quantitative analysis. Furthermore, quercetin markedly inhibited the expression of anti-apoptotic protein Bcl-2 but hardly influenced Bcl-XL. These results suggest that the inhibition of quercetin on invasiveness and migration of B16-BL6 cells are closely associated with the arrest of cell cycle as well as the induction of apoptosis by decreasing the Bcl-2 expression.

  10. TIC10/ONC201 synergizes with Bcl-2/Bcl-xL inhibition in glioblastoma by suppression of Mcl-1 and its binding partners in vitro and in vivo.

    Science.gov (United States)

    Karpel-Massler, Georg; Bâ, Maïmouna; Shu, Chang; Halatsch, Marc-Eric; Westhoff, Mike-Andrew; Bruce, Jeffrey N; Canoll, Peter; Siegelin, Markus D

    2015-11-03

    Glioblastoma is the most frequent primary brain tumor in adults. Current therapeutic options are sparse and the prognosis of patients suffering from this disease is grim. Abundance in intratumoral heterogeneity among different deregulated signaling pathways is a hallmark of glioblastoma and likely accounts for its recurrence and resistance to treatment. Glioblastomas harbor a plethora of deregulated pathways driving tumor formation and growth. In this study, we show that TIC10/ONC201, a promising compound that is currently in planned clinical development, along with Bcl-2/Bcl-xL inhibition by ABT263 yields a strong synergistic antiproliferative effect on pediatric, adult, proneural glioblastoma and glioma stem-like cells. On the molecular level, treatment with TIC10/ONC201 results in a posttranslational decrease of the anti-apoptotic Bcl-2 family member, myeloid cell leukemia 1 (Mcl-1), through modulation of the chaperone Bag3 and the deubiquitinase Usp9X. Consistently, the combination treatment of TIC10/ONC201 and ABT263 required the presence of functional BAX and BAK to drive intrinsic apoptosis, but is surprisingly independent of the extrinsic apoptotic pathway. Moreover, the expression of Noxa protein was required for efficient apoptosis induction by TIC10/ONC201 and ABT263. Importantly, the drug combination of TIC10/ONC201 and the BH3-mimetic, ABT263, led to a regression of tumors in vivo, without any notable toxicity and side effects. Overall, TIC10/ONC201 along with Bcl-2/Bcl-xL inhibition holds significant promise as a novel potential approach for the treatment of recalcitrant tumors such as glioblastoma.

  11. NF-κB activation fails to protect cells to TNFα-induced apoptosis in the absence of Bcl-xL, but not Mcl-1, Bcl-2 or Bcl-w.

    Science.gov (United States)

    Casanelles, Elisenda; Gozzelino, Raffaella; Marqués-Fernández, Fernando; Iglesias-Guimarais, Victoria; Garcia-Belinchón, Mercè; Sánchez-Osuna, María; Solé, Carme; Moubarak, Rana S; Comella, Joan X; Yuste, Victor J

    2013-05-01

    TNFα can promote either cell survival or cell death. The activation of NF-κB plays a central role in cell survival while its inhibition makes TNFα-triggered cytotoxicity possible. Here, we report that the overexpression of a non-degradable mutant of the inhibitor of NF-κB (super-repressor (SR)-IκBα) sensitizes HeLa cells towards TNFα-induced apoptosis, involving caspases activation and cytocrome C release from the mitochondria. Interestingly, we describe that the specific knockdown of Bcl-xL, but not that of Bcl-2, Bcl-w or Mcl-1, renders cells sensitive to TNFα-induced apoptosis. This cytotoxic effect occurs without altering the activation of NF-κB. Then, the activation of the NF-κB pathway is not sufficient to protect Bcl-xL-downregulated cells from TNFα-induced cell death, meaning that TNFα is not able to promote cell survival in the absence of Bcl-xL. In addition, Bcl-xL silencing does not potentiate the cytotoxicity afforded by the cytokine in SR-IκBα-overexpressing cells. This indicates that TNFα-induced apoptosis in SR-IκBα-overexpressing cells relies on the protein levels of Bcl-xL. We have corroborated these findings using RD and DU-145 cells, which also become sensitive to TNFα-induced apoptosis after Bcl-xL knockdown despite that NF-κB remains activated. Altogether, our results point out that the impairment of the anti-apoptotic function of Bcl-xL should make cells sensitive towards external insults circumventing the TNFα-triggered NF-κB-mediated cytoprotective effect. Hence, the specific inhibition of Bcl-xL could be envisaged as a promising alternative strategy against NF-κB-dependent highly chemoresistant proliferative malignancies. Copyright © 2013 Elsevier B.V. All rights reserved.

  12. B1-induced caspase-independent apoptosis in MCF-7 cells is mediated by down-regulation of Bcl-2 via p53 binding to P2 promoter TATA box

    International Nuclear Information System (INIS)

    Liang Xin; Xu Ke; Xu Yufang; Liu Jianwen; Qian Xuhong

    2011-01-01

    The Bcl-2 family contains a panel of proteins which are conserved regulators of apoptosis in mammalian cells, like the anti-apoptotic protein Bcl-2. According to its significant role in altering susceptibility to apoptosis, the deciphering of the mechanism of Bcl-2 expression modulation may be crucial for identifying therapeutics strategies for cancer. Treatment with naphthalimide-based DNA intercalators, including M2-A and R16, generally leads to a decrease in Bcl-2 intracellular amounts. Whereas the interest for these chemotherapeutics is accompanied by advances in the fundamental understanding of their anticancer properties, the molecular mechanism underlying changes in Bcl-2 expression remains poorly understood. We report here that p53 contributes to Bcl-2 down-regulation induced by B1, a novel naphthalimide-based DNA intercalating agent. Indeed, the decrease in Bcl-2 protein levels observed during B1-induced apoptosis was correlated to the decrease in mRNA levels, as a result of the inhibition of Bcl-2 transcription and promoter activity. In this context, we evaluated p53 contribution in the Bcl-2 transcriptional down-regulation. We found a significant increase of p53 binding to P 2 promoter TATA box in MCF7 cells by chromatin immunoprecipitation. These data suggest that B1-induced caspase-independent apoptosis in MCF-7 cells is associated with the activation of p53 and the down-regulation of Bcl-2. Our study strengthens the links between p53 and Bcl-2 at a transcriptional level, upon naphthalimide-based DNA intercalator treatment. - Research highlights: → B1 induced apoptosis in MCF-7 cells, following a transcriptional decrease in Bcl-2. → B1 treatment triggered p53 activation and leads to a p53-dependent down-regulation of Bcl-2. → B1 induced significant increase of p53 binding to Bcl-2 P 2 promoter TATA box.

  13. Effect of Bcl-2/Bax gene expression on apoptosis of spermatogenic cells of mouse testes induced by low dose radiation

    International Nuclear Information System (INIS)

    Liu Guangwei; Wang Chunyan; Lu Zhe; Liu Shunchun; Gong Shouliang

    2003-01-01

    The different kinds of spermatogenic cells were separated using density gradient centrifugation and their apoptosis and Bcl-2 and Bax protein expression were measured with flow cytometry and immunohistochemical method, respectively. The results showed the apoptosis in all kinds of spermatogenic cells induced by low dose radiation (LDR) had a obvious regularity. When the doses were 0.025 and 0.05 Gy, spermatogonia apoptosis was dominant. With the increase of irradiation dose (0.075-0.2 Gy), spermatocytes also showed an apoptotic change, but the apoptotic percentage of spermatogonia was significantly higher than that of spermatocytes. Moreover, the apoptosis of spermatids and spermatozoa scarcely occurred after LDR. Bax protein was primarily expressed in spermatogonia and spermatocytes, and the former was significantly higher than that of the latter after LDR. With the increase of irradiation dose, Bax protein expression showed a upgrading tendency, but that of spermatids and spermatozoa scarcely occurred. Bcl-2 protein was primarily expressed in spermatids and spermatozoa, but the Bcl-2 protein expressions of spermatogonia and spermatocytes scarcely occurred after LDR. These results imply that the interacting regulation of Bcl-2 and Bax gene expression might be involved in selective apoptosis of spermatogenic cells induced by LDR, which provided an experimental evidence for further exploring the apoptotic mechanism of adaptive response of spermatogenic cells by LDR

  14. Temporal activation of anti- and pro-apoptotic factors in human gingival fibroblasts infected with the periodontal pathogen, Porphyromonas gingivalis: potential role of bacterial proteases in host signalling

    Directory of Open Access Journals (Sweden)

    Takehara Tadamichi

    2006-03-01

    Full Text Available Abstract Background Porphyromonas gingivalis is the foremost oral pathogen of adult periodontitis in humans. However, the mechanisms of bacterial invasion and the resultant destruction of the gingival tissue remain largely undefined. Results We report host-P. gingivalis interactions in primary human gingival fibroblast (HGF cells. Quantitative immunostaining revealed the need for a high multiplicity of infection for optimal infection. Early in infection (2–12 h, P. gingivalis activated the proinflammatory transcription factor NF-kappa B, partly via the PI3 kinase/AKT pathway. This was accompanied by the induction of cellular anti-apoptotic genes, including Bfl-1, Boo, Bcl-XL, Bcl2, Mcl-1, Bcl-w and Survivin. Late in infection (24–36 h the anti-apoptotic genes largely shut down and the pro-apoptotic genes, including Nip3, Hrk, Bak, Bik, Bok, Bax, Bad, Bim and Moap-1, were activated. Apoptosis was characterized by nuclear DNA degradation and activation of caspases-3, -6, -7 and -9 via the intrinsic mitochondrial pathway. Use of inhibitors revealed an anti-apoptotic function of NF-kappa B and PI3 kinase in P. gingivalis-infected HGF cells. Use of a triple protease mutant P. gingivalis lacking three major gingipains (rgpA rgpB kgp suggested a role of some or all these proteases in myriad aspects of bacteria-gingival interaction. Conclusion The pathology of the gingival fibroblast in P. gingivalis infection is affected by a temporal shift from cellular survival response to apoptosis, regulated by a number of anti- and pro-apoptotic molecules. The gingipain group of proteases affects bacteria-host interactions and may directly promote apoptosis by intracellular proteolytic activation of caspase-3.

  15. Involvement of p53 and Bcl-2 in sensory cell degeneration in aging rat cochleae.

    Science.gov (United States)

    Xu, Yang; Yang, Wei Ping; Hu, Bo Hua; Yang, Shiming; Henderson, Donald

    2017-06-01

    p53 and Bcl-2 (B-cell lymphoma 2) are involved in the process of sensory cell degeneration in aging cochleae. To determine molecular players in age-related hair cell degeneration, this study examined the changes in p53 and Bcl-2 expression at different stages of apoptotic and necrotic death of hair cells in aging rat cochleae. Young (3-4 months) and aging (23-24 months) Fisher 344/NHsd rats were used. The thresholds of the auditory brainstem response (ABR) were measured to determine the auditory function. Immunolabeling was performed to determine the expression of p53 and Bcl-2 proteins in the sensory epithelium. Propidium iodide staining was performed to determine the morphologic changes in hair cell nuclei. Aging rats exhibited a significant elevation in ABR thresholds at all tested frequencies (p aging hair cells showing the early signs of apoptotic changes in their nuclei. The Bcl-2 expression increase was also observed in hair cells displaying early signs of necrosis. As the hair cell degenerative process advanced, p53 and Bcl-2 immunoreactivity became reduced or absent. In the areas where no detectable nuclear staining was present, p53 and Bcl-2 immunoreactivity was absent.

  16. HAMLET triggers apoptosis but tumor cell death is independent of caspases, Bcl-2 and p53.

    Science.gov (United States)

    Hallgren, O; Gustafsson, L; Irjala, H; Selivanova, G; Orrenius, S; Svanborg, C

    2006-02-01

    HAMLET (Human alpha-lactalbumin Made Lethal to Tumor cells) triggers selective tumor cell death in vitro and limits tumor progression in vivo. Dying cells show features of apoptosis but it is not clear if the apoptotic response explains tumor cell death. This study examined the contribution of apoptosis to cell death in response to HAMLET. Apoptotic changes like caspase activation, phosphatidyl serine externalization, chromatin condensation were detected in HAMLET-treated tumor cells, but caspase inhibition or Bcl-2 over-expression did not prolong cell survival and the caspase response was Bcl-2 independent. HAMLET translocates to the nuclei and binds directly to chromatin, but the death response was unrelated to the p53 status of the tumor cells. p53 deletions or gain of function mutations did not influence the HAMLET sensitivity of tumor cells. Chromatin condensation was partly caspase dependent, but apoptosis-like marginalization of chromatin was also observed. The results show that tumor cell death in response to HAMLET is independent of caspases, p53 and Bcl-2 even though HAMLET activates an apoptotic response. The use of other cell death pathways allows HAMLET to successfully circumvent fundamental anti-apoptotic strategies that are present in many tumor cells.

  17. Involvement of Bax and Bcl2 in Neuroprotective Effect of Curcumin in Kainic Acid-Induced Model of Temporal Lobe Epilepsy in Male Rat

    Directory of Open Access Journals (Sweden)

    zahra Kiasalari

    2016-04-01

    Full Text Available Background & objectives: Temporal lobe epilepsy is associated with neuronal apoptosis. Curcumin has antioxidant and anticonvulsant activities, therefore this study was conducted to assess involvement of Bax and Bcl2 in protective effect of curcumin in epileptic rats. Methods: 28 rats were divided into sham, curcumin-pretreated sham, epileptic (kainate, and curcumin-pretreated epileptic groups. Experimental model of epilepsy was induced by intrahippocampal administration of kainic acid. Rats received curcumin at a dose of 100 mg/kg. Finally, Nissl staining and Bax and Bcl2 immunohistochemistry were conducted on hippocampal sections and data were analyzed using one-way ANOVA and unpaired t-test. The p-value less than 0.05was considered statistically significant. Results: Induction of epilepsy was followed by a significant seizure and curcumin pretreatment significantly reduced seizure intensity (p<0.01. In addition, there were no significant differences between the groups in Nissl staining of CA3 area neurons. In addition, Bax positive neurons were observed in CA3 area in kainate group and significantly decreased in curcumin pretreated rats (p<0.05. Meanwhile, Bcl2 positive neurons were also moderately observed in kainate group and curcumin pretreatment significantly increased it (p<0.05. Conclusion: Curcumin pretreatment exhibits anticonvulsant activity in epileptic rats. It also decreases the expression of pro-apoptotic protein Bax and significantly enhances the expression of anti-apoptotic protein Bcl2 and hence could reduce neuronal apoptosis.

  18. Micro-Economics of Apoptosis in Cancer: ncRNAs Modulation of BCL-2 Family Members.

    Science.gov (United States)

    Villanova, Lidia; Careccia, Silvia; De Maria, Ruggero; Fiori, Micol E

    2018-03-23

    In the last few years, non-coding RNAs (ncRNAs) have been a hot topic in cancer research. Many ncRNAs were found to regulate the apoptotic process and to play a role in tumor cell resistance to treatment. The apoptotic program is on the frontline as self-defense from cancer onset, and evasion of apoptosis has been classified as one of the hallmarks of cancer responsible for therapy failure. The B-cell lymphoma 2 (BCL-2) family members are key players in the regulation of apoptosis and mediate the activation of the mitochondrial death machinery in response to radiation, chemotherapeutic agents and many targeted therapeutics. The balance between the pro-survival and the pro-apoptotic BCL-2 proteins is strictly controlled by ncRNAs. Here, we highlight the most common mechanisms exerted by microRNAs, long non-coding RNAs and circular RNAs on the main mediators of the intrinsic apoptotic cascade with particular focus on their significance in cancer biology.

  19. An Integrated Bioinformatics and Computational Biology Approach Identifies New BH3-Only Protein Candidates.

    Science.gov (United States)

    Hawley, Robert G; Chen, Yuzhong; Riz, Irene; Zeng, Chen

    2012-05-04

    In this study, we utilized an integrated bioinformatics and computational biology approach in search of new BH3-only proteins belonging to the BCL2 family of apoptotic regulators. The BH3 (BCL2 homology 3) domain mediates specific binding interactions among various BCL2 family members. It is composed of an amphipathic α-helical region of approximately 13 residues that has only a few amino acids that are highly conserved across all members. Using a generalized motif, we performed a genome-wide search for novel BH3-containing proteins in the NCBI Consensus Coding Sequence (CCDS) database. In addition to known pro-apoptotic BH3-only proteins, 197 proteins were recovered that satisfied the search criteria. These were categorized according to α-helical content and predictive binding to BCL-xL (encoded by BCL2L1) and MCL-1, two representative anti-apoptotic BCL2 family members, using position-specific scoring matrix models. Notably, the list is enriched for proteins associated with autophagy as well as a broad spectrum of cellular stress responses such as endoplasmic reticulum stress, oxidative stress, antiviral defense, and the DNA damage response. Several potential novel BH3-containing proteins are highlighted. In particular, the analysis strongly suggests that the apoptosis inhibitor and DNA damage response regulator, AVEN, which was originally isolated as a BCL-xL-interacting protein, is a functional BH3-only protein representing a distinct subclass of BCL2 family members.

  20. Pectenotoxin-2 from Marine Sponges: A Potential Anti-Cancer Agent—A Review

    Directory of Open Access Journals (Sweden)

    Wun-Jae Kim

    2011-11-01

    Full Text Available Pectenotoxin-2 (PTX-2, which was first identified as a cytotoxic entity in marine sponges, has been reported to display significant cytotoxicity to human cancer cells where it inhibits mitotic separation and cytokinesis through the depolymerization of actin filaments. In the late stage of endoreduplication, the effects of PTX-2 on different cancer cells involves: (i down-regulation of anti-apoptotic Bcl-2 members and IAP family proteins; (ii up-regulation of pro-apoptotic Bax protein and tumor necrosis factor-related apoptosis-inducing ligand (TRAIL-receptor 1/receptor 2 (DR4/DR5; and (iii mitochondrial dysfunction. In addition, PTX-2 induces apoptotic effects through suppression of the nuclear factor κB (NF-κB signaling pathway in several cancer cells. Analysis of cell cycle regulatory proteins showed that PTX-2 increases phosphorylation of Cdc25c and decreases protein levels of Cdc2 and cyclin B1. Cyclin-dependent kinase (Cdk inhibitor p21 and Cdk2, which are associated with the induction of endoreduplication, were upregulated. Furthermore, it was found that PTX-2 suppressed telomerase activity through the transcriptional and post-translational suppression of hTERT. The purpose of this review was to provide an update regarding the anti-cancer mechanism of PTX-2, with a special focus on its effects on different cellular signaling cascades.

  1. Association of anti-apoptotic Mcl-1L isoform expression with radioresistance of oral squamous carcinoma cells

    International Nuclear Information System (INIS)

    Palve, Vinayak C; Teni, Tanuja R

    2012-01-01

    Oral cancer is a common cancer and a major health problem in the Indian subcontinent. At our laboratory Mcl-1, an anti-apoptotic member of the Bcl-2 family has been demonstrated to be overexpressed in oral cancers and to predict outcome in oral cancer patients treated with definitive radiotherapy. To study the role of Mcl-1 isoforms in radiation response of oral squamous carcinoma cells (OSCC), we investigated in the present study, the association of Mcl-1 isoform expression with radiosensitivity of OSCC, using siRNA strategy. The time course expression of Mcl-1 splice variants (Mcl-1L, Mcl-1S & Mcl-1ES) was studied by RT-PCR, western blotting & immunofluorescence, post-irradiation in oral cell lines [immortalized FBM (radiosensitive) and tongue cancer AW8507 & AW13516 (radioresistant)]of relatively differing radiosensitivities. The effect of Mcl-1L knockdown alone or in combination with ionizing radiation (IR) on cell proliferation, apoptosis & clonogenic survival, was investigated in AW8507 & AW13516 cells. Further the expression of Mcl-1L protein was assessed in radioresistant sublines generated by fractionated ionizing radiation (FIR). Three to six fold higher expression of anti-apoptotic Mcl-1L versus pro-apoptotic Mcl-1S was observed at mRNA & protein levels in all cell lines, post-irradiation. Sustained high levels of Mcl-1L, downregulation of pro-apoptotic Bax & Bak and a significant (P < 0.05) reduction in apoptosis was observed in the more radioresistant AW8507, AW13516 versus FBM cells, post-IR. The ratios of anti to pro-apoptotic proteins were high in AW8507 as compared to FBM. Treatment with Mcl-1L siRNA alone or in combination with IR significantly (P < 0.01) increased apoptosis viz. 17.3% (IR), 25.3% (siRNA) and 46.3% (IR plus siRNA) and upregulated pro-apoptotic Bax levels in AW8507 cells. Combination of siRNA & IR treatment significantly (P < 0.05) reduced cell proliferation and clonogenic survival of radioresistant AW8507 & AW13516 cells

  2. Bcl-2 inhibitors potentiate the cytotoxic effects of radiation in Bcl-2 overexpressing radioresistant tumor cells

    International Nuclear Information System (INIS)

    Hara, Takamitsu; Omura-Minamisawa, Motoko; Chao Cheng; Nakagami, Yoshihiro; Ito, Megumi; Inoue, Tomio

    2005-01-01

    Purpose: Bcl-2, an inhibitor of apoptosis frequently shows elevated expression in human tumors, thus resulting in resistance to radiation therapy. Therefore, inhibiting Bcl-2 function may enhance the radiosensitivity of tumor cells. Tetrocarcin A (TC-A) and bcl-2 antisense oligonucleotides exhibit antitumor activity by inhibiting Bcl-2 function and transcription, respectively. We investigated whether these antitumor agents would enhance the cytotoxic effects of radiation in tumor cells overexpressing Bcl-2. Methods and materials: We used HeLa/bcl-2 cells, a stable Bcl-2-expressing cell line derived from wild-type HeLa (HeLa/wt) cells. Cells were incubated with TC-A and bcl-2 antisense oligonucleotides for 24 h after irradiation, and cell viability was then determined. Apoptotic cells were quantified by flow cytometric assay. Results: The HeLa/bcl-2 cells were more resistant to radiation than HeLa/wt cells. At concentrations that are not inherently cytotoxic, both TC-A and bcl-2 antisense oligonucleotides increased the cytotoxic effects of radiation in HeLa/bcl-2 cells, but not in HeLa/wt cells. However, in HeLa/bcl-2 cells, additional treatment with TC-A in combination with radiation did not significantly increase apoptosis. Conclusions: The present results suggest that TC-A and bcl-2 antisense oligonucleotides reduce radioresistance of tumor cells overexpressing Bcl-2. Therefore, a combination of radiotherapy and Bcl-2 inhibitors may prove to be a useful therapeutic approach for treating tumors that overexpress Bcl-2

  3. Superior anti-tumor activity of the MDM2 antagonist idasanutlin and the Bcl-2 inhibitor venetoclax in p53 wild-type acute myeloid leukemia models

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    Christian Lehmann

    2016-06-01

    Full Text Available Abstract Background Venetoclax, a small molecule BH3 mimetic which inhibits the anti-apoptotic protein Bcl-2, and idasanutlin, a selective MDM2 antagonist, have both shown activity as single-agent treatments in pre-clinical and clinical studies in acute myeloid leukemia (AML. In this study, we deliver the rationale and molecular basis for the combination of idasanutlin and venetoclax for treatment of p53 wild-type AML. Methods The effect of idasanutlin and venetoclax combination on cell viability, apoptosis, and cell cycle progression was investigated in vitro using established AML cell lines. In vivo efficacy was demonstrated in subcutaneous and orthotopic xenograft models generated in female nude or non-obese diabetic/severe combined immunodeficiency (NOD/SCID mice. Mode-of-action analyses were performed by means of cell cycle kinetic studies, RNA sequencing as well as western blotting experiments. Results Combination treatment with venetoclax and idasanutlin results in synergistic anti-tumor activity compared with the respective single-agent treatments in vitro, in p53 wild-type AML cell lines, and leads to strongly superior efficacy in vivo, in subcutaneous and orthotopic AML models. The inhibitory effects of idasanutlin were cell-cycle dependent, with cells arresting in G1 in consecutive cycles and the induction of apoptosis only evident after cells had gone through at least two cell cycles. Combination treatment with venetoclax removed this dependency, resulting in an acceleration of cell death kinetics. As expected, gene expression studies using RNA sequencing showed significant alterations to pathways associated with p53 signaling and cell cycle arrest (CCND1 pathway in response to idasanutlin treatment. Only few gene expression changes were observed for venetoclax treatment and combination treatment, indicating that their effects are mediated mainly at the post-transcriptional level. Protein expression studies demonstrated that

  4. BCL-x{sub L}/MCL-1 inhibition and RARγ antagonism work cooperatively in human HL60 leukemia cells

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    Perri, Mariarita; Yap, Jeremy L.; Yu, Jianshi [Department of Pharmaceutical Sciences, University of Maryland School of Pharmacy, 20 N Pine Street, Baltimore, MD 21201 (United States); Cione, Erika [Department of Pharmacy, Health and Nutritional Sciences, Ed. Polifunzionale, University of Calabria, 87036 Rende, CS (Italy); Fletcher, Steven [Department of Pharmaceutical Sciences, University of Maryland School of Pharmacy, 20 N Pine Street, Baltimore, MD 21201 (United States); Kane, Maureen A., E-mail: mkane@rx.umaryland.edu [Department of Pharmaceutical Sciences, University of Maryland School of Pharmacy, 20 N Pine Street, Baltimore, MD 21201 (United States)

    2014-10-01

    The acute promyelocytic leukemia (APL) subtype of acute myeloid leukemia (AML) is characterized by chromosomal translocations that result in fusion proteins, including the promyelocytic leukemia–retinoic acid receptor, alpha fusion protein (PML–RARα). All-trans retinoic acid (atRA) treatment is the standard drug treatment for APL yielding cure rates >80% by activating transcription and proteasomal degradation of retinoic acid receptor, alpha (RARα). Whereas combination therapy with As{sub 2}O{sub 3} has increased survival further, patients that experience relapse and are refractory to atRA and/or As{sub 2}O{sub 3} is a clinically significant problem. BCL-2 family proteins regulate apoptosis and over-expression of anti-apoptotic B-cell leukemia/lymphoma 2 (BCL-2) family proteins has been associated with chemotherapeutic resistance in APL including impairment of the ability of atRA to induce growth arrest and differentiation. Here we investigated the novel BH3 domain mimetic, JY-1-106, which antagonizes the anti-apoptotic BCL-2 family members B-cell lymphoma-extra large (BCL-x{sub L}) and myeloid cell leukemia-1 (MCL-1) alone and in combination with retinoids including atRA, AM580 (RARα agonist), and SR11253 (RARγ antagonist). JY-1-106 reduced cell viability in HL-60 cells alone and in combination with retinoids. The combination of JY-1-106 and SR11253 had the greatest impact on cell viability by stimulating apoptosis. These studies indicate that dual BCL-x{sub L}/MCL-1 inhibitors and retinoids could work cooperatively in leukemia treatment. - Highlights: • Novel Bcl-x{sub L}/Mcl-1 inhibitor JY-1-106 reduces HL60 cell viability. • JY-1-106 is investigated in combination with retinoic acid, AM580, and SR11253. • AM580 is an RARα agonist; SR11253 is an RARγ antagonist. • Combined use of JY-1-106/SR11253 exhibited the greatest cell viability reduction. • JY-1-106 alone or in combination with retinoids induces apoptosis.

  5. 7α-Hydroxy-β-Sitosterol from Chisocheton tomentosus Induces Apoptosis via Dysregulation of Cellular Bax/Bcl-2 Ratio and Cell Cycle Arrest by Downregulating ERK1/2 Activation

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    Mohammad Tasyriq

    2012-01-01

    Full Text Available In continuation of our interest towards the elucidation of apoptotic pathways of cytotoxic phytocompounds, we have embarked upon a study on the anticancer effects of 7α-hydroxy-β-sitosterol (CT1, a rare natural phytosterol oxide isolated from Chisocheton tomentosus. CT1 was found to be cytotoxic on three different human tumor cell lines with minimal effects on normal cell controls, where cell viability levels were maintained ≥80% upon treatment. Our results showed that cell death in MCF-7 breast tumor cells was achieved through the induction of apoptosis via downregulation of the ERK1/2 signaling pathway. CT1 was also found to increase proapoptotic Bax protein levels, while decreasing anti-apoptotic Bcl-2 protein levels, suggesting the involvement of the intrinsic pathway. Reduced levels of initiator procaspase-9 and executioner procaspase-3 were also observed following CT1 exposure, confirming the involvement of cytochrome c-mediated apoptosis via the mitochondrial pathway. These results demonstrated the cytotoxic and apoptotic ability of 7α-hydroxy-β-sitosterol and suggest its potential anti-cancer use particularly on breast adenocarcinoma cells.

  6. Asymmetric Synthesis and Evaluation of Danshensu-Cysteine Conjugates as Novel Potential Anti-Apoptotic Drug Candidates

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    Pan, Li-Long; Wang, Jie; Jia, Yao-Ling; Zheng, Hong-Ming; Wang, Yang; Zhu, Yi-Zhun

    2014-01-01

    We have previously reported that the danshensu-cysteine conjugate N-((R)-3-benzylthio-1-methoxy-1-oxo-2-propanyl)-2-acetoxy-3-(3,4-diacetoxyphenyl) propanamide (DSC) is a potent anti-oxidative and anti-apoptotic agent. Herein, we further design and asymmetrically synthesize two diastereoisomers of DSC and explore their potential bioactivities. Our results show that DSC and its two diastereoisomers exert similar protective effects in hydrogen peroxide (H2O2)-induced cellular injury in SH-SY5Y cells, as evidenced by the increase of cell viability, superoxide dismutase (SOD), and reduced glutathione (GSH) activity, and glutathione peroxidase (GPx) expression, and the decrease of cellular morphological changes and nuclear condensation, lactate dehydrogenase (LDH) release, and malondialdehyde (MDA) production. In H2O2-stimulated human umbilical vein endothelial cells (HUVEC), DSC concentration-dependently attenuates H2O2-induced cell death, LDH release, mitochondrial membrane potential collapse, and modulates the expression of apoptosis-related proteins (Bcl-2, Bax, caspase-3, and caspase-9). Our results provide strong evidence that DSC and its two diastereoisomers have similar anti-oxidative activity and that DSC exerts significant vascular-protective effects, at least in part, through inhibition of apoptosis and modulation of endogenous antioxidant enzymes. PMID:25551606

  7. The Role of Bcl-2 Family Proteins in Therapy Responses of Malignant Astrocytic Gliomas: Bcl2L12 and Beyond

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    Fotini M. Kouri

    2012-01-01

    Full Text Available Glioblastoma (GBM is a highly aggressive and lethal brain cancer with a median survival of less than two years after diagnosis. Hallmarks of GBM tumors include soaring proliferative indices, high levels of angiogenesis, diffuse invasion into normal brain parenchyma, resistance toward therapy-induced apoptosis, and pseudopallisading necrosis. Despite the recent advances in neurosurgery, radiation therapy, and the development of targeted chemotherapeutic regimes, GBM remains one of the deadliest types of cancer. Particularly, the alkylating agent temozolomide (TMZ in combination with radiation therapy prolonged patient survival only marginally, and clinical studies assessing efficacies of targeted therapies, foremost ATP mimetics inhibiting the activity of receptor tyrosine kinases (RTKs, revealed only few initial responders; tumor recurrence is nearly universal, and salvage therapies to combat such progression remain ineffective. Consequently, myriad preclinical and clinical studies began to define the molecular mechanisms underlying therapy resistance of GBM tumors, and pointed to the Bcl-2 protein family, in particular the atypical member Bcl2-Like 12 (Bcl2L12, as important regulators of therapy-induced cell death. This review will discuss the multi-faceted modi operandi of Bcl-2 family proteins, describe their roles in therapy resistance of malignant glioma, and outline current and future drug development efforts to therapeutically target Bcl-2 proteins.

  8. Genetic ablation of Bcl-x attenuates invasiveness without affecting apoptosis or tumor growth in a mouse model of pancreatic neuroendocrine cancer.

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    Jeffrey H Hager

    Full Text Available Tumor cell death is modulated by an intrinsic cell death pathway controlled by the pro- and anti-apoptotic members of the Bcl-2 family. Up-regulation of anti-apoptotic Bcl-2 family members has been shown to suppress cell death in pre-clinical models of human cancer and is implicated in human tumor progression. Previous gain-of-function studies in the RIP1-Tag2 model of pancreatic islet carcinogenesis, involving uniform or focal/temporal over-expression of Bcl-x(L, demonstrated accelerated tumor formation and growth. To specifically assess the role of endogenous Bcl-x in regulating apoptosis and tumor progression in this model, we engineered a pancreatic beta-cell-specific knockout of both alleles of Bcl-x using the Cre-LoxP system of homologous recombination. Surprisingly, there was no appreciable effect on tumor cell apoptosis rates or on tumor growth in the Bcl-x knockout mice. Other anti-apoptotic Bcl-2 family members were expressed but not substantively altered at the mRNA level in the Bcl-x-null tumors, suggestive of redundancy without compensatory transcriptional up-regulation. Interestingly, the incidence of invasive carcinomas was reduced, and tumor cells lacking Bcl-x were impaired in invasion in a two-chamber trans-well assay under conditions mimicking hypoxia. Thus, while the function of Bcl-x in suppressing apoptosis and thereby promoting tumor growth is evidently redundant, genetic ablation implicates Bcl-x in selectively facilitating invasion, consistent with a recent report documenting a pro-invasive capability of Bcl-x(L upon exogenous over-expression.

  9. Fragment-based discovery of potent inhibitors of the anti-apoptotic MCL-1 protein.

    Science.gov (United States)

    Petros, Andrew M; Swann, Steven L; Song, Danying; Swinger, Kerren; Park, Chang; Zhang, Haichao; Wendt, Michael D; Kunzer, Aaron R; Souers, Andrew J; Sun, Chaohong

    2014-03-15

    Apoptosis is regulated by the BCL-2 family of proteins, which is comprised of both pro-death and pro-survival members. Evasion of apoptosis is a hallmark of malignant cells. One way in which cancer cells achieve this evasion is thru overexpression of the pro-survival members of the BCL-2 family. Overexpression of MCL-1, a pro-survival protein, has been shown to be a resistance factor for Navitoclax, a potent inhibitor of BCL-2 and BCL-XL. Here we describe the use of fragment screening methods and structural biology to drive the discovery of novel MCL-1 inhibitors from two distinct structural classes. Specifically, cores derived from a biphenyl sulfonamide and salicylic acid were uncovered in an NMR-based fragment screen and elaborated using high throughput analog synthesis. This culminated in the discovery of selective and potent inhibitors of MCL-1 that may serve as promising leads for medicinal chemistry optimization efforts. Copyright © 2014 Elsevier Ltd. All rights reserved.

  10. Clinical profiling of BCL-2 family members in the setting of BRAF inhibition offers a rationale for targeting de novo resistance using BH3 mimetics.

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    Dennie T Frederick

    Full Text Available While response rates to BRAF inhibitiors (BRAFi are high, disease progression emerges quickly. One strategy to delay the onset of resistance is to target anti-apoptotic proteins such as BCL-2, known to be associated with a poor prognosis. We analyzed BCL-2 family member expression levels of 34 samples from 17 patients collected before and 10 to 14 days after treatment initiation with either vemurafenib or dabrafenib/trametinib combination. The observed changes in mRNA and protein levels with BRAFi treatment led us to hypothesize that combining BRAFi with a BCL-2 inhibitor (the BH3-mimetic navitoclax would improve outcome. We tested this hypothesis in cell lines and in mice. Pretreatment mRNA levels of BCL-2 negatively correlated with maximal tumor regression. Early increases in mRNA levels were seen in BIM, BCL-XL, BID and BCL2-W, as were decreases in MCL-1 and BCL2A. No significant changes were observed with BCL-2. Using reverse phase protein array (RPPA, significant increases in protein levels were found in BIM and BID. No changes in mRNA or protein correlated with response. Concurrent BRAF (PLX4720 and BCL2 (navitoclax inhibition synergistically reduced viability in BRAF mutant cell lines and correlated with down-modulation of MCL-1 and BIM induction after PLX4720 treatment. In xenograft models, navitoclax enhanced the efficacy of PLX4720. The combination of a selective BRAF inhibitor with a BH3-mimetic promises to be an important therapeutic strategy capable of enhancing the clinical efficacy of BRAF inhibition in many patients that might otherwise succumb quickly to de novo resistance. Trial registrations: ClinicalTrials.gov NCT01006980; ClinicalTrials.gov NCT01107418; ClinicalTrials.gov NCT01264380; ClinicalTrials.gov NCT01248936; ClinicalTrials.gov NCT00949702; ClinicalTrials.gov NCT01072175.

  11. Protective effects of phosphodiesterase 2 inhibitor on depression- and anxiety-like behaviors: involvement of antioxidant and anti-apoptotic mechanisms.

    Science.gov (United States)

    Ding, Lianshu; Zhang, Chong; Masood, Anbrin; Li, Jianxin; Sun, Jiao; Nadeem, Ahmed; Zhang, Han-Ting; O' Donnell, James M; Xu, Ying

    2014-07-15

    Stress occurs in everyday life, but the relationship between stress and the onset or development of depression/anxiety remains unknown. Increasing evidence suggests that the impairment of antioxidant defense and the neuronal cell death are important in the process of emotional disorders. Chronic stress impairs the homeostasis of antioxidants/oxidation, which results in the aberrant stimulation of the cell cycle proteins where cGMP-PKG signaling is thought to have an inhibitory role. Phosphodiesterase 2 (PDE2) is linked to cGMP-PKG signaling and highly expressed in the limbic brain regions including hippocampus and amygdala, which may play important roles in the treatment of depression and anxiety. To address the possible effects of PDE2 inhibitors on depression-/anxiety-like behaviors and the underlying mechanisms, Bay 60-7550 (0.75, 1.5 and 3 mg/kg, i.p.) was administered 30 min before chronic stress. The results suggested that Bay 60-7550 not only restored the behavioral changes but also regulated Cu/Zn superoxide dismutase (SOD) levels differentially in hippocampus and amygdala, which were increased in the hippocampus while decreased in the amygdala. It was also significant that Bay 60-7550 regulated the abnormalities of pro- and anti-apoptotic components, such as Bax, Caspase 3 and Bcl-2, and the indicator of PKG signaling characterized by pVASP(ser239), in these two brain regions. The results suggested that Bay 60-7550 is able to alleviate oxidative stress and mediate part of the apoptotic machinery in neuronal cells possibly through SOD-cGMP/PKG-anti-apoptosis signaling and that inhibition of PDE2 may represent a novel therapeutic target for psychiatric disorders, such as depression and anxiety. Copyright © 2014 Elsevier B.V. All rights reserved.

  12. The roles of Bcl-xL in modulating apoptosis during development of Xenopus laevis

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    Calderon-Segura Maria

    2005-09-01

    Full Text Available Abstract Background Apoptosis is a common and essential aspect of development. It is particularly prevalent in the central nervous system and during remodelling processes such as formation of the digits and in amphibian metamorphosis. Apoptosis, which is dependent upon a balance between pro- and anti-apoptotic factors, also enables the embryo to rid itself of cells damaged by gamma irradiation. In this study, the roles of the anti-apoptotic factor Bcl-xL in protecting cells from apoptosis were examined in Xenopus laevis embryos using transgenesis to overexpress the XR11 gene, which encodes Bcl-xL. The effects on developmental, thyroid hormone-induced and γ-radiation-induced apoptosis in embryos were examined in these transgenic animals. Results Apoptosis was abrogated in XR11 transgenic embryos. However, the transgene did not prevent the apoptotic response of tadpoles to thyroid hormone during metamorphosis. Post-metamorphic XR11 frogs were reared to sexual maturity, thus allowing us to produce second-generation embryos and enabling us to distinguish between the maternal and zygotic contributions of Bcl-xL to the γ-radiation apoptotic response. Wild-type embryos irradiated before the mid-blastula transition (MBT underwent normal cell division until reaching the MBT, after which they underwent massive, catastrophic apoptosis. Over-expression of Bcl-xL derived from XR11 females, but not males, provided partial protection from apoptosis. Maternal expression of XR11 was also sufficient to abrogate apoptosis triggered by post-MBT γ-radiation. Tolerance to post-MBT γ-radiation from zygotically-derived XR11 was acquired gradually after the MBT in spite of abundant XR11 protein synthesis. Conclusion Our data suggest that Bcl-xL is an effective counterbalance to proapoptotic factors during embryonic development but has no apparent effect on the thyroid hormone-induced apoptosis that occurs during metamorphosis. Furthermore, post-MBT apoptosis

  13. Hypoxic human cancer cells are sensitized to BH-3 mimetic–induced apoptosis via downregulation of the Bcl-2 protein Mcl-1

    Science.gov (United States)

    Harrison, Luke R.E.; Micha, Dimitra; Brandenburg, Martin; Simpson, Kathryn L.; Morrow, Christopher J.; Denneny, Olive; Hodgkinson, Cassandra; Yunus, Zaira; Dempsey, Clare; Roberts, Darren; Blackhall, Fiona; Makin, Guy; Dive, Caroline

    2011-01-01

    Solid tumors contain hypoxic regions in which cancer cells are often resistant to chemotherapy-induced apoptotic cell death. Therapeutic strategies that specifically target hypoxic cells and promote apoptosis are particularly appealing, as few normal tissues experience hypoxia. We have found that the compound ABT-737, a Bcl-2 homology domain 3 (BH-3) mimetic, promotes apoptotic cell death in human colorectal carcinoma and small cell lung cancer cell lines exposed to hypoxia. This hypoxic induction of apoptosis was mediated through downregulation of myeloid cell leukemia sequence 1 (Mcl-1), a Bcl-2 family protein that serves as a biomarker for ABT-737 resistance. Downregulation of Mcl-1 in hypoxia was independent of hypoxia-inducible factor 1 (HIF-1) activity and was consistent with decreased global protein translation. In addition, ABT-737 induced apoptosis deep within tumor spheroids, consistent with an optimal hypoxic oxygen tension being necessary to promote ABT-737–induced cell death. Tumor xenografts in ABT-737–treated mice also displayed significantly more apoptotic cells within hypoxic regions relative to normoxic regions. Synergies between ABT-737 and other cytotoxic drugs were maintained in hypoxia, suggesting that this drug may be useful in combination with chemotherapeutic agents. Taken together, these findings suggest that Mcl-1–sparing BH-3 mimetics may induce apoptosis in hypoxic tumor cells that are resistant to other chemotherapeutic agents and may have a role in combinatorial chemotherapeutic regimens for treatment of solid tumors. PMID:21393866

  14. Characterization of a TK6-Bcl-xL gly-159-ala Human Lymphoblast Clone

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    Chyall, L.: Gauny, S.; Kronenberg, A.

    2006-01-01

    TK6 cells are a well-characterized human B-lymphoblast cell line derived from WIL-2 cells. A derivative of the TK6 cell line that was stably transfected to express a mutated form of the anti-apoptotic protein Bcl-xL (TK6-Bcl-xL gly-159- ala clone #38) is compared with the parent cell line. Four parameters were evaluated for each cell line: growth under normal conditions, plating efficiency, and frequency of spontaneous mutation to 6‑thioguanine resistance (hypoxanthine phosphoribosyl transferase locus) or trifluorothymidine resistance (thymidine kinase locus). We conclude that the mutated Bcl-xL protein did not affect growth under normal conditions, plating efficiency or spontaneous mutation frequencies at the thymidine kinase (TK) locus. Results at the hypoxanthine phosphoribosyl transferase (HPRT) locus were inconclusive. A mutant fraction for TK6‑Bcl-xL gly-159-ala clone #38 cells exposed to 150cGy of 160kVp x-rays was also calculated. Exposure to x-irradiation increased the mutant fraction of TK6‑Bcl-xL gly-159-ala clone #38 cells.

  15. EGFR and Bcl-2 in gastric mucosa of children infected with Helicobacter pylori

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    Ewa Ryszczuk

    2016-03-01

    Full Text Available Aim: The aim of the study was to evaluate the expression of EGFR and Bcl-2 proteins as inhibitory markers of apoptosis in surface epithelial cells and gland cells of antral gastric mucosa in children infected with Helicobacter pylori according to the severity and activity of antral gastritis and to assess the correlation between the number of cells expressing EGFR and the number of cells expressing Bcl-2 in H. pylori infected children.Materials and methods: The study included 44 children: 68.2% with chronic gastritis and positive IgG against H. pylori, and 31.8% with functional disorders of the gastrointestinal tract and with normal IgG against H. pylori. The evaluation of EGFR expression in gastric mucosa was performed immunohistochemically using monoclonal mouse anti-EGFR antibody. The polyclonal antibody was used to determine the expression of anti-Bcl-2.Results: A significant increase in the number of cells expressing EGFR and Bcl-2 protein was found in the epithelial cells in severe as well as mild and moderate gastritis in the group of children infected with H. pylori. An increase in the number of cells expressing EGFR and Bcl-2 protein was also found in the epithelial cells in group I according to the activity of gastritis. There was a statistically significant positive correlation between the numbers of cells expressing EGFR and Bcl-2 in H. pylori infected children.Conclusion: Increased expression of EGFR and Bcl-2 proteins in the epithelial cells and a statistically significant positive correlation between the numbers of cells expressing EGFR and Bcl-2 in H. pylori infected children could suggest increased regeneration abilities of gastric mucosa.

  16. MicroRNAs expression in ox-LDL treated HUVECs: MiR-365 modulates apoptosis and Bcl-2 expression

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    Qin, Bing; Xiao, Bo [Department of Neurology, Xiangya Hospital, Central South University, Changsha, Hunan 410008 (China); Liang, Desheng [State Key Laboratory of Medical Genetics, Central South University, Changsha, Hunan 410078 (China); Xia, Jian; Li, Ye [Department of Neurology, Xiangya Hospital, Central South University, Changsha, Hunan 410008 (China); Yang, Huan, E-mail: yangh69@yahoo.cn [Department of Neurology, Xiangya Hospital, Central South University, Changsha, Hunan 410008 (China)

    2011-06-24

    Highlights: {yields} We evaluated the role of miRNAs in ox-LDL induced apoptosis in ECs. {yields} We found 4 up-regulated and 11 down-regulated miRNAs in apoptotic ECs. {yields} Target genes of the dysregulated miRNAs regulate ECs apoptosis and atherosclerosis. {yields} MiR-365 promotes ECs apoptosis via suppressing Bcl-2 expression. {yields} MiR-365 inhibitor alleviates ECs apoptosis induced by ox-LDL. -- Abstract: Endothelial cells (ECs) apoptosis induced by oxidized low-density lipoprotein (ox-LDL) is thought to play a critical role in atherosclerosis. MicroRNAs (miRNAs) are a class of noncoding RNAs that posttranscriptionally regulate the expression of genes involved in diverse cell functions, including differentiation, growth, proliferation, and apoptosis. However, whether miRNAs are associated with ox-LDL induced apoptosis and their effect on ECs is still unknown. Therefore, this study evaluated potential miRNAs and their involvement in ECs apoptosis in response to ox-LDL stimulation. Microarray and qRT-PCR analysis performed on human umbilical vein endothelial cells (HUVECs) exposed to ox-LDL identified 15 differentially expressed (4 up- and 11 down-regulated) miRNAs. Web-based query tools were utilized to predict the target genes of the differentially expressed miRNAs, and the potential target genes were classified into different function categories with the gene ontology (GO) term and KEGG pathway annotation. In particular, bioinformatics analysis suggested that anti-apoptotic protein B-cell CLL/lymphoma 2 (Bcl-2) is a target gene of miR-365, an apoptomir up-regulated by ox-LDL stimulation in HUVECs. We further showed that transfection of miR-365 inhibitor partly restored Bcl-2 expression at both mRNA and protein levels, leading to a reduction of ox-LDL-mediated apoptosis in HUVECs. Taken together, our findings indicate that miRNAs participate in ox-LDL-mediated apoptosis in HUVECs. MiR-365 potentiates ox-LDL-induced ECs apoptosis by regulating the

  17. American Ginseng Stimulates Insulin Production and Prevents Apoptosis through Regulation of Uncoupling Protein-2 in Cultured β Cells

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    John Zeqi Luo

    2006-01-01

    Full Text Available American ginseng root displays the ability to achieve glucose homeostasis both experimentally and clinically but the unknown mechanism used by ginseng to achieve its therapeutic effects on diabetes limits its application. Disruption in the insulin secretion of pancreatic β cells is considered the major cause of diabetes. A mitochondrial protein, uncoupling protein-2 (UCP-2 has been found to play a critical role in insulin synthesis and β cell survival. Our preliminary studies found that the extracts of American ginseng inhibit UCP-2 expression which may contribute to the ability of ginseng protecting β cell death and improving insulin synthesis. Therefore, we hypothesized that ginseng extracts suppress UCP-2 in the mitochondria of pancreatic β cells, promoting insulin synthesis and anti-apoptosis (a programmed cell-death mechanism. To test the hypothesis, the serum-deprived quiescent β cells were cultured with or without interleukin-1β (IL-1β, (200 pg ml−1, a cytokine to induce β cell apoptosis and water extracts of American ginseng (25 μg per 5 μl administered to wells of 0.5 ml culture for 24 h. We evaluated effects of ginseng on UCP-2 expression, insulin production, anti-/pro-apoptotic factors Bcl-2/caspase-9 expression and cellular ATP levels. We found that ginseng suppresses UCP-2, down-regulates caspase-9 while increasing ATP and insulin production/secretion and up-regulates Bcl-2, reducing apoptosis. These findings suggest that stimulation of insulin production and prevention of β cell loss by American ginseng extracts can occur via the inhibition of mitochondrial UCP-2, resulting in increase in the ATP level and the anti-apoptotic factor Bcl-2, while down-regulation of pro-apoptotic factor caspase-9 occurs, lowering the occurrence of apoptosis, which support the hypothesis.

  18. Influence of p53 and bcl-2 on chemosensitivity in benign and malignant prostatic cell lines.

    Science.gov (United States)

    Serafin, Antonio M; Bohm, Lothar

    2005-01-01

    The administration of cancer chemotherapeutic agents results in an increase in the apoptotic cells in the tumor: therefore, it has been assumed that anticancer drugs exhibit their cytotoxic effects via apoptotic signaling pathways. Characteristics that confer sensitivity to drug-induced apoptosis are, a functional p53 protein and expression of the apoptosis-promoting protein, bax. The role of p53 and bax/bcl-2 in drug-induced apoptosis was assessed in six prostate cell lines, 1532T, 1535T, 1542T, 1542N, BPH-1 and LNCaP using TD(50) concentrations of etoposide, vinblastine and estramustine. Cell death was monitored morphologically by fluorescent microscopy, and by flow cytometry (Annexin-V assay). Apoptotic morphology was rather low and ranged from 0.1% to 12.1%, 3.0% to 6.0% and 0.1% to 8.5% for etoposide, estramustine and vinblastine, respectively. Annexin-V binding and flow cytometry indicated apoptotic propensities of 0% to 4%, 0% to 3% and 0% to 5%, respectively. The percentage of cells responding to drug-induced apoptosis was, on average, higher in the tumor cell lines than in the normal cell lines, but showed no correlation with p53 status. The percentage of cells showing necrosis, assessed by Annexin binding and Propidium Iodide permeability in aqueous medium, tended to be much higher, and was found to be at the level of 5% to 30%. Immunoblotting demonstrated that bax and bcl-2 proteins were expressed at a basal level in all cell lines, but did not increase after exposure to TD(50) doses of the three drugs. The ratio of bax and bcl-2, measured by laser scanning densitometry, was not altered by the drug-induced DNA damage. The results suggest that apoptosis is not a major mechanism of drug-induced cell death in prostate cell lines and appears to be independent of p53 status and bax/bcl-2 expression.

  19. Arsenite induces apoptosis in human mesenchymal stem cells by altering Bcl-2 family proteins and by activating intrinsic pathway

    International Nuclear Information System (INIS)

    Yadav, Santosh; Shi Yongli; Wang Feng; Wang He

    2010-01-01

    Purpose: Environmental exposure to arsenic is an important public health issue. The effects of arsenic on different tissues and organs have been intensively studied. However, the effects of arsenic on bone marrow mesenchymal stem cells (MSCs) have not been reported. This study is designed to investigate the cell death process caused by arsenite and its related underlying mechanisms on MSCs. The rationale is that absorbed arsenic in the blood circulation can reach to the bone marrow and may affect the cell survival of MSCs. Methods: MSCs of passage 1 were purchased from Tulane University, grown till 70% confluency level and plated according to the experimental requirements followed by treatment with arsenite at various concentrations and time points. Arsenite (iAs III ) induced cytotoxic effects were confirmed by cell viability and cell cycle analysis. For the presence of canonic apoptosis markers; DNA damage, exposure of intramembrane phosphotidylserine, protein and m-RNA expression levels were analyzed. Results: iAs III induced growth inhibition, G2-M arrest and apoptotic cell death in MSCs, the apoptosis induced by iAs III in the cultured MSCs was, via altering Bcl-2 family proteins and by involving intrinsic pathway. Conclusion: iAs III can induce apoptosis in bone marrow-derived MSCs via Bcl-2 family proteins, regulating intrinsic apoptotic pathway. Due to the multipotency of MSC, acting as progenitor cells for a variety of connective tissues including bone, adipose, cartilage and muscle, these effects of arsenic may be important in assessing the health risk of the arsenic compounds and understanding the mechanisms of arsenic-induced harmful effects.

  20. Energetic heavy ions overcome tumor radioresistance caused by overexpression of Bcl-2

    International Nuclear Information System (INIS)

    Hamada, Nobuyuki; Hara, Takamitsu; Omura-Minamisawa, Motoko; Funayama, Tomoo; Sakashita, Tetsuya; Sora, Sakura; Yokota, Yuichiro; Nakano, Takashi

    2008-01-01

    Background and purpose: Overexpression of Bcl-2 is frequent in human cancers and has been associated with radioresistance. Here we investigated the potential impact of heavy ions on Bcl-2 overexpressing tumors. Materials and methods: Bcl-2 cells (Bcl-2 overexpressing HeLa cells) and Neo cells (neomycin resistant gene-expressing HeLa cells) exposed to γ-rays or heavy ions were assessed for the clonogenic survival, apoptosis and cell cycle distribution. Results: Whereas Bcl-2 cells were more resistant to γ-rays (0.2 keV/μm) and helium ions (16.2 keV/μm) than Neo cells, heavy ions (76.3-1610 keV/μm) yielded similar survival regardless of Bcl-2 overexpression. Carbon ions (108 keV/μm) decreased the difference in the apoptotic incidence between Bcl-2 and Neo cells, and prolonged G 2 /M arrest that occurred more extensively in Bcl-2 cells than in Neo cells. Conclusions: High-LET heavy ions overcome tumor radioresistance caused by Bcl-2 overexpression, which may be explained at least in part by the enhanced apoptotic response and prolonged G 2 /M arrest. Thus, heavy-ion therapy may be a promising modality for Bcl-2 overexpressing radioresistant tumors

  1. Molecular basis of Bcl-X(L-p53 interaction: insights from molecular dynamics simulations.

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    Nagakumar Bharatham

    Full Text Available Bcl-X(L, an antiapoptotic Bcl-2 family protein, plays a central role in the regulation of the apoptotic pathway. Heterodimerization of the antiapoptotic Bcl-2 family proteins with the proapoptotic family members such as Bad, Bak, Bim and Bid is a crucial step in the apoptotic regulation. In addition to these conventional binding partners, recent evidences reveal that the Bcl-2 family proteins also interact with noncanonical binding partners such as p53. Our previous NMR studies showed that Bcl-X(L: BH3 peptide and Bcl-X(L: SN15 peptide (a peptide derived from residues S15-N29 of p53 complex structures share similar modes of bindings. To further elucidate the molecular basis of the interactions, here we have employed molecular dynamics simulations coupled with MM/PBSA approach. Bcl-X(L and other Bcl-2 family proteins have 4 hydrophobic pockets (p1-p4, which are occupied by four systematically spaced hydrophobic residues (h1-h4 of the proapoptotic Bad and Bak BH3 peptides. We observed that three conserved hydrophobic residues (F19, W23 and L26 of p53 (SN15 peptide anchor into three hydrophobic pockets (p2-p4 of Bcl-X(L in a similar manner as BH3 peptide. Our results provide insights into the novel molecular recognition by Bcl-X(L with p53.

  2. Simultaneous gene silencing of Bcl-2, XIAP and Survivin re-sensitizes pancreatic cancer cells towards apoptosis

    International Nuclear Information System (INIS)

    Rückert, Felix; Samm, Nicole; Lehner, Anne-Kathrin; Saeger, Hans-Detlev; Grützmann, Robert; Pilarsky, Christian

    2010-01-01

    Pancreatic ductal adenocarcinoma shows a distinct apoptosis resistance, which contributes significantly to the aggressive nature of this tumor and constrains the effectiveness of new therapeutic strategies. Apoptosis resistance is determined by the net balance of the cells pro-and anti-apoptotic 'control mechanisms'. Numerous dysregulated anti-apoptotic genes have been identified in pancreatic cancer and seem to contribute to the high anti-apoptotic buffering capacity. We aimed to compare the benefit of simultaneous gene silencing (SGS) of several candidate genes with conventional gene silencing of single genes. From literature search we identified the anti-apoptotic genes XIAP, Survivin and Bcl-2 as commonly upregulated in pancreatic cancer. We performed SGS and silencing of single candidate genes using siRNA molecules in two pancreatic cancer cell lines. Effectiveness of SGS was assessed by qRT-PCR and western blotting. Apoptosis induction was measured by flow cytometry and caspase activation. Simultaneous gene silencing reduced expression of the three target genes effectively. Compared to silencing of a single target or control, SGS of these genes resulted in a significant higher induction of apoptosis in pancreatic cancer cells. In the present study we performed a subliminal silencing of different anti-apoptotic target genes simultaneously. Compared to silencing of single target genes, SGS had a significant higher impact on apoptosis induction in pancreatic cancer cells. Thereby, we give further evidence for the concept of an anti-apoptotic buffering capacity of pancreatic cancer cells

  3. Expression of Bcl-2 and Bax in extrahepatic biliary tract carcinoma and dysplasia

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    Li, Sheng-Mian; Yao, Shu-Kun; Yamamura, Nobuyoshi; Nakamura, Toshitsugu

    2003-01-01

    AIM: To compare the difference of expression of Bcl-2 and Bax in extrahepatic biliary tract carcinoma and dysplasia, and to analyze the role of Bcl-2 and Bax proteins in the progression from dysplasia to carcinoma and to evaluate the correlation of Bcl-2/Bax protein expression with the biological behaviors. METHODS: Expressions of Bcl-2 and Bax were examined immunohistochemically in 27 cases of extrahepatic biliary tract carcinomas (bile duct carcinoma: n = 21, carcinoma of ampulla of Vater: n = 6), and 10 cases of atypical dysplasia. Five cases of normal biliary epithelial tissues were used as controls. A semiquantitative scoring system was used to assess the Bcl-2 and Bax reactivity. RESULTS: The expression of Bcl-2 was observed in 10 out of 27 (37.0%) invasive carcinomas, 1 out of 10 dysplasias, none out of 5 normal epithelial tissues. Bax expression rate was 74.1% (20/27) in invasive carcinoma, 30% (3/10) in dysplasia, and 40% (2/5) in normal biliary epithelium. Bcl-2 and Bax activities were more intense in carcinoma than in dysplasia, with no significant difference in Bcl-2 expression (P = 0.110), and significant difference in Bax expression (P = 0.038). Level of Bax expression was higher in invasive carcinoma than in dysplasia and normal tissue (P = 0.012). Bcl-2 expression was correlated to Bax expression (P = 0.0059). However, Bcl-2/Bax expression had no correlation with histological subtype, grade of differentiation, or level of invasion. CONCLUSION: Increased Bcl-2/Bax expression from dysplasia to invasive tumors supports the view that this is the usual route for the development of extrahepatic biliary tract carcinoma. Bcl-2/Bax may be involved, at least in part, in the apoptotic activity in extrahepatic biliary carcinoma. PMID:14606101

  4. Bcl-2 silencing attenuates hypoxia-induced apoptosis resistance in pulmonary microvascular endothelial cells.

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    Cao, Yongmei; Jiang, Zhen; Zeng, Zhen; Liu, Yujing; Gu, Yuchun; Ji, Yingying; Zhao, Yupeng; Li, Yingchuan

    2016-01-01

    Pulmonary arterial hypertension (PAH) is a life-threatening disorder that ultimately causes heart failure. While the underlying causes of this condition are not well understood, previous studies suggest that the anti-apoptotic nature of pulmonary microvascular endothelial cells (PMVECs) in hypoxic environments contributes to PAH pathogenesis. In this study, we focus on the contribution of Bcl-2 and hypoxia response element (HRE) to apoptosis-resistant endothelial cells and investigate the mechanism. PMVECs obtained from either normal rats or apoptosis-resistant PMVECs obtained from PAH rats were transduced with recombinant lentiviral vectors carrying either Bcl-2-shRNA or HRE combined Bcl-2-shRNA, and then cultured these cells for 24 h under hypoxic (5% O2) or normoxic (21% O2) conditions. In normal PMVECs, Bcl-2-shRNA or HRE combined with Bcl-2-shRNA transduction successfully decreased Bcl-2 expression, while increasing apoptosis as well as caspase-3 and P53 expression in a normoxic environment. In a hypoxic environment, the effects of Bcl-2-shRNA treatment on cell apoptosis, and on Bcl-2, caspase-3, P53 expression were significantly suppressed. Conversely, HRE activation combined with Bcl-2-shRNA transduction markedly enhanced cell apoptosis and upregulated caspase-3 and P53 expression, while decreasing Bcl-2 expression. Furthermore, in apoptosis-resistant PMVECs, HRE-mediated Bcl-2 silencing effectively enhanced cell apoptosis and caspase-3 activity. The apoptosis rate was significantly depressed when Lv-HRE-Bcl-2-shRNA was combined with Lv-P53-shRNA or Lv-caspase3-shRNA transduction in a hypoxic environment. These results suggest that HRE-mediated Bcl-2 inhibition can effectively attenuate hypoxia-induced apoptosis resistance in PMVECs by downregulating Bcl-2 expression and upregulating caspase-3 and P53 expression. This study therefore reveals critical insight into potential therapeutic targets for treating PAH.

  5. Silymarin modulates doxorubicin-induced oxidative stress, Bcl-xL and p53 expression while preventing apoptotic and necrotic cell death in the liver

    International Nuclear Information System (INIS)

    Patel, Nirav; Joseph, Cecil; Corcoran, George B.; Ray, Sidhartha D.

    2010-01-01

    The emergence of silymarin (SMN) as a natural remedy for liver diseases, coupled with its entry into NIH clinical trial, signifies its hepatoprotective potential. SMN is noted for its ability to interfere with apoptotic signaling while acting as an antioxidant. This in vivo study was designed to explore the hepatotoxic potential of Doxorubicin (Dox), the well-known cardiotoxin, and in particular whether pre-exposures to SMN can prevent hepatotoxicity by reducing Dox-induced free radical mediated oxidative stress, by modulating expression of apoptotic signaling proteins like Bcl-xL, and by minimizing liver cell death occurring by apoptosis or necrosis. Groups of male ICR mice included Control, Dox alone, SMN alone, and Dox with SMN pre/co-treatment. Control and Dox groups received saline i.p. for 14 days. SMN was administered p.o. for 14 days at 16 mg/kg/day. An approximate LD 50 dose of Dox, 60 mg/kg, was administered i.p. on day 12 to animals receiving saline or SMN. Animals were euthanized 48 h later. Dox alone induced frank liver injury (> 50-fold increase in serum ALT) and oxidative stress (> 20-fold increase in malondialdehyde [MDA]), as well as direct damage to DNA (> 15-fold increase in DNA fragmentation). Coincident genomic damage and oxidative stress influenced genomic stability, reflected in increased PARP activity and p53 expression. Decreases in Bcl-xL protein coupled with enhanced accumulation of cytochrome c in the cytosol accompanied elevated indexes of apoptotic and necrotic cell death. Significantly, SMN exposure reduced Dox hepatotoxicity and associated apoptotic and necrotic cell death. The effects of SMN on Dox were broad, including the ability to modulate changes in both Bcl-xL and p53 expression. In animals treated with SMN, tissue Bcl-xL expression exceeded control values after Dox treatment. Taken together, these results demonstrated that SMN (i) reduced, delayed onset, or prevented toxic effects of Dox which are typically associated with

  6. Bcl-2 protein expression is associated with p27 and p53 protein expressions and MIB-1 counts in breast cancer

    International Nuclear Information System (INIS)

    Tsutsui, Shinichi; Yasuda, Kazuhiro; Suzuki, Kosuke; Takeuchi, Hideya; Nishizaki, Takashi; Higashi, Hidefumi; Era, Shoichi

    2006-01-01

    Recent experimental studies have shown that Bcl-2, which has been established as a key player in the control of apoptosis, plays a role in regulating the cell cycle and proliferation. The aim of this study was to investigate the relationship between Bcl-2 and p27 protein expression, p53 protein expression and the proliferation activity as defined by the MIB-1 counts. The prognostic implication of Bcl-2 protein expression in relation to p27 and p53 protein expressions and MIB-1 counts for breast cancer was also evaluated. The immunohistochemical expression of Bcl-2 protein was evaluated in a series of 249 invasive ductal carcinomas of the breast, in which p27 and p53 protein expressions and MIB-1 counts had been determined previously. The Bcl-2 protein expression was found to be decreased in 105 (42%) cases. A decreased Bcl-2 protein expression was significantly correlated with a nuclear grade of III, a negative estrogen receptor, a decreased p27 protein expression, a positive p53 protein expression, positive MIB-1 counts and a positive HER2 protein expression. The incidence of a nuclear grade of III and positive MIB-1 counts increased as the number of abnormal findings of Bcl-2, p27 and p53 protein expressions increased. A univariate analysis indicated a decreased Bcl-2 protein expression to be significantly (p = 0.0089) associated with a worse disease free survival (DFS), while a multivariate analysis indicated the lymph node status and MIB-1 counts to be independently significant prognostic factors for the DFS. The Bcl-2 protein expression has a close correlation with p27 and p53 protein expressions and the proliferation activity determined by MIB-1 counts in invasive ductal carcinoma of the breast. The prognostic value of Bcl-2 as well as p27 and p53 protein expressions was dependent on the proliferation activity in breast cancer

  7. Bcl-2 protein expression is associated with p27 and p53 protein expressions and MIB-1 counts in breast cancer

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    Nishizaki Takashi

    2006-07-01

    Full Text Available Abstract Background Recent experimental studies have shown that Bcl-2, which has been established as a key player in the control of apoptosis, plays a role in regulating the cell cycle and proliferation. The aim of this study was to investigate the relationship between Bcl-2 and p27 protein expression, p53 protein expression and the proliferation activity as defined by the MIB-1 counts. The prognostic implication of Bcl-2 protein expression in relation to p27 and p53 protein expressions and MIB-1 counts for breast cancer was also evaluated. Methods The immunohistochemical expression of Bcl-2 protein was evaluated in a series of 249 invasive ductal carcinomas of the breast, in which p27 and p53 protein expressions and MIB-1 counts had been determined previously. Results The Bcl-2 protein expression was found to be decreased in 105 (42% cases. A decreased Bcl-2 protein expression was significantly correlated with a nuclear grade of III, a negative estrogen receptor, a decreased p27 protein expression, a positive p53 protein expression, positive MIB-1 counts and a positive HER2 protein expression. The incidence of a nuclear grade of III and positive MIB-1 counts increased as the number of abnormal findings of Bcl-2, p27 and p53 protein expressions increased. A univariate analysis indicated a decreased Bcl-2 protein expression to be significantly (p = 0.0089 associated with a worse disease free survival (DFS, while a multivariate analysis indicated the lymph node status and MIB-1 counts to be independently significant prognostic factors for the DFS. Conclusion The Bcl-2 protein expression has a close correlation with p27 and p53 protein expressions and the proliferation activity determined by MIB-1 counts in invasive ductal carcinoma of the breast. The prognostic value of Bcl-2 as well as p27 and p53 protein expressions was dependent on the proliferation activity in breast cancer.

  8. Antisense oligonucleotides and all-trans retinoic acid have a synergistic anti-tumor effect on oral squamous cell carcinoma

    International Nuclear Information System (INIS)

    Xu, Qin; Zhang, Zhiyuan; Zhang, Ping; Chen, Wantao

    2008-01-01

    Antisense oligonucleotides against hTR (As-ODN-hTR) have shown promising results as treatment strategies for various human malignancies. All-trans retinoic acid (ATRA) is a signalling molecule with important roles in differentiation and apoptosis. Biological responses to ATRA are currently used therapeutically in various human cancers. The aim of this study was to evaluate the anti-tumor effects of As-ODN-hTR combined with ATRA in vivo. In situ human oral squamous cell carcinoma (OSCC) models were established by subcutaneous injection of Tca8113 cells. Mice were treated with sense oligonucleotides against hTR(S-ODN-hTR) alone, As-ODN-hTR alone, ATRA alone, As-ODN-hTR plus ATRA, or S-ODN-hTR plus ATRA. Tumor size and weight were assessed in the mice. Telomerase activity was detected by a TRAP assay, apoptotic cells were evaluated with a Tunel assay, the expression of apoptosis-related proteins (Bcl-2 and Bax) was evaluated by immunohistochemistry and ultrastructural morphological changes in the tumor specimen were examined. Both As-ODN-hTR and ATRA can significantly inhibit tumor growth in this OSCC xenograft solid-tumor model, and the combination of the two agents had a synergistic anti-tumorogenic effect. We also demonstrated that this anti-tumor effect correlated with inhibition of telomerase activity. Furthermore, significant increases in the number of apoptotic cells, typical apoptotic morphology and a downregulation of the anti-apoptotic protein, bcl-2 were observed in the treated tissues. The combination of As-ODN-hTR and ATRA has a synergistic anti-tumor effect. This anti-tumor effect can be mainly attributed to apoptosis induced by a decrease in telomerase activity. Bcl-2 plays an important role in this process. Therefore, combining As-ODN-hTR and ATRA may be an approach for the treatment of human oral squamous cell carcinoma

  9. Effect of low dose ionizing radiation on Bcl-2 transcription level of Peyer's patches in mouse

    International Nuclear Information System (INIS)

    Liu Jiamei; Chen Dong; Zheng Yongchen; Liu Shuzheng

    2001-01-01

    Objective: To study the effect of whole body irradiation (WBI) with different doses of X-rays on apoptosis in cells of mouse Peyer's patches and its molecular mechanism. Methods: RT-PCR was used to detect the changes of Bcl-2 transcription level. Agarose electrophoresis and flow cytometry were used to detect the changes of DNA and apoptotic bodies in Peyer's patches after WBI with different doses of X-rays. Results: The apoptotic was increased and Bcl-2 transcription level was decreased in Peyer's patches after 2 Gy X-rays. The apoptotic rate was decreased and Bcl-2 transcription level was increased in Peyer's patches after 75 mGy X-rays. Conclusion: Bcl-2 participates in the regulation of radiation-induced apoptosis in Peyer's patches

  10. Cycloheximide Can Induce Bax/Bak Dependent Myeloid Cell Death Independently of Multiple BH3-Only Proteins.

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    Katharine J Goodall

    Full Text Available Apoptosis mediated by Bax or Bak is usually thought to be triggered by BH3-only members of the Bcl-2 protein family. BH3-only proteins can directly bind to and activate Bax or Bak, or indirectly activate them by binding to anti-apoptotic Bcl-2 family members, thereby relieving their inhibition of Bax and Bak. Here we describe a third way of activation of Bax/Bak dependent apoptosis that does not require triggering by multiple BH3-only proteins. In factor dependent myeloid (FDM cell lines, cycloheximide induced apoptosis by a Bax/Bak dependent mechanism, because Bax-/-Bak-/- lines were profoundly resistant, whereas FDM lines lacking one or more genes for BH3-only proteins remained highly sensitive. Addition of cycloheximide led to the rapid loss of Mcl-1 but did not affect the expression of other Bcl-2 family proteins. In support of these findings, similar results were observed by treating FDM cells with the CDK inhibitor, roscovitine. Roscovitine reduced Mcl-1 abundance and caused Bax/Bak dependent cell death, yet FDM lines lacking one or more genes for BH3-only proteins remained highly sensitive. Therefore Bax/Bak dependent apoptosis can be regulated by the abundance of anti-apoptotic Bcl-2 family members such as Mcl-1, independently of several known BH3-only proteins.

  11. Involvement of ERK, Bcl-2 family and caspase 3 in recombinant human activin A-induced apoptosis in A549

    International Nuclear Information System (INIS)

    Wang Baiding; Feng Yuling; Song Xingbo; Liu Qingqing; Ning Yunye; Ou Xuemei; Yang Jie; Zhang Xiaohong; Wen, Fuqiang

    2009-01-01

    Background: Activins are members of the transforming growth factor-β (TGF-β) superfamily. Previous studies have shown that activin A may have a central role in regulating both apoptosis and proliferation. However, direct studies of recombination human activin A on human NSCLC A549 cells have not yet been reported. The purpose of this study was to investigate whether activin A could induce apoptosis in A549 cells and the possible mechanisms via which it worked. Methods: Cellular apoptosis induced by activin A was detected by TUNEL assay and the levels of protein expression were detected by western blot. Results: Recombination human activin A induced apoptosis in human NSCLC A549 cells in a concentrate-dependent manner. Activin A-induced A549 apoptosis was accompanied by the up-regulation of Bax, Bad and Bcl-Xs and down-regulation of Bcl-2. Moreover, activin A treatment increased the expression of its typeII receptors, activated ERK and caspase 3 in A549. These results clearly demonstrate that the induction of apoptosis by activin-A involves multiple cellular/molecular pathways and strongly suggest that pro- and anti-apoptotic Bcl-2 family proteins and caspase 3 participate in activin A-induced apoptotic process in A549 cells. On the other hand, activin A treatment had little effect on primary human small airway epithelial cells (SAECs). Conclusion: Recombination human activin A induced apoptosis in A549 cells, at least partially, through ERK and mitochondrial pathway. The result that activin A did not affect the normal SAEC revealed activin A might be considered as a potential anticancer agent and worthy of further studies

  12. Using Förster-Resonance Energy Transfer to Measure Protein Interactions Between Bcl-2 Family Proteins on Mitochondrial Membranes.

    Science.gov (United States)

    Pogmore, Justin P; Pemberton, James M; Chi, Xiaoke; Andrews, David W

    2016-01-01

    The Bcl-2 family of proteins regulates the process of mitochondrial outer membrane permeabilization, causing the release of cytochrome c and committing a cell to apoptosis. The majority of the functional interactions between these proteins occur at, on, or within the mitochondrial outer membrane, complicating structural studies of the proteins and complexes. As a result most in vitro studies of these protein-protein interactions use truncated proteins and/or detergents which can cause artificial interactions. Herein, we describe a detergent-free, fluorescence-based, in vitro technique to study binding between full-length recombinant Bcl-2 family proteins, particularly cleaved BID (cBID) and BCL-XL, on the membranes of purified mitochondria.

  13. Effect of polysaccharides from Angelica sinensis on Bcl-2 and Bax protein expression of irradiated liver cells

    International Nuclear Information System (INIS)

    Sun Yuanlin; Tang Jian; Gu Xiaohong; Li Deyuan

    2009-01-01

    Objective: To investigate the effect of polysaccharides from Angelica sinensis (ASP3) on Bcl-2 and Bax protein expression of irradiated liver cells from mice. Methods: Bcl-2 and Bax protein expression of liver cells in vitro exposed to 2.0 Gy rays were examined by using immunohistochemistry method. Results: The expression of apoptosis-accelerating protein Bax in the irradiation group was enhanced obviously (70.83%), while apoptosis inhibiting protein Bcl-2 tended to decline (55.60%), with the statistically significant difference (P <0.01) compared with that of the control. ASP3 pretreatment could regulate Bcl-2 and Bax protein expression of liver cells, inhibiting Bax protein expression(64.14/58.37%) and increasing Bcl-2 protein expression(59.21%/ 67.45%). The differences between the high dosage (100 mg/L of ASP3) and the irradiation group were statistically significant (P<0.05). Conclusions: ASP3 pretreatment could prohibit the apoptosis of radiation- damaged liver cells due to abnormal expression of Bcl-2 and Bax, and reduce the cell apoptosis by increasing Bcl-2/Bax protein expression so as to enhance the radiation endurance of liver cells. (authors)

  14. Poncirin Induces Apoptosis in AGS Human Gastric Cancer Cells through Extrinsic Apoptotic Pathway by up-Regulation of Fas Ligand.

    Science.gov (United States)

    Saralamma, Venu Venkatarame Gowda; Nagappan, Arulkumar; Hong, Gyeong Eun; Lee, Ho Jeong; Yumnam, Silvia; Raha, Suchismita; Heo, Jeong Doo; Lee, Sang Joon; Lee, Won Sup; Kim, Eun Hee; Kim, Gon Sup

    2015-09-18

    Poncirin, a natural bitter flavanone glycoside abundantly present in many species of citrus fruits, has various biological benefits such as anti-oxidant, anti-microbial, anti-inflammatory and anti-cancer activities. The anti-cancer mechanism of Poncirin remains elusive to date. In this study, we investigated the anti-cancer effects of Poncirin in AGS human gastric cancer cells (gastric adenocarcinoma). The results revealed that Poncirin could inhibit the proliferation of AGS cells in a dose-dependent manner. It was observed Poncirin induced accumulation of sub-G1 DNA content, apoptotic cell population, apoptotic bodies, chromatin condensation, and DNA fragmentation in a dose-dependent manner in AGS cells. The expression of Fas Ligand (FasL) protein was up-regulated dose dependently in Poncirin-treated AGS cells Moreover, Poncirin in AGS cells induced activation of Caspase-8 and -3, and subsequent cleavage of poly(ADP-ribose) polymerase (PARP). Inhibitor studies' results confirm that the induction of caspase-dependent apoptotic cell death in Poncirin-treated AGS cells was led by the Fas death receptor. Interestingly, Poncirin did not show any effect on mitochondrial membrane potential (ΔΨm), pro-apoptotic proteins (Bax and Bak) and anti-apoptotic protein (Bcl-xL) in AGS-treated cells followed by no activation in the mitochondrial apoptotic protein caspase-9. This result suggests that the mitochondrial-mediated pathway is not involved in Poncirin-induced cell death in gastric cancer. These findings suggest that Poncirin has a potential anti-cancer effect via extrinsic pathway-mediated apoptosis, possibly making it a strong therapeutic agent for human gastric cancer.

  15. Atherosclerosis-Associated Endothelial Cell Apoptosis by MiR-429-Mediated Down Regulation of Bcl-2

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    Tao Zhang

    2015-10-01

    Full Text Available Background/Aims: Endothelial cell injury and subsequent apoptosis play a key role in the development and pathogenesis of atherosclerosis, which is hallmarked by dysregulated lipid homeostasis, aberrant immunity and inflammation, and plaque-instability-associated coronary occlusion. Nevertheless, our understanding of the mechanisms underlying endothelial cell apoptosis is still limited. MicroRNA-429 (miR-29 is a known cancer suppressor that promotes cancer cell apoptosis. However, it is unknown whether miR-429 may be involved in the development of atherosclerosis through similar mechanisms. We addressed these questions in the current study. Methods: We examined the levels of endothelial cell apoptosis in ApoE (-/- mice suppled with high-fat diet (HFD, a mouse model for atherosclerosis (simplified as HFD mice. We analyzed the levels of anti-apoptotic protein Bcl-2 and the levels of miR-429 in the purified CD31+ endothelial cells from mouse aorta. Prediction of the binding between miR-429 and 3'-UTR of Bcl-2 mRNA was performed by bioinformatics analyses and confirmed by a dual luciferase reporter assay. The effects of miR-429 were further analyzed in an in vitro model using oxidized low-density lipoprotein (ox-LDL-treated human aortic endothelial cells (HAECs. Results: HFD mice developed atherosclerosis in 12 weeks, while the control ApoE (-/- mice that had received normal diet (simplified as NOR mice did not. HFD mice had significantly lower percentage of endothelial cells and significantly higher percentage of mesenchymal cells in the aorta than NOR mice. Significantly higher levels of endothelial cell apoptosis were detected in HFD mice, resulting from decreases in Bcl-2 protein, but not mRNA. The decreases in Bcl-2 in endothelial cells were due to increased levels of miR-429, which suppressed the translation of Bcl-2 mRNA via 3'-UTR binding. These in vivo findings were reproduced in vitro on ox-LDL-treated HAECs. Conclusion: Atherosclerosis

  16. Natural proteasome inhibitor celastrol suppresses androgen-independent prostate cancer progression by modulating apoptotic proteins and NF-kappaB.

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    Yao Dai

    Full Text Available Celastrol is a natural proteasome inhibitor that exhibits promising anti-tumor effects in human malignancies, especially the androgen-independent prostate cancer (AIPC with constitutive NF-κB activation. Celastrol induces apoptosis by means of proteasome inhibition and suppresses prostate tumor growth. However, the detailed mechanism of action remains elusive. In the current study, we aim to test the hypothesis that celastrol suppresses AIPC progression via inhibiting the constitutive NF-κB activity as well as modulating the Bcl-2 family proteins.We examined the efficacy of celastrol both in vitro and in vivo, and evaluated the role of NF-κB in celastrol-mediated AIPC regression. We found that celastrol inhibited cell proliferation in all three AIPC cell lines (PC-3, DU145 and CL1, with IC₅₀ in the range of 1-2 µM. Celastrol also suppressed cell migration and invasion. Celastrol significantly induced apoptosis as evidenced by increased sub-G1 population, caspase activation and PARP cleavage. Moreover, celastrol promoted cleavage of the anti-apoptotic protein Mcl-1 and activated the pro-apoptotic protein Noxa. In addition, celastrol rapidly blocked cytosolic IκBα degradation and nuclear translocation of RelA. Likewise, celastrol inhibited the expression of multiple NF-κB target genes that are involved in proliferation, invasion and anti-apoptosis. Celastrol suppressed AIPC tumor progression by inhibiting proliferation, increasing apoptosis and decreasing angiogenesis, in PC-3 xenograft model in nude mouse. Furthermore, increased cellular IκBα and inhibited expression of various NF-κB target genes were observed in tumor tissues.Our data suggest that, via targeting the proteasome, celastrol suppresses proliferation, invasion and angiogenesis by inducing the apoptotic machinery and attenuating constitutive NF-κB activity in AIPC both in vitro and in vivo. Celastrol as an active ingredient of traditional herbal medicine could thus be

  17. Effect of acetone extract of Rumex japonicas Houtt on hydrogen ...

    African Journals Online (AJOL)

    is the most important executor in the apoptotic process [25]. Furthermore, Bax is a pro-apoptotic protein in the mitochondria-mediated apoptosis, whereas Bcl-2 is an anti-apoptotic protein [24]. In the present study, AER down-regulated the caspase-3 and Bax, but up-regulated Bcl-2, indicating that AER suppresses apoptosis ...

  18. THE EXPRESSION OF Bcl-2 AND PRO-CASPASE 3 IN HEAD AND NECK SQUAMOUS CELL CARCINOMA

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    Andrej Cör

    2002-12-01

    Full Text Available Background. Head and neck squamous cell carcinoma (HNSCC is the sixth most common cancer and accounts for 6% of cancers worldwide. A better understanding of its biology could lead to improved treatment options. Generally, the goal of cancer treatment is to abolish cell proliferation and to induce necrotic or aptoptotic cell death. Apoptosis has been recognized as a key mechanism of tumour cell elimination. Different apoptotic signals converge to induce caspase cascade activation. Caspase 3 is the central executioner caspase and is necessary for effective apoptotic cell death. Bcl-2 protein family regulates apoptosis. The Bcl-2 protein itself is a product of a proto-oncogene and has an antiapoptotic action.Methods. In our study, the expression of Bcl-2 and pro-caspase 3 by immunohistochemistry in 28 HNSCC graded into well, moderately and poorly differentiated cancers were investigated.Results. Our results of Bcl-2 expression confirm and extend previous reports in which Bcl-2 over-expression has been recognised as an important parameter in HNSCC biological behaviour. Three of 28 tumours (11% showed significant Bcl-2 expression. Two of them were poorly and one was moderately differentiated. Pro-caspase 3 immunoreactivity was confined mainly to the cytoplasm. Absent or low pro-caspase 3 immunoreactivity was found only in 1 of 6 well differentiated and in 1of 10 moderately differentiated tumours in contrast to 5 of 12 poorly differentiated tumours. In six of 12 poorly differentiated tumours procasapse 3 immunoreactivity was strongly positive. In two cases hyperplastic epithelium was strongly positive in contrast to adjacent HNSCC in the same slide which was completely negative for pro-caspase 3.Conclusions. Our results indicate downregulation of pro-caspase 3 expression, especially in poorly differentiated HNSCC. Further studies are needed to test whether this is related to HNSCC behaviour and predict treatment outcome.

  19. FLASH knockdown sensitizes cells to Fas-mediated apoptosis via down-regulation of the anti-apoptotic proteins, MCL-1 and Cflip short.

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    Song Chen

    Full Text Available FLASH (FLICE-associated huge protein or CASP8AP2 is a large multifunctional protein that is involved in many cellular processes associated with cell death and survival. It has been reported to promote apoptosis, but we show here that depletion of FLASH in HT1080 cells by siRNA interference can also accelerate the process. As shown previously, depletion of FLASH halts growth by down-regulating histone biosynthesis and arrests the cell cycle in S-phase. FLASH knockdown followed by stimulating the cells with Fas ligand or anti-Fas antibodies was found to be associated with a more rapid cleavage of PARP, accelerated activation of caspase-8 and the executioner caspase-3 and rapid progression to cellular disintegration. As is the case for most anti-apoptotic proteins, FLASH was degraded soon after the onset of apoptosis. Depletion of FLASH also resulted in the reduced intracellular levels of the anti-apoptotic proteins, MCL-1 and the short isoform of cFLIP. FLASH knockdown in HT1080 mutant cells defective in p53 did not significantly accelerate Fas mediated apoptosis indicating that the effect was dependent on functional p53. Collectively, these results suggest that under some circumstances, FLASH suppresses apoptosis.

  20. Bim and Mcl-1 exert key roles in regulating JAK2V617F cell survival

    International Nuclear Information System (INIS)

    Rubert, Joëlle; Qian, Zhiyan; Andraos, Rita; Guthy, Daniel A; Radimerski, Thomas

    2011-01-01

    The JAK2 V617F mutation plays a major role in the pathogenesis of myeloproliferative neoplasms and is found in the vast majority of patients suffering from polycythemia vera and in roughly every second patient suffering from essential thrombocythemia or from primary myelofibrosis. The V617F mutation is thought to provide hematopoietic stem cells and myeloid progenitors with a survival and proliferation advantage. It has previously been shown that activated JAK2 promotes cell survival by upregulating the anti-apoptotic STAT5 target gene Bcl-xL. In this study, we have investigated the role of additional apoptotic players, the pro-apoptotic protein Bim as well as the anti-apoptotic protein Mcl-1. Pharmacological inhibition of JAK2/STAT5 signaling in JAK2 V617F mutant SET-2 and MB-02 cells was used to study effects on signaling, cell proliferation and apoptosis by Western blot analysis, WST-1 proliferation assays and flow cytometry. Cells were transfected with siRNA oligos to deplete candidate pro- and anti-apoptotic proteins. Co-immunoprecipitation assays were performed to assess the impact of JAK2 inhibition on complexes of pro- and anti-apoptotic proteins. Treatment of JAK2 V617F mutant cell lines with a JAK2 inhibitor was found to trigger Bim activation. Furthermore, Bim depletion by RNAi suppressed JAK2 inhibitor-induced cell death. Bim activation following JAK2 inhibition led to enhanced sequestration of Mcl-1, besides Bcl-xL. Importantly, Mcl-1 depletion by RNAi was sufficient to compromise JAK2 V617F mutant cell viability and sensitized the cells to JAK2 inhibition. We conclude that Bim and Mcl-1 have key opposing roles in regulating JAK2 V617F cell survival and propose that inactivation of aberrant JAK2 signaling leads to changes in Bim complexes that trigger cell death. Thus, further preclinical evaluation of combinations of JAK2 inhibitors with Bcl-2 family antagonists that also tackle Mcl-1, besides Bcl-xL, is warranted to assess the therapeutic potential

  1. Anti-apoptotic BFL-1 is the major effector in activation-induced human mast cell survival.

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    Maria Ekoff

    Full Text Available Mast cells are best known for their role in allergic reactions, where aggregation of FcεRI leads to the release of mast cell mediators causing allergic symptoms. The activation also induces a survival program in the cells, i.e., activation-induced mast cell survival. The aim of the present study was to investigate how the activation-induced survival is mediated. Cord blood-derived mast cells and the mast cell line LAD-2 were activated through FcεRI crosslinking, with or without addition of chemicals that inhibit the activity or expression of selected Bcl-2 family members (ABT-737; roscovitine. Cell viability was assessed using staining and flow cytometry. The expression and function of Bcl-2 family members BFL-1 and MCL-1 were investigated using real-time quantitative PCR and siRNA treatment. The mast cell expression of Bfl-1 was investigated in skin biopsies. FcεRI crosslinking promotes activation-induced survival of human mast cells and this is associated with an upregulation of the anti-apoptotic Bcl-2 family member Bfl-1. ABT-737 alone or in combination with roscovitine decreases viability of human mast cells although activation-induced survival is sustained, indicating a minor role for Bcl-X(L, Bcl-2, Bcl-w and Mcl-1. Reducing BFL-1 but not MCL-1 levels by siRNA inhibited activation-induced mast cell survival. We also demonstrate that mast cell expression of Bfl-1 is elevated in birch-pollen-provocated skin and in lesions of atopic dermatitis and psoriasis patients. Taken together, our results highlight Bfl-1 as a major effector in activation-induced human mast cell survival.

  2. Relationship between bcl-2, bax, beclin-1, and cathepsin-D proteins during postovulatory follicular regression in fish ovary.

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    Morais, Roberto D V S; Thomé, Ralph G; Santos, Hélio B; Bazzoli, Nilo; Rizzo, Elizete

    2016-04-01

    In fish ovaries, postovulatory follicles (POFs) are key biomarkers of breeding and provide an interesting model for studying the relationship between autophagy and apoptosis. In this study, we investigated the immunohistochemical expression of autophagic and apoptotic proteins to improve the knowledge on the mechanisms regulating ovarian remodeling after spawning. Females from three neotropical fish species kept in captivity were submitted to hormonal induction. After ova stripping, ovarian sections were sampled daily until 5 days postspawning (dps). Similar events of POF regression were detected by histology, terminal transferase-mediated dUTP nick-end labeling (TUNEL), and electron microscopy in the three species: follicular cells hypertrophy, progressive disintegration of the basement membrane, gradual closing of the follicular lumen, theca thickening, and formation of large autophagic vacuoles preceding apoptosis of the follicular cells. Autophagic and apoptotic proteins were assessed by immunohistochemistry. Morphometric analysis of the immunolabeling revealed a more intense reaction for bcl-2 and beclin-1 (BECN1) in POFs at 0 to 1 dps and for bax at 2 to 3 dps (P family, BECN1, and cathepsin-D can be involved in the regulation of ovarian remodeling in teleost fish. Copyright © 2016 Elsevier Inc. All rights reserved.

  3. N-myc downstream-regulated gene 1 promotes oxaliplatin-triggered apoptosis in colorectal cancer cells via enhancing the ubiquitination of Bcl-2.

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    Yang, Xiao; Zhu, Fan; Yu, Chaoran; Lu, Jiaoyang; Zhang, Luyang; Lv, Yanfeng; Sun, Jing; Zheng, Minhua

    2017-07-18

    N-myc downstream-regulated gene1 (NDRG1) has been identified as a potent tumor suppressor gene. The molecular mechanisms of anti-tumor activity of NDRG1 involve its suppressive effects on a variety of tumorigenic signaling pathways. The purpose of this study was to investigate the role of NDRG1 in the apoptosis of colorectal cancer (CRC) cells. We first collected the clinical data of locally advanced rectal cancer (LARC) patients receiving oxaliplatin-based neoadjuvant chemotherapy in our medical center. Correlation analysis revealed that NDRG1 positively associated with the downstaging rates and prognosis of patients. Then, the effects of over-expression and depletion of NDRG1 gene on apoptosis of colorectal cancer were tested in vitro and in vivo. NDRG1 over-expression promoted apoptosis in colorectal cancer cells whereas depletion of NDRG1 resulted in resistance to oxaliplatin treatment. Furthermore, we observed that Bcl-2, a major anti-apoptotic protein, was regulated by NDRG1 at post-transcriptional level. By binding Protein kinase Cα (PKCα), a classical regulating factor of Bcl-2, NDRG1 enhanced the ubiquitination and degradation of Bcl-2, thus promoting apoptosis in CRC cells. In addition, NDRG1 inhibited tumor growth and promoted apoptosis in mouse xenograft model. In conclusion,NDRG1 promotes oxaliplatin-triggered apoptosis in colorectal cancer. Therefore, colorectal cancer patients can be stratified by the expression level of NDRG1. NDRG1-positive patients may benefit from oxaliplatin-containing chemotherapy regimens whereas those with negative NDRG1 expression should avoid the usage of this cytotoxic drug.

  4. BET inhibition silences expression of MYCN and BCL2 and induces cytotoxicity in neuroblastoma tumor models.

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    Anastasia Wyce

    Full Text Available BET family proteins are epigenetic regulators known to control expression of genes involved in cell growth and oncogenesis. Selective inhibitors of BET proteins exhibit potent anti-proliferative activity in a number of hematologic cancer models, in part through suppression of the MYC oncogene and downstream Myc-driven pathways. However, little is currently known about the activity of BET inhibitors in solid tumor models, and whether down-regulation of MYC family genes contributes to sensitivity. Here we provide evidence for potent BET inhibitor activity in neuroblastoma, a pediatric solid tumor associated with a high frequency of MYCN amplifications. We treated a panel of neuroblastoma cell lines with a novel small molecule inhibitor of BET proteins, GSK1324726A (I-BET726, and observed potent growth inhibition and cytotoxicity in most cell lines irrespective of MYCN copy number or expression level. Gene expression analyses in neuroblastoma cell lines suggest a role of BET inhibition in apoptosis, signaling, and N-Myc-driven pathways, including the direct suppression of BCL2 and MYCN. Reversal of MYCN or BCL2 suppression reduces the potency of I-BET726-induced cytotoxicity in a cell line-specific manner; however, neither factor fully accounts for I-BET726 sensitivity. Oral administration of I-BET726 to mouse xenograft models of human neuroblastoma results in tumor growth inhibition and down-regulation MYCN and BCL2 expression, suggesting a potential role for these genes in tumor growth. Taken together, our data highlight the potential of BET inhibitors as novel therapeutics for neuroblastoma, and suggest that sensitivity is driven by pleiotropic effects on cell growth and apoptotic pathways in a context-specific manner.

  5. Pre-apoptotic response to therapeutic DNA damage involves protein modulation of Mcl-1, Hdm2 and Flt3 in acute myeloid leukemia cells

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    Hovland Randi

    2007-05-01

    Full Text Available Abstract Background Acute myeloid leukemia (AML cells are characterized by non-mutated TP53, high levels of Hdm2, and frequent mutation of the Flt3 receptor tyrosine kinase. The juxtamembrane mutation of FLT3 is the strongest independent marker for disease relapse and is associated with elevated Bcl-2 protein and p53 hyper-phosphorylation in AML. DNA damage forms the basic mechanism of cancer cell eradication in current therapy of AML. Hdm2 and pro-apoptotic Bcl-2 members are among the most intensely induced genes immediately after chemotherapy and Hdm2 is proposed a role in receptor tyrosine kinase regulation. Thus we examined the DNA damage related modulation of these proteins in relation to FLT3 mutational status and induction of apoptosis. Results Within one hour after exposure to ionizing radiation (IR, the AML cells (NB4, MV4-11, HL-60, primary AML cells showed an increase in Flt3 protein independent of mRNA levels, while the Hdm2 protein decreased. The FLT3 mutant MV4-11 cells were resistant to IR accompanied by presence of both Mcl-1 and Hdm2 protein three hours after IR. In contrast, the FLT3 wild type NB4 cells responded to IR with apoptosis and pre-apoptotic Mcl-1 down regulation. Daunorubicin (DNR induced continuing down regulation of Hdm2 and Mcl-1 in both cell lines followed by apoptosis. Conclusion Both IR and DNR treatment resulted in concerted protein modulations of Mcl-1, Hdm2 and Flt3. Cell death induction was associated with persistent attenuation of Mcl-1 and Hdm2. These observations suggest that defining the pathway(s modulating Flt3, Hdm2 and Mcl-1 may propose new strategies to optimize therapy for the relapse prone FLT3 mutated AML patients.

  6. Genetic and pharmacological screens converge in identifying FLIP, BCL2 and IAP proteins as key regulators of sensitivity to the TRAIL-inducing anti-cancer agent ONC201/TIC10

    Science.gov (United States)

    Allen, Joshua E.; Prabhu, Varun V.; Talekar, Mala; van den Heuvel, AP; Lim, Bora; Dicker, David T.; Fritz, Jennifer L.; Beck, Adam; El-Deiry, Wafik S.

    2015-01-01

    ONC201/TIC10 is a small molecule inducer of the TRAIL gene under current investigation as a novel anticancer agent. In this study, we identify critical molecular determinants of ONC201 sensitivity offering potential utility as pharmacodynamic or predictive response markers. By screening a library of kinase siRNAs in combination with a subcytotoxic dose of ONC201, we identified several kinases that ablated tumor cell sensitivity, including the MAPK pathway inducer KSR1. Unexpectedly, KSR1 silencing did not affect MAPK signaling in the presence or absence of ONC201, but instead reduced expression of the anti-apoptotic proteins FLIP, Mcl-1, Bcl-2, cIAP1, cIAP2, and survivin. In parallel to this work, we also conducted a synergy screen in which ONC201 was combined with approved small molecule anticancer drugs. In multiple cancer cell populations, ONC201 synergized with diverse drug classes including the multi-kinase inhibitor sorafenib. Notably, combining ONC201 and sorafenib led to synergistic induction of TRAIL and its receptor DR5 along with a potent induction of cell death. In a mouse xenograft model of hepatocellular carcinoma, we demonstrated that ONC201 and sorafenib cooperatively and safely triggered tumor regressions. Overall, our results established a set of determinants for ONC201 sensitivity that may predict therapeutic response, particularly in settings of sorafenib co-treatment to enhance anticancer responses. PMID:25681273

  7. The apoptotic response in HCT116BAX-/- cancer cells becomes rapidly saturated with increasing expression of a GFP-BAX fusion protein

    International Nuclear Information System (INIS)

    Semaan, Sheila J; Nickells, Robert W

    2010-01-01

    Many chemotherapeutic agents promote tumor cell death by activating the intrinsic pathway of apoptosis. Intrinsic apoptosis involves permeabilization of the mitochondrial outer membrane and the release of cytochrome c, a process that is controlled by proteins of the BCL2 gene family. Chemoresistance is often associated with abnormalities in concentrations of BCL2 family proteins. Although stoichiometirc interactions between anti-apoptotic and BH3-only BCL2 family proteins have been well documented as affecting cell death, the association between changes in BAX concentration and intrinsic apoptosis are poorly understood. Exogenous GFP-murine Bax fusion constructs were transfected into BAX-deficient HCT116 cells. To titrate the expression of the fusion protein, GFP-BAX was cloned into a tetracycline sensitive expression cassette and cotransfected with a plasmid expressing the rtTA transcription factor into HCT116 BAX-/- cells. Linear expression of the fusion gene was induced with doxycycline and monitored by quantitative PCR and immunoblotting. Cell death was assayed by DAPI staining cells after exposure to indomethacin, and scoring nuclei for condensed chromatin and fragmented nuclei. HCT116 BAX-/- cells were resistant to indomethacin, but susceptibility could be recovered in cells expressing a GFP-BAX fusion protein. Titration of GFP-BAX expression revealed that the concentration of BAX required to induce a saturating apoptosis response from baseline, was rapidly achieved. Increased levels of GFP-BAX were unable to stimulate higher levels of cell death. Examination of GFP-BAX distribution before and after indomethacin treatment indicated that BAX protein did not form aggregates when present at sub-lethal concentrations. Within the limitations of this experimental system, BAX-dependent apoptosis in HCT116 cells exhibits an all-or-none response depending on the level of BAX protein present. The lack of BAX aggregation at sub-saturation levels suggests that the

  8. Defibrotide Stimulates Angiogenesis and Protects Endothelial Cells from Calcineurin Inhibitor-Induced Apoptosis via Upregulation of AKT/Bcl-xL.

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    Wang, Xiangmin; Pan, Bin; Hashimoto, Yuko; Ohkawara, Hiroshi; Xu, Kailin; Zeng, Lingyu; Ikezoe, Takayuki

    2018-01-01

    Sinusoidal obstruction syndrome is a life-threatening complication that can occur after haematopoietic stem cell transplantation. Defibrotide (DF) has been approved for the treatment of individuals with severe sinusoidal obstruction syndrome following haematopoietic stem cell transplantation in the European Union and the United States. However, the precise mechanisms by which DF protects endothelial cells remain to be elucidated. In this study, we found that DF stimulated angiogenesis in vitro and in vivo as assessed by vascular tube formation, scratch-wound repair and Matrigel plug assays. These effects were associated with an activation of pro-survival signalling pathways, including AKT (protein kinase B), ERK (extracellular signal-regulated kinases) and p38. More importantly, DF alleviated calcineurin inhibitor-induced growth inhibition and apoptosis of human umbilical vein endothelial cells and human hepatic sinusoidal endothelial cells in parallel with upregulation of anti-apoptotic protein B-cell lymphoma-extra-large (Bcl-xL), which was mediated by AKT (protein kinase B). Notably, these effects were abrogated when Bcl-xL was depleted by small interfering RNA (ribonucleic acid). In addition, DF counteracted calcineurin inhibitor-induced activation of nuclear factor-κB and Janus kinase 2 (JAK2)/Signal Transducer and Activator of Transcription 3 (STAT3) signalling and production of cytokines in vascular endothelial cell-derived EA.hy926 cells. Taken together, DF has pro-angiogenic, anti-apoptotic and anti-inflammatory effects on endothelial cells. DF is a potentially useful agent to prevent the development of, and treat individuals with, endothelial cell injury-related complications after haematopoietic stem cell transplantation. Schattauer GmbH Stuttgart.

  9. Hexavalent chromium-induced apoptosis of granulosa cells involves selective sub-cellular translocation of Bcl-2 members, ERK1/2 and p53

    International Nuclear Information System (INIS)

    Banu, Sakhila K.; Stanley, Jone A.; Lee, JeHoon; Stephen, Sam D.; Arosh, Joe A.; Hoyer, Patricia B.; Burghardt, Robert C.

    2011-01-01

    Hexavalent chromium (CrVI) has been widely used in industries throughout the world. Increased usage of CrVI and atmospheric emission of CrVI from catalytic converters of automobiles, and its improper disposal causes various health hazards including female infertility. Recently we have reported that lactational exposure to CrVI induced a delay/arrest in follicular development at the secondary follicular stage. In order to investigate the underlying mechanism, primary cultures of rat granulosa cells were treated with 10 μM potassium dichromate (CrVI) for 12 and 24 h, with or without vitamin C pre-treatment for 24 h. The effects of CrVI on intrinsic apoptotic pathway(s) were investigated. Our data indicated that CrVI: (i) induced DNA fragmentation and increased apoptosis, (ii) increased cytochrome c release from the mitochondria to cytosol, (iii) downregulated anti-apoptotic Bcl-2, Bcl-XL, HSP70 and HSP90; upregulated pro-apoptotic BAX and BAD, (iv) altered translocation of Bcl-2, Bcl-XL, BAX, BAD, HSP70 and HSP90 to the mitochondria, (v) upregulated p-ERK and p-JNK, and selectively translocated p-ERK to the mitochondria and nucleus, (vi) activated caspase-3 and PARP, and (vii) increased phosphorylation of p53 at ser-6, ser-9, ser-15, ser-20, ser-37, ser-46 and ser-392, increased p53 transcriptional activation, and downregulated MDM-2. Vitamin C pre-treatment mitigated CrVI effects on apoptosis and related pathways. Our study, for the first time provides a clear insight into the effect of CrVI on multiple pathways that lead to apoptosis of granulosa cells which could be mitigated by vitamin C.

  10. Bcl-2 protein expression in mucoepidermoid carcinoma of salivary glands: a single institution experience.

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    Janjua, Omer Sefvan; Qureshi, Sana Mehmood; Khan, Tariq Sarfraz; Alamgir, Wajiha

    2012-01-01

    Mucoepidermoid carcinoma is the most common salivary gland tumor with varying behavior among different histopathological grades. The objective of this study was to determine the expression of Bcl-2 protein in mucoepidermoid carcinoma (MEC) and to correlate with histological grades. The records of 40 cases of MEC were collected from the histopathology department. Fresh slides were prepared and fresh diagnoses were made using the grading criteria for MEC. Immunohistochemical markers for Bcl-2 were applied and the results analyzed using the chi-square test. Of 40 cases, 20 were males and 20 were females. The range in age of the patients was 6 to 67 years mean (SD) was 42.6 (1.85) years. Twenty-two were low grade (55%), 11 high grade (27.5%) and 7 (17.5%) were intermediate grade MEC. Among these 40 cases, Bcl-2 expression was positive in 24 cases and negative in 16 cases. In 22 cases of low-grade MEC, 19 were positive while only 3 were negative. In high-grade tumors, all 11 cases were found to have a negative expression of Bcl-2 protein. In intermediate-grade MEC, 5 cases showed positive expression while only 2 cases showed negative expression. Bcl-2 protein expression showed positive expression in low-grade and negative expression in high-grade MEC. Intermediate grade showed more than 50% positive results for Bcl-2. Correlation between grades of MEC and expression of Bcl-2 is statistically significant and can be used for the depicting the prognosis of MEC along with other prognostic and clinico-pathological parameters.

  11. [Distribution of Pathogenic Bacteria and Its Influence on Expression of BCL-2 and BAX Protein after HSCT in the Patients with Hematological Malignancies].

    Science.gov (United States)

    Su, Gui-Ping; Dai, Yan; Huang, Lai-Quan; Jiang, Yi-Zhi; Geng, Liang-Quan; Ding, Kai-Yang; Huang, Dong-Ping

    2016-06-01

    To investigate the distribution of pathogenic bacteria in the patients with hematologic malignancies received hematopoietic stem cell transplantation (HSCT) and its influence on the expression of BCL-2 and BAX proteins. The clinical data of 64 patients with malignant lymphoma (ML) received auto-HSCT from January 2011 to December 2015 in our hospital were analyzed. On basis of post-treansplant infection, the patients were divided into infection group (36 cases) and non-infection group (28 cases). The distribution of pathogenic bacteria in 2 groups was identified, the T lymphocyte subsets of peripheral blood, expression level of apoptotic proteins and C-reaction protein (CRP) in 2 group were detected. Thirty-six strains of pathogenic bacteria were isolated from 36 case of hematological malignancy after HSCT, including 24 strains of Gram-negative bacteria (66.67%) with predominamce of klebsiella pneumoniae (19.44%). The periperal blood CD4+ (t=2.637, Ppathogenic bacteria infecting ML patients after HSCT were mainly Gram-negative bacteria. The post-transplant infection can promote the expression up-regulation of related inflammatory factors and apoptotic proteins. The pathogens may be involved in cell apoptisis that provides a new strategy to treat the hematologic malignancies.

  12. Huperzine A ameliorates damage induced by acute myocardial infarction in rats through antioxidant, anti-apoptotic and anti-inflammatory mechanisms.

    Science.gov (United States)

    Sui, Xizhong; Gao, Changqing

    2014-01-01

    Huperzine A (HupA), an alkaloid used in traditional Chinese medicine and isolated from Huperzia serrata, has been shown to possess diverse biological activities. The present study was undertaken to evaluate the cardioprotective potential of HupA in myocardial ischemic damage using a rat model of acute myocardial infarction. HupA significantly diminished the infarct size and inhibited the activities of myocardial enzymes, including creatine kinase (CK), the MB isoenzyme of creatine kinase (CK-MB), lactate dehydrogenase (LDH) and cardiac troponin T (cTnT). A significantly reduced activity of malondialdehyde (MDA) and elevated activities of superoxide dismutase (SOD), of the non-enzymatic scavenger enzyme, glutathione (GSH), as well as of glutathione peroxidase (GSH-PX) were found in the HupA-treated groups. Furthermore, decreased protein levels of caspase-3 and Bax, and increased levels of Bcl-2 were observed in the infarcted hearts of the rats treated with various concentrations of HupA. In addition, treatment with HupA markedly inhibited the expression of the nuclear factor-κB (NF-κB) subunit p65, tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β). These findings suggest that the cardioprotective potential of HupA is associated with its antioxidant, anti-apoptotic and anti-inflammatory properties in acute myocardial infarction in rats.

  13. NDV-induced apoptosis in absence of Bax; evidence of involvement of apoptotic proteins upstream of mitochondria

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    Molouki Aidin

    2012-08-01

    Full Text Available Abstract Background Recently it was shown that following infection of HeLa cells with Newcastle disease virus (NDV, the matrix (M protein binds to Bax and subsequently the intrinsic pathway of apoptosis is activated. Moreover, there was very little alteration on mRNA and protein levels of Bax and Bcl-2 after infection with NDV. Finding In order to further investigate the role of members of the Bcl-2 family, Bax-knockout and wild-type HCT116 cells were infected with NDV strain AF2240. Although both cells underwent apoptosis through the activation of the intrinsic pathway and the release of cytochrome c from mitochondria, the percentage of dead Bax-knockout cells was significantly lower than wt cells (more than 10% at 48 h post-infection. In a parallel experiment, the effect of NDV on HT29 cells, that are originally Bcl-2-free, was studied. Apoptosis in HT29 cells was associated with Bax redistribution from cytoplasm to mitochondria, similar to that of HeLa and wt HCT116 cells. Conclusion Although the presence of Bax during NDV-induced apoptosis contributes to a faster cell death, it was concluded that other apoptotic protein(s upstream of mitochondria are also involved since cancer cells die whether in the presence or absence of Bax. Therefore, the classic Bax/Bcl-2 ratio may not be a major determinant in NDV-induced apoptosis.

  14. Atractylenolide-I Protects Human SH-SY5Y Cells from 1-Methyl-4-Phenylpyridinium-Induced Apoptotic Cell Death

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    Sandeep Vasant More

    2017-05-01

    Full Text Available Oxidative stress and apoptosis are the major mechanisms that induce dopaminergic cell death. Our study investigates the protective effects of atractylenolide-I (ATR-I on 1-methyl-4-phenylpyridinium (MPP+-induced cytotoxicity in human dopaminergic SH-SY5Y cells, as well as its underlying mechanism. Our experimental data indicates that ATR-I significantly inhibits the loss of cell viability induced by MPP+ in SH-SY5Y cells. To further unravel the mechanism, we examined the effect of ATR-I on MPP+-induced apoptotic cell death characterized by an increase in the Bax/Bcl-2 mRNA ratio, the release of cytochrome-c, and the activation of caspase-3 leading to elevated levels of cleaved poly(ADP-ribose polymerase (PARP resulting in SH-SY5Y cell death. Our results demonstrated that ATR-I decreases the level of pro-apoptotic proteins induced by MPP+ and also restored Bax/Bcl-2 mRNA levels, which are critical for inducing apoptosis. In addition, ATR-I demonstrated a significant increase in the protein expression of heme-oxygenase in MPP+-treated SH-SY5Y cells. These results suggest that the pharmacological effect of ATR-I may be, at least in part, caused by the reduction in pro-apoptotic signals and also by induction of anti-oxidant protein.

  15. Suppression of chondrosarcoma cells by 15-deoxy-Δ12,14-prostaglandin J2 is associated with altered expression of Bax/Bcl-xL and p21

    International Nuclear Information System (INIS)

    Shen, Zheng-Nan; Nishida, Keiichiro; Doi, Hideyuki; Oohashi, Toshitaka; Hirohata, Satoshi; Ozaki, Toshifumi; Yoshida, Aki; Ninomiya, Yoshifumi; Inoue, Hajime

    2005-01-01

    We previously reported that 15-deoxy-Δ 12,14 -prostaglandin J 2 (15d-PGJ 2 ), the most potent agonist for peroxisome proliferator-activated receptor γ (PPARγ), induces apoptosis of human chondrosarcoma cell line OUMS-27. The current study aimed to explore the mechanism of 15d-PGJ 2 -induced apoptosis and inhibition of cell proliferation in OUMS-27 cells. The preliminary results of cDNA microarray analysis showed the down-regulation of anti-apoptotic Bcl-xL and up-regulation of pro-apoptotic Bax in the process of 15d-PGJ 2 -induced apoptosis. These changes were further confirmed at mRNA and protein levels by RT-PCR and Western blot analysis, respectively. Among cyclin-dependent kinase inhibitors, p21 was induced and up-regulated by 15d-PGJ 2 , but p16 and p27 were not changed, suggesting that the involvement of p21 in inhibition of cell proliferation. Activation of caspase-3 by 15d-PGJ 2 was partly, but not completely, blocked by PPARγ antagonist (GW9662) suggesting the 15d-PGJ 2 exerted its effect by PPARγ-dependent and -independent pathways. Interestingly, immunohistochemical study on human chondrosarcoma samples revealed that Bcl-xL is frequently expressed by tumor cells. The results of the current study suggest that the potential ability of 15d-PGJ 2 in regulation of cell cycle and inhibition of Bcl-xL expression might be beneficial in the development of novel pharmacological agents for chondrosarcoma

  16. Clusterin silencing sensitizes pancreatic cancer MIA-PaCa-2 cells to gmcitabine via regulation of NF-kB/Bcl-2 signaling.

    Science.gov (United States)

    Xu, Miao; Chen, Xiumei; Han, Yanling; Ma, Chunqing; Ma, Lin; Li, Shirong

    2015-01-01

    Clusterin (CLU) is known as a multifunctional protein involved in a variety of physiological processes including lipid transport, epithelial cell differentiation, tumorigenesis, and apoptosis. Our recent study has demonstrated that knockdown of clusterin sensitizes pancreatic cancer cell lines to gmcitabine treatment. However the details of this survival mechanism remain undefined. Of the various downstream targets of CLU, we examined activation of the NF-kB transcription factor and subsequent transcriptional regulation of BCL-2 gene in pancreatic cancer cell MIA-PaCa-2. The MIA-PaCa-2 cells were transfected with an antisense oligonucleotide (ASO) against clusterin, which led to a decreased protein level of the antiapoptotic gene BCL-2. Furthermore, inhibition of CLU decreased the function of NF-kB, which is capable of transcriptional regulation of the BCL-2 gene. Inhibiting this pathway increased the apoptotic effect of gmcitabine chemotherapy. Re-activated NF-kB resulted in attenuation of ASO-induced effects, followed by the bcl-2 upregulation, and bcl-2 re-inhibition resulted in attenuation of Re-activated NF-kB -induced effects. Animals injected with ASO CLU in MIA-PaCa-2 cells combined with gmcitabine treatment had fewer tumors than gmcitabine or ASO CLU alone. These findings suggest that knockdown of CLU sensitized MIA-PaCa-2 cells to gmcitabine chemotherapy through modulating NF-Kb/bcl-2 pathway.

  17. Different immunophenotypical apoptotic profiles characterise megakaryocytes of essential thrombocythaemia and primary myelofibrosis.

    Science.gov (United States)

    Florena, A M; Tripodo, C; Di Bernardo, A; Iannitto, E; Guarnotta, C; Porcasi, R; Ingrao, S; Abbadessa, V; Franco, V

    2009-04-01

    Essential thrombocythaemia (ET) and primary myelofibrosis (PMF) share some clinical and pathological features, but show different biological behaviour and prognosis. The latest contributions to understanding the nature of these disorders have focused on bone marrow microenvironment remodelling and proliferative stress, recognising megakaryocytes (MKCs) as "key-cells". The aim of this study was to investigate the apoptotic profile of ET and PMF MKCs in order to further characterise the biology of these disorders. Bone marrow biopsy samples from 30 patients with ET, and 30 patients with PMF, were immunophenotypically studied for the expression of pro-apoptotic (Fas, Fas-L, Bax, Bad) and anti-apoptotic (Bcl-2, Bcl-XL, hTERT (human telomerase reverse transcriptase)) molecules and the "executioner" molecule caspase-3. The fraction of MKCs undergoing apoptosis was assessed by deoxynucleotidyl transferase-mediated dUTP nick-end labelling. Only the mitochondrial pathway seemed to be involved in MKC apoptosis. The anti-apoptotic molecule Bcl-XL was predominantly found in ET MKCs (50.5% of ET MKCs versus 35% of PMF MKCs; p = 0.036), while pro-apoptotic molecules Bax and Bad showed a prevalent expression in PMF MKCs (30.5% of ET MKCs versus 55% of PMF MKCs; 41% of ET MKCs versus 52% of PMF MKCs; p = 0.001 and p = 0.068, respectively). A significant fraction of PMF MKCs were committed to apoptosis according to caspase-3 expression and TUNEL, while only few ET cells were committed to apoptosis. hTERT was significantly more expressed in PMF (32% of ET MKCs versus 46% of PMF MKCs; p = 0.022), in agreement with the proliferative nature of this disease. It was found that ET and PMF MKCs, which barely differ in terms of morphology and aggregation, are characterised by markedly different apoptotic profiles. The rather high apoptotic fraction of PMF was able to support the fibrotic nature of this process, while the anti-apoptotic profile of ET cells fits well with their "steady

  18. Anti-apoptotic effect of heat shock protein 90 on hypoxia-mediated cardiomyocyte damage is mediated via the phosphatidylinositol 3-kinase/AKT pathway.

    Science.gov (United States)

    Wang, Wei; Peng, Yizhi; Wang, Yuanyuan; Zhao, Xiaohui; Yuan, Zhiqiang

    2009-09-01

    1. Hypoxia-induced cardiomyocyte apoptosis contributes significantly to cardiac dysfunction following trauma, shock and burn injury. There is evidence that heat shock protein (HSP) 90 is anti-apoptotic in cardiomyocytes subjected to a variety of apoptotic stimuli. Because HSP90 acts as an upstream regulator of the serine/threonine protein kinase Akt survival pathway during cellular stress, we hypothesized that HSP90 exerts a cardioprotective effect via the phosphatidylinositol 3-kinase (PI3-K)/Akt pathway. 2. Neonatal rat cardiomyocytes were subjected to normoxia or hypoxia in the absence or presence of the HSP90 inhibitor geldanamycin (1 μg/mL). Cardiomyocyte apoptosis was assessed by release of lactate dehydrogenase (LDH), terminal deoxyribonucleotidyl transferase-mediated dUTP-digoxigenin nick end-labelling (TUNEL) staining and caspase 3 activity. Expression of HSP90, Akt, Bad and cytochrome c release was determined by western blot analysis. 3. Following exposure of cells to hypoxia, HSP90 was markedly elevated in a time-dependent manner, reaching a peak at 6 h (eightfold increase). Geldanamycin significantly increased hypoxia-induced release of LDH by 114%, the percentage of apoptotic cardiomyocytes by 102% and caspase 3 activity by 78%. Pretreatment of cells with geldanamycin also suppressed phosphorylation of both Akt and its downstream target Bad, but promoted the mitochondrial release of cytochrome c. 4. In conclusion, HSP90 activity is enhanced in cardiomyocytes following hypoxic insult. The anti-apoptotic effect of HSP90 on cardiomyocytes subjected to hypoxia is mediated, at least in part, by the PI3-K/Akt pathway. Key words: apoptosis, cardiomyocyte, heart failure, heat shock protein 90, hypoxia, phosphatidylinositol 3-kinase/Akt signalling pathway, serine/threonine protein kinase Akt.

  19. Increased expression of Bcl-2 during mucous cell metaplasia induced by endotoxin and ozone

    Energy Technology Data Exchange (ETDEWEB)

    Tesfaigzi, J.; Ray, L.M.; Hotchkiss, J.A. [Michigan State Univ., East Lansing, MI (United States)] [and others

    1995-12-01

    Apoptosis or programmed cell death is accompanied by characteristic morphological changes that distinguish apoptosis from other forms of cell death. These changes include DNA fragmentation, chromatin condensation, cell shrinkage, cell surface pseudopodia, and finally the cellular collapse into membrane-enclosed apoptotic bodies which are rapidly engulfed by macrophages or neighboring cells. Although the morphological features of apoptotic cells are well studied, the biochemical events that control apoptosis are not understood. Programmed cell death is triggered by a variety of pathways that are initiated by different stimuli including noxious agents, DNA damage, the activation of TNF receptors, or the withdrawl of growth factors. The central process of programmed cell death involves a cascade of biochemical events that begins with the initiation of a family of cysteine proteases, including the interleukin-1-{Beta}-converting enzyme, CPP-32, and Apopain. The ratio of Bax, a death-inducer gene, to Bcl-2, an apoptosis suppressor gene, determines whether or not the main apoptotic pathyway is blocked. Apoptosis is suppressed if the ratio of Bcl-2/Bax is > 1, and cells undergo apoptosis if the ratio is < 1. The overexpression of Bcl-2 has been shown to block the apoptotic program triggered by a variety of agents. Therefore, Bcl-2 must be involved in blocking the central pathway of the cell death program. In conclusion, this study showed that high levels of Bcl-2 were detected in some mucous cells at specific time points during mucous cell metaplasia, and this expression was reduced at later time points or was absent after remodeling of this epithelium.

  20. Apoptotic potential and cell sensitivity to fractionated radiotherapy

    International Nuclear Information System (INIS)

    Rupnow, Brent A.; Murtha, Albert D.; Alarcon, Rodolfo M.; Giaccia, Amato J.; Knox, Susan J.

    1997-01-01

    Purpose/Objective: At present, the relationship between sensitivity to radiation-induced apoptosis and overall cellular radiosensitivity remains unclear. In particular, the relationship of apoptotic sensitivity to the survival of cells following fractionated irradiation has not been well studied. The purpose of the present study was to determine if increasing cell sensitivity to radiation-induced apoptosis would result in decreased clonogenic survival following single dose and fractionated irradiation in vitro. Materials and Methods: To address this, we chose a cell line (Rat-1MycER) in which the sensitivity to radiation-induced apoptosis could be altered by switching on or off the activity of a conditional c-Myc allele (c-MycER). The c-MycER construct expresses a full length c-Myc protein fused to a modified hormone binding domain of the estrogen receptor. Only in the presence of the estrogen analog 4-hydroxytamoxifen (4HT), does the conditional c-MycER become active. Apoptosis following irradiation in these cells (with and without c-MycER activation) was analyzed by flow cytometry to determine the percentage of cells undergoing apoptosis following various radiation doses and at different times after irradiation. Additionally, clonogenic survival analysis was performed following single radiation doses from 0 to 10 Gy and following five fractions of 2 or 4 Gy each. Survival of cells with and without c-MycER activation was compared. Furthermore, the effect of overexpressing the anti-apoptotic Bcl-2 gene on apoptosis induction and clonogenic survival of these cells was examined. Results: Rat-1MycER cells were strongly sensitized to radiation-induced apoptosis in a dose and time dependent manner when MycER was activated relative to cells treated without c-MycER activation. This c-Myc-mediated sensitivity to radiation-induced apoptosis was suppressed by overexpression of the anti-apoptotic protein Bcl-2. In addition to increasing apoptosis, activating c-MycER prior to

  1. Deletion of AU-rich elements within the Bcl2 3'UTR reduces protein expression and B cell survival in vivo.

    Directory of Open Access Journals (Sweden)

    Manuel D Díaz-Muñoz

    Full Text Available Post-transcriptional mRNA regulation by RNA binding proteins (RBPs associated with AU-rich elements (AREs present in the 3' untranslated region (3'UTR of specific mRNAs modulates transcript stability and translation in eukaryotic cells. Here we have functionally characterised the importance of the AREs present within the Bcl2 3'UTR in order to maintain Bcl2 expression. Gene targeting deletion of 300 nucleotides of the Bcl2 3'UTR rich in AREs diminishes Bcl2 mRNA stability and protein levels in primary B cells, decreasing cell lifespan. Generation of chimeric mice indicates that Bcl2-ARE∆/∆ B cells have an intrinsic competitive disadvantage compared to wild type cells. Biochemical assays and predictions using a bioinformatics approach show that several RBPs bind to the Bcl2 AREs, including AUF1 and HuR proteins. Altogether, association of RBPs to Bcl2 AREs contributes to Bcl2 protein expression by stabilizing Bcl2 mRNA and promotes B cell maintenance.

  2. Astro research fellowship: the role of bcl-2 and glutathione in an antioxidant pathway to prevent radiation-induced apoptosis

    International Nuclear Information System (INIS)

    Vlachaki, Maria T.; Meyn, Raymond E.

    1998-01-01

    Purpose: The expression of the bcl-2 proto-oncogene has been associated with resistance to radiation-induced apoptosis. There is evidence that the bcl-2 protein acts in an antioxidant pathway to block the effects of reactive oxygen species that mediate apoptosis possibly by increasing the levels of intracellular glutathione. Our hypothesis is that pretreatment of radiation-sensitive cells, known to lack bcl-2 expression, with antioxidants will reduce radiation-induced apoptosis. For this purpose, the apoptotic response to radiation and the intracellular levels of GSH were tested before and after pretreatment with antioxidants in two murine lymphoma cell lines, a radiation-resistant, bcl-2- expressing (LY-ar) line and a radiation-sensitive, non-bcl-2-expressing (LY-as) line. Methods and Materials: LY-ar and LY-as cells were irradiated at 0,1,2,3, and 4 hours before collection. The intracellular levels of reduced (GSH) and oxidized (GSSG) glutathione were determined by the use of the fluorescent dye o-phthalaldehyde. LY-as cells were treated with GSH ethyl-ester for 1 and 2 hours after irradiation. Apoptotic response was measured by the DNA fragmentation assay. The radiation dose was 2.5 Gy. Results: After irradiation, the apoptotic rate of LY-ar and LY-as cells was 10-20% and 50-70% respectively. LY-ar cells had higher intracellular GSH and GSSG levels compared to LY-as cells by 69.9% and 91.9% respectively and the GSH/GSSG ratio in LY-ar and LY-as cells was 15.09 and 17.09 respectively. GSH levels did not change during the first 2 hours after irradiation; however, there was a 49% and 84% reduction at 3 and 4 hours after irradiation, respectively, times at which the LY-as cells have already fragmented their DNA. Treatment of LY-as cells with GSH ethyl-ester at a concentration of 7 mM for 1 and 2 hours resulted in 70% and 231% increases in the intracellular GSH levels respectively. Treatment of LY-as cells with GSH ethyl-ester for 1 and 2 hours also conferred a 25

  3. The role of apoptosis repressor with a CARD domain (ARC) in the therapeutic resistance of renal cell carcinoma (RCC): the crucial role of ARC in the inhibition of extrinsic and intrinsic apoptotic signalling.

    Science.gov (United States)

    Toth, Csaba; Funke, Sarah; Nitsche, Vanessa; Liverts, Anna; Zlachevska, Viktoriya; Gasis, Marcia; Wiek, Constanze; Hanenberg, Helmut; Mahotka, Csaba; Schirmacher, Peter; Heikaus, Sebastian

    2017-05-02

    Renal cell carcinomas (RCCs) display broad resistance against conventional radio- and chemotherapies, which is due at least in part to impairments in both extrinsic and intrinsic apoptotic pathways. One important anti-apoptotic factor that is strongly overexpressed in RCCs and known to inhibit both apoptotic pathways is ARC (apoptosis repressor with a CARD domain). Expression and subcellular distribution of ARC in RCC tissue samples and RCC cell lines were determined by immunohistochemistry and fluorescent immunohistochemistry, respectively. Extrinsic and intrinsic apoptosis signalling were induced by TRAIL (TNF-related apoptosis-inducing ligand), ABT-263 or topotecan. ARC knock-down was performed in clearCa-12 cells using lentiviral transduction of pGIPZ. shRNAmir constructs. Extrinsic respectively intrinsic apoptosis were induced by TRAIL (TNF-related apoptosis-inducing ligand), ABT263 or topotecan. Potential synergistic effects were tested by pre-treatment with topotecan and subsequent treatment with ABT263. Activation of different caspases and mitochondrial depolarisation (JC-1 staining) were analysed by flow cytometry. Protein expression of Bcl-2 family members and ARC in RCC cell lines was measured by Western blotting. Statistical analysis was performed by Student's t-test. Regarding the extrinsic pathway, ARC knockdown strongly enhanced TRAIL-induced apoptosis by increasing the activation level of caspase-8. Regarding the intrinsic pathway, ARC, which was only weakly expressed in the nuclei of RCCs in vivo, exerted its anti-apoptotic effect by impairing mitochondrial activation rather than inhibiting p53. Topotecan- and ABT-263-induced apoptosis was strongly enhanced following ARC knockdown in RCC cell lines. In addition, topotecan pre-treatment enhanced ABT-263-induced apoptosis and this effect was amplified in ARC-knockdown cells. Taken together, our results are the first to demonstrate the importance of ARC protein in the inhibition of both the extrinsic

  4. Anti-apoptotic effect of insulin in the control of cell death and neurologic deficit after acute spinal cord injury in rats.

    Science.gov (United States)

    Wu, Xing-Huo; Yang, Shu-Hua; Duan, De-Yu; Cheng, Heng-Hui; Bao, Yu-Ting; Zhang, Yukun

    2007-09-01

    Recent studies confirmed that the new cell survival signal pathway of Insulin-PI3K-Akt exerted cyto-protective actions involving anti-apoptosis. This study was undertaken to investigate the potential neuroprotective effects of insulin in the pathogenesis of spinal cord injury (SCI) and evaluate its therapeutic effects in adult rats. SCI was produced by extradural compression using modified Allen's stall with damage energy of 40 g-cm force. One group of rats was subjected to SCI in combination with the administration of recombinant human insulin dissolved in 50% glucose solution at the dose of 1 IU/kg day, for 7 days. At the same time, another group of rats was subjected to SCI in combination with the administration of an equal volume of sterile saline solution. Functional recovery was evaluated using open-field walking, inclined plane tests, and motor evoked potentials (MEPs) during the first 14 days post-trauma. Levels of protein for B-cell lymphoma/leukemia-2 gene (Bcl-2), Caspase-3, inducible nitric oxide synthase (iNOS), and cyclooxygenase-2 (COX-2) were quantified in the injured spinal cord by Western blot analysis. Neuronal apoptosis was detected by TUNEL, and spinal cord blood flow (SCBF) was measured by laser-Doppler flowmetry (LDF). Ultimately, the data established the effectiveness of insulin treatment in improving neurologic recovery, increasing the expression of anti-apoptotic bcl-2 proteins, inhibiting caspase-3 expression decreasing neuronal apoptosis, reducing the expression of proinflammatory cytokines iNOS and COX-2, and ameliorating microcirculation of injured spinal cord after moderate contusive SCI in rats. In sum, this study reported the beneficial effects of insulin in the treatment of SCI, with the suggestion that insulin should be considered as a potential therapeutic agent.

  5. Apoptosis and the BCL-2 gene family - patterns of expression and prognostic value in STAGE I and II follicular center lymphoma

    International Nuclear Information System (INIS)

    Logsdon, Mark D.; Meyn, Raymond E.; Besa, Pelayo C.; Pugh, William C.; Stephens, L. Clifton; Peters, Lester J.; Milas, Luka; Cox, James D.; Cabanillas, Fernando; Brisbay, Shawn; Andersen, Margret; McDonnell, Timothy J.

    1999-01-01

    Purpose: The prognostic significance of spontaneous levels of apoptosis and Bcl-2, Bax, and Bcl-x protein expression in follicular center lymphoma (FCL) is unknown. The objectives of this retrospective study were (1) to investigate the relationship between pretreatment apoptosis levels and long-term treatment outcome in patients with Stage I and II FCL; (2) to define the incidence and patterns of Bax and Bcl-x protein expression in human FC; and (3) to determine the relationship of Bcl-2, Bax, and Bcl-x expression with spontaneous apoptosis levels and clinical outcome in localized FCL. Methods and Materials: Between 1974 and 1988, 144 patients with Stage I or II FCL were treated. Hematoxylin and eosin (H and E) stained tissue sections of pretreatment specimens were retrieved for 96 patients. Treatment consisted of regional radiation therapy (XRT) for 25 patients, combined modality therapy (CMT) consisting of combination chemotherapy and XRT for 57 patients, and other treatments for 14 patients. Median follow-up for living patients was nearly 12 years. The apoptotic index (AI) was calculated by dividing the number of apoptotic cells by the total number of cells counted and multiplying by 100. Expression of Bcl-2, Bax, and Bcl-x proteins was assessed using immunohistochemistry. Results: The mean and median AI values for the entire group were 0.53 and 0.4, respectively (range: 0-5.2). The AI strongly correlated with cytologic grade, with mean AI values of 0.25 for grade 1, 0.56 for grade 2, and 0.84 for grade 3 (p < 0.0005; Kendall correlation). A positive correlation was present between grouped AI and grouped mitotic index (MI) (p = 0.014). For patients treated with CMT, an AI < 0.4 correlated with improved freedom from relapse (FFR) (p = 0.0145) and overall survival (OS) (p = 0.0081). An AI < 0.4 did not correlate with clinical outcome for the entire cohort or for patients receiving XRT only. Staining of tumor follicles for the Bcl-2 protein was positive, variable

  6. The role of the expression of bcl-2, p53 gene in tamoxifen-induced apoptosis of breast cancer cells and its relationship with hormone receptor status

    Energy Technology Data Exchange (ETDEWEB)

    Noh, Woo Chul; Ham, Yong Ho [Korea Cancer Center Hospital, Seoul (Korea, Republic of)

    1998-01-01

    To investigate the relationship of bcl-2, p53, ER and tamoxifen-induced apoptosis of breast cancer cells, MCF-7 (ER+/bcl-2+/p53-) and MB MDA 468 (ER-/bcl-2-/p53+) cell line were cultured in estrogen-free condition. E2(10`-`9M) and tamoxifen (10`-`5M) were added to the media. The changes of bcl-2 and mutant p53 protein were checked by Western blot and apoptosis were measured by flowcytometry. In MCF-7 cells, we found that treatment with tamoxifen resulted in a decrease in bcl-2 protein level, but produced no change in mutant p53. In MB MDA 468 cell however, there were no changes of bcl-2 and mutant p53 protein level when E2 or tamoxifen were added. Apoptotic cells increased with time-dependent pattern when tamoxifen was added to MCF-7 cells. According to these result, ER+/blc-2+/mutant p53- cells, when treated with tamoxifen, were converted into bcl-2/mutant p53- cells which were more prone to apoptosis than bcl-2-/mutant p53+ cells. The paradoxical correlation of bcl-2 and ER which had been observed in clinical studies might be explained with this results and bcl-2 protein seems to be one of important factors that can predict the effect of hormone therapy. (author). 26 refs., 5 figs

  7. The role of the expression of bcl-2, p53 gene in tamoxifen-induced apoptosis of breast cancer cells and its relationship with hormone receptor status

    International Nuclear Information System (INIS)

    Noh, Woo Chul; Ham, Yong Ho

    1998-01-01

    To investigate the relationship of bcl-2, p53, ER and tamoxifen-induced apoptosis of breast cancer cells, MCF-7 (ER+/bcl-2+/p53-) and MB MDA 468 (ER-/bcl-2-/p53+) cell line were cultured in estrogen-free condition. E2(10'-'9M) and tamoxifen (10'-'5M) were added to the media. The changes of bcl-2 and mutant p53 protein were checked by Western blot and apoptosis were measured by flowcytometry. In MCF-7 cells, we found that treatment with tamoxifen resulted in a decrease in bcl-2 protein level, but produced no change in mutant p53. In MB MDA 468 cell however, there were no changes of bcl-2 and mutant p53 protein level when E2 or tamoxifen were added. Apoptotic cells increased with time-dependent pattern when tamoxifen was added to MCF-7 cells. According to these result, ER+/blc-2+/mutant p53- cells, when treated with tamoxifen, were converted into bcl-2/mutant p53- cells which were more prone to apoptosis than bcl-2-/mutant p53+ cells. The paradoxical correlation of bcl-2 and ER which had been observed in clinical studies might be explained with this results and bcl-2 protein seems to be one of important factors that can predict the effect of hormone therapy. (author). 26 refs., 5 figs

  8. Stress-induced activation of the brainstem Bcl-xL gene expression in rats treated with fluoxetine: correlations with serotonin metabolism and depressive-like behavior.

    Science.gov (United States)

    Shishkina, Galina T; Kalinina, Tatyana S; Berezova, Inna V; Dygalo, Nikolay N

    2012-01-01

    Mechanisms underlying stress-induced depression and antidepressant drug action were shown to involve alterations in serotonergic (5-HT) neurotransmission and expression of genes coding for proteins associated with neurotrophic signaling pathways and cell-survival in the hippocampus and cortex. Expression of these genes in the brainstem containing 5-HT neurons may also be related to vulnerability or resilience to stress-related psychopathology. Here we investigated 5-HT markers and expression of genes for Brain-Derived Neurotrophic Factor (BDNF) and apoptotic proteins in the brainstem in relation to swim stress-induced behavioral despair. We found that anti-apoptotic Bcl-xL gene is sensitive to stress during the course of fluoxetine administration. Responsiveness of this gene to stress appeared concomitantly with an antidepressant-like effect of fluoxetine in the forced swim test. Bcl-xL transcript levels showed negative correlations with duration of immobility in the test and 5-HT turnover in the brainstem. In contrast, BDNF and pro-apoptotic protein Bax mRNA levels were unchanged by either fluoxetine or stress, suggesting specificity of Bcl-xL gene responses to these treatments. We also found that the levels of mRNAs for tryptophan hydroxylase-2 (TPH2) and 5-HT transporter (5-HTT) were significantly down-regulated following prolonged treatment with fluoxetine, but were not affected by stress. Unlike TPH2 and 5-HTT, 5-HT1A receptor mRNA levels were not altered by fluoxetine but significantly increased in response to swim stress. These data show that long-term fluoxetine treatment leads to changes in 5-HT and Bcl-xL responses to stress associated with antidepressant-like effects of the drug. This article is part of a Special Issue entitled 'Anxiety and Depression'. Copyright © 2011 Elsevier Ltd. All rights reserved.

  9. The anti-apoptotic effect of fluid mechanics preconditioning by cells membrane and mitochondria in rats brain microvascular endothelial cells.

    Science.gov (United States)

    Tian, Shan; Zhu, Fengping; Hu, Ruiping; Tian, Song; Chen, Xingxing; Lou, Dan; Cao, Bing; Chen, Qiulei; Li, Bai; Li, Fang; Bai, Yulong; Wu, Yi; Zhu, Yulian

    2018-01-01

    Exercise preconditioning is a simple and effective way to prevent ischemia. This paper further provided the mechanism in hemodynamic aspects at the cellular level. To study the anti-apoptotic effects of fluid mechanics preconditioning, Cultured rats brain microvascular endothelial cells were given fluid intervention in a parallel plate flow chamber before oxygen glucose deprivation. It showed that fluid mechanics preconditioning could inhibit the apoptosis of endothelial cells, and this process might be mediated by the shear stress activation of Tie-2 on cells membrane surface and Bcl-2 on the mitochondria surface. Copyright © 2017 Elsevier B.V. All rights reserved.

  10. Molecular basis for the interplay of apoptosis and proliferation mediated by Bcl-xL:Bim interactions in pancreatic cancer cells

    International Nuclear Information System (INIS)

    Abrol, Ravinder; Edderkaoui, Mouad; Goddard, William A.; Pandol, Stephen J.

    2012-01-01

    Highlights: ► Direct role of Bcl-2 protein interactions in cell proliferation is not clear. ► Designed Bcl-xL mutants show opposite effects on apoptosis and proliferation. ► Disrupting Bcl-xL:Bim interaction increased apoptosis in pancreatic cancer. ► Disrupting Bcl-xL:Bim interaction decreased proliferation in pancreatic cancer. ► Bcl-xL:Bim interaction can control both apoptosis and proliferation. -- Abstract: A major mechanism through which cancer cells avoid apoptosis is by promoting the association of anti-apoptotic members of the pro-survival Bcl-2 protein family (like Bcl-2 and Bcl-xL) with BH 3 domain-only proteins (like Bim and Bid). Apoptosis and cell proliferation have been shown to be linked for many cancers but the molecular basis for this link is far from understood. We have identified the Bcl-xL:Bim protein–protein interface as a direct regulator of proliferation and apoptosis in pancreatic cancer cells. We were able to predict and subsequently verify experimentally the effect of various Bcl-xL single-point mutants (at the position A142) on binding to Bim by structural analysis and computational modeling of the inter-residue interactions at the Bcl-xL:Bim protein–protein interface. The mutants A142N, A142Q, and A142Y decreased binding of Bim to Bcl-xL and A142S increased this binding. The Bcl-xL mutants, with decreased affinity for Bim, caused an increase in apoptosis and a corresponding decrease in cell proliferation. However, we could prevent these effects by introducing a small interfering RNA (siRNA) targeted at Bim. These results show a novel role played by the Bcl-xL:Bim interaction in regulating proliferation of pancreatic cancer cells at the expense of apoptosis. This study presents a physiologically relevant model of the Bcl-xL:Bim interface that can be used for rational therapeutic design for the inhibition of proliferation and cancer cell resistance to apoptosis.

  11. Seasonal variations of anti-/apoptotic and antioxidant proteins in the heart and gastrocnemius muscle of the water frog Pelophylax ridibundus.

    Science.gov (United States)

    Feidantsis, Konstantinos; Anestis, Andreas; Michaelidis, Basile

    2013-10-01

    In the present work we investigated the seasonal variations of apoptotic and antioxidant proteins in the heart and gastrocnemius muscle of the amphibian Pelophylax ridibundus. Particularly processes studied included the evaluation of hypoxia through the levels of transcriptional factor Hif-1α, of apoptosis through the determination of Bcl-2 and Bax, ubiquitin conjugates levels and the antioxidant defense through the determination of the activity of enzymes such as superoxide dismutase, catalase and glutathione peroxidase. Due to a general metabolic depression during overwintering, levels of the above mentioned proteins and enzymes are generally retained at low levels of expression and activity in the examined tissues of P. ridibundus. On the other hand recovery from overwintering induces oxidative stress, followed by increased levels of the specific proteins and enzymes. A milder up-regulation of antioxidant enzymes during overwintering probably prepares P. ridibundus for oxidative stress during arousal. The seasonal activation of these mechanisms seems to protect this species from these unfavourable conditions. Copyright © 2013 Elsevier Inc. All rights reserved.

  12. Cyanide-induced death of dopaminergic cells is mediated by uncoupling protein-2 up-regulation and reduced Bcl-2 expression

    International Nuclear Information System (INIS)

    Zhang, X.; Li, L.; Zhang, L.; Borowitz, J.L.; Isom, G.E.

    2009-01-01

    Cyanide is a potent inhibitor of mitochondrial oxidative metabolism and produces mitochondria-mediated death of dopaminergic neurons and sublethal intoxications that are associated with a Parkinson-like syndrome. Cyanide toxicity is enhanced when mitochondrial uncoupling is stimulated following up-regulation of uncoupling protein-2 (UCP-2). In this study, the role of a pro-survival protein, Bcl-2, in cyanide-mediated cell death was determined in a rat dopaminergic immortalized mesencephalic cell line (N27 cells). Following pharmacological up-regulation of UCP-2 by treatment with Wy14,643, cyanide reduced cellular Bcl-2 expression by increasing proteasomal degradation of the protein. The increased turnover of Bcl-2 was mediated by an increase of oxidative stress following UCP-2 up-regulation. The oxidative stress involved depletion of mitochondrial glutathione (mtGSH) and increased H 2 O 2 generation. Repletion of mtGSH by loading cells with glutathione ethyl ester reduced H 2 O 2 generation and in turn blocked the cyanide-induced decrease of Bcl-2. To determine if UCP-2 mediated the response, RNAi knock down was conducted. The RNAi decreased cyanide-induced depletion of mtGSH, reduced H 2 O 2 accumulation, and inhibited down-regulation of Bcl-2, thus blocking cell death. To confirm the role of Bcl-2 down-regulation in the cell death, it was shown that over-expression of Bcl-2 by cDNA transfection attenuated the enhancement of cyanide toxicity after UCP-2 up-regulation. It was concluded that UCP-2 up-regulation sensitizes cells to cyanide by increasing cellular oxidative stress, leading to an increase of Bcl-2 degradation. Then the reduced Bcl-2 levels sensitize the cells to cyanide-mediated cell death.

  13. Correlation of mammographical imaging signs with the expression of bcl-2 and bax proteins in breast cancer

    International Nuclear Information System (INIS)

    Zhang Yili; Du Hongwen; Zhang Yun; Zhang Yuelang; Kuang Fangjun; Guo Zuomin

    2004-01-01

    Objective: To discuss the correlation of mammographical imaging signs with the expression of bcl-2 and bax proteins in breast cancer for early diagnosis and forecast of its prognoses. Methods: Fifty-four breast cancers and 26 benign diseases were proved by pathologic methods and all cases underwent mammography. Immunohistochemical technique was used to measure the expression of bcl-2 and bax proteins in these tissues. The correlation of imaging signs with the expression of bcl-2 and bax proteins in breast cancer and benign lesion was analyzed. Results: The expression of bcl-2 or bax protein in the breast cancer was higher than that in breast benign diseases (χ 2 =15.116, 11.361, P 2 =10.358, 12.818, P 2 =10.996, 10.667, P 2 =10.405, P 2 =6.841, P<0.05). Conclusion: Some imaging signs of breast cancer were closely related to the expression of bcl-2 and bax proteins and these signs could reflect the biological behavior of tumor cells and prognoses. Therefore it could be helpful to the early diagnosis and treatment of breast cancer. (authors)

  14. In vitro anti-inflammatory and anti-cancer activities of Cuscuta reflexa Roxb.

    Science.gov (United States)

    Suresh, V; Sruthi, V; Padmaja, B; Asha, V V

    2011-04-12

    To determine anti-inflammatory and anti-cancer activities of Cuscuta reflexa in cell lines (in vitro). Anti-inflammatory activity of the water extract was analysed in vitro using lipopolysaccharide (LPS) induced inflammatory reactions in murine macrophage cell line RAW264.7. The expression of COX-2 and TNF-α genes involved in inflammation was analysed by SQ RT-PCR. EMSA was conducted to analyse the influence of the extract on NF-κB signalling. Anti-cancer activity was analysed on Hep3B cells by MTT assay, DAPI staining, annexin V staining and SQ-RT PCR analysis of BAX, Bcl-2, p53 and survivin. The extract down regulated LPS induced over expression of TNF-α and COX-2 in RAW264.7 cells; blocked NF-κB binding to its motifs and induced apoptosis in Hep3B cells as evidenced from MTT, DAPI staining and annexin V staining assays. The extract up regulated pro-apoptotic factors BAX and p53, and down regulated anti-apoptotic factors Bcl-2 and survivin. The study showed that Cuscuta reflexa inhibits LPS induced inflammatory responses in RAW264.7 cells through interplay of TNF-α, COX-2 and NF-κB signalling. It induced apoptosis in Hep3B cells through the up regulation of p53, BAX and down regulation of Bcl-2 and survivin. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

  15. 2'-Hydroxyflavanone: A novel strategy for targeting breast cancer.

    Science.gov (United States)

    Singhal, Jyotsana; Nagaprashantha, Lokesh; Chikara, Shireen; Awasthi, Sanjay; Horne, David; Singhal, Sharad S

    2017-09-26

    Breast cancer is the most common cancer in women that is driven by cross-talk with hormonal and cellular signaling pathways. The natural phytochemicals, due to broad-spectrum anti-inflammatory and anti-cancerous properties, present with novel opportunities for targeting breast cancer. Intake of citrus fruits is known to reduce the risk for incidence of breast cancer. Hence, we tested the efficacy of citrus flavonoid 2'-hydroxyflavanone (2HF) in breast cancer. 2HF inhibited survival, clonogenic ability, cell cycle progression and induced apoptosis in breast cancer cells. 2HF also decreased VEGF levels and inhibited migratory capacity of breast cancer cells. Administration of 2HF led to regression of triple-negative MDA-MB-231 tumors in the mice xenograft model. 2HF decreased the levels of RLIP76 both in vitro studies and in vivo MDA-MB-231 xenograft model of breast cancer. Western blot and histopathological analyses of resected tumors showed a decline in the levels of survival and proliferation markers Ki67, pAkt, survivin, and cell cycle proteins CDK4 and cyclin B1. 2HF treatment led to inhibition of angiogenesis as determined by decreased VEGF levels in vitro and angiogenesis marker CD31 in vivo . 2HF reversed the pro-/anti-apoptotic ratio of BAX/BCL-2 by decreasing anti-apoptotic protein BCL-2 and increasing pro-apoptotic proteins BAX and BIM in vivo . 2HF also decreased the mesenchymal markers vimentin and fibronectin along with causing a parallel increase in pro-differentiation protein E-cadherin. Collectively, the ability of 2HF to decrease RLIP76, VEGF and regulate critical proliferative, apoptotic and differentiation proteins together provides strong rationale to further develop 2HF based interventions for targeting breast cancer.

  16. Gene expression profiles in BCL11B-siRNA treated malignant T cells

    Directory of Open Access Journals (Sweden)

    Grabarczyk Piotr

    2011-05-01

    Full Text Available Abstract Background Downregulation of the B-cell chronic lymphocytic leukemia (CLL/lymphoma11B (BCL11B gene by small interfering RNA (siRNA leads to growth inhibition and apoptosis of the human T-cell acute lymphoblastic leukemia (T-ALL cell line Molt-4. To further characterize the molecular mechanism, a global gene expression profile of BCL11B-siRNA -treated Molt-4 cells was established. The expression profiles of several genes were further validated in the BCL11B-siRNA -treated Molt-4 cells and primary T-ALL cells. Results 142 genes were found to be upregulated and 109 genes downregulated in the BCL11B-siRNA -treated Molt-4 cells by microarray analysis. Among apoptosis-related genes, three pro-apoptotic genes, TNFSF10, BIK, BNIP3, were upregulated and one anti-apoptotic gene, BCL2L1 was downregulated. Moreover, the expression of SPP1 and CREBBP genes involved in the transforming growth factor (TGF-β pathway was down 16-fold. Expression levels of TNFSF10, BCL2L1, SPP1, and CREBBP were also examined by real-time PCR. A similar expression pattern of TNFSF10, BCL2L1, and SPP1 was identified. However, CREBBP was not downregulated in the BLC11B-siRNA -treated Molt-4 cells. Conclusion BCL11B-siRNA treatment altered expression profiles of TNFSF10, BCL2L1, and SPP1 in both Molt-4 T cell line and primary T-ALL cells.

  17. Molecular basis for the interplay of apoptosis and proliferation mediated by Bcl-xL:Bim interactions in pancreatic cancer cells

    Energy Technology Data Exchange (ETDEWEB)

    Abrol, Ravinder, E-mail: abrol@wag.caltech.edu [Materials and Process Simulation Center, Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, CA 91125 (United States); Edderkaoui, Mouad [Veterans Affairs Greater Los Angeles Healthcare System and UCLA, Los Angeles, CA 90073 (United States); Goddard, William A. [Materials and Process Simulation Center, Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, CA 91125 (United States); Pandol, Stephen J., E-mail: stephen.pandol@va.gov [Veterans Affairs Greater Los Angeles Healthcare System and UCLA, Los Angeles, CA 90073 (United States)

    2012-06-15

    Highlights: Black-Right-Pointing-Pointer Direct role of Bcl-2 protein interactions in cell proliferation is not clear. Black-Right-Pointing-Pointer Designed Bcl-xL mutants show opposite effects on apoptosis and proliferation. Black-Right-Pointing-Pointer Disrupting Bcl-xL:Bim interaction increased apoptosis in pancreatic cancer. Black-Right-Pointing-Pointer Disrupting Bcl-xL:Bim interaction decreased proliferation in pancreatic cancer. Black-Right-Pointing-Pointer Bcl-xL:Bim interaction can control both apoptosis and proliferation. -- Abstract: A major mechanism through which cancer cells avoid apoptosis is by promoting the association of anti-apoptotic members of the pro-survival Bcl-2 protein family (like Bcl-2 and Bcl-xL) with BH{sub 3} domain-only proteins (like Bim and Bid). Apoptosis and cell proliferation have been shown to be linked for many cancers but the molecular basis for this link is far from understood. We have identified the Bcl-xL:Bim protein-protein interface as a direct regulator of proliferation and apoptosis in pancreatic cancer cells. We were able to predict and subsequently verify experimentally the effect of various Bcl-xL single-point mutants (at the position A142) on binding to Bim by structural analysis and computational modeling of the inter-residue interactions at the Bcl-xL:Bim protein-protein interface. The mutants A142N, A142Q, and A142Y decreased binding of Bim to Bcl-xL and A142S increased this binding. The Bcl-xL mutants, with decreased affinity for Bim, caused an increase in apoptosis and a corresponding decrease in cell proliferation. However, we could prevent these effects by introducing a small interfering RNA (siRNA) targeted at Bim. These results show a novel role played by the Bcl-xL:Bim interaction in regulating proliferation of pancreatic cancer cells at the expense of apoptosis. This study presents a physiologically relevant model of the Bcl-xL:Bim interface that can be used for rational therapeutic design for the

  18. Apoptosis and BCL-2 expression as predictors of survival in radiation-treated non-small-cell lung cancer

    International Nuclear Information System (INIS)

    Hwang, Jun-Hwa; Lim, Sung-Chul; Kim, Young-Chul; Park, Kyung-Ok; Ahn, Sung-Ja; Chung, Woong-Ki

    2001-01-01

    Objectives: We assessed the role of apoptosis and the expression of bcl-2, p53, and c-myc oncoproteins in pretreatment histologic specimens as a predictor of response to radiation therapy and survival in non-small-cell lung cancer (NSCLC) patients. Methods: Pretreatment biopsy specimens of 68 patients with NSCLC (62 squamous cell carcinoma, 6 adenocarcinoma) were stained with hematoxylin and eosin. From 5 high-powered fields, the apoptotic index (AI) was calculated as the ratio of apoptotic tumor cells to the total number of tumor cells. Bcl-2, p53, and c-myc oncoprotein expression was detected by immunohistochemical staining. Results: Twenty-nine cases showed partial or complete remission, whereas 39 showed no response. AI ranged from 0.2 to 12.0% (mean ± SD; 4.3±2.6%, median 4.0%). There was no difference in AI between responders (4.0±2.3) and nonresponders (4.5±2.8, p>0.05). However, in the responders, AI was correlated with the degree of change in tumor volume (r=0.41, p<0.05). In an analysis of 53 subjects who survived more than 1 month after the completion of radiation therapy, the patients with a higher AI (n=27, MST=22.8 m) survived longer than those with a lower AI (n=26, MST=9.2, log-rank, p=0.03). Patients expressing bcl-2 had poorer survival (n=22, MST=6.0 m) than patients without bcl-2 (n=31, 22.8 m, p<0.003). According to multivariate analysis, three variables, bcl-2 expression, AI, and response to radiation, were independent prognostic factors for survival. Conclusion: A low level of spontaneous apoptosis and expression of apoptosis blocking bcl-2 protein in pretreatment histology predict a poor prognosis for radiation-treated NSCLC patients

  19. Endogenous PKI gamma limits the duration of the anti-apoptotic effects of PTH and beta-adrenergic agonists in osteoblasts.

    Science.gov (United States)

    Chen, Xin; Song, In-Hwan; Dennis, James E; Greenfield, Edward M

    2007-05-01

    PKI gamma knockdown substantially extended the anti-apoptotic effects of PTH and beta-adrenergic agonists, whereas PKI gamma overexpression decreased these effects. Therefore, inhibition of PKI gamma activity may provide a useful co-therapy in combination with intermittent PTH or beta-adrenergic agonists for bone loss in conditions such as osteoporosis. PTH has both catabolic and anabolic effects on bone, which are primarily caused by cAMP/protein kinase A (PKA) signaling and regulation of gene expression. We previously showed that protein kinase inhibitor-gamma (PKI gamma) is required for efficient termination of cAMP/PKA signaling and gene expression after stimulation with PTH or beta-adrenergic agonists. Inhibition of osteoblast apoptosis is thought to be an important, but transient, mechanism partly responsible for the anabolic effects of intermittent PTH. Therefore, we hypothesized that endogenous PKI gamma also terminates the anti-apoptotic effect of PTH. PKI gamma knockdown by antisense transfection or siRNA was used to examine the ability of endogenous PKI gamma to modulate the anti-apoptotic effects of PTH and beta-adrenergic agonists in ROS 17/2.8 cells. Knockdown of PKI gamma substantially extended the anti-apoptotic effects of PTH, whether apoptosis was induced by etoposide or dexamethasone. In contrast, overexpression of PKI gamma decreased the anti-apoptotic effect of PTH pretreatment. This study is also the first demonstration that beta-adrenergic agonists mimic the anti-apoptotic effects of PTH in osteoblasts. Moreover, PKI gamma knockdown also substantially extended this anti-apoptotic effect of beta-adrenergic agonists. Taken together, these results show that endogenous PKI gamma limits the duration of the anti-apoptotic effects of cAMP/PKA signaling in osteoblasts. Because significant individual variability exists in the anabolic responses to PTH therapy in current clinical treatment of osteoporosis, inhibition of PKI gamma activity may provide a

  20. Taurine protects HK-2 cells from oxidized LDL-induced cytotoxicity via the ROS-mediated mitochondrial and p53-related apoptotic pathways

    Energy Technology Data Exchange (ETDEWEB)

    Chang, Chun-Yu [Graduate Institute of Biomedical Sciences, National Chung Hsing University, Taichung, Taiwan (China); Shen, Chao-Yu [School of Medical Imaging and Radiological Sciences, Chung Shan Medical University, Taichung, Taiwan (China); Department of Medical Imaging, Chung Shan Medical University Hospital, Taichung, Taiwan (China); School of Medicine, Chung Shan Medical University, Taichung, Taiwan (China); Kang, Chao-Kai [Department of Life Sciences, National Chung Hsing University, Taichung, Taiwan, (China); Sher, Yuh-Pyng [Graduate Institute of Clinical Medical Science, China Medical University, Taichung, Taiwan (China); Center for Molecular Medicine, China Medical University Hospital, Taichung 404, Taiwan (China); Sheu, Wayne H.-H. [Graduate Institute of Biomedical Sciences, National Chung Hsing University, Taichung, Taiwan (China); Division of Endocrinology and Metabolism, Department of Internal Medicine, Taichung Veterans General Hospital, Taichung, Taiwan (China); School of Medicine, National Yang Ming University, Taipei, Taiwan (China); School of Medicine, National Defense Medical Center, Taipei, Taiwan (China); Chang, Chia-Che, E-mail: chia_che@dragon.nchu.edu.tw [Graduate Institute of Biomedical Sciences, National Chung Hsing University, Taichung, Taiwan (China); Agricultural Biotechnology Center, National Chung Hsing University, Taichung, Taiwan (China); Lee, Tsung-Han, E-mail: thlee@email.nchu.edu.tw [Department of Life Sciences, National Chung Hsing University, Taichung, Taiwan, (China); Graduate Institute of Clinical Medical Science, China Medical University, Taichung, Taiwan (China); Agricultural Biotechnology Center, National Chung Hsing University, Taichung, Taiwan (China); Department of Biological Science and Technology, China Medical University, Taichung, Taiwan (China)

    2014-09-15

    Oxidized LDL (oxLDL) induces a pro-oxidative environment and promotes apoptosis, causing the progression of renal diseases in humans. Taurine is a semi-essential amino acid in mammals and has been shown to be a potent endogenous antioxidant. The kidney plays a pivotal role in maintaining the balance of taurine. However, the mechanisms underlying the protective effects of taurine against oxLDL-induced injury in renal epithelial cells have not been clarified. In the present study, we investigated the anti-apoptotic effects of taurine on human proximal tubular epithelial (HK-2) cells exposed to oxLDL and explored the related mechanisms. We observed that oxLDL increased the contents of ROS and of malondialdehyde (MDA), which is a lipid peroxidation by-product that acts as an indicator of the cellular oxidation status. In addition, oxLDL induced cell death and apoptosis in HK-2 cells. Pretreatment with taurine at 100 μM significantly attenuated the oxLDL-induced cytotoxicity. We determined that oxLDL triggered the phosphorylation of ERK and, in turn, the activation of p53 and other apoptosis-related events, including calcium accumulation, destabilization of the mitochondrial permeability and disruption of the balance between pro-apoptotic Bax and anti-apoptotic Bcl-2 proteins. The malfunctions induced by oxLDL were effectively blocked by taurine. Thus, our results suggested that taurine exhibits potential therapeutic activity by preventing oxLDL-induced nephrotoxicity. The inhibition of oxLDL-induced epithelial apoptosis by taurine was at least partially due to its anti-oxidant activity and its ability to modulate the ERK and p53 apoptotic pathways. - Highlights: • Oxidized LDL induced cytotoxicity and apoptosis in HK-2 cells. • Pretreatment with taurine attenuated oxLDL-induced nephrotoxicity. • Taurine protected against renal damages through inhibition of ROS generation. • Taurine prevented apoptosis through modulation of the p53 phosphorylation.

  1. Taurine protects HK-2 cells from oxidized LDL-induced cytotoxicity via the ROS-mediated mitochondrial and p53-related apoptotic pathways

    International Nuclear Information System (INIS)

    Chang, Chun-Yu; Shen, Chao-Yu; Kang, Chao-Kai; Sher, Yuh-Pyng; Sheu, Wayne H.-H.; Chang, Chia-Che; Lee, Tsung-Han

    2014-01-01

    Oxidized LDL (oxLDL) induces a pro-oxidative environment and promotes apoptosis, causing the progression of renal diseases in humans. Taurine is a semi-essential amino acid in mammals and has been shown to be a potent endogenous antioxidant. The kidney plays a pivotal role in maintaining the balance of taurine. However, the mechanisms underlying the protective effects of taurine against oxLDL-induced injury in renal epithelial cells have not been clarified. In the present study, we investigated the anti-apoptotic effects of taurine on human proximal tubular epithelial (HK-2) cells exposed to oxLDL and explored the related mechanisms. We observed that oxLDL increased the contents of ROS and of malondialdehyde (MDA), which is a lipid peroxidation by-product that acts as an indicator of the cellular oxidation status. In addition, oxLDL induced cell death and apoptosis in HK-2 cells. Pretreatment with taurine at 100 μM significantly attenuated the oxLDL-induced cytotoxicity. We determined that oxLDL triggered the phosphorylation of ERK and, in turn, the activation of p53 and other apoptosis-related events, including calcium accumulation, destabilization of the mitochondrial permeability and disruption of the balance between pro-apoptotic Bax and anti-apoptotic Bcl-2 proteins. The malfunctions induced by oxLDL were effectively blocked by taurine. Thus, our results suggested that taurine exhibits potential therapeutic activity by preventing oxLDL-induced nephrotoxicity. The inhibition of oxLDL-induced epithelial apoptosis by taurine was at least partially due to its anti-oxidant activity and its ability to modulate the ERK and p53 apoptotic pathways. - Highlights: • Oxidized LDL induced cytotoxicity and apoptosis in HK-2 cells. • Pretreatment with taurine attenuated oxLDL-induced nephrotoxicity. • Taurine protected against renal damages through inhibition of ROS generation. • Taurine prevented apoptosis through modulation of the p53 phosphorylation

  2. The apoptotic response in HCT116BAX-/- cancer cells becomes rapidly saturated with increasing expression of a GFP-BAX fusion protein

    Directory of Open Access Journals (Sweden)

    Semaan Sheila J

    2010-10-01

    Full Text Available Abstract Background Many chemotherapeutic agents promote tumor cell death by activating the intrinsic pathway of apoptosis. Intrinsic apoptosis involves permeabilization of the mitochondrial outer membrane and the release of cytochrome c, a process that is controlled by proteins of the BCL2 gene family. Chemoresistance is often associated with abnormalities in concentrations of BCL2 family proteins. Although stoichiometirc interactions between anti-apoptotic and BH3-only BCL2 family proteins have been well documented as affecting cell death, the association between changes in BAX concentration and intrinsic apoptosis are poorly understood. Methods Exogenous GFP-murine Bax fusion constructs were transfected into BAX-deficient HCT116 cells. To titrate the expression of the fusion protein, GFP-BAX was cloned into a tetracycline sensitive expression cassette and cotransfected with a plasmid expressing the rtTA transcription factor into HCT116BAX-/- cells. Linear expression of the fusion gene was induced with doxycycline and monitored by quantitative PCR and immunoblotting. Cell death was assayed by DAPI staining cells after exposure to indomethacin, and scoring nuclei for condensed chromatin and fragmented nuclei. Results HCT116BAX-/- cells were resistant to indomethacin, but susceptibility could be recovered in cells expressing a GFP-BAX fusion protein. Titration of GFP-BAX expression revealed that the concentration of BAX required to induce a saturating apoptosis response from baseline, was rapidly achieved. Increased levels of GFP-BAX were unable to stimulate higher levels of cell death. Examination of GFP-BAX distribution before and after indomethacin treatment indicated that BAX protein did not form aggregates when present at sub-lethal concentrations. Conclusion Within the limitations of this experimental system, BAX-dependent apoptosis in HCT116 cells exhibits an all-or-none response depending on the level of BAX protein present. The lack of

  3. Deregulation of apoptosis-related genes is associated with PRV1 overexpression and JAK2 V617F allele burden in Essential Thrombocythemia and Myelofibrosis

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    Tognon Raquel

    2012-02-01

    Full Text Available Abstract Background Essential Thrombocythemia (ET and Primary Myelofibrosis (PMF are Chronic Myeloproliferative Neoplasms (MPN characterized by clonal myeloproliferation/myeloaccumulation without cell maturation impairment. The JAK2 V617F mutation and PRV1 gene overexpression may contribute to MPN physiopathology. We hypothesized that deregulation of the apoptotic machinery may also play a role in the pathogenesis of ET and PMF. In this study we evaluated the apoptosis-related gene and protein expression of BCL2 family members in bone marrow CD34+ hematopoietic stem cells (HSC and peripheral blood leukocytes from ET and PMF patients. We also tested whether the gene expression results were correlated with JAK2 V617F allele burden percentage, PRV1 overexpression, and clinical and laboratory parameters. Results By real time PCR assay, we observed that A1, MCL1, BIK and BID, as well as A1, BCLW and BAK gene expression were increased in ET and PMF CD34+ cells respectively, while pro-apoptotic BAX and anti-apoptotic BCL2 mRNA levels were found to be lower in ET and PMF CD34+ cells respectively, in relation to controls. In patients' leukocytes, we detected an upregulation of anti-apoptotic genes A1, BCL2, BCL-XL and BCLW. In contrast, pro-apoptotic BID and BIMEL expression were downregulated in ET leukocytes. Increased BCL-XL protein expression in PMF leukocytes and decreased BID protein expression in ET leukocytes were observed by Western Blot. In ET leukocytes, we found a correlation between JAK2 V617F allele burden and BAX, BIK and BAD gene expression and between A1, BAX and BIK and PRV1 gene expression. A negative correlation between PRV1 gene expression and platelet count was observed, as well as a positive correlation between PRV1 gene expression and splenomegaly. Conclusions Our results suggest the participation of intrinsic apoptosis pathway in the MPN physiopathology. In addition, PRV1 and JAK2 V617F allele burden were linked to deregulation

  4. The anti-cell death FNK protein protects cells from death induced by freezing and thawing

    International Nuclear Information System (INIS)

    Sudo, Kentaro; Asoh, Sadamitsu; Ohsawa, Ikuroh; Ozaki, Daiya; Yamagata, Kumi; Ito, Hiromoto; Ohta, Shigeo

    2005-01-01

    The FNK protein, constructed from anti-apoptotic Bcl-x L with enhanced activity, was fused with the protein transduction domain (PTD) of the HIV/Tat protein to mediate the delivery of FNK into cells. The fusion protein PTD-FNK was introduced into chondrocytes in isolated articular cartilage-bone sections, cultured neurons, and isolated bone marrow mononuclear cells to evaluate its ability to prevent cell death induced by freezing and thawing. PTD-FNK protected the cells from freeze-thaw damage in a concentration-dependent manner. Addition of PTD-FNK with conventional cryoprotectants (dimethyl sulfoxide and hydroxyethyl starch) increased surviving cell numbers around 2-fold compared with controls treated only with the cryoprotectants. Notably, PTD-FNK allowed CD34 + cells among bone marrow mononuclear cells to survive more efficiently (12-fold more than the control cells) from two successive freeze-thaw cycles. Thus, PTD-FNK prevented cell death induced by freezing and thawing, suggesting that it provides for the successful cryopreservation of biological materials

  5. Dynamin inhibitors induce caspase-mediated apoptosis following cytokinesis failure in human cancer cells and this is blocked by Bcl-2 overexpression

    Directory of Open Access Journals (Sweden)

    Braithwaite Antony W

    2011-06-01

    Full Text Available Abstract Background The aim of both classical (e.g. taxol and targeted anti-mitotic agents (e.g. Aurora kinase inhibitors is to disrupt the mitotic spindle. Such compounds are currently used in the clinic and/or are being tested in clinical trials for cancer treatment. We recently reported a new class of targeted anti-mitotic compounds that do not disrupt the mitotic spindle, but exclusively block completion of cytokinesis. This new class includes MiTMAB and OcTMAB (MiTMABs, which are potent inhibitors of the endocytic protein, dynamin. Like other anti-mitotics, MiTMABs are highly cytotoxic and possess anti-proliferative properties, which appear to be selective for cancer cells. The cellular response following cytokinesis failure and the mechanistic pathway involved is unknown. Results We show that MiTMABs induce cell death specifically following cytokinesis failure via the intrinsic apoptotic pathway. This involves cleavage of caspase-8, -9, -3 and PARP, DNA fragmentation and membrane blebbing. Apoptosis was blocked by the pan-caspase inhibitor, ZVAD, and in HeLa cells stably expressing the anti-apoptotic protein, Bcl-2. This resulted in an accumulation of polyploid cells. Caspases were not cleaved in MiTMAB-treated cells that did not enter mitosis. This is consistent with the model that apoptosis induced by MiTMABs occurs exclusively following cytokinesis failure. Cytokinesis failure induced by cytochalasin B also resulted in apoptosis, suggesting that disruption of this process is generally toxic to cells. Conclusion Collectively, these data indicate that MiTMAB-induced apoptosis is dependent on both polyploidization and specific intracellular signalling components. This suggests that dynamin and potentially other cytokinesis factors are novel targets for development of cancer therapeutics.

  6. Hypoxic human cancer cells are sensitized to BH-3 mimetic–induced apoptosis via downregulation of the Bcl-2 protein Mcl-1

    OpenAIRE

    Harrison, Luke R.E.; Micha, Dimitra; Brandenburg, Martin; Simpson, Kathryn L.; Morrow, Christopher J.; Denneny, Olive; Hodgkinson, Cassandra; Yunus, Zaira; Dempsey, Clare; Roberts, Darren; Blackhall, Fiona; Makin, Guy; Dive, Caroline

    2011-01-01

    Solid tumors contain hypoxic regions in which cancer cells are often resistant to chemotherapy-induced apoptotic cell death. Therapeutic strategies that specifically target hypoxic cells and promote apoptosis are particularly appealing, as few normal tissues experience hypoxia. We have found that the compound ABT-737, a Bcl-2 homology domain 3 (BH-3) mimetic, promotes apoptotic cell death in human colorectal carcinoma and small cell lung cancer cell lines exposed to hypoxia. This hypoxic indu...

  7. Is upregulation of BCL2 a determinant of tumor development driven by inactivation of CDH1/E-cadherin?

    Directory of Open Access Journals (Sweden)

    Inga Karch

    Full Text Available Inactivation of CDH1, encoding E-cadherin, promotes cancer initiation and progression. According to a newly proposed molecular mechanism, loss of E-cadherin triggers an upregulation of the anti-apoptotic oncoprotein BCL2. Conversely, reconstitution of E-cadherin counteracts overexpression of BCL2. This reciprocal regulation is thought to be critical for early tumor development. We determined the relevance of this new concept in human infiltrating lobular breast cancer (ILBC, the prime tumor entity associated with CDH1 inactivation. BCL2 expression was examined in human ILBC cell lines (IPH-926, MDA-MB-134, SUM-44 harboring deleterious CDH1 mutations. To test for an intact regulatory axis between E-cadherin and BCL2, wild-type E-cadherin was reconstituted in ILBC cells by ectopic expression. Moreover, BCL2 and E-cadherin were evaluated in primary invasive breast cancers and in synchronous lobular carcinomas in situ (LCIS. MDA-MB-134 and IPH-926 showed little or no BCL2 expression, while SUM-44 ILBC cells were BCL2-positive. Reconstitution of E-cadherin failed to impact on BCL2 expression in all cell lines tested. Primary ILBCs were almost uniformly E-cadherin-negative (97% and were frequently BCL2-negative (46%. When compared with an appropriate control group, ILBCs showed a trend towards an increased frequency of BCL2-negative cases (P = 0.064. In terminal duct-lobular units affected by LCIS, the E-cadherin-negative neoplastic component showed a similar or a reduced BCL2-immunoreactivity, when compared with the adjacent epithelium. In conclusion, upregulation of BCL2 is not involved in lobular breast carcinogenesis and is unlikely to represent an important determinant of tumor development driven by CDH1 inactivation.

  8. H pylori receptor MHC class II contributes to the dynamic gastric epithelial apoptotic response

    Science.gov (United States)

    Bland, David A; Suarez, Giovanni; Beswick, Ellen J; Sierra, Johanna C; Reyes, Victor E

    2006-01-01

    AIM: To investigate the role of MHC class II in the modulation of gastric epithelial cell apoptosis induced by H pylori infection. METHODS: After stimulating a human gastric epithelial cell line with bacteria or agonist antibodies specific for MHC class II and CD95, the quantitation of apoptotic and anti-apoptotic events, including caspase activation, BCL-2 activation, and FADD recruitment, was performed with a fluorometric assay, a cytometric bead array, and confocal microscopy, respectively. RESULTS: Pretreatment of N87 cells with the anti-MHC class II IgM antibody RFD1 resulted in a reduction in global caspase activation at 24 h of H pylori infection. When caspase 3 activation was specifically measured, crosslinking of MHC class II resulted in a marked reduced caspase activation, while simple ligation of MHC class II did not. Crosslinking of MHC class II also resulted in an increased activation of the anti-apoptosis molecule BCL-2 compared to simple ligation. Confocal microscope analysis demonstrated that the pretreatment of gastric epithelial cells with a crosslinking anti-MHC class II IgM blocked the recruitment of FADD to the cell surface. CONCLUSION: The results presented here demonstrate that the ability of MHC class II to modulate gastric epithelial apoptosis is at least partially dependent on its crosslinking. Furthermore, while previous research has demonstrated that MHC class II signaling can be pro-apoptotic during extended ligation, we have shown that the crosslinking of this molecule has anti-apoptotic effects during the earlier time points of H pylori infection. This effect is possibly mediated by the ability of MHC class II to modulate the activation of the pro-apoptotic receptor Fas by blocking the recruitment of the accessory molecule FADD, and this delay in apoptosis induction could allow for prolonged cytokine secretion by H pylori-infected gastric epithelial cells. PMID:16981259

  9. Knock-down of NDRG2 sensitizes cervical cancer Hela cells to cisplatin through suppressing Bcl-2 expression

    International Nuclear Information System (INIS)

    Liu, Junye; Guo, Guozhen; Yang, Le; Zhang, Jian; Zhang, Jing; Chen, Yongbin; Li, Kangchu; Li, Yurong; Li, Yan; Yao, Libo

    2012-01-01

    NDRG2, a member of N-Myc downstream regulated gene family, plays some roles in cellular stress, cell differentiation and tumor suppression. We have found that NDRG2 expression in cervical cancer Hela cells increases significantly upon stimulation with cisplatin, the most popular chemotherapeutic agent currently used for the treatment of advanced cervical cancer. This interesting phenomenon drove us to evaluate the role of NDRG2 in chemosensitivity of Hela cells. In the present study, RNA interference was employed to down-regulate NDRG2 expression in Hela cells. RT-PCR and Western blot were used to detect expression of NDRG2, Bcl-2 and Bax in cancer cells. Real-time PCR was applied to detect miR-15b and miR-16 expression levels. Drug sensitivity was determined with MTT assay. Cell cloning efficiency was evaluated by Colony-forming assay. Apoptotic cells were detected with annexin V staining and flow cytometry. In vitro drug sensitivity assay revealed that suppression of NDRG2 could sensitize Hela cells to cisplatin. Down-regulation of NDRG2 didn’t influence the colony-forming ability but promoted cisplatin-induced apoptosis of Hela cells. Inhibition of NDRG2 in Hela cells was accompanied by decreased Bcl-2 protein level. However, Bcl-2 mRNA level was not changed in Hela cells with down-regulation of NDRG2. Further study indicated that miR-15b and miR-16, two microRNAs targetting Bcl-2, were significantly up-regulated in NDRG2-suppressed Hela cells. These data suggested that down-regulation of NDRG2 could enhance sensitivity of Hela cells to cisplatin through inhibiting Bcl-2 protein expression, which might be mediated by up-regulating miR-15b and miR-16

  10. Apoptotic and anti-proliferative effects of all-trans retinoic acid

    International Nuclear Information System (INIS)

    Zamora, Monica; Ortega, Juan Alberto; Alana, Lide; Vinas, Octavi; Mampel, Teresa

    2006-01-01

    We examined the apoptotic and anti-proliferative effects of all-trans retinoic acid (atRA) in HeLa cells. Our results demonstrated that HeLa cells were more sensitive to the anti-proliferative effects of atRA than to its apoptotic effects. Furthermore, we demonstrated that caspase inhibition attenuates cell death but does not alter the atRA-dependent reduction in cell proliferation, which suggests that atRA-induced apoptosis is independent of the arrest in cell proliferation. To check whether ANT proteins mediated these atRA effects, we transiently transfected cells with expression vectors encoding for individual ANT (adenine nucleotide translocase 1-3). Our results revealed that ANT1 and ANT3 over-expressing HeLa cells increased their atRA sensitivity. Thus, our results not only demonstrate the different functional activities of ANT isoforms, but also contribute to a better understanding of the properties of atRA as an anti-tumoral agent used in cancer therapy

  11. Transcriptional profiling of Vero E6 cells over-expressing SARS-CoV S2 subunit: Insights on viral regulation of apoptosis and proliferation

    International Nuclear Information System (INIS)

    Yeung, Y.-S.; Yip, C.-W.; Hon, C.-C.; Chow, Ken Y.C.; Ma, Iris C.M.; Zeng Fanya; Leung, Frederick C.C.

    2008-01-01

    We have previously demonstrated that over-expression of spike protein (S) of severe acute respiratory syndrome coronavirus (SARS-CoV) or its C-terminal subunit (S2) is sufficient to induce apoptosis in vitro. To further investigate the possible roles of S2 in SARS-CoV-induced apoptosis and pathogenesis of SARS, we characterized the host expression profiles induced upon S2 over-expression in Vero E6 cells by oligonucleotide microarray analysis. Possible activation of mitochondrial apoptotic pathway in S2 expressing cells was suggested, as evidenced by the up-regulation of cytochrome c and down-regulation of the Bcl-2 family anti-apoptotic members. Inhibition of Bcl-2-related anti-apoptotic pathway was further supported by the diminution of S2-induced apoptosis in Vero E6 cells over-expressing Bcl-xL. In addition, modulation of CCN E2 and CDKN 1A implied the possible control of cell cycle arrest at G1/S phase. This study is expected to extend our understanding on the pathogenesis of SARS at a molecular level

  12. Expression of Anti-apoptotic Protein BAG3 in Human Sebaceous Gland Carcinoma of the Eyelid.

    Science.gov (United States)

    Yunoki, Tatsuya; Tabuchi, Yoshiaki; Hayashi, Atsushi

    2017-04-01

    Bcl-2-associated athanogene 3 (BAG3), a co-chaperone of heat shock protein 70 (HSP70), has been shown to play a role in anti-apoptosis of various malignant tumors. In this study, the expression of BAG3 was examined in human sebaceous gland carcinoma of the eyelid. The expression of BAG3 was evaluated by immunohistochemistry of surgical samples from 5 patients with sebaceous gland carcinoma in the eyelid. BAG3 was positive diffusely in the cytoplasm in all patients. The average positive rate of BAG3 was 73.0±26.0% in tumor cells of all patients. BAG3 was highly expressed in sebaceous gland carcinoma of the eyelid. BAG3 may play an important role in the pathogenesis and progression of sebaceous gland carcinoma of the eyelid. Copyright© 2017, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.

  13. Human Adipose-Derived Stem Cells Delay Retinal Degeneration in Royal College of Surgeons Rats Through Anti-Apoptotic and VEGF-Mediated Neuroprotective Effects.

    Science.gov (United States)

    Li, Z; Wang, J; Gao, F; Zhang, J; Tian, H; Shi, X; Lian, C; Sun, Y; Li, W; Xu, J-Y; Li, P; Zhang, J; Gao, Z; Xu, J; Wang, F; Lu, L; Xu, G-T

    2016-01-01

    Stem cell therapy is a promising therapeutic approach for retinal degeneration (RD). Our study investigated the effects of human adipose derived stem cell (hADSCs) on Royal College of Surgeons (RCS) rats. Green fluorescent protein (GFP)-labeled hADSCs were transplanted subretinally into RCS rats at postnatal (PN) 21 days to explore potential therapeutic effects, while adeno-associated viral vector (AAV2)-vascular endothelial growth factor (VEGF) and siVEGF-hADSCs were used to aid the mechanistic dissections. Visual function was evaluated by Electroretinogram (ERG) recording. Potential transdifferentiations were examined by Immunofluorescence (IF) and gene expressions were analyzed by quantitative reverse transcription-polymerase chain reaction (qRT-PCR). Apoptotic retinal cells were detected by Terminal Deoxynucleotidyl Transferase dUTP Nick End Labeling (TUNEL) assay and the cytokines secreted by hADSCs were measured by Enzyme-linked Immunosorbent Assay (ELISA). The visual function of RCS rats began to decrease one week after their eyes opened at PN week 3 and almost lost in PN 5 weeks, accompanied by the loss of retinal outer nuclear layer (ONL). Subretinal transplantation of hADSCs significantly improved the visual function 2 weeks after the transplantation and such therapeutic effect persisted up to 8 weeks after the treatment (PN 11 weeks), with 3-4 rows of photoreceptors remained in the ONL and reduced apoptosis. Consistent with these phenotypic changes, the gene expression of rod photoreceptor markers Rhodopsin (Rho), Crx and Opsin (Opn1) in RCS rats showed obvious decreasing trends over time after PN 3 weeks, but were elevated with hADSC treatment. hADSC transplantation also repressed the expressions of Bax, Bak and Caspase 3, but not the expression of anti-apoptotic genes, including Bcl-2 and Bcl-XL. Finally, substantial VEGF, hepatocyte growth factor (HGF) and pigment epithelium-derived factor (PEDF) secretions from hADSCs were detected, while endogenous

  14. Active fragments from pro- and antiapoptotic BCL-2 proteins have distinct membrane behavior reflecting their functional divergence.

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    Yannis Guillemin

    Full Text Available BACKGROUND: The BCL-2 family of proteins includes pro- and antiapoptotic members acting by controlling the permeabilization of mitochondria. Although the association of these proteins with the outer mitochondrial membrane is crucial for their function, little is known about the characteristics of this interaction. METHODOLOGY/PRINCIPAL FINDINGS: Here, we followed a reductionist approach to clarify to what extent membrane-active regions of homologous BCL-2 family proteins contribute to their functional divergence. Using isolated mitochondria as well as model lipid Langmuir monolayers coupled with Brewster Angle Microscopy, we explored systematically and comparatively the membrane activity and membrane-peptide interactions of fragments derived from the central helical hairpin of BAX, BCL-xL and BID. The results show a connection between the differing abilities of the assayed peptide fragments to contact, insert, destabilize and porate membranes and the activity of their cognate proteins in programmed cell death. CONCLUSION/SIGNIFICANCE: BCL-2 family-derived pore-forming helices thus represent structurally analogous, but functionally dissimilar membrane domains.

  15. Downregulation of PI3-K/Akt/PTEN pathway and activation of mitochondrial intrinsic apoptosis by Diclofenac and Curcumin in colon cancer.

    Science.gov (United States)

    Rana, Chandan; Piplani, Honit; Vaish, Vivek; Nehru, Bimla; Sanyal, S N

    2015-04-01

    Phosphatidylinositol 3-kinase (PI3-K)/PTEN/Akt signaling is over activated in various tumors including colon cancer. Activation of this pathway regulates multiple biological processes such as apoptosis, metabolism, cell proliferation, and cell growth that underlie the biology of a cancer cell. In the present study, the chemopreventive effects have been observed of Diclofenac, a preferential COX-2 inhibitory non-steroidal anti-inflammatory drugs, and Curcumin, a natural anti-inflammatory agent, in the early stage of colorectal carcinogenesis induced by 1,2-dimethylhydrazine dihydrochloride in rats. The tumor-promoting role of PI3-K/Akt/PTEN signal transduction pathway and its association with anti-apoptotic family of proteins are also observed. Both Diclofenac and Curcumin downregulated the PI3-K and Akt expression while promoting the apoptotic mechanism. Diclofenac and Curcumin administration significantly increased the expression of pro-apoptotic Bcl-2 family members (Bad and Bax) while decreasing the anti-apoptotic Bcl-2 protein. An up-regulation of cysteine protease family apoptosis executioner, such as caspase-3 and -9, is seen. Diclofenac and Curcumin inhibited the Bcl-2 protein by directly interacting at the active site by multiple hydrogen bonding, as also evident by negative glide score of Bcl-2. These drugs stimulated apoptosis by increasing reactive oxygen species (ROS) generation and simultaneously decreasing the mitochondrial membrane potential (ΔΨ M). Diclofenac and Curcumin showed anti-neoplastic effects by downregulating PI3-K/Akt/PTEN pathway, inducing apoptosis, increasing ROS generation, and decreasing ΔΨ M. The anti-neoplastic and apoptotic effects were found enhanced when both Diclofenac and Curcumin were administered together, rather than individually.

  16. Effects of voluntary and treadmill exercise on spontaneous withdrawal signs, cognitive deficits and alterations in apoptosis-associated proteins in morphine-dependent rats.

    Science.gov (United States)

    Mokhtari-Zaer, Amin; Ghodrati-Jaldbakhan, Shahrbanoo; Vafaei, Abbas Ali; Miladi-Gorji, Hossein; Akhavan, Maziar M; Bandegi, Ahmad Reza; Rashidy-Pour, Ali

    2014-09-01

    Chronic exposure to morphine results in cognitive deficits and alterations of apoptotic proteins in favor of cell death in the hippocampus, a brain region critically involved in learning and memory. Physical activity has been shown to have beneficial effects on brain health. In the current work, we examined the effects of voluntary and treadmill exercise on spontaneous withdrawal signs, the associated cognitive defects, and changes of apoptotic proteins in morphine-dependent rats. Morphine dependence was induced through bi-daily administrations of morphine (10mg/kg) for 10 days. Then, the rats were trained under two different exercise protocols: mild treadmill exercise or voluntary wheel exercise for 10 days. After exercise training, their spatial learning and memory and aversive memory were examined by a water maze and by an inhibitory avoidance task, respectively. The expression of the pro-apoptotic protein Bax and the anti-apoptotic protein Bcl-2 in the hippocampus were determined by immunoblotting. We found that chronic exposure to morphine impaired spatial and aversive memory and remarkably suppressed the expression of Bcl-2, but Bax expression remained constant. Both voluntary and treadmill exercise alleviated memory impairment, increased the expression of Bcl-2 protein, and only the later suppressed the expression of Bax protein in morphine-dependent animals. Moreover, both exercise protocols diminished the occurrence of spontaneous morphine withdrawal signs. Our findings showed that exercise reduces the spontaneous morphine-withdrawal signs, blocks the associated impairment of cognitive performance, and overcomes morphine-induced alterations in apoptotic proteins in favor of cell death. Thus, exercise may be a useful therapeutic strategy for cognitive and behavioral deficits in addict individuals. Copyright © 2014 Elsevier B.V. All rights reserved.

  17. Relationship between apoptotic markers in semen from fertile men and demographic, hormonal and seminal characteristics

    DEFF Research Database (Denmark)

    Specht, Ina; Spanò, Marcello; Hougaard, Karin S

    2012-01-01

    and biological correlates of the pro-apoptotic marker Fas and the anti-apoptotic marker Bcl-xL in sperm cells of fertile men. Six hundred and four men from Greenland, Poland and Ukraine were consecutively enrolled during their pregnant wife's antenatal visits. Semen analysis was performed as recommended...

  18. p53 dependent apoptotic cell death induces embryonic malformation in Carassius auratus under chronic hypoxia.

    Directory of Open Access Journals (Sweden)

    Paramita Banerjee Sawant

    Full Text Available Hypoxia is a global phenomenon affecting recruitment as well as the embryonic development of aquatic fauna. The present study depicts hypoxia induced disruption of the intrinsic pathway of programmed cell death (PCD, leading to embryonic malformation in the goldfish, Carrasius auratus. Constant hypoxia induced the early expression of pro-apoptotic/tumor suppressor p53 and concomitant expression of the cell death molecule, caspase-3, leading to high level of DNA damage and cell death in hypoxic embryos, as compared to normoxic ones. As a result, the former showed delayed 4 and 64 celled stages and a delay in appearance of epiboly stage. Expression of p53 efficiently switched off expression of the anti-apoptotic Bcl-2 during the initial 12 hours post fertilization (hpf and caused embryonic cell death. However, after 12 hours, simultaneous downregulation of p53 and Caspase-3 and exponential increase of Bcl-2, caused uncontrolled cell proliferation and prevented essential programmed cell death (PCD, ultimately resulting in significant (p<0.05 embryonic malformation up to 144 hpf. Evidences suggest that uncontrolled cell proliferation after 12 hpf may have been due to downregulation of p53 abundance, which in turn has an influence on upregulation of anti-apoptotic Bcl-2. Therefore, we have been able to show for the first time and propose that hypoxia induced downregulation of p53 beyond 12 hpf, disrupts PCD and leads to failure in normal differentiation, causing malformation in gold fish embryos.

  19. Insulin receptor substrate-3, interacting with Bcl-3, enhances p50 NF-{kappa}B activity

    Energy Technology Data Exchange (ETDEWEB)

    Kabuta, Tomohiro [Departments of Animal Sciences and Applied Biological Chemistry, Graduate School of Agriculture and Life Sciences, The University of Tokyo, Tokyo 113-8657 (Japan); Department of Degenerative Neurological Diseases, National Institute of Neuroscience, National Center of Neurology and Psychiatry, Kodaira, Tokyo 187-8502 (Japan); Hakuno, Fumihiko; Cho, Yoshitake; Yamanaka, Daisuke; Chida, Kazuhiro [Departments of Animal Sciences and Applied Biological Chemistry, Graduate School of Agriculture and Life Sciences, The University of Tokyo, Tokyo 113-8657 (Japan); Asano, Tomoichiro [Graduate School of Biomedical Science, Hiroshima University, Hiroshima 734-8551 (Japan); Wada, Keiji [Department of Degenerative Neurological Diseases, National Institute of Neuroscience, National Center of Neurology and Psychiatry, Kodaira, Tokyo 187-8502 (Japan); Takahashi, Shin-Ichiro, E-mail: atkshin@mail.ecc.u-tokyo.ac.jp [Departments of Animal Sciences and Applied Biological Chemistry, Graduate School of Agriculture and Life Sciences, The University of Tokyo, Tokyo 113-8657 (Japan)

    2010-04-09

    The insulin receptor substrate (IRS) proteins are major substrates of both insulin receptor and insulin-like growth factor (IGF)-I receptor tyrosine kinases. Previously, we reported that IRS-3 is localized to both cytosol and nucleus, and possesses transcriptional activity. In the present study, we identified Bcl-3 as a novel binding protein to IRS-3. Bcl-3 is a nuclear protein, which forms a complex with the homodimer of p50 NF-{kappa}B, leading to enhancement of transcription through p50 NF-{kappa}B. We found that Bcl-3 interacts with the pleckstrin homology domain and the phosphotyrosine binding domain of IRS-3, and that IRS-3 interacts with the ankyrin repeat domain of Bcl-3. In addition, IRS-3 augmented the binding activity of p50 to the NF-{kappa}B DNA binding site, as well as the tumor necrosis factor (TNF)-{alpha}-induced transcriptional activity of NF-{kappa}B. Lastly, IRS-3 enhanced NF-{kappa}B-dependent anti-apoptotic gene induction and consequently inhibited TNF-{alpha}-induced cell death. This series of results proposes a novel function for IRS-3 as a transcriptional regulator in TNF-{alpha} signaling, distinct from its function as a substrate of insulin/IGF receptor kinases.

  20. Distinct apoptotic blocks mediate resistance to panHER inhibitors in HER2+ breast cancer cells.

    Science.gov (United States)

    Karakas, Bahriye; Ozmay, Yeliz; Basaga, Huveyda; Gul, Ozgur; Kutuk, Ozgur

    2018-05-04

    Despite the development of novel targeted therapies, de novo or acquired chemoresistance remains a significant factor for treatment failure in breast cancer therapeutics. Neratinib and dacomitinib are irreversible panHER inhibitors, which block their autophosphorylation and downstream signaling. Moreover, neratinib and dacomitinib have been shown to activate cell death in HER2-overexpressing cell lines. Here we showed that increased MCL1 and decreased BIM and PUMA mediated resistance to neratinib in ZR-75-30 and SKBR3 cells while increased BCL-XL and BCL-2 and decreased BIM and PUMA promoted neratinib resistance in BT474 cells. Cells were also cross-resistant to dacomitinib. BH3 profiles of HER2+ breast cancer cells efficiently predicted antiapoptotic protein dependence and development of resistance to panHER inhibitors. Reactivation of ERK1/2 was primarily responsible for acquired resistance in SKBR3 and ZR-75-30 cells. Adding specific ERK1/2 inhibitor SCH772984 to neratinib or dacomitinib led to increased apoptotic response in neratinib-resistant SKBR3 and ZR-75-30 cells, but we did not detect a similar response in neratinib-resistant BT474 cells. Accordingly, suppression of BCL-2/BCL-XL by ABT-737 was required in addition to ERK1/2 inhibition for neratinib- or dacomitinib-induced apoptosis in neratinib-resistant BT474 cells. Our results showed that different mitochondrial apoptotic blocks mediated acquired panHER inhibitor resistance in HER2+ breast cancer cell lines as well as highlighted the potential of BH3 profiling assay in prediction of panHER inhibitor resistance in breast cancer cells. Copyright © 2018 Elsevier B.V. All rights reserved.

  1. Immunohistochemical assessment of Survivin and Bcl3 expression as potential biomarkers for NF-κB activation in the Barrett metaplasia-dysplasia-adenocarcinoma sequence.

    Science.gov (United States)

    Puccio, Ignazio; Khan, Saif; Butt, Adil; Graham, David; Sehgal, Vinay; Patel, Dominic; Novelli, Marco; Lovat, Laurence B; Rodriguez-Justo, Manuel; Hamoudi, Rifat A

    2018-02-01

    Non-dysplastic Barrett's oesophagus (NDBE) occurs as a consequence of an inflammatory response triggered through prolonged gastro-oesophageal reflux and it may precede the development of oesophageal adenocarcinoma. NF-κB activation as a result of the inflammatory response has been shown in NDBE, but the possible mechanism involved in the process is unknown. The aim of this study was to assess, using immunohistochemistry, Survivin and Bcl3 expression as potential biomarkers for NF-κB activation along the oesophageal metaplasia-dysplasia-adenocarcinoma sequence. Survivin is an NF-κB-inducible anti-apoptotic protein, and Bcl3 is a negative regulator of NF-κB. There was progressive upregulation of Survivin expression along the oesophageal metaplasia-dysplasia-adenocarcinoma sequence. Bcl3 expression was upregulated in non-dysplastic Barrett's oesophagus, low-grade, high-grade dysplasia and oesophageal adenocarcinoma when compared to squamous group. The study shows the differential expression of Bcl3 between the squamous and Barrett's stage, suggesting that Bcl3 could be a surrogate marker for early event involving constitutive NF-κB activation. In addition, the study suggests that NF-κB activation may infer resistance to apoptosis through the expression of anti-apoptotic genes such as Survivin, which showed progressive increase in expression throughout the oesophageal metaplasia-dysplasia-adenocarcinoma sequence. This ability to avoid apoptosis may underlie the persistence and malignant predisposition of Barrett's metaplasia. © 2018 The Authors. International Journal of Experimental Pathology © 2018 International Journal of Experimental Pathology.

  2. Identification of Bax-Interacting Proteins in Oligodendrocyte Progenitors during Glutamate Excitotoxicity and Perinatal Hypoxia–Ischemia

    Directory of Open Access Journals (Sweden)

    Sopio Simonishvili

    2013-11-01

    Full Text Available OPC (oligodendrocyte progenitor cell death contributes significantly to the pathology and functional deficits following hypoxic-ischemic injury in the immature brain and to deficits resulting from demyelinating diseases, trauma and degenerative disorders in the adult CNS. Glutamate toxicity is a major cause of oligodendroglial death in diverse CNS disorders, and previous studies have demonstrated that AMPA/kainate receptors require the pro-apoptotic protein Bax in OPCs undergoing apoptosis. The goal of the present study was to define the pro-apoptotic and anti-apoptotic effectors that regulate Bax in healthy OPCs and after exposure to excess glutamate in vitro and following H–I (hypoxia–ischemia in the immature rat brain. We show that Bax associates with a truncated form of Bid, a BH3-only domain protein, subsequent to glutamate treatment. Furthermore, glutamate exposure reduces Bax association with the anti-apoptotic Bcl family member, Bcl-xL. Cell fractionation studies demonstrated that both Bax and Bid translocate from the cytoplasm to mitochondria during the early stages of cell death consistent with a role for Bid as an activator, whereas Bcl-xL, which normally complexes with both Bax and Bid, disassociates from these complexes when OPCs are exposed to excess glutamate. Bax remained unactivated in the presence of insulin-like growth factor-1, and the Bcl-xL complexes were protected. Our data similarly demonstrate loss of Bcl-xL–Bax association in white matter following H–I and implicate active Bad in Bax-mediated OPC death. To identify other Bax-binding partners, we used proteomics and identified cofilin as a Bax-associated protein in OPCs. Cofilin and Bax associated in healthy OPCs, whereas the Bax–cofilin association was disrupted during glutamate-induced OPC apoptosis.

  3. Arctigenin Treatment Protects against Brain Damage through an Anti-Inflammatory and Anti-Apoptotic Mechanism after Needle Insertion

    Science.gov (United States)

    Song, Jie; Li, Na; Xia, Yang; Gao, Zhong; Zou, Sa-feng; Kong, Liang; Yao, Ying-Jia; Jiao, Ya-Nan; Yan, Yu-Hui; Li, Shao-Heng; Tao, Zhen-Yu; Lian, Guan; Yang, Jing-Xian; Kang, Ting-Guo

    2016-01-01

    Convection enhanced delivery (CED) infuses drugs directly into brain tissue. Needle insertion is required and results in a stab wound injury (SWI). Subsequent secondary injury involves the release of inflammatory and apoptotic cytokines, which have dramatic consequences on the integrity of damaged tissue, leading to the evolution of a pericontusional-damaged area minutes to days after in the initial injury. The present study investigated the capacity for arctigenin (ARC) to prevent secondary brain injury and the determination of the underlying mechanism of action in a mouse model of SWI that mimics the process of CED. After CED, mice received a gavage of ARC from 30 min to 14 days. Neurological severity scores (NSS) and wound closure degree were assessed after the injury. Histological analysis and immunocytochemistry were used to evaluated the extent of brain damage and neuroinflammation. Terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) was used to detect universal apoptosis. Enzyme-linked immunosorbent assays (ELISA) was used to test the inflammatory cytokines (tumor necrosis factor (TNF)-α, interleukin (IL)-6 and IL-10) and lactate dehydrogenase (LDH) content. Gene levels of inflammation (TNF-α, IL-6, and IL-10) and apoptosis (Caspase-3, Bax and Bcl-2) were detected by reverse transcription-polymerase chain reaction (RT-PCR). Using these, we analyzed ARC’s efficacy and mechanism of action. Results: ARC treatment improved neurological function by reducing brain water content and hematoma and accelerating wound closure relative to untreated mice. ARC treatment reduced the levels of TNF-α and IL-6 and the number of allograft inflammatory factor (IBA)- and myeloperoxidase (MPO)-positive cells and increased the levels of IL-10. ARC-treated mice had fewer TUNEL+ apoptotic neurons and activated caspase-3-positive neurons surrounding the lesion than controls, indicating increased neuronal survival. Conclusions: ARC treatment confers

  4. PI3K and Bcl-2 inhibition primes glioblastoma cells to apoptosis through downregulation of Mcl-1 and Phospho-BAD.

    Science.gov (United States)

    Pareja, Fresia; Macleod, David; Shu, Chang; Crary, John F; Canoll, Peter D; Ross, Alonzo H; Siegelin, Markus D

    2014-07-01

    Glioblastoma multiforme (GBM) is a highly malignant human brain neoplasm with limited therapeutic options. GBMs display a deregulated apoptotic pathway with high levels of the antiapoptotic Bcl-2 family of proteins and overt activity of the phosphatidylinositol 3-kinase (PI3K) signaling pathway. Therefore, combined interference of the PI3K pathway and the Bcl-2 family of proteins is a reasonable therapeutic strategy. ABT-263 (Navitoclax), an orally available small-molecule Bcl-2 inhibitor, and GDC-0941, a PI3K inhibitor, were used to treat established glioblastoma and glioblastoma neurosphere cells, alone or in combination. Although GDC-0941 alone had a modest effect on cell viability, treatment with ABT-263 displayed a marked reduction of cell viability and induction of apoptotic cell death. Moreover, combinatorial therapy using ABT-263 and GDC-0941 showed an enhanced effect, with a further decrease in cellular viability. Furthermore, combination treatment abrogated the ability of stem cell-like glioma cells to form neurospheres. ABT-263 and GDC-0941, in combination, resulted in a consistent and significant increase of Annexin V positive cells and loss of mitochondrial membrane potential compared with either monotherapy. The combination treatment led to enhanced cleavage of both initiator and effector caspases. Mechanistically, GDC-0941 depleted pAKT (Serine 473) levels and suppressed Mcl-1 protein levels, lowering the threshold for the cytotoxic actions of ABT-263. GDC-0941 decreased Mcl-1 in a posttranslational manner and significantly decreased the half-life of Mcl-1 protein. Ectopic expression of human Mcl-1 mitigated apoptotic cell death induced by the drug combination. Furthermore, GDC-0941 modulated the phosphorylation status of BAD, thereby further enhancing ABT-263-mediated cell death. Combination therapy with ABT-263 and GDC-0941 has novel therapeutic potential by specifically targeting aberrantly active, deregulated pathways in GBM, overcoming

  5. Antioxidant and apoptotic effects of an aqueous extract of Urtica dioica on the MCF-7 human breast cancer cell line.

    Science.gov (United States)

    Fattahi, Sadegh; Ardekani, Ali Motevalizadeh; Zabihi, Ebrahim; Abedian, Zeinab; Mostafazadeh, Amrollah; Pourbagher, Roghayeh; Akhavan-Niaki, Haleh

    2013-01-01

    Breast cancer is the most prevalent cancer and one of the leading causes of death among women in the world. Plants and herbs may play an important role in complementary or alternative treatment. The aim of this study was to evaluate the antioxidant and anti-proliferative potential of Urtica dioica. The anti oxidant activity of an aqueous extract of Urtica dioica leaf was measured by MTT assay and the FRAP method while its anti-proliferative activity on the human breast cancer cell line (MCF-7) and fibroblasts isolated from foreskin tissue was evaluated using MTT assay. Mechanisms leading to apoptosis were also investigated at the molecular level by measuring the amount of anti and pro-apoptotic proteins and at the cellular level by studying DNA fragmentation and annexin V staining by flow cytometry. The aqueous extract of Urtica dioica showed antioxidant effects with a correlation coefficient of r(2)=0.997. Dose-dependent and anti-proliferative effects of the extract were observed only on MCF-7 cells after 72 hrs with an IC50 value of 2 mg/ml. This anti proliferative activity was associated with an increase of apoptosis as demonstrated by DNA fragmentation, the appearance of apoptotic cells in flow cytometry analysis and an increase of the amount of calpain 1, calpastatin, caspase 3, caspase 9, Bax and Bcl-2, all proteins involved in the apoptotic pathway. This is the first time such in vitro antiproliferative effect of aqueous extract of Urtica dioica leaf has been described for a breast cancer cell line. Our findings warrant further research on Urtica dioica as a potential chemotherapeutic agent for breast cancer.

  6. Discovery of Novel Bromophenol Hybrids as Potential Anticancer Agents through the Ros-Mediated Apoptotic Pathway: Design, Synthesis and Biological Evaluation

    Directory of Open Access Journals (Sweden)

    Li-Jun Wang

    2017-11-01

    Full Text Available A series of bromophenol hybrids with N-containing heterocyclic moieties were designed, and their anticancer activities against a panel of five human cancer cell lines (A549, Bel7402, HepG2, HCT116 and Caco2 using MTT assay in vitro were explored. Among them, thirteen compounds (17a, 17b, 18a, 19a, 19b, 20a, 20b, 21a, 21b, 22a, 22b, 23a, and 23b exhibited significant inhibitory activity against the tested cancer cell lines. The structure-activity relationships (SARs of bromophenol derivatives were discussed. The promising candidate compound 17a could induce cell cycle arrest at G0/G1 phase and induce apoptosis in A549 cells, as well as caused DNA fragmentations, morphological changes and ROS generation by the mechanism studies. Furthermore, compound 17a suppression of Bcl-2 levels (decrease in the expression of the anti-apoptotic proteins Bcl-2 and down-regulation in the expression levels of Bcl-2 in A549 cells were observed, along with activation caspase-3 and PARP, which indicated that compound 17a induced A549 cells apoptosis in vitro through the ROS-mediated apoptotic pathway. These results might be useful for bromophenol derivatives to be explored and developed as novel anticancer drugs.

  7. Exhaustive Training Increases Uncoupling Protein 2 Expression and Decreases Bcl-2/Bax Ratio in Rat Skeletal Muscle

    Directory of Open Access Journals (Sweden)

    W. Y. Liu

    2013-01-01

    Full Text Available This work investigates the effects of oxidative stress due to exhaustive training on uncoupling protein 2 (UCP2 and Bcl-2/Bax in rat skeletal muscles. A total of 18 Sprague-Dawley female rats were randomly divided into three groups: the control group (CON, the trained control group (TC, and the exhaustive trained group (ET. Malondialdehyde (MDA, superoxide dismutase (SOD, xanthine oxidase (XOD, ATPase, UCP2, and Bcl-2/Bax ratio in red gastrocnemius muscles were measured. Exhaustive training induced ROS increase in red gastrocnemius muscles, which led to a decrease in the cell antiapoptotic ability (Bcl-2/Bax ratio. An increase in UCP2 expression can reduce ROS production and affect mitochondrial energy production. Thus, oxidative stress plays a significant role in overtraining.

  8. Anti-hepatoma activity of a novel compound glaucocalyxin H in vivo and in vitro.

    Science.gov (United States)

    Hai, Guangfan; Zhang, Chong; Jia, Yanlong; Bai, Suping; Han, Jinfen; Guo, Lanqing; Cui, Taizhen; Niu, Bingxuan; Huang, Feng; Song, Yu

    2015-06-01

    Glaucocalyxin H (GLH) is a new compound isolated from a traditional Chinese medical herb Isodon japonica var. glaucocalyx which has been used for folk medicine. This study was carried out for the first time to investigate the potential role of GLH in anti-hepatoma activity and underlying mechanisms in it. GLH could inhibit the growth of tumor in mice and induce HepG2 cells to death as assessed by the tumor reduction assay, toxic assay, morphological change, and survival rate assay. Many antitumor drugs originated from plants could inhibit the growth of tumor by inducing cells to apoptosis. The morphological changes of HepG2 cells treated with different concentrations of GLH under fluorescence and electron microscope and apoptotic rates were detected to verify its effect on apoptosis. As shown in the study, GLH could induce HepG2 cells to apoptosis in a dose-dependent manner. Bcl2 and Bax proteins played important roles in apoptosis and the disequilibrium between Bcl2 and Bax might result in apoptosis. The expression of Bax protein was upregulated and Bcl2 protein was downregulated in HepG2 cells treated with GLH assessed by Western blotting, and they were in a dose-dependent manner. Taken together, GLH can inhibit the growth of hepatoma cells in vivo and in vitro by inducing cell apoptosis due to the decreased Bcl2 and increased Bax proteins suggesting that GLH could be a potential candidate as an anti-hepatoma agent for the therapeutic treatment of hepatoma.

  9. Phosphorylation of Rad9 at serine 328 by cyclin A-Cdk2 triggers apoptosis via interfering Bcl-xL.

    Directory of Open Access Journals (Sweden)

    Zhuo Zhan

    Full Text Available Cyclin A-Cdk2, a cell cycle regulated Ser/Thr kinase, plays important roles in a variety of apoptoticprocesses. However, the mechanism of cyclin A-Cdk2 regulated apoptosis remains unclear. Here, we demonstrated that Rad9, a member of the BH3-only subfamily of Bcl-2 proteins, could be phosphorylated by cyclin A-Cdk2 in vitro and in vivo. Cyclin A-Cdk2 catalyzed the phosphorylation of Rad9 at serine 328 in HeLa cells during apoptosis induced by etoposide, an inhibitor of topoisomeraseII. The phosphorylation of Rad9 resulted in its translocation from the nucleus to the mitochondria and its interaction with Bcl-xL. The forced activation of cyclin A-Cdk2 in these cells by the overexpression of cyclin A,triggered Rad9 phosphorylation at serine 328 and thereby promoted the interaction of Rad9 with Bcl-xL and the subsequent initiation of the apoptotic program. The pro-apoptotic effects regulated by the cyclin A-Cdk2 complex were significantly lower in cells transfected with Rad9S328A, an expression vector that encodes a Rad9 mutant that is resistant to cyclin A-Cdk2 phosphorylation. These findings suggest that cyclin A-Cdk2 regulates apoptosis through a mechanism that involves Rad9phosphorylation.

  10. Cisplatin induces expression of drug resistance-related genes through c-jun N-terminal kinase pathway in human lung cancer cells.

    Science.gov (United States)

    Xu, Li; Fu, Yingya; Li, Youlun; Han, Xiaoli

    2017-08-01

    Change of multidrug resistance-related genes (e.g., lung resistance protein, LRP) and overexpression of anti-apoptotic genes (Bcl-2, Bcl-Xl, XIAP, Survivin) are responsible for cisplatin resistance. In our study, we investigated the mechanism by which cisplatin induces LRP, Bcl-2, Bcl-xL, XIAP, and Survivin expression in human lung adenocarcinoma A549 cells and human H446 small cell lung cancer cells at mRNA and protein levels. In our study, cell proliferation was assessed with CCK-8 assays, and cell apoptosis was assessed with flow cytometric analysis and Annexin-V/PI staining. qPCR was used to complete RNA experiments. Protein expression was assessed with Western blotting. Cisplatin increased Bcl-2, LRP, and Survivin expression, but decreased Bcl-xL and XIAP expression in a dose-dependent manner. Preincubation with JNK-specific inhibitor, SP600125, significantly inhibited these genes' expression at mRNA and protein levels, enhanced chemosensitivity of lung cancer cells to cisplatin, and promoted cisplatin-induced apoptosis. Our data suggest that the JNK signaling pathway plays an important role in cisplatin resistance. Lung resistance protein (LRP) and anti-apoptotic genes (Bcl-2, Bcl-Xl, XIAP, Survivin) are involved in the process. The results reminded us of a novel therapy target for lung cancer treatment.

  11. Targeting the Anti-Apoptotic Protein c-FLIP for Cancer Therapy

    International Nuclear Information System (INIS)

    Safa, Ahmad R.; Pollok, Karen E.

    2011-01-01

    Cellular FLICE (FADD-like IL-1beta-converting enzyme)-inhibitory protein (c-FLIP) is a major resistance factor and critical anti-apoptotic regulator that inhibits tumor necrosis factor-alpha (TNF-alpha), Fas-L, and TNF-related apoptosis-inducing ligand (TRAIL)-induced apoptosis as well as chemotherapy-triggered apoptosis in malignant cells. c-FLIP is expressed as long (c-FLIP L ), short (c-FLIP S ), and c-FLIP R splice variants in human cells. c-FLIP binds to FADD and/or caspase-8 or -10 in a ligand-dependent and-independent fashion, which in turn prevents death-inducing signaling complex (DISC) formation and subsequent activation of the caspase cascade. Moreover, c-FLIP L and c-FLIP S are known to have multifunctional roles in various signaling pathways, as well as activating and/or upregulating several cytoprotective signaling molecules. Upregulation of c-FLIP has been found in various tumor types, and its downregulation has been shown to restore apoptosis triggered by cytokines and various chemotherapeutic agents. Hence, c-FLIP is an important target for cancer therapy. For example, small interfering RNAs (siRNAs) that specifically knockdown the expression of c-FLIP L in diverse human cancer cell lines augmented TRAIL-induced DISC recruitment and increased the efficacy of chemotherapeutic agents, thereby enhancing effector caspase stimulation and apoptosis. Moreover, small molecules causing degradation of c-FLIP as well as decreasing mRNA and protein levels of c-FLIP L and c-FLIP S splice variants have been found, and efforts are underway to develop other c-FLIP-targeted cancer therapies. This review focuses on (1) the functional role of c-FLIP splice variants in preventing apoptosis and inducing cytokine and drug resistance; (2) the molecular mechanisms that regulate c-FLIP expression; and (3) strategies to inhibit c-FLIP expression and function

  12. Deregulated expression of A1, Bcl-2, Bcl-xL, and Mcl-1 antiapoptotic proteins and Bid, Bad, and Bax proapoptotic genes in polycythemia vera patients

    Directory of Open Access Journals (Sweden)

    Elainy Patricia Lino Gasparotto

    2011-12-01

    Full Text Available Apoptosis deregulation might have a role in the pathophysiology of polycythemia vera (PV. This study evaluated Bcl-2 molecule expression in CD34+ cells and leukocytes in 12 PV patients. Gene expression was investigated by real time PCR using SybrGreen Quantitect kit and protein expression was evaluated by western-blotting. JAK2 V617F mutation was detected according to Baxter et al (2005. CD34+ cells from PV patients presented higher levels of A1 and Mcl-1 expression (median: 22.6 and 5.2, respectively in comparison with controls (0.9 and 0.5, p=0.004 and p=0.020; while Bcl-2 and Bcl-xL expression decreased in PV patients (0.18 and 1.19 compared with controls (1.39 and 2.01, p=0.006 and p=0.020. CD34+ cells in PV patients showed an elevated Bid expression (14.4 in comparison with healthy subjects (1.0; p=0.002. Patients' leukocytes showed an A1 augmentation (7.41, p=0.001 and a reduced expression of Bax (0.19; p=0.040 and Bad (0.2; p=0.030. There was no correlation between JAK2 V617F allele burden and molecular expression. PV patients showed alterations in Bcl-2 members' expression, which may interfere with control of apoptotic machinery and contribute to disease pathogenesis.A desregulação da apoptose parece participar da fisiopatologia da policitemia vera (PV. Este estudo avaliou a expressão das moléculas da família Bcl-2 em células hematopoéticas CD34 + e leucócitos de 12 pacientes com PV. Foram realizados: a quantificação da expressão gênica por PCR em tempo real utilizando kit Sybrgreen Quantitect, avaliação da expressão de proteínas por western-blot e detecção da mutação JAK2 V617F segundo Baxter et al. (2005. Células CD34 + dos pacientes com PV apresentaram maior expressão de A1 e Mcl-1 (mediana: 22,6 e 5,2, respectivamente em comparação com controles (0,9 e 0,5, p = 0,004 e p = 0,020 e expressão de Bcl-2 e Bcl-xL diminuída nestes pacientes (0,18 e 1,19 em relação aos controles (1,39 e 2,01, p = 0,006 e p = 0

  13. Pan-Cancer Analysis Links PARK2 to BCL-XL-Dependent Control of Apoptosis

    Directory of Open Access Journals (Sweden)

    Yongxing Gong

    2017-02-01

    Full Text Available Mutation of the PARK2 gene can promote both Parkinson's Disease and cancer, yet the underlying mechanisms of how PARK2 controls cellular physiology is incompletely understood. Here, we show that the PARK2 tumor suppressor controls the apoptotic regulator BCL-XL and modulates programmed cell death. Analysis of approximately 10,000 tumor genomes uncovers a striking pattern of mutual exclusivity between PARK2 genetic loss and amplification of BCL2L1, implicating these genes in a common pathway. PARK2 directly binds to and ubiquitinates BCL-XL. Inactivation of PARK2 leads to aberrant accumulation of BCL-XL both in vitro and in vivo, and cancer-specific mutations in PARK2 abrogate the ability of the ubiquitin E3 ligase to target BCL-XL for degradation. Furthermore, PARK2 modulates mitochondrial depolarization and apoptosis in a BCL-XL-dependent manner. Thus, like genes at the nodal points of growth arrest pathways such as p53, the PARK2 tumor suppressor is able to exert its antiproliferative effects by regulating both cell cycle progression and programmed cell death.

  14. Pattern of MAP kinases p44/42 and JNK activation by non-lethal doses of tributyltin in human natural killer cells

    Energy Technology Data Exchange (ETDEWEB)

    Aluoch, Aloice O. [Tennessee State University, Department of Biological Sciences, Nashville, TN (United States); Odman-Ghazi, Sabah O.; Whalen, Margaret M. [Tennessee State University, Department of Chemistry, Nashville, TN (United States)

    2007-04-15

    Tributyltin (TBT) has been shown to disrupt the ability of natural killer (NK) cells to destroy tumor targets in vitro even at exposures of 25 nM for 24 h, but cell viability was not significantly impacted. Thus, evaluation of intracellular molecular events that regulate cell viability in TBT exposed NK cells are of interest. It has been suggested that activation of the mitogen-activated protein kinase (MAPK), c-Jun N-terminal kinase (JNK), may promote apoptosis while activation of the MAPK p44/42 may be crucial in mediating anti-apoptotic stimuli. However, it is well established that increases in pro-apoptotic BCL-2 family members, such as Bax, results in cell death. We have set out to study the effects of a range of TBT concentrations on the MAPKs, JNK and p44/42. Additionally, we examined the effects of TBT on the levels of pro-apoptotic proteins Bax and p53 as well as anti-apoptotic protein Bcl-2. The results show that 300-25 nM TBT activated JNK within 10 min. MAPK p44/42 was also activated by 300-50 nM TBT within 10 min. These data show that while 300-200 nM TBT activates p44/42 significantly more than JNK, the pattern of 100-25 nM TBT activation of these MAPKs may be similar. TBT exposure alters neither pro-apoptotic proteins Bax and p53 nor anti-apoptotic protein Bcl-2 levels at any exposure studied. The results suggest that exposure to TBT activated the anti-apoptotic regulatory p44/42 pathway to a greater extent than the pro-apoptotic JNK pathway, which may explain to some extent how NK cell viability is maintained. (orig.)

  15. Effect of pregabalin on apoptotic regulatory genes in hippocampus of rats with chronic temporal lobe epilepsy

    Directory of Open Access Journals (Sweden)

    ZHANG Yi-dan

    2012-04-01

    Full Text Available Objective To observe the effect of pregabalin on the expression of Bcl-2 and Bax in hippocampus of chronic epileptic rats induced by pilocarpine, to explore the anti-epileptic pharmacology mechanism of pregabalin, and its anti-apoptotic effect on hippocampal neurons of rats. Methods The model of chronic temporal lobe epileptic rats induced by lithium-pilocarpine was established, then the rats in pregabalin treatment group received intraperitoneal injection of pregabalin (40 mg/kg once daily for three weeks. The expression of Bcl-2 and Bax in hippocampus of all rats was detected by immunohistochemical technique and Western blotting. Results Compared with normal saline group rats, the expression of Bcl-2 and Bax in hippocampus of rats with chronic temporal lobe epilepsy was significantly increased (P = 0.000, for all. Pregabalin can down-regulate the expression of Bax and up-regulate the expression of Bcl-2 in hippocampus of rats compared to model group rats (P = 0.000, for all. Conclusion Pregabalin may have the effects of inhibiting cell apoptosis and protecting neurons through lowing Bax level and increasing Bcl-2 level in hippocampus of chronic temporal lobe epileptic rats.

  16. Caspase-Mediated Anti-Apoptotic Effect of Ginsenoside Rg5, a Main Rare Ginsenoside, on Acetaminophen-Induced Hepatotoxicity in Mice.

    Science.gov (United States)

    Wang, Zi; Hu, Jun-Nan; Yan, Meng-Han; Xing, Jing-Jing; Liu, Wen-Cong; Li, Wei

    2017-10-25

    Frequent overdose of acetaminophen (APAP) is one of the most common and important incentives of acute hepatotoxicity. Prior to this work, our research group confirmed that black ginseng (Panax ginseng, BG) showed powerful protective effects on APAP-induced ALI. However, it is not clear which kind of individual ginsenoside from BG plays such a liver protection effect. The objective of the current investigation was to evaluate whether ginsenoside Rg5 (G-Rg5) protected against APAP-induced hepatotoxicity and the involved action mechanisms. Mice were administrated with G-Rg5 at two dosages of 10 or 20 mg/kg for 7 consecutive days. After the last treatment, all of the animals that received a single intraperitoneal injection of APAP (250 mg/kg) showed severe liver toxicity after 24 h, and the liver protection effects of G-Rg5 were examined. The results clearly indicated that pretreatment with G-Rg5 remarkably inhibited the production of serum tumor necrosis factor (TNF-α) and interleukin-1β (IL-1β) compared with the APAP group. Meanwhile, G-Rg5 decreased the hepatic malondialdehyde (MDA) content, the protein expression levels of 4-hydroxynonenal (4-HNE) and cytochrome P450 2E1 (CYP2E1) in the liver tissues. G-Rg5 decreased APAP caused the hepatic overexpression of cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS). Furthermore, analysis of immunohistochemistry and Western blotting also indicated that G-Rg5 pretreatment inhibited activation of apoptotic pathways mainly via increasing the expression of Bcl-2 protein, decreasing the expression of Bax protein, proliferating cell nuclear antigen (PCNA), cytochrome c, caspase-3, caspase-8, and caspase-9. Liver histopathological observation provided further evidence that pretreatment with G-Rg5 could significantly inhibit hepatocyte necrosis, inflammatory cell infiltration, and apoptosis caused by APAP. In conclusion, the present study clearly demonstrates that G-Rg5 exerts a liver protection effect against

  17. Effect of bcl-2 antisense oligodexynucleotides on chemotherapy efficacy of Vp-16 on human small cell lung cancer cell line NCI-H69

    International Nuclear Information System (INIS)

    He Wenqian; Liu Zhonghua

    2007-01-01

    Objective: To study the effect of bcl-2 antisense oligodexynucleotides on chemotherapy efficacy of Vp-16 on human small cell lung cancer cell line NCI-H69. Methods: Cultured NCI-H69 cells were derided into 4 groups: bcl-2 antisense oligodexynucleotides (ASODN) added, sense oligodexynucleotides (SODN) added, nonsense oligodexynucleotides (NSODN) added and control (no nucleotides added), the oligodexynucleotides were transfected into the cultured cells with oligofectamine. The cellular expression of Bcl-2 protein 72h later was examined with Western-Blot. The four different groups of cultured tumor cells were treated with etopside(Vp-16) at different concentrations (0, 0.25, 0.5, 1.0, 2.0 and 4.0 μg/ml) for 48hr then the cell survival fraction was assessed with MTY test. Results: The apoptotic rate of cells in the ASODN group was significantly higher than that of the control group, also, the survival fraction of cells in ASODN group was significantly lower than that of the control group. The Bcl-2 protein expression in ASODN group was significantly lower than that in the control group, but no inhibition was observed in SODN and NSODN groups. Conclusion: The bcl-2 ASODN could enhance the sensitivity to chemotherapy with Vp-16 in small cell lung cancer cell line NCI-H69 by effectively blocking bcl-2 gene expression. (authors)

  18. An Epstein-Barr virus anti-apoptotic protein constitutively expressed in transformed cells and implicated in burkitt lymphomagenesis: the Wp/BHRF1 link.

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    Gemma L Kelly

    2009-03-01

    Full Text Available Two factors contribute to Burkitt lymphoma (BL pathogenesis, a chromosomal translocation leading to c-myc oncogene deregulation and infection with Epstein-Barr virus (EBV. Although the virus has B cell growth-transforming ability, this may not relate to its role in BL since many of the transforming proteins are not expressed in the tumor. Mounting evidence supports an alternative role, whereby EBV counteracts the high apoptotic sensitivity inherent to the c-myc-driven growth program. In that regard, a subset of BLs carry virus mutants in a novel form of latent infection that provides unusually strong resistance to apoptosis. Uniquely, these virus mutants use Wp (a viral promoter normally activated early in B cell transformation and express a broader-than-usual range of latent antigens. Here, using an inducible system to express the candidate antigens, we show that this marked apoptosis resistance is mediated not by one of the extended range of EBNAs seen in Wp-restricted latency but by Wp-driven expression of the viral bcl2 homologue, BHRF1, a protein usually associated with the virus lytic cycle. Interestingly, this Wp/BHRF1 connection is not confined to Wp-restricted BLs but appears integral to normal B cell transformation by EBV. We find that the BHRF1 gene expression recently reported in newly infected B cells is temporally linked to Wp activation and the presence of W/BHRF1-spliced transcripts. Furthermore, just as Wp activity is never completely eclipsed in in vitro-transformed lines, low-level BHRF1 transcripts remain detectable in these cells long-term. Most importantly, recognition by BHRF1-specific T cells confirms that such lines continue to express the protein independently of any lytic cycle entry. This work therefore provides the first evidence that BHRF1, the EBV bcl2 homologue, is constitutively expressed as a latent protein in growth-transformed cells in vitro and, in the context of Wp-restricted BL, may contribute to virus

  19. Combination of Bcl-2 and MYC protein expression improves high-risk stratification in diffuse large B-cell lymphoma

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    Wang J

    2015-09-01

    Full Text Available Jing Wang,* Min Zhou,* Jing-Yan Xu,* Bing Chen, Jian OuyangDepartment of Hematology, The Affiliated Drum Tower Hospital of Nanjing University Medical School, Nanjing, Jiangsu, People’s Republic of China*These authors contributed equally to this work and should be considered as cofirst authorsPurpose: To evaluate whether the addition of two biological markers (MYC and BCL-2 protein overexpression improves the stratification of high-risk patients with diffuse large B-cell lymphoma (DLBCL.Method: Seven risk factors were identified at diagnosis, and a maximum of 7 points were assigned to each patient. The patients were classified according to four risk groups: low (0–1, low-intermediate (2–3, high-intermediate (4, and high (5–7. Only high-risk patients with DLBCL were included in this analysis. We retrospectively examined 20 cases from 2008 to 2013 at the Nanjing Drum Tower Hospital.Results: The median expression of MYC protein was 60%, and 17 of 20 (65% evaluable cases overexpressed MYC. The median expression of BCL-2 protein was also 60%. Eighteen of 20 (90% evaluable cases showed BCL-2 overexpression. Additionally, 12 out of 20 cases (60% demonstrated coexpression of MYC and BCL-2 proteins. The percentages of overall survival and progression-free survival at the median follow-up time (36 months were 33.3%±16.1% and 16.9%±13.5%, respectively. By comparison, nine, four, and 20 patients were classified as high risk based on the International Prognostic Index (IPI, National Comprehensive Cancer Network(NCCN-IPI, and revised IPI criteria, respectively. According to the IPI and NCCN-IPI stratification, the risk groups demonstrated closely overlapping survival curves. In addition, four out of 20 cases were identified as low-intermediate risk according to the NCCN-IPI criteria.Conclusion: The addition of MYC and BCL-2 protein expression to the IPI could identify a subset of DLBCL patients with high-risk clinicopathological characteristics and

  20. BCL-2 family protein, BAD is down-regulated in breast cancer and inhibits cell invasion.

    Science.gov (United States)

    Cekanova, Maria; Fernando, Romaine I; Siriwardhana, Nalin; Sukhthankar, Mugdha; De la Parra, Columba; Woraratphoka, Jirayus; Malone, Christine; Ström, Anders; Baek, Seung J; Wade, Paul A; Saxton, Arnold M; Donnell, Robert M; Pestell, Richard G; Dharmawardhane, Suranganie; Wimalasena, Jay

    2015-02-01

    We have previously demonstrated that the anti-apoptotic protein BAD is expressed in normal human breast tissue and shown that BAD inhibits expression of cyclin D1 to delay cell-cycle progression in breast cancer cells. Herein, expression of proteins in breast tissues was studied by immunohistochemistry and results were analyzed statistically to obtain semi-quantitative data. Biochemical and functional changes in BAD-overexpressing MCF7 breast cancer cells were evaluated using PCR, reporter assays, western blotting, ELISA and extracellular matrix invasion assays. Compared to normal tissues, Grade II breast cancers expressed low total/phosphorylated forms of BAD in both cytoplasmic and nuclear compartments. BAD overexpression decreased the expression of β-catenin, Sp1, and phosphorylation of STATs. BAD inhibited Ras/MEK/ERK and JNK signaling pathways, without affecting the p38 signaling pathway. Expression of the metastasis-related proteins, MMP10, VEGF, SNAIL, CXCR4, E-cadherin and TlMP2 was regulated by BAD with concomitant inhibition of extracellular matrix invasion. Inhibition of BAD by siRNA increased invasion and Akt/p-Akt levels. Clinical data and the results herein suggest that in addition to the effect on apoptosis, BAD conveys anti-metastatic effects and is a valuable prognostic marker in breast cancer. Copyright © 2014 Elsevier Inc. All rights reserved.

  1. Niclosamide, an anti-helminthic molecule, downregulates the retroviral oncoprotein Tax and pro-survival Bcl-2 proteins in HTLV-1-transformed T lymphocytes

    Energy Technology Data Exchange (ETDEWEB)

    Xiang, Di [Penn State Hershey Cancer Institute, Penn State University College of Medicine, Hershey, PA 17033 (United States); Yuan, Yunsheng [Penn State Hershey Cancer Institute, Penn State University College of Medicine, Hershey, PA 17033 (United States); Engineering Research Center of Cell and Therapeutic Antibody, Ministry of Education, School of Pharmacy, Shanghai Jiao Tong University, Shanghai (China); Chen, Li [Pharmacy College, Fujian University of Traditional Chinese Medicine, Fuzhou (China); Institute of Human Virology, University of Maryland School of Medicine, Baltimore, MD 21201 (United States); Liu, Xin; Belani, Chandra [Penn State Hershey Cancer Institute, Penn State University College of Medicine, Hershey, PA 17033 (United States); Cheng, Hua, E-mail: hcheng@ihv.umaryland.edu [Institute of Human Virology, University of Maryland School of Medicine, Baltimore, MD 21201 (United States); Marlene and Stewart Greenebaum Cancer Center, University of Maryland School of Medicine, Baltimore, MD 21201 (United States); Department of Medicine, University of Maryland School of Medicine, Baltimore, MD 21201 (United States); Department Microbiology and Immunology, University of Maryland School of Medicine, Baltimore, MD 21201 (United States)

    2015-08-14

    Adult T cell leukemia and lymphoma (ATL) is a highly aggressive form of hematological malignancy and is caused by chronic infection of human T cell leukemia virus type 1 (HTLV-1). The viral genome encodes an oncogenic protein, Tax, which plays a key role in transactivating viral gene transcription and in deregulating cellular oncogenic signaling to promote survival, proliferation and transformation of virally infected T cells. Hence, Tax is a desirable therapeutic target, particularly at early stage of HTLV-1-mediated oncogenesis. We here show that niclosamide, an anti-helminthic molecule, induced apoptosis of HTLV-1-transformed T cells. Niclosamide facilitated degradation of the Tax protein in proteasome. Consistent with niclosamide-mediated Tax degradation, this compound inhibited activities of MAPK/ERK1/2 and IκB kinases. In addition, niclosamide downregulated Stat3 and pro-survival Bcl-2 family members such as Mcl-1 and repressed the viral gene transcription of HTLV-1 through induction of Tax degradation. Since Tax, Stat3 and Mcl-1 are crucial molecules for promoting survival and growth of HTLV-1-transformed T cells, our findings demonstrate a novel mechanism of niclosamide in inducing Tax degradation and downregulating various cellular pro-survival molecules, thereby promoting apoptosis of HTLV-1-associated leukemia cells. - Highlights: • Niclosamide is a promising therapeutic candidate for adult T cell leukemia. • Niclosamide employs a novel mechanism through proteasomal degradation of Tax. • Niclosamide downregulates certain cellular pro-survival molecules.

  2. The Bcl-2 Family in Host-Virus Interactions.

    Science.gov (United States)

    Kvansakul, Marc; Caria, Sofia; Hinds, Mark G

    2017-10-06

    Members of the B cell lymphoma-2 (Bcl-2) family are pivotal arbiters of mitochondrially mediated apoptosis, a process of fundamental importance during tissue development, homeostasis, and disease. At the structural and mechanistic level, the mammalian members of the Bcl-2 family are increasingly well understood, with their interplay ultimately deciding the fate of a cell. Dysregulation of Bcl-2-mediated apoptosis underlies a plethora of diseases, and numerous viruses have acquired homologs of Bcl-2 to subvert host cell apoptosis and autophagy to prevent premature death of an infected cell. Here we review the structural biology, interactions, and mechanisms of action of virus-encoded Bcl-2 proteins, and how they impact on host-virus interactions to ultimately enable successful establishment and propagation of viral infections.

  3. Nickel oxide nanoparticles exert cytotoxicity via oxidative stress and induce apoptotic response in human liver cells (HepG2).

    Science.gov (United States)

    Ahamed, Maqusood; Ali, Daoud; Alhadlaq, Hisham A; Akhtar, Mohd Javed

    2013-11-01

    Increasing use of nickel oxide nanoparticles (NiO NPs) necessitates an improved understanding of their potential impact on human health. Previously, toxic effects of NiO NPs have been investigated, mainly on airway cells. However, information on effect of NiO NPs on human liver cells is largely lacking. In this study, we investigated the reactive oxygen species (ROS) mediated cytotoxicity and induction of apoptotic response in human liver cells (HepG2) due to NiO NPs exposure. Prepared NiO NPs were crystalline and spherical shaped with an average diameter of 44 nm. NiO NPs induced cytotoxicity (cell death) and ROS generation in HepG2 cells in dose-dependent manner. Further, ROS scavenger vitamin C reduced cell death drastically caused by NiO NPs exposure indicating that oxidative stress plays an important role in NiO NPs toxicity. Micronuclei induction, chromatin condensation and DNA damage in HepG2 cells treated with NiO NPs suggest that NiO NPs induced cell death via apoptotic pathway. Quantitative real-time PCR analysis showed that following the exposure of HepG2 cells to NiO NPs, the expression level of mRNA of apoptotic genes (bax and caspase-3) were up-regulated whereas the expression level of anti-apoptotic gene bcl-2 was down-regulated. Moreover, activity of caspase-3 enzyme was also higher in NiO NPs treated cells. To the best of our knowledge this is the first report demonstrating that NiO NPs caused cytotoxicity via ROS and induced apoptosis in HepG2 cells, which is likely to be mediated through bax/bcl-2 pathway. This work warrants careful assessment of Ni NPs before their commercial and industrial applications. Copyright © 2013 Elsevier Ltd. All rights reserved.

  4. Inhibition of p38 MAPK enhances ABT-737-induced cell death in melanoma cell lines: novel regulation of PUMA.

    Science.gov (United States)

    Keuling, Angela M; Andrew, Susan E; Tron, Victor A

    2010-06-01

    The mitogen-activated protein kinase (MAPK) pathway is constitutively activated in the majority of melanomas, promoting cell survival, proliferation and migration. In addition, anti-apoptotic Bcl-2 family proteins Mcl-1, Bcl-xL and Bcl-2 are frequently overexpressed, contributing to melanoma's well-documented chemoresistance. Recently, it was reported that the combination of MAPK pathway inhibition by specific MEK inhibitors and Bcl-2 family inhibition by BH3-mimetic ABT-737 synergistically induces apoptotic cell death in melanoma cell lines. Here we provide the first evidence that inhibition of another key MAPK, p38, synergistically induces apoptosis in melanoma cells in combination with ABT-737. We also provide novel mechanistic data demonstrating that inhibition of p38 increases expression of pro-apoptotic Bcl-2 protein PUMA. Furthermore, we demonstrate that PUMA can be cleaved by a caspase-dependent mechanism during apoptosis and identify what appears to be the PUMA cleavage product. Thus, our findings suggest that the combination of ABT-737 and inhibition of p38 is a promising, new treatment strategy that acts through a novel PUMA-dependent mechanism.

  5. Inhibition of doxorubicin-induced senescence by PPARδ activation agonists in cardiac muscle cells: cooperation between PPARδ and Bcl6.

    Directory of Open Access Journals (Sweden)

    Paola Altieri

    Full Text Available Senescence and apoptosis are two distinct cellular programs that are activated in response to a variety of stresses. Low or high doses of the same stressor, i.e., the anticancer drug doxorubicin, may either induce apoptosis or senescence, respectively, in cardiac muscle cells. We have demonstrated that PPARδ, a ligand-activated transcriptional factor that controls lipid metabolism, insulin sensitivity and inflammation, is also involved in the doxorubicin-induced senescence program. This occurs through its interference with the transcriptional repressor protein B cell lymphoma-6 (Bcl6. Low doses of doxorubicin increase the expression of PPARδ that sequesters Bcl6, thus preventing it from exerting its anti-senescent effects. We also found that L-165041, a specific PPARδ activator, is highly effective in protecting cardiomyocytes from doxorubicin-induced senescence through a Bcl6 related mechanism. In fact, L-165041 increases Bcl6 expression via p38, JNK and Akt activation, and at the same time it induces the release of Bcl6 from PPARδ, thereby enabling Bcl6 to bind to its target genes. L-165041 also prevented apoptosis induced by higher doses of doxorubicin. However, while experiments performed with siRNA analysis techniques very clearly showed the weight of Bcl6 in the cellular senescence program, no role was found for Bcl6 in the anti-apoptotic effects of L-165041, thus confirming that senescence and apoptosis are two very distinct stress response cellular programs. This study increases our understanding of the molecular mechanism of anthracycline cardiotoxicity and suggests a potential role for PPARδ agonists as cardioprotective agents.

  6. A Subpopulation of the K562 Cells Are Killed by Curcumin Treatment after G2/M Arrest and Mitotic Catastrophe.

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    Macario Martinez-Castillo

    Full Text Available Curcumin is extensively investigated as a good chemo-preventive agent in the development of many cancers and particularly in leukemia, including treatment of chronic myelogenous leukemia and it has been proposed as an adjuvant for leukemia therapies. Human chronic myeloid leukemia cells (K562, were treated with 20 μM of curcumin, and we found that a subpopulation of these cells were arrested and accumulate in the G2/M phase of the cell cycle. Characterization of this cell subpopulation showed that the arrested cells presented nuclear morphology changes resembling those described for mitotic catastrophe. Mitotic cells displayed abnormal chromatin organization, collapse of the mitotic spindle and abnormal chromosome segregation. Then, these cells died in an apoptosis dependent manner and showed diminution in the protein levels of BCL-2 and XIAP. Moreover, our results shown that a transient activation of the nuclear factor κB (NFκB occurred early in these cells, but decreased after 6 h of the treatment, explaining in part the diminution of the anti-apoptotic proteins. Additionally, P73 was translocated to the cell nuclei, because the expression of the C/EBPα, a cognate repressor of the P73 gene, was decreased, suggesting that apoptosis is trigger by elevation of P73 protein levels acting in concert with the diminution of the two anti-apoptotic molecules. In summary, curcumin treatment might produce a P73-dependent apoptotic cell death in chronic myelogenous leukemia cells (K562, which was triggered by mitotic catastrophe, due to sustained BAX and survivin expression and impairment of the anti-apoptotic proteins BCL-2 and XIAP.

  7. Complex molecular mechanisms cooperate to mediate histone deacetylase inhibitors anti-tumour activity in neuroblastoma cells

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    Nardou Katya

    2008-06-01

    Full Text Available Abstract Background Histone deacetylase inhibitors (HDACi are a new class of promising anti-tumour agent inhibiting cell proliferation and survival in tumour cells with very low toxicity toward normal cells. Neuroblastoma (NB is the second most common solid tumour in children still associated with poor outcome in higher stages and, thus NB strongly requires novel treatment modalities. Results We show here that the HDACi Sodium Butyrate (NaB, suberoylanilide hydroxamic acid (SAHA and Trichostatin A (TSA strongly reduce NB cells viability. The anti-tumour activity of these HDACi involved the induction of cell cycle arrest in the G2/M phase, followed by the activation of the intrinsic apoptotic pathway, via the activation of the caspases cascade. Moreover, HDACi mediated the activation of the pro-apoptotic proteins Bid and BimEL and the inactivation of the anti-apoptotic proteins XIAP, Bcl-xL, RIP and survivin, that further enhanced the apoptotic signal. Interestingly, the activity of these apoptosis regulators was modulated by several different mechanisms, either by caspases dependent proteolytic cleavage or by degradation via the proteasome pathway. In addition, HDACi strongly impaired the hypoxia-induced secretion of VEGF by NB cells. Conclusion HDACi are therefore interesting new anti-tumour agents for targeting highly malignant tumours such as NB, as these agents display a strong toxicity toward aggressive NB cells and they may possibly reduce angiogenesis by decreasing VEGF production by NB cells.

  8. Anti-apoptotic signaling and failure of apoptosis in the ischemic rat hippocampus

    DEFF Research Database (Denmark)

    Müller, Georg Johannes; Lassmann, Hans; Johansen, Flemming Fryd

    2007-01-01

    Several anti-apoptotic proteins are induced in CA1 neurons after transient forebrain ischemia (TFI), but fail to protect the majority of these cells from demise. Correlating cell death morphologies (apoptosis-like and necrosis-like death) with immunohistochemistry (IHC), we investigated whether...... anti-apoptosis contributes to survival, compromises apoptosis effector functions and/or delays death in CA1 neurons 1-7 days after TFI. As surrogate markers for bioenergetic failure, the IHC of respiratory chain complex (RCC) subunits was investigated. Dentate granule cell (DGC) apoptosis following...... colchicine injection severed as a reference for classical apoptosis. Heat shock protein 70 (Hsp70), neuronal apoptosis inhibitory protein (NAIP) and manganese superoxide dismutase (MnSOD) were upregulated in the majority of intact CA1 neurons paralleling the occurrence of CA1 neuronal death (days 3...

  9. Homologous recombination in mammalian cells: effect of p53 and Bcl-2 proteins, replication inhibition and ionizing radiations

    International Nuclear Information System (INIS)

    Saintigny, Yannick

    1999-01-01

    The control of cell cycle, associated with the mechanisms of replication, DNA repair/recombination allows the cells to maintain their genetic integrity. The p53 protein ensures the control of G1/S transition. Its inactivation would allow to initial replication on damaged matrix and lead to the block of replication forks followed by DNA strand breaks, good substrates for recombination. This work shows that the expression of mutant p53 protein stimulates both spontaneous and radio-induced homologous recombination, independently of the control of cell cycle. Moreover, the use of a set of replication inhibitors show that inhibition of the replication elongation stimulates recombination more strongly than the initiation inhibition. Replication arrest by these inhibitors also significantly increases the number of DNA strand breaks. These results highlighted a point of action of p53 protein on the ultimate stages of the homologous recombination mechanism. Lastly, the expression of Bcl-2 protein inhibits apoptosis and increases survival, but specifically inhibits conservative recombination, after radiation as well as in absence of apoptotic stress. The extinction of this mechanism of DNA repair is associated with an increase of mutagenesis. Taken together, these results allow ta consider the maintenance of the genetic stability as a cellular network involving different pathways. A multiple stages model for tumoral progression can be deduced. (author) [fr

  10. Bcl-2 overexpression: effects on transmembrane calcium movement

    International Nuclear Information System (INIS)

    Rangaswami, Arun A.; Premack, Brett; Walleczek, Jan; Killoran, Pamela; Gardner, Phyllis; Knox, Susan J.

    1996-01-01

    Purpose/Objective: High levels of expression of the proto-oncogene bcl-2 and its 26 kD protein product Bcl-2 have been correlated with the inhibition of apoptosis and the increased resistance of tumor cells to cytotoxic drugs and ionizing radiation. Unfortunately, the specific mechanism of action of Bcl-2 remains poorly understood. In the studies described here, the role of intracellular calcium fluxes and plasma membrane calcium cycling in the induction of apoptosis, and the effect of Bcl-2 expression on the modulation of transmembrane calcium fluxes following treatment of cells with cytotoxic agents were studied. The relationship between intracellular calcium release, capacitive calcium entry, and the plasma membrane potential were also investigated. Materials and Methods: Human B-cell lymphoma (PW) and human promyelocytic leukemia (HL60) cell lines were transfected with Bcl-2 and a control vector. The Bcl-2 transfectants over expressed the Bcl-2 onco-protein and were more resistant to irradiation than the control cells. Cells were loaded with fluorescent indicators indo-1 and fura-2 AM to quantify the cytosolic calcium concentration and subsequent calcium responses to a variety of cytotoxic stimuli, including the microsomal ATPase inhibitor, thapsigargin, using fluorometric measurements. Comparisons of resting and stimulated cytosolic calcium concentrations were made between the parental, neomycin control, and bcl-2 transfected cells. In order to determine the actual calcium influx rate, cells were loaded with either indo-1 or fura-2 and then exposed to 0.1 mM extracellular manganese, which enters the cells through calcium influx channels and quenches the fluorescent signal in proportion to the calcium influx rate. In order to determine the role of the membrane potential in driving calcium influx, cells were treated with either 0.1 μM Valinomycin or isotonic potassium chloride to either hyper polarize or depolarize the resting membrane potential, and the

  11. The BH3 mimetic ABT-737 targets selective Bcl-2 proteins and efficiently induces apoptosis via Bak/Bax if Mcl-1 is neutralized

    OpenAIRE

    van Delft, Mark F.; Wei, Andrew H.; Mason, Kylie D.; Vandenberg, Cassandra J.; Chen, Lin; Czabotar, Peter E.; Willis, Simon N.; Scott, Clare L.; Day, Catherine L.; Cory, Suzanne; Adams, Jerry M.; Roberts, Andrew W.; Huang, David C.S.

    2006-01-01

    Since apoptosis is impaired in malignant cells overexpressing pro-survival Bcl-2 proteins, drugs mimicking their natural antagonists, BH3-only proteins, might overcome chemoresistance. Of seven putative BH3 mimetics tested, only ABT-737 triggered Bax/Bak-mediated apoptosis. Despite its high affinity for Bcl-2, Bcl-xL and Bcl-w, many cell types proved refractory to ABT-737. We show that this resistance reflects its inability to target another pro-survival relative, Mcl-1. Down-regulation of Mc...

  12. ROS-mediated apoptotic cell death in prostate cancer LNCaP cells induced by biosurfactant stabilized CdS quantum dots.

    Science.gov (United States)

    Singh, Braj R; Singh, Brahma N; Khan, W; Singh, H B; Naqvi, A H

    2012-08-01

    Cadmium sulfide (CdS) quantum dots (QDs) have raised great attention because of their superior optical properties and wide utilization in biological and biomedical studies. However, little is known about the cell death mechanisms of CdS QDs in human cancer cells. This study was designed to investigate the possible mechanisms of apoptosis induced by biosurfactant stabilized CdS QDs (denoted as "bsCdS QDs") in human prostate cancer LNCaP cells. It was also noteworthy that apoptosis correlated with reactive oxygen species (ROS) production, mitochondrial damage, oxidative stress and chromatin condensation in a dose- and time-dependent manner. Results also showed involvement of caspases, Bcl-2 family proteins, heat shock protein 70, and a cell-cycle checkpoint protein p53 in apoptosis induction by bsCdS QDs in LNCaP cells. Moreover, pro-apoptotic protein Bax was upregulated and the anti-apoptotic proteins, survivin and NF-κB were downregulated in bsCdS QDs exposed cells. Protection of N-acetyl cysteine (NAC) against ROS clearly suggested the implication of ROS in hyper-activation of apoptosis and cell death. It is encouraging to conclude that biologically stabilized CdS QDs bear the potential of its applications in biomedicine, such as tumor therapy specifically by inducing caspase-dependent apoptotic cell death of human prostate cancer LNCaP cells. Crown Copyright © 2012. Published by Elsevier Ltd. All rights reserved.

  13. The combinatorial PP1-binding consensus Motif (R/Kx( (0,1V/IxFxx(R/Kx(R/K is a new apoptotic signature.

    Directory of Open Access Journals (Sweden)

    Angélique N Godet

    Full Text Available BACKGROUND: Previous studies established that PP1 is a target for Bcl-2 proteins and an important regulator of apoptosis. The two distinct functional PP1 consensus docking motifs, R/Kx((0,1V/IxF and FxxR/KxR/K, involved in PP1 binding and cell death were previously characterized in the BH1 and BH3 domains of some Bcl-2 proteins. PRINCIPAL FINDINGS: In this study, we demonstrate that DPT-AIF(1, a peptide containing the AIF(562-571 sequence located in a c-terminal domain of AIF, is a new PP1 interacting and cell penetrating molecule. We also showed that DPT-AIF(1 provoked apoptosis in several human cell lines. Furthermore, DPT-APAF(1 a bi-partite cell penetrating peptide containing APAF-1(122-131, a non penetrating sequence from APAF-1 protein, linked to our previously described DPT-sh1 peptide shuttle, is also a PP1-interacting death molecule. Both AIF(562-571 and APAF-1(122-131 sequences contain a common R/Kx((0,1V/IxFxxR/KxR/K motif, shared by several proteins involved in control of cell survival pathways. This motif combines the two distinct PP1c consensus docking motifs initially identified in some Bcl-2 proteins. Interestingly DPT-AIF(2 and DPT-APAF(2 that carry a F to A mutation within this combinatorial motif, no longer exhibited any PP1c binding or apoptotic effects. Moreover the F to A mutation in DPT-AIF(2 also suppressed cell penetration. CONCLUSION: These results indicate that the combinatorial PP1c docking motif R/Kx((0,1V/IxFxxR/KxR/K, deduced from AIF(562-571 and APAF-1(122-131 sequences, is a new PP1c-dependent Apoptotic Signature. This motif is also a new tool for drug design that could be used to characterize potential anti-tumour molecules.

  14. Silver Nanoparticles Exhibit the Dose-Dependent Anti-Proliferative Effect against Human Squamous Carcinoma Cells Attenuated in the Presence of Berberine

    Directory of Open Access Journals (Sweden)

    Arkadiusz Dziedzic

    2016-03-01

    Full Text Available The biological activity of nanosize silver particles towards oral epithelium-derived carcinoma seems to be still underinvestigated. We evaluated the influence of low doses of nanosize scale silver particles on the proliferation and viability of malignant oral epithelial keratinocytes in vitro, alone and in conjunction with the plant alkaloid berberine. Cells of human tongue squamous carcinoma SCC-25 (ATCC CRL-1628, cultivated with the mixture of Dulbecco's modified Eagle’s medium, were exposed to silver nanoparticles alone (AgNPs, concentrations from 0.31 to 10 μg/mL and to a combination of AgNPs with berberine chloride (BER, 1/2 IC50 concentration during 24 h and 48 h. The cytotoxic activity of AgNPs with diameters of 10 nm ± 4 nm was measured by 3-(4,5-dimethyl-2-thiazyl-2,5-diphenyl-2H-tetrazolium bromide (MTT assay. Cell cycle analysis was performed by treating cells with propidium iodide followed by flow-activated cell sorting. RT-QPCR reaction was used to assess expression of anti-apoptotic proteins Bcl-2 and pro-apoptotic protein Bcl-2-associated X protein Bax genes expression. Monodisperse silver nanoparticles at a concentration of 10 μg/mL arrested SCC-25 cells cycle after 48 h at the G0/G1 phase in a dose- and time-dependent manner through disruption G0/G1 checkpoint, with increase of Bax/Bcl-2 ratio gene expression. AgNPs exhibit cytotoxic effects on SCC-25 malignant oral epithelial keratinocytes, which is diminished when combined with BER. The AgNPs concentration required to inhibit the growth of carcinoma cells by 50% (IC50 after 48 h was estimated at 5.19 μg/mL. AgNPs combined with BER increased the expression of Bcl-2 while decreasing the ratio of Bax/Bcl-2 in SCC-25 cells. Silver particles at low doses therefore reduce the proliferation and viability of oral squamous cell carcinoma cells. SCC-25 cells are susceptible to damage from AgNPs-induced stress, which can be regulated by the natural alkaloid berberine, suggesting

  15. Apoptosis, proliferation, Bax, Bcl-2 and p53 status prior to and after preoperative radiochemotherapy for locally advanced rectal cancer

    International Nuclear Information System (INIS)

    Tannapfel, Andrea; Nuesslein, Siegfried; Fietkau, Rainer; Katalinic, Alexander; Koeckerling, Ferdinand; Wittekind, Christian

    1998-01-01

    Purpose: To investigate the relationship between apoptotic cell death, proliferative activity, and the expression of apoptosis regulating proteins in rectal cancer prior to and after radiochemotherapy. Materials and Methods: In 32 patients dispositioned to receive preoperative radiochemotherapy for locally advanced rectal carcinoma, pretherapy biopsies and the final resected specimen after radiochemotherapy were available for analyses. Apoptotic cells were identified and quantified using in situ end labeling (ISEL) technique. The expression of the bax protein was assessed immunohistochemically. Additionally, double immunostaining was performed for apoptotic cells and bax expression. The proliferative activity was determined by immunohistochemical assessment of the Ki67 (MIB-1) and the proliferating cell nuclear antigen (PCNA). p53- and bcl-2 expression was analyzed immunohistochemically. A clinical-to-pathologic downstaging after radiochemotherapy was achieved in 25 of 32 patients (78%). During follow-up, tumor recurrence was observed in six cases. In one case, no residual tumor was detected after radiochemotherapy. Results: After radiochemotherapy, the apoptotic index increased significantly in almost every case examined. In contrast, the proliferative activity was significantly decreased in resected specimens as compared to biopsies. Bax immunostaining was detected in 12/31 (39%) biopsies and in 26/31 (84%) resected specimens. In the resected specimen, significantly more apoptotic cells that were bax-positive were found than in biopsies. Bcl-2 immunostaining occurred in 15/31 biopsies and 12/31 resected specimens, respectively. Tumors that were immunohistochemically negative for p53 (20/31 [65%]) generally exhibited a higher apoptotic index and a high expression level of bax than p53-positive tumors (11/31 [35%]). However, we did not find any correlation between the (pre- and post-therapeutic) rate of apoptosis or the level of bax expression and the degree of

  16. Anti-inflammatory and apoptotic effects of the polyphenol curcumin on human fibroblast-like synoviocytes.

    Science.gov (United States)

    Kloesch, Burkhard; Becker, Tatjana; Dietersdorfer, Elisabeth; Kiener, Hans; Steiner, Guenter

    2013-02-01

    It has recently been reported that the polyphenol curcumin has pronounced anti-carcinogenic, anti-inflammatory and pro-apoptotic properties. This study investigated possible anti-inflammatory and apoptotic effects of curcumin on the human synovial fibroblast cell line MH7A, and on fibroblast-like synoviocytes (FLS) derived from patients with rheumatoid arthritis (RA). MH7A cells and RA-FLS were stimulated either with interleukin (IL)-1β or phorbol 12-myristate 13 acetate (PMA), and treated simultaneously or sequentially with increasing concentrations of curcumin. Release of interleukin (IL)-6 and vascular endothelial growth factor (VEGF)-A was quantified by enzyme-linked immunosorbent assays (ELISAs). In MH7A cells, modulation of the transcription factor nuclear factor kappa-B (NF-κB) and mitogen-activated protein kinases (MAPKs) such as p38 and extracellular-signal regulated kinase (ERK1/2) were analysed by a reporter gene assay and Western blot, respectively. Pro-apoptotic events were monitored by Annexin-V/7-AAD based assay. Cleavage of pro-caspase-3 and -7 was checked with specific antibodies. Curcumin effectively blocked IL-1β and PMA-induced IL-6 expression both in MH7A cells and RA-FLS. VEGF-A expression could only be detected in RA-FLS and was induced by PMA, but not by IL-1β. Furthermore, curcumin inhibited activation of NF-κB and induced dephosphorylation of ERK1/2. Treatment of FLS with high concentrations of curcumin was associated with a decrease in cell viability and induction of apoptosis. The natural compound curcumin represents strong anti-inflammatory properties and induces apoptosis in FLS. This study provides an insight into possible molecular mechanisms of this substance and suggests it as a natural remedy for the treatment of chronic inflammatory diseases like RA. Copyright © 2013 Elsevier B.V. All rights reserved.

  17. Loss of functional E-cadherin renders cells more resistant to the apoptotic agent taxol in vitro

    International Nuclear Information System (INIS)

    Ferreira, Paulo; Oliveira, Maria Jose; Beraldi, Eliana; Mateus, Ana Rita; Nakajima, Takashi; Gleave, Martin; Yokota, Jun; Carneiro, Fatima; Huntsman, David; Seruca, Raquel; Suriano, Gianpaolo

    2005-01-01

    Experimental evidence supports a role for E-cadherin in suppressing invasion, metastasis, and proliferation. Germline mutations of the E-cadherin represent the genetic cause of hereditary diffuse gastric cancer (HDGC). In this type of tumor, isolated cancer cells permeate the basal membrane and paradoxically survive in the gastric wall in the absence of contact with neighbor epithelial cells or with the extracellular matrix. This suggests that upon E-cadherin deregulation, cells acquired resistance to apoptosis. To test this hypothesis, CHO cells stably expressing either wild-type E-cadherin or the HDGC-related germline mutations T340A and V832M were seeded either on a thin layer of collagen type I or on plastic and then subjected to the apoptotic agent taxol. We found that in vitro functional E-cadherin renders cells more sensitive to the effect of taxol. Our results also indicate that this effect is associated to decreased level of the anti-apoptotic bcl-2 protein

  18. Sheeppox virus SPPV14 encodes a Bcl-2-like cell death inhibitor that counters a distinct set of mammalian proapoptotic proteins.

    Science.gov (United States)

    Okamoto, Toru; Campbell, Stephanie; Mehta, Ninad; Thibault, John; Colman, Peter M; Barry, Michele; Huang, David C S; Kvansakul, Marc

    2012-11-01

    Many viruses express inhibitors of programmed cell death (apoptosis), thereby countering host defenses that would otherwise rapidly clear infected cells. To counter this, viruses such as adenoviruses and herpesviruses express recognizable homologs of the mammalian prosurvival protein Bcl-2. In contrast, the majority of poxviruses lack viral Bcl-2 (vBcl-2) homologs that are readily identified by sequence similarities. One such virus, myxoma virus, which is the causative agent of myxomatosis, expresses a virulence factor that is a potent inhibitor of apoptosis. In spite of the scant sequence similarity to Bcl-2, myxoma virus M11L adopts an almost identical 3-dimensional fold. We used M11L as bait in a sequence similarity search for other Bcl-2-like proteins and identified six putative vBcl-2 proteins from poxviruses. Some are potent inhibitors of apoptosis, in particular sheeppox virus SPPV14, which inhibited cell death induced by multiple agents. Importantly, SPPV14 compensated for the loss of antiapoptotic F1L in vaccinia virus and acts to directly counter the cell death mediators Bax and Bak. SPPV14 also engages a unique subset of the death-promoting BH3-only ligands, including Bim, Puma, Bmf, and Hrk. This suggests that SPPV14 may have been selected for specific biological roles as a virulence factor for sheeppox virus.

  19. Bad and Bid - potential background players in preneoplastic to neoplastic shift in human endometrium.

    Science.gov (United States)

    Driak, D; Dvorska, M; Bolehovska, P; Svandova, I; Novotny, J; Halaska, M

    2014-01-01

    The most common malignancies of the female genital tract are endometrial carcinomas, whose are generally proceeded by hyperplasia. The maintenance of tissue homeostasis is to great extent governed by apoptosis, whose defects can lead to the preneoplastic and/or cancerous changes. Endometrial apoptosis involves among others three groups of proteins of the Bcl-2 family. First group contains anti-apoptotic proteins (e. g. Bcl-2, Bcl-xL). The other two groups belong to the pro-apoptotic proteins with three (e. g. Bax, Bak) or one (e. g. Bad, Bid) so-called BH domains. Bad and Bid trigger the oligomerization of Bak and Bax protein, which permeabilize the outer mitochondrial wall. Unlike Bid, Bad cannot directly trigger apoptosis. Instead, Bad lowers the threshold at which apoptosis is induced, by binding anti-apoptotic Bcl-2 proteins. However, their mutual counterbalance or synergism in the human endometrium has not been reported yet.In this study, the levels of Bid and Bad were measured using SDS-PAGE and Western blotting with specific antibodies, with the aim to analyse expression of Bid and Bad proteins in normal (NE), hyperplastic (HE) and cancerous (CE) endometrium. We demonstrated that Bid expression in CE reached only 47% and 50% of this observed in NE and HE. Conversely, Bad expression in HE reached only 40% and 36% of this observed in NE and CE, respectively. We detected no significant changes of Bid expression between HE and NE, and levels of Bad protein were not different between CE and NE.Trend of Bid and Bad protein expression is clearly opposite in HE and CE. We hypothesise that disrupted apoptotic program in CE seems to be reduced further by lowering levels of direct apoptotic trigger protein Bid. We suggest that the adenocarcinoma tissue of human endometrium thus tries to strengthen its apoptotic effort by lowering the apoptotic threshold via higher Bad levels.

  20. BH3-only protein Bim inhibits activity of antiapoptotic members of Bcl-2 family when expressed in yeast.

    Science.gov (United States)

    Juhásová, Barbora; Mentel, Marek; Bhatia-Kiššová, Ingrid; Zeman, Igor; Kolarov, Jordan; Forte, Michael; Polčic, Peter

    2011-09-02

    Proteins of the Bcl-2 family regulate programmed cell death in mammals by promoting the release of cytochrome c from mitochondria in response to various proapoptotic stimuli. The mechanism by which BH3-only members of the family activate multidomain proapoptotic proteins Bax and Bak to form a pore in mitochondrial membranes remains under dispute. We report that cell death promoting activity of BH3-only protein Bim can be reconstituted in yeast when both Bax and antiapoptotic protein Bcl-X(L) are present, suggesting that Bim likely activates Bax indirectly by inhibiting antiapoptotic proteins. Copyright © 2011 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.

  1. BCL-2: Long and winding path from discovery to therapeutic target

    International Nuclear Information System (INIS)

    Schenk, Robyn L.; Strasser, Andreas; Dewson, Grant

    2017-01-01

    In 1988, the BCL-2 protein was found to promote cancer by limiting cell death rather than enhancing proliferation. This discovery set the wheels in motion for an almost 30 year journey involving many international research teams that has recently culminated in the approval for a drug, ABT-199/venetoclax/Venclexta that targets this protein in the treatment of cancer. This review will describe the long and winding path from the discovery of this protein and understanding the fundamental process of apoptosis that BCL-2 and its numerous homologues control, through to its exploitation as a drug target that is set to have significant benefit for cancer patients. - Highlights: • BCL-2 proteins control the intrinsic or mitochondrial pathway of apoptosis. • Defective apoptosis is a hallmark of cancer. • BH3-mimetics inhibit pro-survival BCL-2 proteins to induce cancer cell death. • ABT-199/venetoclax is approved for treatment of chronic lymphocytic leukaemia.

  2. Canonical Bcl-2 motifs of the Na+/K+ pump revealed by the BH3 mimetic chelerythrine: early signal transducers of apoptosis?

    Science.gov (United States)

    Lauf, Peter K; Heiny, Judith; Meller, Jarek; Lepera, Michael A; Koikov, Leonid; Alter, Gerald M; Brown, Thomas L; Adragna, Norma C

    2013-01-01

    Chelerythrine [CET], a protein kinase C [PKC] inhibitor, is a prop-apoptotic BH3-mimetic binding to BH1-like motifs of Bcl-2 proteins. CET action was examined on PKC phosphorylation-dependent membrane transporters (Na+/K+ pump/ATPase [NKP, NKA], Na+-K+-2Cl+ [NKCC] and K+-Cl- [KCC] cotransporters, and channel-supported K+ loss) in human lens epithelial cells [LECs]. K+ loss and K+ uptake, using Rb+ as congener, were measured by atomic absorption/emission spectrophotometry with NKP and NKCC inhibitors, and Cl- replacement by NO3ˉ to determine KCC. 3H-Ouabain binding was performed on a pig renal NKA in the presence and absence of CET. Bcl-2 protein and NKA sequences were aligned and motifs identified and mapped using PROSITE in conjunction with BLAST alignments and analysis of conservation and structural similarity based on prediction of secondary and crystal structures. CET inhibited NKP and NKCC by >90% (IC50 values ~35 and ~15 μM, respectively) without significant KCC activity change, and stimulated K+ loss by ~35% at 10-30 μM. Neither ATP levels nor phosphorylation of the NKA α1 subunit changed. 3H-ouabain was displaced from pig renal NKA only at 100 fold higher CET concentrations than the ligand. Sequence alignments of NKA with BH1- and BH3-like motifs containing pro-survival Bcl-2 and BclXl proteins showed more than one BH1-like motif within NKA for interaction with CET or with BH3 motifs. One NKA BH1-like motif (ARAAEILARDGPN) was also found in all P-type ATPases. Also, NKA possessed a second motif similar to that near the BH3 region of Bcl-2. Findings support the hypothesis that CET inhibits NKP by binding to BH1-like motifs and disrupting the α1 subunit catalytic activity through conformational changes. By interacting with Bcl-2 proteins through their complementary BH1- or BH3-like-motifs, NKP proteins may be sensors of normal and pathological cell functions, becoming important yet unrecognized signal transducers in the initial phases of apoptosis. CET

  3. p32, a novel binding partner of Mcl-1, positively regulates mitochondrial Ca{sup 2+} uptake and apoptosis

    Energy Technology Data Exchange (ETDEWEB)

    Xiao, Kang [Division of Life Science, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong (China); Wang, Yinyin; Chang, Zhijie [School of Medicine, Tsinghua University, Beijing (China); Lao, Yuanzhi, E-mail: laurence_ylao@163.com [School of Pharmacy, Shanghai University of Traditional Chinese Medicine, Shanghai (China); Chang, Donald C., E-mail: bochang@ust.hk [Division of Life Science, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong (China)

    2014-08-22

    Highlights: • p32 binds to Mcl-1. • p32 affects apoptosis. • p32 and Mcl-1 regulate mitochondrial Ca{sup 2+}. - Abstract: Mcl-1 is a major anti-apoptotic Bcl-2 family protein. It is well known that Mcl-1 can interact with certain pro-apoptotic Bcl-2 family proteins in normal cells to neutralize their pro-apoptotic functions, thus prevent apoptosis. In addition, it was recently found that Mcl-1 can also inhibit mitochondrial calcium uptake. The detailed mechanism, however, is still not clear. Based on Yeast Two-Hybrid screening and co-immunoprecipitation, we identified a mitochondrial protein p32 (C1qbp) as a novel binding partner of Mcl-1. We found that p32 had a number of interesting properties: (1) p32 can positively regulate UV-induced apoptosis in HeLa cells. (2) Over-expressing p32 could significantly promote mitochondrial calcium uptake, while silencing p32 by siRNA suppressed it. (3) In p32 knockdown cells, Ruthenium Red treatment (an inhibitor of mitochondrial calcium uniporter) showed no further suppressive effect on mitochondrial calcium uptake. In addition, in Ruthenium Red treated cells, Mcl-1 also failed to suppress mitochondrial calcium uptake. Taken together, our findings suggest that p32 is part of the putative mitochondrial uniporter that facilitates mitochondrial calcium uptake. By binding to p32, Mcl-1 can interfere with the uniporter function, thus inhibit the mitochondrial Ca{sup 2+} uploading. This may provide a novel mechanism to explain the anti-apoptotic function of Mcl-1.

  4. Ethyl acetate extract of Chinese medicinal herb Sarcandra glabra induces growth inhibition on human leukemic HL-60 cells, associated with cell cycle arrest and up-regulation of pro-apoptotic Bax/Bcl-2 ratio.

    Science.gov (United States)

    Li, W Y; Chiu, Lawrence C M; Lam, W S; Wong, W Y; Chan, Y T; Ho, Y P; Wong, Elaine Y L; Wong, Y S; Ooi, Vincent E C

    2007-02-01

    Sarcandra glabra (Thunb.) Nakai, colloquially known as Caoshanhu, is a Chinese medicinal herb with reported anti-tumor, anti-inflammatory, anti-viral and non-specific immunoenhancing properties. Although the plant has been clinically used for treating a variety of diseases, its bioactive ingredients are largely unknown and its mode of action has never been investigated. In this study, the anti-tumor property of ethyl acetate (EA) extract of S. glabra was investigated by determining its in vitro growth-inhibitory effects on a panel of human cancer cell lines of different histotypes. Growth inhibition of the EA extract on the cancer cells seemed to be selective, and the leukemic HL-60 was found to be the most responsive after 48 h of treatment (IC50=58 microg/ml). Flow cytometric studies further illustrated that the extract might interfere with DNA replication and thus arrested the cell cycle at S phase in the leukemic cells, followed by DNA fragmentation and loss of phospholipid asymmetry in the plasma membrane after 72 h of treatment. Concurrently, the pro-apoptotic Bax/Bcl-2 ratio was also up-regulated by more than 178% of the control level. All these findings suggested that the extract had initiated apoptosis to kill the leukemic cells. Results from this pioneer study help to establish a scientific foundation for future research and development of the bioactive ingredients in EA extract of S. glabra as efficacious anti-cancer agents.

  5. Expression of bcl-2 in the Epithelial Lining of Odontogenic Keratocysts

    Directory of Open Access Journals (Sweden)

    Gh. Jahanshahi

    2006-03-01

    Full Text Available Statement of Problem: The aggressive nature and high recurrence rate of Odontogenic Keratocysts (OKCs may be due to unknown factors inherent in the epithelium or because of enzymatic activity in the fibrous wall. Bcl-2 protein is characterized by its ability to inhibit apoptosis.Purpose: The aim of the present study was to analyze the expression of bcl-2 protein in OKCs and to compare it with the more common radicular and dentigerous cysts. The possible relationship between inflammation and bcl-2 expression was also investigated.Materials and Methods: Formalin fixed paraffin-embedded tissue sections of 20 OKCs, 20 radicular and 20 dentigerous cysts were immunohistochemically analyzed for immunoreactivity of the bcl-2 protein.Results: Bcl-2 expression was observed in 19 OKCs (95%, one radicular cyst (5%and one dentigerous cyst (5%. There was no statistically significant relationship between inflammation and the number of bcl-2 positive cells. Immunoreactivity was mainly noted in the basal or basal/supra basal layers.Conclusion: Considering the fact that bcl-2 over expression may lead to increased survival of epithelial cells, present study may demonstrate a possible relationship between the aggressive nature of OKC and the intrinsic growth potential of its lining epithelium. Furthermore a basal/supra basal distribution of bcl-2 positive cells was seen in some odontogenic keratocysts which may have a significant impact on the behavior of this cyst.

  6. Ultra-High-Throughput Screening of Natural Product Extracts to Identify Proapoptotic Inhibitors of Bcl-2 Family Proteins.

    Science.gov (United States)

    Hassig, Christian A; Zeng, Fu-Yue; Kung, Paul; Kiankarimi, Mehrak; Kim, Sylvia; Diaz, Paul W; Zhai, Dayong; Welsh, Kate; Morshedian, Shana; Su, Ying; O'Keefe, Barry; Newman, David J; Rusman, Yudi; Kaur, Harneet; Salomon, Christine E; Brown, Susan G; Baire, Beeraiah; Michel, Andrew R; Hoye, Thomas R; Francis, Subhashree; Georg, Gunda I; Walters, Michael A; Divlianska, Daniela B; Roth, Gregory P; Wright, Amy E; Reed, John C

    2014-09-01

    Antiapoptotic Bcl-2 family proteins are validated cancer targets composed of six related proteins. From a drug discovery perspective, these are challenging targets that exert their cellular functions through protein-protein interactions (PPIs). Although several isoform-selective inhibitors have been developed using structure-based design or high-throughput screening (HTS) of synthetic chemical libraries, no large-scale screen of natural product collections has been reported. A competitive displacement fluorescence polarization (FP) screen of nearly 150,000 natural product extracts was conducted against all six antiapoptotic Bcl-2 family proteins using fluorochrome-conjugated peptide ligands that mimic functionally relevant PPIs. The screens were conducted in 1536-well format and displayed satisfactory overall HTS statistics, with Z'-factor values ranging from 0.72 to 0.83 and a hit confirmation rate between 16% and 64%. Confirmed active extracts were orthogonally tested in a luminescent assay for caspase-3/7 activation in tumor cells. Active extracts were resupplied, and effort toward the isolation of pure active components was initiated through iterative bioassay-guided fractionation. Several previously described altertoxins were isolated from a microbial source, and the pure compounds demonstrate activity in both Bcl-2 FP and caspase cellular assays. The studies demonstrate the feasibility of ultra-high-throughput screening using natural product sources and highlight some of the challenges associated with this approach. © 2014 Society for Laboratory Automation and Screening.

  7. Role and regulation of apoptotic cell death in the kidney. Y2K update.

    Science.gov (United States)

    Ortiz, A; Lorz, C; Catalan, M P; Justo, P; Egido, J

    2000-08-01

    Apoptosis is an active form of cell death that, in balance with mitosis, regulates cell number. Cell number abnormalities are a frequent feature of renal disease. We now review current concepts on the molecular regulation of apoptotic cell death, including the influence of survival and lethal factors from the extracellular microenvironment as well as the role of intracellular regulators of apoptosis, such as death receptors, proapoptotic and antiapoptotic bcl2-related proteins, the mitochondria and caspases. In addition the role of apoptosis in the genesis, persistence and progression and remodeling and resolution of renal injury is discussed. Information on the expression and function of apoptosis regulatory proteins in specific renal syndromes is summarized. Finally, future perspectives in research and clinical intervention are discussed.

  8. Neuroprotection with metformin and thymoquinone against ethanol-induced apoptotic neurodegeneration in prenatal rat cortical neurons

    Directory of Open Access Journals (Sweden)

    Ullah Ikram

    2012-01-01

    Full Text Available Abstract Background Exposure to ethanol during early development triggers severe neuronal death by activating multiple stress pathways and causes neurological disorders, such as fetal alcohol effects or fetal alcohol syndrome. This study investigated the effect of ethanol on intracellular events that predispose developing neurons for apoptosis via calcium-mediated signaling. Although the underlying molecular mechanisms of ethanol neurotoxicity are not completely determined, mitochondrial dysfunction, altered calcium homeostasis and apoptosis-related proteins have been implicated in ethanol neurotoxicity. The present study was designed to evaluate the neuroprotective mechanisms of metformin (Met and thymoquinone (TQ during ethanol toxicity in rat prenatal cortical neurons at gestational day (GD 17.5. Results We found that Met and TQ, separately and synergistically, increased cell viability after ethanol (100 mM exposure for 12 hours and attenuated the elevation of cytosolic free calcium [Ca2+]c. Furthermore, Met and TQ maintained normal physiological mitochondrial transmembrane potential (ΔψM, which is typically lowered by ethanol exposure. Increased cytosolic free [Ca2+]c and lowered mitochondrial transmembrane potential after ethanol exposure significantly decreased the expression of a key anti-apoptotic protein (Bcl-2, increased expression of Bax, and stimulated the release of cytochrome-c from mitochondria. Met and TQ treatment inhibited the apoptotic cascade by increasing Bcl-2 expression. These compounds also repressed the activation of caspase-9 and caspase-3 and reduced the cleavage of PARP-1. Morphological conformation of cell death was assessed by TUNEL, Fluoro-Jade-B, and PI staining. These staining methods demonstrated more cell death after ethanol treatment, while Met, TQ or Met plus TQ prevented ethanol-induced apoptotic cell death. Conclusion These findings suggested that Met and TQ are strong protective agents against ethanol

  9. Structural Studies of Bcl-xL/ligand Complexes using {sup 19}F NMR

    Energy Technology Data Exchange (ETDEWEB)

    Yu Liping; Hajduk, Philip J.; Mack, Jamey; Olejniczak, Edward T. [GPRD, Abbott Laboratories, Pharmaceutical Discovery Division (United States)], E-mail: Edward.olejniczak@abbott.com

    2006-04-15

    Fluorine atoms are often incorporated into drug molecules as part of the lead optimization process in order to improve affinity or modify undesirable metabolic and pharmacokinetic profiles. From an NMR perspective, the abundance of fluorinated drug leads provides an exploitable niche for structural studies using {sup 19}F NMR in the drug discovery process. As {sup 19}F has no interfering background signal from biological sources, {sup 19}F NMR studies of fluorinated drugs bound to their protein receptors can yield easily interpretable and unambiguous structural constraints. {sup 19}F can also be selectively incorporated into proteins to obtain additional constraints for structural studies. Despite these advantages, {sup 19}F NMR has rarely been exploited for structural studies due to its broad lines in macromolecules and their ligand complexes, leading to weak signals in {sup 1}H/{sup 19}F heteronuclear NOE experiments. Here we demonstrate several different experimental strategies that use {sup 19}F NMR to obtain ligand-protein structural constraints for ligands bound to the anti-apoptotic protein Bcl-xL, a drug target for anti-cancer therapy. These examples indicate the applicability of these methods to typical structural problems encountered in the drug development process.

  10. The role of BCL-2 and glutathione in an antioxidant pathway to prevent radiation-induced apoptosis

    International Nuclear Information System (INIS)

    Vlachaki, Maria T.; Meyn, Raymond E.

    1997-01-01

    Objective: The expression of the bcl-2 gene has been associated with resistance to radiation induced apoptosis. There is evidence that the bcl-2 protein acts in the antioxidant pathways to block the effects of reactive oxygen spieces that mediate apoptosis possibly by increasing the levels of intracellular glutathione. Our hypothesis is that pretreatment of radiation-sensitive cells, known to lack bcl-2 expression, with antioxidants will reduce radiation-induced apoptosis. For this purpose, the apoptotic response to radiation and the intracellular levels of glutathione were tested before and after pretreatment with antioxidants in two murine lymphoma cell lines, a radiation resistant-bcl-2 expressing (Ly-ar) line and a radiation sensitive (Ly-as) line. Methods and Materials: Ly-ar and Ly-as cells were irradiated at 0,1,2,3 and 4 hours before collection. The intracellular levels of reduced (GSH) and oxidized (GSSG) glutathione were determined by the use of the fluorescent dye ophthalaldehyde. Ly-as cells were pretreated with dihydrolipoic acid and lipoamide for 1 hour before irradiation. Apoptosis response was measured by the DNA fragmentation assay. The radiation dose was 2.5 Gy. Results: After irradiation, the apoptotic rate of Ly-ar and Ly-as cells is 11-19% and 66-87% respectively. Ly-ar cells have higher intracellular GSH and GSSG levels compared to Ly-as cells by 69.9% and 91.9% respectively and the GSH/GSSG ratio in Ly-ar and Ly-as cells is 17.09 and 15.09 respectively (a difference of 13.25%). GSH levels do not change during the first three hours after irradiation; however there is a 46% reduction at four hours after irradiation, a time at which the Ly-as cells have already fragmented their DNA. Pretreatment of cells with dihydrolipoic acid or lipoamide at concentrations of 4mM and 2mM respectively was toxic and resulted in cell death in the absence of irradiation. Conclusions: GSH and GSSG levels are elevated in radiation-resistant murine lymphoma cells

  11. BAG3 regulates contractility and Ca2+ homeostasis in adult mouse ventricular myocytes

    OpenAIRE

    Feldman, Arthur M.; Gordon, Jennifer; Wang, JuFang; Song, Jianliang; Zhang, Xue-Qian; Myers, Valerie D.; Tilley, Douglas G.; Gao, Erhe; Hoffman, Nicholas E.; Tomar, Dhanendra; Madesh, Muniswamy; Rabinowitz, Joseph; Koch, Walter J.; Su, Feifei; Khalili, Kamel

    2016-01-01

    Bcl2-associated athanogene 3 (BAG3) is a 575 amino acid anti-apoptotic protein that is constitutively expressed in the heart. BAG3 mutations, including mutations leading to loss of protein, are associated with familial cardiomyopathy. Furthermore, BAG3 levels have been found to be reduced in end-stage non-familial failing myocardium. In contrast to neonatal myocytes in which BAG3 is found in the cytoplasm and involved in protein quality control and apoptosis, in adult mouse left ventricular (...

  12. Melatonin promotes Bax sequestration to mitochondria reducing cell susceptibility to apoptosis via the lipoxygenase metabolite 5-hydroxyeicosatetraenoic acid

    KAUST Repository

    Radogna, Flavia

    2015-03-01

    Extra-neurological functions of melatonin include control of the immune system and modulation of apoptosis. We previously showed that melatonin inhibits the intrinsic apoptotic pathway in leukocytes via stimulation of high affinity MT1/MT2 receptors, thereby promoting re-localization of the anti-apoptotic Bcl-2 protein to mitochondria. Here we show that Bcl-2 sequesters pro-apoptotic Bax into mitochondria in an inactive form after melatonin treatment, thus reducing cell propensity to apoptosis. Bax translocation and the anti-apoptotic effect of melatonin are strictly dependent on the presence of Bcl-2, and on the 5-lipoxygenase (5-LOX) metabolite 5-hydroxyeicosatetraenoic acid (5-HETE), which we have previously shown to be produced as a consequence of melatonin binding to its low affinity target calmodulin. Therefore, the anti-apoptotic effect of melatonin requires the simultaneous, independent interaction with high (MT1/MT2) and low (calmodulin) affinity targets, eliciting two independent signal transduction pathways converging into Bax sequestration and inactivation. MT1/MT2 vs. lipoxygenase pathways are activated by 10-9 vs. 10-5M melatonin, respectively; the anti-apoptotic effect of melatonin is achieved at 10-5M, but drops to 10-9M upon addition of exogenous 5-HETE, revealing that lipoxygenase activation is the rate-limiting pathway. Therefore, in areas of inflammation with increased 5-HETE levels, physiological nanomolar concentrations of melatonin may suffice to maintain leukocyte viability.

  13. Paraquat induces extrinsic pathway of apoptosis in A549 cells by induction of DR5 and repression of anti-apoptotic proteins, DDX3 and GSK3 expression.

    Science.gov (United States)

    Hathaichoti, Sasiphen; Visitnonthachai, Daranee; Ngamsiri, Pronrumpa; Niyomchan, Apichaya; Tsogtbayar, Oyu; Wisessaowapak, Churaibhon; Watcharasit, Piyajit; Satayavivad, Jutamaad

    2017-08-01

    Paraquat (PQ) is a bipyridyl derivative herbicide known to cause lung toxicity partly through induction of apoptosis. Here we demonstrated that PQ caused apoptosis in A549 cells. PQ increased cleavage of caspase-8 and Bid, indicating caspase-8 activation and truncated Bid, the two key mediators of extrinsic apoptosis. Additionally, PQ treatment caused an increase in DR5 (death receptor-5) and caspase-8 interaction, indicating formation of DISC (death-inducing signaling complex). These results indicate that PQ induces apoptosis through extrinsic pathway in A549 cells. Moreover, PQ drastically increased DR5 expression and membrane localization. Furthermore, PQ caused prominent concentration dependent reductions of DDX3 (the DEAD box protein-3) and GSK3 (glycogen synthase kinase-3) which can associate with DR5 and prevent DISC formation. Additionally, PQ decreased DR5-DDX3 interaction, suggesting a reduction of DDX3/GSK3 anti-apoptotic complex. Inhibition of GSK3, which is known to promote extrinsic apoptosis by its pharmacological inhibitor, BIO accentuated PQ-induced apoptosis. Moreover, GSK3 inhibition caused a further decrease in PQ-reduced DR5-DDX3 interaction. Taken together, these results suggest that PQ may induce extrinsic pathway of apoptosis in A549 cells through upregulation of DR5 and repression of anti-apoptotic proteins, DDX3/GSK3 leading to reduction of anti-apoptotic complex. Copyright © 2017 Elsevier Ltd. All rights reserved.

  14. Anti-Proliferation Effects of Garlic (Allium sativum L.) on the Progression of Benign Prostatic Hyperplasia.

    Science.gov (United States)

    Chung, Kyung-Sook; Shin, Su-Jin; Lee, Na Young; Cheon, Se-Yun; Park, Wansu; Sun, Seung-Ho; An, Hyo-Jin

    2016-07-01

    Benign prostatic hyperplasia (BPH) is a urologic disease that affects most of men over the age 50. But until now there is no such perfect cure without side effects. Because of diverse adverse effects, it is desirable to develop effective and long term-safety-herbal medicines to inhibit the progress of BPH. In spite of garlic's large use and a wide spectrum of studies, including anti-hyperlipidemic, cardio-protective, and anti-inflammatory activities, there was none to prove efficacy for BPH. In this study, we evaluated the efficacy of garlic to prove its suppressing effects on BPH. Garlic administration decreased relative prostate weight ratio, suppressed mRNA expression level of AR, DHT serum levels, and the growth of prostatic tissue in BPH-induced rats. Moreover, garlic administration decreased the levels of inflammatory proteins, iNOS, and COX-2 in prostatic tissue. Further investigation showed that garlic induced accumulation of death-inducing signal complex and activation of AMPK and decreased the levels of anti-apoptotic proteins, such as Bcl-2, Bcl-xL, and survivin. These results suggest that garlic may have suppressing effects on BPH and it has great potential to be developed as treatment for BPH. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

  15. Characterization of the enhanced apoptotic response to azidothymidine by pharmacological inhibition of NF-kB.

    Science.gov (United States)

    Matteucci, Claudia; Minutolo, Antonella; Marino-Merlo, Francesca; Grelli, Sandro; Frezza, Caterina; Mastino, Antonio; Macchi, Beatrice

    2015-04-15

    The present study addresses the issue of enhanced apoptotic response to AZT following co-treatment with an NF-kB inhibitor. To investigate this issue, different cell lines were assayed for susceptibility to AZT-mediated apoptosis without or with the addition of the NF-kB inhibitor Bay-11-7085. For further investigation, U937 cells were selected as good-responder cells to the combination treatment with 32 or 128 μM AZT, and 1 μM Bay-11-7085. Inhibition of NF-kB activation by Bay-11-7085 in cells treated with AZT was assayed through Western blot analysis of p65 expression and by EMSA. Involvement of the mitochondrial pathway of apoptosis in mechanisms underlying the improved effect of AZT following Bay-11-7085 co-treatment, was evaluated by assaying the cytochrome c release and the mitochondrial membrane potential (MMP) status using the JC-1 dye. Moreover, the transcriptional activity of both anti- and pro-apoptotic genes in U937 cells after combination treatment was quantitatively evaluated through real-time PCR. We found that the combined treatment induced high levels of cytochrome c release and of MMP collapse in association with evident changes in the expression of both anti- and pro-apoptotic genes of the Bcl-2 family. Overexpression of Bcl-2 significantly suppressed the sensitization of U937 cells to an enhanced apoptotic response to AZT following co-treatment with the NF-kB inhibitor. The new findings suggest that a combination regimen based on AZT plus an NF-kB inhibitor could represent a new chemotherapeutic tool for retrovirus-related pathologies.

  16. Role of reactive oxygen species and Bcl-2 family proteins in TNF-α-induced apoptosis of lymphocytes.

    Science.gov (United States)

    Ryazanceva, N V; Novickiy, V V; Zhukova, O B; Biktasova, A K; Chechina, O E; Sazonova, E V; Belkina, M V; Chasovskih, N Yu; Khaitova, Z K

    2010-08-01

    We studied the in vitro apoptosis-inducing effect of recombinant TNF-α (rTNF-α) on blood lymphocytes from healthy donors. rTNF-α-induced apoptosis was accompanied by an increase in the number of cells with low mitochondrial transmembrane potential, increased intracellular content of reactive oxygen species, reduced content of Bcl-2, Bcl-xL, and Bax proteins, and elevated Bad content. The molecular mechanisms of these changes are discussed.

  17. The anti-apoptotic and cardioprotective effects of salvianolic acid a on rat cardiomyocytes following ischemia/reperfusion by DUSP-mediated regulation of the ERK1/2/JNK pathway.

    Directory of Open Access Journals (Sweden)

    Tongda Xu

    Full Text Available The purpose of this study was to observe the effects of salvianolic acid A (SAA pretreatment on the myocardium during ischemia/reperfusion (I/R and to illuminate the interrelationships among dual specificity protein phosphatase (DUSP 2/4/16, ERK1/2 and JNK pathways during myocardial I/R, with the ultimate goal of elucidating how SAA exerts cardioprotection against I/R injury (IRI. Wistar rats were divided into the following six groups: control group (CON, I/R group, SAA+I/R group, ERK1/2 inhibitor PD098059+I/R group (PD+I/R, PD+SAA+I/R group, and JNK inhibitor SP600125+I/R group (SP+I/R. The cardioprotective effects of SAA on the myocardium during I/R were investigated with a Langendorff device. Heart rate (HR, left ventricular systolic pressure (LVSP, left ventricular end-diastolic pressure (LVEDP, maximum rate of ventricular pressure rise and fall (±dp/dtmax, myocardial infarction areas (MIA, lactate dehydrogenase (LDH, and cardiomyocytes apoptosis were monitored. To determine the crosstalk betwee JNK and ERK1/2 via DUSP2/4/16 with SAA pretreatment, siRNA-DUSP2/4/16 were performed. The expression levels of Bcl-2, Bax, caspase 3, p-JNK, p-ERK1/2 and DUSP2/4/16 in cardiomyocytes were assayed by Western blot. Our results showed that LDH, MIA and cell apoptosis were decreased, and various parameters of heart function were improved by SAA pretreatment and SP application. In the I/R group, the expression levels of p-ERK1/2 and DUSP4/16 were not significantly different compared with the CON group, however, the protein expression levels of p-ERK1/2, Bcl-2 and DUSP4/16 were higher, while p-JNK, Bax, caspase 3 and DUSP2 levels were reduced among the SAA+I/R, PD+SAA+I/R and SP+I/R groups. The above indices were not significantly different between the SAA+I/R and SP+I/R groups. Compared with the SAA+I/R group, p-ERK1/2 was increased and p-JNK was decreased in the SAA+si-DUSP2+I/R, however, p-ERK was downregulated and p-JNK was upregulated in SAA+si-DUSP4

  18. The calcimimetic R-568 induces apoptotic cell death in prostate cancer cells

    Directory of Open Access Journals (Sweden)

    Cheng Guangming

    2009-07-01

    Full Text Available Abstract Background Increased serum level of parathyroid hormone (PTH was found in metastatic prostate cancers. Calcimimetic R-568 was reported to reduce PTH expression, to suppress cell proliferation and to induce apoptosis in parathyroid cells. In this study, we investigated the effect of R-568 on cellular survival of prostate cancer cells. Methods Prostate cancer cell lines LNCaP and PC-3 were used in this study. Cellular survival was determined with MTT, trypan blue exclusion and fluorescent Live/Death assays. Western blot assay was utilized to assess apoptotic events induced by R-568 treatment. JC-1 staining was used to evaluate mitochondrial membrane potential. Results In cultured prostate cancer LNCaP and PC-3 cells, R-568 treatment significantly reduced cellular survival in a dose- and time-dependent manner. R-568-induced cell death was an apoptotic event, as evidenced by caspase-3 processing and PARP cleavage, as well as JC-1 color change in mitochondria. Knocking down calcium sensing receptor (CaSR significantly reduced R-568-induced cytotoxicity. Enforced expression of Bcl-xL gene abolished R-568-induced cell death, while loss of Bcl-xL expression led to increased cell death in R-568-treated LNCaP cells,. Conclusion Taken together, our data demonstrated that calcimimetic R-568 triggers an intrinsic mitochondria-related apoptotic pathway, which is dependent on the CaSR and is modulated by Bcl-xL anti-apoptotic pathway.

  19. Adoptive Transfer of Dying Cells Causes Bystander-Induced Apoptosis

    Science.gov (United States)

    Schwulst, Steven J.; Davis, Christopher G.; Coopersmith, Craig M.; Hotchkiss, Richard S.

    2009-01-01

    The anti-apoptotic Bcl-2 protein has the remarkable ability to prevent cell death from several noxious stimuli. Intriguingly, Bcl-2 overexpression in one cell type has been reported to protect against cell death in neighboring non-Bcl-2 overexpressing cell types. The mechanism of this “trans” protection has been speculated to be secondary to the release of a cytoprotective factor by Bcl-2 overexpressing cells. We employed a series of adoptive transfer experiments in which lymphocytes that overexpress Bcl-2 were administered to either wild type mice or mice lacking mature T and B cells (Rag-1-/-) to detect the presence or absence of the putative protective factor. We were unable to demonstrate “trans” protection. However, adoptive transfer of apoptotic or necrotic cells exacerbated the degree of apoptotic death in neighboring non-Bcl-2 overexpressing cells (p≤0.05). Therefore, this data suggests that dying cells emit signals triggering cell death in neighboring non-Bcl-2 overexpressing cells, i.e. a “trans” destructive effect. PMID:17194455

  20. Fisetin Induces Apoptosis of HSC3 Human Oral Cancer Cells Through Endoplasmic Reticulum Stress and Dysfunction of Mitochondria-mediated Signaling Pathways.

    Science.gov (United States)

    Shih, Yung-Luen; Hung, Fang-Ming; Lee, Ching-Hsiao; Yeh, Ming-Yang; Lee, Mei-Hui; Lu, Hsu-Feng; Chen, Yung-Liang; Liu, Jia-You; Chung, Jing-Gung

    2017-01-01

    Oral cancer has been reported to be one of the major cancer-related diseases in human populations and the treatment of oral cancer is still unsatisfied. Fisetin, is a flavonoid from plants and has several biological activities such as antioxidant, anti-inflammatory and anticancer function, but its cytotoxicity in human oral cancer cells is unknown. In the present study, we investigated fisetin-induced cytotoxic effects on HSC3 human oral cancer cells in vitro. Materials and Methods/Results: We used flow cytometric assay to show fisetin induced apoptotic cell death through increased reactive oxygen species and Ca 2+ , but reduced the mitochondrial membrane potential and increased caspase-8, -9 and -3 activities in HSC3 cells. Furthermore, we also used 4' 6-diamidino-2-phenylindole staining to show that fisetin induced chromatin condensation (apoptotic cell death), and Comet assay to show that fisetin induced DNA damage in HSC3 cells. Western blotting was used to examine the levels of apoptotic-associated protein and results indicated that fisetin increased expression of pro-apoptotic proteins such as B-cell lymphoma 2 (BCL2) antagonist/killer (BAK) and BCL2-associated X (BAX) but reduced that of anti-apoptotic protein such as BCL2 and BCL-x, and increased the cleaved forms of caspase-3, -8 and -9, and cytochrome c, apoptosis-inducing factor (AIF) and endonuclease G (ENDO G) in HSC3 cells. Confocal microscopy showed that fisetin increased the release of cytochrome c, AIF and ENDO G from mitochondria into the cytoplasm. Based on these observations, we suggest that fisetin induces apoptotic cell death through endoplasmic reticulum stress- and mitochondria-dependent pathways. Copyright© 2017, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.

  1. Bcl-2 prevents loss of mitochondria in CCCP-induced apoptosis

    International Nuclear Information System (INIS)

    Graaf, Aniek O. de; Heuvel, Lambert P. van den; Dijkman, Henry B.P.M.; Abreu, Ronney A. de; Birkenkamp, Kim U.; Witte, Theo de; Reijden, Bert A. van der; Smeitink, Jan A.M.; Jansen, Joop H.

    2004-01-01

    Bcl-2 family proteins regulate apoptosis at the level of mitochondria. To examine the mechanism of Bcl-2 function, we investigated the effects of the protonophore carbonyl cyanide m-chlorophenyl hydrazone (CCCP) on two hematopoietic cell lines and Bcl-2 overexpressing transfectants. CCCP directly interferes with mitochondrial function and induces apoptosis. We show that Bcl-2 inhibits apoptosis and that the antiapoptotic effect of Bcl-2 takes place upstream of caspase activation and nuclear changes associated with apoptosis, since these were markedly inhibited in cells overexpressing Bcl-2. Bcl-2 does not prevent the decrease in mitochondrial membrane potential nor the alterations in cellular ATP content induced by CCCP in FL5.12 and Jurkat cells. A higher number of mitochondria was observed in untreated Bcl-2 transfected cells compared to parental cells, as shown by electron microscopy. Exposure to CCCP induced a dramatic decrease in the number of mitochondria and severely disrupted mitochondrial ultrastructure, with apparent swelling and loss of cristae in parental cells. Bcl-2 clearly diminished the disruption of mitochondrial structure and preserved a higher number of mitochondria. These data suggest that CCCP induces apoptosis by structural disruption of mitochondria and that Bcl-2 prevents apoptosis and mitochondrial degeneration by preserving mitochondrial integrity

  2. Bcl-2 prevents loss of mitochondria in CCCP-induced apoptosis.

    Science.gov (United States)

    de Graaf, Aniek O; van den Heuvel, Lambert P; Dijkman, Henry B P M; de Abreu, Ronney A; Birkenkamp, Kim U; de Witte, Theo; van der Reijden, Bert A; Smeitink, Jan A M; Jansen, Joop H

    2004-10-01

    Bcl-2 family proteins regulate apoptosis at the level of mitochondria. To examine the mechanism of Bcl-2 function, we investigated the effects of the protonophore carbonyl cyanide m-chlorophenyl hydrazone (CCCP) on two hematopoietic cell lines and Bcl-2 overexpressing transfectants. CCCP directly interferes with mitochondrial function and induces apoptosis. We show that Bcl-2 inhibits apoptosis and that the antiapoptotic effect of Bcl-2 takes place upstream of caspase activation and nuclear changes associated with apoptosis, since these were markedly inhibited in cells overexpressing Bcl-2. Bcl-2 does not prevent the decrease in mitochondrial membrane potential nor the alterations in cellular ATP content induced by CCCP in FL5.12 and Jurkat cells. A higher number of mitochondria was observed in untreated Bcl-2 transfected cells compared to parental cells, as shown by electron microscopy. Exposure to CCCP induced a dramatic decrease in the number of mitochondria and severely disrupted mitochondrial ultrastructure, with apparent swelling and loss of cristae in parental cells. Bcl-2 clearly diminished the disruption of mitochondrial structure and preserved a higher number of mitochondria. These data suggest that CCCP induces apoptosis by structural disruption of mitochondria and that Bcl-2 prevents apoptosis and mitochondrial degeneration by preserving mitochondrial integrity.

  3. Growth inhibitory, apoptotic and anti-inflammatory activities ...

    Indian Academy of Sciences (India)

    naturally abundant oleanolic acid, displayed diverse biolog- ical activities ... triterpenoids and natural products. CDDO and its .... ration was determined by treating with anti-BrdU antibody and Texas red ..... apoptotic and necrotic in the tumour tissue. Thus .... Palmer RM, Ashton DS and Moncada S 1988 Vascular endothelial.

  4. Induction of Bim and Bid gene expression during accelerated apoptosis in severe sepsis.

    Science.gov (United States)

    Weber, Stefan U; Schewe, Jens-Christian; Lehmann, Lutz E; Müller, Stefan; Book, Malte; Klaschik, Sven; Hoeft, Andreas; Stüber, Frank

    2008-01-01

    In transgenic animal models of sepsis, members of the Bcl-2 family of proteins regulate lymphocyte apoptosis and survival of sepsis. This study investigates the gene regulation of pro-apoptotic and anti-apoptotic members of the Bcl-2 family of proteins in patients with early stage severe sepsis. In this prospective case-control study, patients were recruited from three intensive care units (ICUs) in a university hospital. Sixteen patients were enrolled when they fulfilled the criteria of severe sepsis. Ten critically ill but non-septic patients and 11 healthy volunteers served as controls. Blood samples were immediately obtained at inclusion. To confirm the presence of accelerated apoptosis in the patient groups, caspase-3 activation and phosphatidylserine externalisation in CD4+, CD8+ and CD19+ lymphocyte subsets were assessed using flow cytometry. Specific mRNAs of Bcl-2 family members were quantified from whole blood by real-time PCR. To test for statistical significance, Kruskal-Wallis testing with Dunn's multiple comparison test for post hoc analysis was performed. In all lymphocyte populations caspase-3 (p < 0.05) was activated, which was reflected in an increased phosphatidylserine externalisation (p < 0.05). Accordingly, lymphocyte counts were decreased in early severe sepsis. In CD4+ T-cells (p < 0.05) and B-cells (p < 0.001) the Bcl-2 protein was decreased in severe sepsis. Gene expression of the BH3-only Bim was massively upregulated as compared with critically ill patients (p < 0.001) and 51.6-fold as compared with healthy controls (p < 0.05). Bid was increased 12.9-fold compared with critically ill patients (p < 0.001). In the group of mitochondrial apoptosis inducers, Bak was upregulated 5.6-fold, while the expression of Bax showed no significant variations. By contrast, the pro-survival members Bcl-2 and Bcl-xl were both downregulated in severe sepsis (p < 0.001 and p < 0.05, respectively). In early severe sepsis a gene expression pattern with

  5. St. John’s Wort Regulates Proliferation and Apoptosis in MCF-7 Human Breast Cancer Cells by Inhibiting AMPK/mTOR and Activating the Mitochondrial Pathway

    Directory of Open Access Journals (Sweden)

    Mi-Kyoung You

    2018-03-01

    Full Text Available St. John’s Wort (SJW has been used as an estrogen agonist in the systems affected by menopause. Also, hypericin, a bioactive compound of SJW, has been used as a photosensitizer in photodynamic therapy. In the present study, we investigate the anti-proliferative and pro-apoptotic effects of SJW to demonstrate the chemo-preventive effect in human breast cancer cells. MCF-7 cells were cultured with DMSO or various concentrations of SJW ethanol extract (SJWE. Cell viability, proliferation, apoptosis, the expression of proteins involved in cell growth and apoptosis, and caspase-3/7 activity were examined. SJWE dose-dependently suppressed cell growth and induced apoptosis of MCF-7 cells. Mechanistically, SJWE enhanced the phosphorylation of AMP-activated protein kinase (AMPK and decreased the expression of p-mammalian target of rapamycin (p-mTOR and p-eukaryotic translation initiation factor 4E (eIF4E-binding protein 1 (4E-BP1. Also, SJWE inhibited the phosphorylation of protein kinase B (Akt and showed increases in the expression of pro-apoptotic proteins Bax and Bad with decreases in the expression of anti-apoptotic proteins including B-cell lymphoma 2 (Bcl-2, B-cell lymphoma-extra large (Bcl-xL, and p-Bcl-2-associated death promoter (p-Bad. SJWE at 50 μg/mL showed markedly enhanced caspase-7 activation. Taken together, our results provide evidence that SJWE shows anti-proliferative and pro-apoptotic effects via inhibition of AMPK/mTOR and activation of a mitochondrial pathway. Therefore, SJWE can be used as a chemo-preventive agent without photo-activation.

  6. The effect of octreotide and bromocriptine on expression of a pro-apoptotic Bax protein in rat prolactinoma.

    Directory of Open Access Journals (Sweden)

    Jolanta Kunert-Radek

    2004-03-01

    Full Text Available It is well established that disruption of apoptosis may lead to tumor initiation, progression or metastasis. It is also well documented that many anticancer drugs induce apoptosis. In the earlier studies, the dopamine D2 receptor agonist bromocriptine (BC and somatostatin analog octreotide (OCT were found to inhibit the growth of the estrogen-induced rat prolactinoma. Our previous investigations, applying the TUNEL method showed the involvement of the pro-apoptotic effect in the action of BC, and to a lesser degree, in the action of OCT. The aim of the present study was to investigate whether the pro-apoptotic action of these drugs involves the increased expression of Bax--a member of Bcl-2 protein family which is known to play an important role in the regulation of apoptosis. Male four-week Fisher 344 rats were used in the experiment. Capsules containing diethylstilboestrol (DES were implanted subcutaneously. Six weeks after the implantation the rats were given OCT (2 x 25 microg/animal/24, BC (3 mg/kg b.w./24 h or OCT and BC at the above doses for 10 days. Bax expression was detected by immunohistochemistry. Prolactin (PRL in blood serum was measured by radioimmunoassay (RIA. It has been found that both OCT and BC, alone or in combination, significantly reduce the tumor weight. Both OCT and BC suppressed PRL levels, but the inhibitory effect of BC was stronger than that of OCT. It has been found that the treatment with OCT and BC, alone or in combination, causes a significant increase in Bax expression in the rat prolactinoma cells. Our findings indicate that anti-tumoral action of bromocriptine and to some extent the action of octreotide in the experimental rat prolactinoma is connected with the induction of apoptosis and is associated with increased Bax expression.

  7. Canonical Bcl-2 Motifs of the Na+/K+ Pump Revealed by the BH3 Mimetic Chelerythrine: Early Signal Transducers of Apoptosis?

    Directory of Open Access Journals (Sweden)

    Peter K. Lauf

    2013-02-01

    Full Text Available Background/Aims: Chelerythrine [CET], a protein kinase C [PKC] inhibitor, is a prop-apoptotic BH3-mimetic binding to BH1-like motifs of Bcl-2 proteins. CET action was examined on PKC phosphorylation-dependent membrane transporters (Na+/K+ pump/ATPase [NKP, NKA], Na+-K+-2Cl+ [NKCC] and K+-Cl- [KCC] cotransporters, and channel-supported K+ loss in human lens epithelial cells [LECs]. Methods: K+ loss and K+ uptake, using Rb+ as congener, were measured by atomic absorption/emission spectrophotometry with NKP and NKCC inhibitors, and Cl- replacement by NO3ˉ to determine KCC. 3H-Ouabain binding was performed on a pig renal NKA in the presence and absence of CET. Bcl-2 protein and NKA sequences were aligned and motifs identified and mapped using PROSITE in conjunction with BLAST alignments and analysis of conservation and structural similarity based on prediction of secondary and crystal structures. Results: CET inhibited NKP and NKCC by >90% (IC50 values ∼35 and ∼15 µM, respectively without significant KCC activity change, and stimulated K+ loss by ∼35% at 10-30 µM. Neither ATP levels nor phosphorylation of the NKA α1 subunit changed. 3H-ouabain was displaced from pig renal NKA only at 100 fold higher CET concentrations than the ligand. Sequence alignments of NKA with BH1- and BH3-like motifs containing pro-survival Bcl-2 and BclXl proteins showed more than one BH1-like motif within NKA for interaction with CET or with BH3 motifs. One NKA BH1-like motif (ARAAEILARDGPN was also found in all P-type ATPases. Also, NKA possessed a second motif similar to that near the BH3 region of Bcl-2. Conclusion: Findings support the hypothesis that CET inhibits NKP by binding to BH1-like motifs and disrupting the α1 subunit catalytic activity through conformational changes. By interacting with Bcl-2 proteins through their complementary BH1- or BH3-like-motifs, NKP proteins may be sensors of normal and pathological cell functions, becoming important yet

  8. Gene Expression ‏‏‏‏Profiles of BAD and Bcl-xL in the CA1 Region of the Hippocampus Following Global Ischemic/Reperfusion and FK-506 Administration.

    Science.gov (United States)

    Badr, Ramak; Hashemi, Mehrdad; Javadi, Gholamreza; Movafagh, Abolfazl; Mahdian, Reza

    2015-12-01

    The hippocampus is a tiny nub in the mammalian brain that is involved in forming, organizing, and storing memories. Global cerebral ischemia (GCI) and reperfusion induced apoptosis lead to cell injury and death. FK-506 is a strong immunosuppressant drug that has neuroprotective effects on the hypoxic-ischemic effects of brain damage. BAD and Bcl-xL are pro-apoptotic and anti-apoptotic genes, respectively. These genes belong to The B-cell lymphoma-2 (Bcl-2) family. In this study, we assessed the neurotrophic properties of FK-506 on expression of the BAD and Bcl-xL genes in the hippocampus following global ischemia and reperfusion. In the present experimental study, adult male Wistar rats were obtained and housed under standard conditions in the Tehran University of Medical Science in Iran. Rats were equally distributed in groups of three among the following groups: normal control, treated-1 (ischemia/reperfusion), and treated-2 (ischemia/reperfusion followed by FK-506). Global ischemia was induced for animals in the treated-1 and treated-2 groups. In treated-2, two doses of FK-506 were injected: one dose as an IV injection immediately after reperfusion and another as an intra-peritoneal (IP) injection after 48 hours. Then, the hippocampus tissue was removed after anaesthetizing the rats. RNA was isolated, cDNA was synthesized, and real-time PCR was performed. Finally, the obtained data were analyzed statistically (P value ˂ 0.05). The quantitative results of real-time PCR show that the mRNA expression ratio of Bcl-xL down-regulated was 0.75 ± 0.06 in the ischemia/reperfusion group versus 1.57 ± 0.09 in the control group (P value BAD up-regulated in the ischemia/reperfusion + FK506 group was 3.65 ± 0.49 compared to Normal control (1.39 ± 0.09) and Ischemia/reperfusion + FK506 was 1.09 ± 0.20 (P value BAD /Bcl-xL) confirmed that expression of the pro-apoptotic gene significantly decreased (P value ˂ 0.001) under the ischemia/reperfusion condition. In contrast

  9. Chemical Constituents from Cimicifuga dahurica and Their Anti-Proliferative Effects on MCF-7 Breast Cancer Cells.

    Science.gov (United States)

    Huyen, Chu Thi Thanh; Luyen, Bui Thi Thuy; Khan, Ghulam Jilany; Oanh, Ha Van; Hung, Ta Manh; Li, Hui-Jun; Li, Ping

    2018-05-04

    This study was designed to search for novel anti-cancer compounds from natural plants. The 70% ethanolic extract from the rizhomes of Cimicifuga dahurica (Turcz.) Maxim. (Ranunculaceae) was found to possess significant in vitro anti-proliferative effects on MCF-7 breast cancer cells. A phytochemical investigation using assay-guided fractionation of the ethanolic extract of C. dahurica resulted in the isolation of one new phenolic amide glycoside 3 , two new lignan glycosides 4 and 7 , one new 9,19-cycloartane triterpenoid glycoside 6 , and thirteen known constituents 1 , 2 , 5 , and 8 ⁻ 17 . The structures of 3 , 4 , 6 , and 7 were established using contemporary NMR methods and from their HRESIMS data. The anti-proliferative effects of isolated compounds were evaluated using the BrdU-proliferation kit. Five among the 17 isolated compounds showed significant anti-proliferative effects ( p ≤ 0.05), wherein compound 7 showed the most significant anti-proliferative and cell cycle arresting effect ( p ≤ 0.05) which followed a dose dependent manner. Western blot protein expression analysis showed a down expression of c-Myc and cyclin D1 which further elucidated the anti-proliferation mechanism of compound 7 while apoptotic effects were found in association with Bcl-2 family protein expression variations. Conclusively this study reports the isolation and identification of 17 compounds from C. dahurica , including four novel molecules, in addition to the fact that compound 7 possesses significant anti-proliferative and apoptotic effects in vitro that may require further exploration.

  10. Photobiomodulation on Bax and Bcl-2 Proteins and SIRT1/PGC-1α Axis mRNA Expression Levels of Aging Rat Skeletal Muscle

    Directory of Open Access Journals (Sweden)

    Fang-Hui Li

    2014-01-01

    Full Text Available Objective. This study aimed to analyze the effects of low level laser irradiation (LLLI on Bax and IGF-1 and Bcl-2 protein contents and SIRT1/PGC-1α axis mRNA expression levels to prevent sarcopenia in aged rats. Material and Methods. Twenty female Sprague Dawley rats (18 months old were randomly divided into two groups (n=10 per group: control (CON and LLLI groups. The gallium-aluminum-arsenium (GaAlAs laser irradiation at 810 nm was used in the single point contact mode (3.75 J/cm2; 0.4 cm2; 125 mW/cm2; 30 s. Bax, Bcl-2, and IGF-1 proteins and SIRT1/PGC-1α axis mRNA expression were assessed 24 h after LLLI on gastrocnemius in aged rat. Results. Gastrocnemius muscle weights, gastrocnemius mass/body mass, Bcl-2/BAX ratio, Bcl-2 protein, IGF-1 protein, and the mRNA contents in SIRT1, PGC-1α, NRF1, TMF, and SOD2 were significantly (P<0.05 increased by LLLI compared to CON group without LLLI. However, levels of BAX protein and caspase 3 mRNA were significantly attenuated by LLLI compared to CON group (P<0.05. Conclusion. LLLI at 810 nm inhibits sarcopenia associated with upregulation of Bcl-2/BAX ratio and IGF-1 and SIRT1/PGC-1α axis mRNA expression in aged rats. This indicates that LLLI has potential to decrease progression of myocyte apoptosis in sarcopenic muscles.

  11. BCL-2 family protein, BAD is down-regulated in breast cancer and inhibits cell invasion

    Energy Technology Data Exchange (ETDEWEB)

    Cekanova, Maria, E-mail: mcekanov@utk.edu [Department of Small Animal Clinical Sciences, College of Veterinary Medicine, The University of Tennessee, Knoxville, TN (United States); Fernando, Romaine I. [Department of Obstetrics and Gynecology, Graduate School of Medicine, Medical Center, The University of Tennessee, Knoxville, TN (United States); Siriwardhana, Nalin [Department of Animal Science, The University of Tennessee, Knoxville, TN (United States); Sukhthankar, Mugdha [Department of Biomedical and Diagnostics Sciences, College of Veterinary Medicine, The University of Tennessee, Knoxville, TN (United States); Parra, Columba de la [Department of Biochemistry, School of Medicine, University of Puerto Rico, Medical Sciences Campus, San Juan, PR (United States); Woraratphoka, Jirayus [Department of Obstetrics and Gynecology, Graduate School of Medicine, Medical Center, The University of Tennessee, Knoxville, TN (United States); Malone, Christine [Laboratory of Molecular Carcinogenesis, National Institute of Environmental Health Sciences, Research Triangle Park, NC (United States); Ström, Anders [Center for Nuclear Receptors and Cell Signaling, Department of Biology and Biochemistry, University of Houston, Houston, TX (United States); Baek, Seung J. [Department of Biomedical and Diagnostics Sciences, College of Veterinary Medicine, The University of Tennessee, Knoxville, TN (United States); Wade, Paul A. [Laboratory of Molecular Carcinogenesis, National Institute of Environmental Health Sciences, Research Triangle Park, NC (United States); Saxton, Arnold M. [Department of Animal Science, The University of Tennessee, Knoxville, TN (United States); Donnell, Robert M. [Department of Biomedical and Diagnostics Sciences, College of Veterinary Medicine, The University of Tennessee, Knoxville, TN (United States); Pestell, Richard G. [Department of Cancer Biology, Sidney Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, PA (United States); and others

    2015-02-01

    We have previously demonstrated that the anti-apoptotic protein BAD is expressed in normal human breast tissue and shown that BAD inhibits expression of cyclin D1 to delay cell-cycle progression in breast cancer cells. Herein, expression of proteins in breast tissues was studied by immunohistochemistry and results were analyzed statistically to obtain semi-quantitative data. Biochemical and functional changes in BAD-overexpressing MCF7 breast cancer cells were evaluated using PCR, reporter assays, western blotting, ELISA and extracellular matrix invasion assays. Compared to normal tissues, Grade II breast cancers expressed low total/phosphorylated forms of BAD in both cytoplasmic and nuclear compartments. BAD overexpression decreased the expression of β-catenin, Sp1, and phosphorylation of STATs. BAD inhibited Ras/MEK/ERK and JNK signaling pathways, without affecting the p38 signaling pathway. Expression of the metastasis-related proteins, MMP10, VEGF, SNAIL, CXCR4, E-cadherin and TlMP2 was regulated by BAD with concomitant inhibition of extracellular matrix invasion. Inhibition of BAD by siRNA increased invasion and Akt/p-Akt levels. Clinical data and the results herein suggest that in addition to the effect on apoptosis, BAD conveys anti-metastatic effects and is a valuable prognostic marker in breast cancer. - Highlights: • BAD and p-BAD expressions are decreased in breast cancer compared with normal breast tissue. • BAD impedes breast cancer invasion and migration. • BAD inhibits the EMT and transcription factors that promote cancer cell migration. • Invasion and migration functions of BAD are distinct from the BAD's role in apoptosis.

  12. BCL-2 family protein, BAD is down-regulated in breast cancer and inhibits cell invasion

    International Nuclear Information System (INIS)

    Cekanova, Maria; Fernando, Romaine I.; Siriwardhana, Nalin; Sukhthankar, Mugdha; Parra, Columba de la; Woraratphoka, Jirayus; Malone, Christine; Ström, Anders; Baek, Seung J.; Wade, Paul A.; Saxton, Arnold M.; Donnell, Robert M.; Pestell, Richard G.

    2015-01-01

    We have previously demonstrated that the anti-apoptotic protein BAD is expressed in normal human breast tissue and shown that BAD inhibits expression of cyclin D1 to delay cell-cycle progression in breast cancer cells. Herein, expression of proteins in breast tissues was studied by immunohistochemistry and results were analyzed statistically to obtain semi-quantitative data. Biochemical and functional changes in BAD-overexpressing MCF7 breast cancer cells were evaluated using PCR, reporter assays, western blotting, ELISA and extracellular matrix invasion assays. Compared to normal tissues, Grade II breast cancers expressed low total/phosphorylated forms of BAD in both cytoplasmic and nuclear compartments. BAD overexpression decreased the expression of β-catenin, Sp1, and phosphorylation of STATs. BAD inhibited Ras/MEK/ERK and JNK signaling pathways, without affecting the p38 signaling pathway. Expression of the metastasis-related proteins, MMP10, VEGF, SNAIL, CXCR4, E-cadherin and TlMP2 was regulated by BAD with concomitant inhibition of extracellular matrix invasion. Inhibition of BAD by siRNA increased invasion and Akt/p-Akt levels. Clinical data and the results herein suggest that in addition to the effect on apoptosis, BAD conveys anti-metastatic effects and is a valuable prognostic marker in breast cancer. - Highlights: • BAD and p-BAD expressions are decreased in breast cancer compared with normal breast tissue. • BAD impedes breast cancer invasion and migration. • BAD inhibits the EMT and transcription factors that promote cancer cell migration. • Invasion and migration functions of BAD are distinct from the BAD's role in apoptosis

  13. Autocrine prostaglandin E2 signaling promotes promonocytic leukemia cell survival via COX-2 expression and MAPK pathway

    Science.gov (United States)

    Lee, Jaetae; Lee, Young Sup

    2015-01-01

    The COX-2/PGE2 pathway has been implicated in the occurrence and progression of cancer. The underlying mechanisms facilitating the production of COX-2 and its mediator, PGE2, in cancer survival remain unknown. Herein, we investigated PGE2-induced COX-2 expression and signaling in HL-60 cells following menadione treatment. Treatment with PGE2 activated anti-apoptotic proteins such as Bcl-2 and Bcl-xL while reducing pro-apoptotic proteins, thereby enhancing cell survival. PGE2 not only induced COX-2 expression, but also prevented casapse-3, PARP, and lamin B cleavage. Silencing and inhibition of COX-2 with siRNA transfection or treatment with indomethacin led to a pronounced reduction of the extracellular levels of PGE2, and restored the menadione-induced cell death. In addition, pretreatment of cells with the MEK inhibitor PD98059 and the PKA inhibitor H89 abrogated the PGE2-induced expression of COX-2, suggesting involvement of the MAPK and PKA pathways. These results demonstrate that PGE2 signaling acts in an autocrine manner, and specific inhibition of PGE2 will provide a novel approach for the treatment of leukemia. [BMB Reports 2015; 48(2): 109-114] PMID:24965577

  14. Tissue factor/FVIIa activates Bcl-2 and prevents doxorubicin-induced apoptosis in neuroblastoma cells

    International Nuclear Information System (INIS)

    Fang, Jun; Gu, Lubing; Zhu, Ningxi; Tang, Hao; Alvarado, Carlos S; Zhou, Muxiang

    2008-01-01

    Tissue factor (TF) is a transmembrane protein that acts as a receptor for activated coagulation factor VII (FVIIa), initiating the coagulation cascade. Recent studies demonstrate that expression of tumor-derived TF also mediates intracellular signaling relevant to tumor growth and apoptosis. Our present study investigates the possible mechanism by which the interaction between TF and FVIIa regulates chemotherapy resistance in neuroblastoma cell lines. Gene and siRNA transfection was used to enforce TF expression in a TF-negative neuroblastoma cell line and to silence endogenous TF expression in a TF-overexpressing neuroblastoma line, respectively. The expression of TF, Bcl-2, STAT5, and Akt as well as the phosphorylation of STAT5 and Akt in gene transfected cells or cells treated with JAK inhibitor and LY294002 were determined by Western blot assay. Tumor cell growth was determined by a clonogenic assay. Cytotoxic and apoptotic effect of doxorubicin on neuroblastoma cell lines was analyzed by WST assay and annexin-V staining (by flow cytometry) respectively. Enforced expression of TF in a TF-negative neuroblastoma cell line in the presence of FVIIa induced upregulation of Bcl-2, leading to resistance to doxorubicin. Conversely, inhibition of endogenous TF expression in a TF-overexpressing neuroblastoma cell line using siRNA resulted in down-regulation of Bcl-2 and sensitization to doxorubicin-induced apoptosis. Additionally, neuroblastoma cells expressing high levels of either endogenous or transfected TF treated with FVIIa readily phosphorylated STAT5 and Akt. Using selective pharmacologic inhibitors, we demonstrated that JAK inhibitor I, but not the PI3K inhibitor LY294002, blocked the TF/FVIIa-induced upregulation of Bcl-2. This study shows that in neuroblastoma cell lines overexpressed TF ligated with FVIIa produced upregulation of Bcl-2 expression through the JAK/STAT5 signaling pathway, resulting in resistance to apoptosis. We surmise that this TF

  15. Quinacrine induces apoptosis in human leukemia K562 cells via p38 MAPK-elicited BCL2 down-regulation and suppression of ERK/c-Jun-mediated BCL2L1 expression

    International Nuclear Information System (INIS)

    Changchien, Jung-Jung; Chen, Ying-Jung; Huang, Chia-Hui; Cheng, Tian-Lu; Lin, Shinne-Ren; Chang, Long-Sen

    2015-01-01

    Although previous studies have revealed the anti-cancer activity of quinacrine, its effect on leukemia is not clearly resolved. We sought to explore the cytotoxic effect and mechanism of quinacrine action in human leukemia K562 cells. Quinacrine induced K562 cell apoptosis accompanied with ROS generation, mitochondrial depolarization, and down-regulation of BCL2L1 and BCL2. Upon exposure to quinacrine, ROS-mediated p38 MAPK activation and ERK inactivation were observed in K562 cells. Quinacrine-induced cell death and mitochondrial depolarization were suppressed by the p38MAPK inhibitor SB202190 and constitutively active MEK1 over-expression. Activation of p38 MAPK was shown to promote BCL2 degradation. Further, ERK inactivation suppressed c-Jun-mediated transcriptional expression of BCL2L1. Over-expression of BCL2L1 and BCL2 attenuated quinacrine-evoked mitochondrial depolarization and rescued the viability of quinacrine-treated cells. Taken together, our data indicate that quinacrine-induced K562 cell apoptosis is mediated through mitochondrial alterations triggered by p38 MAPK-mediated BCL2 down-regulation and suppression of ERK/c-Jun-mediated BCL2L1 expression. - Highlights: • Quinacrine induces K562 cell apoptosis via down-regulation of BCL2 and BCL2L1. • Quinacrine induces p38 MAPK activation and ERK inactivation in K562 cells. • Quinacrine elicits p38 MAPK-mediated BCL2 down-regulation. • Quinacrine suppresses ERK/c-Jun-mediated BCL2L1 expression

  16. Caspase activity and expression of cell death genes during development of human preimplantation embryos.

    Science.gov (United States)

    Spanos, S; Rice, S; Karagiannis, P; Taylor, D; Becker, D L; Winston, R M L; Hardy, K

    2002-09-01

    It has been observed that apoptosis occurs in human blastocysts. In other types of cell, the characteristic morphological changes seen in apoptotic cells are executed by caspases, which are regulated by the BCL-2 family of proteins. This study investigated whether these components of the apoptotic cascade are present throughout human preimplantation development. Developing and arrested two pronucleate embryos at all stages were incubated with a fluorescently tagged caspase inhibitor that binds only to active caspases, fixed, counterstained with 4,6-diamidino-2-phenylindole (DAPI) to assess nuclear morphology and examined using confocal microscopy. Active caspases were detected only after compaction, at the morula and blastocyst stages, and were frequently associated with apoptotic nuclei. Occasional labelling was seen in arrested embryos. Expression of proapoptotic BAX and BAD and anti-apoptotic BCL-2 was examined in single embryos using RT-PCR and immunohistochemistry. BAX and BCL-2 mRNAs were expressed throughout development, whereas BAD mRNA was expressed mainly after compaction. Simultaneous expression of BAX and BCL-2 proteins within individual embryos was confirmed using immunohistochemistry. The onset of caspase activity and BAD expression after compaction correlates with the previously reported appearance of apoptotic nuclei. As in other types of cell, human embryos express common molecular components of the apoptotic cascade, although apoptosis appears to be suppressed before compaction and differentiation.

  17. Regulation of apoptotic mediators reveals dynamic responses to thermal stress in the reef building coral Acropora millepora.

    Science.gov (United States)

    Pernice, Mathieu; Dunn, Simon R; Miard, Thomas; Dufour, Sylvie; Dove, Sophie; Hoegh-Guldberg, Ove

    2011-01-24

    Mass coral bleaching is increasing in scale and frequency across the world's coral reefs and is being driven primarily by increased levels of thermal stress arising from global warming. In order to understand the impacts of projected climate change upon corals reefs, it is important to elucidate the underlying cellular mechanisms that operate during coral bleaching and subsequent mortality. In this respect, increased apoptotic cell death activity is an important cellular process that is associated with the breakdown of the mutualistic symbiosis between the cnidarian host and their dinoflagellate symbionts. The PRESENT study reports the impacts of different stressors (colchicine and heat stress) on three phases of apoptosis: (i) the potential initiation by differential expression of Bcl-2 members, (ii) the execution of apoptotic events by activation of caspase 3-like proteases and (iii) and finally, the cell disposal indicated by DNA fragmentation in the reef building coral Acropora millepora. In corals incubated with colchicine, an increase in caspase 3-like activity and DNA fragmentation was associated with a relative down-regulation of Bcl-2, suggesting that the initiation of apoptosis may be mediated by the suppression of an anti-apoptotic mechanism. In contrast, in the early steps of heat stress, the induction of caspase-dependent apoptosis was related to a relative up-regulation of Bcl-2 consecutively followed by a delayed decrease in apoptosis activity. In the light of these results, we propose a model of heat stress in coral hosts whereby increasing temperatures engage activation of caspase 3-dependent apoptosis in cells designated for termination, but also the onset of a delayed protective response involving overexpression of Bcl-2 in surviving cells. This mitigating response to thermal stress could conceivably be an important regulatory mechanism for cell survival in corals exposed to sudden environmental changes.

  18. Regulation of apoptotic mediators reveals dynamic responses to thermal stress in the reef building coral Acropora millepora.

    Directory of Open Access Journals (Sweden)

    Mathieu Pernice

    2011-01-01

    Full Text Available Mass coral bleaching is increasing in scale and frequency across the world's coral reefs and is being driven primarily by increased levels of thermal stress arising from global warming. In order to understand the impacts of projected climate change upon corals reefs, it is important to elucidate the underlying cellular mechanisms that operate during coral bleaching and subsequent mortality. In this respect, increased apoptotic cell death activity is an important cellular process that is associated with the breakdown of the mutualistic symbiosis between the cnidarian host and their dinoflagellate symbionts.The PRESENT study reports the impacts of different stressors (colchicine and heat stress on three phases of apoptosis: (i the potential initiation by differential expression of Bcl-2 members, (ii the execution of apoptotic events by activation of caspase 3-like proteases and (iii and finally, the cell disposal indicated by DNA fragmentation in the reef building coral Acropora millepora. In corals incubated with colchicine, an increase in caspase 3-like activity and DNA fragmentation was associated with a relative down-regulation of Bcl-2, suggesting that the initiation of apoptosis may be mediated by the suppression of an anti-apoptotic mechanism. In contrast, in the early steps of heat stress, the induction of caspase-dependent apoptosis was related to a relative up-regulation of Bcl-2 consecutively followed by a delayed decrease in apoptosis activity.In the light of these results, we propose a model of heat stress in coral hosts whereby increasing temperatures engage activation of caspase 3-dependent apoptosis in cells designated for termination, but also the onset of a delayed protective response involving overexpression of Bcl-2 in surviving cells. This mitigating response to thermal stress could conceivably be an important regulatory mechanism for cell survival in corals exposed to sudden environmental changes.

  19. p53-Dependent radiation-induced apoptosis in vivo: relationship to Bcl-2 and Bax expression

    International Nuclear Information System (INIS)

    Hasegawa, Masatoshi; Suzuki, Yoshiyuki; Furuta, Masaya; Yamakawa, Michitaka; Maebayashi, Katsuya; Hayakawa, Kayoko; Saito, Yoshihiro; Mitsuhashi, Norio; Niibe, Hideo

    1997-01-01

    Purpose: A close correlation between p53 protein expression and radiation-induced apoptosis has already been reported, however, Bcl-2 and Bax expression and the ratio of Bcl-2 to Bax have been also suggested to play an important role in the regulation of apoptotic cell death. In this study, we investigated the relationship between p53-dependent radiation-induced apoptosis and expression of Bcl-2 and Bax by using human tumors transplanted into nude mice. Materials and Methods: Three human tumors (an ependymoblastoma, a glioblastoma, and a small cell lung cancer) were subcutaneously transplanted into nude mice and irradiated with single doses of 1, 2, 5, or 10 Gy. The tumors were excised 1, 3, 6, 12, 24, and 48 hours after irradiation, fixed in 10% formalin for 24 hours, and embedded in paraffin. Slides were stained with hematoxylin and eosin for morphologic examination. Immunohistochemical studies were performed with mouse monoclonal antibodies to demonstrate p53, p21 (WAF-1), Bcl-2, and Bax expression. TdT-mediated dUTP-biotin nick-end labeling (TUNEL) and electron microscopic studies were performed to identify apoptosis, and PCR-SSCP analysis was used to evaluate p53 gene mutation. Results: All of the tumors showed only a few cells undergoing apoptosis before irradiation. Beginning several hours after irradiation, only the ependymoblastoma showed a large increase in the number of cells undergoing apoptosis, peaking at 6 hours after irradiation, and there was a clear dose-effect relationship. In contrast, the other tumors showed much less change following irradiation, and the dose-effect relationship was not as clear as in the ependymoblastoma. Immunohistochemically, the non-irradiated ependymoblastoma was negative for p53, p21, Bcl-2, and Bax. Following irradiation, however, many of the tumor cells became positive for p53 and p21, and a few cells became positive for bcl-2. In contrast, the glioblastoma and the small cell lung cancer were positive for p53 and Bcl-2

  20. CASP10-BCL::Fold efficiently samples topologies of large proteins.

    Science.gov (United States)

    Heinze, Sten; Putnam, Daniel K; Fischer, Axel W; Kohlmann, Tim; Weiner, Brian E; Meiler, Jens

    2015-03-01

    During CASP10 in summer 2012, we tested BCL::Fold for prediction of free modeling (FM) and template-based modeling (TBM) targets. BCL::Fold assembles the tertiary structure of a protein from predicted secondary structure elements (SSEs) omitting more flexible loop regions early on. This approach enables the sampling of conformational space for larger proteins with more complex topologies. In preparation of CASP11, we analyzed the quality of CASP10 models throughout the prediction pipeline to understand BCL::Fold's ability to sample the native topology, identify native-like models by scoring and/or clustering approaches, and our ability to add loop regions and side chains to initial SSE-only models. The standout observation is that BCL::Fold sampled topologies with a GDT_TS score > 33% for 12 of 18 and with a topology score > 0.8 for 11 of 18 test cases de novo. Despite the sampling success of BCL::Fold, significant challenges still exist in clustering and loop generation stages of the pipeline. The clustering approach employed for model selection often failed to identify the most native-like assembly of SSEs for further refinement and submission. It was also observed that for some β-strand proteins model refinement failed as β-strands were not properly aligned to form hydrogen bonds removing otherwise accurate models from the pool. Further, BCL::Fold samples frequently non-natural topologies that require loop regions to pass through the center of the protein. © 2015 Wiley Periodicals, Inc.

  1. Bcl-2 antisense therapy in B-cell malignant proliferative disorders.

    Science.gov (United States)

    Chanan-Khan, Asher; Czuczman, Myron S

    2004-08-01

    Overexpression of Bcl-2 oncogene has been clinically associated with an aggressive clinical course, chemotherapy and radiotherapy resistance, and poor survival in patients with malignant B-cell disorders. Patients with relapsed or refractory chronic lymphocytic leukemia, multiple myeloma, or non-Hodgkin's lymphoma have limited therapeutic options. Preclinical and early clinical data have shown that Bcl-2 oncoprotein can be decreased by Bcl-2 antisense therapy. Also, downregulation of Bcl-2 protein can result in reversal of chemotherapy resistance and improved antitumor activity of biologic agents. Various clinical trials are evaluating the role of targeting Bcl-2 as a mechanism to enhance the antitumor potential of chemotherapy and immunotherapy. Early results from these clinical studies are encouraging and confirm the proof of principle for antisense therapy. As current data mature, these trials will hopefully validate preliminary results and establish Bcl-2 antisense as an important addition to the current armamentarium used in the treatment of patients with B-cell neoplasms.

  2. Synergistic and complete reversal of the multidrug resistance of mitoxantrone hydrochloride by three-in-one multifunctional lipid-sodium glycocholate nanocarriers based on simultaneous BCRP and Bcl-2 inhibition.

    Science.gov (United States)

    Ling, Guixia; Zhang, Tianhong; Zhang, Peng; Sun, Jin; He, Zhonggui

    Multidrug resistance (MDR) is a severe obstacle to successful chemotherapy due to its complicated nature that involves multiple mechanisms, such as drug efflux by transporters (P-glycoprotein and breast cancer resistance protein, BCRP) and anti-apoptotic defense (B-cell lymphoma, Bcl-2). To synergistically and completely reverse MDR by simultaneous inhibition of pump and non-pump cellular resistance, three-in-one multifunctional lipid-sodium glycocholate (GcNa) nanocarriers (TMLGNs) have been designed for controlled co-delivery of water-soluble cationic mitoxantrone hydrochloride (MTO), cyclosporine A (CsA - BCRP inhibitor), and GcNa (Bcl-2 inhibitor). GcNa and dextran sulfate were incorporated as anionic compounds to enhance the encapsulation efficiency of MTO (up to 97.8%±1.9%) and sustain the release of cationic MTO by electrostatic interaction. The results of a series of in vitro and in vivo investigations indicated that the TMLGNs were taken up by the resistant cancer cells by an endocytosis pathway that escaped the efflux induced by BCRP, and the simultaneous release of CsA with MTO further efficiently inhibited the efflux of the released MTO by BCRP; meanwhile GcNa induced the apoptosis process, and an associated synergistic antitumor activity and reversion of MDR were achieved because the reversal index was almost 1.0.

  3. Regulation of apoptotic pathways by Stylophora pistillata (Anthozoa, Pocilloporidae to survive thermal stress and bleaching.

    Directory of Open Access Journals (Sweden)

    Hagit Kvitt

    Full Text Available Elevated seawater temperatures are associated with coral bleaching events and related mortality. Nevertheless, some coral species are able to survive bleaching and recover. The apoptotic responses associated to this ability were studied over 3 years in the coral Stylophora pistillata from the Gulf of Eilat subjected to long term thermal stress. These include caspase activity and the expression profiles of the S. pistillata caspase and Bcl-2 genes (StyCasp and StyBcl-2-like cloned in this study. In corals exposed to thermal stress (32 or 34°C, caspase activity and the expression levels of the StyBcl-2-like gene increased over time (6-48 h and declined to basal levels within 72 h of thermal stress. Distinct transcript levels were obtained for the StyCasp gene, with stimulated expression from 6 to 48 h of 34°C thermal stress, coinciding with the onset of bleaching. Increased cell death was detected in situ only between 6 to 48 h of stress and was limited to the gastroderm. The bleached corals survived up to one month at 32°C, and recovered back symbionts when placed at 24°C. These results point to a two-stage response in corals that withstand thermal stress: (i the onset of apoptosis, accompanied by rapid activation of anti-oxidant/anti-apoptotic mediators that block the progression of apoptosis to other cells and (ii acclimatization of the coral to the chronic thermal stress alongside the completion of symbiosis breakdown. Accordingly, the coral's ability to rapidly curb apoptosis appears to be the most important trait affecting the coral's thermotolerance and survival.

  4. Identification of an HLA-A*0201 restricted Bcl2-derived epitope expressed on tumors

    DEFF Research Database (Denmark)

    Wang, Mingjun; Johansen, Britta; Nissen, Mogens H

    2006-01-01

    A large number of human tumor-associated antigen-derived peptides have been identified that are recognized by CTLs in a MHC-I restricted fashion. The apoptosis inhibitory protein Bcl2 is overexpressed in many human cancers as part of their neoplastic phenotype. Since inhibition or loss of Bcl2...... from the amino acid sequence of the Bcl2 protein and its binding affinity for HLA-A*0201 was confirmed using a biochemical binding assay. We here demonstrate that the 9-mer peptide Bcl2(85-93) induces specific CTL reactivity in immunized C57-A2K(b) or -A2D(b) tg mice. These Bcl2(85-93) specific CTLs...... react with and lyse Bcl2-expressing human colon carcinoma CCL220 cells which have been transfected with a chimeric HLA-A*0201/H2-K(b) DNA construct similar to that expressed in the transgenic mice. Based on these observations, we suggest that Bcl2(85-93) may be a target for immune therapy....

  5. Azithromycin Synergistically Enhances Anti-Proliferative Activity of Vincristine in Cervical and Gastric Cancer Cells

    International Nuclear Information System (INIS)

    Zhou, Xuezhang; Zhang, Yuyan; Li, Yong; Hao, Xiujing; Liu, Xiaoming; Wang, Yujiong

    2012-01-01

    In this study, the anti-proliferative and anticancer activity of azithromycin (AZM) was examined. In the presence of AZM, cell growth was inhibited more effectively in Hela and SGC-7901 cancer cells, relative to transformed BHK-21 cells. The respective 50% inhibition of cell growth (IC 50 ) values for Hela, SGC-7901 and BHK-21 were 15.66, 26.05 and 91.00 µg/mL at 72 h post incubation, indicative of a selective cytotoxicity against cancer cells. Cell apoptosis analysis using Hoechst nuclear staining and annexin V-FITC binding assay further demonstrated that AZM was capable of inducing apoptosis in both cancer cells and transformed cells. The apoptosis induced by AZM was partly through a caspase-dependent mechanism with an up-regulation of apoptotic protein cleavage PARP and caspase-3 products, as well as a down-regulation of anti-apoptotic proteins, Mcl-1, bcl-2 and bcl-X1. More importantly, a combination of AZM and a low dose of the common anti-cancer chemotherapeutic agent vincristine (VCR), produced a selectively synergistic effect on apoptosis of Hela and SGC-7901 cells, but not BHK-21 cells. In the presence of 12.50 μg/mL of VCR, the respective IC 50 values of Hela, SGC-7901 and BHK-21 cells to AZM were reduced to 9.47 µg/mL, 8.43 µg/mL and 40.15 µg/mL at 72 h after the incubation, suggesting that the cytotoxicity of AZM had a selective anti-cancer effect on cancer over transformed cells in vitro. These results imply that AZM may be a potential anticancer agent for use in chemotherapy regimens, and it may minimize side effects via reduction of dosage and enhancing the effectiveness common chemotherapeutic drugs

  6. Involvement of Bax and Bcl-2 in Induction of Apoptosis by Essential Oils of Three Lebanese Salvia Species in Human Prostate Cancer Cells

    Directory of Open Access Journals (Sweden)

    Alessandra Russo

    2018-01-01

    Full Text Available Prostate cancer is one of the most common forms of cancer in men, and research to find more effective and less toxic drugs has become necessary. In the frame of our ongoing program on traditionally used Salvia species from the Mediterranean Area, here we report the biological activities of Salvia aurea, S. judaica and S. viscosa essential oils against human prostate cancer cells (DU-145. The cell viability was measured by 3(4,5-dimethyl-thiazol-2-yl2,5-diphenyl-tetrazolium bromide (MTT test and lactate dehydrogenase (LDH release was used to quantify necrosis cell death. Genomic DNA, caspase-3 activity, expression of cleaved caspase-9, B-cell lymphoma 2 (Bcl-2 and Bcl-2 associated X (Bax proteins were analyzed in order to study the apoptotic process. The role of reactive oxygen species in cell death was also investigated. We found that the three essential oils, containing caryophyllene oxide as a main constituent, are capable of reducing the growth of human prostate cancer cells, activating an apoptotic process and increasing reactive oxygen species generation. These results suggest it could be profitable to further investigate the effects of these essential oils for their possible use as anticancer agents in prostate cancer, alone or in combination with chemotherapy agents.

  7. Pan-Bcl-2 inhibitor obatoclax delays cell cycle progression and blocks migration of colorectal cancer cells.

    Directory of Open Access Journals (Sweden)

    Bruno Christian Koehler

    Full Text Available Despite the fact that new treatment regimes have improved overall survival of patients challenged by colorectal cancer (CRC, prognosis in the metastatic situation is still restricted. The Bcl-2 family of proteins has been identified as promising anti cancer drug target. Even though small molecules targeting Bcl-2 proteins are in clinical trials, little is known regarding their effects on CRC. The aim of this study was to preclinically investigate the value of ABT-737 and Obatoclax as anticancer drugs for CRC treatment. The effects of the BH3-mimetics ABT-737 and Obatoclax on CRC cells were assessed using viability and apoptosis assays. Wound healing migration and boyden chamber invasion assays were applied. 3-dimensional cell cultures were used for long term assessment of invasion and proliferation. Clinically relevant concentrations of pan-Bcl-2 inhibitor Obatoclax did not induce cell death. In contrast, the BH3-mimetic ABT-737 induced apoptosis in a dose dependent manner. Obatoclax caused a cell line specific slowdown of CRC cell growth. Furthermore, Obatoclax, but not ABT-737, recovered E-Cadherin expression and led to impaired migration and invasion of CRC cells. The proliferative capacity and invasiveness of CRC cells was strikingly inhibited by low dose Obatoclax in long term 3-dimensional cell cultures. Obatoclax, but not ABT-737, caused a G1-phase arrest accompanied by a downregulation of Cyclin D1 and upregulation of p27 and p21. Overexpression of Mcl-1, Bcl-xL or Bcl-2 reversed the inhibitory effect of Obatoclax on migration but failed to restore the proliferative capacity of Obatoclax-treated CRC cells. The data presented indicate broad and multifaceted antitumor effects of the pan-Bcl-2 inhibitor Obatoclax on CRC cells. In contrast to ABT-737, Obatoclax inhibited migration, invasion and proliferation in sublethal doses. In summary, this study recommends pan-Bcl-2 inhibition as a promising approach for clinical trials in CRC.

  8. Air pollution induces enhanced mitochondrial oxidative stress in cystic fibrosis airway epithelium.

    Science.gov (United States)

    Kamdar, O; Le, Wei; Zhang, J; Ghio, A J; Rosen, G D; Upadhyay, D

    2008-10-29

    We studied the effects of airborne particulate matters (PM) on cystic fibrosis (CF) epithelium. We noted that PM enhanced human CF bronchial epithelial apoptosis, activated caspase-9 and PARP-1; and reduced mitochondrial membrane potential. Mitochondrial inhibitors (4,4-diisothiocyanatostilbene-2,2'disulfonic acid, rotenone and thenoyltrifluoroacetone) blocked PM-induced generation of reactive oxygen species and apoptosis. PM upregulated pro-apoptotic Bad, Bax, p53 and p21; and enhanced mitochondrial localization of Bax. The anti-apoptotic Bcl-2, Bcl-xl, Mcl-1 and Xiap remained unchanged; however, overexpression of Bcl-xl blocked PM-induced apoptosis. Accordingly, we provide the evidence that PM enhances oxidative stress and mitochondrial signaling mediated apoptosis via the modulation of Bcl family proteins in CF.

  9. Enrichment of Druggable Conformations from Apo Protein Structures Using Cosolvent-Accelerated Molecular Dynamics

    Directory of Open Access Journals (Sweden)

    Andrew Kalenkiewicz

    2015-04-01

    Full Text Available Here we describe the development of an improved workflow for utilizing experimental and simulated protein conformations in the structure-based design of inhibitors for anti-apoptotic Bcl-2 family proteins. Traditional structure-based approaches on similar targets are often constrained by the sparsity of available structures and difficulties in finding lead compounds that dock against flat, flexible protein-protein interaction surfaces. By employing computational docking of known small molecule inhibitors, we have demonstrated that structural ensembles derived from either accelerated MD (aMD or MD in the presence of an organic cosolvent generally give better scores than those assessed from analogous conventional MD. Furthermore, conformations obtained from combined cosolvent aMD simulations started with the apo-Bcl-xL structure yielded better average and minimum docking scores for known binders than an ensemble of 72 experimental apo- and ligand-bound Bcl-xL structures. A detailed analysis of the simulated conformations indicates that the aMD effectively enhanced conformational sampling of the flexible helices flanking the main Bcl-xL binding groove, permitting the cosolvent acting as small ligands to penetrate more deeply into the binding pocket and shape ligand-bound conformations not evident in conventional simulations. We believe this approach could be useful for identifying inhibitors against other protein-protein interaction systems involving highly flexible binding sites, particularly for targets with less accumulated structural data.

  10. BAD-mediated apoptotic pathway is associated with human cancer development.

    Science.gov (United States)

    Stickles, Xiaomang B; Marchion, Douglas C; Bicaku, Elona; Al Sawah, Entidhar; Abbasi, Forough; Xiong, Yin; Bou Zgheib, Nadim; Boac, Bernadette M; Orr, Brian C; Judson, Patricia L; Berry, Amy; Hakam, Ardeshir; Wenham, Robert M; Apte, Sachin M; Berglund, Anders E; Lancaster, Johnathan M

    2015-04-01

    The malignant transformation of normal cells is caused in part by aberrant gene expression disrupting the regulation of cell proliferation, apoptosis, senescence and DNA repair. Evidence suggests that the Bcl-2 antagonist of cell death (BAD)-mediated apoptotic pathway influences cancer chemoresistance. In the present study, we explored the role of the BAD-mediated apoptotic pathway in the development and progression of cancer. Using principal component analysis to derive a numeric score representing pathway expression, we evaluated clinico-genomic datasets (n=427) from corresponding normal, pre-invasive and invasive cancers of different types, such as ovarian, endometrial, breast and colon cancers in order to determine the associations between the BAD-mediated apoptotic pathway and cancer development. Immunofluorescence was used to compare the expression levels of phosphorylated BAD [pBAD (serine-112, -136 and -155)] in immortalized normal and invasive ovarian, colon and breast cancer cells. The expression of the BAD-mediated apoptotic pathway phosphatase, PP2C, was evaluated by RT-qPCR in the normal and ovarian cancer tissue samples. The growth-promoting effects of pBAD protein levels in the immortalized normal and cancer cells were assessed using siRNA depletion experiments with MTS assays. The expression of the BAD-mediated apoptotic pathway was associated with the development and/or progression of ovarian (n=106, pBAD-mediated apoptotic pathway is thus associated with the development of human cancers likely influenced by the protein levels of pBAD.

  11. Unraveling the Molecular Mechanism of Benzothiophene and Benzofuran scaffold merged compounds binding to anti-apoptotic Myeloid cell leukemia 1.

    Science.gov (United States)

    Marimuthu, Parthiban; Singaravelu, Kalaimathy

    2018-05-10

    Myeloid cell leukemia 1 (Mcl1), is an anti-apoptotic member of the Bcl-2 family proteins, has gained considerable importance due to its overexpression activity prevents the oncogenic cells to undergo apoptosis. This overexpression activity of Mcl1 eventually develops strong resistance to a wide variety of anticancer agents. Therefore, designing novel inhibitors with potentials to elicit higher binding affinity and specificity to inhibit Mcl1 activity is of greater importance. Thus, Mcl1 acts as an attractive cancer target. Despite recent experimental advancement in the identification and characterization of Benzothiophene and Benzofuran scaffold merged compounds the molecular mechanisms of their binding to Mcl1 are yet to be explored. The current study demonstrates an integrated approach -pharmacophore-based 3D-QSAR, docking, Molecular Dynamics (MD) simulation and free-energy estimation- to access the precise and comprehensive effects of current inhibitors targeting Mcl1 together with its known activity values. The pharmacophore -ANRRR.240- based 3D-QSAR model from the current study provided high confidence (R 2 =0.9154, Q 2 =0.8736, and RMSE=0.3533) values. Furthermore, the docking correctly predicted the binding mode of highly active compound 42. Additionally, the MD simulation for docked complex under explicit-solvent conditions together with free-energy estimation exhibited stable interaction and binding strength over the time period. Also, the decomposition analysis revealed potential energy contributing residues -M231, M250, V253, R265, L267, and F270- to the complex stability. Overall, the current investigation might serve as a valuable insight, either to (i) improve the binding affinity of the current compounds or (ii) discover new generation anti-cancer agents that can effectively downregulate Mcl1 activity.

  12. Clinical significance of proliferation, apoptosis and senescence of nasopharyngeal cells by the simultaneously blocking EGF, IGF-1 receptors and Bcl-xl genes

    International Nuclear Information System (INIS)

    Dai, Guodong; Peng, Tao; Zhou, Xuhong; Zhu, Jun; Kong, Zhihua; Ma, Li; Xiong, Zhi; Yuan, Yulin

    2013-01-01

    Highlight: •Construction of shRNA segments expression vectors is valid by the investigation of RT-PCR for IGF1R, EGFR and Bcl-xl mRNA and protein expression. •Studies have suggested that the vectors in blocking these genes of the growth factor receptors and anti- apoptosis is capable of breaking the balance of tumor growth so that tumor trend apoptosis and senescence. •Simultaneously blocking multiple genes that are abnormally expressed may be more effective in treating cancer cells than silencing a single gene. -- Abstract: Background: In previous work, we constructed short hairpin RNA (shRNA) expression plasmids that targeted human EGF and IGF-1 receptors messenger RNA, respectively, and demonstrated that these vectors could induce apoptosis of human nasopharyngeal cell lines (CNE2) and inhibit ligand-induced pAkt and pErk activation. Method: We have constructed multiple shRNA expression vectors of targeting EGFR, IGF1R and Bcl-xl, which were transfected to the CNE2 cells. The mRNA expression was assessed by RT-PCR. The growth of the cells, cell cycle progression, apoptosis of the cells, senescent tumor cells and the proteins of EGFR, IGF1R and Bcl-xl were analyzed by MTT, flow cytometry, cytochemical therapy or Western blot. Results: In group of simultaneously blocking EGFR, IGF1R and Bcl-xl genes, the mRNA of EGFR, IGF1R and Bcl-xl expression was decreased by (66.66 ± 3.42)%, (73.97 ± 2.83)% and (64.79 ± 2.83)%, and the protein expressions was diminished to (67.69 ± 4.02)%, (74.32 ± 2.30)%, and (60.00 ± 3.34)%, respectively. Meanwhile, the cell apoptosis increased by 65.32 ± 0.18%, 65.16 ± 0.25% and 55.47 ± 0.45%, and senescent cells increased by 1.42 ± 0.15%, 2.26 ± 0.15% and 3.22 ± 0.15% in the second, third and fourth day cultures, respectively. Conclusions: Simultaneously blocking EGFR, IGF1R and Bcl-xl genes is capable of altering the balance between proliferating versus apoptotic and senescent cells in the favor of both of apoptosis and

  13. Clinical significance of proliferation, apoptosis and senescence of nasopharyngeal cells by the simultaneously blocking EGF, IGF-1 receptors and Bcl-xl genes

    Energy Technology Data Exchange (ETDEWEB)

    Dai, Guodong [Anatomy and Embryology, Wuhan University School of Medicine, Wuhan, Hubei 430071 (China); Peng, Tao; Zhou, Xuhong [Department of Otolaryngology-Head and Neck Surgery, Zhongnan Hospital of Wuhan University, Wuhan 430071 (China); Zhu, Jun; Kong, Zhihua; Ma, Li; Xiong, Zhi [Anatomy and Embryology, Wuhan University School of Medicine, Wuhan, Hubei 430071 (China); Yuan, Yulin, E-mail: yuanyulin19620120@126.com [Anatomy and Embryology, Wuhan University School of Medicine, Wuhan, Hubei 430071 (China)

    2013-11-01

    Highlight: •Construction of shRNA segments expression vectors is valid by the investigation of RT-PCR for IGF1R, EGFR and Bcl-xl mRNA and protein expression. •Studies have suggested that the vectors in blocking these genes of the growth factor receptors and anti- apoptosis is capable of breaking the balance of tumor growth so that tumor trend apoptosis and senescence. •Simultaneously blocking multiple genes that are abnormally expressed may be more effective in treating cancer cells than silencing a single gene. -- Abstract: Background: In previous work, we constructed short hairpin RNA (shRNA) expression plasmids that targeted human EGF and IGF-1 receptors messenger RNA, respectively, and demonstrated that these vectors could induce apoptosis of human nasopharyngeal cell lines (CNE2) and inhibit ligand-induced pAkt and pErk activation. Method: We have constructed multiple shRNA expression vectors of targeting EGFR, IGF1R and Bcl-xl, which were transfected to the CNE2 cells. The mRNA expression was assessed by RT-PCR. The growth of the cells, cell cycle progression, apoptosis of the cells, senescent tumor cells and the proteins of EGFR, IGF1R and Bcl-xl were analyzed by MTT, flow cytometry, cytochemical therapy or Western blot. Results: In group of simultaneously blocking EGFR, IGF1R and Bcl-xl genes, the mRNA of EGFR, IGF1R and Bcl-xl expression was decreased by (66.66 ± 3.42)%, (73.97 ± 2.83)% and (64.79 ± 2.83)%, and the protein expressions was diminished to (67.69 ± 4.02)%, (74.32 ± 2.30)%, and (60.00 ± 3.34)%, respectively. Meanwhile, the cell apoptosis increased by 65.32 ± 0.18%, 65.16 ± 0.25% and 55.47 ± 0.45%, and senescent cells increased by 1.42 ± 0.15%, 2.26 ± 0.15% and 3.22 ± 0.15% in the second, third and fourth day cultures, respectively. Conclusions: Simultaneously blocking EGFR, IGF1R and Bcl-xl genes is capable of altering the balance between proliferating versus apoptotic and senescent cells in the favor of both of apoptosis and

  14. Evaluation of Apoptotic and Growth Inhibitory Activity of Phloretin in ...

    African Journals Online (AJOL)

    Nuclear Magnetic Resonance (NMR), 13C-NMR and electrospray ionization tandem ... this effectively induced cleavage of anti-poly (ADP-ribose) polymerase (PARP) as well as downregulation of Bcl2 protein expression in BGC823 cells after 24 h ...

  15. α-linolenic acid reduces TNF-induced apoptosis in C2C12 myoblasts by regulating expression of apoptotic proteins

    Directory of Open Access Journals (Sweden)

    Felicia Carotenuto

    2016-11-01

    Full Text Available Impaired regeneration and consequent muscle wasting is a major feature of muscle degenerative diseases. Nutritional interventions as adjuvant strategy for preventing such conditions are recently gaining increasing attention. Ingestion of n3-polyunsaturated fatty acids has been suggested to have a positive impact on muscle diseases. We recently demonstrated that the dietary n3-fatty acid, alpha-linolenic acid (ALA, exerts potent beneficial effects in preserving skeletal muscle regeneration in models of muscle dystrophy. To better elucidate the underlying mechanism we investigate here on the expression level of the anti- and pro-apototic proteins, as well as caspase-3 activity, in C2C12 myoblasts challenged with pathological levels of TNF. The results demonstrated that ALA protective effect on C2C12 myoblasts was associated to an increased Bcl-2/Bax ratio. Indeed, the effect of ALA was directed to rescue Bcl-2 expression and decrease Bax expression both affected in an opposite way by TNF treatment. This effect was associated with a decrease in caspase-3 activity by ALA. TNF is a major pro-inflammatory cytokine that is expressed in damaged skeletal muscle, therefore, counteract inflammatory signals in the muscle microenvironment represents a critical strategy to ameliorate skeletal muscle pathologies

  16. The Anti-Apoptotic Properties of APEX1 in the Endothelium Require the First 20 Amino Acids and Converge on Thioredoxin-1.

    Science.gov (United States)

    Dyballa-Rukes, Nadine; Jakobs, Philipp; Eckers, Anna; Ale-Agha, Niloofar; Serbulea, Vlad; Aufenvenne, Karin; Zschauer, Tim-Christian; Rabanter, Lothar L; Jakob, Sascha; von Ameln, Florian; Eckermann, Olaf; Leitinger, Norbert; Goy, Christine; Altschmied, Joachim; Haendeler, Judith

    2017-04-20

    The APEX nuclease (multifunctional DNA repair enzyme) 1 (APEX1) has a disordered N-terminus, a redox, and a DNA repair domain. APEX1 has anti-apoptotic properties, which have been linked to both domains depending on cell type and experimental conditions. As protection against apoptosis is a hallmark of vessel integrity, we wanted to elucidate whether APEX1 acts anti-apoptotic in primary human endothelial cells and, if so, what the underlying mechanisms are. APEX1 inhibits apoptosis in endothelial cells by reducing Cathepsin D (CatD) cleavage, potentially by binding to the unprocessed form. Diminished CatD activation results in increased Thioredoxin-1 protein levels leading to reduced Caspase 3 activation. Consequently, apoptosis rates are decreased. This depends on the first twenty amino acids in APEX1, because APEX1 (21-318) induces CatD activity, decreases Thioredoxin-1 protein levels, and, thus, increases Caspase 3 activity and apoptosis. Along the same lines, APEX1 (1-20) inhibits Caspase 3 cleavage and apoptosis. Furthermore, re-expression of Thioredoxin-1 via lentiviral transduction rescues endothelial cells from APEX1 (21-318)-induced apoptosis. In an in vivo model of restenosis, which is characterized by oxidative stress, endothelial activation, and smooth muscle cell proliferation, Thioredoxin-1 protein levels are reduced in the endothelium of the carotids. APEX1 acts anti-apoptotic in endothelial cells. This anti-apoptotic effect depends on the first 20 amino acids of APEX1. As proper function of the endothelium during life span is a hallmark for individual health span, a detailed characterization of the functions of the APEX1N-terminus is required to understand all its cellular properties. Antioxid. Redox Signal. 26, 616-629.

  17. Differential control of growth, apoptotic activity and gene expression in human colon cancer cells by extracts derived from medicinal herbs, Rhazya stricta and Zingiber officinale and their combination.

    Science.gov (United States)

    Elkady, Ayman I; Hussein, Rania Abd El Hamid; Abu-Zinadah, Osama A

    2014-11-07

    To investigate the effects of extracts from Rhazya stricta (R. stricta) and Zingiber officinale (Z. officinale) on human colorectal cancer cells. Human colorectal cancer cells (HCT116) were subjected to increasing doses of crude alkaloid extracts from R. stricta (CAERS) and crude flavonoid extracts from Z. officinale (CFEZO). Cells were then harvested after 24, 48 or 72 h and cell viability was examined by trypan blue exclusion dye test; clonogenicity and soft agar colony-forming assays were also carried out. Nuclear stain (Hoechst 33342), acridine orange/ethidium bromide double staining, agarose gel electrophoresis and comet assays were performed to assess pro-apoptotic potentiality of the extracts. Quantitative reverse transcription-polymerase chain reaction (qRT-PCR), using gene-specific primers and Western blot analyses were performed to assess the impact of CAERS and CFEZO on the expression levels of key regulatory proteins in HCT116 cells. Treatment with a combination of CAERS and CFEZO synergistically suppressed the proliferation, colony formation and anchorage-independent growth of HCT116 cells. Calculated IC50, after 24, 48 and 72 h, were 70, 90 and 130 μg/mL for CAERS, 65, 85 and 120 μg/mL for CFEZO and 20, 25 and 45 μg/mL for both agents, respectively. CAERS- and CFEZO-treated cells exhibited morphologic and biochemical features of apoptotic cell death. The induction of apoptosis was associated with the release of mitochondrial cytochrome c, an increase in the Bax/Bcl-2 ratio, activation of caspases 3 and 9 and cleavage of poly ADP-ribose polymerase. CAERS and CFEZO treatments downregulated expression levels of anti-apoptotic proteins including Bcl-2, Bcl-X, Mcl-1, survivin and XIAP, and upregulated expression levels of proapoptotic proteins such as Bad and Noxa. CAERS and CFEZO treatments elevated expression levels of the oncosuppressor proteins, p53, p21 and p27, and reduced levels of the oncoproteins, cyclin D1, cyclin/cyclin-dependent kinase-4 and

  18. The anti-apoptotic BAG3 protein is involved in BRAF inhibitor resistance in melanoma cells.

    Science.gov (United States)

    Guerriero, Luana; Palmieri, Giuseppe; De Marco, Margot; Cossu, Antonio; Remondelli, Paolo; Capunzo, Mario; Turco, Maria Caterina; Rosati, Alessandra

    2017-10-06

    BAG3 protein, a member of BAG family of co-chaperones, has a pro-survival role in several tumour types. BAG3 anti-apoptotic properties rely on its characteristic to bind several intracellular partners, thereby modulating crucial events such as apoptosis, differentiation, cell motility, and autophagy. In human melanomas, BAG3 positivity is correlated with the aggressiveness of the tumour cells and can sustain IKK-γ levels, allowing a sustained activation of NF-κB. Furthermore, BAG3 is able to modulate BRAFV600E levels and activity in thyroid carcinomas. BRAFV600E is the most frequent mutation detected in malignant melanomas and is targeted by Vemurafenib, a specific inhibitor found to be effective in the treatment of advanced melanoma. However, patients with BRAF-mutated melanoma may result insensitive ab initio or, mostly, develop acquired resistance to the treatment with this molecule. Here we show that BAG3 down-modulation interferes with BRAF levels in melanoma cells and sensitizes them to Vemurafenib treatment. Furthermore, the down-modulation of BAG3 protein in an in vitro model of acquired resistance to Vemurafenib can induce sensitization to the BRAFV600E specific inhibition by interfering with BRAF pathway through reduction of ERK phosphorylation, but also on parallel survival pathways. Future studies on BAG3 molecular interactions with key proteins responsible of acquired BRAF inhibitor resistance may represent a promising field for novel multi-drugs treatment design.

  19. Chemical Constituents from Cimicifuga dahurica and Their Anti-Proliferative Effects on MCF-7 Breast Cancer Cells

    Directory of Open Access Journals (Sweden)

    Chu Thi Thanh Huyen

    2018-05-01

    Full Text Available This study was designed to search for novel anti-cancer compounds from natural plants. The 70% ethanolic extract from the rizhomes of Cimicifuga dahurica (Turcz. Maxim. (Ranunculaceae was found to possess significant in vitro anti-proliferative effects on MCF-7 breast cancer cells. A phytochemical investigation using assay-guided fractionation of the ethanolic extract of C. dahurica resulted in the isolation of one new phenolic amide glycoside 3, two new lignan glycosides 4 and 7, one new 9,19-cycloartane triterpenoid glycoside 6, and thirteen known constituents 1, 2, 5, and 8–17. The structures of 3, 4, 6, and 7 were established using contemporary NMR methods and from their HRESIMS data. The anti-proliferative effects of isolated compounds were evaluated using the BrdU-proliferation kit. Five among the 17 isolated compounds showed significant anti-proliferative effects (p ≤ 0.05, wherein compound 7 showed the most significant anti-proliferative and cell cycle arresting effect (p ≤ 0.05 which followed a dose dependent manner. Western blot protein expression analysis showed a down expression of c-Myc and cyclin D1 which further elucidated the anti-proliferation mechanism of compound 7 while apoptotic effects were found in association with Bcl-2 family protein expression variations. Conclusively this study reports the isolation and identification of 17 compounds from C. dahurica, including four novel molecules, in addition to the fact that compound 7 possesses significant anti-proliferative and apoptotic effects in vitro that may require further exploration.

  20. Downregulated TIPE2 is associated with poor prognosis and promotes cell proliferation in non-small cell lung cancer

    International Nuclear Information System (INIS)

    Li, Yuexia; Li, Xiaohui; Liu, Gang; Sun, Rongqing; Wang, Lirui; Wang, Jing; Wang, Hongmin

    2015-01-01

    Highlights: • TIPE2 is down-regulated in NSCLC tissues. • TIPE2 inhibits NSCLC cell proliferation, colony formation and invasion. • TIPE2 reduces the anti-apoptotic Bcl-XL protein and mesenchymal marker N-cadherin expression. - Abstract: The present study aims to investigate the expression pattern of TIPE2 protein and its clinical significance in human non-small cell lung cancer (NSCLC). We investigated the expression levels of TIPE2 in 96 NSCLC tumor samples by immunohistochemistry and then analyzed its clinical significance. Furthermore, the role of TIPE2 on the biological properties of the NSCLC cell line H1299 and A549 was experimentally tested in vitro and in vivo. We found that the expression level of TIPE2 was significantly higher in normal lung tissues compared with NSCLC tissues (P < 0.001), and TIPE2 downregulation was significantly correlated with advanced TNM stage (P = 0.006). TIPE2 expression was lower in lung cancer cell lines than normal bronchial cell line HBE. Transfection of TIPE2 plasmid was performed in H1299 and A549 cells. TIPE2 overexpression inhibited lung cancer cell proliferation, colony formation and cell invasive in vitro, and prevented lung tumor growth in vivo. In addition, TIPE2 transfection reduced the anti-apoptotic Bcl-XL protein and mesenchymal marker N-cadherin expression. Taken together, our results demonstrate that TIPE2 might serve as a tumor suppressor in NSCLC progression

  1. Downregulated TIPE2 is associated with poor prognosis and promotes cell proliferation in non-small cell lung cancer

    Energy Technology Data Exchange (ETDEWEB)

    Li, Yuexia [Intensive Care Unit, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan 450052 (China); Li, Xiaohui [Department of Cardiovascular Surgery, Henan Provincial People’s Hospital, Zhengzhou, Henan 450003 (China); Liu, Gang; Sun, Rongqing; Wang, Lirui [Intensive Care Unit, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan 450052 (China); Wang, Jing, E-mail: jing_wang1980@163.com [Department of Respiratory Medicine, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan 450052 (China); Wang, Hongmin, E-mail: hmwangzz@126.com [Department of Respiratory Medicine, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan 450052 (China)

    2015-01-30

    Highlights: • TIPE2 is down-regulated in NSCLC tissues. • TIPE2 inhibits NSCLC cell proliferation, colony formation and invasion. • TIPE2 reduces the anti-apoptotic Bcl-XL protein and mesenchymal marker N-cadherin expression. - Abstract: The present study aims to investigate the expression pattern of TIPE2 protein and its clinical significance in human non-small cell lung cancer (NSCLC). We investigated the expression levels of TIPE2 in 96 NSCLC tumor samples by immunohistochemistry and then analyzed its clinical significance. Furthermore, the role of TIPE2 on the biological properties of the NSCLC cell line H1299 and A549 was experimentally tested in vitro and in vivo. We found that the expression level of TIPE2 was significantly higher in normal lung tissues compared with NSCLC tissues (P < 0.001), and TIPE2 downregulation was significantly correlated with advanced TNM stage (P = 0.006). TIPE2 expression was lower in lung cancer cell lines than normal bronchial cell line HBE. Transfection of TIPE2 plasmid was performed in H1299 and A549 cells. TIPE2 overexpression inhibited lung cancer cell proliferation, colony formation and cell invasive in vitro, and prevented lung tumor growth in vivo. In addition, TIPE2 transfection reduced the anti-apoptotic Bcl-XL protein and mesenchymal marker N-cadherin expression. Taken together, our results demonstrate that TIPE2 might serve as a tumor suppressor in NSCLC progression.

  2. Interaction of DNA-lesions induced by sodium fluoride and radiation and its influence in apoptotic induction in cancer cell lines

    Directory of Open Access Journals (Sweden)

    Santosh Podder

    2015-01-01

    Full Text Available Fluoride is an essential trace element but also an environmental contaminant with major sources of exposure being drinking water, food and pesticides. Previous studies showed that sodium fluoride (NaF at 5 mM or more is required to induce apoptosis and chromosome aberrations and proposed that DNA damage and apoptosis play an important role in toxicity of excessive fluoride. The aim of this study is directed to understand the nature of DNA-lesions induced by NaF by allowing its interaction with radiation induced DNA-lesions. NaF 5 mM was used after observing inability to induce DNA damages and apoptosis by single exposure with 50 μM or 1 mM NaF. Co-exposure to NaF and radiation significantly increased the frequency of aberrant metaphases and exchange aberrations in human lymphocytes and arrested the cells in G1 stage instead of apoptotic death. Flow cytometric analysis, DNA fragmentation and PARP-cleavage analysis clearly indicated that 5 mM NaF together with radiation (1 Gy induced apoptosis in both U87 and K562 cells due to down regulation of expression of anti-apoptotic proteins, like Bcl2 in U87 and inhibitors of apoptotic proteins like survivin and cIAP in K562 cells. This study herein suggested that single exposure with extremely low concentration of NaF unable to induce DNA lesions whereas higher concentration induced DNA lesions interact with the radiation-induced DNA lesions. Both are probably repaired rapidly thus showed increased interactive effect. Coexposure to NaF and radiation induces more apoptosis in cancer cell lines which could be due to increased exchange aberrations through lesions interaction and downregulating anti-apoptotic genes.

  3. Mis-targeting of the mitochondrial protein LIPT2 leads to apoptotic cell death.

    Directory of Open Access Journals (Sweden)

    Emanuele Bernardinelli

    Full Text Available Lipoyl(Octanoyl Transferase 2 (LIPT2 is a protein involved in the post-translational modification of key energy metabolism enzymes in humans. Defects of lipoic acid synthesis and transfer start to emerge as causes of fatal or severe early-onset disease. We show that the first 31 amino acids of the N-terminus of LIPT2 represent a mitochondrial targeting sequence and inhibition of the transit of LIPT2 to the mitochondrion results in apoptotic cell death associated with activation of the apoptotic volume decrease (AVD current in normotonic conditions, as well as over-activation of the swelling-activated chloride current (IClswell, mitochondrial membrane potential collapse, caspase-3 cleavage and nuclear DNA fragmentation. The findings presented here may help elucidate the molecular mechanisms underlying derangements of lipoic acid biosynthesis.

  4. Immunohistochemical expression of p53, BCL-2, BAX and VEGFR1 proteins in nephroblastomas A expressão imuno-histoquímica das proteínas p53, BCL-2, BAX e VEGFR1 em nefroblastomas

    Directory of Open Access Journals (Sweden)

    Ana Paula Percicote

    2013-02-01

    Full Text Available INTRODUCTION: Nephroblastoma or Wilms' tumor is the most frequent renal cancer in children. Although its prognosis is favorable for most patients, it may relapse or have a fatal outcome. The characterization of risk groups by applying immunohistochemical biomarkers aims to adapt the treatment to its corresponding group as well as to reduce relapses and fatal outcome. p53, B-cell lymphoma 2 (BCL-2, BCL-2 associated protein X (BAX and vascular endothelial growth factor receptor 1 (VEGFR1 are among the most widely studied biomarkers, which are related to the apoptotic pathway, DNA repair and neovascularization. OBJECTIVE: The objective of this study is to assess the immunohistochemical expression of p53, BCL-2, BAX and VEGFR1 in samples of human nephroblastoma and to correlate them with clinicopathological prognostic factors. MATERIAL AND METHODS: Twenty-nine surgical specimens of nephroblastoma diagnosed from 1994 to 2007 were selected from the Anatomopathological Service of two hospitals in Curitiba. The immunohistochemical analysis of tissue microarrays was performed through immunoperoxidase staining and the yielded results were compared with clinicopathological prognostic factors. RESULTS: The major immunohistochemical expression of VEGFR1 in blastema and epithelium presented positive association with the risk group. Hence this may be related to higher vascular neoplastic invasion apparently caused by the endothelial growth factor, which maximizes the chances of metastasis and ultimately changes tumor staging, risk group and clinical evolution. CONCLUSIONS: The immunohistochemical expression of VEGFR1 substantiated a directly proportional association with the nephroblastoma risk group.INTRODUÇÃO: O nefroblastoma, ou tumor de Wilms, é a neoplasia renal mais frequente na infância. Embora o prognóstico seja favorável para a maioria dos pacientes, muitos evoluem para recidiva ou óbito. A caracterização de grupos de risco por meio de

  5. Phospho-Bcl-xL(Ser62) influences spindle assembly and chromosome segregation during mitosis.

    Science.gov (United States)

    Wang, Jianfang; Beauchemin, Myriam; Bertrand, Richard

    2014-01-01

    Functional analysis of a series of phosphorylation mutants reveals that Bcl-xL(Ser62Ala) influences cell entry into anaphase and mitotic exit in taxol-exposed cells compared with cells expressing wild-type Bcl-xL or a series of other phosphorylation mutants, an effect that appears to be independent of its anti-apoptotic activity. During normal mitosis progression, Bcl-xL(Ser62) is strongly phosphorylated by PLK1 and MAPK14/SAPKp38α at the prometaphase, metaphase, and the anaphase boundaries, while it is de-phosphorylated at telophase and cytokinesis. Phospho-Bcl-xL(Ser62) localizes in centrosomes with γ-tubulin and in the mitotic cytosol with some spindle-assembly checkpoint signaling components, including PLK1, BubR1, and Mad2. In taxol- and nocodazole-exposed cells, phospho-Bcl-xL(Ser62) also binds to Cdc20- Mad2-, BubR1-, and Bub3-bound complexes, while Bcl-xL(Ser62Ala) does not. Silencing Bcl-xL expression and expressing the phosphorylation mutant Bcl-xL(Ser62Ala) lead to an increased number of cells harboring mitotic spindle defects including multipolar spindle, chromosome lagging and bridging, aneuploidy with micro-, bi-, or multi-nucleated cells, and cells that fail to resolve undergo mitosis within 6 h. Together, the data indicate that during mitosis, Bcl-xL(Ser62) phosphorylation impacts on spindle assembly and chromosome segregation, influencing chromosome stability. Observations of mitotic cells harboring aneuploidy with micro-, bi-, or multi-nucleated cells, and cells that fail to resolve undergo mitosis within 6 h were also made with cells expressing the phosphorylation mutant Bcl-xL(Ser49Ala) and dual mutant Bcl-xL(Ser49/62Ala).

  6. Electromagnetic radiation at 900 MHz induces sperm apoptosis through bcl-2, bax and caspase-3 signaling pathways in rats.

    Science.gov (United States)

    Liu, Qi; Si, Tianlei; Xu, Xiaoyun; Liang, Fuqiang; Wang, Lufeng; Pan, Siyi

    2015-08-04

    The decreased reproductive capacity of men is an important factor contributing to infertility. Accumulating evidence has shown that Electromagnetic radiation potentially has negative effects on human health. However, whether radio frequency electromagnetic radiation (RF-EMR) affects the human reproductive system still requires further investigation. Therefore, The present study investigates whether RF-EMR at a frequency of 900 MHz can trigger sperm cell apoptosis and affect semen morphology, concentration, and microstructure. Twenty four rats were exposed to 900 MHz electromagnetic radiation with a special absorption rate of 0.66 ± 0.01 W/kg for 2 h/d. After 50d, the sperm count, morphology, apoptosis, reactive oxygen species (ROS), and total antioxidant capacity (TAC), representing the sum of enzymatic and nonenzymatic antioxidants, were investigated. Western blotting and reverse transcriptase PCR were used to determine the expression levels of apoptosis-related proteins and genes, including bcl-2, bax, cytochrome c, and capase-3. In the present study, the percentage of apoptotic sperm cells in the exposure group was significantly increased by 91.42% compared with the control group. Moreover, the ROS concentration in exposure group was increased by 46.21%, while the TAC was decreased by 28.01%. Radiation also dramatically decreased the protein and mRNA expression of bcl-2 and increased that of bax, cytochrome c, and capase-3. RF-EMR increases the ROS level and decreases TAC in rat sperm. Excessive oxidative stress alters the expression levels of apoptosis-related genes and triggers sperm apoptosis through bcl-2, bax, cytochrome c and caspase-3 signaling pathways.

  7. Bax/Bcl-2 expression ratio in prediction of response to breast cancer radiotherapy

    Directory of Open Access Journals (Sweden)

    Hosein Azimian

    2018-03-01

    Full Text Available Objective(s: Radiotherapy is one of the most effective modalities of cancer therapy, but clinical responses of individual patients varies considerably. To enhance treatment efficiency it is essential to implement an individual-based treatment. The aim of present study was to identify the mechanism of intrinsic apoptosis pathway on radiosensitivity and normal tissue complications caused by the radiotherapy. Materials and Methods: Peripheral blood mononuclear cells from ten breast cancer patients were exposed to 6MV X-rays to deliver 1 and 2 Gy. Expression levels of Bax, Bcl-2, and Bax/Bcl-2 ratio were examined by relative quantitative RT-PCR. All the patients received similar tangential irradiation of the whole breast and conventional fractionation. Skin dosimetry was done by GAFChromic EBT-3 film and clinical radiosensitivity was determined using the acute reactions to radiotherapy of the skin according to Radiation Therapy Oncology Group score. All statistical analyses were performed using GraphPad Prism, version 7.01. Results: In the in-vitro experiment, Bax and Bax/Bcl-2 ratios were significantly increased with 1 and 2 Gy doses (PP0.05 for all patients. Conclusion: Significant correlation between Bax/Bcl-2 ratio determined before radiation therapy and clinical response in the patients, can be used as a biomarker to identify radiosensitive individuals. However, further studies are required to validate radiation-induced apoptotic biomarkers.

  8. Analysis of signal transducer and activator of transcription 3 (Stat 3) pathway in multiple myeloma: Stat 3 activation and cyclin D1 dysregulation are mutually exclusive events.

    Science.gov (United States)

    Quintanilla-Martinez, Leticia; Kremer, Marcus; Specht, Katja; Calzada-Wack, Julia; Nathrath, Michaela; Schaich, Robert; Höfler, Heinz; Fend, Falko

    2003-05-01

    The signal transducer and activator of transcription molecules (Stats) play key roles in cytokine-induced signal transduction. Recently, it was proposed that constitutively activated Stat 3 (Stat 3 phosphorylated) contributes to the pathogenesis of multiple myeloma (MM) by preventing apoptosis and inducing proliferation. The study aim was to investigate Stat 3 activation in a series of multiple myeloma (MM) cases and its effect on downstream targets such as the anti-apoptotic proteins Bcl-xL, Mcl-1, and Bcl-2, and the cell-cycle protein cyclin D1. Forty-eight cases of MM were analyzed. Immunohistochemistry was performed on paraffin sections using antibodies against cyclin D1, Bcl-2, Bcl-xL, Mcl-1, p21, Stat 3, and Stat 3 phosphorylated (P). Their specificity was corroborated by Western blot analysis using eight human MM cell lines as control. The proliferation rate was assessed with the antibody MiB1. In addition, the mRNA levels of cyclin D1 and Stat 3 were determined by quantitative real-time reverse transcriptase-polymerase chain reaction of paraffin-embedded microdissected tissue. Three different groups determined by the expression of Stat 3P and cyclin D1 (protein and mRNA) were identified: group 1, Stat 3-activated (23 cases, 48%). All cases revealed nuclear expression of Stat 3P. No elevation of Stat 3 mRNA was identified in any of the cases. Three cases in this group showed intermediate to low cyclin D1 protein and mRNA expression. Group 2 included 15 (31%) cases with cyclin D1 staining and lack of Stat 3P. All cases showed intermediate to high levels of cyclin D1 mRNA expression. Group 3 included 10 (21%) cases with no expression of either cyclin D1 or Stat 3P. High levels of anti-apoptotic proteins Bcl-xL and Mcl-1 were identified in 89% and 100% of all cases, respectively. In contrast to Bcl-xL and Mcl-1, the expression of Bcl-2 showed an inverse correlation with proliferation rate (P: 0.0003). No significant differences were found between the three

  9. THE EXPRESSION AND CLINICAL VALUE OF APOPTOSIS CONTROL GENE Bcl-2 AND Bax IN BREAST CANCER

    Institute of Scientific and Technical Information of China (English)

    ZHENG Jun; YAO Zhen-xiang; ZHANG Jing

    1999-01-01

    Objective: To study the expression and clinical value of apoptosis control gene bcl-2 and bax in breast cancer.Methods: Protein bax and bcl-2 in 41 breast cancers obtained from operations in our hospital in 1996 were detected using ABC immunohistochemical stain assay and compared with 10 cases with normal breast tissues.Results: The positive rate of bax in normal breast tissue was 90% and in breast cancer was 59%, with a significant statistical difference between them (P<0.05), but there was no statistical difference in bcl-2 protein expression. Among the 41 breast cancer, the group with lymph node metastasis (21 cases) had obviously low bax expression (43%) and high bcl-2 expression (76%), showing significant difference to the group without lymph node metastasis (P<0.05).Conclusion: The antiapoptosis function of bcl-2 was stronger than bax in breast cancer. Protein bax and bcl-2 assay may be useful in understanding the biological behaviors of breast cancer.

  10. PENGARUH EKSTRAK ETHANOL PROPOLIS TERHADAP EKSPRESI PROTEIN Bcl2, CYCLIN D1 DAN INDUKSI APOPTOSIS PADA KULTUR SEL KANKER KOLON

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    Haryono Yuniarto

    2017-06-01

    Full Text Available Kanker kolorektal menempati urutan kejadian kanker ketiga di seluruh dunia, dengan lebih dari 1 juta angka kejadian tiap tahunnya. Berbagai strategi terapi pengobatan kanker kolorektal tetapi relatif belum optimal. Oleh karena itu, terdapat kebutuhan mengembangkan terapi alternatif sebagai pendamping. Propolis menunjukkan aktivitas proapoptosis pada berbagai jenis sel kanker. Mengetahui pengaruh pemberian propolis yang berasal dari Kerjo, Karanganyar, Indonesia terhadap induksi proses apoptosis dan aktivitas antiproliferasi, terutama terkait dengan penekanan ekspresi protein Bcl 2 dan cyclin D1 pada kultur sel WiDr (cell line kanker kolon. Penelitian eksperimental laboratorik menggunakan post test with control group design. Penelitian dilakukan pada kultur sel WiDr (sel kanker kolon dengan pemberian propolis. Pengamatan ekspresi protein Cyclin D1 dan Bcl2 dilakukan dengan metode imunositokimia, sedangkan pengamatan induksi apoptosis dilakukan dengan flowcytometry. Analisis statistik dengan uji Kruskal-Wallis, signifikan bila p <0,05. Rata-rata ekspresi Bcl2 pada kelima kelompok yaitu kontrol 83.40 ± 0.69 μg/ml, EEP 1/2 IC50 60.63 ± 0.40, EEP IC50 33.77 ± 1.08 μg/ml, EEP 2 IC50 24.28 ± 1.91 μg/ml, 5fluorouracil 12.74 ± 2.19 μg/ml. Terdapat perbedaan bermakna ekspresi Bcl2 antara kelompok uji dibandingkan kelompok kontrol (p < 0,001. Rata-rata ekspresi cyclin D1 pada kelima kelompok yaitu kontrol 83.77 ± 0.39 μg/ml, EEP 1/2 IC50 61.44 ± 0.41, EEP IC50 36.67 ± 1.18 μg/ml, EEP 2 IC50 24.50 ± 0.38 μg/ml, 5fluorouracil 13.42 ± 1.04μg/ml. Terdapat perbedaan bermakna ekspresi cyclin D1 antara kelompok uji dibandingkan kelompok kontrol (p < 0,001. Pemberian ekstrak etanol propolis mempunyai pengaruh menekan ekspresi Bcl2, cyclin D1, dan menginduksi apoptosis pada kultur sel kanker kolon (WiDr Cell Line.   Kata Kunci: Ekstrak Ethanol Propolis, Bcl2, cyclin D1, Sel WiDr

  11. Onco-miR-24 regulates cell growth and apoptosis by targeting BCL2L11 in gastric cancer

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    Haiyang Zhang

    2016-01-01

    Full Text Available ABSTRACT Gastric cancer is one of the most common malignancies worldwide; however, the molecular mechanism in tumorigenesis still needs exploration. BCL2L11 belongs to the BCL-2 family, and acts as a central regulator of the intrinsic apoptotic cascade and mediates cell apoptosis. Although miRNAs have been reported to be involved in each stage of cancer development, the role of miR-24 in GC has not been reported yet. In the present study, miR-24 was found to be up-regulated while the expression of BCL2L11 was inhibited in tumor tissues of GC. Studies from both in vitro and in vivo shown that miR-24 regulates BCL2L11 expression by directly binding with 3′UTR of mRNA, thus promoting cell growth, migration while inhibiting cell apoptosis. Therefore, miR-24 is a novel onco-miRNA that can be potential drug targets for future clinical use.

  12. Carbon ions of different linear energy transfer (LET values induce apoptosis & G2 cell cycle arrest in radio-resistant melanoma cells

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    Žakula Jelena

    2016-01-01

    Full Text Available Background & objectives: The main goal when treating malignancies with radiation is to deprive tumour cells of their reproductive potential. One approach is to induce tumour cell apoptosis. This study was conducted to evaluate the ability of carbon ions ( [12] C to induce apoptosis and cell cycle arrest in human HTB140 melanoma cells. Methods: In this in vitro study, human melanoma HTB140 cells were irradiated with the 62 MeV/n carbon ( [12] C ion beam, having two different linear energy transfer (LET values: 197 and 382 keV/μm. The dose range was 2 to 16 Gy. Cell viability was estimated by the sulforhodamine B assay seven days after irradiation. The cell cycle and apoptosis were evaluated 48 h after irradiation using flow cytometry. At the same time point, protein and gene expression of apoptotic regulators were estimated using the Western blot and q-PCR methods, respectively. Results: Cell viability experiments indicated strong anti-tumour effects of [12] C ions. The analysis of cell cycle showed that [12] C ions blocked HTB140 cells in G2 phase and induced the dose dependent increase of apoptosis. The maximum value of 21.8 per cent was attained after irradiation with LET of 197 keV/μm at the dose level of 16 Gy. Pro-apoptotic effects of [12] C ions were confirmed by changes of key apoptotic molecules: the p53, Bax, Bcl-2, poly ADP ribose polymerase (PARP as well as nuclear factor kappa B (NFκB. At the level of protein expression, the results indicated significant increases of p53, NFκB and Bax/Bcl-2 ratio and PARP cleavage. The Bax/Bcl-2 mRNA ratio was also increased, while no change was detected in the level of NFκB mRNA. Interpretation & conclusions: The present results indicated that anti-tumour effects of [12] C ions in human melanoma HTB140 cells were accomplished through induction of the mitochondrial apoptotic pathway as well as G2 arrest.

  13. Discovery and molecular characterization of a Bcl-2-regulated cell death pathway in schistosomes.

    Science.gov (United States)

    Lee, Erinna F; Clarke, Oliver B; Evangelista, Marco; Feng, Zhiping; Speed, Terence P; Tchoubrieva, Elissaveta B; Strasser, Andreas; Kalinna, Bernd H; Colman, Peter M; Fairlie, W Douglas

    2011-04-26

    Schistosomiasis is an infectious disease caused by parasites of the phylum platyhelminthe. Here, we describe the identification and characterization of a Bcl-2-regulated apoptosis pathway in Schistosoma japonicum and S. mansoni. Genomic, biochemical, and cell-based mechanistic studies provide evidence for a tripartite pathway, similar to that in humans including BH3-only proteins that are inhibited by prosurvival Bcl-2-like molecules, and Bax/Bak-like proteins that facilitate mitochondrial outer-membrane permeabilization. Because Bcl-2 proteins have been successfully targeted with "BH3 mimetic" drugs, particularly in the treatment of cancer, we investigated whether schistosome apoptosis pathways could provide targets for future antischistosomal drug discovery efforts. Accordingly, we showed that a schistosome prosurvival protein, sjA, binds ABT-737, a well-characterized BH3 mimetic. A crystal structure of sjA bound to a BH3 peptide provides direct evidence for the feasibility of developing BH3 mimetics to target Bcl-2 prosurvival proteins in schistosomes, suggesting an alternative application for this class of drugs beyond cancer treatment.

  14. RBP2 Promotes Adult Acute Lymphoblastic Leukemia by Upregulating BCL2.

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    Xiaoming Wang

    Full Text Available Despite recent increases in the cure rate of acute lymphoblastic leukemia (ALL, adult ALL remains a high-risk disease that exhibits a high relapse rate. In this study, we found that the histone demethylase retinoblastoma binding protein-2 (RBP2 was overexpressed in both on-going and relapse cases of adult ALL, which revealed that RBP2 overexpression was not only involved in the pathogenesis of ALL but that its overexpression might also be related to relapse of the disease. RBP2 knockdown induced apoptosis and attenuated leukemic cell viability. Our results demonstrated that BCL2 is a novel target of RBP2 and supported the notion of RBP2 being a regulator of BCL2 expression via directly binding to its promoter. As the role of RBP2 in regulating apoptosis was confirmed, RBP2 overexpression and activation of BCL2 might play important roles in ALL development and progression.

  15. In vitro and in vivo anti-tumor effect of metformin as a novel therapeutic agent in human oral squamous cell carcinoma

    International Nuclear Information System (INIS)

    Luo, Qingqiong; Hu, Dan; Hu, Shuiqing; Yan, Ming; Sun, Zujun; Chen, Fuxiang

    2012-01-01

    Metformin, which is widely used as an antidiabetic agent, has recently been reported to reduce cancer risk and improve prognosis in certain malignancies. However, the specific mechanisms underlying the effect of metformin on the development and progression of several cancers including oral squamous cell carcinoma (OSCC) remain unclear. In the present study, we investigated the effects of metformin on OSCC cells in vitro and in vivo. OSCC cells treated with or without metformin were counted using a hemocytometer. The clonogenic ability of OSCC cells after metformin treatment was determined by colony formation assay. Cell cycle progression and apoptosis were assessed by flow cytometry, and the activation of related signaling pathways was examined by immunoblotting. The in vivo anti-tumor effect of metformin was examined using a xenograft mouse model. Immunohistochemistry and TUNEL staining were used to determine the expression of cyclin D1 and the presence of apoptotic cells in tumors from mice treated with or without metformin. Metformin inhibited proliferation in the OSCC cell lines CAL27, WSU-HN6 and SCC25 in a time- and dose-dependent manner, and significantly reduced the colony formation of OSCC cells in vitro. Metformin induced an apparent cell cycle arrest at the G0/G1 phase, which was accompanied by an obvious activation of the AMP kinase pathway and a strongly decreased activation of mammalian target of rapamycin and S6 kinase. Metformin treatment led to a remarkable decrease of cyclin D1, cyclin-dependent kinase (CDK) 4 and CDK6 protein levels and phosphorylation of retinoblastoma protein, but did not affect p21 or p27 protein expression in OSCC cells. In addition, metformin induced apoptosis in OSCC cells, significantly down-regulating the anti-apoptotic proteins Bcl-2 and Bcl-xL and up-regulating the pro-apoptotic protein Bax. Metformin also markedly reduced the expression of cyclin D1 and increased the numbers of apoptotic cells in vivo, thus inhibiting

  16. S phase entry causes homocysteine-induced death while ataxia telangiectasia and Rad3 related protein functions anti-apoptotically to protect neurons.

    Science.gov (United States)

    Ye, Weizhen; Blain, Stacy W

    2010-08-01

    A major phenotype seen in neurodegenerative disorders is the selective loss of neurons due to apoptotic death and evidence suggests that inappropriate re-activation of cell cycle proteins in post-mitotic neurons may be responsible. To investigate whether reactivation of the G1 cell cycle proteins and S phase entry was linked with apoptosis, we examined homocysteine-induced neuronal cell death in a rat cortical neuron tissue culture system. Hyperhomocysteinaemia is a physiological risk factor for a variety of neurodegenerative diseases, including Alzheimer's disease. We found that in response to homocysteine treatment, cyclin D1, and cyclin-dependent kinases 4 and 2 translocated to the nucleus, and p27 levels decreased. Both cyclin-dependent kinases 4 and 2 regained catalytic activity, the G1 gatekeeper retinoblastoma protein was phosphorylated and DNA synthesis was detected, suggesting transit into S phase. Double-labelling immunofluorescence showed a 95% co-localization of anti-bromodeoxyuridine labelling with apoptotic markers, demonstrating that those cells that entered S phase eventually died. Neurons could be protected from homocysteine-induced death by methods that inhibited G1 phase progression, including down-regulation of cyclin D1 expression, inhibition of cyclin-dependent kinases 4 or 2 activity by small molecule inhibitors, or use of the c-Abl kinase inhibitor, Gleevec, which blocked cyclin D and cyclin-dependent kinase 4 nuclear translocation. However, blocking cell cycle progression post G1, using DNA replication inhibitors, did not prevent apoptosis, suggesting that death was not preventable post the G1-S phase checkpoint. While homocysteine treatment caused DNA damage and activated the DNA damage response, its mechanism of action was distinct from that of more traditional DNA damaging agents, such as camptothecin, as it was p53-independent. Likewise, inhibition of the DNA damage sensors, ataxia-telangiectasia mutant and ataxia telangiectasia and Rad

  17. Ampelopsin-induced reactive oxygen species enhance the apoptosis of colon cancer cells by activating endoplasmic reticulum stress-mediated AMPK/MAPK/XAF1 signaling

    Science.gov (United States)

    Park, Ga Bin; Jeong, Jee-Yeong; Kim, Daejin

    2017-01-01

    Ampelopsin (Amp) is bioactive natural product and exerts anti-cancer effects against several cancer types. The present study investigated the anti-colon cancer activity of Amp and explored its mechanism of action. The treatment of colon cancer cells with Amp resulted in the dose- and time-dependent induction of apoptosis via the activation of endoplasmic reticulum (ER) stress, 5′ adenosine monophosphate-activated protein kinase (AMPK), and c-Jun N-terminal protein kinase (JNK)/p38 mitogen-activated protein kinases (MAPKs). Salubrinal, an ER stress inhibitor, prevented the upregulation of ER stress-associated proteins, including phosphorylated protein kinase RNA-like ER kinase, phosphorylated eukaryotic translation initiation factor 2α, glucose-regulated protein 78, and CCAAT/enhancer-binding protein homologous protein, as well as suppressing AMPK activation and the MAPK signaling pathway. Knockdown of AMPK by RNA interference failed to block ER stress. Additionally, SP600125 (a JNK inhibitor) and SB203580 (a p38-MAPK inhibitor) effectively inhibited apoptosis and attenuated the expression of X-linked IAP-associated factor 1 (XAF1) and apoptotic Bcl-2 family proteins (BCL2 antagonist/killer 1 and BCL2-associated X protein) in Amp-treated colon cancer cells. Furthermore, reactive oxygen species (ROS)-mediated ER stress/AMPK apoptotic signaling pathway in Amp-treated colon cancer cells were markedly inhibited by treatment with N-acetyl-L-cysteine, a ROS scavenger. These results demonstrate that treatment with Amp induces the apoptotic death of colon cancer cells through ER stress-initiated AMPK/MAPK/XAF1 signaling. These results also provide experimental information for developing Amp as therapeutic drug against colon cancer. PMID:29250183

  18. Effect of doxorubicin, oxaliplatin, and methotrexate administration on the transcriptional activity of BCL-2 family gene members in stomach cancer cells.

    Science.gov (United States)

    Florou, Dimitra; Patsis, Christos; Ardavanis, Alexandros; Scorilas, Andreas

    2013-07-01

    Defective apoptosis comprises the main reason for tumor aggressiveness and chemotherapy tolerance in solid neoplasias. Among the BCL-2 family members, whose mRNA or protein expression varies considerably in different human malignancies, BCL2L12 is the one for which we have recently shown its propitious prognostic value in gastric cancer. The purpose of the current work was to investigate the expression behavior of BCL2L12, BAX, and BCL-2 in human stomach adenocarcinoma cells following their exposure to anti-tumor substances. The 3-(4,5-dimethyl thiazol-2-yl)-2,5-diphenyl tetrazolium bromide and trypan blue methods assessed the impact of doxorubicin, oxaliplatin and methotrexate on AGS cells' viability and growth. Following isolation from cells, total RNA was reverse-transcribed to cDNA. Quantification of target genes' expression was performed with real-time PCR using SYBR Green detection system. The relative changes in their mRNA levels between drug-exposed and untreated cells were calculated with the comparative Ct method (2(-ddCt)). All three drugs, as a result of their administration to AGS cancer cells for particular time intervals, provoked substantial fluctuations in the transcriptional levels of the apoptosis-related genes studied. While BAX was principally upregulated, striking similar were the notable changes regarding BCL-2 and BCL2L12 expression in our cellular system. Our findings indicate the growth suppressive effects of doxorubicin, oxaliplatin and methotrexate treatment on stomach carcinoma cells and the implication of BCL2L12, BAX, and BCL-2 expression profiles in the molecular signaling pathways triggered by chemotherapy.

  19. Anti- and pro-tumor functions of autophagy.

    Science.gov (United States)

    Morselli, Eugenia; Galluzzi, Lorenzo; Kepp, Oliver; Vicencio, José-Miguel; Criollo, Alfredo; Maiuri, Maria Chiara; Kroemer, Guido

    2009-09-01

    Autophagy constitutes one of the major responses to stress in eukaryotic cells, and is regulated by a complex network of signaling cascades. Not surprisingly, autophagy is implicated in multiple pathological processes, including infection by pathogens, inflammatory bowel disease, neurodegeneration and cancer. Both oncogenesis and tumor survival are influenced by perturbations of the molecular machinery that controls autophagy. Numerous oncoproteins, including phosphatidylinositol 3-kinase, Akt1 and anti-apoptotic members of the Bcl-2 family suppress autophagy. Conversely, several tumor suppressor proteins (e.g., Atg4c; beclin 1; Bif-1; BH3-only proteins; death-associated protein kinase 1; LKB1/STK11; PTEN; UVRAG) promote the autophagic pathway. This does not entirely apply to p53, one of the most important tumor suppressor proteins, which regulates autophagy in an ambiguous fashion, depending on its subcellular localization. Irrespective of the controversial role of p53, basal levels of autophagy appear to inhibit tumor development. On the contrary, chemotherapy- and metabolic stress-induced activation of the autophagic pathway reportedly contribute to the survival of formed tumors, thereby favoring resistance. In this context, autophagy inhibition would represent a major therapeutic target for chemosensitization. Here, we will review the current knowledge on the dual role of autophagy as an anti- and pro-tumor mechanism.

  20. Corn silk maysin induces apoptotic cell death in PC-3 prostate cancer cells via mitochondria-dependent pathway.

    Science.gov (United States)

    Lee, Jisun; Lee, Seul; Kim, Sun-Lim; Choi, Ji Won; Seo, Jeong Yeon; Choi, Doo Jin; Park, Yong Il

    2014-12-05

    Despite recent advances in prostate cancer diagnostics and therapeutics, the overall survival rate still remains low. This study was aimed to assess potential anti-cancer activity of maysin, a major flavonoid of corn silk (CS, Zea mays L.), in androgen-independent human prostate cancer cells (PC-3). Maysin was isolated from CS of Kwangpyeongok, a Korean hybrid corn, via methanol extraction and preparative C18 reverse phase column chromatography. Maysin cytotoxicity was determined by either monitoring cell viability in various cancer cell lines by MTT assay or morphological changes. Apoptotic cell death was assessed by annexin V-FITC/PI double staining, depolarization of mitochondrial membrane potential (MMP), expression levels of Bcl-2 and pro-caspase-3 and by terminal transferase mediated dUTP-fluorescein nick end labeling (TUNEL) staining. Underlying mechanism in maysin-induced apoptosis of PC-3 cells was explored by evaluating its effects on Akt and ERK pathway. Maysin dose-dependently reduced the PC-3 cell viability, with an 87% reduction at 200 μg/ml. Maysin treatment significantly induced apoptotic cell death, DNA fragmentation, depolarization of MMP, and reduction in Bcl-2 and pro-caspase-3 expression levels. Maysin also significantly attenuated phosphorylation of Akt and ERK. A combined treatment with maysin and other known anti-cancer agents, including 5-FU, etoposide, cisplatin, or camptothecin, synergistically enhanced PC-3 cell death. These results suggested for the first time that maysin inhibits the PC-3 cancer cell growth via stimulation of mitochondria-dependent apoptotic cell death and may have a strong therapeutic potential for the treatment of either chemo-resistant or androgen-independent human prostate cancer. Copyright © 2014 Elsevier Inc. All rights reserved.

  1. Estrogen receptor β exhibited anti-tumor effects on osteosarcoma cells by regulating integrin, IAP, NF-kB/BCL-2 and PI3K/Akt signal pathway

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    Minfei Yang

    2017-11-01

    Full Text Available This study aimed to investigate the effects of Estrogen receptor β (ERβ on osteosarcoma cells, and explore the regulatory mechanisms involved in this process. Osteosarcoma U2-OS cells consisted four groups, and treated by E2, E2 + LY294002 (ERβ agonists, E2 + ERβ siRNA, E2 + ERβ siRNA + LY294002, respectively. Cell counting kit 8 (CCK-8 assay was performed to detect the cell viability of U2-OS cells in each group. The effects of ERβ on the migration and invasion ability of U2-OS cells were examined by wound healing assay and transwell cell culture chamber, respectively. The expression of Inhibitor of apoptosis protein (IAP and integrin α5 in U2-OS cells of each group was detected by quantitative RT-PCR, and the expression of phosphorylated p65 (p-p65, p-AKT and Bcl-2 was detected by western blotting. The cell viability, migration and invasion ability of U2-OS cells were significantly increased by ERβ siRNA, but inhibited by ERβ agonists LY294002 (p < 0.05. ERβ siRNA significantly downregulated Integrin α5 and unregulated IAP in U2-OS cells (p < 0.05. The expression of p-p65, p-AKT and Bcl-2 was significantly reduced by LY294002, but increased by ERβ siRNA (p < 0.05. In conclusion, ERβ exhibited obvious anti-tumor effects on osteosarcoma cells by regulating integrin, IAP, NF-kBBCL-2 and PI3K/Akt signal pathway. Keywords: Estrogen receptor β, Osteosarcoma, Anti-tumor, Regulatory mechanism

  2. MYC/BCL2/BCL6 triple hit lymphoma: a study of 40 patients with a comparison to MYC/BCL2 and MYC/BCL6 double hit lymphomas.

    Science.gov (United States)

    Huang, Wenting; Medeiros, L Jeffrey; Lin, Pei; Wang, Wei; Tang, Guilin; Khoury, Joseph; Konoplev, Sergej; Yin, C Cameron; Xu, Jie; Oki, Yasuhiro; Li, Shaoying

    2018-05-21

    High-grade B-cell lymphomas with MYC, BCL2, and BCL6 rearrangements (triple hit lymphoma) are uncommon. We studied the clinicopathologic features of 40 patients with triple hit lymphoma and compared them to 157 patients with MYC/BCL2 double hit lymphoma and 13 patients with MYC/BCL6 double hit lymphoma. The triple hit lymphoma group included 25 men and 15 women with a median age of 61 years (range, 34-85). Nine patients had a history of B-cell lymphoma. Histologically, 23 (58%) cases were diffuse large B-cell lymphoma and 17 cases had features of B-cell lymphoma, unclassifiable, with features intermediate between diffuse large B-cell lymphoma and Burkitt lymphoma. Most cases of triple hit lymphoma were positive for CD10 (100%), BCL2 (95%), BCL6 (82%), MYC (74%), and 71% with MYC and BCL2 coexpression. P53 was overexpressed in 29% of triple hit lymphoma cases. The clinicopathological features of triple hit lymphoma patients were similar to patients with MYC/BCL2 and MYC/BCL6 double hit lymphoma, except that triple hit lymphoma cases were more often CD10 positive compared with MYC/BCL6 double hit lymphoma (p hit lymphoma and double hit lymphoma and overall survival in triple hit lymphoma patients was 17.6 months, similar to the overall survival of patients with double hit lymphoma (p = 0.67). Patients with triple hit lymphoma showing P53 overexpression had significantly worse overall survival compared with those without P53 overexpression (p = 0.04). On the other hand, double expressor status and prior history of B-cell lymphoma did not correlate with overall survival. In conclusion, most patients with triple hit lymphoma have an aggressive clinical course and poor prognosis and these tumors have a germinal center B-cell immunophenotype, similar to patients with double hit lymphomas. P53 expression is a poor prognostic factor in patients with triple hit lymphoma.

  3. Discovery and molecular characterization of a Bcl-2–regulated cell death pathway in schistosomes

    Science.gov (United States)

    Lee, Erinna F.; Clarke, Oliver B.; Evangelista, Marco; Feng, Zhiping; Speed, Terence P.; Tchoubrieva, Elissaveta B.; Strasser, Andreas; Kalinna, Bernd H.; Colman, Peter M.; Fairlie, W. Douglas

    2011-01-01

    Schistosomiasis is an infectious disease caused by parasites of the phylum platyhelminthe. Here, we describe the identification and characterization of a Bcl-2–regulated apoptosis pathway in Schistosoma japonicum and S. mansoni. Genomic, biochemical, and cell-based mechanistic studies provide evidence for a tripartite pathway, similar to that in humans including BH3-only proteins that are inhibited by prosurvival Bcl-2–like molecules, and Bax/Bak-like proteins that facilitate mitochondrial outer-membrane permeabilization. Because Bcl-2 proteins have been successfully targeted with “BH3 mimetic” drugs, particularly in the treatment of cancer, we investigated whether schistosome apoptosis pathways could provide targets for future antischistosomal drug discovery efforts. Accordingly, we showed that a schistosome prosurvival protein, sjA, binds ABT-737, a well-characterized BH3 mimetic. A crystal structure of sjA bound to a BH3 peptide provides direct evidence for the feasibility of developing BH3 mimetics to target Bcl-2 prosurvival proteins in schistosomes, suggesting an alternative application for this class of drugs beyond cancer treatment. PMID:21444803

  4. Berberine prevents nitric oxide-induced rat chondrocyte apoptosis and cartilage degeneration in a rat osteoarthritis model via AMPK and p38 MAPK signaling.

    Science.gov (United States)

    Zhou, Yan; Liu, Shi-Qing; Yu, Ling; He, Bin; Wu, Shi-Hao; Zhao, Qi; Xia, Shao-Qiang; Mei, Hong-Jun

    2015-09-01

    Chondrocyte apoptosis is an important mechanism involved in osteoarthritis (OA). Berberine (BBR), a plant alkaloid derived from Chinese medicine, is characterized by multiple pharmacological effects, such as anti-inflammatory and anti-apoptotic activities. This study aimed to evaluate the chondroprotective effect and underlying mechanisms of BBR on sodium nitroprusside (SNP)-stimulated chondrocyte apoptosis and surgically-induced rat OA model. The in vitro results revealed that BBR suppressed SNP-stimulated chondrocyte apoptosis as well as cytoskeletal remodeling, down-regulated expressions of inducible nitric oxide synthase (iNOS) and caspase-3, and up-regulated Bcl-2/Bax ratio and Type II collagen (Col II) at protein levels, which were accompanied by increased adenosine monophosphate-activated protein kinase (AMPK) phosphorylation and decreased phosphorylation of p38 mitogen-activated protein kinase (MAPK). Furthermore, the anti-apoptotic effect of BBR was blocked by AMPK inhibitor Compound C (CC) and adenosine-9-β-D-arabino-furanoside (Ara A), and enhanced by p38 MAPK inhibitor SB203580. In vivo experiment suggested that BBR ameliorated cartilage degeneration and exhibited an anti-apoptotic effect on articular cartilage in a rat OA model, as demonstrated by histological analyses, TUNEL assay and immunohistochemical analyses of caspase-3, Bcl-2 and Bax expressions. These findings suggest that BBR suppresses SNP-stimulated chondrocyte apoptosis and ameliorates cartilage degeneration via activating AMPK signaling and suppressing p38 MAPK activity.

  5. Herpesvirus pan encodes a functional homologue of BHRF1, the Epstein-Barr virus v-Bcl-2

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    Williams Tracey

    2005-02-01

    Full Text Available Abstract Background Epstein-Barr virus (EBV latently infects about 90% of the human population and is associated with benign and malignant diseases of lymphoid and epithelial origin. BHRF1, an early lytic cycle antigen, is an apoptosis suppressing member of the Bcl-2 family. In vitro studies imply that BHRF1 is dispensable for both virus replication and transformation. However, the fact that BHRF1 is highly conserved not only in all EBV isolates studied to date but also in the analogous viruses Herpesvirus papio and Herpesvirus pan that infect baboons and chimpanzees respectively, suggests BHRF1 may play an important role in vivo. Results Herpesvirus papio BHRF1 has been shown to function in an analogous manner to EBV BHRF1 in response to DNA damaging agents in human keratinocytes. In this study we show that the heterologous expression of the previously uncharacterised Herpesvirus pan BHRF1 in the human Burkitt's lymphoma cell line Ramos-BL provides similar anti-apoptotic functions to that of EBV BHRF1 in response to apoptosis triggered by serum withdrawal, etoposide treatment and ultraviolet (UV radiation. We also map the amino acid changes onto the recently solved structure of the EBV BHRF1 and reveal that these changes are unlikely to alter the 3D structure of the protein. Conclusions These findings show that the functional conservation of BHRF1 extends to a lymphoid background, suggesting that the primate virus proteins interact with cellular proteins that are themselves highly conserved across the higher primates. Further weight is added to this suggestion when we show that the difference in amino acid sequences map to regions on the 3D structure of EBV BHRF1 that are unlikely to change the conformation of the protein.

  6. BH3 mimetics inhibit growth of chondrosarcoma--a novel targeted-therapy for candidate models.

    Science.gov (United States)

    Morii, Takeshi; Ohtsuka, Kouki; Ohnishi, Hiroaki; Mochizuki, Kazuo; Yoshiyama, Akira; Aoyagi, Takayuki; Hornicek, Francis J; Ichimura, Shoichi

    2014-11-01

    Chondrosarcoma is refractory to conventional chemotherapy. BH-3 mimetics ABT-737 and ABT-263 are synthetic small-molecule inhibitors of anti-apoptotic proteins B-cell lymphoma-2 (Bcl2) and Bcl-xL, which play a critical role in survival of chondrosarcoma cells. Chondrosarcoma cell lines SW-1353 and CS-1 were used as the disease model. We used immunoblotting to assess the expression of target molecules Bcl2 and Bcl-xL, and the apoptotic inducers Bcl2-associated X (Bax) and Bcl2-antagonist/killer (Bak). In vitro growth inhibition by BH-3 mimetics was confirmed by photomicroscopic cell counting and 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium, inner salt (MTS) assay. Apoptotic induction was confirmed by Enzyme-Linked ImmunoSorbent Assay (ELISA). In vivo growth inhibition was assessed in a non-obese diabetic/severe combined immunodeficient (NOD/SCID) mouse model. Expression of the target and effector molecules was confirmed in chondrosarcoma cell lines. BH3 mimetics significantly inhibited cell growth and induced apoptosis in vitro. Administration of ABT-263 inhibited chondrosarcoma growth and improved survival in a mouse model. BH3 mimetics represent a novel treatment modality for chondrosarcoma. Copyright© 2014 International Institute of Anticancer Research (Dr. John G. Delinassios), All rights reserved.

  7. Changes in proliferating and apoptotic markers of leiomyoma following treatment with a selective progesterone receptor modulator or gonadotropin-releasing hormone agonist.

    Science.gov (United States)

    Yun, Bo Seong; Seong, Seok Ju; Cha, Dong Hyun; Kim, Ji Yeon; Kim, Mi-La; Shim, Jeong Yun; Park, Ji Eun

    2015-08-01

    To evaluate changes in proliferating and apoptotic markers of myoma tissue from patients treated with a selective progesterone receptor modulator (SPRM) or GnRH agonist by measuring expression of PDGF-A mRNA, IGF-1 mRNA, bcl-2 mRNA, and PCNA and caspase-3 protein. Between December 2013 and July 2014, women with symptomatic leiomyoma were divided into control (no treatment before surgery), SPRM (treatment with ulipristal acetate [SPRM] for 3 months before surgery), and GnRHa (treatment with leuprolide acetate [GnRH agonist] for 3 months before surgery) groups. Tissue specimens were collected from the myoma core and normal myometrium of all patients. The expression of mRNA and protein was assessed by quantitative real-time reverse transcriptase-polymerase chain reaction and Western blot. A total of 38 patients were enrolled (control group, n=14; SPRM group, n=13; GnRHa group, n=11). PDGF-A mRNA expression was lower in both the myoma core and normal myometrium tissues of the SPRM compared with the control group, but there was no difference between the control and GnRHa group. There were also no group differences in bcl-2 mRNA or IGF-1 mRNA expression. Both PCNA and caspase-3 protein expression were higher in the leiomyoma tissue of the SPRM compared with the control group, but there was no difference between the control and GnRHa groups in the expression of either protein. Both proliferation and apoptosis were increased in the leiomyoma of patients after SPRM treatment, but there was no change following GnRH agonist treatment, in vivo. However, PDGF-A mRNA was decreased after SPRM treatment, indicating a dual effect of progesterone on the regulation of growth factors. Furthermore, there was an increase in caspase-3 protein, but not bcl-2 mRNA, expression in the SPRM group suggesting that SPRM may exert its effects in pathways other than the bcl-2 apoptotic pathway. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  8. Drosophila larvae lacking the bcl-2 gene, buffy, are sensitive to nutrient stress, maintain increased basal target of rapamycin (Tor signaling and exhibit characteristics of altered basal energy metabolism

    Directory of Open Access Journals (Sweden)

    Monserrate Jessica P

    2012-07-01

    Full Text Available Abstract Background B cell lymphoma 2 (Bcl-2 proteins are the central regulators of apoptosis. The two bcl-2 genes in Drosophila modulate the response to stress-induced cell death, but not developmental cell death. Because null mutants are viable, Drosophila provides an optimum model system to investigate alternate functions of Bcl-2 proteins. In this report, we explore the role of one bcl-2 gene in nutrient stress responses. Results We report that starvation of Drosophila larvae lacking the bcl-2 gene, buffy, decreases survival rate by more than twofold relative to wild-type larvae. The buffy null mutant reacted to starvation with the expected responses such as inhibition of target of rapamycin (Tor signaling, autophagy initiation and mobilization of stored lipids. However, the autophagic response to starvation initiated faster in larvae lacking buffy and was inhibited by ectopic buffy. We demonstrate that unusually high basal Tor signaling, indicated by more phosphorylated S6K, was detected in the buffy mutant and that removal of a genomic copy of S6K, but not inactivation of Tor by rapamycin, reverted the precocious autophagy phenotype. Instead, Tor inactivation also required loss of a positive nutrient signal to trigger autophagy and loss of both was sufficient to activate autophagy in the buffy mutant even in the presence of enforced phosphoinositide 3-kinase (PI3K signaling. Prior to starvation, the fed buffy mutant stored less lipid and glycogen, had high lactate levels and maintained a reduced pool of cellular ATP. These observations, together with the inability of buffy mutant larvae to adapt to nutrient restriction, indicate altered energy metabolism in the absence of buffy. Conclusions All animals in their natural habitats are faced with periods of reduced nutrient availability. This study demonstrates that buffy is required for adaptation to both starvation and nutrient restriction. Thus, Buffy is a Bcl-2 protein that plays an

  9. Overexpression of Endogenous Anti-Oxidants with Selenium Supplementation Protects Trophoblast Cells from Reactive Oxygen Species-Induced Apoptosis in a Bcl-2-Dependent Manner.

    Science.gov (United States)

    Khera, Alisha; Vanderlelie, Jessica J; Holland, Olivia; Perkins, Anthony V

    2017-06-01

    The human placenta provides life support for the developing foetus, and a healthy placenta is a prerequisite to a healthy start to life. Placental tissue is subject to oxidative stress which can lead to pathological conditions of pregnancy such as preeclampsia, preterm labour and intrauterine growth restriction. Up-regulation of endogenous anti-oxidants may alleviate placental oxidative stress and provide a therapy for these complications of pregnancy. In this study, selenium supplementation, as inorganic sodium selenite (NaSel) or organic selenomethionine (SeMet), was used to increase the protein production and cellular activity of the important redox active proteins glutathione peroxidase (GPx) and thioredoxin reductase (Thx-Red). Placental trophoblast cell lines, BeWo, JEG-3 and Swan-71, were cultured in various concentrations of NaSel or SeMet for 24 h and cell extracts prepared for western blots and enzyme assays. Rotenone and antimycin were used to stimulate mitochondrial reactive oxygen species (ROS) production and induce apoptosis. Trophoblast cells supplemented with 100 nM NaSel and 500 nM SeMet exhibited significantly enhanced expression and activity of both GPx and Thx-Red. Antimycin and rotenone were found to generate ROS when measured by 2',7'-dichlorofluorescein diacetate (DCFDA) assay, and selenium supplementation was shown to reduce ROS production in a dose-dependent manner. Rotenone, 100 μM treatment for 4 h, caused trophoblast cell apoptosis as evidenced by increased Annexin V binding and decreased expression of Bcl-2. In both assays of apoptosis, selenium supplementation was able to prevent apoptosis, preserve Bcl-2 expression and protect trophoblast cells from mitochondrial oxidative stress. This data suggests that selenoproteins such as GPx and Thx-Red have an important role in protecting trophoblast cells from mitochondrial oxidative stress and that selenium supplementation may be important in treating some placental pathologies.

  10. The Role of Bcl-xL in Synergistic Induction of Apoptosis by Mapatumumab and Oxaliplatin in Combination with Hyperthermia on Human Colon Cancer

    Science.gov (United States)

    Song, Xinxin; Kim, Seog-Young; Lee, Yong J.

    2012-01-01

    Colorectal cancer is the third leading cause of cancer-related mortality in the world. The main cause of death of colorectal cancer is hepatic metastases which can be treated using isolated hepatic perfusion (IHP), allowing treatment of colorectal metastasis with various methods. In this study we present a novel potent multimodality strategy comprising humanized death receptor 4 (DR4) antibody mapatumumab (Mapa) in combination with oxaliplatin and hyperthermia to treat human colon cancer cells. Oxaliplatin and hyperthermia sensitized colon cancer cells to Mapa in the mitochondrial dependent apoptotic pathway and increased reactive oxygen species production, leading to Bcl-xL phosphorylation at Serine 62 in a c-Jun N-terminal kinase (JNK)-dependent manner. Overexpression of Bcl-xL reduced the efficacy of the multimodality treatment, while phosphorylation of Bcl-xL decreased its anti-apoptotic activity. The multimodality treatment dissociated Bcl-xL from Bax, allowing Bax oligomerization to induce cytochrome c release from mitochondria. In addition, the multimodality treatment significantly inhibited colorectal cancer xenografts’ tumor growth. The successful outcome of this study will support the application of multimodality strategy to colorectal hepatic metastases. PMID:23051936

  11. Membrane microdomain-associated uroplakin IIIa contributes to Src-dependent mechanisms of anti-apoptotic proliferation in human bladder carcinoma cells

    Directory of Open Access Journals (Sweden)

    Shigeru Kihira

    2012-08-01

    Our previous study demonstrated that tyrosine phosphorylation of p145met/β-subunit of hepatocyte growth factor receptor by epidermal growth factor receptor and Src contributes to the anti-apoptotic growth of human bladder carcinoma cell 5637 under serum-starved conditions. Here, we show that some other cell lines of human bladder carcinoma, but not other types of human cancer cells, also exhibit Src-dependent, anti-apoptotic proliferation under serum-starved conditions, and that low-density, detergent-insoluble membrane microdomains (MD serve as a structural platform for signaling events involving p145met, EGFR, and Src. As an MD-associated molecule that may contribute to bladder carcinoma-specific cellular function, we identified uroplakin IIIa (UPIIIa, an urothelium-specific protein. Results obtained so far revealed: 1 UPIIIa undergoes partial proteolysis in serum-starved cells; 2 a specific antibody to the extracellular domain of UPIIIa inhibits the proteolysis of UPIIIa and the activation of Src, and promotes apoptosis in serum-starved cells; and 3 knockdown of UPIIIa by short interfering RNA also promotes apoptosis in serum-starved cells. GM6001, a potent inhibitor of matrix metalloproteinase (MMP, inhibits the proteolysis of UPIIIa and promotes apoptosis in serum-starved cells. Furthermore, serum starvation promotes expression and secretion of the heparin-binding EGF-like growth factor in a manner that depends on the functions of MMP, Src, and UPIIIa. These results highlight a hitherto unknown signaling network involving a subset of MD-associated molecules in the anti-apoptotic mechanisms of human bladder carcinoma cells.

  12. The role of the acidity of N-heteroaryl sulfonamides as inhibitors of bcl-2 family protein-protein interactions.

    Science.gov (United States)

    Touré, B Barry; Miller-Moslin, Karen; Yusuff, Naeem; Perez, Lawrence; Doré, Michael; Joud, Carol; Michael, Walter; DiPietro, Lucian; van der Plas, Simon; McEwan, Michael; Lenoir, Francois; Hoe, Madelene; Karki, Rajesh; Springer, Clayton; Sullivan, John; Levine, Kymberly; Fiorilla, Catherine; Xie, Xiaoling; Kulathila, Raviraj; Herlihy, Kara; Porter, Dale; Visser, Michael

    2013-02-14

    Overexpression of the antiapoptotic members of the Bcl-2 family of proteins is commonly associated with cancer cell survival and resistance to chemotherapeutics. Here, we describe the structure-based optimization of a series of N-heteroaryl sulfonamides that demonstrate potent mechanism-based cell death. The role of the acidic nature of the sulfonamide moiety as it relates to potency, solubility, and clearance is examined. This has led to the discovery of novel heterocyclic replacements for the acylsulfonamide core of ABT-737 and ABT-263.

  13. Apoptotic role of natural isothiocyanate from broccoli (Brassica oleracea italica) in experimental chemical lung carcinogenesis.

    Science.gov (United States)

    Kalpana Deepa Priya, D; Gayathri, R; Gunassekaran, G R; Murugan, S; Sakthisekaran, D

    2013-05-01

    Sulforaphane (SFN) [1-isothiocyanato-4-(methylsulfinyl)butane] is a naturally occurring isothiocyanate found in cruciferous vegetables such as broccoli [Brassica oleracea L. var. italica Plenck. (Brassicaceae)]. Since it is among the most potent bioactive components with antioxidant and antitumor properties, it has received intense attention in the recent years for its chemopreventive properties. The present work determined the rehabilitating role in alleviating the oxidative damage caused by benzo(a)pyrene [B(a)P] to biomolecules and the apoptotic cascade mediated by orally administered isothiocyanate-SFN (9 µmol/mouse/day) against B(a)P (100 mg/kg body weight, i.p.) induced pulmonary carcinogenesis in Swiss albino mice. Oxidative damage was assessed by measuring lipid peroxidation, 8-hydroxydeoxyguanosine, hydrogen peroxide (H2O2) production, glycoprotein components, protein carbonyl levels and DNA-protein crosslinks. DNA fragmentation by agarose gel electrophoresis and caspase-3 activity by ELISA proved apoptotic induction by SFN along with the protein expression of Bcl-2, Bax and Cyt c. SFN treatment was found to decrease the H2O2 production (p < 0.001) in cancer induced animals, proving its antioxidant potential. Apoptosis was induced by increasing the release of Cyt c (p < 0.001) from mitochondria, decreasing and increasing the expression of Bcl-2 (p < 0.01) and Bax (p < 0.001), respectively. Caspase-3 activity was also enhanced (p < 0.001) which leads to DNA fragmentation in SFN treated groups. Our results reflect the rehabilitating role of SFN in B(a)P induced lung carcinogenesis.

  14. [Survival of patients with primary central nervous system diffuse large B-cell lymphoma: impact of gene aberrations and protein overexpression of bcl-2 and C-MYC, and selection of chemotherapy regimens].

    Science.gov (United States)

    Yin, W J; Zhu, X; Yang, H Y; Sun, W Y; Wu, M J

    2018-01-08

    Objective: To investigate the impact of clinicopathological features, gene rearrangements and protein expression of bcl-6, bcl-2, C-MYC and chemotherapy regime on the prognosis of patients with primary central nervous system diffuse large B-cell lymphoma (PCNS-DLBCL). Methods: Thirty-three cases of PCNS-DLBCL diagnosed from January 2006 to December 2016 at Zhejiang Cancer Hospital were collected. The expression of CD10, bcl-6, bcl-2, MUM1 and MYC were detected by immunohistochemical staining (IHC). The presence of EB virus was detected by in situ hybridization(EBER). Copy number variation (ICN) and translocation status of bcl-6, bcl-2 and C-MYC genes were detected by fluorescence in situ hybridization (FISH). The relationship between the above indexes and the prognosis was analyzed by univariate, bivariate survival analysis and multiple Cox hazard regression analysis. Results: The study included 33 patients of PCNS-DLBCL, without evidence of primary or secondary immunodeficient disease. Male to female ratio was 1.36∶1.00, and the average age was 56 years. Twenty cases had single lesion while 13 had multiple lesions. Deep brain involvement was seen in 12 cases. All patients underwent partial or total tumor resection. Five patients received whole brain post-surgery radiotherapy, nine patients received high-dose methotrexate (HD-MTX) based chemotherapy, and 12 patients received whole-brain radiotherapy combined with HD-MTX based chemotherapy. Severn patients received no further treatment and rituximab was used in 8 patients. According to the Hans model, 27 cases were classified as non-GCB subtypes (81.8%). Bcl-2 was positive in 25 cases (75.8%, 25/33) and highly expressed in 8 (24.2%). MYC was positive in 12 cases (36.4%) and double expression of bcl-2 and MYC was seen in 6 cases. EBER positive rate was 10.0%(3/30), all of which had multiple lesions. Two bcl-6 gene translocations and 3 amplifications were found in 28 patients. Two translocations, 3 ICN or with both

  15. Induction of Apoptosis by the Severe Acute Respiratory Syndrome Coronavirus 7a Protein Is Dependent on Its Interaction with the Bcl-XL Protein▿

    Science.gov (United States)

    Tan, Ying-Xim; Tan, Timothy H. P.; Lee, Marvin J.-R.; Tham, Puay-Yoke; Gunalan, Vithiagaran; Druce, Julian; Birch, Chris; Catton, Mike; Fu, Nai Yang; Yu, Victor C.; Tan, Yee-Joo

    2007-01-01

    The severe acute respiratory syndrome coronavirus (SARS-CoV) 7a protein, which is not expressed by other known coronaviruses, can induce apoptosis in various cell lines. In this study, we show that the overexpression of Bcl-XL, a prosurvival member of the Bcl-2 family, blocks 7a-induced apoptosis, suggesting that the mechanism for apoptosis induction by 7a is at the level of or upstream from the Bcl-2 family. Coimmunoprecipitation experiments showed that 7a interacts with Bcl-XL and other prosurvival proteins (Bcl-2, Bcl-w, Mcl-1, and A1) but not with the proapoptotic proteins (Bax, Bak, Bad, and Bid). A good correlation between the abilities of 7a deletion mutants to induce apoptosis and to interact with Bcl-XL was observed, suggesting that 7a triggers apoptosis by interfering directly with the prosurvival function of Bcl-XL. Interestingly, amino acids 224 and 225 within the C-terminal transmembrane domain of Bcl-XL are essential for the interaction with the 7a protein, although the BH3 domain of Bcl-XL also contributes to this interaction. In addition, fractionation experiments showed that 7a colocalized with Bcl-XL at the endoplasmic reticulum as well as the mitochondria, suggesting that they may form complexes in different membranous compartments. PMID:17428862

  16. LncRNA TUG1 sponges microRNA-9 to promote neurons apoptosis by up-regulated Bcl2l11 under ischemia.

    Science.gov (United States)

    Chen, Shengcai; Wang, Mengdie; Yang, Hang; Mao, Ling; He, Quanwei; Jin, Huijuan; Ye, Zi-Ming; Luo, Xue-Ying; Xia, Yuan-Peng; Hu, Bo

    2017-03-25

    Emerging studies have illustrated that LncRNAs TUG1 play critical roles in multiple biologic processes. However, the LncRNA TUG1 expression and function in ischemic stroke have not been reported yet. In this study, we found that LncRNA TUG1 expression was significantly up-regulated in brain ischemic penumbra from rat middle carotid artery occlusion (MCAO) model, while similar results were also observed in cultured neurons under oxygen-glucose deprivation (OGD) insult. Knockdown of TUG1 decreased the ratio of apoptotic cells and promoted cells survival in vitro, which may be regulated by the elevated miRNA-9 expression and decreased Bcl2l11 protein. Furthermore, TUG1 could directly interact with miR-9 and down-regulating miR-9 could efficiently reverse the function of TUG1 on the Bcl2l11 expression. In summary, our result sheds light on the role of LncRNA TUG1 as a miRNA sponge for ischemic stroke, possibly providing a new therapeutic target in stroke. Copyright © 2017 Elsevier Inc. All rights reserved.

  17. A study on apoptotic signaling pathway in HL-60 cells induced by radiation

    International Nuclear Information System (INIS)

    Kim, Hye Jung; Moon, Sung Keun; Lee, Jae Hoon; Moon, Sun Rock

    2001-01-01

    The mechanical insights of death at cancer cells by ionizing radiation are not yet clearly defined. Recent evidences have demonstrated that radiation therapy may induce cell death via activation of signaling pathway for apoptosis in target cells. This study is designed whether ionizing radiation may activate the signaling cascades of apoptosis including caspase family cysteine proteases, Bcl2/Bax, cytochrome c and Fas/Fas-L in target cells. HL-60 cells were irradiated in vitro with 6 MV X-ray at dose ranges from 2 Gy to 32 Gy. The cell viability was tested by MTT assay and the extent of apoptosis was determined using agarose gel electrophoresis. The activities of caspase proteases were measured by proteolytic cleavages of substrates. Western blot analysis was used to monitor PARP, caspase-3, Cytochrome-c, BcI-2, Bax, Fas and Fas-L. Ionizing radiation decreases the viability of HL -60 cells in a time and dose dependent manner. Ionizing radiation-induced death in HL- 60 cells is an apoptotic death which is revealed as characteristic ladder-pattern fragmentation at genomic DNA over 16 Gy at 4 hours. Ionizing radiation induces the activation of caspase-2, 3, 6, 8 and 9 of HL --60 cells in a time-dependent manner. The activation of caspase- 3 protease is also evidenced by the digestion of poly (ADP-ribose) polymerase and procaspase 3 with 16Gy ionizing irradiation. Anti-apoptotic Bcl2 expression is decreased but apoptotic Bax expression is increased with mitochondrial cytochrome c release in a time- dependent manner. In addition, expression of Fas and Fas-L is also increased in a time dependent manner. These data suggest that ionizing radiation-induced apoptosis is mediated by the activation of various signaling pathways including caspase family cysteine proteases, BcI 2 /Bax, Fas and Fas-L in a time and dose dependent manner

  18. Cypripedin, a phenanthrenequinone from Dendrobium densiflorum, sensitizes non-small cell lung cancer H460 cells to cisplatin-mediated apoptosis.

    Science.gov (United States)

    Wattanathamsan, Onsurang; Treesuwan, Surassawadee; Sritularak, Boonchoo; Pongrakhananon, Varisa

    2018-03-01

    The life-threatening potential of lung cancer has increased over the years due to its acquisition of chemotherapeutic resistance, especially to cisplatin, a first-line therapy. In response to this development, researchers have turned their attention to several compounds derived from natural origins, including cypripedin (CYP), a phenanthrenequinone substance extracted from Dendrobium densiflorum. The aim of the present study was to investigate the ability of CYP to induce apoptosis and enhance cisplatin-mediated death of human lung cancer NCI-H460 cells using cell viability and apoptosis assays. The induction of apoptosis by CYP was observed at a concentration of > 50 μM with the appearance of morphological changes, including DNA condensation and chromatin fragmentation. Together with, CYP was able to activate caspase-3 and downregulate the anti-apoptotic proteins Bcl-2 and Bcl-xL. Also, a non-cytotoxic dose of CYP synergistically potentiated the effect of cisplatin in non-small cell lung cancer line H460 cells, which clearly exhibited the apoptotic phenotype. Western blot analysis revealed that the underlying mechanism involved the downregulation of anti-apoptotic Bcl-xL, whereas the levels of other apoptotic regulatory proteins were not altered. This study provides interesting information on the potent effect of CYP as a chemotherapeutic sensitizer that could be further developed to improve the clinical outcomes of lung cancer patients.

  19. Nitric oxide synthase-I containing cortical interneurons co-express antioxidative enzymes and anti-apoptotic Bcl-2 following focal ischemia: evidence for direct and indirect mechanisms towards their resistance to neuropathology.

    Science.gov (United States)

    Bidmon, H J; Emde, B; Kowalski, T; Schmitt, M; Mayer, B; Kato, K; Asayama, K; Witte, O W; Zilles, K

    2001-09-01

    Neuronal nitric oxide-I is constitutively expressed in approximately 2% of cortical interneurons and is co-localized with gamma-amino butric acid, somatostatin or neuropeptide Y. These interneurons additionally express high amounts of glutamate receptors which mediate the glutamate-induced hyperexcitation following cerebral injury, under these conditions nitric oxide production increases contributing to a potentiation of oxidative stress. However, perilesional nitric oxide synthase-I containing neurons are known to be resistant to ischemic and excitotoxic injury. In vitro studies show that nitrosonium and nitroxyl ions inactivate N-methyl-D-aspartate receptors, resulting in neuroprotection. The question remains of how these cells are protected against their own high intracellular nitric oxide production after activation. In this study, we investigated immunocytochemically nitric oxide synthase-I containing cortical neurons in rats after unilateral, cortical photothrombosis. In this model of focal ischemia, perilesional, constitutively nitric oxide synthase-I containing neurons survived and co-expressed antioxidative enzymes, such as manganese- and copper-zinc-dependent superoxide dismutases, heme oxygenase-2 and cytosolic glutathione peroxidase. This enhanced antioxidant expression was accompanied by a strong perinuclear presence of the antiapoptotic Bcl-2 protein. No colocalization was detectable with upregulated heme oxygenase-1 in glia and the superoxide and prostaglandin G(2)-producing cyclooxygenase-2 in neurons. These results suggest that nitric oxide synthase-I containing interneurons are protected against intracellular oxidative damage and apoptosis by Bcl-2 and several potent antioxidative enzymes. Since nitric oxide synthase-I positive neurons do not express superoxide-producing enzymes such as cyclooxygenase-1, xanthine oxidase and cyclooxygenase-2 in response to injury, this may additionally contribute to their resistance by reducing their internal

  20. Stress Hormone Cortisol Enhances Bcl2 Like-12 Expression to Inhibit p53 in Hepatocellular Carcinoma Cells.

    Science.gov (United States)

    Wu, Weizhong; Liu, Sanguang; Liang, Yunfei; Zhou, Zegao; Bian, Wei; Liu, Xueqing

    2017-12-01

    The pathogenesis of hepatocellular carcinoma (HC) is unclear. It is suggested that psychological stress associates with the pathogenesis of liver cancer. Bcl2-like protein 12 (Bcl2L12) suppresses p53 protein. This study tests a hypothesis that the major stress hormone, cortisol, inhibits the expression of p53 in HC cells (HCC) via up regulating the expression of Bcl2L12. Peripheral blood samples were collected from patients with HC to be analyzed for the levels of cortisol. HCC were cultured to assess the role of cortisol in the regulation of the expression of Bcl2L12 and p53 in HCC. We observed that the serum cortisol levels were higher in HC patients. Expression of Bcl2L12 in HCC was correlated with serum cortisol. Cortisol enhanced the Bcl2L12 expression in HCC. Bcl2L12 binding to the TP53 promoter was correlated with p53 expression in HCC. Cortisol increased the Bcl2L12 expression in HCC to inhibit p53 expression. Stress hormone cortisol suppresses p53 in HCC via enhancing Bcl2L12 expression in HCC. The results suggest that cortisol may be a therapeutic target for the treatment of HC.

  1. Primary central nervous system diffuse large B-cell lymphoma shows an activated B-cell-like phenotype with co-expression of C-MYC, BCL-2, and BCL-6.

    Science.gov (United States)

    Li, Xiaomei; Huang, Ying; Bi, Chengfeng; Yuan, Ji; He, Hong; Zhang, Hong; Yu, QiuBo; Fu, Kai; Li, Dan

    2017-06-01

    Diffuse large B-cell lymphoma (DLBCL) is the most common non-Hodgkin lymphoma, whose main prognostic factor is closely related to germinal center B-cell-like subtype (GCB- DLBCL) or activated B-cell-like type (non-GCB-DLBCL). The most common type of primary central nervous system lymphoma is diffuse large B-cell type with poor prognosis and the reason is unclear. This study aims to stratify primary central nervous system diffuse large B-cell lymphoma (PCNS-DLBCL) according to the cell-of-origin (COO) and to investigate the multiple proteins expression of C-MYC, BCL-6, BCL-2, TP53, further to elucidate the reason why primary central nervous system diffuse large B-cell lymphoma possesses a poor clinical outcome as well. Nineteen cases of primary central nervous system DLBCL were stratified according to immunostaining algorithms of Hans, Choi and Meyer (Tally) and we investigated the multiple proteins expression of C-MYC, BCL-6, BCL-2, TP53. The Epstein-Barr virus and Borna disease virus infection were also detected. Among nineteen cases, most (15-17 cases) were assigned to the activated B-cell-like subtype, highly expression of C-MYC (15 cases, 78.9%), BCL-2 (10 cases, 52.6%), BCL-6 (15 cases, 78.9%). Unfortunately, two cases were positive for PD-L1 while PD-L2 was not expressed in any case. Two cases infected with BDV but no one infected with EBV. In conclusion, most primary central nervous system DLBCLs show an activated B-cell-like subtype characteristic and have multiple expressions of C-MYC, BCL-2, BCL-6 protein, these features might be significant factor to predict the outcome and guide treatment of PCNS-DLBCLs. Copyright © 2017 Elsevier GmbH. All rights reserved.

  2. Can Bcl-XL expression predict the radio sensitivity of Bilharzial-related squamous bladder carcinoma? a prospective comparative study

    Directory of Open Access Journals (Sweden)

    Kamel Nermen A

    2011-01-01

    Full Text Available Abstract Background Local pelvic recurrence after radical cystectomy for muscle invasive bilharzial related squamous cell carcinoma accounts for 75% of treatment failures even in organ confined tumors. Despite the proven value of lymphadenectomy, up to 60% of patients undergoing cystectomy do not have it. These factors are in favor of adjuvant radiotherapy reevaluation. objectives: to evaluate the effect of adjuvant radiotherapy on disease free survival in muscle invasive bilharzial related squamous cell carcinoma of the urinary bladder and to test the predictability of radio-sensitivity using the anti apoptotic protein Bcl-XL. Methods The study prospectively included 71 patients, (47 males, 24 females with muscle invasive bilharzial related squamous cell carcinoma of the bladder (Stage pT2a-T3N0-N3M0 who underwent radical cystectomy in Assiut university hospitals between January 2005 and December 2006. Thirty eight patients received adjuvant radiotherapy to the pelvis in the dose of 50Gy/25 fractions/5 weeks (Group 1, while 33 patients did not receive adjuvant radiotherapy (group 2. Immunohistochemical characterization for bcl-xL expression was done. Follow up was done every 3 months for 12 to 36 months with a mean of 16 ± 10 months. All data were analyzed using SPSS version 16. Three years cumulative disease free survival was calculated and adjusted to Bcl-XL expression and side effects of the treatment were recorded. Results The disease free cumulative survival was 48% for group 1 and 29% for group 2 (log rank p value 0.03. The multivariate predictors of tumor recurrence were the positive Bcl-XL expression (odd ratio 41.1, 95% CI 8.4 - 102.3, p Conclusions Adjuvant radiotherapy for muscle invasive bilharzial related squamous cell carcinoma of the urinary bladder has potential effectiveness and minor side effects. Moreover, Bcl-XL expression is a valuable tool for predicting those who might not respond to this adjuvant treatment.

  3. Immunohistochemical study of integrin α₅β₁, fibronectin, and Bcl-2 in normal oral mucosa, inflammatory fibroepithelial hyperplasia, oral epithelial dysplasia, and oral squamous cell carcinoma.

    Science.gov (United States)

    Núñez, Manuel Antonio Gordón; de Matos, Felipe Rodrigues; Freitas, Roseana de Almeida; Galvão, Hébel Cavalcanti

    2013-07-01

    The objective of this study was to compare the immunoexpression of integrin α₅β₁, fibronectin, and the Bcl-2 protein in normal oral mucosa (NOM), inflammatory fibroepithelial hyperplasia (IFH), oral epithelial dysplasia (OED), and oral squamous cell carcinoma (OSCC). Eleven cases of NOM, 16 IFH, 20 OED, and 27 OSCC were selected for analysis of the immunoexpression of integrin α₅β₁, fibronectin, and bcl-2 protein. There was an association between the intensity and location of the integrin α₅β₁ expression, especially in the OSCC, that 48.1% of cases showed weak immunoreactivity and 40.7% in the suprabasal layer (P < 0.05). There was an association between the pattern and distribution of fibronectin expression in basement membrane, where 90% of NOM showed a pattern of linear continuous and 80% of OED exhibited focal distribution (P < 0.05). The fibronectin expression in connective tissue was predominantly intense with an association of staining pattern among the different specimens, where 37% of OSCC showed a reticular pattern (P < 0.05). There was an association of bcl-2 protein among the types of specimens, especially in IFH and OSCC, where 100% of the cases exhibited scores 1 of staining (P < 0.05). Within this context, the interaction of integrin α₅β₁ with its main ligand in the extracellular matrix, fibronectin, is suggested to influence the survival of tumor cells and to favor their proliferation by modulating apoptosis through the upregulation of antiapoptotic proteins or the suppression of apoptotic mediators.

  4. No dramatic age-related loss of hair cells and spiral ganglion neurons in Bcl-2 over-expression mice or Bax null mice

    Directory of Open Access Journals (Sweden)

    Ohlemiller Kevin K

    2010-07-01

    Full Text Available Abstract Age-related decline of neuronal function is associated with age-related structural changes. In the central nervous system, age-related decline of cognitive performance is thought to be caused by synaptic loss instead of neuronal loss. However, in the cochlea, age-related loss of hair cells and spiral ganglion neurons (SGNs is consistently observed in a variety of species, including humans. Since age-related loss of these cells is a major contributing factor to presbycusis, it is important to study possible molecular mechanisms underlying this age-related cell death. Previous studies suggested that apoptotic pathways were involved in age-related loss of hair cells and SGNs. In the present study, we examined the role of Bcl-2 gene in age-related hearing loss. In one transgenic mouse line over-expressing human Bcl-2, there were no significant differences between transgenic mice and wild type littermate controls in their hearing thresholds during aging. Histological analysis of the hair cells and SGNs showed no significant conservation of these cells in transgenic animals compared to the wild type controls during aging. These data suggest that Bcl-2 overexpression has no significant effect on age-related loss of hair cells and SGNs. We also found no delay of age-related hearing loss in mice lacking Bax gene. These findings suggest that age-related hearing loss is not through an apoptotic pathway involving key members of Bcl-2 family.

  5. Application of a widely-used tropical anti-worm agent, mebendazole ...

    African Journals Online (AJOL)

    well-known anti-parasitic drug widely used in the tropical areas, inhibits cancer cell growth. Preclinical .... Bcl-2 and related proteins, encoded by the Bcl-2 oncogene ... homodimer that acts as an apoptosis inducer, while the ... Figure 1: Schematic presentation of proposed mebendazole anticancer mechanisms of action in.

  6. Cobalt iron oxide nanoparticles induce cytotoxicity and regulate the apoptotic genes through ROS in human liver cells (HepG2).

    Science.gov (United States)

    Ahamed, Maqusood; Akhtar, Mohd Javed; Khan, M A Majeed; Alhadlaq, Hisham A; Alshamsan, Aws

    2016-12-01

    Cobalt iron oxide (CoFe 2 O 4 ) nanoparticles (CIO NPs) have been one of the most widely explored magnetic NPs because of their excellent chemical stability, mechanical hardness and heat generating potential. However, there is limited information concerning the interaction of CIO NPs with biological systems. In this study, we investigated the reactive oxygen species (ROS) mediated cytotoxicity and apoptotic response of CIO NPs in human liver cells (HepG2). Diameter of crystalline CIO NPs was found to be 23nm with a band gap of 1.97eV. CIO NPs induced cell viability reduction and membrane damage, and degree of induction was dose- and time-dependent. CIO NPs were also found to induce oxidative stress revealed by induction of ROS, depletion of glutathione and lower activity of superoxide dismutase enzyme. Real-time PCR data has shown that mRNA level of tumor suppressor gene p53 and apoptotic genes (bax, CASP3 and CASP9) were higher, while the expression level of anti-apoptotic gene bcl-2 was lower in cells following exposure to CIO NPs. Activity of caspase-3 and caspase-9 enzymes was also higher in CIO NPs exposed cells. Furthermore, co-exposure of N-acetyl-cysteine (ROS scavenger) efficiently abrogated the modulation of apoptotic genes along with the prevention of cytotoxicity caused by CIO NPs. Overall, we observed that CIO NPs induced cytotoxicity and apoptosis in HepG2 cells through ROS via p53 pathway. This study suggests that toxicity mechanisms of CIO NPs should be further investigated in animal models. Copyright © 2016 Elsevier B.V. All rights reserved.

  7. Bioactive compounds from crocodile (Crocodylus siamensis) white blood cells induced apoptotic cell death in hela cells.

    Science.gov (United States)

    Patathananone, Supawadee; Thammasirirak, Sompong; Daduang, Jureerut; Chung, Jing Gung; Temsiripong, Yosapong; Daduang, Sakda

    2016-08-01

    Crocodile (Crocodylus siamensis) white blood cell extracts (WBCex) were examined for anticancer activity in HeLa cell lines using the MTT assay. The percentage viability of HeLa cells significantly deceased after treatment with WBCex in a dose- and time-dependent manner. The IC50 dose was suggested to be approximately 225 μg/mL protein. Apoptotic cell death occurred in a time-dependent manner based on investigation by flow cytometry using annexin V-FITC and PI staining. DAPI nucleic acid staining indicated increased chromatin condensation. Caspase-3, -8 and -9 activities also increased, suggesting the induction of the caspase-dependent apoptotic pathway. Furthermore, the mitochondrial membrane potential (ΔΨm ) of HeLa cells was lost as a result of increasing levels of Bax and reduced levels of Bcl-2, Bcl-XL, Bcl-Xs, and XIAP. The decreased ΔΨm led to the release of cytochrome c and the activation of caspase-9 and -3. Apoptosis-inducing factor translocated into the nuclei, and endonuclease G (Endo G) was released from the mitochondria. These results suggest that anticancer agents in WBCex can induce apoptosis in HeLa cells via both caspase-dependent and -independent pathways. © 2015 Wiley Periodicals, Inc. Environ Toxicol 31: 986-997, 2016. © 2015 Wiley Periodicals, Inc.

  8. Matrix metalloproteinase-9 is involved in chronic lymphocytic leukemia cell response to fludarabine and arsenic trioxide.

    Directory of Open Access Journals (Sweden)

    Irene Amigo-Jiménez

    Full Text Available Matrix metalloproteinase-9 (MMP-9 contributes to chronic lymphocytic leukemia (CLL pathology by regulating cell migration and preventing spontaneous apoptosis. It is not known if MMP-9 is involved in CLL cell response to chemotherapy and we address this in the present study, using arsenic trioxide (ATO and fludarabine as examples of cytotoxic drugs.We used primary cells from the peripheral blood of CLL patients and MEC-1 cells stably transfected with an empty vector or a vector containing MMP-9. The effect of ATO and fludarabine was determined by flow cytometry and by the MTT assay. Expression of mRNA was measured by RT-PCR and qPCR. Secreted and cell-bound MMP-9 was analyzed by gelatin zymography and flow cytometry, respectively. Protein expression was analyzed by Western blotting and immunoprecipitation. Statistical analyses were performed using the two-tailed Student's t-test.In response to ATO or fludarabine, CLL cells transcriptionally upregulated MMP-9, preceding the onset of apoptosis. Upregulated MMP-9 primarily localized to the membrane of early apoptotic cells and blocking apoptosis with Z-VAD prevented MMP-9 upregulation, thus linking MMP-9 to the apoptotic process. Culturing CLL cells on MMP-9 or stromal cells induced drug resistance, which was overcome by anti-MMP-9 antibodies. Accordingly, MMP-9-MEC-1 transfectants showed higher viability upon drug treatment than Mock-MEC-1 cells, and this effect was blocked by silencing MMP-9 with specific siRNAs. Following drug exposure, expression of anti-apoptotic proteins (Mcl-1, Bcl-xL, Bcl-2 and the Mcl-1/Bim, Mcl-1/Noxa, Bcl-2/Bax ratios were higher in MMP-9-cells than in Mock-cells. Similar results were obtained upon culturing primary CLL cells on MMP-9.Our study describes for the first time that MMP-9 induces drug resistance by modulating proteins of the Bcl-2 family and upregulating the corresponding anti-apoptotic/pro-apoptotic ratios. This is a novel role for MMP-9 contributing to CLL

  9. The effect of Astragalus polysaccharides on attenuation of diabetic cardiomyopathy through inhibiting the extrinsic and intrinsic apoptotic pathways in high glucose -stimulated H9C2 cells.

    Science.gov (United States)

    Sun, Shuqin; Yang, Shuo; Dai, Min; Jia, Xiujuan; Wang, Qiyan; Zhang, Zheng; Mao, Yongjun

    2017-06-13

    Apoptosis plays a critical role in the progression of diabetic cardiomyopathy (DC). Astragalus polysaccharides (APS), an extract of astragalus membranaceus (AM), is an effective cardioprotectant. Currently, little is known about the detailed mechanisms underlying cardioprotective effects of APS. The aims of this study were to investigate the potential effects and mechanisms of APS on apoptosis employing a model of high glucose induction of apoptosis in H9C2 cells. A model of high glucose induction of H9C2 cell apoptosis was adopted in this research. The cell viabilities were analyzed by MTT assay, and the apoptotic response was quantified by flow cytometry. The expression levels of the apoptosis related proteins were determined by Real-time PCR and western blotting. Incubation of H9C2 cells with various concentrations of glucose (i.e., 5.5, 12.5, 25, 33 and 44 mmol/L) for 24 h revealed that cell viability was reduced by high glucose dose-dependently. Pretreatment of cells with APS could inhibit high glucose-induced H9C2 cell apoptosis by decreasing the expressions of caspases and the release of cytochrome C from mitochondria to cytoplasm. Further experiments also showed that APS could modulate the ratio of Bcl-2 to Bax in mitochondria. APS decreases high glucose-induced H9C2 cell apoptosis by inhibiting the expression of pro-apoptotic proteins of both the extrinsic and intrinsic pathways and modulating the ratio of Bcl-2 to Bax in mitochondria.

  10. Pokemon reduces Bcl-2 expression through NF-κ Bp65: A possible mechanism of hepatocellular carcinoma.

    Science.gov (United States)

    Zhao, Xinkai; Ning, Qiaoming; Sun, Xiaoning; Tian, De'an

    2011-06-01

    To investigate the relationship among Pokemon, NF-κ B p65 and Bcl-2 in hepatoma cells. HCC cell HepG2, SMMC7721 and human fetal liver cell line LO2 cells were used, and expression of Pokemon, NF-κ B p65 and Bcl-2 in three cells were detected by real-time PCR and western blot. Then siRNA of Pokemon was applied to inhibit the expression of Pokemon and NF-κ B p65 and apoptotic rate was determined by flow cytometric analysis. Expressions of Pokemon, NF-κ B p65 and Bcl-2 in human hepatoma cell HepG2, SMMC7721 expression were significantly higher than those in human embryonic stem cells LO2. siRNA of Pokemon inhibited the expression of Pokemon, NF-κ B p65 and Bcl-2 in liver cancer cells, and significantly increased apoptosis of liver cells. While siRNA of NF-κ B p65 inhibited the expression of NF-κ B p65 and Bcl-2, but Pokemon expression in hepatoma cells had no significant change. The proto-oncogene Pokemon can inhibit P14ARF by specific transcription regulation of cell cycle and can induce tumors. In addition, Pokemon can regulate NF-κ B p65 through the expression of apoptosis repressor, and promote the development of liver cancer. It suggests signal network in the liver include the regulation of new non-classical NF-κ B regulatory pathway. Copyright © 2011 Hainan Medical College. Published by Elsevier B.V. All rights reserved.

  11. Overexpression of the human BCL-2 gene product results in growth enhancement of Epstein-Barr virus-immortalized B cells

    International Nuclear Information System (INIS)

    Tsujimoto, Yoshihide

    1989-01-01

    The biological activity of the human BCL-2 gene product was analyzed in an Epstein-Barr virus (EBV)-infected human lymphoblastoid B-cell line transfected with BCL-2 sequences driven by the simian virus 40 promoter and enhancer. Overproduction of the BCL-2 protein conferred a selective growth advantage to the EBV-infected B cells as compared with control transfectants in low-serum medium and also after seeding at limiting dilution but did not render the cells tumorigenic in athymic nude mice. This growth enhancement was also seen in cells transfected with the BCL-2 gene with its own promoter juxtaposed to the immunoglobulin heavy chain gene enhancer, which represents the translocated form of the BCL-2 gene observed in follicular lymphomas with the t(14;18) translocation. The growth advantage of EBV-infected B cells overproducing the BCL-2 protein is neither due to the enhanced growth factor production nor due to an enhanced sensitivity of the BCL-2 transfectants to interleukins 1 or 6, although both lymphokines are known to stimulate proliferation of EBV-infected B-cell lines. The growth advantage of EBV-infected B-cell lines. The growth advantage of EBV-infected B cells by overproduction of the BCL-2 protein suggests the direct involvement of the BCL-2 gene product in the pathogenesis of follicular lymphoma

  12. Xanthurenic acid translocates proapoptotic Bcl-2 family proteins into mitochondria and impairs mitochondrial function

    Directory of Open Access Journals (Sweden)

    Hess Otto M

    2004-04-01

    Full Text Available Abstract Background Xanthurenic acid is an endogenous molecule produced by tryptophan degradation, produced in the cytoplasm and mitochondria. Its accumulation can be observed in aging-related diseases, e.g. senile cataract and infectious disease. We previously reported that xanthurenic acid provokes apoptosis, and now present a study of the response of mitochondria to xanthurenic acid. Results Xanthurenic acid at 10 or 20 μM in culture media of human aortic smooth muscle cells induces translocation of the proteins Bax, Bak, Bclxs, and Bad into mitochondria. In 20 μM xanthurenic acid, Bax is also translocated to the nucleus. In isolated mitochondria xanthurenic acid leads to Bax and Bclxs oligomerization, accumulation of Ca2+, and increased oxygen consumption. Conclusion Xanthurenic acid interacts directly with Bcl-2 family proteins, inducing mitochondrial pathways of apoptosis and impairing mitochondrial functions.

  13. Regulation of Intrinsic and Extrinsic Apoptotic Pathways in Osteosarcoma Cells Following Oleandrin Treatment.

    Science.gov (United States)

    Ma, Yunlong; Zhu, Bin; Yong, Lei; Song, Chunyu; Liu, Xiao; Yu, Huilei; Wang, Peng; Liu, Zhongjun; Liu, Xiaoguang

    2016-11-23

    Our previous study has reported the anti-tumor effect of oleandrin on osteosarcoma (OS) cells. In the current study, we mainly explored its potential regulation on intrinsic and extrinsic apoptotic pathway in OS cells. Cells apoptosis, reactive oxygen species (ROS) and mitochondrial membrane potential (MMP) were detected using fluorescence staining and flow cytometry. Caspase-3 activity was detected using a commercial kit. The levels of cytoplasmic cytochrome c, mitochondrial cytochrome c, bcl-2, bax, caspase-9, Fas, FasL, caspase-8 and caspase-3 were detected by Western blotting. z-VAD-fmk was applied to block both intrinsic and extrinsic apoptosis pathways, and cells apoptosis was also tested. Furthermore, we used z-LEHD-fmk and Fas blocking antibody to inhibit intrinsic and extrinsic pathways, separately, and the selectivity of oleandrin on these pathways was explored. Results showed that oleandrin induced the apoptosis of OS cells, which was accompanied by an increase in ROS and a decrease in MMP. Furthermore, cytochrome c level was reduced in mitochondria but elevated in the cytoplasm. Caspase-3 activity was enhanced by oleandrin in a concentration- and time-dependent manner. Oleandrin also down-regulated the expression of bcl-2, but up-regulated bax, caspase-9, Fas, FasL, caspase-8 and caspase-3. In addition, the suppression of both apoptotic pathways by z-VAD-fmk greatly reverted the oleandrin-induced apoptosis. Moreover, the suppression of one pathway by a corresponding inhibitor did not affect the regulation of oleandrin on another pathway. Taken together, we concluded that oleandrin induced apoptosis of OS cells via activating both intrinsic and extrinsic apoptotic pathways.

  14. Expression of Bcl-2, p53, and MDM2 in Localized Prostate Cancer With Respect to the Outcome of Radical Radiotherapy Dose Escalation

    International Nuclear Information System (INIS)

    Vergis, Roy; Corbishley, Catherine M.; Thomas, Karen

    2010-01-01

    Purpose: Established prognostic factors in localized prostate cancer explain only a moderate proportion of variation in outcome. We analyzed tumor expression of apoptotic markers with respect to outcome in men with localized prostate cancer in two randomized controlled trials of radiotherapy dose escalation. Methods and Materials: Between 1995 and 2001, 308 patients with localized prostate cancer received neoadjuvant androgen deprivation and radical radiotherapy at our institution in one of two dose-escalation trials. The biopsy specimens in 201 cases were used to make a biopsy tissue microarray. We evaluated tumor expression of Bcl-2, p53, and MDM2 by immunohistochemistry with respect to outcome. Results: Median follow-up was 7 years, and 5-year freedom from biochemical failure (FFBF) was 70.4% (95% CI, 63.5-76.3%). On univariate analysis, expression of Bcl-2 (p < 0.001) and p53 (p = 0.017), but not MDM2 (p = 0.224), was significantly associated with FFBF. Expression of Bcl-2 remained significantly associated with FFBF (p = 0.001) on multivariate analysis, independently of T stage, Gleason score, initial prostate-specific antigen level, and radiotherapy dose. Seven-year biochemical control was 61% vs. 41% (p = 0.0122) for 74 Gy vs. 64 Gy, respectively, among patients with Bcl-2-positive tumors and 87% vs. 81% (p = 0.423) for 74 Gy vs. 64 Gy, respectively, among patients with Bcl-2-negative tumors. There was no statistically significant interaction between dose and Bcl-2 expression. Conclusions: Bcl-2 expression was a significant, independent determinant of biochemical control after neoadjuvant androgen deprivation and radical radiotherapy for prostate cancer. These data generate the hypothesis that Bcl-2 expression could be used to inform the choice of radiotherapy dose in individual patients.

  15. Hepatitis C virus positive diffuse large B-cell lymphomas have distinct molecular features and lack BCL2 translocations

    DEFF Research Database (Denmark)

    Visco, Carlo; Wang, Jinfen; Tisi, Maria Chiara

    2017-01-01

    apoptotic pathways, have higher proliferative index, and lack BCL2 translocations. CONCLUSIONS: HCV-positive DLBCL have distinct molecular and pathological features compared to the HCV-negative counterparts.British Journal of Cancer advance online publication, 26 September 2017; doi:10.1038/bjc.2017.345 www.bjcancer.com....... in lymphomagenesis, as witnessed by the curative potential of antiviral therapy in HCV-related low-grade B-cell lymphomas. METHODS: We performed a case-control study including 44 HCV-positive cases of de novo DLBCL, comparing them with 132 HCV-negative patients as controls (ratio 3 to 1). Cases and controls were...... for MYC, BCL2 and BCL6, TP53 mutations, and diagnostic specimens reviewed to exclude transformation from low-grade lymphoma. RESULTS: Compared to the HCV-negative controls, patients with HCV-positive de novo DLBCL had differential expression of genes that regulate innate immune response and modulate...

  16. Curcumin induces apoptotic cell death of activated human CD4+ T cells via increasing endoplasmic reticulum stress and mitochondrial dysfunction.

    Science.gov (United States)

    Zheng, Min; Zhang, Qinggao; Joe, Yeonsoo; Lee, Bong Hee; Ryu, Do Gon; Kwon, Kang Beom; Ryter, Stefan W; Chung, Hun Taeg

    2013-03-01

    Curcumin, a natural polyphenolic antioxidant compound, exerts well-known anti-inflammatory and immunomodulatory effects, the latter which can influence the activation of immune cells including T cells. Furthermore, curcumin can inhibit the expression of pro-inflammatory cytokines and chemokines, through suppression of the NF-κB signaling pathway. The beneficial effects of curcumin in diseases such as arthritis, allergy, asthma, atherosclerosis, diabetes and cancer may be due to its immunomodulatory properties. We studied the potential of curcumin to modulate CD4+ T cells-mediated autoimmune disease, by examining the effects of this compound on human CD4+ lymphocyte activation. Stimulation of human T cells with PHA or CD3/CD28 induced IL-2 mRNA expression and activated the endoplasmic reticulum (ER) stress response. The treatment of T cells with curcumin induced the unfolded protein response (UPR) signaling pathway, initiated by the phosphorylation of PERK and IRE1. Furthermore, curcumin increased the expression of the ER stress associated transcriptional factors XBP-1, cleaved p50ATF6α and C/EBP homologous protein (CHOP) in human CD4+ and Jurkat T cells. In PHA-activated T cells, curcumin further enhanced PHA-induced CHOP expression and reduced the expression of the anti-apoptotic protein Bcl-2. Finally, curcumin treatment induced apoptotic cell death in activated T cells via eliciting an excessive ER stress response, which was reversed by the ER-stress inhibitor 4-phenylbutyric acid or transfection with CHOP-specific siRNA. These results suggest that curcumin can impact both ER stress and mitochondria functional pathways, and thereby could be used as a promising therapy in the context of Th1-mediated autoimmune diseases. Copyright © 2013 Elsevier B.V. All rights reserved.

  17. Novel Indole-based Tambjamine-Analogues Induce Apoptotic Lung Cancer Cell Death through p38 Mitogen-Activated Protein Kinase Activation.

    Science.gov (United States)

    Manuel-Manresa, Pilar; Korrodi-Gregório, Luís; Hernando, Elsa; Villanueva, Alberto; Martínez-García, David; Rodilla, Ananda M; Ramos, Ricard; Fardilha, Margarida; Moya, Juan; Quesada, Roberto; Soto-Cerrato, Vanessa; Pérez-Tomás, Ricardo

    2017-07-01

    Lung cancer has become the leading killer cancer worldwide, due to late diagnosis and lack of efficient anticancer drugs. We have recently described novel natural-derived tambjamine analogues that are potent anion transporters capable of disrupting cellular ion balance, inducing acidification of the cytosol and hyperpolarization of cellular plasma membranes. Although these tambjamine analogues were able to compromise cell survival, their molecular mechanism of action remains largely unknown. Herein we characterize the molecular cell responses induced by highly active indole-based tambjamine analogues treatment in lung cancer cells. Expression changes produced after compounds treatment comprised genes related to apoptosis, cell cycle, growth factors and its receptors, protein kinases and topoisomerases, among others. Dysregulation of BCL2 and BIRC5 /survivin genes suggested the apoptotic pathway as the induced molecular cell death mechanism. In fact, activation of several proapoptotic markers (caspase-9, caspase-3, and PARP) and reversion of the cytotoxic effect upon treatment with an apoptosis inhibitor (Z-VAD-FMK) were observed. Moreover, members of the Bcl-2 protein family suffered changes after tambjamine analogues treatment, with a concomitant protein decrease towards the prosurvival members. Besides this, it was observed cellular accumulation of ROS upon compound treatment and an activation of the stress-kinase p38 MAPK route that, when inhibited, reverted the cytotoxic effect of the tambjamine analogues. Finally, a significant therapeutic effect of these compounds was observed in subcutaneous and orthotopic lung cancer mice models. Taken together, these results shed light on the mechanism of action of novel cytotoxic anionophores and demonstrate the therapeutic effects against lung cancer. Mol Cancer Ther; 16(7); 1224-35. ©2017 AACR . ©2017 American Association for Cancer Research.

  18. Pharmacological and protein profiling suggest venetoclax (ABT-199) as optimal partner with ibrutinib in chronic lymphocytic leukemia

    Science.gov (United States)

    Cervantes-Gomez, Fabiola; Lamothe, Betty; Woyach, Jennifer A.; Wierda, William G.; Keating, Michael J.; Balakrishnan, Kumudha; Gandhi, Varsha

    2015-01-01

    Purpose Bruton’s tyrosine kinase (BTK) is a critical enzyme in the B-cell receptor pathway and is inhibited by ibrutinib due to covalent binding to the kinase domain. Though ibrutinib results in impressive clinical activity in chronic lymphocytic leukemia (CLL), most patients achieve only partial remission due to residual disease. We performed a pharmacologic profiling of residual circulating CLL cells from patients receiving ibrutinib to identify optimal agents that could induce cell death of these lymphocytes. Experimental design Ex vivo serial samples of CLL cells from patients on ibrutinib were obtained prior and after (weeks 2, 4, and 12) the start of treatment. These cells were incubated with PI3K inhibitors (idelalisib or IPI-145), bendamustine, additional ibrutinib, or BCL-2 antagonists (ABT-737 or ABT-199) and cell death was measured. In vitro investigations complemented ex vivo studies. Immunoblots for BTK signaling pathway and antiapoptotic proteins were performed. Results The BCL-2 antagonists, especially ABT-199, induced high cell death during ex vivo incubations. In concert with the ex vivo data, in vitro combinations also resulted highly cytotoxicity. Serial samples of CLL cells obtained before and 2, 4, 12, or 36 weeks after the start of ibrutinib showed inhibition of BTK activity and sensitivity to ABTs. Among the three BCL-2 family anti-apoptotic proteins that are overexpressed in CLL, levels of MCL-1 and BCL-XL were decreased after ibrutinib while ABT-199 selectively antagonizes BCL-2. Conclusions Our biological and molecular results suggest that ibrutinib and ABT-199 combination should be tested clinically against CLL. PMID:25829398

  19. PURIFICATION AND FRACTIONAL ANALYSIS OF METHANOLIC EXTRACT OF WEDELIA TRILOBATA POSSESSING APOPTOTIC AND ANTI-LEUKEMIC ACTIVITY

    Science.gov (United States)

    Venkatesh, Uday; Javarasetty, Chethan; Murari, Satish Kumar

    2017-01-01

    Background: Wedelia trilobata (L.) Hitch (WT), commonly known as yellow dots or creeping daisy, is a shrub possessing potent biological activities, and is traditionally used a medicinal plant in Ayurveda, Siddha and Unani systems of medicines, and it has also been tried against leukemia cell line MEG- 01. In the present study, purification and screening of the plant was done for bioactive compounds in methanolic extract of WT for apoptotic and anti-leukemia activity. Materials and methods: The methanolic extract of WT was initially purified through thin layer chromatography (TLC) and screened for the apoptotic and anti-leukemia activities. The positive band of TLC was subjected to silica gel column chromatography for further purification and the fractions obtained from it were screened again for anti-leukemia activity through thymidine uptake assay and apoptotic activity by DNA fragmentation, nuclear staining and flow cytometry assays. The fraction with positive result was subjected to HPLC for analysis of bioactive components. Results: Out of many combinations of solvents, the methanol and dichloromethane combination in the ratio 6:4 has revealed two bands in TLC, among which the second band showed positive results for apoptotic and anti-leukemic activities. Further purification of second band through silica gel chromatography gave five fractions in which the 3rd fraction gave positive results and it shows single peak during compositional analysis through HPLC. Conclusion: The single peak revealed through HPLC indicates the presence of pure compound with apoptotic and anti-leukemia activities encouraging for further structural analysis. PMID:28480428

  20. Predictive value of bcl-2 immunoreactivity in prostate cancer patients treated with radiotherapy

    International Nuclear Information System (INIS)

    Bylund, A.; Widmark, A.; Stattin, P.; Bergh, A.

    1998-01-01

    Background and purpose: Recent experimental evidence suggests that overexpression of bcl-2, a protein functioning by blocking apoptosis, may influence the treatment outcome in human tumours, including prostate cancer. To test the clinical implications of this hypothesis, tumours from patients with prostate cancer treated with external beam radiotherapy were investigated for bcl-2 immunoreactivity (IR) and correlated with prognosis and treatment outcome. Materials and methods: Bcl-2 IR was evaluated in archival tumour specimens obtained through transurethral resection from 42 patients with localized prostate cancer (T0-T4, N0 and M0). Bcl-2 IR expression was related to stage, grade and cancer-specific survival. Specimens were obtained prior to administrating routine radiotherapy for all patients. Results: Bcl-2 IR was present in 19/42 (45%) tumours. The bcl-2-positive patients had a significantly longer cancer-specific survival than the bcl-2-negative patients (10.3 versus 3.4 years, P<0.04). At follow-up (7-19 years), nine patients were still alive, 26 patients had died of prostate cancer and seven patients had died of other causes. Conclusions: This study indicates that pre-treatment bcl-2 overexpression is related to a favourable outcome in prostate cancer treated with radiotherapy. Low bcl-2 along with a high stage may be a predictor of poor prognosis and these patients might benefit from additional treatment. (Copyright (c) 1998 Elsevier Science B.V., Amsterdam. All rights reserved.)

  1. DHT inhibits the Aβ25-35-induced apoptosis by regulation of seladin-1, survivin, XIAP, bax, and bcl-xl expression through a rapid PI3-K/Akt signaling in C6 glial cell lines.

    Science.gov (United States)

    Bing, Lelin; Wu, Junfeng; Zhang, Jianfeng; Chen, Yinghui; Hong, Zhen; Zu, Hengbing

    2015-01-01

    Previous evidences indicate that androgen is neuroprotective in the brain. However, the underling mechanisms remain to be fully elucidated. Moreover, it is controversial whether dihydrotestosterone (DHT) modulates the expression of apoptosis-related effectors, such as survivin, XIAP, bax, and bcl-xl proteins mediated by the PI3-K/Akt pathway, which contributes to androgen neuroprotection. In this study using a C6 glial cell model, apoptotic cells were detected by flow cytometry. Akt, seladin-1, survivin, XIAP, bcl-xl, and bax protein expression is investigated by Western blot. After amyloid β-protein fragment (Aβ25-35) treatment, apoptotic cells at early (annexin V+, PI-) and late (annexin V+, PI+) stages were significantly increased. Apoptosis at early and late was obviously inhibited in the presence of DHT. The effect of DHT was markedly blocked by PI3-K inhibitor LY294002.To elicit the mechanism of DHT protection, the expression of seladin-1, survivin, XIAP, bax, and bcl-xl protein was determined in C6 cells treated with Aβ25-35, DHT, or LY294002. Aβ25-35 significantly downregulated the expression of seladin-1, survivin, XIAP, bcl-xl protein and upregulated the expression of bax protein. DHT significantly inhibited the expression of bax, seladin-1, survivin, XIAP, and bcl-xl protein induced by Aβ25-35. Further, we found the effect of DHT was significantly inhibited by LY294002. Collectively, in a C6 glial cell model, we firstly found that DHT inhibits Aβ25-35-induced apoptosis by a rapid nongenic PI-3K/Akt activation as well as regulation of seladin-1, survivin, XIAP, bcl-xl, and bax proteins.

  2. Fisetin inhibits growth, induces G2/M arrest and apoptosis of human epidermoid carcinoma A431 cells: Role of mitochondrial membrane potential disruption and consequent caspases activation

    Science.gov (United States)

    Pal, Harish C.; Sharma, Samriti; Elmets, Craig A.; Athar, Mohammad; Afaq, Farrukh

    2013-01-01

    Non-melanoma skin cancers (NMSCs) one of the most common neoplasms causes serious morbidity and mortality. Therefore, identification of non-toxic phytochemicals for prevention/treatment of NMSCs is highly desirable. Fisetin (3,3′,4′,7-tetrahydroxyflavone), a dietary flavonoid, present in fruits and vegetables possesses anti-oxidant and anti-proliferative properties. The aim of this study was to investigate the chemotherapeutic potential of fisetin in cultured human epidermoid carcinoma A431 cells. Treatment of A431 cells with fistein (5-80 μM) resulted in a significant decrease in cell viability in a dose- and time-dependent manner. Employing clonogenic assay, we found that fisetin treatment significantly reduced colony formation in A431 cells. Fisetin treatment of A431 cells resulted in G2/M arrest and induction of apoptosis. Furthermore, treatment of A431 cells with fisetin resulted in (i) decreased expression of anti-apoptotic proteins (Bcl2, Bcl-xL and Mcl-1), (ii) increased expression of pro-apoptotic proteins (Bax, Bak and Bad), (iii) disruption of mitochondrial potential, (iv) release of cytchrome c and Smac/DIABLO from mitochondria, (v) activation of caspases, and (vi) cleavage of PARP protein. Pretreatment of A431 cells with the pan-caspase inhibitor (Z-VAD-FMK) blocked fisetin-induced cleavage of caspases and PARP. Taken together, these data provide evidence that fisetin possesses chemotherapeutic potential against human epidermoid carcinoma A431 cells. Overall, these results suggest that fisetin could be developed as a novel therapeutic agent for the management of NMSCs. PMID:23800058

  3. Role of Apoptosis in the Development of Uterine Leiomyoma: Analysis of Expression Patterns of Bcl-2 and Bax in Human Leiomyoma Tissue With Clinical Correlations.

    Science.gov (United States)

    Csatlós, Éva; Máté, Szabolcs; Laky, Marcella; Rigó, János; Joó, József Gábor

    2015-07-01

    To describe gene expression patterns of the apoptotic regulatory genes Bcl and Bax in human uterine leiomyoma tissue. To investigate the relationship between alterations of gene expression patterns and several relevant clinical parameters. We obtained samples from 101 cases undergoing surgery for uterine leiomyoma for gene expression analysis of the Bcl-2 and Bax genes. Gene expression was quantified using RT-PCR technique. In the leiomyoma group, the Bcl-2 gene was significantly overexpressed compared with the control group although there was no such difference in the gene expression of Bax. Gene activity of Bcl-2 positively correlated with the tumor number in individual uterine leiomyoma cases. Although there was no significant correlation between the length of the cumulative lactation period before the development of uterine leiomyoma and Bcl-2 gene expression in the leiomyoma tissue, we observed a trend for a shorter cumulative lactation period to be associated with overexpression of the Bcl-2 gene. Overexpression of the antiapoptotic Bcl-2 gene appeared to be a factor in the development of uterine leiomyoma, whereas gene activity of the proapoptotic Bax gene did not seem to play a role in the process.

  4. Identification and characterization of the Bcl-2- associated ...

    African Journals Online (AJOL)

    Identification and characterization of the Bcl-2- associated athanogene (BAG) protein family in rice. ... Data obtained from real-time PCR of OsBAG genes under heat stress showed that maximum induction in the expression of all the genes occurred after one hour exposure to heat stress, while reduction in the expression ...

  5. Biochemical responses and mitochondrial mediated activation of apoptosis on long-term effect of aspartame in rat brain

    Directory of Open Access Journals (Sweden)

    Iyaswamy Ashok

    2014-01-01

    Full Text Available Aspartame, an artificial sweetener, is very widely used in many foods and beverages. But there are controversies about its metabolite which is marked for its toxicity. Hence it is believed to be unsafe for human use. Previous studies have reported on methanol exposure with involvements of free radicals on excitotoxicity of neuronal apoptosis. Hence, this present study is proposed to investigate whether or not chronic aspartame (FDA approved Daily Acceptable Intake (ADI,40 mg/kg bwt administration could release methanol, and whether or not it can induce changes in brain oxidative stress status and gene and protein expression of anti-apoptotic Bcl-2 and pro-apoptotic Bax and caspase-3 in the rat brain region. To mimic the human methanol metabolism, Methotrexate (MTX-treated Wistar strain male albino rats were used and after the oral administration of aspartame, the effects were studied along with controls and MTX-treated controls. Aspartame exposure resulted with a significant increase in the enzymatic activity in protein carbonyl, lipid peroxidation levels, superoxide dismutase, glutathione-S-transferase, glutathione peroxidase and catalase activity in (aspartame MTX-treated animals and with a significant decrease in reduced glutathione, glutathione reductase and protein thiol, pointing out the generation of free radicals. The gene and protein expression of pro apoptotic marker Bax showed a marked increase whereas the anti-apoptotic marker Bcl-2 decreased markedly indicating the aspartame is harmful at cellular level. It is clear that long term aspartame exposure could alter the brain antioxidant status, and can induce apoptotic changes in brain.

  6. Biochemical responses and mitochondrial mediated activation of apoptosis on long-term effect of aspartame in rat brain.

    Science.gov (United States)

    Ashok, Iyaswamy; Sheeladevi, Rathinasamy

    2014-01-01

    Aspartame, an artificial sweetener, is very widely used in many foods and beverages. But there are controversies about its metabolite which is marked for its toxicity. Hence it is believed to be unsafe for human use. Previous studies have reported on methanol exposure with involvements of free radicals on excitotoxicity of neuronal apoptosis. Hence, this present study is proposed to investigate whether or not chronic aspartame (FDA approved Daily Acceptable Intake (ADI),40 mg/kg bwt) administration could release methanol, and whether or not it can induce changes in brain oxidative stress status and gene and protein expression of anti-apoptotic Bcl-2 and pro-apoptotic Bax and caspase-3 in the rat brain region. To mimic the human methanol metabolism, Methotrexate (MTX)-treated Wistar strain male albino rats were used and after the oral administration of aspartame, the effects were studied along with controls and MTX-treated controls. Aspartame exposure resulted with a significant increase in the enzymatic activity in protein carbonyl, lipid peroxidation levels, superoxide dismutase, glutathione-S-transferase, glutathione peroxidase and catalase activity in (aspartame MTX)-treated animals and with a significant decrease in reduced glutathione, glutathione reductase and protein thiol, pointing out the generation of free radicals. The gene and protein expression of pro apoptotic marker Bax showed a marked increase whereas the anti-apoptotic marker Bcl-2 decreased markedly indicating the aspartame is harmful at cellular level. It is clear that long term aspartame exposure could alter the brain antioxidant status, and can induce apoptotic changes in brain.

  7. Inhibition of Bcl-2 or IAP proteins does not provoke mutations in surviving cells

    Energy Technology Data Exchange (ETDEWEB)

    Shekhar, Tanmay M. [Department of Biochemistry, La Trobe Institute for Molecular Science, La Trobe University, Bundoora 3083 (Australia); Green, Maja M. [Department of Biochemistry, La Trobe Institute for Molecular Science, La Trobe University, Bundoora 3083 (Australia); Department of Anatomy & Neuroscience, The University of Melbourne, Parkville 3010 (Australia); Rayner, David M.; Miles, Mark A.; Cutts, Suzanne M. [Department of Biochemistry, La Trobe Institute for Molecular Science, La Trobe University, Bundoora 3083 (Australia); Hawkins, Christine J., E-mail: c.hawkins@latrobe.edu.au [Department of Biochemistry, La Trobe Institute for Molecular Science, La Trobe University, Bundoora 3083 (Australia)

    2015-07-15

    Graphical abstract: - Highlights: • Mutagenicities of anti-cancer drugs were tested using HPRT, γH2AX and comet assays. • TRAIL, doxorubicin and etoposide were more mutagenic than BH3- or Smac-mimetics. • Physiologically achievable levels of the BH3-mimetic ABT-737 were not mutagenic. • High concentrations of ABT-737 provoked mutations via an off-target mechanism. • Even very high concentrations of IAP antagonists were not mutagenic. - Abstract: Chemotherapy and radiotherapy can cause permanent damage to the genomes of surviving cells, provoking severe side effects such as second malignancies in some cancer survivors. Drugs that mimic the activity of death ligands, or antagonise pro-survival proteins of the Bcl-2 or IAP families have yielded encouraging results in animal experiments and early phase clinical trials. Because these agents directly engage apoptosis pathways, rather than damaging DNA to indirectly provoke tumour cell death, we reasoned that they may offer another important advantage over conventional therapies: minimisation or elimination of side effects such as second cancers that result from mutation of surviving normal cells. Disappointingly, however, we previously found that concentrations of death receptor agonists like TRAIL that would be present in vivo in clinical settings provoked DNA damage in surviving cells. In this study, we used cell line model systems to investigate the mutagenic capacity of drugs from two other classes of direct apoptosis-inducing agents: the BH3-mimetic ABT-737 and the IAP antagonists LCL161 and AT-406. Encouragingly, our data suggest that IAP antagonists possess negligible genotoxic activity. Doses of ABT-737 that were required to damage DNA stimulated Bax/Bak-independent signalling and exceeded concentrations detected in the plasma of animals treated with this drug. These findings provide hope that cancer patients treated by BH3-mimetics or IAP antagonists may avoid mutation-related illnesses that afflict

  8. Inhibition of Bcl-2 or IAP proteins does not provoke mutations in surviving cells

    International Nuclear Information System (INIS)

    Shekhar, Tanmay M.; Green, Maja M.; Rayner, David M.; Miles, Mark A.; Cutts, Suzanne M.; Hawkins, Christine J.

    2015-01-01

    Graphical abstract: - Highlights: • Mutagenicities of anti-cancer drugs were tested using HPRT, γH2AX and comet assays. • TRAIL, doxorubicin and etoposide were more mutagenic than BH3- or Smac-mimetics. • Physiologically achievable levels of the BH3-mimetic ABT-737 were not mutagenic. • High concentrations of ABT-737 provoked mutations via an off-target mechanism. • Even very high concentrations of IAP antagonists were not mutagenic. - Abstract: Chemotherapy and radiotherapy can cause permanent damage to the genomes of surviving cells, provoking severe side effects such as second malignancies in some cancer survivors. Drugs that mimic the activity of death ligands, or antagonise pro-survival proteins of the Bcl-2 or IAP families have yielded encouraging results in animal experiments and early phase clinical trials. Because these agents directly engage apoptosis pathways, rather than damaging DNA to indirectly provoke tumour cell death, we reasoned that they may offer another important advantage over conventional therapies: minimisation or elimination of side effects such as second cancers that result from mutation of surviving normal cells. Disappointingly, however, we previously found that concentrations of death receptor agonists like TRAIL that would be present in vivo in clinical settings provoked DNA damage in surviving cells. In this study, we used cell line model systems to investigate the mutagenic capacity of drugs from two other classes of direct apoptosis-inducing agents: the BH3-mimetic ABT-737 and the IAP antagonists LCL161 and AT-406. Encouragingly, our data suggest that IAP antagonists possess negligible genotoxic activity. Doses of ABT-737 that were required to damage DNA stimulated Bax/Bak-independent signalling and exceeded concentrations detected in the plasma of animals treated with this drug. These findings provide hope that cancer patients treated by BH3-mimetics or IAP antagonists may avoid mutation-related illnesses that afflict

  9. Chemically Induced Degradation of the Oncogenic Transcription Factor BCL6

    Directory of Open Access Journals (Sweden)

    Nina Kerres

    2017-09-01

    Full Text Available The transcription factor BCL6 is a known driver of oncogenesis in lymphoid malignancies, including diffuse large B cell lymphoma (DLBCL. Disruption of its interaction with transcriptional repressors interferes with the oncogenic effects of BCL6. We used a structure-based drug design to develop highly potent compounds that block this interaction. A subset of these inhibitors also causes rapid ubiquitylation and degradation of BCL6 in cells. These compounds display significantly stronger induction of expression of BCL6-repressed genes and anti-proliferative effects than compounds that merely inhibit co-repressor interactions. This work establishes the BTB domain as a highly druggable structure, paving the way for the use of other members of this protein family as drug targets. The magnitude of effects elicited by this class of BCL6-degrading compounds exceeds that of our equipotent non-degrading inhibitors, suggesting opportunities for the development of BCL6-based lymphoma therapeutics.

  10. Design and synthesis of novel C14-urea-tetrandrine derivatives with potent anti-cancer activity.

    Science.gov (United States)

    Lan, Junjie; Huang, Lan; Lou, Huayong; Chen, Chao; Liu, Tangjingjun; Hu, Shengcao; Yao, Yao; Song, Junrong; Luo, Jun; Liu, Yazhou; Xia, Bin; Xia, Lei; Zeng, Xueyi; Ben-David, Yaacov; Pan, Weidong

    2018-01-01

    Tetrandrine is a dibenzyltetrahydroisoquinoline alkaloid, isolated from traditional Chinese medicinal plant Stephania tetrandra, with anti-tumor activity. Our previous study identified several derivatives of tetrandrine showing better activities than parental compound against human hepatocellular carcinoma cells. To increase diversity and cytotoxic activities of the original compound, a series of novel 14-urea-tetrandrine derivatives were synthesized through structural modification of tetrandrine. These derivaties demonstrated a moderate to strong anti-proliferative activities against human cell lines HEL and K562 (Leukemia), prostate (PC3), breast (MDA-MB-231) and melanoma (WM9). Compound 4g showed strongest cytotoxic effect against PC3 cells with IC 50 value of 0.64 μM, which was 12-fold, 31-fold and 26-fold lower than the parental tetrandrine, 5-fluorouracil and cisplatin, respectively. Preliminary structure-activity relationship study indicated that urea subsititution was the key pharmacophore for the enhancement of their antitumor activities. Induction of apoprosis by 4g was associated with the activation of pro-apoptotic protein BAX and inhibition of antiapoptosis proteins survivin as well as Bcl-2. Moreover, activation of caspases led to increase cleavage of PARP, which further accelerates apoptotic cell death. These results reveal that the compound 4g may be used as a potential anticancer drug candidate. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  11. Ceramide-Induced Apoptosis in Renal Tubular Cells: A Role of Mitochondria and Sphingosine-1-Phoshate

    Science.gov (United States)

    Ueda, Norishi

    2015-01-01

    Ceramide is synthesized upon stimuli, and induces apoptosis in renal tubular cells (RTCs). Sphingosine-1 phosphate (S1P) functions as a survival factor. Thus, the balance of ceramide/S1P determines ceramide-induced apoptosis. Mitochondria play a key role for ceramide-induced apoptosis by altered mitochondrial outer membrane permeability (MOMP). Ceramide enhances oligomerization of pro-apoptotic Bcl-2 family proteins, ceramide channel, and reduces anti-apoptotic Bcl-2 proteins in the MOM. This process alters MOMP, resulting in generation of reactive oxygen species (ROS), cytochrome C release into the cytosol, caspase activation, and apoptosis. Ceramide regulates apoptosis through mitogen-activated protein kinases (MAPKs)-dependent and -independent pathways. Conversely, MAPKs alter ceramide generation by regulating the enzymes involving ceramide metabolism, affecting ceramide-induced apoptosis. Crosstalk between Bcl-2 family proteins, ROS, and many signaling pathways regulates ceramide-induced apoptosis. Growth factors rescue ceramide-induced apoptosis by regulating the enzymes involving ceramide metabolism, S1P, and signaling pathways including MAPKs. This article reviews evidence supporting a role of ceramide for apoptosis and discusses a role of mitochondria, including MOMP, Bcl-2 family proteins, ROS, and signaling pathways, and crosstalk between these factors in the regulation of ceramide-induced apoptosis of RTCs. A balancing role between ceramide and S1P and the strategy for preventing ceramide-induced apoptosis by growth factors are also discussed. PMID:25751724

  12. BL-038, a Benzofuran Derivative, Induces Cell Apoptosis in Human Chondrosarcoma Cells through Reactive Oxygen Species/Mitochondrial Dysfunction and the Caspases Dependent Pathway.

    Science.gov (United States)

    Liu, Ju-Fang; Chen, Chien-Yu; Chen, Hsien-Te; Chang, Chih-Shiang; Tang, Chih-Hsin

    2016-09-07

    Chondrosarcoma is a highly malignant cartilage-forming bone tumor that has the capacity to invade locally and cause distant metastasis. Moreover, chondrosarcoma is intrinsically resistant to conventional chemotherapy or radiotherapy. The novel benzofuran derivative, BL-038 (2-amino-3-(2,6-dichlorophenyl)-6-(4-methoxyphenyl)benzofuran-4-yl acetate), has been evaluated for its anticancer effects in human chondrosarcoma cells. BL-038 caused cell apoptosis in two human chondrosarcoma cell lines, JJ012 and SW1353, but not in primary chondrocytes. Treatment of chondrosarcoma with BL-038 also induced reactive oxygen species (ROS) production. Furthermore, BL-038 decreased mitochondrial membrane potential (MMP) and changed mitochondrial-related apoptosis, by downregulating the anti-apoptotic activity members (Bcl-2, Bcl-xL) and upregulating pro-apoptotic members (Bax, Bak) of the B-cell lymphoma 2 (Bcl-2) family of proteins, key regulators of the apoptotic machinery in cells. These results demonstrate that in human chondrosarcoma cells, the apoptotic and cytotoxic effects of BL-038 are mediated by the intrinsic mitochondria-mediated apoptotic pathway, which in turn causes the release of cytochrome c, the activation of caspase-9 and caspase-3, and the cleavage of poly (ADP-ribose) polymerase (PARP), to elicit apoptosis response. Our results show that the benzofuran derivative BL-038 induces apoptosis in chondrosarcoma cells.

  13. rno-miR-665 targets BCL2L1 (Bcl-xl) and increases vulnerability to propofol in developing astrocytes.

    Science.gov (United States)

    Sun, Wen-Chong; Pei, Ling

    2016-07-01

    Propofol exerts a cytotoxic influence over immature neurocytes. Our previous study revealed that clinically relevant doses of propofol accelerated apoptosis of primary cultured astrocytes of developing rodent brains via rno-miR-665 regulation. However, the role of rno-miR-665 during the growth spurt of neonatal rodent brains in vivo is still uncertain. Post-natal day 7 (P7) rats received a single injection of propofol 30 mg/kg intraperitoneally (i.p.), and neuroapoptosis of hippocampal astrocytes was analyzed by immunofluorescence and scanning electron microscopy. The differential expression of rno-miR-665, BCL2L1 (Bcl-xl), and cleaved caspase 3 (CC3) was surveyed by qRT-PCR and western blotting. In addition, the utility of A-1155463, a highly potent and BCL2L1-selective antagonist, was aimed to assess the contribution of BCL2L1 for neuroglial survival. Following the intraventricular injection of lentivirus rno-miR-665, neuroprotection was detected by 5-point scale measurement. The single dose of propofol 30 mg/kg triggered dose-dependent apoptosis of developing hippocampal astrocytes. Meanwhile, propofol triggered both rno-miR-665 and CC3, and depressed BCL2L1, which was predicted as one target gene of rno-miR-665. Combination treatment with A-1155463 and propofol induced lower mRNA and protein levels of BCL2L1 and more CC3 activation than propofol treatment alone in vivo. The lentivirus-mediated knockdown of rno-miR-665 elevated BCL2L1 and attenuated CC3 levels, whereas up-regulation of rno-miR-665 suppressed BCL2L1 and induced CC3 expression in vivo. More importantly, rno-miR-665 antagomir infusion improved neurological outcomes of pups receiving propofol during the brain growth spurt. Rno-miR-665, providing a potential target for alternative therapeutics for pediatric anesthesia, is susceptible to propofol by negatively targeting antiapoptotic BCL2L1. Relatively little is known about the association between exposure of astrocytes to brief propofol

  14. Reversing multidrug resistance in Caco-2 by silencing MDR1, MRP1, MRP2, and BCL-2/BCL-xL using liposomal antisense oligonucleotides.

    Directory of Open Access Journals (Sweden)

    Yu-Li Lo

    Full Text Available Multidrug resistance (MDR is a major impediment to chemotherapy. In the present study, we designed antisense oligonucleotides (ASOs against MDR1, MDR-associated protein (MRP1, MRP2, and/or BCL-2/BCL-xL to reverse MDR transporters and induce apoptosis, respectively. The cationic liposomes (100 nm composed of N-[1-(2,3-dioleyloxypropyl]-n,n,n-trimethylammonium chloride and dioleoyl phosphotidylethanolamine core surrounded by a polyethylene glycol (PEG shell were prepared to carry ASOs and/or epirubicin, an antineoplastic agent. We aimed to simultaneously suppress efflux pumps, provoke apoptosis, and enhance the chemosensitivity of human colon adenocarcinoma Caco-2 cells to epirubicin. We evaluated encapsulation efficiency, particle size, cytotoxicity, intracellular accumulation, mRNA levels, cell cycle distribution, and caspase activity of these formulations. We found that PEGylated liposomal ASOs significantly reduced Caco-2 cell viability and thus intensified epirubicin-mediated apoptosis. These formulations also decreased the MDR1 promoter activity levels and enhanced the intracellular retention of epirubicin in Caco-2 cells. Epirubicin and ASOs in PEGylated liposomes remarkably decreased mRNA expression levels of human MDR1, MRP1, MRP2, and BCL-2. The combined treatments all significantly increased the mRNA expressions of p53 and BAX, and activity levels of caspase-3, -8, and -9. The formulation of epirubicin and ASOs targeting both pump resistance of MDR1, MRP1, and MRP2 and nonpump resistance of BCL-2/BCL-xL demonstrated more superior effect to all the other formulations used in this study. Our results provide a novel insight into the mechanisms by which PEGylated liposomal ASOs against both resistance types act as activators to epirubicin-induced apoptosis through suppressing MDR1, MRP1, and MRP2, as well as triggering intrinsic mitochondrial and extrinsic death receptor pathways. The complicated regulation of MDR highlights the necessity

  15. Discovery and molecular characterization of a Bcl-2–regulated cell death pathway in schistosomes

    OpenAIRE

    Lee, Erinna F.; Clarke, Oliver B.; Evangelista, Marco; Feng, Zhiping; Speed, Terence P.; Tchoubrieva, Elissaveta B.; Strasser, Andreas; Kalinna, Bernd H.; Colman, Peter M.; Fairlie, W. Douglas

    2011-01-01

    Schistosomiasis is an infectious disease caused by parasites of the phylum platyhelminthe. Here, we describe the identification and characterization of a Bcl-2–regulated apoptosis pathway in Schistosoma japonicum and S. mansoni. Genomic, biochemical, and cell-based mechanistic studies provide evidence for a tripartite pathway, similar to that in humans including BH3-only proteins that are inhibited by prosurvival Bcl-2–like molecules, and Bax/Bak-like proteins that facilitate mitochondrial ou...

  16. Real world data on young patients with high-risk diffuse large B-cell lymphoma treated with R-CHOP or R-CHOEP - MYC, BCL2 and BCL6 as prognostic biomarkers

    DEFF Research Database (Denmark)

    Pedersen, Mette Ølgod; Gang, Anne Ortved; Brown, Peter

    2017-01-01

    BACKGROUND: Double expression of MYC and BCL2 proteins (DE) and double-hit MYC+BCL2/BCL6 translocations (DH) were established as important biomarkers in patients with diffuse large B-cell lymphoma (DLBCL) by the 2016 revision of the World Health Organization classification of lymphoid neoplasms...... in situ hybridization (FISH). RESULTS: DE with MYC>75% and BCL2>85% was an independent negative prognostic marker of progression free survival (PFS) in patients treated with R-CHOP but not R-CHOEP (peffect of DE for response (PFS) to R...

  17. Evaluation of chemical composition, antioxidant, antibacterial, cytotoxic and apoptotic effects of Aloysia citrodora extract on colon cancer cell line

    Directory of Open Access Journals (Sweden)

    Amir Mirzaie

    2016-06-01

    Full Text Available Background: Aloysia citrodora belongs to the Verbenaceae family of plants, a well-known herbal medicine in Iran. The aim of the present study was to investigate the chemical composition, antioxidant, antibacterial, cytotoxic and apoptotic effect of A. citrodora extract against human colon cancer (HT29 cells by using real-time polymerase chain reaction and flow-cytometry methods. Methods: This experimental study was carried out in Islamic Azad University, East Tehran Branch, from March to September of 2014. At first, the A. citrodora chemical constituents were analyzed by gas chromatography-mass spectrometry (GC-MS technique. In addition, antioxidant assay, antibacterial and anti-cancer effect was performed using 1,1-diphenyl-2-picrylhydrazyl (DPPH, disk diffusion and 3-(4,5-dimethylthiazol-2-yl-2,5-diphenyltetrazolium bromide (MTT methods, respectively. The half maximal inhibitory concentration (IC50 value was calculated. We extracted total RNA molecules by using RNX solution, after which cDNA was synthesized. Finally, the pro-apoptotic (Bax and anti-apoptotic (Bcl2 gene expression was performed by real-time polymerase chain reaction and apoptotic effects were analyzed using Flow-cytometry method. Results: GC-MS analysis of Aloysia citrodora extract was shown 37 major components and the most frequent component was belonged to Spathulenol (17.57% and Caryophyllene oxide (15.15% The antioxidant activity of the extract was IC50= 0.6±0.03 mg/ml. The maximum and minimum antibacterial effects of extract were belonged to gram-negative and gram-positive bacteria, respectively. Cytotoxic results revealed that the A.citrodora extract have IC50= 20.1±0.78 mg/ml against colon cancer (HT29 cell line and real-time polymerase chain reaction results showed the expression level of Bax and Bcl2 was increased and decreased respectively in colon cancer cell line (3.470±0.72 (P< 0.05, 0.43±0.35 (P< 0.05. In addition, the flow-cytometry results indicated the 38

  18. Mcl-1 Ubiquitination: Unique Regulation of an Essential Survival Protein

    Directory of Open Access Journals (Sweden)

    Barbara Mojsa

    2014-05-01

    Full Text Available Mcl-1 is an anti-apoptotic protein of the Bcl-2 family that is essential for the survival of multiple cell lineages and that is highly amplified in human cancer. Under physiological conditions, Mcl-1 expression is tightly regulated at multiple levels, involving transcriptional, post-transcriptional and post-translational processes. Ubiquitination of Mcl-1, that targets it for proteasomal degradation, allows for rapid elimination of the protein and triggering of cell death, in response to various cellular events. In the last decade, a number of studies have elucidated different pathways controlling Mcl-1 ubiquitination and degradation. Four different E3 ubiquitin-ligases (e.g., Mule, SCFβ-TrCP, SCFFbw7 and Trim17 and one deubiquitinase (e.g., USP9X, that respectively mediate and oppose Mcl-1 ubiquitination, have been formerly identified. The interaction between Mule and Mcl-1 can be modulated by other Bcl-2 family proteins, while recognition of Mcl-1 by the other E3 ubiquitin-ligases and deubiquitinase is influenced by phosphorylation of specific residues in Mcl-1. The protein kinases and E3 ubiquitin-ligases that are involved in the regulation of Mcl-1 stability vary depending on the cellular context, highlighting the complexity and pivotal role of Mcl-1 regulation. In this review, we attempt to recapitulate progress in understanding Mcl-1 regulation by the ubiquitin-proteasome system.

  19. The Apoptotic Effect of Ursolic Acid on SK-Hep-1 Cells is Regulated by the PI3K/Akt, p38 and JNK MAPK Signaling Pathways

    Directory of Open Access Journals (Sweden)

    Wan-Ling Chuang

    2016-04-01

    Full Text Available Ursolic acid (UA is a pentacyclic triterpene acid that is present in a wide variety of medicinal herbs and edible plants. This study investigated the effect of UA on apoptosis and proliferation of hepatocellular carcinoma SK-Hep-1 cells. After treatment of SK-Hep-1 cells with different concentrations of UA, we observed that cell viability was reduced in a dose- and time-dependent manner. Furthermore, there was a dose-dependent increase in the percentage of cells in the sub-G1 and G2/M phases, with cells treated with 60 μM showing the highest percentages of cells in those phases. UA-induced chromatin condensation of nuclei was observed by using DAPI staining. The western blot results revealed that exposure to UA was associated with decreased expression of the anti-apoptotic proteins Mcl-1, Bcl-xL, Bcl-2, and TCTP and increased expression of apoptosis-related proteins TNF-α, Fas, FADD, Bax, cleaved caspase-3, caspase-8, caspase-9, and PARP. Immunocytochemistry staining showed that treatment with UA resulted in increased expression of caspase-3. Moreover, exposure to UA resulted in the inhibition of the PI3K/Akt and p38 MAPK signaling pathways. These findings suggest that UA inhibits the proliferation of SK-Hep-1 cells and induces apoptosis.

  20. VDAC1: from structure to cancer therapy

    International Nuclear Information System (INIS)

    Shoshan-Barmatz, Varda; Mizrachi, Dario

    2012-01-01

    Here, we review current evidence pointing to the function of VDAC1 in cell life and death, and highlight these functions in relation to cancer. Found at the outer mitochondrial membrane, VDAC1 assumes a crucial position in the cell, controlling the metabolic cross-talk between mitochondria and the rest of the cell. Moreover, its location at the boundary between the mitochondria and the cytosol enables VDAC1 to interact with proteins that mediate and regulate the integration of mitochondrial functions with other cellular activities. As a metabolite transporter, VDAC1 contributes to the metabolic phenotype of cancer cells. This is reflected by VDAC1 over-expression in many cancer types, and by inhibition of tumor development upon silencing VDAC1 expression. Along with regulating cellular energy production and metabolism, VDAC1 is also a key protein in mitochondria-mediated apoptosis, participating in the release of apoptotic proteins and interacting with anti-apoptotic proteins. The involvement of VDAC1 in the release of apoptotic proteins located in the inter-membranal space is discussed, as is VDAC1 oligomerization as an important step in apoptosis induction. VDAC also serves as an anchor point for mitochondria-interacting proteins, some of which are also highly expressed in many cancers, such as hexokinase (HK), Bcl2, and Bcl-xL. By binding to VDAC, HK provides both metabolic benefit and apoptosis-suppressive capacity that offers the cell a proliferative advantage and increases its resistance to chemotherapy. VDAC1-based peptides that bind specifically to HK, Bcl2, or Bcl-xL abolished the cell’s abilities to bypass the apoptotic pathway. Moreover, these peptides promote cell death in a panel of genetically characterized cell lines derived from different human cancers. These and other functions point to VDAC1 as a rational target for the development of a new generation of therapeutics.

  1. Crosstalk between apoptosis and autophagy within the Beclin 1 interactome.

    Science.gov (United States)

    Maiuri, Maria Chiara; Criollo, Alfredo; Kroemer, Guido

    2010-02-03

    Although the essential genes for autophagy (Atg) have been identified, the molecular mechanisms through which Atg proteins control 'self eating' in mammalian cells remain elusive. Beclin 1 (Bec1), the mammalian orthologue of yeast Atg6, is part of the class III phosphatidylinositol 3-kinase (PI3K) complex that induces autophagy. The first among an increasing number of Bec1-interacting proteins that has been identified is the anti-apoptotic protein Bcl-2. The dissociation of Bec1 from Bcl-2 is essential for its autophagic activity, and Bcl-2 only inhibits autophagy when it is present in the endoplasmic reticulum (ER). A paper in this issue of the EMBO Journal has identified a novel protein, NAF-1 (nutrient-deprivation autophagy factor-1), that binds Bcl-2 at the ER. NAF-1 is a component of the inositol-1,4,5 trisphosphate (IP3) receptor complex, which contributes to the interaction of Bcl-2 with Bec1 and is required for Bcl-2 to functionally antagonize Bec1-mediated autophagy. This work provides mechanistic insights into how autophagy- and apoptosis-regulatory molecules crosstalk at the ER.

  2. Alternation of apoptotic and implanting genes expression of mouse embryos after re-vitrification

    Science.gov (United States)

    Majidi Gharenaz, Nasrin; Movahedin, Mansoureh; Mazaheri, Zohreh; Pour beiranvand, Shahram

    2016-01-01

    Background: Nowadays, oocytes and embryos vitrification has become a routine technique. Based on clinical judgment, re-vitrification maybe required. But little is known about re-vitrification impact on genes expression. Objective: The impact of re-vitrification on apoptotic and implanting genes, Bax, Bcl-2 and ErbB4, at compaction stage embryos were evaluated in this study. Materials and Methods: In this experimental study, 8 cell embryos (n=240) were collected from female mature mice, 60-62 hr post HCG injection. The embryos were divided randomly to 3 groups included: fresh (n=80), vitrified at 8 cell stage (n=80), vitrified at 8 cell stage thawed and re-vitrified at compaction stage (n=80). Embryos were vitrified by using cryolock, (open system) described by Kuwayama. Q-PCR was used to examine the expression of Bax, Bcl2 ErbB4 genes in derived blastocysts. Results: Our result showed that expanded blastocyst rate was similar between vitrified and re-vitrified groups, while re-vitrified embryos showed significant decrease in expanded blastocyst rate comparing with fresh embryos (p=0.03). In addition, significant difference was observed on apoptotic gene expression when comparing re-vitrified and fresh embryos (p=0.004), however expression of Bax and Bcl-2 (apoptotic) genes didn't demonstrate a significant difference between re-vitrified and vitrified groups. The expression rate of ErbB4, an implantation gene was decreased in re-vitrified embryos comparing with fresh embryos (p=0.003), but it was similar between re-vitrified and vitrified embryos. Conclusion: Re-vitrification can alter the expression of Bax, Bcl-2 and ErbB4 genes and developmental rate of mouse embryos in compaction stage. PMID:27679826

  3. The catechin flavonoid reduces proliferation and induces apoptosis of murine lymphoma cells LB02 through modulation of antiapoptotic proteins

    Directory of Open Access Journals (Sweden)

    Daniela Laura Papademetrio

    2013-06-01

    Full Text Available Flavonoids are products of secondary metabolism of plants. They are present in herbs and trees and also act as natural chemopreventives and anticancer agents. Ligaria cuneifolia (Ruiz & Pav. Tiegh., Loranthaceae, is a hemiparasite species that belongs to Argentine flora. Phytochemical studies have disclosed the presence of quercetin, catechin-4β-ol and pro-anthocyanidine as polyphenolic compounds in the active extracts. We previously demonstrated that ethyl acetate extract was capable of reducing cell proliferation and inducing apoptotic death of lymphoid tumor cells. The aim of the current study is to determine whether or not catechin, isolated from L. cuneifolia extracts can induce leukemia cell death and to determine its effect on the cytoplasmatic proteins that modulate cell survival. Our results show that catechin can reduce proliferation of murine lymphoma cell line LB02. The effect is mediated by apoptosis at concentrations upper to 100 µg/mL. Cell death is related to the loss of mitochondrial membrane potential (ΔΨm and a down regulation of survivin and Bcl-2 together with the increase of pro-apoptotic protein Bax. In summary, the current study indicates that catechin present in the extract of L. cuneifolia is in part, responsible for the anti-proliferative activity of whole extracts by induction of ΔΨm disruption and modulation of the anti-apoptotic proteins over expressed in tumor cells. These results give new findings into the potential anticancer and chemopreventive activities of L. cuneifolia.

  4. The catechin flavonoid reduces proliferation and induces apoptosis of murine lymphoma cells LB02 through modulation of antiapoptotic proteins

    Directory of Open Access Journals (Sweden)

    Daniela Laura Papademetrio

    2013-03-01

    Full Text Available Flavonoids are products of secondary metabolism of plants. They are present in herbs and trees and also act as natural chemopreventives and anticancer agents. Ligaria cuneifolia (Ruiz & Pav. Tiegh., Loranthaceae, is a hemiparasite species that belongs to Argentine flora. Phytochemical studies have disclosed the presence of quercetin, catechin-4β-ol and pro-anthocyanidine as polyphenolic compounds in the active extracts. We previously demonstrated that ethyl acetate extract was capable of reducing cell proliferation and inducing apoptotic death of lymphoid tumor cells. The aim of the current study is to determine whether or not catechin, isolated from L. cuneifolia extracts can induce leukemia cell death and to determine its effect on the cytoplasmatic proteins that modulate cell survival. Our results show that catechin can reduce proliferation of murine lymphoma cell line LB02. The effect is mediated by apoptosis at concentrations upper to 100 µg/mL. Cell death is related to the loss of mitochondrial membrane potential (ΔΨm and a down regulation of survivin and Bcl-2 together with the increase of pro-apoptotic protein Bax. In summary, the current study indicates that catechin present in the extract of L. cuneifolia is in part, responsible for the anti-proliferative activity of whole extracts by induction of ΔΨm disruption and modulation of the anti-apoptotic proteins over expressed in tumor cells. These results give new findings into the potential anticancer and chemopreventive activities of L. cuneifolia.

  5. In Vitro Proliferation and Anti-Apoptosis of the Papain-Generated Casein and Soy Protein Hydrolysates towards Osteoblastic Cells (hFOB1.19).

    Science.gov (United States)

    Pan, Xiao-Wen; Zhao, Xin-Huai

    2015-06-17

    Casein and soy protein were digested by papain to three degrees of hydrolysis (DH) 7.3%-13.3%, to obtain respective six casein and soy protein hydrolysates, aiming to clarify their in vitro proliferation and anti-apoptosis towards a human osteoblastic cell line (hFOB1.19 cells). Six casein and soy protein hydrolysates at five levels (0.01-0.2 mg/mL) mostly showed proliferation as positive 17β-estradiol did, because they conferred the osteoblasts with cell viability of 100%-114% and 104%-123%, respectively. The hydrolysates of higher DH values had stronger proliferation. Casein and soy protein hydrolysates of the highest DH values altered cell cycle progression, and enhanced cell proportion of S-phase from 50.5% to 56.5% and 60.5%. The two also antagonized etoposide- and NaF-induced osteoblast apoptosis. In apoptotic prevention, apoptotic cells were decreased from 31.6% to 22.6% and 15.6% (etoposide treatment), or from 19.5% to 17.7% and 12.4% (NaF treatment), respectively. In apoptotic reversal, soy protein hydrolysate decreased apoptotic cells from 13.3% to 11.7% (etoposide treatment), or from 14.5% to 11.0% (NaF treatment), but casein hydrolysate showed no reversal effect. It is concluded that the hydrolysates of two kinds had estradiol-like action on the osteoblasts, and soy protein hydrolysates had stronger proliferation and anti-apoptosis on the osteoblasts than casein hydrolysates.

  6. Effect of hrHPV infection on anti-apoptotic gene and pro-apoptotic gene expression in cervical cancer tissue

    Directory of Open Access Journals (Sweden)

    Min-Er Tang

    2016-09-01

    Full Text Available Objective: To study the effect of hrHPV infection on anti-apoptotic gene and pro-apoptotic gene expression in cervical cancer tissue. Methods: A total of 56 patients with cervical cancer, 94 cases of patients with cervical intraepithelial neoplasia and 48 cases of patients with chronic cervicitis who were treated in our hospital from May 2013 to December 2015 were selected for study and included in malignant group, precancerous lesion group and benign group respectively. hrHPV infection as well as the expression of anti-apoptotic genes and proapoptotic genes in cervical tissue were detected. Results: hrHPV infection rate and viral load in cervical tissue of malignant group were significantly higher than those of precancerous lesion group and benign group; P27 and p16 levels in cervical tissue of malignant group were significantly lower than those of precancerous lesion group and benign group, and K-ras, c-myc, Prdx4 and TNFAIP8 levels were significantly higher than those of precancerous lesion group and benign group; the greater the HPV virus load, the lower the p27 and p16 levels and the higher the K-ras, c-myc, Prdx4 and TNFAIP8 levels in cervical tissue. Conclusions: hrHPV infection can result in tumor suppressor genes p27 and p16 expression deletion and increase the expression of proto-oncogene and apoptosis-inhibiting genes, and it is associated with the occurrence and development of cervical cancer.

  7. Phospholipase D1 increases Bcl-2 expression during neuronal differentiation of rat neural stem cells.

    Science.gov (United States)

    Park, Shin-Young; Ma, Weina; Yoon, Sung Nyo; Kang, Min Jeong; Han, Joong-Soo

    2015-01-01

    We studied the possible role of phospholipase D1 (PLD1) in the neuronal differentiation, including neurite formation of neural stem cells. PLD1 protein and PLD activity increased during neuronal differentiation. Bcl-2 also increased. Downregulation of PLD1 by transfection with PLD1 siRNA or a dominant-negative form of PLD1 (DN-PLD1) inhibited both neurite outgrowth and Bcl-2 expression. PLD activity was dramatically reduced by a PLCγ (phospholipase Cγ) inhibitor (U73122), a Ca(2+)chelator (BAPTA-AM), and a PKCα (protein kinase Cα) inhibitor (RO320432). Furthermore, treatment with arachidonic acid (AA) which is generated by the action of PLA2 (phospholipase A2) on phosphatidic acid (a PLD1 product), increased the phosphorylation of p38 MAPK and CREB, as well as Bcl-2 expression, indicating that PLA2 is involved in the differentiation process resulting from PLD1 activation. PGE2 (prostaglandin E2), a cyclooxygenase product of AA, also increased during neuronal differentiation. Moreover, treatment with PGE2 increased the phosphorylation of p38 MAPK and CREB, as well as Bcl-2 expression, and this effect was inhibited by a PKA inhibitor (Rp-cAMP). As expected, inhibition of p38 MAPK resulted in loss of CREB activity, and when CREB activity was blocked with CREB siRNA, Bcl-2 production also decreased. We also showed that the EP4 receptor was required for the PKA/p38MAPK/CREB/Bcl-2 pathway. Taken together, these observations indicate that PLD1 is activated by PLCγ/PKCα signaling and stimulate Bcl-2 expression through PLA2/Cox2/EP4/PKA/p38MAPK/CREB during neuronal differentiation of rat neural stem cells.

  8. Upregulation of ER signaling as an adaptive mechanism of cell survival in HER2-positive breast tumors treated with anti-HER2 therapy

    Science.gov (United States)

    Giuliano, Mario; Hu, Huizhong; Wang, Yen-Chao; Fu, Xiaoyong; Nardone, Agostina; Herrera, Sabrina; Mao, Sufeng; Contreras, Alejandro; Gutierrez, Carolina; Wang, Tao; Hilsenbeck, Susan G.; De Angelis, Carmine; Wang, Nicholas J.; Heiser, Laura M.; Gray, Joe W.; Lopez-Tarruella, Sara; Pavlick, Anne C.; Trivedi, Meghana V.; Chamness, Gary C.; Chang, Jenny C.; Osborne, C. Kent; Rimawi, Mothaffar F.; Schiff, Rachel

    2015-01-01

    Purpose To investigate the direct effect and therapeutic consequences of epidermal growth factor receptor 2 (HER2)-targeting therapy on expression of estrogen receptor (ER) and Bcl2 in preclinical models and clinical tumor samples. Experimental design Archived xenograft tumors from two preclinical models (UACC812 and MCF7/HER2-18) treated with ER and HER2-targeting therapies, and also HER2+ clinical breast cancer specimens collected in a lapatinib neoadjuvant trial (baseline and week 2 post treatment), were used. Expression levels of ER and Bcl2 were evaluated by immunohistochemistry and western blot. The effects of Bcl2 and ER inhibition, by ABT-737 and fulvestrant respectively, were tested in parental versus lapatinib-resistant UACC812 cells in vitro. Results Expression of ER and Bcl2 was significantly increased in xenograft tumors with acquired resistance to anti-HER2 therapy, compared with untreated tumors, in both preclinical models (UACC812: ER p=0.0014; Bcl2 p<0.001. MCF7/HER2-18: ER p=0.0007; Bcl2 p=0.0306). In the neoadjuvant clinical study, lapatinib treatment for two weeks was associated with parallel upregulation of ER and Bcl2 (Spearman’s coefficient: 0.70; p=0.0002). Importantly, 18% of tumors originally ER-negative (ER−) converted to ER+ upon anti-HER2 therapy. In ER−/HER2+ MCF7/HER2-18 xenografts, ER re-expression was primarily observed in tumors responding to potent combination of anti-HER2 drugs. Estrogen deprivation added to this anti-HER2 regimen significantly delayed tumor progression (p=0.018). In the UACC812 cells, fulvestrant, but not ABT-737, was able to completely inhibit anti-HER2-resistant growth (p<0.0001). Conclusion HER2 inhibition can enhance or restore ER expression with parallel Bcl2 upregulation, representing an ER-dependent survival mechanism potentially leading to anti-HER2 resistance. PMID:26015514

  9. Combined Targeting of JAK2 and Bcl-2/Bcl-xL to Cure Mutant JAK2-Driven Malignancies and Overcome Acquired Resistance to JAK2 Inhibitors

    Directory of Open Access Journals (Sweden)

    Michaela Waibel

    2013-11-01

    Full Text Available To design rational therapies for JAK2-driven hematological malignancies, we functionally dissected the key survival pathways downstream of hyperactive JAK2. In tumors driven by mutant JAK2, Stat1, Stat3, Stat5, and the Pi3k and Mek/Erk pathways were constitutively active, and gene expression profiling of TEL-JAK2 T-ALL cells revealed the upregulation of prosurvival Bcl-2 family genes. Combining the Bcl-2/Bcl-xL inhibitor ABT-737 with JAK2 inhibitors mediated prolonged disease regressions and cures in mice bearing primary human and mouse JAK2 mutant tumors. Moreover, combined targeting of JAK2 and Bcl-2/Bcl-xL was able to circumvent and overcome acquired resistance to single-agent JAK2 inhibitor treatment. Thus, inhibiting the oncogenic JAK2 signaling network at two nodal points, at the initiating stage (JAK2 and the effector stage (Bcl-2/Bcl-xL, is highly effective and provides a clearly superior therapeutic benefit than targeting just one node. Therefore, we have defined a potentially curative treatment for hematological malignancies expressing constitutively active JAK2.

  10. miR-24-2 controls H2AFX expression regardless of gene copy number alteration and induces apoptosis by targeting antiapoptotic gene BCL-2: a potential for therapeutic intervention.

    Science.gov (United States)

    Srivastava, Niloo; Manvati, Siddharth; Srivastava, Archita; Pal, Ranjana; Kalaiarasan, Ponnusamy; Chattopadhyay, Shilpi; Gochhait, Sailesh; Dua, Raina; Bamezai, Rameshwar N K

    2011-04-04

    New levels of gene regulation with microRNA (miR) and gene copy number alterations (CNAs) have been identified as playing a role in various cancers. We have previously reported that sporadic breast cancer tissues exhibit significant alteration in H2AX gene copy number. However, how CNA affects gene expression and what is the role of miR, miR-24-2, known to regulate H2AX expression, in the background of the change in copy number, are not known. Further, many miRs, including miR-24-2, are implicated as playing a role in cell proliferation and apoptosis, but their specific target genes and the pathways contributing to them remain unexplored. Changes in gene copy number and mRNA/miR expression were estimated using real-time polymerase chain reaction assays in two mammalian cell lines, MCF-7 and HeLa, and in a set of sporadic breast cancer tissues. In silico analysis was performed to find the putative target for miR-24-2. MCF-7 cells were transfected with precursor miR-24-2 oligonucleotides, and the gene expression levels of BRCA1, BRCA2, ATM, MDM2, TP53, CHEK2, CYT-C, BCL-2, H2AFX and P21 were examined using TaqMan gene expression assays. Apoptosis was measured by flow cytometric detection using annexin V dye. A luciferase assay was performed to confirm BCL-2 as a valid cellular target of miR-24-2. It was observed that H2AX gene expression was negatively correlated with miR-24-2 expression and not in accordance with the gene copy number status, both in cell lines and in sporadic breast tumor tissues. Further, the cells overexpressing miR-24-2 were observed to be hypersensitive to DNA damaging drugs, undergoing apoptotic cell death, suggesting the potentiating effect of mir-24-2-mediated apoptotic induction in human cancer cell lines treated with anticancer drugs. BCL-2 was identified as a novel cellular target of miR-24-2. mir-24-2 is capable of inducing apoptosis by modulating different apoptotic pathways and targeting BCL-2, an antiapoptotic gene. The study suggests

  11. Anti-inflammatory drugs suppress proliferation and induce apoptosis through altering expressions of cell cycle regulators and pro-apoptotic factors in cultured human osteoblasts

    International Nuclear Information System (INIS)

    Chang, J.-K.; Li, C.-J.; Liao, H.-J.; Wang, C.-K.; Wang, G.-J.; Ho, M.-L.

    2009-01-01

    It has been reported that anti-inflammatory drugs (AIDs) inhibited bone repair in animal studies, and suppressed proliferation and induced cell death in rat osteoblast cultures. In this study, we further investigated the molecular mechanisms of AID effects on proliferation and cell death in human osteoblasts (hOBs). We examined the effects of dexamethasone (10 -7 and 10 -6 M), non-selective non-steroidal anti-inflammatory drugs (NSAIDs): indomethacin, ketorolac, piroxicam and diclofenac (10 -5 and 10 -4 M), and COX-2 inhibitor: celecoxib (10 -6 and 10 -5 M) on proliferation, cytotoxicity, cell death, and mRNA and protein levels of cell cycle and apoptosis-related regulators in hOBs. All the tested AIDs significantly inhibited proliferation and arrested cell cycle at G0/G1 phase in hOBs. Celecoxib and dexamethasone, but not non-selective NSAIDs, were found to have cytotoxic effects on hOB, and further demonstrated to induce apoptosis and necrosis (at higher concentration) in hOBs. We further found that indomethacin, celecoxib and dexamethasone increased the mRNA and protein expressions of p27 kip1 and decreased those of cyclin D2 and p-cdk2 in hOBs. Bak expression was increased by celecoxib and dexamethasone, while Bcl-XL level was declined only by dexamethasone. Furthermore, the replenishment of PGE1, PGE2 or PGF2α did not reverse the effects of AIDs on proliferation and expressions of p27 kip1 and cyclin D2 in hOBs. We conclude that the changes in expressions of regulators of cell cycle (p27 kip1 and cyclin D2) and/or apoptosis (Bak and Bcl-XL) by AIDs may contribute to AIDs caused proliferation suppression and apoptosis in hOBs. This effect might not relate to the blockage of prostaglandin synthesis by AIDs

  12. Activation of mitochondrial promoter PH-binding protein in a radio-resistant Chinese hamster cell strain associated with Bcl-2

    International Nuclear Information System (INIS)

    Roychoudhury, Paromita; Ghosh, Utpal; Bhattacharyya, Nitai P.; Chaudhuri, Keya

    2006-01-01

    The cellular response to ionizing radiation is mediated by a complex interaction of number of proteins involving different pathways. Previously, we have shown that up regulation of mitochondrial genes ND1, ND4, and COX1 transcribed from the heavy strand promoter (P H ) has been increased in a radio-resistant cell strain designated as M5 in comparison with the parental Chinese hamster V79 cells. These genes are also up regulated in Chinese hamster V79 cells VB13 that express exogenous human Bcl2. In the present study, the expression of the gene ND6 that is expressed from the light strand promoter (P L ) was found to be similar in both the cell lines, as determined by RT-PCR. To test the possibility that this differential expression of mitochondrial genes under these two promoters was mediated by differences in proteins' affinity to interact with these promoters, we have carried out electrophoretic mobility shift assay (EMSA) using mitochondrial cell extracts from these two cell lines. Our result of these experiments revealed that two different proteins formed complex with the synthetic promoters and higher amount of protein from M5 cell extracts interacted with the P H promoter in comparison to that observed with cell extracts from Chinese hamster V79 cells. The promoter-specific differential binding of proteins was also observed in VB13. These results showed that differential mitochondrial gene expression observed earlier in the radio-resistant M5 cells was due to enhanced interaction proteins with the promoters P H and mediated by the expression of Bcl2

  13. Different apoptotic responses to Plasmodium chabaudi malaria in ...

    African Journals Online (AJOL)

    hope&shola

    2010-11-08

    Nov 8, 2010 ... The purpose of this study is to determine whether the apoptotic responses to Plasmodium chabaudi malaria in spleen and liver via mRNA expression of three genes involved in apoptosis (Bax, Bcl-2 and. Caspase-3) are similar or not and to detect if these genes could be a good marker for apoptosis due to.

  14. Curcumin Anti-Apoptotic Action in a Model of Intestinal Epithelial Inflammatory Damage.

    Science.gov (United States)

    Loganes, Claudia; Lega, Sara; Bramuzzo, Matteo; Vecchi Brumatti, Liza; Piscianz, Elisa; Valencic, Erica; Tommasini, Alberto; Marcuzzi, Annalisa

    2017-06-06

    The purpose of this study is to determine if a preventive treatment with curcumin can protect intestinal epithelial cells from inflammatory damage induced by IFNγ. To achieve this goal we have used a human intestinal epithelial cell line (HT29) treated with IFNγ to undergo apoptotic changes that can reproduce the damage of intestinal epithelia exposed to inflammatory cytokines. In this model, we measured the effect of curcumin (curcuminoid from Curcuma Longa ) added as a pre-treatment at different time intervals before stimulation with IFNγ. Curcumin administration to HT29 culture before the inflammatory stimulus IFNγ reduced the cell apoptosis rate. This effect gradually declined with the reduction of the curcumin pre-incubation time. This anti-apoptotic action by curcumin pre-treatment was paralleled by a reduction of secreted IL7 in the HT29 culture media, while there was no relevant change in the other cytokine levels. Even though curcumin pre-administration did not impact the activation of the NF-κB pathway, a slight effect on the phosphorylation of proteins in this inflammatory signaling pathway was observed. In conclusion, curcumin pre-treatment can protect intestinal cells from inflammatory damage. These results can be the basis for studying the preventive role of curcumin in inflammatory bowel diseases.

  15. miR-326 targets antiapoptotic Bcl-xL and mediates apoptosis in human platelets.

    Directory of Open Access Journals (Sweden)

    Shifang Yu

    Full Text Available Platelets play crucial roles in hemostasis, thrombosis, wound healing, inflammation, angiogenesis, and tumor metastases. Because they are anucleated blood cells, platelets lack nuclear DNA, but they do contain mitochondrial DNA, which plays a key role in regulating apoptosis. Recent evidence has suggested that miRNAs are also involved in regulating gene expression and apoptosis in platelets. Our previous study showed that the expression of miR-326 increased visibly when apheresis platelets were stored in vitro. The antiapoptotic Bcl-2 family regulator Bcl-xL has been identified as a putative target of miR-326. In the present study, dual reporter luciferase assays were used to characterize the function of miR-326 in the regulation of the apoptosis of platelet cells. These assays demonstrated that miR-326 bound to the 3'-translated region of Bcl-xL. To directly assess the functional effects of miR-326 expression, levels of Bcl-xL and the apoptotic status of stored apheresis platelets were measured after transfection of miR-326 mimic or inhibitor. Results indicated that miR-326 inhibited Bcl-xL expression and induced apoptosis in stored platelets. Additionally, miR-326 inhibited Bcl-2 protein expression and enhanced Bak expression, possibly through an indirect mechanism, though there was no effect on the expression of Bax. The effect of miR-326 appeared to be limited to apoptosis, with no significant effect on platelet activation. These results provide new insight into the molecular mechanisms affecting differential platelet gene regulation, which may increase understanding of the role of platelet apoptosis in multiple diseases.

  16. Melatonin may play a role in modulation of bax and bcl-2 expression levels to protect rat peripheral blood lymphocytes from gamma irradiation-induced apoptosis

    International Nuclear Information System (INIS)

    Mohseni, Mehran; Mihandoost, Ehsan; Shirazi, Alireza; Sepehrizadeh, Zargham; Bazzaz, Javad Tavakkoly; Ghazi-khansari, Mahmoud

    2012-01-01

    The close relationship between free radicals effects and apoptosis process has been proved. Melatonin has been reported as a direct free radical scavenger. We investigated the capability of melatonin in the modification of radiation-induced apoptosis and apoptosis-associated upstream regulators expression in rat peripheral blood lymphocytes. Rats were irradiated with a single whole body Cobalt 60-gamma radiation dose of 8 Gy at a dose rate of 101 cGy/min with or without melatonin pretreatments at different concentrations of 10 and 100 mg/kg body weight. The rats were divided into eight groups of control, irradiation-only, vehicle-only, vehicle plus irradiation, 10 mg/kg melatonin alone, 10 mg/kg melatonin plus irradiation, 100 mg/kg melatonin alone and 100 mg/kg melatonin plus irradiation. Rats were given an intraperitoneal (IP) injection of melatonin or the same volume of vehicle alone 1 h prior to irradiation. Blood samples were taken 4, 24, 48 and 72 h after irradiation for evaluation of flow cytometric analysis of apoptotic lymphocytes using Annexin V/PI assay and measurement of bax and bcl-2 expression using quantitative real-time PCR (RT 2 qPCR). Irradiation-only and vehicle plus irradiation showed an increase in the percentage of apoptotic lymphocytes significantly different from control group (P < 0.01), while melatonin pretreatments in a dose-dependent manner reduced it as compared with the irradiation-only and vehicle plus irradiation groups (P < 0.01) in all time points. This reduced apoptosis by melatonin was related to the downregulation of bax, upregulation of bcl-2, and therefore reduction of bax/bcl-2 ratio. Our results suggest that melatonin in these doses may provide modulation of bax and bcl-2 expression as well as bax/bcl-2 ratio to protect rat peripheral blood lymphocytes from gamma irradiation-induced apoptosis.

  17. Melatonin may play a role in modulation of bax and bcl-2 expression levels to protect rat peripheral blood lymphocytes from gamma irradiation-induced apoptosis

    Energy Technology Data Exchange (ETDEWEB)

    Mohseni, Mehran [Department of Radiology and Medical Physics, Faculty of Paramedicine, Kashan University of Medical Sciences, Kashan (Iran, Islamic Republic of); Mihandoost, Ehsan, E-mail: mihandoost.e@gmail.com [Department of Medical Radiation Engineering, Science and Research Branch, Islamic Azad University, Tehran (Iran, Islamic Republic of); Shirazi, Alireza [Department of Medical Physics and Biomedical Engineering, Faculty of Medicine, Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of); Sepehrizadeh, Zargham [Department of Pharmaceutical Biotechnology, Faculty of Pharmacy, Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of); Bazzaz, Javad Tavakkoly [Department of Medical Genetics, Faculty of Medicine, Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of); Ghazi-khansari, Mahmoud [Department of Pharmacology, Faculty of Medicine, Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of)

    2012-10-15

    The close relationship between free radicals effects and apoptosis process has been proved. Melatonin has been reported as a direct free radical scavenger. We investigated the capability of melatonin in the modification of radiation-induced apoptosis and apoptosis-associated upstream regulators expression in rat peripheral blood lymphocytes. Rats were irradiated with a single whole body Cobalt 60-gamma radiation dose of 8 Gy at a dose rate of 101 cGy/min with or without melatonin pretreatments at different concentrations of 10 and 100 mg/kg body weight. The rats were divided into eight groups of control, irradiation-only, vehicle-only, vehicle plus irradiation, 10 mg/kg melatonin alone, 10 mg/kg melatonin plus irradiation, 100 mg/kg melatonin alone and 100 mg/kg melatonin plus irradiation. Rats were given an intraperitoneal (IP) injection of melatonin or the same volume of vehicle alone 1 h prior to irradiation. Blood samples were taken 4, 24, 48 and 72 h after irradiation for evaluation of flow cytometric analysis of apoptotic lymphocytes using Annexin V/PI assay and measurement of bax and bcl-2 expression using quantitative real-time PCR (RT{sup 2}qPCR). Irradiation-only and vehicle plus irradiation showed an increase in the percentage of apoptotic lymphocytes significantly different from control group (P < 0.01), while melatonin pretreatments in a dose-dependent manner reduced it as compared with the irradiation-only and vehicle plus irradiation groups (P < 0.01) in all time points. This reduced apoptosis by melatonin was related to the downregulation of bax, upregulation of bcl-2, and therefore reduction of bax/bcl-2 ratio. Our results suggest that melatonin in these doses may provide modulation of bax and bcl-2 expression as well as bax/bcl-2 ratio to protect rat peripheral blood lymphocytes from gamma irradiation-induced apoptosis.

  18. Anti-tumor effects of flavonoids from the ethnic medicine Docynia delavayi (Franch.) Schneid. and its possible mechanism.

    Science.gov (United States)

    Deng, Xukun; Zhao, Xiangpei; Lan, Zhou; Jiang, Jie; Yin, Wu; Chen, Lvyi

    2014-07-01

    This study investigated the active components and the anti-tumor efficacy and mechanisms of the flavonoids from Docynia delavayi (Franch.) Schneid. (DDS). MTT assay was used to examine the growth inhibitory effects of the four flavonoids, including chrysin, quercetin, naringenin, and avicularin that were isolated from the rhizome of DDS, on human hematomas cell (HepG2), esophageal carcinoma cell (EC109), human cervical adenocarcinoma cell (Hela), human colon adenocarcinoma cell (SW480), and African green monkey kidney cell (Vero cells). The anti-tumor mechanism of chrysin on HepG2 was further investigated by the methods of fluorescence staining, flow cytometry, and immunoblotting. The results showed that the inhibitory activity of chrysin was much stronger than the other three flavonoids on HepG2, EC109, Hela, and SW480 cells for 48 h treatment in vitro. Moreover, no inhibiting effect of chrysin on the proliferation of normal cells (Vero cells) was observed. Further study revealed that chrysin caused HepG2 cell shrinkage, membrane blebbing, and apoptotic body formation, all of which were typical characteristics of apoptosis programmed cell death. Flow cytometric analysis demonstrated that chrysin increased the sub G0/G1 population, which indicated the increased cell apoptosis, thus preventing cells from entering the S phase as the population in G2/M or S phase declined; whereas in G0/G1 phase, it increased. In addition, immunoblot results showed that chrysin significantly increased the expression levels of caspase-3 and Bax proteins, and it decreased the expression level of B-cell lymphoma/leukemia-2 (Bcl-2) protein. These findings indicate that chrysin is the major flavonoid present in DDS, and it induces HepG2 cell death via apoptosis, probably through the participation of caspase-3, Bax, and Bcl-2 proteins.

  19. Curcumin induces apoptosis and inhibits prostaglandin E(2) production in synovial fibroblasts of patients with rheumatoid arthritis.

    Science.gov (United States)

    Park, Cheol; Moon, Dong-Oh; Choi, Il-Whan; Choi, Byung Tae; Nam, Taek-Jeong; Rhu, Chung-Ho; Kwon, Taeg Kyu; Lee, Won Ho; Kim, Gi-Young; Choi, Yung Hyun

    2007-09-01

    Rheumatoid arthritis (RA) is a chronic inflammatory disease that is characterized by hyperplasia of the synovial fibroblasts, which is partly the result of decreased apoptosis. This study investigated the mechanisms through which curcumin, a polyphenolic compound from the rhizome of Curcuma longa, exerts its anti-proliferative action in the synovial fibroblasts obtained from patients with RA. Exposure of the synovial fibroblasts to curcumin resulted in growth inhibition and the induction of apoptosis, as measured by MTT assay, fluorescent microscopy and Annexin-V-based assay. RT-PCR and immunoblotting showed that treating the cells with curcumin resulted in the down-regulation of anti-apoptotic Bcl-2 and the X-linked inhibitor of the apoptosis protein as well as the up-regulation of pro-apoptotic Bax expression in a concentration-dependent manner. Curcumin-induced apoptosis was also associated with the proteolytic activation of caspase-3 and caspase-9, and the concomitant degradation of poly(ADP-ribose) polymerase protein. Furthermore, curcumin decreased the expression levels of the cyclooxygenase (COX)-2 mRNA and protein without causing significant changes in the COX-1 levels, which was correlated with the inhibition of prostaglandin E(2) synthesis. These results show that curcumin might help identify a new therapeutic pathway against hyperplasia of the synovial fibroblasts in RA.

  20. Bee venom protects SH-SY5Y human neuroblastoma cells from 1-methyl-4-phenylpyridinium-induced apoptotic cell death.

    Science.gov (United States)

    Doo, Ah-Reum; Kim, Seung-Nam; Kim, Seung-Tae; Park, Ji-Yeun; Chung, Sung-Hyun; Choe, Bo-Young; Chae, Younbyoung; Lee, Hyejung; Yin, Chang-Shik; Park, Hi-Joon

    2012-01-06

    Parkinson's disease (PD) is a progressive neurodegenerative disorder characterized by progressive selective loss of dopaminergic neurons in the substantia nigra. Recently, bee venom was reported to protect dopaminergic neurons in the 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine induced mice PD model, however, the underlying mechanism is not fully understood. The objective of the present study is to investigate the neuroprotective mechanism of bee venom against Parkinsonian toxin, 1-methyl-4-phenylpyridine (MPP(+)), in SH-SY5Y human neuroblastoma cells. Our results revealed that bee venom pretreatment (1-100 ng/ml) increased the cell viability and decreased apoptosis assessed by DNA fragmentation and caspase-3 activity assays in MPP(+)-induced cytotoxicity in SH-SY5Y cells. Bee venom increased the anti-apoptotic Bcl-2 expression and decreased the pro-apoptotic Bax, cleaved PARP expressions. In addition, bee venom prevented the MPP(+)-induced suppression of Akt phosphorylation, and the neuroprotective effect of bee venom against MPP(+)-induced cytotoxicity was inhibited by a phosphatidylinositol 3-kinase (PI3K) inhibitor, LY294002. These results suggest that the anti-apoptotic effect of bee venom is mediated by the cell survival signaling, the PI3K/Akt pathway. These results provide new evidence for elucidating the mechanism of neuroprotection of bee venom against PD. Copyright © 2011 Elsevier B.V. All rights reserved.

  1. Combination of Vorinostat and caspase-8 inhibition exhibits high anti-tumoral activity on endometrial cancer cells.

    Science.gov (United States)

    Bergadà, Laura; Sorolla, Annabel; Yeramian, Andree; Eritja, Nuria; Mirantes, Cristina; Matias-Guiu, Xavier; Dolcet, Xavier

    2013-08-01

    Histone deacetylase inhibitors such as Vorinostat display anti-neoplastic activity against a variety of solid tumors. Here, we have investigated the anti-tumoral activity of Vorinostat on endometrial cancer cells. We have found that Vorinostat caused cell growth arrest, loss of clonogenic growth and apoptosis of endometrial cancer cells. Vorinostat-induced the activation of caspase-8 and -9, the initiators caspases of the extrinsic and the intrinsic apoptotic pathways, respectively. Next, we investigated the role of the extrinsic pathway in apoptosis triggered by Vorinostat. We found that Vorinostat caused a dramatic decrease of FLIP mRNA and protein levels. However, overexpression of the long from of FLIP did not block Vorinostat-induced apoptosis. To further investigate the role of extrinsic apoptotic pathway in Vorinostat-induced apoptosis, we performed an shRNA-mediated knock-down of caspase-8. Surprisingly, downregulation of caspase-8 alone caused a marked decrease in clonogenic ability and reduced the growth of endometrial cancer xenografts in vivo, revealing that targeting caspase-8 may be an attractive target for anticancer therapy on endometrial tumors. Furthermore, combination of caspase-8 inhibition and Vorinostat treatment caused an enhancement of apoptotic cell death and a further decrease of clonogenic growth of endometrial cancer cells. More importantly, combination of Vorinostat and caspase-8 inhibition caused a nearly complete inhibition of tumor xenograft growth. Finally, we demonstrate that cell death triggered by Vorinostat alone or in combination with caspase-8 shRNAs was inhibited by the anti-apoptotic protein Bcl-XL. Our results suggest that combinatory therapies using Vorinostat treatment and caspase-8 inhibition can be an effective treatment for endometrial carcinomas. Copyright © 2013 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.

  2. Electroporation increases antitumoral efficacy of the bcl-2 antisense G3139 and chemotherapy in a human melanoma xenograft

    Directory of Open Access Journals (Sweden)

    Baldi Alfonso

    2011-07-01

    Full Text Available Abstract Background Nucleic acids designed to modulate the expression of target proteins remain a promising therapeutic strategy in several diseases, including cancer. However, clinical success is limited by the lack of efficient intracellular delivery. In this study we evaluated whether electroporation could increase the delivery of antisense oligodeoxynucleotides against bcl-2 (G3139 as well as the efficacy of combination chemotherapy in human melanoma xenografts. Methods Melanoma-bearing nude mice were treated i.v. with G3139 and/or cisplatin (DDP followed by the application of trains of electric pulses to tumors. Western blot, immunohistochemistry and real-time PCR were performed to analyze protein and mRNA expression. The effect of electroporation on muscles was determined by histology, while tumor apoptosis and the proliferation index were analyzed by immunohistochemistry. Antisense oligodeoxynucleotides tumor accumulation was measured by FACS and confocal microscopy. Results The G3139/Electroporation combined therapy produced a significant inhibition of tumor growth (TWI, more than 50% accompanied by a marked tumor re-growth delay (TRD, about 20 days. The efficacy of this treatment was due to the higher G3139 uptake in tumor cells which led to a marked down-regulation of bcl-2 protein expression. Moreover, the G3139/EP combination treatment resulted in an enhanced apoptotic index and a decreased proliferation rate of tumors. Finally, an increased tumor response was observed after treatment with the triple combination G3139/DDP/EP, showing a TWI of about 75% and TRD of 30 days. Conclusions These results demonstrate that electroporation is an effective strategy to improve the delivery of antisense oligodeoxynucleotides within tumor cells in vivo and it may be instrumental in optimizing the response of melanoma to chemotherapy. The high response rate observed in this study suggest to apply this strategy for the treatment of melanoma patients.

  3. Ligation of major histocompatibility complex class I antigens (MHC-I) prevents apoptosis induced by Fas or SAPK/JNK activation in T-lymphoma cells

    DEFF Research Database (Denmark)

    Lamberth, K; Claesson, M H

    2001-01-01

    Early apoptosis in Jurkat T-lymphoma cells was induced by agonistic anti-Fas Ab or by anisomycin which activates the stress kinases SAPK/JNK. Apoptosis was inhibited by ligation of major histocompatibility complex class I antigens (MHC-I). MHC-I ligation induced upregulation of the anti-apoptotic......Early apoptosis in Jurkat T-lymphoma cells was induced by agonistic anti-Fas Ab or by anisomycin which activates the stress kinases SAPK/JNK. Apoptosis was inhibited by ligation of major histocompatibility complex class I antigens (MHC-I). MHC-I ligation induced upregulation of the anti......-apoptotic Bcl-2 protein and stabilized the mitochondrial membrane potential (Deltapsim). MHC-I ligation also prevented downregulation of Bcl-2 and destabilization of Deltapsim induced by anti-Fas Ab treatment or anisomycin exposure. Studies on three different Jurkat cell mutants deficient for src p56(lck), ZAP......-70 kinase, or TCR/CD3 gamma-chain showed that the cells undergo apoptosis after Fas ligation. Anisomycin exposure induced apoptosis in the src p56(lck)-deficient cell line but not in the two other mutant cell lines. Simultaneous cross-linking of MHC-I and Fas ligation inhibited apoptosis in the ZAP...

  4. Alternation of apoptotic and implanting genes expression of mouse embryos after re-vitrification

    Directory of Open Access Journals (Sweden)

    Nasrin Majidi Gharenaz

    2016-08-01

    Full Text Available Background: Nowadays, oocytes and embryos vitrification has become a routine technique. Based on clinical judgment, re-vitrification maybe required. But little is known about re-vitrification impact on genes expression. Objective: The impact of re-vitrification on apoptotic and implanting genes, Bax, Bcl-2 and ErbB4, at compaction stage embryos were evaluated in this study. Materials and Methods: In this experimental study, 8 cell embryos (n=240 were collected from female mature mice, 60-62 hr post HCG injection. The embryos were divided randomly to 3 groups included: fresh (n=80, vitrified at 8 cell stage (n=80, vitrified at 8 cell stage thawed and re-vitrified at compaction stage (n=80. Embryos were vitrified by using cryolock, (open system described by Kuwayama. Q-PCR was used to examine the expression of Bax, Bcl2 ErbB4 genes in derived blastocysts. Results: Our result showed that expanded blastocyst rate was similar between vitrified and re-vitrified groups, while re-vitrified embryos showed significant decrease in expanded blastocyst rate comparing with fresh embryos (p=0.03. In addition, significant difference was observed on apoptotic gene expression when comparing re-vitrified and fresh embryos (p=0.004, however expression of Bax and Bcl-2 (apoptotic genes didn't demonstrate a significant difference between re-vitrified and vitrified groups. The expression rate of ErbB4, an implantation gene was decreased in re-vitrified embryos comparing with fresh embryos (p=0.003, but it was similar between re-vitrified and vitrified embryos. Conclusion: Re-vitrification can alter the expression of Bax, Bcl-2 and ErbB4 genes and developmental rate of mouse embryos in compaction stage

  5. Single Nucleotide Polymorphisms in Selected Apoptotic Genes and BPDE-Induced Apoptotic Capacity in Apparently Normal Primary Lymphocytes: A Genotype-Phenotype Correlation Analysis

    International Nuclear Information System (INIS)

    Hu, Z.; Li, Ch.; Chen, K.; Wang, L.E.; Sturgis, E.M.; Spitz, M.R.; Wei, Q.; Sturgis, E.M.

    2008-01-01

    Apoptotic capacity (AC) in primary lymphocytes may be a marker for cancer susceptibility, and functional single nucleotide polymorphisms (SNPs) in genes involved in apoptotic pathways may modulate cellular AC in response to DNA damage. To further examine the correlation between apoptotic genotypes and phenotype, we geno typed 14 published SNPs in 11 apoptosis-related genes (i.e., p53, Bcl-2, BAX, CASP9, DR4, Fas, FasL, CASP8, CASP10, CASP3, and CASP7) and assessed the AC in response to benzo[a]pyrene-7,8-9,10-diol epoxide (BPDE) in cultured primary lymphocytes from 172 cancer-free subjects. We found that among these 14 SNPs, R72P, intron 3 16-bp del/ins, and intron 6 G>A in , −938C>A in Bcl-2, and I522L in CASP10 were significant predictors of the BPDE-induced lymphocytic AC in single-locus analysis. In the combined analysis of the three variants, we found that the individuals with the diplotypes carrying 0-1 copy of the common R-del-G haplotype had higher AC values compared to other genotypes. Although the study size may not have the statistical power to detect the role of other SNPs in AC, our findings suggest that some SNPs in genes involved in the intrinsic apoptotic pathway may modulate lymphocytic AC in response to BPDE exposure in the general population. Larger studies are needed to validate these findings for further studying individual susceptibility to cancer and other apoptosis-related diseases

  6. Activation of the intrinsic-apoptotic pathway in LNCaP prostate cancer cells by genistein- topotecan combination treatments

    Directory of Open Access Journals (Sweden)

    Vanessa Hörmann

    2013-03-01

    Full Text Available ABSTRACTBackground: Prostate cancer is the second most common cancer in American men. The development of alternative preventative and/or treatment options utilizing a combination of phytochemicals and chemotherapeutic drugs could be an attractive alternative compared to conventional carcinoma treatments. Genistein isoflavone is the primary dietary phytochemical found in soy and has demonstrated anti-tumor activities in LNCaP prostate cancer cells. Topotecan Hydrochloride (Hycamtin is an FDA-approved chemotherapy for secondary treatment of lung, ovarian and cervical cancers. The purpose of this study was to detail the potential activation of the intrinsic apoptotic pathway in LNCaP prostate cancer cells through genistein-topotecan combination treatments.Methods: LNCaP cells were cultured in complete RPMI medium in a monolayer (70-80% confluency at 37ºC and 5% CO2. Treatment consisted of single and combination groups of genistein and topotecan for 24 hours. The treated cells were assayed for i growth inhibition through trypan blue exclusion assay and microphotography , ii classification of cellular death through acridine/ ethidium bromide fluorescent staining, and iii activation of the intrinsic apoptotic pathway through Jc-1: mitochondrial membrane potential assay, cytochrome c release and Bcl-2 protein expression.Results: The overall data indicated that genistein-topotecan combination was significantly more efficacious in reducing the prostate carcinoma’s viability compared to the single treatment options. In all treatment groups, cell death occurred primarily through the activation of the intrinsic apoptotic pathway.Conclusion: The combination of topotecan and genistein has the potential to lead to treatment options with equal therapeutic efficiency as traditional chemo- and radiation therapies, but lower cell cytotoxicity and fewer side effects in patients.

  7. Targeting multiple pro-apoptotic signaling pathways with curcumin in prostate cancer cells.

    Directory of Open Access Journals (Sweden)

    Mariela Rivera

    Full Text Available Curcumin, an extract from the turmeric rhizome (Curcuma longa, is known to exhibit anti-inflammatory, antioxidant, chemopreventive and antitumoral activities against aggressive and recurrent cancers. Accumulative data indicate that curcumin may induce cancer cell death. However, the detailed mechanism underlying its pro-apoptotic and anti-cancer effects remains to be elucidated. In the present study, we examined the signaling pathways triggered by curcumin, specifically, the exact molecular mechanisms of curcumin-induced apoptosis in highly metastatic human prostate cancer cells. The effect of curcumin was evaluated using for the first time in prostate cancer, a gel-free shotgun quantitative proteomic analysis coupled with Tandem Mass Tag isobaric labeling-based-signaling networks. Results were confirmed at the gene expression level by qRT-PCR and at the protein expression level by western blot and flow cytometry. Our findings revealed that curcumin induced an Endoplasmic Reticulum stress-mediated apoptosis in PC3. The mechanisms by which curcumin promoted cell death in these cells were associated with cell cycle arrest, increased reactive oxygen species, autophagy and the Unfolded Protein Response. Furthermore, the upregulation of ER stress was measured using key indicators of ER stress: Glucose-Regulated Protein 78, Inositol-Requiring Enzyme 1 alpha, Protein Disulfide isomerase and Calreticulin. Chronic ER stress induction was concomitant with the upregulation of pro-apoptotic markers (caspases 3,9,12 and Poly (ADP-ribose polymerase. The downregulated proteins include anti-apoptotic and anti-tumor markers, supporting their curcumin-induced pro-apoptotic role in prostate cancer cells. Taken together, these data suggest that curcumin may serve as a promising anticancer agent by inducing a chronic ER stress mediated cell death and activation of cell cycle arrest, UPR, autophagy and oxidative stress responses.

  8. Targeting multiple pro-apoptotic signaling pathways with curcumin in prostate cancer cells

    Science.gov (United States)

    Rivera, Mariela; Ramos, Yanilda; Rodríguez-Valentín, Madeline; López-Acevedo, Sheila; Cubano, Luis A.; Zou, Jin; Zhang, Qiang; Wang, Guangdi

    2017-01-01

    Curcumin, an extract from the turmeric rhizome (Curcuma longa), is known to exhibit anti-inflammatory, antioxidant, chemopreventive and antitumoral activities against aggressive and recurrent cancers. Accumulative data indicate that curcumin may induce cancer cell death. However, the detailed mechanism underlying its pro-apoptotic and anti-cancer effects remains to be elucidated. In the present study, we examined the signaling pathways triggered by curcumin, specifically, the exact molecular mechanisms of curcumin-induced apoptosis in highly metastatic human prostate cancer cells. The effect of curcumin was evaluated using for the first time in prostate cancer, a gel-free shotgun quantitative proteomic analysis coupled with Tandem Mass Tag isobaric labeling-based-signaling networks. Results were confirmed at the gene expression level by qRT-PCR and at the protein expression level by western blot and flow cytometry. Our findings revealed that curcumin induced an Endoplasmic Reticulum stress-mediated apoptosis in PC3. The mechanisms by which curcumin promoted cell death in these cells were associated with cell cycle arrest, increased reactive oxygen species, autophagy and the Unfolded Protein Response. Furthermore, the upregulation of ER stress was measured using key indicators of ER stress: Glucose-Regulated Protein 78, Inositol-Requiring Enzyme 1 alpha, Protein Disulfide isomerase and Calreticulin. Chronic ER stress induction was concomitant with the upregulation of pro-apoptotic markers (caspases 3,9,12) and Poly (ADP-ribose) polymerase. The downregulated proteins include anti-apoptotic and anti-tumor markers, supporting their curcumin-induced pro-apoptotic role in prostate cancer cells. Taken together, these data suggest that curcumin may serve as a promising anticancer agent by inducing a chronic ER stress mediated cell death and activation of cell cycle arrest, UPR, autophagy and oxidative stress responses. PMID:28628644

  9. Expression of Bcl-2 in canine osteosarcoma

    Science.gov (United States)

    Piro, F.; Leonardi, L.

    2015-01-01

    Osteosarcoma (OS) is the most common primary malignancy of bone. It is responsible for 80-85% of the primary bone tumors affecting dogs and it is characterized by aggressive and invasive behavior, with a high metastatic potential. Several studies on cancer and related tumorigenesis, show an involvement of the mechanisms of programmed cell death and cell survival. Many signals seem to be involved in the related mechanism of autophagy and in particular, our interest is focused on the expression of a family of Bcl-2 that seems to be involved either in the control of biomolecular mechanisms like autophagy and apoptosis. In this study we investigated the expression of Bcl-2 in different cases of spontaneous canine osteosarcoma and the related preliminary results are described. We found Bcl-2 activity was increased in OS tissue compared to normal bone tissue. These results suggested that Bcl-2 activity may play an important role in the formation of OS and as a diagnostic for neoplastic activity. However, further research is needed to confirm the role of Bcl-2 activity in OS in canines. PMID:26623359

  10. The anti-apoptotic effect of IGF-1 on tissue resident stem cells is mediated via PI3-kinase dependent secreted frizzled related protein 2 (Sfrp2) release

    International Nuclear Information System (INIS)

    Gehmert, Sebastian; Sadat, Sanga; Song Yaohua; Yan Yasheng; Alt, Eckhard

    2008-01-01

    Previous studies suggest that IGF-1 may be used as an adjuvant to stem cell transfer in order to improve cell engraftment in ischemic tissue. In the current study, we investigated the effect of IGF-1 on serum deprivation and hypoxia induced stem cell apoptosis and the possible mechanisms involved. Exposure of adipose tissue derived stem cells (ASCs) to serum deprivation and hypoxia resulted in significant apoptosis in ASC which is partially prevented by IGF-1. IGF-1's anti-apoptotic effect was abolished in ASCs transfected with Sfrp2 siRNA but not by the control siRNA. Using Western blot analysis, we demonstrated that serum deprivation and hypoxia reduced the expression of nuclear β-catenin, which is reversed by IGF-1. IGF-1's effect on β-catenin expression was abolished by the presence of PI3-kinase inhibitor LY294002 or in ASCs transfected with Sfrp2 siRNA. These results suggest that IGF-1, through the release of the Sfrp2, contributes to cell survival by stabilizing β-catenin

  11. Copper excess in liver HepG2 cells interferes with apoptosis and lipid metabolic signaling at the protein level.

    Science.gov (United States)

    Liu, Yu; Yang, Huarong; Song, Zhi; Gu, Shaojuan

    2014-12-01

    Copper is an essential trace element that serves as an important catalytic cofactor for cuproenzymes, carrying out major biological functions in growth and development. Although Wilson's disease (WD) is unquestionably caused by mutations in the ATP7B gene and subsequent copper overload, the precise role of copper in inducing pathological changes remains poorly understood. Our study aimed to explore, in HepG2 cells exposed to copper, the cell viability and apoptotic cells was tested by MTT and Hoechst 33342 stainning respectively, and the signaling pathways involved in oxidative stress response, apoptosis and lipid metabolism were determined by real time RT-PCR and Western blot analysis. The results demonstrate dose- and time-dependent cell viability and apoptosis in HepG2 cells following treatment with 10 μM, 200 μM and 500 μM of copper sulfate for 8 and 24 h. Copper overload significantly induced the expression of HSPA1A (heat shock 70 kDa protein 1A), an oxidative stress-responsive signal gene, and BAG3 (BCL2 associated athanogene3), an anti-apoptotic gene, while expression of HMGCR (3-hydroxy-3-methylglutaryl-CoA reductase), a lipid biosynthesis and lipid metabolism gene, was inhibited. These findings provide new insights into possible mechanisms accounting for the development of liver apoptosis and steatosis in the early stages of Wilson's disease.

  12. Mcl-1 is essential for germinal center formation and B cell memory

    NARCIS (Netherlands)

    Vikstrom, Ingela; Carotta, Sebastian; Lüthje, Katja; Peperzak, Victor; Jost, Philipp J.; Glaser, Stefan; Busslinger, Meinrad; Bouillet, Philippe; Strasser, Andreas; Nutt, Stephen L.; Tarlinton, David M.

    2010-01-01

    Lymphocyte survival during immune responses is controlled by the relative expression of pro- and anti-apoptotic molecules, regulating the magnitude, quality, and duration of the response. We investigated the consequences of deleting genes encoding the anti-apoptotic molecules Mcl1 and Bcl2l1

  13. High expression of BCL-2 predicts favorable outcome in non-small cell lung cancer patients with non squamous histology

    International Nuclear Information System (INIS)

    Anagnostou, Valsamo K; Boffa, Daniel; Gettinger, Scott; Detterbeck, Frank; Homer, Robert J; Dougenis, Dimitrios; Rimm, David L; Syrigos, Konstantinos N; Lowery, Frank J; Zolota, Vassiliki; Tzelepi, Vassiliki; Gopinath, Arun; Liceaga, Camil; Panagopoulos, Nikolaos; Frangia, Konstantina; Tanoue, Lynn

    2010-01-01

    Bcl-2 promotes cell survival by inhibiting adapters needed for the activation and cleavage of caspases thus blocking the proteolytic cascade that ultimately dismantles the cell. Bcl-2 has been investigated as a prognostic factor in non small cell lung cancer (NSCLC) patients with conflicting results. Here, we quantitatively assessed Bcl-2 expression in two large and independent cohorts to investigate the impact of Bcl-2 on survival. AQUA ® , a fluorescent-based method for analysis of in situ protein expression, was used to measure Bcl-2 protein levels and classify tumors by Bcl-2 expression in a cohort of 180 NSCLC patients. An independent cohort of 354 NSCLC patients was used to validate Bcl-2 classification and evaluate outcome. Fifty % and 52% of the cases were classified as high expressers in training and validation cohorts respectively. Squamous cell carcinomas were more likely to be high expressers compared to adenocarcinomas (63% vs. 45%, p = 0.002); Bcl-2 was not associated with other clinical or pathological characteristics. Survival analysis showed that patients with high BCL-2 expression had a longer median survival compared to low expressers (22 vs. 17.5 months, log rank p = 0.014) especially in the subset of non-squamous tumors (25 vs. 13.8 months, log rank p = 0.04). Multivariate analysis revealed an independent lower risk for all patients with Bcl-2 expressing tumors (HR = 0.53, 95% CI 0.37-0.75, p = 0.0003) and for patients with non-squamous tumors (HR = 0.5, 95% CI 0.31-0.81, p = 0.005). Bcl-2 expression defines a subgroup of patients with a favorable outcome and may be useful for prognostic stratification of NSCLC patients

  14. Mycoplasma hyopneumoniae-derived lipid-associated membrane proteins induce inflammation and apoptosis in porcine peripheral blood mononuclear cells in vitro.

    Science.gov (United States)

    Bai, Fangfang; Ni, Bo; Liu, Maojun; Feng, Zhixin; Xiong, Qiyan; Shao, Guoqing

    2015-01-30

    Mycoplasma hyopneumoniae is the causative agent of swine enzootic pneumonia (EP), a disease that causes considerable economic losss in swine industry. Lipid-associated membrane proteins (LAMPs) of mycoplasma play important roles in causing mycoplasma diseases. The present study explores the pathogenic mechanisms of M. hyopneumoniae LAMPs by elucidating their role in modulating the inflammation, apoptosis, and relevant signaling pathways of peripheral blood mononuclear cells (PBMCs) of pig. LAMP treatment inhibited the growth of PBMCs. Up-regulation of cytokines, such as IL-6 and IL-1β, as well as increased production of nitric oxide (NO) and superoxide anion were all detected in the supernatant of LAMPs-treated PBMCs. Furthermore, flow cytometric analysis using dual staining with annexin-V-FITC and propidium iodide (PI) showed that LAMPs of M. hyopneumoniae induced a time-dependent apoptosis in lymphocyts and monocytes from PBMCs, which was blocked by NOS inhibitor or antioxidant. In addition, LAMPs induced the phosphorylation of p38, the ratio of pro-apoptotic Bax protein to anti-apoptotic Bcl-2, activation of caspase-3 and caspase-8, and poly ADP-ribose polymerase (PARP) cleavage in PBMCs. These findings demonstrated that M. hyopneumoniae LAMPs induced the production of proinflammatory cytokines, NO and reactive oxygen species (ROS), and apoptosis of PBMCs in vitro through p38 MAPK and Bax/Bcl-2 signaling pathways, as well as caspase activation. Copyright © 2014 Elsevier B.V. All rights reserved.

  15. Codelivery for Paclitaxel and Bcl-2 Conversion Gene by PHB-PDMAEMA Amphiphilic Cationic Copolymer for Effective Drug Resistant Cancer Therapy.

    Science.gov (United States)

    Wang, Xiaoyuan; Liow, Sing Shy; Wu, Qiaoqiong; Li, Chuang; Owh, Cally; Li, Zibiao; Loh, Xian Jun; Wu, Yun-Long

    2017-11-01

    Antiapoptotic Bcl-2 protein's upregulated expression is a key reason for drug resistance leading to failure of chemotherapy. In this report, a series of biocompatible amphiphilic cationic poly[(R)-3-hydroxybutyrate] (PHB)-b-poly(2-(dimethylamino)ethyl methacrylate) (PDMAEMA) copolymer, comprising hydrophobic PHB block and cationic PDMAEMA block, is designed to codeliver hydrophobic chemotherapeutic paclitaxel and Bcl-2 converting gene Nur77/ΔDBD with enhanced stability, due to the micelle formation by hydrophobic PHB segment. This copolymer shows less toxicity but similar gene transfection efficiency to polyethyenimine (25k). More importantly, this codelivery approach by PHB-PDMAEMA leads to increased drug resistant HepG2/Bcl-2 cancer cell death, by increased expression of Nur77 proteins in the Bcl-2 present intracellular mitochondria. This work signifies for the first time that cationic amphiphilic PHB-b-PDMAEMA copolymers can be utilized for the drug and gene codelivery to drug resistant cancer cells with high expression of antiapoptosis Bcl-2 protein and the positive results are encouraging for the further design of codelivery platforms for combating drug resistant cancer cells. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. BCL2 genotypes and prostate cancer survival

    Energy Technology Data Exchange (ETDEWEB)

    Renner, Wilfried [Medical University of Graz, Clinical Institute of Medical and Chemical Laboratory Diagnostics, Graz (Austria); Langsenlehner, Uwe [GKK Outpatient Department, Division of Internal Medicine, Graz (Austria); Krenn-Pilko, Sabine; Langsenlehner, Tanja [Medical University of Graz, Department of Therapeutic Radiology and Oncology, Graz (Austria); Eder, Petra [University Hospital Wuerzburg, Department of Internal Medicine I, Wuerzburg (Germany)

    2017-06-15

    The antiapoptotic B-cell lymphoma 2 (BCL2) gene is a key player in cancer development and progression. A functional single-nucleotide polymorphism (c.-938C>A, rs2279115) in the inhibitory P2 BCL2 gene promoter has been associated with clinical outcomes in various types of cancer. Aim of the present study was to analyze the role of BCL2-938C>A genotypes in prostate cancer mortality. The association between BCL2-938C>A (rs2279115) genotypes and prostate cancer outcome was studied within the prospective PROCAGENE study comprising 702 prostate cancer patients. During a median follow-up time of 92 months, 120 (17.1%) patients died. A univariate Cox regression model showed a significant association of the CC genotype with reduced cancer-specific survival (CSS; hazard ratio, HR, 2.13, 95% confidence interval, CI, 1.10-4.12; p = 0.024) and overall survival (OS; HR 2.34, 95% CI 1.58-3.47; p < 0.001). In a multivariate Cox regression model including age at diagnosis, risk group, and androgen deprivation therapy, the CC genotype remained a significant predictor of poor CSS (HR 2.05, 95% CI 1.05-3.99; p = 0.034) and OS (HR 2.25, 95% CI 1.51-3.36; p < 0.001). This study provides evidence that the homozygous BCL2-938 CC genotype is associated with OS and C in prostate cancer patients. (orig.) [German] Das antiapoptotische Gen B cell lymphoma 2 (BCL2) spielt eine Schluesselrolle in der Entstehung und Progression von Krebserkrankungen. Ein funktioneller Einzelnukleotid-Polymorphismus (c.-938C>A, rs2279115) im inhibitorischen P2-BCL2-Promotor wurde mit dem klinischen Outcome verschiedener Krebserkrankungen verknuepft. Ziel der vorliegenden Studie war die Untersuchung der Rolle von BCL2-938C>A-Genotypen fuer die Mortalitaet bei Patienten mit Prostatakarzinom. Der Zusammenhang zwischen BCL2-938C>A-Genotypen (rs2279115) und dem Outcome bei Prostatakrebs wurde in der prospektiven PROCAGENE-Studie, die 702 Patienten mit Prostatakarzinom umfasste, untersucht. Waehrend der medianen

  17. Caspase-Dependent Apoptosis Induced by Telomere Cleavage and TRF2 Loss

    Directory of Open Access Journals (Sweden)

    Asha S. Multani

    2000-07-01

    Full Text Available Chromosomal abnormalities involving telomeric associations (TAs often precede replicative senescence and abnormal chromosome configurations. We report here that telomere cleavage following exposure to proapoptotic agents is an early event in apoptosis. Exposure of human and murine cancer cells to a variety of pro-apoptotic stimuli (staurosporine, thapsigargin, anti-Fas antibody, cancer chemotherapeutic agents resulted in telomere cleavage and aggregation, finally their extrusion from the nuclei. Telomere loss was associated with arrest of cells in G2/M phase and preceded DNA fragmentation. Telomere erosion and subsequent large-scale chromatin cleavage were inhibited by overexpression of the anti -apoptotic protein, bcl-2, two peptide caspase inhibitors (BACMK and zVADfmk, indicating that both events are regulated by caspase activation. The results demonstrate that telomere cleavage is an early chromatin alteration detected in various cancer cell lines leading to drug-induced apoptosis, suggest that this event contributes to mitotic catastrophe and induction of cell death. Results also suggest that the decrease of telomeric-repeat binding factor 2 (TRF2 may be the earliest event in the ara-C-induced telomere shortening, induction of endoreduplication and chromosomal fragmentation leading to cell death.

  18. Non-genomic effects of the NR4A1/Nur77/TR3/NGFIB orphan nuclear receptor.

    Science.gov (United States)

    Pawlak, Alicja; Strzadala, Leon; Kalas, Wojciech

    2015-03-01

    The orphan nuclear receptor NR4A1/Nur77/TR3/NGFIB acts primarily as a transcription factor to regulate the expression of multiple genes. However, increasing research attention has recently been given to non-genomic activities of NR4A1. The first description of a non-genomic action of NR4A1 referred to the conversion of anti-apoptotic Bcl-2 into a pro-apoptotic protein by direct interaction with NR4A1. In response to certain apoptotic stimuli, NR4A1 translocates from the nucleus to the mitochondrial outer membrane (MOM) where it associates with Bcl-2 and thereby causes apoptosis. Afterwards, it appeared that NR4A1 could also bind and convert other anti-apoptotic Bcl-2 family members. The latest studies indicate a significant role of NR4A1 in the process of autophagy. For example, a new NR4A1-mediated pathway specific for melanoma cells has been described where NR4A1 interacts with the adenine nucleotide translocase 1 (ANT1) on the mitochondrial inner membrane (MIM) leading to induction of the autophagy pathway. Moreover, NR4A1 interaction with cytoplasmic p53 may also contribute to the induction of autophagy. In addition to mitochondria, NR4A1 could be translocated to the outer membrane of the endoplasmic reticulum (ER) and associate with Bcl-2 or translocon-associated protein subunit γ (TRAPγ) causing ER stress-induced apoptosis. NR4A1 also contributes to the proteasomal degradation of β-catenin in colon cancer cells in vitro and in vivo, as well as to the stabilization of hypoxia-inducible factor-1α (HIF-1α) under non-hypoxic conditions. This review summarizes research findings on non-genomic effects of NR4A1 in normal and cancer cells. Copyright © 2015 Elsevier Inc. All rights reserved.

  19. The marine cytotoxin portimine is a potent and selective inducer of apoptosis.

    Science.gov (United States)

    Cuddihy, Sarah L; Drake, Sarah; Harwood, D Tim; Selwood, Andrew I; McNabb, Paul S; Hampton, Mark B

    2016-12-01

    Portimine is a recently discovered member of a class of marine micro-algal toxins called cyclic imines. In dramatic contrast to related compounds in this toxin class, portimine has very low acute toxicity to mice but is highly cytotoxic to cultured cells. In this study we show that portimine kills human Jurkat T-lymphoma cells and mouse embryonic fibroblasts (MEFs), with LC 50 values of 6 and 2.5 nM respectively. Treated cells displayed rapid caspase activation and phosphatidylserine exposure, indicative of apoptotic cell death. Jurkat cells overexpressing the anti-apoptotic protein Bcl-2 or Bax/Bak knockout MEFs were completely protected from portimine. This protection was apparent even at high concentrations of portimine, with no evidence of necrotic cell death, indicating that portimine is a selective chemical inducer of apoptosis. Treatment of the Bcl-2-overexpressing cells with both portimine and the Bcl-2 inhibitor ABT-737 proved a powerful combination, causing >90 % death. We conclude that portimine is one of the most potent naturally derived inducers of apoptosis to be discovered, and it displays strong selectivity for the induction of apoptotic pathways.

  20. Chlorella vulgaris triggers apoptosis in hepatocarcinogenesis-induced rats*

    Science.gov (United States)

    Mohd Azamai, Emey Suhana; Sulaiman, Suhaniza; Mohd Habib, Shafina Hanim; Looi, Mee Lee; Das, Srijit; Abdul Hamid, Nor Aini; Wan Ngah, Wan Zurinah; Mohd Yusof, Yasmin Anum

    2009-01-01

    Chlorella vulgaris (CV) has been reported to have antioxidant and anticancer properties. We evaluated the effect of CV on apoptotic regulator protein expression in liver cancer-induced rats. Male Wistar rats (200~250 g) were divided into eight groups: control group (normal diet), CDE group (choline deficient diet supplemented with ethionine in drinking water to induce hepatocarcinogenesis), CV groups with three different doses of CV (50, 150, and 300 mg/kg body weight), and CDE groups treated with different doses of CV (50, 150, and 300 mg/kg body weight). Rats were sacrificed at various weeks and liver tissues were embedded in paraffin blocks for immunohistochemistry studies. CV, at increasing doses, decreased the expression of anti-apoptotic protein, Bcl-2, but increased the expression of pro-apoptotic protein, caspase 8, in CDE rats, which was correlated with decreased hepatoctyes proliferation and increased apoptosis as determined by bromodeoxy-uridine (BrdU) labeling and terminal deoxynucleotidyl transferase mediated dUTP nick-end labeling (TUNEL) assay, respectively. Our study shows that CV has definite chemopreventive effect by inducing apoptosis via decreasing the expression of Bcl-2 and increasing the expression of caspase 8 in hepatocarcinogenesis-induced rats. PMID:19198018

  1. Micropropagation effect on the anti-carcinogenic activitiy of polyphenolics from Mexican oregano (Poliomintha glabrescens Gray) in human colon cancer cells HT-29.

    Science.gov (United States)

    García-Pérez, Enrique; Noratto, Giuliana D; García-Lara, Silverio; Gutiérrez-Uribe, Janet A; Mertens-Talcott, Susanne U

    2013-06-01

    Phenolic extracts obtained from spices are known to have anti-carcinogenic activities but little is known about the effect of micropropagation on these beneficial effects. The main objective of this study was to evaluate the cytotoxic activity of flavonoid-enriched extracts (FEE) from the leaves of wild (WT), in vitro (IN), and ex vitro (EX) grown oregano plants in colon cancer cells HT-29 and the non-cancer cells CCD-18Co. Cell proliferation of HT-29 cells was reduced to 50 % by WT, IN, and EX at concentrations of 4.01, 1.32, and 4.84 mg of gallic acid equivalents (GAE)/L, respectively. In contrast, in CCD-18Co cells, higher concentrations were required for the same cytotoxic effect. At 6 mg GAE/L, WT and IN reduced the production of reactive oxygen species (ROS) of lipopolysaccharides (LPS)-stimulated control cells to 59.89 and 59.43 %, respectively, and EX to 73.89 %. The mRNA of Caspase-3 was increased 1.53-fold when cells were treated with 4 mg GAE/L of IN extract, and tumor necrosis factor receptor superfamily, member 6 (FAS), and BCL2-associated X protein (BAX) mRNA increased 2.55 and 1.53 fold, respectively. Results on protein expression corroborated the apoptotic effects with a significant decrease of B-cell lymphoma 2 (BCL2) expression for all treatments but more remarkable for EX that also showed the most intense signal of BAX. Overall, FEE extracts derived from micropropagation had increased pro-apoptotic effects, however extracts from the in vitro plants produced more efficacy at the transcriptional level while extracts from the ex vitro plant were superior at the traductional level.

  2. Expression of Bcl-2 in canine osteosarcoma

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    F. Piro

    2015-03-01

    Full Text Available Osteosarcoma (OS is the most common primary malignancy of bone. It is responsible for 80-85% of the primary bone tumors affecting dogs and it is characterized by aggressive and invasive behavior, with a high metastatic potential. Several studies on cancer and related tumorigenesis, show an involvement of the mechanisms of programmed cell death and cell survival. Many signals seem to be involved in the related mechanism of autophagy and in particular, our interest is focused on the expression of a family of Bcl-2 that seems to be involved either in the control of biomolecular mechanisms like autophagy and apoptosis. In this study we investigated the expression of Bcl-2 in different cases of spontaneous canine osteosarcoma and the related preliminary results are described. We found Bcl-2 activity was increased in OS tissue compared to normal bone tissue. These results suggested that Bcl-2 activity may play an important role in the formation of OS and as a diagnostic for neoplastic activity. However, further research is needed to confirm the role of Bcl-2 activity in OS in canines.

  3. Lithium-Induced Neuroprotection is Associated with Epigenetic Modification of Specific BDNF Gene Promoter and Altered Expression of Apoptotic-Regulatory Proteins

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    Tushar eDwivedi

    2015-01-01

    Full Text Available Bipolar disorder (BD, one of the most debilitating mental disorders, is associated with increased morbidity and mortality. Lithium is the first line of treatment option for BD and is often used for maintenance therapy. Recently, the neuroprotective action of lithium has gained tremendous attention, given that BD is associated with structural and functional abnormalities of the brain. However, the precise molecular mechanism by which lithium exerts its neuroprotective action is not clearly understood. In hippocampal neurons, the effects of lithium on neuronal viability against glutamate-induced cytotoxicity, dendritic length and number, and expression and methylation of BDNF promoter exons and expression of apoptotic regulatory genes were studied. In rat hippocampal neurons, lithium not only increased dendritic length and number, but also neuronal viability against glutamate-induced cytotoxicity. While lithium increased the expression of BDNF as well as genes associated with neuroprotection such as Bcl2 and Bcl-XL, it decreased the expression of pro-apoptotic genes Bax, Bad, and caspases 3. Interestingly, lithium activated transcription of specific exon IV to induce BDNF gene expression. This was accompanied by hypomethylation of BDNF exon IV promoter. This study delineates mechanisms by which lithium mediates its effects in protecting neurons.

  4. The Antioxidant, Anti-Inflammatory and Anti-Apoptotic Activities of the Bauhinia Championii Flavone are Connected with Protection Against Myocardial Ischemia/Reperfusion Injury.

    Science.gov (United States)

    Jian, Jie; Xuan, Feifei; Qin, Feizhang; Huang, Renbin

    2016-01-01

    Previous studies have demonstrated that Bauhinia championii flavone (BCF) exhibits anti-oxidative, anti-hypoxic and anti-stress properties. This study was designed to investigate whether BCF has a cardioprotective effect against myocardial ischemia/reperfusion (I/R) injuries in rats and to shed light on its possible mechanism. The model of I/R was established by ligating the left anterior descending coronary artery for 30 min, then reperfusing for 180 min. Hemodynamic changes were continuously monitored. The content of malondialdehyde (MDA) as well as the lactate dehydrogenase (LDH), superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) activities were assessed. The release of interleukin-6 (IL-6) was measured by enzyme-linked immunosorbent assay (ELISA). Apoptosis of cardiomyocytes was determined by caspase-3 activity and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) staining. The expression of TLR4, NF-x03BA;Bp65, Bcl-2 and Bax were detected by western blotting. Pretreatment with BCF significantly reduced the serum levels of LDH, MDA and IL-6, but increased the activities of SOD and GSH-Px. It also attenuated myocardial infarct size, reduced the apoptosis rate and preserved cardiac function. Furthermore, BCF inhibited caspase-3 activity and the expression of TLR4, phosphorylated NF-x03BA;Bp65 and Bax, but enhanced the expression of Bcl-2. These results provide substantial evidence that BCF exerts a protective effect on myocardial I/R injury, which may be attributed to attenuating lipid peroxidation, the inflammatory response and apoptosis. © 2016 The Author(s) Published by S. Karger AG, Basel.

  5. Effect of Bcl-xL overexpression on sialylation of Fc-fusion protein in recombinant Chinese hamster ovary cell cultures.

    Science.gov (United States)

    Lee, Jong Hyun; Kim, Yeon-Gu; Lee, Gyun Min

    2015-01-01

    The sialic acid of glycoproteins secreted by recombinant Chinese hamster ovary (rCHO) cells can be impaired by sialidase under culture conditions which promote the extracellular accumulation of this enzyme. To investigate the effect of Bcl-xL overexpression on the sialylation of glycoproteins produced in rCHO cell culture, two rCHO cell lines producing the same Fc-fusion protein, which were derived from DUKX-B11 and DG44, respectively, were engineered to have regulated Bcl-xL overexpression using the Tet-off system. For both cell lines, Bcl-xL overexpression improved cell viability and extended culture longevity in batch cultures. As a result, a maximum Fc-fusion protein titer increased by Bcl-xL overexpression though the extent of titer enhancement differed between the two cell lines. With Bcl-xL overexpression, the sialylation of Fc-fusion protein, which was assessed by isoelectric focusing gel and sialic acid content analyses, decreased more slowly toward the end of batch cultures. This was because Bcl-xL overexpression delayed the extracellular accumulation of sialidase activity by reducing cell lysis during batch cultures. Taken together, Bcl-xL overexpression in rCHO cell culture increased Fc-fusion protein production and also reduced the impairment of sialylation of Fc-fusion protein by maintaining high viability during batch cultures. © 2015 American Institute of Chemical Engineers.

  6. Bioactives in cactus (Opuntia ficus-indica) stems possess potent antioxidant and pro-apoptotic activities through COX-2 involvement.

    Science.gov (United States)

    Kim, Jinhee; Soh, Soon Yil; Shin, Juha; Cho, Chi-Woung; Choi, Young Hee; Nam, Sang-Yong

    2015-10-01

    Bioactives extracted from cactus (Opuntia ficus-indica) stems were investigated for their chemopreventive activities using human cancer cells in vitro. The bioactives present in crude extracts were detected and quantified using high-performance liquid chromatography. Among all the extracts, such as hexane, ethyl acetate (EtOAc), acetone, methanol (MeOH), and MeOH:water (80:20), the MeOH extract had the highest amount of polyphenolic compounds and the acetone extract exhibited the most potent effect at scavenging the 2,2,-diphenyl-1-picrylhydrazyl (DPPH) and 2,2'-azino-di-(3-ethylbenzothiazoline)-6-sulfonic acid (ABTS(•+) ) radical. In addition, most of the extracts, with the exception of hexane, exhibited significant cytotoxicity in human SW480 colon and MCF7 breast cancer cells. Overall, the SW480 cells were more sensitive than the MCF7 cells to the cytotoxic effect of the O. ficus-indica extracts (OFEs). Cell death by OFE treatment caused significant inhibition of cyclooxygenase-2 and increased the Bax/Bcl2 ratio in both SW480 and MCF7 cell lines. However, degradation of poly (ADP-ribose) polymerase was significantly increased by OFE only in the MCF7 cells, thereby inducing apoptosis. These findings demonstrate the health-benefit roles, including anti-oxidative and anti-proliferative activities as well as pro-apoptotic effects, of bioactive compounds in OFEs, suggesting a chemopreventive role in human cancer cells. © 2014 Society of Chemical Industry.

  7. Characterization of vNr-13, the first alphaherpesvirus gene of the bcl-2 family

    International Nuclear Information System (INIS)

    Aouacheria, Abdel; Banyai, Michelle; Rigal, Dominique; Schmidt, Carl J.; Gillet, Germain

    2003-01-01

    The Bcl-2 family, including antiapoptotic and proapoptotic members, plays key regulating roles in programmed cell death. We report the characterization of a new member of the bcl-2 family, encoded by herpesvirus of turkeys (HVT). The product of this gene shares 80% homology with Nr-13, an apoptosis inhibitor, which is overexpressed in avian cells transformed by the v-src oncogene. This new gene, that we propose to call vnr-13, is the first member of the bcl-2 family to be isolated among α-herpesviruses. Results from cells expressing the HVT-vnr-13 gene product show that the encoded protein inhibits apoptosis and also reduces the rate of cellular proliferation. Contrary to all bcl-2 homologues found in γ-herpesvirus, which are intronless, vnr-13 has the same organization as the cellular nr-13 gene. Hence, the HVT vnr-13 gene may have been acquired from a reverse transcriptase product of an unspliced precursor RNA, or via direct recombination with the host chromosomal DNA

  8. Alterations in glutathione levels and apoptotic regulators are associated with acquisition of arsenic trioxide resistance in multiple myeloma.

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    Shannon M Matulis

    Full Text Available Arsenic trioxide (ATO has been tested in relapsed/refractory multiple myeloma with limited success. In order to better understand drug mechanism and resistance pathways in myeloma we generated an ATO-resistant cell line, 8226/S-ATOR05, with an IC50 that is 2-3-fold higher than control cell lines and significantly higher than clinically achievable concentrations. Interestingly we found two parallel pathways governing resistance to ATO in 8226/S-ATOR05, and the relevance of these pathways appears to be linked to the concentration of ATO used. We found changes in the expression of Bcl-2 family proteins Bfl-1 and Noxa as well as an increase in cellular glutathione (GSH levels. At low, clinically achievable concentrations, resistance was primarily associated with an increase in expression of the anti-apoptotic protein Bfl-1 and a decrease in expression of the pro-apoptotic protein Noxa. However, as the concentration of ATO increased, elevated levels of intracellular GSH in 8226/S-ATOR05 became the primary mechanism of ATO resistance. Removal of arsenic selection resulted in a loss of the resistance phenotype, with cells becoming sensitive to high concentrations of ATO within 7 days following drug removal, indicating changes associated with high level resistance (elevated GSH are dependent upon the presence of arsenic. Conversely, not until 50 days without arsenic did cells once again become sensitive to clinically relevant doses of ATO, coinciding with a decrease in the expression of Bfl-1. In addition we found cross-resistance to melphalan and doxorubicin in 8226/S-ATOR05, suggesting ATO-resistance pathways may also be involved in resistance to other chemotherapeutic agents used in the treatment of multiple myeloma.

  9. Anti-apoptotic effect of hyperglycemia can allow survival of potentially autoreactive T cells.

    Science.gov (United States)

    Ramakrishnan, P; Kahn, D A; Baltimore, D

    2011-04-01

    Thymocyte development is a tightly controlled multi-step process involving selective elimination of self-reactive and non-functional T cells by apoptosis. This developmental process depends on signaling by Notch, IL-7 and active glucose metabolism. In this study, we explored the requirement of glucose for thymocyte survival and found that in addition to metabolic regulation, glucose leads to the expression of anti-apoptotic genes. Under hyperglycemic conditions, both mouse and human thymocytes demonstrate enhanced survival. We show that glucose-induced anti-apoptotic genes are dependent on NF-κB p65 because high glucose is unable to attenuate normal ongoing apoptosis of thymocytes isolated from p65 knockout mice. Furthermore, we demonstrate that in vivo hyperglycemia decreases apoptosis of thymocytes allowing for survival of potentially self-reactive thymocytes. These results imply that hyperglycemic conditions could contribute to the development of autoimmunity through dysregulated thymic selection. © 2011 Macmillan Publishers Limited

  10. Primary bovine skeletal muscle cells enters apoptosis rapidly via the intrinsic pathway when available oxygen is removed.

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    Sissel Beate Rønning

    Full Text Available Muscle cells undergo changes post-mortem during the process of converting muscle into meat, and this complex process is far from revealed. Recent reports have suggested programmed cell death (apoptosis to be important in the very early period of converting muscle into meat. The dynamic balance that occurs between anti-apoptotic members, such as Bcl-2, and pro-apoptotic members (Bid, Bim helps determine whether the cell initiates apoptosis. In this study, we used primary bovine skeletal muscle cells, cultured in monolayers in vitro, to investigate if apoptosis is induced when oxygen is removed from the growth medium. Primary bovine muscle cells were differentiated to form myotubes, and anoxia was induced for 6h. The anoxic conditions significantly increased (P<0.05 the relative gene expression of anti- and pro-apoptotic markers (Aif, Bcl-2, Bid and Bim, and the PARK7 (P<0.05 and Grp75 (Hsp70 protein expressions were transiently increased. The anoxic conditions also led to a loss of mitochondrial membrane potential, which is an early apoptotic event, as well as cytochrome c release from the mitochondria. Finally, reorganization and degradation of cytoskeletal filaments occurred. These results suggest that muscle cells enters apoptosis via the intrinsic pathway rapidly when available oxygen in the muscle diminishes post-mortem.

  11. Bag3 promotes resistance to apoptosis through Bcl-2 family members in non-small cell lung cancer.

    Science.gov (United States)

    Zhang, Yong; Wang, Jian-Hua; Lu, Qiang; Wang, Yun-Jie

    2012-01-01

    In non-small cell lung cancer (NSCLC) certain molecular characteristics, which are related to molecular alterations have been investigated. These are responsible for both the initiation and maintenance of the malignancy in lung cancer. The aim of this study was to evaluate the influence of Bag3 (Bcl-2 associated athanogene 3) in the regulation of apoptosis on NSCLC. Bag3 and Hsp70 expression were examined by immunohistochemistry to confirm their potential roles in the prevalence of NSCLC. We also established human normal bronchial epithelial cells and HOP-62 cell line as the model to analyze cell apoptosis and the expression of Hsp70, Bcl-XL and Bcl-2, which were affected by Bag3. In this study, we found that Bag3 and Hsp70 are highly expressed in few tissues and cell lines of NSCLC. Bag3 inhibits apoptosis in human normal bronchial epithelial cell lines and sustain the survival of NSCLC cells. Bag3, Hsp70, Bcl-XL and Bcl-2 are up-regulated in NSCLC cell lines. At the same time, the silencing of Bag3 results in diminishing protein levels of Bcl-XL and Bcl-2. The results of immunoprecipitation identified that Bag3 could interact with Hsp70, Bcl-XL and Bcl-2 NSCLC cells directly or indirectly. We conclude that NSCLC cells were protected from apoptosis through increasing Bag3 expression and consequently promoted the expression of Bcl-XL and Bcl-2.

  12. Oxidative stress and toxicity induced by the nucleoside reverse transcriptase inhibitor (NRTI)--2',3'-dideoxycytidine (ddC): relevance to HIV-dementia.

    Science.gov (United States)

    Opii, Wycliffe O; Sultana, Rukhsana; Abdul, Hafiz Mohmmad; Ansari, Mubeen Ahmad; Nath, Avindra; Butterfield, D Allan

    2007-03-01

    Human immunodeficiency virus dementia (HIVD) is the most common form of dementia occurring among young adults. In HIVD, neuronal cell loss occurs in the absence of neuronal infection. With the advent of highly active anti-retroviral therapy (HAART), the incidence of HIVD has drastically reduced, though prevalence of milder forms of HIVD continues to rise. Though these agents have been used successfully in suppressing viral production, they have also been associated with a number of side effects. Here we examine the possible role of NRTIs, in particular 2',3'-dideoxycytidine (ddC), in the neuropathology of HIVD. Synaptosomes and isolated mitochondria treated and incubated for 6 h with CSF-achievable concentrations of ddC, i.e., 6-11 ng/ml, were found to show a significant increase in oxidative stress with 40 nM ddC as measured by protein carbonyls and 3-nitrotyrosine (3NT), effects that were not observed in the more tolerable NRTI, 3TC. Protection against protein oxidation induced by ddC was observed when brain mitochondria were isolated from gerbils 1 h after injection i.p. with the brain accessible antioxidant and glutathione mimetic, tricyclodecan-9-yl-xanthogenate (D609). In addition, there is a significant reduction in the levels of anti-apoptotic protein Bcl-2 and a significant increase in cytochrome c release and also a significant increase in the expression of pro-apoptotic protein caspase-3 after mitochondria were treated with 40 nM ddC. The results reported here show that ddC at 40 nM can induce oxidative stress, cause the release of cytochrome c, and in addition, reduce the levels of anti-apoptotic proteins, increase the levels of pro-apoptotic proteins, thereby increasing the possibility for induction of apoptosis. These findings are consistent with the notion of a possible role of the NRTIs, and in particular, ddC, in the mechanisms involved in HIVD.

  13. A synthetic coumarin (4-methyl-7 hydroxy coumarin) has anti-cancer potentials against DMBA-induced skin cancer in mice.

    Science.gov (United States)

    Bhattacharyya, Soumya S; Paul, Saili; Mandal, Sushil K; Banerjee, Antara; Boujedaini, Naoual; Khuda-Bukhsh, Anisur R

    2009-07-01

    Scopoletin, an alkaloid separated from ethanolic extract of the medicinal plant, Gelsemium sempervirens (Fam: Loganiaceae) has been reported to have anti-cancer potentials. The synthetic coumarin (4-Methyl-7 hydroxy coumarin) derived from resorcinol and ethyl aceto-acetate in presence of concentrated sulphuric acid is structurally close to scopoletin, being a coumarin derivative. Whether this synthetic compound also has anti-cancer potentials has been evaluated in vivo on DMBA (7,12-Dimethylbenz[a]anthracene) induced skin cancer in mice by analyzing results of several cytogenetic endpoints, Comet assay, and fluorescence activated cell sorting (FACS). Further, expressions of signal proteins like Aryl hydrocarbon receptor , p53, PCNA, Akt, Bcl-2, Bcl-xL, Bad, Bax, NF-kappaB Apaf, IL-6, Cytochrome-c, Caspase-3 and Caspase-9 were studied by immunoblot analysis along with histology of skin and immuno-histochemical localization of Aryl hydrocarbon receptor and PCNA in DMBA treated mice vis-a-vis carcinogen treated synthetic coumarin fed mice. Feeding of this synthetic coumarin induced positive modulations in expression of all biomarkers in DMBA administered mice, giving clues on its possible signaling pathway(s) - primarily through down-regulation of Aryl hydrocarbon receptor and PCNA and up-regulation of apoptotic proteins like Bax, Bad, Cytochrome c, Apaf, Caspase-3 and Caspase-9, resulting in an appreciable reduction in growth of papilloma in mice. Therefore, this synthetic coumarin shows promise for use in cancer therapy, particularly in skin cancer.

  14. 1800 MHz mobile phone irradiation induced oxidative and nitrosative stress leads to p53 dependent Bax mediated testicular apoptosis in mice, Mus musculus.

    Science.gov (United States)

    Shahin, Saba; Singh, Surya P; Chaturvedi, Chandra M

    2018-09-01

    Present study was carried out to investigate the effect of long-term mobile phone radiation exposure in different operative modes (Dialing, Receiving, and Stand-by) on immature male mice. Three-week old male mice were exposed to mobile phone (1800 MHz) radiation for 3 hr/day for 120 days in different operative modes. To check the changes/alteration in testicular histoarchitecture and serum testosterone level, HE staining and ELISA was performed respectively. Further, we have checked the redox status (ROS, NO, MDA level, and antioxidant enzymes: SOD, CAT, and GPx) by biochemical estimation, alteration in the expression of pro-apoptotic proteins (p53 and Bax), active executioner caspase-3, full length/uncleaved PARP-1 (DNA repair enzyme), anti-apoptotic proteins (Bcl-2 and Bcl-x L ) in testes by immunofluorescence and cytosolic cytochrome-c by Western blot. Decreased seminiferous tubule diameter, sperm count, and viability along with increased germ cells apoptosis and decreased serum testosterone level, was observed in the testes of all the mobile phone exposed mice compared with control. We also observed that, mobile phone radiation exposure in all the three different operative modes alters the testicular redox status via increasing ROS, NO, and MDA level, and decreasing antioxidant enzymes levels leading to enhanced apoptosis of testicular cells by increasing the expression of pro-apoptotic and apoptotic proteins along with decreasing the expression of anti-apoptotic protein. On the basis of results, it is conclude that long-term mobile phone radiation exposure induced oxidative stress leads to apoptosis of testicular cells and thus impairs testicular function. © 2018 Wiley Periodicals, Inc.

  15. Anti-cancer effect of bee venom toxin and melittin in ovarian cancer cells through induction of death receptors and inhibition of JAK2/STAT3 pathway

    International Nuclear Information System (INIS)

    Jo, Miran; Park, Mi Hee; Kollipara, Pushpa Saranya; An, Byeong Jun; Song, Ho Sueb; Han, Sang Bae; Kim, Jang Heub; Song, Min Jong; Hong, Jin Tae

    2012-01-01

    We investigated whether bee venom and melittin, a major component of bee venom, inhibit cell growth through enhancement of death receptor expressions in the human ovarian cancer cells, SKOV3 and PA-1. Bee venom (1–5 μg/ml) and melittin (0.5–2 μg/ml) inhibited the growth of SKOV3 and PA-1 ovarian cancer cells by the induction of apoptotic cell death in a dose dependent manner. Consistent with apoptotic cell death, expression of death receptor (DR) 3 and DR6 was increased in both cancer cells, but expression of DR4 was increased only in PA-1 cells. Expression of DR downstream pro-apoptotic proteins including caspase-3, 8, and Bax was concomitantly increased, but the phosphorylation of JAK2 and STAT3 and the expression of Bcl-2 were inhibited by treatment with bee venom and melittin in SKOV3 and PA-1 cells. Expression of cleaved caspase-3 was increased in SKOV3, but cleaved caspase-8 was increased in PA-1 cells. Moreover, deletion of DR3, DR4, and DR6 by small interfering RNA significantly reversed bee venom and melittin-induced cell growth inhibitory effect as well as down regulation of STAT3 by bee venom and melittin in SKOV3 and PA-1 ovarian cancer cell. These results suggest that bee venom and melittin induce apoptotic cell death in ovarian cancer cells through enhancement of DR3, DR4, and DR6 expression and inhibition of STAT3 pathway. -- Highlights: ► Some studies have showed that bee venom and/or melittin have anti-cancer effects. ► We found that bee venom and melittin inhibited cell growth in ovarian cancer cells. ► Bee venom and melittin induce apoptosis in SKOV3 and PA-1.

  16. Comprehensive predictions of target proteins based on protein-chemical interaction using virtual screening and experimental verifications.

    Science.gov (United States)

    Kobayashi, Hiroki; Harada, Hiroko; Nakamura, Masaomi; Futamura, Yushi; Ito, Akihiro; Yoshida, Minoru; Iemura, Shun-Ichiro; Shin-Ya, Kazuo; Doi, Takayuki; Takahashi, Takashi; Natsume, Tohru; Imoto, Masaya; Sakakibara, Yasubumi

    2012-04-05

    Identification of the target proteins of bioactive compounds is critical for elucidating the mode of action; however, target identification has been difficult in general, mostly due to the low sensitivity of detection using affinity chromatography followed by CBB staining and MS/MS analysis. We applied our protocol of predicting target proteins combining in silico screening and experimental verification for incednine, which inhibits the anti-apoptotic function of Bcl-xL by an unknown mechanism. One hundred eighty-two target protein candidates were computationally predicted to bind to incednine by the statistical prediction method, and the predictions were verified by in vitro binding of incednine to seven proteins, whose expression can be confirmed in our cell system.As a result, 40% accuracy of the computational predictions was achieved successfully, and we newly found 3 incednine-binding proteins. This study revealed that our proposed protocol of predicting target protein combining in silico screening and experimental verification is useful, and provides new insight into a strategy for identifying target proteins of small molecules.

  17. Comprehensive predictions of target proteins based on protein-chemical interaction using virtual screening and experimental verifications

    Directory of Open Access Journals (Sweden)

    Kobayashi Hiroki

    2012-04-01

    Full Text Available Abstract Background Identification of the target proteins of bioactive compounds is critical for elucidating the mode of action; however, target identification has been difficult in general, mostly due to the low sensitivity of detection using affinity chromatography followed by CBB staining and MS/MS analysis. Results We applied our protocol of predicting target proteins combining in silico screening and experimental verification for incednine, which inhibits the anti-apoptotic function of Bcl-xL by an unknown mechanism. One hundred eighty-two target protein candidates were computationally predicted to bind to incednine by the statistical prediction method, and the predictions were verified by in vitro binding of incednine to seven proteins, whose expression can be confirmed in our cell system. As a result, 40% accuracy of the computational predictions was achieved successfully, and we newly found 3 incednine-binding proteins. Conclusions This study revealed that our proposed protocol of predicting target protein combining in silico screening and experimental verification is useful, and provides new insight into a strategy for identifying target proteins of small molecules.

  18. Low-Dose Ethanol Preconditioning Protects Against Oxygen-Glucose Deprivation/Reoxygenation-Induced Neuronal Injury By Activating Large Conductance, Ca2+-Activated K+ Channels In Vitro

    Institute of Scientific and Technical Information of China (English)

    Fang Su; An-Chen Guo; Wei-Wei Li; Yi-Long Zhao; Zheng-Yi Qu; Yong-Jun Wang; Qun Wang; Yu-Lan Zhu

    2017-01-01

    Increasing evidence suggests that low to moderate ethanol ingestion protects against the deleterious effects of subsequent ischemia/reperfusion;however,the underlying mechanism has not been elucidated.In the present study,we showed that expression of the neuronal large-conductance,Ca2+-activated K+ channel (BKCa) α-subunit was upregulated in cultured neurons exposed to oxygen-glucose deprivatior/reoxygenation (OGD/R) compared with controls.Preconditioning with low-dose ethanol (10 mmol/L) increased cell survival rate in neurons subjected to OGD/R,attenuated the OGD/R-induced elevation of cytosolic Ca2+ levels,and reduced the number of apoptotic neurons.Western blots revealed that ethanol preconditioning upregulated expression of the anti-apoptotic protein Bcl-2 and downregulated the pro-apoptotic protein Bax.The protective effect of ethanol preconditioning was antagonized by a BKCa channel inhibitor,paxilline.Inside-out patches in primary neurons also demonstrated the direct activation of the BKCa channel by 10 mmol/L ethanol.The above results indicated that low-dose ethanol preconditioning exerts its neuroprotective effects by attenuating the elevation of cytosolic Ca2+ and preventing neuronal apoptosis,and this is mediated by BKCa channel activation.

  19. Low-Dose Ethanol Preconditioning Protects Against Oxygen-Glucose Deprivation/Reoxygenation-Induced Neuronal Injury By Activating Large Conductance, Ca2+-Activated K+ Channels In Vitro.

    Science.gov (United States)

    Su, Fang; Guo, An-Chen; Li, Wei-Wei; Zhao, Yi-Long; Qu, Zheng-Yi; Wang, Yong-Jun; Wang, Qun; Zhu, Yu-Lan

    2017-02-01

    Increasing evidence suggests that low to moderate ethanol ingestion protects against the deleterious effects of subsequent ischemia/reperfusion; however, the underlying mechanism has not been elucidated. In the present study, we showed that expression of the neuronal large-conductance, Ca 2+ -activated K + channel (BK Ca ) α-subunit was upregulated in cultured neurons exposed to oxygen-glucose deprivation/reoxygenation (OGD/R) compared with controls. Preconditioning with low-dose ethanol (10 mmol/L) increased cell survival rate in neurons subjected to OGD/R, attenuated the OGD/R-induced elevation of cytosolic Ca 2+ levels, and reduced the number of apoptotic neurons. Western blots revealed that ethanol preconditioning upregulated expression of the anti-apoptotic protein Bcl-2 and downregulated the pro-apoptotic protein Bax. The protective effect of ethanol preconditioning was antagonized by a BK Ca channel inhibitor, paxilline. Inside-out patches in primary neurons also demonstrated the direct activation of the BK Ca channel by 10 mmol/L ethanol. The above results indicated that low-dose ethanol preconditioning exerts its neuroprotective effects by attenuating the elevation of cytosolic Ca 2+ and preventing neuronal apoptosis, and this is mediated by BK Ca channel activation.

  20. Bcl-2 and N-Myc Coexpression Increases IGF-IR and Features of Malignant Growth in Neuroblastoma Cell Lines

    Directory of Open Access Journals (Sweden)

    Rama Jasty

    2001-01-01

    Full Text Available The bcl-2 and c-myc oncogenes cooperate to transform multiple cell types. In the pediatric malignancy NB2, Bcl2 is highly expressed. In tumors with a poor prognosis, N-Myc, a protein homologous to c-Myc, is overexpressed as a result of gene amplification. The present study was designed to determine whether Bcl-2 cooperates with N-Myc to bestow a tumorigenic phenotype to neuroblastoma (NB cells. NB cell lines that at baseline express neither Bcl-2 nor N-Myc were stably transfected to express these gene products. In this model, we found Bcl-2 rescues N-Myc-expressing cells from apoptosis induced by serum withdrawal. Coexpression of Bcl-2 and N-Myc supports growth in low serum conditions and anchorage-independent growth in soft agar. Similarly, in vivo tumorigenic and angiogenic activity was dependent on coexpression. Our data further suggests that the mechanism underlying these changes involves the receptor for insulin growth factor type I (IGF-IR.

  1. Nutrient-intake-level-dependent regulation of intestinal development in newborn intrauterine growth-restricted piglets via glucagon-like peptide-2.

    Science.gov (United States)

    Liu, J; Liu, Z; Gao, L; Chen, L; Zhang, H

    2016-10-01

    The objective of the present study was to investigate the intestinal development of newborn intrauterine growth-restricted (IUGR) piglets subjected to normal nutrient intake (NNI) or restricted nutrient intake (RNI). Newborn normal birth weight (NBW) and IUGR piglets were allotted to NNI or RNI levels for 4 weeks from day 8 postnatal. IUGR piglets receiving NNI had similar growth performance compared with that of NBW piglets. Small intestine length and villous height were greater in IUGR piglets fed the NNI than that of piglets fed the RNI. Lactase activity was increased in piglets fed the NNI compared with piglets fed the RNI. Absorptive function, represented by active glucose transport by the Ussing chamber method and messenger RNA (mRNA) expressions of two main intestinal glucose transporters, Na+-dependent glucose transporter 1 (SGLT1) and glucose transporter 2 (GLUT2), were greater in IUGR piglets fed the NNI compared with piglets fed the RNI regimen. The apoptotic process, characterized by caspase-3 activity (a sign of activated apoptotic cells) and mRNA expressions of p53 (pro-apoptotic), bcl-2-like protein 4 (Bax) (pro-apoptotic) and B-cell lymphoma-2 (Bcl-2) (anti-apoptotic), were improved in IUGR piglets fed the NNI regimen. To test the hypothesis that improvements in intestinal development of IUGR piglets fed NNI might be mediated through circulating glucagon-like peptide-2 (GLP-2), GLP-2 was injected subcutaneously to IUGR piglets fed the RNI from day 8 to day 15 postnatal. Although the intestinal development of IUGR piglets fed the RNI regimen was suppressed compared with those fed the NNI regimen, an exogenous injection of GLP-2 was able to bring intestinal development to similar levels as NNI-fed IUGR piglets. Collectively, our results demonstrate that IUGR neonates that have NNI levels could improve intestinal function via the regulation of GLP-2.

  2. Disruption of apoptosis pathways involved in zebrafish gonad differentiation by 17α-ethinylestradiol and fadrozole exposures

    International Nuclear Information System (INIS)

    Luzio, Ana; Matos, Manuela; Santos, Dércia; Fontaínhas-Fernandes, António A.; Monteiro, Sandra M.

    2016-01-01

    Highlights: • Apoptosis in females is avoided by anti-apoptotic pathways and in males is essential to the “juvenile ovary” failure. • BIRC5 is central to the regulation of zebrafish spermatogenesis. • EE2 did not change sex ratios, but Fadrozole induced masculinization with a significant increase in male proportion. • The few females identified after exposure to Fadrozole may have avoided sex reversal by increasing anti-apoptotic proteins. • EE2 increased the pro-apoptotic genes/proteins in males, promoting gonad differentiation. - Abstract: Zebrafish (Danio rerio) sex determination seems to involve genetic factors (GSD) but also environmental factors (ESD), such as endocrine disrupting chemicals (EDCs) that are known to mimic endogenous hormones and disrupt gonad differentiation. Apoptosis has also been proposed to play a crucial role in zebrafish gonad differentiation. Nevertheless, the interactions between EDCs and apoptosis have received little attention. Thus, this study aimed to assess if and which apoptotic pathways are involved in zebrafish gonad differentiation and how EDCs may interfere with this process. With these purposes, zebrafish were exposed to 17α-ethinylestradiol (EE_2, 4 ng/L) and fadrozole (Fad, 50 μg/L) from 2 h to 35 days post-fertilization (dpf). Afterwards, a gene expression analysis by qRT-PCR and a stereological analysis, based on systematic sampling and protein immunohistochemistry, were performed. The death receptors (FAS; TRADD), anti-apoptotic (BCL-2; MDM2), pro-apoptotic (CASP-2 and −6) and cell proliferation (BIRC5/survivin; JUN) genes and proteins were evaluated. In general, apoptosis was inhibited in females through the involvement of anti-apoptotic pathways, while in males apoptosis seemed to be crucial to the failure of the “juvenile ovary” development and the induction of testes transformation. The JUN protein was shown to be necessary in juvenile ovaries, while the BIRC5 protein seemed to be involved in

  3. Disruption of apoptosis pathways involved in zebrafish gonad differentiation by 17α-ethinylestradiol and fadrozole exposures

    Energy Technology Data Exchange (ETDEWEB)

    Luzio, Ana, E-mail: aluzio@utad.pt [Centre for the Research and Technology of Agro-Environmental and Biological Sciences, CITAB, Departamento de Biologia e Ambiente (DeBA), University of Trás-os-Montes and Alto Douro, UTAD, Quinta de Prados, Vila Real, 5000-801 (Portugal); Life Sciences and Environment School, University of Trás-os-Montes and Alto Douro, UTAD, Quinta de Prados, Vila Real, 5000-801 (Portugal); Matos, Manuela [University of Lisbon, Faculty of Sciences, BioISI– Biosystems & Integrative Sciences Institute, Campo Grande, 1749-016 Lisbon (Portugal); Department of Genetics and Biotechnology, Life Sciences and Environment School (ECVA), University of Trás-os-Montes and Alto Douro, UTAD, Quinta de Prados, Vila Real, 5000-801 (Portugal); Santos, Dércia [Life Sciences and Environment School, University of Trás-os-Montes and Alto Douro, UTAD, Quinta de Prados, Vila Real, 5000-801 (Portugal); Fontaínhas-Fernandes, António A.; Monteiro, Sandra M. [Centre for the Research and Technology of Agro-Environmental and Biological Sciences, CITAB, Departamento de Biologia e Ambiente (DeBA), University of Trás-os-Montes and Alto Douro, UTAD, Quinta de Prados, Vila Real, 5000-801 (Portugal); Life Sciences and Environment School, University of Trás-os-Montes and Alto Douro, UTAD, Quinta de Prados, Vila Real, 5000-801 (Portugal); and others

    2016-08-15

    Highlights: • Apoptosis in females is avoided by anti-apoptotic pathways and in males is essential to the “juvenile ovary” failure. • BIRC5 is central to the regulation of zebrafish spermatogenesis. • EE2 did not change sex ratios, but Fadrozole induced masculinization with a significant increase in male proportion. • The few females identified after exposure to Fadrozole may have avoided sex reversal by increasing anti-apoptotic proteins. • EE2 increased the pro-apoptotic genes/proteins in males, promoting gonad differentiation. - Abstract: Zebrafish (Danio rerio) sex determination seems to involve genetic factors (GSD) but also environmental factors (ESD), such as endocrine disrupting chemicals (EDCs) that are known to mimic endogenous hormones and disrupt gonad differentiation. Apoptosis has also been proposed to play a crucial role in zebrafish gonad differentiation. Nevertheless, the interactions between EDCs and apoptosis have received little attention. Thus, this study aimed to assess if and which apoptotic pathways are involved in zebrafish gonad differentiation and how EDCs may interfere with this process. With these purposes, zebrafish were exposed to 17α-ethinylestradiol (EE{sub 2}, 4 ng/L) and fadrozole (Fad, 50 μg/L) from 2 h to 35 days post-fertilization (dpf). Afterwards, a gene expression analysis by qRT-PCR and a stereological analysis, based on systematic sampling and protein immunohistochemistry, were performed. The death receptors (FAS; TRADD), anti-apoptotic (BCL-2; MDM2), pro-apoptotic (CASP-2 and −6) and cell proliferation (BIRC5/survivin; JUN) genes and proteins were evaluated. In general, apoptosis was inhibited in females through the involvement of anti-apoptotic pathways, while in males apoptosis seemed to be crucial to the failure of the “juvenile ovary” development and the induction of testes transformation. The JUN protein was shown to be necessary in juvenile ovaries, while the BIRC5 protein seemed to be involved

  4. Effect of API-1 and FR180204 on cell proliferation and apoptosis in human DLD-1 and LoVo colorectal cancer cells.

    Science.gov (United States)

    Saglam, Atiye Seda Yar; Alp, Ebru; Elmazoglu, Zubeyir; Menevse, Emine Sevda

    2016-10-01

    The activation of the phosphatidylinositol-3 kinase/v-akt murine thymoma viral oncogene homolog (Akt) and mitogen activated protein kinase kinase/extracellular signal-regulated kinase (ERK) pathways are implicated in the majority of cancers. Selective inhibition of Akt and ERK represents a potential approach for cancer therapy. Therefore, the present study aimed to investigate the apoptotic and anti-proliferative effects of the novel and selective Akt inhibitor 4-amino-5,8-dihydro-5-oxo-8-β-D-ribofuranosyl-pyrido[2,3-d]pyrimidine-6-carboxamide (API-1) and selective ERK1/2 inhibitor FR180204 (FR) alone and in combination on colorectal cancer (CRC) cells (DLD-1 and LoVo). In addition, the effects of API-1 and FR on Akt and ERK signaling pathways were also investigated. The effects of the agents on DLD-1 and LoVo cells were evaluated in terms of cell viability, cytotoxicity, DNA synthesis rate, DNA fragmentation and caspase-3 activity levels. In addition, quantitative reverse transcription-polymerase chain reaction and western blot analysis were performed to examine relevant mRNA and protein levels. The present study observed that the combination of FR with API-1 resulted in significant apoptosis and cytotoxicity compared with any single agent alone in a time-dependent manner in these cells. Also, treatment with FR and API-1 in combination decreased the expression levels of B-cell lymphoma-2 (BCL2), Bcl-2-like1, cyclin D1 and cMYC, and increased the expression levels of BCL2-associated X protein and BCL2 antagonist/killer via phosphorylated Akt and phosphorylated ERK1/2 downregulation. The combination of Akt and ERK1/2 inhibitors resulted in enhanced apoptotic and anti-proliferative effects against CRC cells. The present study hypothesizes that the combination of FR and API-1 in CRC cells may contribute toward potential anti-carcinogenic effects. Additional analyses using other cancer cell lines and animal models are required to confirm these findings in vitro and in

  5. Aconitine-induced Ca2+ overload causes arrhythmia and triggers apoptosis through p38 MAPK signaling pathway in rats

    International Nuclear Information System (INIS)

    Sun, Gui-bo; Sun, Hong; Meng, Xiang-bao; Hu, Jin; Zhang, Qiang; Liu, Bo; Wang, Min; Xu, Hui-bo; Sun, Xiao-bo

    2014-01-01

    Aconitine is a major bioactive diterpenoid alkaloid with high content derived from herbal aconitum plants. Emerging evidence indicates that voltage-dependent Na + channels have pivotal roles in the cardiotoxicity of aconitine. However, no reports are available on the role of Ca 2+ in aconitine poisoning. In this study, we explored the importance of pathological Ca 2+ signaling in aconitine poisoning in vitro and in vivo. We found that Ca 2+ overload lead to accelerated beating rhythm in adult rat ventricular myocytes and caused arrhythmia in conscious freely moving rats. To investigate effects of aconitine on myocardial injury, we performed cytotoxicity assay in neonatal rat ventricular myocytes (NRVMs), as well as measured lactate dehydrogenase level in the culture medium of NRVMs and activities of serum cardiac enzymes in rats. The results showed that aconitine resulted in myocardial injury and reduced NRVMs viability dose-dependently. To confirm the pro-apoptotic effects, we performed flow cytometric detection, cardiac histology, transmission electron microscopy and terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling assay. The results showed that aconitine stimulated apoptosis time-dependently. The expression analysis of Ca 2+ handling proteins demonstrated that aconitine promoted Ca 2+ overload through the expression regulation of Ca 2+ handling proteins. The expression analysis of apoptosis-related proteins revealed that pro-apoptotic protein expression was upregulated, and anti-apoptotic protein BCL-2 expression was downregulated. Furthermore, increased phosphorylation of MAPK family members, especially the P-P38/P38 ratio was found in cardiac tissues. Hence, our results suggest that aconitine significantly aggravates Ca 2+ overload and causes arrhythmia and finally promotes apoptotic development via phosphorylation of P38 mitogen-activated protein kinase. - Highlights: • Aconitine-induced Ca 2+ overload causes arrhythmia in rats

  6. Mapping of the bcl-2 oncogene on mouse chromosome 1.

    Science.gov (United States)

    Mock, B A; Givol, D; D'Hoostelaere, L A; Huppi, K; Seldin, M F; Gurfinkel, N; Unger, T; Potter, M; Mushinski, J F

    1988-01-01

    Two bcl-2 alleles have been identified in inbred strains of mice by restriction fragment length polymorphism (RFLP). Analysis of a bcl-2 RFLP in a series of bilineal congenic strains (C.D2), developed as a tool for chromosomal mapping studies, revealed linkage of bcl-2 to the Idh-1/Pep-3 region of murine chromosome 1. The co-segregation of bcl-2 alleles with allelic forms of two other chromosome 1 loci, Ren-1,2 and Spna-1, in a set of back-cross progeny, positions bcl-2 7.8 cM centromeric from Ren-1,2.

  7. The targeted inhibition of mitochondrial Hsp90 overcomes the apoptosis resistance conferred by Bcl-2 in Hep3B cells via necroptosis

    Energy Technology Data Exchange (ETDEWEB)

    Yan, Chunlan [Department of Anatomy and Cell Biology, Dong-A University College of Medicine and Mitochondria Hub Regulation Center, Busan, 602-714 (Korea, Republic of); Department of Physiology, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310058 (China); Oh, Joon Seok; Yoo, Seung Hee; Lee, Jee Suk [Department of Anatomy and Cell Biology, Dong-A University College of Medicine and Mitochondria Hub Regulation Center, Busan, 602-714 (Korea, Republic of); Yoon, Young Geol [Department of Anatomy and Cell Biology, Dong-A University College of Medicine and Mitochondria Hub Regulation Center, Busan, 602-714 (Korea, Republic of); Department of Biomedical Science, Institute for Biomedical and Health Sciences, Jungwon University, Chungbuk, 367-805 (Korea, Republic of); Oh, Yoo Jin; Jang, Min Seok [Department of Anatomy and Cell Biology, Dong-A University College of Medicine and Mitochondria Hub Regulation Center, Busan, 602-714 (Korea, Republic of); Lee, Sang Yeob [Department of Rheumatology, Dong-A University College of Medicine, Busan, 602-714 (Korea, Republic of); Yang, Jun [Department of Toxicology, Hangzhou Normal University School of Public Health, Hangzhou, Zhejiang, 310036 China (China); Lee, Sang Hwa [Department of Microbiology and, Dong-A University College of Medicine, Busan, 602-714 (Korea, Republic of); Kim, Hye Young [Department of Anatomy and Cell Biology, Dong-A University College of Medicine and Mitochondria Hub Regulation Center, Busan, 602-714 (Korea, Republic of); Yoo, Young Hyun, E-mail: yhyoo@dau.ac.kr [Department of Anatomy and Cell Biology, Dong-A University College of Medicine and Mitochondria Hub Regulation Center, Busan, 602-714 (Korea, Republic of)

    2013-01-01

    Previous studies have reported that a Gamitrinib variant containing triphenylphosphonium (G-TPP) binds to mitochondrial Hsp90 and rapidly inhibits its activity, thus inducing the apoptotic pathway in the cells. Accordingly, G-TPP shows a potential as a promising drug for the treatment of cancer. A cell can die from different types of cell death such as apoptosis, necrosis, necroptosis, and autophagic cell death. In this study, we further investigated the mechanisms and modes of cell death in the G-TPP-treated Hep3B and U937 cell lines. We discovered that G-TPP kills the U937 cells through the apoptotic pathway and the overexpression of Bcl-2 significantly inhibits U937 cell death to G-TPP. We further discovered that G-TPP kills the Hep3B cells by activating necroptosis in combination with the partial activation of caspase-dependent apoptosis. Importantly, G-TPP overcomes the apoptosis resistance conferred by Bcl-2 in Hep3B cells via necroptosis. We also observed that G-TPP induces compensatory autophagy in the Hep3B cell line. We further found that whereas there is a Bcl-2-Beclin 1 interaction in response to G-TPP, silencing the beclin 1 gene failed to block LC3-II accumulation in the Hep3B cells, indicating that G-TPP triggers Beclin 1-independent protective autophagy in Hep3B cells. Taken together, these data reveal that G-TPP induces cell death through a combination of death pathways, including necroptosis and apoptosis, and overcomes the apoptosis resistance conferred by Bcl-2 in Hep3B cells via necroptosis. These findings are important for the therapeutic exploitation of necroptosis as an alternative cell death program to bypass the resistance to apoptosis. Highlights: ► G-TPP binds to mitochondrial Hsp90. ► G-TPP induces apoptosis in U937 human leukemia cancer cells. ► G-TPP induces combination of death pathways in Hep3B cell. ► G-TPP overcomes the resistance conferred by Bcl-2 in Hep3B cells via necroptosis. ► G-TPP triggers Beclin 1-independent

  8. Light induced apoptosis is accelerated in transgenic retina overexpressing human EAT/mcl-1, an anti-apoptotic bcl-2 related gene.

    Science.gov (United States)

    Shinoda, K; Nakamura, Y; Matsushita, K; Shimoda, K; Okita, H; Fukuma, M; Yamada, T; Ohde, H; Oguchi, Y; Hata, J; Umezawa, A

    2001-10-01

    EAT/mcl-1 (EAT), an immediate early gene, functions in a similar way to bcl-2 in neutralising Bax mediated cytotoxicity, suggesting that EAT is a blocker of cell death. The aim of this study was to determine the effect of overexpression of the human EAT gene on light induced retinal cell apoptosis. EAT transgenic mice incorporating the EF-1alpha promoter were utilised, and expression of human EAT was detected by RT-PCR. Light damage was induced by raising mice under constant illumination. Two groups of animals, EAT transgenic mice (n=14) and littermates (n=13), were examined by ERG testing and histopathology at regular time points up to 20 weeks of constant light stimulation. Electrophysiological and histopathological findings were evaluated by established systems of arbitrary scoring as scores 0-2 and scores 0-3, respectively. The mean score (SD) of ERG response was significantly lower in EAT transgenic mice (0.79 (0.89)) than in littermates (1.69 (0.48)) (pstatistical significance (p=0.1156), the estimated incidence of electrophysiological retinal damage was higher in EAT mice (0.0495/mouse/week; 95% confidence interval (CI) 0.0347-0.0500) than in littermates (0. 0199/mouse/week; 95% CI 0.0035-0.0364). The mean scores (SD) for histopathological retinal degeneration were 2.31 (0.63) in littermates and 1.43 (1.22) in EAT transgenic mice (p=0.065). However, Kaplan-Meier curves for histopathological failure in two groups of mice showed that retinal photoreceptor cells were preserved significantly against constant light in the littermate compared with transgenic mice (p=0.0241). The estimated incidence of histopathological retinal damage was 0.0042/mouse/week in the littermates (95% CI 0-0.0120) and 0.0419/mouse/week in the EAT mice (95% CI 0.0286-0.0500). Retinal photoreceptor cell apoptosis under constant light stimulation is likely to be accelerated in transgenic retina overexpressing EAT.

  9. Real world data on young patients with high-risk diffuse large B-cell lymphoma treated with R-CHOP or R-CHOEP - MYC, BCL2 and BCL6 as prognostic biomarkers.

    Directory of Open Access Journals (Sweden)

    Mette Ølgod Pedersen

    Full Text Available Double expression of MYC and BCL2 proteins (DE and double-hit MYC+BCL2/BCL6 translocations (DH were established as important biomarkers in patients with diffuse large B-cell lymphoma (DLBCL by the 2016 revision of the World Health Organization classification of lymphoid neoplasms. Whether this applies to the subgroup of young patients with high risk DLBCL is not known. We previously found that in a uniform retrospective population-based cohort of patients aged 18-60 years with high-risk DLBCL, the addition of etoposide to R-CHOP chemotherapy (R-CHOEP resulted in improved survival mainly in patients with germinal center B-cell like (GCB immunophenotype. The aim of this study was to investigate the prognostic and predictive value of DE and DH in this patient cohort.Data on all young Danish patients diagnosed with de novo high-risk DLBCL 2004-2008 and treated with R-CHOP or R-CHOEP were obtained from the Danish Lymphoma database (n = 159. Tumor samples were available from 103 patients. MYC and BCL2 proteins were analyzed with quantitative immunohistochemistry (IHC using different cut off values. MYC-, BCL2- and BCL6-translocations were examined with fluorescent in situ hybridization (FISH.DE with MYC>75% and BCL2>85% was an independent negative prognostic marker of progression free survival (PFS in patients treated with R-CHOP but not R-CHOEP (p<0.001, also after exclusion of patients with DH. A predictive effect of DE for response (PFS to R-CHOEP vs. R-CHOP was almost significant (p = 0.07. DH was not prognostic in this patient cohort.In young patients with high-risk DLBCL, treatment with R-CHOEP may overcome the negative prognostic impact of DE observed in patients treated with R-CHOP.

  10. Methamphetamine induces apoptosis in immortalized neural cells: protection by the proto-oncogene, bcl-2.

    Science.gov (United States)

    Cadet, J L; Ordonez, S V; Ordonez, J V

    1997-02-01

    Methamphetamine (METH) is an amphetamine analog that produces degeneration of the dopaminergic system in mammals. The neurotoxic effects of the drug are thought to be mediated by oxygen-based free radicals. In the present report, we have used immortalized neural cells obtained from rat mesencephalon in order to further assess the role of oxidative stress in METH-induced neurotoxicity. We thus tested if the anti-death proto-oncogene, bcl-2 could protect against METH-induced cytotoxicity. METH caused dose-dependent loss of cellular viability in control cells while bcl-2-expressing cells were protected against these deleterious effects. Using flow cytometry, immunofluorescent staining, and DNA electrophoresis, we also show that METH exposure can cause DNA strand breaks, chromatin condensation, nuclear fragmentation, and DNA laddering. All these changes were prevented by bcl-2 expression. These observations provide further support for the involvement of oxidative stress in the toxic effects of amphetamine analogs. They also document that METH-induced cytotoxicity is secondary to apoptosis. These findings may be of relevance to the cause(s) of Parkinson's disease which involves degeneration of the nigrostriatal dopaminergic pathway.

  11. Saponins from Panax japonicus attenuate D-galactose-induced cognitive impairment through its anti-oxidative and anti-apoptotic effects in rats.

    Science.gov (United States)

    Wang, Ting; Di, Guojie; Yang, Li; Dun, Yaoyan; Sun, Zhiwei; Wan, Jingzhi; Peng, Ben; Liu, Chaoqi; Xiong, Guangrun; Zhang, Changcheng; Yuan, Ding

    2015-09-01

    To investigate the neuroprotective effects of saponins from Panax japonicus (SPJ) on D-galactose (D-gal)-induced brain ageing, and further explore the underlying mechanisms. SPJ were analysed using high-pressure liquid chromatography. Male Wistar rats weighing 200 ± 20 g were randomly divided into four groups: control group (saline), D-gal-treated group (400 mg/kg, subcutaneously), D-gal + SPJ groups (50, 100 and 200 mg/kg, orally) and vitamin E group (100 mg/kg). Rats were injected corresponding drugs once daily for 8 weeks. Neuroprotective effects of SPJ were evaluated by Morris water maze, histopathological observations, biochemical assays, western blot analysis and quantitative real-time polymerase chain reaction (PCR) analysis in vivo as well as reactive oxygen species (ROS) measurement and apoptosis assay in vitro. Our present study showed that D-gal had a neurotoxic effect in rats and in SH-SY5Y cells due to oxidative stress induction, including decreased total anti-oxidant capacity, superoxide dismutase (SOD) and glutathione peroxidase activity, ultimately leading to spatial learning and memory impairment in rats and ROS accumulation in SH-SY5Y cells. SPJ improved spatial learning and memory deficits, attenuated hippocampus histopathological injury and restored impaired anti-oxidative as well as anti-apoptotic capacities in D-gal-induced ageing rats. In addition, SPJ remarkably decreased lipofuscin levels, increased hippocampus nuclear factor erythroid 2-related factor 2 (Nrf2) and silent mating type information regulation 2 homologue (SIRT1) protein levels and anti-oxidant genes expression such as manganese superoxide dismutase (Mn-SOD), heme oxygenase (HO-1), NAD(P)H quinone oxidoreductase 1 (NQO1) and cysteine ligase catalytic (GCLC) in D-gal-induced brain ageing. Our data suggested that D-gal induced multiple molecular and functional changes in brain similar to natural ageing process. SPJ protected brain from D-gal-induced neuronal

  12. Bcl-w, a Radio-resistant Protein, Promotes the Gastric Cancer Cell Migration by inducing the phosphorylation of Focal Adhesion Kinase

    International Nuclear Information System (INIS)

    Bae, In Hwa; Yoon, Sung Hwan; Um, Hong Duck

    2008-01-01

    Gastric cancer is one of the leading malignancies in many countries and lethal for the high incidence of recurrence even after drastic surgical resection. Because local invasion and subsequent metastasis contributes to the failure of anticancer treatments of gastric cancer, a better understanding of the mechanisms involved in tumor invasiveness within the stomach seems to be essential for the control of this disease. Bcl-w is a prosurvival member of the Bcl-2 protein family, and thus protects cells from γ-irradiation. Recent reports suggest that Bcl-w can be upregulated in gastric cancer cells in a manner associated with the infiltrative (diffuse) types of the tumor. An analysis of Bcl-w function consistently revealed that Bcl-w can also promote the migratory and invasive potentials of gastric cancer cells. While it was shown that Bcl-w increases the invasiveness of cancer cells by sequentially inducing PI3K, Akt, SP1, and MMP-2, cellular components involved in Bcl-w-induced cell migration remain to be determined. This was the reason why we undertook the present study, which shows that FAK is a critical mediator of the cell migration induced by Bcl-w

  13. Aconitine-induced Ca{sup 2+} overload causes arrhythmia and triggers apoptosis through p38 MAPK signaling pathway in rats

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Gui-bo; Sun, Hong; Meng, Xiang-bao [Key Laboratory of Bioactive Substances and Resources Utilization of Chinese Herbal Medicine, Ministry of Education, Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, 100193 (China); Hu, Jin; Zhang, Qiang; Liu, Bo [Academy of Chinese Medical Sciences of Jilin Province, Changchun, Jilin 130021 (China); Wang, Min [Key Laboratory of Bioactive Substances and Resources Utilization of Chinese Herbal Medicine, Ministry of Education, Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, 100193 (China); Xu, Hui-bo, E-mail: xhb_6505@163.com [Academy of Chinese Medical Sciences of Jilin Province, Changchun, Jilin 130021 (China); Sun, Xiao-bo, E-mail: sun_xiaobo163@163.com [Key Laboratory of Bioactive Substances and Resources Utilization of Chinese Herbal Medicine, Ministry of Education, Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, 100193 (China)

    2014-08-15

    Aconitine is a major bioactive diterpenoid alkaloid with high content derived from herbal aconitum plants. Emerging evidence indicates that voltage-dependent Na{sup +} channels have pivotal roles in the cardiotoxicity of aconitine. However, no reports are available on the role of Ca{sup 2+} in aconitine poisoning. In this study, we explored the importance of pathological Ca{sup 2+} signaling in aconitine poisoning in vitro and in vivo. We found that Ca{sup 2+} overload lead to accelerated beating rhythm in adult rat ventricular myocytes and caused arrhythmia in conscious freely moving rats. To investigate effects of aconitine on myocardial injury, we performed cytotoxicity assay in neonatal rat ventricular myocytes (NRVMs), as well as measured lactate dehydrogenase level in the culture medium of NRVMs and activities of serum cardiac enzymes in rats. The results showed that aconitine resulted in myocardial injury and reduced NRVMs viability dose-dependently. To confirm the pro-apoptotic effects, we performed flow cytometric detection, cardiac histology, transmission electron microscopy and terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling assay. The results showed that aconitine stimulated apoptosis time-dependently. The expression analysis of Ca{sup 2+} handling proteins demonstrated that aconitine promoted Ca{sup 2+} overload through the expression regulation of Ca{sup 2+} handling proteins. The expression analysis of apoptosis-related proteins revealed that pro-apoptotic protein expression was upregulated, and anti-apoptotic protein BCL-2 expression was downregulated. Furthermore, increased phosphorylation of MAPK family members, especially the P-P38/P38 ratio was found in cardiac tissues. Hence, our results suggest that aconitine significantly aggravates Ca{sup 2+} overload and causes arrhythmia and finally promotes apoptotic development via phosphorylation of P38 mitogen-activated protein kinase. - Highlights: • Aconitine-induced Ca

  14. Ellagic acid protects against neuron damage in ischemic stroke through regulating the ratio of Bcl-2/Bax expression.

    Science.gov (United States)

    Liu, Qing-Shan; Deng, Ran; Li, Shuran; Li, Xu; Li, Keqin; Kebaituli, Gulibanumu; Li, Xueli; Liu, Rui

    2017-08-01

    An oxygen-glucose deprivation and reoxygenation model in primary cultured rat cortical neurons was developed for this study to investigate the effects of ellagic acid (EA), a low-molecular-weight polyphenol, on neuron cells and their function, and to evaluate whether EA can be safely utilized by humans as a functional food or therapeutic agent. Administration of EA significantly decreased the volume of cerebrum infarction and the neurological deficit scores of the rats; EA treatment also increased the number of Bcl-2-positive cells and the ratio of Bcl-2-positive to Bax-positive neurons in the semidarkness zone near the brain ischemic focus in the photothrombotic cerebral ischemia model. Treatment of EA resulted in increased neuron viability, cell nuclear integrity, and the ratio of Bcl-2/Bax expression in the primary cultured neuron model; EA treatment also lead to a decrease in the number of apoptotic cells. Our results therefore suggest a specific mechanism for the beneficial effects of EA, providing new insights into how it provides neuroprotection. To the best of our knowledge, these results represent new insights on the mechanisms of the brain cell protective activity of EA. Thus, EA may be used in functional foods or medicines to help treat nerve dysfunction, neurodegenerative disease, and aging.

  15. Polyalthia longifolia Methanolic Leaf Extracts (PLME) induce apoptosis, cell cycle arrest and mitochondrial potential depolarization by possibly modulating the redox status in hela cells.

    Science.gov (United States)

    Vijayarathna, Soundararajan; Oon, Chern Ein; Chen, Yeng; Kanwar, Jagat R; Sasidharan, Sreenivasan

    2017-05-01

    Medicinal plants have been accepted as a gold mine, with respect to the diversity of their phytochemicals. Many medicinal plants extracts are potential anticancer agents. Polyalthia longifolia var. angustifolia Thw. (Annonaceae) is one of the most significant native medicinal plants and is found throughout Malaysia. Hence, the present study was intended to assess the anticancer properties of P. longifolia leaf methanolic extract (PLME) and its underlying mechanisms. The Annexin V/PI flow cytometry analysis showed that PLME induces apoptosis in HeLa cells in dose-dependent manner whereas the PI flow cytometric analysis for cell cycle demonstrated the accumulation of cells at sub G0/G1, G0/G1 and G2/M phases. Investigation with JC-1 flow cytometry analysis indicated increase in mitochondria membrane potential depolarisation corresponding to increase in PLME concentrations. PLME was also shown to influence intracellular reactive oxygen species (ROS) by exerting anti-oxidant (half IC 50 ) and pro-oxidant (IC 50 and double IC 50 ) affect against HeLa cells. PLME treatment also displayed DNA damage in HeLa cells in concentration depended fashion. The proteomic profiling array exposed the expression of pro-apoptotic and anti-apoptotic proteins upon PLME treatment at IC 50 concentration in HeLa cells. Pro-apoptotic proteins; BAX, BAD, cytochrome c, caspase-3, p21, p27 and p53 were found to be significantly up-regulated while anti-apoptotic proteins; BCL-2 and BCL-w were found to be significantly down-regulated. This investigation postulated the role of p53 into mediating apoptosis, cell cycle arrest and mitochondrial potential depolarisation by modulating the redox status of HeLa cells. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  16. Clusterin Reduces Cold Ischemia-Reperfusion Injury in Heart Transplantation Through Regulation of NF-kB Signaling and Bax/Bcl-xL Expression

    Directory of Open Access Journals (Sweden)

    Guodong Liu

    2018-02-01

    Full Text Available Background/Aims: Ischemia-reperfusion (I/R injury is an unavoidable event occurring during heart transplantation and is a key factor in graft failure and the long-term survival rate of recipients. Therefore, there is an urgent need for the development of new therapies to prevent I/R injury. Clusterin is a hetero-dimeric glycoprotein with an antiapoptotic function. In this study, we investigated whether clusterin was cardioprotective in heart transplantation against I/R injury using an in vivo rat model and an in vitro cell culture system, and examined the underlying mechanisms of I/R injury. Methods: Heart grafts from wild-type C57BL/6 mice were preserved in UW solution (control or UW solution containing recombinant human apolipoprotein-J (hr clusterin for 24 h. The preserved hearts were implanted into recipient mice of the same strain as the donors for 72 h, and the heart grafts were then taken for histopathological and gene expression analyses. An in vitro ischemia reperfusion model using H9C2 cells or H9C2/clusterin cDNA cells was constructed. The expression of clusterin, p65, Bax, Bcl-xL, IL-1β, and TNF-α protein and mRNA in heart tissue and H9C2 cells was detected by western blot, reverse transcription-polymerase chain reaction (RT-PCR, and quantitative RT-PCR assays; IL-1β and TNF-α protein was detected by enzyme-linked immunosorbent assays; NF-kB activity was detected by an electrophoretic mobility shift assay; cell apoptosis was detected by terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling and flow cytometric analyses. Results: Cold I/R caused severe morphologic myocardial injury to heart grafts from wild-type C57BL/6 mice, whereas grafts from hr clusterin preservation showed less damage, as demonstrated by decreased cell apoptosis/death, decreased neutrophil infiltration, and the preservation of the normal structure of the heart. Clusterin reduced the expression of p65, pre-inflammatory IL-1β, and TNF-α, and

  17. Clusterin Reduces Cold Ischemia-Reperfusion Injury in Heart Transplantation Through Regulation of NF-kB Signaling and Bax/Bcl-xL Expression.

    Science.gov (United States)

    Liu, Guodong; Zhang, Hongmei; Hao, Fengyun; Hao, Jing; Pan, Lixiao; Zhao, Qing; Wo, Jinshan

    2018-01-01

    Ischemia-reperfusion (I/R) injury is an unavoidable event occurring during heart transplantation and is a key factor in graft failure and the long-term survival rate of recipients. Therefore, there is an urgent need for the development of new therapies to prevent I/R injury. Clusterin is a hetero-dimeric glycoprotein with an antiapoptotic function. In this study, we investigated whether clusterin was cardioprotective in heart transplantation against I/R injury using an in vivo rat model and an in vitro cell culture system, and examined the underlying mechanisms of I/R injury. Heart grafts from wild-type C57BL/6 mice were preserved in UW solution (control) or UW solution containing recombinant human apolipoprotein-J (hr clusterin) for 24 h. The preserved hearts were implanted into recipient mice of the same strain as the donors for 72 h, and the heart grafts were then taken for histopathological and gene expression analyses. An in vitro ischemia reperfusion model using H9C2 cells or H9C2/clusterin cDNA cells was constructed. The expression of clusterin, p65, Bax, Bcl-xL, IL-1β, and TNF-α protein and mRNA in heart tissue and H9C2 cells was detected by western blot, reverse transcription-polymerase chain reaction (RT-PCR), and quantitative RT-PCR assays; IL-1β and TNF-α protein was detected by enzyme-linked immunosorbent assays; NF-kB activity was detected by an electrophoretic mobility shift assay; cell apoptosis was detected by terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling and flow cytometric analyses. Cold I/R caused severe morphologic myocardial injury to heart grafts from wild-type C57BL/6 mice, whereas grafts from hr clusterin preservation showed less damage, as demonstrated by decreased cell apoptosis/death, decreased neutrophil infiltration, and the preservation of the normal structure of the heart. Clusterin reduced the expression of p65, pre-inflammatory IL-1β, and TNF-α, and the pro-apoptotic gene Bax, while it enhanced the

  18. Clinicopathological and genomic analysis of double-hit follicular lymphoma: comparison with high-grade B-cell lymphoma with MYC and BCL2 and/or BCL6 rearrangements.

    Science.gov (United States)

    Miyaoka, Masashi; Kikuti, Yara Y; Carreras, Joaquim; Ikoma, Haruka; Hiraiwa, Shinichiro; Ichiki, Akifumi; Kojima, Minoru; Ando, Kiyoshi; Yokose, Tomoyuki; Sakai, Rika; Hoshikawa, Masahiro; Tomita, Naoto; Miura, Ikuo; Takata, Katsuyoshi; Yoshino, Tadashi; Takizawa, Jun; Bea, Silvia; Campo, Elias; Nakamura, Naoya

    2018-02-01

    lymphomas tended to be high-grade histology, high MYC protein expression, high MYC/IGH fusion, and minimal common region of gain at 2p16.1. Double-hit follicular lymphomas seemed to be a different disease from high-grade B-cell lymphomas with MYC and BCL2 and/or BCL6 rearrangements and have an indolent clinical behavior similar to follicular lymphomas without MYC rearrangement.

  19. Tuberin and PRAS40 are anti-apoptotic gatekeepers during early human amniotic fluid stem-cell differentiation.

    Science.gov (United States)

    Fuchs, Christiane; Rosner, Margit; Dolznig, Helmut; Mikula, Mario; Kramer, Nina; Hengstschläger, Markus

    2012-03-01

    Embryoid bodies (EBs) are three-dimensional multicellular aggregates allowing the in vitro investigation of stem-cell differentiation processes mimicking early embryogenesis. Human amniotic fluid stem (AFS) cells harbor high proliferation potential, do not raise the ethical issues of embryonic stem cells, have a lower risk for tumor development, do not need exogenic induction of pluripotency and are chromosomal stable. Starting from a single human AFS cell, EBs can be formed accompanied by the differentiation into cells of all three embryonic germ layers. Here, we report that siRNA-mediated knockdown of the endogenous tuberous sclerosis complex-2 (TSC2) gene product tuberin or of proline-rich Akt substrate of 40 kDa (PRAS40), the two major negative regulators of mammalian target of rapamycin (mTOR), leads to massive apoptotic cell death during EB development of human AFS cells without affecting the endodermal, mesodermal and ectodermal cell differentiation spectrum. Co-knockdown of endogenous mTOR demonstrated these effects to be mTOR-dependent. Our findings prove this enzyme cascade to be an essential anti-apoptotic gatekeeper of stem-cell differentiation during EB formation. These data allow new insights into the regulation of early stem-cell maintenance and differentiation and identify a new role of the tumor suppressor tuberin and the oncogenic protein PRAS40 with the relevance for a more detailed understanding of the pathogenesis of diseases associated with altered activities of these gene products.

  20. Proposed Pharmacological Countermeasures Against Apoptotic Cell Death in Experimental Models Mimicking Space Environment Damage

    Science.gov (United States)

    Lulli, Matteo; Papucci, Laura; Witort, Ewa; Donnini, Martino; Lapucci, Andrea; Lazzarano, Stefano; Mazzoni, Tiziano; Simoncini, Madine; Falciani, Piergiuseppe; Capaccioli, Sergio

    2008-06-01

    Several damaging agents have been suggested to affect human vision during long term space travels. Recently, apoptosis induced by DNA-damaging agents has emerged as frequent pathogenetic mechanism of ophthalmologic pathologies. Here, we propose two countermeasures: coenzyme Q10 and bcl-2 downregulation preventing antisense oligoribonucleotides (ORNs), aimed to inhibit cellular apoptotic death. Our studies have been carried out on retina and neuronal cultured cells treated with the following apoptotic stimuli mimicking space environment: a several-day exposure to either 3H-labeled tymidine or to the genotoxic drug doxorubicin, UV irradiation, hypoxia and glucose/growth factor starvation (Locke medium). The preliminary results clearly indicate that CoQ10, as well as bcl-2 down-regulation preventing ORNs, significantly counteract apoptosis in response to different DNA damaging agents in cultured eye and in neuronal cells. This supports the possibility that both could be optimal countermeasures against ophthalmologic lesions during space explorations.

  1. Anti-Proliferative and Apoptotic Effects of Beta-Ionone in Human Leukemia Cell Line K562

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    Zohreh Faezizadeh

    2016-06-01

    Full Text Available Background Beta-ionone is an aroma compound found in the Rosaceae family. Some evidence supported that beta-ionone has a great potential for cancer prevention. To date, the anti-proliferative and apoptotic effects of beta-ionone in human leukemia cell line K562 were not studied. Objectives Hence, we investigated whether beta-ionone could inhibit cell growth and induce apoptosis in the K562 cells. Materials and Methods In this experimental study, human leukemia cell line K562 was cultured and anti-proliferation effect of beta-ionone with different doses (25 - 400 µm at different times (24 - 96 hours on treated cells was evaluated by the MTT assay. To determine apoptosis rate, the Hoechst 33342 staining and flow cytometry was performed. Results The MTT assay showed that beta-ionone inhibited proliferation of K562 cells in a dose-dependent manner significantly (P = 0.0008. Moreover, the increased apoptotic rate was found after incubation of K562 cells with 200 µm beta-ionone. The Hoechst staining and flow cytometry analysis indicated that beta-ionone could increase apoptosis of K562 cells in a dose-dependent manner. Conclusions The results demonstrated that beta-ionone has anti-proliferative and apoptotic effects on K562 cells, and in the future may be used in the treatment of some leukemia sub-types.

  2. Protection by polyphenol extract from olive stones against apoptosis produced by oxidative stress in human neuroblastoma cells

    Science.gov (United States)

    Cortés-Castell, Ernesto; Veciana-Galindo, Carmen; Torró-Montell, Luis; Palazón-Bru, Antonio; Sirvent-Segura, Elia; Gil-Guillén, Vicente; Rizo-Baeza, Mercedes

    2016-02-16

    We evaluated the protective activity of an extract from a by-product such as olive stones, through its ability to inhibit H202 induced apoptosis in the SH-SY5Y human neuroblastoma cell line. To such end, 20,000 cells/well were cultivated and differentiation with retinoic acid was initiated. Once the cells were differentiated, apoptosis was induced with and without H2O2 extract. Finally, cDNA extraction was performed, and pro-apoptotic genes Bax and anti-apoptotic genes Bcl-2 were analyzed. Quantification of the gene expression was performed using the GAPDH gene marker. Cell viability with the extract is 97.6% (SD 5.7) with 10 mg/l and 62.8% (SD 1.2) to 50 mg/l, using 10 mg/l for the biomarker assay. The retinoic acid differentiated SH-S cell line (10 μM) shows a clear apoptosis when treated with H2O2 150 μM, with a Bax/Bcl-2 ratio of 3.75 (SD 0.80) in contrast to the differentiated control cells subjected to H2O2 and with extract, which have the same ratio of 1.02 (SD 0.01-0.03). The olive stone extract shows anti-apoptotic activity in the provoked cell death of SH-SY5Y human neuroblastoma cells in their normal state, defending them from oxidative stress which produces a significant increase in the apoptotic gene ratio in contrast to anti-apoptotic genes (Bax/Bcl-2).

  3. Evaluation of Bcl-2, Bcl-x and Cleaved Caspase-3 in Malignant Peripheral Nerve Sheath Tumors and Neurofibromas

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    KARIN S. CUNHA

    2013-11-01

    Full Text Available AIMS: To study the expression of Bcl-2, Bcl-x, as well the presence of cleaved caspase-3 in neurofibromas and malignant peripheral nerve sheath tumors. The expression of Bcl-2 and Bcl-x and the presence of cleaved caspase 3 were compared to clinicopathological features of malignant peripheral nerve sheath tumors and their impact on survival rates were also investigated. MATERIALS AND METHODS: The evaluation of Bcl-2, Bcl-x and cleaved caspase-3 was performed by immunohistochemistry using tissue microarrays in 28 malignant peripheral nerve sheath tumors and 38 neurofibromas. Immunoquantification was performed by computerized digital image analysis. CONCLUSIONS: Apoptosis is altered in neurofibromas and mainly in malignant peripheral nerve sheath tumors. High levels of cleaved caspase-3 are more common in tumors with more aggressive histological features and it is associated with lower disease free survival of patients with malignant peripheral nerve sheath tumors.

  4. Tetramethylpyrazine analogue CXC195 protects against cerebral ischemia/reperfusion-induced apoptosis through PI3K/Akt/GSK3β pathway in rats.

    Science.gov (United States)

    Chen, Lin; Wei, Xinbing; Hou, Yunfeng; Liu, Xiaoqian; Li, Senpeng; Sun, Baozhu; Liu, Xinyong; Liu, Huiqing

    2014-01-01

    CXC195 showed strongest protective effects among the ligustrazine derivatives in cells and prevented apoptosis induced by H2O2 injury. We recently demonstrated that CXC195 protected against cerebral ischemia/reperfusion (I/R) injury by its antioxidant activity. However, whether the anti-apoptotic action of CXC195 is involved in cerebral I/R injury is unknown. Here, we investigated the role of CXC195 in apoptotic processes induced by cerebral I/R and the possible signaling pathways. Male Wistar rats were submitted to transient middle cerebral artery occlusion for 2h, followed by 24h reperfusion. CXC195 was injected intraperitoneally at 2h and 12h after the onset of ischemia. The number of apoptotic cells was measured by TUNEL assay, apoptosis-related protein cleaved caspase-3, Bcl-2, Bax and the phosphorylation levels of Akt and GSK3β in ischemic penumbra were assayed by western blot. The results showed that administration of CXC195 at the doses of 3mg/kg and 10mg/kg significantly inhibited the apoptosis by decreasing the number of apoptotic cells, decreasing the level of cleaved caspase-3 and Bax, and increasing the level of Bcl-2 in rats subjected to I/R injury. Simultaneously, CXC195 treatment markedly increased the phosphorylation of Akt and GSK3β. Blockade of PI3K activity by wortmannin, dramatically abolished its anti-apoptotic effect and lowered both Akt and GSK3β phosphorylation levels. Our study firstly demonstrated that CXC195 protected against cerebral I/R injury by reducing apoptosis in vivo and PI3K/Akt/GSK3β pathway involved in the anti-apoptotic effect. Crown Copyright © 2014. Published by Elsevier Ltd. All rights reserved.

  5. Nitric oxide and bcl-2 mediated the apoptosis induced by nickel(II) in human T hybridoma cells

    International Nuclear Information System (INIS)

    Guan Fuqin; Zhang Dongmei; Wang Xinchang; Chen Junhui

    2007-01-01

    Although effects of nickel(II) on the immune system have long been recognized, little is known about the effects of nickel(II) on the induction of apoptosis and related signaling events in T cells. In the present study, we investigated the roles and signaling pathways of nickel(II) in the induction of apoptosis in a human T cell line jurkat. The results showed that the cytotoxic effects of Ni involved significant morphological changes and chromosomal condensation (Hoechst 33258 staining). Analyses of hypodiploid cells and FITC-Annexin V and PI double staining showed significant increase of apoptosis in jurkat cells 6, 12 and 24 h after nickel(II) treatment. Flow cytometry analysis also revealed that the loss of mitochondrial membrane potential (MMP) occurred concomitantly with the onset of NiCl 2 -induced apoptosis. Induction of apoptotic cell death by nickel was mediated by reduction of bcl-2 expression. Furthermore, nickel stimulated the generation of nitric oxide (NO). These results suggest that nickel(II) chloride induces jurkat cells apoptosis via nitric oxide generation, mitochondrial depolarization and bcl-2 suppression

  6. Moxifloxacin and ciprofloxacin induces S-phase arrest and augments apoptotic effects of cisplatin in human pancreatic cancer cells via ERK activation

    International Nuclear Information System (INIS)

    Yadav, Vikas; Varshney, Pallavi; Sultana, Sarwat; Yadav, Jyoti; Saini, Neeru

    2015-01-01

    Pancreatic cancer, one of the most dreadful gastrointestinal tract malignancies, with the current chemotherapeutic drugs has posed a major impediment owing to poor prognosis and chemo-resistance thereby suggesting critical need for additional drugs as therapeutics in combating the situation. Fluoroquinolones have shown promising and significant anti-tumor effects on several carcinoma cell lines. Previously, we reported growth inhibitory effects of fourth generation fluoroquinolone Gatifloxacin, while in the current study we have investigated the anti-proliferative and apoptosis-inducing mechanism of older generation fluoroquinolones Moxifloxacin and Ciprofloxacin on the pancreatic cancer cell-lines MIA PaCa-2 and Panc-1. Cytotoxicity was measured by MTT assay. Apoptosis induction was evaluated using annexin assay, cell cycle assay and activation of caspase-3, 8, 9 were measured by western blotting and enzyme activity assay. Herein, we found that both the fluoroquinolones suppressed the proliferation of pancreatic cancer cells by causing S-phase arrest and apoptosis. Blockade in S-phase of cell cycle was associated with decrease in the levels of p27, p21, CDK2, cyclin-A and cyclin-E. Herein we also observed triggering of extrinsic as well as intrinsic mitochondrial apoptotic pathway as suggested by the activation of caspase-8, 9, 3, and Bid respectively. All this was accompanied by downregulation of antiapoptotic protein Bcl-xL and upregulation of proapoptotic protein Bak. Our results strongly suggest the role of extracellular-signal-regulated kinases (ERK1/2), but not p53, p38 and c-JUN N-terminal kinase (JNK) in fluoroquinolone induced growth inhibitory effects in both the cell lines. Additionally, we also found both the fluoroquinolones to augment the apoptotic effects of broad spectrum anticancer drug Cisplatin via ERK. The fact that these fluoroquinolones synergize the effect of cisplatin opens new insight into therapeutic index in treatment of pancreatic

  7. Mutational analysis of Bax and Bcl-2 in childhood acute lymphoblastic leukaemia

    NARCIS (Netherlands)

    Salomons, G. S.; Buitenhuis, C. K.; Martínez Muñoz, C.; Verwijs-Jassen, M.; Behrendt, H.; Zsiros, J.; Smets, L. A.

    1998-01-01

    In childhood acute lymphoblastic leukaemia there are large interpatient variations in levels of the apoptosis-regulating proteins Bax and Bcl-2, but the molecular basis for this variation is unknown. Point-mutations in bax have been reported in cell lines derived from haematological malignancies.

  8. Therapeutic potential of genistein in ovariectomy-induced pancreatic injury in diabetic rats: The regulation of MAPK pathway and apoptosis

    Directory of Open Access Journals (Sweden)

    Hadi Yousefi

    2017-09-01

    Full Text Available Objective(s: Genistein, as a phytoestrogen found in legumes, has several biological activities in general and anti-diabetic activity particularly. In this study, we investigated the effect of genistein on proteins involved in β-cell proliferation, survival and apoptosis to further reveal its anti-diabetic potential in the ovariectomized diabetic rat. Materials and Methods: We used three-month-old female Wistar rats that either underwent ovariectomy (OVX or received a sham surgery (Sham. In a subsequent series of experiments, OVX rats received high-fat diet and low dose STZ to induce diabetes (OVX.D and genistein treatment (OVX.D.G. Western blot analysis was used for the assessment of phosphorylation of ERK1/2 and AKT and expression of Bcl-2 and caspase-3 in pancreas tissue. Hematoxylin-Eosin (H&E staining was used for histopathological assessment. Results: Genistein induced AKT and ERK1/2 phosphorylation protein expression of Bcl-2 in the pancreas. In addition, genistein suppressed protein level of caspase-3. Administration of genistein significantly improved hyperglycemia in ovariectomized diabetic rat, concomitant with improved islet β-cell morphology and mass. Conclusion: These findings suggest that the beneficial antidiabetic effect of genistein partially mediated by directly modulating pancreatic β-cell function via activation of the AKT, ERK1/2, and Bcl-2, as cell survival and anti-apoptotic factors, and decreasing of proapoptotic caspase-3.

  9. Conjugated linoleic acid induces apoptosis through estrogen receptor alpha in human breast tissue

    International Nuclear Information System (INIS)

    Wang, Li-Shu; Huang, Yi-Wen; Liu, Suling; Yan, Pearlly; Lin, Young C

    2008-01-01

    Conjugated linoleic acid (CLA), a naturally occurring fatty acid found in ruminant products such as milk and beef, has been shown to possess anti-cancer activities in in vivo animal models and in vitro cell culture systems. In human breast cancer, the overall duration of estrogen exposure is the most important risk factor for developing estrogen-responsive breast cancer. Accordingly, it has been suggested that estrogen exposure reduces apoptosis through the up-regulation of the anti-apoptosis protein, Bcl-2. Bcl-2, an anti-apoptotic protein, regulates apoptosis and plays a crucial role in the development and growth regulation of normal and cancerous cells. Our research interest is to examine the effects of CLA on the induction of apoptosis in human breast tissues. The localization of Bcl-2 in both normal and cancerous human breast tissues was determined by immunohistochemical staining and the Bcl-2 protein expression was tested by western blot analysis. Co-culture of epithelial cells and stromal cells was carried out in the presence or absence of CLA to evaluate apoptosis in the context of a cell-cell interaction. The results showed that both normal and cancerous breast tissues were positive for Bcl-2 staining, which was higher overall in mammary ducts but very low in the surrounding stromal compartment. Interestingly, by quantifying the western blot data, basal Bcl-2 protein levels were higher in normal breast epithelial cells than in cancerous epithelial cells. Furthermore, treatment with 17β-estradiol (E 2 ) stimulated growth and up-regulated Bcl-2 expression in estrogen responsive breast epithelial cells; however, these carcinogenic effects were diminished by either CLA or 4-Hydroxytamoxifen (Tam) and were suppressed further by the combination of CLA and Tam. In both one cell type cultured and co-culture systems, CLA induced cell apoptosis in ERα transfected MDA-MB-231 cells but not in the wild type MDA-MB-231 cells. These data, therefore, demonstrate that

  10. Conjugated linoleic acid induces apoptosis through estrogen receptor alpha in human breast tissue

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    Liu Suling

    2008-07-01

    Full Text Available Abstract Background Conjugated linoleic acid (CLA, a naturally occurring fatty acid found in ruminant products such as milk and beef, has been shown to possess anti-cancer activities in in vivo animal models and in vitro cell culture systems. In human breast cancer, the overall duration of estrogen exposure is the most important risk factor for developing estrogen-responsive breast cancer. Accordingly, it has been suggested that estrogen exposure reduces apoptosis through the up-regulation of the anti-apoptosis protein, Bcl-2. Bcl-2, an anti-apoptotic protein, regulates apoptosis and plays a crucial role in the development and growth regulation of normal and cancerous cells. Our research interest is to examine the effects of CLA on the induction of apoptosis in human breast tissues. Methods The localization of Bcl-2 in both normal and cancerous human breast tissues was determined by immunohistochemical staining and the Bcl-2 protein expression was tested by western blot analysis. Co-culture of epithelial cells and stromal cells was carried out in the presence or absence of CLA to evaluate apoptosis in the context of a cell-cell interaction. Results The results showed that both normal and cancerous breast tissues were positive for Bcl-2 staining, which was higher overall in mammary ducts but very low in the surrounding stromal compartment. Interestingly, by quantifying the western blot data, basal Bcl-2 protein levels were higher in normal breast epithelial cells than in cancerous epithelial cells. Furthermore, treatment with 17β-estradiol (E2 stimulated growth and up-regulated Bcl-2 expression in estrogen responsive breast epithelial cells; however, these carcinogenic effects were diminished by either CLA or 4-Hydroxytamoxifen (Tam and were suppressed further by the combination of CLA and Tam. In both one cell type cultured and co-culture systems, CLA induced cell apoptosis in ERα transfected MDA-MB-231 cells but not in the wild type MDA

  11. U1 Adaptor Oligonucleotides Targeting BCL2 and GRM1 Suppress Growth of Human Melanoma Xenografts In Vivo

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    Rafal Goraczniak

    2013-01-01

    Full Text Available U1 Adaptor is a recently discovered oligonucleotide-based gene-silencing technology with a unique mechanism of action that targets nuclear pre-mRNA processing. U1 Adaptors have two distinct functional domains, both of which must be present on the same oligonucleotide to exert their gene-silencing function. Here, we present the first in vivo use of U1 Adaptors by targeting two different human genes implicated in melanomagenesis, B-cell lymphoma 2 (BCL2 and metabotropic glutamate receptor 1 (GRM1, in a human melanoma cell xenograft mouse model system. Using a newly developed dendrimer delivery system, anti-BCL2 U1 Adaptors were very potent and suppressed tumor growth at doses as low as 34 µg/kg with twice weekly intravenous (iv administration. Anti-GRM1 U1 Adaptors suppressed tumor xenograft growth with similar potency. Mechanism of action was demonstrated by showing target gene suppression in tumors and by observing that negative control U1 Adaptors with just one functional domain show no tumor suppression activity. The anti-BCL2 and anti-GRM1 treatments were equally effective against cell lines harboring either wild-type or a mutant V600E B-RAF allele, the most common mutation in melanoma. Treatment of normal immune-competent mice (C57BL6 indicated no organ toxicity or immune stimulation. These proof-of-concept studies represent an in-depth (over 800 mice in ~108 treatment groups validation that U1 Adaptors are a highly potent gene-silencing therapeutic and open the way for their further development to treat other human diseases.

  12. Combined Targeting of BCL-2 and BCR-ABL Tyrosine Kinase Eradicates Chronic Myeloid Leukemia Stem Cells

    Science.gov (United States)

    Mak, Po Yee; Mu, Hong; Zhou, Hongsheng; Mak, Duncan H.; Schober, Wendy; Leverson, Joel D.; Zhang, Bin; Bhatia, Ravi; Huang, Xuelin; Cortes, Jorge; Kantarjian, Hagop; Konopleva, Marina

    2016-01-01

    BCR-ABL tyrosine kinase inhibitors (TKIs) are effective against chronic myeloid leukemia (CML), but they rarely eliminate CML stem cells. Disease relapse is common upon therapy cessation, even in patients with complete molecular responses. Furthermore, once CML progresses to blast crisis (BC), treatment outcomes are dismal. We hypothesized that concomitant targeting of BCL-2 and BCR-ABL tyrosine kinase could overcome these limitations. We demonstrate increased BCL-2 expression at the protein level in bone marrow cells, particularly in Lin−Sca-1+cKit+ cells of inducible CML in mice as determined by CyTOF mass cytometry. Further, selective inhibition of BCL-2, aided by TKI-mediated MCL-1 and BCL-XL inhibition, markedly decreased leukemic Lin−Sca-1+cKit+ cell numbers and long-term stem cell frequency, and prolonged survival in a murine CML model. Additionally, this combination effectively eradicated CD34+CD38−, CD34+CD38+, and quiescent stem/progenitor CD34+ cells from BC CML patient samples. Our results suggest that BCL-2 is a key survival factor for CML stem/progenitor cells and that combined inhibition of BCL-2 and BCR-ABL tyrosine kinase has the potential to significantly improve depth of response and cure rates of chronic phase and BC CML. PMID:27605552

  13. Prognostic Importance of Bcl-2 Expression in Colon Cancer

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    Arsenal Alikanoðlu

    2012-09-01

    Full Text Available Aim: TNM classification, that had been established according to pathologic and anatomic characteristics of the lesion , is the most important factor in decision of adjuvant therapy in colon cancer. Despite curative resection, recurrence can ocur with a rate of 20-30% in early stage disease. Therefore efficieny of TNM classification is controversial. In recent years ,significance of molecular characteristics of the tumors besides their anatomic and pathologic characteristics in determining the biological behaviour and response to treatment have been discussed. In our study, relation between expression of Bcl-2 and the other known prognostic factors in colon cancer had been searched. Material and Method: Patients who had been followed up in our clinic were enrolled in this study. Expression of Bcl-2 was searched by immunohistochemical method. Results: A total of 52, 19 (%36.5 female and 33 (%63.5 male patients were enrolled in this study. Bcl-2 expression was found positive in 7 (%13.5 and negative in 45 (%86.5 patients. Statistically no significant relationship was found between Bcl-2 expression and sex, stage, regional lymph node involvement, presence of distant metastasis and histologic grade. Discussion: In our study, although not in a statistical significance, we found that Bcl-2 expression is related to early stage disease. Bcl-2 is a low-priced and easily accessible prognostic marker. We think that establishing expression of Bcl-2 by immunohistohemistry may play a role in determining prognosis of patients with colon cancer.

  14. Isoegomaketone induces apoptosis in SK-MEL-2 human melanoma cells through mitochondrial apoptotic pathway via activating the PI3K/Akt pathway.

    Science.gov (United States)

    Kwon, Soon-Jae; Lee, Ju-Hye; Moon, Kwang-Deog; Jeong, Il-Yun; Yee, Sung-Tae; Lee, Mi-Kyung; Seo, Kwon-Il

    2014-11-01

    Isoegomaketone (IK) is a major biologically active component of Perilla frutescens. In this study, we investigated the contribution of reactive oxygen species (ROS) to IK-induced apoptosis in human melanoma SK-MEL-2 cells. We found that IK inhibited the proliferation of SK-MEL-2 human melanoma cells in a dose-dependent manner. IK also induced sub-G1 DNA accumulation, formation of apoptotic bodies, nuclear condensation, and a DNA ladder in SK-MEL-2 cells. IK also induced activation of caspase-3 and -9, whereas caspase‑8 was unaffected. Further, N-acetyl-L-cysteine (NAC, ROS scavenger) treatment to SK-MEL-2 cells significantly reduced IK-induced cell death. Pretreatment of NAC to SK-MEL-2 cells followed by 100 µM IK reduced the protein levels of Bax and cytochrome c as well as PARP cleavage, whereas the protein level of Bcl-2 increased. Moreover, IK inhibited the phosphorylation of AKT/mTOR protein and cell proliferation induced by LY294002, a PI3K inhibitor. In conclusion, IK-induced ROS generation regulates cell growth inhibition and it induces apoptosis through caspase‑dependent and -independent pathways via modulation of PI3K/AKT signaling in SK-MEL-2 cells.

  15. Inter- and intratumoral heterogeneity of BCL2 correlates with IgH expression and prognosis in follicular lymphoma

    International Nuclear Information System (INIS)

    Barreca, A; Martinengo, C; Annaratone, L; Righi, L; Chiappella, A; Ladetto, M; Demurtas, A; Chiusa, L; Stacchini, A; Crosetto, N; Oudenaarden, A van; Chiarle, R

    2014-01-01

    Most follicular lymphomas (FLs) are genetically defined by the t(14;18)(q32;q21) translocation that juxtaposes the BCL2 gene to the immunoglobulin heavy chain (IgH) 3' regulatory regions (IgH-3'RRs). Despite this recurrent translocation, FL cases are heterogeneous in terms of intratumoral clonal diversity for acquired mutations and variations in the tumor microenvironment. Here we describe an additional mechanism that contributes to inter- and intratumoral heterogeneity in FLs. By applying a novel single-molecule RNA fluorescence-based in situ hybridization (FISH) technique to detect mRNA molecules of BCL2 and IgH in single cells, we found marked heterogeneity in the number of BCL2 mRNA transcripts within individual lymphoma cells. Moreover, BCL2 mRNA molecules correlated with IgH mRNA molecules in individual cells both in t(14;18) lymphoma cell lines and in patient samples. Consistently, a strong correlation between BCL2 and IgH protein levels was found in a series of 205 primary FL cases by flow cytometry and immunohistochemistry. Inter- and intratumoral heterogeneity of BCL2 expression determined resistance to drugs commonly used in FL treatment and affected overall survival of FL patients. These data demonstrate that BCL2 and IgH expressions are heterogeneous and coregulated in t(14;18)-translocated cells, and determine the response to therapy in FL patients

  16. Pentoxifylline sensitizes human cervical tumor cells to cisplatin-induced apoptosis by suppressing NF-kappa B and decreased cell senescence

    International Nuclear Information System (INIS)

    Hernandez-Flores, Georgina; Bravo-Cuellar, Alejandro; Ortiz-Lazareno, Pablo C; Lerma-Diaz, Jose Manuel; Dominguez-Rodriguez, Jorge R; Jave-Suarez, Luis F; Aguilar-Lemarroy, Adriana del C; Celis-Carrillo, Ruth de; Toro-Arreola, Susana del; Castellanos-Esparza, Yessica C

    2011-01-01

    Worldwide, cervical cancer is the second most common causes of cancer in women and represents an important mortality rate. Cisplatin (CIS) is a very important antitumoral agent and can lead tumor cells toward two important cellular states: apoptosis and senescence. In some types of cancers pentoxifylline (PTX) sensitizes these cells to the toxic action of chemotherapeutics drugs such as adriamycin, inducing apoptosis. In the present work, we studied in vitro whether PTX alone or in combination with CIS induces apoptosis and/or senescence in cervix cancer HeLa and SiHa cell lines infected with HPV types 16 and 18, respectively, as well as in immortalized keratinocytyes HaCaT cells. HeLa (HPV 18+), SiHa (HPV 16+) cervix cancer cells and non-tumorigenic immortalized HaCaT cells (control) were treated with PTX, CIS or both. The cellular toxicity and survival fraction of PTX and CIS were determinate by WST-1 and clonogenic assays respectively. Apoptosis, caspase activation and phosphorylation of ERK1/2, p38, p65 (NF-κB), Bcl-2 and Bcl-XL anti-apoptotic proteins were determinated by flow cytometry. Senescence by microscopy. Phosphorylation of IκBα and IκB total were measured by ELISA. Pro-apoptotic, anti-apoptotic and senescence genes, as well as HPV-E6/7 mRNA expression, were detected by RT-PCR. Our results show that after 24 hours of incubation PTX per se is toxic for cancer cells affecting cell viability and inducing apoptosis. The toxicity in HaCaT cells was minimal. CIS induces apoptosis in HeLa and SiHa cells and its effect was significantly increases when the cells were treated with PTX + CIS. In all studies there was a direct correlation with levels of caspases (-3, -6, -7, -9 and -8) activity and apoptosis. CIS induces important levels of senescence and phosphorylation of ERK1/2, p38, p65/RELA, and IκBα, and decreased the expression of anti-apoptotic protein Bcl-XL. Surprisingly these levels were significantly reduced by PTX in tumor cells, and at the same

  17. Effect of citral on the cytotoxicity of doxorubicin in human B-lymphoma cells.

    Science.gov (United States)

    Dangkong, Darinee; Limpanasithikul, Wacharee

    2015-02-01

    Doxorubicin is a chemotherapy agent used in non-Hodgkin's lymphoma but side effects limit its use. Citral is a mixture of neral and geranial found in essential oils of lemon grass. We evaluated the activity of citral, doxorubicin, and combination on cytotoxicity, apoptosis, and anti-proliferative effects using human lymphoma Ramos cells. Cells were treated with doxorubicin alone or in combination with citral (10, 20, and 40 μM). Cytotoxic and apoptosis studies were done after 24 and 18 h incubations, respectively. Cytotoxic effects of citral on normal human peripheral blood mononuclear cells (PBMCs) were also investigated for its safety. Changes in the expression of BCL-2 family genes were analyzed by quantitative RT-PCR. Citral had cytotoxicity on cells with an IC50 value of 77.19 ± 4.95 µM. Citral at concentrations of 10, 20, and 40 µM additively increased the cytotoxic and apoptotic effects of doxorubicin, leading to decreased IC50 (µM) of the drug from 2.50 ± 0.01 to 2.16 ± 0.03, 1.90 ± 0.04, and 1.23 ± 0.04, respectively. Enhanced cytotoxicity was not observed in normal human PBMCs. Citral (40 µM) in combination with doxorubicin (1.5 µM) increased the expression of pro-apoptotic protein BAK but significantly decreased the expression of anti-apoptotic protein BCL-XL to 5.26-fold compared with doxorubicin-treated cells. It did not change the anti-proliferative activity of drug. Citral potentiated cytotoxicity of doxorubicin by increasing apoptotic effects. We conclude that citral may have beneficial effects in patients with B cell lymphoma treated with chemotherapy.

  18. Maternal exposure to titanium dioxide nanoparticles during pregnancy and lactation alters offspring hippocampal mRNA BAX and Bcl-2 levels, induces apoptosis and decreases neurogenesis.

    Science.gov (United States)

    Ebrahimzadeh Bideskan, Alireza; Mohammadipour, Abbas; Fazel, Alireza; Haghir, Hossein; Rafatpanah, Houshang; Hosseini, Mahmoud; Rajabzadeh, Aliakbar

    2017-07-05

    The usage of Titanium dioxide nanoparticles (TiO 2 -NPs) covers a vast area in different fields ranging from cosmetics and food to the production of drugs. Maternal exposure to TiO 2 -NPs during developmental period has been associated with hippocampal injury and with a decrease in learning and memory status of the offspring. However, little is known about its injury mechanism. This paper describes the in vivo neurotoxic effects of TiO 2 -NPs on rat offspring hippocampus during developmental period. Pregnant and lactating Wistar rats received intragastric TiO 2 -NPs (100mg/kg body weight) daily from gestational day (GD) 2 to (GD) 21 and postnatal day (PD) 2 to (PD) 21 respectively. Animals in the control groups received an equal volume of distilled water via gavage. At the end of the treatment process, offspring were deeply anesthetized and sacrificed. Then brains of each group were collected and sections of the rat offspring's brains were stained using TUNEL staining (for detection of apoptotic cells) and immunostaining (for neurogenesis). Moreover, the right hippocampus (n=6 per each group) were removed from the right hemisphere for evaluating the expression of Bax and Bcl-2 level. Results of histopatological examination by TUNEL staining showed that maternal exposure to TiO 2 -NPs during pregnancy and lactation periods increased apoptotic cells significantly (P<0.01) in the offspring hippocampus. The immunolabeling of double cortin (DCX) protein as neurogenesis marker also showed that TiO 2 -NPs reduced neurogenesis in the hippocampus of the offspring (P<0.05). Moreover, in comparison with the control group, the mRNA levels of Bax and Bcl-2 in the TiO 2 -NPs group significantly increased and decreased, respectively (P<0.01). These findings provide strong evidence that maternal exposure to TiO 2 -NPs significantly impact hippocampal neurogenesis and apoptosis in the offspring. The potential impact of nanoparticle exposure for millions of pregnant mothers and

  19. 1-(2,6-Dihydroxy-4-methoxyphenyl-2-(4-hydroxyphenyl Ethanone-Induced Cell Cycle Arrest in G1/G0 in HT-29 Cells Human Colon Adenocarcinoma Cells

    Directory of Open Access Journals (Sweden)

    Ma Ma Lay

    2014-01-01

    Full Text Available 1-(2,6-Dihydroxy-4-methoxyphenyl-2-(4-hydroxyphenyl ethanone (DMHE was isolated from the ethyl acetate fraction of Phaleria macrocarpa (Scheff. Boerl fruits and the structure confirmed by GC-MS (gas chromatography-mass spectrometry and NMR (nuclear magnetic resonance analysis. This compound was tested on the HT-29 human colon adenocarcinoma cell line using MTT (method of transcriptional and translational cell proliferation assay. The results of MTT assay showed that DMHE exhibited good cytotoxic effect on HT-29 cells in a dose- and time-dependent manner but no cytotoxic effect on the MRC-5 cell line after 72 h incubation. Morphological features of apoptotic cells upon treatment by DMHE, e.g., cell shrinkage and membrane blebbing, were examined by an inverted and phase microscope. Other features, such as chromatin condension and nuclear fragmentation were studied using acridine orange and propidium iodide staining under the fluorescence microscope. Future evidence of apoptosis/necrosis was provided by result fromannexin V-FITC/PI (fluorescein-isothiocyanate/propidium iodide staining revealed the percentage of early apoptotic, late apoptotic, necrotic and live cells in a dose- and time-dependent manner using flow cytometry. Cell cycle analysis showed G0/G1 arrest in a time-dependent manner. A western blot analysis indicated that cell death might be associated with the up-regulation of the pro-apoptotic proteins Bax PUMA. However, the anit-apotptic proteins Bcl-2, Bcl-xL, and Mcl-1 were also found to increase in a time-dependent manner. The expression of the pro-apoptotic protein Bak was not observed.

  20. Apoptose e expressão de Bcl-2 e das caspases 3 e 8 em placenta bovina, em diferentes estádios de gestação Apoptosis and expression of Bcl-2 and caspases 3 and 8 in placenta of cows at different pregnancy stages

    Directory of Open Access Journals (Sweden)

    K.K.O.L. Meça

    2010-04-01

    Full Text Available Apoptose e seus mecanismos reguladores são eventos fisiológicos cruciais para a manutenção da homeostase placentária, e o desequilíbrio desses processos pode comprometer a função placentária e, consequentemente, o sucesso da gravidez. Neste estudo, investigou-se a apoptose utilizando-se histomorfometria em lâminas coradas em HE e submetidas à reação de TUNEL. Além disso, avaliou-se a expressão de Bcl-2 e das caspases 8 e 3, pela reação de polimerase em cadeia em tempo real, em placentas saudáveis em diferentes estádios de gestação. Amostras de placentônios de vacas com quatro, seis e nove meses de gestação foram colhidas e processadas. O índice apoptótico aumentou progressivamente com o avanço da gestação. Tanto o Bcl-2 quanto as caspases 3 e 8 foram expressas nos três períodos estudados, sendo a expressão de Bcl-2 menor que a de caspase 8, que é menor que a de caspase 3. Estes resultados indicam que essas moléculas estão envolvidas na via apoptótica ativada na maturação placentária, exibindo um padrão de expressão ao longo da gestação e contribuindo para o equilíbrio fisiológico da celularidade e renovação celular na placenta bovina.Apoptosis and its regulating mechanisms are crucial physiological events for the maintenance of the placental homostasis; and disequilibrium of these processes may compromise placental function and the success of the pregnancy. In this study, apoptosis was investigated by histomorphometry using slides stained with HE and TUNEL reaction. Besides that, Bcl-2 and caspases 8 and 3 expression were evaluated by real time polymerase chain reaction in healthy placentas under different gestacional ages. Samples of placentones of cows at 4th, 6th, and 9th months of gestation were harvested and processed. The apoptotic index gradually increased with the advance of the gestation. Bcl-2 and caspases 3 and 8 were expressed in all the studied periods, being the expression of Bcl-2