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Sample records for growth cycle arrest

  1. Growth inhibitory effect of 4-phenyl butyric acid on human gastric cancer cells is associated with cell cycle arrest.

    Science.gov (United States)

    Li, Long-Zhu; Deng, Hong-Xia; Lou, Wen-Zhu; Sun, Xue-Yan; Song, Meng-Wan; Tao, Jing; Xiao, Bing-Xiu; Guo, Jun-Ming

    2012-01-07

    To investigate the growth effects of 4-phenyl butyric acid (PBA) on human gastric carcinoma cells and their mechanisms. Moderately-differentiated human gastric carcinoma SGC-7901 and lowly-differentiated MGC-803 cells were treated with 5, 10, 20, 40, and 60 μmol/L PBA for 1-4 d. Cell proliferation was detected using the MTT colorimetric assay. Cell cycle distributions were examined using flow cytometry. The proliferation of gastric carcinoma cells was inhibited by PBA in a dose- and time-dependent fashion. Flow cytometry showed that SGC-7901 cells treated with low concentrations of PBA were arrested at the G₀/G₁ phase, whereas cells treated with high concentrations of PBA were arrested at the G₂/M phase. Although MGC-803 cells treated with low concentrations of PBA were also arrested at the G₀/ G₁ phase, cells treated with high concentrations of PBA were arrested at the S phase. The growth inhibitory effect of PBA on gastric cancer cells is associated with alteration of the cell cycle. For moderately-differentiated gastric cancer cells, the cell cycle was arrested at the G₀ /G₁ and G₂/M phases. For lowly-differentiated gastric cancer cells, the cell cycle was arrested at the G₀/G₁ and S phases.

  2. Impacts of weld residual stresses and fatigue crack growth threshold on crack arrest under high-cycle thermal fluctuations

    International Nuclear Information System (INIS)

    Taheri, Said; Julan, Emricka; Tran, Xuan-Van; Robert, Nicolas

    2017-01-01

    Highlights: • For crack growth analysis, weld residual stress field must be considered through its SIF in presence of a crack. • Presence of cracks of same depth proves their arrest, where equal depth is because mean stress acts only on crack opening. • Not considering amplitudes under a fatigue crack growth threshold (FCGT) does not compensate the lack of FGCT in Paris law. • Propagation rates are close for axisymmetric and circumferential semi-elliptical cracks. - Abstract: High cycle thermal crazing has been observed in some residual heat removal (RHR) systems made of 304 stainless steel in PWR nuclear plants. This paper deals with two types of analyses including logical argumentation and simulation. Crack arrest in networks is demonstrated due to the presence of two cracks of the same depth in the network. This identical depth may be proved assuming that mean stress acts only on crack opening and that cracks are fully open during the load cycle before arrest. Weld residual stresses (WRS) are obtained by an axisymmetric simulation of welding on a tube with a chamfer. Axisymmetric and 3D parametric studies of crack growth on: representative sequences for variable amplitude thermal loading, fatigue crack growth threshold (FCGT), permanent mean stress, cyclic counting methods and WRS, are performed with Code-Aster software using XFEM methodology. The following results are obtained on crack depth versus time: the effect of WRS on crack growth cannot be determined by the initial WRS field in absence of crack, but by the associated stress intensity factor. Moreover the relation between crack arrest depth and WRS is analyzed. In the absence of FCGT Paris’s law may give a significant over-estimation of crack depth even if amplitudes of loading smaller than FCGT have not been considered. Appropriate depth versus time may be obtained using different values of FCGT, but axisymmetric simulations do not really show a possibility of arrest for shallow cracks in

  3. Impacts of weld residual stresses and fatigue crack growth threshold on crack arrest under high-cycle thermal fluctuations

    Energy Technology Data Exchange (ETDEWEB)

    Taheri, Said, E-mail: Said.taheri@edf.fr [EDF-LAB, IMSIA, 7 Boulevard Gaspard Monge, 91120 Palaiseau Cedex (France); Julan, Emricka [EDF-LAB, AMA, 7 Boulevard Gaspard Monge, 91120 Palaiseau Cedex (France); Tran, Xuan-Van [EDF Energy R& D UK Centre/School of Mechanical, Aerospace and Civil Engineering, The University of Manchester, Manchester M13 9PL (United Kingdom); Robert, Nicolas [EDF-DPN, UNIE, Strategic Center, Saint Denis (France)

    2017-01-15

    Highlights: • For crack growth analysis, weld residual stress field must be considered through its SIF in presence of a crack. • Presence of cracks of same depth proves their arrest, where equal depth is because mean stress acts only on crack opening. • Not considering amplitudes under a fatigue crack growth threshold (FCGT) does not compensate the lack of FGCT in Paris law. • Propagation rates are close for axisymmetric and circumferential semi-elliptical cracks. - Abstract: High cycle thermal crazing has been observed in some residual heat removal (RHR) systems made of 304 stainless steel in PWR nuclear plants. This paper deals with two types of analyses including logical argumentation and simulation. Crack arrest in networks is demonstrated due to the presence of two cracks of the same depth in the network. This identical depth may be proved assuming that mean stress acts only on crack opening and that cracks are fully open during the load cycle before arrest. Weld residual stresses (WRS) are obtained by an axisymmetric simulation of welding on a tube with a chamfer. Axisymmetric and 3D parametric studies of crack growth on: representative sequences for variable amplitude thermal loading, fatigue crack growth threshold (FCGT), permanent mean stress, cyclic counting methods and WRS, are performed with Code-Aster software using XFEM methodology. The following results are obtained on crack depth versus time: the effect of WRS on crack growth cannot be determined by the initial WRS field in absence of crack, but by the associated stress intensity factor. Moreover the relation between crack arrest depth and WRS is analyzed. In the absence of FCGT Paris’s law may give a significant over-estimation of crack depth even if amplitudes of loading smaller than FCGT have not been considered. Appropriate depth versus time may be obtained using different values of FCGT, but axisymmetric simulations do not really show a possibility of arrest for shallow cracks in

  4. A novel peptide sansalvamide analogue inhibits pancreatic cancer cell growth through G0/G1 cell-cycle arrest

    International Nuclear Information System (INIS)

    Ujiki, Michael B.; Milam, Ben; Ding Xianzhong; Roginsky, Alexandra B.; Salabat, M. Reza; Talamonti, Mark S.; Bell, Richard H.; Gu Wenxin; Silverman, Richard B.; Adrian, Thomas E.

    2006-01-01

    Patients with pancreatic cancer have little hope for cure because no effective therapies are available. Sansalvamide A is a cyclic depsipeptide produced by a marine fungus. We investigated the effect of a novel sansalvamide A analogue on growth, cell-cycle phases, and induction of apoptosis in human pancreatic cancer cells in vitro. The sansalvamide analogue caused marked time- and concentration-dependent inhibition of DNA synthesis and cell proliferation of two human pancreatic cancer cell lines (AsPC-1 and S2-013). The analogue induced G0/G1 phase cell-cycle arrest and morphological changes suggesting induction of apoptosis. Apoptosis was confirmed by annexin V binding. This novel sansalvamide analogue inhibits growth of pancreatic cancer cells through G0/G1 arrest and induces apoptosis. Sansalvamide analogues may be valuable for the treatment of pancreatic cancer

  5. Isoalantolactone inhibits UM-SCC-10A cell growth via cell cycle arrest and apoptosis induction.

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    Minjun Wu

    Full Text Available Isoalantolactone is a sesquiterpene lactone compound isolated from the roots of Inula helenium L. Previous studies have demonstrated that isoalantolactone possesses antifungal, anti-bacterial, anti-helminthic and anti-proliferative properties in a variety of cells, but there are no studies concerning its effects on head and neck squamous cell carcinoma (HNSCC. In the present study, an MTT assay demonstrated that isoalantolactone has anti-proliferative activity against the HNSCC cell line (UM-SCC-10A. Immunostaining identified that this compound induced UM-SCC-10A cell apoptosis but not necrosis. To explain the molecular mechanisms underlying its effects, flow cytometry and western blot analysis showed that the apoptosis was associated with cell cycle arrest during the G1 phase, up-regulation of p53 and p21, and down-regulation of cyclin D. Furthermore, our results revealed that induction of apoptosis through a mitochondrial pathway led to up-regulation of pro-apoptotic protein expression (Bax, down-regulation of anti-apoptotic protein expression (Bcl-2, mitochondrial release of cytochrome c (Cyto c, reduction of mitochondrial membrane potential (MMP and activation of caspase-3 (Casp-3. Involvement of the caspase apoptosis pathway was confirmed using caspase inhibitor Z-VAD-FMK pretreatment. Together, our findings suggest that isoalantolactone induced caspase-dependent apoptosis via a mitochondrial pathway and was associated with cell cycle arrest in the G1 phase in UM-SCC-10A cells. Therefore, isoalantolactone may become a potential drug for treating HNSCC.

  6. TEAD4-YAP interaction regulates tumoral growth by controlling cell-cycle arrest at the G1 phase

    International Nuclear Information System (INIS)

    Takeuchi, Shin; Kasamatsu, Atsushi; Yamatoji, Masanobu; Nakashima, Dai; Endo-Sakamoto, Yosuke; Koide, Nao; Takahara, Toshikazu; Shimizu, Toshihiro; Iyoda, Manabu; Ogawara, Katsunori; Shiiba, Masashi; Tanzawa, Hideki; Uzawa, Katsuhiro

    2017-01-01

    TEA domain transcription factor 4 (TEAD4), which has critical functions in the process of embryonic development, is expressed in various cancers. However, the important role of TEAD4 in human oral squamous cell carcinomas (OSCCs) remain unclear. Here we investigated the TEAD4 expression level and the functional mechanism in OSCC using quantitative reverse transcriptase-polymerase chain reaction, Western blot analysis, and immunohistochemistry. Furthermore, TEAD4 knockdown model was used to evaluate cellular proliferation, cell-cycle analysis, and the interaction between TEAD4 and Yes-associated protein (YAP) which was reported to be a transcription coactivator of cellular proliferation. In the current study, we found that TEAD4 expression increased significantly in vitro and in vivo and correlated with tumoral size in OSCC patients. TEAD4 knockdown OSCC cells showed decreased cellular proliferation resulting from cell-cycle arrest in the G1 phase by down-regulation of cyclins, cyclin-dependent kinases (CDKs), and up-regulation of CDK inhibitors. We also found that the TEAD4-YAP complex in the nuclei may be related closely to transcriptions of G1 arrest-related genes. Taken together, we concluded that TEAD4 might play an important role in tumoral growth and have potential to be a therapeutic target in OSCCs. - Highlights: • TEAD4 contributes to tumor progression in OSCCs. • TEAD4 knockdown results in cell-cycle arrest at the G1phase in OSCC cells. • In TEAD4 knockdown cells, the amount of YAP in the nucleus decreases. • Activation of the TEAD4-YAP complex is an important factor in OSCC tumor growth. • TEAD4 might be a critical biomarker and a therapeutic target for OSCCs.

  7. H4 histamine receptors mediate cell cycle arrest in growth factor-induced murine and human hematopoietic progenitor cells.

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    Anne-France Petit-Bertron

    Full Text Available The most recently characterized H4 histamine receptor (H4R is expressed preferentially in the bone marrow, raising the question of its role during hematopoiesis. Here we show that both murine and human progenitor cell populations express this receptor subtype on transcriptional and protein levels and respond to its agonists by reduced growth factor-induced cell cycle progression that leads to decreased myeloid, erythroid and lymphoid colony formation. H4R activation prevents the induction of cell cycle genes through a cAMP/PKA-dependent pathway that is not associated with apoptosis. It is mediated specifically through H4R signaling since gene silencing or treatment with selective antagonists restores normal cell cycle progression. The arrest of growth factor-induced G1/S transition protects murine and human progenitor cells from the toxicity of the cell cycle-dependent anticancer drug Ara-C in vitro and reduces aplasia in a murine model of chemotherapy. This first evidence for functional H4R expression in hematopoietic progenitors opens new therapeutic perspectives for alleviating hematotoxic side effects of antineoplastic drugs.

  8. NBPF1, a tumor suppressor candidate in neuroblastoma, exerts growth inhibitory effects by inducing a G1 cell cycle arrest

    International Nuclear Information System (INIS)

    Andries, Vanessa; Vandepoele, Karl; Staes, Katrien; Berx, Geert; Bogaert, Pieter; Van Isterdael, Gert; Ginneberge, Daisy; Parthoens, Eef; Vandenbussche, Jonathan; Gevaert, Kris; Roy, Frans van

    2015-01-01

    NBPF1 (Neuroblastoma Breakpoint Family, member 1) was originally identified in a neuroblastoma patient on the basis of its disruption by a chromosomal translocation t(1;17)(p36.2;q11.2). Considering this genetic defect and the frequent genomic alterations of the NBPF1 locus in several cancer types, we hypothesized that NBPF1 is a tumor suppressor. Decreased expression of NBPF1 in neuroblastoma cell lines with loss of 1p36 heterozygosity and the marked decrease of anchorage-independent clonal growth of DLD1 colorectal carcinoma cells with induced NBPF1 expression further suggest that NBPF1 functions as tumor suppressor. However, little is known about the mechanisms involved. Expression of NBPF was analyzed in human skin and human cervix by immunohistochemistry. The effects of NBPF1 on the cell cycle were evaluated by flow cytometry. We investigated by real-time quantitative RT-PCR the expression profile of a panel of genes important in cell cycle regulation. Protein levels of CDKN1A-encoded p21 CIP1/WAF1 were determined by western blotting and the importance of p53 was shown by immunofluorescence and by a loss-of-function approach. LC-MS/MS analysis was used to investigate the proteome of DLD1 colon cancer cells with induced NBPF1 expression. Possible biological interactions between the differentially regulated proteins were investigated with the Ingenuity Pathway Analysis tool. We show that NBPF is expressed in the non-proliferative suprabasal layers of squamous stratified epithelia of human skin and cervix. Forced expression of NBPF1 in HEK293T cells resulted in a G1 cell cycle arrest that was accompanied by upregulation of the cyclin-dependent kinase inhibitor p21 CIP1/WAF1 in a p53-dependent manner. Additionally, forced expression of NBPF1 in two p53-mutant neuroblastoma cell lines also resulted in a G1 cell cycle arrest and CDKN1A upregulation. However, CDKN1A upregulation by NBPF1 was not observed in the DLD1 cells, which demonstrates that NBPF1 exerts cell

  9. Stromal interaction molecule 1 (STIM1) silencing inhibits tumor growth and promotes cell cycle arrest and apoptosis in hypopharyngeal carcinoma.

    Science.gov (United States)

    Sun, Yuanhao; Cui, Xiaobo; Wang, Jun; Wu, Shuai; Bai, Yunfei; Wang, Yaping; Wang, Boqian; Fang, Jugao

    2015-05-01

    As an important pathway maintaining the balance of intracellular calcium (Ca(2+)), store-operated Ca(2+) entry (SOCE) is critical for cellular functions. Stromal interaction molecule 1 (STIM1), a key component of SOCE, plays a dual role as an endoplasmic reticulum Ca(2+) receptor and an SOCE exciter. Aberrant expression of STIM1 could be discovered in several human cancer cells. However, the role of STIM1 in regulating human hypopharyngeal carcinoma still remains unclear. Real-time polymerase chain reaction (PCR) was used to detect expression of STIM1 in human hypopharyngeal carcinoma cell line FaDu. STIM1 on FaDu cells was knocked down by lentiviral transduction method. The biological impacts after knocking down of STIM1 on FaDu cells were investigated in vitro and in vivo. The result of real-time PCR showed that STIM1 was expressed in FaDu cells. Lentiviral transduction efficiently downregulated the expression of STIM1 in FaDu cells at both mRNA and protein levels. Significant downregulation of STIM1 on FaDu cells inhibited cell proliferation, induced cell cycle arrest in G0/G1 phase, promoted cell apoptosis, and restrained cell growth rate. The antigrowth effect of STIM1 silencing was also discovered in FaDu hypopharyngeal tumor model. Our findings indicate that STIM1 is likely to become a new therapeutic target for hypopharyngeal carcinoma treatment.

  10. Andrographis paniculata extracts and major constituent diterpenoids inhibit growth of intrahepatic cholangiocarcinoma cells by inducing cell cycle arrest and apoptosis.

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    Suriyo, Tawit; Pholphana, Nanthanit; Rangkadilok, Nuchanart; Thiantanawat, Apinya; Watcharasit, Piyajit; Satayavivad, Jutamaad

    2014-05-01

    Andrographis paniculata is an important herbal medicine widely used in several Asian countries for the treatment of various diseases due to its broad range of pharmacological activities. The present study reports that A. paniculata extracts potently inhibit the growth of liver (HepG2 and SK-Hep1) and bile duct (HuCCA-1 and RMCCA-1) cancer cells. A. paniculata extracts with different contents of major diterpenoids, including andrographolide, 14-deoxy-11,12-didehydroandrographolide, neoandrographolide, and 14-deoxyandrographolide, exhibited a different potency of growth inhibition. The ethanolic extract of A. paniculata at the first true leaf stage, which contained a high amount of 14-deoxyandrographolide but a low amount of andrographolide, showed a cytotoxic effect to cancer cells about 4 times higher than the water extract of A. paniculata at the mature leaf stage, which contained a high amount of andrographolide but a low amount of 14-deoxyandrographolide. Andrographolide, not 14-deoxy-11,12-didehydroandrographolide, neoandrographolide, or 14-deoxyandrographolide, possessed potent cytotoxic activity against the growth of liver and bile duct cancer cells. The cytotoxic effect of the water extract of A. paniculata at the mature leaf stage could be explained by the present amount of andrographolide, while the cytotoxic effect of the ethanolic extract of A. paniculata at the first true leaf stage could not. HuCCA-1 cells showed more sensitivity to A. paniculata extracts and andrographolide than RMCCA-1 cells. Furthermore, the ethanolic extract of A. paniculata at the first true leaf stage increased cell cycle arrest at the G0/G1 and G2/M phases, and induced apoptosis in both HuCCA-1 and RMCCA-1 cells. The expressions of cyclin-D1, Bcl-2, and the inactive proenzyme form of caspase-3 were reduced by the ethanolic extract of A. paniculata in the first true leaf stage treatment, while a proapoptotic protein Bax was increased. The cleavage of poly (ADP

  11. Hericium erinaceus polysaccharide-protein HEG-5 inhibits SGC-7901 cell growth via cell cycle arrest and apoptosis.

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    Zan, Xinyi; Cui, Fengjie; Li, Yunhong; Yang, Yan; Wu, Di; Sun, Wenjing; Ping, Lifeng

    2015-05-01

    HEG-5 is a novel polysaccharide-protein purified from the fermented mycelia of Hericium erinaceus CZ-2. The present study aims to investigate the effects of HEG-5 on proliferation, cell cycle and apoptosis of human gastric cancer cells SGC-7901. Here, we first uncover that HEG-5 significantly inhibited the proliferation and colony formation of SGC-7901 cells by promoting apoptosis and cell cycle arrest at S phase. RT-PCR and Western blot analysis suggested that HEG-5 could decrease the expressions of Bcl2, PI3K and AKT1, while increase the expressions of Caspase-8, Caspase-3, p53, CDK4, Bax and Bad. These findings indicated that the Caspase-8/-3-dependent, p53-dependent mitochondrial-mediated and PI3k/Akt signaling pathways involved in the molecular events of HEG-5 induced apoptosis and cell cycle arrest. Thus, our study provides in vitro evidence that HEG-5 may be taken as a potential candidate for treating gastric cancer. Copyright © 2015 Elsevier B.V. All rights reserved.

  12. Casticin impairs cell growth and induces cell apoptosis via cell cycle arrest in human oral cancer SCC-4 cells.

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    Chou, Guan-Ling; Peng, Shu-Fen; Liao, Ching-Lung; Ho, Heng-Chien; Lu, Kung-Wen; Lien, Jin-Cherng; Fan, Ming-Jen; La, Kuang-Chi; Chung, Jing-Gung

    2018-02-01

    Casticin, a polymethoxyflavone, present in natural plants, has been shown to have biological activities including anti-cancer activities. Herein, we investigated the anti-oral cancer activity of casticin on SCC-4 cells in vitro. Viable cells, cell cycle distribution, apoptotic cell death, reactive oxygen species (ROS) production, and Ca 2+ production, levels of ΔΨ m and caspase activity were measured by flow cytometric assay. Cell apoptosis associated protein expressions were examined by Western blotting and confocal laser microscopy. Results indicated that casticin induced cell morphological changes, DNA condensation and damage, decreased the total viable cells, induced G 2 /M phase arrest in SCC-4 cells. Casticin promoted ROS and Ca 2+ productions, decreases the levels of ΔΨ m , promoted caspase-3, -8, and -9 activities in SCC-4 cells. Western blotting assay demonstrated that casticin affect protein level associated with G2/M phase arrest and apoptosis. Confocal laser microscopy also confirmed that casticin increased the translocation of AIF and cytochrome c in SCC-4 cells. In conclusion, casticin decreased cell number through G 2 /M phase arrest and the induction of cell apoptosis through caspase- and mitochondria-dependent pathways in SCC-4 cells. © 2017 Wiley Periodicals, Inc.

  13. Effects of gamma-radiation on cell growth, cycle arrest, death, and superoxide dismutase expression by DU 145 human prostate cancer cells

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    Vucic V.

    2006-01-01

    Full Text Available Gamma-irradiation (gamma-IR is extensively used in the treatment of hormone-resistant prostate carcinoma. The objective of the present study was to investigate the effects of 60Co gamma-IR on the growth, cell cycle arrest and cell death of the human prostate cancer cell line DU 145. The viability of DU 145 cells was measured by the Trypan blue exclusion assay and the 3(4,5-dimethylthiazol-2-yl-2,5,diphenyltetrazolium bromide test. Bromodeoxyuridine incorporation was used for the determination of cell proliferation. Cell cycle arrest and cell death were analyzed by flow cytometry. Superoxide dismutase (SOD, specifically CuZnSOD and MnSOD protein expression, after 10 Gy gamma-IR, was determined by Western immunoblotting analysis. gamma-IR treatment had a significant (P < 0.001 antiproliferative and cytotoxic effect on DU 145 cells. Both effects were time and dose dependent. Also, the dose of gamma-IR which inhibited DNA synthesis and cell proliferation by 50% was 9.7 Gy. Furthermore, gamma-IR induced cell cycle arrest in the G2/M phase and the percentage of cells in the G2/M phase was increased from 15% (control to 49% (IR cells, with a nonsignificant induction of apoptosis. Treatment with 10 Gy gamma-IR for 24, 48, and 72 h stimulated CuZnSOD and MnSOD protein expression in a time-dependent manner, approximately by 3- to 3.5-fold. These data suggest that CuZnSOD and MnSOD enzymes may play an important role in the gamma-IR-induced changes in DU 145 cell growth, cell cycle arrest and cell death.

  14. A class of DNA-binding peptides from wheat bud causes growth inhibition, G2 cell cycle arrest and apoptosis induction in HeLa cells

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    Elgjo Kjell

    2009-07-01

    Full Text Available Abstract Background Deproteinized DNA from eukaryotic and prokaryotic cells still contains a low-molecular weight peptidic fraction which can be dissociated by alkalinization of the medium. This fraction inhibits RNA transcription and tumor cell growth. Removal from DNA of normal cells causes amplification of DNA template activity. This effect is lower or absent in several cancer cell lines. Likewise, the amount of active peptides in cancer cell DNA extracts is lower than in DNA preparation of the corresponding normal cells. Such evidence, and their ubiquitous presence, suggests that they are a regulatory, conserved factor involved in the control of normal cell growth and gene expression. Results We report that peptides extracted from wheat bud chromatin induce growth inhibition, G2 arrest and caspase-dependent apoptosis in HeLa cells. The growth rate is decreased in cells treated during the S phase only and it is accompanied by DNA damage and DNA synthesis inhibition. In G2 cells, this treatment induces inactivation of the CDK1-cyclin B1 complex and an increase of active chk1 kinase expression. Conclusion The data indicate that the chromatin peptidic pool inhibits HeLa cell growth by causing defective DNA replication which, in turn, arrests cell cycle progression to mitosis via G2 checkpoint pathway activation.

  15. The Growth Suppressing Effects of Girinimbine on Hepg2 Involve Induction of Apoptosis and Cell Cycle Arrest

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    Tang Sook Wah

    2011-08-01

    Full Text Available Murraya koenigii is an edible herb widely used in folk medicine. Here we report that girinimbine, a carbazole alkaloid isolated from this plant, inhibited the growth and induced apoptosis in human hepatocellular carcinoma, HepG2 cells. The MTT and LDH assay results showed that girinimbine decreased cell viability and increased cytotoxicity in a dose-and time-dependent manner selectively. Girinimbine-treated HepG2 cells showed typical morphological features of apoptosis, as observed from normal inverted microscopy and Hoechst 33342 assay. Furthermore, girinimbine treatment resulted in DNA fragmentation and elevated levels of caspase-3 in HepG2 cells. Girinimbine treatment also displayed a time-dependent accumulation of the Sub-G0/G1 peak (hypodiploid and caused G0/G1-phase arrest. Together, these results demonstrated for the first time that girinimbine could effectively induce programmed cell death in HepG2 cells and suggests the importance of conducting further investigations in preclinical human hepatocellular carcinoma models, especially on in vivo efficacy, to promote girinimbine for use as an anticancer agent against hepatocellular carcinoma.

  16. Cell cycle arrest induced by radiation

    International Nuclear Information System (INIS)

    Okaichi, Yasuo; Matsumoto, Hideki; Ohnishi, Takeo

    1994-01-01

    It is known that various chemical reactions, such as cell cycle arrest, DNA repair and cell killing, can occur within the cells when exposed to ionizing radiation and ultraviolet radiation. Thus protein dynamics involved in such chemical reactions has received considerable attention. In this article, cell cycle regulation is first discussed in terms of the G2/M-phase and the G1/S-phase. Then, radiation-induced cell cycle arrest is reviewed. Cell cycle regulation mechanism involved in the G2 arrest, which is well known to occur when exposed to radiation, has recently been investigated using yeasts. In addition, recent study has yielded a noticeable finding that the G1 arrest can occur with intracellular accumulation of p53 product following ionization radiation. p53 is also shown to play an extremely important role in both DNA repair and cell killing due to DNA damage. Studies on the role of genes in protein groups induced by radiation will hold promise for the elucidation of cell cycle mechanism. (N.K.) 57 refs

  17. UV-B inhibition of hypocotyl growth in etiolated Arabidopsis thaliana seedlings is a consequence of cell cycle arrest initiated by photodimer accumulation

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    Biever, Jessica J.; Brinkman, Doug; Gardner, Gary

    2014-01-01

    Ultraviolet (UV) radiation is an important constituent of sunlight that determines plant morphology and growth. It induces photomorphogenic responses but also causes damage to DNA. Arabidopsis mutants of the endonucleases that function in nucleotide excision repair, xpf-3 and uvr1-1, showed hypersensitivity to UV-B (280–320nm) in terms of inhibition of hypocotyl growth. SOG1 is a transcription factor that functions in the DNA damage signalling response after γ-irradiation. xpf mutants that carry the sog1-1 mutation showed hypocotyl growth inhibition after UV-B irradiation similar to the wild type. A DNA replication inhibitor, hydroxyurea (HU), also inhibited hypocotyl growth in etiolated seedlings, but xpf-3 was not hypersensitive to HU. UV-B irradiation induced accumulation of the G2/M-specific cell cycle reporter construct CYCB1;1-GUS in wild-type Arabidopsis seedlings that was consistent with the expected accumulation of photodimers and coincided with the time course of hypocotyl growth inhibition after UV-B treatment. Etiolated mutants of UVR8, a recently described UV-B photoreceptor gene, irradiated with UV-B showed inhibition of hypocotyl growth that was not different from that of the wild type, but they lacked UV-B-specific expression of chalcone synthase (CHS), as expected from previous reports. CHS expression after UV-B irradiation was not different in xpf-3 compared with the wild type, nor was it altered after HU treatment. These results suggest that hypocotyl growth inhibition by UV-B light in etiolated Arabidopsis seedlings, a photomorphogenic response, is dictated by signals originating from UV-B absorption by DNA that lead to cell cycle arrest. This process occurs distinct from UVR8 and its signalling pathway responsible for CHS induction. PMID:24591052

  18. Licoricidin inhibits the growth of SW480 human colorectal adenocarcinoma cells in vitro and in vivo by inducing cycle arrest, apoptosis and autophagy

    Energy Technology Data Exchange (ETDEWEB)

    Ji, Shuai [State Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences, Peking University, 38 Xueyuan Road, Beijing 100191 (China); Jiangsu Key Laboratory of New Drug Research and Clinical Pharmacy, School of Pharmacy, Xuzhou Medical University, 209 Tongshan Road, Xuzhou 221004 (China); Tang, Shunan; Li, Kai; Li, Ziwei; Liang, Wenfei; Qiao, Xue; Wang, Qi [State Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences, Peking University, 38 Xueyuan Road, Beijing 100191 (China); Yu, Siwang, E-mail: swang_yu@bjmu.edu.cn [State Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences, Peking University, 38 Xueyuan Road, Beijing 100191 (China); Ye, Min, E-mail: yemin@bjmu.edu.cn [State Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences, Peking University, 38 Xueyuan Road, Beijing 100191 (China)

    2017-07-01

    Licorice (Glycyrrhiza uralensis Fisch.) possesses significant anti-cancer activities, but the active ingredients and underlying mechanisms have not been revealed. By screening the cytotoxic activities of 122 licorice compounds against SW480 human colorectal adenocarcinoma cells, we found that licoricidin (LCD) inhibited SW480 cell viability with an IC{sub 50} value of 7.2 μM. Further studies indicated that LCD significantly induced G1/S cell cycle arrest and apoptosis in SW480 cells, accompanied by inhibition of cyclins/CDK1 expression and activation of caspase-dependent pro-apoptotic signaling. Meanwhile, LCD promoted autophagy in SW480 cells, and activated AMPK signaling and inhibited Akt/mTOR pathway. Overexpression of a dominant-negative AMPKα2 abolished LCD-induced inhibition of Akt/mTOR, autophagic and pro-apoptotic signaling pathways, and significantly reversed loss of cell viability, suggesting activation of AMPK is essential for the anti-cancer activity of LCD. In vivo anti-tumor experiments indicated that LCD (20 mg/kg, i.p.) significantly inhibited the growth of SW480 xenografts in nude mice with an inhibitory rate of 43.5%. In addition, we obtained the glycosylated product LCDG by microbial transformation, and found that glycosylation slightly enhanced the in vivo anti-cancer activities of LCD. This study indicates that LCD could inhibit SW480 cells by inducing cycle arrest, apoptosis and autophagy, and is a potential chemopreventive or chemotherapeutic agent against colorectal cancer. - Highlights: • Molecular mechanisms for cytotoxic activity of licoricidin (LCD) were investigated. • LCD promoted autophagy of SW480 cells through AMPK and Akt/mTOR signaling pathways. • Both LCD and its glucoside showed in vivo anti-colorectal cancer activities.

  19. Paeoniflorin inhibits cell growth and induces cell cycle arrest through inhibition of FoxM1 in colorectal cancer cells.

    Science.gov (United States)

    Yue, Meng; Li, Shiquan; Yan, Guoqiang; Li, Chenyao; Kang, Zhenhua

    2018-01-01

    Paeoniflorin (PF) exhibits tumor suppressive functions in a variety of human cancers. However, the function of PF and molecular mechanism in colorectal cancer are elusive. In the present study, we investigated whether PF could exert its antiproliferative activity, anti-migration, and anti-invasive function in colorectal cancer cells. We found that PF inhibited cell growth and induced apoptosis and blocked cell cycle progression in the G0/G1 phase in colorectal cancer cells. Moreover, we found that PF suppressed cell migration and invasion in colorectal cancer cells. FoxM1 has been reported to play an important oncogenic role in human cancers. We also determine whether PF inhibited the expression of FoxM1, leading to its anti-cancer activity. We found that PF treatment in colorectal cancer cells resulted in down-regulation of FoxM1. The rescue experiments showed that overexpression of FoxM1 abrogated the tumor suppressive function induced by PF treatment. Notably, depletion of FoxM1 promoted the anti-tumor activity of PF in colorectal cancer cells. Therefore, inhibition of FoxM1 could participate in the anti-tumor activity of PF in colorectal cancer cells.

  20. A novel muscarinic antagonist R2HBJJ inhibits non-small cell lung cancer cell growth and arrests the cell cycle in G0/G1.

    Directory of Open Access Journals (Sweden)

    Nan Hua

    Full Text Available Lung cancers express the cholinergic autocrine loop, which facilitates the progression of cancer cells. The antagonists of mAChRs have been demonstrated to depress the growth of small cell lung cancers (SCLCs. In this study we intended to investigate the growth inhibitory effect of R2HBJJ, a novel muscarinic antagonist, on non-small cell lung cancer (NSCLC cells and the possible mechanisms. The competitive binding assay revealed that R2HBJJ had a high affinity to M3 and M1 AChRs. R2HBJJ presented a strong anticholinergic activity on carbachol-induced contraction of guinea-pig trachea. R2HBJJ markedly suppressed the growth of NSCLC cells, such as H1299, H460 and H157. In H1299 cells, both R2HBJJ and its leading compound R2-PHC displayed significant anti-proliferative activity as M3 receptor antagonist darifenacin. Exogenous replenish of ACh could attenuate R2HBJJ-induced growth inhibition. Silencing M3 receptor or ChAT by specific-siRNAs resulted in a growth inhibition of 55.5% and 37.9% on H1299 cells 96 h post transfection, respectively. Further studies revealed that treatment with R2HBJJ arrested the cell cycle in G0/G1 by down-regulation of cyclin D1-CDK4/6-Rb. Therefore, the current study reveals that NSCLC cells express an autocrine and paracrine cholinergic system which stimulates the growth of NSCLC cells. R2HBJJ, as a novel mAChRs antagonist, can block the local cholinergic loop by antagonizing predominantly M3 receptors and inhibit NSCLC cell growth, which suggest that M3 receptor antagonist might be a potential chemotherapeutic regimen for NSCLC.

  1. Antitumor action of 3-bromopyruvate implicates reorganized tumor growth regulatory components of tumor milieu, cell cycle arrest and induction of mitochondria-dependent tumor cell death.

    Science.gov (United States)

    Yadav, Saveg; Kujur, Praveen Kumar; Pandey, Shrish Kumar; Goel, Yugal; Maurya, Babu Nandan; Verma, Ashish; Kumar, Ajay; Singh, Rana Pratap; Singh, Sukh Mahendra

    2018-01-15

    Evidences demonstrate that metabolic inhibitor 3-bromopyruvate (3-BP) exerts a potent antitumor action against a wide range of malignancies. However, the effect of 3-BP on progression of the tumors of thymic origin remains unexplored. Although, constituents of tumor microenvironment (TME) plays a pivotal role in regulation of tumor progression, it remains unclear if 3-BP can alter the composition of the crucial tumor growth regulatory components of the external surrounding of tumor cells. Thus, the present investigation attempts to understand the effect of 3-BP administration to a host bearing a progressively growing tumor of thymic origin on tumor growth regulatory soluble, cellular and biophysical components of tumor milieu vis-à-vis understanding its association with tumor progression, accompanying cell cycle events and mode of cell death. Further, the expression of cell survival regulatory molecules and hemodynamic characteristics of the tumor milieu were analysed to decipher mechanisms underlying the antitumor action of 3-BP. Administration of 3-BP to tumor-bearing hosts retarded tumor progression accompanied by induction of tumor cell death, cell cycle arrest, declined metabolism, inhibited mitochondrial membrane potential, elevated release of cytochrome c and altered hemodynamics. Moreover, 3-BP reconstituted the external milieu, in concurrence with deregulated glucose and pH homeostasis and increased tumor infiltration by NK cells, macrophages, and T lymphocytes. Further, 3-BP administration altered the expression of key regulatory molecules involved in glucose uptake, intracellular pH and tumor cell survival. The outcomes of this study will help in optimizing the therapeutic application of 3-BP by targeting crucial tumor growth regulatory components of tumor milieu. Copyright © 2017 Elsevier Inc. All rights reserved.

  2. SOX4 inhibits GBM cell growth and induces G0/G1 cell cycle arrest through Akt-p53 axis.

    Science.gov (United States)

    Zhang, Jing; Jiang, Huawei; Shao, Jiaofang; Mao, Ruifang; Liu, Jie; Ma, Yingying; Fang, Xuefeng; Zhao, Na; Zheng, Shu; Lin, Biaoyang

    2014-11-01

    SOX4 is a transcription factor required for tissue development and differentiation in vertebrates. Overexpression of SOX4 has been reported in many cancers including glioblastoma multiforme (GBM), however, the underlying mechanism of actions has not been studied. In this study, we investigated the role of SOX4 in GBM. Kaplan-Meier analysis was performed to assess the association between SOX4 expression levels and survival times in primary GBM samples. Cre/lox P system was used to generate gain or loss of SOX4 in GBM cells, and microarray analysis uncovered the regulation network of SOX4 in GBM cells. High SOX4 expression was significantly associated with good prognosis of primary GBMs. SOX4 inhibited the growth of GBM cell line LN229, A172G and U87MG, partly via the activation of p53-p21 signaling and down-regulation of phosphorylated AKT1. Gene expression profiling and subsequent gene ontology analysis showed that SOX4 influenced several key pathways including the Wnt/ beta-catenin and TGF-beta signaling pathways. Our study found that SOX4 acts as a tumor suppressor in GBM cells by induce cell cycle arrest and inhibiting cell growth.

  3. Tofacitinib induces G1 cell-cycle arrest and inhibits tumor growth in Epstein-Barr virus-associated T and natural killer cell lymphoma cells.

    Science.gov (United States)

    Ando, Shotaro; Kawada, Jun-Ichi; Watanabe, Takahiro; Suzuki, Michio; Sato, Yoshitaka; Torii, Yuka; Asai, Masato; Goshima, Fumi; Murata, Takayuki; Shimizu, Norio; Ito, Yoshinori; Kimura, Hiroshi

    2016-11-22

    Epstein-Barr virus (EBV) infects not only B cells, but also T cells and natural killer (NK) cells, and is associated with T or NK cell lymphoma. These lymphoid malignancies are refractory to conventional chemotherapy. We examined the activation of the JAK3/STAT5 pathway in EBV-positive and -negative B, T and NK cell lines and in cell samples from patients with EBV-associated T cell lymphoma. We then evaluated the antitumor effects of the selective JAK3 inhibitor, tofacitinib, against these cell lines in vitro and in a murine xenograft model. We found that all EBV-positive T and NK cell lines and patient samples tested displayed activation of the JAK3/STAT5 pathway. Treatment of these cell lines with tofacitinib reduced the levels of phospho-STAT5, suppressed proliferation, induced G1 cell-cycle arrest and decreased EBV LMP1 and EBNA1 expression. An EBV-negative NK cell line was also sensitive to tofacitinib, whereas an EBV-infected NK cell line was more sensitive to tofacitinib than its parental line. Tofacitinib significantly inhibited the growth of established tumors in NOG mice. These findings suggest that tofacitinib may represent a useful therapeutic agent for patients with EBV-associated T and NK cell lymphoma.

  4. Distinct mechanisms act in concert to mediate cell cycle arrest.

    Science.gov (United States)

    Toettcher, Jared E; Loewer, Alexander; Ostheimer, Gerard J; Yaffe, Michael B; Tidor, Bruce; Lahav, Galit

    2009-01-20

    In response to DNA damage, cells arrest at specific stages in the cell cycle. This arrest must fulfill at least 3 requirements: it must be activated promptly; it must be sustained as long as damage is present to prevent loss of genomic information; and after the arrest, cells must re-enter into the appropriate cell cycle phase to ensure proper ploidy. Multiple molecular mechanisms capable of arresting the cell cycle have been identified in mammalian cells; however, it is unknown whether each mechanism meets all 3 requirements or whether they act together to confer specific functions to the arrest. To address this question, we integrated mathematical models describing the cell cycle and the DNA damage signaling networks and tested the contributions of each mechanism to cell cycle arrest and re-entry. Predictions from this model were then tested with quantitative experiments to identify the combined action of arrest mechanisms in irradiated cells. We find that different arrest mechanisms serve indispensable roles in the proper cellular response to DNA damage over time: p53-independent cyclin inactivation confers immediate arrest, whereas p53-dependent cyclin downregulation allows this arrest to be sustained. Additionally, p21-mediated inhibition of cyclin-dependent kinase activity is indispensable for preventing improper cell cycle re-entry and endoreduplication. This work shows that in a complex signaling network, seemingly redundant mechanisms, acting in a concerted fashion, can achieve a specific cellular outcome.

  5. Growth arrest despite growth hormone replacement, post-craniopharyngioma surgery.

    Science.gov (United States)

    DeVile, C J; Hayward, R D; Neville, B G; Grant, D B; Stanhope, R

    1995-01-01

    Children with growth failure, whether secondary to an endocrinopathy such as growth hormone deficiency or secondary to neurological handicap with poor nutrient intake, grow at a subnormal rate but it is most unusual for a child to have complete growth arrest. PMID:7745571

  6. Caffeic acid phenethyl ester induced cell cycle arrest and growth inhibition in androgen-independent prostate cancer cells via regulation of Skp2, p53, p21Cip1 and p27Kip1

    OpenAIRE

    Lin, Hui-Ping; Lin, Ching-Yu; Huo, Chieh; Hsiao, Ping-Hsuan; Su, Liang-Cheng; Jiang, Shih Sheng; Chan, Tzu-Min; Chang, Chung-Ho; Chen, Li-Tzong; Kung, Hsing-Jien; Wang, Horng-Dar; Chuu, Chih-Pin

    2015-01-01

    Prostate cancer (PCa) patients receiving the androgen ablation therapy ultimately develop recurrent castration-resistant prostate cancer (CRPC) within 1?3 years. Treatment with caffeic acid phenethyl ester (CAPE) suppressed cell survival and proliferation via induction of G1 or G2/M cell cycle arrest in LNCaP 104-R1, DU-145, 22Rv1, and C4?2 CRPC cells. CAPE treatment also inhibited soft agar colony formation and retarded nude mice xenograft growth of LNCaP 104-R1 cells. We identified that CAP...

  7. Alpinia pricei Rhizome Extracts Induce Cell Cycle Arrest in Human Squamous Carcinoma KB Cells and Suppress Tumor Growth in Nude Mice

    Directory of Open Access Journals (Sweden)

    You-Cheng Hseu

    2011-01-01

    Full Text Available Alpinia pricei has been shown to induce apoptosis in human squamous carcinoma (KB cells. In this study, we report the effectiveness of the ethanol (70% extracts of A. pricei rhizome (AP extracts in terms of tumor regression as determined using both in vitro cell culture and in vivo athymic nude mice models of KB cells. We found that the AP extract (25–200 μg/mL treatment decreased the proliferation of KB cells by arresting progression through the G2/M phase of the cell cycle. This cell cycle blockade was associated with reductions in cyclin A and B1, Cdc2, and Cdc25C, and increased p21/WAF1, Wee1, p53 and phospho-p53 (p-p53 in a dose- and time-dependent manner. Moreover, we found that AP extract treatment decreased metalloproteinase-9 (MMP-9 and urokinase plasminogen activator (u-PA expression, while expression of their endogenous inhibitors, tissue inhibitor of MMP-1 (TIMP-1 and plasminogen activator inhibitor-1 (PAI-1, were increased in KB cells. Furthermore, AP extract treatment effectively delayed tumor incidence in nude mice inoculated with KB cells and reduced the tumor burden. AP extract treatment also induced apoptotic DNA fragmentation, as detected by in situ TUNEL staining. Thus, A. pricei may possess antitumor activity in human squamous carcinoma (KB cells.

  8. Resveratrol analogue 3,4,4′,5-tetramethoxystilbene inhibits growth, arrests cell cycle and induces apoptosis in ovarian SKOV‐3 and A-2780 cancer cells

    Energy Technology Data Exchange (ETDEWEB)

    Piotrowska, Hanna; Myszkowski, Krzysztof; Ziółkowska, Alicja [Department of Toxicology, Poznan University of Medical Sciences, Poznan (Poland); Kulcenty, Katarzyna [Chair of Medical Biotechnology, Poznan University of Medical Sciences, Poznan (Poland); Wierzchowski, Marcin [Department of Chemical Technology of Drugs, Poznan University of Medical Sciences, Poznan (Poland); Kaczmarek, Mariusz [Department of Clinical Immunology, Poznan University of Medical Sciences, Poznan (Poland); Murias, Marek [Department of Toxicology, Poznan University of Medical Sciences, Poznan (Poland); Kwiatkowska-Borowczyk, Eliza [Chair of Medical Biotechnology, Poznan University of Medical Sciences, Poznan (Poland); Department of Cancer Diagnostics and Immunology, Greater Poland Cancer Centre, Poznan (Poland); Jodynis-Liebert, Jadwiga, E-mail: liebert@ump.edu.pl [Department of Toxicology, Poznan University of Medical Sciences, Poznan (Poland)

    2012-08-15

    In the screening studies, cytotoxicity of 12 methylated resveratrol analogues on 11 human cancer cell lines was examined. The most active compound 3,4,4′5-tetramethoxystilbene (DMU-212) and two ovarian cancer cell lines A-2780 (IC{sub 50} = 0.71 μM) and SKOV-3 (IC{sub 50} = 11.51 μM) were selected for further investigation. To determine the mechanism of DMU-212 cytotoxicity, its ability to induce apoptosis was examined. DMU-212 arrested cell cycle in the G2/M or G0/G1 phase which resulted in apoptosis of both cell lines. The expression level of 84 apoptosis-related genes was investigated. In SKOV-3 cells DMU-212 caused up-regulation of pro-apoptotic Bax, Apaf-1 and p53 genes, specific to intrinsic pathway of apoptosis, and a decrease in Bcl-2 and Bcl 2110 mRNA expressions. Conversely, in A-2780 cells an increased expression of pro-apoptotic genes Fas, FasL, TNF, TNFRSF10A, TNFRSF21, TNFRSF16 specific to extracellular mechanism of apoptosis was observed. There are no data published so far regarding the receptor mediated apoptosis induced by DMU-212. The activation of caspase-3/7 was correlated with decreased TRAF-1 and BIRC-2 expression level in A-2780 cells exposed to DMU-212. DMU-212 caused a decrease in CYP1A1 and CYP1B1 mRNA levels in A-2780 by 50% and 75%, and in SKOV-3 cells by 15% and 45%, respectively. The protein expression was also reduced in both cell lines. It is noteworthy that the expression of CYP1B1 protein was entirely inhibited in A-2780 cells treated with DMU-212. It can be suggested that different CYP1B1 expression patterns in either ovarian cell line may affect their sensitivity to cytotoxic activity of DMU-212. -- Highlights: ► DMU-212 was the most cytotoxic among 12 O-methylated resveratrol analogues. ► DMU-212 arrested cell cycle at G2/M and G0/G1phase ► DMU-212 triggered mitochondria- and receptor‐mediated apoptosis. ► DMU-212 entirely inhibited CYP1B1 protein expression in A-2780 cells.

  9. Resveratrol analogue 3,4,4′,5-tetramethoxystilbene inhibits growth, arrests cell cycle and induces apoptosis in ovarian SKOV‐3 and A-2780 cancer cells

    International Nuclear Information System (INIS)

    Piotrowska, Hanna; Myszkowski, Krzysztof; Ziółkowska, Alicja; Kulcenty, Katarzyna; Wierzchowski, Marcin; Kaczmarek, Mariusz; Murias, Marek; Kwiatkowska-Borowczyk, Eliza; Jodynis-Liebert, Jadwiga

    2012-01-01

    In the screening studies, cytotoxicity of 12 methylated resveratrol analogues on 11 human cancer cell lines was examined. The most active compound 3,4,4′5-tetramethoxystilbene (DMU-212) and two ovarian cancer cell lines A-2780 (IC 50 = 0.71 μM) and SKOV-3 (IC 50 = 11.51 μM) were selected for further investigation. To determine the mechanism of DMU-212 cytotoxicity, its ability to induce apoptosis was examined. DMU-212 arrested cell cycle in the G2/M or G0/G1 phase which resulted in apoptosis of both cell lines. The expression level of 84 apoptosis-related genes was investigated. In SKOV-3 cells DMU-212 caused up-regulation of pro-apoptotic Bax, Apaf-1 and p53 genes, specific to intrinsic pathway of apoptosis, and a decrease in Bcl-2 and Bcl 2110 mRNA expressions. Conversely, in A-2780 cells an increased expression of pro-apoptotic genes Fas, FasL, TNF, TNFRSF10A, TNFRSF21, TNFRSF16 specific to extracellular mechanism of apoptosis was observed. There are no data published so far regarding the receptor mediated apoptosis induced by DMU-212. The activation of caspase-3/7 was correlated with decreased TRAF-1 and BIRC-2 expression level in A-2780 cells exposed to DMU-212. DMU-212 caused a decrease in CYP1A1 and CYP1B1 mRNA levels in A-2780 by 50% and 75%, and in SKOV-3 cells by 15% and 45%, respectively. The protein expression was also reduced in both cell lines. It is noteworthy that the expression of CYP1B1 protein was entirely inhibited in A-2780 cells treated with DMU-212. It can be suggested that different CYP1B1 expression patterns in either ovarian cell line may affect their sensitivity to cytotoxic activity of DMU-212. -- Highlights: ► DMU-212 was the most cytotoxic among 12 O-methylated resveratrol analogues. ► DMU-212 arrested cell cycle at G2/M and G0/G1phase ► DMU-212 triggered mitochondria- and receptor‐mediated apoptosis. ► DMU-212 entirely inhibited CYP1B1 protein expression in A-2780 cells.

  10. Curcumin inhibits growth potential by G1 cell cycle arrest and induces apoptosis in p53-mutated COLO 320DM human colon adenocarcinoma cells.

    Science.gov (United States)

    Dasiram, Jade Dhananjay; Ganesan, Ramamoorthi; Kannan, Janani; Kotteeswaran, Venkatesan; Sivalingam, Nageswaran

    2017-02-01

    Curcumin, a natural polyphenolic compound and it is isolated from the rhizome of Curcuma longa, have been reported to possess anticancer effect against stage I and II colon cancer. However, the effect of curcumin on colon cancer at Dukes' type C metastatic stage III remains still unclear. In the present study, we have investigated the anticancer effects of curcumin on p53 mutated COLO 320DM human colon adenocarcinoma cells derived from Dukes' type C metastatic stage. The cellular viability and proliferation were assessed by trypan blue exclusion assay and MTT assay, respectively. The cytotoxicity effect was examined by lactate dehydrogenase (LDH) cytotoxicity assay. Apoptosis was analyzed by DNA fragmentation analysis, Hoechst and propidium iodide double fluorescent staining and confocal microscopy analysis. Cell cycle distribution was performed by flow cytometry analysis. Here we have observed that curcumin treatment significantly inhibited the cellular viability and proliferation potential of p53 mutated COLO 320DM cells in a dose- and time-dependent manner. In addition, curcumin treatment showed no cytotoxic effects to the COLO 320DM cells. DNA fragmentation analysis, Hoechst and propidium iodide double fluorescent staining and confocal microscopy analysis revealed that curcumin treatment induced apoptosis in COLO 320DM cells. Furthermore, curcumin caused cell cycle arrest at the G1 phase, decreased the cell population in the S phase and induced apoptosis in COLO 320DM colon adenocarcinoma cells. Together, these data suggest that curcumin exerts anticancer effects and induces apoptosis in p53 mutated COLO 320DM human colon adenocarcinoma cells derived from Dukes' type C metastatic stage. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  11. Synchronization and Arrest of the Budding Yeast Cell Cycle Using Chemical and Genetic Methods.

    Science.gov (United States)

    Rosebrock, Adam P

    2017-01-03

    The cell cycle of budding yeast can be arrested at specific positions by different genetic and chemical methods. These arrests enable study of cell cycle phase-specific phenotypes that would be missed during examination of asynchronous cultures. Some methods for arrest are reversible, with kinetics that enable release of cells back into a synchronous cycling state. Benefits of chemical and genetic methods include scalability across a large range of culture sizes from a few milliliters to many liters, ease of execution, the absence of specific equipment requirements, and synchronization and release of the entire culture. Of note, cell growth and division are decoupled during arrest and block-release experiments. Cells will continue transcription, translation, and accumulation of protein while arrested. If allowed to reenter the cell cycle, cells will do so as a population of mixed, larger-than-normal cells. Despite this important caveat, many aspects of budding yeast physiology are accessible using these simple chemical and genetic tools. Described here are methods for the block and release of cells in G 1 phase and at the M/G 1 transition using α-factor mating pheromone and the temperature-sensitive cdc15-2 allele, respectively, in addition to methods for arresting the cell cycle in early S phase and at G 2 /M by using hydroxyurea and nocodazole, respectively. © 2017 Cold Spring Harbor Laboratory Press.

  12. EGFR-targeted plasmonic magnetic nanoparticles suppress lung tumor growth by abrogating G2/M cell-cycle arrest and inducing DNA damage

    Directory of Open Access Journals (Sweden)

    Kuroda S

    2014-08-01

    Full Text Available Shinji Kuroda,1 Justina Tam,2 Jack A Roth,1 Konstantin Sokolov,2 Rajagopal Ramesh3–5 1Department of Thoracic and Cardiovascular Surgery, 2Department of Imaging Physics, The University of Texas MD Anderson Cancer Center, Houston, TX, USA; 3Department of Pathology, 4Graduate Program in Biomedical Sciences, 5Stephenson Cancer Center, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA Background: We have previously demonstrated the epidermal growth factor receptor (EGFR-targeted hybrid plasmonic magnetic nanoparticles (225-NP produce a therapeutic effect in human lung cancer cell lines in vitro. In the present study, we investigated the molecular mechanism of 225-NP-mediated antitumor activity both in vitro and in vivo using the EGFR-mutant HCC827 cell line. Methods: The growth inhibitory effect of 225-NP on lung tumor cells was determined by cell viability and cell-cycle analysis. Protein expression related to autophagy, apoptosis, and DNA-damage were determined by Western blotting and immunofluorescence. An in vivo efficacy study was conducted using a human lung tumor xenograft mouse model. Results: The 225-NP treatment markedly reduced tumor cell viability at 72 hours compared with the cell viability in control treatment groups. Cell-cycle analysis showed the percentage of cells in the G2/M phase was reduced when treated with 225-NP, with a concomitant increase in the number of cells in Sub-G1 phase, indicative of cell death. Western blotting showed LC3B and PARP cleavage, indicating 225-NP-treatment activated both autophagy- and apoptosis-mediated cell death. The 225-NP strongly induced γH2AX and phosphorylated histone H3, markers indicative of DNA damage and mitosis, respectively. Additionally, significant γH2AX foci formation was observed in 225-NP-treated cells compared with control treatment groups, suggesting 225-NP induced cell death by triggering DNA damage. The 225-NP-mediated DNA damage involved abrogation of the

  13. Growth arrest specific protein (GAS) 6

    DEFF Research Database (Denmark)

    Haase, T N; Rasmussen, Morten; Jaksch, C A M

    2013-01-01

    using RNA microarray and quantitative PCR. The role of a differentially expressed gene, growth arrest specific protein 6 (GAS6), was evaluated in vitro using neonatal rat islets. Results The mRNA level of Gas6, known to be mitogenic in other tissues, was reduced in LP offspring. The mRNA content of Mafa...... was increased in LP offspring suggesting an early maturation of beta cells. When applied in vitro, GAS6 increased proliferation of neonatal pancreatic beta cells, while reducing glucose-stimulated insulin secretion without changing the total insulin content of the islets. In addition, GAS6 decreased the m......RNA content of Mafa. Conclusions/interpretation We propose a role for GAS6 in the regulation of pancreatic beta cells in the critical period around the time of birth. Our results support the hypothesis that the reduced beta cell mass seen in LP offspring is caused by a change in the intra-uterine environment...

  14. Cell cycle arrest and cell survival induce reverse trends of cardiolipin remodeling.

    Directory of Open Access Journals (Sweden)

    Yu-Jen Chao

    Full Text Available Cell survival from the arrested state can be a cause of the cancer recurrence. Transition from the arrest state to the growth state is highly regulated by mitochondrial activity, which is related to the lipid compositions of the mitochondrial membrane. Cardiolipin is a critical phospholipid for the mitochondrial integrity and functions. We examined the changes of cardiolipin species by LC-MS in the transition between cell cycle arrest and cell reviving in HT1080 fibrosarcoma cells. We have identified 41 cardiolipin species by MS/MS and semi-quantitated them to analyze the detailed changes of cardiolipin species. The mass spectra of cardiolipin with the same carbon number form an envelope, and the C64, C66, C68, C70 C72 and C74 envelopes in HT1080 cells show a normal distribution in the full scan mass spectrum. The cardiolipin quantity in a cell decreases while entering the cell cycle arrest, but maintains at a similar level through cell survival. While cells awakening from the arrested state and preparing itself for replication, the groups with short acyl chains, such as C64, C66 and C68 show a decrease of cardiolipin percentage, but the groups with long acyl chains, such as C70 and C72 display an increase of cardiolipin percentage. Interestingly, the trends of the cardiolipin species changes during the arresting state are completely opposite to cell growing state. Our results indicate that the cardiolipin species shift from the short chain to long chain cardiolipin during the transition from cell cycle arrest to cell progression.

  15. 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.

  16. Lobaplatin arrests cell cycle progression in human hepatocellular carcinoma cells

    Directory of Open Access Journals (Sweden)

    Chen Chang-Jie

    2010-10-01

    Full Text Available Abstract Background Hepatocellular carcinoma (HCC still is a big burden for China. In recent years, the third-generation platinum compounds have been proposed as potential active agents for HCC. However, more experimental and clinical data are warranted to support the proposal. In the present study, the effect of lobaplatin was assessed in five HCC cell lines and the underlying molecular mechanisms in terms of cell cycle kinetics were explored. Methods Cytotoxicity of lobaplatin to human HCC cell lines was examined using MTT cell proliferation assay. Cell cycle distribution was determined by flow cytometry. Expression of cell cycle-regulated genes was examined at both the mRNA (RT-PCR and protein (Western blot levels. The phosphorylation status of cyclin-dependent kinases (CDKs and retinoblastoma (Rb protein was also examined using Western blot analysis. Results Lobaplatin inhibited proliferation of human HCC cells in a dose-dependent manner. For the most sensitive SMMC-7721 cells, lobaplatin arrested cell cycle progression in G1 and G2/M phases time-dependently which might be associated with the down-regulation of cyclin B, CDK1, CDC25C, phosphorylated CDK1 (pCDK1, pCDK4, Rb, E2F, and pRb, and the up-regulation of p53, p21, and p27. Conclusion Cytotoxicity of lobaplatin in human HCC cells might be due to its ability to arrest cell cycle progression which would contribute to the potential use of lobaplatin for the management of HCC.

  17. Prolyl oligopeptidase inhibition-induced growth arrest of human gastric cancer cells

    Energy Technology Data Exchange (ETDEWEB)

    Suzuki, Kanayo [Laboratory of Cell Biology, Osaka University of Pharmaceutical Sciences, 4-20-1 Nasahara, Takatsuki, Osaka 569-1094 (Japan); Sakaguchi, Minoru, E-mail: sakaguti@gly.oups.ac.jp [Laboratory of Cell Biology, Osaka University of Pharmaceutical Sciences, 4-20-1 Nasahara, Takatsuki, Osaka 569-1094 (Japan); Tanaka, Satoshi [Laboratory of Cell Biology, Osaka University of Pharmaceutical Sciences, 4-20-1 Nasahara, Takatsuki, Osaka 569-1094 (Japan); Yoshimoto, Tadashi [Department of Life Science, Setsunan University, 17-8 Ikeda-Nakamachi, Neyagawa, Osaka 572-8508 (Japan); Takaoka, Masanori [Laboratory of Cell Biology, Osaka University of Pharmaceutical Sciences, 4-20-1 Nasahara, Takatsuki, Osaka 569-1094 (Japan)

    2014-01-03

    Highlights: •We examined the effects of prolyl oligopeptidase (POP) inhibition on p53 null gastric cancer cell growth. •POP inhibition-induced cell growth suppression was associated with an increase in a quiescent G{sub 0} state. •POP might regulate the exit from and/or reentry into the cell cycle. -- Abstract: Prolyl oligopeptidase (POP) is a serine endopeptidase that hydrolyzes post-proline peptide bonds in peptides that are <30 amino acids in length. We recently reported that POP inhibition suppressed the growth of human neuroblastoma cells. The growth suppression was associated with pronounced G{sub 0}/G{sub 1} cell cycle arrest and increased levels of the CDK inhibitor p27{sup kip1} and the tumor suppressor p53. In this study, we investigated the mechanism of POP inhibition-induced cell growth arrest using a human gastric cancer cell line, KATO III cells, which had a p53 gene deletion. POP specific inhibitors, 3-((4-[2-(E)-styrylphenoxy]butanoyl)-L-4-hydroxyprolyl)-thiazolidine (SUAM-14746) and benzyloxycarbonyl-thioprolyl-thioprolinal, or RNAi-mediated POP knockdown inhibited the growth of KATO III cells irrespective of their p53 status. SUAM-14746-induced growth inhibition was associated with G{sub 0}/G{sub 1} cell cycle phase arrest and increased levels of p27{sup kip1} in the nuclei and the pRb2/p130 protein expression. Moreover, SUAM-14746-mediated cell cycle arrest of KATO III cells was associated with an increase in the quiescent G{sub 0} state, defined by low level staining for the proliferation marker, Ki-67. These results indicate that POP may be a positive regulator of cell cycle progression by regulating the exit from and/or reentry into the cell cycle by KATO III cells.

  18. Metazoan operons accelerate recovery from growth arrested states

    Science.gov (United States)

    Zaslaver, Alon; Baugh, L. Ryan; Sternberg, Paul W.

    2011-01-01

    Summary Existing theories explain why operons are advantageous in prokaryotes, but their occurrence in metazoans is an enigma. Nematode operon genes, typically consisting of growth genes, are significantly up-regulated during recovery from growth-arrested states. This expression pattern is anti-correlated to non-operon genes consistent with a competition for transcriptional resources. We find that transcriptional resources are initially limiting during recovery, and that recovering animals are highly sensitive to any additional decrease in transcriptional resources. Operons become advantageous because by clustering growth genes into operons, fewer promoters compete for the limited transcriptional machinery, effectively increasing the concentration of transcriptional resources, and accelerating recovery. Mathematical modeling reveals how a moderate increase in transcriptional resources can substantially enhance transcription rate and recovery. This design principle occurs in different nematodes and the chordate C. intestinalis. As transition from arrest to rapid growth is shared by many metazoans, operons could have evolved to facilitate these processes. PMID:21663799

  19. Piperine causes G1 phase cell cycle arrest and apoptosis in melanoma cells through checkpoint kinase-1 activation.

    Directory of Open Access Journals (Sweden)

    Neel M Fofaria

    Full Text Available In this study, we determined the cytotoxic effects of piperine, a major constituent of black and long pepper in melanoma cells. Piperine treatment inhibited the growth of SK MEL 28 and B16 F0 cells in a dose and time-dependent manner. The growth inhibitory effects of piperine were mediated by cell cycle arrest of both the cell lines in G1 phase. The G1 arrest by piperine correlated with the down-regulation of cyclin D1 and induction of p21. Furthermore, this growth arrest by piperine treatment was associated with DNA damage as indicated by phosphorylation of H2AX at Ser139, activation of ataxia telangiectasia and rad3-related protein (ATR and checkpoint kinase 1 (Chk1. Pretreatment with AZD 7762, a Chk1 inhibitor not only abrogated the activation of Chk1 but also piperine mediated G1 arrest. Similarly, transfection of cells with Chk1 siRNA completely protected the cells from G1 arrest induced by piperine. Piperine treatment caused down-regulation of E2F1 and phosphorylation of retinoblastoma protein (Rb. Apoptosis induced by piperine was associated with down-regulation of XIAP, Bid (full length and cleavage of Caspase-3 and PARP. Furthermore, our results showed that piperine treatment generated ROS in melanoma cells. Blocking ROS by tiron protected the cells from piperine mediated cell cycle arrest and apoptosis. These results suggest that piperine mediated ROS played a critical role in inducing DNA damage and activation of Chk1 leading to G1 cell cycle arrest and apoptosis.

  20. Middle infrared radiation induces G2/M cell cycle arrest in A549 lung cancer cells.

    Science.gov (United States)

    Chang, Hsin-Yi; Shih, Meng-Her; Huang, Hsuan-Cheng; Tsai, Shang-Ru; Juan, Hsueh-Fen; Lee, Si-Chen

    2013-01-01

    There were studies investigating the effects of broadband infrared radiation (IR) on cancer cell, while the influences of middle-infrared radiation (MIR) are still unknown. In this study, a MIR emitter with emission wavelength band in the 3-5 µm region was developed to irradiate A549 lung adenocarcinoma cells. It was found that MIR exposure inhibited cell proliferation and induced morphological changes by altering the cellular distribution of cytoskeletal components. Using quantitative PCR, we found that MIR promoted the expression levels of ATM (ataxia telangiectasia mutated), ATR (ataxia-telangiectasia and Rad3-related and Rad3-related), TP53 (tumor protein p53), p21 (CDKN1A, cyclin-dependent kinase inhibitor 1A) and GADD45 (growth arrest and DNA-damage inducible), but decreased the expression levels of cyclin B coding genes, CCNB1 and CCNB2, as well as CDK1 (Cyclin-dependent kinase 1). The reduction of protein expression levels of CDC25C, cyclin B1 and the phosphorylation of CDK1 at Thr-161 altogether suggest G(2)/M arrest occurred in A549 cells by MIR. DNA repair foci formation of DNA double-strand breaks (DSB) marker γ-H2AX and sensor 53BP1 was induced by MIR treatment, it implies the MIR induced G(2)/M cell cycle arrest resulted from DSB. This study illustrates a potential role for the use of MIR in lung cancer therapy by initiating DSB and blocking cell cycle progression.

  1. Dihydromyricetin induces cell cycle arrest and apoptosis in melanoma SK-MEL-28 cells.

    Science.gov (United States)

    Zeng, Guofang; Liu, Jie; Chen, Hege; Liu, Bin; Zhang, Qingyu; Li, Mingyi; Zhu, Runzhi

    2014-06-01

    Dihydromyricetin (DHM) exhibits multiple pharmacological activities; however, the role of DHM in anti-melanoma activities and the underlying molecular mechanisms are unclear. The aim of the present study was to evaluate the effects of DHM on cell proliferation, cell cycle distribution and apoptosis in the human melanoma SK-MEL-28 cell line, and to explore the related mechanisms. The effect of DHM on cell proliferation was investigated by MTT assay, and cell cycle distribution was determined by flow cytometry. TUNEL assay was used to evaluate DHM-mediated apoptosis, and western blotting was applied to examine expression levels of p53, p21, Cdc25A, Cdc2, P-Cdc2, Bax, IKK-α, NF-κB p65, p38 and P-p38 proteins. The results revealed that DHM suppressed cell proliferation of SK-MEL-28 cells in a concentration- and time-dependent manner, and caused cell cycle arrest at the G1/S phase. DHM increased the production of p53 and p21 proteins and downregulated the production of Cdc25A, Cdc2 and P-Cdc2 proteins, which induced cell cycle arrest. Additionally, DHM significantly induced the apoptosis of SK-MEL-28 cells, and enhanced the expression levels of Bax proteins and decreased the protein levels of IKK-α, NF-κB (p65) and P-p38. The results suggest that DHM may be a novel and effective candidate agent to inhibit the growth of melanoma.

  2. G2 phase arrest of cell cycle induced by ionizing radiation

    International Nuclear Information System (INIS)

    Liu Guangwei; Gong Shouliang

    2002-01-01

    The exposure of mammalian cells to X rays results in the prolongation of the cell cycle, including the delay or the arrest in G 1 , S and G 2 phase. The major function of G 1 arrest may be to eliminate the cells containing DNA damage and only occurs in the cells with wild type p53 function whereas G 2 arrest following ionizing radiation has been shown to be important in protecting the cells from death and occurs in all cells regardless of p53 status. So the study on G 2 phase arrest of the cell cycle induced by ionizing radiation has currently become a focus at radiobiological fields

  3. Berberine induces p53-dependent cell cycle arrest and apoptosis of human osteosarcoma cells by inflicting DNA damage

    International Nuclear Information System (INIS)

    Liu Zhaojian; Liu Qiao; Xu Bing; Wu Jingjing; Guo Chun; Zhu Faliang; Yang Qiaozi; Gao Guimin; Gong Yaoqin; Shao Changshun

    2009-01-01

    Alkaloid berberine is widely used for the treatment of diarrhea and other diseases. Many laboratory studies showed that it exhibits anti-proliferative activity against a wide spectrum of cancer cells in culture. In this report we studied the mechanisms underlying the inhibitory effects of berberine on human osteosarcoma cells and on normal osteoblasts. The inhibition was largely attributed to cell cycle arrest at G1 and G2/M, and to a less extent, to apoptosis. The G1 arrest was dependent on p53, as G1 arrest was abolished in p53-deficient osteosarcoma cells. The induction of G1 arrest and apoptosis was accompanied by a p53-dependent up-regulation of p21 and pro-apoptotic genes. However, the G2/M arrest could be induced by berberine regardless of the status of p53. Interestingly, DNA double-strand breaks, as measured by the phosphorylation of H2AX, were remarkably accumulated in berberine-treated cells in a dose-dependent manner. Thus, one major mechanism by which berberine exerts its growth-inhibitory effect is to inflict genomic lesions on cells, which in turn trigger the activation of p53 and the p53-dependent cellular responses including cell cycle arrest and apoptosis

  4. Berberine induces p53-dependent cell cycle arrest and apoptosis of human osteosarcoma cells by inflicting DNA damage

    Energy Technology Data Exchange (ETDEWEB)

    Liu Zhaojian; Liu Qiao; Xu Bing; Wu Jingjing [Key Laboratory of Experimental Teratology of Ministry of Education and Institute of Molecular Medicine and Genetics, Shandong University School of Medicine, Jinan, Shandong 250012 (China); Guo Chun; Zhu Faliang [Institute of Immunology, Shandong University School of Medicine, Jinan, Shandong 250012 (China); Yang Qiaozi [Department of Genetics, Rutgers University, Piscataway, NJ 08854 (United States); Gao Guimin [Key Laboratory of Experimental Teratology of Ministry of Education and Institute of Molecular Medicine and Genetics, Shandong University School of Medicine, Jinan, Shandong 250012 (China); Gong Yaoqin [Key Laboratory of Experimental Teratology of Ministry of Education and Institute of Molecular Medicine and Genetics, Shandong University School of Medicine, Jinan, Shandong 250012 (China)], E-mail: yxg8@sdu.edu.cn; Shao Changshun [Key Laboratory of Experimental Teratology of Ministry of Education and Institute of Molecular Medicine and Genetics, Shandong University School of Medicine, Jinan, Shandong 250012 (China); Department of Genetics, Rutgers University, Piscataway, NJ 08854 (United States)], E-mail: shao@biology.rutgers.edu

    2009-03-09

    Alkaloid berberine is widely used for the treatment of diarrhea and other diseases. Many laboratory studies showed that it exhibits anti-proliferative activity against a wide spectrum of cancer cells in culture. In this report we studied the mechanisms underlying the inhibitory effects of berberine on human osteosarcoma cells and on normal osteoblasts. The inhibition was largely attributed to cell cycle arrest at G1 and G2/M, and to a less extent, to apoptosis. The G1 arrest was dependent on p53, as G1 arrest was abolished in p53-deficient osteosarcoma cells. The induction of G1 arrest and apoptosis was accompanied by a p53-dependent up-regulation of p21 and pro-apoptotic genes. However, the G2/M arrest could be induced by berberine regardless of the status of p53. Interestingly, DNA double-strand breaks, as measured by the phosphorylation of H2AX, were remarkably accumulated in berberine-treated cells in a dose-dependent manner. Thus, one major mechanism by which berberine exerts its growth-inhibitory effect is to inflict genomic lesions on cells, which in turn trigger the activation of p53 and the p53-dependent cellular responses including cell cycle arrest and apoptosis.

  5. Galiellalactone induces cell cycle arrest and apoptosis through the ATM/ATR pathway in prostate cancer cells.

    Science.gov (United States)

    García, Víctor; Lara-Chica, Maribel; Cantarero, Irene; Sterner, Olov; Calzado, Marco A; Muñoz, Eduardo

    2016-01-26

    Galiellalactone (GL) is a fungal metabolite that presents antitumor activities on prostate cancer in vitro and in vivo. In this study we show that GL induced cell cycle arrest in G2/M phase, caspase-dependent apoptosis and also affected the microtubule organization and migration ability in DU145 cells. GL did not induce double strand DNA break but activated the ATR and ATM-mediated DNA damage response (DDR) inducing CHK1, H2AX phosphorylation (fH2AX) and CDC25C downregulation. Inhibition of the ATM/ATR activation with caffeine reverted GL-induced G2/M cell cycle arrest, apoptosis and DNA damage measured by fH2AX. In contrast, UCN-01, a CHK1 inhibitor, prevented GL-induced cell cycle arrest but enhanced apoptosis in DU145 cells. Furthermore, we found that GL did not increase the levels of intracellular ROS, but the antioxidant N-acetylcysteine (NAC) completely prevented the effects of GL on fH2AX, G2/M cell cycle arrest and apoptosis. In contrast to NAC, other antioxidants such as ambroxol and EGCG did not interfere with the activity of GL on cell cycle. GL significantly suppressed DU145 xenograft growth in vivo and induced the expression of fH2AX in the tumors. These findings identify for the first time that GL activates DDR in prostate cancer.

  6. Curcumin Induces Autophagy, Apoptosis, and Cell Cycle Arrest in Human Pancreatic Cancer Cells

    Directory of Open Access Journals (Sweden)

    Yaping Zhu

    2017-01-01

    Full Text Available Objective. Curcumin is an active extract from turmeric. The aim of this study was to identify the underlying mechanism of curcumin on PCa cells and the role of autophagy in this process. Methods. The inhibitory effect of curcumin on the growth of PANC1 and BxPC3 cell lines was detected by CCK-8 assay. Cell cycle distribution and apoptosis were tested by flow cytometry. Autophagosomes were tested by cell immunofluorescence assay. The protein expression was detected by Western blot. The correlation between LC3II/Bax and cell viability was analyzed. Results. Curcumin inhibited the cell proliferation in a dose- and time-dependent manner. Curcumin could induce cell cycle arrest at G2/M phase and apoptosis of PCa cells. The autophagosomes were detected in the dosing groups. Protein expression of Bax and LC3II was upregulated, while Bcl2 was downregulated in the high dosing groups of curcumin. There was a significant negative correlation between LC3II/Bax and cell viability. Conclusions. Autophagy could be triggered by curcumin in the treatment of PCa. Apoptosis and cell cycle arrest also participated in this process. These findings imply that curcumin is a multitargeted agent for PCa cells. In addition, autophagic cell death may predominate in the high concentration groups of curcumin.

  7. Cell cycle arrest in the jewel wasp Nasonia vitripennis in larval diapause.

    Science.gov (United States)

    Shimizu, Yuta; Mukai, Ayumu; Goto, Shin G

    2018-04-01

    Insects enter diapause to synchronise their life cycle with biotic and abiotic environmental conditions favourable for their development, reproduction, and survival. One of the most noticeable characteristics of diapause is the blockage of ontogeny. Although this blockage should occur with the cessation of cellular proliferation, i.e. cell cycle arrest, it was confirmed only in a few insect species and information on the molecular pathways involved in cell cycle arrest is limited. In the present study, we investigated developmental and cell cycle arrest in diapause larvae of the jewel wasp Nasonia vitripennis. Developmental and cell cycle arrest occur in the early fourth instar larval stage of N. vitripennis under short days. By entering diapause, the S fraction of the cell cycle disappears and approximately 80% and 20% of cells arrest their cell cycle in the G0/G1 and G2 phases, respectively. We further investigated expression of cell cycle regulatory genes and some housekeeping genes to dissect molecular mechanisms underlying the cell cycle arrest. Copyright © 2016 Elsevier Ltd. All rights reserved.

  8. Proteomic analysis of the response to cell cycle arrests in human myeloid leukemia cells.

    Science.gov (United States)

    Ly, Tony; Endo, Aki; Lamond, Angus I

    2015-01-02

    Previously, we analyzed protein abundance changes across a 'minimally perturbed' cell cycle by using centrifugal elutriation to differentially enrich distinct cell cycle phases in human NB4 cells (Ly et al., 2014). In this study, we compare data from elutriated cells with NB4 cells arrested at comparable phases using serum starvation, hydroxyurea, or RO-3306. While elutriated and arrested cells have similar patterns of DNA content and cyclin expression, a large fraction of the proteome changes detected in arrested cells are found to reflect arrest-specific responses (i.e., starvation, DNA damage, CDK1 inhibition), rather than physiological cell cycle regulation. For example, we show most cells arrested in G2 by CDK1 inhibition express abnormally high levels of replication and origin licensing factors and are likely poised for genome re-replication. The protein data are available in the Encyclopedia of Proteome Dynamics (

  9. Sulforaphane induces cell cycle arrest by protecting RB-E2F-1 complex in epithelial ovarian cancer cells

    Directory of Open Access Journals (Sweden)

    Morris Robert

    2010-03-01

    Full Text Available Abstract Background Sulforaphane (SFN, an isothiocyanate phytochemical present predominantly in cruciferous vegetables such as brussels sprout and broccoli, is considered a promising chemo-preventive agent against cancer. In-vitro exposure to SFN appears to result in the induction of apoptosis and cell-cycle arrest in a variety of tumor types. However, the molecular mechanisms leading to the inhibition of cell cycle progression by SFN are poorly understood in epithelial ovarian cancer cells (EOC. The aim of this study is to understand the signaling mechanisms through which SFN influences the cell growth and proliferation in EOC. Results SFN at concentrations of 5 - 20 μM induced a dose-dependent suppression of growth in cell lines MDAH 2774 and SkOV-3 with an IC50 of ~8 μM after a 3 day exposure. Combination treatment with chemotherapeutic agent, paclitaxel, resulted in additive growth suppression. SFN at ~8 μM decreased growth by 40% and 20% on day 1 in MDAH 2774 and SkOV-3, respectively. Cells treated with cytotoxic concentrations of SFN have reduced cell migration and increased apoptotic cell death via an increase in Bak/Bcl-2 ratio and cleavage of procaspase-9 and poly (ADP-ribose-polymerase (PARP. Gene expression profile analysis of cell cycle regulated proteins demonstrated increased levels of tumor suppressor retinoblastoma protein (RB and decreased levels of E2F-1 transcription factor. SFN treatment resulted in G1 cell cycle arrest through down modulation of RB phosphorylation and by protecting the RB-E2F-1 complex. Conclusions SFN induces growth arrest and apoptosis in EOC cells. Inhibition of retinoblastoma (RB phosphorylation and reduction in levels of free E2F-1 appear to play an important role in EOC growth arrest.

  10. Mechanisms involved in alternariol-induced cell cycle arrest

    Energy Technology Data Exchange (ETDEWEB)

    Solhaug, A., E-mail: Anita.Solhaug@vetinst.no [Norwegian Veterinary Institute, Oslo (Norway); Vines, L.L. [Michigan State University, Department of Food Science and Human Nutrition, East Lansing, MI (United States); Ivanova, L.; Spilsberg, B. [Norwegian Veterinary Institute, Oslo (Norway); Holme, J.A. [Norwegian Institute of Public Health, Division of Environmental Medicine, Oslo (Norway); Pestka, J. [Michigan State University, Department of Food Science and Human Nutrition, East Lansing, MI (United States); Collins, A. [University of Oslo, Department of Nutrition, Faculty of Medicine, Oslo (Norway); Eriksen, G.S. [Norwegian Veterinary Institute, Oslo (Norway)

    2012-10-15

    Alternariol (AOH), a mycotoxin produced by Alternaria sp, is often found as a contaminant in fruit and cereal products. Here we employed the murine macrophage cell line RAW 264.7 to test the hypothesis that AOH causes toxicity as a response to DNA damage. AOH at concentrations of 15-30 {mu}M almost completely blocked cell proliferation. Within 30 min treatment, AOH (30 {mu}M) significantly increased the level of reactive oxygen species (ROS). Furthermore, DNA base oxidations as well as DNA strand breaks and/or alkaline labile sites were detected by the comet assay after 2 h exposure of AOH. Cell death (mostly necrosis) was observed after prolonged exposure to the highest concentration of AOH (60 {mu}M for 24 and 48 h) in our study. The DNA damage response involved phosphorylation (activation) of histone H2AX and check point kinase-1- and 2 (Chk-1/2). Moreover, AOH activated p53 and increased the expression of p21, Cyclin B, MDM2, and Sestrin 2; likewise the level of several miRNA was affected. AOH-induced Sestrin 2 expression was regulated by p53 and could at least partly be inhibited by antioxidants, suggesting a role of ROS in the response. Interestingly, the addition of antioxidants did not inhibit cell cycle arrest. Although the formation of ROS by itself was not directly linked cell proliferation, AOH-induced DNA damage and resulting transcriptional changes in p21, MDM2, and Cyclin B likely contribute to the reduced cell proliferation; while Sestrin 2 would contribute to the oxidant defense.

  11. Mechanisms involved in alternariol-induced cell cycle arrest

    International Nuclear Information System (INIS)

    Solhaug, A.; Vines, L.L.; Ivanova, L.; Spilsberg, B.; Holme, J.A.; Pestka, J.; Collins, A.; Eriksen, G.S.

    2012-01-01

    Alternariol (AOH), a mycotoxin produced by Alternaria sp, is often found as a contaminant in fruit and cereal products. Here we employed the murine macrophage cell line RAW 264.7 to test the hypothesis that AOH causes toxicity as a response to DNA damage. AOH at concentrations of 15–30 μM almost completely blocked cell proliferation. Within 30 min treatment, AOH (30 μM) significantly increased the level of reactive oxygen species (ROS). Furthermore, DNA base oxidations as well as DNA strand breaks and/or alkaline labile sites were detected by the comet assay after 2 h exposure of AOH. Cell death (mostly necrosis) was observed after prolonged exposure to the highest concentration of AOH (60 μM for 24 and 48 h) in our study. The DNA damage response involved phosphorylation (activation) of histone H2AX and check point kinase-1- and 2 (Chk-1/2). Moreover, AOH activated p53 and increased the expression of p21, Cyclin B, MDM2, and Sestrin 2; likewise the level of several miRNA was affected. AOH-induced Sestrin 2 expression was regulated by p53 and could at least partly be inhibited by antioxidants, suggesting a role of ROS in the response. Interestingly, the addition of antioxidants did not inhibit cell cycle arrest. Although the formation of ROS by itself was not directly linked cell proliferation, AOH-induced DNA damage and resulting transcriptional changes in p21, MDM2, and Cyclin B likely contribute to the reduced cell proliferation; while Sestrin 2 would contribute to the oxidant defense.

  12. Growth-arrest-specific protein 2 inhibits cell division in Xenopus embryos.

    Directory of Open Access Journals (Sweden)

    Tong Zhang

    Full Text Available Growth-arrest-specific 2 gene was originally identified in murine fibroblasts under growth arrest conditions. Furthermore, serum stimulation of quiescent, non-dividing cells leads to the down-regulation of gas2 and results in re-entry into the cell cycle. Cytoskeleton rearrangements are critical for cell cycle progression and cell division and the Gas2 protein has been shown to co-localize with actin and microtubules in interphase mammalian cells. Despite these findings, direct evidence supporting a role for Gas2 in the mechanism of cell division has not been reported.To determine whether the Gas2 protein plays a role in cell division, we over-expressed the full-length Gas2 protein and Gas2 truncations containing either the actin-binding CH domain or the tubulin-binding Gas2 domain in Xenopus laevis embryos. We found that both the full-length Gas2 protein and the Gas2 domain, but not the CH domain, inhibited cell division and resulted in multinucleated cells. The observation that Gas2 domain alone can arrest cell division suggests that Gas2 function is mediated by microtubule binding. Gas2 co-localized with microtubules at the cell cortex of Gas2-injected Xenopus embryos using cryo-confocal microscopy and co-sedimented with microtubules in cytoskeleton co-sedimentation assays. To investigate the mechanism of Gas2-induced cell division arrest, we showed, using a wound-induced contractile array assay, that Gas2 stabilized microtubules. Finally, electron microscopy studies demonstrated that Gas2 bundled microtubules into higher-order structures.Our experiments show that Gas2 inhibits cell division in Xenopus embryos. We propose that Gas2 function is mediated by binding and bundling microtubules, leading to cell division arrest.

  13. Economic growth and business cycles

    NARCIS (Netherlands)

    Canton, E.J.F.

    1997-01-01

    This thesis contains five essays on economic growth and business cycles. The main focus is on the interaction between economic growth and the cycle: is cyclical variability good or bad for the long-run rate of economic growth? The introduction aims to provide some empirical evidence for an

  14. TGEV nucleocapsid protein induces cell cycle arrest and apoptosis through activation of p53 signaling

    International Nuclear Information System (INIS)

    Ding, Li; Huang, Yong; Du, Qian; Dong, Feng; Zhao, Xiaomin; Zhang, Wenlong; Xu, Xingang; Tong, Dewen

    2014-01-01

    Highlights: • TGEV N protein reduces cell viability by inducing cell cycle arrest and apoptosis. • TGEV N protein induces cell cycle arrest and apoptosis by regulating p53 signaling. • TGEV N protein plays important roles in TGEV-induced cell cycle arrest and apoptosis. - Abstract: Our previous studies showed that TGEV infection could induce cell cycle arrest and apoptosis via activation of p53 signaling in cultured host cells. However, it is unclear which viral gene causes these effects. In this study, we investigated the effects of TGEV nucleocapsid (N) protein on PK-15 cells. We found that TGEV N protein suppressed cell proliferation by causing cell cycle arrest at the S and G2/M phases and apoptosis. Characterization of various cellular proteins that are involved in regulating cell cycle progression demonstrated that the expression of N gene resulted in an accumulation of p53 and p21, which suppressed cyclin B1, cdc2 and cdk2 expression. Moreover, the expression of TGEV N gene promoted translocation of Bax to mitochondria, which in turn caused the release of cytochrome c, followed by activation of caspase-3, resulting in cell apoptosis in the transfected PK-15 cells following cell cycle arrest. Further studies showed that p53 inhibitor attenuated TGEV N protein induced cell cycle arrest at S and G2/M phases and apoptosis through reversing the expression changes of cdc2, cdk2 and cyclin B1 and the translocation changes of Bax and cytochrome c induced by TGEV N protein. Taken together, these results demonstrated that TGEV N protein might play an important role in TGEV infection-induced p53 activation and cell cycle arrest at the S and G2/M phases and apoptosis occurrence

  15. Rapamycin causes growth arrest and inhibition of invasion in human chondrosarcoma cells.

    Science.gov (United States)

    Song, Jian; Wang, Xiaobo; Zhu, Jiaxue; Liu, Jun

    2016-01-01

    Chondrosarcoma is a highly malignant tumor that is characterized by a potent capacity to invade locally and cause distant metastasis and notable for its lack of response to conventional chemotherapy or radiotherapy. Rapamycin, the inhibitor of mammalian target of rapamycin (mTOR), is a valuable drug with diverse clinical applications and regulates many cellular processes. However, the effects of rapamycin on cell growth and invasion of human chondrosarcoma cells are not well known. We determined the effect of rapamycin on cell proliferation, cell cycle arrest and invasion by using MTS, flow cytometry and invasion assays in two human chondrosarcoma cell lines, SW1353 and JJ012. Cell cycle regulatory and invasion-related genes' expression analysis was performed by quantitative RT-PCR (qRT-PCR). We also evaluated the effect of rapamycin on tumor growth by using mice xenograph models. Rapamycin significantly inhibited the cell proliferation, induced cell cycle arrest and decreased the invasion ability of human chondrosarcoma cells. Meanwhile, rapamycin modulated the cell cycle regulatory and invasion-related genes' expression. Furthermore, the tumor growth of mice xenograph models with human chondrosarcoma cells was significantly inhibited by rapamycin. These results provided further insight into the role of rapamycin in chondrosarcoma. Therefore, rapamycin targeted therapy may be a potential treatment strategy for chondrosarcoma.

  16. N-(4-Hydroxyphenyl) retinamide potentiated paclitaxel for cell cycle arrest and apoptosis in glioblastoma C6 and RG2 cells

    Science.gov (United States)

    Janardhanan, Rajiv; Butler, Jonathan T.; Banik, Naren L.; Ray, Swapan K.

    2009-01-01

    Glioblastoma grows aggressively due to its ability to maintain abnormally high potentials for cell proliferation. The present study examines the synergistic actions of N-(4-hdroxyphenyl) retinamide (4-HPR) and paclitaxel (PTX) to control the growth of rat glioblastoma C6 and RG2 cell lines. 4-HPR induced astrocytic differentiation was accompanied by increased expression of the tight junction protein e-cadherin and sustained down regulation of Id2 (member of inhibitor of differentiation family), catalytic subunit of rat telomerase reverse transcriptase (rTERT), and proliferating cell nuclear antigen (PCNA). Flow cytometric analysis showed that the microtubule stabilizer PTX caused cell cycle deregulation due to G2/M arrest. This in turn could alter the fate of kinetochore-spindletube dynamics thereby halting cell cycle progression. An interesting observation was induction of G1/S arrest by combination of 4-HPR and PTX, altering the G2/M arrest induced by PTX alone. This was further ratified by the upregulation of tumor suppressor protein retinoblastoma, which repressed the expression of the key signaling moieties to induce G1/S arrest. Collectively, combination of 4-HPR and PTX diminished the survival factors (e.g., rTERT, PCNA, and Bcl-2) to make glioblastoma cells highly prone to apoptosis with activation of cysteine proteases (e.g., calpain, cathepsins, caspase-8, caspase-3) in two glioblastoma cell lines. Hence, combination 4-HPR and PTX can be considered as an effective therapeutic strategy for controlling the growth of heterogeneous glioblastoma cell populations. PMID:19285047

  17. Andrographolide Induces Cell Cycle Arrest and Apoptosis of Chondrosarcoma by Targeting TCF-1/SOX9 Axis.

    Science.gov (United States)

    Zhang, Huan-Tian; Yang, Jie; Liang, Gui-Hong; Gao, Xue-Juan; Sang, Yuan; Gui, Tao; Liang, Zu-Jian; Tam, Man-Seng; Zha, Zhen-Gang

    2017-12-01

    Chondrosarcoma is the second most malignant bone tumor with poor prognosis and limited treatment options. Thus, development of more effective treatments has become urgent. Recently, natural compounds derived from medicinal plants have emerged as promising therapeutic options via targeting multiple key cellular molecules. Andrographolide (Andro) is such a compound, which has previously been shown to induce cell cycle arrest and apoptosis in several human cancers. However, the molecular mechanism through which Andro exerts its anti-cancer effect on chondrosarcoma remains to be elucidated. In the present study, we showed that Andro-induced G2/M cell cycle arrest of chondrosarcoma by fine-tuning the expressions of several cell cycle regulators such as p21, p27, and Cyclins, and that prolonged treatment of cells with Andro caused pronounced cell apoptosis. Remarkably, we found that SOX9 was highly expressed in poor-differentiated chondrosarcoma, and that knockdown of SOX9 suppressed chondrosarcoma cell growth. Further, our results showed that Andro dose-dependently down-regulated SOX9 expression in chondrosarcoma cells. Concomitantly, an inhibition of T cell factor 1 (TCF-1) mRNA expression and an enhancement of TCF-1 protein degradation by Andro were observed. In contrast, the expression and subcellular localization of β-catenin were not altered upon the treatment of Andro, suggesting that β-catenin might not function as the primary target of Andro. Additionally, we provided evidence that there was a mutual regulation between TCF-1 and SOX9 in chondrosarcoma cells. In conclusion, these results highlight the potential therapeutic effects of Andro in treatment of chondrosarcoma via targeting the TCF-1/SOX9 axis. J. Cell. Biochem. 118: 4575-4586, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

  18. Cell cycle age dependence for radiation-induced G2 arrest: evidence for time-dependent repair

    International Nuclear Information System (INIS)

    Rowley, R.

    1985-01-01

    Exponentially growing eucaryotic cells, irradiated in interphase, are delayed in progression to mitosis chiefly by arrest in G 2 . The sensitivity of Chinese hamster ovary cells to G 2 arrest induction by X rays increases through the cell cycle, up to the X-ray transition point (TP) in G 2 . This age response can be explained by cell cycle age-dependent changes in susceptibility of the target(s) for G 2 arrest and/or by changes in capability for postirradiation recovery from G 2 arrest damage. Discrimination between sensitivity changes and repair phenomena is possible only if the level of G 2 arrest-causing damage sustained by a cell at the time of irradiation and the level ultimately expressed as arrest can be determined. The ability of caffeine to ameliorate radiation-induced G 2 arrest, while inhibiting repair of G 2 arrest-causing damage makes such an analysis possible. In the presence of caffeine, progression of irradiated cells was relatively unperturbed, but on caffeine removal, G 2 arrest was expressed. The duration of G 2 arrest was independent of the length of the prior caffeine exposure. This finding indicates that the target for G 2 arrest induction is present throughout the cell cycle and that the level of G 2 arrest damage incurred is initially constant for all cell cycle phases. The data are consistent with the existence of a time-dependent recovery mechanism to explain the age dependence for radiation induction of G 2 arrest

  19. Capsaicin induces cell cycle arrest and apoptosis in human KB cancer cells.

    Science.gov (United States)

    Lin, Chia-Han; Lu, Wei-Cheng; Wang, Che-Wei; Chan, Ya-Chi; Chen, Mu-Kuan

    2013-02-25

    Capsaicin, a pungent phytochemical in a variety of red peppers of the genus Capsicum, has shown an anti-proliferative effect on various human cancer cell lines. In contrast, capsaicin has also been considered to promote the growth of cancer cells. Thus, the effects of capsaicin on various cell types need to be explored. The anti-proliferative effects of capsaicin on human KB cancer cells are still unknown. Therefore, we examined the viability, cell cycle progression, and factors associated with apoptosis in KB cells treated with capsaicin. The cell proliferation/viability and cytotoxicity of KB cells exposed to capsaicin were determined by a sulforhodamine B colorimetric assay and trypan blue exclusion. Apoptosis was detected by Hoechst staining and confirmed by western blot analysis of poly-(ADP-ribose) polymerase cleavage. Cell cycle distribution and changes of the mitochondrial membrane potential were analyzed by flow cytometry. Furthermore, the expression of caspase 3, 8 and 9 was evaluated by immunoblotting. We found that treatment of KB cells with capsaicin significantly reduced cell proliferation/viability and induced cell death in a dose-dependent manner compared with that in the untreated control. Cell cycle analysis indicated that exposure of KB cells to capsaicin resulted in cell cycle arrest at G2/M phase. Capsaicin-induced growth inhibition of KB cells appeared to be associated with induction of apoptosis. Moreover, capsaicin induced disruption of the mitochondrial membrane potential as well as activation of caspase 9, 3 and poly-(ADP-ribose) polymerase in KB cells. Our data demonstrate that capsaicin modulates cell cycle progression and induces apoptosis in human KB cancer cells through mitochondrial membrane permeabilization and caspase activation. These observations suggest an anti-cancer activity of capsaicin.

  20. Tributyltin induces G2/M cell cycle arrest via NAD(+)-dependent isocitrate dehydrogenase in human embryonic carcinoma cells.

    Science.gov (United States)

    Asanagi, Miki; Yamada, Shigeru; Hirata, Naoya; Itagaki, Hiroshi; Kotake, Yaichiro; Sekino, Yuko; Kanda, Yasunari

    2016-04-01

    Organotin compounds, such as tributyltin (TBT), are well-known endocrine-disrupting chemicals (EDCs). We have recently reported that TBT induces growth arrest in the human embryonic carcinoma cell line NT2/D1 at nanomolar levels by inhibiting NAD(+)-dependent isocitrate dehydrogenase (NAD-IDH), which catalyzes the irreversible conversion of isocitrate to α-ketoglutarate. However, the molecular mechanisms by which NAD-IDH mediates TBT toxicity remain unclear. In the present study, we examined whether TBT at nanomolar levels affects cell cycle progression in NT2/D1 cells. Propidium iodide staining revealed that TBT reduced the ratio of cells in the G1 phase and increased the ratio of cells in the G2/M phase. TBT also reduced cell division cycle 25C (cdc25C) and cyclin B1, which are key regulators of G2/M progression. Furthermore, apigenin, an inhibitor of NAD-IDH, mimicked the effects of TBT. The G2/M arrest induced by TBT was abolished by NAD-IDHα knockdown. Treatment with a cell-permeable α-ketoglutarate analogue recovered the effect of TBT, suggesting the involvement of NAD-IDH. Taken together, our data suggest that TBT at nanomolar levels induced G2/M cell cycle arrest via NAD-IDH in NT2/D1 cells. Thus, cell cycle analysis in embryonic cells could be used to assess cytotoxicity associated with nanomolar level exposure of EDCs.

  1. Dynamical principles of cell-cycle arrest: Reversible, irreversible, and mixed strategies

    Science.gov (United States)

    Pfeuty, Benjamin

    2012-08-01

    Living cells often alternate between proliferating and nonproliferating states as part of individual or collective strategies to adapt to complex and changing environments. To this aim, they have evolved a biochemical regulatory network enabling them to switch between cell-division cycles (i.e., oscillatory state) and cell-cycle arrests (i.e., steady state) in response to extracellular cues. This can be achieved by means of a variety of bifurcation mechanisms that potentially give rise to qualitatively distinct cell-cycle arrest properties. In this paper, we study the dynamics of a minimal biochemical network model in which a cell-division oscillator and a differentiation switch mutually antagonize. We identify the existence of three biologically plausible bifurcation scenarios organized around a codimension-four swallowtail-homoclinic singularity. As a result, the model exhibits a broad repertoire of cell-cycle arrest properties in terms of reversibility of these arrests, tunability of interdivision time, and ability to track time-varying signals. This dynamic versatility would explain the diversity of cell-cycle arrest strategies developed in different living species and functional contexts.

  2. Mitochondrial ribosomal protein L41 mediates serum starvation-induced cell-cycle arrest through an increase of p21WAF1/CIP1

    International Nuclear Information System (INIS)

    Kim, Mi Jin; Yoo, Young A.; Kim, Hyung Jung; Kang, Seongman; Kim, Yong Geon; Kim, Jun Suk; Yoo, Young Do

    2005-01-01

    Ribosomal proteins not only act as components of the translation apparatus but also regulate cell proliferation and apoptosis. A previous study reported that MRPL41 plays an important role in p53-dependent apoptosis. It also showed that MRPL41 arrests the cell cycle by stabilizing p27 Kip1 in the absence of p53. This study found that MRPL41 mediates the p21 WAF1/CIP1 -mediated G1 arrest in response to serum starvation. The cells were released from serum starvation-induced G1 arrest via the siRNA-mediated blocking of MRPL41 expression. Overall, these results suggest that MRPL41 arrests the cell cycle by increasing the p21 WAF1/CIP1 and p27 Kip1 levels under the growth inhibitory conditions

  3. Rotavirus replication is correlated with S/G2 interphase arrest of the host cell cycle.

    Directory of Open Access Journals (Sweden)

    Selene Glück

    Full Text Available In infected cells rotavirus (RV replicates in viroplasms, cytosolic structures that require a stabilized microtubule (MT network for their assembly, maintenance of the structure and perinuclear localization. Therefore, we hypothesized that RV could interfere with the MT-breakdown that takes place in mitosis during cell division. Using synchronized RV-permissive cells, we show that RV infection arrests the cell cycle in S/G2 phase, thus favoring replication by improving viroplasms formation, viral protein translation, and viral assembly. The arrest in S/G2 phase is independent of the host or viral strain and relies on active RV replication. RV infection causes cyclin B1 down-regulation, consistent with blocking entry into mitosis. With the aid of chemical inhibitors, the cytoskeleton network was linked to specific signaling pathways of the RV-induced cell cycle arrest. We found that upon RV infection Eg5 kinesin was delocalized from the pericentriolar region to the viroplasms. We used a MA104-Fucci system to identify three RV proteins (NSP3, NSP5, and VP2 involved in cell cycle arrest in the S-phase. Our data indicate that there is a strong correlation between the cell cycle arrest and RV replication.

  4. Paris Saponin I Sensitizes Gastric Cancer Cell Lines to Cisplatin via Cell Cycle Arrest and Apoptosis.

    Science.gov (United States)

    Song, Shuichuan; Du, Leiwen; Jiang, Hao; Zhu, Xinhai; Li, Jinhui; Xu, Ji

    2016-10-18

    BACKGROUND Dose-related toxicity is the major restriction of cisplatin and cisplatin-combination chemotherapy, and is a challenge for advanced gastric cancer treatment. We explored the possibility of using Paris saponin I as an agent to sensitize gastric cancer cells to cisplatin, and examined the underlying mechanism. MATERIAL AND METHODS Growth inhibition was detected by MTT assay. The cell cycle and apoptosis were detected using flow cytometry and Annexin V/PI staining. The P21waf1/cip1, Bcl-2, Bax, and caspase-3 protein expression were detected using Western blot analysis. RESULTS The results revealed that PSI sensitized gastric cancer cells to cisplatin, with low toxicity. The IC50 value of cisplatin in SGC-7901 cell lines was decreased when combined with PSI. PSI promoted cisplatin-induced G2/M phase arrest and apoptosis in a cisplatin concentration-dependent manner. Bcl-2 protein expression decreased, but Bax, caspase-3, and P21waf1/cip1 protein expression increased with PSI treatment. CONCLUSIONS The underlying mechanism of Paris saponin I may be related to targeting the apoptosis pathway and cell cycle blocking, which suggests that PSI is a potential therapeutic sensitizer for cisplatin in treating gastric cancer.

  5. Induction of cell cycle arrest and apoptosis by Ormenis eriolepis a ...

    African Journals Online (AJOL)

    Induction of cell cycle arrest and apoptosis by Ormenis eriolepis a Morrocan endemic plant in various human cancer cell lines. Lamiae Belayachi, Clara Aceves-Luquero, Nawel Merghoub, Silvia Fernández de Mattos, Saaïd Amzazi, Priam Villalonga, Youssef Bakri ...

  6. Abnormal mitosis triggers p53-dependent cell cycle arrest in human tetraploid cells.

    Science.gov (United States)

    Kuffer, Christian; Kuznetsova, Anastasia Yurievna; Storchová, Zuzana

    2013-08-01

    Erroneously arising tetraploid mammalian cells are chromosomally instable and may facilitate cell transformation. An increasing body of evidence shows that the propagation of mammalian tetraploid cells is limited by a p53-dependent arrest. The trigger of this arrest has not been identified so far. Here we show by live cell imaging of tetraploid cells generated by an induced cytokinesis failure that most tetraploids arrest and die in a p53-dependent manner after the first tetraploid mitosis. Furthermore, we found that the main trigger is a mitotic defect, in particular, chromosome missegregation during bipolar mitosis or spindle multipolarity. Both a transient multipolar spindle followed by efficient clustering in anaphase as well as a multipolar spindle followed by multipolar mitosis inhibited subsequent proliferation to a similar degree. We found that the tetraploid cells did not accumulate double-strand breaks that could cause the cell cycle arrest after tetraploid mitosis. In contrast, tetraploid cells showed increased levels of oxidative DNA damage coinciding with the p53 activation. To further elucidate the pathways involved in the proliferation control of tetraploid cells, we knocked down specific kinases that had been previously linked to the cell cycle arrest and p53 phosphorylation. Our results suggest that the checkpoint kinase ATM phosphorylates p53 in tetraploid cells after abnormal mitosis and thus contributes to proliferation control of human aberrantly arising tetraploids.

  7. Sevoflurane anesthesia induces apoptosis and cell cycle arrest in ...

    African Journals Online (AJOL)

    effects of sevoflurane on growth and induction of apoptotic changes in NPC-039 cells. ... population of apoptotic NPC-039 cells compared with cells treated with sevoflurane alone. The .... peroxidase-conjugated anti-rabbit IgG secondary.

  8. SUMO modification of Stra13 is required for repression of cyclin D1 expression and cellular growth arrest.

    Directory of Open Access Journals (Sweden)

    Yaju Wang

    Full Text Available Stra13, a basic helix-loop-helix (bHLH transcription factor is involved in myriad biological functions including cellular growth arrest, differentiation and senescence. However, the mechanisms by which its transcriptional activity and function are regulated remain unclear. In this study, we provide evidence that post-translational modification of Stra13 by Small Ubiquitin-like Modifier (SUMO dramatically potentiates its ability to transcriptionally repress cyclin D1 and mediate G(1 cell cycle arrest in fibroblast cells. Mutation of SUMO acceptor lysines 159 and 279 located in the C-terminal repression domain has no impact on nuclear localization; however, it abrogates association with the co-repressor histone deacetylase 1 (HDAC1, attenuates repression of cyclin D1, and prevents Stra13-mediated growth suppression. HDAC1, which promotes cellular proliferation and cell cycle progression, antagonizes Stra13 sumoylation-dependent growth arrest. Our results uncover an unidentified regulatory axis between Stra13 and HDAC1 in progression through the G(1/S phase of the cell cycle, and provide new mechanistic insights into regulation of Stra13-mediated transcriptional repression by sumoylation.

  9. Sevoflurane anesthesia induces apoptosis and cell cycle arrest in ...

    African Journals Online (AJOL)

    Purpose: To determine the effects of sevoflurane on NPC-039 nasopharyngeal carcinoma cells. Methods: WST-8 assays and flow cytometry with annexin V/PI staining were used to analyze the effects of sevoflurane on growth and induction of apoptotic changes in NPC-039 cells. Cell viability was performed on a microplate ...

  10. Change of cell cycle arrest of tumor cell lines after 60Co γ-irradiation

    International Nuclear Information System (INIS)

    Tang Yi; Liu Wenli; Zhou Jianfeng; Gao Qinglei; Wu Jianhong

    2003-01-01

    Objective: To observe the cell cycle arrest changes in peripheral blood mononuclear cells (PBMNCs) of normal persons and several kinds of tumor cell lines after 60 Co γ-irradiation. Methods: PBMNCs of normal persons, HL-60, K562, SiHA and 113 tumor cell lines were irradiated with 60 Co γ-rays at the absorbed doses of 6, 10,15 Gy. Cell cycles changes were checked 6, 12, 24, 48 and 60 h after the irradiation. Results: A stasis state was observed in normal person PBMNCs, 95 percents of which were in G 1 phase, and they still remained stasis after the irradiation. Except the 113 cell line manifesting G 1 phase arrest, all other tumor cell lines showed G 2 /M phase arrest after irradiation. The radiation sensitivity of HL-60 was higher than that of SiHA cell line. Conclusion: Different cell lines have different cell cycle arrest reaction to radiation and their radiation sensitivity are also different

  11. Dux4 induces cell cycle arrest at G1 phase through upregulation of p21 expression

    International Nuclear Information System (INIS)

    Xu, Hongliang; Wang, Zhaoxia; Jin, Suqin; Hao, Hongjun; Zheng, Lemin; Zhou, Boda; Zhang, Wei; Lv, He; Yuan, Yun

    2014-01-01

    Highlights: • Dux4 induced TE671 cell proliferation defect and G1 phase arrest. • Dux4 upregulated p21 expression without activating p53. • Silencing p21 rescued Dux4 mediated proliferation defect and cell cycle arrest. • Sp1 binding site was required for Dux4-induced p21 promoter activation. - Abstract: It has been implicated that Dux4 plays crucial roles in development of facioscapulohumeral dystrophy. But the underlying myopathic mechanisms and related down-stream events of this retrogene were far from clear. Here, we reported that overexpression of Dux4 in a cell model TE671 reduced cell proliferation rate, and increased G1 phase accumulation. We also determined the impact of Dux4 on p53/p21 signal pathway, which controls the checkpoint in cell cycle progression. Overexpression of Dux4 increased p21 mRNA and protein level, while expression of p53, phospho-p53 remained unchanged. Silencing p21 rescued Dux4 mediated proliferation defect and cell cycle arrest. Furthermore, we demonstrated that enhanced Dux4 expression increased p21 promoter activity and elevated expression of Sp1 transcription factor. Mutation of Sp1 binding site decreased dux4 induced p21 promoter activation. Chromatin immunoprecipitation (ChIP) assays confirmed the Dux4-induced binding of Sp1 to p21 promoter in vivo. These results suggest that Dux4 might induce proliferation inhibition and G1 phase arrest through upregulation of p21

  12. Dux4 induces cell cycle arrest at G1 phase through upregulation of p21 expression

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Hongliang; Wang, Zhaoxia; Jin, Suqin; Hao, Hongjun [Department of Neurology, Peking University First Hospital, Beijing 100034 (China); Zheng, Lemin [The Institute of Cardiovascular Sciences, Peking University Health Science Center, Key Laboratory of Molecular Cardiovascular Sciences of Education Ministry, Key Laboratory of Cardiovascular Molecular Biology and Regulatory Peptides of Health Ministry, Beijing 100191 (China); Zhou, Boda [The Department of Cardiology, Peking University Third Hospital, Beijing 100191 (China); Zhang, Wei; Lv, He [Department of Neurology, Peking University First Hospital, Beijing 100034 (China); Yuan, Yun, E-mail: yuanyun2002@sohu.com [Department of Neurology, Peking University First Hospital, Beijing 100034 (China)

    2014-03-28

    Highlights: • Dux4 induced TE671 cell proliferation defect and G1 phase arrest. • Dux4 upregulated p21 expression without activating p53. • Silencing p21 rescued Dux4 mediated proliferation defect and cell cycle arrest. • Sp1 binding site was required for Dux4-induced p21 promoter activation. - Abstract: It has been implicated that Dux4 plays crucial roles in development of facioscapulohumeral dystrophy. But the underlying myopathic mechanisms and related down-stream events of this retrogene were far from clear. Here, we reported that overexpression of Dux4 in a cell model TE671 reduced cell proliferation rate, and increased G1 phase accumulation. We also determined the impact of Dux4 on p53/p21 signal pathway, which controls the checkpoint in cell cycle progression. Overexpression of Dux4 increased p21 mRNA and protein level, while expression of p53, phospho-p53 remained unchanged. Silencing p21 rescued Dux4 mediated proliferation defect and cell cycle arrest. Furthermore, we demonstrated that enhanced Dux4 expression increased p21 promoter activity and elevated expression of Sp1 transcription factor. Mutation of Sp1 binding site decreased dux4 induced p21 promoter activation. Chromatin immunoprecipitation (ChIP) assays confirmed the Dux4-induced binding of Sp1 to p21 promoter in vivo. These results suggest that Dux4 might induce proliferation inhibition and G1 phase arrest through upregulation of p21.

  13. Effect of Irradiation on Apoptosis, Cell Cycle Arrest and Calcified Nodule Formation of Rat Calvarial Osteoblast

    International Nuclear Information System (INIS)

    Lee, Young Mi; Choi, Hang Moon; Heo, Min Suk; Lee, Sam Sun; Choi, Soon Chul; Park, Tae Won

    2000-01-01

    The study was aimed to detect the induction of apoptosis, cell cycle arrest and calcified nodule formation after irradiation on primarily cultured osteoblasts. Using rat calvarial osteoblasts, the effects of irradiation on apoptosis, cell cycle arrest, and calcified nodule formation were studied. The single irradiation of 10, 20 Gy was done with 5.38 Gy/min dose rate using the 137 Cs cell irradiator at 4th and 14th day of culture. Apoptosis induction and cell cycle arrest were assayed by the flow cytometry at 1, 2, 3, and 4 days after irradiation. The formation of calcified nodules was observed by alizarin red staining at 1, 3, 10, 14 days after irradiation at 4th day of culture, and at 1, 4, 5 days after irradiation at 14th day of culture. Apoptosis was not induced by 10 or 20 Gy independent of irradiation and culture period. Irradiation did not induced G1 arrest in post-irradiated osteoblasts. After irradiation at 4th-day of culture, G2 arrest was induced but it was not statistically significant after irradiation at 14th-day of culture. In the case of irradiated cells at 4th day of culture, calcified nodules were not formed and at 14th-day of culture after irradiation, calcified nodule formation did not affected. Taken together, these results suggest that irradiation at the dose of 10-20 Gy would not affect apoptosis induction of osteoblasts. Cell cycle and calcified nodule formation were influenced by the level of differentiation of osteblasts.

  14. Drosophila cell cycle under arrest: uncapped telomeres plead guilty.

    Science.gov (United States)

    Cenci, Giovanni

    2009-04-01

    Telomeres are specialized structures that protect chromosome ends from degradation and fusion events. In most organisms, telomeres consist of short, repetitive G-rich sequences added to chromosome ends by a reverse transcriptase with an internal RNA template, called telomerase. Specific DNA-binding protein complexes associate with telomeric sequences preventing chromosome ends from being recognized as DNA double strand breaks (DSBs). Telomeres that lose their cap activate the DNA damage response (DDR) likewise DSBs and, if inappropriately repaired, generate telomeric fusions, which eventually lead to genome instability. In Drosophila there is not telomerase, and telomere length is maintained by transposition of three specialized retroelements. However, fly telomeres are protected by multi protein complexes like their yeast and vertebrate counterparts; these complexes bind chromosome ends in a sequence-independent fashion and are required to prevent checkpoint activation and end-to-end fusion. Uncapped Drosophila telomeres elicit a DDR just as dysfunctional human telomeres. Most interestingly, uncapped Drosophila telomeres also activate the spindle assembly checkpoint (SAC) by recruiting the SAC kinase BubR1. BubR1 accumulations at chromosome ends trigger the SAC that inhibits the metaphase-to-anaphase transition. These findings, reviewed here, highlight an intriguing and unsuspected connection between telomeres and cell cycle regulation, providing a clue to understand human telomere function.

  15. The cancer-germline antigen SSX2 causes cell cycle arrest and DNA damage in cancer cells

    DEFF Research Database (Denmark)

    Greve, Katrine Buch Vidén; Lindgreen, Jonas; Terp, Mikkel Green

    2011-01-01

    The SSX family of cancer and germline antigens is mainly expressed in the germ cells of healthy individuals as well as wide range of cancers and is therefore potential targets for immunotherapy. However, little is known about the role of SSX proteins in tumorigenesis and normal cell function. Here......, we show that SSX2 is involved in regulation of cancer cell growth. We found that ectopic expression of SSX2 in melanoma and colon cancer cells strongly reduced cell growth and induced apoptosis in vitro. Importantly, in a xenograft mouse model, the growth of tumors derived from SSX2 overexpressing...... melanoma cells was severely reduced compared to those derived from the isogenic parental cell line. Cell cycle analysis showed that SSX2 caused an accumulation of cells arrested in G1. Consistent with this, we observed a marked decrease in cells expressing the proliferation marker Ki67 and concomitantly...

  16. Parafibromin inhibits cancer cell growth and causes G1 phase arrest

    International Nuclear Information System (INIS)

    Zhang Chun; Kong Dong; Tan, M.-H.; Pappas, Donald L.; Wang, P.-F.; Chen, Jindong; Farber, Leslie; Zhang Nian; Koo, H.-M.; Weinreich, Michael; Williams, Bart O.; Teh, B.T.

    2006-01-01

    The HRPT2 (hereditary hyperparathyroidism type 2) tumor suppressor gene encodes a ubiquitously expressed 531 amino acid protein termed parafibromin. Inactivation of parafibromin predisposes one to the development of HPT-JT syndrome. To date, the role of parafibromin in tumorigenesis is largely unknown. Here, we report that parafibromin is a nuclear protein that possesses anti-proliferative properties. We show that overexpression of parafibromin inhibits colony formation and cellular proliferation, and induces cell cycle arrest in the G1 phase. Moreover, HPT-JT syndrome-derived mutations in HRPT2 behave in a dominant-negative manner by abolishing the ability of parafibromin to suppress cell proliferation. These findings suggest that parafibromin has a critical role in cell growth, and mutations in HRPT2 can directly inhibit this role

  17. Downregulation of HDAC9 inhibits cell proliferation and tumor formation by inducing cell cycle arrest in retinoblastoma

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Yiting; Wu, Dan; Xia, Fengjie; Xian, Hongyu; Zhu, Xinyue [Medical School of Nanjing University, Department of Ophthalmology, Jinling Hospital, Nanjing, 210002 (China); Cui, Hongjuan, E-mail: hcui@swu.edu.cn [State Key Laboratory of Silkworm Genome Biology, Institute of Sericulture and Systems Biology, Southwest University, Chongqing, 400716 (China); Huang, Zhenping, E-mail: huangzhenping19633@163.com [Medical School of Nanjing University, Department of Ophthalmology, Jinling Hospital, Nanjing, 210002 (China)

    2016-04-29

    Histone deacetylase 9 (HDAC9) is a member of class II HDACs, which regulates a wide variety of normal and abnormal physiological functions. Recently, HDAC9 has been found to be overexpressed in some types of human cancers. However, the role of HDAC9 in retinoblastoma remains unclear. In this study, we found that HDAC9 was commonly expressed in retinoblastoma tissues and HDAC9 was overexpressed in prognostically poor retinoblastoma patients. Through knocking down HDAC9 in Y79 and WERI-Rb-1 cells, the expression level of HDAC9 was found to be positively related to cell proliferation in vitro. Further investigation indicated that knockdown HDAC9 could significantly induce cell cycle arrest at G1 phase in retinoblastoma cells. Western blot assay showed downregulation of HDAC9 could significantly decrease cyclin E2 and CDK2 expression. Lastly, xenograft study in nude mice showed that downregulation of HDAC9 inhibited tumor growth and development in vivo. Therefore, our results suggest that HDAC9 could serve as a novel potential therapeutic target in the treatment of retinoblastoma. - Highlights: • High expression of HDAC9 correlates with poor patient prognosis. • Downregulation of HDAC9 inhibits cell proliferation in retinoblastoma cells. • Downregulation of HDAC9 induces cell cycle arrest at G1 phase in retinoblastoma cells. • Downregulation of HDAC9 suppresses tumor growth in nude mice.

  18. Boletus edulis biologically active biopolymers induce cell cycle arrest in human colon adenocarcinoma cells.

    Science.gov (United States)

    Lemieszek, Marta Kinga; Cardoso, Claudia; Ferreira Milheiro Nunes, Fernando Hermínio; Ramos Novo Amorim de Barros, Ana Isabel; Marques, Guilhermina; Pożarowski, Piotr; Rzeski, Wojciech

    2013-04-25

    The use of biologically active compounds isolated from edible mushrooms against cancer raises global interest. Anticancer properties are mainly attributed to biopolymers including mainly polysaccharides, polysaccharopeptides, polysaccharide proteins, glycoproteins and proteins. In spite of the fact that Boletus edulis is one of the widely occurring and most consumed edible mushrooms, antitumor biopolymers isolated from it have not been exactly defined and studied so far. The present study is an attempt to extend this knowledge on molecular mechanisms of their anticancer action. The mushroom biopolymers (polysaccharides and glycoproteins) were extracted with hot water and purified by anion-exchange chromatography. The antiproliferative activity in human colon adenocarcinoma cells (LS180) was screened by means of MTT and BrdU assays. At the same time fractions' cytotoxicity was examined on the human colon epithelial cells (CCD 841 CoTr) by means of the LDH assay. Flow cytometry and Western blotting were applied to cell cycle analysis and protein expression involved in anticancer activity of the selected biopolymer fraction. In vitro studies have shown that fractions isolated from Boletus edulis were not toxic against normal colon epithelial cells and in the same concentration range elicited a very prominent antiproliferative effect in colon cancer cells. The best results were obtained in the case of the fraction designated as BE3. The tested compound inhibited cancer cell proliferation which was accompanied by cell cycle arrest in the G0/G1-phase. Growth inhibition was associated with modulation of the p16/cyclin D1/CDK4-6/pRb pathway, an aberration of which is a critical step in the development of many human cancers including colon cancer. Our results indicate that a biopolymer BE3 from Boletus edulis possesses anticancer potential and may provide a new therapeutic/preventive option in colon cancer chemoprevention.

  19. Fisetin and hesperetin induced apoptosis and cell cycle arrest in chronic myeloid leukemia cells accompanied by modulation of cellular signaling.

    Science.gov (United States)

    Adan, Aysun; Baran, Yusuf

    2016-05-01

    Fisetin and hesperetin, naturally occurring flavonoids, have been reported as novel antioxidants with chemopreventive/chemotherapeutic potential against various types of cancer. However, their mechanism of action in CML is still unknown. This particular study aims to evaluate the therapeutic potentials of fisetin and hesperetin and their effects on cell proliferation, apoptosis, and cell cycle progression in human K562 CML cells. The results indicated that fisetin and hesperetin inhibited cell proliferation and triggered programmed cell death in these cells. The latter was confırmed by mitochondrial membrane depolarization and an increase in caspase-3 activation. In addition to that, we have detected S and G2/M cell cycle arrests and G0/G1 arrest upon fisetin and hesperetin treatment, respectively. To identify the altered genes and genetic networks in response to fisetin and hesperetin, whole-genome microarray analysis was performed. The microarray gene profiling analysis revealed some important signaling pathways including JAK/STAT pathway, KIT receptor signaling, and growth hormone receptor signaling that were altered upon fisetin and hesperetin treatment. Moreover, microarray data suggested potential candidate genes for targeted CML therapy. Fisetin and hesperetin significantly modulated the expression of genes involved in cell proliferation and division, apoptosis, cell cycle regulation, and other significant cellular processes such as replication, transcription, and translation. In conclusion, our results suggest that fisetin and hesperetin as potential natural agents for CML therapy.

  20. High fat diet triggers cell cycle arrest and excessive apoptosis of granulosa cells during the follicular development

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Yanqing; Zhang, Zhenghong; Liao, Xinghui; Wang, Zhengchao, E-mail: zcwang@fjnu.edu.cn

    2015-10-23

    The regulatory mechanism of granulosa cells (GCs) proliferation during the follicular development is complicated and multifactorial, which is essential for the oocyte growth and normal ovarian functions. To investigate the role of high fat diet (HFD) on the proliferation of GCs, 4-week old female mice were fed with HFD or normal control diet (NC) for 15 weeks or 20 weeks and then detected the expression level of some regulatory molecules of cell cycle and apoptosis. The abnormal ovarian morphology was observed at 20 weeks. Further mechanistic studies indicated that HFD induced-obesity caused elevated apoptotic levels in GCs of the ovaries in a time-dependent manner. Moreover, cell cycle progress was also impacted after HFD fed. The cell cycle inhibitors, p27{sup Kip1} and p21{sup Cip1}, were significantly induced in the ovaries from the mice in HFD group when compared with that in the ovaries from the mice in NC group. Subsequently, the expression levels of Cyclin D1, D3 and CDK4 were also significantly influenced in the ovaries from the mice fed with HFD in a time-dependent manner. The present results suggested that HFD induced-obesity may trigger cell cycle arrest and excessive apoptosis of GCs, causing the abnormal follicular development and ovarian function failure. - Highlights: • HFD induced-obesity leads to abnormal ovarian morphology. • HFD induced-obesity triggers excessive apoptosis in the ovary. • HFD induced-obesity up-regulates cell cycle inhibitors p21{sup Cip1} and p27{sup Kip1} in the ovary. • HFD induced-obesity causes cell cycle arrest in the ovary.

  1. Cell cycle arrest and the evolution of chronic kidney disease from acute kidney injury.

    Science.gov (United States)

    Canaud, Guillaume; Bonventre, Joseph V

    2015-04-01

    For several decades, acute kidney injury (AKI) was generally considered a reversible process leading to complete kidney recovery if the individual survived the acute illness. Recent evidence from epidemiologic studies and animal models, however, have highlighted that AKI can lead to the development of fibrosis and facilitate the progression of chronic renal failure. When kidney injury is mild and baseline function is normal, the repair process can be adaptive with few long-term consequences. When the injury is more severe, repeated, or to a kidney with underlying disease, the repair can be maladaptive and epithelial cell cycle arrest may play an important role in the development of fibrosis. Indeed, during the maladaptive repair after a renal insult, many tubular cells that are undergoing cell division spend a prolonged period in the G2/M phase of the cell cycle. These tubular cells recruit intracellular pathways leading to the synthesis and the secretion of profibrotic factors, which then act in a paracrine fashion on interstitial pericytes/fibroblasts to accelerate proliferation of these cells and production of interstitial matrix. Thus, the tubule cells assume a senescent secretory phenotype. Characteristic features of these cells may represent new biomarkers of fibrosis progression and the G2/M-arrested cells may represent a new therapeutic target to prevent, delay or arrest progression of chronic kidney disease. Here, we summarize recent advances in our understanding of the biology of the cell cycle and how cell cycle arrest links AKI to chronic kidney disease. © The Author 2014. Published by Oxford University Press on behalf of ERA-EDTA. All rights reserved.

  2. Oestrogen receptor evaluation in Pomeranian dogs with hair cycle arrest (alopecia X) on melatonin supplementation.

    Science.gov (United States)

    Frank, Linda A; Donnell, Robert L; Kania, Stephen A

    2006-08-01

    The role of oestrogen receptors in dogs with hair cycle arrest (alopecia X) was investigated by immunohistochemistry. The purpose of this study was to determine if hair regrowth in dogs with hair cycle arrest treated with melatonin was associated with a decrease in follicular oestrogen receptors. Fifteen Pomeranians (excluding intact females) with hair cycle arrest were enrolled. Two biopsies were obtained from alopecic areas of the trunk before and after 3 months on melatonin. Haematoxylin and eosin-stained tissues were examined and oestrogen receptor-alpha was demonstrated immunohistochemically. Common histopathological findings included hyperkeratosis, follicular keratosis, excessive tricholemmal keratinization (flame follicles), thin epidermis, few small anagen bulbs, epidermal pigmentation and melanin aggregates within follicular keratin. Melanin aggregates within basal cells and hair were an occasional finding. After 3 months, 40% (six) dogs had mild to moderate hair regrowth. Biopsies from six dogs showed histological evidence of an increase in anagen hairs and eight dogs had a decrease in epidermal pigmentation. Moderate to marked staining intensity of oestrogen receptor-alpha was noted in all sebaceous gland basal cells, all small hair bulbs and follicular epithelium of telogen hairs. There was no oestrogen receptor-alpha staining of nuclei within the epidermis, apocrine glands or dermal fibroblasts. Large anagen hair bulbs had minimal to no oestrogen receptor staining. Hair regrowth was not associated with a change in oestrogen receptor-alpha staining.

  3. Prolonged mechanical ventilation induces cell cycle arrest in newborn rat lung.

    Directory of Open Access Journals (Sweden)

    Andreas A Kroon

    Full Text Available RATIONALE: The molecular mechanism(s by which mechanical ventilation disrupts alveolar development, a hallmark of bronchopulmonary dysplasia, is unknown. OBJECTIVE: To determine the effect of 24 h of mechanical ventilation on lung cell cycle regulators, cell proliferation and alveolar formation in newborn rats. METHODS: Seven-day old rats were ventilated with room air for 8, 12 and 24 h using relatively moderate tidal volumes (8.5 mL.kg⁻¹. MEASUREMENT AND MAIN RESULTS: Ventilation for 24 h (h decreased the number of elastin-positive secondary crests and increased the mean linear intercept, indicating arrest of alveolar development. Proliferation (assessed by BrdU incorporation was halved after 12 h of ventilation and completely arrested after 24 h. Cyclin D1 and E1 mRNA and protein levels were decreased after 8-24 h of ventilation, while that of p27(Kip1 was significantly increased. Mechanical ventilation for 24 h also increased levels of p57(Kip2, decreased that of p16(INK4a, while the levels of p21(Waf/Cip1 and p15(INK4b were unchanged. Increased p27(Kip1 expression coincided with reduced phosphorylation of p27(Kip1 at Thr¹⁵⁷, Thr¹⁸⁷ and Thr¹⁹⁸ (p<0.05, thereby promoting its nuclear localization. Similar -but more rapid- changes in cell cycle regulators were noted when 7-day rats were ventilated with high tidal volume (40 mL.kg⁻¹ and when fetal lung epithelial cells were subjected to a continuous (17% elongation cyclic stretch. CONCLUSION: This is the first demonstration that prolonged (24 h of mechanical ventilation causes cell cycle arrest in newborn rat lungs; the arrest occurs in G₁ and is caused by increased expression and nuclear localization of Cdk inhibitor proteins (p27(Kip1, p57(Kip2 from the Kip family.

  4. Absence of p53 in Clara cells favours multinucleation and loss of cell cycle arrest

    Directory of Open Access Journals (Sweden)

    Clarke Alan R

    2002-11-01

    Full Text Available Abstract Background The p53 oncosuppressor protein is a critical mediator of the response to injury in mammalian cells and is mutationally inactivated in the majority of lung malignancies. In this analysis, the effects of p53-deficiency were investigated in short-term primary cultures of murine bronchiolar Clara cells. Clara cells, isolated from gene-targeted p53-deficient mice, were compared to cells derived from wild type littermates. Results p53 null cultures displayed abnormal morphology; specifically, a high incidence of multinucleation, which increased with time in culture. Multinucleated cells were proficient in S phase DNA synthesis, as determined by BrdU incorporation. However, multinucleation did not reflect altered rates of S phase synthesis, which were similar between wild type and p53-/- cultures. Nucleation defects in p53-/- Clara cells associated with increased centrosome number, as determined by confocal microscopy of pericentrin-stained cultures, and may highlight a novel role of p53 in preserving genomic integrity in lung epithelial cells. Effects of p53-deficiency were also studied following exposure to DNA damage. A p53-dependent reduction in the BrdU index was observed in Clara cells following ionizing radiation. The reduction in BrdU index in wild type cells displayed serum-dependency, and occurred only in the absence of serum. Taken together, these findings demonstrate that in murine primary Clara cell culture, cell cycle arrest is a p53-mediated response to DNA damage, and that extracellular factors, such as serum, influence this response. Conclusion These findings highlight functions of wild type p53 protein in bipolar spindle formation, centrosome regulation, and growth control in bronchiolar Clara cells.

  5. Cell cycle arrest in plants: what distinguishes quiescence, dormancy and differentiated G1?

    Science.gov (United States)

    Velappan, Yazhini; Signorelli, Santiago; Considine, Michael J

    2017-10-17

    Quiescence is a fundamental feature of plant life, which enables plasticity, renewal and fidelity of the somatic cell line. Cellular quiescence is defined by arrest in a particular phase of the cell cycle, typically G1 or G2; however, the regulation of quiescence and proliferation can also be considered across wider scales in space and time. As such, quiescence is a defining feature of plant development and phenology, from meristematic stem cell progenitors to terminally differentiated cells, as well as dormant or suppressed seeds and buds. While the physiology of each of these states differs considerably, each is referred to as 'cell cycle arrest' or 'G1 arrest'. Here the physiology and molecular regulation of (1) meristematic quiescence, (2) dormancy and (3) terminal differentiation (cell cycle exit) are considered in order to determine whether and how the molecular decisions guiding these nuclear states are distinct. A brief overview of the canonical cell cycle regulators is provided, and the genetic and genomic, as well as physiological, evidence is considered regarding two primary questions: (1) Are the canonical cell cycle regulators superior or subordinate in the regulation of quiescence? (2) Are these three modes of quiescence governed by distinct molecular controls? Meristematic quiescence, dormancy and terminal differentiation are each predominantly characterized by G1 arrest but regulated distinctly, at a level largely superior to the canonical cell cycle. Meristematic quiescence is intrinsically linked to non-cell-autonomous regulation of meristem cell identity, and particularly through the influence of ubiquitin-dependent proteolysis, in partnership with reactive oxygen species, abscisic acid and auxin. The regulation of terminal differentiation shares analogous features with meristematic quiescence, albeit with specific activators and a greater role for cytokinin signalling. Dormancy meanwhile appears to be regulated at the level of chromatin

  6. Genistein induces G2/M cell cycle arrest and apoptosis via ATM/p53-dependent pathway in human colon cancer cells.

    Science.gov (United States)

    Zhang, Zhiyu; Wang, Chong-Zhi; Du, Guang-Jian; Qi, Lian-Wen; Calway, Tyler; He, Tong-Chuan; Du, Wei; Yuan, Chun-Su

    2013-07-01

    Soybean isoflavones have been used as a potential preventive agent in anticancer research for many years. Genistein is one of the most active flavonoids in soybeans. Accumulating evidence suggests that genistein alters a variety of biological processes in estrogen-related malignancies, such as breast and prostate cancers. However, the molecular mechanism of genistein in the prevention of human colon cancer remains unclear. Here we attempted to elucidate the anticarcinogenic mechanism of genistein in human colon cancer cells. First we evaluated the growth inhibitory effect of genistein and two other isoflavones, daidzein and biochanin A, on HCT-116 and SW-480 human colon cancer cells. In addition, flow cyto-metry was performed to observe the morphological changes in HCT-116/SW-480 cells undergoing apoptosis or cell cycle arrest, which had been visualized using Annexin V-FITC and/or propidium iodide staining. Real-time PCR and western blot analyses were also employed to study the changes in expression of several important genes associated with cell cycle regulation. Our data showed that genistein, daidzein and biochanin A exhibited growth inhibitory effects on HCT-116/SW-480 colon cancer cells and promoted apoptosis. Genistein showed a significantly greater effect than the other two compounds, in a time- and dose-dependent manner. In addition, genistein caused cell cycle arrest in the G2/M phase, which was accompanied by activation of ATM/p53, p21waf1/cip1 and GADD45α as well as downregulation of cdc2 and cdc25A demonstrated by q-PCR and immunoblotting assay. Interestingly, genistein induced G2/M cell cycle arrest in a p53-dependent manner. These findings exemplify that isoflavones, especially genistein, could promote colon cancer cell growth inhibition and facilitate apoptosis and cell cycle arrest in the G2/M phase. The ATM/p53-p21 cross-regulatory network may play a crucial role in mediating the anticarcinogenic activities of genistein in colon cancer.

  7. High-dose irradiation induces cell cycle arrest, apoptosis, and developmental defects during Drosophila oogenesis.

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    Hee Jin Shim

    Full Text Available Ionizing radiation (IR treatment induces a DNA damage response, including cell cycle arrest, DNA repair, and apoptosis in metazoan somatic cells. Because little has been reported in germline cells, we performed a temporal analysis of the DNA damage response utilizing Drosophila oogenesis as a model system. Oogenesis in the adult Drosophila female begins with the generation of 16-cell cyst by four mitotic divisions of a cystoblast derived from the germline stem cells. We found that high-dose irradiation induced S and G2 arrests in these mitotically dividing germline cells in a grp/Chk1- and mnk/Chk2-dependent manner. However, the upstream kinase mei-41, Drosophila ATR ortholog, was required for the S-phase checkpoint but not for the G2 arrest. As in somatic cells, mnk/Chk2 and dp53 were required for the major cell death observed in early oogenesis when oocyte selection and meiotic recombination occurs. Similar to the unscheduled DNA double-strand breaks (DSBs generated from defective repair during meiotic recombination, IR-induced DSBs produced developmental defects affecting the spherical morphology of meiotic chromosomes and dorsal-ventral patterning. Moreover, various morphological abnormalities in the ovary were detected after irradiation. Most of the IR-induced defects observed in oogenesis were reversible and were restored between 24 and 96 h after irradiation. These defects in oogenesis severely reduced daily egg production and the hatch rate of the embryos of irradiated female. In summary, irradiated germline cells induced DSBs, cell cycle arrest, apoptosis, and developmental defects resulting in reduction of egg production and defective embryogenesis.

  8. Glioblastoma Stem Cells Respond to Differentiation Cues but Fail to Undergo Commitment and Terminal Cell-Cycle Arrest

    Directory of Open Access Journals (Sweden)

    Helena Carén

    2015-11-01

    Full Text Available Glioblastoma (GBM is an aggressive brain tumor whose growth is driven by stem cell-like cells. BMP signaling triggers cell-cycle exit and differentiation of GBM stem cells (GSCs and, therefore, might have therapeutic value. However, the epigenetic mechanisms that accompany differentiation remain poorly defined. It is also unclear whether cell-cycle arrest is terminal. Here we find only a subset of GSC cultures exhibit astrocyte differentiation in response to BMP. Although overtly differentiated non-cycling astrocytes are generated, they remain vulnerable to cell-cycle re-entry and fail to appropriately reconfigure DNA methylation patterns. Chromatin accessibility mapping identified loci that failed to alter in response to BMP and these were enriched in SOX transcription factor-binding motifs. SOX transcription factors, therefore, may limit differentiation commitment. A similar propensity for cell-cycle re-entry and de-differentiation was observed in GSC-derived oligodendrocyte-like cells. These findings highlight significant obstacles to BMP-induced differentiation as therapy for GBM.

  9. Methyl Sartortuoate Inhibits Colon Cancer Cell Growth by Inducing Apoptosis and G2/M-Phase Arrest.

    Science.gov (United States)

    Lan, Qiusheng; Li, Shoufeng; Lai, Wei; Xu, Heyang; Zhang, Yang; Zeng, Yujie; Lan, Wenjian; Chu, Zhonghua

    2015-08-17

    The potential anti-neoplastic activity of terpenoids is of continued interest. In this study, we investigate whether methyl sartortuoate, a terpenoid isolated from soft coral, induced cell cycle arrest and apoptosis in a human colon cancer cell line. Culture studies found that methyl sartortuoate inhibited colon cancer cell (LoVo and RKO) growth and caused apoptotic death in a concentration- and time-dependent manner, by activation of caspase-8, caspase-9, caspase-3, p53 and Bax, and inactivation of B-cell lymphoma 2 (Bcl-2) apoptosis regulating proteins. Methyl sartortuoate treatment led to reduced expression of cdc2 and up-regulated p21 and p53, suggesting that Methyl sartortuoate induced G2-M arrest through modulation of p53/p21/cdc2 pathways. Methyl sartortuoate also up-regulated phospho-JNK and phospho-p38 expression levels. This resulted in cell cycle arrest at the G2-M phase and apoptosis in LoVo and RKO cells. Treatment with the JNK inhibitor SP600125 and the p38 MAPK inhibitor SB203580 prevented methyl sartortuoate-induced apoptosis in LoVo cells. Moreover, methyl sartortuoate also prevented neoplasm growth in NOD-SCID nude mice inoculated with LoVo cells. Taken together, these findings suggest that methyl sartortuoate is capable of leading to activation of caspase-8, -9, -3, increasing p53 and Bax/Bcl-2 ratio apoptosis through MAPK-dependent apoptosis and results in G2-M phase arrest in LoVo and RKO cells. Thus, methyl sartortuoate may be a promising anticancer candidate.

  10. Adrenal steroid hormone concentrations in dogs with hair cycle arrest (Alopecia X) before and during treatment with melatonin and mitotane.

    Science.gov (United States)

    Frank, Linda A; Hnilica, Keith A; Oliver, Jack W

    2004-10-01

    The purpose of the study was to evaluate intermediate adrenal steroid hormones (ISH) in neutered dogs with hair cycle arrest (Alopecia X) during treatment with melatonin, and to see if hair re-growth is associated with sex hormone concentrations within the normal ranges. Twenty-nine neutered, euthyroid, and normo-cortisolemic dogs were enrolled in the study (23 Pomeranians, three keeshonds, two miniature poodles, and one Siberian husky). Coat assessment and an ACTH stimulation test were performed pre-treatment and approximately every 4 months for a year post treatment. Melatonin was administered initially at 3-6 mg, every 12 h. Based on clinical progression, each dog was continued on the current dose of melatonin, given an increased dose of melatonin or changed to mitotane. Partial to complete hair re-growth occurred in 14/23 Pomeranians, and partial re-growth in 3/3 keeshond and 1/2 poodle dogs. A Siberian husky dog failed to re-grow hair. Fifteen dogs had partial hair re-growth at the first re-evaluation. Melatonin dosage was increased in eight dogs but only one had improved hair re-growth. On mitotane treatment, partial to complete hair re-growth was seen in 4/6 dogs and no re-growth in 2/6 dogs. No significant decrease in sex hormone concentrations were seen during melatonin or mitotane treatment. Concentrations of ISH in dogs with hair re-growth did not differ significantly from pre-treatment values. At the completion of the study, androstenedione, progesterone and 17-hydroxyprogesterone were still above reference ranges in 21, 64 and 36%, respectively, of dogs with partial to complete hair re-growth. In conclusion, 62% of dogs had partial to complete hair re-growth. However, not all dogs with hair re-growth had concentrations of ISH within the normal range.

  11. Soaking RNAi in Bombyx mori BmN4-SID1 Cells Arrests Cell Cycle Progression

    Science.gov (United States)

    Mon, Hiroaki; Li, Zhiqing; Kobayashi, Isao; Tomita, Shuichiro; Lee, JaeMan; Sezutsu, Hideki; Tamura, Toshiki; Kusakabe, Takahiro

    2013-01-01

    RNA interference (RNAi) is an evolutionarily conserved mechanism for sequence-specific gene silencing. Previously, the BmN4-SID1 cell expressing Caenorhabditis ele gans SID-1 was established, in which soaking RNAi could induce effective gene silencing. To establish its utility, 6 cell cycle progression related cDNAs, CDK1, MYC, MYB, RNRS, CDT1, and GEMININ, were isolated from the silkworm, Bombyx mori L. (Lepidoptera: Bombycidae), and their expressions were further silenced by soaking RNAi in the BmN4-SID1 cells. The cell cycle progression analysis using flow cytometer demonstrated that the small amount of double stranded RNA was enough to arrest cell cycle progression at the specific cell phases. These data suggest that RNAi in the BmN4-SID1 cells can be used as a powerful tool for loss-of-function analysis of B. mori genes. PMID:24773378

  12. Vitisin A inhibits adipocyte differentiation through cell cycle arrest in 3T3-L1 cells

    International Nuclear Information System (INIS)

    Kim, Soon-hee; Park, Hee-Sook; Lee, Myoung-su; Cho, Yong-Jin; Kim, Young-Sup; Hwang, Jin-Taek; Sung, Mi Jeong; Kim, Myung Sunny; Kwon, Dae Young

    2008-01-01

    Inhibition of adipocyte differentiation is one approach among the anti-obesity strategies. This study demonstrates that vitisin A, a resveratrol tetramer, inhibits adipocyte differentiation most effectively of 18 stilbenes tested. Fat accumulation and PPARγ expression were decreased by vitisin A in a dose-dependent manner. Vitisin A significantly inhibited preadipocyte proliferation and consequent differentiation within the first 2 days of treatment, indicating that the anti-adipogenic effect of vitisin A was derived from anti-proliferation. Based on cell cycle analysis, vitisin A blocked the cell cycle at the G1-S phase transition, causing cells to remain in the preadipocyte state. Vitisin A increased p21 expression, while the Rb phosphorylation level was reduced. Therefore, vitisin A seems to induce G1 arrest through p21- and consequent Rb-dependent suppression of transcription. On the other hand, ERK and Akt signaling pathways were not involved in the anti-mitotic regulation by vitisin A. Taken together, these results suggest that vitisin A inhibits adipocyte differentiation through preadipocyte cell cycle arrest

  13. Wogonin induced G1 cell cycle arrest by regulating Wnt/β-catenin signaling pathway and inactivating CDK8 in human colorectal cancer carcinoma cells

    International Nuclear Information System (INIS)

    He, Licheng; Lu, Na; Dai, Qinsheng; Zhao, Yue; Zhao, Li; Wang, Hu; Li, Zhiyu; You, Qidong; Guo, Qinglong

    2013-01-01

    Highlights: • Wogonin inhibited HCT116 cells growth and arrested at G1 phase of the cell cycle. • Wogonin down-regulated the canonical Wnt/β-catenin signaling pathway. • Wogonin interfered in the combination of β-catenin and TCF/Lef. • Wogonin limited the kinase activity of CDK8. - Abstract: Wogonin, a naturally occurring mono-flavonoid, has been reported to have tumor therapeutic potential and good selectivity both in vitro and in vivo. Herein, we investigated the anti-proliferation effects and associated mechanisms of wogonin in human colorectal cancer in vitro. The flow-cytometric analysis showed that wogonin induced a G1 phase cell cycle arrest in HCT116 cells in a concentration- and time-dependent manner. Meanwhile, the cell cycle-related proteins, such as cyclin A, E, D1, and CDK2, 4 were down-regulated in wogonin-induced G1 cell cycle arrest. Furthermore, we showed that the anti-proliferation and G1 arrest effect of wogonin on HCT116 cells was associated with deregulation of Wnt/β-catenin signaling pathway. Wogonin-treated cells showed decreased intracellular levels of Wnt proteins, and activated degradation complex to phosphorylated and targeted β-catenin for proteasomal degradation. Wogonin inhibited β-catenin-mediated transcription by interfering in the transcriptional activity of TCF/Lef, and repressing the kinase activity of CDK8 which has been considered as an oncogene involving in the development of colorectal cancers. Moreover, CDK8 siRNA-transfected HCT116 cells showed similar results to wogonin treated cells. Thus, our data suggested that wogonin induced anti-proliferation and G1 arrest via Wnt/β-catenin signaling pathway and it can be developed as a therapeutic agent against human colorectal cancer

  14. F-box protein FBXO31 is a dedicated checkpoint protein to facilitate cell cycle arrest through activation of regulators in radiation induced DNA damage

    International Nuclear Information System (INIS)

    Santra, Manas Kumar

    2017-01-01

    In response to radiation-induced DNA damage, eukaryotic cells initiate a complex signalling pathway, termed the DNA damage response (DDR), which coordinates cell cycle arrest with DNA repair. Previous study showed that induction of G1 arrest in response to radiation induced DNA damage is minimally a two-step process: a fast p53-independent initiation of G1 arrest mediated by cyclin D1 proteolysis and a slower maintenance of arrest resulting from increased p53 stability. We elucidated the molecular mechanism of slow and fast response of radiation induced DDR. We showed that FBXO31, a member of F-box family proteins, plays important role in DDR induced by ionizing radiation. We show that FBXO31 is responsible for promoting MDM2 degradation following radiation. FBXO31 interacts with and directs the degradation of MDM2 in ATM dependent phosphorylation of MDM2. FBXO31-mediated loss of MDM2 leads to elevated levels of p53, resulting in growth arrest. In cells depleted of FBXO31, MDM2 is not degraded and p53 levels do not increase following genotoxic stress. Thus, FBXO31 is essential for the classic robust increase in p53 levels following DNA damage

  15. Eriocalyxin B induces apoptosis and cell cycle arrest in pancreatic adenocarcinoma cells through caspase- and p53-dependent pathways

    International Nuclear Information System (INIS)

    Li, Lin; Yue, Grace G.L.; Lau, Clara B.S.; Sun, Handong; Fung, Kwok Pui; Leung, Ping Chung; Han, Quanbin; Leung, Po Sing

    2012-01-01

    Pancreatic cancer is difficult to detect early and responds poorly to chemotherapy. A breakthrough in the development of new therapeutic agents is urgently needed. Eriocalyxin B (EriB), isolated from the Isodon eriocalyx plant, is an ent-kaurane diterpenoid with promise as a broad-spectrum anti-cancer agent. The anti-leukemic activity of EriB, including the underlying mechanisms involved, has been particularly well documented. In this study, we demonstrated for the first time EriB's potent cytotoxicity against four pancreatic adenocarcinoma cell lines, namely PANC-1, SW1990, CAPAN-1, and CAPAN-2. The effects were comparable to that of the chemotherapeutic camptothecin (CAM), but with much lower toxicity against normal human liver WRL68 cells. EriB's cytoxicity against CAPAN-2 cells was found to involve caspase-dependent apoptosis and cell cycle arrest at the G2/M phase. Moreover, the p53 pathway was found to be activated by EriB in these cells. Furthermore, in vivo studies showed that EriB inhibited the growth of human pancreatic tumor xenografts in BALB/c nude mice without significant secondary adverse effects. These results suggest that EriB should be considered a candidate for pancreatic cancer treatment. -- Highlights: ► We study Eriocalyxin B (EriB)'s cytotoxic effects on pancreatic cancer cell lines. ► EriB inhibits cell proliferation via mediation of apoptosis and cell cycle arrest. ► The effects are involved in caspase-dependent apoptosis and p53 pathway. ► In vivo study also shows EriB inhibits the growth of human pancreatic tumor. ► EriB can be a good candidate for chemotherapy in pancreatic cancer.

  16. Eriocalyxin B induces apoptosis and cell cycle arrest in pancreatic adenocarcinoma cells through caspase- and p53-dependent pathways

    Energy Technology Data Exchange (ETDEWEB)

    Li, Lin [School of Biomedical Sciences, The Chinese University of Hong Kong, Hong Kong (China); Institute of Chinese Medicine, The Chinese University of Hong Kong, Hong Kong (China); State Key Laboratory of Phytochemistry and Plant Resources in West China, The Chinese University of Hong Kong, Hong Kong (China); Yue, Grace G.L. [Institute of Chinese Medicine, The Chinese University of Hong Kong, Hong Kong (China); State Key Laboratory of Phytochemistry and Plant Resources in West China, The Chinese University of Hong Kong, Hong Kong (China); Lau, Clara B.S. [Institute of Chinese Medicine, The Chinese University of Hong Kong, Hong Kong (China); Institute of Chinese Medicine, The Chinese University of Hong Kong, Hong Kong (China); Sun, Handong [State Key Laboratory of Phytochemistry and Plant Resources in West China, Kunming Institute of Botany, CAS, Yunnan (China); Fung, Kwok Pui [School of Biomedical Sciences, The Chinese University of Hong Kong, Hong Kong (China); Institute of Chinese Medicine, The Chinese University of Hong Kong, Hong Kong (China); State Key Laboratory of Phytochemistry and Plant Resources in West China, The Chinese University of Hong Kong, Hong Kong (China); Leung, Ping Chung [Institute of Chinese Medicine, The Chinese University of Hong Kong, Hong Kong (China); State Key Laboratory of Phytochemistry and Plant Resources in West China, The Chinese University of Hong Kong, Hong Kong (China); Han, Quanbin, E-mail: simonhan@hkbu.edu.hk [Institute of Chinese Medicine, The Chinese University of Hong Kong, Hong Kong (China); State Key Laboratory of Phytochemistry and Plant Resources in West China, The Chinese University of Hong Kong, Hong Kong (China); School of Chinese Medicine, The Hong Kong Baptist University, Hong Kong (China); Leung, Po Sing, E-mail: psleung@cuhk.edu.hk [School of Biomedical Sciences, The Chinese University of Hong Kong, Hong Kong (China)

    2012-07-01

    Pancreatic cancer is difficult to detect early and responds poorly to chemotherapy. A breakthrough in the development of new therapeutic agents is urgently needed. Eriocalyxin B (EriB), isolated from the Isodon eriocalyx plant, is an ent-kaurane diterpenoid with promise as a broad-spectrum anti-cancer agent. The anti-leukemic activity of EriB, including the underlying mechanisms involved, has been particularly well documented. In this study, we demonstrated for the first time EriB's potent cytotoxicity against four pancreatic adenocarcinoma cell lines, namely PANC-1, SW1990, CAPAN-1, and CAPAN-2. The effects were comparable to that of the chemotherapeutic camptothecin (CAM), but with much lower toxicity against normal human liver WRL68 cells. EriB's cytoxicity against CAPAN-2 cells was found to involve caspase-dependent apoptosis and cell cycle arrest at the G2/M phase. Moreover, the p53 pathway was found to be activated by EriB in these cells. Furthermore, in vivo studies showed that EriB inhibited the growth of human pancreatic tumor xenografts in BALB/c nude mice without significant secondary adverse effects. These results suggest that EriB should be considered a candidate for pancreatic cancer treatment. -- Highlights: ► We study Eriocalyxin B (EriB)'s cytotoxic effects on pancreatic cancer cell lines. ► EriB inhibits cell proliferation via mediation of apoptosis and cell cycle arrest. ► The effects are involved in caspase-dependent apoptosis and p53 pathway. ► In vivo study also shows EriB inhibits the growth of human pancreatic tumor. ► EriB can be a good candidate for chemotherapy in pancreatic cancer.

  17. Cellular Senescence in Postmitotic Cells: Beyond Growth Arrest.

    Science.gov (United States)

    Sapieha, Przemyslaw; Mallette, Frédérick A

    2018-04-25

    In mitotic cells, cellular senescence is a permanent state of G1 arrest, that may have evolved in parallel to apoptosis, to limit proliferation of damaged cells and oncogenesis. Recent studies have suggested that postmitotic cells are also capable of entering a state of senescence, although the repercussions of postmitotic cellular senescence (PoMiCS) on tissue health and function are currently ill-defined. In tissues made largely of post-mitotic cells, it is evolutionary advantageous to preserve cellular integrity and cellular senescence of post-mitotic cells may prevent stressor-induced tissue degeneration and promote tissue repair. Paradoxically, PoMiCS may also contribute to disease progression through the generation of inflammatory mediators, termed the senescence-associated secretory phenotype. Here, we discuss the potential roles of PoMiCS and propose to enlarge the current definition of cellular senescence to postmitotic terminally differentiated cells. Copyright © 2018 Elsevier Ltd. All rights reserved.

  18. Betulinic Acid Inhibits Growth of Cultured Vascular Smooth Muscle Cells In Vitro by Inducing G1 Arrest and Apoptosis

    Directory of Open Access Journals (Sweden)

    Raja Kumar Vadivelu

    2012-01-01

    Full Text Available Betulinic acid is a widely available plant-derived triterpene which is reported to possess selective cytotoxic activity against cancer cells of neuroectodermal origin and leukemia. However, the potential of betulinic acid as an antiproliferative and cytotoxic agent on vascular smooth muscle (VSMC is still unclear. This study was carried out to demonstrate the antiproliferative and cytotoxic effect of betulinic acid on VSMCs using 3-[4,5-dimethylthizol-2-yl]-2,5-diphenyltetrazolium bromide (MTT assay, flow cytometry cell cycle assay, BrdU proliferation assay, acridine orange/propidium iodide staining, and comet assay. Result from MTT and BrdU assays indicated that betulinic acid was able to inhibit the growth and proliferation of VSMCs in a dose-dependent manner with IC50 of 3.8 μg/mL significantly (P<0.05. Nevertheless, betulinic acid exhibited G1 cell cycle arrest in flow cytometry cell cycle profiling and low level of DNA damage against VSMC in acridine orange/propidium iodide and comet assay after 24 h of treatment. In conclusion, betulinic acid induced G1 cell cycle arrest and dose-dependent DNA damage on VSMC.

  19. Nek1 silencing slows down DNA repair and blocks DNA damage-induced cell cycle arrest.

    Science.gov (United States)

    Pelegrini, Alessandra Luíza; Moura, Dinara Jaqueline; Brenner, Bethânia Luise; Ledur, Pitia Flores; Maques, Gabriela Porto; Henriques, João Antônio Pegas; Saffi, Jenifer; Lenz, Guido

    2010-09-01

    Never in mitosis A (NIMA)-related kinases (Nek) are evolutionarily conserved proteins structurally related to the Aspergillus nidulans mitotic regulator NIMA. Nek1 is one of the 11 isoforms of the Neks identified in mammals. Different lines of evidence suggest the participation of Nek1 in response to DNA damage, which is also supported by the interaction of this kinase with proteins involved in DNA repair pathways and cell cycle regulation. In this report, we show that cells with Nek1 knockdown (KD) through stable RNA interference present a delay in DNA repair when treated with methyl-methanesulfonate (MMS), hydrogen peroxide (H(2)O(2)) and cisplatin (CPT). In particular, interstrand cross links induced by CPT take much longer to be resolved in Nek1 KD cells when compared to wild-type (WT) cells. In KD cells, phosphorylation of Chk1 in response to CPT was strongly reduced. While WT cells accumulate in G(2)/M after DNA damage with MMS and H(2)O(2), Nek1 KD cells do not arrest, suggesting that G(2)/M arrest induced by the DNA damage requires Nek1. Surprisingly, CPT-treated Nek1 KD cells arrest with a 4N DNA content similar to WT cells. This deregulation in cell cycle control in Nek1 KD cells leads to an increased sensitivity to genotoxic agents when compared to WT cells. These results suggest that Nek1 is involved in the beginning of the cellular response to genotoxic stress and plays an important role in preventing cell death induced by DNA damage.

  20. Linalool Induces Cell Cycle Arrest and Apoptosis in Leukemia Cells and Cervical Cancer Cells through CDKIs

    Directory of Open Access Journals (Sweden)

    Mei-Yin Chang

    2015-11-01

    Full Text Available Plantaginaceae, a popular traditional Chinese medicine, has long been used for treating various diseases from common cold to cancer. Linalool is one of the biologically active compounds that can be isolated from Plantaginaceae. Most of the commonly used cytotoxic anticancer drugs have been shown to induce apoptosis in susceptible tumor cells. However, the signaling pathway for apoptosis remains undefined. In this study, the cytotoxic effect of linalool on human cancer cell lines was investigated. Water-soluble tetrazolium salts (WST-1 based colorimetric cellular cytotoxicity assay, was used to test the cytotoxic ability of linalool against U937 and HeLa cells, and flow cytometry (FCM and genechip analysis were used to investigate the possible mechanism of apoptosis. These results demonstrated that linalool exhibited a good cytotoxic effect on U937 and HeLa cells, with the IC50 value of 2.59 and 11.02 μM, respectively, compared with 5-FU with values of 4.86 and 12.31 μM, respectively. After treating U937 cells with linalool for 6 h, we found an increased sub-G1 peak and a dose-dependent phenomenon, whereby these cells were arrested at the G0/G1 phase. Furthermore, by using genechip analysis, we observed that linalool can promote p53, p21, p27, p16, and p18 gene expression. Therefore, this study verified that linalool can arrest the cell cycle of U937 cells at the G0/G1 phase and can arrest the cell cycle of HeLa cells at the G2/M phase. Its mechanism facilitates the expression of the cyclin-dependent kinases inhibitors (CDKIs p53, p21, p27, p16, and p18, as well as the non-expression of cyclin-dependent kinases (CDKs activity.

  1. Knockdown of human deubiquitinase PSMD14 induces cell cycle arrest and senescence

    Energy Technology Data Exchange (ETDEWEB)

    Byrne, Ann; McLaren, Rajashree P.; Mason, Paul; Chai, Lilly; Dufault, Michael R.; Huang, Yinyin; Liang, Beirong; Gans, Joseph D.; Zhang, Mindy; Carter, Kara; Gladysheva, Tatiana B.; Teicher, Beverly A.; Biemann, Hans-Peter N.; Booker, Michael; Goldberg, Mark A.; Klinger, Katherine W.; Lillie, James [Genzyme Corporation, 49 New York Avenue, Framingham, MA 01701 (United States); Madden, Stephen L., E-mail: steve.madden@genzyme.com [Genzyme Corporation, 49 New York Avenue, Framingham, MA 01701 (United States); Jiang, Yide, E-mail: yide.jiang@genzyme.com [Genzyme Corporation, 49 New York Avenue, Framingham, MA 01701 (United States)

    2010-01-15

    The PSMD14 (POH1, also known as Rpn11/MPR1/S13/CepP1) protein within the 19S complex (19S cap; PA700) is responsible for substrate deubiquitination during proteasomal degradation. The role of PSMD14 in cell proliferation and senescence was explored using siRNA knockdown in carcinoma cell lines. Our results reveal that down-regulation of PSMD14 by siRNA transfection had a considerable impact on cell viability causing cell arrest in the G0-G1 phase, ultimately leading to senescence. The molecular events associated with decreased cell proliferation, cell cycle arrest and senescence include down-regulation of cyclin B1-CDK1-CDC25C, down-regulation of cyclin D1 and up-regulation of p21{sup /Cip} and p27{sup /Kip1}. Most notably, phosphorylation of the retinoblastoma protein was markedly reduced in PSMD14 knockdown cells. A comparative study with PSMB5, a subunit of the 20S proteasome, revealed that PSMB5 and PSMD14 have different effects on cell cycle, senescence and associated molecular events. These data support the view that the 19S and 20S subunits of the proteasome have distinct biological functions and imply that targeting 19S and 20S would have distinct molecular consequences on tumor cells.

  2. α-Mangostin Induces Apoptosis and Cell Cycle Arrest in Oral Squamous Cell Carcinoma Cell

    Directory of Open Access Journals (Sweden)

    Hyun-Ho Kwak

    2016-01-01

    Full Text Available Mangosteen has long been used as a traditional medicine and is known to have antibacterial, antioxidant, and anticancer effects. Although the effects of α-mangostin, a natural compound extracted from the pericarp of mangosteen, have been investigated in many studies, there is limited data on the effects of the compound in human oral squamous cell carcinoma (OSCC. In this study, α-mangostin was assessed as a potential anticancer agent against human OSCC cells. α-Mangostin inhibited cell proliferation and induced cell death in OSCC cells in a dose- and time-dependent manner with little to no effect on normal human PDLF cells. α-Mangostin treatment clearly showed apoptotic evidences such as nuclear fragmentation and accumulation of annexin V and PI-positive cells on OSCC cells. α-Mangostin treatment also caused the collapse of mitochondrial membrane potential and the translocation of cytochrome c from the mitochondria into the cytosol. The expressions of the mitochondria-related proteins were activated by α-mangostin. Treatment with α-mangostin also induced G1 phase arrest and downregulated cell cycle-related proteins (CDK/cyclin. Hence, α-mangostin specifically induces cell death and inhibits proliferation in OSCC cells via the intrinsic apoptosis pathway and cell cycle arrest at the G1 phase, suggesting that α-mangostin may be an effective agent for the treatment of OSCC.

  3. Live-Cell Imaging Visualizes Frequent Mitotic Skipping During Senescence-Like Growth Arrest in Mammary Carcinoma Cells Exposed to Ionizing Radiation

    International Nuclear Information System (INIS)

    Suzuki, Masatoshi; Yamauchi, Motohiro; Oka, Yasuyoshi; Suzuki, Keiji; Yamashita, Shunichi

    2012-01-01

    Purpose: Senescence-like growth arrest in human solid carcinomas is now recognized as the major outcome of radiotherapy. This study was designed to analyze cell cycle during the process of senescence-like growth arrest in mammary carcinoma cells exposed to X-rays. Methods and Materials: Fluorescent ubiquitination-based cell cycle indicators were introduced into the human mammary carcinoma cell line MCF-7. Cell cycle was sequentially monitored by live-cell imaging for up to 5 days after exposure to 10 Gy of X-rays. Results: Live-cell imaging revealed that cell cycle transition from G2 to G1 phase without mitosis, so-called mitotic skipping, was observed in 17.1% and 69.8% of G1- and G2-irradiated cells, respectively. Entry to G1 phase was confirmed by the nuclear accumulation of mKO 2 -hCdt1 as well as cyclin E, which was inversely correlated to the accumulation of G2-specific markers such as mAG-hGeminin and CENP-F. More than 90% of cells skipping mitosis were persistently arrested in G1 phase and showed positive staining for the senescent biochemical marker, which is senescence-associated ß-galactosidase, indicating induction of senescence-like growth arrest accompanied by mitotic skipping. While G2 irradiation with higher doses of X-rays induced mitotic skipping in approximately 80% of cells, transduction of short hairpin RNA (shRNA) for p53 significantly suppressed mitotic skipping, suggesting that ionizing radiation-induced mitotic skipping is associated with p53 function. Conclusions: The present study found the pathway of senescence-like growth arrest in G1 phase without mitotic entry following G2-irradiation.

  4. Live-Cell Imaging Visualizes Frequent Mitotic Skipping During Senescence-Like Growth Arrest in Mammary Carcinoma Cells Exposed to Ionizing Radiation

    Energy Technology Data Exchange (ETDEWEB)

    Suzuki, Masatoshi, E-mail: msuzuki@nagasaki-u.ac.jp [Department of Radiation Medical Sciences, Atomic Bomb Disease Institute, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki (Japan); Yamauchi, Motohiro; Oka, Yasuyoshi; Suzuki, Keiji; Yamashita, Shunichi [Department of Radiation Medical Sciences, Atomic Bomb Disease Institute, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki (Japan)

    2012-06-01

    Purpose: Senescence-like growth arrest in human solid carcinomas is now recognized as the major outcome of radiotherapy. This study was designed to analyze cell cycle during the process of senescence-like growth arrest in mammary carcinoma cells exposed to X-rays. Methods and Materials: Fluorescent ubiquitination-based cell cycle indicators were introduced into the human mammary carcinoma cell line MCF-7. Cell cycle was sequentially monitored by live-cell imaging for up to 5 days after exposure to 10 Gy of X-rays. Results: Live-cell imaging revealed that cell cycle transition from G2 to G1 phase without mitosis, so-called mitotic skipping, was observed in 17.1% and 69.8% of G1- and G2-irradiated cells, respectively. Entry to G1 phase was confirmed by the nuclear accumulation of mKO{sub 2}-hCdt1 as well as cyclin E, which was inversely correlated to the accumulation of G2-specific markers such as mAG-hGeminin and CENP-F. More than 90% of cells skipping mitosis were persistently arrested in G1 phase and showed positive staining for the senescent biochemical marker, which is senescence-associated ss-galactosidase, indicating induction of senescence-like growth arrest accompanied by mitotic skipping. While G2 irradiation with higher doses of X-rays induced mitotic skipping in approximately 80% of cells, transduction of short hairpin RNA (shRNA) for p53 significantly suppressed mitotic skipping, suggesting that ionizing radiation-induced mitotic skipping is associated with p53 function. Conclusions: The present study found the pathway of senescence-like growth arrest in G1 phase without mitotic entry following G2-irradiation.

  5. Acetate supplementation induces growth arrest of NG2/PDGFRα-positive oligodendroglioma-derived tumor-initiating cells.

    Directory of Open Access Journals (Sweden)

    Patrick M Long

    Full Text Available Cancer is associated with globally hypoacetylated chromatin and considerable attention has recently been focused on epigenetic therapies. N-acetyl-L-aspartate (NAA, the primary storage form of acetate in the brain, and aspartoacylase (ASPA, the enzyme responsible for NAA catalysis to generate acetate and ultimately acetyl-Coenzyme A for histone acetylation, are reduced in oligodendroglioma. The short chain triglyceride glyceryl triacetate (GTA, which increases histone acetylation and inhibits histone deacetylase expression, has been safely used for acetate supplementation in Canavan disease, a leukodystrophy due to ASPA mutation. We demonstrate that GTA induces cytostatic G0 growth arrest of oligodendroglioma-derived cells in vitro, without affecting normal cells. Sodium acetate, at doses comparable to that generated by complete GTA catalysis, but not glycerol also promoted growth arrest, whereas long chain triglycerides promoted cell growth. To begin to elucidate its mechanism of action, the effects of GTA on ASPA and acetyl-CoA synthetase protein levels and differentiation of established human oligodendroglioma cells (HOG and Hs683 and primary tumor-derived oligodendroglioma cells that exhibit some features of cancer stem cells (grade II OG33 and grade III OG35 relative to an oligodendrocyte progenitor line (Oli-Neu were examined. The nuclear localization of ASPA and acetyl-CoA synthetase-1 in untreated cells was regulated during the cell cycle. GTA-mediated growth arrest was not associated with apoptosis or differentiation, but increased expression of acetylated proteins. Thus, GTA-mediated acetate supplementation may provide a safe, novel epigenetic therapy to reduce the growth of oligodendroglioma cells without affecting normal neural stem or oligodendrocyte progenitor cell proliferation or differentiation.

  6. Deficiency of G1 regulators P53, P21Cip1 and/or pRb decreases hepatocyte sensitivity to TGFβ cell cycle arrest

    Directory of Open Access Journals (Sweden)

    Harrison David J

    2007-11-01

    Full Text Available Abstract Background TGFβ is critical to control hepatocyte proliferation by inducing G1-growth arrest through multiple pathways leading to inhibition of E2F transcription activity. The retinoblastoma protein pRb is a key controller of E2F activity and G1/S transition which can be inhibited in viral hepatitis. It is not known whether the impairment of pRb would alter the growth inhibitory potential of TGFβ in disease. We asked how Rb-deficiency would affect responses to TGFβ-induced cell cycle arrest. Results Primary hepatocytes isolated from Rb-floxed mice were infected with an adenovirus expressing CRE-recombinase to delete the Rb gene. In control cells treatment with TGFβ prevented cells to enter S phase via decreased cMYC activity, activation of P16INK4A and P21Cip and reduction of E2F activity. In Rb-null hepatocytes, cMYC activity decreased slightly but P16INK4A was not activated and the great majority of cells continued cycling. Rb is therefore central to TGFβ-induced cell cycle arrest in hepatocytes. However some Rb-null hepatocytes remained sensitive to TGFβ-induced cell cycle arrest. As these hepatocytes expressed very high levels of P21Cip1 and P53 we investigated whether these proteins regulate pRb-independent signaling to cell cycle arrest by evaluating the consequences of disruption of p53 and p21Cip1. Hepatocytes deficient in p53 or p21Cip1 showed diminished growth inhibition by TGFβ. Double deficiency had a similar impact showing that in cells containing functional pRb; P21Cip and P53 work through the same pathway to regulate G1/S in response to TGFβ. In Rb-deficient cells however, p53 but not p21Cip deficiency had an additive effect highlighting a pRb-independent-P53-dependent effector pathway of inhibition of E2F activity. Conclusion The present results show that otherwise genetically normal hepatocytes with disabled p53, p21Cip1 or Rb genes respond less well to the antiproliferative effects of TGFβ. As the function of

  7. Dimethylfumarate induces cell cycle arrest and apoptosis via regulating intracellular redox systems in HeLa cells.

    Science.gov (United States)

    Han, Guocan; Zhou, Qiang

    2016-12-01

    Dimethylfumarate (DMF) is cytotoxic to several kinds of cells and serves as an anti-tumor drug. This study was designed to investigate the effects and underlying mechanism of DMF on cervical cancer cells. HeLa cells were cultured and treated with 0, 50, 100, 150, and 200 μM DMF, respectively. After 24 h, cell growth was evaluated using Cell Counting Kit-8 (CCK-8) assay and the cell cycle was examined using flow cytometry. In addition, cell apoptosis was detected by Annexin V/propidium iodide (PI) staining and the expressions of caspase-3 and poly-ADP-ribose polymerase (PARP) were detected using western blotting. The redox-related factors were then assessed. Furthermore, all of the indicators were detected in HeLa cells after combined treatment of DMF and N-acetyl-L-cysteine (NAC, an oxygen-free radical scavenger). The cell number and cell growth of HeLa were obviously inhibited by DMF in a dose-dependent manner, as the cell cycle was arrested at G0/G1 phase (P HeLa cells were markedly increased, and the expression levels of caspase-3 and PARP were significantly increased in a DMF concentration-dependent way (P cell proliferation and apoptosis of HeLa cells was mainly related to the intracellular redox systems by depletion of intracellular GSH.

  8. P53-dependent upregulation of neutral sphingomyelinase-2: role in doxorubicin-induced growth arrest.

    Science.gov (United States)

    Shamseddine, A A; Clarke, C J; Carroll, B; Airola, M V; Mohammed, S; Rella, A; Obeid, L M; Hannun, Y A

    2015-10-29

    Neutral sphingomyelinase-2 (nSMase2) is a ceramide-generating enzyme that has been implicated in growth arrest, apoptosis and exosome secretion. Although previous studies have reported transcriptional upregulation of nSMase2 in response to daunorubicin, through Sp1 and Sp3 transcription factors, the role of the DNA damage pathway in regulating nSMase2 remains unclear. In this study, we show that doxorubicin induces a dose-dependent induction of nSMase2 mRNA and protein with concomitant increases in nSMase activity and ceramide levels. Upregulation of nSMase2 was dependent on ATR, Chk1 and p53, thus placing it downstream of the DNA damage pathway. Moreover, overexpression of p53 was sufficient to transcriptionally induce nSMase2, without the need for DNA damage. DNA-binding mutants as well as acetylation mutants of p53 were unable to induce nSMase2, suggesting a role of nSMase2 in growth arrest. Moreover, knockdown of nSMase2 prevented doxorubicin-induced growth arrest. Finally, p53-induced nSMase2 upregulation appears to occur via a novel transcription start site upstream of exon 3. These results identify nSMase2 as a novel p53 target gene, regulated by the DNA damage pathway to induce cell growth arrest.

  9. Pleiotropic role of growth arrest-specific gene 6 in atherosclerosis

    NARCIS (Netherlands)

    Tjwa, Marc; Moons, Lieve; Lutgens, Esther

    2009-01-01

    Growth arrest-specific gene 6 (Gas6) belongs to the family of vitamin K-dependent coagulation proteins, but in contrast to its other members, has only a limited role in hemostasis. Instead, Gas6 plays a prominent role in conditions of injury, inflammation and repair. Gas6 amplifies the activation of

  10. Gene expression signature in organized and growth arrested mammaryacini predicts good outcome in breast cancer

    Energy Technology Data Exchange (ETDEWEB)

    Fournier, Marcia V.; Martin, Katherine J.; Kenny, Paraic A.; Xhaja, Kris; Bosch, Irene; Yaswen, Paul; Bissell, Mina J.

    2006-02-08

    To understand how non-malignant human mammary epithelial cells (HMEC) transit from a disorganized proliferating to an organized growth arrested state, and to relate this process to the changes that occur in breast cancer, we studied gene expression changes in non-malignant HMEC grown in three-dimensional cultures, and in a previously published panel of microarray data for 295 breast cancer samples. We hypothesized that the gene expression pattern of organized and growth arrested mammary acini would share similarities with breast tumors with good prognoses. Using Affymetrix HG-U133A microarrays, we analyzed the expression of 22,283 gene transcripts in two HMEC cell lines, 184 (finite life span) and HMT3522 S1 (immortal non-malignant), on successive days post-seeding in a laminin-rich extracellular matrix assay. Both HMECs underwent growth arrest in G0/G1 and differentiated into polarized acini between days 5 and 7. We identified gene expression changes with the same temporal pattern in both lines. We show that genes that are significantly lower in the organized, growth arrested HMEC than in their proliferating counterparts can be used to classify breast cancer patients into poor and good prognosis groups with high accuracy. This study represents a novel unsupervised approach to identifying breast cancer markers that may be of use clinically.

  11. Identification of Fitness Determinants during Energy-Limited Growth Arrest in Pseudomonas aeruginosa.

    Science.gov (United States)

    Basta, David W; Bergkessel, Megan; Newman, Dianne K

    2017-11-28

    Microbial growth arrest can be triggered by diverse factors, one of which is energy limitation due to scarcity of electron donors or acceptors. Genes that govern fitness during energy-limited growth arrest and the extent to which they overlap between different types of energy limitation are poorly defined. In this study, we exploited the fact that Pseudomonas aeruginosa can remain viable over several weeks when limited for organic carbon (pyruvate) as an electron donor or oxygen as an electron acceptor. ATP values were reduced under both types of limitation, yet more severely in the absence of oxygen. Using transposon-insertion sequencing (Tn-seq), we identified fitness determinants in these two energy-limited states. Multiple genes encoding general functions like transcriptional regulation and energy generation were required for fitness during carbon or oxygen limitation, yet many specific genes, and thus specific activities, differed in their relevance between these states. For instance, the global regulator RpoS was required during both types of energy limitation, while other global regulators such as DksA and LasR were required only during carbon or oxygen limitation, respectively. Similarly, certain ribosomal and tRNA modifications were specifically required during oxygen limitation. We validated fitness defects during energy limitation using independently generated mutants of genes detected in our screen. Mutants in distinct functional categories exhibited different fitness dynamics: regulatory genes generally manifested a phenotype early, whereas genes involved in cell wall metabolism were required later. Together, these results provide a new window into how P. aeruginosa survives growth arrest. IMPORTANCE Growth-arrested bacteria are ubiquitous in nature and disease yet understudied at the molecular level. For example, growth-arrested cells constitute a major subpopulation of mature biofilms, serving as an antibiotic-tolerant reservoir in chronic

  12. DNA Damage and Cell Cycle Arrest Induced by Protoporphyrin IX in Sarcoma 180 Cells

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    Qing Li

    2013-09-01

    Full Text Available Background: Porphyrin derivatives have been widely used in photodynamic therapy as effective sensitizers. Protoporphyrin IX (PpIX, a well-known hematoporphyrin derivative component, shows great potential to enhance light induced tumor cell damage. However, PpIX alone could also exert anti-tumor effects. The mechanisms underlying those direct effects are incompletely understood. This study thus investigated the putative mechanisms underlying the anti-tumor effects of PpIX on sarcoma 180 (S180 cells. Methods: S180 cells were treated with different concentrations of PpIX. Following the treatment, cell viability was evaluated by the 3-(4, 5- dimethylthiazol-2-yl-2, 5-diphenyltetrazoliumbromide (MTT assay; Disruption of mitochondrial membrane potential was measured by flow cytometry; The trans-location of apoptosis inducer factor (AIF from mitochondria to nucleus was visualized by confocal laser scanning microscopy; DNA damage was detected by single cell gel electrophoresis; Cell cycle distribution was analyzed by DNA content with flow cytometry; Cell cycle associated proteins were detected by western blotting. Results: PpIX (≥ 1 µg/ml significantly inhibited proliferation and reduced viability of S180 cells in a dose-dependent manner. PpIX rapidly and significantly triggered mitochondrial membrane depolarization, AIF (apoptosis inducer factor translocation from mitochondria to nucleus and DNA damage, effects partially relieved by the specific inhibitor of MPTP (mitochondrial permeability transition pore. Furthermore, S phase arrest and upregulation of the related proteins of P53 and P21 were observed following 12 and 24 h PpIX exposure. Conclusion: PpIX could inhibit tumor cell proliferation by induction of DNA damage and cell cycle arrest in the S phase.

  13. Canthin-6-one induces cell death, cell cycle arrest and differentiation in human myeloid leukemia cells.

    Science.gov (United States)

    Vieira Torquato, Heron F; Ribeiro-Filho, Antonio C; Buri, Marcus V; Araújo Júnior, Roberto T; Pimenta, Renata; de Oliveira, José Salvador R; Filho, Valdir C; Macho, Antonio; Paredes-Gamero, Edgar J; de Oliveira Martins, Domingos T

    2017-04-01

    Canthin-6-one is a natural product isolated from various plant genera and from fungi with potential antitumor activity. In the present study, we evaluate the antitumor effects of canthin-6-one in human myeloid leukemia lineages. Kasumi-1 lineage was used as a model for acute myeloid leukemia. Cells were treated with canthin-6-one and cell death, cell cycle and differentiation were evaluated in both total cells (Lin + ) and leukemia stem cell population (CD34 + CD38 - Lin -/low ). Among the human lineages tested, Kasumi-1 was the most sensitive to canthin-6-one. Canthin-6-one induced cell death with apoptotic (caspase activation, decrease of mitochondrial potential) and necrotic (lysosomal permeabilization, double labeling of annexin V/propidium iodide) characteristics. Moreover, canthin-6-one induced cell cycle arrest at G 0 /G 1 (7μM) and G 2 (45μM) evidenced by DNA content, BrdU incorporation and cyclin B1/histone 3 quantification. Canthin-6-one also promoted differentiation of Kasumi-1, evidenced by an increase in the expression of myeloid markers (CD11b and CD15) and the transcription factor PU.1. Furthermore, a reduction of the leukemic stem cell population and clonogenic capability of stem cells were observed. These results show that canthin-6-one can affect Kasumi-1 cells by promoting cell death, cell cycle arrest and cell differentiation depending on concentration used. Canthin-6-one presents an interesting cytotoxic activity against leukemic cells and represents a promising scaffold for the development of molecules for anti-leukemic applications, especially by its anti-leukemic stem cell activity. Copyright © 2017 Elsevier B.V. All rights reserved.

  14. An evaluation of the choice of feeder cell growth arrest for the production of cultured epidermis.

    Science.gov (United States)

    Chugh, Rishi Man; Chaturvedi, Madhusudan; Yerneni, Lakshmana Kumar

    2015-12-01

    Growth arrested 3T3 cells have been used as feeder cells in human epidermal keratinocyte cultures to produce cultured epidermal autografts for the treatment of burns. The feeder cells were ideally growth-arrested by gamma-irradiation. Alternatively, growth arrest by mitomycin C treatment is a cost effective option. We compared the functional efficacy of these two approaches in keratinocyte cultures by colony forming efficiency, the net growth area of colonies, BrdU labeling and histological features of cultured epidermal sheets. The growth area estimation involved a semi-automated digital technique using the Adobe Photoshop and comprised of isolation and enumeration of red pixels in Rhodamine B-stained keratinocyte colonies. A further refinement of the technique led to the identification of critical steps to increasing the degree of accuracy and enabling its application as an extension of colony formation assay. The results on feeder cell functionality revealed that the gamma irradiated feeders influenced significantly higher colony forming efficiency and larger growth area than the mitomycin C treated feeders. The BrdU labeling study indicated significant stimulation of the overall keratinocyte proliferation by the gamma irradiated feeders. The cultured epidermal sheets produced by gamma feeders were relatively thicker than those produced by mitomycin C feeders. We discussed the clinical utility of mitomycin C feeders from the viewpoint of cost-effective burn care in developing countries. Copyright © 2015 Elsevier Ltd and ISBI. All rights reserved.

  15. Cancer Preventive Efficacy of Marine Carotenoid Fucoxanthin: Cell Cycle Arrest and Apoptosis

    Directory of Open Access Journals (Sweden)

    Thamaraiselvan Rengarajan

    2013-12-01

    Full Text Available Epidemiological investigations have shown that overcoming the risk of cancer is related to the consumption of green vegetables and fruits. Many compounds from different origins, such as terrestrial plants and marine and microbial sources, have been reported to have therapeutic effects of which marine sources are the most important because the diversity of marine life is more varied than other sources. Fucoxanthin is one important compound with a marine origin and belongs to the group of carotenoids; it can be found in marine brown seaweeds, macroalgae, and diatoms, all of which have remarkable biological properties. Numerous studies have shown that fucoxanthin has considerable medicinal potential and promising applications in human health. In this review, we summarize the anticancer effects of fucoxanthin through several different mechanisms including anti-proliferation, induction of apoptosis, cell cycle arrest and anti-angiogenesis, and its possible role in the treatment of cancer.

  16. Arecoline decreases interleukin-6 production and induces apoptosis and cell cycle arrest in human basal cell carcinoma cells

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Li-Wen [Department of Medical Laboratory Science and Biotechnology, Kaohsiung Medical University, Kaohsiung 80708, Taiwan (China); Hsieh, Bau-Shan; Cheng, Hsiao-Ling [Department of Biochemistry, Faculty of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung 80708, Taiwan (China); Hu, Yu-Chen [Graduate Institute of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung 80708, Taiwan (China); Chang, Wen-Tsan [Graduate Institute of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung 80708, Taiwan (China); Division of Hepatobiliarypancreatic Surgery, Department of Surgery, Kaohsiung Medical University Hospital, Kaohsiung 80708, Taiwan (China); Chang, Kee-Lung, E-mail: Chang.KeeLung@msa.hinet.net [Department of Biochemistry, Faculty of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung 80708, Taiwan (China); Graduate Institute of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung 80708, Taiwan (China)

    2012-01-15

    Arecoline, the most abundant areca alkaloid, has been reported to decrease interleukin-6 (IL-6) levels in epithelial cancer cells. Since IL-6 overexpression contributes to the tumorigenic potency of basal cell carcinoma (BCC), this study was designed to investigate whether arecoline altered IL-6 expression and its downstream regulation of apoptosis and the cell cycle in cultured BCC-1/KMC cells. BCC-1/KMC cells and a human keratinocyte cell line, HaCaT, were treated with arecoline at concentrations ranging from 10 to 100 μg/ml, then IL-6 production and expression of apoptosis- and cell cycle progress-related factors were examined. After 24 h exposure, arecoline inhibited BCC-1/KMC cell growth and decreased IL-6 production in terms of mRNA expression and protein secretion, but had no effect on HaCaT cells. Analysis of DNA fragmentation and chromatin condensation showed that arecoline induced apoptosis of BCC-1/KMC cells in a dose-dependent manner, activated caspase-3, and decreased expression of the anti-apoptotic protein Bcl-2. In addition, arecoline induced progressive and sustained accumulation of BCC-1/KMC cells in G2/M phase as a result of reducing checkpoint Cdc2 activity by decreasing Cdc25C phosphatase levels and increasing p53 levels. Furthermore, subcutaneous injection of arecoline led to decreased BCC-1/KMC tumor growth in BALB/c mice by inducing apoptosis. This study demonstrates that arecoline has potential for preventing BCC tumorigenesis by reducing levels of the tumor cell survival factor IL-6, increasing levels of the tumor suppressor factor p53, and eliciting cell cycle arrest, followed by apoptosis. Highlights: ► Arecoline has potential to prevent against basal cell carcinoma tumorigenesis. ► It has more effectiveness on BCC as compared with a human keratinocyte cell line. ► Mechanisms involved including reducing tumor cells’ survival factor IL-6, ► Decreasing Cdc25C phosphatase, enhancing tumor suppressor factor p53, ► Eliciting G2/M

  17. Znhit1 causes cell cycle arrest and down-regulates CDK6 expression

    International Nuclear Information System (INIS)

    Yang, Zhengmin; Cao, Yonghao; Zhu, Xiaoyan; Huang, Ying; Ding, Yuqiang; Liu, Xiaolong

    2009-01-01

    Cyclin-dependent kinase 6 (CDK6) is the key element of the D-type cyclin holoenzymes which has been found to function in the regulation of G1-phase of the cell cycle and is presumed to play important roles in T cell function. In this study, Znhit1, a member of a new zinc finger protein family defined by a conserved Zf-HIT domain, induced arrest in the G1-phase of the cell cycle in NIH/3T3 cells. Of the G1 cell cycle factors examined, the expression of CDK6 was found to be strongly down-regulated by Znhit1 via transcriptional repression. This effect may have correlations with the decreased acetylation level of histone H4 in the CDK6 promoter region. In addition, considering that CDK6 expression predominates in T cells, the negative regulatory role of Znhit1 in TCR-induced T cell proliferation was validated using transgenic mice. These findings identified Znhit1 as a CDK6 regulator that plays an important role in cell proliferation.

  18. Physeal growth arrest after tibial lengthening in achondroplasia

    Science.gov (United States)

    2012-01-01

    Background and purpose Bilateral tibial lengthening has become one of the standard treatments for upper segment-lower segment disproportion and to improve quality of life in achondroplasia. We determined the effect of tibial lengthening on the tibial physis and compared tibial growth that occurred at the physis with that in non-operated patients with acondroplasia. Methods We performed a retrospective analysis of serial radiographs until skeletal maturity in 23 achondroplasia patients who underwent bilateral tibial lengthening before skeletal maturity (lengthening group L) and 12 achondroplasia patients of similar height and age who did not undergo tibial lengthening (control group C). The mean amount of lengthening of tibia in group L was 9.2 cm (lengthening percentage: 60%) and the mean age at the time of lengthening was 8.2 years. The mean duration of follow-up was 9.8 years. Results Skeletal maturity (fusion of physis) occurred at 15.2 years in group L and at 16.0 years in group C. The actual length of tibia (without distraction) at skeletal maturity was 238 mm in group L and 277 mm in group C (p = 0.03). The mean growth rates showed a decrease in group L relative to group C from about 2 years after surgery. Physeal closure was most pronounced on the anterolateral proximal tibial physis, with relative preservation of the distal physis. Interpretation Our findings indicate that physeal growth rate can be disturbed after tibial lengthening in achondroplasia, and a close watch should be kept for such an occurrence—especially when lengthening of more than 50% is attempted. PMID:22489887

  19. Smad4 sensitizes colorectal cancer to 5-fluorouracil through cell cycle arrest by inhibiting the PI3K/Akt/CDC2/survivin cascade.

    Science.gov (United States)

    Zhang, Binhao; Leng, Chao; Wu, Chao; Zhang, Zhanguo; Dou, Lei; Luo, Xin; Zhang, Bixiang; Chen, Xiaoping

    2016-03-01

    5-Fluorouracil (5-FU), a cell cycle-specific antimetabolite, is one of the most commonly used chemotherapeutic agents for colorectal cancer (CRC). Yet, resistance to 5-FU-based chemotherapy is still an obstacle to the treatment of this malignancy. Mutation or loss of Smad4 in CRC is pivotal for chemoresistance. However, the mechanism by which Smad4 regulates the chemosensitivity of CRC remains unclear. In the present study, we investigated the role of Smad4 in the chemosensitivity of CRC to 5-FU, and whether Smad4-regulated cell cycle arrest is involved in 5-FU chemoresistance. We used Smad4-expressing CT26 and Smad4-null SW620 cell lines as experimental models, by knockdown or transgenic overexpression. Cells or tumors were treated with 5-FU to determine chemosensitivity by cell growth, tumorigenicity assay and a mouse model. Cell cycle distribution was examined with flow cytometric analysis, and cell cycle-related proteins were examined by western blotting. Smad4 deficiency in CT26 and SW620 cells induced chemoresistance to 5-FU both in vitro and in vivo. Smad4 deficiency attenuated G1 or G2 cell cycle arrest by activating the PI3K/Akt/CDC2/survivin pathway. The PI3K inhibitor, LY294002, reversed the activation of the Akt/CDC2/survivin cascade in the Smad4-deficient cells, while it had little effect on cells with high Smad4 expression. In conclusion, we discovered a novel mechanism mediated by Smad4 to trigger 5-FU chemosensitivity through cell cycle arrest by inhibiting the PI3K/Akt/CDC2/survivin cascade. The present study also implies that LY294002 has potential therapeutic value to reverse the chemosensitivity of CRC with low Smad4 expression.

  20. Pyrogallol, ROS generator inhibits As4.1 juxtaglomerular cells via cell cycle arrest of G2 phase and apoptosis

    International Nuclear Information System (INIS)

    Park, Woo Hyun; Han, Yong Hwan; Kim, Suhn Hee; Kim, Sung Zoo

    2007-01-01

    Pyrogallol as a catechin compound has been employed as an O 2 · - generator and often used to investigate the role of ROS in the biological system. Here, we investigated the in vitro effect of pyrogallol on cell growth, cell cycle and apoptosis in As4.1 juxtaglomerular cells. Dose-dependent inhibition of cell growth was observed with IC 50 of about 60 μM for 48 h using MTT assay. Pyrogallol (100 μM) did not alter intracellular H 2 O 2 level and catalase activity, but increased the intracellular O 2 · - level and decreased SOD activity in As4.1 cells. DNA flow cytometric analysis indicated that 50 and 100 μM pyrogallol significantly increased G2 phase cells as compared with those of pyrogallol-untreated cells. Also, pyrogallol induced apoptosis as evidenced by flow cytometric detection of sub-G1 DNA content, annexin V binding assay and DAPI staining. This apoptosis process was accompanied with the loss of mitochondrial transmembrane potential (ΔΨ m ), Bcl-2 decrease, caspase-3 activation and PARP cleavage. Pan caspase inhibitor (Z-VAD) could significantly rescue As4.1 cells from pyrogallol-induced cell death. But, the inhibitors of caspase-3, caspase-8, and caspase-9 did not prevent apoptotic events in pyrogallol-treated As4.1 cells. Taken together, we have demonstrated that an ROS inducer, pyrogallol inhibits the growth of As4.1 JG cells via cell cycle arrest and apoptosis, and suggest that the compound exhibits an anti-proliferative efficacy on these cells

  1. Characterisation of cell cycle arrest and terminal differentiation in a maximally proliferative human epithelial tissue: Lessons from the human hair follicle matrix.

    Science.gov (United States)

    Purba, Talveen S; Brunken, Lars; Peake, Michael; Shahmalak, Asim; Chaves, Asuncion; Poblet, Enrique; Ceballos, Laura; Gandarillas, Alberto; Paus, Ralf

    2017-09-01

    Human hair follicle (HF) growth and hair shaft formation require terminal differentiation-associated cell cycle arrest of highly proliferative matrix keratinocytes. However, the regulation of this complex event remains unknown. CIP/KIP family member proteins (p21 CIP1 , p27 KIP1 and p57 KIP2 ) regulate cell cycle progression/arrest, endoreplication, differentiation and apoptosis. Since they have not yet been adequately characterized in the human HF, we asked whether and where CIP/KIP proteins localise in the human hair matrix and pre-cortex in relation to cell cycle activity and HF-specific epithelial cell differentiation that is marked by keratin 85 (K85) protein expression. K85 expression coincided with loss or reduction in cell cycle activity markers, including in situ DNA synthesis (EdU incorporation), Ki-67, phospho-histone H3 and cyclins A and B1, affirming a post-mitotic state of pre-cortical HF keratinocytes. Expression of CIP/KIP proteins was found abundantly within the proliferative hair matrix, concomitant with a role in cell cycle checkpoint control. p21 CIP1 , p27 KIP1 and cyclin E persisted within post-mitotic keratinocytes of the pre-cortex, whereas p57 KIP2 protein decreased but became nuclear. These data imply a supportive role for CIP/KIP proteins in maintaining proliferative arrest, differentiation and anti-apoptotic pathways, promoting continuous hair bulb growth and hair shaft formation in anagen VI. Moreover, post-mitotic hair matrix regions contained cells with enlarged nuclei, and DNA in situ hybridisation showed cells that were >2N in the pre-cortex. This suggests that CIP/KIP proteins might counterbalance cyclin E to control further rounds of DNA replication in a cell population that has a propensity to become tetraploid. These data shed new light on the in situ-biography of human hair matrix keratinocytes on their path of active cell cycling, arrest and terminal differentiation, and showcase the human HF as an excellent, clinically

  2. Cell cycle G2/M arrest through an S phase-dependent mechanism by HIV-1 viral protein R.

    Science.gov (United States)

    Li, Ge; Park, Hyeon U; Liang, Dong; Zhao, Richard Y

    2010-07-07

    Cell cycle G2 arrest induced by HIV-1 Vpr is thought to benefit viral proliferation by providing an optimized cellular environment for viral replication and by skipping host immune responses. Even though Vpr-induced G2 arrest has been studied extensively, how Vpr triggers G2 arrest remains elusive. To examine this initiation event, we measured the Vpr effect over a single cell cycle. We found that even though Vpr stops the cell cycle at the G2/M phase, but the initiation event actually occurs in the S phase of the cell cycle. Specifically, Vpr triggers activation of Chk1 through Ser345 phosphorylation in an S phase-dependent manner. The S phase-dependent requirement of Chk1-Ser345 phosphorylation by Vpr was confirmed by siRNA gene silencing and site-directed mutagenesis. Moreover, downregulation of DNA replication licensing factors Cdt1 by siRNA significantly reduced Vpr-induced Chk1-Ser345 phosphorylation and G2 arrest. Even though hydroxyurea (HU) and ultraviolet light (UV) also induce Chk1-Ser345 phosphorylation in S phase under the same conditions, neither HU nor UV-treated cells were able to pass through S phase, whereas vpr-expressing cells completed S phase and stopped at the G2/M boundary. Furthermore, unlike HU/UV, Vpr promotes Chk1- and proteasome-mediated protein degradations of Cdc25B/C for G2 induction; in contrast, Vpr had little or no effect on Cdc25A protein degradation normally mediated by HU/UV. These data suggest that Vpr induces cell cycle G2 arrest through a unique molecular mechanism that regulates host cell cycle regulation in an S-phase dependent fashion.

  3. Cell cycle G2/M arrest through an S phase-dependent mechanism by HIV-1 viral protein R

    Directory of Open Access Journals (Sweden)

    Liang Dong

    2010-07-01

    Full Text Available Abstract Background Cell cycle G2 arrest induced by HIV-1 Vpr is thought to benefit viral proliferation by providing an optimized cellular environment for viral replication and by skipping host immune responses. Even though Vpr-induced G2 arrest has been studied extensively, how Vpr triggers G2 arrest remains elusive. Results To examine this initiation event, we measured the Vpr effect over a single cell cycle. We found that even though Vpr stops the cell cycle at the G2/M phase, but the initiation event actually occurs in the S phase of the cell cycle. Specifically, Vpr triggers activation of Chk1 through Ser345 phosphorylation in an S phase-dependent manner. The S phase-dependent requirement of Chk1-Ser345 phosphorylation by Vpr was confirmed by siRNA gene silencing and site-directed mutagenesis. Moreover, downregulation of DNA replication licensing factors Cdt1 by siRNA significantly reduced Vpr-induced Chk1-Ser345 phosphorylation and G2 arrest. Even though hydroxyurea (HU and ultraviolet light (UV also induce Chk1-Ser345 phosphorylation in S phase under the same conditions, neither HU nor UV-treated cells were able to pass through S phase, whereas vpr-expressing cells completed S phase and stopped at the G2/M boundary. Furthermore, unlike HU/UV, Vpr promotes Chk1- and proteasome-mediated protein degradations of Cdc25B/C for G2 induction; in contrast, Vpr had little or no effect on Cdc25A protein degradation normally mediated by HU/UV. Conclusions These data suggest that Vpr induces cell cycle G2 arrest through a unique molecular mechanism that regulates host cell cycle regulation in an S-phase dependent fashion.

  4. Cell growth and division cycle

    International Nuclear Information System (INIS)

    Darzynkiewicz, Z.

    1986-01-01

    The concept of the cell cycle in its present form was introduced more than three decades ago. Studying incorporation of DNA precursors by autoradiography, these authors observed that DNA synthesis in individual cells was discontinuous and occupied a discrete portion of the cell life (S phase). Mitotic division was seen to occur after a certain period of time following DNA replication. A distinct time interval between mitosis and DNA replication was also apparent. Thus, the cell cycle was subdivided into four consecutive phases, G/sub 1/, S, G/sub 2/, and M. The G/sub 1/ and G/sub 2/ phases represented the ''gaps'' between mitosis and the start of DNA replication, and between the end of DNA replication and the onset of mitosis, respectively. The cell cycle was defined as the interval between the midpoint of mitosis and the midpoint of the subsequent mitosis of the daughter cell(s). The authors' present knowledge on the cell cycle benefited mostly from the development of four different techniques: autoradiography, time-lapse cinematography, cell synchronization and flow cytometry. Of these, autoradiography has been the most extensively used, especially during the past two decades. By providing a means to analyse incorporation of precursors of DNA, RNA or proteins by individual cells and, in combination with various techniques of cell synchronization, autoradiography yielded most of the data fundamental to the current understanding of the cell cycle-related phenomena. Kinetics of cell progression through the cell cycle could be analysed in great detail after development of such sophisticated autoradiographic approaches as measurements of the fraction of labeled mitoses (''FLM curves'') or multiple sequential cell labelling with /sup 3/H- and /sup 14/C-TdR

  5. Reversal of growth arrest in adolescents with Crohn's disease after parenteral alimentation.

    Science.gov (United States)

    Layden, T; Rosenberg, F; Nemchausky, G; Elson, C; Rosenberg, I

    1976-06-01

    Growth arrest and delayed onset of puberty often complicate childhood onset Crohn's disease of the small bowel (granulomatous enteritis). Nutritional deficits arising from inadequate dietary intake, malabsorption, and increased caloric needs may contribute to growth retardation. To assess whether a sustained high caloric and nitrogen intake could reestablish growth, 4 children with extensive Crohn's disease of the small bowel were studied before and after parenteral alimentation which was instituted for symtomatic disease control. Weight gain, positive nitrogen balance, and improved nutritional status were achieved during parenteral alimentation in each patient. In 2 patients weight gain was sustained using oral nutritional supplements, and a substantial increase in linear skeletal growth continued in the ensuing months. One patient entered puberty within 4 months of parenteral alimentation and another had the onset of menarche and the development of secondary sex characteristics 4 months after parenteral alimentation and resection of diseased bowel. Growth may be reestablished in some growth-arrested children if intake is sufficient to establish a sustained positive caloric and nitrogen balance. Nutritional requirements imposed by the demands of growth and active disease and often compounded by the catabolic effects of corticosteroids may be excessive; growth may occur only if these needs are met orally and/or parenterally.

  6. Glucose capped silver nanoparticles induce cell cycle arrest in HeLa cells.

    Science.gov (United States)

    Panzarini, Elisa; Mariano, Stefania; Vergallo, Cristian; Carata, Elisabetta; Fimia, Gian Maria; Mura, Francesco; Rossi, Marco; Vergaro, Viviana; Ciccarella, Giuseppe; Corazzari, Marco; Dini, Luciana

    2017-06-01

    This study aims to determine the interaction (uptake and biological effects on cell viability and cell cycle progression) of glucose capped silver nanoparticles (AgNPs-G) on human epithelioid cervix carcinoma (HeLa) cells, in relation to amount, 2×10 3 or 2×10 4 NPs/cell, and exposure time, up to 48h. The spherical and well dispersed AgNPs (30±5nm) were obtained by using glucose as reducing agent in a green synthesis method that ensures to stabilize AgNPs avoiding cytotoxic soluble silver ions Ag + release. HeLa cells take up abundantly and rapidly AgNPs-G resulting toxic to cells in amount and incubation time dependent manner. HeLa cells were arrested at S and G2/M phases of the cell cycle and subG1 population increased when incubated with 2×10 4 AgNPs-G/cell. Mitotic index decreased accordingly. The dissolution experiments demonstrated that the observed effects were due only to AgNPs-G since glucose capping prevents Ag + release. The AgNPs-G influence on HeLa cells viability and cell cycle progression suggest that AgNPs-G, alone or in combination with chemotherapeutics, may be exploited for the development of novel antiproliferative treatment in cancer therapy. However, the possible influence of the cell cycle on cellular uptake of AgNPs-G and the mechanism of AgNPs entry in cells need further investigation. Copyright © 2017 Elsevier B.V. All rights reserved.

  7. Nucleoporins redistribute inside the nucleus after cell cycle arrest induced by histone deacetylases inhibition.

    Science.gov (United States)

    Pérez-Garrastachu, Miguel; Arluzea, Jon; Andrade, Ricardo; Díez-Torre, Alejandro; Urtizberea, Marta; Silió, Margarita; Aréchaga, Juan

    2017-09-03

    Nucleoporins are the main components of the nuclear-pore complex (NPC) and were initially considered as mere structural elements embedded in the nuclear envelope, being responsible for nucleocytoplasmic transport. Nevertheless, several recent scientific reports have revealed that some nucleoporins participate in nuclear processes such as transcription, replication, DNA repair and chromosome segregation. Thus, the interaction of NPCs with chromatin could modulate the distribution of chromosome territories relying on the epigenetic state of DNA. In particular, the nuclear basket proteins Tpr and Nup153, and the FG-nucleoporin Nup98 seem to play key roles in all these novel functions. In this work, histone deacetylase inhibitors (HDACi) were used to induce a hyperacetylated state of chromatin and the behavior of the mentioned nucleoporins was studied. Our results show that, after HDACi treatment, Tpr, Nup153 and Nup98 are translocated from the nuclear pore toward the interior of the cell nucleus, accumulating as intranuclear nucleoporin clusters. These transitory structures are highly dynamic, and are mainly present in the population of cells arrested at the G0/G1 phase of the cell cycle. Our results indicate that the redistribution of these nucleoporins from the nuclear envelope to the nuclear interior may be implicated in the early events of cell cycle initialization, particularly during the G1 phase transition.

  8. Biochemical effects of veterinary antibiotics on proliferation and cell cycle arrest of human HEK293 cells.

    Science.gov (United States)

    Kim, Hyeon Young; Kim, Ki-Tae; Kim, Sang Don

    2012-08-01

    The purpose of this study was to examine the effects of veterinary antibiotics, including amoxicillin (AMX), chlortetracycline (CTC) and tylosin (TYL), on the biochemical mechanism of human embryonic kidney cells (HEK293). CTC and TYL inhibited HEK293 cell proliferation, in both time- and dose-dependent manners, and changed the cell morphology; whereas, AMX showed no cytotoxic effects. The cell cycle analysis of CTC and TYL revealed G1-arrest in HEK293 cells. Western blot analysis also showed that CTC and TYL affected the activation of DNA damage responsive proteins, as well as cell cycle regulatory proteins, such as p53, p21(Waf1/Cip1) and Rb protein, which are crucial in the G1-S transition. The activation of p21(Waf1/Cip1) was significantly up-regulated over time, but there was no change in the level of CDK2 expression. The results of this study suggest that veterinary antibiotics, even at low level concentrations on continuous exposure, can potentially risk the development of human cells.

  9. Resveratrol induces cell cycle arrest and apoptosis in human eosinophils from asthmatic individuals.

    Science.gov (United States)

    Hu, Xin; Wang, Jing; Xia, Yu; Simayi, Mihereguli; Ikramullah, Syed; He, Yuanbing; Cui, Shihong; Li, Shuang; Wushouer, Qimanguli

    2016-12-01

    Eosinophils exert a number of inflammatory effects through the degranulation and release of intracellular mediators, and are considered to be key effector cells in allergic disorders, including asthma. In order to investigate the regulatory effects of the natural polyphenol, resveratrol, on eosinophils derived from asthmatic individuals, the cell counting Kit‑8 assay and flow cytometry analysis were used to determine cell proliferation and cell cycle progression in these cells, respectively. Cellular apoptosis was detected using annexin V-fluorescein isothiocyanate/propidium iodide double‑staining. The protein expression levels of p53, p21, cyclin‑dependent kinase 2 (CDK2), cyclin A, cyclin E, Bim, B‑cell lymphoma (Bcl)‑2 and Bcl‑2‑associated X protein (Bax) were measured by western blot analysis following resveratrol treatment. The results indicated that resveratrol effectively suppressed the proliferation of eosinophils from asthmatic patients in a concentration‑ and time‑dependent manner. In addition, resveratrol was observed to arrest cell cycle progression in G1/S phase by increasing the protein expression levels of p53 and p21, and concurrently reducing the protein expression levels of CDK2, cyclin A and cyclin E. Furthermore, resveratrol treatment significantly induced apoptosis in eosinophils, likely through the upregulation of Bim and Bax protein expression levels and the downregulation of Bcl‑2 protein expression. These findings suggested that resveratrol may be a potential agent for the treatment of asthma by decreasing the number of eosinophils.

  10. The production of monokaryotic hyphae by Cryptococcus neoformans can be induced by high temperature arrest of the cell cycle and is independent of same-sex mating.

    Science.gov (United States)

    Fu, Jianmin; Morris, Ian R; Wickes, Brian L

    2013-01-01

    Cryptococcus neoformans is a heterothallic fungal pathogen of humans and animals. Although the fungus grows primarily as a yeast, hyphae are produced during the sexual phase and during a process called monokaryotic fruiting, which is also believed to involve sexual reproduction, but between cells of the same mating type. Here we report a novel monokaryotic fruiting mechanism that is dependent on the cell cycle and occurs in haploid cells in the absence of sexual reproduction. Cells grown at 37°C were found to rapidly produce hyphae (∼4 hrs) and at high frequency (∼40% of the population) after inoculation onto hyphae-inducing agar. Microscopic examination of the 37°C seed culture revealed a mixture of normal-sized and enlarged cells. Micromanipulation of single cells demonstrated that only enlarged cells were able to produce hyphae and genetic analysis confirmed that hyphae did not arise from α-α mating or endoduplication. Cell cycle analysis revealed that cells grown at 37°C had an increased population of cells in G2 arrest, with the proportion correlated with the frequency of monokaryotic fruiting. Cell sorting experiments demonstrated that enlarged cells were only found in the G2-arrested population and only this population contained cells able to produce hyphae. Treatment of cells at low temperature with the G2 cell cycle arrest agent, nocodazole, induced hyphal growth, confirming the role of the cell cycle in this process. Taken together, these results reveal a mating-independent mechanism for monokaryotic fruiting, which is dependent on the cell cycle for induction of hyphal competency.

  11. Circadian cycles in growth and feeding rates of heterotrophic protist plankton

    DEFF Research Database (Denmark)

    Jakobsen, Hans Henrik; Strom, S.L.

    2004-01-01

    Growth and feeding rates of four species of planktonic marine heterotrophic protists showed pronounced diel cycles. In most cases, rates were higher during the day and lower at night. However, for the ciliate Strobilidium sp., growth was highest at night. In another ciliate species, Balanion...... comatum, no day-night difference in growth and feeding rates was found. Maintenance of day-night rate differences during 24-h exposures to continuous darkness demonstrated that most of these protists had circadian cycles. The heterotrophic dinoflagellate Oxyrrhis marina exhibited a clear irradiance...... to culturing in a day: night light cycle in O. marina and found that resetting the circadian cycle in this dinoflagellate temporarily arrested growth and feeding. We suggest that protists use a time-integrated light threshold rather than an instantaneous irradiance to maintain the circadian cell cycle...

  12. Porcine epidemic diarrhea virus through p53-dependent pathway causes cell cycle arrest in the G0/G1 phase.

    Science.gov (United States)

    Sun, Pei; Wu, Haoyang; Huang, Jiali; Xu, Ying; Yang, Feng; Zhang, Qi; Xu, Xingang

    2018-05-22

    Porcine epidemic diarrhea virus (PEDV), an enteropathogenic Alphacoronavirus, has caused enormous economic losses in the swine industry. p53 protein exists in a wide variety of animal cells, which is involved in cell cycle regulation, apoptosis, cell differentiation and other biological functions. In this study, we investigated the effects of PEDV infection on the cell cycle of Vero cells and p53 activation. The results demonstrated that PEDV infection induces cell cycle arrest at G0/G1 phase in Vero cells, while UV-inactivated PEDV does not cause cell cycle arrest. PEDV infection up-regulates the levels of p21, cdc2, cdk2, cdk4, Cyclin A protein and down-regulates Cyclin E protein. Further research results showed that inhibition of p53 signaling pathway can reverse the cell cycle arrest in G0/G1 phase induced by PEDV infection and cancel out the up-regulation of p21 and corresponding Cyclin/cdk mentioned above. In addition, PEDV infection of the cells synchronized in various stages of cell cycle showed that viral subgenomic RNA and virus titer were higher in the cells released from G0/G1 phase synchronized cells than that in the cells released from the G1/S phase and G2/M phase synchronized or asynchronous cells after 18 h p.i.. This is the first report to demonstrate that the p53-dependent pathway plays an important role in PEDV induced cell cycle arrest and beneficially contributes to viral infection. Copyright © 2018 Elsevier B.V. All rights reserved.

  13. MR imaging of pituitary hyperplasia in a child with growth arrest and primary hypothyroidism

    International Nuclear Information System (INIS)

    Papakonstantinou, O.; Bakantaki, A.; Papadaki, E.; Gourtsoyiannis, N.; Bitsori, M.; Mamoulakis, D.

    2000-01-01

    Magnetic resonance imaging of pituitary hyperplasia has been rarely described in children with primary hypothyroidism. We report a case of pituitary hyperplasia in a child presented with significant growth arrest and laboratory evidence of hypothyroidism. Magnetic resonance imaging revealed symmetrical pituitary enlargement simulating macroadenoma. After thyroid hormone replacement therapy, the child's height increased and pituitary enlargement regressed to normal. Awareness of MRI appearance of pituitary hyperplasia in children with laboratory evidence of hypothyroidism might avoid misdiagnosis for pituitary tumor, which may also manifest as growth disorder, obviating unnecessary surgery. (orig.)

  14. Deoxyelephantopin from Elephantopus scaber L. induces cell-cycle arrest and apoptosis in the human nasopharyngeal cancer CNE cells

    International Nuclear Information System (INIS)

    Su, Miaoxian; Chung, Hau Yin; Li, Yaolan

    2011-01-01

    Highlights: → Deoxyelephantopin (ESD) inhibited cell proliferation in the human nasopharyngeal cancer CNE cells. → ESD induced cell cycle arrest in S and G2/M phases via modulation of cell cycle regulatory proteins. → ESD triggered apoptosis by dysfunction of mitochondria and induction of both intrinsic and extrinsic apoptotic signaling pathways. → ESD also triggered Akt, ERK, and JNK signaling pathways. -- Abstract: Deoxyelephantopin (ESD), a naturally occurring sesquiterpene lactone present in the Chinese medicinal herb, Elephantopus scaber L. exerted anticancer effects on various cultured cancer cells. However, the cellular mechanisms by which it controls the development of the cancer cells are unavailable, particularly the human nasopharyngeal cancer CNE cells. In this study, we found that ESD inhibited the CNE cell proliferation. Cell cycle arrest in S and G2/M phases was also found. Western blotting analysis showed that modulation of cell cycle regulatory proteins was responsible for the ESD-induced cell cycle arrest. Besides, ESD also triggered apoptosis in CNE cells. Dysfunction in mitochondria was found to be associated with the ESD-induced apoptosis as evidenced by the loss of mitochondrial membrane potential (ΔΨm), the translocation of cytochrome c, and the regulation of Bcl-2 family proteins. Despite the Western blotting analysis showed that both intrinsic and extrinsic apoptotic pathways (cleavage of caspases-3, -7, -8, -9, and -10) were triggered in the ESD-induced apoptosis, additional analysis also showed that the induction of apoptosis could be achieved by the caspase-independent manner. Besides, Akt, ERK and JNK pathways were found to involve in ESD-induced cell death. Overall, our findings provided the first evidence that ESD induced cell cycle arrest, and apoptosis in CNE cells. ESD could be a potential chemotherapeutic agent in the treatment of nasopharyngeal cancer (NPC).

  15. Deoxyelephantopin from Elephantopus scaber L. induces cell-cycle arrest and apoptosis in the human nasopharyngeal cancer CNE cells

    Energy Technology Data Exchange (ETDEWEB)

    Su, Miaoxian [Biology Programme (Formally Biology Dept.), School of Life Sciences, The Chinese University of Hong Kong, Hong Kong SAR (China); Chung, Hau Yin, E-mail: anthonychung@cuhk.edu.hk [Biology Programme (Formally Biology Dept.), School of Life Sciences, The Chinese University of Hong Kong, Hong Kong SAR (China); Food and Nutritional Sciences Programme, School of Life Sciences, The Chinese University of Hong Kong, Hong Kong SAR (China); Li, Yaolan [Institute of Traditional Chinese Medicine and Natural Products, College of Pharmacy, Jinan University, Guangzhou (China); Guangdong Province Key Laboratory of Pharmacodynamic Constituents of TCM and New Drug Research, Guangzhou (China)

    2011-07-29

    Highlights: {yields} Deoxyelephantopin (ESD) inhibited cell proliferation in the human nasopharyngeal cancer CNE cells. {yields} ESD induced cell cycle arrest in S and G2/M phases via modulation of cell cycle regulatory proteins. {yields} ESD triggered apoptosis by dysfunction of mitochondria and induction of both intrinsic and extrinsic apoptotic signaling pathways. {yields} ESD also triggered Akt, ERK, and JNK signaling pathways. -- Abstract: Deoxyelephantopin (ESD), a naturally occurring sesquiterpene lactone present in the Chinese medicinal herb, Elephantopus scaber L. exerted anticancer effects on various cultured cancer cells. However, the cellular mechanisms by which it controls the development of the cancer cells are unavailable, particularly the human nasopharyngeal cancer CNE cells. In this study, we found that ESD inhibited the CNE cell proliferation. Cell cycle arrest in S and G2/M phases was also found. Western blotting analysis showed that modulation of cell cycle regulatory proteins was responsible for the ESD-induced cell cycle arrest. Besides, ESD also triggered apoptosis in CNE cells. Dysfunction in mitochondria was found to be associated with the ESD-induced apoptosis as evidenced by the loss of mitochondrial membrane potential ({Delta}{Psi}m), the translocation of cytochrome c, and the regulation of Bcl-2 family proteins. Despite the Western blotting analysis showed that both intrinsic and extrinsic apoptotic pathways (cleavage of caspases-3, -7, -8, -9, and -10) were triggered in the ESD-induced apoptosis, additional analysis also showed that the induction of apoptosis could be achieved by the caspase-independent manner. Besides, Akt, ERK and JNK pathways were found to involve in ESD-induced cell death. Overall, our findings provided the first evidence that ESD induced cell cycle arrest, and apoptosis in CNE cells. ESD could be a potential chemotherapeutic agent in the treatment of nasopharyngeal cancer (NPC).

  16. Scoulerine affects microtubule structure, inhibits proliferation, arrests cell cycle and thus culminates in the apoptotic death of cancer cells.

    Science.gov (United States)

    Habartova, Klara; Havelek, Radim; Seifrtova, Martina; Kralovec, Karel; Cahlikova, Lucie; Chlebek, Jakub; Cermakova, Eva; Mazankova, Nadezda; Marikova, Jana; Kunes, Jiri; Novakova, Lucie; Rezacova, Martina

    2018-03-19

    Scoulerine is an isoquinoline alkaloid, which indicated promising suppression of cancer cells growth. However, the mode of action (MOA) remained unclear. Cytotoxic and antiproliferative properties were determined in this study. Scoulerine reduces the mitochondrial dehydrogenases activity of the evaluated leukemic cells with IC 50 values ranging from 2.7 to 6.5 µM. The xCELLigence system revealed that scoulerine exerted potent antiproliferative activity in lung, ovarian and breast carcinoma cell lines. Jurkat and MOLT-4 leukemic cells treated with scoulerine were decreased in proliferation and viability. Scoulerine acted to inhibit proliferation through inducing G2 or M-phase cell cycle arrest, which correlates well with the observed breakdown of the microtubule network, increased Chk1 Ser345, Chk2 Thr68 and mitotic H3 Ser10 phosphorylation. Scoulerine was able to activate apoptosis, as determined by p53 upregulation, increase caspase activity, Annexin V and TUNEL labeling. Results highlight the potent antiproliferative and proapoptotic function of scoulerine in cancer cells caused by its ability to interfere with the microtubule elements of the cytoskeleton, checkpoint kinase signaling and p53 proteins. This is the first study of the mechanism of scoulerine at cellular and molecular level. Scoulerine is a potent antimitotic compound and that it merits further investigation as an anticancer drug.

  17. Ponatinib promotes a G1 cell-cycle arrest of merlin/NF2-deficient human schwann cells.

    Science.gov (United States)

    Petrilli, Alejandra M; Garcia, Jeanine; Bott, Marga; Klingeman Plati, Stephani; Dinh, Christine T; Bracho, Olena R; Yan, Denise; Zou, Bing; Mittal, Rahul; Telischi, Fred F; Liu, Xue-Zhong; Chang, Long-Sheng; Welling, D Bradley; Copik, Alicja J; Fernández-Valle, Cristina

    2017-05-09

    Neurofibromatosis type 2 (NF2) is a genetic syndrome that predisposes individuals to multiple benign tumors of the central and peripheral nervous systems, including vestibular schwannomas. Currently, there are no FDA approved drug therapies for NF2. Loss of function of merlin encoded by the NF2 tumor suppressor gene leads to activation of multiple mitogenic signaling cascades, including platelet-derived growth factor receptor (PDGFR) and SRC in Schwann cells. The goal of this study was to determine whether ponatinib, an FDA-approved ABL/SRC inhibitor, reduced proliferation and/or survival of merlin-deficient human Schwann cells (HSC). Merlin-deficient HSC had higher levels of phosphorylated PDGFRα/β, and SRC than merlin-expressing HSC. A similar phosphorylation pattern was observed in phospho-protein arrays of human vestibular schwannoma samples compared to normal HSC. Ponatinib reduced merlin-deficient HSC viability in a dose-dependent manner by decreasing phosphorylation of PDGFRα/β, AKT, p70S6K, MEK1/2, ERK1/2 and STAT3. These changes were associated with decreased cyclin D1 and increased p27Kip1levels, leading to a G1 cell-cycle arrest as assessed by Western blotting and flow cytometry. Ponatinib did not modulate ABL, SRC, focal adhesion kinase (FAK), or paxillin phosphorylation levels. These results suggest that ponatinib is a potential therapeutic agent for NF2-associated schwannomas and warrants further in vivo investigation.

  18. A potent transrepression domain in the retinoblastoma protein induces a cell cycle arrest when bound to E2F sites.

    Science.gov (United States)

    Sellers, W R; Rodgers, J W; Kaelin, W G

    1995-01-01

    An intact T/E1A-binding domain (the pocket) is necessary, but not sufficient, for the retinoblastoma protein (RB) to bind to DNA-protein complexes containing E2F and for RB to induce a G1/S block. Indirect evidence suggests that the binding of RB to E2F may, in addition to inhibiting E2F transactivation function, generate a complex capable of functioning as a transrepressor. Here we show that a chimera in which the E2F1 transactivation domain was replaced with the RB pocket could, in a DNA-binding and pocket-dependent manner, mimic the ability of RB to repress transcription and induce a cell cycle arrest. In contrast, a transdominant negative E2F1 mutant that is capable of blocking E2F-dependent transactivation did not. Fusion of the RB pocket to a heterologous DNA-binding domain unrelated to E2F likewise generated a transrepressor protein when scored against a suitable reporter. These results suggest that growth suppression by RB is due, at least in part, to transrepression mediated by the pocket domain bound to certain promoters via E2F. Images Fig. 4 Fig. 5 PMID:8524800

  19. Sulforaphane induces cell cycle arrest and apoptosis in acute lymphoblastic leukemia cells.

    Directory of Open Access Journals (Sweden)

    Koramit Suppipat

    Full Text Available Acute lymphoblastic leukemia (ALL is the most common hematological cancer in children. Although risk-adaptive therapy, CNS-directed chemotherapy, and supportive care have improved the survival of ALL patients, disease relapse is still the leading cause of cancer-related death in children. Therefore, new drugs are needed as frontline treatments in high-risk disease and as salvage agents in relapsed ALL. In this study, we report that purified sulforaphane, a natural isothiocyanate found in cruciferous vegetables, has anti-leukemic properties in a broad range of ALL cell lines and primary lymphoblasts from pediatric T-ALL and pre-B ALL patients. The treatment of ALL leukemic cells with sulforaphane resulted in dose-dependent apoptosis and G2/M cell cycle arrest, which was associated with the activation of caspases (3, 8, and 9, inactivation of PARP, p53-independent upregulation of p21(CIP1/WAF1, and inhibition of the Cdc2/Cyclin B1 complex. Interestingly, sulforaphane also inhibited the AKT and mTOR survival pathways in most of the tested cell lines by lowering the levels of both total and phosphorylated proteins. Finally, the administration of sulforaphane to the ALL xenograft models resulted in a reduction of tumor burden, particularly following oral administration, suggesting a potential role as an adjunctive agent to improve the therapeutic response in high-risk ALL patients with activated AKT signaling.

  20. MiR-107 and MiR-185 can induce cell cycle arrest in human non small cell lung cancer cell lines.

    Directory of Open Access Journals (Sweden)

    Yukari Takahashi

    Full Text Available BACKGROUND: MicroRNAs (miRNAs are short single stranded noncoding RNAs that suppress gene expression through either translational repression or degradation of target mRNAs. The annealing between messenger RNAs and 5' seed region of miRNAs is believed to be essential for the specific suppression of target gene expression. One miRNA can have several hundred different targets in a cell. Rapidly accumulating evidence suggests that many miRNAs are involved in cell cycle regulation and consequentially play critical roles in carcinogenesis. METHODOLOGY/PRINCIPAL FINDINGS: Introduction of synthetic miR-107 or miR-185 suppressed growth of the human non-small cell lung cancer cell lines. Flow cytometry analysis revealed these miRNAs induce a G1 cell cycle arrest in H1299 cells and the suppression of cell cycle progression is stronger than that by Let-7 miRNA. By the gene expression analyses with oligonucleotide microarrays, we find hundreds of genes are affected by transfection of these miRNAs. Using miRNA-target prediction analyses and the array data, we listed up a set of likely targets of miR-107 and miR-185 for G1 cell cycle arrest and validate a subset of them using real-time RT-PCR and immunoblotting for CDK6. CONCLUSIONS/SIGNIFICANCE: We identified new cell cycle regulating miRNAs, miR-107 and miR-185, localized in frequently altered chromosomal regions in human lung cancers. Especially for miR-107, a large number of down-regulated genes are annotated with the gene ontology term 'cell cycle'. Our results suggest that these miRNAs may contribute to regulate cell cycle in human malignant tumors.

  1. Proteasome-mediated degradation of cell division cycle 25C and cyclin-dependent kinase 1 in phenethyl isothiocyanate-induced G2-M-phase cell cycle arrest in PC-3 human prostate cancer cells.

    Science.gov (United States)

    Xiao, Dong; Johnson, Candace S; Trump, Donald L; Singh, Shivendra V

    2004-05-01

    Phenethyl isothiocyanate (PEITC), a constituent of many cruciferous vegetables, offers significant protection against cancer in animals induced by a variety of carcinogens. The present study demonstrates that PEITC suppresses proliferation of PC-3 cells in a dose-dependent manner by causing G(2)-M-phase cell cycle arrest and apoptosis. Interestingly, phenyl isothiocyanate (PITC), which is a structural analogue of PEITC but lacks the -CH(2) spacers that link the aromatic ring to the -N=C=S group, neither inhibited PC-3 cell viability nor caused cell cycle arrest or apoptosis. These results indicated that even a subtle change in isothiocyanate (ITC) structure could have a significant impact on its biological activity. The PEITC-induced cell cycle arrest was associated with a >80% reduction in the protein levels of cyclin-dependent kinase 1 (Cdk1) and cell division cycle 25C (Cdc25C; 24 h after treatment with 10 micro M PEITC), which led to an accumulation of Tyr(15) phosphorylated (inactive) Cdk1. On the other hand, PITC treatment neither reduced protein levels of Cdk1 or Cdc25C nor affected Cdk1 phosphorylation. The PEITC-induced decline in Cdk1 and Cdc25C protein levels and cell cycle arrest were significantly blocked on pretreatment of PC-3 cells with proteasome inhibitor lactacystin. A 24 h exposure of PC-3 cells to 10 micro M PEITC, but not PITC, resulted in about 56% and 44% decrease in the levels of antiapoptotic proteins Bcl-2 and Bcl-X(L), respectively. However, ectopic expression of Bcl-2 failed to alter sensitivity of PC-3 cells to growth inhibition or apoptosis induction by PEITC. Treatment of cells with PEITC, but not PITC, also resulted in cleavage of procaspase-3, procaspase-9, and procaspase-8. Moreover, the PEITC-induced apoptosis was significantly attenuated in the presence of general caspase inhibitor and specific inhibitors of caspase-8 and caspase-9. In conclusion, our data indicate that PEITC-induced cell cycle arrest in PC-3 cells is likely due

  2. Cyclin G2 is a centrosome-associated nucleocytoplasmic shuttling protein that influences microtubule stability and induces a p53-dependent cell cycle arrest

    International Nuclear Information System (INIS)

    Arachchige Don, Aruni S.; Dallapiazza, Robert F.; Bennin, David A.; Brake, Tiffany; Cowan, Colleen E.; Horne, Mary C.

    2006-01-01

    Cyclin G2 is an atypical cyclin that associates with active protein phosphatase 2A. Cyclin G2 gene expression correlates with cell cycle inhibition; it is significantly upregulated in response to DNA damage and diverse growth inhibitory stimuli, but repressed by mitogenic signals. Ectopic expression of cyclin G2 promotes cell cycle arrest, cyclin dependent kinase 2 inhibition and the formation of aberrant nuclei [Bennin, D. A., Don, A. S., Brake, T., McKenzie, J. L., Rosenbaum, H., Ortiz, L., DePaoli-Roach, A. A., and Horne, M. C. (2002). Cyclin G2 associates with protein phosphatase 2A catalytic and regulatory B' subunits in active complexes and induces nuclear aberrations and a G 1 /S-phase cell cycle arrest. J Biol Chem 277, 27449-67]. Here we report that endogenous cyclin G2 copurifies with centrosomes and microtubules (MT) and that ectopic G2 expression alters microtubule stability. We find exogenous and endogenous cyclin G2 present at microtubule organizing centers (MTOCs) where it colocalizes with centrosomal markers in a variety of cell lines. We previously reported that cyclin G2 forms complexes with active protein phosphatase 2A (PP2A) and colocalizes with PP2A in a detergent-resistant compartment. We now show that cyclin G2 and PP2A colocalize at MTOCs in transfected cells and that the endogenous proteins copurify with isolated centrosomes. Displacement of the endogenous centrosomal scaffolding protein AKAP450 that anchors PP2A at the centrosome resulted in the depletion of centrosomal cyclin G2. We find that ectopic expression of cyclin G2 induces microtubule bundling and resistance to depolymerization, inhibition of polymer regrowth from MTOCs and a p53-dependent cell cycle arrest. Furthermore, we determined that a 100 amino acid carboxy-terminal region of cyclin G2 is sufficient to both direct GFP localization to centrosomes and induce cell cycle inhibition. Colocalization of endogenous cyclin G2 with only one of two GFP-centrin-tagged centrioles, the

  3. Piper nigrum ethanolic extract rich in piperamides causes ROS overproduction, oxidative damage in DNA leading to cell cycle arrest and apoptosis in cancer cells.

    Science.gov (United States)

    de Souza Grinevicius, Valdelúcia Maria Alves; Kviecinski, Maicon Roberto; Santos Mota, Nádia Sandrini Ramos; Ourique, Fabiana; Porfirio Will Castro, Luiza Sheyla Evenni; Andreguetti, Rafaela Rafognato; Gomes Correia, João Francisco; Filho, Danilo Wilhem; Pich, Claus Tröger; Pedrosa, Rozangela Curi

    2016-08-02

    Ayurvedic and Chinese traditional medicine and tribal people use herbal preparations containing Piper nigrum fruits for the treatment of many health disorders like inflammation, fever, asthma and cancer. In Brazil, traditional maroon culture associates the spice Piper nigrum to health recovery and inflammation attenuation. The aim of the current work was to evaluate the relationship between reactive oxygen species (ROS) overproduction, DNA fragmentation, cell cycle arrest and apoptosis induced by Piper nigrum ethanolic extract and its antitumor activity. The plant was macerated in ethanol. Extract constitution was assessed by TLC, UV-vis and ESI-IT-MS/MS spectrometry. The cytotoxicity, proliferation and intracellular ROS generation was evaluated in MCF-7 cells. DNA damage effects were evaluated through intercalation into CT-DNA, plasmid DNA cleavage and oxidative damage in CT-DNA. Tumor growth inhibition, survival time increase, apoptosis, cell cycle arrest and oxidative stress were assessed in Ehrlich ascites carcinoma-bearing mice. Extraction yielded 64mg/g (36% piperine and 4.2% piperyline). Treatments caused DNA damage and reduced cell viability (EC50=27.1±2.0 and 80.5±6.6µg/ml in MCF-7 and HT-29 cells, respectively), inhibiting cell proliferation by 57% and increased ROS generation in MCF-7 cells (65%). Ehrlich carcinoma was inhibited by the extract, which caused reduction of tumor growth (60%), elevated survival time (76%), cell cycle arrest and induced apoptosis. The treatment with extract increased Bax and p53 and inhibited Bcl-xL and cyclin A expression. It also induced an oxidative stress in vivo verified as enhanced lipid peroxidation and carbonyl proteins content and increased activities of glutathione reductase, superoxide dismutase and catalase. GSH concentration was decreased in tumor tissue from mice. The ethanolic extract has cytotoxic and antiproliferative effect on MCF-7 cells and antitumor effect in vivo probably due to ROS overproduction

  4. Antitumor Activity of Tenacissoside H on Esophageal Cancer through Arresting Cell Cycle and Regulating PI3K/Akt-NF-κB Transduction Cascade

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    Yong-sen Jia

    2015-01-01

    Full Text Available Objective. The purpose of the study was to elucidate the molecular mechanism of tenacissoside H (TDH inhibiting esophageal carcinoma infiltration and proliferation. Methods. In vitro, EC9706 cells were treated with TDH. Cells proliferation and cell cycle were assayed. PI3K and NF-κB mRNAs expression were determined by real time PCR. In vivo, model of nude mice with tumor was established. Mice were treated with TDH. Inhibition ratio of tumor volume was calculated. PCNA expression was examined. Protein expression in PI3K/Akt-NF-κB signaling pathway was determined. Results. In vitro, TDH significantly inhibited cells proliferation in a time-and-dose-dependent manner. TDH arrested the cell cycle in S phase and significantly inhibited PI3K and NF-κB mRNA expression, compared with blank controlled group (P<0.05. In vivo, TDH strongly inhibits tumor growth and volume. PCNA expression was significantly decreased after treatment of TDH. TDH downregulated proteins expression in PI3K/Akt-NF-κB transduction cascade (P<0.05. Conclusion. TDH inhibited esophageal carcinoma infiltration and proliferation both in vitro and in vivo. The anticancer activity has relation to arresting the cell cycle at the S phase, inhibited the PCNA expression of transplanted tumors in nude mice, and regulated the protein expression in the PI3K/Akt-NF-κB transduction cascade.

  5. Phytol isolated from watermelon (Citrullus lanatus) sprouts induces cell death in human T-lymphoid cell line Jurkat cells via S-phase cell cycle arrest.

    Science.gov (United States)

    Itoh, Tomohiro; Ono, Akito; Kawaguchi, Kaori; Teraoka, Sayaka; Harada, Mayo; Sumi, Keitaro; Ando, Masashi; Tsukamasa, Yasuyuki; Ninomiya, Masayuki; Koketsu, Mamoru; Hashizume, Toshiharu

    2018-05-01

    The phytol isolated from watermelon (Citrullus lanatus) sprouts inhibited the growth of a human T-cell leukemia line Jurkat cell and suppressed tumor progression in a xenograft model of human lung adenocarcinoma epithelial cell line A549 in nude mice. To elucidate the mechanisms underlying the phytol-induced cell death in the present study, we examined the changes in cell morphology, DNA fragmentation, and intracellular reactive oxygen species (ROS) levels and performed flow cytometric analysis to evaluate cell cycle stage. There were no significant changes in apoptosis, autophagy, and necrosis marker in cells treated with the phytol. But, we found, for the first time, that phytol remarkably induced S-phase cell cycle arrest accompanied with intracellular ROS production. Western blot analyses showed that phytolinduced S-phase cell cycle arrest was mediated through the decreased expression of cyclins A and D and the downregulations of MAPK and PI3K/Akt. The tumor volume levels in mice treated with phytol were lower than those of non-treatment groups, and it showed very similar suppression compared with those of mice treated with cyclophosphamide. Based on the data of in vitro and in vivo studies and previous studies, we suggest phytol as a potential therapeutic compound for cancer. Copyright © 2018 Elsevier Ltd. All rights reserved.

  6. Solena amplexicaulis induces cell cycle arrest, apoptosis and inhibits angiogenesis in hepatocarcinoma cells and HUVECs.

    Science.gov (United States)

    Ren, Jie; Xu, Yuan Yuan; Jiang, He Fei; Yang, Meng; Huang, Qian Hui; Yang, Jie; Hu, Kun; Wei, Kun

    2014-01-01

    Solena amplexicaulis (Lam.) Gandhi (SA) has been used as a traditional medicine for the treatment of dysentery, multiple abscess, gastralgia, urethritis, and eczema in the minority area of China. This study was aimed to examine the cell proliferation inhibitory activity of the SA extract (SACE) and its mechanism of action in human hepatoma cell line (HepG2) and evaluate its anti-angiogenesis activity in human umbilical vein endothelial cell line (HUVEC). SACE could inhibit the growth of HepG2 cells in a dose- and time-dependent manner. FCM analysis showed that SACE could induce G2/M phase arrest, cell apoptosis, the mitochondrial membrane potential loss (ΔΨm) and increase the production of intracellular ROS of HepG2 cells. After treatment with SACE, topical morphological changes of apoptotic body formation, obvious increase of apoptosis-related protein expressions, such as Bax, cytochrome c, caspase-3, PARP-1, and decrease of Bcl-2, procaspase-9 protein expressions were observed at the same time. Moreover, SACE caused the significant inhibition of endothelial cell migration and tube formation in HUVEC cells. The results suggested that SACE could act as an angiogenesis inhibitor and induce cell apoptosis via a caspase-dependent mitochondrial pathway. Therefore, SACE could be a potent candidate for the prevention and treatment of liver cancer.

  7. 2-Methoxy-4-vinylphenol can induce cell cycle arrest by blocking the hyper-phosphorylation of retinoblastoma protein in benzo[a]pyrene-treated NIH3T3 cells

    International Nuclear Information System (INIS)

    Jeong, Jin Boo; Jeong, Hyung Jin

    2010-01-01

    Research highlights: → 2M4VP activated the expression of p21 and p15 protein, and down-regulated the expression of cyclin D1 and cyclin E. → 2M4VP inhibited hyper-phosphorylation of Rb protein. → 2M4VP induced cell cycle arrest from G1 to S. → 2M4VP inhibited hyper-proliferation of the cells in BaP-treated cells. → 2M4VP induces growth arrest of BaP-treated cells by blocking hyper-phosphorylation of Rb via regulating the expression of cell cycle-related proteins. -- Abstract: Benzo[a]pyrene (BaP) is an environment carcinogen that can enhance cell proliferation by disturbing the signal transduction pathways in cell cycle regulation. In this study, the effects of 2M4VP on cell proliferation, cell cycle and cell cycle regulatory proteins were studied in BaP-treated NIH 3T3 cells to establish the molecular mechanisms of 2M4VP as anti-proliferative agents. 2M4VP exerted a dose-dependent inhibitory effect on cell growth correlated with a G1 arrest. Analysis of G1 cell cycle regulators expression revealed 2M4VP increased expression of CDK inhibitor, p21Waf1/Cip1 and p15 INK4b, decreased expression of cyclin D1 and cyclin E, and inhibited kinase activities of CDK4 and CDK2. However, 2M4VP did not affect the expression of CDK4 and CDK2. Also, 2M4VP inhibited the hyper-phosphorylation of Rb induced by BaP. Our results suggest that 2M4VP induce growth arrest of BaP-treated NIH 3T3 cells by blocking the hyper-phosphorylation of Rb via regulating the expression of cell cycle-related proteins.

  8. 2-Methoxy-4-vinylphenol can induce cell cycle arrest by blocking the hyper-phosphorylation of retinoblastoma protein in benzo[a]pyrene-treated NIH3T3 cells

    Energy Technology Data Exchange (ETDEWEB)

    Jeong, Jin Boo [Bioresource Sciences, Andong National University, Andong 760749 (Korea, Republic of); Jeong, Hyung Jin, E-mail: jhj@andong.ac.kr [Bioresource Sciences, Andong National University, Andong 760749 (Korea, Republic of)

    2010-10-01

    Research highlights: {yields} 2M4VP activated the expression of p21 and p15 protein, and down-regulated the expression of cyclin D1 and cyclin E. {yields} 2M4VP inhibited hyper-phosphorylation of Rb protein. {yields} 2M4VP induced cell cycle arrest from G1 to S. {yields} 2M4VP inhibited hyper-proliferation of the cells in BaP-treated cells. {yields} 2M4VP induces growth arrest of BaP-treated cells by blocking hyper-phosphorylation of Rb via regulating the expression of cell cycle-related proteins. -- Abstract: Benzo[a]pyrene (BaP) is an environment carcinogen that can enhance cell proliferation by disturbing the signal transduction pathways in cell cycle regulation. In this study, the effects of 2M4VP on cell proliferation, cell cycle and cell cycle regulatory proteins were studied in BaP-treated NIH 3T3 cells to establish the molecular mechanisms of 2M4VP as anti-proliferative agents. 2M4VP exerted a dose-dependent inhibitory effect on cell growth correlated with a G1 arrest. Analysis of G1 cell cycle regulators expression revealed 2M4VP increased expression of CDK inhibitor, p21Waf1/Cip1 and p15 INK4b, decreased expression of cyclin D1 and cyclin E, and inhibited kinase activities of CDK4 and CDK2. However, 2M4VP did not affect the expression of CDK4 and CDK2. Also, 2M4VP inhibited the hyper-phosphorylation of Rb induced by BaP. Our results suggest that 2M4VP induce growth arrest of BaP-treated NIH 3T3 cells by blocking the hyper-phosphorylation of Rb via regulating the expression of cell cycle-related proteins.

  9. Silkworm Pupa Protein Hydrolysate Induces Mitochondria-Dependent Apoptosis and S Phase Cell Cycle Arrest in Human Gastric Cancer SGC-7901 Cells

    Directory of Open Access Journals (Sweden)

    Xiaotong Li

    2018-03-01

    Full Text Available Silkworm pupae (Bombyx mori are a high-protein nutrition source consumed in China since more than 2 thousand years ago. Recent studies revealed that silkworm pupae have therapeutic benefits to treat many diseases. However, the ability of the compounds of silkworm pupae to inhibit tumourigenesis remains to be elucidated. Here, we separated the protein of silkworm pupae and performed alcalase hydrolysis. Silkworm pupa protein hydrolysate (SPPH can specifically inhibit the proliferation and provoke abnormal morphologic features of human gastric cancer cells SGC-7901 in a dose- and time-dependent manner. Moreover, flow cytometry indicated that SPPH can induce apoptosis and arrest the cell-cycle in S phase. Furthermore, SPPH was shown to provoke accumulation of reactive oxygen species (ROS and depolarization of mitochondrial membrane potential. Western blotting analysis indicated that SPPH inhibited Bcl-2 expression and promoted Bax expression, and subsequently induced apoptosis-inducing factor and cytochrome C release, which led to the activation of initiator caspase-9 and executioner caspase-3, cleavage of poly (ADP-ribose polymerase (PARP, eventually caused cell apoptosis. Moreover, SPPH-induced S-phase arrest was mediated by up-regulating the expression of E2F1 and down-regulating those of cyclin E, CDK2 and cyclin A2. Transcriptome sequencing and gene set enrichment analysis (GSEA also revealed that SPPH treatment could affect gene expression and pathway regulation related to tumourigenesis, apoptosis and cell cycle. In summary, our results suggest that SPPH could specifically suppress cell growth of SGC-7901 through an intrinsic apoptotic pathway, ROS accumulation and cell cycle arrest, and silkworm pupae have a potential to become a source of anticancer agents in the future.

  10. Radiotherapy induces cell cycle arrest and cell apoptosis in nasopharyngeal carcinoma via the ATM and Smad pathways.

    Science.gov (United States)

    Li, Ming-Yi; Liu, Jin-Quan; Chen, Dong-Ping; Li, Zhou-Yu; Qi, Bin; He, Lu; Yu, Yi; Yin, Wen-Jin; Wang, Meng-Yao; Lin, Ling

    2017-09-02

    Nasopharyngeal carcinoma (NPC) is a common malignant neoplasm of the head and neck which is harmful to human's health. Radiotherapy is commonly used in the treatment of NPC and it induces immediate cell cycle arrest and cell apoptosis. However, the mechanism remains unknown. Evidences suggested the activation of Ataxia telangiectasia mutated (ATM) pathway and Smad pathway are 2 of the important crucial mediators in the function of radiotherapy. In this study, we performed in vitro assays with human nasopharyngeal carcinoma CNE-2 cells and in vivo assays with nude mice to investigate the role of the ATM and Smad pathways in the treatment of nasopharyngeal carcinoma with radiotherapy. The results suggested that radiation induced activation of ATM pathway by inducing expression of p-ATM, p-CHK1, p-CHK2, p15 and inhibiting expression of p-Smad3. In addition, Caspase3 expression was increased while CDC25A was decreased, leading to cell cycle arrest and cell apoptosis. On the other hand, activation of Smad3 can inhibited the ATM pathway and attenuated the efficacy of radiation. In summary, we suggest that both ATM and Smad pathways contribute to the cell cycle arrest and cell apoptosis during nasopharyngeal carcinoma cells treated with radiation.

  11. The potential role of ribosomal protein S5 on cell cycle arrest and initiation of murine erythroleukemia cell differentiation.

    Science.gov (United States)

    Matragkou, Christina N; Papachristou, Eleni T; Tezias, Sotirios S; Tsiftsoglou, Asterios S; Choli-Papadopoulou, Theodora; Vizirianakis, Ioannis S

    2008-07-01

    Evidence now exists to indicate that some ribosomal proteins besides being structural components of the ribosomal subunits are involved in the regulation of cell differentiation and apoptosis. As we have shown earlier, initiation of erythroid differentiation of murine erythroleukemia (MEL) cells is associated with transcriptional inactivation of genes encoding ribosomal RNAs and ribosomal proteins S5 (RPS5) and L35a. In this study, we extended these observations and investigated whether transfection of MEL cells with RPS5 cDNA affects the onset of initiation of erythroid maturation and their entrance in cell cycle arrest. Stably transfected MEL cloned cells (MEL-C14 and MEL-C56) were established and assessed for their capacity to produce RPS5 RNA transcript and its translated product. The impact of RPS5 cDNA transfection on the RPS5 gene expression patterns and the accumulation of RPS5 protein in inducible transfected MEL cells were correlated with their ability to: (a) initiate differentiation, (b) enter cell cycle arrest at G(1)/G(0) phase, and (c) modulate the level of cyclin-dependent kinases CDK2, CDK4, and CDK6. The data presented indicate that deregulation of RPS5 gene expression (constitutive expression) affects RPS5 protein level and delays both the onset of initiation of erythroid maturation and entrance in cell cycle arrest in inducer-treated MEL cells. 2008 Wiley-Liss, Inc.

  12. PPARγ-independent induction of growth arrest and apoptosis in prostate and bladder carcinoma

    International Nuclear Information System (INIS)

    Chaffer, Christine L; Thomas, David M; Thompson, Erik W; Williams, Elizabeth D

    2006-01-01

    Although PPARγ antagonists have shown considerable pre-clinical efficacy, recent studies suggest PPARγ ligands induce PPARγ-independent effects. There is a need to better define such effects to permit rational utilization of these agents. We have studied the effects of a range of endogenous and synthetic PPARγ ligands on proliferation, growth arrest (FACS analysis) and apoptosis (caspase-3/7 activation and DNA fragmentation) in multiple prostate carcinoma cell lines (DU145, PC-3 and LNCaP) and in a series of cell lines modelling metastatic transitional cell carcinoma of the bladder (TSU-Pr1, TSU-Pr1-B1 and TSU-Pr1-B2). 15-deoxy-prostaglandin J 2 (15dPGJ2), troglitazone (TGZ) and to a lesser extent ciglitazone exhibited inhibitory effects on cell number; the selective PPARγ antagonist GW9662 did not reverse these effects. Rosiglitazone and pioglitazone had no effect on proliferation. In addition, TGZ induced G0/G1 growth arrest whilst 15dPGJ2 induced apoptosis. Troglitazone and 15dPGJ2 inhibit growth of prostate and bladder carcinoma cell lines through different mechanisms and the effects of both agents are PPARγ-independent

  13. Growth Arrest-Specific 6 (Gas6) and TAM Receptors in Mouse Platelets.

    Science.gov (United States)

    Uras, Fikriye; Küçük, Burhanettin; Bingöl Özakpınar, Özlem; Demir, Ahmet Muzaffer

    2015-03-05

    Growth arrest-specific 6 (Gas6) is a newly discovered vitamin K-dependent protein, which is a ligand for TAM receptors [Tyro3 (Sky), Axl, and Mer] from the tyrosine kinase family. Gas6 knockout mice were resistant to venous and arterial thrombosis. There are contradictory reports on the presence of Gas6 and its receptors in mouse platelets. The objective of this study was to investigate whether Gas6 and its receptors were present in mouse platelets or not. Specific pathogen-free BALB/c male and female mice of 8-10 weeks old and 25-30 g in weight were anesthetized under light ether anesthesia and blood samples were taken from their hearts. RNAs were isolated from isolated platelets, and then mRNAs encoding Gas6 and TAM receptors were detected by reverse transcription-polymerase chain reaction (RT-PCR). Protein concentrations of Gas6 and TAM receptors in platelets were measured by ELISA, but not those of Mer, because of the absence of any commercial ELISA kit for mouse specimens. RT-PCR results indicated the presence of mRNAs encoding Gas6 and Mer in mouse platelets. However, although RT-PCR reactions were performed at various temperatures and cycles, we could not detect the presence of mRNAs encoding Axl and Tyro3 (Sky). Receptor protein levels of Axl and Tyro3 were below the detection limits of the ELISA method. We found the presence of mRNAs encoding Gas6 and the receptor Mer in mouse platelets, but not Axl and Tyro3. Gas6, Axl, and Tyro3 protein levels were below the detection limits of the ELISA. The presence of mRNA is not obvious evidence of protein expression in platelets that have no nucleus or DNA. Further studies are required to clarify the presence of Gas6/TAM receptors in platelets using real-time PCR and more sensitive immunological methods, and future studies on mechanisms will indicate whether the Gas6/TAM pathway is a strategy for treatment of disorders.

  14. Constitutively active Notch1 induces growth arrest of HPV-positive cervical cancer cells via separate signaling pathways

    International Nuclear Information System (INIS)

    Talora, Claudio; Cialfi, Samantha; Segatto, Oreste; Morrone, Stefania; Kim Choi, John; Frati, Luigi; Paolo Dotto, Gian; Gulino, Alberto; Screpanti, Isabella

    2005-01-01

    Notch signaling plays a key role in cell-fate determination and differentiation in different organisms and cell types. Several reports suggest that Notch signaling may be involved in neoplastic transformation. However, in primary keratinocytes, Notch1 can function as a tumor suppressor. Similarly, in HPV-positive cervical cancer cells, constitutively active Notch1 signaling was found to cause growth suppression. Activated Notch1 in these cells represses viral E6/E7 expression through AP-1 down-modulation, resulting in increased p53 expression and a block of pRb hyperphosphorylation. Here we show that in cervical cancer cell lines in which Notch1 ability to repress AP-1 activity is impaired, Notch1-enforced expression elicits an alternative pathway leading to growth arrest. Indeed, activated Notch1 signaling suppresses activity of the helix-loop-helix transcription factor E47, via ERK1/2 activation, resulting in inhibition of cell cycle progression. Moreover, we found that RBP-Jκ-dependent Notch signaling is specifically repressed in cervical cancer cells and this repression could provide one such mechanism that needs to be activated for cervical carcinogenesis. Finally, we show that inhibition of endogenous Notch1 signaling, although results in a proliferative advantage, sensitizes cervical cancer cell lines to drug-induced apoptosis. Together, our results provide novel molecular insights into Notch1-dependent growth inhibitory effects, counteracting the transforming potential of HPV

  15. Induction of apoptosis and antiproliferative activity of naringenin in human epidermoid carcinoma cell through ROS generation and cell cycle arrest.

    Directory of Open Access Journals (Sweden)

    Md Sultan Ahamad

    Full Text Available A natural predominant flavanone naringenin, especially abundant in citrus fruits, has a wide range of pharmacological activities. The search for antiproliferative agents that reduce skin carcinoma is a task of great importance. The objective of this study was to analyze the anti-proliferative and apoptotic mechanism of naringenin using MTT assay, DNA fragmentation, nuclear condensation, change in mitochondrial membrane potential, cell cycle kinetics and caspase-3 as biomarkers and to investigate the ability to induce reactive oxygen species (ROS initiating apoptotic cascade in human epidermoid carcinoma A431 cells. Results showed that naringenin exposure significantly reduced the cell viability of A431 cells (p<0.01 with a concomitant increase in nuclear condensation and DNA fragmentation in a dose dependent manner. The intracellular ROS generation assay showed statistically significant (p<0.001 dose-related increment in ROS production for naringenin. It also caused naringenin-mediated epidermoid carcinoma apoptosis by inducing mitochondrial depolarization. Cell cycle study showed that naringenin induced cell cycle arrest in G0/G1 phase of cell cycle and caspase-3 analysis revealed a dose dependent increment in caspase-3 activity which led to cell apoptosis. This study confirms the efficacy of naringenin that lead to cell death in epidermoid carcinoma cells via inducing ROS generation, mitochondrial depolarization, nuclear condensation, DNA fragmentation, cell cycle arrest in G0/G1 phase and caspase-3 activation.

  16. Securinine from Phyllanthus glaucus Induces Cell Cycle Arrest and Apoptosis in Human Cervical Cancer HeLa Cells.

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    Justyna Stefanowicz-Hajduk

    Full Text Available The Securinega-type alkaloids occur in plants belonging to Euphorbiaceae family. One of the most widely distributed alkaloid of this group is securinine, which was identified next to allosecurinine in Phyllanthus glaucus (leafflower. Recently, some Securinega-type alkaloids have paid attention to its antiproliferative potency towards different cancer cells. However, the cytotoxic properties of allosecurinine have not yet been evaluated.The cytotoxicity of the extract, alkaloid fraction obtained from P. glaucus, isolated securinine and allosecurinine against HeLa cells was evaluated by real-time xCELLigence system and 3-(4,5-dimethylthiazol-2-yl-2,5-diphenyltetrazolium bromide (MTT assay. Apoptosis was detected by annexin V and 7-amino-actinomycin (7-AAD staining and confirmed with fluorescent Hoechst 33342 dye. The assessment of mitochondrial membrane potential (MMP, reactive oxygen species (ROS generation, the level of extracellular signal-regulated protein kinases 1 and 2 (ERK1/2, caspase-3/7 activity and cell cycle analysis were measured by flow cytometry. The enzymatic activity of caspase-9 was assessed by a luminometric assay. The expression of apoptosis associated genes was analyzed by real-time PCR.The experimental data revealed that securinine and the alkaloid fraction were significantly potent on HeLa cells growth inhibition with IC50 values of 7.02 ± 0.52 μg/ml (32.3 μM and 25.46 ± 1.79 μg/ml, respectively. The activity of allosecurinine and Phyllanthus extract were much lower. Furthermore, our study showed that the most active securinine induced apoptosis in a dose-dependent manner in the tested cells, increased the percentage of ROS positive cells and depolarized cells as well as stimulated the activity of ERK1/2, caspase-9 and -3/7. Securinine also induced cell cycle arrest in S phase. Real-time PCR analysis showed high expression of TNFRSF genes in the cells stimulated with securinine.Securinine induces apoptosis and activates

  17. Bypass of cell cycle arrest induced by transient DNMT1 post-transcriptional silencing triggers aneuploidy in human cells

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    Barra Viviana

    2012-02-01

    Full Text Available Abstract Background Aneuploidy has been acknowledged as a major source of genomic instability in cancer, and it is often considered the result of chromosome segregation errors including those caused by defects in genes controlling the mitotic spindle assembly, centrosome duplication and cell-cycle checkpoints. Aneuploidy and chromosomal instability has been also correlated with epigenetic alteration, however the molecular basis of this correlation is poorly understood. Results To address the functional connection existing between epigenetic changes and aneuploidy, we used RNA-interference to silence the DNMT1 gene, encoding for a highly conserved member of the DNA methyl-transferases. DNMT1 depletion slowed down proliferation of near-diploid human tumor cells (HCT116 and triggered G1 arrest in primary human fibroblasts (IMR90, by inducing p53 stabilization and, in turn, p21waf1 transactivation. Remarkably, p53 increase was not caused by DNA damage and was not observed after p14-ARF post-transcriptional silencing. Interestingly, DNMT1 silenced cells with p53 or p14-ARF depleted did not arrest in G1 but, instead, underwent DNA hypomethylation and became aneuploid. Conclusion Our results suggest that DNMT1 depletion triggers a p14ARF/p53 dependent cell cycle arrest to counteract the aneuploidy induced by changes in DNA methylation.

  18. Facile construction of fused benzimidazole-isoquinolinones that induce cell-cycle arrest and apoptosis in colorectal cancer cells.

    Science.gov (United States)

    He, Liu-Jun; Yang, Dong-Lin; Li, Shi-Qiang; Zhang, Ya-Jun; Tang, Yan; Lei, Jie; Frett, Brendan; Lin, Hui-Kuan; Li, Hong-Yu; Chen, Zhong-Zhu; Xu, Zhi-Gang

    2018-06-12

    Colorectal cancer (CRC) is one of the most frequent, malignant gastrointestinal tumors, and strategies and effectiveness of current therapy are limited. A series of benzimidazole-isoquinolinone derivatives (BIDs) was synthesized and screened to identify novel scaffolds for CRC. Of the compounds evaluated, 7g exhibited the most promising anti-cancer properties. Employing two CRC cell lines, SW620 and HT29, 7g was found to suppress growth and proliferation of the cell lines at a concentration of ∼20 µM. Treatment followed an increase in G 2 /M cell cycle arrest, which was attributed to cyclin B1 and cyclin-dependent kinase 1 (CDK1) signaling deficiencies with simultaneous enhancement in p21 and p53 activity. In addition, mitochondrial-mediated apoptosis was induced in CRC cells. Interestingly, 7g decreased phosphorylated AKT, mTOR and 4E-BP1 levels, while promoting the expression/stability of PTEN. Since PTEN controls input into the PI3K/AKT/mTOR pathway, antiproliferative effects can be attributed to PTEN-mediated tumor suppression. Collectively, these results suggest that BIDs exert antitumor activity in CRC by impairing PI3K/AKT/mTOR signaling. Against a small kinase panel, 7g exhibited low affinity at 5 µM suggesting anticancer properties likely stem through a non-kinase mechanism. Because of the novelty of BIDs, the structure can serve as a lead scaffold to design new CRC therapies. Copyright © 2018. Published by Elsevier Ltd.

  19. Arctigenin, a natural lignan compound, induces G0/G1 cell cycle arrest and apoptosis in human glioma cells.

    Science.gov (United States)

    Maimaitili, Aisha; Shu, Zunhua; Cheng, Xiaojiang; Kaheerman, Kadeer; Sikandeer, Alifu; Li, Weimin

    2017-02-01

    The aim of the current study was to investigate the anticancer potential of arctigenin, a natural lignan compound, in malignant gliomas. The U87MG and T98G human glioma cell lines were treated with various concentrations of arctigenin for 48 h and the effects of arctigenin on the aggressive phenotypes of glioma cells were assessed. The results demonstrated that arctigenin dose-dependently inhibited the growth of U87MG and T98G cells, as determined using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide and bromodeoxyuridine incorporation assays. Arctigenin exposure also induced a 60-75% reduction in colony formation compared with vehicle-treated control cells. However, arctigenin was not observed to affect the invasiveness of glioma cells. Arctigenin significantly increased the proportion of cells in the G 0 /G 1 phase and reduced the number of cells in the S phase, as compared with the control group (Parctigenin increased the expression levels of p21, retinoblastoma and p53 proteins, and significantly decreased the expression levels of cyclin D1 and cyclin-dependent kinase 4 proteins. Additionally, arctigenin was able to induce apoptosis in glioma cells, coupled with increased expression levels of cleaved caspase-3 and the pro-apoptotic BCL2-associated X protein. Furthermore, arctigenin-induced apoptosis was significantly suppressed by the pretreatment of cells with Z-DEVD-FMK, a caspase-3 inhibitor. In conclusion, the results suggest that arctigenin is able to inhibit cell proliferation and may induce apoptosis and cell cycle arrest at the G 0 /G 1 phase in glioma cells. These results warrant further investigation of the anticancer effects of arctigenin in animal models of gliomas.

  20. The Brazilian business and growth cycles

    Directory of Open Access Journals (Sweden)

    Chauvet Marcelle

    2002-01-01

    Full Text Available This paper uses several produceres to date and analyse the Brazilian business and growth cycles. In particular, a Markov switching model is fitted to quarterly and annual real production data. The smoothed probabilities of the Markov states are used as predictive rules to define different phases of cyclical fluctuations of real Brazilian production. The results are compared with different non-parametric rules. All methods implemented yield similar dating and reveal asymmetries across the different states of the Brazilian business and growth cycles, in which slowdowns and recessions are short and abrupt, while high growth phases and expansions are longer and less steep. The resulting dating of the Brazilian economic cycles can be used as a reference point for construction and evaluation of the predictive performance of coincident, leading, or lagging indicators of economic activity. In addition, the filtered probabilities obtained from the Markov switching model allow early recognition of the transition to a new business cycle phase, wich can be used, for example, for evaluation of the adequate strength and timing of countercyclical policies, for reassessment of projected sales or profits by businesses and investors, or for monitoring of inflation pressures.

  1. Silica Nanoparticles Sensitize Human Multiple Myeloma Cells to Snake (Walterinnesia aegyptia Venom-Induced Apoptosis and Growth Arrest

    Directory of Open Access Journals (Sweden)

    Douaa Sayed

    2012-01-01

    Full Text Available Background. Multiple myeloma (MM, an almost incurable disease, is the second most common blood cancer. Initial chemotherapeutic treatment could be successful; however, resistance development urges the use of higher toxic doses accompanied by hematopoietic stem cell transplantation. The establishment of more effective treatments that can overcome or circumvent chemoresistance has become a priority. We recently demonstrated that venom extracted from Walterinnesia aegyptia (WEV either alone or in combination with silica nanoparticles (WEV+NPs mediated the growth arrest and apoptosis of prostate cancer cells. In the present study, we evaluated the impact of WEV alone and WEV+NP on proliferation and apoptosis of MM cells. Methods. The impacts of WEV alone and WEV+NP were monitored in MM cells from 70 diagnosed patients. The influences of WEV and WEV+NP were assessed with flow cytometry analysis. Results. WEV alone and WEV+NP decreased the viability of MM cells. Using a CFSE proliferation assay, we found that WEV+NP strongly inhibited MM cell proliferation. Furthermore, analysis of the cell cycle using the propidium iodide (PI staining method indicated that WEV+NP strongly altered the cell cycle of MM cells and enhanced the induction of apoptosis. Conclusions. Our data reveal the biological effects of WEV and WEV+NP on MM cells that enable these compounds to function as effective treatments for MM.

  2. Vitamin E δ-tocotrienol induces p27(Kip1-dependent cell-cycle arrest in pancreatic cancer cells via an E2F-1-dependent mechanism.

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    Pamela J Hodul

    Full Text Available Vitamin E δ-tocotrienol has been shown to have antitumor activity, but the precise molecular mechanism by which it inhibits the proliferation of cancer cells remains unclear. Here, we demonstrated that δ-tocotrienol exerted significant cell growth inhibition pancreatic ductal cancer (PDCA cells without affecting normal human pancreatic ductal epithelial cell growth. We also showed that δ-tocotrienol-induced growth inhibition occurred concomitantly with G(1 cell-cycle arrest and increased p27(Kip1 nuclear accumulation. This finding is significant considering that loss of nuclear p27(Kip1 expression is a well-established adverse prognostic factor in PDCA. Furthermore, δ-tocotrienol inactivated RAF-MEK-ERK signaling, a pathway known to suppress p27(Kip1 expression. To determine whether p27(Kip1 induction is required for δ-tocotrienol inhibition of PDCA cell proliferation, we stably silenced the CDKN1B gene, encoding p27(Kip1, in MIAPaCa-2 PDCA cells and demonstrated that p27(Kip1 silencing suppressed cell-cycle arrest induced by δ-tocotrienol. Furthermore, δ-tocotrienol induced p27(Kip1 mRNA expression but not its protein degradation. p27(Kip1 gene promoter activity was induced by δ-tocotrienol through the promoter's E2F-1 binding site, and this activity was attenuated by E2F-1 depletion using E2F-1 small interfering RNA. Finally, decreased proliferation, mediated by Ki67 and p27(Kip1 expression by δ-tocotrienol, was confirmed in vivo in a nude mouse xenograft pancreatic cancer model. Our findings reveal a new mechanism, dependent on p27(Kip1 induction, by which δ-tocotrienol can inhibit proliferation in PDCA cells, providing a new rationale for p27(Kip1 as a biomarker for δ-tocotrienol efficacy in pancreatic cancer prevention and therapy.

  3. Oridonin nanosuspension was more effective than free oridonin on G2/M cell cycle arrest and apoptosis in the human pancreatic cancer PANC-1 cell line

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    Qi XL

    2012-04-01

    Full Text Available Xiaoli Qi1, Dianrui Zhang2, Xia Xu1, Feifei Feng2, Guijie Ren1, Qianqian Chu1, Qiang Zhang3, Keli Tian11Department of Biochemistry and Molecular Biology, Shandong University School of Medicine, Jinan, 2Department of Pharmaceutics, College of Pharmacy, Shandong University, Jinan, 3State Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences, Peking University, Beijing, People's Republic of ChinaAbstract: Oridonin, a diterpenoid isolated from Rabdosia rubescencs, has been reported to have antitumor effects. However, low solubility has limited its clinical applications. Preparation of drugs in the form of nanosuspensions is an extensively utilized protocol. In this study, we investigated the anticancer activity of oridonin and oridonin nanosuspension on human pancreatic carcinoma PANC-1 cells. 3-(4,5-dimethylthiazol-2-yl-2,5-diphenyltetrazolium bromide assay was performed to investigate the effect of oridonin on cell growth. Propidium iodide and Hoechst 33342 staining were used to detect morphologic changes. The percentage of apoptosis and cell cycle progression was determined by flow cytometric method staining with propidium iodide. Annexin V-fluorescein isothiocyanate (FITC/PI staining was used to evaluate cell apoptosis by flow cytometry. Caspase-3 activity was measured by spectrophotometry. The apoptotic and cell cycle protein expression were determined by Western blot analysis. Both oridonin and oridonin nanosuspension induced apoptosis and G2/M phase cell cycle arrest, and the latter had a more significant cytotoxic effect. The ratio of Bcl-2/Bax protein expression was decreased and caspase-3 activity was stimulated. The expression of cyclin B1 and p-cdc2 (T161 was suppressed. Our results showed that oridonin nanosuspension was more effective than free oridonin on G2/M cell cycle arrest and apoptosis in the human pancreatic cancer PANC-1 cell line.Keywords: cyclin B1, cdc2, caspase-3, Bcl-2, Bax

  4. Microvesicles derived from human Wharton's Jelly mesenchymal stem cells ameliorate ischemia-reperfusion-induced renal fibrosis by releasing from G2/M cell cycle arrest.

    Science.gov (United States)

    Chen, Wenxia; Yan, Yongbin; Song, Chundong; Ding, Ying; Du, Tao

    2017-12-14

    Studies have demonstrated that microvesicles (MVs) derived from human Wharton's Jelly mesenchymal stromal cells (hWJMSCs) could ameliorate renal ischemia/reperfusion injury (IRI); however, the underlying mechanisms were not clear yet. Here, MVs were isolated and injected intravenously into rats immediately after ischemia of the left kidney, and Erk1/2 activator hepatocyte growth factor (HGF) or inhibitor U0126 was administrated. Tubular cell proliferation and apoptosis were identified by Ki67 or terminal-deoxynucleotidyl transferase-mediated nick end labeling immunostaining. Masson's tri-chrome straining and alpha-smooth muscle actin staining were used for assessing renal fibrosis. The mRNA or protein expression in the kidney was measured by quantitative reverse transcription-PCR or Western blot, respectively. The total collagen concentration was also determined. In vitro , NRK-52E cells that treated with MVs under hypoxia injury and with HGF or U0126 administration were used, and cell cycle analysis was performed. The effects of hWJMSC-MVs on enhancing the proliferation and mitigating the apoptosis of renal cells, abrogating IRI-induced fibrosis, improving renal function, decreasing collagen deposition, and altering the expression levels of epithelial-mesenchymal transition and cell cycle-related proteins in IRI rats were found. In vitro experiment showed that hWJMSC-MVs could induce G2/M cell cycle arrest and decrease the expression of collagen deposition-related proteins in NRK-52E cells after 24 or 48 h. However, U0126 treatment reversed these effects. In conclusion, MVs derived from hWJMSCs ameliorate IR-induced renal fibrosis by inducing G2/M cell cycle arrest via Erk1/2 signaling. © 2017 The Author(s). Published by Portland Press Limited on behalf of the Biochemical Society.

  5. RBP-J-interacting and tubulin-associated protein induces apoptosis and cell cycle arrest in human hepatocellular carcinoma by activating the p53–Fbxw7 pathway

    International Nuclear Information System (INIS)

    Wang, Haihe; Yang, Zhanchun; Liu, Chunbo; Huang, Shishun; Wang, Hongzhi; Chen, Yingli; Chen, Guofu

    2014-01-01

    Highlights: • RITA overexpression increased protein expression of p53 and Fbxw7 and downregulated the expression of cyclin D1, cyclin E, CDK2, Hes-1 and NF-κB p65. • RITA can significantly inhibit the in vitro growth of SMMC7721 and HepG2 cells. • RITA exerts tumor-suppressive effects in hepatocarcinogenesis through induction of G0/G1 cell cycle arrest and apoptosis and suggest a therapeutic application of RITA in HCC. - Abstract: Aberrant Notch signaling is observed in human hepatocellular carcinoma (HCC) and has been associated with the modulation of cell growth. However, the role of Notch signaling in HCC and its underlying mechanism remain elusive. RBP-J-interacting and tubulin-associated (RITA) mediates the nuclear export of RBP-J to tubulin fibers and downregulates Notch-mediated transcription. In this study, we found that RITA overexpression increased protein expression of p53 and Fbxw7 and downregulated the expression of cyclin D1, cyclin E, CDK2, Hes-1 and NF-κB p65. These changes led to growth inhibition and induced G0/G1 cell cycle arrest and apoptosis in SMMC7721 and HepG2 cells. Our findings indicate that RITA exerts tumor-suppressive effects in hepatocarcinogenesis through induction of G0/G1 cell cycle arrest and apoptosis and suggest a therapeutic application of RITA in HCC

  6. The inhibition of polo kinase by matrimony maintains G2 arrest in the meiotic cell cycle.

    Directory of Open Access Journals (Sweden)

    Youbin Xiang

    2007-12-01

    Full Text Available Many meiotic systems in female animals include a lengthy arrest in G2 that separates the end of pachytene from nuclear envelope breakdown (NEB. However, the mechanisms by which a meiotic cell can arrest for long periods of time (decades in human females have remained a mystery. The Drosophila Matrimony (Mtrm protein is expressed from the end of pachytene until the completion of meiosis I. Loss-of-function mtrm mutants result in precocious NEB. Coimmunoprecipitation experiments reveal that Mtrm physically interacts with Polo kinase (Polo in vivo, and multidimensional protein identification technology mass spectrometry analysis reveals that Mtrm binds to Polo with an approximate stoichiometry of 1:1. Mutation of a Polo-Box Domain (PBD binding site in Mtrm ablates the function of Mtrm and the physical interaction of Mtrm with Polo. The meiotic defects observed in mtrm/+ heterozygotes are fully suppressed by reducing the dose of polo+, demonstrating that Mtrm acts as an inhibitor of Polo. Mtrm acts as a negative regulator of Polo during the later stages of G2 arrest. Indeed, both the repression of Polo expression until stage 11 and the inactivation of newly synthesized Polo by Mtrm until stage 13 play critical roles in maintaining and properly terminating G2 arrest. Our data suggest a model in which the eventual activation of Cdc25 by an excess of Polo at stage 13 triggers NEB and entry into prometaphase.

  7. Studies with GFP-Vpr fusion proteins: induction of apoptosis but ablation of cell-cycle arrest despite nuclear membrane or nuclear localization

    International Nuclear Information System (INIS)

    Waldhuber, Megan G.; Bateson, Michael; Tan, Judith; Greenway, Alison L.; McPhee, Dale A.

    2003-01-01

    The human immunodeficiency virus type 1 (HIV-1) Vpr protein is known to arrest the cell cycle in G 2 /M and induce apoptosis following arrest. The functions of Vpr relative to its location in the cell remain unresolved. We now demonstrate that the location and function of Vpr are dependent on the makeup of fusion proteins and that the functions of G 2 /M arrest and apoptosis are separable. Using green fluorescence protein mutants (EGFP or EYFP), we found that fusion at either the N- or C-terminus compromised the ability of Vpr to arrest cell cycling, relative to that of His-Vpr or wild-type protein. Additionally, utilizing the ability to specifically identify cells expressing the fusion proteins, we confirm that Vpr can induce apoptosis, but appears to be independent of cell-cycle arrest in G 2 /M. Both N- and C-terminal Vpr/EYFP fusion proteins induced apoptosis but caused minimal G 2 /M arrest. These studies with Vpr fusion proteins indicate that the functions of Vpr leading to G 2 /M arrest and apoptosis are separable and that fusion of Vpr to EGFP or EYFP affected the localization of the protein. Our findings suggest that nuclear membrane localization and nuclear import and export are strongly governed by modification of the N-terminus of Vpr

  8. Activation of PPARγ mediates icaritin-induced cell cycle arrest and apoptosis in glioblastoma multiforme.

    Science.gov (United States)

    Liu, Yongji; Shi, Ling; Liu, Yuan; Li, Peng; Jiang, Guoping; Gao, Xiaoning; Zhang, Yongbin; Jiang, Chuanwu; Zhu, Weiping; Han, Hongxing; Ju, Fang

    2018-04-01

    Glioblastoma multiforme (GBM) is the most prevalent primary malignancy of the brain. This study was designed to investigate whether icaritin exerts anti-neoplastic activity against GBM in vitro. Cell Counting Kit-8 (CCK-8) assay was utilized to examine the viability of GBM cells. The apoptotic cell population was measured by flow cytometry analysis. Cell cycle distribution was detected by flow cytometry as well. Western blot analysis was performed to examine the level of biomarker proteins in GBM cells. Levels of PPARγ mRNA and protein were detected by qPCR and western blot analysis, respectively. To examine the role of PPARγ in the anti-neoplastic activity of icaritin, PPARγ antagonist GW9662 or PPARγ siRNA was used. The activity of PPARγ was determined by DNA binding and luciferase assays. Our findings revealed that icaritin markedly suppresses cell growth in a dose-dependent and time-dependent fashion. The cell population at the G0/G1 phase of the cell cycle was significantly increased following icaritin treatment. Meanwhile, icaritin promoted apoptotic cell death in T98G and U87MG cells. Further investigation showed upregulation of PPARγ played a key role in the anti-neoplastic activities of icaritin. Moreover, our result demonstrated activation of AMPK signaling by icaritin mediated the modulatory effect of icaritin on PPARγ. Our results suggest the PPARγ may mediate anti-neoplastic activities against GBM. Copyright © 2018 Elsevier Masson SAS. All rights reserved.

  9. Inhibitory effect of turmeric curcuminoids on FLT3 expression and cell cycle arrest in the FLT3-overexpressing EoL-1 leukemic cell line.

    Science.gov (United States)

    Tima, Singkome; Ichikawa, Hideki; Ampasavate, Chadarat; Okonogi, Siriporn; Anuchapreeda, Songyot

    2014-04-25

    Leukemia is a hematologic malignancy with a frequent incidence and high mortality rate. Previous studies have shown that the FLT3 gene is overexpressed in leukemic blast cells, especially in acute myeloid leukemia. In this study, a commercially available curcuminoid mixture (1), pure curcumin (2), pure demethoxycurcumin (3), and pure bisdemethoxycurcumin (4) were investigated for their inhibitory effects on cell growth, FLT3 expression, and cell cycle progression in an FLT3-overexpressing EoL-1 leukemic cell line using an MTT assay, Western blotting, and flow cytometry, respectively. The mixture (1) and compounds 2-4 demonstrated cytotoxic effects with IC50 values ranging from 6.5 to 22.5 μM. A significant decrease in FLT3 protein levels was found after curcuminoid treatment with IC20 doses, especially with mixture 1 and compound 2. In addition, mixture 1 and curcumin (2) showed activity on cell cycle arrest at the G0/G1 phase and decreased the FLT3 and STAT5A protein levels in a dose-dependent manner. Compound 2 demonstrated the greatest potential for inhibiting cell growth, cell cycle progression, and FLT3 expression in EoL-1 cells. This investigation has provided new findings regarding the effect of turmeric curcuminoids on FLT3 expression in leukemic cells.

  10. Boron neutron capture therapy induces cell cycle arrest and cell apoptosis of glioma stem/progenitor cells in vitro

    International Nuclear Information System (INIS)

    Sun, Ting; Zhang, Zizhu; Li, Bin; Chen, Guilin; Xie, Xueshun; Wei, Yongxin; Wu, Jie; Zhou, Youxin; Du, Ziwei

    2013-01-01

    Glioma stem cells in the quiescent state are resistant to clinical radiation therapy. An almost inevitable glioma recurrence is due to the persistence of these cells. The high linear energy transfer associated with boron neutron capture therapy (BNCT) could kill quiescent and proliferative cells. The present study aimed to evaluate the effects of BNCT on glioma stem/progenitor cells in vitro. The damage induced by BNCT was assessed using cell cycle progression, apoptotic cell ratio and apoptosis-associated proteins expression. The surviving fraction and cell viability of glioma stem/progenitor cells were decreased compared with differentiated glioma cells using the same boronophenylalanine pretreatment and the same dose of neutron flux. BNCT induced cell cycle arrest in the G2/M phase and cell apoptosis via the mitochondrial pathway, with changes in the expression of associated proteins. Glioma stem/progenitor cells, which are resistant to current clinical radiotherapy, could be effectively killed by BNCT in vitro via cell cycle arrest and apoptosis using a prolonged neutron irradiation, although radiosensitivity of glioma stem/progenitor cells was decreased compared with differentiated glioma cells when using the same dose of thermal neutron exposure and boronophenylalanine pretreatment. Thus, BNCT could offer an appreciable therapeutic advantage to prevent tumor recurrence, and may become a promising treatment in recurrent glioma

  11. Investigation Analysis of Crack Growth Arresting with Fasteners in Hybrid Laminated Skin-Stiffener Joint

    Science.gov (United States)

    Jeevan Kumar, N.; Ramesh Babu, P.

    2018-02-01

    In recent years carbon fibre-reinforced polymers (CFRP) emerged its increasing demand in aerospace engineering. Due to their high specific strength to weight ratio, these composites offer more characteristics and considerable advantages compared to metals. Metals, unlike composites, offer plasticity effects to evade high stress concentrations during postbuckling. Under compressive load, composite structures show a wide range of damage mechanisms where a set of damage modes combined together might lead to the eventual structural collapse. Crack is one of the most critical damages in fiber composites, which are being employed in primary aircraft structures. A parametric study is conducted to investigate the arrest mechanism of the delamination or crack growth with installation of multiple fasteners when the delamination is embedded in between the skin and stiffener interface.

  12. The transcriptional network that controls growth arrest and differentiation in a human myeloid leukemia cell line

    DEFF Research Database (Denmark)

    Suzuki, Harukazu; Forrest, Alistair R R; van Nimwegen, Erik

    2009-01-01

    , we identified the key transcription regulators, their time-dependent activities and target genes. Systematic siRNA knockdown of 52 transcription factors confirmed the roles of individual factors in the regulatory network. Our results indicate that cellular states are constrained by complex networks......Using deep sequencing (deepCAGE), the FANTOM4 study measured the genome-wide dynamics of transcription-start-site usage in the human monocytic cell line THP-1 throughout a time course of growth arrest and differentiation. Modeling the expression dynamics in terms of predicted cis-regulatory sites...... involving both positive and negative regulatory interactions among substantial numbers of transcription factors and that no single transcription factor is both necessary and sufficient to drive the differentiation process....

  13. Kefir induces cell-cycle arrest and apoptosis in HTLV-1-negative malignant T-lymphocytes

    Science.gov (United States)

    Maalouf, Katia; Baydoun, Elias; Rizk, Sandra

    2011-01-01

    Background: Adult lymphoblastic leukemia (ALL) is a malignancy that occurs in white blood cells. The overall cure rate in children is 85%, whereas it is only 40% in adults. Kefir is an important probiotic that contains many bioactive ingredients, which give it unique health benefits. It has been shown to control several cellular types of cancer. Purpose: The present study investigates the effect of a cell-free fraction of kefir on CEM and Jurkat cells, which are human T-lymphotropic virus type I (HTLV-1)-negative malignant T-lymphocytes. Methods: Cells were incubated with different kefir concentrations. The cytotoxicity of the compound was evaluated by determining the percentage viability of cells. The effect of all the noncytotoxic concentrations of kefir on the proliferation of CEM and Jurkat cells was then assessed. The levels of transforming growth factor-alpha (TGF-α), transforming growth factor- beta1 (TGF-β1), matrix metalloproteinase-2 (MMP-2), and MMP-9 mRNA upon kefir treatment were then analyzed using reverse transcriptase polymerase chain reaction (RT-PCR). Finally, the growth inhibitory effects of kefir on cell-cycle progression/apoptosis were assessed by Cell Death Detection (ELISA) and flow cytometry. Results: The maximum cytotoxicity recorded after 48-hours treatment with 80 μg/μL kefir was only 42% and 39% in CEM and Jurkat cells, respectively. The percent reduction in proliferation was very significant, and was dose-, and time-dependent. In both cell lines, kefir exhibited its antiproliferative effect by downregulating TGF-α and upregulating TGF-β1 mRNA expression. Upon kefir treatment, a marked increase in cell-cycle distribution was noted in the preG1 phase of CEM and Jurkat cells, indicating the proapoptotic effect of kefir, which was further confirmed by Cell Death Detection ELISA. However, kefir did not affect the mRNA expression of metalloproteinases needed for the invasion of leukemic cell lines. Conclusion: In conclusion, kefir is

  14. Kefir induces cell-cycle arrest and apoptosis in HTLV-1-negative malignant T-lymphocytes

    Directory of Open Access Journals (Sweden)

    Katia Maalouf

    2011-02-01

    Full Text Available Katia Maalouf1, Elias Baydoun2, Sandra Rizk11Department of Natural Sciences, Lebanese American University, Beirut, Lebanon; 2Department of Biology, American University of Beirut, Beirut, LebanonBackground: Adult lymphoblastic leukemia (ALL is a malignancy that occurs in white blood cells. The overall cure rate in children is 85%, whereas it is only 40% in adults. Kefir is an important probiotic that contains many bioactive ingredients, which give it unique health benefits. It has been shown to control several cellular types of cancer.Purpose: The present study investigates the effect of a cell-free fraction of kefir on CEM and Jurkat cells, which are human T-lymphotropic virus type I (HTLV-1-negative malignant T-lymphocytes.Methods: Cells were incubated with different kefir concentrations. The cytotoxicity of the compound was evaluated by determining the percentage viability of cells. The effect of all the noncytotoxic concentrations of kefir on the proliferation of CEM and Jurkat cells was then assessed. The levels of transforming growth factor-alpha (TGF-α, transforming growth factor- beta1 (TGF-β1, matrix metalloproteinase-2 (MMP-2, and MMP-9 mRNA upon kefir treatment were then analyzed using reverse transcriptase polymerase chain reaction (RT-PCR. Finally, the growth inhibitory effects of kefir on cell-cycle progression/apoptosis were assessed by Cell Death Detection (ELISA and flow cytometry.Results: The maximum cytotoxicity recorded after 48-hours treatment with 80 µg/µL kefir was only 42% and 39% in CEM and Jurkat cells, respectively. The percent reduction in proliferation was very significant, and was dose-, and time-dependent. In both cell lines, kefir exhibited its antiproliferative effect by downregulating TGF-α and upregulating TGF- β1 mRNA expression. Upon kefir treatment, a marked increase in cell-cycle distribution was noted in the preG1 phase of CEM and Jurkat cells, indicating the proapoptotic effect of kefir, which was

  15. Kefir induces cell-cycle arrest and apoptosis in HTLV-1-negative malignant T-lymphocytes

    International Nuclear Information System (INIS)

    Maalouf, Katia; Baydoun, Elias; Rizk, Sandra

    2011-01-01

    Adult lymphoblastic leukemia (ALL) is a malignancy that occurs in white blood cells. The overall cure rate in children is 85%, whereas it is only 40% in adults. Kefir is an important probiotic that contains many bioactive ingredients, which give it unique health benefits. It has been shown to control several cellular types of cancer. The present study investigates the effect of a cell-free fraction of kefir on CEM and Jurkat cells, which are human T-lymphotropic virus type I (HTLV-1)-negative malignant T-lymphocytes. Cells were incubated with different kefir concentrations. The cytotoxicity of the compound was evaluated by determining the percentage viability of cells. The effect of all the noncytotoxic concentrations of kefir on the proliferation of CEM and Jurkat cells was then assessed. The levels of transforming growth factor-alpha (TGF-α), transforming growth factor- beta1 (TGF-β1), matrix metalloproteinase-2 (MMP-2), and MMP-9 mRNA upon kefir treatment were then analyzed using reverse transcriptase polymerase chain reaction (RT-PCR). Finally, the growth inhibitory effects of kefir on cell-cycle progression/apoptosis were assessed by Cell Death Detection (ELISA) and flow cytometry. The maximum cytotoxicity recorded after 48-hours treatment with 80 μg/μL kefir was only 42% and 39% in CEM and Jurkat cells, respectively. The percent reduction in proliferation was very significant, and was dose-, and time-dependent. In both cell lines, kefir exhibited its antiproliferative effect by downregulating TGF-α and upregulating TGF-β1 mRNA expression. Upon kefir treatment, a marked increase in cell-cycle distribution was noted in the preG 1 phase of CEM and Jurkat cells, indicating the proapoptotic effect of kefir, which was further confirmed by Cell Death Detection ELISA. However, kefir did not affect the mRNA expression of metalloproteinases needed for the invasion of leukemic cell lines. In conclusion, kefir is effective in inhibiting proliferation and inducing

  16. Selective cerebral perfusion prevents abnormalities in glutamate cycling and neuronal apoptosis in a model of infant deep hypothermic circulatory arrest and reperfusion.

    Science.gov (United States)

    Kajimoto, Masaki; Ledee, Dolena R; Olson, Aaron K; Isern, Nancy G; Robillard-Frayne, Isabelle; Des Rosiers, Christine; Portman, Michael A

    2016-11-01

    Deep hypothermic circulatory arrest is often required for the repair of complex congenital cardiac defects in infants. However, deep hypothermic circulatory arrest induces neuroapoptosis associated with later development of neurocognitive abnormalities. Selective cerebral perfusion theoretically provides superior neural protection possibly through modifications in cerebral substrate oxidation and closely integrated glutamate cycling. We tested the hypothesis that selective cerebral perfusion modulates glucose utilization, and ameliorates abnormalities in glutamate flux, which occur in association with neuroapoptosis during deep hypothermic circulatory arrest. Eighteen infant male Yorkshire piglets were assigned randomly to two groups of seven (deep hypothermic circulatory arrest or deep hypothermic circulatory arrest with selective cerebral perfusion for 60 minutes at 18℃) and four control pigs without cardiopulmonary bypass support. Carbon-13-labeled glucose as a metabolic tracer was infused, and gas chromatography-mass spectrometry and nuclear magnetic resonance were used for metabolic analysis in the frontal cortex. Following 2.5 h of cerebral reperfusion, we observed similar cerebral adenosine triphosphate levels, absolute levels of lactate and citric acid cycle intermediates, and carbon-13 enrichment among three groups. However, deep hypothermic circulatory arrest induced significant abnormalities in glutamate cycling resulting in reduced glutamate/glutamine and elevated γ-aminobutyric acid/glutamate along with neuroapoptosis, which were all prevented by selective cerebral perfusion. The data suggest that selective cerebral perfusion prevents these modifications in glutamate/glutamine/γ-aminobutyric acid cycling and protects the cerebral cortex from apoptosis. © The Author(s) 2016.

  17. Arecoline-induced growth arrest and p21WAF1 expression are dependent on p53 in rat hepatocytes

    International Nuclear Information System (INIS)

    Chou, W.-W.; Guh, J.-Y.; Tsai, J.-F.; Hwang, C.-C.; Chen, H.-C.; Huang, J.-S.; Yang, Y.-L.; Hung, W.-C.; Chuang, L.-Y.

    2008-01-01

    Betel-quid use is associated with the risk of liver cirrhosis and hepatocellular carcinoma and arecoline, the major alkaloid of betel-quid, is hepatotoxic in mice. Therefore, we studied the cytotoxic and genotoxic effects of arecoline in normal rat hepatocytes (Clone-9 cells). Arecoline dose-dependently (0.1-1 mM) decreased cell cycle-dependent proliferation while inducing DNA damage at 24 h. Moreover, arecoline (1 mM)-induced apoptosis and necrosis at 24 h. Arecoline dose-dependently (0.1-0.5 mM) increased transforming growth factor-β (TGF-β) mRNA, gene transcription and bioactivity and neutralizing TGF-β antibody attenuated arecoline (0.5 mM)-inhibited cell proliferation at 24 h. Arecoline (0.5 mM) also increased p21 WAF1 protein expression and p21 WAF1 gene transcription. Moreover, arecoline (0.5 mM) time-dependently (8-24 h) increased p53 serine 15 phosphorylation. Pifithrin-α (p53 inhibitor) and the loss of the two p53-binding elements in the p21 WAF1 gene promoter attenuated arecoline-induced p21 WAF1 gene transcription at 24 h. Pifithrin-α also attenuated arecoline (0.5 mM)-inhibited cell proliferation at 24 h. We concluded that arecoline induces cytotoxicity, DNA damage, G 0 /G 1 cell cycle arrest, TGF-β1, p21 WAF1 and activates p53 in Clone-9 cells. Moreover, arecoline-induced p21 WAF1 is dependent on p53 while arecoline-inhibited growth is dependent on both TGF-β and p53

  18. Curcumin analog WZ35 induced cell death via ROS-dependent ER stress and G2/M cell cycle arrest in human prostate cancer cells

    International Nuclear Information System (INIS)

    Zhang, Xiuhua; Chen, Minxiao; Zou, Peng; Kanchana, Karvannan; Weng, Qiaoyou; Chen, Wenbo; Zhong, Peng; Ji, Jiansong; Zhou, Huiping; He, Langchong; Liang, Guang

    2015-01-01

    Prostate cancer is the most commonly diagnosed malignancy among men. The Discovery of new agents for the treatment of prostate cancer is urgently needed. Compound WZ35, a novel analog of the natural product curcumin, exhibited good anti-prostate cancer activity, with an IC 50 of 2.2 μM in PC-3 cells. However, the underlying mechanism of WZ35 against prostate cancer cells is still unclear. Human prostate cancer PC-3 cells and DU145 cells were treated with WZ35 for further proliferation, apoptosis, cell cycle, and mechanism analyses. NAC and CHOP siRNA were used to validate the role of ROS and ER stress, respectively, in the anti-cancer actions of WZ35. Our results show that WZ35 exhibited much higher cell growth inhibition than curcumin by inducing ER stress-dependent cell apoptosis in human prostate cells. The reduction of CHOP expression by siRNA partially abrogated WZ35-induced cell apoptosis. WZ35 also dose-dependently induced cell cycle arrest in the G2/M phase. Furthermore, we found that WZ35 treatment for 30 min significantly induced reactive oxygen species (ROS) production in PC-3 cells. Co-treatment with the ROS scavenger NAC completely abrogated the induction of WZ35 on cell apoptosis, ER stress activation, and cell cycle arrest, indicating an upstream role of ROS generation in mediating the anti-cancer effect of WZ35. Taken together, this work presents the novel anticancer candidate WZ35 for the treatment of prostate cancer, and importantly, reveals that increased ROS generation might be an effective strategy in human prostate cancer treatment. The online version of this article (doi:10.1186/s12885-015-1851-3) contains supplementary material, which is available to authorized users

  19. Anaphase-promoting complex/cyclosome protein Cdc27 is a target for curcumin-induced cell cycle arrest and apoptosis

    Science.gov (United States)

    2012-01-01

    Background Curcumin (diferuloylmethane), the yellow pigment in the Asian spice turmeric, is a hydrophobic polyphenol from the rhizome of Curcuma longa. Because of its chemopreventive and chemotherapeutic potential with no discernable side effects, it has become one of the major natural agents being developed for cancer therapy. Accumulating evidence suggests that curcumin induces cell death through activation of apoptotic pathways and inhibition of cell growth and proliferation. The mitotic checkpoint, or spindle assembly checkpoint (SAC), is the major cell cycle control mechanism to delay the onset of anaphase during mitosis. One of the key regulators of the SAC is the anaphase promoting complex/cyclosome (APC/C) which ubiquitinates cyclin B and securin and targets them for proteolysis. Because APC/C not only ensures cell cycle arrest upon spindle disruption but also promotes cell death in response to prolonged mitotic arrest, it has become an attractive drug target in cancer therapy. Methods Cell cycle profiles were determined in control and curcumin-treated medulloblastoma and various other cancer cell lines. Pull-down assays were used to confirm curcumin binding. APC/C activity was determined using an in vitro APC activity assay. Results We identified Cdc27/APC3, a component of the APC/C, as a novel molecular target of curcumin and showed that curcumin binds to and crosslinks Cdc27 to affect APC/C function. We further provide evidence that curcumin preferably induces apoptosis in cells expressing phosphorylated Cdc27 usually found in highly proliferating cells. Conclusions We report that curcumin directly targets the SAC to induce apoptosis preferably in cells with high levels of phosphorylated Cdc27. Our studies provide a possible molecular mechanism why curcumin induces apoptosis preferentially in cancer cells and suggest that phosphorylation of Cdc27 could be used as a biomarker to predict the therapeutic response of cancer cells to curcumin. PMID:22280307

  20. Anaphase-promoting complex/cyclosome protein Cdc27 is a target for curcumin-induced cell cycle arrest and apoptosis

    International Nuclear Information System (INIS)

    Lee, Seung Joon; Langhans, Sigrid A

    2012-01-01

    Curcumin (diferuloylmethane), the yellow pigment in the Asian spice turmeric, is a hydrophobic polyphenol from the rhizome of Curcuma longa. Because of its chemopreventive and chemotherapeutic potential with no discernable side effects, it has become one of the major natural agents being developed for cancer therapy. Accumulating evidence suggests that curcumin induces cell death through activation of apoptotic pathways and inhibition of cell growth and proliferation. The mitotic checkpoint, or spindle assembly checkpoint (SAC), is the major cell cycle control mechanism to delay the onset of anaphase during mitosis. One of the key regulators of the SAC is the anaphase promoting complex/cyclosome (APC/C) which ubiquitinates cyclin B and securin and targets them for proteolysis. Because APC/C not only ensures cell cycle arrest upon spindle disruption but also promotes cell death in response to prolonged mitotic arrest, it has become an attractive drug target in cancer therapy. Cell cycle profiles were determined in control and curcumin-treated medulloblastoma and various other cancer cell lines. Pull-down assays were used to confirm curcumin binding. APC/C activity was determined using an in vitro APC activity assay. We identified Cdc27/APC3, a component of the APC/C, as a novel molecular target of curcumin and showed that curcumin binds to and crosslinks Cdc27 to affect APC/C function. We further provide evidence that curcumin preferably induces apoptosis in cells expressing phosphorylated Cdc27 usually found in highly proliferating cells. We report that curcumin directly targets the SAC to induce apoptosis preferably in cells with high levels of phosphorylated Cdc27. Our studies provide a possible molecular mechanism why curcumin induces apoptosis preferentially in cancer cells and suggest that phosphorylation of Cdc27 could be used as a biomarker to predict the therapeutic response of cancer cells to curcumin

  1. Anaphase-promoting complex/cyclosome protein Cdc27 is a target for curcumin-induced cell cycle arrest and apoptosis

    Directory of Open Access Journals (Sweden)

    Lee Seung Joon

    2012-01-01

    Full Text Available Abstract Background Curcumin (diferuloylmethane, the yellow pigment in the Asian spice turmeric, is a hydrophobic polyphenol from the rhizome of Curcuma longa. Because of its chemopreventive and chemotherapeutic potential with no discernable side effects, it has become one of the major natural agents being developed for cancer therapy. Accumulating evidence suggests that curcumin induces cell death through activation of apoptotic pathways and inhibition of cell growth and proliferation. The mitotic checkpoint, or spindle assembly checkpoint (SAC, is the major cell cycle control mechanism to delay the onset of anaphase during mitosis. One of the key regulators of the SAC is the anaphase promoting complex/cyclosome (APC/C which ubiquitinates cyclin B and securin and targets them for proteolysis. Because APC/C not only ensures cell cycle arrest upon spindle disruption but also promotes cell death in response to prolonged mitotic arrest, it has become an attractive drug target in cancer therapy. Methods Cell cycle profiles were determined in control and curcumin-treated medulloblastoma and various other cancer cell lines. Pull-down assays were used to confirm curcumin binding. APC/C activity was determined using an in vitro APC activity assay. Results We identified Cdc27/APC3, a component of the APC/C, as a novel molecular target of curcumin and showed that curcumin binds to and crosslinks Cdc27 to affect APC/C function. We further provide evidence that curcumin preferably induces apoptosis in cells expressing phosphorylated Cdc27 usually found in highly proliferating cells. Conclusions We report that curcumin directly targets the SAC to induce apoptosis preferably in cells with high levels of phosphorylated Cdc27. Our studies provide a possible molecular mechanism why curcumin induces apoptosis preferentially in cancer cells and suggest that phosphorylation of Cdc27 could be used as a biomarker to predict the therapeutic response of cancer cells to

  2. Recombinant Escherichia coli Trx-JZTX-III represses the proliferation of mouse hepatocellular carcinoma cells through induction of cell cycle arrest.

    Science.gov (United States)

    Sun, Mei-Na; Zhao, Xue-Jiao; Zhao, Han-Dong; Zhang, Wei-Guang; Li, Feng-Lan; Chen, Ming-Zi; Li, Hui; Li, Guangchao

    2013-06-01

    The aim of the present study was to investigate the effects of recombinant Escherichia coli (E. coli) Trx-jingzhaotoxin (JZTX)-III on cell growth in the mouse hepatocellular carcinoma (HCC) cell line Hepa1-6. The JZTX-III gene sequence was synthesized and cloned into the pET-32a(+) vector to construct the recombinant fusion protein Trx-JZTX-III, which was subsequently purified. Hepa1-6 cells were treated with 0 to 1,000-µg/ml concentrations of Trx-JZTX-III; this was demonstrated to affect cell viability, as determined by the 3-(4,5-dimethylthiazol‑2-yl)-2,5-diphenyltetra-zolium bromide (MTT) assay. The expression of the proliferating cell nuclear antigen (PCNA) protein was investigated using western blot analysis. A colony formation assay was used to determine Hepa1-6 cell proliferation, and the migration ability of cells was determined using a wound‑healing assay. Additionally, flow cytometry was employed to observe changes in the cell cycle. The MTT assay and quantification of PCNA expression indicated that recombinant E. coli Trx-JZTX-III significantly repressed the proliferation of Hepa1-6 cells. Colony formation and the migration of malignant cells was inhibited following treatment with recombinant E. coli Trx-JZTX-III. Flow cytometry showed that recombinant E. coli Trx-JZTX-III induced G0/G1 cell cycle arrest. In conclusion, recombinant E. coli Trx-JZTX-III functions as a tumor suppressor drug in mouse HCC and its underlying mechanism may involve the induction of G0/G1 cell cycle arrest.

  3. The ethanol extract of Scutellaria baicalensis and the active compounds induce cell cycle arrest and apoptosis including upregulation of p53 and Bax in human lung cancer cells

    International Nuclear Information System (INIS)

    Gao Jiayu; Morgan, Winston A.; Sanchez-Medina, Alberto; Corcoran, Olivia

    2011-01-01

    Despite a lack of scientific authentication, Scutellaria baicalensis is clinically used in Chinese medicine as a traditional adjuvant to chemotherapy of lung cancer. In this study, cytotoxicity assays demonstrated that crude ethanolic extracts of S. baicalensis were selectively toxic to human lung cancer cell lines A549, SK-LU-1 and SK-MES-1 compared with normal human lung fibroblasts. The active compounds baicalin, baicalein and wogonin did not exhibit such selectivity. Following exposure to the crude extracts, cellular protein expression in the cancer cell lines was assessed using 2D gel electrophoresis coupled with MALDI-TOF-MS/Protein Fingerprinting. The altered protein expression indicated that cell growth arrest and apoptosis were potential mechanisms of cytotoxicity. These observations were supported by PI staining cell cycle analysis using flow cytometry and Annexin-V apoptotic analysis by fluorescence microscopy of cancer cells treated with the crude extract and pure active compounds. Moreover, specific immunoblotting identification showed the decreased expression of cyclin A results in the S phase arrest of A549 whereas the G 0 /G 1 phase arrest in SK-MES-1 cells results from the decreased expression of cyclin D1. Following treatment, increased expression in the cancer cells of key proteins related to the enhancement of apoptosis was observed for p53 and Bax. These results provide further insight into the molecular mechanisms underlying the clinical use of this herb as an adjuvant to lung cancer therapy. - Research highlights: → Scutellaria baicalensis is a clinical adjuvant to lung cancer chemotherapy in China. → Scutellaria ethanol extracts selectively toxic to A549, SK-LU-1 and SK-MES-1. → Baicalin, baicalein and wogonin were toxic to all lung cancer cell lines. → Proteomics identified increased p53 and BAX in response to Scutellaria extracts.

  4. Analysis of Mode I and Mode II Crack Growth Arrest Mechanism with Z-Fibre Pins in Composite Laminated Joint

    Science.gov (United States)

    Jeevan Kumar, N.; Ramesh Babu, P.

    2018-04-01

    This paper presents the numerical study of the mode I and mode II interlaminar crack growth arrest in hybrid laminated curved composite stiffened joint with Z-fibre reinforcement. A FE model of hybrid laminated skin-stiffener joint reinforced with Z-pins is developed to investigate the effect of Z- fibre pins on mode I and mode II crack growth where the delamination is embedded inbetween the skin and stiffener interface. A finite element model was developed using S4R element of a 4-node doubly curved thick shell elements to model the composite laminates and non linear interface elements to simulate the reinforcements. The numerical analyses revealed that Z-fibre pinning were effective in suppressing the delamination growth when propagated due to applied loads. Therefore, the Z-fibre technique effectively improves the crack growth resistance and hence arrests or delays crack growth extension.

  5. The centrosome protein NEDD1 as a potential pharmacological target to induce cell cycle arrest

    Directory of Open Access Journals (Sweden)

    Etievant Chantal

    2009-02-01

    Full Text Available Abstract Background NEDD1 is a protein that binds to the gamma-tubulin ring complex, a multiprotein complex at the centrosome and at the mitotic spindle that mediates the nucleation of microtubules. Results We show that NEDD1 is expressed at comparable levels in a variety of tumor-derived cell lines and untransformed cells. We demonstrate that silencing of NEDD1 expression by treatment with siRNA has differential effects on cells, depending on their status of p53 expression: p53-positive cells arrest in G1, whereas p53-negative cells arrest in mitosis with predominantly aberrant monopolar spindles. However, both p53-positive and -negative cells arrest in mitosis if treated with low doses of siRNA against NEDD1 combined with low doses of the inhibitor BI2536 against the mitotic kinase Plk1. Simultaneous reduction of NEDD1 levels and inhibition of Plk1 act in a synergistic manner, by potentiating the anti-mitotic activity of each treatment. Conclusion We propose that NEDD1 may be a promising target for controlling cell proliferation, in particular if targeted in combination with Plk1 inhibitors.

  6. Measles virus C protein suppresses gamma-activated factor formation and virus-induced cell growth arrest

    International Nuclear Information System (INIS)

    Yokota, Shin-ichi; Okabayashi, Tamaki; Fujii, Nobuhiro

    2011-01-01

    Measles virus (MeV) produces two accessory proteins, V and C, from the P gene. These accessory proteins have been reported to contribute to efficient virus proliferation through the modulation of host cell events. Our previous paper described that Vero cell-adapted strains of MeV led host cells to growth arrest through the upregulation of interferon regulatory factor 1 (IRF-1), and wild strains did not. In the present study, we found that C protein expression levels varied among MeV strains in infected SiHa cells. C protein levels were inversely correlated with IRF-1 expression levels and with cell growth arrest. Forced expression of C protein released cells from growth arrest. C-deficient recombinant virus efficiently upregulated IRF-1 and caused growth arrest more efficiently than the wild-type virus. C protein preferentially bound to phosphorylated STAT1 and suppressed STAT1 dimer formation. We conclude that MeV C protein suppresses IFN-γ signaling pathway via inhibition of phosphorylated STAT1 dimerization.

  7. Endosulfan inhibiting the meiosis process via depressing expressions of regulatory factors and causing cell cycle arrest in spermatogenic cells.

    Science.gov (United States)

    Guo, Fang-Zi; Zhang, Lian-Shuang; Wei, Jia-Liu; Ren, Li-Hua; Zhang, Jin; Jing, Li; Yang, Man; Wang, Ji; Sun, Zhi-Wei; Zhou, Xian-Qing

    2016-10-01

    Endosulfan is a persistent organic pollutant and widely used in agriculture as a pesticide. It is present in air, water, and soil worldwide; therefore, it is a health risk affecting especially the reproductive system. The aim of this study was to evaluate the toxicity of endosulfan in the reproductive system. To investigate the effect of endosulfan on meiosis process, 32 rats were divided into four groups, treated with 0, 1, 5, and 10 mg/kg/day endosulfan, respectively, and sacrificed after the 21 days of treatments. Results show that endosulfan caused the reductions in sperm concentration and motility rate, which resulted into an increased in sperm abnormality rate; further, endosulfan induced downregulation of spermatogenesis- and oogenesis-specific basic helix-loop-helix transcription factor (Sohlh1) which controls the switch on meiosis in mammals, as well cyclin A1, cyclin-dependent kinases 1 (CDK1), and cyclin-dependent kinases 2 (CDK2). In vitro, endosulfan induced G2/M phase arrest in the spermatogenic cell cycle and caused proliferation inhibition. Moreover, endosulfan induced oxidative stress and DNA damage in vivo and vitro. The results suggested that endosulfan could inhibit the start of meiosis by downregulating the expression of Sohlh1 and induce G2/M phase arrest of cell cycle by decreasing the expression of cyclin A1, CDK1, and CDK2 via oxidative damage, which inhibits the meiosis process, and therefore decrease the amount of sperm.

  8. Calotropin from Asclepias curasavica induces cell cycle arrest and apoptosis in cisplatin-resistant lung cancer cells.

    Science.gov (United States)

    Mo, En-Pan; Zhang, Rong-Rong; Xu, Jun; Zhang, Huan; Wang, Xiao-Xiong; Tan, Qiu-Tong; Liu, Fang-Lan; Jiang, Ren-Wang; Cai, Shao-Hui

    2016-09-16

    Calotropin (M11), an active compound isolated from Asclepias curasavica L., was found to exert strong inhibitory and pro-apoptotic activity specifically against cisplatin-induced resistant non-small cell lung cancer (NSCLC) cells (A549/CDDP). Molecular mechanism study revealed that M11 induced cell cycle arrest at the G2/M phase through down-regulating cyclins, CDK1, CDK2 and up-regulating p53 and p21. Furthermore, M11 accelerated apoptosis through the mitochondrial apoptotic pathway which was accompanied by increase Bax/Bcl-2 ratio, decrease in mitochondrial membrane potential, increase in reactive oxygen species production, activations of caspases 3 and 9 as well as cleavage of poly ADP-ribose polymerase (PARP). The activation and phosphorylation of JNK was also found to be involved in M11-induced apoptosis, and SP610025 (specific JNK inhibitor) partially prevented apoptosis induced by M11. In contrast, all of the effects that M11 induce cell cycle arrest and apoptosis in A549/CDDP cells were not significant in A549 cells. Drugs with higher sensitivity against resistant tumor cells than the parent cells are rather rare. Results of this study supported the potential application of M11 on the non-small lung cancer (NSCLC) with cisplatin resistance. Copyright © 2016 Elsevier Inc. All rights reserved.

  9. A Flavone Constituent from Myoporum bontioides Induces M-Phase Cell Cycle Arrest of MCF-7 Breast Cancer Cells

    Directory of Open Access Journals (Sweden)

    Jing-Ru Weng

    2017-03-01

    Full Text Available Abstract: Myoporum bontioides is a traditional medicinal plant in Asia with various biological activities, including anti-inflammatory and anti-bacterial characteristics. To identify the bioactive constituents from M. bontioides, a newly-identified flavone, 3,4′-dimethoxy-3′,5,7-trihydroxyflavone (compound 1, along with eight known compounds, were investigated in human MCF-7 breast cancer, SCC4 oral cancer, and THP-1 monocytic leukemia cells. Among these compounds, compound 1 exhibited the strongest antiproliferative activity with half-maximal inhibitory concentration (IC50 values ranging from 3.3 μM (MCF-7 to 8.6 μM (SCC4. Flow cytometric analysis indicated that compound 1 induced G2/M cell cycle arrest in MCF-7 cells. Mechanistic evidence suggests that the G2/M arrest could be attributable to compound 1’s modulatory effects on the phosphorylation and expression of numerous key signaling effectors, including cell division cycle 2 (CDC2, CDC25C, and p53. Notably, compound 1 downregulated the expression of histone deacetylase 2 (HDAC2 and HDAC4, leading to increased histone H3 acetylation and p21 upregulation. Together, these findings suggest the translational potential of compound 1 as a breast cancer treatment.

  10. The nonstructural protein NP1 of human bocavirus 1 induces cell cycle arrest and apoptosis in Hela cells

    International Nuclear Information System (INIS)

    Sun, Bin; Cai, Yingyue; Li, Yongshu; Li, Jingjing; Liu, Kaiyu; Li, Yi; Yang, Yongbo

    2013-01-01

    Human bocavirus type 1 (HBoV1) is a newly identified pathogen associated with human respiratory tract illnesses. Previous studies demonstrated that proteins of HBoV1 failed to cause cell death, which is considered as a possible common feature of bocaviruses. However, our work showed that the NP1 of HBoV1 induced apoptotic cell death in Hela cells in the absence of viral genome replication and expression of other viral proteins. Mitochondria apoptotic pathway was involved in the NP1-induced apoptosis that was confirmed by apoptotic characteristics including morphological changes, DNA fragmentation and caspase activation. We also demonstrated that the cell cycle of NP1-transfected Hela cells was transiently arrested at G2/M phase followed by rapid appearance of apoptosis and that the N terminal domain of NP1 was critical to its nuclear localization and function in apoptosis induction in Hela cells. These findings might provide alternative information for further study of mechanism of HBoV1 pathogenesis. - Highlights: ► NP1 protein of HBoV1 induced apoptosis in Hela cells was first reported. ► NP1 induced-apoptosis followed the cell cycle arrest at G2/M phase. ► The NP1 induced-apoptosis was mediated by mitochondrion apoptotic pathway. ► N terminal of NP1 was critical for apoptosis induction and nuclear localization

  11. p27Kip1 Is Required to Mediate a G1 Cell Cycle Arrest Downstream of ATM following Genotoxic Stress.

    Directory of Open Access Journals (Sweden)

    Erica K Cassimere

    Full Text Available The DNA damage response (DDR is a coordinated signaling network that ensures the maintenance of genome stability under DNA damaging stress. In response to DNA lesions, activation of the DDR leads to the establishment of cell cycle checkpoints that delay cell-cycle progression and allow repair of the defects. The tumor suppressor p27Kip1 is a cyclin-CDK inhibitor that plays an important role in regulating quiescence in a variety of tissues. Several studies have suggested that p27Kip1 also plays a role in the maintenance of genomic integrity. Here we demonstrate that p27Kip1 is essential for the establishment of a G1 checkpoint arrest after DNA damage. We also uncovered that ATM phosphorylates p27Kip1 on a previously uncharacterized residue (Ser-140, which leads to its stabilization after induction of DNA double-strand breaks. Inhibition of this stabilization by replacing endogenous p27Kip1 with a Ser-140 phospho-mutant (S140A significantly sensitized cells to IR treatments. Our findings reveal a novel role for p27Kip1 in the DNA damage response pathway and suggest that part of its tumor suppressing functions relies in its ability to mediate a G1 arrest after the induction of DNA double strand breaks.

  12. The nonstructural protein NP1 of human bocavirus 1 induces cell cycle arrest and apoptosis in Hela cells

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Bin; Cai, Yingyue; Li, Yongshu [College of Life Science, Central China Normal University, Wuhan 430079, Hubei (China); Li, Jingjing [College of Life Science, Hubei Normal University, Huangshi 435002, Hubei (China); Liu, Kaiyu [College of Life Science, Central China Normal University, Wuhan 430079, Hubei (China); Li, Yi, E-mail: johnli2668@hotmail.com [College of Life Science, Central China Normal University, Wuhan 430079, Hubei (China); Bioengineering Department, Wuhan Bioengineering Institute, Wuhan 430415, Hubei (China); Yang, Yongbo, E-mail: yongboyang@mail.ccnu.edu.cn [College of Life Science, Central China Normal University, Wuhan 430079, Hubei (China)

    2013-05-25

    Human bocavirus type 1 (HBoV1) is a newly identified pathogen associated with human respiratory tract illnesses. Previous studies demonstrated that proteins of HBoV1 failed to cause cell death, which is considered as a possible common feature of bocaviruses. However, our work showed that the NP1 of HBoV1 induced apoptotic cell death in Hela cells in the absence of viral genome replication and expression of other viral proteins. Mitochondria apoptotic pathway was involved in the NP1-induced apoptosis that was confirmed by apoptotic characteristics including morphological changes, DNA fragmentation and caspase activation. We also demonstrated that the cell cycle of NP1-transfected Hela cells was transiently arrested at G2/M phase followed by rapid appearance of apoptosis and that the N terminal domain of NP1 was critical to its nuclear localization and function in apoptosis induction in Hela cells. These findings might provide alternative information for further study of mechanism of HBoV1 pathogenesis. - Highlights: ► NP1 protein of HBoV1 induced apoptosis in Hela cells was first reported. ► NP1 induced-apoptosis followed the cell cycle arrest at G2/M phase. ► The NP1 induced-apoptosis was mediated by mitochondrion apoptotic pathway. ► N terminal of NP1 was critical for apoptosis induction and nuclear localization.

  13. Overexpression of 15-lipoxygenase-1 induces growth arrest through phosphorylation of p53 in human colorectal cancer cells.

    Science.gov (United States)

    Kim, Jong-Sik; Baek, Seung Joon; Bottone, Frank G; Sali, Tina; Eling, Thomas E

    2005-09-01

    To investigate the function of 15-lipoxygenase-1 (15-LOX-1) in human colorectal cancer, we overexpressed 15-LOX-1 in HCT-116 human colorectal cancer cells. Clones expressing the highest levels of 15-LOX-1 displayed reduced viability compared with the HCT-116-Vector control cells. Further, by cell cycle gene array analyses, the cyclin-dependent kinase inhibitor p21WAF1/CIP1 and MDM2 genes were up-regulated in 15-LOX-1-overexpressing cells. The induction of p21(WAF1/CIP1) and MDM2 were linked to activation of p53 by 15-LOX-1, as there was a dramatic induction of phosphorylated p53 (Ser15) in 15-LOX-1-overesxpressing cells. However, the 15-LOX-1 metabolites 13(S)-hydroxyoctadecadienoic acid and 15(S)-hydroxyeicosatetraenoic acid failed to induce phosphorylation of p53 at Ser15, and the 15-LOX-1 inhibitor PD146176 did not inhibit the phosphorylation of p53 at Ser15 in 15-LOX-1-overexpressing cells. Nonetheless, the growth-inhibitory effects of 15-LOX-1 were p53 dependent, as 15-LOX-1 overexpression had no effect on cell growth in p53 (-/-) HCT-116 cells. Finally, treatment of HCT-116-15-LOX-1 cells with different kinase inhibitors suggested that the effects of 15-LOX-1 on p53 phosphorylation and activation were due to effects on DNA-dependent protein kinase. Collectively, these findings suggest a new mechanism to explain the biological activity of 15-LOX-1, where 15-LOX plays a stoichiometric role in activating a DNA-dependent protein kinase-dependent pathway that leads to p53-dependent growth arrest.

  14. Cdk5 phosphorylates non-genotoxically overexpressed p53 following inhibition of PP2A to induce cell cycle arrest/apoptosis and inhibits tumor progression

    Directory of Open Access Journals (Sweden)

    Kumari Ratna

    2010-07-01

    Full Text Available Abstract Background p53 is the most studied tumor suppressor and its overexpression may or may not cause cell death depending upon the genetic background of the cells. p53 is degraded by human papillomavirus (HPV E6 protein in cervical carcinoma. Several stress activated kinases are known to phosphorylate p53 and, among them cyclin dependent kinase 5 (Cdk5 is one of the kinase studied in neuronal cell system. Recently, the involvement of Cdk5 in phosphorylating p53 has been shown in certain cancer types. Phosphorylation at specific serine residues in p53 is essential for it to cause cell growth inhibition. Activation of p53 under non stress conditions is poorly understood. Therefore, the activation of p53 and detection of upstream kinases that phosphorylate non-genotoxically overexpressed p53 will be of therapeutic importance for cancer treatment. Results To determine the non-genotoxic effect of p53; Tet-On system was utilized and p53 inducible HPV-positive HeLa cells were developed. p53 overexpression in HPV-positive cells did not induce cell cycle arrest or apoptosis. However, we demonstrate that overexpressed p53 can be activated to upregulate p21 and Bax which causes G2 arrest and apoptosis, by inhibiting protein phosphatase 2A. Additionally, we report that the upstream kinase cyclin dependent kinase 5 interacts with p53 to phosphorylate it at Serine20 and Serine46 residues thereby promoting its recruitment on p21 and bax promoters. Upregulation and translocation of Bax causes apoptosis through intrinsic mitochondrial pathway. Interestingly, overexpressed activated p53 specifically inhibits cell-growth and causes regression in vivo tumor growth as well. Conclusion Present study details the mechanism of activation of p53 and puts forth the possibility of p53 gene therapy to work in HPV positive cervical carcinoma.

  15. A temperature-sensitive dcw1 mutant of Saccharomyces cerevisiae is cell cycle arrested with small buds which have aberrant cell walls.

    Science.gov (United States)

    Kitagaki, Hiroshi; Ito, Kiyoshi; Shimoi, Hitoshi

    2004-10-01

    Dcw1p and Dfg5p in Saccharomyces cerevisiae are homologous proteins that were previously shown to be involved in cell wall biogenesis and to be essential for growth. Dcw1p was found to be a glycosylphosphatidylinositol-anchored membrane protein. To investigate the roles of these proteins in cell wall biogenesis and cell growth, we constructed mutant alleles of DCW1 by random mutagenesis, introduced them into a Deltadcw1 Deltadfg5 background, and isolated a temperature-sensitive mutant, DC61 (dcw1-3 Deltadfg5). When DC61 cells were incubated at 37 degrees C, most cells had small buds, with areas less than 20% of those of the mother cells. This result indicates that DC61 cells arrest growth with small buds at 37 degrees C. At 37 degrees C, fewer DC61 cells had 1N DNA content and most of them still had a single nucleus located apart from the bud neck. In addition, in DC61 cells incubated at 37 degrees C, bipolar spindles were not formed. These results indicate that DC61 cells, when incubated at 37 degrees C, are cell cycle arrested after DNA replication and prior to the separation of spindle pole bodies. The small buds of DC61 accumulated chitin in the bud cortex, and some of them were lysed, which indicates that they had aberrant cell walls. A temperature-sensitive dfg5 mutant, DF66 (Deltadcw1 dfg5-29), showed similar phenotypes. DCW1 and DFG5 mRNA levels peaked in the G1 and S phases, respectively. These results indicate that Dcw1p and Dfg5p are involved in bud formation through their involvement in biogenesis of the bud cell wall.

  16. Growth arrest specific gene 2 in tilapia (Oreochromis niloticus): molecular characterization and functional analysis under low-temperature stress.

    Science.gov (United States)

    Yang, ChangGeng; Wu, Fan; Lu, Xing; Jiang, Ming; Liu, Wei; Yu, Lijuan; Tian, Juan; Wen, Hua

    2017-07-17

    Growth arrest specific 2 (gas2) gene is a component of the microfilament system that plays a major role in the cell cycle, regulation of microfilaments, and cell morphology during apoptotic processes. However, little information is available on fish gas2. In this study, the tilapia (Oreochromis niloticus) gas2 gene was cloned and characterized for the first time. The open reading frame was 1020 bp, encoding 340 amino acids; the 5'-untranslated region (UTR) was 140 bp and the 3'-UTR was 70 bp, with a poly (A) tail. The highest promoter activity occurred in the regulatory region (-3000 to -2400 bp). The Gas2-GFP fusion protein was distributed within the cytoplasm. Quantitative reverse transcription-polymerase chain reaction and western blot analyses revealed that gas2 gene expression levels in the liver, muscle, and brain were clearly affected by low temperature stress. The results of gas2 RNAi showed decreased expression of the gas2 and P53 genes. These results suggest that the tilapia gas2 gene may be involved in low temperature stress-induced apoptosis.

  17. Anthocyanins from roselle extract arrest cell cycle G2/M phase transition via ATM/Chk pathway in p53-deficient leukemia HL-60 cells.

    Science.gov (United States)

    Tsai, Tsung-Chang; Huang, Hui-Pei; Chang, Kai-Ting; Wang, Chau-Jong; Chang, Yun-Ching

    2017-04-01

    Cell cycle regulation is an important issue in cancer therapy. Delphinidin and cyanidin are two major anthocyanins of the roselle plant (Hibiscus sabdariffa). In the present study, we investigated the effect of Hibiscus anthocyanins (HAs) on cell cycle arrest in human leukemia cell line HL-60 and the analyzed the underlying molecular mechanisms. HAs extracted from roselle calyces (purity 90%) markedly induced G2/M arrest evaluated with flow cytometry analysis. Western blot analyses revealed that HAs (0.1-0.7 mg mL -1 ) induced G2/M arrest via increasing Tyr15 phosphorylation of Cdc2, and inducing Cdk inhibitors p27 and p21. HAs also induced phosphorylation of upstream signals related to G2/M arrest such as phosphorylation of Cdc25C tyrosine phosphatase at Ser216, increasing the binding of pCdc25C with 14-3-3 protein. HAs-induced phosphorylation of Cdc25C could be activated by ATM checkpoint kinases, Chk1, and Chk2. We first time confirmed that ATM-Chk1/2-Cdc25C pathway as a critical mechanism for G2/M arrest in HAs-induced leukemia cell cycle arrest, indicating that this compound could be a promising anticancer candidate or chemopreventive agents for further investigation. © 2016 Wiley Periodicals, Inc. Environ Toxicol 32: 1290-1304, 2017. © 2016 Wiley Periodicals, Inc.

  18. The p75NTR tumor suppressor induces cell cycle arrest facilitating caspase mediated apoptosis in prostate tumor cells

    International Nuclear Information System (INIS)

    Khwaja, Fatima; Tabassum, Arshia; Allen, Jeff; Djakiew, Daniel

    2006-01-01

    The p75 neurotrophin receptor (p75 NTR ) is a death receptor which belongs to the tumor necrosis factor receptor super-family of membrane proteins. This study shows that p75 NTR retarded cell cycle progression by induced accumulation of cells in G0/G1 and a reduction in the S phase of the cell cycle. The rescue of tumor cells from cell cycle progression by a death domain deleted (ΔDD) dominant-negative antagonist of p75 NTR showed that the death domain transduced anti-proliferative activity in a ligand-independent manner. Conversely, addition of NGF ligand rescued retardation of cell cycle progression with commensurate changes in components of the cyclin/cdk holoenzyme complex. In the absence of ligand, p75 NTR -dependent cell cycle arrest facilitated an increase in apoptotic nuclear fragmentation of the prostate cancer cells. Apoptosis of p75 NTR expressing cells occurred via the intrinsic mitochondrial pathway leading to a sequential caspase-9 and -7 cascade. Since the death domain deleted dominant-negative antagonist of p75 NTR rescued intrinsic caspase associated apoptosis in PC-3 cells, this shows p75 NTR was integral to ligand independent induction of apoptosis. Moreover, the ability of ligand to ameliorate the p75 NTR -dependent intrinsic apoptotic cascade indicates that NGF functioned as a survival factor for p75 NTR expressing prostate cancer cells

  19. The p75{sup NTR} tumor suppressor induces cell cycle arrest facilitating caspase mediated apoptosis in prostate tumor cells

    Energy Technology Data Exchange (ETDEWEB)

    Khwaja, Fatima [Department of Biochemistry and Molecular and Cellular Biology, Georgetown University Medical Center, Washington, DC 20057-1436 (United States); Tabassum, Arshia [Toronto Western Hospital, Toronto, ON, M5T258 (Canada); Allen, Jeff [National Center for Complementary and Alternative Medicine, N.I.H., Bethesda, MD 20892 (United States); Djakiew, Daniel [Department of Biochemistry and Molecular and Cellular Biology, Georgetown University Medical Center, Washington, DC 20057-1436 (United States) and Lombardi Comprehensive Cancer Center, Georgetown University Medical Center, Washington, DC 20057-1436 (United States)

    2006-03-24

    The p75 neurotrophin receptor (p75{sup NTR}) is a death receptor which belongs to the tumor necrosis factor receptor super-family of membrane proteins. This study shows that p75{sup NTR} retarded cell cycle progression by induced accumulation of cells in G0/G1 and a reduction in the S phase of the cell cycle. The rescue of tumor cells from cell cycle progression by a death domain deleted ({delta}DD) dominant-negative antagonist of p75{sup NTR} showed that the death domain transduced anti-proliferative activity in a ligand-independent manner. Conversely, addition of NGF ligand rescued retardation of cell cycle progression with commensurate changes in components of the cyclin/cdk holoenzyme complex. In the absence of ligand, p75{sup NTR}-dependent cell cycle arrest facilitated an increase in apoptotic nuclear fragmentation of the prostate cancer cells. Apoptosis of p75{sup NTR} expressing cells occurred via the intrinsic mitochondrial pathway leading to a sequential caspase-9 and -7 cascade. Since the death domain deleted dominant-negative antagonist of p75{sup NTR} rescued intrinsic caspase associated apoptosis in PC-3 cells, this shows p75{sup NTR} was integral to ligand independent induction of apoptosis. Moreover, the ability of ligand to ameliorate the p75{sup NTR}-dependent intrinsic apoptotic cascade indicates that NGF functioned as a survival factor for p75{sup NTR} expressing prostate cancer cells.

  20. Three-dimensional MR imaging in the assessment of physeal growth arrest.

    Science.gov (United States)

    Sailhan, Frédéric; Chotel, Franck; Guibal, Anne-Laure; Gollogly, Sohrab; Adam, Philippe; Bérard, Jérome; Guibaud, Laurent

    2004-09-01

    The purpose of this study is to describe an imaging method for identifying and characterising physeal growth arrest following physeal plate aggression. The authors describe the use of three-dimensional MRI performed with fat-suppressed three-dimensional spoiled gradient-recalled echo sequences followed by manual image reconstruction to create a 3D model of the physeal plate. This retrospective series reports the analysis of 33 bony physeal bridges in 28 children (mean age 10.5 years) with the use of fat-suppressed three-dimensional spoiled gradient-recalled echo imaging and 3D reconstructions from the source images. 3D reconstructions were obtained after the outlining was done manually on each source image. Files of all patients were reviewed for clinical data at the time of MRI, type of injury, age at MRI and bone bridge characteristics on reconstructions. Twenty-one (63%) of the 33 bridges were post-traumatic and were mostly situated in the lower extremities (19/21). The distal tibia was involved in 66% (14/21) of the cases. Bridges due to causes other than trauma were located in the lower extremities in 10/12 cases, and the distal femur represented 60% of these cases. Of the 28 patients, five presented with two bridges involving two different growth plates making a total of 33 physeal bone bars. The location and shape of each bridge was accurately identified in each patient, and in post-traumatic cases, 89% of bone bars were of Ogden type III (central) or I (peripheral). Reconstructions were obtained in 15 min and are easy to interpret. Volumes of the physeal bone bridge(s) and of the remaining normal physis were calculated. The bone bridging represented less than 1% to 47% of the total physeal plate volume. The precise shape and location of the bridge can be visualised on the 3D reconstructions. This information is useful in the surgical management of these deformities; as for the eight patients who underwent bone bar resection, an excellent correspondence was

  1. Three-dimensional MR imaging in the assessment of physeal growth arrest

    Energy Technology Data Exchange (ETDEWEB)

    Sailhan, Frederic; Chotel, Franck; Gollogly, Sohrab; Adam, Philippe; Berard, Jerome [Department of Orthopaedics, Hopital Bebrousse, 29 rue Soeur Bouvier, 69005, Lyon (France); Guibal, Anne-Laure; Guibaud, Laurent [Department of Radiology, Hopital Bebrousse, 29 rue Soeur Bouvier, 69005, Lyon (France)

    2004-09-01

    The purpose of this study is to describe an imaging method for identifying and characterising physeal growth arrest following physeal plate aggression. The authors describe the use of three-dimensional MRI performed with fat-suppressed three-dimensional spoiled gradient-recalled echo sequences followed by manual image reconstruction to create a 3D model of the physeal plate. This retrospective series reports the analysis of 33 bony physeal bridges in 28 children (mean age 10.5 years) with the use of fat-suppressed three-dimensional spoiled gradient-recalled echo imaging and 3D reconstructions from the source images. 3D reconstructions were obtained after the outlining was done manually on each source image. Files of all patients were reviewed for clinical data at the time of MRI, type of injury, age at MRI and bone bridge characteristics on reconstructions. Twenty-one (63%) of the 33 bridges were post-traumatic and were mostly situated in the lower extremities (19/21). The distal tibia was involved in 66% (14/21) of the cases. Bridges due to causes other than trauma were located in the lower extremities in 10/12 cases, and the distal femur represented 60% of these cases. Of the 28 patients, five presented with two bridges involving two different growth plates making a total of 33 physeal bone bars. The location and shape of each bridge was accurately identified in each patient, and in post-traumatic cases, 89% of bone bars were of Ogden type III (central) or I (peripheral). Reconstructions were obtained in 15 min and are easy to interpret. Volumes of the physeal bone bridge(s) and of the remaining normal physis were calculated. The bone bridging represented less than 1% to 47% of the total physeal plate volume. The precise shape and location of the bridge can be visualised on the 3D reconstructions. This information is useful in the surgical management of these deformities; as for the eight patients who underwent bone bar resection, an excellent correspondence was

  2. Three-dimensional MR imaging in the assessment of physeal growth arrest

    International Nuclear Information System (INIS)

    Sailhan, Frederic; Chotel, Franck; Gollogly, Sohrab; Adam, Philippe; Berard, Jerome; Guibal, Anne-Laure; Guibaud, Laurent

    2004-01-01

    The purpose of this study is to describe an imaging method for identifying and characterising physeal growth arrest following physeal plate aggression. The authors describe the use of three-dimensional MRI performed with fat-suppressed three-dimensional spoiled gradient-recalled echo sequences followed by manual image reconstruction to create a 3D model of the physeal plate. This retrospective series reports the analysis of 33 bony physeal bridges in 28 children (mean age 10.5 years) with the use of fat-suppressed three-dimensional spoiled gradient-recalled echo imaging and 3D reconstructions from the source images. 3D reconstructions were obtained after the outlining was done manually on each source image. Files of all patients were reviewed for clinical data at the time of MRI, type of injury, age at MRI and bone bridge characteristics on reconstructions. Twenty-one (63%) of the 33 bridges were post-traumatic and were mostly situated in the lower extremities (19/21). The distal tibia was involved in 66% (14/21) of the cases. Bridges due to causes other than trauma were located in the lower extremities in 10/12 cases, and the distal femur represented 60% of these cases. Of the 28 patients, five presented with two bridges involving two different growth plates making a total of 33 physeal bone bars. The location and shape of each bridge was accurately identified in each patient, and in post-traumatic cases, 89% of bone bars were of Ogden type III (central) or I (peripheral). Reconstructions were obtained in 15 min and are easy to interpret. Volumes of the physeal bone bridge(s) and of the remaining normal physis were calculated. The bone bridging represented less than 1% to 47% of the total physeal plate volume. The precise shape and location of the bridge can be visualised on the 3D reconstructions. This information is useful in the surgical management of these deformities; as for the eight patients who underwent bone bar resection, an excellent correspondence was

  3. DNA fragmentation and cell cycle arrest: a hallmark of apoptosis induced by crocin from kashmiri saffron in a human pancreatic cancer cell line.

    Science.gov (United States)

    Bakshi, Hamid; Sam, Smitha; Rozati, Roya; Sultan, Phalisteen; Islam, Tajamul; Rathore, Babita; Lone, Zahoor; Sharma, Manik; Triphati, Jagrati; Saxena, Ramesh Chand

    2010-01-01

    Apoptosis, a widely important mechanism that contributes to cell growth reduction, is reported to be induced by Crocus sativus in different cancer types. The present study was designed to elucidate apoptosis induction by crocin, a main component of Crocus sativus in a human pancreatic cancer cell line (BxPC-3). Cell viability was measured by MTT assay, Hoechest33258 staining was used to detect the chromatin condensation characteristic of apoptosis, and DNA fragmentation was assessed by gel electrophoresis and cell cycle analysis by flow cytometry. Crocin induced apoptosis and G1-phase cell cycle arrest of BxPC-3 cells, while decreasing cell viability in a dose dependent and time dependent manner. Cells treated with 10μg/L crocin exhibited apoptotic morphology (brightly blue-fluorescent condensed nuclei on Hoechst 33258 staining) and reduction of volume. DNA analysis revealed typical ladders as early as 12 hours after treatment indicative of apoptosis. Our preclinical study demonstrated a pancreatic cancer cell line to be highly sensitive to crocin-mediated growth inhibition and apoptotic cell death. Although the molecular mechanisms of crocin action are not yet clearly understood, it appears to have potential as a therapeutic agent.

  4. Induction of cell cycle arrest and apoptosis with downregulation of Hsp90 client proteins and histone modification by 4β-hydroxywithanolide E isolated from Physalis peruviana.

    Science.gov (United States)

    Park, Eun-Jung; Sang-Ngern, Mayuramas; Chang, Leng Chee; Pezzuto, John M

    2016-06-01

    Physalis peruviana (Solanaceae) is used for culinary and medicinal purposes. We currently report withanolides, isolated from P. peruviana, inhibit the growth of colon cancer monolayer and spheroid cultures. A detailed mechanistic evaluation was performed with 4β-hydroxywithanolide E (4HWE). Treatment of HT-29 cells with low concentrations of 4HWE inhibited growth while enhancing levels of p21(Waf1/Cip1) and reducing levels of several cell cycle-related proteins. Apoptosis was induced at higher concentrations. In addition, 4HWE treatment downregulated the levels of Hsp90 client proteins. Nuclear sirtuin 1 (SIRT1) was increased and histone H3 acetylated at lysine 9 was decreased. An additional consequence of SIRT1 elevation in the nucleus may be inhibition of c-Jun activity. The expression of 21 genes was altered, including downregulation of PTGS2, and this correlated with reduced protein levels of cyclooxygenase-2 (COX-2). Overall, efficacious induction of G0/G1 cell cycle arrest at low concentrations, and induction of apoptosis at higher concentrations are interesting 4HWE-mediated phenomena that are accompanied by a complex array of molecular events. Considering the worldwide prevalence of colon cancer, and the unique mode of action mediated by 4HWE, it is reasonable to investigate additional mechanistic details and the potential utility of this compound. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. The long non-coding RNA HOTAIR promotes the proliferation of serous ovarian cancer cells through the regulation of cell cycle arrest and apoptosis

    Energy Technology Data Exchange (ETDEWEB)

    Qiu, Jun-jun [Department of Gynecology, Obstetrics and Gynecology Hospital, Fudan University, 419 Fangxie Road, Shanghai 200011 (China); Department of Obstetrics and Gynecology of Shanghai Medical College, Fudan University, 138 Yixueyuan Road, Shanghai 200032 (China); Shanghai Key Laboratory of Female Reproductive Endocrine-Related Diseases, 413 Zhaozhou Road, Shanghai 200011 (China); Wang, Yan [Cancer Institute, Fudan University Shanghai Cancer Center, 270 Dong' an Road, Shanghai 200032 (China); Department of Oncology, Shanghai Medical College, Fudan University, 130 Dong' an Road, Shanghai 200032 (China); Ding, Jing-xin; Jin, Hong-yan [Department of Gynecology, Obstetrics and Gynecology Hospital, Fudan University, 419 Fangxie Road, Shanghai 200011 (China); Department of Obstetrics and Gynecology of Shanghai Medical College, Fudan University, 138 Yixueyuan Road, Shanghai 200032 (China); Shanghai Key Laboratory of Female Reproductive Endocrine-Related Diseases, 413 Zhaozhou Road, Shanghai 200011 (China); Yang, Gong, E-mail: yanggong@fudan.edu.cn [Cancer Institute, Fudan University Shanghai Cancer Center, 270 Dong' an Road, Shanghai 200032 (China); Department of Oncology, Shanghai Medical College, Fudan University, 130 Dong' an Road, Shanghai 200032 (China); Hua, Ke-qin, E-mail: huakeqin@126.com [Department of Gynecology, Obstetrics and Gynecology Hospital, Fudan University, 419 Fangxie Road, Shanghai 200011 (China); Department of Obstetrics and Gynecology of Shanghai Medical College, Fudan University, 138 Yixueyuan Road, Shanghai 200032 (China); Shanghai Key Laboratory of Female Reproductive Endocrine-Related Diseases, 413 Zhaozhou Road, Shanghai 200011 (China)

    2015-05-01

    HOX transcript antisense RNA (HOTAIR) is a well-known long non-coding RNA (lncRNA) whose dysregulation correlates with poor prognosis and malignant progression in many forms of cancer. Here, we investigate the expression pattern, clinical significance, and biological function of HOTAIR in serous ovarian cancer (SOC). Clinically, we found that HOTAIR levels were overexpressed in SOC tissues compared with normal controls and that HOTAIR overexpression was correlated with an advanced FIGO stage and a high histological grade. Multivariate analysis revealed that HOTAIR is an independent prognostic factor for predicting overall survival in SOC patients. We demonstrated that HOTAIR silencing inhibited A2780 and OVCA429 SOC cell proliferation in vitro and that the anti-proliferative effects of HOTAIR silencing also occurred in vivo. Further investigation into the mechanisms responsible for the growth inhibitory effects by HOTAIR silencing revealed that its knockdown resulted in the induction of cell cycle arrest and apoptosis through certain cell cycle-related and apoptosis-related proteins. Together, these results highlight a critical role of HOTAIR in SOC cell proliferation and contribute to a better understanding of the importance of dysregulated lncRNAs in SOC progression. - Highlights: • HOTAIR overexpression correlates with an aggressive tumour phenotype and a poor prognosis in SOC. • HOTAIR promotes SOC cell proliferation both in vitro and in vivo. • The proliferative role of HOTAIR is associated with regulation of the cell cycle and apoptosis.

  6. Sensitization of gastric cancer cells to alkylating agents by glaucocalyxin B via cell cycle arrest and enhanced cell death.

    Science.gov (United States)

    Ur Rahman, Muhammad Saif; Zhang, Ling; Wu, Lingyan; Xie, Yuqiong; Li, Chunchun; Cao, Jiang

    2017-01-01

    Severe side effects are major problems with chemotherapy of gastric cancer (GC). These side effects can be reduced by using sensitizing agents in combination with therapeutic drugs. In this study, the low/nontoxic dosage of glaucocalyxin B (GLB) was used with other DNA linker agents mitomycin C (MMC), cisplatin (DDP), or cyclophosphamide (CTX) to treat GC cells. Combined effectiveness of GLB with drugs was determined by proliferation assay. The molecular mechanisms associated with cell proliferation, migration, invasion, cell cycle, DNA repair/replication, apoptosis, and autophagy were investigated by immunoblotting for key proteins involved. Cell cycle and apoptosis analysis were performed by flow cytometry. Reactive oxygen species level was also examined for identification of its role in apoptosis. Proliferation assay revealed that the addition of 5 µM GLB significantly sensitizes gastric cancer SGC-7901 cells to MMC, DDP, and CTX by decreasing half-maximal inhibitory concentration (IC 50 ) by up to 75.40%±5%, 45.10%±5%, and 52.10%±5%, respectively. GLB + drugs decreased the expression level of proteins involved in proliferation and migration, suggesting the anticancer potential of GLB + drugs. GLB + MMC, GLB + CTX, and GLB + DDP arrest the cells in G 0 /G 1 and G 1 /S phase, respectively, which may be the consequence of significant decrease in the level of enzymes responsible for DNA replication and telomerase shortening. Combined use of GLB with these drugs also induces DNA damage and apoptosis by activating caspase/PARP pathways and increased production of reactive oxygen species and increased autophagy in GC cells. GLB dosage sensitizes GC cells to the alkylating agents via arresting the cell cycle and enhancing cell death. This is of significant therapeutic importance in the reduction of side effects associated with these drugs.

  7. SB225002 Induces Cell Death and Cell Cycle Arrest in Acute Lymphoblastic Leukemia Cells through the Activation of GLIPR1

    Science.gov (United States)

    Leal, Paulo C.; Bhasin, Manoj K.; Zenatti, Priscila Pini; Nunes, Ricardo J.; Yunes, Rosendo A.; Nowill, Alexandre E.; Libermann, Towia A.; Zerbini, Luiz Fernando; Yunes, José Andrés

    2015-01-01

    Acute Lymphoblastic Leukemia (ALL) is the most frequent childhood malignancy. In the effort to find new anti-leukemic agents, we evaluated the small drug SB225002 (N-(2-hydroxy-4-nitrophenyl)-N’-(2-bromophenyl)urea). Although initially described as a selective antagonist of CXCR2, later studies have identified other cellular targets for SB225002, with potential medicinal use in cancer. We found that SB225002 has a significant pro-apoptotic effect against both B- and T-ALL cell lines. Cell cycle analysis demonstrated that treatment with SB225002 induces G2-M cell cycle arrest. Transcriptional profiling revealed that SB225002-mediated apoptosis triggered a transcriptional program typical of tubulin binding agents. Network analysis revealed the activation of genes linked to the JUN and p53 pathways and inhibition of genes linked to the TNF pathway. Early cellular effects activated by SB225002 included the up-regulation of GLIPR1, a p53-target gene shown to have pro-apoptotic activities in prostate and bladder cancer. Silencing of GLIPR1 in B- and T-ALL cell lines resulted in increased resistance to SB225002. Although SB225002 promoted ROS increase in ALL cells, antioxidant N-Acetyl Cysteine pre-treatment only modestly attenuated cell death, implying that the pro-apoptotic effects of SB225002 are not exclusively mediated by ROS. Moreover, GLIPR1 silencing resulted in increased ROS levels both in untreated and SB225002-treated cells. In conclusion, SB225002 induces cell cycle arrest and apoptosis in different B- and T-ALL cell lines. Inhibition of tubulin function with concurrent activation of the p53 pathway, in particular, its downstream target GLIPR1, seems to underlie the anti-leukemic effect of SB225002. PMID:26302043

  8. DNA fragmentation and cell cycle arrest: a hallmark of apoptosis induced by Ruta graveolens in human colon cancer cells.

    Science.gov (United States)

    Arora, Shagun; Tandon, Simran

    2015-01-01

    In the present study, we investigated the anti-cancer effect of various potencies of Ruta graveolens (Ruta) on COLO-205 cell line, as evidenced by cytotoxicity, migration, clonogenecity, morphological and biochemical changes and modification in the levels of genes associated with apoptosis and cell cycle. On treatment of COLO-205 cells maximal effects were seen with mother tincture (MT) and 30C potencies, wherein decrease in cell viability along with reduced clonogenecity and migration capabilities were noted. In addition morphological and biochemical alterations such as nuclear changes (fragmented nuclei with condensed chromatin) and DNA ladder-like pattern (increased amount of fragmented DNA) in COLO-205 cells indicating apoptotic related cell death were seen. The expression of apoptosis and cell-cycle related regulatory genes assessed by reverse transcriptase-PCR revealed an up-regulation of caspase 9, caspase-3, Bax, p21 and p27 expression and down-regulation of Bcl-2 expression in treated cells. The mode of cell death was suggestive of intrinsic apoptotic pathway along with cell cycle arrest at the G2/M of the cell cycle. Our findings indicate that phytochemicals present in Ruta showed potential for natural therapeutic product development for colon carcinoma. Copyright © 2014 The Faculty of Homeopathy. Published by Elsevier Ltd. All rights reserved.

  9. SUN1 silencing inhibits cell growth through G0/G1 phase arrest in lung adenocarcinoma

    Directory of Open Access Journals (Sweden)

    Huang W

    2017-06-01

    Full Text Available Weiyi Huang,* Haihua Huang,* Lei Wang, Jiong Hu, Weifeng Song Department of Oncology, The First People’s Hospital Affiliated to Shanghai Jiaotong University, Shanghai, People’s Republic of China *These authors contributed equally to this work Purpose: Cytoskeleton is critical for carcinoma cell proliferation, migration, and invasion. Sad-1 and UNC-84 domain containing 1 (SUN1 is one of the core linkers of nucleoskeleton and cytoskeleton. However, the functions of SUN1 in lung adenocarcinoma are largely unknown.Methods: In this study, we first transduced the lentivirus delivering the short hairpin RNA (shRNA against SUN1 to lung adenocarcinoma cells (A549 and 95D cells with high efficiency. After lentivirus infection, quantitative real-time polymerase chain reaction and Western blotting were used to detect the expressions of SUN1 mRNA and protein. The cell proliferation and colony formation were detected by MTT assay and colony formation assay, respectively. The cell distribution in the cell cycle was analyzed by flow cytometry.Results: Both mRNA and protein levels of SUN1 were significantly decreased in A549 and 95D cells after lentivirus infection, as indicated by quantitative real-time polymerase chain reaction and Western blot. Next, we found that cell proliferation and colony formation were markedly reduced in SUN1 silenced cells. Moreover, suppression of SUN1 led to cell cycle arrest at G0/G1 phase. Furthermore, Cyclin D1, CDK6, and CDK2 expressions were obviously reduced in A549 cells after SUN1 silencing.Conclusion: These results suggest that SUN1 plays an essential role in proliferation of lung adenocarcinoma cells in vitro and may be used as a potential therapeutic target for the treatment of lung adenocarcinoma in the future. Keywords: SUN1, lung cancer, proliferation

  10. Characterization of the N-methoxyindole-3-carbinol (NI3C)–Induced Cell Cycle Arrest in Human Colon Cancer Cell Lines

    DEFF Research Database (Denmark)

    Neave, Antje S.; Sarup, Sussi; Seidelin, Michel

    2005-01-01

    Recent results have shown that indole-3-carbinol (I3C) inhibits the cellular growth of human cancer cell lines. In some cruciferous vegetables, another indole, N-methoxyindole-3-carbinol (NI3C), is found beside I3C. Knowledge about the biological effects of NI3C is limited. The aim of the present...... study was to show the effect of NI3C on cell growth of two human colon cancer cell lines, DLD-1 and HCT-116. For the first time it is shown that NI3C inhibits cellular growth of DLD-1 and HCT-116 and that NI3C is a more potent inhibitor of cell proliferation than I3C. In addition to the inhibition...... of cellular proliferation, NI3C caused an accumulation of HCT-116 cells in the G2/M phase, in contrast to I3C, which led to an accumulation of the colon cells in G0/G1 phase. Furthermore, NI3C delays the G1-S phase transition of synchronized HCT-116 cells. The indole-mediated cell-cycle arrest may be related...

  11. Oxygen-Glucose Deprivation Induces G2/M Cell Cycle Arrest in Brain Pericytes Associated with ERK Inactivation.

    Science.gov (United States)

    Wei, Wenjie; Yu, Zhiyuan; Xie, Minjie; Wang, Wei; Luo, Xiang

    2017-01-01

    Growing evidence has revealed that brain pericytes are multifunctional and contribute to the pathogenesis of a number of neurological disorders. However, the role of pericytes in cerebral ischemia, and especially the pathophysiological alterations in pericytes, remains unclear. In the present study, our aim was to determine whether the proliferation of pericytes is affected by cerebral ischemia and, if so, to identify the underlying mechanism(s). Cultured brain pericytes subjected to oxygen-glucose deprivation (OGD) were used as our model of cerebral ischemia; the protein expression levels of cyclin D1, cyclin E, cdk4, and cyclin B1 were determined by Western blot analysis, and cell cycle analysis was assessed by flow cytometry. The OGD treatment reduced the brain pericyte proliferation by causing G2/M phase arrest and downregulating the protein levels of cyclin D1, cyclin E, cdk4, and cyclin B1. Further studies demonstrated a simultaneous decrease in the activity of extracellular regulated protein kinases (ERK), suggesting a critical role of the ERK signaling cascade in the inhibition of OGD-induced pericyte proliferation. We suggest that OGD inhibition of the proliferation of brain pericytes is associated with the inactivation of the ERK signaling pathway, which arrests them in the G2/M phase.

  12. The cytotoxic effect of oxybuprocaine on human corneal epithelial cells by inducing cell cycle arrest and mitochondria-dependent apoptosis.

    Science.gov (United States)

    Fan, W-Y; Wang, D-P; Wen, Q; Fan, T-J

    2017-08-01

    Oxybuprocaine (OBPC) is a widely used topical anesthetic in eye clinic, and prolonged and repeated usage of OBPC might be cytotoxic to the cornea, especially to the outmost corneal epithelium. In this study, we characterized the cytotoxic effect of OBPC on human corneal epithelial (HCEP) cells and investigated its possible cellular and molecular mechanisms using an in vitro model of non-transfected HCEP cells. Our results showed that OBPC at concentrations ranging from 0.025% to 0.4% had a dose- and time-dependent cytotoxicity to HCEP cells. Moreover, OBPC arrested the cells at S phase and induced apoptosis of these cells by inducing plasma membrane permeability, phosphatidylserine externalization, DNA fragmentation, and apoptotic body formation. Furthermore, OBPC could trigger the activation of caspase-2, -3, and -9, downregulate the expression of Bcl-xL, upregulate the expression of Bax along with the cytoplasmic amount of mitochondria-released apoptosis-inducing factor, and disrupt mitochondrial transmembrane potential. Our results suggest that OBPC has a dose- and time-dependent cytotoxicity to HCEP cells by inducing cell cycle arrest and cell apoptosis via a death receptor-mediated mitochondria-dependent proapoptotic pathway, and this novel finding provides new insights into the acute cytotoxicity and its toxic mechanisms of OBPC on HCEP cells.

  13. Polycomb Group Protein PHF1 Regulates p53-dependent Cell Growth Arrest and Apoptosis*

    Science.gov (United States)

    Yang, Yang; Wang, Chenji; Zhang, Pingzhao; Gao, Kun; Wang, Dejie; Yu, Hongxiu; Zhang, Ting; Jiang, Sirui; Hexige, Saiyin; Hong, Zehui; Yasui, Akira; Liu, Jun O.; Huang, Haojie; Yu, Long

    2013-01-01

    Polycomb group protein PHF1 is well known as a component of a novel EED-EZH2·Polycomb repressive complex 2 complex and plays important roles in H3K27 methylation and Hox gene silencing. PHF1 is also involved in the response to DNA double-strand breaks in human cells, promotes nonhomologous end-joining processes through interaction with Ku70/Ku80. Here, we identified another function of PHF1 as a potential p53 pathway activator in a pathway screen using luminescence reporter assay. Subsequent studies showed PHF1 directly interacts with p53 proteins both in vivo and in vitro and co-localized in nucleus. PHF1 binds to the C-terminal regulatory domain of p53. Overexpression of PHF1 elevated p53 protein level and prolonged its turnover. Knockdown of PHF1 reduced p53 protein level and its target gene expression both in normal state and DNA damage response. Mechanically, PHF1 protects p53 proteins from MDM2-mediated ubiquitination and degradation. Furthermore, we showed that PHF1 regulates cell growth arrest and etoposide-induced apoptosis in a p53-dependent manner. Finally, PHF1 expression was significantly down-regulated in human breast cancer samples. Taken together, we establish PHF1 as a novel positive regulator of the p53 pathway. These data shed light on the potential roles of PHF1 in tumorigenesis and/or tumor progression. PMID:23150668

  14. Chromosome Mis-segregation Generates Cell-Cycle-Arrested Cells with Complex Karyotypes that Are Eliminated by the Immune System.

    Science.gov (United States)

    Santaguida, Stefano; Richardson, Amelia; Iyer, Divya Ramalingam; M'Saad, Ons; Zasadil, Lauren; Knouse, Kristin A; Wong, Yao Liang; Rhind, Nicholas; Desai, Arshad; Amon, Angelika

    2017-06-19

    Aneuploidy, a state of karyotype imbalance, is a hallmark of cancer. Changes in chromosome copy number have been proposed to drive disease by modulating the dosage of cancer driver genes and by promoting cancer genome evolution. Given the potential of cells with abnormal karyotypes to become cancerous, do pathways that limit the prevalence of such cells exist? By investigating the immediate consequences of aneuploidy on cell physiology, we identified mechanisms that eliminate aneuploid cells. We find that chromosome mis-segregation leads to further genomic instability that ultimately causes cell-cycle arrest. We further show that cells with complex karyotypes exhibit features of senescence and produce pro-inflammatory signals that promote their clearance by the immune system. We propose that cells with abnormal karyotypes generate a signal for their own elimination that may serve as a means for cancer cell immunosurveillance. Copyright © 2017 Elsevier Inc. All rights reserved.

  15. Hesperidin inhibits HeLa cell proliferation through apoptosis mediated by endoplasmic reticulum stress pathways and cell cycle arrest

    International Nuclear Information System (INIS)

    Wang, Yaoxian; Yu, Hui; Zhang, Jin; Gao, Jing; Ge, Xin; Lou, Ge

    2015-01-01

    Hesperidin (30, 5, 9-dihydroxy-40-methoxy-7-orutinosyl flavanone) is a flavanone that is found mainly in citrus fruits and has been shown to have some anti-neoplastic effects. The aim of the present study was to investigate the effect of hesperidin on apoptosis in human cervical cancer HeLa cells and to identify the mechanism involved. Cells were treated with hesperidin (0, 20, 40, 60, 80, and 100 μM) for 24, 48, or 72 h and relative cell viability was assessed using the 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) assay. Hesperidin inhibited the proliferation of HeLa cells in a concentration- and time-dependent manner. Hesperidin-induced apoptosis in HeLa cells was characterized by increased nuclear condensation and DNA fragmentation. Furthermore, increased levels of GADD153/CHOP and GRP78 indicated hesperidin-induced apoptosis in HeLa cells involved a caspase-dependent pathway, presumably downstream of the endoplasmic reticulum stress pathway. Both of these proteins are hallmarks of endoplasmic reticulum stress. Hesperidin also promoted the formation of reactive oxygen species, mobilization of intracellular Ca 2+ , loss of mitochondrial membrane potential (ΔΨm), increased release of cytochrome c and apoptosis-inducing factor from mitochondria, and promoted capase-3 activation. It also arrested HeLa cells in the G0/G1 phase in the cell cycle by downregulating the expression of cyclinD1, cyclinE1, and cyclin-dependent kinase 2 at the protein level. The effect of hesperidin was also verified on the human colon cancer cell HT-29 cells. We concluded that hesperidin inhibited HeLa cell proliferation through apoptosis involving endoplasmic reticulum stress pathways and cell cycle arrest

  16. Supercritical carbon dioxide extract of Physalis peruviana induced cell cycle arrest and apoptosis in human lung cancer H661 cells.

    Science.gov (United States)

    Wu, Shu-Jing; Chang, Shun-Pang; Lin, Doung-Liang; Wang, Shyh-Shyan; Hou, Fwu-Feuu; Ng, Lean-Teik

    2009-06-01

    Physalis peruviana L. (PP) is a popular folk medicine used for treating cancer, leukemia, hepatitis, rheumatism and other diseases. In this study, our objectives were to examine the total flavonoid and phenol content of different PP extracts (aqueous: HWEPP; ethanolic: EEPP; supercritical carbon dioxide: SCEPP-0, SCEPP-4 and SCEPP-5) and their antiproliferative effects in human lung cancer H661 cells. Among all the extracts tested, results showed that SCEPP-5 possessed the highest total flavonoid (226.19 +/- 4.15 mg/g) and phenol (100.82 +/- 6.25 mg/g) contents. SCEPP-5 also demonstrated the most potent inhibitory effect on H661 cell proliferation. Using DNA ladder and flow cytometry analysis, SCEPP-5 effectively induced H661 cell apoptosis as demonstrated by the accumulation of Sub-G1 peak and fragmentation of DNA. SCEPP-5 not only induced cell cycle arrest at S phase, it also up-regulated the expression of pro-apoptotic protein (Bax) and down-regulated the inhibitor of apoptosis protein (IAP). Furthermore, the apoptotic induction in H661 cells was found to associate with an elevated p53 protein expression, cytochrome c release, caspase-3 activation and PARP cleavage. Taken together, these results conclude that SCEPP-5 induced cell cycle arrest at S phase, and its apoptotic induction could be mediated through the p53-dependent pathway and modification of Bax and XIAP proteins expression. The results have also provided important pharmacological backgrounds for the potential use of PP supercritical fluid extract as products for cancer prevention.

  17. Growth Arrest-Specific Protein 6 is Hepatoprotective Against Ischemia/Reperfusion Injury

    Science.gov (United States)

    Llacuna, Laura; Bárcena, Cristina; Bellido-Martín, Lola; Fernández, Laura; Stefanovic, Milica; Marí, Montserrat; García-Ruiz, Carmen; Fernández-Checa, José C.; de Frutos, Pablo García; Morales, Albert

    2010-01-01

    Growth arrest-specific gene 6 (GAS6) promotes growth and cell survival during tissue repair and development in different organs, including the liver. However, the specific role of GAS6 in liver ischemia/reperfusion (I/R) injury has not been previously addressed. Here, we report an early increase in serum GAS6 levels following I/R exposure. Moreover, unlike wild type mice, Gas6-/- mice were highly sensitive to partial hepatic I/R, with 90% of mice dying within 12 hours of reperfusion due to massive hepatocellular injury. I/R induced early hepatic AKT phosphorylation in wild type but not in Gas6-/- mice, without significant changes in JNK phosphorylation or nuclear NF-κB translocation, whereas hepatic IL-1β and TNF mRNA levels were higher in Gas6-/- mice compared to wild type mice. In line with the in vivo data, in vitro studies indicated that GAS6 induced AKT phosphorylation in primary mouse hepatocytes protecting them from hypoxia-induced cell death, while GAS6 diminished lipopolysaccharide (LPS)-induced cytokine expression (IL-1β and TNF) in murine macrophages. Finally, in vivo recombinant GAS6 treatment not only rescued GAS6 knockout mice from I/R-induced severe liver damage, but also attenuated hepatic damage in wild type mice following I/R. In conclusion, our data uncover GAS6 as a new player in liver I/R injury, emerging as a potential therapeutic target to reduce post-ischemic hepatic damage. PMID:20730776

  18. Growth arrest-specific protein 6 is hepatoprotective against murine ischemia/reperfusion injury.

    Science.gov (United States)

    Llacuna, Laura; Bárcena, Cristina; Bellido-Martín, Lola; Fernández, Laura; Stefanovic, Milica; Marí, Montserrat; García-Ruiz, Carmen; Fernández-Checa, José C; García de Frutos, Pablo; Morales, Albert

    2010-10-01

    Growth arrest-specific gene 6 (GAS6) promotes growth and cell survival during tissue repair and development in different organs, including the liver. However, the specific role of GAS6 in liver ischemia/reperfusion (I/R) injury has not been previously addressed. Here we report an early increase in serum GAS6 levels after I/R exposure. Moreover, unlike wild-type (WT) mice, Gas6(-/-) mice were highly sensitive to partial hepatic I/R, with 90% of the mice dying within 12 hours of reperfusion because of massive hepatocellular injury. I/R induced early hepatic protein kinase B (AKT) phosphorylation in WT mice but not in Gas6(-/-) mice without significant changes in c-Jun N-terminal kinase phosphorylation or nuclear factor kappa B translocation, whereas hepatic interleukin-1β (IL-1β) and tumor necrosis factor (TNF) messenger RNA levels were higher in Gas6(-/-) mice versus WT mice. In line with the in vivo data, in vitro studies indicated that GAS6 induced AKT phosphorylation in primary mouse hepatocytes and thus protected them from hypoxia-induced cell death, whereas GAS6 diminished lipopolysaccharide-induced cytokine expression (IL-1β and TNF) in murine macrophages. Finally, recombinant GAS6 treatment in vivo not only rescued GAS6 knockout mice from severe I/R-induced liver damage but also attenuated hepatic damage in WT mice after I/R. Our data have revealed GAS6 to be a new player in liver I/R injury that is emerging as a potential therapeutic target for reducing postischemic hepatic damage.

  19. Increased Susceptibility to Apoptosis and Growth Arrest of Human Breast Cancer Cells Treated by a Snake Venom-Loaded Silica Nanoparticles

    Directory of Open Access Journals (Sweden)

    Gamal Badr

    2014-11-01

    Full Text Available Background: The development of effective treatments against metastatic cancers, including breast cancer, is among the most important challenges in current experimental and clinical cancer research. We recently demonstrated that Walterinnesia aegyptia venom (WEV, either alone or in combination with silica nanoparticles (WEV+NP, resulted in the growth arrest and apoptosis of different cancer cell lines. Aims: In the present study, we evaluated the impact of WEV alone and WEV+NP on human breast cancer cells isolated from cancer biopsies. Methods: The potential effects of WEV alone and WEV+NP on the proliferation, induction of apoptosis and generation of free radicals in breast cancer cells isolated from 80 patients clinically diagnosed with breast cancer were evaluated by flow cytometry and ELISA. Results: WEV alone and WEV+NP inhibited the proliferation, altered the cell cycle and enhanced the induction of apoptosis of the breast cancer cells by increasing the activities of caspase-3, caspase-8 and caspase-9. In addition, the combination of WEV and NP robustly sensitized the breast cancer cells to growth arrest and apoptosis by increasing the generation of free radicals, including reactive oxygen species (ROS, hydroperoxide and nitric oxide. The combination of WEV with NP significantly enhanced the anti-tumor effect of WEV in breast cancer cells. Conclusion: Our data indicate the therapeutic potential of the nanoparticle-sustained delivery of snake venom for the treatment of breast cancer.

  20. Effects of maple (Acer) plant part extracts on proliferation, apoptosis and cell cycle arrest of human tumorigenic and non-tumorigenic colon cells.

    Science.gov (United States)

    González-Sarrías, Antonio; Li, Liya; Seeram, Navindra P

    2012-07-01

    Phenolic-enriched extracts of maple sap and syrup, obtained from the sugar and red maple species (Acer saccharum Marsh, A. rubrum L., respectively), are reported to show anticancer effects. Despite traditional medicinal uses of various other parts of these plants by Native Americans, they have not been investigated for anticancer activity. Here leaves, stems/twigs, barks and sapwoods of both maple species were evaluated for antiproliferative effects against human colon tumorigenic (HCT-116, HT-29, Caco-2) and non-tumorigenic (CCD-18Co) cells. Extracts were standardized to total phenolic and ginnalin-A (isolated in our laboratory) levels. Overall, the extracts inhibited the growth of the colon cancer more than normal cells (over two-fold), their activities increased with their ginnalin-A levels, with red > sugar maple extracts. The red maple leaf extract, which contained the highest ginnalin-A content, was the most active extract (IC₅₀  = 35 and 16 µg/mL for extract and ginnalin-A, respectively). The extracts were not cytotoxic nor did they induce apoptosis of the colon cancer cells. However, cell cycle analyses revealed that the antiproliferative effects of the extracts were mediated through cell cycle arrest in the S-phase. The results from the current study suggest that these maple plant part extracts may have potential anticolon cancer effects. Copyright © 2011 John Wiley & Sons, Ltd.

  1. Growth patterns and annual growth cycle of Acacia karroo Hayne in ...

    African Journals Online (AJOL)

    ... karroo; alice; botany; compensatory growth; condition; development; eastern cape; emergence; environmental conditions; field study; growth cycle; growth initiation; growth patterns; growth strategy; leaf growth; plant growth; savanna; shoot growth; soil depth; soil moisture; south africa; university of fort hare; water stress ...

  2. Benzylidene derivatives of andrographolide inhibit growth of breast and colon cancer cells in vitro by inducing G1 arrest and apoptosis

    Science.gov (United States)

    Jada, S R; Matthews, C; Saad, M S; Hamzah, A S; Lajis, N H; Stevens, M F G; Stanslas, J

    2008-01-01

    Background and purpose: Andrographolide, the major phytoconstituent of Andrographis paniculata, was previously shown by us to have activity against breast cancer. This led to synthesis of new andrographolide analogues to find compounds with better activity than the parent compound. Selected benzylidene derivatives were investigated for their mechanisms of action by studying their effects on the cell cycle progression and cell death. Experimental approach: Microculture tetrazolium, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) and sulphorhodamine B (SRB) assays were utilized in assessing the in vitro growth inhibition and cytotoxicity of compounds. Flow cytometry was used to analyse the cell cycle distribution of control and treated cells. CDK1 and CDK4 levels were determined by western blotting. Apoptotic cell death was assessed by fluorescence microscopy and flow cytometry. Key results: Compounds, in nanomolar to micromolar concentrations, exhibited growth inhibition and cytotoxicity in MCF-7 (breast) and HCT-116 (colon) cancer cells. In the NCI screen, 3,19-(2-bromobenzylidene) andrographolide (SRJ09) and 3,19-(3-chloro-4-fluorobenzylidene) andrographolide (SRJ23) showed greater cytotoxic potency and selectivity than andrographolide. SRJ09 and SRJ23 induced G1 arrest and apoptosis in MCF-7 and HCT-116 cells, respectively. SRJ09 downregulated CDK4 but not CDK1 level in MCF-7 cells. Apoptosis induced by SRJ09 and SRJ23 in HCT-116 cells was confirmed by annexin V-FITC/PI flow cytometry analysis. Conclusion and implications: The new benzylidene derivatives of andrographolide are potential anticancer agents. SRJ09 emerged as the lead compound in this study, exhibiting anticancer activity by downregulating CDK4 to promote a G1 phase cell cycle arrest, coupled with induction of apoptosis. PMID:18806812

  3. Combination of HDAC inhibitor TSA and silibinin induces cell cycle arrest and apoptosis by targeting survivin and cyclinB1/Cdk1 in pancreatic cancer cells.

    Science.gov (United States)

    Feng, Wan; Cai, Dawei; Zhang, Bin; Lou, Guochun; Zou, Xiaoping

    2015-08-01

    Histone deacetylases (HDAC) are involved in diverse biological processes and therefore emerge as potential targets for pancreatic cancer. Silibinin, an active component of silymarin, is known to inhibit growth of pancreatic cancer in vivo and in vitro. Herein, we examined the cytotoxic effects of TSA in combination with silibinin and investigated the possible mechanism in two pancreatic cancer cell lines (Panc1 and Capan2). Our study found that combination treatment of HDAC inhibitor and silibinin exerted additive growth inhibitory effect on pancreatic cancer cell. Annexin V-FITC/PI staining and flow cytometry analysis demonstrated that combination therapy induced G2/M cell cycle arrest and apoptosis in Panc1and Capan2 cells. The induction of apoptosis was further confirmed by evaluating the activation of caspases. Moreover, treatment with TSA and silibinin resulted in a profound reduction in the expression of cyclinA2, cyclinB1/Cdk1 and survivin. Taken together, our study might indicate that the novel combination of HDAC inhibitor and silibinin could offer therapeutic potential against pancreatic cancer. Copyright © 2015. Published by Elsevier Masson SAS.

  4. Cell cycle arrest as a hallmark of insect diapause: Changes in gene transcription during diapause induction in the drosophilid fly, Chymomyza costata

    Czech Academy of Sciences Publication Activity Database

    Košťál, Vladimír; Šimůnková, P.; Kobelková, Alena; Shimada, K.

    2009-01-01

    Roč. 39, č. 12 (2009), s. 875-883 ISSN 0965-1748 R&D Projects: GA MŠk LC07032 Institutional research plan: CEZ:AV0Z50070508 Keywords : Drosophila * cell cycle arrest * diapause Subject RIV: ED - Physiology Impact factor: 3.117, year: 2009

  5. Toona Sinensis Extracts Induced Cell Cycle Arrest and Apoptosis in the Human Lung Large Cell Carcinoma

    Directory of Open Access Journals (Sweden)

    Cheng-Yuan Wang

    2010-02-01

    Full Text Available Toona sinensis extracts have been shown to exhibit anti-cancer effects in human ovarian cancer cell lines, human promyelocytic leukemia cells and human lung adenocarcinoma. Its safety has also been confirmed in animal studies. However, its anti-cancer properties in human lung large cell carcinoma have not been studied. Here, we used a powder obtained by freeze-drying the super-natant of centrifuged crude extract from Toona sinensis leaves (TSL-1 to treat the human lung carcinoma cell line H661. Cell viability was evaluated by the 3-(4-,5-dimethylthiazol-2-yl-2,5-diphenyl tetrazolium bromide assay. Flow cytometry analysis revealed that TSL-1 blocked H661 cell cycle progression. Western blot analysis showed decreased expression of cell cycle proteins that promote cell cycle progression, including cyclin-dependent kinase 4 and cyclin D1, and increased the expression of proteins that inhibit cell cycle progression, including p27. Furthermore, flow cytometry analysis showed that TSL-1 induced H661 cell apoptosis. Western blot analysis showed that TSL-1 reduced the expression of the anti-apoptotic protein B-cell lymphoma 2, and degraded the DNA repair protein, poly(ADP-ribose polymerase. TSL-1 shows potential as a novel therapeutic agent or for use as an adjuvant for treating human lung large cell carcinoma.

  6. Resveratrol Improves Cell Cycle Arrest in Chronic Prostatitis Rats, by C-kit/SCF Suppression.

    Science.gov (United States)

    He, Yi; Zeng, Huizhi; Yu, Yang; Zhang, Jiashu; Zeng, Xiaona; Gong, Fengtao; Liu, Qi; Yang, Bo

    2017-08-01

    Chronic prostatitis (CP) with complex pathogenesis is difficult for treatment. c-kit has been associated with the control of cell proliferation of prostate cells. This study aims to evaluate the role of resveratrol, an activator of Sirt1, in regulating the expression of c-kit in CP and investigate the consequent effects on cell cycle. Rat model of CP was established through subcutaneous injections of diphtheria-pertussis-tetanus vaccine and subsequently treated with resveratrol. Hematoxylin and eosin staining was performed to identify the histopathological changes in prostates. Western blotting and immunohistochemical staining examined the expression level of c-kit, stem cell factor (SCF), Sirt1, and cell cycle-associated proteins. The model group exhibited severe diffuse chronic inflammation, characterized by leukocyte infiltration and papillary frond protrusion into the gland cavities, and a notable increase in prostatic epithelial height. Gland lumen diameter was also significantly smaller; the activity of c-kit/SCF in the CP rats was increased significantly compared to the control group. Meanwhile, the cell cycle proteins are dysregulated significantly in CP rats. Resveratrol treatment significantly improved these factors by Sirt1 activation. Dysregulation of cell cycle was involved in the pathological processes of CP, which was improved after resveratrol treatment by the downregulation of c-kit/SCF by activating Sirt1.

  7. Mutation of Growth Arrest Specific 8 Reveals a Role in Motile Cilia Function and Human Disease.

    Science.gov (United States)

    Lewis, Wesley R; Malarkey, Erik B; Tritschler, Douglas; Bower, Raqual; Pasek, Raymond C; Porath, Jonathan D; Birket, Susan E; Saunier, Sophie; Antignac, Corinne; Knowles, Michael R; Leigh, Margaret W; Zariwala, Maimoona A; Challa, Anil K; Kesterson, Robert A; Rowe, Steven M; Drummond, Iain A; Parant, John M; Hildebrandt, Friedhelm; Porter, Mary E; Yoder, Bradley K; Berbari, Nicolas F

    2016-07-01

    Ciliopathies are genetic disorders arising from dysfunction of microtubule-based cellular appendages called cilia. Different cilia types possess distinct stereotypic microtubule doublet arrangements with non-motile or 'primary' cilia having a 9+0 and motile cilia have a 9+2 array of microtubule doublets. Primary cilia are critical sensory and signaling centers needed for normal mammalian development. Defects in their structure/function result in a spectrum of clinical and developmental pathologies including abnormal neural tube and limb patterning. Altered patterning phenotypes in the limb and neural tube are due to perturbations in the hedgehog (Hh) signaling pathway. Motile cilia are important in fluid movement and defects in motility result in chronic respiratory infections, altered left-right asymmetry, and infertility. These features are the hallmarks of Primary Ciliary Dyskinesia (PCD, OMIM 244400). While mutations in several genes are associated with PCD in patients and animal models, the genetic lesion in many cases is unknown. We assessed the in vivo functions of Growth Arrest Specific 8 (GAS8). GAS8 shares strong sequence similarity with the Chlamydomonas Nexin-Dynein Regulatory Complex (NDRC) protein 4 (DRC4) where it is needed for proper flagella motility. In mammalian cells, the GAS8 protein localizes not only to the microtubule axoneme of motile cilia, but also to the base of non-motile cilia. Gas8 was recently implicated in the Hh signaling pathway as a regulator of Smoothened trafficking into the cilium. Here, we generate the first mouse with a Gas8 mutation and show that it causes severe PCD phenotypes; however, there were no overt Hh pathway phenotypes. In addition, we identified two human patients with missense variants in Gas8. Rescue experiments in Chlamydomonas revealed a subtle defect in swim velocity compared to controls. Further experiments using CRISPR/Cas9 homology driven repair (HDR) to generate one of these human missense variants in

  8. Mutation of Growth Arrest Specific 8 Reveals a Role in Motile Cilia Function and Human Disease.

    Directory of Open Access Journals (Sweden)

    Wesley R Lewis

    2016-07-01

    Full Text Available Ciliopathies are genetic disorders arising from dysfunction of microtubule-based cellular appendages called cilia. Different cilia types possess distinct stereotypic microtubule doublet arrangements with non-motile or 'primary' cilia having a 9+0 and motile cilia have a 9+2 array of microtubule doublets. Primary cilia are critical sensory and signaling centers needed for normal mammalian development. Defects in their structure/function result in a spectrum of clinical and developmental pathologies including abnormal neural tube and limb patterning. Altered patterning phenotypes in the limb and neural tube are due to perturbations in the hedgehog (Hh signaling pathway. Motile cilia are important in fluid movement and defects in motility result in chronic respiratory infections, altered left-right asymmetry, and infertility. These features are the hallmarks of Primary Ciliary Dyskinesia (PCD, OMIM 244400. While mutations in several genes are associated with PCD in patients and animal models, the genetic lesion in many cases is unknown. We assessed the in vivo functions of Growth Arrest Specific 8 (GAS8. GAS8 shares strong sequence similarity with the Chlamydomonas Nexin-Dynein Regulatory Complex (NDRC protein 4 (DRC4 where it is needed for proper flagella motility. In mammalian cells, the GAS8 protein localizes not only to the microtubule axoneme of motile cilia, but also to the base of non-motile cilia. Gas8 was recently implicated in the Hh signaling pathway as a regulator of Smoothened trafficking into the cilium. Here, we generate the first mouse with a Gas8 mutation and show that it causes severe PCD phenotypes; however, there were no overt Hh pathway phenotypes. In addition, we identified two human patients with missense variants in Gas8. Rescue experiments in Chlamydomonas revealed a subtle defect in swim velocity compared to controls. Further experiments using CRISPR/Cas9 homology driven repair (HDR to generate one of these human missense

  9. Algerian Propolis Potentiates Doxorubicin Mediated Anticancer Effect against Human Pancreatic PANC-1 Cancer Cell Line through Cell Cycle Arrest, Apoptosis Induction and P-Glycoprotein Inhibition.

    Science.gov (United States)

    Rouibah, Hassiba; Mesbah, Lahouel; Kebsa, Wided; Zihlif, Malek; Ahram, Mamoun; Aburmeleih, Bachaer; Mostafa, Ibtihal; El Amir, Hemzeh

    2018-01-10

    Pancreatic cancer is one of the most aggressive and lethal cancer, with poor prognosis and high resistant to current chemotherapeutic agents. Therefore, new therapeutic strategies and targets are underscored. Propolis has been reported to exhibit a broad spectrum of biological activities including anticancer activity. This study was carried out to assess the possible efficacy of Algerian propolis on the antitumor effect of doxorubicin on human pancreatic cancer cell line (PANC-1). Modifications in cell viability, apoptosis and cell cycle progression, Pgp activity and intracellular accumulation of DOX were monitored to study the synergistic effect of Algerian propolis on the antitumor effects of DOX in PANC-1 cell line. Both propolis and its combination with doxorubicin inhibited cell growth in a dose-dependent manner by inducing cell cycle arrest and apoptosis. In the presence of 100 µg/ml of propolis, the IC50 of DOX against PANC-1 cells decreased by 10.9-fold. Propolis combined with DOX increased after 48h, the number of cells in the G0G1 phase with dramatical increase in sub-G1 phase to reach 47% of total cells, corresponding to an increase of senescence or apoptotic state of the cells. Dead cell assay with annexinV/PI staining demonstrated that propolis and propolis-DOX treatment resulted in a remarkable induction of apoptosis as detected by flow cytometry. It was interesting to note that propolis at its 5IC50 was found as the most potent inducer of apoptosis. Our finding revealed that induced apoptosis in our conditions was caspase-3 and caspase-9 dependent. Flow cytometry showed that propolis increased the accumulation of doxorubicin within PANC-1 cells. Moreover, fluorescent intensity detection revealed that propolis remarkably increased the retention of rhodamine-123, 7-fold compared to 3-fold of verapamil, the most effective P-gp inhibitor. In conclusion, propolis sensitize pancreatic cancer cells to DOX via enhancing the intracellular retention of DOX

  10. Sensitization of gastric cancer cells to alkylating agents by glaucocalyxin B via cell cycle arrest and enhanced cell death

    Directory of Open Access Journals (Sweden)

    Ur Rahman MS

    2017-08-01

    Full Text Available Muhammad Saif Ur Rahman,1 Ling Zhang,2 Lingyan Wu,1 Yuqiong Xie,1 Chunchun Li,1 Jiang Cao1 1Clinical Research Center, 2Cardiovascular Key Laboratory of Zhejiang Province, The Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang Province, People’s Republic of China Abstract: Severe side effects are major problems with chemotherapy of gastric cancer (GC. These side effects can be reduced by using sensitizing agents in combination with therapeutic drugs. In this study, the low/nontoxic dosage of glaucocalyxin B (GLB was used with other DNA linker agents mitomycin C (MMC, cisplatin (DDP, or cyclophosphamide (CTX to treat GC cells. Combined effectiveness of GLB with drugs was determined by proliferation assay. The molecular mechanisms associated with cell proliferation, migration, invasion, cell cycle, DNA repair/replication, apoptosis, and autophagy were investigated by immunoblotting for key proteins involved. Cell cycle and apoptosis analysis were performed by flow cytometry. Reactive oxygen species level was also examined for identification of its role in apoptosis. Proliferation assay revealed that the addition of 5 µM GLB significantly sensitizes gastric cancer SGC-7901 cells to MMC, DDP, and CTX by decreasing half-maximal inhibitory concentration (IC50 by up to 75.40%±5%, 45.10%±5%, and 52.10%±5%, respectively. GLB + drugs decreased the expression level of proteins involved in proliferation and migration, suggesting the anticancer potential of GLB + drugs. GLB + MMC, GLB + CTX, and GLB + DDP arrest the cells in G0/G1 and G1/S phase, respectively, which may be the consequence of significant decrease in the level of enzymes responsible for DNA replication and telomerase shortening. Combined use of GLB with these drugs also induces DNA damage and apoptosis by activating caspase/PARP pathways and increased production of reactive oxygen species and increased autophagy in GC cells. GLB dosage sensitizes GC

  11. Histological Lesions, Cell Cycle Arrest, Apoptosis and T Cell Subsets Changes of Spleen in Chicken Fed Aflatoxin-contaminated Corn

    Directory of Open Access Journals (Sweden)

    Xi Peng

    2014-08-01

    Full Text Available The purpose of this study was to evaluate the effects of corn naturally contaminated with aflatoxin B1 and aflatoxin B2 on pathological lesions, apoptosis, cell cycle phases and T lymphocyte subsets of spleen, and to provide an experimental basis for understanding the mechanism of aflatoxin-induced immunosuppression. A total of 900 COBB500 male broilers were randomly allocated into five groups with six replicates per group and 30 birds per replicate. The experiment lasted for 6 weeks and the five dietary treatments consisted of control, 25% contaminated corn, 50% contaminated corn, 75% contaminated corn and 100% contaminated corn groups. The histopathological spleen lesions from the contaminated corn groups was characterized as congestion of red pulp, increased necrotic cells and vacuoles in the splenic corpuscle and periarterial lymphatic sheath. The contaminated corn intake significantly increased relative weight of spleen, percentages of apoptotic splenocytes, induced cell cycle arrest of splenocytes, increased the percentages of CD3+CD8+ T cells and decreased the ratios of CD3+CD4+ to CD3+CD8+. The results suggest that AFB-induced immunosuppression maybe closely related to the lesions of spleen.

  12. Nucleolar TRF2 attenuated nucleolus stress-induced HCC cell-cycle arrest by altering rRNA synthesis.

    Science.gov (United States)

    Yuan, Fuwen; Xu, Chenzhong; Li, Guodong; Tong, Tanjun

    2018-05-03

    The nucleolus is an important organelle that is responsible for the biogenesis of ribosome RNA (rRNA) and ribosomal subunits assembly. It is also deemed to be the center of metabolic control, considering the critical role of ribosomes in protein translation. Perturbations of rRNA synthesis are closely related to cell proliferation and tumor progression. Telomeric repeat-binding factor 2 (TRF2) is a member of shelterin complex that is responsible for telomere DNA protection. Interestingly, it was recently reported to localize in the nucleolus of human cells in a cell-cycle-dependent manner, while the underlying mechanism and its role on the nucleolus remained unclear. In this study, we found that nucleolar and coiled-body phosphoprotein 1 (NOLC1), a nucleolar protein that is responsible for the nucleolus construction and rRNA synthesis, interacted with TRF2 and mediated the shuttle of TRF2 between the nucleolus and nucleus. Abating the expression of NOLC1 decreased the nucleolar-resident TRF2. Besides, the nucleolar TRF2 could bind rDNA and promoted rRNA transcription. Furthermore, in hepatocellular carcinoma (HCC) cell lines HepG2 and SMMC7721, TRF2 overexpression participated in the nucleolus stress-induced rRNA inhibition and cell-cycle arrest.

  13. Conditional inactivation of PDCD2 induces p53 activation and cell cycle arrest

    Directory of Open Access Journals (Sweden)

    Celine J. Granier

    2014-08-01

    Full Text Available PDCD2 (programmed cell death domain 2 is a highly conserved, zinc finger MYND domain-containing protein essential for normal development in the fly, zebrafish and mouse. The molecular functions and cellular activities of PDCD2 remain unclear. In order to better understand the functions of PDCD2 in mammalian development, we have examined PDCD2 activity in mouse blastocyst embryos, as well as in mouse embryonic stem cells (ESCs and embryonic fibroblasts (MEFs. We have studied mice bearing a targeted PDCD2 locus functioning as a null allele through a splicing gene trap, or as a conditional knockout, by deletion of exon2 containing the MYND domain. Tamoxifen-induced knockout of PDCD2 in MEFs, as well as in ESCs, leads to defects in progression from the G1 to the S phase of cell cycle, associated with increased levels of p53 protein and p53 target genes. G1 prolongation in ESCs was not associated with induction of differentiation. Loss of entry into S phase of the cell cycle and marked induction of nuclear p53 were also observed in PDCD2 knockout blastocysts. These results demonstrate a unique role for PDCD2 in regulating the cell cycle and p53 activation during early embryonic development of the mouse.

  14. Lebein, a snake venom disintegrin, suppresses human colon cancer cells proliferation and tumor-induced angiogenesis through cell cycle arrest, apoptosis induction and inhibition of VEGF expression.

    Science.gov (United States)

    Zakraoui, Ons; Marcinkiewicz, Cezary; Aloui, Zohra; Othman, Houcemeddine; Grépin, Renaud; Haoues, Meriam; Essafi, Makram; Srairi-Abid, Najet; Gasmi, Ammar; Karoui, Habib; Pagès, Gilles; Essafi-Benkhadir, Khadija

    2017-01-01

    Lebein, is an heterodimeric disintegrin isolated from Macrovipera lebetina snake venom that was previously characterized as an inhibitor of ADP-induced platelet aggregation. In this study, we investigated the effect of Lebein on the p53-dependent growth of human colon adenocarcinoma cell lines. We found that Lebein significantly inhibited LS174 (p53wt), HCT116 (p53wt), and HT29 (p53mut) colon cancer cell viability by inducing cell cycle arrest through the modulation of expression levels of the tumor suppression factor p53, cell cycle regulating proteins cyclin D1, CDK2, CDK4, retinoblastoma (Rb), CDK1, and cyclin-dependent kinase inhibitors p21 and p27. Interestingly, Lebein-induced apoptosis of colon cancer cells was dependent on their p53 status. Thus, in LS174 cells, cell death was associated with PARP cleavage and the activation of caspases 3 and 8 while in HCT116 cells, Lebein induced caspase-independent apoptosis through increased expression of apoptosis inducing factor (AIF). In LS174 cells, Lebein triggers the activation of the MAPK ERK1/2 pathway through induction of reactive oxygen species (ROS). It also decreased cell adhesion and migration to fibronectin through down regulation of α5β1 integrin. Moreover, Lebein significantly reduced the expression of two angiogenesis stimulators, Vascular Endothelial Growth Factor (VEGF) and Neuropilin 1 (NRP1). It inhibited the VEGF-induced neovascularization process in the quail embryonic CAM system and blocked the development of human colon adenocarcinoma in nude mice. Overall, our work indicates that Lebein may be useful to design a new therapy against colon cancer. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  15. Inhibition of human prostate cancer cells proliferation by a selective alpha1-adrenoceptor antagonist labedipinedilol-A involves cell cycle arrest and apoptosis

    International Nuclear Information System (INIS)

    Liou, S.-F.; Lin, H.-H.; Liang, J.-C.; Chen, I.-J.; Yeh, J.-L.

    2009-01-01

    In this research, we conducted an in vitro analysis to evaluate the prostate cancer cells response to labedipinedilol-A in order to determine the effect of this selective α 1 -adrenoceptor antagonist to suppress prostate cancer cell growth by affecting cell proliferation and apoptosis. Here, we report that treatment of androgen-sensitive (LNCaP) and androgen-insensitive (PC-3) prostate cancer cells with labedipinedilol-A inhibited cell proliferation in concentration-dependent and time-dependent manners. Moreover, norepinephrine-stimulated proliferation of both cell lines are markedly inhibited by labedipinedilol-A. The probable involvement of α 1 -adrenoceptors in this cellular response is suggested. Labedipinedilol-A-induced growth inhibition was associated with G 0 /G 1 arrest, and G 2 /M arrest depending upon concentrations. Cell cycle blockade was associated with reduced amounts of cyclin D1/2, cyclin E, Cdk2, Cdk4, and Cdk6 and increased levels of the Cdk inhibitory proteins (Cip1/p21 and Kip1/p27). In addition, labedipinedilol-A also induced apoptosis in PC-3 cells, as determined by using Hoechst 33342 staining, DNA fragmentation, and Annexin V staining assay. Furthermore, labedipinedilol-A triggered the mitochondrial apoptotic pathway, as indicated by increasing the expression of Bax, but decreasing the level of Bcl-2, resulting in mitochondrial membrane potential loss, cytochrome c release, and activation of caspase-9 and -3. We further investigated the role of MAPK cascades in the anti-proliferative and apoptosis effects of labedipinedilol-A, and confirmed that labedipinedilol-A could activate JNK1/2 but not p38 in both cell lines. Unlike JNK1/2, however, labedipinedilol-A treatment resulted in down-regulation of phospho-ERK1/2 expression. We concluded that labedipinedilol-A possessed the growth-suppressive and apoptotic effects on LNCaP and PC-3 cells by its α 1 -adrenoceptor blockade, and the apoptotic effects of labedipinedilol-A primarily through

  16. Eco-Friendly Formulated Zinc Oxide Nanoparticles: Induction of Cell Cycle Arrest and Apoptosis in the MCF-7 Cancer Cell Line.

    Science.gov (United States)

    Boroumand Moghaddam, Amin; Moniri, Mona; Azizi, Susan; Abdul Rahim, Raha; Bin Ariff, Arbakariya; Navaderi, Mohammad; Mohamad, Rosfarizan

    2017-10-20

    Green products have strong potential in the discovery and development of unique drugs. Zinc oxide nanoparticles (ZnO NPs) have been observed to have powerful cytotoxicity against cells that cause breast cancer. The present study aims to examine the cell cycle profile, status of cell death, and pathways of apoptosis in breast cancer cells (MCF-7) treated with biosynthesized ZnO NPs. The anti-proliferative activity of ZnO NPs was determined using MTT assay. Cell cycle analysis and the mode of cell death were evaluated using a flow cytometry instrument. Quantitative real-time-PCR (qRT-PCR) was employed to investigate the expression of apoptosis in MCF-7 cells. ZnO NPs were cytotoxic to the MCF-7 cells in a dose-dependent manner. The 50% growth inhibition concentration (IC 50 ) of ZnO NPs at 24 h was 121 µg/mL. Cell cycle analysis revealed that ZnO NPs induced sub-G₁ phase (apoptosis), with values of 1.87% at 0 μg/mL (control), 71.49% at IC 25 , 98.91% at IC 50 , and 99.44% at IC 75 . Annexin V/propidium iodide (PI) flow cytometry analysis confirmed that ZnO NPs induce apoptosis in MCF-7 cells. The pro-apoptotic genes p53 , p21 , Bax , and JNK were upregulated, whereas anti-apoptotic genes Bcl-2 , AKT1 , and ERK1/2 were downregulated in a dose-dependent manner. The arrest and apoptosis of MCF-7 cells were induced by ZnO NPs through several signalling pathways.

  17. Induction of G1 and G2/M cell cycle arrests by the dietary compound 3,3'-diindolylmethane in HT-29 human colon cancer cells

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    Choi Hyun

    2009-05-01

    Full Text Available Abstract Background 3,3'-Diindolylmethane (DIM, an indole derivative produced in the stomach after the consumption of broccoli and other cruciferous vegetables, has been demonstrated to exert anti-cancer effects in both in vivo and in vitro models. We have previously determined that DIM (0 – 30 μmol/L inhibited the growth of HT-29 human colon cancer cells in a concentration-dependent fashion. In this study, we evaluated the effects of DIM on cell cycle progression in HT-29 cells. Methods HT-29 cells were cultured with various concentrations of DIM (0 – 30 μmol/L and the DNA was stained with propidium iodide, followed by flow cytometric analysis. [3H]Thymidine incorporation assays, Western blot analyses, immunoprecipitation and in vitro kinase assays for cyclin-dependent kinase (CDK and cell division cycle (CDC2 were conducted. Results The percentages of cells in the G1 and G2/M phases were dose-dependently increased and the percentages of cells in S phase were reduced within 12 h in DIM-treated cells. DIM also reduced DNA synthesis in a dose-dependent fashion. DIM markedly reduced CDK2 activity and the levels of phosphorylated retinoblastoma proteins (Rb and E2F-1, and also increased the levels of hypophosphorylated Rb. DIM reduced the protein levels of cyclin A, D1, and CDK4. DIM also increased the protein levels of CDK inhibitors, p21CIP1/WAF1 and p27KIPI. In addition, DIM reduced the activity of CDC2 and the levels of CDC25C phosphatase and cyclin B1. Conclusion Here, we have demonstrated that DIM induces G1 and G2/M phase cell cycle arrest in HT-29 cells, and this effect may be mediated by reduced CDK activity.

  18. Induction of G1 and G2/M cell cycle arrests by the dietary compound 3,3'-diindolylmethane in HT-29 human colon cancer cells.

    Science.gov (United States)

    Choi, Hyun Ju; Lim, Do Young; Park, Jung Han Yoon

    2009-05-29

    3,3'-Diindolylmethane (DIM), an indole derivative produced in the stomach after the consumption of broccoli and other cruciferous vegetables, has been demonstrated to exert anti-cancer effects in both in vivo and in vitro models. We have previously determined that DIM (0 - 30 micromol/L) inhibited the growth of HT-29 human colon cancer cells in a concentration-dependent fashion. In this study, we evaluated the effects of DIM on cell cycle progression in HT-29 cells. HT-29 cells were cultured with various concentrations of DIM (0 - 30 micromol/L) and the DNA was stained with propidium iodide, followed by flow cytometric analysis. [3H]Thymidine incorporation assays, Western blot analyses, immunoprecipitation and in vitro kinase assays for cyclin-dependent kinase (CDK) and cell division cycle (CDC)2 were conducted. The percentages of cells in the G1 and G2/M phases were dose-dependently increased and the percentages of cells in S phase were reduced within 12 h in DIM-treated cells. DIM also reduced DNA synthesis in a dose-dependent fashion. DIM markedly reduced CDK2 activity and the levels of phosphorylated retinoblastoma proteins (Rb) and E2F-1, and also increased the levels of hypophosphorylated Rb. DIM reduced the protein levels of cyclin A, D1, and CDK4. DIM also increased the protein levels of CDK inhibitors, p21CIP1/WAF1 and p27KIPI. In addition, DIM reduced the activity of CDC2 and the levels of CDC25C phosphatase and cyclin B1. Here, we have demonstrated that DIM induces G1 and G2/M phase cell cycle arrest in HT-29 cells, and this effect may be mediated by reduced CDK activity.

  19. Effect of Scopoletin on Apoptosis and Cell Cycle Arrest in Human ...

    African Journals Online (AJOL)

    treatment with increasing doses compared to control cells, scopoletin treatment resulted in cell ... Conclusion: These results reveal that scopoletin may be used as a natural chemotherapeutic agent .... apoptosis, and necrosis in LNCaP cells .... Pan R, Dai Y, Gao XH, Lu D, Xia YF. Inhibition of vascular endothelial growth.

  20. The production of reactive oxygen species and the mitochondrial membrane potential are modulated during onion oil-induced cell cycle arrest and apoptosis in A549 cells.

    Science.gov (United States)

    Wu, Xin-jiang; Stahl, Thorsten; Hu, Ying; Kassie, Fekadu; Mersch-Sundermann, Volker

    2006-03-01

    Protective effects of Allium vegetables against cancers have been shown extensively in experimental animals and epidemiologic studies. We investigated cell proliferation and the induction of apoptosis by onion oil extracted from Allium cepa, a widely consumed Allium vegetable, in human lung cancer A549 cells. GC/MS analysis suggested that propyl sulfides but not allyl sulfides are major sulfur-containing constituents of onion oil. Onion oil at 12.5 mg/L significantly induced apoptosis (13% increase of apoptotic cells) as indicated by sub-G1 DNA content. It also caused cell cycle arrest at the G2/M phase; 25 mg/L onion oil increased the percentage of G2/M cells almost 6-fold compared with the dimethyl sulfoxide control. The action of onion oil may occur via a reactive oxygen species-dependent pathway because cell cycle arrest and apoptosis were blocked by the antioxidants N-acetylcysteine and exogenous glutathione. Marked collapse of the mitochondrial membrane potential suggested that dysfunction of the mitochondria may be involved in the oxidative burst and apoptosis induced by onion oil. Expression of phospho-cdc2 and phospho-cyclin B1 were downregulated by onion oil, perhaps accounting for the G2/M arrest. Overall, these results suggest that onion oil may exert chemopreventive action by inducing cell cycle arrest and apoptosis in tumor cells.

  1. Parvovirus B19 NS1 protein induces cell cycle arrest at G2-phase by activating the ATR-CDC25C-CDK1 pathway.

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    Peng Xu

    2017-03-01

    Full Text Available Human parvovirus B19 (B19V infection of primary human erythroid progenitor cells (EPCs arrests infected cells at both late S-phase and G2-phase, which contain 4N DNA. B19V infection induces a DNA damage response (DDR that facilitates viral DNA replication but is dispensable for cell cycle arrest at G2-phase; however, a putative C-terminal transactivation domain (TAD2 within NS1 is responsible for G2-phase arrest. To fully understand the mechanism underlying B19V NS1-induced G2-phase arrest, we established two doxycycline-inducible B19V-permissive UT7/Epo-S1 cell lines that express NS1 or NS1mTAD2, and examined the function of the TAD2 domain during G2-phase arrest. The results confirm that the NS1 TAD2 domain plays a pivotal role in NS1-induced G2-phase arrest. Mechanistically, NS1 transactivated cellular gene expression through the TAD2 domain, which was itself responsible for ATR (ataxia-telangiectasia mutated and Rad3-related activation. Activated ATR phosphorylated CDC25C at serine 216, which in turn inactivated the cyclin B/CDK1 complex without affecting nuclear import of the complex. Importantly, we found that the ATR-CHK1-CDC25C-CDK1 pathway was activated during B19V infection of EPCs, and that ATR activation played an important role in B19V infection-induced G2-phase arrest.

  2. Arctigenin induces cell cycle arrest by blocking the phosphorylation of Rb via the modulation of cell cycle regulatory proteins in human gastric cancer cells.

    Science.gov (United States)

    Jeong, Jin Boo; Hong, Se Chul; Jeong, Hyung Jin; Koo, Jin Suk

    2011-10-01

    Gastric cancer is a leading cause of cancer-related deaths, worldwide being second only to lung cancer as a cause of death. Arctigenin, a representative dibenzylbutyrolactone lignan, occurs in a variety of plants. However, the molecular mechanisms of arctigenin for anti-tumor effect on gastric cancer have not been examined. This study examined the biological effects of arctigenin on the human gastric cancer cell line SNU-1 and AGS. Cell proliferation was determined by MTT assay. In MTT assay, the proliferation of SNU-1 and AGS cells was significantly inhibited by arctigenin in a time and dose dependent manner, as compared with SNU-1 and AGS cells cultured in the absence of arctigenin. Inhibition of cell proliferation by arctigenin was in part associated with apoptotic cell death, as shown by changes in the expression ratio of Bcl-2 to Bax by arctigenin. Also, arctigenin blocked cell cycle arrest from G(1) to S phase by regulating the expression of cell cycle regulatory proteins such as Rb, cyclin D1, cyclin E, CDK4, CDK2, p21Waf1/Cip1 and p15 INK4b. The antiproliferative effect of arctigenin on SNU-1 and AGS gastric cancer cells revealed in this study suggests that arctigenin has intriguing potential as a chemopreventive or chemotherapeutic agent. Crown Copyright © 2011. Published by Elsevier B.V. All rights reserved.

  3. The use of cell cycle arrest biomarkers in the early detection of acute kidney injury. Is this the new renal troponin?

    Science.gov (United States)

    Ortega, Luis M; Heung, Michael

    2018-04-05

    Acute kidney injury (AKI) has a high prevalence in critical care patients. Early detection might prevent patients from developing chronic kidney disease and requirement for renal replacement therapy. If we compare AKI with acute coronary syndrome, in which an increase in cardiac troponin may trigger early diagnosis and therapeutic intervention, we could extrapolate a similar technique in patients with early AKI without changes in urinary frequency or serum creatinine. The objective is to identify biomarker-positive, creatinine-negative patients that would allow therapeutic interventions to be initiated before finding changes in serum creatinine, preventing kidney damage. Tissue inhibitor of metalloproteinase 2 and insulin-like growth factor binding protein 7 are cell cycle arrest biomarkers that have demonstrated, in recent clinical trials, to have good sensitivity and specificity for early detection of AKI. Other recent studies have shown that the joint use of these biomarkers with serum creatinine and urine production could improve the prognosis of AKI in critical patients. The application of these biomarkers in clinical practice would enable the early identification of patients at risk of AKI, establishing interventions that would improve the survival of renal function. Copyright © 2017 Sociedad Española de Nefrología. Published by Elsevier España, S.L.U. All rights reserved.

  4. Capilliposide Isolated from Lysimachia capillipes Hemsl. Induces ROS Generation, Cell Cycle Arrest, and Apoptosis in Human Nonsmall Cell Lung Cancer Cell Lines

    Directory of Open Access Journals (Sweden)

    Zheng-hua Fei

    2014-01-01

    Full Text Available Several data has reported that capilliposide, extracted from a traditional Chinese medicine, Lysimachia capillipes Hemsl. (LC could exhibit inhibitory effect on cell proliferation in various cancers. The current study investigated the antitumor efficacy of Capilliposide and elucidated its potential molecular mechanism involved in vivo and vitro. Our results indicated that LC capilliposide inhibited proliferation of lung cancer cells in a dose-dependent manner. LC capilliposide induced cell cycle arrest at the S stage and enhanced apoptosis in NSCLC cells. Treatment with LC capilliposide increased the intracellular level of ROS, which activated the mitochondrial apoptotic pathway. Blockage of ROS by NAC highly reversed the effect of LC capilliposide on apoptosis. Xenograft tumor growth was significantly lower in the LC-treated group compared with the untreated control group (P<0.05. The results also show that LC treatment does not produce any overt signs of acute toxicity in vivo. These findings demonstrate that LC capilliposide could exert an anti-tumor effect on NSCLC through mitochondrial-mediated apoptotic pathway and the activation of ROS is involved.

  5. CXXC5 suppresses hepatocellular carcinoma by promoting TGF-β-induced cell cycle arrest and apoptosis.

    Science.gov (United States)

    Yan, Xiaohua; Wu, Jingyi; Jiang, Quanlong; Cheng, Hao; Han, Jing-Dong J; Chen, Ye-Guang

    2018-02-01

    Evading TGF-β-mediated growth inhibition is often associated with tumorigenesis in liver, including hepatocellular carcinoma (HCC). To better understand the functions and the underlying molecular mechanisms of TGF-β in HCC initiation and progression, we carried out transcriptome sequencing (RNA-Seq) to identify the target genes of TGF-β. CXXC5, a member of the CXXC-type zinc finger domain-containing protein family, was identified as a novel TGF-β target gene in Hep3B HCC cells. Knockdown of CXXC5 attenuated the expression of a substantial portion of TGF-β target genes and ameliorated TGF-β-induced growth inhibition or apoptosis of Hep3B cells, suggesting that CXXC5 is required for TGF-β-mediated inhibition of HCC progression. Analysis of the TCGA database indicated that CXXC5 expression is reduced in the majority of HCC tissue samples in comparison to that in normal tissues. Furthermore, CXXC5 associates with the histone deacetylase HDAC1 and competes its interaction with Smad2/3, thereby abolishing the inhibitory effect of HDAC1 on TGF-β signaling. These observations together suggest that CXXC5 may act as a tumor suppressor by promoting TGF-β signaling via a positive feedback loop, and reveal a strategy for HCC to bypass TGF-β-mediated cytostasis by disrupting the positive feedback regulation. Our findings shed new light on TGF-β signaling regulation and demonstrate the function of CXXC5 in HCC development.

  6. Resveratrol induces cell cycle arrest and apoptosis in malignant NK cells via JAK2/STAT3 pathway inhibition.

    Science.gov (United States)

    Quoc Trung, Ly; Espinoza, J Luis; Takami, Akiyoshi; Nakao, Shinji

    2013-01-01

    Natural killer (NK) cell malignancies, particularly aggressive NK cell leukaemias and lymphomas, have poor prognoses. Although recent regimens with L-asparaginase substantially improved outcomes, novel therapeutic approaches are still needed to enhance clinical response. Resveratrol, a naturally occurring polyphenol, has been extensively studied for its anti-inflammatory, cardioprotective and anti-cancer activities. In this study, we investigated the potential anti-tumour activities of resveratrol against the NK cell lines KHYG-1, NKL, NK-92 and NK-YS. Resveratrol induced robust G0/G1 cell cycle arrest, significantly suppressed cell proliferation and induced apoptosis in a dose- and time-dependent manner for all four cell lines. In addition, resveratrol suppressed constitutively active STAT3 in all the cell lines and inhibited JAK2 phosphorylation but had no effect on other upstream mediators of STAT3 activation, such as PTEN, TYK2, and JAK1. Resveratrol also induced downregulation of the anti-apoptotic proteins MCL1 and survivin, two downstream effectors of the STAT3 pathway. Finally, resveratrol induced synergistic effect on the apoptotic and antiproliferative activities of L-asparaginase against KHYG-1, NKL and NK-92 cells. These results suggest that resveratrol may have therapeutic potential against NK cell malignancies. Furthermore, our finding that resveratrol is a bonafide JAK2 inhibitor extends its potential benefits to other diseases with dysregulated JAK2 signaling.

  7. Resveratrol induces cell cycle arrest and apoptosis in malignant NK cells via JAK2/STAT3 pathway inhibition.

    Directory of Open Access Journals (Sweden)

    Ly Quoc Trung

    Full Text Available Natural killer (NK cell malignancies, particularly aggressive NK cell leukaemias and lymphomas, have poor prognoses. Although recent regimens with L-asparaginase substantially improved outcomes, novel therapeutic approaches are still needed to enhance clinical response. Resveratrol, a naturally occurring polyphenol, has been extensively studied for its anti-inflammatory, cardioprotective and anti-cancer activities. In this study, we investigated the potential anti-tumour activities of resveratrol against the NK cell lines KHYG-1, NKL, NK-92 and NK-YS. Resveratrol induced robust G0/G1 cell cycle arrest, significantly suppressed cell proliferation and induced apoptosis in a dose- and time-dependent manner for all four cell lines. In addition, resveratrol suppressed constitutively active STAT3 in all the cell lines and inhibited JAK2 phosphorylation but had no effect on other upstream mediators of STAT3 activation, such as PTEN, TYK2, and JAK1. Resveratrol also induced downregulation of the anti-apoptotic proteins MCL1 and survivin, two downstream effectors of the STAT3 pathway. Finally, resveratrol induced synergistic effect on the apoptotic and antiproliferative activities of L-asparaginase against KHYG-1, NKL and NK-92 cells. These results suggest that resveratrol may have therapeutic potential against NK cell malignancies. Furthermore, our finding that resveratrol is a bonafide JAK2 inhibitor extends its potential benefits to other diseases with dysregulated JAK2 signaling.

  8. Tocotrienol-Rich Fraction Prevents Cell Cycle Arrest and Elongates Telomere Length in Senescent Human Diploid Fibroblasts

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    Suzana Makpol

    2011-01-01

    Full Text Available This study determined the molecular mechanisms of tocotrienol-rich fraction (TRF in preventing cellular senescence of human diploid fibroblasts (HDFs. Primary culture of HDFs at various passages were incubated with 0.5 mg/mL TRF for 24 h. Telomere shortening with decreased telomerase activity was observed in senescent HDFs while the levels of damaged DNA and number of cells in G0/G1 phase were increased and S phase cells were decreased. Incubation with TRF reversed the morphology of senescent HDFs to resemble that of young cells with decreased activity of SA-β-gal, damaged DNA, and cells in G0/G1 phase while cells in the S phase were increased. Elongated telomere length and restoration of telomerase activity were observed in TRF-treated senescent HDFs. These findings confirmed the ability of tocotrienol-rich fraction in preventing HDFs cellular ageing by restoring telomere length and telomerase activity, reducing damaged DNA, and reversing cell cycle arrest associated with senescence.

  9. Phytometabolite Dehydroleucodine Induces Cell Cycle Arrest, Apoptosis, and DNA Damage in Human Astrocytoma Cells through p73/p53 Regulation.

    Directory of Open Access Journals (Sweden)

    Natalia Bailon-Moscoso

    Full Text Available Accumulating evidence supports the idea that secondary metabolites obtained from medicinal plants (phytometabolites may be important contributors in the development of new chemotherapeutic agents to reduce the occurrence or recurrence of cancer. Our study focused on Dehydroleucodine (DhL, a sesquiterpene found in the provinces of Loja and Zamora-Chinchipe. In this study, we showed that DhL displayed cytostatic and cytotoxic activities on the human cerebral astrocytoma D384 cell line. With lactone isolated from Gynoxys verrucosa Wedd, a medicinal plant from Ecuador, we found that DhL induced cell death in D384 cells by triggering cell cycle arrest and inducing apoptosis and DNA damage. We further found that the cell death resulted in the increased expression of CDKN1A and BAX proteins. A marked induction of the levels of total TP73 and phosphorylated TP53, TP73, and γ-H2AX proteins was observed in D384 cells exposed to DhL, but no increase in total TP53 levels was detected. Overall these studies demonstrated the marked effect of DhL on the diminished survival of human astrocytoma cells through the induced expression of TP73 and phosphorylation of TP73 and TP53, suggesting their key roles in the tumor cell response to DhL treatment.

  10. Phytometabolite Dehydroleucodine Induces Cell Cycle Arrest, Apoptosis, and DNA Damage in Human Astrocytoma Cells through p73/p53 Regulation.

    Science.gov (United States)

    Bailon-Moscoso, Natalia; González-Arévalo, Gabriela; Velásquez-Rojas, Gabriela; Malagon, Omar; Vidari, Giovanni; Zentella-Dehesa, Alejandro; Ratovitski, Edward A; Ostrosky-Wegman, Patricia

    2015-01-01

    Accumulating evidence supports the idea that secondary metabolites obtained from medicinal plants (phytometabolites) may be important contributors in the development of new chemotherapeutic agents to reduce the occurrence or recurrence of cancer. Our study focused on Dehydroleucodine (DhL), a sesquiterpene found in the provinces of Loja and Zamora-Chinchipe. In this study, we showed that DhL displayed cytostatic and cytotoxic activities on the human cerebral astrocytoma D384 cell line. With lactone isolated from Gynoxys verrucosa Wedd, a medicinal plant from Ecuador, we found that DhL induced cell death in D384 cells by triggering cell cycle arrest and inducing apoptosis and DNA damage. We further found that the cell death resulted in the increased expression of CDKN1A and BAX proteins. A marked induction of the levels of total TP73 and phosphorylated TP53, TP73, and γ-H2AX proteins was observed in D384 cells exposed to DhL, but no increase in total TP53 levels was detected. Overall these studies demonstrated the marked effect of DhL on the diminished survival of human astrocytoma cells through the induced expression of TP73 and phosphorylation of TP73 and TP53, suggesting their key roles in the tumor cell response to DhL treatment.

  11. Mechanism for ginkgolic acid (15 : 1)-induced MDCK cell necrosis: Mitochondria and lysosomes damages and cell cycle arrest.

    Science.gov (United States)

    Yao, Qing-Qing; Liu, Zhen-Hua; Xu, Ming-Cheng; Hu, Hai-Hong; Zhou, Hui; Jiang, Hui-Di; Yu, Lu-Shan; Zeng, Su

    2017-05-01

    Ginkgolic acids (GAs), primarily found in the leaves, nuts, and testa of ginkgo biloba, have been identified with suspected allergenic, genotoxic and cytotoxic properties. However, little information is available about GAs toxicity in kidneys and the underlying mechanism has not been thoroughly elucidated so far. Instead of GAs extract, the renal cytotoxicity of GA (15 : 1), which was isolated from the testa of Ginkgo biloba, was assessed in vitro by using MDCK cells. The action of GA (15 : 1) on cell viability was evaluated by the MTT and neutral red uptake assays. Compared with the control, the cytotoxicity of GA (15 : 1) on MDCK cells displayed a time- and dose-dependent manner, suggesting the cells mitochondria and lysosomes were damaged. It was confirmed that GA (15 : 1) resulted in the loss of cells mitochondrial trans-membrane potential (ΔΨm). In propidium iodide (PI) staining analysis, GA (15 : 1) induced cell cycle arrest at the G0/G1 and G2/M phases, influencing on the DNA synthesis and cell mitosis. Characteristics of necrotic cell death were observed in MDCK cells at the experimental conditions, as a result of DNA agarose gel electrophoresis and morphological observation of MDCK cells. In conclusion, these findings might provide useful information for a better understanding of the GA (15 : 1) induced renal toxicity. Copyright © 2017 China Pharmaceutical University. Published by Elsevier B.V. All rights reserved.

  12. Distinctive adaptive response to repeated exposure to hydrogen peroxide associated with upregulation of DNA repair genes and cell cycle arrest

    Directory of Open Access Journals (Sweden)

    Gloria A. Santa-Gonzalez

    2016-10-01

    Full Text Available Many environmental and physiological stresses are chronic. Thus, cells are constantly exposed to diverse types of genotoxic insults that challenge genome stability, including those that induce oxidative DNA damage. However, most in vitro studies that model cellular response to oxidative stressors employ short exposures and/or acute stress models. In this study, we tested the hypothesis that chronic and repeated exposure to a micromolar concentration of hydrogen peroxide (H2O2 could activate DNA damage responses, resulting in cellular adaptations. For this purpose, we developed an in vitro model in which we incubated mouse myoblast cells with a steady concentration of ~50 μM H2O2 for one hour daily for seven days, followed by a final challenge of a 10 or 20X higher dose of H2O2 (0.5 or 1 mM. We report that intermittent long-term exposure to this oxidative stimulus nearly eliminated cell toxicity and significantly decreased genotoxicity (in particular, a >5-fold decreased in double-strand breaks resulting from subsequent acute exposure to oxidative stress. This protection was associated with cell cycle arrest in G2/M and induction of expression of nine DNA repair genes. Together, this evidence supports an adaptive response to chronic, low-level oxidative stress that results in genomic protection and up-regulated maintenance of cellular homeostasis.

  13. Crack growth prediction for low-cycle fatigue regime

    International Nuclear Information System (INIS)

    Kamaya, Masayuki

    2017-01-01

    The objective of this study is to show a crack growth prediction procedure for the low-cycle fatigue regime. First, fatigue crack growth tests using Type 316 stainless steel specimens at room temperature were reviewed. It was seen that the crack growth rates correlated well with the equivalent stress intensify factor, which was derived using strain range instead of stress range. Furthermore, the effective equivalent stress intensify factor derived using the effective strain range exhibited excellent correlation with the crack growth rates obtained under various specimen geometries and loading conditions including high and low-cycle regimens. The obtained crack growth rates were also compared with the growth rate prescribed in the fitness-for-service code of the Japan Society of Mechanical Engineers (JSME). The test results agreed with the growth rate of JSME code. Finally, the procedure for predicting the low-cycle fatigue crack growth was shown. Although the JSME code is aimed at predicting fatigue crack growth for the so-called small scale yielding condition (high-cycle fatigue regime), the material constants determined for the high-cycle fatigue regime can be used even for the low-cycle fatigue regime. (author)

  14. Cape gooseberry (Physalis peruviana) juice as a modulator agent for hepatocellular carcinoma-linked apoptosis and cell cycle arrest.

    Science.gov (United States)

    Hassan, Hanaa A; Serag, Hanaa M; Qadir, Makwan S; Ramadan, Mohamed Fawzy

    2017-10-01

    Cape gooseberry (Physalis peruviana) fruit is highly nutritious with high content of health-promoting compounds including minerals, phenolic compounds, as well as vitamins A and C. Physalis peruviana fruits were used as mutagenic, antispasmodic, anticoagulant, and antileucemis agents. The objective of the present work was to study the role of cape gooseberry juice (CG) as a natural modulator agent for adverse aspects associated with hepatocellular carcinoma (HCC). The results recorded that HCC rats had a significant disturbance in blood indices. An elevation in serum level of the inflammatory (TNF-ά, CRP, and Argenase), hepatic apoptotic markers (P53, Bax, and Caspase 3) and a reduction of Blc2% were recorded in HCC rats. The results exhibited the significant disturbance and arrest in hepatic cell cycle (% of M1: SubG1 phase, M2: G0/1 phase of diploid cycle, M3: S phase, and M4: G2/M phase) as well as liver cell viability status in HCC rats. Numerous histopathological alterations were detected in hepatic tissues of HCC rats such as inflammation, damage of hepatocytes, dilated congested central vein with degenerated endothelial cells and congested blood sinusoids in addition to collagen fibers in hepatocytes and central vein indicating hepatic fibrosis. The tested parameters were little improved upon treatment of HCC rats with Adriamycin (ADR, Doxorubicin is a generic name of a drug). HCC rats received CG showed an improvement in all tested parameters. The effects of CG were through down regulation of p53 expression and up-regulation of Bcl2 domain protected hepatic structure from extensive damage. CG plus ADR exhibited an enhanced antitumor impact in HCC and this combination might have an important value in the treatment of HCC. CG was more effective than ADR, and it has a remarkable role in the management of hepatic disorders besides its success as a chemo-sensitizer for ADR treatment of hepatocellular carcinoma. Copyright © 2017 Elsevier Masson SAS. All rights

  15. Effects of low priming dose irradiation on cell cycle arrest of HepG2 cells caused by high dose irradiation

    International Nuclear Information System (INIS)

    Xia Jingguang; Jin Xiaodong; Chinese Academy of Sciences, Beijing; Li Wenjian; Wang Jufang; Guo Chuanling; Gao Qingxiang

    2005-01-01

    Human hepatoma cells hepG2 were irradiated twice by 60 Co γ-rays with a priming dose of 5 cGy and a higher dose of 3 Gy performed 4h or 8h after the low dose irradiation. Effects of the priming dose irradiation on cell cycle arrest caused by high dose were examined with flow cytometry. Cells in G 2 /M phase accumulated temporarily after the 5 cGy irradiation, and proliferation of tumor cells was promoted significantly by the low dose irradiation. After the 3 Gy irradiation, G 2 phase arrest occurred, and S phase delayed temporally. In comparison with 3 kGy irradiation only, the priming dose delivered 4h prior to the high dose irradiation facilitated accumulation of hepG2 cells in G 2 /M phase, whereas the priming dose delivered 8h prior to the high dose irradiation helped the cells to overcome G 2 arrest. It was concluded that effects of the priming dose treatment on cell cycle arrest caused by high dose irradiation were dependent on time interval between the two irradiations. (authors)

  16. Dynamic analysis of crack growth and arrest in a pressure vessel subjected to thermal and pressure loading

    International Nuclear Information System (INIS)

    Brickstad, B.

    1984-01-01

    Predictions of crack arrest behaviour are performed for a cracked reactor pressure vessel under both thermal and pressure loading. The object is to compare static and dynamic calculations. The dynamic calculations are made using an explicit finite element technique where crack growth is simulated by gradual nodal release. Three different load cases and the effect of different velocity dependence on the crack propagation toughness are studied. It is found that for the analysed cases the static analysis is slightly conservative, thus justifying its use for these problems. (orig.)

  17. Inhibition of DNA methyltransferase induces G2 cell cycle arrest and apoptosis in human colorectal cancer cells via inhibition of JAK2/STAT3/STAT5 signalling.

    Science.gov (United States)

    Xiong, Hua; Chen, Zhao-Fei; Liang, Qin-Chuan; Du, Wan; Chen, Hui-Min; Su, Wen-Yu; Chen, Guo-Qiang; Han, Ze-Guang; Fang, Jing-Yuan

    2009-09-01

    DNA methyltransferase inhibitors (MTIs) have recently emerged as promising chemotherapeutic or preventive agents for cancer, despite their poorly characterized mechanisms of action. The present study shows that DNA methylation is integral to the regulation of SH2-containing protein tyrosine phosphatase 1 (SHP1) expression, but not for regulation of suppressors of cytokine signalling (SOCS)1 or SOCS3 in colorectal cancer (CRC) cells. SHP1 expression correlates with down-regulation of Janus kinase/signal transducers and activators of transcription (JAK2/STAT3/STAT5) signalling, which is mediated in part by tyrosine dephosphorylation events and modulation of the proteasome pathway. Up-regulation of SHP1 expression was achieved using a DNA MTI, 5-aza-2'-deoxycytidine (5-aza-dc), which also generated significant down-regulation of JAK2/STAT3/STAT5 signalling. We demonstrate that 5-aza-dc suppresses growth of CRC cells, and induces G2 cell cycle arrest and apoptosis through regulation of downstream targets of JAK2/STAT3/STAT5 signalling including Bcl-2, p16(ink4a), p21(waf1/cip1) and p27(kip1). Although 5-aza-dc did not significantly inhibit cell invasion, 5-aza-dc did down-regulate expression of focal adhesion kinase and vascular endothelial growth factor in CRC cells. Our results demonstrate that 5-aza-dc can induce SHP1 expression and inhibit JAK2/STAT3/STAT5 signalling. This study represents the first evidence towards establishing a mechanistic link between inhibition of JAK2/STAT3/STAT5 signalling and the anticancer action of 5-aza-dc in CRC cells that may lead to the use of MTIs as a therapeutic intervention for human colorectal cancer.

  18. Poly[3-(3, 4-dihydroxyphenyl) glyceric acid] from Comfrey exerts anti-cancer efficacy against human prostate cancer via targeting androgen receptor, cell cycle arrest and apoptosis.

    Science.gov (United States)

    Shrotriya, Sangeeta; Gagan, Deep; Ramasamy, Kumaraguruparan; Raina, Komal; Barbakadze, Vakhtang; Merlani, Maia; Gogilashvili, Lali; Amiranashvili, Lela; Mulkijanyan, Karen; Papadopoulos, Kyriakos; Agarwal, Chapla; Agarwal, Rajesh

    2012-08-01

    The major obstacles in human prostate cancer (PCA) treatment are the development of resistance to androgen ablation therapy leading to hormone-refractory state and the toxicity associated with chemotherapeutic drugs. Thus, the identification of additional non-toxic agents that are effective against both androgen-dependent and androgen-independent PCA is needed. In the present study, we investigated the efficacy of a novel phytochemical poly[3-(3, 4-dihydroxyphenyl)glyceric acid] (p-DGA) from Caucasian species of comfrey (Symphytum caucasicum) and its synthetic derivative syn-2, 3-dihydroxy-3-(3, 4-dihydroxyphenyl) propionic acid (m-DGA) against PCA LNCaP and 22Rv1 cells. We found that both p-DGA and m-DGA suppressed the growth and induced death in PCA cells, with comparatively lesser cytotoxicity towards non-neoplastic human prostate epithelial cells. Furthermore, we also found that both p-DGA and m-DGA caused G(1) arrest in PCA cells through modulating the expression of cell cycle regulators, especially an increase in CDKIs (p21 and p27). In addition, p-DGA and m-DGA induced apoptotic death by activating caspases, and also strongly decreased AR and PSA expression. Consistent with in vitro results, our in vivo study showed that p-DGA feeding strongly inhibited 22Rv1 tumors growth by 76% and 88% at 2.5 and 5mg/kg body weight doses, respectively, without any toxicity, together with a strong decrease in PSA level in plasma; and a decrease in PCNA, AR and PSA expression but increase in p21/p27 expression and apoptosis in tumor tissues from p-DGA-fed mice. Overall, present study identifies p-DGA as a potent agent against PCA without any toxicity, and supports its clinical application.

  19. Plant HDAC inhibitor chrysin arrest cell growth and induce p21WAF1 by altering chromatin of STAT response element in A375 cells

    International Nuclear Information System (INIS)

    Pal-Bhadra, Manika; Bhadra, Utpal; Ramaiah, M Janaki; Reddy, T Lakshminarayan; Krishnan, Anita; Pushpavalli, SNCVL; Babu, K Suresh; Tiwari, Ashok K; Rao, J Madhusudana; Yadav, Jhillu S

    2012-01-01

    Chrysin and its analogues, belongs to flavonoid family and possess potential anti-tumour activity. The aim of this study is to determine the molecular mechanism by which chrysin controls cell growth and induce apoptosis in A375 cells. Effect of chrysin and its analogues on cell viability and cell cycle analysis was determined by MTT assay and flowcytometry. A series of Western blots was performed to determine the effect of chrysin on important cell cycle regulatory proteins (Cdk2, cyclin D1, p53, p21, p27). The fluorimetry and calorimetry based assays was conducted for characterization of chrysin as HDAC inhibitor. The changes in histone tail modification such as acetylation and methylation was studied after chrysin treatment was estimated by immuno-fluorescence and western blot analysis. The expression of Bcl-xL, survivin and caspase-3 was estimated in chrysin treated cells. The effect of chrysin on p21 promoter activity was studied by luciferase and ChIP assays. Chrysin cause G1 cell cycle arrest and found to inhibit HDAC-2 and HDAC-8. Chrysin treated cells have shown increase in the levels of H3acK14, H4acK12, H4acK16 and decrease in H3me2K9 methylation. The p21 induction by chrysin treatment was found to be independent of p53 status. The chromatin remodelling at p21 WAF1 promoter induces p21 activity, increased STAT-1 expression and epigenetic modifications that are responsible for ultimate cell cycle arrest and apoptosis. Chrysin shows in vitro anti-cancer activity that is correlated with induction of histone hyperacetylation and possible recruitment of STAT-1, 3, 5 proteins at STAT (−692 to −684) region of p21 promoter. Our results also support an unexpected action of chrysin on the chromatin organization of p21 WAF1 promoter through histone methylation and hyper-acetylation. It proposes previously unknown sequence specific chromatin modulations in the STAT responsive elements for regulating cell cycle progression negatively via the induction of the CDK

  20. The role of reactive oxygen species (ROS) production on diallyl disulfide (DADS) induced apoptosis and cell cycle arrest in human A549 lung carcinoma cells

    International Nuclear Information System (INIS)

    Wu Xinjiang; Kassie, Fekadu; Mersch-Sundermann, Volker

    2005-01-01

    Diallyl disulfide (DADS), an oil soluble constituent of garlic (Allium sativum), has been reported to cause antimutagentic and anticarcinogenic effects in vitro and in vivo by modulating phases I and II enzyme activities. In recent years, several studies suggested that the chemopreventive effects of DADS can also be attributed to induction of cell cycle arrest and apoptosis in cancer cells. In the present study, we reported that DADS-induced cell cycle arrest at G2/M and apoptosis in human A549 lung cancer cells in a time- and dose-dependent manner. Additionally, a significant increase of intracellular reactive oxygen species (ROS) was induced in A549 cells less than 0.5 h after DADS treatment, indicating that ROS may be an early event in DADS-modulated apoptosis. Treatment of A549 cells with N-acetyl cysteine (NAC) completely abrogated DADS-induced cell cycle arrest and apoptosis. The result indicated that oxidative stress modulates cell proliferation and cell death induced by DADS

  1. Cell cycle arrest induced by inhibitors of epigenetic modifications in maize (Zea mays) seedling leaves: characterization of the process and possible mechanisms involved.

    Science.gov (United States)

    Wang, Pu; Zhang, Hao; Hou, Haoli; Wang, Qing; Li, Yingnan; Huang, Yan; Xie, Liangfu; Gao, Fei; He, Shibin; Li, Lijia

    2016-07-01

    Epigenetic modifications play crucial roles in the regulation of chromatin architecture and are involved in cell cycle progression, including mitosis and meiosis. To explore the relationship between epigenetic modifications and the cell cycle, we treated maize (Zea mays) seedlings with six different epigenetic modification-related inhibitors and identified the postsynthetic phase (G2 ) arrest via flow cytometry analysis. Total H4K5ac levels were significantly increased and the distribution of H3S10ph signalling was obviously changed in mitosis under various treatments. Further statistics of the cells in different periods of mitosis confirmed that the cell cycle was arrested at preprophase. Concentrations of hydrogen peroxide were relatively higher in the treated plants and the antioxidant thiourea could negate the influence of the inhibitors. Moreover, all of the treated plants displayed negative results in the terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick end labelling (TUNEL) and γ-H2AX immunostaining assays after exposure for 3 d. Additionally, the expression level of topoisomerase genes in the treated plants was relatively lower than that in the untreated plants. These results suggest that these inhibitors of epigenetic modifications could cause preprophase arrest via reactive oxygen species formation inhibiting the expression of DNA topoisomerase genes, accompanied by changes in the H4K5ac and H3S10ph histone modifications. © 2016 The Authors. New Phytologist © 2016 New Phytologist Trust.

  2. The role of reactive oxygen species (ROS) production on diallyl disulfide (DADS) induced apoptosis and cell cycle arrest in human A549 lung carcinoma cells

    Energy Technology Data Exchange (ETDEWEB)

    Wu Xinjiang [Institute of Indoor and Environmental Toxicology, Faculty of Medicine, Justus-Liebig-University of Giessen, Aulweg 123, D-35385 Giessen (Germany); Kassie, Fekadu [Institute of Indoor and Environmental Toxicology, Faculty of Medicine, Justus-Liebig-University of Giessen, Aulweg 123, D-35385 Giessen (Germany); Mersch-Sundermann, Volker [Institute of Indoor and Environmental Toxicology, Faculty of Medicine, Justus-Liebig-University of Giessen, Aulweg 123, D-35385 Giessen (Germany)]. E-mail: Volker.mersch-sundermann@uniklinikum-giessen.de

    2005-11-11

    Diallyl disulfide (DADS), an oil soluble constituent of garlic (Allium sativum), has been reported to cause antimutagentic and anticarcinogenic effects in vitro and in vivo by modulating phases I and II enzyme activities. In recent years, several studies suggested that the chemopreventive effects of DADS can also be attributed to induction of cell cycle arrest and apoptosis in cancer cells. In the present study, we reported that DADS-induced cell cycle arrest at G2/M and apoptosis in human A549 lung cancer cells in a time- and dose-dependent manner. Additionally, a significant increase of intracellular reactive oxygen species (ROS) was induced in A549 cells less than 0.5 h after DADS treatment, indicating that ROS may be an early event in DADS-modulated apoptosis. Treatment of A549 cells with N-acetyl cysteine (NAC) completely abrogated DADS-induced cell cycle arrest and apoptosis. The result indicated that oxidative stress modulates cell proliferation and cell death induced by DADS.

  3. A methoxyflavanone derivative from the Asian medicinal herb (Perilla frutescens) induces p53-mediated G2/M cell cycle arrest and apoptosis in A549 human lung adenocarcinoma.

    Science.gov (United States)

    Abd El-Hafeez, Amer Ali; Fujimura, Takashi; Kamei, Rikiya; Hirakawa, Noriko; Baba, Kenji; Ono, Kazuhisa; Kawamoto, Seiji

    2017-07-14

    Perilla frutescens is an Asian dietary herb consumed as an essential seasoning in Japanese cuisine as well as used for a Chinese medicine. Here, we report that a newly found methoxyflavanone derivative from P. frutescens (Perilla-derived methoxyflavanone, PDMF; 8-hydroxy-5,7-dimethoxyflavanone) shows carcinostatic activity on human lung adenocarcinoma, A549. We found that treatment with PDMF significantly inhibited cell proliferation and decreased viability through induction of G 2 /M cell cycle arrest and apoptosis. The PDMF stimulation induces phosphorylation of tumor suppressor p53 on Ser15, and increases its protein amount in conjunction with up-regulation of downstream cyclin-dependent kinase inhibitor p21 Cip1/Waf1 and proapoptotic caspases, caspase-9 and caspase-3. We also found that small interfering RNA knockdown of p53 completely abolished the PDMF-induced G 2 /M cell cycle arrest, and substantially abrogated its proapoptotic potency. These results suggest that PDMF represents a useful tumor-preventive phytochemical that triggers p53-driven G 2 /M cell cycle arrest and apoptosis.

  4. Indole-3-carbinol induces G1 cell cycle arrest and apoptosis through aryl hydrocarbon receptor in THP-1 monocytic cell line.

    Science.gov (United States)

    Mohammadi, Saeed; Seyedhosseini, Fakhri Sadat; Behnampour, Nasser; Yazdani, Yaghoub

    2017-10-01

    The role of aryl hydrocarbon receptor (AhR) in carcinogenesis has been studied recently. Indole-3-carbinol (I3C) is an AhR agonist and a potential anticancer agent. Here, we investigated the effects of I3C on cell cycle progression and apoptosis through activation of AhR on THP-1 acute myeloid leukemia (AML) cell line. MTT viability assay was used to measure the cytotoxic effects of I3C on THP-1 cells. Apoptosis and cell cycle assays were investigated using flow cytometry. Real time RT-PCR was conducted to measure the alterations in the expression of AhR gene, key genes associated with AhR activation (IL1β and CYP1A1) and major genes involved in cell cycle regulation and apoptosis including P27, P21, CDK2, P53, BCL2 and FasR. Our findings revealed that I3C inhibits the proliferation of THP-1 cells in a dose- and time-dependent manner with minimal toxicity over normal monocytes. The AhR target genes (CYP1A1, IL1β) were overexpressed upon I3C treatment (p cycle arrest was also observed using flow cytometry. G1-acting cell cycle genes (P21, P27 and P53) were overexpressed (p cycle arrest in a dose- and time-dependent manner. Therefore, AhR could be targeted as a novel treatment possibility in AML.

  5. A novel curcumin derivative which inhibits P-glycoprotein, arrests cell cycle and induces apoptosis in multidrug resistance cells.

    Science.gov (United States)

    Lopes-Rodrigues, Vanessa; Oliveira, Ana; Correia-da-Silva, Marta; Pinto, Madalena; Lima, Raquel T; Sousa, Emília; Vasconcelos, M Helena

    2017-01-15

    Cancer multidrug resistance (MDR) is a major limitation to the success of cancer treatment and is highly associated with the overexpression of drug efflux pumps such as P-glycoprotein (P-gp). In order to achieve more effective chemotherapeutic treatments, it is important to develop P-gp inhibitors to block/decrease its activity. Curcumin (1) is a secondary metabolite isolated from the turmeric of Curcuma longa L.. Diverse biological activities have been identified for this compound, particularly, MDR modulation in various cancer cell models. However, curcumin (1) has low chemical stability, which severely limits its application. In order to improve stability and P-gp inhibitory effect, two potential more stable curcumin derivatives were synthesized as building blocks, followed by several curcumin derivatives. These compounds were then analyzed in terms of antitumor and anti-P-gp activity, in two MDR and sensitive tumor lines (from chronic myeloid leukemia and non-small cell lung cancer). We identified from a series of curcumin derivatives a novel curcumin derivative (1,7-bis(3-methoxy-4-(prop-2-yn-1-yloxy)phenyl)hepta-1,6-diene-3,5-dione, 10) with more potent antitumor and anti-P-gp activity than curcumin (1). This compound (10) was shown to promote cell cycle arrest (at the G2/M phase) and induce apoptosis in the MDR chronic myeloid leukemia cell line. Therefore it is a really interesting P-gp inhibitor due to its ability to inhibit both P-gp function and expression. Copyright © 2016 Elsevier Ltd. All rights reserved.

  6. Interaction of E-cadherin and PTEN regulates morphogenesis and growth arrest in human mammary epithelial cells

    Energy Technology Data Exchange (ETDEWEB)

    Fournier, Marcia V.; Fata, Jimmie E.; Martin, Katherine J.; Yaswen, Paul; Bissell, Mina J.

    2009-06-03

    PTEN is a dual function phosphatase with tumor suppressor function compromised in a wide spectrum of cancers. Because tissue polarity and architecture are crucial modulators of normal and malignant behavior, we postulated that PTEN may play a role in maintenance of tissue integrity. We used two non-malignant human mammary epithelial cell lines (HMECs) that form polarized, growth-arrested structures (acini) when cultured in 3-dimensional laminin-rich extracellular matrix gels (3D lrECM). As acini begin to form, PTEN accumulates in both the cytoplasm, and at cell-cell contacts where it colocalizes with E-cadherin/{beta}-catenin complex. Reduction of PTEN levels by shRNA in lrECM prevents formation of organized breast acini and disrupts growth arrest. Importantly, disruption of acinar polarity and cell-cell contact by E-cadherin function-blocking antibodies reduces endogenous PTEN protein levels and inhibits its accumulation at cell-cell contacts. Conversely, in SKBR3 breast cancer cells lacking endogenous E-cadherin expression, exogenous introduction of E-cadherin gene causes induction of PTEN expression and its accumulation at sites of cell interactions. These studies provide evidence that E-cadherin regulates both the PTEN protein levels and its recruitment to cell-cell junctions in 3D lrECM indicating a dynamic reciprocity between architectural integrity and the levels and localization of PTEN. This interaction thus appears to be a critical integrator of proliferative and morphogenetic signaling in breast epithelial cells.

  7. Flavagline analog FL3 induces cell cycle arrest in urothelial carcinoma cell of the bladder by inhibiting the Akt/PHB interaction to activate the GADD45α pathway.

    Science.gov (United States)

    Yuan, Gangjun; Chen, Xin; Liu, Zhuowei; Wei, Wensu; Shu, Qinghai; Abou-Hamdan, Hussein; Jiang, Lijuan; Li, Xiangdong; Chen, Rixin; Désaubry, Laurent; Zhou, Fangjian; Xie, Dan

    2018-02-07

    Prohibitin 1 (PHB) is a potential target for the treatment of urothelial carcinoma of the bladder (UCB). FL3 is a newly synthesized agent that inhibits cancer cell proliferation by targeting the PHB protein; however, the effect of FL3 in UCB cells remains unexplored. FL3 was identified to be a potent inhibitor of UCB cell viability using CCK-8 (cell counting kit-8) assay. Then a series of in vitro and in vivo experiments were conducted to further demonstrate the inhibitory effect of FL3 on UCB cell proliferation and to determine the underlying mechanisms. FL3 inhibited UCB cell proliferation and growth both in vitro and in vivo. By targeting the PHB protein, FL3 inhibited the interaction of Akt and PHB as well as Akt-mediated PHB phosphorylation, which consequently decreases the localization of PHB in the mitochondria. In addition, FL3 treatment resulted in cell cycle arrest in the G2/M phase, and this inhibitory effect of FL3 could be mimicked by knockdown of PHB. Through the microarray analysis of mRNA expression after FL3 treatment and knockdown of PHB, we found that the mRNA expression of the growth arrest and DNA damage-inducible alpha (GADD45α) gene were significantly upregulated. When knocked down the expression of GADD45α, the inhibitory effect of FL3 on cell cycle was rescued, suggesting that FL3-induced cell cycle inhibition is GADD45α dependent. Our data provide that FL3 inhibits the interaction of Akt and PHB, which in turn activates the GADD45α-dependent cell cycle inhibition in the G2/M phase.

  8. Circulating vascular endothelial growth factor during the normal menstrual cycle

    NARCIS (Netherlands)

    Kusumanto, YH; Hospers, GAP; Sluiter, WJ; Dam, WA; Meijer, C; Mulder, NH

    2004-01-01

    Background: The purpose of the study was to investigate whether cycle-related variations in circulating Vascular Endothelial Growth Factor (VEGF) levels would increase the metastatic potential at specific times during the menstrual cycle. Materials and Methods: VEGF levels in serum and whole blood

  9. Chikusetsusaponin IVa methyl ester induces cell cycle arrest by the inhibition of nuclear translocation of β-catenin in HCT116 cells

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Kyung-Mi [Natural Products Research Institute, College of Pharmacy, Seoul National University, Seoul (Korea, Republic of); Yun, Ji Ho [Natural Products Research Center, Korea Institute of Science and Technology, Gangneung, 210-340 (Korea, Republic of); Lee, Dong Hwa [Department of Food Science and Nutrition, Andong National University, Andong 760-749 (Korea, Republic of); Park, Young Gyun [Natural Products Research Center, Korea Institute of Science and Technology, Gangneung, 210-340 (Korea, Republic of); Son, Kun Ho [Department of Food Science and Nutrition, Andong National University, Andong 760-749 (Korea, Republic of); Nho, Chu Won, E-mail: cwnho@kist.re.kr [Natural Products Research Center, Korea Institute of Science and Technology, Gangneung, 210-340 (Korea, Republic of); Kim, Yeong Shik, E-mail: kims@snu.ac.kr [Natural Products Research Institute, College of Pharmacy, Seoul National University, Seoul (Korea, Republic of)

    2015-04-17

    We demonstrate that chikusetsusaponin IVa methyl ester (CME), a triterpenoid saponin from the root of Achyranthes japonica, has an anticancer activity. We investigate its molecular mechanism in depth in HCT116 cells. CME reduces the amount of β-catenin in nucleus and inhibits the binding of β-catenin to specific DNA sequences (TCF binding elements, TBE) in target gene promoters. Thus, CME appears to decrease the expression of cell cycle regulatory proteins such as Cyclin D1, as a representative target for β-catenin, as well as CDK2 and CDK4. As a result of the decrease of the cell cycle regulatory proteins, CME inhibits cell proliferation by arresting the cell cycle at the G0/G1 phase. Therefore, we suggest that CME as a novel Wnt/β-catenin inhibitor can be a putative agent for the treatment of colorectal cancers. - Highlights: • CME inhibits cell proliferation in HCT116 cells. • CME increases cell cycle arrest at G0/G1 phase and apoptosis. • CME attenuates cyclin D1 and regulates cell cycle regulatory proteins. • CME inhibits β-catenin translocation to nucleus.

  10. Chikusetsusaponin IVa methyl ester induces cell cycle arrest by the inhibition of nuclear translocation of β-catenin in HCT116 cells

    International Nuclear Information System (INIS)

    Lee, Kyung-Mi; Yun, Ji Ho; Lee, Dong Hwa; Park, Young Gyun; Son, Kun Ho; Nho, Chu Won; Kim, Yeong Shik

    2015-01-01

    We demonstrate that chikusetsusaponin IVa methyl ester (CME), a triterpenoid saponin from the root of Achyranthes japonica, has an anticancer activity. We investigate its molecular mechanism in depth in HCT116 cells. CME reduces the amount of β-catenin in nucleus and inhibits the binding of β-catenin to specific DNA sequences (TCF binding elements, TBE) in target gene promoters. Thus, CME appears to decrease the expression of cell cycle regulatory proteins such as Cyclin D1, as a representative target for β-catenin, as well as CDK2 and CDK4. As a result of the decrease of the cell cycle regulatory proteins, CME inhibits cell proliferation by arresting the cell cycle at the G0/G1 phase. Therefore, we suggest that CME as a novel Wnt/β-catenin inhibitor can be a putative agent for the treatment of colorectal cancers. - Highlights: • CME inhibits cell proliferation in HCT116 cells. • CME increases cell cycle arrest at G0/G1 phase and apoptosis. • CME attenuates cyclin D1 and regulates cell cycle regulatory proteins. • CME inhibits β-catenin translocation to nucleus

  11. Fisetin, a novel dietary flavonoid, causes apoptosis and cell cycle arrest in human prostate cancer LNCaP cells

    Science.gov (United States)

    Khan, Naghma; Afaq, Farrukh; Syed, Deeba N.; Mukhtar, Hasan

    2008-01-01

    Novel dietary agents for prevention and therapy of prostate cancer (PCa) are desired. The aim of this study was to determine the effect of fisetin, a tetrahydroxyflavone, on inhibition of cell growth and induction of apoptosis in human PCa cells. Treatment of fisetin (10–60 μM, 48 h) was found to result in a decrease in the viability of LNCaP, CWR22Rυ1 and PC-3 cells but had only minimal effects on normal prostate epithelial cells as assessed by 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl tetrazoliumbromide assay. Treatment of LNCaP cells with fisetin also resulted in G1-phase arrest that was associated with a marked decrease in the protein expression of cyclins D1, D2 and E and their activating partner cyclin-dependent kinases 2, 4 and 6 with concomitant induction of WAF1/p21 and KIP1/p27. Fisetin treatment also resulted in induction of apoptosis, poly (ADP-ribose) polymerase (PARP) cleavage, modulation in the expressions of Bcl-2 family proteins, inhibition of phosphatidyl inositol 3-kinase and phosphorylation of Akt at Ser473 and Thr308. There was also induction of mitochondrial release of cytochrome c into cytosol, downregulation of X-linked inhibitor of apoptosis protein and upregulation of second mitochondria-derived activator of caspase/direct inhibitor of apoptosis-binding protein with low pI on treatment of cells with fisetin. Treatment of cells with fisetin also resulted in significant activation of caspases-3, -8 and -9. Pretreatment of cells with caspase inhibitor (Z-VAD-FMK) blocked fisetin-induced activation of caspases. These data provide the first evidence that fisetin could be developed as an agent against PCa. PMID:18359761

  12. Atherosclerotic renal artery stenosis is associated with elevated cell cycle arrest markers related to reduced renal blood flow and postcontrast hypoxia.

    Science.gov (United States)

    Saad, Ahmed; Wang, Wei; Herrmann, Sandra M S; Glockner, James F; Mckusick, Michael A; Misra, Sanjay; Bjarnason, Haraldur; Lerman, Lilach O; Textor, Stephen C

    2016-11-01

    Atherosclerotic renal artery stenosis (ARAS) reduces renal blood flow (RBF), ultimately leading to kidney hypoxia and inflammation. Insulin-like growth factor binding protein-7 (IGFBP-7) and tissue inhibitor of metalloproteinases-2 (TIMP-2) are biomarkers of cell cycle arrest, often increased in ischemic conditions and predictive of acute kidney injury (AKI). This study sought to examine the relationships between renal vein levels of IGFBP-7, TIMP-2, reductions in RBF and postcontrast hypoxia as measured by blood oxygen level-dependent (BOLD) magnetic resonance imaging. Renal vein levels of IGFBP-7 and TIMP-2 were obtained in an ARAS cohort (n= 29) scheduled for renal artery stenting and essential hypertensive (EH) healthy controls (n = 32). Cortical and medullary RBFs were measured by multidetector computed tomography (CT) immediately before renal artery stenting and 3 months later. BOLD imaging was performed before and 3 months after stenting in all patients, and a subgroup (N = 12) underwent repeat BOLD imaging 24 h after CT/stenting to examine postcontrast/procedure levels of hypoxia. Preintervention IGFBP-7 and TIMP-2 levels were elevated in ARAS compared with EH (18.5 ± 2.0 versus 15.7 ± 1.5 and 97.4 ± 23.1 versus 62.7 ± 9.2 ng/mL, respectively; Pblood flow (r = -0.59, P= 0.004). These data demonstrate elevated IGFBP-7 and TIMP-2 levels in ARAS as a function of the degree of reduced RBF. Elevated baseline IGFBP-7 levels were associated with protection against postimaging hypoxia, consistent with 'ischemic preconditioning'. Despite contrast injection and stenting, AKI in these high-risk ARAS subjects with elevated IGFBP-7/TIMP-2 was rare and did not affect long-term kidney function. © The Author 2016. Published by Oxford University Press on behalf of ERA-EDTA. All rights reserved.

  13. Predominantly elastic crack growth under combined creep-fatigue cycling

    International Nuclear Information System (INIS)

    Lloyd, G.J.

    1979-01-01

    A rationalization of the various observed effects of combined creep-fatigue cycling upon predominantly elastic fatigue-crack propagation in austenitic steel is presented. Existing and new evidence is used to show two main groups of behaviour: (i) material and cycling conditions which lead to modest increases (6-8 times) in the rate of crack growth are associated with relaxation-induced changes in the material deformation characteristics, and (ii) material and cycling conditions severe enough to generate internal fracture damage lead to significant (up to a factor of 30) increases in crack growth rate when compared with fast-cycling crack propagation rates at the same temperature. A working hypothesis is presented to show that the boundary between the two groups occurs when the scale of the nucleated creep damage is of the same magnitude as the crack tip opening displacement. This leads to the possibility of unstable crack advance. Creep crack growth rates are shown to provide an upper bound to creep-fatigue crack growth rates when crack advance is unstable. If the deformation properties only are affected by the creep-fatigue cycling then creep crack growth rates provide a lower bound. The role of intergranular oxygen corrosion in very low frequency crack growth tests is also briefly discussed. (author)

  14. N-Methyl-N'-nitro-N-nitrosoguanidine-induced senescence-like growth arrest in colon cancer cells is associated with loss of adenomatous polyposis coli protein, microtubule organization, and telomeric DNA

    Directory of Open Access Journals (Sweden)

    Narayan Satya

    2004-01-01

    Full Text Available Abstract Background Cellular senescence is a state in which mammalian cells enter into an irreversible growth arrest and altered biological functions. The senescence response in mammalian cells can be elicited by DNA-damaging agents. In the present study we report that the DNA-damaging agent N-methyl-N'-nitro-N-nitrosoguanidine (MNNG is able to induce senescence in the HCT-116 colon cancer cell line. Results Cells treated with lower concentrations of MNNG (0–25 microM for 50 h showed a dose-dependent increase in G2/M phase arrest and apoptosis; however, cells treated with higher concentrations of MNNG (50–100 microM showed a senescence-like G0/G1 phase arrest which was confirmed by increased expression of β-galactosidase, a senescence induced marker. The G2/M phase arrest and apoptosis were found to be associated with increased levels of p53 protein, but the senescence-like G0/G1 phase arrest was dissociated with p53 protein levels, since the p53 protein levels decreased in senescence-like arrested cells. We further, determined whether the decreased level of p53 was a transcriptional or a translational phenomenon. The results revealed that the decreased level of p53 protein in senescence-like arrested cells was a transcriptional phenomenon since p53 mRNA levels simultaneously decreased after treatment with higher concentrations of MNNG. We also examined the effect of MNNG treatment on other cell cycle-related proteins such as p21, p27, cyclin B1, Cdc2, c-Myc and max. The expression levels of these proteins were increased in cells treated with lower concentrations of MNNG, which supported the G2/M phase arrest. However, cells treated with higher concentrations of MNNG showed decreased levels of these proteins, and hence, may not play a role in cell cycle arrest. We then examined a possible association of the expression of APC protein and telomeric DNA signals with cellular senescence in MNNG-treated cells. We found that protein and m

  15. The inhibition of activated hepatic stellate cells proliferation by arctigenin through G0/G1 phase cell cycle arrest: persistent p27(Kip1) induction by interfering with PI3K/Akt/FOXO3a signaling pathway.

    Science.gov (United States)

    Li, Ao; Wang, Jun; Wu, Mingjun; Zhang, Xiaoxun; Zhang, Hongzhi

    2015-01-15

    Proliferation of hepatic stellate cells (HSCs) is vital for the development of fibrosis during liver injury. In this study, we describe that arctigenin (ATG), a major bioactive component of Fructus Arctii, exhibited selective cytotoxic activity via inhibiting platelet-derived growth factor-BB (PDGF-BB)-activated HSCs proliferation and arrested cell cycle at G0/G1 phase, which could not be observed in normal human hepatocytes in vitro. The cyclin-dependent kinase (CDK) 4/6 activities could be strongly inhibited by ATG through down-regulation of cyclin D1 and CDK4/6 expression in early G1 phase arrest. In the ATG-treated HSCs, the expression level of p27(Kip1) and the formation of CDK2-p27(Kip1) complex were also increased. p27(Kip1) silencing significantly attenuated the effect of ATG, including cell cycle arrest and suppression of proliferation in activated HSCs. We also found that ATG suppressed PDGF-BB-induced phosphorylation of Akt and its downstream transcription factor Forkhead box O 3a (FOXO3a), decreased binding of FOXO3a to 14-3-3 protein, and stimulated nuclear translocation of FOXO3a in activated HSCs. Furthermore, knockdown of FOXO3a expression by FOXO3a siRNA attenuated ATG-induced up-regulation of p27(Kip1) in activated HSCs. All the above findings suggested that ATG could increase the levels of p27(Kip1) protein through inhibition of Akt and improvement of FOXO3a activity, in turn inhibited the CDK2 kinase activity, and eventually caused an overall inhibition of HSCs proliferation. Copyright © 2014 Elsevier B.V. All rights reserved.

  16. RRR-alpha-tocopheryl succinate inhibits EL4 thymic lymphoma cell growth by inducing apoptosis and DNA synthesis arrest.

    Science.gov (United States)

    Yu, W; Sanders, B G; Kline, K

    1997-01-01

    RRR-alpha-tocopheryl succinate (vitamin E succinate, VES) treatment of murine EL4 T lymphoma cells induced the cells to undergo apoptosis. After 48 hours of VES treatment at 20 micrograms/ml, 95% of cells were apoptotic. Evidence for the induction of apoptosis by VES treatments is based on staining of DNA for detection of chromatin condensation/fragmentation, two-color flow-cytometric analyses of DNA content, and end-labeled DNA and electrophoretic analyses for detection of DNA ladder formation. VES-treated EL4 cells were blocked in the G1 cell cycle phase; however, apoptotic cells came from all cell cycle phases. Analyses of mRNA expression of genes involved in apoptosis revealed decreased c-myc and increased bcl-2, c-fos, and c-jun mRNAs within three to six hours after treatment. Western analyses showed increased c-Jun, c-Fos, and Bcl-2 protein levels. Electrophoretic mobility shift assays showed increased AP-1 binding at 6, 12, and 24 hours after treatment and decreased c-Myc binding after 12 and 24 hours of VES treatment. Treatments of EL4 cells with VES+RRR-alpha-to-copherol reduced apoptosis without effecting DNA synthesis arrest. Treatments of EL4 cells with VES+rac-6-hydroxyl-2, 5,7,8-tetramethyl-chroman-2-carboxylic acid, butylated hydroxytoluene, or butylated hydroxyanisole had no effect on apoptosis or DNA synthesis arrest caused by VES treatments. Analyses of bcl-2, c-myc, c-jun, and c-fos mRNA levels in cells receiving VES + RRR-alpha-tocopherol treatments showed no change from cells receiving VES treatments alone, implying that these changes are correlated with VES treatments but are not causal for apoptosis. However, treatments with VES + RRR-alpha-tocopherol decreased AP-1 binding to consensus DNA oligomer, suggesting AP-1 involvement in apoptosis induced by VES treatments.

  17. Inhibition of PI3K by ZSTK474 suppressed tumor growth not via apoptosis but G0/G1 arrest

    International Nuclear Information System (INIS)

    Dan, Shingo; Yoshimi, Hisashi; Okamura, Mutsumi; Mukai, Yumiko; Yamori, Takao

    2009-01-01

    Phosphoinositide 3-kinase (PI3K) is a potential target in cancer therapy. Inhibition of PI3K is believed to induce apoptosis. We recently developed a novel PI3K inhibitor ZSTK474 with antitumor efficacy. In this study, we have examined the underlying mode of action by which ZSTK474 exerts its antitumor efficacy. In vivo, ZSTK474 effectively inhibited the growth of human cancer xenografts. In parallel, ZSTK474 treatment suppressed the expression of phospho-Akt, suggesting effective PI3K inhibition, and also suppressed the expression of nuclear cyclin D1 and Ki67, both of which are hallmarks of proliferation. However, ZSTK474 treatment did not increase TUNEL-positive apoptotic cells. In vitro, ZSTK474 induced marked G 0 /G 1 arrest, but did not increase the subdiploid cells or activate caspase, both of which are hallmarks of apoptosis. These results clearly indicated that inhibition of PI3K by ZSTK474 did not induce apoptosis but rather induced strong G 0 /G 1 arrest, which might cause its efficacy in tumor cells.

  18. 5-(2-Carboxyethenyl) isatin derivative induces G2/M cell cycle arrest and apoptosis in human leukemia K562 cells

    International Nuclear Information System (INIS)

    Zhou, Yao; Zhao, Hong-Ye; Han, Kai-Lin; Yang, Yao; Song, Bin-Bin; Guo, Qian-Nan; Fan, Zhen-Chuan; Zhang, Yong-Min; Teng, Yu-Ou; Yu, Peng

    2014-01-01

    Highlights: • 5-(2-Carboxyethenyl) isatin derivative (HKL 2H) inhibited K562’s proliferation. • HKL 2H caused the morphology change of G 2 /M phase arrest and typical apoptosis. • HKL 2H induced G2/M cell cycle phase arrest in K562 cells. • HKL 2H induced apoptosis in K562 cells through the mitochondrial pathway. - Abstract: Our previous study successfully identified that the novel isatin derivative (E)-methyl 3-(1-(4-methoxybenzyl)-2,3-dioxoindolin-5-yl) acrylate (HKL 2H) acts as an anticancer agent at an inhibitory concentration (IC 50 ) level of 3 nM. In this study, the molecular mechanism how HKL 2H induces cytotoxic activity in the human chronic myelogenous leukemia K562 cells was investigated. Flow cytometric analysis showed that the cells were arrested in the G 2 /M phase and accumulated subsequently in the sub-G 1 phase in the presence of HKL 2H. HKL 2H treatment down-regulated the expressions of CDK1 and cyclin B but up-regulated the level of phosphorylated CDK1. Annexin-V staining and the classic DNA ladder studies showed that HKL 2H induced the apoptosis of K562 cells. Our study further showed that HKL 2H treatment caused the dissipation of mitochondrial membrane potential, activated caspase-3 and lowered the Bcl-2/Bax ratio in K562 cells, suggesting that the HKL 2H-causing programmed cell death of K562 cells was caused via the mitochondrial apoptotic pathway. Taken together, our data demonstrated that HKL 2H, a 5-(2-carboxyethenyl) isatin derivative, notably induces G 2 /M cell cycle arrest and mitochondrial-mediated apoptosis in K562 cells, indicating that this compound could be a promising anticancer candidate for further investigation

  19. 5-(2-Carboxyethenyl) isatin derivative induces G{sub 2}/M cell cycle arrest and apoptosis in human leukemia K562 cells

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Yao; Zhao, Hong-Ye; Han, Kai-Lin; Yang, Yao; Song, Bin-Bin; Guo, Qian-Nan [Key Laboratory of Industrial Microbiology, Ministry of Education, College of Biotechnology, Tianjin University of Science and Technology, Tianjin 300457 (China); Tianjin Key Laboratory of Industry Microbiology, College of Biotechnology, Tianjin University of Science and Technology, Tianjin 300457 (China); Fan, Zhen-Chuan [Key Laboratory of Food Nutrition and Safety (Tianjin University of Science and Technology), Ministry of Education, Tianjin 300457 (China); Obesita and Algaegen LLC, College Station, TX 77845 (United States); Zhang, Yong-Min [Université Pierre et Marie Curie-Paris 6, Institut Parisien de Chimie Moléculaire UMR CNRS 8232, 4 Place Jussieu, 75005 Paris (France); Teng, Yu-Ou, E-mail: tyo201485@tust.edu.cn [Key Laboratory of Industrial Microbiology, Ministry of Education, College of Biotechnology, Tianjin University of Science and Technology, Tianjin 300457 (China); Tianjin Key Laboratory of Industry Microbiology, College of Biotechnology, Tianjin University of Science and Technology, Tianjin 300457 (China); Yu, Peng, E-mail: yupeng@tust.edu.cn [Key Laboratory of Industrial Microbiology, Ministry of Education, College of Biotechnology, Tianjin University of Science and Technology, Tianjin 300457 (China); Tianjin Key Laboratory of Industry Microbiology, College of Biotechnology, Tianjin University of Science and Technology, Tianjin 300457 (China)

    2014-08-08

    Highlights: • 5-(2-Carboxyethenyl) isatin derivative (HKL 2H) inhibited K562’s proliferation. • HKL 2H caused the morphology change of G{sub 2}/M phase arrest and typical apoptosis. • HKL 2H induced G2/M cell cycle phase arrest in K562 cells. • HKL 2H induced apoptosis in K562 cells through the mitochondrial pathway. - Abstract: Our previous study successfully identified that the novel isatin derivative (E)-methyl 3-(1-(4-methoxybenzyl)-2,3-dioxoindolin-5-yl) acrylate (HKL 2H) acts as an anticancer agent at an inhibitory concentration (IC{sub 50}) level of 3 nM. In this study, the molecular mechanism how HKL 2H induces cytotoxic activity in the human chronic myelogenous leukemia K562 cells was investigated. Flow cytometric analysis showed that the cells were arrested in the G{sub 2}/M phase and accumulated subsequently in the sub-G{sub 1} phase in the presence of HKL 2H. HKL 2H treatment down-regulated the expressions of CDK1 and cyclin B but up-regulated the level of phosphorylated CDK1. Annexin-V staining and the classic DNA ladder studies showed that HKL 2H induced the apoptosis of K562 cells. Our study further showed that HKL 2H treatment caused the dissipation of mitochondrial membrane potential, activated caspase-3 and lowered the Bcl-2/Bax ratio in K562 cells, suggesting that the HKL 2H-causing programmed cell death of K562 cells was caused via the mitochondrial apoptotic pathway. Taken together, our data demonstrated that HKL 2H, a 5-(2-carboxyethenyl) isatin derivative, notably induces G{sub 2}/M cell cycle arrest and mitochondrial-mediated apoptosis in K562 cells, indicating that this compound could be a promising anticancer candidate for further investigation.

  20. Tributyltin induces a G2/M cell cycle arrest in human amniotic cells via PP2A inhibition-mediated inactivation of the ERK1/2 cascades.

    Science.gov (United States)

    Zhang, Yali; Guo, Zonglou; Xu, Lihong

    2014-03-01

    The molecular mechanisms underlying the cell cycle alterations induced by tributyltin (TBT), a highly toxic environmental contaminant, remain elusive. In this study, cell cycle progression and some key regulators in G2/M phase were investigated in human amniotic cells treated with TBT. Furthermore, protein phosphatase (PP) 2A and the ERK cascades were examined. The results showed that TBT caused a G2/M cell cycle arrest that was accompanied by a decrease in the total cdc25C protein level and an increase in the p-cdc2 level in the nucleus. TBT caused a decrease in PP2A activity and inhibited the ERK cascade by inactivating Raf-1, resulting in the dephosphorylation of MEK1/2, ERK1/2, and c-Myc. Taken together, TBT leads to a G2/M cell cycle arrest in FL cells, an increase in p-cdc2 and a decrease in the levels of total cdc25C protein, which may be caused by the PP2A inhibition-mediated inactivation of the ERK1/2 cascades. Copyright © 2014 Elsevier B.V. All rights reserved.

  1. Suppression of urinary bladder urothelial carcinoma cell by the ethanol extract of pomegranate fruit through cell cycle arrest and apoptosis.

    Science.gov (United States)

    Lee, Song-Tay; Lu, Min-Hua; Chien, Lan-Hsiang; Wu, Ting-Feng; Huang, Li-Chien; Liao, Gwo-Ing

    2013-12-21

    Pomegranate possesses many medicinal properties such as antioxidant, anti-inflammation and antitumor. It has been extensively used as a folk medicine by many cultures. Pomegranate fruit has been shown to have the inhibitory efficacy against prostate cancer and lung cancer in vitro and in vivo. It can be exploited in chemoprevention and chemotherapy of prostate cancer. In this study we examined the anti-cancer efficacy of pomegranate fruit grown in Taiwan against urinary bladder urothelial carcinoma (UBUC) and its mechanism of action. Edible portion of Taiwanese pomegranate was extracted using ethanol and the anti-cancer effectiveness of ethanol extract was evaluated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. Flow cytometry and western immunoblotting were exploited to uncover the molecular pathways underlying anti-UBUC activity of Taiwanese pomegranate ethanol extract. This study demonstrated that Taiwanese pomegranate fruit ethanol extract (PEE) could effectively restrict the proliferation of UBUC T24 and J82 cells. Cell cycle analyses indicated that the S phase arrest induced by PEE treatment might be caused by an increase in cyclin A protein level and a decrease in the expression of cyclin-dependent kinase 1. The results of western immunoblotting demonstrated that PEE treatment could not only evoke the activation of pro-caspase-3, -8,-9 but also increase Bax/Bcl-2 ratio in T24 cells. The above observations implicated that PEE administration might trigger the apoptosis in T24 cells through death receptor signaling and mitochondrial damage pathway. Besides we found that PEE exposure to T24 cells could provoke intensive activation of procaspase-12 and enhance the expressions of CHOP and Bip, endoplasmic reticulum (ER) stress marker, suggesting that ER stress might be the cardinal apoptotic mechanism of PEE-induced inhibition of bladder cancer cell. The analytical results of this study help to provide insight into the molecular mechanism

  2. Role of insulin-like growth factor-1 (IGF-1) in regulating cell cycle progression

    Energy Technology Data Exchange (ETDEWEB)

    Ma, Qi-lin; Yang, Tian-lun [Department of Cardiology, Xiangya Hospital, Central South University, Changsha 410008, Hunan (China); Yin, Ji-ye [Institute of Clinical Pharmacology, Hunan Key Laboratory of Pharmacogenetics, Xiangya School of Medicine, Central South University, Changsha 410078, Hunan (China); Peng, Zhen-yu [Department of Cardiology, Xiangya Hospital, Central South University, Changsha 410008, Hunan (China); Yu, Min [Institute of Clinical Pharmacology, Hunan Key Laboratory of Pharmacogenetics, Xiangya School of Medicine, Central South University, Changsha 410078, Hunan (China); Liu, Zhao-qian, E-mail: liuzhaoqian63@126.com [Institute of Clinical Pharmacology, Hunan Key Laboratory of Pharmacogenetics, Xiangya School of Medicine, Central South University, Changsha 410078, Hunan (China); Chen, Fang-ping, E-mail: xychenfp@public.cs.hn.Cn [Department of Haematology, Xiangya Hospital, Central South University, Changsha 410008, Hunan (China)

    2009-11-06

    Aims: Insulin-like growth factor-1 (IGF-1) is a polypeptide protein hormone, similar in molecular structure to insulin, which plays an important role in cell migration, cell cycle progression, cell survival and proliferation. In this study, we investigated the possible mechanisms of IGF-1 mediated cell cycle redistribution and apoptosis of vascular endothelial cells. Method: Human umbilical vein endothelial cells (HUVECs) were pretreated with 0.1, 0.5, or 2.5 {mu}g/mL of IGF-1 for 30 min before the addition of Ang II. Cell cycle redistribution and apoptosis were examined by flow cytometry. Expression of Ang II type 1 (AT{sub 1}) mRNA and cyclin E protein were determined by RT-PCR and Western blot, respectively. Results: Ang II (1 {mu}mol/L) induced HUVECs arrested at G{sub 0}/G{sub 1}, enhanced the expression level of AT{sub 1} mRNA in a time-dependent manner, reduced the enzymatic activity of nitric oxide synthase (NOS) and nitric oxide (NO) content as well as the expression level of cyclin E protein. However, IGF-1 enhanced NOS activity, NO content, and the expression level of cyclin E protein, and reduced the expression level of AT{sub 1} mRNA. L-NAME significantly counteracted these effects of IGF-1. Conclusions: Our data suggests that IGF-1 can reverse vascular endothelial cells arrested at G{sub 0}/G{sub 1} and apoptosis induced by Ang II, which might be mediated via a NOS-NO signaling pathway and is likely associated with the expression levels of AT1 mRNA and cyclin E proteins.

  3. Role of insulin-like growth factor-1 (IGF-1) in regulating cell cycle progression

    International Nuclear Information System (INIS)

    Ma, Qi-lin; Yang, Tian-lun; Yin, Ji-ye; Peng, Zhen-yu; Yu, Min; Liu, Zhao-qian; Chen, Fang-ping

    2009-01-01

    Aims: Insulin-like growth factor-1 (IGF-1) is a polypeptide protein hormone, similar in molecular structure to insulin, which plays an important role in cell migration, cell cycle progression, cell survival and proliferation. In this study, we investigated the possible mechanisms of IGF-1 mediated cell cycle redistribution and apoptosis of vascular endothelial cells. Method: Human umbilical vein endothelial cells (HUVECs) were pretreated with 0.1, 0.5, or 2.5 μg/mL of IGF-1 for 30 min before the addition of Ang II. Cell cycle redistribution and apoptosis were examined by flow cytometry. Expression of Ang II type 1 (AT 1 ) mRNA and cyclin E protein were determined by RT-PCR and Western blot, respectively. Results: Ang II (1 μmol/L) induced HUVECs arrested at G 0 /G 1 , enhanced the expression level of AT 1 mRNA in a time-dependent manner, reduced the enzymatic activity of nitric oxide synthase (NOS) and nitric oxide (NO) content as well as the expression level of cyclin E protein. However, IGF-1 enhanced NOS activity, NO content, and the expression level of cyclin E protein, and reduced the expression level of AT 1 mRNA. L-NAME significantly counteracted these effects of IGF-1. Conclusions: Our data suggests that IGF-1 can reverse vascular endothelial cells arrested at G 0 /G 1 and apoptosis induced by Ang II, which might be mediated via a NOS-NO signaling pathway and is likely associated with the expression levels of AT1 mRNA and cyclin E proteins.

  4. Rare sugar D-allose induces specific up-regulation of TXNIP and subsequent G1 cell cycle arrest in hepatocellular carcinoma cells by stabilization of p27kip1.

    Science.gov (United States)

    Yamaguchi, Fuminori; Takata, Maki; Kamitori, Kazuyo; Nonaka, Machiko; Dong, Youyi; Sui, Li; Tokuda, Masaaki

    2008-02-01

    'Rare sugars' are defined as monosaccharides that exist in nature but are only present in limited quantities. The development of mass production method of rare sugars revealed some interesting physiological effects of these on animal cells, but the mechanisms have not been well studied. We examined the effect of D-allose on the proliferation of cancer cells and the underlying molecular mechanism of the action. The HuH-7 hepatocellular carcinoma cells were treated with various monosaccharides for 48 h and D-allose was shown to inhibit cell growth by 40% in a dose-dependent manner. D-allose induced G1 cell cycle arrest but not apoptosis. The microarray analysis revealed that D-allose significantly up-regulated thioredoxin interacting protein (TXNIP) gene expression, which is often suppressed in tumor cells and western blot analysis confirmed its increase at protein level. The overexpression of TXNIP also induced G1 cell cycle arrest. Analysis of cell cycle regulatory genes showed p27kip1, a key regulator of G1/S cell cycle transition, to be increased at the protein but not the transcriptional level. Protein interaction between TXNIP and jab1, and p27kip1 and jab1, was observed, suggesting stabilization of p27kip1 protein by the competitive inhibition of jab1-mediated nuclear export of p27kip1 by TXNIP. In addition, increased interaction and nuclear localization of TXNIP and p27kip1 were apparent after D-allose treatment. Our findings surprisingly suggest that D-allose, a simple monosaccharide, may act as a novel anticancer agent via unique TXNIP induction and p27kip1 protein stabilization.

  5. Deoxyinosine triphosphate induces MLH1/PMS2- and p53-dependent cell growth arrest and DNA instability in mammalian cells

    Science.gov (United States)

    Yoneshima, Yasuto; Abolhassani, Nona; Iyama, Teruaki; Sakumi, Kunihiko; Shiomi, Naoko; Mori, Masahiko; Shiomi, Tadahiro; Noda, Tetsuo; Tsuchimoto, Daisuke; Nakabeppu, Yusaku

    2016-01-01

    Deoxyinosine (dI) occurs in DNA either by oxidative deamination of a previously incorporated deoxyadenosine residue or by misincorporation of deoxyinosine triphosphate (dITP) from the nucleotide pool during replication. To exclude dITP from the pool, mammals possess specific hydrolysing enzymes, such as inosine triphosphatase (ITPA). Previous studies have shown that deficiency in ITPA results in cell growth suppression and DNA instability. To explore the mechanisms of these phenotypes, we analysed ITPA-deficient human and mouse cells. We found that both growth suppression and accumulation of single-strand breaks in nuclear DNA of ITPA-deficient cells depended on MLH1/PMS2. The cell growth suppression of ITPA-deficient cells also depended on p53, but not on MPG, ENDOV or MSH2. ITPA deficiency significantly increased the levels of p53 protein and p21 mRNA/protein, a well-known target of p53, in an MLH1-dependent manner. Furthermore, MLH1 may also contribute to cell growth arrest by increasing the basal level of p53 activity. PMID:27618981

  6. Fibroblasts from long-lived Snell dwarf mice are resistant to oxygen-induced in vitro growth arrest

    DEFF Research Database (Denmark)

    Maynard, Scott P; Miller, Richard A

    2006-01-01

    Snell dwarf mice live longer than controls, and show lower age-adjusted rates of lethal neoplastic diseases. Fibroblast cells from adult dwarf mice are resistant to the lethal effects of oxidative and nonoxidative stresses, including the carcinogen methyl methanesulfonate. We now report that dwar...... in skin fibroblasts by the hormonal milieu of the Snell dwarf lead to resistance to multiple forms of injury, including the oxidative damage that contributes to growth arrest in vitro and neoplasia in intact mice.......Snell dwarf mice live longer than controls, and show lower age-adjusted rates of lethal neoplastic diseases. Fibroblast cells from adult dwarf mice are resistant to the lethal effects of oxidative and nonoxidative stresses, including the carcinogen methyl methanesulfonate. We now report that dwarf...

  7. The Forkhead Transcription Factor FOXP2 Is Required for Regulation of p21WAF1/CIP1 in 143B Osteosarcoma Cell Growth Arrest.

    Science.gov (United States)

    Gascoyne, Duncan M; Spearman, Hayley; Lyne, Linden; Puliyadi, Rathi; Perez-Alcantara, Marta; Coulton, Les; Fisher, Simon E; Croucher, Peter I; Banham, Alison H

    2015-01-01

    Mutations of the forkhead transcription factor FOXP2 gene have been implicated in inherited speech-and-language disorders, and specific Foxp2 expression patterns in neuronal populations and neuronal phenotypes arising from Foxp2 disruption have been described. However, molecular functions of FOXP2 are not completely understood. Here we report a requirement for FOXP2 in growth arrest of the osteosarcoma cell line 143B. We observed endogenous expression of this transcription factor both transiently in normally developing murine osteoblasts and constitutively in human SAOS-2 osteosarcoma cells blocked in early osteoblast development. Critically, we demonstrate that in 143B osteosarcoma cells with minimal endogenous expression, FOXP2 induced by growth arrest is required for up-regulation of p21WAF1/CIP1. Upon growth factor withdrawal, FOXP2 induction occurs rapidly and precedes p21WAF1/CIP1 activation. Additionally, FOXP2 expression could be induced by MAPK pathway inhibition in growth-arrested 143B cells, but not in traditional cell line models of osteoblast differentiation (MG-63, C2C12, MC3T3-E1). Our data are consistent with a model in which transient upregulation of Foxp2 in pre-osteoblast mesenchymal cells regulates a p21-dependent growth arrest checkpoint, which may have implications for normal mesenchymal and osteosarcoma biology.

  8. Citric acid induces cell-cycle arrest and apoptosis of human immortalized keratinocyte cell line (HaCaT) via caspase- and mitochondrial-dependent signaling pathways.

    Science.gov (United States)

    Ying, Tsung-Ho; Chen, Chia-Wei; Hsiao, Yu-Ping; Hung, Sung-Jen; Chung, Jing-Gung; Yang, Jen-Hung

    2013-10-01

    Citric acid is an alpha-hydroxyacid (AHA) widely used in cosmetic dermatology and skincare products. However, there is concern regarding its safety for the skin. In this study, we investigated the cytotoxic effects of citric acid on the human keratinocyte cell line HaCaT. HaCaT cells were treated with citric acid at 2.5-12.5 mM for different time periods. Cell-cycle arrest and apoptosis were investigated by 4,6-diamidino-2-phenylindole dihydrochloride (DAPI) staining, flow cytometry, western blot and confocal microscopy. Citric acid not only inhibited proliferation of HaCaT cells in a dose-dependent manner, but also induced apoptosis and cell cycle-arrest at the G2/M phase (before 24 h) and S phase (after 24 h). Citric acid increased the level of Bcl-2-associated X protein (BAX) and reduced the levels of B-cell lymphoma-2 (BCL-2), B-cell lymphoma-extra large (BCL-XL) and activated caspase-9 and caspase-3, which subsequently induced apoptosis via caspase-dependent and caspase-independent pathways. Citric acid also activated death receptors and increased the levels of caspase-8, activated BH3 interacting-domain death agonist (BID) protein, Apoptosis-inducing factor (AIF), and Endonuclease G (EndoG). Therefore, citric acid induces apoptosis through the mitochondrial pathway in the human keratinocyte cell line HaCaT. The study results suggest that citric acid is cytotoxic to HaCaT cells via induction of apoptosis and cell-cycle arrest in vitro.

  9. Nucleolin down-regulation is involved in ADP-induced cell cycle arrest in S phase and cell apoptosis in vascular endothelial cells.

    Directory of Open Access Journals (Sweden)

    Wenmeng Wang

    Full Text Available High concentration of extracellular ADP has been reported to induce cell apoptosis, but the molecular mechanisms remain not fully elucidated. In this study, we found by serendipity that ADP treatment of human umbilical vein endothelial cells (HUVEC and human aortic endothelial cells (HAEC down-regulated the protein level of nucleolin in a dose- and time-dependent manner. ADP treatment did not decrease the transcript level of nucloelin, suggesting that ADP might induce nucleolin protein degradation. HUVEC and HAEC expressed ADP receptor P2Y13 receptor, but did not express P2Y1 or P2Y12 receptors. However, P2Y1, 12, 13 receptor antagonists MRS2179, PSB0739, MRS2211 did not inhibit ADP-induced down-regulation of nucleolin. Moreover, MRS2211 itself down-regulated nucleolin protein level. In addition, 2-MeSADP, an agonist for P2Y1, 12 and 13 receptors, did not down-regulate nucleolin protein. These results suggested that ADP-induced nucleolin down-regulation was not due to the activation of P2Y1, 12, or 13 receptors. We also found that ADP treatment induced cell cycle arrest in S phase, cell apoptosis and cell proliferation inhibition via nucleolin down-regulation. The over-expression of nucleolin by gene transfer partly reversed ADP-induced cell cycle arrest, cell apoptosis and cell proliferation inhibition. Furthermore, ADP sensitized HUVEC to cisplatin-induced cell death by the down-regulation of Bcl-2 expression. Taken together, we found, for the first time to our knowledge, a novel mechanism by which ADP regulates cell proliferation by induction of cell cycle arrest and cell apoptosis via targeting nucelolin.

  10. Cisplatin resistance in non-small cell lung cancer cells is associated with an abrogation of cisplatin-induced G2/M cell cycle arrest.

    Directory of Open Access Journals (Sweden)

    Navin Sarin

    Full Text Available The efficacy of cisplatin-based chemotherapy in cancer is limited by the occurrence of innate and acquired drug resistance. In order to better understand the mechanisms underlying acquired cisplatin resistance, we have compared the adenocarcinoma-derived non-small cell lung cancer (NSCLC cell line A549 and its cisplatin-resistant sub-line A549rCDDP2000 with regard to cisplatin resistance mechanisms including cellular platinum accumulation, DNA-adduct formation, cell cycle alterations, apoptosis induction and activation of key players of DNA damage response. In A549rCDDP2000 cells, a cisplatin-induced G2/M cell cycle arrest was lacking and apoptosis was reduced compared to A549 cells, although equitoxic cisplatin concentrations resulted in comparable platinum-DNA adduct levels. These differences were accompanied by changes in the expression of proteins involved in DNA damage response. In A549 cells, cisplatin exposure led to a significantly higher expression of genes coding for proteins mediating G2/M arrest and apoptosis (mouse double minute 2 homolog (MDM2, xeroderma pigmentosum complementation group C (XPC, stress inducible protein (SIP and p21 compared to resistant cells. This was underlined by significantly higher protein levels of phosphorylated Ataxia telangiectasia mutated (pAtm and p53 in A549 cells compared to their respective untreated control. The results were compiled in a preliminary model of resistance-associated signaling alterations. In conclusion, these findings suggest that acquired resistance of NSCLC cells against cisplatin is the consequence of altered signaling leading to reduced G2/M cell cycle arrest and apoptosis.

  11. Umbilical Cord Tissue-Derived Mesenchymal Stem Cells Induce T Lymphocyte Apoptosis and Cell Cycle Arrest by Expression of Indoleamine 2, 3-Dioxygenase

    Directory of Open Access Journals (Sweden)

    Xiuying Li

    2016-01-01

    Full Text Available It has been reported that human mesenchymal stem cells are able to inhibit T lymphocyte activation; however, the discrepancy among different sources of MSCs is not well documented. In this study, we have compared the MSCs from bone marrow (BM, adipose tissue (AT, placenta (PL, and umbilical cord (UC to determine which one displayed the most efficient immunosuppressive effects on phytohemagglutinin-induced T cell proliferation. Among them we found that hUC-MSC has the strongest effects on inhibiting T cell proliferation and is chosen to do the further study. We observed that T lymphocyte spontaneously released abundant IFN-γ. And IFN-γ secreted by T lymphocyte could induce the expression of indoleamine 2, 3-dioxygenase (IDO in hUC-MSCs. IDO was previously reported to induce T lymphocyte apoptosis and cell cycle arrest in S phase. When cocultured with hUC-MSCs, T lymphocyte expression of caspase 3 was significantly increased, while Bcl2 and CDK4 mRNA expression decreased dramatically. Addition of 1-methyl tryptophan (1-MT, an IDO inhibitor, restored T lymphocyte proliferation, reduced apoptosis, and induced resumption of the cell cycle. In addition, the changes in caspase 3, CDK4, and Bcl2 expression were reversed by 1-MT. These findings demonstrate that hUC-MSCs induce T lymphocyte apoptosis and cell cycle arrest by expressing abundant IDO and provide an explanation for some of the immunomodulatory effects of MSCs.

  12. A phthalide derivative isolated from endophytic fungi Pestalotiopsis photiniae induces G1 cell cycle arrest and apoptosis in human HeLa cells

    Energy Technology Data Exchange (ETDEWEB)

    Chen, C. [College of Life Science, Hebei University, Baoding (China); Yang, R.L. [Key Laboratory of Microbial Diversity Research and Application of Hebei Province, Baoding, China, Key Laboratory of Microbial Diversity Research and Application of Hebei Province, Baoding (China)

    2013-07-30

    MP [4-(3′,3′-dimethylallyloxy)-5-methyl-6-methoxyphthalide] was obtained from liquid culture of Pestalotiopsis photiniae isolated from the Chinese Podocarpaceae plant Podocarpus macrophyllus. MP significantly inhibited the proliferation of HeLa tumor cell lines. After treatment with MP, characteristic apoptotic features such as DNA fragmentation and chromatin condensation were observed in DAPI-stained HeLa cells. Flow cytometry showed that MP induced G1 cell cycle arrest and apoptosis in a dose-dependent manner. Western blotting and real-time reverse transcription-polymerase chain reaction were used to investigate protein and mRNA expression. MP caused significant cell cycle arrest by upregulating the cyclin-dependent kinase inhibitor p27{sup KIP1} protein and p21{sup CIP1} mRNA levels in HeLa cells. The expression of p73 protein was increased after treatment with various MP concentrations. mRNA expression of the cell cycle-related genes, p21{sup CIP1}, p16{sup INK4a} and Gadd45α, was significantly upregulated and mRNA levels demonstrated significantly increased translation of p73, JunB, FKHR, and Bim. The results indicate that MP may be a potential treatment for cervical cancer.

  13. The neem limonoids azadirachtin and nimbolide induce cell cycle arrest and mitochondria-mediated apoptosis in human cervical cancer (HeLa) cells.

    Science.gov (United States)

    Priyadarsini, R Vidya; Murugan, R Senthil; Sripriya, P; Karunagaran, D; Nagini, S

    2010-06-01

    Limonoids from the neem tree (Azadirachta indica) have attracted considerable research attention in recent years owing to their potent antioxidant and anti-proliferative effects. The present study was designed to investigate the cellular and molecular mechanisms by which azadirachtin and nimbolide exert cytotoxic effects in the human cervical cancer (HeLa) cell line. Both azadirachtin and nimbolide significantly suppressed the viability of HeLa cells in a dose-dependent manner by inducing cell cycle arrest at G0/G1 phase accompanied by p53-dependent p21 accumulation and down-regulation of the cell cycle regulatory proteins cyclin B, cyclin D1 and PCNA. Characteristic changes in nuclear morphology, presence of a subdiploid peak and annexin-V staining pointed to apoptosis as the mode of cell death. Increased generation of reactive oxygen species with decline in the mitochondrial transmembrane potential and release of cytochrome c confirmed that the neem limonoids transduced the apoptotic signal via the mitochondrial pathway. Altered expression of the Bcl-2 family of proteins, inhibition of NF-kappaB activation and over-expression of caspases and survivin provide compelling evidence that azadirachtin and nimbolide induce a shift of balance toward a pro-apoptotic phenotype. Antioxidants such as azadirachtin and nimbolide that can simultaneously arrest the cell cycle and target multiple molecules involved in mitochondrial apoptosis offer immense potential as anti-cancer therapeutic drugs.

  14. A phthalide derivative isolated from endophytic fungi Pestalotiopsis photiniae induces G1 cell cycle arrest and apoptosis in human HeLa cells

    International Nuclear Information System (INIS)

    Chen, C.; Yang, R.L.

    2013-01-01

    MP [4-(3′,3′-dimethylallyloxy)-5-methyl-6-methoxyphthalide] was obtained from liquid culture of Pestalotiopsis photiniae isolated from the Chinese Podocarpaceae plant Podocarpus macrophyllus. MP significantly inhibited the proliferation of HeLa tumor cell lines. After treatment with MP, characteristic apoptotic features such as DNA fragmentation and chromatin condensation were observed in DAPI-stained HeLa cells. Flow cytometry showed that MP induced G1 cell cycle arrest and apoptosis in a dose-dependent manner. Western blotting and real-time reverse transcription-polymerase chain reaction were used to investigate protein and mRNA expression. MP caused significant cell cycle arrest by upregulating the cyclin-dependent kinase inhibitor p27 KIP1 protein and p21 CIP1 mRNA levels in HeLa cells. The expression of p73 protein was increased after treatment with various MP concentrations. mRNA expression of the cell cycle-related genes, p21 CIP1 , p16 INK4a and Gadd45α, was significantly upregulated and mRNA levels demonstrated significantly increased translation of p73, JunB, FKHR, and Bim. The results indicate that MP may be a potential treatment for cervical cancer

  15. Inhibition of c-Myc by 10058-F4 induces growth arrest and chemosensitivity in pancreatic ductal adenocarcinoma.

    Science.gov (United States)

    Zhang, Meng; Fan, Hai-Yan; Li, Sheng-Chao

    2015-07-01

    Pancreatic ductal adenocarcinoma (PDAC) is a formidable medical challenge due to its malignancies and the absence of effective treatment. c-Myc, as an important transcription factor, plays crucial roles in cell cycle progression, apoptosis and cellular transformation. The c-Myc inhibitor, 10058-F4, has been reported act as a tumor suppressor in several different tumors. In current study, the tumor-suppressive roles of 10058-F4 was observed in human pancreatic cancer cells in vitro as demonstrated by decreased cell viability, cell cycle arrest at the G1/S transition and increased caspase3/7 activity. And tumor responses to gemcitabine were also significantly enhanced by 10058-F4 in PANC-1 and SW1990 cells. In a subcutaneous xenograft model, however, 10058-F4 showed no significant influence on pancreatic tumorigenesis. When combined with gemcitabine, tumorigenesis was drastically attenuated compared with gemcitabine group or 10058-F4 group; this synergistic effect was accompanied with decreased PCNA-positive cells and reduced TUNEL-positive cells in the combined treated group. Subsequent studies revealed that decreased glycolysis may be involved in the inhibitory effect of 10058-F4 on PDAC. Taken together, this study demonstrates the roles of 10058-F4 in PDAC and provides evidence that 10058-F4 in combination with gemcitabine showed significant clinical benefit over the usage of gemcitabine alone. Copyright © 2015. Published by Elsevier Masson SAS.

  16. Folate deprivation induces cell cycle arrest at G0/G1 phase and apoptosis in hippocampal neuron cells through down-regulation of IGF-1 signaling pathway.

    Science.gov (United States)

    Yang, Yang; Li, Xi; Sun, Qinwei; He, Bin; Jia, Yimin; Cai, Demin; Zhao, Ruqian

    2016-10-01

    Folate deficiency contributes to impaired adult hippocampal neurogenesis, yet the mechanisms remain unclear. Here we use HT-22 hippocampal neuron cells as model to investigate the effect of folate deprivation (FD) on cell proliferation and apoptosis, and to elucidate the underlying mechanism. FD caused cell cycle arrest at G0/G1 phase and increased the rate of apoptosis, which was associated with disrupted expression of folate transport and methyl transfer genes. FOLR1 and SLC46A1 were (Pmethyl transfer pathway and hypermethylation of IGF-1 gene promoter. Copyright © 2016 Elsevier Ltd. All rights reserved.

  17. The SWI/SNF chromatin-remodeling gene AtCHR12 mediates temporary growth arrest in Arabidopsis thaliana upon perceiving environmental stress

    NARCIS (Netherlands)

    Mlynarova, L.; Nap, J.P.H.; Bisseling, T.

    2007-01-01

    One of the earliest responses of plants to environmental stress is establishing a temporary growth arrest that allows adaptation to adverse conditions. The response to abiotic stress requires the modulation of gene expression, which may be mediated by the alteration of chromatin structures. This

  18. Salicylic acid antagonizes abscisic acid inhibition of shoot growth and cell cycle progression in rice

    Science.gov (United States)

    Meguro, Ayano; Sato, Yutaka

    2014-04-01

    We analysed effects of abscisic acid (ABA, a negative regulatory hormone), alone and in combination with positive or neutral hormones, including salicylic acid (SA), on rice growth and expression of cell cycle-related genes. ABA significantly inhibited shoot growth and induced expression of OsKRP4, OsKRP5, and OsKRP6. A yeast two-hybrid assay showed that OsKRP4, OsKRP5, and OsKRP6 interacted with OsCDKA;1 and/or OsCDKA;2. When SA was simultaneously supplied with ABA, the antagonistic effect of SA completely blocked ABA inhibition. SA also blocked ABA inhibition of DNA replication and thymidine incorporation in the shoot apical meristem. These results suggest that ABA arrests cell cycle progression by inducing expression of OsKRP4, OsKRP5, and OsKRP6, which inhibit the G1/S transition, and that SA antagonizes ABA by blocking expression of OsKRP genes.

  19. Glycoprotein 5 of porcine reproductive and respiratory syndrome virus strain SD16 inhibits viral replication and causes G2/M cell cycle arrest, but does not induce cellular apoptosis in Marc-145 cells

    International Nuclear Information System (INIS)

    Mu, Yang; Li, Liangliang; Zhang, Beibei; Huang, Baicheng; Gao, Jiming

    2015-01-01

    Cell apoptosis is common after infection with porcine reproductive and respiratory syndrome virus (PRRSV). PRRSV GP5 has been reported to induce cell apoptosis. To further understand the role of GP5 in PRRSV induced cell apoptosis, we established Marc-145 cell lines stably expressing full-length GP5, GP5 Δ84-96 (aa 84-96 deletion), and GP5 Δ97-119 (aa 97-119 deletion). Cell proliferation, cell cycle progression, cell apoptosis and virus replication in these cell lines were evaluated. Neither truncated nor full-length GP5 induced cell apoptosis in Marc-145 cells. However, GP5 Δ97-119 , but not full-length or GP5 Δ84-96 , induced a cell cycle arrest at the G2/M phase resulting in a reduction in the growth of Marc-145 cells. Additionally, GP5 Δ84-96 inhibited the replication of PRRSV in Marc-145 cells through induction of IFN-β. These findings suggest that PRRSV GP5 is not responsible for inducing cell apoptosis in Marc-145 cells under these experimental conditions; however it has other important roles in virus/host cell biology. - Highlights: • Marc-145 cell lines stable expression PRRSV GP5 or truncated GP5 were constructed. • GP5 Δ97-119 expression in Marc-145 cell induced cell cycle arrest at G2/M phase. • Expression of GP5 and truncated GP5 could not induce Marc-145 cells apoptosis. • PRRSV replication in Marc-145-GP5 Δ84-96 was significantly inhibited

  20. Ziyuglycoside I Inhibits the Proliferation of MDA-MB-231 Breast Carcinoma Cells through Inducing p53-Mediated G2/M Cell Cycle Arrest and Intrinsic/Extrinsic Apoptosis.

    Science.gov (United States)

    Zhu, Xue; Wang, Ke; Zhang, Kai; Zhang, Ting; Yin, Yongxiang; Xu, Fei

    2016-11-22

    Due to the aggressive clinical behavior, poor outcome, and lack of effective specific targeted therapies, triple-negative breast cancer (TNBC) has currently been recognized as one of the most malignant types of tumors. In the present study, we investigated the cytotoxic effect of ziyuglycoside I, one of the major components extracted from Chinese anti-tumor herbal Radix Sanguisorbae , on the TNBC cell line MDA-MB-231. The underlying molecular mechanism of the cytotoxic effect ziyuglycoside I on MDA-MB-231 cells was investigated with cell viability assay, flow cytometric analysis and Western blot. Compared to normal mammary gland Hs 578Bst cells, treatment of ziyuglycoside I resulted in a significant growth inhibitory effect on MDA-MB-231 cells. Ziyuglycoside I induced the G2/M phase arrest and apoptosis of MDA-MB-231 cells in a dose-dependent manner. These effects were found to be partially mediated through the up-regulation of p53 and p21 WAF1 , elevated Bax/Bcl-2 ratio, and the activation of both intrinsic (mitochondrial-initiated) and extrinsic (Fas/FasL-initiated) apoptotic pathways. Furthermore, the p53 specific siRNA attenuated these effects. Our study suggested that ziyuglycoside I-triggered MDA-MB-231 cell cycle arrest and apoptosis were probably mediated by p53. This suggests that ziyuglycoside I might be a potential drug candidate for treating TNBC.

  1. Fiscal multipliers over the growth cycle : evidence from Malaysia

    OpenAIRE

    Rafiq, Sohrab; Zeufack, Albert

    2012-01-01

    This paper explores the stabilisation properties of fiscal policy in Malaysia using a model incorporating nonlinearities into the dynamic relationship between fiscal policy and real economic activity over the growth cycle. The paper also investigates how output multipliers for government purchases may alter for different components of government spending. The authors find that fiscal polic...

  2. Review of capital investment in economic growth cycle

    Science.gov (United States)

    Shaffie, Siti Salihah; Jaaman, Saiful Hafizah; Mohamad, Daud

    2016-11-01

    The study of linkages of macroeconomics factors is prominent in order to understand how the economic cycle affects one another. These factors include interest rate, growth rate, saving and capital investment which are mutually correlated to stabilize the GDP. Part of this study, it will look upon the impact of investment which emphasize the efficiency of capital investment to the economic growth. Capital investment is one investment appraisal that gives impact to the economic growth. It is a long term investment and involve with large amount of capital to incorporate the development of private and public capital investment.

  3. Effects of DNA double-strand and single-strand breaks on intrachromosomal recombination events in cell-cycle-arrested yeast cells

    International Nuclear Information System (INIS)

    Galli, A.; Schiestl, R.H.

    1998-01-01

    Intrachromosomal recombination between repeated elements can result in deletion (DEL recombination) events. We investigated the inducibility of such intrachromosomal recombination events at different stages of the cell cycle and the nature of the primary DNA lesions capable of initiating these events. Two genetic systems were constructed in Saccharomyces cerevisiae that select for DEL recombination events between duplicated alleles of CDC28 and TUB2. We determined effects of double-strand breaks (DSBs) and single-strand breaks (SSBs) between the duplicated alleles on DEL recombination when induced in dividing cells or cells arrested in G1 or G2. Site-specific DSBs and SSBs were produced by overexpression of the I-Sce I endonuclease and the gene II protein (gIIp), respectively. I-Sce I-induced DSBs caused an increase in DEL recombination frequencies in both dividing and cell-cycle-arrested cells, indicating that G1- and G2-arrested cells are capable of completing DSB repair. In contrast, gIIp-induced SSBs caused an increase in DEL recombination frequency only in dividing cells. To further examine these phenomena we used both γ-irradiation, inducing DSBs as its most relevant lesion, and UV, inducing other forms of DNA damage. UV irradiation did not increase DEL recombination frequencies in G1 or G2, whereas γ-rays increased DEL recombination frequencies in both phases. Both forms of radiation, however, induced DEL recombination in dividing cells. The results suggest that DSBsbut not SSBs induce DEL recombination, probably via the single-strand annealing pathway. Further, DSBs in dividing cells may result from the replication of a UV or SSB-damaged template. Alternatively, UV induced events may occur by replication slippage after DNA polymerase pausing in front of the damage. (author)

  4. Growth versus immunity--a redirection of the cell cycle?

    Science.gov (United States)

    Eichmann, Ruth; Schäfer, Patrick

    2015-08-01

    Diseases caused by plant pathogens significantly reduce growth and yield in agricultural crop production. Raising immunity in crops is therefore a major aim in breeding programs. However, efforts to enhance immunity are challenged by the occurrence of growth inhibition triggered by immunity that can be as detrimental as diseases. In this review, we will propose molecular models to explain the inhibitory growth-immunity crosstalk. We will briefly discuss why the resource reallocation model might not represent the driving force for the observed growth-immunity trade-offs. We suggest a model in which immunity redirects and initiates hormone signalling activities that can impair plant growth by antagonising cell cycle regulation and meristem activities. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

  5. Development of cell-based quantitative evaluation method for cell cycle-arrest type cancer drugs for apoptosis by high precision surface plasmon resonance sensor

    Science.gov (United States)

    Ona, Toshihiro; Nishijima, Hiroshi; Kosaihira, Atsushi; Shibata, Junko

    2008-04-01

    In vitro rapid and quantitative cell-based assay is demanded to verify the efficacy prediction of cancer drugs since a cancer patient may have unconventional aspects of tumor development. Here, we show the rapid and non-label quantitative verifying method and instrumentation of apoptosis for cell cycle-arrest type cancer drugs (Roscovitine and D-allose) by reaction analysis of living liver cancer cells cultured on a sensor chip with a newly developed high precision (50 ndeg s -1 average fluctuation) surface plasmon resonance (SPR) sensor. The time-course cell reaction as the SPR angle change rate for 10 min from 30 min cell culture with a drug was significantly related to cell viability. By the simultaneous detection of differential SPR angle change and fluorescence by specific probes using the new instrument, the SPR angle was related to the nano-order potential decrease in inner mitochondrial membrane potential. The results obtained are universally valid for the cell cycle-arrest type cancer drugs, which mediate apoptosis through different cell-signaling pathways, by a liver cancer cell line of Hep G2 (P<0.001). This system towards the application to evaluate personal therapeutic potentials of drugs using cancer cells from patients in clinical use.

  6. An Ingenol Derived from Euphorbia kansui Induces Hepatocyte Cytotoxicity by Triggering G0/G1 Cell Cycle Arrest and Regulating the Mitochondrial Apoptosis Pathway in Vitro

    Directory of Open Access Journals (Sweden)

    Xiaojing Yan

    2016-06-01

    Full Text Available Natural product lingenol, a purified diterpenoid compound derived from the root of Euphorbia kansui, exerts serious hepatotoxicity; however, the molecular mechanisms remain to be defined. In the present study, cell counting Kit-8 (CCK-8, inverted phase contrast microscope and flow cytometry were used to demonstrate that lingenol significantly inhibited L-O2 cells proliferation, and induced cell cycle arrest and apoptosis. Moreover, the results investigated that lingenol markedly disrupted mitochondrial functions by high content screening (HCS. In addition, the up-regulation of cytochrome c, AIF and Apaf-1 and activation of caspases were found in L-O2 cells detected by Western blotting and ELISA assay, which was required for lingenol activation of cytochrome c-mediated caspase cascades and AIF-mediated DNA damage. Mechanistic investigations revealed that lingenol significantly down-regulated the Bcl-2/Bax ratio and enhanced the reactive oxygen species (ROS in L-O2 cells. These data collectively indicated that lingenol modulation of ROS and Bcl-2/Bax ratio led to cell cycle arrest and mitochondrial-mediated apoptosis in L-O2 cells in vitro. All of these results will be helpful to reveal the hepatotoxicity mechanism of Euphorbia kansui and to effectively guide safer and better clinical application of this herb.

  7. 53BP1 and USP28 mediate p53-dependent cell cycle arrest in response to centrosome loss and prolonged mitosis.

    Science.gov (United States)

    Fong, Chii Shyang; Mazo, Gregory; Das, Tuhin; Goodman, Joshua; Kim, Minhee; O'Rourke, Brian P; Izquierdo, Denisse; Tsou, Meng-Fu Bryan

    2016-07-02

    Mitosis occurs efficiently, but when it is disturbed or delayed, p53-dependent cell death or senescence is often triggered after mitotic exit. To characterize this process, we conducted CRISPR-mediated loss-of-function screens using a cell-based assay in which mitosis is consistently disturbed by centrosome loss. We identified 53BP1 and USP28 as essential components acting upstream of p53, evoking p21-dependent cell cycle arrest in response not only to centrosome loss, but also to other distinct defects causing prolonged mitosis. Intriguingly, 53BP1 mediates p53 activation independently of its DNA repair activity, but requiring its interacting protein USP28 that can directly deubiquitinate p53 in vitro and ectopically stabilize p53 in vivo. Moreover, 53BP1 can transduce prolonged mitosis to cell cycle arrest independently of the spindle assembly checkpoint (SAC), suggesting that while SAC protects mitotic accuracy by slowing down mitosis, 53BP1 and USP28 function in parallel to select against disturbed or delayed mitosis, promoting mitotic efficiency.

  8. Cucurbitacin B inhibits proliferation, induces G2/M cycle arrest and autophagy without affecting apoptosis but enhances MTT reduction in PC12 cells

    Directory of Open Access Journals (Sweden)

    Chuanhong Wu

    2016-03-01

    Full Text Available In the present study, the effect of cucurbitacin B (a natural product with anti-cancer effect was studied on PC12 cells. It significantly reduced the cell number, changed cell morphology and inhibited colony formation while MTT results showed increased cell viability. Cucurbitacin B treatment increased activity of succinode hydrogenase. No alteration in the integrity of mem-brane, the release of lactic dehydrogenase, the mitochondrial membrane potential, and the expression of apoptotic proteins suggested that cucurbitacin B did not induce apoptosis. The cell cycle was remarkably arrested at G2/M phase. Furthermore, cucurbitacin B induced autophagy as evidence by accumulation of autophagic vacuoles and the increase of LC3II. In addition, cucurbitacin B up-regulated the expression of p-beclin-1, p-ULK1, p-Wee1, p21 and down-regulated p-mTOR, p-p70S6K, CDC25C, CDK1, Cyclin B1. In conclusion, cucurbitacin B inhibited PC12 proliferation but caused MTT pitfall. Cucurbitacin B induced G2/M cell cycle arrest, autophagy, but not the apoptosis in PC12 cells.

  9. Alkali-soluble polysaccharide, isolated from Lentinus edodes, induces apoptosis and G2/M cell cycle arrest in H22 cells through microtubule depolymerization.

    Science.gov (United States)

    You, Ru-Xu; Liu, Jin-Yu; Li, Shi-Jun; Wang, Liu; Wang, Kai-Ping; Zhang, Yu

    2014-12-01

    The aim of the study was to evaluate the pro-apoptotic effects of polysaccharides derived from Lentinus edodes and further elucidated the mechanisms of this action. Our results demonstrated that marked morphological changes of apoptosis were observed after treatment of L. edodes polysaccharides [Lentinan (LTN)]. Moreover, LTN-induced cell apoptosis was characterized by a rapid stimulation of reactive oxygen species production, the loss of mitochondrial membrane potential and an increase in intracellular concentration of Ca(2+) . In addition, the results of the haematoxylin and eosin and TUNEL assay further confirmed that LTN-induced apoptosis in vivo. Furthermore, flow cytometry analysis showed that LTN could arrest the cell cycle at G2/M phase, and immunofluorescence showed LTN caused disruption of microtubule. These results suggest that disruption of cellular microtubule network, arrest of the cell cycle at G2/M phase and induction of apoptosis may be one of the possible mechanisms of anti-tumour effect of LTN. Copyright © 2014 John Wiley & Sons, Ltd.

  10. Hexamethoxylated Monocarbonyl Analogues of Curcumin Cause G2/M Cell Cycle Arrest in NCI-H460 Cells via Michael Acceptor-Dependent Redox Intervention.

    Science.gov (United States)

    Li, Yan; Zhang, Li-Ping; Dai, Fang; Yan, Wen-Jing; Wang, Hai-Bo; Tu, Zhi-Shan; Zhou, Bo

    2015-09-09

    Curcumin, derived from the dietary spice turmeric, holds promise for cancer prevention. This prompts much interest in investigating the action mechanisms of curcumin and its analogues. Two symmetrical hexamethoxy-diarylpentadienones (1 and 2) as cucumin analogues were reported to possess significantly enhanced cytotoxicity compared with the parent molecule. However, the detailed mechanisms remain unclear. In this study, compounds 1 and 2 were identified as the G2/M cell cycle arrest agents to mediate the cytotoxicity toward NCI-H460 cells via Michael acceptor-dependent redox intervention. Compared with curcumin, they could more easily induce a burst of reactive oxygen species (ROS) and collapse of the redox buffering system. One possible reason is that they could more effectively target intracellular TrxR to convert this antioxidant enzyme into a ROS promoter. Additionally, they caused up-regulation of p53 and p21 and down-regulation of redox-sensitive Cdc25C along with cyclin B1/Cdk1 in a Michael acceptor- and ROS-dependent fashion. Interestingly, in comparison with compound 2, compound 1 displayed a relatively weak ability to generate ROS but increased cell cycle arrest activity and cytotoxicity probably due to its Michael acceptor-dependent microtubule-destabilizing effect and greater GST-inhibitory activity, as well as its enhanced cellular uptake. This work provides useful information for understanding Michael acceptor-dependent and redox-mediated cytotoxic mechanisms of curcumin and its active analogues.

  11. Induction of cell cycle arrest at G1 and S phases and cAMP-dependent differentiation in C6 glioma by low concentration of cycloheximide

    Directory of Open Access Journals (Sweden)

    Zhang Samuel S

    2010-12-01

    Full Text Available Abstract Background Differentiation therapy has been shown effective in treatment of several types of cancer cells and may prove to be effective in treatment of glioblastoma multiforme, the most common and most aggressive primary brain tumor. Although extensively used as a reagent to inhibit protein synthesis in mammalian cells, whether cycloheximide treatment leads to glioma cell differentiation has not been reported. Methods C6 glioma cell was treated with or without cycloheximide at low concentrations (0.5-1 μg/ml for 1, 2 and 3 days. Cell proliferation rate was assessed by direct cell counting and colony formation assays. Apoptosis was assessed by Hoechst 33258 staining and FACS analysis. Changes in several cell cycle regulators such as Cyclins D1 and E, PCNA and Ki67, and several apoptosis-related regulators such as p53, p-JNK, p-AKT, and PARP were determined by Western blot analysis. C6 glioma differentiation was determined by morphological characterization, immunostaining and Western blot analysis on upregulation of GFAP and o p-STAT3 expression, and upregulation of intracellular cAMP. Results Treatment of C6 cell with low concentration of cycloheximide inhibited cell proliferation and depleted cells at both G2 and M phases, suggesting blockade at G1 and S phases. While no cell death was observed, cells underwent profound morphological transformation that indicated cell differentiation. Western blotting and immunostaining analyses further indicated that changes in expression of several cell cycle regulators and the differentiation marker GFAP were accompanied with cycloheximide-induced cell cycle arrest and cell differentiation. Increase in intracellular cAMP, a known promoter for C6 cell differentiation, was found to be elevated and required for cycloheximide-promoted C6 cell differentiation. Conclusion Our results suggest that partial inhibition of protein synthesis in C6 glioma by low concentration of cycloheximide induces cell cycle

  12. Nanotechnology and mesenchymal stem cells with chondrocytes in prevention of partial growth plate arrest in pigs

    Czech Academy of Sciences Publication Activity Database

    Plánka, L.; Srnec, R.; Rauser, P.; Starý, D.; Filová, Eva; Jančář, J.; Juhásová, Jana; Křen, J.; Nečas, A.; Gál, P.

    2012-01-01

    Roč. 156, č. 2 (2012), s. 128-134 ISSN 1213-8118 R&D Projects: GA MZd(CZ) NS9896 Institutional research plan: CEZ:AV0Z50390512; CEZ:AV0Z50450515 Institutional support: RVO:68378041 ; RVO:67985904 Keywords : mesenchymal stem cells * growth plate defect * bone bridge Subject RIV: FI - Traumatology, Orthopedics Impact factor: 0.990, year: 2012

  13. Physeal growth arrest after tibial lengthening in achondroplasia: 23 children followed to skeletal maturity.

    Science.gov (United States)

    Song, Sang-Heon; Agashe, Mandar Vikas; Huh, Young-Jae; Hwang, Soon-Young; Song, Hae-Ryong

    2012-06-01

    Bilateral tibial lengthening has become one of the standard treatments for upper segment-lower segment disproportion and to improve quality of life in achondroplasia. We determined the effect of tibial lengthening on the tibial physis and compared tibial growth that occurred at the physis with that in non-operated patients with achondroplasia. We performed a retrospective analysis of serial radiographs until skeletal maturity in 23 achondroplasia patients who underwent bilateral tibial lengthening before skeletal maturity (lengthening group L) and 12 achondroplasia patients of similar height and age who did not undergo tibial lengthening (control group C). The mean amount of lengthening of tibia in group L was 9.2 cm (lengthening percentage: 60%) and the mean age at the time of lengthening was 8.2 years. The mean duration of follow-up was 9.8 years. Skeletal maturity (fusion of physis) occurred at 15.2 years in group L and at 16.0 years in group C. The actual length of tibia (without distraction) at skeletal maturity was 238 mm in group L and 277 mm in group C (p = 0.03). The mean growth rates showed a decrease in group L relative to group C from about 2 years after surgery. Physeal closure was most pronounced on the anterolateral proximal tibial physis, with relative preservation of the distal physis. Our findings indicate that physeal growth rate can be disturbed after tibial lengthening in achondroplasia, and a close watch should be kept for such an occurrence-especially when lengthening of more than 50% is attempted.

  14. MiR-7 triggers cell cycle arrest at the G1/S transition by targeting multiple genes including Skp2 and Psme3.

    Directory of Open Access Journals (Sweden)

    Noelia Sanchez

    Full Text Available MiR-7 acts as a tumour suppressor in many cancers and abrogates proliferation of CHO cells in culture. In this study we demonstrate that miR-7 targets key regulators of the G1 to S phase transition, including Skp2 and Psme3, to promote increased levels of p27(KIP and temporary growth arrest of CHO cells in the G1 phase. Simultaneously, the down-regulation of DNA repair-specific proteins via miR-7 including Rad54L, and pro-apoptotic regulators such as p53, combined with the up-regulation of anti-apoptotic factors like p-Akt, promoted cell survival while arrested in G1. Thus miR-7 can co-ordinate the levels of multiple genes and proteins to influence G1 to S phase transition and the apoptotic response in order to maintain cellular homeostasis. This work provides further mechanistic insight into the role of miR-7 as a regulator of cell growth in times of cellular stress.

  15. Cr(VI) induces DNA damage, cell cycle arrest and polyploidization: a flow cytometric and comet assay study in Pisum sativum.

    Science.gov (United States)

    Rodriguez, Eleazar; Azevedo, Raquel; Fernandes, Pedro; Santos, Conceição

    2011-07-18

    Chromium(VI) is recognized as the most toxic valency of Cr, but its genotoxicity and cytostaticity in plants is still poorly studied. In order to analyze Cr(VI) cyto- and gentotoxicity, Pisum sativum L. plants were grown in soil and watered with solutions with different concentrations of Cr up to 2000 mg/L. After 28 days of exposure, leaves showed no significant variations in either cell cycle dynamics or ploidy level. As for DNA damage, flow cytometric (FCM) histograms showed significant differences in full peak coefficient of variation (FPCV) values, suggesting clastogenicity. This is paralleled by the Comet assay results, showing an increase in DNA damage for 1000 and 2000 mg/L. In roots, exposure to 2000 mg/L resulted in cell cycle arrest at the G(2)/M checkpoint. It was also verified that under the same conditions 40% of the individuals analyzed suffered polyploidization having both 2C and 4C levels. DNA damage analysis by the Comet assay and FCM revealed dose-dependent increases in DNA damage and FPCV. Through this, we have unequivocally demonstrated for the first time in plants that Cr exposure can result in DNA damage, cell cycle arrest, and polyploidization. Moreover, we critically compare the validity of the Comet assay and FCM in evaluating cytogenetic toxicity tests in plants and demonstrate that the data provided by both techniques complement each other and present high correlation levels. In conclusion, the data presented provides new insight on Cr effects in plants in general and supports the use of the parameters tested in this study as reliable endpoints for this metal toxicity in plants. © 2011 American Chemical Society

  16. Ajwa Date (Phoenix dactylifera L. Extract Inhibits Human Breast Adenocarcinoma (MCF7 Cells In Vitro by Inducing Apoptosis and Cell Cycle Arrest.

    Directory of Open Access Journals (Sweden)

    Fazal Khan

    Full Text Available Phoenix dactylifera L (Date palm is a native plant of the Kingdom of Saudi Arabia (KSA and other Middle Eastern countries. Ajwa date has been described in the traditional and alternative medicine to provide several health benefits including anticholesteremic, antioxidant, hepatoprotective and anticancer effects, but most remains to be scientifically validated. Herein, we evaluated the anticancer effects of the Methanolic Extract of Ajwa Date (MEAD on human breast adenocarcinoma (MCF7 cells in vitro.MCF7 cells were treated with various concentrations (5, 10, 15, 20 and 25 mg/ml of MEAD for 24, 48 and 72 h and changes in cell morphology, cell cycle, apoptosis related protein and gene expression were studied.Phase contrast microscopy showed various morphological changes such as cell shrinkage, vacuolation, blebbing and fragmentation. MTT (2-(4,5-dimethylthiazol-2-yl-2,5-diphenyltetrazolium bromide assay demonstrated statistically significant dose-dependent inhibitions of MCF7 cell proliferation from 35% to 95%. Annexin V-FITC and TUNEL assays showed positive staining for apoptosis of MCF7 cells treated with MEAD (15 mg and 25 mg for 48 h. Flow cytometric analyses of MCF7 cells with MEAD (15 mg/ml and 20 mg/ml for 24 h demonstrated cell cycle arrest at 'S' phase; increased p53, Bax protein expression; caspase 3activation and decreased the mitochondrial membrane potential (MMP. Quantitative real time PCR (qRT-PCR analysis showed up-regulation of p53, Bax, Fas, and FasL and down-regulation of Bcl-2.MEAD inhibited MCF7 cells in vitro by the inducing cell cycle arrest and apoptosis. Our results indicate the anticancer effects of Ajwa dates, which therefore may be used as an adjunct therapy with conventional chemotherapeutics to achieve a synergistic effect against breast cancer.

  17. Metformin Induces Apoptosis and Cell Cycle Arrest Mediated by Oxidative Stress, AMPK and FOXO3a in MCF-7 Breast Cancer Cells

    Science.gov (United States)

    Queiroz, Eveline A. I. F.; Puukila, Stephanie; Eichler, Rosangela; Sampaio, Sandra C.; Forsyth, Heidi L.; Lees, Simon J.; Barbosa, Aneli M.; Dekker, Robert F. H.; Fortes, Zuleica B.; Khaper, Neelam

    2014-01-01

    Recent studies have demonstrated that the anti-diabetic drug, metformin, can exhibit direct antitumoral effects, or can indirectly decrease tumor proliferation by improving insulin sensitivity. Despite these recent advances, the underlying molecular mechanisms involved in decreasing tumor formation are not well understood. In this study, we examined the antiproliferative role and mechanism of action of metformin in MCF-7 cancer cells treated with 10 mM of metformin for 24, 48, and 72 hours. Using BrdU and the MTT assay, it was found that metformin demonstrated an antiproliferative effect in MCF-7 cells that occurred in a time- and concentration- dependent manner. Flow cytometry was used to analyze markers of cell cycle, apoptosis, necrosis and oxidative stress. Exposure to metformin induced cell cycle arrest in G0-G1 phase and increased cell apoptosis and necrosis, which were associated with increased oxidative stress. Gene and protein expression were determined in MCF-7 cells by real time RT-PCR and western blotting, respectively. In MCF-7 cells metformin decreased the activation of IRβ, Akt and ERK1/2, increased p-AMPK, FOXO3a, p27, Bax and cleaved caspase-3, and decreased phosphorylation of p70S6K and Bcl-2 protein expression. Co-treatment with metformin and H2O2 increased oxidative stress which was associated with reduced cell number. In the presence of metformin, treating with SOD and catalase improved cell viability. Treatment with metformin resulted in an increase in p-p38 MAPK, catalase, MnSOD and Cu/Zn SOD protein expression. These results show that metformin has an antiproliferative effect associated with cell cycle arrest and apoptosis, which is mediated by oxidative stress, as well as AMPK and FOXO3a activation. Our study further reinforces the potential benefit of metformin in cancer treatment and provides novel mechanistic insight into its antiproliferative role. PMID:24858012

  18. Overexpression of cell cycle regulator CDCA3 promotes oral cancer progression by enhancing cell proliferation with prevention of G1 phase arrest

    International Nuclear Information System (INIS)

    Uchida, Fumihiko; Uzawa, Katsuhiro; Kasamatsu, Atsushi; Takatori, Hiroaki; Sakamoto, Yosuke; Ogawara, Katsunori; Shiiba, Masashi; Tanzawa, Hideki; Bukawa, Hiroki

    2012-01-01

    Cell division cycle associated 3 (CDCA3), part of the Skp1-cullin-F-box (SCF) ubiquitin ligase, refers to a trigger of mitotic entry and mediates destruction of the mitosis inhibitory kinase. Little is known about the relevance of CDCA3 to human malignancy including oral squamous cell carcinoma (OSCC). We aimed to characterize the expression state and function of CDCA3 in OSCC. We evaluated CDCA3 mRNA and protein expression in both OSCC-derived cell lines and primary OSCCs and performed functional analyses of CDCA3 in OSCC-derived cells using the shRNA system. The CDCA3 expression at both the mRNA and protein levels was frequently up-regulated in all cell lines examined and primary tumors (mRNA, 51/69, 74 %; protein, 79/95, 83 %) compared to normal controls (p < 0.001). In contrast, no significant level of CDCA3 protein expression was seen in oral premalignant lesions (OPLs) (n = 20) compared with the expression in OSCCs. Among the clinical variables analyzed, the CDCA3 expression status was closely related to tumor size (p < 0.05). In addition, suppression of CDCA3 expression with shRNA significantly (p < 0.05) inhibited cellular proliferation compared with the control cells by arresting cell-cycle progression at the G1 phase. Further, there was up-regulation of the cyclin-dependent kinase inhibitors (p21 Cip1 , p27 Kip1 , p15 INK4B , and p16 INK4A ) in the knockdown cells. The current results showed that overexpression of CDCA3 occurs frequently during oral carcinogenesis and this overexpression might be associated closely with progression of OSCCs by preventing the arrest of cell-cycle progression at the G1 phase via decreased expression of the cyclin-dependent kinase inhibitors

  19. Growth arrest line mimicking lymphoma involvement: The findings of {sup 99m}Tc-MDP bone SPECT/CT and serial bone scan in a child with non-Hodgkin's lymphoma

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Chan Woo; Kim, Ji Young; Choi, Yun Young; Lee, Seung Hun; Lee, Young Ho [Hanyang University Medical Center, Seoul (Korea, Republic of)

    2016-06-15

    Growth arrest lines appear as dense sclerotic lines parallel to the growth plate of long bones on radiography. We describe the case of a 9-year-old female with growth arrest lines initially masquerading as lymphoma involvement on {sup 99m}Tc-MDP bone scintigraphy who had been treated with chemotherapy for non-Hodgkin's lymphoma about 3 years previously. Subsequent regional bone SPECT/CT clearly diagnosed the growth arrest lines, and retrograde review of previous bone scintigraphy demonstrated line migration in this patient. Growth arrest lines should be considered a possible diagnosis on bone scintigraphy, especially in the surveillance of children who have experienced severe childhood infections, malnutrition, immobilization, or treatment with immunosuppressive or chemotherapeutic drugs that may inhibit bone growth.

  20. Growth arrest line mimicking lymphoma involvement: The findings of 99mTc-MDP bone SPECT/CT and serial bone scan in a child with non-Hodgkin's lymphoma

    International Nuclear Information System (INIS)

    Kim, Chan Woo; Kim, Ji Young; Choi, Yun Young; Lee, Seung Hun; Lee, Young Ho

    2016-01-01

    Growth arrest lines appear as dense sclerotic lines parallel to the growth plate of long bones on radiography. We describe the case of a 9-year-old female with growth arrest lines initially masquerading as lymphoma involvement on 99m Tc-MDP bone scintigraphy who had been treated with chemotherapy for non-Hodgkin's lymphoma about 3 years previously. Subsequent regional bone SPECT/CT clearly diagnosed the growth arrest lines, and retrograde review of previous bone scintigraphy demonstrated line migration in this patient. Growth arrest lines should be considered a possible diagnosis on bone scintigraphy, especially in the surveillance of children who have experienced severe childhood infections, malnutrition, immobilization, or treatment with immunosuppressive or chemotherapeutic drugs that may inhibit bone growth

  1. Epistatic participation of REV1 and REV3 in the formation of UV-induced frameshift mutations in cell cycle-arrested yeast cells

    Energy Technology Data Exchange (ETDEWEB)

    Heidenreich, Erich [Institute of Cancer Research, Department of Medicine I, Medical University of Vienna, Borschkegasse 8a, A-1090 Vienna (Austria)]. E-mail: erich.heidenreich@meduniwien.ac.at; Eisler, Herfried [Institute of Cancer Research, Department of Medicine I, Medical University of Vienna, Borschkegasse 8a, A-1090 Vienna (Austria); Steinboeck, Ferdinand [Institute of Cancer Research, Department of Medicine I, Medical University of Vienna, Borschkegasse 8a, A-1090 Vienna (Austria)

    2006-01-29

    Mutations arising in times of cell cycle arrest may provide a selective advantage for unicellular organisms adapting to environmental changes. For multicellular organisms, however, they may pose a serious threat, in that such mutations in somatic cells contribute to carcinogenesis and ageing. The budding yeast Saccharomyces cerevisiae presents a convenient model system for studying the incidence and the mechanisms of stationary-phase mutation in a eukaryotic organism. Having studied the emergence of frameshift mutants after several days of starvation-induced cell cycle arrest, we previously reported that all (potentially error-prone) translesion synthesis (TLS) enzymes identified in S. cerevisiae did not contribute to the basal level of spontaneous stationary-phase mutations. However, we observed that an increased frequency of stationary-phase frameshift mutations, brought about by a defective nucleotide excision repair (NER) pathway or by UV irradiation, was dependent on Rev3p, the catalytic subunit of the TLS polymerase zeta (Pol {zeta}). Employing the same two conditions, we now examined the effect of deletions of the genes coding for polymerase eta (Pol {eta}) (RAD30) and Rev1p (REV1). In a NER-deficient strain background, the increased incidence of stationary-phase mutations was only moderately influenced by a lack of Pol {eta} but completely reduced to wild type level by a knockout of the REV1 gene. UV-induced stationary-phase mutations were abundant in wild type and rad30{delta} strains, but substantially reduced in a rev1{delta} as well as a rev3{delta} strain. The similarity of the rev1{delta} and the rev3{delta} phenotype and an epistatic relationship evident from experiments with a double-deficient strain suggests a participation of Rev1p and Rev3p in the same mutagenic pathway. Based on these results, we propose that the response of cell cycle-arrested cells to an excess of exo- or endogenously induced DNA damage includes a novel replication

  2. Differential biologic effects of CPD and 6-4PP UV-induced DNA damage on the induction of apoptosis and cell-cycle arrest

    International Nuclear Information System (INIS)

    Lo, Hsin-Lung; Nakajima, Satoshi; Ma, Lisa; Walter, Barbara; Yasui, Akira; Ethell, Douglas W; Owen, Laurie B

    2005-01-01

    UV-induced damage can induce apoptosis or trigger DNA repair mechanisms. Minor DNA damage is thought to halt the cell cycle to allow effective repair, while more severe damage can induce an apoptotic program. Of the two major types of UV-induced DNA lesions, it has been reported that repair of CPD, but not 6-4PP, abrogates mutation. To address whether the two major forms of UV-induced DNA damage, can induce differential biological effects, NER-deficient cells containing either CPD photolyase or 6-4 PP photolyase were exposed to UV and examined for alterations in cell cycle and apoptosis. In addition, pTpT, a molecular mimic of CPD was tested in vitro and in vivo for the ability to induce cell death and cell cycle alterations. NER-deficient XPA cells were stably transfected with CPD-photolyase or 6-4PP photolyase to specifically repair only CPD or only 6-4PP. After 300 J/m 2 UVB exposure photoreactivation light (PR, UVA 60 kJ/m 2 ) was provided for photolyase activation and DNA repair. Apoptosis was monitored 24 hours later by flow cytometric analysis of DNA content, using sub-G1 staining to indicate apoptotic cells. To confirm the effects observed with CPD lesions, the molecular mimic of CPD, pTpT, was also tested in vitro and in vivo for its effect on cell cycle and apoptosis. The specific repair of 6-4PP lesions after UVB exposure resulted in a dramatic reduction in apoptosis. These findings suggested that 6-4PP lesions may be the primary inducer of UVB-induced apoptosis. Repair of CPD lesions (despite their relative abundance in the UV-damaged cell) had little effect on the induction of apoptosis. Supporting these findings, the molecular mimic of CPD, (dinucleotide pTpT) could mimic the effects of UVB on cell cycle arrest, but were ineffective to induce apoptosis. The primary response of the cell to UV-induced 6-4PP lesions is to trigger an apoptotic program whereas the response of the cell to CPD lesions appears to principally involve cell cycle arrest. These

  3. Preferential cytotoxicity of ZnO nanoparticle towards cervical cancer cells induced by ROS-mediated apoptosis and cell cycle arrest for cancer therapy

    Energy Technology Data Exchange (ETDEWEB)

    Sirelkhatim, Amna, E-mail: amnasirelkhatim@yahoo.co.uk; Mahmud, Shahrom [Universiti Sains Malaysia (USM), Institute of Nano-Optoelectronics Research and Technology (INOR), School of Physics (Malaysia); Seeni, Azman [Universiti Sains Malaysia (USM), Advanced Medical and Dental Institute, Cluster of Integrative Medicine (Malaysia); Kaus, Noor Haida Mohd [Universiti Sains Malaysia (USM), School of Chemical Sciences (Malaysia)

    2016-08-15

    benefit from the synergistic influence of size and nanostructure when designing anticancer agents.Graphical AbstractMechanism of cell death by ZnO-NPs, displaying ROS formation and Zn{sup 2+} release that induced apoptosis and arrested cell cycle progression. Apoptosis involved DNA fragmentation, chromatin condensation, membrane shrinkage, and formation of apoptotic bodies. The synergistic effect of ZnO-NPs size (20, 40, 80 nm) and nanostructure (nanorods, nanogranules) impacted the inhibition of HeLa cells growth and eventually death.

  4. Preferential cytotoxicity of ZnO nanoparticle towards cervical cancer cells induced by ROS-mediated apoptosis and cell cycle arrest for cancer therapy

    International Nuclear Information System (INIS)

    Sirelkhatim, Amna; Mahmud, Shahrom; Seeni, Azman; Kaus, Noor Haida Mohd

    2016-01-01

    benefit from the synergistic influence of size and nanostructure when designing anticancer agents.Graphical AbstractMechanism of cell death by ZnO-NPs, displaying ROS formation and Zn"2"+ release that induced apoptosis and arrested cell cycle progression. Apoptosis involved DNA fragmentation, chromatin condensation, membrane shrinkage, and formation of apoptotic bodies. The synergistic effect of ZnO-NPs size (20, 40, 80 nm) and nanostructure (nanorods, nanogranules) impacted the inhibition of HeLa cells growth and eventually death.

  5. CpG oligodeoxynucleotide induces apoptosis and cell cycle arrest in A20 lymphoma cells via TLR9-mediated pathways.

    Science.gov (United States)

    Qi, Xu-Feng; Zheng, Li; Kim, Cheol-Su; Lee, Kyu-Jae; Kim, Dong-Heui; Cai, Dong-Qing; Qin, Jun-Wen; Yu, Yan-Hong; Wu, Zheng; Kim, Soo-Ki

    2013-07-01

    Recent studies have suggested that the anti-cancer activity of CpG-oligodeoxynucleotides (CpG-ODNs) is owing to their immunomodulatory effects in tumor-bearing host. The purpose of this study is to investigate the directly cytotoxic activity of KSK-CpG, a novel CpG-ODN with an alternative CpG motif, against A20 and EL4 lymphoma cells in comparison with previously used murine CpG motif (1826-CpG). To evaluate the potential cytotoxic effects of KSK-CpG on lymphoma cells, cell viability assay, confocal microscopy, flow cytometry, DNA fragmentation, Western blotting, and reverse transcription-polymerase chain reaction (RT-PCR) analysis were used. We found that KSK-CpG induced direct cytotoxicity in A20 lymphoma cells, but not in EL4 lymphoma cells, at least in part via TLR9-mediated pathways. Apoptotic cell death was demonstrated to play an important role in CpG-ODNs-induced cytotoxicity. In addition, both mitochondrial membrane potential decrease and G1-phase arrest were involved in KSK-CpG-induced apoptosis in A20 cells. The activities of apoptotic molecules such as caspase-3, PARP, and Bax were increased, but the activation of p27 Kip1 and ERK were decreased in KSK-CpG-treated A20 cells. Furthermore, autocrine IFN-γ partially contributed to apoptotic cell death in KSK-CpG-treated A20 cells. Collectively, our findings suggest that KSK-CpG induces apoptotic cell death in A20 lymphoma cells at least in part by inducing G1-phase arrest and autocrine IFN-γ via increasing TLR9 expression, without the need for immune system of tumor-bearing host. This new understanding supports the development of TLR9-targeted therapy with CpG-ODN as a direct therapeutic agent for treating B lymphoma. Copyright © 2013 Elsevier Ltd. All rights reserved.

  6. Selective cerebral perfusion prevents abnormalities in glutamate cycling and neuronal apoptosis in a model of infant deep hypothermic circulatory arrest and reperfusion

    Energy Technology Data Exchange (ETDEWEB)

    Kajimoto, Masaki; Ledee, Dolena R.; Olson, Aaron K.; Isern, Nancy G.; Robillard-Frayne, Isabelle; Des Rosiers, Christine; Portman, Michael A.

    2016-10-01

    Rationale: Deep hypothermic circulatory arrest (DHCA) is often required for the repair of complex congenital cardiac defects in infants. However, DHCA induces neuroapoptosis associated with later development of neurocognitive abnormalities. Selective cerebral perfusion (SCP) theoretically provides superior neural protection possibly through modifications in cerebral substrate oxidation and closely integrated glutamate cycling. Objectives: We tested the hypothesis that SCP modulates glucose entry into the citric acid cycle, and ameliorates abnormalities in glutamate flux which occur in association neuroapoptosis during DHCA. Methods and Results: Eighteen male Yorkshire piglets (age 34-44 days) were assigned randomly to 2 groups of 7 (DHCA or DHCA with SCP for 60 minutes at 18 °C) and 4 control pigs without cardiopulmonary bypass support. After the completion of rewarming from DHCA, 13-Carbon-labeled (13C) glucose as a metabolic tracer was infused. We used gas chromatography-mass spectrometry (GCMS) and nuclear magnetic resonance for metabolic analysis in the frontal cortex. Following 2.5 hours of cerebral reperfusion, we observed similar cerebral ATP levels, absolute levels of lactate and citric acid cycle intermediates, and 13C-enrichment. However, DHCA induced significant abnormalities in glutamate cycling resulting in reduced glutamate/glutamine and elevated γ-aminobutyric acid (GABA)/glutamate along with neuroapoptosis (TUNEL), which were all prevented by SCP. Conclusions: DHCA alone induces abnormalities in cycling of the major neurotransmitters in association with neuroapoptosis, but does not alter cerebral glucose utilization during reperfusion. The data suggest that SCP prevents these modifications in glutamate/glutamine/GABA cycling and protects the cerebral cortex from neuroapoptosis.

  7. Resveratrol induces growth arrest and apoptosis through activation of FOXO transcription factors in prostate cancer cells.

    Directory of Open Access Journals (Sweden)

    Qinghe Chen

    2010-12-01

    Full Text Available Resveratrol, a naturally occurring phytopolyphenol compound, has attracted extensive interest in recent years because of its diverse pharmacological characteristics. Although resveratrol possesses chemopreventive properties against several cancers, the molecular mechanisms by which it inhibits cell growth and induces apoptosis have not been clearly understood. The present study was carried out to examine whether PI3K/AKT/FOXO pathway mediates the biological effects of resveratrol.Resveratrol inhibited the phosphorylation of PI3K, AKT and mTOR. Resveratrol, PI3K inhibitors (LY294002 and Wortmannin and AKT inhibitor alone slightly induced apoptosis in LNCaP cells. These inhibitors further enhanced the apoptosis-inducing potential of resveratrol. Overexpression of wild-type PTEN slightly induced apoptosis. Wild type PTEN and PTEN-G129E enhanced resveratrol-induced apoptosis, whereas PTEN-G129R had no effect on proapoptotic effects of resveratrol. Furthermore, apoptosis-inducing potential of resveratrol was enhanced by dominant negative AKT, and inhibited by wild-type AKT and constitutively active AKT. Resveratrol has no effect on the expression of FKHR, FKHRL1 and AFX genes. The inhibition of FOXO phosphorylation by resveratrol resulted in its nuclear translocation, DNA binding and transcriptional activity. The inhibition of PI3K/AKT pathway induced FOXO transcriptional activity resulting in induction of Bim, TRAIL, p27/KIP1, DR4 and DR5, and inhibition of cyclin D1. Similarly, resveratrol-induced FOXO transcriptional activity was further enhanced when activation of PI3K/AKT pathway was blocked. Over-expression of phosphorylation deficient mutants of FOXO proteins (FOXO1-TM, FOXO3A-TM and FOXO4-TM induced FOXO transcriptional activity, which was further enhanced by resveratrol. Inhibition of FOXO transcription factors by shRNA blocked resveratrol-induced upregulation of Bim, TRAIL, DR4, DR5, p27/KIP1 and apoptosis, and inhibition of cyclin D1 by

  8. The ubiquitin peptidase UCHL1 induces G0/G1 cell cycle arrest and apoptosis through stabilizing p53 and is frequently silenced in breast cancer.

    Directory of Open Access Journals (Sweden)

    Tingxiu Xiang

    Full Text Available Breast cancer (BrCa is a complex disease driven by aberrant gene alterations and environmental factors. Recent studies reveal that abnormal epigenetic gene regulation also plays an important role in its pathogenesis. Ubiquitin carboxyl- terminal esterase L1 (UCHL1 is a tumor suppressor silenced by promoter methylation in multiple cancers, but its role and alterations in breast tumorigenesis remain unclear.We found that UCHL1 was frequently downregulated or silenced in breast cancer cell lines and tumor tissues, but readily expressed in normal breast tissues and mammary epithelial cells. Promoter methylation of UCHL1 was detected in 9 of 10 breast cancer cell lines (90% and 53 of 66 (80% primary tumors, but rarely in normal breast tissues, which was statistically correlated with advanced clinical stage and progesterone receptor status. Pharmacologic demethylation reactivated UCHL1 expression along with concomitant promoter demethylation. Ectopic expression of UCHL1 significantly suppressed the colony formation and proliferation of breast tumor cells, through inducing G0/G1 cell cycle arrest and apoptosis. Subcellular localization study showed that UCHL1 increased cytoplasmic abundance of p53. We further found that UCHL1 induced p53 accumulation and reduced MDM2 protein level, and subsequently upregulated the expression of p21, as well as cleavage of caspase3 and PARP, but not in catalytic mutant UCHL1 C90S-expressed cells.UCHL1 exerts its tumor suppressive functions by inducing G0/G1cell cycle arrest and apoptosis in breast tumorigenesis, requiring its deubiquitinase activity. Its frequent silencing by promoter CpG methylation may serve as a potential tumor marker for breast cancer.

  9. Zerumbone-loaded nanostructured lipid carrier induces G2/M cell cycle arrest and apoptosis via mitochondrial pathway in a human lymphoblastic leukemia cell line

    Directory of Open Access Journals (Sweden)

    Rahman HS

    2014-01-01

    Full Text Available Heshu Sulaiman Rahman,1–3 Abdullah Rasedee,1,2 Ahmad Bustamam Abdul,2,4 Nazariah Allaudin Zeenathul,1,2 Hemn Hassan Othman,1,3 Swee Keong Yeap,2 Chee Wun How,2 Wan Abd Ghani Wan Nor Hafiza4,51Faculty of Veterinary Medicine, 2Institute of Bioscience, Universiti Putra Malaysia, Selangor, Malaysia; 3Faculty of Veterinary Medicine, University of Sulaimanyah, Sulaimanyah City, Kurdistan Region, Northern Iraq; 4Faculty of Medicine and Health Science, Universiti Putra Malaysia, Selangor, Malaysia; 5College of Medical Laboratory Technology, Institute for Medical Research, Kuala Lumpur, MalaysiaAbstract: This investigation evaluated the antileukemia properties of a zerumbone (ZER-loaded nanostructured lipid carrier (NLC prepared by hot high-pressure homogenization techniques in an acute human lymphoblastic leukemia (Jurkat cell line in vitro. The apoptogenic effect of the ZER-NLC on Jurkat cells was determined by fluorescent and electron microscopy, Annexin V-fluorescein isothiocyanate, Tdt-mediated dUTP nick-end labeling assay, cell cycle analysis, and caspase activity. An MTT (3-(4,5-dimethylthiazol-2-yl-2,5 diphenyltetrazolium bromide assay showed that ZER-NLC did not have adverse effects on normal human peripheral blood mononuclear cells. ZER-NLC arrested the Jurkat cells at G2/M phase with inactivation of cyclin B1 protein. The study also showed that the antiproliferative effect of ZER-NLC on Jurkat cells is through the intrinsic apoptotic pathway via activation of caspase-3 and caspase-9, release of cytochrome c from the mitochondria into the cytosol, and subsequent cleavage of poly (adenosine diphosphate-ribose polymerase (PARP. These findings show that the ZER-NLC is a potentially useful treatment for acute lymphoblastic leukemia in humans.Keywords: zerumbone-loaded nanostructured lipid carrier, cell cycle arrest, apoptosis, mitochondrial pathway

  10. Korean Byungkyul - Citrus platymamma Hort.et Tanaka flavonoids induces cell cycle arrest and apoptosis, regulating MMP protein expression in Hep3B hepatocellular carcinoma cells.

    Science.gov (United States)

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

    2017-02-01

    Citrus platymamma Hort.et Tanaka is an indigenous fruit of Jeju island in Korea. In this study the bioactivity of C. platymamma flavonoids were evaluated on human hepatoma Hep3B cell lines. Eleven flavonoids were identified from the peels of C. platymamma Hort.et Tanaka through high-performance liquid chromatography-Tandem mass spectrometry and the anticancer effect of these C. platymamma flavonoids on human hepatoma Hep3B were studied. Chromatin condensation was observed in Hep3B cells treated with C. platymamma flavonoids. DNA fragmentation was confirmed through agarose gel electrophoresis and TUNEL assay. An increase in the total apoptotic cells and G2/M cell cycle arrest with decreased protein expression of CDC25C, CDK1, cyclin B1 and p21 were observed in Hep3B cells treated with flavonoids of C. platymamma. Further, protein expression of Bcl-XL, Bax, caspase-3 and -9 were also modulated by C. platymamma flavonoids treatment indicating that cell death is through intrinsic apoptotic pathway. Moreover, C. platymamma flavonoids also regulated the phosphorylation of MAPKs, PI3K, and Akt in Hep3B cells. Relevant to inhibiting metastasis, C. platymamma treatment reduced wound closure of Hep3B cells and the protein expression of matrix metalloproteinase-2 and -9 were reduced in C. platymamma treated cells. The results show that C. platymamma flavonoids induce cell cycle arrest and apoptosis following activation of MAPKs and suppression of PI3K/Akt pathway which eventually inhibits cell migration in Hep3B cells. The finding provides evidence on biochemical activities of C. platymamma Hort.et Tanaka, which would be an essential agent for hepatocellular carcinoma (HCC) treatment.

  11. The role of the RACK1 ortholog Cpc2p in modulating pheromone-induced cell cycle arrest in fission yeast.

    Directory of Open Access Journals (Sweden)

    Magdalena Mos

    Full Text Available The detection and amplification of extracellular signals requires the involvement of multiple protein components. In mammalian cells the receptor of activated C kinase (RACK1 is an important scaffolding protein for signal transduction networks. Further, it also performs a critical function in regulating the cell cycle by modulating the G1/S transition. Many eukaryotic cells express RACK1 orthologs, with one example being Cpc2p in the fission yeast Schizosaccharomyces pombe. In contrast to RACK1, Cpc2p has been described to positively regulate, at the ribosomal level, cells entry into M phase. In addition, Cpc2p controls the stress response pathways through an interaction with Msa2p, and sexual development by modulating Ran1p/Pat1p. Here we describe investigations into the role, which Cpc2p performs in controlling the G protein-mediated mating response pathway. Despite structural similarity to Gβ-like subunits, Cpc2p appears not to function at the G protein level. However, upon pheromone stimulation, cells overexpressing Cpc2p display substantial cell morphology defects, disorientation of septum formation and a significantly protracted G1 arrest. Cpc2p has the potential to function at multiple positions within the pheromone response pathway. We provide a mechanistic interpretation of this novel data by linking Cpc2p function, during the mating response, with its previous described interactions with Ran1p/Pat1p. We suggest that overexpressing Cpc2p prolongs the stimulated state of pheromone-induced cells by increasing ste11 gene expression. These data indicate that Cpc2p regulates the pheromone-induced cell cycle arrest in fission yeast by delaying cells entry into S phase.

  12. Alteronol induces cell cycle arrest and apoptosis via increased reactive oxygen species production in human breast cancer T47D cells.

    Science.gov (United States)

    Ren, Boxue; Li, Defang; Si, Lingling; Ding, Yangfang; Han, Jichun; Chen, Xiaoyu; Zheng, Qiusheng

    2018-04-01

    Emerging evidence showed that alteronol has a potential antitumour effect in several tumour cells. However, the antitumour effect of alteronol on breast cancer has not been reported. This study investigated the mechanisms of alteronol-induced cell proliferation inhibition in human breast cancer T47D cells. After treatment with alteronol, T47D cell proliferation was examined by MTT assay. The cell cycle distribution, cell apoptosis, reactive oxygen species level and mitochondrial membrane potential were evaluated via flow cytometry. Next, the protein levels of cyclin B1, cdc2, p21, p-cyclin B1, p-cdc2, p53, Bax, Bcl-2 and cytochrome c were analysed using Western blot analysis. Meanwhile, the mRNA levels of cyclin B1, cdc2, p21 and p53 were examined by qRT-PCR. Our data showed that alteronol inhibited the proliferation of T47D cells via inducing G2-phase arrest and cell apoptosis. Compared with control group, alteronol significantly increased ROS level and triggered mitochondrial dysfunction in alteronol-treated T47D cells. Further studies showed that the mRNA and protein levels of cdc2 and cyclin B1 were downregulated, while the mRNA and protein levels of p21, p53, p-cyclin B1, p-cdc2 and cytochrome c were upregulated. In addition, the expression level of Bax was increased, and the expression level of Bcl-2 was decreased. Alteronol induced T47D cell cycle arrest and cell apoptosis through increasing ROS production and triggering mitochondrial dysfunction, and subsequently inhibiting T47D cell proliferation. © 2018 Royal Pharmaceutical Society.

  13. Inhibition of mTORC2 Induces Cell-Cycle Arrest and Enhances the Cytotoxicity of Doxorubicin by Suppressing MDR1 Expression in HCC Cells.

    Science.gov (United States)

    Chen, Bryan Wei; Chen, Wei; Liang, Hui; Liu, Hao; Liang, Chao; Zhi, Xiao; Hu, Li-Qiang; Yu, Xia-Zhen; Wei, Tao; Ma, Tao; Xue, Fei; Zheng, Lei; Zhao, Bin; Feng, Xin-Hua; Bai, Xue-Li; Liang, Ting-Bo

    2015-08-01

    mTOR is aberrantly activated in hepatocellular carcinoma (HCC) and plays pivotal roles in tumorigenesis and chemoresistance. Rapamycin has been reported to exert antitumor activity in HCC and sensitizes HCC cells to cytotoxic agents. However, due to feedback activation of AKT after mTOR complex 1 (mTORC1) inhibition, simultaneous targeting of mTORC1/2 may be more effective. In this study, we examined the interaction between the dual mTORC1/2 inhibitor OSI-027 and doxorubicin in vitro and in vivo. OSI-027 was found to reduce phosphorylation of both mTORC1 and mTORC2 substrates, including 4E-BP1, p70S6K, and AKT (Ser473), and inhibit HCC cell proliferation. Similar to OSI-027 treatment, knockdown of mTORC2 induced G0-G1 phase cell-cycle arrest. In contrast, rapamycin or knockdown of mTORC1 increased phosphorylation of AKT (Ser473), yet had little antiproliferative effect. Notably, OSI-027 synergized with doxorubicin for the antiproliferative efficacy in a manner dependent of MDR1 expression in HCC cells. The synergistic antitumor effect of OSI-027 and doxorubicin was also observed in a HCC xenograft mouse model. Moreover, AKT was required for OSI-027-induced cell-cycle arrest and downregulation of MDR1. Our findings provide a rationale for dual mTORC1/mTORC2 inhibitors, such as OSI-027, as monotherapy or in combination with cytotoxic agents to treat HCC. Mol Cancer Ther; 14(8); 1805-15. ©2015 AACR. ©2015 American Association for Cancer Research.

  14. The novel anthraquinone derivative IMP1338 induces death of human cancer cells by p53-independent S and G2/M cell cycle arrest.

    Science.gov (United States)

    Choi, Hyun Kyung; Ryu, Hwani; Son, A-Rang; Seo, Bitna; Hwang, Sang-Gu; Song, Jie-Young; Ahn, Jiyeon

    2016-04-01

    To identify novel small molecules that induce selective cancer cell death, we screened a chemical library containing 1040 compounds in HT29 colon cancer and CCD18-Co normal colon cells, using a phenotypic cell-based viability assay system with the Cell Counting Kit-8 (CCK-8). We discovered a novel anthraquinone derivative, N-(4-[{(9,10-dioxo-9,10-dihydro-1-anthracenyl)sulfonyl}amino]phenyl)-N-methylacetamide (IMP1338), which was cytotoxic against the human colon cancer cells tested. The MTT cell viability assay showed that treatment with IMP1338 selectively inhibited HCT116, HCT116 p53(-/-), HT29, and A549 cancer cell proliferation compared to that of Beas2B normal epithelial cells. To elucidate the cellular mechanism underlying the cytotoxicity of IMP1338, we examined the effect of IMP1338 on the cell cycle distribution and death of cancer cells. IMP1338 treatment significantly arrested the cell cycle at S and G2/M phases by DNA damage and led to apoptotic cell death, which was determined using FACS analysis with Annexin V/PI double staining. Furthermore, IMP1338 increased caspase-3 cleavage in wild-type p53, p53 knockout HCT116, and HT29 cells as determined using immunoblotting. In addition, IMP1338 markedly induced the phosphorylation of histone H2AX and Chk1 in both cell lines while the combination of 5-fluorouracil (5-FU) and radiation inhibited the viability of HCT116, HCT116 p53(-/-), and HT29 cells compared to 5-FU or radiation alone. Our findings indicated that IMP1338 induced p53-independent cell death through S and G2/M phase arrest as well as DNA damage. These results provide a basis for future investigations assessing the promising anticancer properties of IMP1338. Copyright © 2016. Published by Elsevier Masson SAS.

  15. Lamprey Prohibitin2 Arrest G2/M Phase Transition of HeLa Cells through Down-regulating Expression and Phosphorylation Level of Cell Cycle Proteins.

    Science.gov (United States)

    Shi, Ying; Guo, Sicheng; Wang, Ying; Liu, Xin; Li, Qingwei; Li, Tiesong

    2018-03-02

    Prohibitin 2(PHB2) is a member of the SFPH trans-membrane family proteins. It is a highly conserved and functionally diverse protein that plays an important role in preserving the structure and function of the mitochondria. In this study, the lamprey PHB2 gene was expressed in HeLa cells to investigate its effect on cell proliferation. The effect of Lm-PHB2 on the proliferation of HeLa cells was determined by treating the cells with pure Lm-PHB2 protein followed by MTT assay. Using the synchronization method with APC-BrdU and PI double staining revealed rLm-PHB2 treatment induced the decrease of both S phase and G0/G1 phase and then increase of G2/M phase. Similarly, cells transfected with pEGFP-N1-Lm-PHB2 also exhibited remarkable reduction in proliferation. Western blot and quantitative real-time PCR(qRT-PCR) assays suggested that Lm-PHB2 caused cell cycle arrest in HeLa cells through inhibition of CDC25C and CCNB1 expression. According to our western blot analysis, Lm-PHB2 was also found to reduce the expression level of Wee1 and PLK1 and the phosphorylation level of CCNB1, CDC25C and CDK1 in HeLa cells. Lamprey prohibitin 2 could arrest G2/M phase transition of HeLa cells through down-regulating expression and phosphorylation level of cell cycle proteins.

  16. Synergistic antitumor effect of 3-bromopyruvate and 5-fluorouracil against human colorectal cancer through cell cycle arrest and induction of apoptosis.

    Science.gov (United States)

    Chong, Dianlong; Ma, Linyan; Liu, Fang; Zhang, Zhirui; Zhao, Surong; Huo, Qiang; Zhang, Pei; Zheng, Hailun; Liu, Hao

    2017-09-01

    3-Bromopyruvic acid (3-BP) is a well-known inhibitor of energy metabolism. It has been proposed as an anticancer agent as well as a chemosensitizer for use in combination with anticancer drugs. 5-Fluorouracil (5-FU) is the first-line chemotherapeutic agent for colorectal cancer; however, most patients develop resistance to 5-FU through various mechanisms. The aim of this study was to investigate whether 3-BP has a synergistic antitumor effect with 5-FU on human colorectal cancer cells. In our study, combined 3-BP and 5-FU treatment upregulated p53 and p21, whereas cyclin-dependent kinase CDK4 and CDK2 were downregulated, which led to G0/G1 phase arrest. Furthermore, there was an increase in reactive oxygen species levels and a decrease in adenosine triphosphate levels. It was also observed that Bax expression increased, whereas Bcl-2 expression reduced, which were indicative of mitochondria-dependent apoptosis. In addition, the combination of 3-BP and 5-FU significantly suppressed tumor growth in the BALB/c mice in vivo. Therefore, 3-BP inhibits tumor proliferation and induces S and G2/M phase arrest. It also exerts a synergistic antitumor effect with 5-FU on SW480 cells.

  17. The indolinone MAZ51 induces cell rounding and G2/M cell cycle arrest in glioma cells without the inhibition of VEGFR-3 phosphorylation: involvement of the RhoA and Akt/GSK3β signaling pathways.

    Directory of Open Access Journals (Sweden)

    Joo-Hee Park

    Full Text Available MAZ51 is an indolinone-based molecule originally synthesized as a selective inhibitor of vascular endothelial growth factor receptor (VEGFR-3 tyrosine kinase. This study shows that exposure of two glioma cell lines, rat C6 and human U251MG, to MAZ51 caused dramatic shape changes, including the retraction of cellular protrusions and cell rounding. These changes were caused by the clustering and aggregation of actin filaments and microtubules. MAZ51 also induced G2/M phase cell cycle arrest. This led to an inhibition of cellular proliferation, without triggering significant cell death. These alterations induced by MAZ51 occurred with similar dose- and time-dependent patterns. Treatment of glioma cells with MAZ51 resulted in increased levels of phosphorylated GSK3β through the activation of Akt, as well as increased levels of active RhoA. Interestingly, MAZ51 did not affect the morphology and cell cycle patterns of rat primary cortical astrocytes, suggesting it selectively targeted transformed cells. Immunoprecipitation-western blot analyses indicated that MAZ51 did not decrease, but rather increased, tyrosine phosphorylation of VEGFR-3. To confirm this unanticipated result, several additional experiments were conducted. Enhancing VEGFR-3 phosphorylation by treatment of glioma cells with VEGF-C affected neither cytoskeleton arrangements nor cell cycle patterns. In addition, the knockdown of VEGFR-3 in glioma cells did not cause morphological or cytoskeletal alterations. Furthermore, treatment of VEGFR-3-silenced cells with MAZ51 caused the same alterations of cell shape and cytoskeletal arrangements as that observed in control cells. These data indicate that MAZ51 causes cytoskeletal alterations and G2/M cell cycle arrest in glioma cells. These effects are mediated through phosphorylation of Akt/GSK3β and activation of RhoA. The anti-proliferative activity of MAZ51 does not require the inhibition of VEGFR-3 phosphorylation, suggesting that it is

  18. 17-Allylamino-17-demethoxygeldanamycin induces downregulation of critical Hsp90 protein clients and results in cell cycle arrest and apoptosis of human urinary bladder cancer cells

    International Nuclear Information System (INIS)

    Karkoulis, Panagiotis K; Stravopodis, Dimitrios J; Margaritis, Lukas H; Voutsinas, Gerassimos E

    2010-01-01

    17-Allylamino-17-demethoxygeldanamycin (17-AAG), a benzoquinone ansamycin antibiotic, specifically targets heat shock protein 90 (Hsp90) and interferes with its function as a molecular chaperone that maintains the structural and functional integrity of various protein clients involved in cellular signaling. In this study, we have investigated the effect of 17-AAG on the regulation of Hsp90-dependent signaling pathways directly implicated in cell cycle progression, survival and motility of human urinary bladder cancer cell lines. We have used MTT-based assays, FACS analysis, Western blotting, semi-quantitative RT-PCR, immunocytochemistry and scratch-wound assay in RT4, RT112 and T24 human urinary bladder cancer cell lines. We have demonstrated that, upon 17-AAG treatment, bladder cancer cells are arrested in the G1 phase of the cell cycle and eventually undergo apoptotic cell death in a dose-dependent manner. Furthermore, 17-AAG administration was shown to induce a pronounced downregulation of multiple Hsp90 protein clients and other downstream effectors, such as IGF-IR, Akt, IKK-α, IKK-β, FOXO1, ERK1/2 and c-Met, resulting in sequestration-mediated inactivation of NF-κB, reduced cell proliferation and decline of cell motility. In total, we have clearly evinced a dose-dependent and cell type-specific effect of 17-AAG on cell cycle progression, survival and motility of human bladder cancer cells, due to downregulation of multiple Hsp90 clients and subsequent disruption of signaling integrity

  19. Human cytochrome c enters murine J774 cells and causes G1 and G2/M cell cycle arrest and induction of apoptosis

    International Nuclear Information System (INIS)

    Hiraoka, Yoshinori; Granja, Ana Teresa; Fialho, Arsenio M.; Schlarb-Ridley, Beatrix G.; Das Gupta, Tapas K.; Chakrabarty, Ananda M.; Yamada, Tohru

    2005-01-01

    Cytochrome c is well known as a carrier of electrons during respiration. Current evidence indicates that cytochrome c also functions as a major component of apoptosomes to induce apoptosis in eukaryotic cells as well as an antioxidant. More recently, a prokaryotic cytochrome c, cytochrome c 551 from Pseudomonas aeruginosa, has been shown to enter in mammalian cells such as the murine macrophage-like J774 cells and causes inhibition of cell cycle progression. Much less is known about such functions by mammalian cytochromes c, particularly the human cytochrome c. We now report that similar to P. aeruginosa cytochrome c 551 , the purified human cytochrome c protein can enter J774 cells and induce cell cycle arrest at the G 1 to S phase, as well as at the G 2 /M phase at higher concentrations. Unlike P. aeruginosa cytochrome c 551 which had no effect on the induction of apoptosis, human cytochrome c induces significant apoptosis and cell death in J774 cells, presumably through inhibition of the cell cycle at the G 2 /M phase. When incubated with human breast cancer MCF-7 and normal mammary epithelial cell line MCF-10A1 cells, human cytochrome c entered in both types of cells but induced cell death only in the normal MCF-10A1 cells. The ability of human cytochrome c to enter J774 cells was greatly reduced at 4 deg. C, suggesting energy requirement in the entry process

  20. Daily Arrests

    Data.gov (United States)

    Montgomery County of Maryland — This dataset provides the public with arrest information from the Montgomery County Central Processing Unit (CPU) systems. The data presented is derived from every...

  1. Cardiac arrest

    Science.gov (United States)

    ... magnesium. These minerals help your heart's electrical system work. Abnormally high or low levels can cause cardiac arrest. Severe physical stress. Anything that causes a severe stress on your ...

  2. Molecular mechanisms of celery seed extract induced apoptosis via s phase cell cycle arrest in the BGC-823 human stomach cancer cell line.

    Science.gov (United States)

    Gao, Lin-Lin; Feng, Lei; Yao, Shu-Tong; Jiao, Peng; Qin, Shu-Cun; Zhang, Wei; Zhang, Ya-Bin; Li, Fu-Rong

    2011-01-01

    Mechanisms of apoptosis in tumor cells is an important field of tumor therapy and cancer molecular biology. Loss of cell cycle control, leading to uncontrolled proliferation, is common in cancer. Therefore, the identification of potent and selective cyclin dependent kinase inhibitors is a priority for anti-cancer drug discovery. There are at least two major apoptotic pathways, initiated by caspase-8 and caspase-9, respectively, which can activate caspase cascades. Apoptosis triggered by activation of the mitochondrial-dependent caspase pathway represents the main programmed cell death mechanism. This is activated by various intracellular stresses that induce permeabilization of the mitochondrial membrane. Anti-tumor effects of celery seed extract (CSE) and related mechanisms regarding apoptosis were here investigated in human gastric cancer BGC-823 cells. CSE was produced by supercritical fluid extraction. Cell viability was analyzed by 3-(4,5-dimethylthiazol-2-yl)- 2,5-diphenyl-tetrazolium bromide (MTT) assay and apoptosis by flow cytometry using Annexin/PI staining and DAPI staining and a laser scanning confocal microscope (LSCM). Cell cycling was evaluated using PI staining with flow cytometry and expression of cell cycle and apoptosis-related proteins cyclin A, CDK2, bcl-2 and bax was assessed by immunohistochemical staining. CSE had an anti-proliferation effect on human gastric cancer BGC-823 cells in a dose- and time-dependent manner. After treatment, the apoptotic rate significantly increased, with morphological changes typical of apoptosis observed with LSCM by DAPI staining. Cell cycle and apoptosis related proteins, such as cyclin A, CDK2 and bcl-2 were all down-regulated, whereas bax was up-regulated. The molecular determinants of inhibition of cell proliferation as well as apoptosis of CSE may be associated with cycle arrest in the S phase.

  3. Serum sex hormone and growth arrest-specific protein 6 levels in male patients with coronary heart disease

    Directory of Open Access Journals (Sweden)

    Rui Zhao

    2016-01-01

    Full Text Available Epidemiological studies have shown a high prevalence of low serum testosterone levels in men with cardiovascular disease. Moreover, the tyrosine kinase receptor Axl, the ligand of which is growth arrest-specific protein 6 (GAS6, is expressed in the vasculature, and serum GAS6 levels are associated with endothelial dysfunction and cardiovascular events. Testosterone regulates GAS6 gene transcription directly, which inhibits calcification of vascular smooth muscle cells and provides a mechanistic insight into the cardioprotective action of androgens. This study was designed to determine the correlation between serum GAS6 and testosterone levels in male patients with coronary heart disease (CHD. We recruited 225 patients with CHD and 102 apparently healthy controls. Serum concentrations of GAS6 and soluble Axl were quantified by an enzyme-linked immunosorbent assay. Levels of high-sensitivity C-reactive protein, testosterone, estradiol, and other routine biochemical markers were also measured. Testosterone decreased from 432.69 ± 14.40 to 300.76 ± 6.23 ng dl−1 (P < 0.001 and GAS6 decreased from 16.20 ± 0.31 to 12.51 ± 0.19 ng ml−1 (P < 0.001 in patients with CHD, compared with control subjects. Multiple linear regression analysis showed that serum testosterone and GAS6 levels were positively associated in male patients with CHD. Alterations in GAS6 levels may influence the development of CHD. Downregulation of GAS6/Axl signaling in the presence of low sex hormone levels during disease progression is a potential mechanism by which GAS6 affects CHD. This study provides novel results regarding the influence of sex hormones on serum GAS6 levels in patients with CHD.

  4. Economic Growth and the Evolution of Material Cycles

    DEFF Research Database (Denmark)

    Zhang, Chao; Chen, Wei Qiang; Liu, Gang

    2017-01-01

    Understanding the relationship between material cycles and economic growth is essential for relieving environmental pressures associated with material extraction, production, and consumption. We developed an integrated analytical framework of dematerialization analysis incorporating both material...... flow and stock indicators. A four-quadrant diagram is designed to classify different stages of dematerialization based on the elasticity of material flow/stock to economic output or well-being. We then conducted a case study on the long-term evolution of aluminum cycle in the U.S., and found...... and secondary material recycling, take effect at different stages of economic development. Comprehensive understanding of dematerialization depends on in-depth analysis on material-economy relationships from an integrated stock and flow perspective....

  5. Mitotic Stress Is an Integral Part of the Oncogene-Induced Senescence Program that Promotes Multinucleation and Cell Cycle Arrest

    Directory of Open Access Journals (Sweden)

    Dina Dikovskaya

    2015-09-01

    Full Text Available Oncogene-induced senescence (OIS is a tumor suppression mechanism that blocks cell proliferation in response to oncogenic signaling. OIS is frequently accompanied by multinucleation; however, the origin of this is unknown. Here, we show that multinucleate OIS cells originate mostly from failed mitosis. Prior to senescence, mutant H-RasV12 activation in primary human fibroblasts compromised mitosis, concordant with abnormal expression of mitotic genes functionally linked to the observed mitotic spindle and chromatin defects. Simultaneously, H-RasV12 activation enhanced survival of cells with damaged mitoses, culminating in extended mitotic arrest and aberrant exit from mitosis via mitotic slippage. ERK-dependent transcriptional upregulation of Mcl1 was, at least in part, responsible for enhanced survival and slippage of cells with mitotic defects. Importantly, mitotic slippage and oncogene signaling cooperatively induced senescence and key senescence effectors p21 and p16. In summary, activated Ras coordinately triggers mitotic disruption and enhanced cell survival to promote formation of multinucleate senescent cells.

  6. Slow growth rates of Amazonian trees: Consequences for carbon cycling

    Science.gov (United States)

    Vieira, Simone; Trumbore, Susan; Camargo, Plinio B.; Selhorst, Diogo; Chambers, Jeffrey Q.; Higuchi, Niro; Martinelli, Luiz Antonio

    2005-01-01

    Quantifying age structure and tree growth rate of Amazonian forests is essential for understanding their role in the carbon cycle. Here, we use radiocarbon dating and direct measurement of diameter increment to document unexpectedly slow growth rates for trees from three locations spanning the Brazilian Amazon basin. Central Amazon trees, averaging only ≈1mm/year diameter increment, grow half as fast as those from areas with more seasonal rainfall to the east and west. Slow growth rates mean that trees can attain great ages; across our sites we estimate 17-50% of trees with diameter >10 cm have ages exceeding 300 years. Whereas a few emergent trees that make up a large portion of the biomass grow faster, small trees that are more abundant grow slowly and attain ages of hundreds of years. The mean age of carbon in living trees (60-110 years) is within the range of or slightly longer than the mean residence time calculated from C inventory divided by annual C allocation to wood growth (40-100 years). Faster C turnover is observed in stands with overall higher rates of diameter increment and a larger fraction of the biomass in large, fast-growing trees. As a consequence, forests can recover biomass relatively quickly after disturbance, whereas recovering species composition may take many centuries. Carbon cycle models that apply a single turnover time for carbon in forest biomass do not account for variations in life strategy and therefore may overestimate the carbon sequestration potential of Amazon forests. PMID:16339903

  7. Plumbagin induces cell cycle arrest and autophagy and suppresses epithelial to mesenchymal transition involving PI3K/Akt/mTOR-mediated pathway in human pancreatic cancer cells

    Science.gov (United States)

    Wang, Feng; Wang, Qi; Zhou, Zhi-Wei; Yu, Song-Ning; Pan, Shu-Ting; He, Zhi-Xu; Zhang, Xueji; Wang, Dong; Yang, Yin-Xue; Yang, Tianxing; Sun, Tao; Li, Min; Qiu, Jia-Xuan; Zhou, Shu-Feng

    2015-01-01

    Plumbagin (PLB), an active naphthoquinone compound, has shown potent anticancer effects in preclinical studies; however, the effect and underlying mechanism of PLB for the treatment of pancreatic cancer is unclear. This study aimed to examine the pancreatic cancer cell killing effect of PLB and investigate the underlying mechanism in human pancreatic cancer PANC-1 and BxPC-3 cells. The results showed that PLB exhibited potent inducing effects on cell cycle arrest in PANC-1 and BxPC-3 cells via the modulation of cell cycle regulators including CDK1/CDC2, cyclin B1, cyclin D1, p21 Waf1/Cip1, p27 Kip1, and p53. PLB treatment concentration- and time-dependently increased the percentage of autophagic cells and significantly increased the expression level of phosphatase and tensin homolog, beclin 1, and the ratio of LC3-II over LC3-I in both PANC-1 and BxPC-3 cells. PLB induced inhibition of phosphatidylinositol 3-kinase (PI3K)/protein kinase B/mammalian target of rapamycin and p38 mitogen-activated protein kinase (p38 MAPK) pathways and activation of 5′-AMP-dependent kinase as indicated by their altered phosphorylation, contributing to the proautophagic activities of PLB in both cell lines. Furthermore, SB202190, a selective inhibitor of p38 MAPK, and wortmannin, a potent, irreversible, and selective PI3K inhibitor, remarkably enhanced PLB-induced autophagy in PANC-1 and BxPC-3 cells, indicating the roles of PI3K and p38 MAPK mediated signaling pathways in PLB-induced autophagic cell death in both cell lines. In addition, PLB significantly inhibited epithelial to mesenchymal transition phenotype in both cell lines with an increase in the expression level of E-cadherin and a decrease in N-cadherin. Moreover, PLB treatment significantly suppressed the expression of Sirt1 in both cell lines. These findings show that PLB promotes cell cycle arrest and autophagy but inhibits epithelial to mesenchymal transition phenotype in pancreatic cancer cells with the involvement of

  8. Carbon ions of different linear energy transfer (LET values induce apoptosis & G2 cell cycle arrest in radio-resistant melanoma cells

    Directory of Open Access Journals (Sweden)

    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.

  9. Vitamin K2 and cotylenin A synergistically induce monocytic differentiation and growth arrest along with the suppression of c-MYC expression and induction of cyclin G2 expression in human leukemia HL-60 cells.

    Science.gov (United States)

    Maniwa, Yasuhisa; Kasukabe, Takashi; Kumakura, Shunichi

    2015-08-01

    Although all-trans retinoic acid (ATRA) is a standard and effective drug used for differentiation therapy in acute promyelocytic leukemia, ATRA-resistant leukemia cells ultimately emerge during this treatment. Therefore, the development of new drugs or effective combination therapy is urgently needed. We demonstrate that the combined treatment of vitamin K2 and cotylenin A synergistically induced monocytic differentiation in HL-60 cells. This combined treatment also synergistically induced NBT-reducing activity and non-specific esterase-positive cells as well as morphological changes to monocyte/macrophage-like cells. Vitamin K2 and cotylenin A cooperatively inhibited the proliferation of HL-60 cells in short-term and long-term cultures. This treatment also induced growth arrest at the G1 phase. Although 5 µg/ml cotylenin A or 5 µM vitamin K2 alone reduced c-MYC gene expression in HL-60 cells to approximately 45% or 80% that of control cells, respectively, the combined treatment almost completely suppressed c-MYC gene expression. We also demonstrated that the combined treatment of vitamin K2 and cotylenin A synergistically induced the expression of cyclin G2, which had a positive effect on the promotion and maintenance of cell cycle arrest. These results suggest that the combination of vitamin K2 and cotylenin A has therapeutic value in the treatment of acute myeloid leukemia.

  10. Growth cycle of Helicobacter pylori in gastric mucous layer.

    Science.gov (United States)

    Nakazawa, Teruko

    2002-12-01

    Helicobacter pylori bacterium is characterized by its strong urease activity. Our studies on the role of H. pylori urease revealed; (i) it is essential for colonization, (ii) exogenous urea is required for acid resistance, (iii) the bacteria have the ability to move toward urea and sodium bicarbonate, (iv) urea hydrolysis accelerates chemotactic locomotion, and (v) decay of urease mRNA to accomplish the active center is pH-regulated; i.e., the mRNA is stabilized and destabilized under acidic and neutral conditions, respectively. Based on the above results, I propose the growth cycle of H. pylori in gastric mucous layer. H. pylori bacteria proliferate on the epithelial cell surface by utilizing nutrients derived from degraded cells. Proliferated bacteria leave the cell surface to pH-variable region where they encounter strong acid. Urease is activated with simultaneous opening of UreI channel so that urea is hydrolyzed to neutralize acid. Chemotaxis of H. pylori toward urea and sodium bicarbonate that are abundant on the cell surface is accelerated by urea hydrolysis so that the bacteria go back to the cell surface for the next round of proliferation. This growth cycle may allow the bacteria to infect persistently in the stomach.

  11. Patulin causes DNA damage leading to cell cycle arrest and apoptosis through modulation of Bax, p53 and p21/WAF1 proteins in skin of mice

    International Nuclear Information System (INIS)

    Saxena, Neha; Ansari, Kausar M.; Kumar, Rahul; Dhawan, Alok; Dwivedi, Premendra D.; Das, Mukul

    2009-01-01

    Patulin (PAT), a mycotoxin found in apples, grapes, oranges, pear and peaches, is a potent genotoxic compound. WHO has highlighted the need for the study of cutaneous toxicity of PAT as manual labour is employed during pre and post harvest stages, thereby causing direct exposure to skin. In the present study cutaneous toxicity of PAT was evaluated following topical application to Swiss Albino mice. Dermal exposure of PAT, to mice for 4 h resulted in a dose (40-160 μg/animal) and time (up to 6 h) dependent enhancement of ornithine decarboxylase (ODC), a marker enzyme of cell proliferation. The ODC activity was found to be normal after 12 and 24 h treatment of patulin. Topical application of PAT (160 μg/100 μl acetone) for 24-72 h caused (a) DNA damage in skin cells showing significant increase (34-63%) in olive tail moment, a parameter of Comet assay (b) significant G 1 and S-phase arrest along with induction of apoptosis (2.8-10 folds) as shown by annexin V and PI staining assay through flow cytometer. Moreover PAT leads to over expression of p 21/WAF1 (3.6-3.9 fold), pro apoptotic protein Bax (1.3-2.6) and tumor suppressor wild type p 53 (2.8-3.9 fold) protein. It was also shown that PAT induced apoptosis was mediated through mitochondrial intrinsic pathway as revealed through the release of cytochrome C protein in cytosol leading to enhancement of caspase-3 activity in skin cells of mice. These results suggest that PAT has a potential to induce DNA damage leading to p 53 mediated cell cycle arrest along with intrinsic pathway mediated apoptosis that may also be correlated with enhanced polyamine production as evident by induction of ODC activity, which may have dermal toxicological implications

  12. The pleiotropic effects of fisetin and hesperetin on human acute promyelocytic leukemia cells are mediated through apoptosis, cell cycle arrest, and alterations in signaling networks.

    Science.gov (United States)

    Adan, Aysun; Baran, Yusuf

    2015-11-01

    Fisetin and hesperetin, flavonoids from various plants, have several pharmaceutical activities including antioxidative, anti-inflammatory, and anticancer effects. However, studies elucidating the role and the mechanism(s) of action of fisetin and hesperetin in acute promyelocytic leukemia are absent. In this study, we investigated the mechanism of the antiproliferative and apoptotic actions exerted by fisetin and hesperetin on human HL60 acute promyelocytic leukemia cells. The viability of HL60 cells was evaluated using the MTT assay, apoptosis by annexin V/propidium iodide (PI) staining and cell cycle distribution using flow cytometry, and changes in caspase-3 enzyme activity and mitochondrial transmembrane potential. Moreover, we performed whole-genome microarray gene expression analysis to reveal genes affected by fisetin and hesperetin that can be important for developing of future targeted therapy. Based on data obtained from microarray analysis, we also described biological networks modulated after fisetin and hesperetin treatment by KEGG and IPA analysis. Fisetin and hesperetin treatment showed a concentration- and time-dependent inhibition of proliferation and induced G2/M arrest for both agents and G0/G1 arrest for hesperetin at only the highest concentrations. There was a disruption of mitochondrial membrane potential together with increased caspase-3 activity. Furthermore, fisetin- and hesperetin-triggered apoptosis was confirmed by annexin V/PI analysis. The microarray gene profiling analysis revealed some important biological pathways including mitogen-activated protein kinases (MAPK) and inhibitor of DNA binding (ID) signaling pathways altered by fisetin and hesperetin treatment as well as gave a list of genes modulated ≥2-fold involved in cell proliferation, cell division, and apoptosis. Altogether, data suggested that fisetin and hesperetin have anticancer properties and deserve further investigation.

  13. Natriuretic peptide receptor A inhibition suppresses gastric cancer development through reactive oxygen species-mediated G2/M cell cycle arrest and cell death.

    Science.gov (United States)

    Li, Zheng; Wang, Ji-Wei; Wang, Wei-Zhi; Zhi, Xiao-Fei; Zhang, Qun; Li, Bo-Wen; Wang, Lin-Jun; Xie, Kun-Ling; Tao, Jin-Qiu; Tang, Jie; Wei, Song; Zhu, Yi; Xu, Hao; Zhang, Dian-Cai; Yang, Li; Xu, Ze-Kuan

    2016-10-01

    Natriuretic peptide receptor A (NPRA), the major receptor for atrial natriuretic peptide (ANP), has been implicated in tumorigenesis; however, the role of ANP-NPRA signaling in the development of gastric cancer remains unclear. Immunohistochemical analyses indicated that NPRA expression was positively associated with gastric tumor size and cancer stage. NPRA inhibition by shRNA induced G2/M cell cycle arrest, cell death, and autophagy in gastric cancer cells, due to accumulation of reactive oxygen species (ROS). Either genetic or pharmacologic inhibition of autophagy led to caspase-dependent cell death. Therefore, autophagy induced by NPRA silencing may represent a cytoprotective mechanism. ROS accumulation activated c-Jun N-terminal kinase (JNK) and AMP-activated protein kinase (AMPK). ROS-mediated activation of JNK inhibited cell proliferation by disturbing cell cycle and decreased cell viability. In addition, AMPK activation promoted autophagy in NPRA-downregulated cancer cells. Overall, our results indicate that the inhibition of NPRA suppresses gastric cancer development and targeting NPRA may represent a promising strategy for the treatment of gastric cancer. Copyright © 2016 Elsevier Inc. All rights reserved.

  14. Capsaicin Suppresses Cell Proliferation, Induces Cell Cycle Arrest and ROS Production in Bladder Cancer Cells through FOXO3a-Mediated Pathways

    Directory of Open Access Journals (Sweden)

    Kaiyu Qian

    2016-10-01

    Full Text Available Capsaicin (CAP, a highly selective agonist for transient receptor potential vanilloid type 1 (TRPV1, has been widely reported to exhibit anti-oxidant, anti-inflammation and anticancer activities. Currently, several therapeutic approaches for bladder cancer (BCa are available, but accompanied by unfavorable outcomes. Previous studies reported a potential clinical effect of CAP to prevent BCa tumorigenesis. However, its underlying molecular mechanism still remains unknown. Our transcriptome analysis suggested a close link among calcium signaling pathway, cell cycle regulation, ROS metabolism and FOXO signaling pathway in BCa. In this study, several experiments were performed to investigate the effects of CAP on BCa cells (5637 and T24 and NOD/SCID mice. Our results showed that CAP could suppress BCa tumorigenesis by inhibiting its proliferation both in vitro and in vivo. Moreover, CAP induced cell cycle arrest at G0/G1 phase and ROS production. Importantly, our studies revealed a strong increase of FOXO3a after treatment with CAP. Furthermore, we observed no significant alteration of apoptosis by CAP, whereas Catalase and SOD2 were considerably upregulated, which could clear ROS and protect against cell death. Thus, our results suggested that CAP could inhibit viability and tumorigenesis of BCa possibly via FOXO3a-mediated pathways.

  15. Lamprey immune protein-1 (LIP-1) from Lampetra japonica induces cell cycle arrest and cell death in HeLa cells.

    Science.gov (United States)

    Chi, Xiaoyuan; Su, Peng; Bi, Dan; Tai, Zhao; Li, Yingying; Pang, Yue; Li, Qingwei

    2018-04-01

    The lamprey (Lampetra japonica), a representative of the jawless vertebrates, is the oldest extant species in the world. LIP-1, which has a jacalin-like domain and an aerolysin pore-forming domain, has previously been identified in Lampetra japonica. However, the structure and function of the LIP-1 protein have not been described. In this study, the LIP-1 gene was overexpressed in HeLa cells and H293T cells. The results showed that the overexpression of LIP-1 in HeLa cells significantly elevated LDH release (P HeLa cells, while it had no effect on H293T cell organelles. Array data indicated that overexpression of LIP-1 primarily upregulated P53 signaling pathways in HeLa cells. Cell cycle assay results confirmed that LIP-1 caused arrest in the G 2 /M phase of the cell cycle in HeLa cells. In summary, our findings provide insights into the function and characterization of LIP-1 genes in vertebrates and establish the foundation for further research into the biological function of LIP-1. Our observations suggest that this lamprey protein has the potential for use in new applications in the medical field. Copyright © 2018. Published by Elsevier Ltd.

  16. The cucurbitacins D, E, and I from Ecballium elaterium (L. upregulate the LC3 gene and induce cell-cycle arrest in human gastric cancer cell line AGS

    Directory of Open Access Journals (Sweden)

    Naser Jafargholizadeh

    2018-03-01

    Full Text Available Objective(s: Cucurbitacins exhibit a range of anti-cancer functions. We investigated the effects of cucurbitacins D, E, and I purified from Ecballium elaterium (L. A. Rich fruits on some apoptotic and autophagy genes in human gastric cancer cell line AGS. Materials and Methods: Using quantitative reverse transcription PCR (qRT-PCR, the expression of LC3, VEGF, BAX, caspase-3, and c-MYC genes were quantified in AGS cells 24 hr after treatment with cucurbitacins D, E, and I at concentrations 0.3, 0.1 and 0.5 μg/ml, respectively. Cell cycle and death were analyzed by flowcytometry. Results: Purified cucurbitacins induced sub-G1 cell-cycle arrest and cell death in AGS cells and upregulated LC3mRNA effectively, but showed a very low effect on BAX, caspase-3, and c-MYC mRNA levels. Also after treatment with cucurbitacin I at concentration 0.5 μg/ml, VEGF mRNA levels were increased about 4.4 times. Pairwise comparison of the effect of cucurbitacins D, E, and I on LC3 mRNA expression showed that the cucurbitacin I effect is 1.3 and 1.1 times that of cucurbitacins E and D, respectively; cucurbitacin D effect is 1.2 times that of cucurbitacin E (P-value

  17. ETME, a novel β-elemene derivative, synergizes with arsenic trioxide in inducing apoptosis and cell cycle arrest in hepatocarcinoma cells via a p53-dependent pathway

    Directory of Open Access Journals (Sweden)

    Zhiying Yu

    2014-12-01

    Full Text Available Arsenic trioxide (ATO has been identified as an effective treatment for acute promyelocytic leukemia (APL but is much less effective against solid tumors such as hepatocellular carcinoma (HCC. In the search for ways to enhance its therapeutic efficacy against solid tumors, we have examined its use in combination with a novel derivative of β-elemene, N-(β-elemene-13-yltryptophan methyl ester (ETME. Here we report the effects of the combination on cell viability, apoptosis, the cell cycle and mitochondria membrane potential (MMP in HCC SMMC-7721 cells. We found that the two compounds acted synergistically to enhance antiproliferative activity and apoptosis. The combination also decreased the MMP, down-regulated Bcl-2 and pro-proteins of the caspase family, and up-regulated Bax and BID, all of which were reversed by the p53 inhibitor, pifithrin-α. In addition, the combination induced cell cycle arrest at the G2/M phase and reduced tumor volume and weight in an xenograft model of nude mice. Overall, the results suggest that ETME in combination with ATO may be useful in the treatment of HCC patients particularly those unresponsive to ATO alone.

  18. Use of a small molecule cell cycle inhibitor to control cell growth and improve specific productivity and product quality of recombinant proteins in CHO cell cultures.

    Science.gov (United States)

    Du, Zhimei; Treiber, David; McCarter, John D; Fomina-Yadlin, Dina; Saleem, Ramsey A; McCoy, Rebecca E; Zhang, Yuling; Tharmalingam, Tharmala; Leith, Matthew; Follstad, Brian D; Dell, Brad; Grisim, Brent; Zupke, Craig; Heath, Carole; Morris, Arvia E; Reddy, Pranhitha

    2015-01-01

    The continued need to improve therapeutic recombinant protein productivity has led to ongoing assessment of appropriate strategies in the biopharmaceutical industry to establish robust processes with optimized critical variables, that is, viable cell density (VCD) and specific productivity (product per cell, qP). Even though high VCD is a positive factor for titer, uncontrolled proliferation beyond a certain cell mass is also undesirable. To enable efficient process development to achieve consistent and predictable growth arrest while maintaining VCD, as well as improving qP, without negative impacts on product quality from clone to clone, we identified an approach that directly targets the cell cycle G1-checkpoint by selectively inhibiting the function of cyclin dependent kinases (CDK) 4/6 with a small molecule compound. Results from studies on multiple recombinant Chinese hamster ovary (CHO) cell lines demonstrate that the selective inhibitor can mediate a complete and sustained G0/G1 arrest without impacting G2/M phase. Cell proliferation is consistently and rapidly controlled in all recombinant cell lines at one concentration of this inhibitor throughout the production processes with specific productivities increased up to 110 pg/cell/day. Additionally, the product quality attributes of the mAb, with regard to high molecular weight (HMW) and glycan profile, are not negatively impacted. In fact, high mannose is decreased after treatment, which is in contrast to other established growth control methods such as reducing culture temperature. Microarray analysis showed major differences in expression of regulatory genes of the glycosylation and cell cycle signaling pathways between these different growth control methods. Overall, our observations showed that cell cycle arrest by directly targeting CDK4/6 using selective inhibitor compound can be utilized consistently and rapidly to optimize process parameters, such as cell growth, qP, and glycosylation profile in

  19. Cellular effect of styrene substituted biscoumarin caused cellular apoptosis and cell cycle arrest in human breast cancer cells.

    Science.gov (United States)

    Perumalsamy, Haribalan; Sankarapandian, Karuppasamy; Kandaswamy, Narendran; Balusamy, Sri Renukadevi; Periyathambi, Dhaiveegan; Raveendiran, Nanthini

    2017-11-01

    Coumarins occurs naturally across plant kingdoms exhibits significant pharmacological properties and pharmacokinetic activity. The conventional, therapeutic agents are often associated with poor stability, absorption and increased side effects. Therefore, identification of a drug that has little or no-side effect on humans is consequential. Here, we investigated the antiproliferative activity of styrene substituted biscoumarin against various human breast cancer cell lines, such as MCF-7, (ER-) MDA-MB-231 and (AR+) MDA-MB-453. Styrene substituted biscoumarin induced cell death by apoptosis in MDA-MB-231 cell line was analyzed. Antiproliferative activity of Styrene substituted biscoumarin was performed by using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay. Styrene substituted biscoumarin induced apoptosis was assessed by Hoechst staining, Annexin V-fluorescein isothiocyanate/propidium iodide (Annexin V-FITC/PI) staining and flow cytometric analysis. Migratory and proliferating characteristic of breast cancer cell line MDA-MB-231 was also analyzed by wound healing and colony formation assay. Furthermore, mRNA expression of BAX and BCL-2 were quantified using qRT-PCR and protein expression level analyzed by Western blot. The inhibition concentration (IC 50 ) of styrene substituted biscoumarin was assayed against three breast cancer cell lines. The inhibition concentration (IC 50 ) value of styrene substituted biscoumarin toward MDA-MB-231, MDA-MB-453 and MCF-7 cell lines was 5.63, 7.30 and 10.84μg/ml respectively. Styrene substituted biscoumarin induced apoptosis was detected by Hoechst staining, DAPI/PI analysis and flow-cytometric analysis. The migration and proliferative efficiency of MDA-MB-231 cells were completely arrested upon styrene substituted biscoumarin treatment. Also, mRNA gene expression and protein expression of pro-apoptotic (BAX) and anti-apoptotic (BCL-2) genes were analyzed by qRT-PCR and western blot analysis upon

  20. Protective effects of estrogen against vascular calcification via estrogen receptor α-dependent growth arrest-specific gene 6 transactivation

    International Nuclear Information System (INIS)

    Nanao-Hamai, Michiko; Son, Bo-Kyung; Hashizume, Tsuyoshi; Ogawa, Sumito; Akishita, Masahiro

    2016-01-01

    Vascular calcification is one of the major complications of cardiovascular disease and is an independent risk factor for myocardial infarction and cardiac death. Postmenopausal women have a higher prevalence of vascular calcification compared with premenopausal women, suggesting protective effects of estrogen (E2). However, the underlying mechanisms of its beneficial effects remain unclear. In the present study, we examined the inhibitory effects of E2 on vascular smooth muscle cell (VSMC) calcification, and found that growth arrest-specific gene 6 (Gas6), a crucial molecule in vascular calcification, is transactivated by estrogen receptor α (ERα) in response to E2. In human aortic smooth muscle cells, physiological levels of E2 inhibited inorganic phosphate (Pi)-induced calcification in a concentration-dependent manner. This inhibitory effect was significantly abolished by MPP, an ERα-selective antagonist, and ERα siRNA, but not by PHTPP, an ERβ-selective antagonist, and ERβ siRNA, implicating an ERα-dependent action. Apoptosis, an essential process for Pi-induced VSMC calcification, was inhibited by E2 in a concentration-dependent manner and further, MPP abolished this inhibition. Mechanistically, E2 restored the inhibited expression of Gas6 and phospho-Akt in Pi-induced apoptosis through ERα. Furthermore, E2 significantly activated Gas6 transcription, and MPP abrogated this E2-dependent Gas6 transactivation. E2-BSA failed to activate Gas6 transcription and to inhibit Ca deposition in VSMC, suggesting beneficial actions of genomic signaling by E2/nuclear ERα. Taken together, these results indicate that E2 exerts inhibitory effects on VSMC apoptosis and calcification through ERα-mediated Gas6 transactivation. These findings indicate a potential therapeutic strategy for the prevention of vascular calcification, especially in postmenopausal women. - Highlights: • E2 inhibits Pi-induced calcification in vascular smooth muscles cells. • E2 inhibits Pi

  1. Curcumin induces growth-arrest and apoptosis in association with the inhibition of constitutively active JAK-STAT pathway in T cell leukemia

    International Nuclear Information System (INIS)

    Rajasingh, Johnson; Raikwar, Himanshu P.; Muthian, Gladson; Johnson, Caroline; Bright, John J.

    2006-01-01

    Adult T cell leukemia is an aggressive and frequently fatal malignancy that expressess constitutively activated growth-signaling pathways in association with deregulated growth and resistance to apoptosis. Curcumin (diferuloylmethane) is a naturally occurring yellow pigment, isolated from the rhizomes of the plant Curcuma longa that has traditionally been used in the treatment of injury and inflammation. But the effect and mechanism of action of curcumin on T cell leukemia is not known. To investigate the antitumor activity of curcumin in T cell leukemia, we examined its effect on constitutive phosphorylation of JAK and STAT proteins, proliferation, and apoptosis in HTLV-I-transformed T cell lines. HTLV-I-transformed T cell leukemia lines, MT-2, HuT-102, and SLB-1, express constitutively phosphorylated JAK3, TYK2, STAT3, and STAT5 signaling proteins. In vitro treatment with curcumin induced a dose-dependent decrease in JAK and STAT phosphorylation resulting in the induction of growth-arrest and apoptosis in T cell leukemia. The induction of growth-arrest and apoptosis in association with the blockade of constitutively active JAK-STAT pathway suggests this be a mechanism by which curcumin induces antitumor activity in T cell leukemia

  2. N-methylpurine DNA glycosylase inhibits p53-mediated cell cycle arrest and coordinates with p53 to determine sensitivity to alkylating agents.

    Science.gov (United States)

    Song, Shanshan; Xing, Guichun; Yuan, Lin; Wang, Jian; Wang, Shan; Yin, Yuxin; Tian, Chunyan; He, Fuchu; Zhang, Lingqiang

    2012-08-01

    Alkylating agents induce genome-wide base damage, which is repaired mainly by N-methylpurine DNA glycosylase (MPG). An elevated expression of MPG in certain types of tumor cells confers higher sensitivity to alkylation agents because MPG-induced apurinic/apyrimidic (AP) sites trigger more strand breaks. However, the determinant of drug sensitivity or insensitivity still remains unclear. Here, we report that the p53 status coordinates with MPG to play a pivotal role in such process. MPG expression is positive in breast, lung and colon cancers (38.7%, 43.4% and 25.3%, respectively) but negative in all adjacent normal tissues. MPG directly binds to the tumor suppressor p53 and represses p53 activity in unstressed cells. The overexpression of MPG reduced, whereas depletion of MPG increased, the expression levels of pro-arrest gene downstream of p53 including p21, 14-3-3σ and Gadd45 but not proapoptotic ones. The N-terminal region of MPG was specifically required for the interaction with the DNA binding domain of p53. Upon DNA alkylation stress, in p53 wild-type tumor cells, p53 dissociated from MPG and induced cell growth arrest. Then, AP sites were repaired efficiently, which led to insensitivity to alkylating agents. By contrast, in p53-mutated cells, the AP sites were repaired with low efficacy. To our knowledge, this is the first direct evidence to show that a DNA repair enzyme functions as a selective regulator of p53, and these findings provide new insights into the functional linkage between MPG and p53 in cancer therapy.

  3. The cytolethal distending toxin from the chancroid bacterium Haemophilus ducreyi induces cell-cycle arrest in the G2 phase.

    Science.gov (United States)

    Cortes-Bratti, X; Chaves-Olarte, E; Lagergård, T; Thelestam, M

    1999-01-01

    The potent cytolethal distending toxin produced by Haemophilus ducreyi is a putative virulence factor in the pathogenesis of chancroid. We studied its action on eukaryotic cells, with the long-term goal of understanding the pathophysiology of the disease. Intoxication of cultured human epithelial-like cells, human keratinocytes, and hamster fibroblasts was irreversible, and appeared as a gradual distention of three- to fivefold the size of control cells. Organized actin assemblies appeared concomitantly with cell enlargement, promoted by a mechanism that probably does not involve small GTPases of the Rho protein family. Intoxicated cells did not proliferate. Similar to cells treated with other cytolethal distending toxins, these cells accumulated in the G2 phase of the cell cycle, demonstrating an increased level of the tyrosine phosphorylated (inactive) form of the cyclin-dependent kinase p34(cdc2). DNA synthesis was not affected until several hours after this increase, suggesting that the toxin acts directly on some kinase/phosphatase in the signaling network controlling the p34(cdc2) activity. We propose that this toxin has an important role both in the generation of chancroid ulcers and in their slow healing. The toxin may also be an interesting new tool for molecular studies of the eukaryotic cell- cycle machinery.

  4. N-(4-Hydroxyphenyl) retinamide potentiated paclitaxel for cell cycle arrest and apoptosis in glioblastoma C6 and RG2 cells

    OpenAIRE

    Janardhanan, Rajiv; Butler, Jonathan T.; Banik, Naren L.; Ray, Swapan K.

    2009-01-01

    Glioblastoma grows aggressively due to its ability to maintain abnormally high potentials for cell proliferation. The present study examines the synergistic actions of N-(4-hdroxyphenyl) retinamide (4-HPR) and paclitaxel (PTX) to control the growth of rat glioblastoma C6 and RG2 cell lines. 4-HPR induced astrocytic differentiation was accompanied by increased expression of the tight junction protein e-cadherin and sustained down regulation of Id2 (member of inhibitor of differentiation family...

  5. Vorinostat, a histone deacetylase (HDAC) inhibitor, promotes cell cycle arrest and re-sensitizes rituximab- and chemo-resistant lymphoma cells to chemotherapy agents.

    Science.gov (United States)

    Xue, Kai; Gu, Juan J; Zhang, Qunling; Mavis, Cory; Hernandez-Ilizaliturri, Francisco J; Czuczman, Myron S; Guo, Ye

    2016-02-01

    evaluated by Western blotting. Finally, cell lines were pre-exposed to vorinostat for 48 h and subsequently exposed to several chemotherapy agents (cisplatin, etoposide, or gemcitabine); changes in cell viability were determined by CellTiter-Glo(®) luminescence assay (Promega, Fitchburg, WI), and synergistic activity was evaluated using the CalcuSyn software. Vorinostat induced dose-dependent cell death in RRCL and in primary tumor cells. In addition, in vitro exposure of RRCL to vorinostat resulted in an increase in p21 and acetylation of histone H3 leading to G1 cell cycle arrest. Vorinostat exposure resulted in apoptosis in RSCL cell lines but not in RRCL. This finding suggests that in RRCL, vorinostat induces cell death by alternative pathways (i.e., irreversible cell cycle arrest). Of interest, vorinostat was found to reverse acquired chemotherapy resistance in RRCL. Our data suggest that vorinostat is active in RRCL with a known defective apoptotic machinery, it can active alternative cell death pathways. Given the multiple pathways affected by HDAC inhibition, vorinostat can potentially be used to overcome acquired resistant to chemotherapy in aggressive B cell lymphoma.

  6. Testing the Goodwin growth-cycle macroeconomic dynamics in Brazil

    Science.gov (United States)

    Moura, N. J.; Ribeiro, Marcelo B.

    2013-05-01

    This paper discusses the empirical validity of Goodwin’s (1967) macroeconomic model of growth with cycles by assuming that the individual income distribution of the Brazilian society is described by the Gompertz-Pareto distribution (GPD). This is formed by the combination of the Gompertz curve, representing the overwhelming majority of the population (˜99%), with the Pareto power law, representing the tiny richest part (˜1%). In line with Goodwin’s original model, we identify the Gompertzian part with the workers and the Paretian component with the class of capitalists. Since the GPD parameters are obtained for each year and the Goodwin macroeconomics is a time evolving model, we use previously determined, and further extended here, Brazilian GPD parameters, as well as unemployment data, to study the time evolution of these quantities in Brazil from 1981 to 2009 by means of the Goodwin dynamics. This is done in the original Goodwin model and an extension advanced by Desai et al. (2006). As far as Brazilian data is concerned, our results show partial qualitative and quantitative agreement with both models in the studied time period, although the original one provides better data fit. Nevertheless, both models fall short of a good empirical agreement as they predict single center cycles which were not found in the data. We discuss the specific points where the Goodwin dynamics must be improved in order to provide a more realistic representation of the dynamics of economic systems.

  7. Arctigenin, a natural lignan compound, induces G0/G1 cell cycle arrest and apoptosis in human glioma cells

    OpenAIRE

    Maimaitili, Aisha; Shu, Zunhua; Cheng, Xiaojiang; Kaheerman, Kadeer; Sikandeer, Alifu; Li, Weimin

    2016-01-01

    The aim of the current study was to investigate the anticancer potential of arctigenin, a natural lignan compound, in malignant gliomas. The U87MG and T98G human glioma cell lines were treated with various concentrations of arctigenin for 48 h and the effects of arctigenin on the aggressive phenotypes of glioma cells were assessed. The results demonstrated that arctigenin dose-dependently inhibited the growth of U87MG and T98G cells, as determined using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphen...

  8. Resistance to ursodeoxycholic acid-induced growth arrest can also result in resistance to deoxycholic acid-induced apoptosis and increased tumorgenicity

    International Nuclear Information System (INIS)

    Powell, Ashley A; Akare, Sandeep; Qi, Wenqing; Herzer, Pascal; Jean-Louis, Samira; Feldman, Rebecca A; Martinez, Jesse D

    2006-01-01

    There is a large body of evidence which suggests that bile acids increase the risk of colon cancer and act as tumor promoters, however, the mechanism(s) of bile acids mediated tumorigenesis is not clear. Previously we showed that deoxycholic acid (DCA), a tumorogenic bile acid, and ursodeoxycholic acid (UDCA), a putative chemopreventive agent, exhibited distinct biological effects, yet appeared to act on some of the same signaling molecules. The present study was carried out to determine whether there is overlap in signaling pathways activated by tumorogenic bile acid DCA and chemopreventive bile acid UDCA. To determine whether there was an overlap in activation of signaling pathways by DCA and UDCA, we mutagenized HCT116 cells and then isolated cell lines resistant to UDCA induced growth arrest. These lines were then tested for their response to DCA induced apoptosis. We found that a majority of the cell lines resistant to UDCA-induced growth arrest were also resistant to DCA-induced apoptosis, implying an overlap in DCA and UDCA mediated signaling. Moreover, the cell lines which were the most resistant to DCA-induced apoptosis also exhibited a greater capacity for anchorage independent growth. We conclude that UDCA and DCA have overlapping signaling activities and that disregulation of these pathways can lead to a more advanced neoplastic phenotype

  9. Step growth of an AB2 monomer, with cycle formation

    DEFF Research Database (Denmark)

    Cameron, Colin; Fawcett, Allan H.; Hetherington, Cecil R.

    1998-01-01

    A computer-based lattice model of the step growth reaction of an AB2 monomer, the next elaborate system after an AB monomer, has been devised that allows the simultaneous and explicit occurrence of inter- and intramolecular reactions of A and B groups of the flexible and moving molecules according...... with fractal characteristics. Growth stops when each molecule contains a cycle. For the model explored, in which six lattice sites are used for each monomer, the limiting value of the number average degree of polymerization, 〈x〉n,∞, is 14.6(±0.3) (after infinite time). The occurrence within the system of rings...... of m residues (m=1,2,3,...) is found to depend upon m and the extent of reaction of the A groups, pa, according to Rm=C0pm am-2.71, the constant C0 reflecting the structure of the lattice and the monomer, and being shown to determine the final degree of polymerization. The exponent of the integers m...

  10. Anti-leukemic effect of a synthetic compound, (±) trans-dihydronarciclasine (HYU-01) via cell-cycle arrest and apoptosis in acute myeloid leukemia.

    Science.gov (United States)

    Kim, Seo Ju; Park, Hyun Ki; Kim, Ju Young; Yoon, Jin Sun; Kim, Eun Shil; Cho, Cheon-Gyu; Kim, Byoung Kook; Park, Byeong Bae; Lee, Young Yiul

    2012-10-01

    (±) trans-Dihydronarciclasine, isolated from Chinese medicinal plant Zephyranthes candida, has been shown to possess quite potent anti-tumoral effect against selected human cancer cell lines. However, little is known about the anti-tumoral effect of (±) trans-dihydronarciclasine in acute myeloid leukemia (AML). This study was performed to investigate the effect of a novel synthetic (±) trans-dihydronarciclasine (code name; HYU-01) in AML. The HYU-01 inhibited the proliferation of various AML cell lines including HL-60 as well as primary leukemic blasts in a dose-dependent manner. To investigate the mechanism of the anti-proliferative effect of HYU-01, cell-cycle analysis was attempted in HL-60 cells, resulting in G1 arrest. The expression levels of CDK2, CDK4, CDK6, cyclin E, and cyclin A were decreased in a time-dependent manner. In addition, HYU-01 up-regulated the expression of the p27, and markedly enhanced the binding of p27 with CDK2, 4, and 6, ultimately resulting in the decrease of their kinase activities. Furthermore, HYU-01 induced the apoptosis through the induction of proapoptotic molecules and reduction of antiapoptotic molecules in association with the activation of caspase-3, -8, and -9. These results suggest that HYU-01 may inhibit the proliferation of HL-60 cells, via apoptosis, as well as G1 block in association with the induction of p27. © 2012 The Authors APMIS © 2012 APMIS.

  11. Non-homologous end joining dependency of {gamma}-irradiation-induced adaptive frameshift mutation formation in cell cycle-arrested yeast cells

    Energy Technology Data Exchange (ETDEWEB)

    Heidenreich, Erich [Institute of Cancer Research, Division of Molecular Genetics, Medical University of Vienna, Borschkegasse 8a, A-1090 Vienna (Austria)]. E-mail: erich.heidenreich@meduniwien.ac.at; Eisler, Herfried [Institute of Cancer Research, Division of Molecular Genetics, Medical University of Vienna, Borschkegasse 8a, A-1090 Vienna (Austria)

    2004-11-22

    There is a strong selective pressure favoring adaptive mutations which relieve proliferation-limiting adverse living conditions. Due to their importance for evolution and pathogenesis, we are interested in the mechanisms responsible for the formation of such adaptive, gain-of-fitness mutations in stationary-phase cells. During previous studies on the occurrence of spontaneous reversions of an auxotrophy-causing frameshift allele in the yeast Saccharomyces cerevisiae, we noticed that about 50% of the adaptive reversions depended on a functional non-homologous end joining (NHEJ) pathway of DNA double-strand break (DSB) repair. Here, we show that the occasional NHEJ component Pol4, which is the yeast ortholog of mammalian DNA polymerase lambda, is not required for adaptive mutagenesis. An artificially imposed excess of DSBs by {gamma}-irradiation resulted in a dramatic increase in the incidence of adaptive, cell cycle arrest-releasing frameshift reversions. By the use of DNA ligase IV-deficient strains we detected that the majority of the {gamma}-induced adaptive mutations were also dependent on a functional NHEJ pathway. This suggests that the same mutagenic NHEJ mechanism acts on spontaneously arising as well as on ionizing radiation-induced DSBs. Inaccuracy of the NHEJ repair pathway may extensively contribute to the incidence of frameshift mutations in resting (non-dividing) eukaryotic cells, and thus act as a driving force in tumor development.

  12. Non-homologous end joining dependency of γ-irradiation-induced adaptive frameshift mutation formation in cell cycle-arrested yeast cells

    International Nuclear Information System (INIS)

    Heidenreich, Erich; Eisler, Herfried

    2004-01-01

    There is a strong selective pressure favoring adaptive mutations which relieve proliferation-limiting adverse living conditions. Due to their importance for evolution and pathogenesis, we are interested in the mechanisms responsible for the formation of such adaptive, gain-of-fitness mutations in stationary-phase cells. During previous studies on the occurrence of spontaneous reversions of an auxotrophy-causing frameshift allele in the yeast Saccharomyces cerevisiae, we noticed that about 50% of the adaptive reversions depended on a functional non-homologous end joining (NHEJ) pathway of DNA double-strand break (DSB) repair. Here, we show that the occasional NHEJ component Pol4, which is the yeast ortholog of mammalian DNA polymerase lambda, is not required for adaptive mutagenesis. An artificially imposed excess of DSBs by γ-irradiation resulted in a dramatic increase in the incidence of adaptive, cell cycle arrest-releasing frameshift reversions. By the use of DNA ligase IV-deficient strains we detected that the majority of the γ-induced adaptive mutations were also dependent on a functional NHEJ pathway. This suggests that the same mutagenic NHEJ mechanism acts on spontaneously arising as well as on ionizing radiation-induced DSBs. Inaccuracy of the NHEJ repair pathway may extensively contribute to the incidence of frameshift mutations in resting (non-dividing) eukaryotic cells, and thus act as a driving force in tumor development

  13. Umbelliferone arrest cell cycle at G0/G1 phase and induces apoptosis in human oral carcinoma (KB) cells possibly via oxidative DNA damage.

    Science.gov (United States)

    Vijayalakshmi, Annamalai; Sindhu, Ganapathy

    2017-08-01

    Umbelliferone (UMB) has widespread pharmacological activity, comprising anti-inflammatory, anti-oxidant, anti-genotoxic and anti-immunomodulatory but the anticancer activity remains unknown in human oral carcinoma (HOC) KB cells. MTT assay determinations was revealed that treatment of KB cells with UMB, prevent and reduce the cell proliferation with the IC 50 - 200μM as well as induces loss of cell viability, morphology change and internucleosomal DNA fragmentation in a concentration dependent manner. Acridine orange and ethidium bromide dual staining assay established that UMB induced apoptosis in KB cells in a dose dependent manner. Alkaline comet assay determination revealed UMB has the potential to increase oxidative DNA damage in KB cells through DNA tail formation significantly (pKB cells. Similarly, we observed increased DNA damage stimulated apoptotic morphological changes in UMB treated cells. Taken together, the present study suggests that UMB exhibits anticancer effect on KB cell line with the increased generation of intracellular ROS, triggered oxidative stress mediated depolarization of mitochondria, which contributes cell death via DNA damage as well as cell cycle arrest at G0/G1 phase. The results have also provided us insight in the pharmacological backgrounds for the potential use of UMB, to target divergent pathways of cell survival and cell death. To conclude UMB could develop as a novel candidate for cancer chemoprevention and therapy, which is our future focus and to develop a connectivity map between in vivo and in vitro activity. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  14. Alisertib induces cell cycle arrest and autophagy and suppresses epithelial-to-mesenchymal transition involving PI3K/Akt/mTOR and sirtuin 1-mediated signaling pathways in human pancreatic cancer cells

    Science.gov (United States)

    Wang, Feng; Li, Hai; Yan, Xiao-Gang; Zhou, Zhi-Wei; Yi, Zhi-Gang; He, Zhi-Xu; Pan, Shu-Ting; Yang, Yin-Xue; Wang, Zuo-Zheng; Zhang, Xueji; Yang, Tianxing; Qiu, Jia-Xuan; Zhou, Shu-Feng

    2015-01-01

    Pancreatic cancer is the most aggressive cancer worldwide with poor response to current therapeutics. Alisertib (ALS), a potent and selective Aurora kinase A inhibitor, exhibits potent anticancer effects in preclinical and clinical studies; however, the effect and underlying mechanism of ALS in the pancreatic cancer treatment remain elusive. This study aimed to examine the effects of ALS on cell growth, autophagy, and epithelial-to-mesenchymal transition (EMT) and to delineate the possible molecular mechanisms in human pancreatic cancer PANC-1 and BxPC-3 cells. The results showed that ALS exerted potent cell growth inhibitory, pro-autophagic, and EMT-suppressing effects in PANC-1 and BxPC-3 cells. ALS remarkably arrested PANC-1 and BxPC-3 cells in G2/M phase via regulating the expression of cyclin-dependent kinases 1 and 2, cyclin B1, cyclin D1, p21 Waf1/Cip1, p27 Kip1, and p53. ALS concentration-dependently induced autophagy in PANC-1 and BxPC-3 cells, which may be attributed to the inhibition of phosphatidylinositol 3-kinase (PI3K)/protein kinase B (Akt)/mammalian target of rapamycin (mTOR), p38 mitogen-activated protein kinase (p38 MAPK), and extracellular signal-regulated kinases 1 and 2 (Erk1/2) but activation of 5′-AMP-dependent kinase signaling pathways. ALS significantly inhibited EMT in PANC-1 and BxPC-3 cells with an increase in the expression of E-cadherin and a decrease in N-cadherin. In addition, ALS suppressed the expression of sirtuin 1 (Sirt1) and pre-B cell colony-enhancing factor/visfatin in both cell lines with a rise in the level of acetylated p53. These findings show that ALS induces cell cycle arrest and promotes autophagic cell death but inhibits EMT in pancreatic cancer cells with the involvement of PI3K/Akt/mTOR, p38 MAPK, Erk1/2, and Sirt1-mediated signaling pathways. Taken together, ALS may represent a promising anticancer drug for pancreatic cancer treatment. More studies are warranted to investigate other molecular targets and

  15. Cell-cycle arrest in mature adipocytes impairs BAT development but not WAT browning, and reduces adaptive thermogenesis in mice.

    Science.gov (United States)

    Okamatsu-Ogura, Yuko; Fukano, Keigo; Tsubota, Ayumi; Nio-Kobayashi, Junko; Nakamura, Kyoko; Morimatsu, Masami; Sakaue, Hiroshi; Saito, Masayuki; Kimura, Kazuhiro

    2017-07-27

    We previously reported brown adipocytes can proliferate even after differentiation. To test the involvement of mature adipocyte proliferation in cell number control in fat tissue, we generated transgenic (Tg) mice over-expressing cell-cycle inhibitory protein p27 specifically in adipocytes, using the aP2 promoter. While there was no apparent difference in white adipose tissue (WAT) between wild-type (WT) and Tg mice, the amount of brown adipose tissue (BAT) was much smaller in Tg mice. Although BAT showed a normal cellular morphology, Tg mice had lower content of uncoupling protein 1 (UCP1) as a whole, and attenuated cold exposure- or β3-adrenergic receptor (AR) agonist-induced thermogenesis, with a decrease in the number of mature brown adipocytes expressing proliferation markers. An agonist for the β3-AR failed to increase the number of proliferating brown adipocytes, UCP1 content in BAT, and oxygen consumption in Tg mice, although the induction and the function of beige adipocytes in inguinal WAT from Tg mice were similar to WT mice. These results show that brown adipocyte proliferation significantly contributes to BAT development and adaptive thermogenesis in mice, but not to induction of beige adipocytes.

  16. Arctigenin anti-tumor activity in bladder cancer T24 cell line through induction of cell-cycle arrest and apoptosis.

    Science.gov (United States)

    Yang, Shucai; Ma, Jing; Xiao, Jianbing; Lv, Xiaohong; Li, Xinlei; Yang, Huike; Liu, Ying; Feng, Sijia; Zhang, Yafang

    2012-08-01

    Bladder cancer is the most common neoplasm in the urinary system. This study assesses arctigenin anti-tumor activity in human bladder cancer T24 cells in vitro and the underlying molecular events. The flow cytometry analysis was used to detect cell-cycle distribution and apoptosis. Western blotting was used to detect changes in protein expression. The data showed that arctigenin treatment reduced viability of bladder cancer T24 cells in a dose- and time-dependent manner after treatment with arctigenin (10, 20, 40, 80, and 100 μmol/L) for 24 hr and 48 hr. Arctigenin treatment clearly arrested tumor cells in the G1 phase of the cell cycle. Apoptosis was detected by hoechst stain and flow cytometry after Annexin-V-FITC/PI double staining. Early and late apoptotic cells were accounted for 2.32-7.01% and 3.07-7.35%, respectively. At the molecular level, arctigenin treatment decreased cyclin D1 expression, whereas CDK4 and CDK6 expression levels were unaffected. Moreover, arctigenin selectively altered the phosphorylation of members of the MAPK superfamily, decreasing phosphorylation of ERK1/2 and activated phosphorylation of p38 significantly in a dose-dependent manner. These results suggest that arctigenin may inhibit cell viability and induce apoptosis by direct activation of the mitochondrial pathway, and the mitogen-activated protein kinase pathway may play an important role in the anti-tumor effect of arctigenin. The data from the current study demonstrate the usefulness of arctigenin in bladder cancer T24 cells, which should further be evaluated in vivo before translation into clinical trials for the chemoprevention of bladder cancer. Copyright © 2012 Wiley Periodicals, Inc.

  17. The immunomodulator PSK induces in vitro cytotoxic activity in tumour cell lines via arrest of cell cycle and induction of apoptosis

    International Nuclear Information System (INIS)

    Jiménez-Medina, Eva; Berruguilla, Enrique; Romero, Irene; Algarra, Ignacio; Collado, Antonia; Garrido, Federico; Garcia-Lora, Angel

    2008-01-01

    Protein-bound polysaccharide (PSK) is derived from the CM-101 strain of the fungus Coriolus versicolor and has shown anticancer activity in vitro and in in vivo experimental models and human cancers. Several randomized clinical trials have demonstrated that PSK has great potential in adjuvant cancer therapy, with positive results in the adjuvant treatment of gastric, esophageal, colorectal, breast and lung cancers. These studies have suggested the efficacy of PSK as an immunomodulator of biological responses. The precise molecular mechanisms responsible for its biological activity have yet to be fully elucidated. The in vitro cytotoxic anti-tumour activity of PSK has been evaluated in various tumour cell lines derived from leukaemias, melanomas, fibrosarcomas and cervix, lung, pancreas and gastric cancers. Tumour cell proliferation in vitro was measured by BrdU incorporation and viable cell count. Effect of PSK on human peripheral blood lymphocyte (PBL) proliferation in vitro was also analyzed. Studies of cell cycle and apoptosis were performed in PSK-treated cells. PSK showed in vitro inhibition of tumour cell proliferation as measured by BrdU incorporation and viable cell count. The inhibition ranged from 22 to 84%. Inhibition mechanisms were identified as cell cycle arrest, with cell accumulation in G 0 /G 1 phase and increase in apoptosis and caspase-3 expression. These results indicate that PSK has a direct cytotoxic activity in vitro, inhibiting tumour cell proliferation. In contrast, PSK shows a synergistic effect with IL-2 that increases PBL proliferation. These results indicate that PSK has cytotoxic activity in vitro on tumour cell lines. This new cytotoxic activity of PSK on tumour cells is independent of its previously described immunomodulatory activity on NK cells

  18. The immunomodulator PSK induces in vitro cytotoxic activity in tumour cell lines via arrest of cell cycle and induction of apoptosis

    Directory of Open Access Journals (Sweden)

    Garrido Federico

    2008-03-01

    Full Text Available Abstract Background Protein-bound polysaccharide (PSK is derived from the CM-101 strain of the fungus Coriolus versicolor and has shown anticancer activity in vitro and in in vivo experimental models and human cancers. Several randomized clinical trials have demonstrated that PSK has great potential in adjuvant cancer therapy, with positive results in the adjuvant treatment of gastric, esophageal, colorectal, breast and lung cancers. These studies have suggested the efficacy of PSK as an immunomodulator of biological responses. The precise molecular mechanisms responsible for its biological activity have yet to be fully elucidated. Methods The in vitro cytotoxic anti-tumour activity of PSK has been evaluated in various tumour cell lines derived from leukaemias, melanomas, fibrosarcomas and cervix, lung, pancreas and gastric cancers. Tumour cell proliferation in vitro was measured by BrdU incorporation and viable cell count. Effect of PSK on human peripheral blood lymphocyte (PBL proliferation in vitro was also analyzed. Studies of cell cycle and apoptosis were performed in PSK-treated cells. Results PSK showed in vitro inhibition of tumour cell proliferation as measured by BrdU incorporation and viable cell count. The inhibition ranged from 22 to 84%. Inhibition mechanisms were identified as cell cycle arrest, with cell accumulation in G0/G1 phase and increase in apoptosis and caspase-3 expression. These results indicate that PSK has a direct cytotoxic activity in vitro, inhibiting tumour cell proliferation. In contrast, PSK shows a synergistic effect with IL-2 that increases PBL proliferation. Conclusion These results indicate that PSK has cytotoxic activity in vitro on tumour cell lines. This new cytotoxic activity of PSK on tumour cells is independent of its previously described immunomodulatory activity on NK cells.

  19. AZD2014 Radiosensitizes Oral Squamous Cell Carcinoma by Inhibiting AKT/mTOR Axis and Inducing G1/G2/M Cell Cycle Arrest.

    Directory of Open Access Journals (Sweden)

    Chih-Chia Yu

    Full Text Available Oral squamous cell carcinoma (OSCC is one of the most common malignant neoplasms in Taiwan. Activation of the mTOR signaling pathway has been linked to decreased radiation responsiveness in human oral cancer, thus it limits efficacy of radiotherapy. To address this question, we investigated the effect of AZD2014, a novel small molecular ATP-competitive inhibitor of mTORC1 and mTORC2 kinase, as a radiosensitizer in primary OSCC and OSCC-derived cell line models.We isolated primary tumor cells from OSCC tissues and cell lines. AZD2014 was administered with and without ionizing radiation. The radiosensitizing effect of AZD2014 were then assessed using cell viability assays, clonogenic survival assays, and cell cycle analyses. Western blotting was used to detect protein expression.Combination treatment with AZD2014 and irradiation resulted in significant reduction in OSCC cell line and primary OSCC cell colony formation due to the enhanced inhibition of AKT and both mTORC1 and mTORC2 activity. Pre-treatment with AZD2014 in irradiated oral cancer cells induced tumor cell cycle arrest at the G1 and G2/M phases, which led to disruption of cyclin D1-CDK4 and cyclin B1-CDC2 complexes. Moreover, AZD2014 synergized with radiation to promote both apoptosis and autophagy by increasing caspase-3 and LC3 in primary OSCC cells.These findings suggest that in irradiated OSCC cells, co-treatment with AZD2014, which targets mTORC1 and mTORC2 blockade, is an effective radiosensitizing strategy for oral squamous cell carcinoma.

  20. 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.

  1. SKLB70326, a novel small-molecule inhibitor of cell-cycle progression, induces G{sub 0}/G{sub 1} phase arrest and apoptosis in human hepatic carcinoma cells

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    Han, Yuanyuan; He, Haiyun [State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, West China Medical School, Sichuan University, Chengdu 610041 (China); Peng, Feng [Department of Thoracic Oncology of the Cancer Center and State Key Laboratory of Biotherapy, West China Hospital, West China Medical School, Sichuan University, Chengdu 610041 (China); Liu, Jiyan; Dai, Xiaoyun; Lin, Hongjun; Xu, Youzhi; Zhou, Tian; Mao, Yongqiu; Xie, Gang; Yang, Shengyong; Yu, Luoting; Yang, Li [State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, West China Medical School, Sichuan University, Chengdu 610041 (China); Zhao, Yinglan, E-mail: alancenxb@sina.com [State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, West China Medical School, Sichuan University, Chengdu 610041 (China)

    2012-05-18

    Highlights: Black-Right-Pointing-Pointer SKLB70326 is a novel compound and has activity of anti-HCC. Black-Right-Pointing-Pointer SKLB70326 induces cell cycle arrest and apoptosis in HepG2 cells. Black-Right-Pointing-Pointer SKLB70326 induces G{sub 0}/G{sub 1} phase arrest via inhibiting the activity of CDK2, CDK4 and CDK6. Black-Right-Pointing-Pointer SKLB70326 induces apoptosis through the intrinsic pathway. -- Abstract: We previously reported the potential of a novel small molecule 3-amino-6-(3-methoxyphenyl)thieno[2.3-b]pyridine-2-carboxamide (SKLB70326) as an anticancer agent. In the present study, we investigated the anticancer effects and possible mechanisms of SKLB70326 in vitro. We found that SKLB70326 treatment significantly inhibited human hepatic carcinoma cell proliferation in vitro, and the HepG2 cell line was the most sensitive to its treatment. The inhibition of cell proliferation correlated with G{sub 0}/G{sub 1} phase arrest, which was followed by apoptotic cell death. The SKLB70326-mediated cell-cycle arrest was associated with the downregulation of cyclin-dependent kinase (CDK) 2, CDK4 and CDK6 but not cyclin D1 or cyclin E. The phosphorylation of the retinoblastoma protein (Rb) was also observed. SKLB70326 treatment induced apoptotic cell death via the activation of PARP, caspase-3, caspase-9 and Bax as well as the downregulation of Bcl-2. The expression levels of p53 and p21 were also induced by SKLB70326 treatment. Moreover, SKLB70326 treatment was well tolerated. In conclusion, SKLB70326, a novel cell-cycle inhibitor, notably inhibits HepG2 cell proliferation through the induction of G{sub 0}/G{sub 1} phase arrest and subsequent apoptosis. Its potential as a candidate anticancer agent warrants further investigation.

  2. MeHg Developing Exposure Causes DNA Double-Strand Breaks and Elicits Cell Cycle Arrest in Spinal Cord Cells

    Directory of Open Access Journals (Sweden)

    Fabiana F. Ferreira

    2015-01-01

    Full Text Available The neurotoxicity caused by methylmercury (MeHg is well documented; however, the developmental neurotoxicity in spinal cord is still not fully understood. Here we investigated whether MeHg affects the spinal cord layers development. Chicken embryos at E3 were treated in ovo with 0.1 μg MeHg/50 μL saline solution and analyzed at E10. Thus, we performed immunostaining using anti-γ-H2A.X to recognize DNA double-strand breaks and antiphosphohistone H3, anti-p21, and anti-cyclin E to identify cells in proliferation and cell cycle proteins. Also, to identify neuronal cells, we used anti-NeuN and anti-βIII-tubulin antibodies. After the MeHg treatment, we observed the increase on γ-H2A.X in response to DNA damage. MeHg caused a decrease in the proliferating cells and in the thickness of spinal cord layers. Moreover, we verified that MeHg induced an increase in the number of p21-positive cells but did not change the cyclin E-positive cells. A significantly high number of TUNEL-positive cells indicating DNA fragmentation were observed in MeHg-treated embryos. Regarding the neuronal differentiation, MeHg induced a decrease in NeuN expression and did not change the expression of βIII-tubulin. These results showed that in ovo MeHg exposure alters spinal cord development by disturbing the cell proliferation and death, also interfering in early neuronal differentiation.

  3. HOXB7 mRNA is overexpressed in pancreatic ductal adenocarcinomas and its knockdown induces cell cycle arrest and apoptosis

    International Nuclear Information System (INIS)

    Chile, Thais; Bacchella, Telésforo; Giorgi, Ricardo Rodrigues; Fortes, Maria Angela Henriques Zanella; Corrêa-Giannella, Maria Lúcia Cardillo; Brentani, Helena Paula; Maria, Durvanei Augusto; Puga, Renato David; Paula, Vanessa de Jesus R de; Kubrusly, Marcia Saldanha; Novak, Estela Maria

    2013-01-01

    Human homeobox genes encode nuclear proteins that act as transcription factors involved in the control of differentiation and proliferation. Currently, the role of these genes in development and tumor progression has been extensively studied. Recently, increased expression of HOXB7 homeobox gene (HOXB7) in pancreatic ductal adenocarcinomas (PDAC) was shown to correlate with an invasive phenotype, lymph node metastasis and worse survival outcomes, but no influence on cell proliferation or viability was detected. In the present study, the effects arising from the knockdown of HOXB7 in PDAC cell lines was investigated. Real time quantitative PCR (qRT-PCR) (Taqman) was employed to assess HOXB7 mRNA expression in 29 PDAC, 6 metastatic tissues, 24 peritumoral tissues and two PDAC cell lines. siRNA was used to knockdown HOXB7 mRNA in the cell lines and its consequences on apoptosis rate and cell proliferation were measured by flow cytometry and MTT assay respectively. Overexpression of HOXB7 mRNA was observed in the tumoral tissues and in the cell lines MIA PaCa-2 and Capan-1. HOXB7 knockdown elicited (1) an increase in the expression of the pro-apoptotic proteins BAX and BAD in both cell lines; (2) a decrease in the expression of the anti-apoptotic protein BCL-2 and in cyclin D1 and an increase in the number of apoptotic cells in the MIA PaCa-2 cell line; (3) accumulation of cell in sub-G1 phase in both cell lines; (4) the modulation of several biological processes, especially in MIA PaCa-2, such as proteasomal ubiquitin-dependent catabolic process and cell cycle. The present study confirms the overexpression of HOXB7 mRNA expression in PDAC and demonstrates that decreasing its protein level by siRNA could significantly increase apoptosis and modulate several biological processes. HOXB7 might be a promising target for future therapies

  4. Plant Growth and Development: An Outline for a Unit Structured Around the Life Cycle of Rapid-Cycling Brassica Rapa.

    Science.gov (United States)

    Becker, Wayne M.

    This outline is intended for use in a unit of 10-12 lectures on plant growth and development at the introductory undergraduate level as part of a course on organismal biology. The series of lecture outlines is structured around the life cycle of rapid-cycling Brassica rapa (RCBr). The unit begins with three introductory lectures on general plant…

  5. Methylselenol, a selenium metabolite, induces cell cycle arrest in G1 phase and apoptosis via the extracellular-regulated kinase 1/2 pathway and other cancer signaling genes.

    Science.gov (United States)

    Zeng, Huawei; Wu, Min; Botnen, James H

    2009-09-01

    Methylselenol has been hypothesized to be a critical selenium (Se) metabolite for anticancer activity in vivo, and our previous study demonstrated that submicromolar methylselenol generated by incubating methionase with seleno-l-methionine inhibits the migration and invasive potential of HT1080 tumor cells. However, little is known about the association between cancer signal pathways and methylselenol's inhibition of tumor cell invasion. In this study, we demonstrated that methylselenol exposure inhibited cell growth and we used a cancer signal pathway-specific array containing 15 different signal transduction pathways involved in oncogenesis to study the effect of methylselenol on cellular signaling. Using real-time RT-PCR, we confirmed that cellular mRNA levels of cyclin-dependent kinase inhibitor 1C (CDKN1C), heme oxygenase 1, platelet/endothelial cell adhesion molecule, and PPARgamma genes were upregulated to 2.8- to 5.7-fold of the control. BCL2-related protein A1, hedgehog interacting protein, and p53 target zinc finger protein genes were downregulated to 26-52% of the control, because of methylselenol exposure. These genes are directly related to the regulation of cell cycle and apoptosis. Methylselenol increased apoptotic cells up to 3.4-fold of the control and inhibited the extracellular-regulated kinase 1/2 (ERK1/2) signaling and cellular myelocytomatosis oncogene (c-Myc) expression. Taken together, our studies identify 7 novel methylselenol responsive genes and demonstrate that methylselenol inhibits ERK1/2 pathway activation and c-Myc expression. The regulation of these genes is likely to play a key role in G1 cell cycle arrest and apoptosis, which may contribute to the inhibition of tumor cell invasion.

  6. Two Chitotriose-Specific Lectins Show Anti-Angiogenesis, Induces Caspase-9-Mediated Apoptosis and Early Arrest of Pancreatic Tumor Cell Cycle.

    Directory of Open Access Journals (Sweden)

    Ruby Singh

    Full Text Available The antiproliferative activity of two chito-specific agglutinins purified from Benincasa hispida (BhL and Datura innoxia (DiL9 of different plant family origin was investigated on various cancer cell lines. Both lectins showed chitotriose specificity, by inhibiting lectin hemagglutinating activity. On further studies, it was revealed that these agglutinins caused remarkable concentration-dependent antiproliferative effect on human pancreatic cancerous cells but not on the normal human umbilical vein endothelial cells even at higher doses determined using MTT assay. The GI50 values were approximately 8.4 μg ml(-1 (0.247 μM and 142 μg ml(-1 (14.8 μM for BhL and DiL9, respectively, against PANC-1 cells. The growth inhibitory effect of these lectins on pancreatic cancer cells were shown to be a consequence of lectin cell surface binding and triggering G0/G1 arrest, mitochondrial membrane depolarization, sustained increase of the intracellular calcium release and the apoptotic signal is amplified by activation of caspases executing cell death. Interestingly, these lectins also showed anti-angiogenic activity by disrupting the endothelial tubulogenesis. Therefore, we report for the first time two chito-specific lectins specifically binding to tumor glycans; they can be considered to be a class of molecules with antitumor activity against pancreatic cancer cells mediated through caspase dependent mitochondrial apoptotic pathway.

  7. Inhibition effect of proteasome inhibitor MG132 combined with X-ray irradiation on cell growth, metastasis and cycle distribution of human lung adenocarcinoma cells

    International Nuclear Information System (INIS)

    Liu Jing; Tang Yiting; Zhou Jundong; Zhang Shuyu; Cao Han; Wu Jinchang; Luo Judong; Chen Guanglie; Cao Jianping

    2014-01-01

    Objective: To study the effects of proteasome inhibitor MG132 on the growth, metastasis, and cell cycle distribution of human lung adenocarcinoma cells A549 irradiated by X-rays. Methods: After treatment of MG132 and irradiation,cell proliferation was detected by MTT assay. Survival was measured by clonogenic assay. Cell migration ability was detected by the Scratch migration assay. Cell invasion ability was detected by transwell migration assay. Cell cycle distribution were analyzed by flow cytometry assay. Protein expression was detected by Western blot assay. Results: MG132 alone inhibited cell growth in a dose-and time-dependent manner. MG132 in combination with radiation significantly suppressed the growth, migration and invasion of A549 cells compared to the control (F =554.78, 954.64, P<0.01). MG132 enhanced radiation-induced G 1 -arrest (t =4.44, 12.41, 3.52, 6.72, P<0.05). The G 1 cell cycle distribution rate of MG132 plus RT group was increased to (71.05 ± 4.17)%. The expressions of MMP-2, MMP-9 and Cyclin D1 were significantly suppressed by MG132 in combination with radiation, while the expression of P53 was up-regulated. Conclusions: MG132 inhibits cell growth, migration and invasion ability, and induces G 1 cell cycle arrest of A549 cells treated with MG132 in combination with radiation, in which the down-regulation of MMPs and Cyclin D1 and up-regulation of P53 may be involved. (authors)

  8. 6-Nitro-2-(3-hydroxypropyl-1H-benz[de]isoquinoline-1,3-dione, a potent antitumor agent, induces cell cycle arrest and apoptosis

    Directory of Open Access Journals (Sweden)

    Singh Shashank K

    2010-12-01

    Full Text Available Abstract Background Anticancer activities of several substituted naphthalimides (1H-benz[de]isoquinoline-1,3-diones are well documented. Some of them have undergone Phase I-II clinical trials. Presently a series of ten N-(hydroxyalkyl naphthalimides (compounds 1a-j were evaluated as antitumor agents. Methods Compounds 1a-j were initially screened in MOLT-4, HL-60 and U-937 human tumor cell lines and results were compared with established clinical drugs. Cytotoxicities of compounds 1d and 1i were further evaluated in a battery of human tumor cell lines and in normal human peripheral blood mononuclear cells. Cell cycle analysis of compound 1i treated MOLT-4 cells was studied by flow cytometry. Its apoptosis inducing effect was carried out in MOLT-4 and HL-60 cells by flow cytometry using annexin V-FITC/PI double staining method. The activities of caspase-3 and caspase-6 in MOLT-4 cells following incubation with compound 1i were measured at different time intervals. Morphology of the MOLT-4 cells after treatment with 1i was examined under light microscope and transmission electron microscope. 3H-Thymidine and 3H-uridine incorporation in S-180 cells in vitro following treatment with 8 μM concentration of compounds 1d and 1i were studied. Results 6-Nitro-2-(3-hydroxypropyl-1H-benz[de]isoquinoline-1,3-dione (compound 1i, has exhibited maximum activity as it induced significant cytotoxicity in 8 out of 13 cell lines employed. Interestingly it did not show any cytotoxicity against human PBMC (IC50 value 273 μM. Cell cycle analysis of compound 1i treated MOLT-4 cells demonstrated rise in sub-G1 fraction and concomitant accumulation of cells in S and G2/M phases, indicating up-regulation of apoptosis along with mitotic arrest and/or delay in exit of daughter cells from mitotic cycle respectively. Its apoptosis inducing effect was confirmed in flow cytometric study in MOLT-4 and the action was mediated by activation of both caspase 3 and 6. Light and

  9. Iodine-131 treatment of thyroid cancer cells leads to suppression of cell proliferation followed by induction of cell apoptosis and cell cycle arrest by regulation of B-cell translocation gene 2-mediated JNK/NF-κB pathways

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, L.M.; Pang, A.X., E-mail: zhaoliming515@126.com [Department of Nuclear Medicine, Linyi People' s Hospital, Linyi (China); Department of Urology, Linyi People' s Hospital, Linyi (China)

    2017-10-01

    Iodine-131 ({sup 131}I) is widely used for the treatment of thyroid-related diseases. This study aimed to investigate the expression of p53 and BTG2 genes following {sup 131}I therapy in thyroid cancer cell line SW579 and the possible underlying mechanism. SW579 human thyroid squamous carcinoma cells were cultured and treated with {sup 131}I. They were then assessed for {sup 131}I uptake, cell viability, apoptosis, cell cycle arrest, p53 expression, and BTG2 gene expression. SW579 cells were transfected with BTG2 siRNA, p53 siRNA and siNC and were then examined for the same aforementioned parameters. When treated with a JNK inhibitor of SP600125 and {sup 131}I or with a NF-kB inhibitor of BMS-345541 and {sup 131}I, non-transfected SW579 cells were assessed in JNK/NFkB pathways. It was observed that {sup 131}I significantly inhibited cell proliferation, promoted cell apoptosis and cell cycle arrest. Both BTG2 and p53 expression were enhanced in a dose-dependent manner. An increase in cell viability by up-regulation in Bcl2 gene, a decrease in apoptosis by enhanced CDK2 gene expression and a decrease in cell cycle arrest at G{sub 0}/G{sub 1} phase were also observed in SW579 cell lines transfected with silenced BTG2 gene. When treated with SP600125 and {sup 131}I, the non transfected SW579 cell lines significantly inhibited JNK pathway, NF-kB pathway and the expression of BTG2. However, when treated with BMS-345541 and {sup 131}I, only the NF-kB pathway was suppressed. {sup 131}I suppressed cell proliferation, induced cell apoptosis, and promoted cell cycle arrest of thyroid cancer cells by up-regulating B-cell translocation gene 2-mediated activation of JNK/NF--κB pathways. (author)

  10. Effect of berberine on cell cycle arrest and cell survival during cerebral ischemia and reperfusion and correlations with p53/cyclin D1 and PI3K/Akt.

    Science.gov (United States)

    Chai, Yu-Shuang; Hu, Jun; Lei, Fan; Wang, Yu-Gang; Yuan, Zhi-Yi; Lu, Xi; Wang, Xin-Pei; Du, Feng; Zhang, Dong; Xing, Dong-Ming; Du, Li-Jun

    2013-05-15

    Berberine acted as a natural medicine with multiple pharmacological activities. In the present study, we examined the effect of berberine against cerebral ischemia damage from cell cycle arrest and cell survival. Oxygen-glucose deprivation of PC12 cells and primary neurons, and carotid artery ligation in mice were used as in vitro and in vivo cerebral ischemia models. We found that the effect of berberine on cell cycle arrest during ischemia was mediated by decreased p53 and cyclin D1, increased phosphorylation of Bad (higher expression of p-Bad and higher ratio of p-Bad to Bad) and decreased cleavage of caspase 3. Meanwhile, berberine activated the PI3K/Akt pathway during the reperfusion, especially the phosphor-activation of Akt, to promote the cell survival. The neural protective effect of berberine was remained in the presence of inhibitor of mitogen-activated protein/extracellular signal-regulated kinase (MEK), but was suppressed by the inhibitors of PI3K and Akt. We demonstrated that berberine induced cell cycle arrest and cell survival to resist cerebral ischemia injury. Copyright © 2013 Elsevier B.V. All rights reserved.

  11. Fe3O4 nanoparticle loaded paclitaxel induce multiple myeloma apoptosis by cell cycle arrest and increase cleavage of caspases in vitro

    Science.gov (United States)

    Yang, Cuiping; He, Xiangfeng; Chen, Junsong; Chen, Dengyu; Liu, Yunjing; Xiong, Fei; Shi, Fangfang; Dou, Jun; Gu, Ning

    2013-08-01

    Multiple myeloma (MM) still remains an incurable disease in spite of extending the patient survival by new therapies. The hypothesis of cancer stem cells (CSCs) states that although chemotherapy kills most tumor cells, it is believed to leave a reservoir of CSCs that allows the tumor cell propagation. The objective of this research was to evaluate the therapeutic effect of new paclitaxel-Fe3O4 nanoparticles (PTX-NPs) with an average size range of 7.17 ± 1.31 nm on MM CSCs in vitro. The characteristics of CD138-CD34- cells, isolated from human MM RPMI 8226 and NCI-H929 cell lines by the magnetic associated cell sorting method, were identified by the assays of colony formation, cell proliferation, drug resistance, cell migration, and tumorigenicity in non-obese diabetic/severe combined immunodeficiency (NOD/SCID) mice, respectively. Inhibitory effects of PTX-NPs on CD138-CD34- cells were evaluated by a variety of assays in vitro. The results showed that the CD138-CD34- cells were capable of forming colonies, exhibited high proliferative and migratory ability, possessed a strong drug resistance, and had powerful tumorigenicity in NOD/SCID mice compared to non-CD138-CD34- cells. PTX-NPs significantly inhibited CD138- CD34- cell viability and invasive ability, and resulted in G0/G1 cell cycle arrest and apoptosis compared with PTX alone. We concluded that the CD138-CD34- phenotype cells might be CSCs in RPMI 8226 and NCI-H929 cell lines. PTX-NPs had an obvious inhibitory effect on MM CD138-CD34- CSCs. The findings may provide a guideline for PTX-NPs' treatment of MM CSCs in preclinical investigation.

  12. Fe{sub 3}O{sub 4} nanoparticle loaded paclitaxel induce multiple myeloma apoptosis by cell cycle arrest and increase cleavage of caspases in vitro

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Cuiping [Medical School, Southeast University, Department of Pathogenic Biology and Immunology (China); He, Xiangfeng [Affiliated Tumor Hospital of Nantong University, Department of Medical Oncology (China); Chen, Junsong; Chen, Dengyu; Liu, Yunjing [Medical School, Southeast University, Department of Pathogenic Biology and Immunology (China); Xiong, Fei [Southeast University, School of Biological Science and Medical Engineering (China); Shi, Fangfang [Zhongda Hospital, Southeast University, Department of Oncology (China); Dou, Jun, E-mail: njdoujun@yahoo.com.cn [Medical School, Southeast University, Department of Pathogenic Biology and Immunology (China); Gu, Ning, E-mail: guning@seu.edu.cn [Southeast University, School of Biological Science and Medical Engineering (China)

    2013-08-15

    Multiple myeloma (MM) still remains an incurable disease in spite of extending the patient survival by new therapies. The hypothesis of cancer stem cells (CSCs) states that although chemotherapy kills most tumor cells, it is believed to leave a reservoir of CSCs that allows the tumor cell propagation. The objective of this research was to evaluate the therapeutic effect of new paclitaxel-Fe{sub 3}O{sub 4} nanoparticles (PTX-NPs) with an average size range of 7.17 {+-} 1.31 nm on MM CSCs in vitro. The characteristics of CD138{sup -}CD34{sup -} cells, isolated from human MM RPMI 8226 and NCI-H929 cell lines by the magnetic associated cell sorting method, were identified by the assays of colony formation, cell proliferation, drug resistance, cell migration, and tumorigenicity in non-obese diabetic/severe combined immunodeficiency (NOD/SCID) mice, respectively. Inhibitory effects of PTX-NPs on CD138{sup -}CD34{sup -} cells were evaluated by a variety of assays in vitro. The results showed that the CD138{sup -}CD34{sup -} cells were capable of forming colonies, exhibited high proliferative and migratory ability, possessed a strong drug resistance, and had powerful tumorigenicity in NOD/SCID mice compared to non-CD138{sup -}CD34{sup -} cells. PTX-NPs significantly inhibited CD138{sup -} CD34{sup -} cell viability and invasive ability, and resulted in G0/G1 cell cycle arrest and apoptosis compared with PTX alone. We concluded that the CD138{sup -}CD34{sup -} phenotype cells might be CSCs in RPMI 8226 and NCI-H929 cell lines. PTX-NPs had an obvious inhibitory effect on MM CD138{sup -}CD34{sup -} CSCs. The findings may provide a guideline for PTX-NPs' treatment of MM CSCs in preclinical investigation.

  13. Interactions between Streptomyces californicus and Stachybotrys chartarum can induce apoptosis and cell cycle arrest in mouse RAW264.7 macrophages

    International Nuclear Information System (INIS)

    Penttinen, Piia; Pelkonen, Jukka; Huttunen, Kati; Toivola, Mika; Hirvonen, Maija-Riitta

    2005-01-01

    Exposure to complex mixtures of bacteria and fungi in moisture-damaged buildings is a potential cause of inflammatory related symptoms among occupants. The present study assessed interactions between two characteristic moldy house microbes Streptomyces californicus and Stachybotrys chartarum. Differences in cytotoxic and inflammatory responses in mouse (RAW264.7) macrophages were studied after exposure to the spores of co-cultivated microbes, the mixture of separately cultivated spores, and the spores of either of these microbes cultivated alone. The RAW264.7 cells were exposed to six doses (1 x 10 4 to 3 x 10 6 spores/ml) for 24 h, and the time course of the induced responses was evaluated after 4, 8, 16, and 24 h of exposure (1 x 10 6 spores/ml). The cytotoxic potential of the spores was characterized by the MTT test, DNA content analysis, and enzyme assay for caspase-3 activity. The production of cytokines (IL-1β, IL-6, IL-10, TNFα, and MIP2) was measured immunochemically and nitric oxide by the Griess method. Co-cultivation increased the ability of the spores to cause apoptosis by more than 4-fold and the proportion of RAW264.7 cells at the G 2 /M stage increased nearly 2-fold when compared to the response induced by the mixture of spores. In contrast, co-cultivation decreased significantly the ability of the spores to trigger the production of NO and IL-6 in RAW264.7 cells. In conclusion, these data suggest that co-culture of S. californicus and S. chartarum can result in microbial interactions that significantly potentiate the ability of the spores to cause apoptosis and cell cycle arrest in mammalian cells

  14. Fe3O4 nanoparticle loaded paclitaxel induce multiple myeloma apoptosis by cell cycle arrest and increase cleavage of caspases in vitro

    International Nuclear Information System (INIS)

    Yang, Cuiping; He, Xiangfeng; Chen, Junsong; Chen, Dengyu; Liu, Yunjing; Xiong, Fei; Shi, Fangfang; Dou, Jun; Gu, Ning

    2013-01-01

    Multiple myeloma (MM) still remains an incurable disease in spite of extending the patient survival by new therapies. The hypothesis of cancer stem cells (CSCs) states that although chemotherapy kills most tumor cells, it is believed to leave a reservoir of CSCs that allows the tumor cell propagation. The objective of this research was to evaluate the therapeutic effect of new paclitaxel-Fe 3 O 4 nanoparticles (PTX-NPs) with an average size range of 7.17 ± 1.31 nm on MM CSCs in vitro. The characteristics of CD138 − CD34 − cells, isolated from human MM RPMI 8226 and NCI-H929 cell lines by the magnetic associated cell sorting method, were identified by the assays of colony formation, cell proliferation, drug resistance, cell migration, and tumorigenicity in non-obese diabetic/severe combined immunodeficiency (NOD/SCID) mice, respectively. Inhibitory effects of PTX-NPs on CD138 − CD34 − cells were evaluated by a variety of assays in vitro. The results showed that the CD138 − CD34 − cells were capable of forming colonies, exhibited high proliferative and migratory ability, possessed a strong drug resistance, and had powerful tumorigenicity in NOD/SCID mice compared to non-CD138 − CD34 − cells. PTX-NPs significantly inhibited CD138 − CD34 − cell viability and invasive ability, and resulted in G0/G1 cell cycle arrest and apoptosis compared with PTX alone. We concluded that the CD138 − CD34 − phenotype cells might be CSCs in RPMI 8226 and NCI-H929 cell lines. PTX-NPs had an obvious inhibitory effect on MM CD138 − CD34 − CSCs. The findings may provide a guideline for PTX-NPs’ treatment of MM CSCs in preclinical investigation

  15. An antioxidant extract of tropical lichen, Parmotrema reticulatum, induces cell cycle arrest and apoptosis in breast carcinoma cell line MCF-7.

    Directory of Open Access Journals (Sweden)

    Nikhil Baban Ghate

    Full Text Available This report highlights the phytochemical analysis, antioxidant potential and anticancer activity against breast carcinoma of 70% methanolic extract of lichen, Parmotrema reticulatum (PRME. Phytochemical analysis of PRME confirms the presence of various phytoconstituents like alkaloids, carbohydrates, flavonoids, glycosides, phenols, saponins, tannins, anthraquinones, and ascorbic acid; among which alkaloids, phenols and flavonoids are found in abundant amount. High performance liquid chromatography (HPLC analysis of PRME revealed the presence of catechin, purpurin, tannic acid and reserpine. Antioxidant activity was evaluated by nine separate methods. PRME showed excellent hydroxyl and hypochlorous radical scavenging as well as moderate DPPH, superoxide, singlet oxygen, nitric oxide and peroxynitrite scavenging activity. Cytotoxicity of PRME was tested against breast carcinoma (MCF-7, lung carcinoma (A549 and normal lung fibroblast (WI-38 using WST-1 method. PRME was found cytotoxic against MCF-7 cells with an IC50 value 130.03 ± 3.11 µg/ml while negligible cytotoxicity was observed on A549 and WI-38 cells. Further flow cytometric study showed that PRME halted the MCF-7 cells in S and G2/M phases and induces apoptosis in dose as well as time dependent manner. Cell cycle arrest was associated with downregulation of cyclin B1, Cdk-2 and Cdc25C as well as slight decrease in the expression of Cdk-1 and cyclin A1 with subsequent upregulation of p53 and p21. Moreover PRME induced Bax and inhibited Bcl-2 expression, which results in increasing Bax/Bcl-2 ratio and activation of caspase cascade. This ultimately leads to PARP degradation and induces apoptosis in MCF-7 cells. It can be hypothesised from the current study that the antioxidant and anticancer potential of the PRME may reside in the phytoconstitutents present in it and therefore, PRME may be used as a possible source of natural antioxidant that may be developed to an anticancer agent.

  16. Prolonged early G(1) arrest by selective CDK4/CDK6 inhibition sensitizes myeloma cells to cytotoxic killing through cell cycle-coupled loss of IRF4.

    Science.gov (United States)

    Huang, Xiangao; Di Liberto, Maurizio; Jayabalan, David; Liang, Jun; Ely, Scott; Bretz, Jamieson; Shaffer, Arthur L; Louie, Tracey; Chen, Isan; Randolph, Sophia; Hahn, William C; Staudt, Louis M; Niesvizky, Ruben; Moore, Malcolm A S; Chen-Kiang, Selina

    2012-08-02

    Dysregulation of cyclin-dependent kinase 4 (CDK4) and CDK6 by gain of function or loss of inhibition is common in human cancer, including multiple myeloma, but success in targeting CDK with broad-spectrum inhibitors has been modest. By selective and reversible inhibition of CDK4/CDK6, we have developed a strategy to both inhibit proliferation and enhance cytotoxic killing of cancer cells. We show that induction of prolonged early-G(1) arrest (pG1) by CDK4/CDK6 inhibition halts gene expression in early-G(1) and prevents expression of genes programmed for other cell-cycle phases. Removal of the early-G(1) block leads to S-phase synchronization (pG1-S) but fails to completely restore scheduled gene expression. Consequently, the IRF4 protein required to protect myeloma cells from apoptosis is markedly reduced in pG1 and further in pG1-S in response to cytotoxic agents, such as the proteasome inhibitor bortezomib. The coordinated loss of IRF4 and gain of Bim sensitize myeloma tumor cells to bortezomib-induced apoptosis in pG1 in the absence of Noxa and more profoundly in pG1-S in cooperation with Noxa in vitro. Induction of pG1 and pG1-S by reversible CDK4/CDK6 inhibition further augments tumor-specific bortezomib killing in myeloma xenografts. Reversible inhibition of CDK4/CDK6 in sequential combination therapy thus represents a novel mechanism-based cancer therapy.

  17. A directed RNAi screen based on larval growth arrest reveals new modifiers of C. elegans insulin signaling.

    Directory of Open Access Journals (Sweden)

    Ola Billing

    Full Text Available Genes regulating Caenorhabditis elegans insulin/IGF signaling (IIS have largely been identified on the basis of their involvement in dauer development or longevity. A third IIS phenotype is the first larval stage (L1 diapause, which is also influenced by asna-1, a regulator of DAF-28/insulin secretion. We reasoned that new regulators of IIS strength might be identified in screens based on the L1 diapause and the asna-1 phenotype. Eighty- six genes were selected for analysis by virtue of their predicted interaction with ASNA-1 and screened for asna-1-like larval arrest. ykt-6, mrps-2, mrps-10 and mrpl-43 were identified as genes which, when inactivated, caused larval arrest without any associated feeding defects. Several tests indicated that IIS strength was weaker and that insulin secretion was defective in these animals. This study highlights the role of the Golgi network and the mitochondria in insulin secretion and provides a new list of genes that modulate IIS in C. elegans.

  18. Dendrobium candidum inhibits MCF-7 cells proliferation by inducing cell cycle arrest at G2/M phase and regulating key biomarkers

    Directory of Open Access Journals (Sweden)

    Sun J

    2015-12-01

    <0.05. The general apoptosis biomarker, Bcl-2, was significantly decreased and the Bax was significantly increased compared to the control group (P<0.05. In contrast to that in MCF-7, D. candidum does not affect cell proliferation at any concentration and any time points in normal breast epithelial cells, MCF10A cells. Conclusion: D. candidum could decrease the cell viability of MCF-7 cells by inducing cell cycle arrest at the G2/M phase and regulating the key biomarkers in breast cancer cells. Keywords: breast cancer, D. candidum, proliferation, biomarker, inhibition

  19. Depletion of intrinsic expression of Interleukin-8 in prostate cancer cells causes cell cycle arrest, spontaneous apoptosis and increases the efficacy of chemotherapeutic drugs

    Directory of Open Access Journals (Sweden)

    Lokeshwar Bal L

    2009-07-01

    Full Text Available Abstract Background The progression of all cancers is characterized by increased-cell proliferation and decreased-apoptosis. The androgen-independent prostate cancer (AIPC is the terminal stage of the disease. Many chemokines and cytokines are suspects to cause this increased tumor cell survival that ultimately leads to resistance to therapy and demise of the host. The AIPC cells, but not androgen-responsive cells, constitutively express abundant amount of the pro-inflammatory chemokine, Interleukin-8 (IL-8. The mechanism of IL-8 mediated survival and therapeutic resistance in AIPC cells is unclear at present. The purpose of this report is to show the pervasive role of IL-8 in malignant progression of androgen-independent prostate cancer (AIPC and to provide a potential new therapeutic avenue, using RNA interference. Results The functional consequence of IL-8 depletion in AIPC cells was investigated by RNA interference in two IL-8 secreting AIPC cell lines, PC-3 and DU145. The non-IL-8 secreting LNCaP and LAPC-4 cells served as controls. Cells were transfected with RISC-free siRNA (control or validated-pool of IL-8 siRNA. Transfection with 50 nM IL-8 siRNA caused >95% depletion of IL-8 mRNA and >92% decrease in IL-8 protein. This reduction in IL-8 led to cell cycle arrest at G1/S boundary and decreases in cell cycle-regulated proteins: Cyclin D1 and Cyclin B1 (both decreased >50% and inhibition of ERK1/2 activity by >50%. Further, the spontaneous apoptosis was increased by >43% in IL-8 depleted cells, evidenced by increases in caspase-9 activation and cleaved-PARP. IL-8 depletion caused significant decreases in anti-apoptotic proteins, BCL-2, BCL-xL due to decrease in both mRNA and post-translational stability, and increased levels of pro-apoptotic BAX and BAD proteins. More significantly, depletion of intracellular IL-8 increased the cytotoxic activity of multiple chemotherapeutic drugs. Specifically, the cytotoxicity of Docetaxel

  20. 4beta-Hydroxywithanolide E from Physalis peruviana (golden berry) inhibits growth of human lung cancer cells through DNA damage, apoptosis and G2/M arrest.

    Science.gov (United States)

    Yen, Ching-Yu; Chiu, Chien-Chih; Chang, Fang-Rong; Chen, Jeff Yi-Fu; Hwang, Chi-Ching; Hseu, You-Cheng; Yang, Hsin-Ling; Lee, Alan Yueh-Luen; Tsai, Ming-Tz; Guo, Zong-Lun; Cheng, Yu-Shan; Liu, Yin-Chang; Lan, Yu-Hsuan; Chang, Yu-Ching; Ko, Ying-Chin; Chang, Hsueh-Wei; Wu, Yang-Chang

    2010-02-18

    The crude extract of the fruit bearing plant, Physalis peruviana (golden berry), demonstrated anti-hepatoma and anti-inflammatory activities. However, the cellular mechanism involved in this process is still unknown. Herein, we isolated the main pure compound, 4beta-Hydroxywithanolide (4betaHWE) derived from golden berries, and investigated its antiproliferative effect on a human lung cancer cell line (H1299) using survival, cell cycle, and apoptosis analyses. An alkaline comet-nuclear extract (NE) assay was used to evaluate the DNA damage due to the drug. It was shown that DNA damage was significantly induced by 1, 5, and 10 microg/mL 4betaHWE for 2 h in a dose-dependent manner (p < 0.005). A trypan blue exclusion assay showed that the proliferation of cells was inhibited by 4betaHWE in both dose- and time-dependent manners (p < 0.05 and 0.001 for 24 and 48 h, respectively). The half maximal inhibitory concentrations (IC50) of 4betaHWE in H1299 cells for 24 and 48 h were 0.6 and 0.71 microg/mL, respectively, suggesting it could be a potential therapeutic agent against lung cancer. In a flow cytometric analysis, 4betaHWE produced cell cycle perturbation in the form of sub-G1 accumulation and slight arrest at the G2/M phase with 1 microg/mL for 12 and 24 h, respectively. Using flow cytometric and annexin V/propidium iodide immunofluorescence double-staining techniques, these phenomena were proven to be apoptosis and complete G2/M arrest for H1299 cells treated with 5 microg/mL for 24 h. In this study, we demonstrated that golden berry-derived 4betaHWE is a potential DNA-damaging and chemotherapeutic agent against lung cancer.

  1. 4β-Hydroxywithanolide E from Physalis peruviana (golden berry) inhibits growth of human lung cancer cells through DNA damage, apoptosis and G2/M arrest

    International Nuclear Information System (INIS)

    Yen, Ching-Yu; Guo, Zong-Lun; Cheng, Yu-Shan; Liu, Yin-Chang; Lan, Yu-Hsuan; Chang, Yu-Ching; Ko, Ying-Chin; Chang, Hsueh-Wei; Wu, Yang-Chang; Chiu, Chien-Chih; Chang, Fang-Rong; Chen, Jeff Yi-Fu; Hwang, Chi-Ching; Hseu, You-Cheng; Yang, Hsin-Ling; Lee, Alan Yueh-Luen; Tsai, Ming-Tz

    2010-01-01

    The crude extract of the fruit bearing plant, Physalis peruviana (golden berry), demonstrated anti-hepatoma and anti-inflammatory activities. However, the cellular mechanism involved in this process is still unknown. Herein, we isolated the main pure compound, 4β-Hydroxywithanolide (4βHWE) derived from golden berries, and investigated its antiproliferative effect on a human lung cancer cell line (H1299) using survival, cell cycle, and apoptosis analyses. An alkaline comet-nuclear extract (NE) assay was used to evaluate the DNA damage due to the drug. It was shown that DNA damage was significantly induced by 1, 5, and 10 μg/mL 4βHWE for 2 h in a dose-dependent manner (p < 0.005). A trypan blue exclusion assay showed that the proliferation of cells was inhibited by 4βHWE in both dose- and time-dependent manners (p < 0.05 and 0.001 for 24 and 48 h, respectively). The half maximal inhibitory concentrations (IC 50 ) of 4βHWE in H1299 cells for 24 and 48 h were 0.6 and 0.71 μg/mL, respectively, suggesting it could be a potential therapeutic agent against lung cancer. In a flow cytometric analysis, 4βHWE produced cell cycle perturbation in the form of sub-G 1 accumulation and slight arrest at the G 2 /M phase with 1 μg/mL for 12 and 24 h, respectively. Using flow cytometric and annexin V/propidium iodide immunofluorescence double-staining techniques, these phenomena were proven to be apoptosis and complete G 2 /M arrest for H1299 cells treated with 5 μg/mL for 24 h. In this study, we demonstrated that golden berry-derived 4βHWE is a potential DNA-damaging and chemotherapeutic agent against lung cancer

  2. 4β-Hydroxywithanolide E from Physalis peruviana (golden berry) inhibits growth of human lung cancer cells through DNA damage, apoptosis and G2/M arrest

    Science.gov (United States)

    2010-01-01

    Background The crude extract of the fruit bearing plant, Physalis peruviana (golden berry), demonstrated anti-hepatoma and anti-inflammatory activities. However, the cellular mechanism involved in this process is still unknown. Methods Herein, we isolated the main pure compound, 4β-Hydroxywithanolide (4βHWE) derived from golden berries, and investigated its antiproliferative effect on a human lung cancer cell line (H1299) using survival, cell cycle, and apoptosis analyses. An alkaline comet-nuclear extract (NE) assay was used to evaluate the DNA damage due to the drug. Results It was shown that DNA damage was significantly induced by 1, 5, and 10 μg/mL 4βHWE for 2 h in a dose-dependent manner (p < 0.005). A trypan blue exclusion assay showed that the proliferation of cells was inhibited by 4βHWE in both dose- and time-dependent manners (p < 0.05 and 0.001 for 24 and 48 h, respectively). The half maximal inhibitory concentrations (IC50) of 4βHWE in H1299 cells for 24 and 48 h were 0.6 and 0.71 μg/mL, respectively, suggesting it could be a potential therapeutic agent against lung cancer. In a flow cytometric analysis, 4βHWE produced cell cycle perturbation in the form of sub-G1 accumulation and slight arrest at the G2/M phase with 1 μg/mL for 12 and 24 h, respectively. Using flow cytometric and annexin V/propidium iodide immunofluorescence double-staining techniques, these phenomena were proven to be apoptosis and complete G2/M arrest for H1299 cells treated with 5 μg/mL for 24 h. Conclusions In this study, we demonstrated that golden berry-derived 4βHWE is a potential DNA-damaging and chemotherapeutic agent against lung cancer. PMID:20167063

  3. 4β-Hydroxywithanolide E from Physalis peruviana (golden berry inhibits growth of human lung cancer cells through DNA damage, apoptosis and G2/M arrest

    Directory of Open Access Journals (Sweden)

    Guo Zong-Lun

    2010-02-01

    Full Text Available Abstract Background The crude extract of the fruit bearing plant, Physalis peruviana (golden berry, demonstrated anti-hepatoma and anti-inflammatory activities. However, the cellular mechanism involved in this process is still unknown. Methods Herein, we isolated the main pure compound, 4β-Hydroxywithanolide (4βHWE derived from golden berries, and investigated its antiproliferative effect on a human lung cancer cell line (H1299 using survival, cell cycle, and apoptosis analyses. An alkaline comet-nuclear extract (NE assay was used to evaluate the DNA damage due to the drug. Results It was shown that DNA damage was significantly induced by 1, 5, and 10 μg/mL 4βHWE for 2 h in a dose-dependent manner (p p 50 of 4βHWE in H1299 cells for 24 and 48 h were 0.6 and 0.71 μg/mL, respectively, suggesting it could be a potential therapeutic agent against lung cancer. In a flow cytometric analysis, 4βHWE produced cell cycle perturbation in the form of sub-G1 accumulation and slight arrest at the G2/M phase with 1 μg/mL for 12 and 24 h, respectively. Using flow cytometric and annexin V/propidium iodide immunofluorescence double-staining techniques, these phenomena were proven to be apoptosis and complete G2/M arrest for H1299 cells treated with 5 μg/mL for 24 h. Conclusions In this study, we demonstrated that golden berry-derived 4βHWE is a potential DNA-damaging and chemotherapeutic agent against lung cancer.

  4. Alternative fuel cycle options: performance characteristics and impact on nuclear power growth potential

    International Nuclear Information System (INIS)

    Chang, Y.I.; Till, C.E.; Rudolph, R.R.; Deen, J.R.; King, M.J.

    1977-09-01

    The fuel utilization characteristics for LWR, SSCR, CANDU and LMFBR reactor concepts are quantified for various fuel cycle options, including once-through cycles, thorium cycles, and denatured cycles. The implications of various alternative reactor deployment strategies on the long-term nuclear power growth potential are then quantified in terms of the maximum nuclear capacity that can be achieved and the growth pattern over time, subject to the constraint of a fixed uranium-resource base. The overall objective of this study is to shed light on any large differences in the long-term potential that exist between various alternative reactor/fuel cycle deployment strategies

  5. Beta-mangostin from Cratoxylum arborescens activates the intrinsic apoptosis pathway through reactive oxygen species with downregulation of the HSP70 gene in the HL60 cells associated with a G0/G1 cell-cycle arrest.

    Science.gov (United States)

    Omer, Fatima Abdelmutaal Ahmed; Hashim, Najihah Binti Mohd; Ibrahim, Mohamed Yousif; Dehghan, Firouzeh; Yahayu, Maizatulakmal; Karimian, Hamed; Salim, Landa Zeenelabdin Ali; Mohan, Syam

    2017-11-01

    Xanthones are phytochemical compounds found in a number of fruits and vegetables. Characteristically, they are noted to be made of diverse properties based on their biological, biochemical, and pharmacological actions. Accordingly, the apoptosis mechanisms induced by beta-mangostin, a xanthone compound isolated from Cratoxylum arborescens in the human promyelocytic leukemia cell line (HL60) in vitro, were examined in this study. The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay was done to estimate the cytotoxicity effect of β-mangostin on the HL60 cell line. Acridine orange/propidium iodide and Hoechst 33342 dyes and Annexin V tests were conducted to detect the apoptosis features. Caspase-3 and caspase-9 activities; reactive oxygen species; real-time polymerase chain reaction for Bcl-2, Bax, caspase-3, and caspase-9 Hsp70 genes; and western blot for p53, cytochrome c, and pro- and cleavage-caspase-3 and caspase-9 were assessed to examine the apoptosis mechanism. Cell-cycle analysis conducted revealed that β-mangostin inhibited the growth of HL60 at 58 µM in 24 h. The administration of β-mangostin with HL60 caused cell morphological changes related to apoptosis which increased the number of early and late apoptotic cells. The β-mangostin-catalyzed apoptosis action through caspase-3, caspase-7, and caspase-9 activation overproduced reactive oxygen species which downregulated the expression of antiapoptotic genes Bcl-2 and HSP70. Conversely, the expression of the apoptotic genes Bax, caspase-3, and caspase-9 were upregulated. Meanwhile, at the protein level, β-mangostin activated the formation of cleaved caspase-3 and caspase-9 and also upregulated the p53. β-mangostin arrested the cell cycle at the G 0 /G 1 phase. Overall, the results for β-mangostin showed an antiproliferative effect in HL60 via stopping the cell cycle at the G 0 /G 1 phase and prompted the intrinsic apoptosis pathway.

  6. Alisertib induces cell cycle arrest and autophagy and suppresses epithelial-to-mesenchymal transition involving PI3K/Akt/mTOR and sirtuin 1-mediated signaling pathways in human pancreatic cancer cells

    Directory of Open Access Journals (Sweden)

    Wang F

    2015-01-01

    Full Text Available Feng Wang,1,2 Hai Li,3 Xiao-Gang Yan,4 Zhi-Wei Zhou,2 Zhi-Gang Yi,5 Zhi-Xu He,6 Shu-Ting Pan,7 Yin-Xue Yang,3 Zuo-Zheng Wang,1 Xueji Zhang,8 Tianxing Yang,9 Jia-Xuan Qiu,7 Shu-Feng Zhou21Department of Hepatobiliary Surgery, General Hospital, Ningxia Medical University, Yinchuan, People’s Republic of China; 2Department of Pharmaceutical Sciences, College of Pharmacy, University of South Florida, Tampa, FL, USA; 3Department of Colorectal Surgery, General Hospital, Ningxia Medical University, 4Department of Oncological Surgery, The First People’s Hospital of Yinchuan, 5Department of General Surgery, Changqing Yangehu Hospital, Yinchuan, 6Guizhou Provincial Key Laboratory for Regenerative Medicine, Stem Cell and Tissue Engineering Research Center and Sino-US Joint Laboratory for Medical Sciences, Guiyang Medical University, Guiyang, 7Department of Oral and Maxillofacial Surgery, The First Affiliated Hospital of Nanchang University, Nanchang, 8Research Center for Bioengineering and Sensing Technology, University of Science and Technology Beijing, Beijing, People’s Republic of China; 9Department of Internal Medicine, University of Utah and Salt Lake Veterans Affairs Medical Center, Salt Lake City, UT, USAAbstract: Pancreatic cancer is the most aggressive cancer worldwide with poor response to current therapeutics. Alisertib (ALS, a potent and selective Aurora kinase A inhibitor, exhibits potent anticancer effects in preclinical and clinical studies; however, the effect and underlying mechanism of ALS in the pancreatic cancer treatment remain elusive. This study aimed to examine the effects of ALS on cell growth, autophagy, and epithelial-to-mesenchymal transition (EMT and to delineate the possible molecular mechanisms in human pancreatic cancer PANC-1 and BxPC-3 cells. The results showed that ALS exerted potent cell growth inhibitory, pro-autophagic, and EMT-suppressing effects in PANC-1 and BxPC-3 cells. ALS remarkably arrested PANC-1 and Bx

  7. Diacerein retards cell growth of chondrosarcoma cells at the G2/M cell cycle checkpoint via cyclin B1/CDK1 and CDK2 downregulation

    International Nuclear Information System (INIS)

    Lohberger, Birgit; Leithner, Andreas; Stuendl, Nicole; Kaltenegger, Heike; Kullich, Werner; Steinecker-Frohnwieser, Bibiane

    2015-01-01

    Chondrosarcoma is characterized for its lack of response to conventional cytotoxic chemotherapy, propensity for developing lung metastases, and low rates of survival. Research within the field of development and expansion of new treatment options for unresectable or metastatic diseases is of particular priority. Diacerein, a symptomatic slow acting drug in osteoarthritis (SYSADOA), implicates a therapeutic benefit for the treatment of chondrosarcoma by an antitumor activity. After treatment with diacerein the growth behaviour of the cells was analyzed with the xCELLigence system and MTS assay. Cell cycle was examined using flow cytometric analysis, RT-PCR, and western blot analysis of specific checkpoint regulators. The status for phosophorylation of mitogen-activated protein kinases (MAPKs) was analyzed with a proteome profiler assay. In addition, the possible impact of diacerein on apoptosis was investigated using cleaved caspase 3 and Annexin V/PI flow cytometric analysis. Diacerein decreased the cell viability and the cell proliferation in two different chondrosarcoma cell lines in a dose dependent manner. Flow cytometric analysis showed a classical G2/M arrest. mRNA and protein analysis revealed that diacerein induced a down-regulation of the cyclin B1-CDK1 complex and a reduction in CDK2 expression. Furthermore, diacerein treatment increased the phosphorylation of p38α and p38β MAPKs, and Akt1, Akt2, and Akt 3 in SW-1353, whereas in Cal-78 the opposite effect has been demonstrated. These observations accordingly to our cell cycle flow cytometric analysis and protein expression data may explain the G2/M phase arrest. In addition, no apoptotic induction after diacerein treatment, neither in the Cal-78 nor in the SW-1353 cell line was observed. Our results demonstrate for the first time that the SYSADOA diacerein decreased the viability of human chondrosarcoma cells and induces G2/M cell cycle arrest by CDK1/cyclin B1 down-regulation

  8. Alopecia of IFN-gamma knockout mouse as a model for disturbance of the hair cycle: a unique arrest of the hair cycle at the anagen phase accompanied by mitosis.

    Science.gov (United States)

    Hirota, Ryuichiro; Tajima, Sadao; Yoneda, Yukio; Tamayama, Takumi; Watanabe, Masahito; Ueda, Kouichi; Kubota, Takahiro; Yoshida, Ryotaro

    2002-09-01

    Interferon-gamma(-/-) (IFN-gamma(-/-)) and IFN-gamma(+/+) C57BL/6 mice (3 weeks of age) completed the production of morphogenesis-derived hair. Around 6 weeks of age, however, most of the IFN-gamma(-/-) but none of the IFN-gamma(+/+) mice began to lose hairs in the dorsal and occipital areas in the absence of inflammatory reactions, and the alopecia was sustained for at least several 10-week periods of observation. A single subcutaneous injection of IFN-gamma to IFN-gamma(-/-) mice at 3, but not 4, 5, or 8 weeks of age could protect all the mice from alopecia, revealing that the lack of IFN-gamma around 3 weeks of age is directly responsible for the alopecia. Histologic features showed that the hair follicles of the IFN-gamma(+/+) mice passed through the anagen (4-5 weeks of age) and catagen/telogen ( approximately 6 weeks of age) phases, whereas those of IFN-gamma(-/-) mice (5 weeks of age or older) stayed in the anagen phase. TUNEL and bromodeoxyuridine experiments suggested that an arrest with unlimited DNA synthesis of the hair cycle in the anagen phase by the lack of IFN-gamma-dependent apoptosis in the midfollicle region and diffuse shedding of previously formed hair induced alopecia in IFN-gamma(-/-) mice.

  9. Isotopomer profiling of Leishmania mexicana promastigotes reveals important roles for succinate fermentation and aspartate uptake in tricarboxylic acid cycle (TCA) anaplerosis, glutamate synthesis, and growth.

    Science.gov (United States)

    Saunders, Eleanor C; Ng, William W; Chambers, Jennifer M; Ng, Milica; Naderer, Thomas; Krömer, Jens O; Likic, Vladimir A; McConville, Malcolm J

    2011-08-05

    Leishmania parasites proliferate within nutritionally complex niches in their sandfly vector and mammalian hosts. However, the extent to which these parasites utilize different carbon sources remains poorly defined. In this study, we have followed the incorporation of various (13)C-labeled carbon sources into the intracellular and secreted metabolites of Leishmania mexicana promastigotes using gas chromatography-mass spectrometry and (13)C NMR. [U-(13)C]Glucose was rapidly incorporated into intermediates in glycolysis, the pentose phosphate pathway, and the cytoplasmic carbohydrate reserve material, mannogen. Enzymes involved in the upper glycolytic pathway are sequestered within glycosomes, and the ATP and NAD(+) consumed by these reactions were primarily regenerated by the fermentation of phosphoenolpyruvate to succinate (glycosomal succinate fermentation). The initiating enzyme in this pathway, phosphoenolpyruvate carboxykinase, was exclusively localized to the glycosome. Although some of the glycosomal succinate was secreted, most of the C4 dicarboxylic acids generated during succinate fermentation were further catabolized in the TCA cycle. A high rate of TCA cycle anaplerosis was further suggested by measurement of [U-(13)C]aspartate and [U-(13)C]alanine uptake and catabolism. TCA cycle anaplerosis is apparently needed to sustain glutamate production under standard culture conditions. Specifically, inhibition of mitochondrial aconitase with sodium fluoroacetate resulted in the rapid depletion of intracellular glutamate pools and growth arrest. Addition of high concentrations of exogenous glutamate alleviated this growth arrest. These findings suggest that glycosomal and mitochondrial metabolism in Leishmania promastigotes is tightly coupled and that, in contrast to the situation in some other trypanosomatid parasites, the TCA cycle has crucial anabolic functions.

  10. Fuel cycle strategies for growth of nuclear power in India

    International Nuclear Information System (INIS)

    Purushotham, D.S.C.; Balu, K.

    2002-01-01

    Nuclear power has been identified as an essential component to meet the growing energy demand of India. The three stage fuel cycle strategy to achieve this with the available resources envisages the use of natural uranium in PHWRs in the first stage, the plutonium-uranium/plutonium-thorium cycles in Fast reactors/Advanced HWRs in the second stage, followed by exploitation of essentially U233 in the third stage. The technologies necessary for this programme, mainly through the back-end of the fuel cycle including reprocessing, waste management and recycle of Pu have been developed accordingly, as a direct result of the closed fuel cycle policy followed by us from the very beginning. This paper addresses the considerations involved in several activities taken up in our programme, their current status and plans for the future. (author)

  11. Organizational Growth and Change: The Life Cycle of a Community Mental Health Center.

    Science.gov (United States)

    Messal, Judith L.

    1980-01-01

    Organizations go through life cycles that affect their behavior. Growth models often relate to leadership. In a study of one mental health center's development, growth is related to funding. If funding remains diversified and productivity is kept high, growth of a mature organization remains manageable. (JAC)

  12. Long Term Exposure to Polyphenols of Artichoke (Cynara scolymus L.) Exerts Induction of Senescence Driven Growth Arrest in the MDA-MB231 Human Breast Cancer Cell Line.

    Science.gov (United States)

    Mileo, Anna Maria; Di Venere, Donato; Abbruzzese, Claudia; Miccadei, Stefania

    2015-01-01

    Polyphenolic extracts from the edible part of artichoke (Cynara scolymus L.) have been shown to be potential chemopreventive and anticancer dietary compounds. High doses of polyphenolic extracts (AEs) induce apoptosis and decrease the invasive potential of the human breast cancer cell line, MDA-MB231. However, the molecular mechanism underlying AEs antiproliferative effects is not completely understood. We demonstrate that chronic and low doses of AEs treatment at sublethal concentrations suppress human breast cancer cell growth via a caspases-independent mechanism. Furthermore, AEs exposure induces a significant increase of senescence-associated β-galactosidase (SA-β-gal) staining and upregulation of tumour suppressor genes, p16(INK4a) and p21(Cip1/Waf1) in MDA-MB231 cells. AEs treatment leads to epigenetic alterations in cancer cells, modulating DNA hypomethylation and lysine acetylation levels in total proteins. Cell growth arrest correlates with increased reactive oxygen species (ROS) production in AEs treated breast cancer cells. Inhibition of ROS generation by N-acetylcysteine (NAC) attenuates the antiproliferative effect. These findings demonstrate that chronic AEs treatment inhibits breast cancer cell growth via the induction of premature senescence through epigenetic and ROS-mediated mechanisms. Our results suggest that artichoke polyphenols could be a promising dietary tool either in cancer chemoprevention or/and in cancer treatment as a nonconventional, adjuvant therapy.

  13. Using quantitative PCR to Identify Kinesin-3 Genes that are Upregulated During Growth Arrest in MouseNIH3T3 Cells

    DEFF Research Database (Denmark)

    Thorsteinsson, Rikke; Christensen, Søren Tvorup; Pedersen, Lotte Bang

    2009-01-01

    Most cells in our body form a single primary cilium when entering growth arrest. During the past decade, a number of studies have revealed a key role for primary cilia in coordinating a variety of signaling pathways that control important cellular and developmental processes. Consequently, signif...

  14. The Dietary Flavonoid Fisetin Causes Cell Cycle Arrest, Caspase-Dependent Apoptosis, and Enhanced Cytotoxicity of Chemotherapeutic Drugs in Triple-Negative Breast Cancer Cells.

    Science.gov (United States)

    Smith, Matthew L; Murphy, Kaylee; Doucette, Carolyn D; Greenshields, Anna L; Hoskin, David W

    2016-08-01

    Fisetin (3,3',4',7-tetrahydroxyflavone), a flavonoid found in a number of fruits and vegetables, has diverse biological activities, including cytotoxic effects on cancer cells. In this study, we investigated the effect of fisetin on triple-negative breast cancer (TNBC) cells. TNBC has a poorer prognosis than other types of breast cancer and treatment options for this disease are limited. Fisetin inhibited the growth of MDA-MB-468 and MDA-MB-231 TNBC cells, as well as their ability to form colonies, without substantially affecting the growth of non-malignant cells. In addition, fisetin inhibited the growth of estrogen receptor-bearing MCF-7 breast cancer cells and human epidermal growth factor receptor 2-overexpressing SK-BR-3 breast cancer cells. Fisetin inhibited TNBC cell division and induced apoptosis, which was associated with mitochondrial membrane permeabilization and the activation of caspase-9 and caspase-8, as well as the cleavage of poly(ADP-ribose) polymerase-1. Induction of caspase-dependent apoptosis by fisetin was confirmed by reduced killing of TNBC cells in the presence of the pan-caspase inhibitors Z-VAD-FMK and BOC-D-FMK. Decreased phosphorylation of histone H3 at serine 10 in fisetin-treated TNBC cells at G2/M phase of the cell cycle suggested that fisetin-induced apoptosis was the result of Aurora B kinase inhibition. Interestingly, the cytotoxic effect of cisplatin, 5-fluorouracil, and 4-hydroxycyclophosphamide metabolite of cyclophosphamide on TNBC cells was increased in the presence of fisetin. These findings suggest that further investigation of fisetin is warranted for possible use in the management of TNBC. J. Cell. Biochem. 117: 1913-1925, 2016. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  15. Apoptosis Induction by Polygonum minus is related to antioxidant capacity, alterations in expression of apoptotic-related genes, and S-phase cell cycle arrest in HepG2 cell line.

    Science.gov (United States)

    Mohd Ghazali, Mohd Alfazari; Al-Naqeb, Ghanya; Krishnan Selvarajan, Kesavanarayanan; Hazizul Hasan, Mizaton; Adam, Aishah

    2014-01-01

    Polygonum minus (Polygonaceae) is a medicinal herb distributed throughout eastern Asia. The present study investigated antiproliferative effect of P. minus and its possible mechanisms. Four extracts (petroleum ether, methanol, ethyl acetate, and water) were prepared by cold maceration. Extracts were subjected to phytochemical screening, antioxidant, and antiproliferative assays; the most bioactive was fractionated using vacuum liquid chromatography into seven fractions (F1-F7). Antioxidant activity was measured via total phenolic content (TPC), 2,2-diphenyl-1-picrylhydrazyl (DPPH), and ferric reducing antioxidant power (FRAP) assays. Antiproliferative activity was evaluated using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Most active fraction was tested for apoptosis induction and cell cycle arrest in HepG2 cells using flow cytometry and confocal microscopy. Apoptotic-related gene expression was studied by RT-PCR. Ethyl acetate extract was bioactive in initial assays. Its fraction, F7, exhibited highest antioxidant capacity (TPC; 113.16 ± 6.2 mg GAE/g extract, DPPH; EC50: 30.5 ± 3.2 μg/mL, FRAP; 1169 ± 20.3 μmol Fe (II)/mg extract) and selective antiproliferative effect (IC50: 25.75 ± 1.5 μg/mL). F7 induced apoptosis in concentration- and time-dependent manner and caused cell cycle arrest at S-phase. Upregulation of proapoptotic genes (Bax, p53, and caspase-3) and downregulation of antiapoptotic gene, Bcl-2, were observed. In conclusion, F7 was antiproliferative to HepG2 cells by inducing apoptosis, cell cycle arrest, and via antioxidative effects.

  16. Exploring Growth (and Mitosis) through a Learning Cycle.

    Science.gov (United States)

    Lawson, Anton E.

    1991-01-01

    Presents a learning cycle lesson plan in which students investigate the question of how cells divide. Students use microscopes to explore actual plant root and stem tissues to generate and test hypotheses to answer the question. Includes teacher material, student material, and teaching tips. (MDH)

  17. Anticipated growth and business cycles in matching models

    NARCIS (Netherlands)

    den Haan, W.J.; Kaltenbrunner, G.

    2009-01-01

    In a business cycle model that incorporates a standard matching framework, employment increases in response to news shocks, even though the wealth effect associated with the increase in expected productivity reduces labor force participation. The reason is that the matching friction induces

  18. Gefitinib and luteolin cause growth arrest of human prostate cancer PC-3 cells via inhibition of cyclin G-associated kinase and induction of miR-630.

    Directory of Open Access Journals (Sweden)

    Minami A Sakurai

    Full Text Available Cyclin G-associated kinase (GAK, a key player in clathrin-mediated membrane trafficking, is overexpressed in various cancer cells. Here, we report that GAK expression is positively correlated with the Gleason score in surgical specimens from prostate cancer patients. Embryonic fibroblasts from knockout mice expressing a kinase-dead (KD form of GAK showed constitutive hyper-phosphorylation of the epidermal growth factor receptor (EGFR. In addition to the well-known EGFR inhibitors gefitinib and erlotinib, the dietary flavonoid luteolin was a potent inhibitor of the Ser/Thr kinase activity of GAK in vitro. Co-administration of luteolin and gefitinib to PC-3 cells had a greater effect on cell viability than administration of either compound alone; this decrease in viability was associated with drastic down-regulation of GAK protein expression. A comprehensive microRNA array analysis revealed increased expression of miR-630 and miR-5703 following treatment of PC-3 cells with luteolin and/or gefitinib, and exogenous overexpression of miR-630 caused growth arrest of these cells. GAK appears to be essential for cell death because co-administration of gefitinib and luteolin to EGFR-deficient U2OS osteosarcoma cells also had a greater effect on cell viability than administration of either compound alone. Taken together, these findings suggest that GAK may be a new therapeutic target for prostate cancer and osteosarcoma.

  19. Saw Palmetto induces growth arrest and apoptosis of androgen-dependent prostate cancer LNCaP cells via inactivation of STAT 3 and androgen receptor signaling.

    Science.gov (United States)

    Yang, Yang; Ikezoe, Takayuki; Zheng, Zhixing; Taguchi, Hirokuni; Koeffler, H Phillip; Zhu, Wei-Guo

    2007-09-01

    PC-SPES is an eight-herb mixture that has an activity against prostate cancer. Recently, we purified Saw Palmetto (Serenoa repens) from PC-SPES and found that Saw Palmetto induced growth arrest of prostate cancer LNCaP, DU145, and PC3 cells with ED50s of approximately 2.0, 2.6, and 3.3 microl/ml, respectively, as measured by mitochondrial-dependent conversion of the the 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) assay. Saw Palmetto induced apoptosis of LNCaP cells in a time- and dose-dependent manner as measured by TUNEL assays. Also, Saw Palmetto increased the expression of p21waf1 and p53 protein in LNCaP cells. In addition, we found that Saw Palmetto down-regulated DHT- or IL-6-induced expression of prostate specific antigen in conjunction with down-regulation of the level of androgen receptor in the nucleus as measured by Western blot analysis. Moreover, Saw Palmetto down-regulated the IL-6-induced level of the phosphorylated form of STAT 3 in LNCaP cells. Furthermore, Saw Palmetto inhibited the growth of LNCaP cells present as tumor xenografts in BALB/c nude mice without adverse effect. These results indicate that Saw Palmetto might be useful for the treatment of individuals with prostate cancer.

  20. Menadione induces G2/M arrest in gastric cancer cells by down-regulation of CDC25C and proteasome mediated degradation of CDK1 and cyclin B1

    OpenAIRE

    Lee, Min Ho; Cho, Yoonjung; Kim, Do Hyun; Woo, Hyun Jun; Yang, Ji Yeong; Kwon, Hye Jin; Yeon, Min Ji; Park, Min; Kim, Sa-Hyun; Moon, Cheol; Tharmalingam, Nagendran; Kim, Tae Ue; Kim, Jong-Bae

    2016-01-01

    Menadione (vitamin K3) has been reported to induce apoptotic cell death and growth inhibition in various types of cancer cells. However, involvement of menadione in cell cycle control has not been considered in gastric cancer cells yet. In the current study, we have investigated whether menadione is involved in the cell cycle regulation and suppression of growth in gastric cancer cells. In the cell cycle analysis, we found that menadione induced G2/M cell cycle arrest in AGS cells. To elucida...

  1. Crack growth through low-cycle fatigue loading of material ARMOX 500T

    Directory of Open Access Journals (Sweden)

    V. Pepel

    2016-10-01

    Full Text Available This paper presents microstructure analysis of the creation and growth of cracks in uniaxial load. Analyse were done for steel Armox 500T (armour sheet. Results show that cracks are present quit early in steel lifetime. First micro cracks occur before the 200th cycles, whereby crack growth is progressive during further loading. Also it can be seen that after a certain number of cycles there are more longer cracks then shorter ones.

  2. High-polyphenol sorghum bran extract inhibits cancer cell growth through DNA damage, cell cycle arrest, and apoptosis

    Science.gov (United States)

    As diet is one of the major controllable factors in cancer development, potentially chemopreventive foods are of significant interest to public health. One such food is sorghum (Sorghum bicolor), a cereal grain that contains varying concentrations of polyphenols. In a panel of 15 sorghum germplasm...

  3. Growth scenarios with thorium fuel cycles in pressurised heavy water reactors

    International Nuclear Information System (INIS)

    Balakrishnan, M.R.

    1991-01-01

    Since India has generous deposits of thorium, the availability of thorium will not be a limiting factor in any growth scenario. It is fairly well accepted that the best system for utilisation of thorium is the heavy water reactor. The growth scenarios possible using thorium in HWRs are considered. The base has been taken as 50,000 tons of natural uranium and practically unlimited thorium. The reference reactor has been assumed to be the PHWR, and all other growth scenarios are compared with the growth scenario provided by the once-through natural cycle in the PHWR. Two reactor types have been considered: the heavy water moderated, heavy water cooled, pressure tube reactor, known as the PHWR; and the heavy water moderated and cooled pressure vessel kind, similar to the ATUCHA reactor in Argentina. For each reactor, a number of different fuel cycles have been studied. All these cycles have been based on thorium. These are: the self-sustaining equilibrium thorium cycle (SSET); the high conversion ratio high burnup cycle; and the once through thorium cycle (OTT). The cycle have been initiated in two ways: one is by starting the cycle with natural uranium, reprocessing the spent fuel to obtain plutonium, and use that plutonium to initiate the thorium cycle; the other is to enrich the uranium to about 2-3% U-235 (the so-called Low Enriched Uranium or LEU), and use the LEU to initiate the thorium cycle. Both cases have been studied, and growth scenarios have been projected for every one of the possible combinations. (author). 1 tab

  4. Aqueous extract of Tribulus terrestris Linn induces cell growth arrest and apoptosis by down-regulating NF-κB signaling in liver cancer cells.

    Science.gov (United States)

    Kim, Hye Jin; Kim, Jin Chul; Min, Jung Sun; Kim, Mi-Jee; Kim, Ji Ae; Kor, Myung Ho; Yoo, Hwa Seung; Ahn, Jeong Keun

    2011-06-14

    A medicinal herb Tribulus terrestris Linn has been used to treat various diseases including hepatocellular carcinoma. The aim of the present study was to investigate the anticancer activity of Tribulus terrestris Linn (TT) in liver cancer cells. The antitumor activity of aqueous TT extract was analyzed by testing the cytotoxicity and the effect on clonogenecity in HepG2 cells. Apoptosis and cell cycle arrest induced by TT were dissected by flow cytometry and its inhibitory effect on NF-κB activity was determined by analyzing the expression levels of NF-κB/IκB subunit proteins. The suppression of NF-κB-regulated gene expression by TT was assessed by RT-PCR. TT extract repressed clonogenecity and proliferation, induced apoptosis, and enhanced accumulation in the G0/G1 phase of liver cancer cells. It also turned out that TT extract inhibited NF-κB-dependent reporter gene expression and NF-κB subunit p50 expression, while it enhanced the cellular level of IκBα by inhibiting the phosphorylation and degradation of IκBα. In addition, IKK activity was inhibited in a dose-dependent manner. Furthermore, TT extract suppressed the transcription of genes associated with cell cycle regulation, anti-apoptosis, and invasion. These data showed that TT extract blocks proliferation and induces apoptosis in human liver cancer cells through the inhibition of NF-κB signaling. Aqueous TT extract can be used as an anticancer drug for hepatocellular carcinoma patients. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

  5. Circulatory Arrest, Brain Arrest and Death Determination

    Directory of Open Access Journals (Sweden)

    Sam David Shemie

    2018-03-01

    Full Text Available Technological advances, particularly in the capacity to support, replace or transplant failing organs, continue to challenge and refine our understanding of human death. Given the ability to reanimate organs before and after death, both inside and outside of the body, through reinstitution of oxygenated circulation, concepts related to death of organs (e.g. cardiac death are no longer valid. This paper advances the rationale for a single conceptual determination of death related to permanent brain arrest, resulting from primary brain injury or secondary to circulatory arrest. The clinical characteristics of brain arrest are the permanent loss of capacity for consciousness and loss of all brainstem functions. In the setting of circulatory arrest, death occurs after the arrest of circulation to the brain rather than death of the heart. Correspondingly, any intervention that resumes oxygenated circulation to the brain after circulatory arrest would invalidate the determination of death.

  6. Persea declinata (Bl. Kosterm Bark Crude Extract Induces Apoptosis in MCF-7 Cells via G0/G1 Cell Cycle Arrest, Bcl-2/Bax/Bcl-xl Signaling Pathways, and ROS Generation

    Directory of Open Access Journals (Sweden)

    Putri Narrima

    2014-01-01

    Full Text Available Persea declinata (Bl. Kosterm is a member of the Lauraceae family, widely distributed in Southeast Asia. It is from the same genus with avocado (Persea americana Mill, which is widely consumed as food and for medicinal purposes. In the present study, we examined the anticancer properties of Persea declinata (Bl. Kosterm bark methanolic crude extract (PDM. PDM exhibited a potent antiproliferative effect in MCF-7 human breast cancer cells, with an IC50 value of 16.68 µg/mL after 48 h of treatment. We observed that PDM caused cell cycle arrest and subsequent apoptosis in MCF-7 cells, as exhibited by increased population at G0/G1 phase, higher lactate dehydrogenase (LDH release, and DNA fragmentation. Mechanistic studies showed that PDM caused significant elevation in ROS production, leading to perturbation of mitochondrial membrane potential, cell permeability, and activation of caspases-3/7. On the other hand, real-time PCR and Western blot analysis showed that PDM treatment increased the expression of the proapoptotic molecule, Bax, but decreased the expression of prosurvival proteins, Bcl-2 and Bcl-xL, in a dose-dependent manner. These findings imply that PDM could inhibit proliferation in MCF-7 cells via cell cycle arrest and apoptosis induction, indicating its potential as a therapeutic agent worthy of further development.

  7. A Novel Bromophenol Derivative BOS-102 Induces Cell Cycle Arrest and Apoptosis in Human A549 Lung Cancer Cells via ROS-Mediated PI3K/Akt and the MAPK Signaling Pathway

    Directory of Open Access Journals (Sweden)

    Chuan-Long Guo

    2018-01-01

    Full Text Available Bromophenol is a type of natural marine product. It has excellent biological activities, especially anticancer activities. In our study of searching for potent anticancer drugs, a novel bromophenol derivative containing indolin-2-one moiety, 3-(4-(3-([1,4′-bipiperidin]-1′-ylpropoxy-3-bromo-5-methoxybenzylidene-N-(4-bromophenyl-2-oxoindoline-5-sulfonamide (BOS-102 was synthesized, which showed excellent anticancer activities on human lung cancer cell lines. A study of the mechanisms indicated that BOS-102 could significantly block cell proliferation in human A549 lung cancer cells and effectively induce G0/G1 cell cycle arrest via targeting cyclin D1 and cyclin-dependent kinase 4 (CDK4. BOS-102 could also induce apoptosis, including activating caspase-3 and poly (ADP-ribose polymerase (PARP, increasing the Bax/Bcl-2 ratio, enhancing reactive oxygen species (ROS generation, decreasing mitochondrial membrane potential (MMP, ΔΨm, and leading cytochrome c release from mitochondria. Further research revealed that BOS-102 deactivated the PI3K/Akt pathway and activated the mitogen-activated protein kinase (MAPK signaling pathway resulting in apoptosis and cell cycle arrest, which indicated that BOS-102 has the potential to develop into an anticancer drug.

  8. The individual life-cycle, annuity market imperfections and economic growth

    NARCIS (Netherlands)

    Heijdra, Ben J.; Mierau, Jochen O.

    We study the effects of an annuity market imperfection on individual agents' life-cycle decisions and on the macroeconomic growth rate in an overlapping generations model with single-sector endogenous growth. Our model features both age-dependent mortality and labour productivity. We model imperfect

  9. Carbamazepine induces mitotic arrest in mammalian Vero cells

    International Nuclear Information System (INIS)

    Perez Martin, J.M.; Fernandez Freire, P.; Labrador, V.; Hazen, M.J.

    2008-01-01

    We reported recently that the anticonvulsant drug carbamazepine, at supratherapeutic concentrations, exerts antiproliferat