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Sample records for apoptosis limits dna

  1. Apoptosis and DNA Methylation

    International Nuclear Information System (INIS)

    Meng, Huan X.; Hackett, James A.; Nestor, Colm; Dunican, Donncha S.; Madej, Monika; Reddington, James P.; Pennings, Sari; Harrison, David J.; Meehan, Richard R.

    2011-01-01

    Epigenetic mechanisms assist in maintaining gene expression patterns and cellular properties in developing and adult tissues. The molecular pathology of disease states frequently includes perturbation of DNA and histone methylation patterns, which can activate apoptotic pathways associated with maintenance of genome integrity. This perspective focuses on the pathways linking DNA methyltransferases and methyl-CpG binding proteins to apoptosis, and includes new bioinformatic analyses to characterize the evolutionary origin of two G/T mismatch-specific thymine DNA glycosylases, MBD4 and TDG

  2. Evasion of apoptosis by DNA viruses.

    Science.gov (United States)

    Cuff, S; Ruby, J

    1996-12-01

    Apoptosis is a form of cell death distinct from necrosis which plays an important role in processes such as homoeostasis and the elimination of damaged cells. It can be triggered by a variety of stimuli including DNA damage and cytotoxic T lymphocyte activity, both of which may be induced in the course of a viral infection. Initially, induction of apoptosis may occur through pathways which have also been shown to be activated on disturbance of the cell cycle or damage to cellular DNA. At later time points during the course of infection, apoptosis can also be triggered by cytokines and immune effector cells. Apoptosis of the host cell before the completion of the viral replication cycle may limit the number of progeny and the spread of infection. The importance of apoptosis as an antiviral defence is illustrated by the presence of multiple pathways for apoptosis induction and inhibition in both the host and virus. In this review, the inhibition of apoptosis is described in adenovirus and poxvirus infection. These examples illustrate two of the divergent paths by which viruses may avoid the apoptotic response.

  3. Small DNA pieces in C. elegans are intermediates of DNA fragmentation during apoptosis.

    Directory of Open Access Journals (Sweden)

    P Joseph Aruscavage

    2010-06-01

    Full Text Available While studying small noncoding RNA in C. elegans, we discovered that protocols used for isolation of RNA are contaminated with small DNA pieces. After electrophoresis on a denaturing gel, the DNA fragments appear as a ladder of bands, approximately 10 nucleotides apart, mimicking the pattern of nuclease digestion of DNA wrapped around a nucleosome. Here we show that the small DNA pieces are products of the DNA fragmentation that occurs during apoptosis, and correspondingly, are absent in mutant strains incapable of apoptosis. In contrast, the small DNA pieces are present in strains defective for the engulfment process of apoptosis, suggesting they are produced in the dying cell prior to engulfment. While the small DNA pieces are also present in a number of strains with mutations in predicted nucleases, they are undetectable in strains containing mutations in nuc-1, which encodes a DNase II endonuclease. We find that the small DNA pieces can be labeled with terminal deoxynucleotidyltransferase only after phosphatase treatment, as expected if they are products of DNase II cleavage, which generates a 3' phosphate. Our studies reveal a previously unknown intermediate in the process of apoptotic DNA fragmentation and thus bring us closer to defining this important pathway.

  4. Helichrysetin Induces DNA Damage that Triggers JNK-Mediated Apoptosis in Ca Ski Cells.

    Science.gov (United States)

    Fong, Ho Yen; Abd Malek, Sri Nurestri; Yee, Hui Shin; Karsani, Saiful Anuar

    2017-01-01

    Cervical cancer has become one of the most common cancers in women and currently available treatment options for cervical cancer are very limited. Naturally occurring chalcones and its derivatives have been studied extensively as a potential anticancer agent in different types of cancer and helichrysetin is naturally occurring chalcone that possess potent antiproliferative activity toward human cancer cells. Inhibitory activity of helichrysetin was evaluated at different concentrations. Ability of helichrysetin to induce apoptosis and its relation with c-Jun N-terminal kinase (JNK)-mediated mechanism of apoptosis was assessed using flow cytometry and Western blotting. Helichrysetin inhibited Ca Ski cells at half maximal inhibitory concentration 30.62 ± 0.38 μM. This compound has the ability to induce DNA damage, mitochondrial membrane disruption, and loss of cell membrane integrity. We have shown that apoptosis was induced through the activation of JNK-mediated apoptosis by DNA damage in the cells then triggering p53-downstream apoptotic pathway with increased expression of pro-apoptotic proteins, Bax and caspase 3, and suppression of Bcl-2 anti-apoptotic protein. DNA damage in the cells also caused phosphorylation of protein ataxia-telangiectasia mutated, an activator of DNA damage response. We conclude that helichrysetin can inhibit Ca Ski cells through DNA damage-induced JNK-mediated apoptotic pathway highlighting the potential of this compound as anticancer agent for cervical cancer. Helichrysetin induced DNA damage in Ca Ski cellsDNA damage caused JNK-mediated phosphorylation of p53 resulting in p53-mediated apoptosisHelichrysetin is a potential DNA damage inducing agent through JNK activation to kill human cervical carcinoma cells. Abbreviations used: ATM: Ataxia-telangiectasia mutated, DAPI: 4',6-diamidino-2-phenylindole, DMSO: Dimethyl sulfoxide, FITC: Fluorescein isothiocyanate, IC 50 : Half maximal inhibitory concentration, JC1-5,5',6,6'-Tetrachloro: 1

  5. DNA fragmentation and apoptosis induced by safranal in human prostate cancer cell line

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    Saeed Samarghandian

    2013-01-01

    Full Text Available Objectives: Apoptosis, an important mechanism that contributes to cell growth reduction, is reported to be induced by Crocus sativus (Saffron in different cancer types. However, limited effort has been made to correlate these effects to the active ingredients of saffron. The present study was designed to elucidate cytotoxic and apoptosis induction by safranal, the major coloring compound in saffron, in a human prostate cancer cell line (PC-3. Materials and Methods: PC-3 and human fetal lung fibroblast (MRC-5 cells were cultured and exposed to safranal (5, 10, 15, and 20 μg/ml. The 3-(4,5-dimethylthiazol-2-yl-2,5-diphenyltetrazolium bromide (MTT assay was performed to assess cytotoxicity. DNA fragmentation was assessed by gel electrophoresis. Cells were incubated with different concentrations of safranal, and cell morphologic changes and apoptosis were determined by the normal inverted microscope, Annexin V, and propidium iodide, followed by flow cytometric analysis, respectively. Results: MTT assay revealed a remarkable and concentration-dependent cytotoxic effect of safranal on PC-3 cells in comparison with non-malignant cell line. The morphologic alterations of the cells confirmed the MTT results. The IC 50 values against PC-3 cells were found to be 13.0 ΁ 0.07 and 6.4 ΁ 0.09 μg/ml at 48 and 72 h, respectively. Safranal induced an early and late apoptosis in the flow cytometry histogram of treated cells, indicating apoptosis is involved in this toxicity. DNA analysis revealed typical ladders as early as 48 and 72 h after treatment, indicative of apoptosis. Conclusions: Our preclinical study demonstrated a prostate cancer cell line to be highly sensitive to safranal-mediated growth inhibition and apoptotic cell death. Although the molecular mechanisms of safranal action are not clearly understood, it appears to have potential as a therapeutic agent.

  6. DNA damage and mitochondria dysfunction in cell apoptosis induced by nonthermal air plasma

    Science.gov (United States)

    Kim, G. J.; Kim, W.; Kim, K. T.; Lee, J. K.

    2010-01-01

    Nonthermal plasma is known to induce animal cell death but the mechanism is not yet clear. Here, cellular and biochemical regulation of cell apoptosis is demonstrated for plasma treated cells. Surface type nonthermal air plasma triggered apoptosis of B16F10 mouse melanoma cancer cells causing DNA damage and mitochondria dysfunction. Plasma treatment activated caspase-3, apoptosis executioner. The plasma treated cells also accumulated gamma-H2A.X, marker for DNA double strand breaks, and p53 tumor suppressor gene as a response to DNA damage. Interestingly, cytochrome C was released from mitochondria and its membrane potential was changed significantly.

  7. Role of DNA mismatch repair and p53 in signaling induction of apoptosis by alkylating agents.

    Science.gov (United States)

    Hickman, M J; Samson, L D

    1999-09-14

    All cells are unavoidably exposed to chemicals that can alkylate DNA to form genotoxic damage. Among the various DNA lesions formed, O(6)-alkylguanine lesions can be highly cytotoxic, and we recently demonstrated that O(6)-methylguanine (O(6)MeG) and O(6)-chloroethylguanine (O(6)CEG) specifically initiate apoptosis in hamster cells. Here we show, in both hamster and human cells, that the MutSalpha branch of the DNA mismatch repair pathway (but not the MutSbeta branch) is absolutely required for signaling the initiation of apoptosis in response to O(6)MeGs and is partially required for signaling apoptosis in response to O(6)CEGs. Further, O(6)MeG lesions signal the stabilization of the p53 tumor suppressor, and such signaling is also MutSalpha-dependent. Despite this, MutSalpha-dependent apoptosis can be executed in a p53-independent manner. DNA mismatch repair status did not influence the response of cells to other inducers of p53 and apoptosis. Thus, it appears that mismatch repair status, rather than p53 status, is a strong indicator of the susceptibility of cells to alkylation-induced apoptosis. This experimental system will allow dissection of the signal transduction events that couple a specific type of DNA base lesion with the final outcome of apoptotic cell death.

  8. Apoptosis-like yeast cell death in response to DNA damage and replication defects

    International Nuclear Information System (INIS)

    Burhans, William C.; Weinberger, Martin; Marchetti, Maria A.; Ramachandran, Lakshmi; D'Urso, Gennaro; Huberman, Joel A.

    2003-01-01

    In budding (Saccharomyces cerevisiae) and fission (Schizosaccharomyces pombe) yeast and other unicellular organisms, DNA damage and other stimuli can induce cell death resembling apoptosis in metazoans, including the activation of a recently discovered caspase-like molecule in budding yeast. Induction of apoptotic-like cell death in yeasts requires homologues of cell cycle checkpoint proteins that are often required for apoptosis in metazoan cells. Here, we summarize these findings and our unpublished results which show that an important component of metazoan apoptosis recently detected in budding yeast - reactive oxygen species (ROS) - can also be detected in fission yeast undergoing an apoptotic-like cell death. ROS were detected in fission and budding yeast cells bearing conditional mutations in genes encoding DNA replication initiation proteins and in fission yeast cells with mutations that deregulate cyclin-dependent kinases (CDKs). These mutations may cause DNA damage by permitting entry of cells into S phase with a reduced number of replication forks and/or passage through mitosis with incompletely replicated chromosomes. This may be relevant to the frequent requirement for elevated CDK activity in mammalian apoptosis, and to the recent discovery that the initiation protein Cdc6 is destroyed during apoptosis in mammals and in budding yeast cells exposed to lethal levels of DNA damage. Our data indicate that connections between apoptosis-like cell death and DNA replication or CDK activity are complex. Some apoptosis-like pathways require checkpoint proteins, others are inhibited by them, and others are independent of them. This complexity resembles that of apoptotic pathways in mammalian cells, which are frequently deregulated in cancer. The greater genetic tractability of yeasts should help to delineate these complex pathways and their relationships to cancer and to the effects of apoptosis-inducing drugs that inhibit DNA replication

  9. The Role of Mitochondrial DNA in Mediating Alveolar Epithelial Cell Apoptosis and Pulmonary Fibrosis

    Science.gov (United States)

    Kim, Seok-Jo; Cheresh, Paul; Jablonski, Renea P.; Williams, David B.; Kamp, David W.

    2015-01-01

    Convincing evidence has emerged demonstrating that impairment of mitochondrial function is critically important in regulating alveolar epithelial cell (AEC) programmed cell death (apoptosis) that may contribute to aging-related lung diseases, such as idiopathic pulmonary fibrosis (IPF) and asbestosis (pulmonary fibrosis following asbestos exposure). The mammalian mitochondrial DNA (mtDNA) encodes for 13 proteins, including several essential for oxidative phosphorylation. We review the evidence implicating that oxidative stress-induced mtDNA damage promotes AEC apoptosis and pulmonary fibrosis. We focus on the emerging role for AEC mtDNA damage repair by 8-oxoguanine DNA glycosylase (OGG1) and mitochondrial aconitase (ACO-2) in maintaining mtDNA integrity which is important in preventing AEC apoptosis and asbestos-induced pulmonary fibrosis in a murine model. We then review recent studies linking the sirtuin (SIRT) family members, especially SIRT3, to mitochondrial integrity and mtDNA damage repair and aging. We present a conceptual model of how SIRTs modulate reactive oxygen species (ROS)-driven mitochondrial metabolism that may be important for their tumor suppressor function. The emerging insights into the pathobiology underlying AEC mtDNA damage and apoptosis is suggesting novel therapeutic targets that may prove useful for the management of age-related diseases, including pulmonary fibrosis and lung cancer. PMID:26370974

  10. Treg cell resistance to apoptosis in DNA vaccination for experimental autoimmune encephalomyelitis treatment.

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    Youmin Kang

    Full Text Available BACKGROUND: Regulatory T (Treg cells can be induced with DNA vaccinations and protect mice from the development of experimental autoimmune encephalomyelitis (EAE, a mouse model of multiple sclerosis (MS. Tacrolimus (FK506 has been shown to have functions on inducing immunosuppression and augmenting apoptosis of pathologic T cells in autoimmune disease. Here we examined the therapeutic effect of DNA vaccine in conjunction with FK506 on EAE. METHODOLOGY/PRINCIPAL FINDINGS: After EAE induction, C57BL/6 mice were treated with DNA vaccine in conjunction with FK506. Functional Treg cells were induced in treated EAE mice and suppressed Th1 and Th17 cell responses. Infiltrated CD4 T cells were reduced while Treg cells were induced in spinal cords of treated EAE mice. Remarkably, the activated CD4 T cells augmented apoptosis, but the induced Treg cells resisted apoptosis in treated EAE mice, resulting in alleviation of clinical EAE severity. CONCLUSIONS/SIGNIFICANCE: DNA vaccine in conjunction with FK506 treatment ameliorates EAE by enhancing apoptosis of CD4 T cells and resisting apoptosis of induced Treg cells. Our findings implicate the potential of tolerogenic DNA vaccines for treating MS.

  11. Ellipticine induces apoptosis in T-cell lymphoma via oxidative DNA damage

    DEFF Research Database (Denmark)

    Savorani, Cecilia; Manfé, Valentina; Biskup, Edyta

    2015-01-01

    (CTCL), a disease that is progressive, chemoresistant and refractory to treatment. We tested the effect of ellipticine in three cell lines with different p53 status: MyLa2000 (p53(wt/wt)), SeAx ((G245S)p53) and Hut-78 ((R196Stop)p53). Ellipticine caused apoptosis in MyLa2000 and SeAx and restored...... the transcriptional activity of (G245S)p53 in SeAx. However, p53 siRNA knockdown experiments revealed that p53 was not required for ellipticine-induced apoptosis in CTCL. The lipophilic antioxidant α-tocopherol inhibited ellipticine-dependent apoptosis and we linked the apoptotic response to the oxidative DNA damage....... Our results provide evidence that ellipticine-induced apoptosis is exerted through DNA damage and does not require p53 activation in T-cell lymphoma....

  12. Radiation induced apoptosis and initial DNA damage are inversely related in locally advanced breast cancer patients

    International Nuclear Information System (INIS)

    Pinar, Beatriz; Henríquez-Hernández, Luis Alberto; Lara, Pedro C; Bordon, Elisa; Rodriguez-Gallego, Carlos; Lloret, Marta; Nuñez, Maria Isabel; De Almodovar, Mariano Ruiz

    2010-01-01

    DNA-damage assays, quantifying the initial number of DNA double-strand breaks induced by radiation, have been proposed as a predictive test for radiation-induced toxicity. Determination of radiation-induced apoptosis in peripheral blood lymphocytes by flow cytometry analysis has also been proposed as an approach for predicting normal tissue responses following radiotherapy. The aim of the present study was to explore the association between initial DNA damage, estimated by the number of double-strand breaks induced by a given radiation dose, and the radio-induced apoptosis rates observed. Peripheral blood lymphocytes were taken from 26 consecutive patients with locally advanced breast carcinoma. Radiosensitivity of lymphocytes was quantified as the initial number of DNA double-strand breaks induced per Gy and per DNA unit (200 Mbp). Radio-induced apoptosis at 1, 2 and 8 Gy was measured by flow cytometry using annexin V/propidium iodide. Radiation-induced apoptosis increased in order to radiation dose and data fitted to a semi logarithmic mathematical model. A positive correlation was found among radio-induced apoptosis values at different radiation doses: 1, 2 and 8 Gy (p < 0.0001 in all cases). Mean DSB/Gy/DNA unit obtained was 1.70 ± 0.83 (range 0.63-4.08; median, 1.46). A statistically significant inverse correlation was found between initial damage to DNA and radio-induced apoptosis at 1 Gy (p = 0.034). A trend toward 2 Gy (p = 0.057) and 8 Gy (p = 0.067) was observed after 24 hours of incubation. An inverse association was observed for the first time between these variables, both considered as predictive factors to radiation toxicity

  13. Viral single-strand DNA induces p53-dependent apoptosis in human embryonic stem cells.

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    Matthew L Hirsch

    Full Text Available Human embryonic stem cells (hESCs are primed for rapid apoptosis following mild forms of genotoxic stress. A natural form of such cellular stress occurs in response to recombinant adeno-associated virus (rAAV single-strand DNA genomes, which exploit the host DNA damage response for replication and genome persistence. Herein, we discovered a unique DNA damage response induced by rAAV transduction specific to pluripotent hESCs. Within hours following rAAV transduction, host DNA damage signaling was elicited as measured by increased gamma-H2AX, ser15-p53 phosphorylation, and subsequent p53-dependent transcriptional activation. Nucleotide incorporation assays demonstrated that rAAV transduced cells accumulated in early S-phase followed by the induction of apoptosis. This lethal signaling sequalae required p53 in a manner independent of transcriptional induction of Puma, Bax and Bcl-2 and was not evident in cells differentiated towards a neural lineage. Consistent with a lethal DNA damage response induced upon rAAV transduction of hESCs, empty AAV protein capsids demonstrated no toxicity. In contrast, DNA microinjections demonstrated that the minimal AAV origin of replication and, in particular, a 40 nucleotide G-rich tetrad repeat sequence, was sufficient for hESC apoptosis. Our data support a model in which rAAV transduction of hESCs induces a p53-dependent lethal response that is elicited by a telomeric sequence within the AAV origin of replication.

  14. G4-Tetra DNA Duplex Induce Lung Cancer Cell Apoptosis in A549 Cells

    Science.gov (United States)

    Xu, Xiaobo; Zhao, YiZhuo; Lu, Hu; Fu, Cuiping; Li, Xiao; Jiang, Liyan; Li, Shanqun

    2016-10-01

    The specific DNA is typically impermeable to the plasma membrane due to its natural characters, but DNA tetra structures (DTNs) can be readily uptake by cells in the absence of transfection agents, providing a new strategy to deliver DNA drugs. In this research, the delivery efficiency of tetrahedral DNA nanostructures was measured on adenocarcinomic human alveolar basal epithelial (A549) cells via delivering AS1411 (G4). The DNA tetra-AS1411 complex was rapidly and abundantly uptake by A549 cells, and the induced apoptosis was enhanced. Furthermore, biodistribution in mouse proved the rapid clearance from non-targeted organs in vivo. This study improved the understanding of potential function in DNA-based drug delivery and proved that DTNs-AS1411 could be potentially useful for the treatment of lung cancer.

  15. Role of DNA mismatch repair and p53 in signaling induction of apoptosis by alkylating agents

    OpenAIRE

    Hickman, Mark J.; Samson, Leona D.

    1999-01-01

    All cells are unavoidably exposed to chemicals that can alkylate DNA to form genotoxic damage. Among the various DNA lesions formed, O6-alkylguanine lesions can be highly cytotoxic, and we recently demonstrated that O6-methylguanine (O6MeG) and O6-chloroethylguanine (O6CEG) specifically initiate apoptosis in hamster cells. Here we show, in both hamster and human cells, that the MutSα branch of the DNA mismatch repair pathway (but not the MutSβ branch) is absolutely required for signaling the ...

  16. Induction of ROS Overload by Alantolactone Prompts Oxidative DNA Damage and Apoptosis in Colorectal Cancer Cells

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    Yushuang Ding

    2016-04-01

    Full Text Available Cancer cells typically display higher than normal levels of reactive oxygen species (ROS, which may promote cancer development and progression but may also render the cancer cells more vulnerable to further ROS insult. Indeed, many of the current anticancer therapeutics kill cancer cells via induction of oxidative stress, though they target both cancer and normal cells. Recently, alantolactone (ATL, a natural sesquiterpene lactone, has been shown to induce apoptosis by increasing ROS levels specifically in cancer cells; however, the molecular mechanisms linking ROS overproduction to apoptosis remain unclear. Here we show that the ATL-induced ROS overload in human SW480 and SW1116 colorectal cancer cells was followed by a prominent accumulation of cellular oxidized guanine (8-oxoG and immediate increase in the number of DNA strand breaks, indicating that increased ROS resulted in extensive oxidative DNA damage. Consequently, the G1/S-CDK suppresser CDKN1B (p21 and pro-apoptotic proteins Bax and activated caspase-3 were upregulated, while anti-apoptotic Bcl-2 was downregulated, which were followed by cell cycle arrest at G1 and marked apoptosis in ATL-treated cancer but not non-cancer cells. These results suggest that the ATL-induced ROS overload triggers cell death through induction of massive oxidative DNA damage and subsequent activation of the intrinsic apoptosis pathway.

  17. Umbelliferone suppresses radiation induced DNA damage and apoptosis in hematopoietic cells of mice

    International Nuclear Information System (INIS)

    Jayakumar, S.; Bhilwade, H.N.; Chaubey, R.C.

    2012-01-01

    Radiotherapy is one of the major modes of treatment for different types of cancers. But the success of radiotherapy is limited by injury to the normal cells. Protection of the normal cells from radiation damage by radioprotectors can increase therapeutic efficiency. These radioprotectors can also be used during nuclear emergency situations. Umbelliferone (UMB) is a wide spread natural product of the coumarin family. It occurs in many plants from the Apiaceae family. In the present study radioprotective effect of UMB was investigated in vitro and in vivo. Anti genotoxic effect of Umbelliferone was tested by treating the splenic lymphocytes with various doses of UMB (6.5 μM - 50 μM) prior to radiation (6Gy) exposure. After the radiation exposure, extent of DNA damage was assessed by comet assay at 5 mm and two hours after radiation exposure. At both the time points, it was observed that the pretreatment of UMB reduced the radiation induced DNA damage to a significant extent in comparison to radiation control. UMB pretreatment also significantly reduced the radiation induced apoptosis enumerated by propidium iodide staining assay. Results of clonogenic survival assay using intestinal cell line showed that pretreatment with UMB significantly protected against radiation induced loss of colony forming units. To assess the anti genotoxic role of umbelliferone in vivo two different doses of UMB (20 mg/Kg and 40 mg/Kg of body weight) were injected into Swiss mice or with vehicle and exposed to radiation. Thirty minutes after the radiation comet assay was performed in peripheral leukocytes. Frequency of micro nucleated erythrocytes was scored in bone marrow cells. It was observed that UMB alone did not cause any significant increase in DNA damage in comparison to control. Animals which are exposed to radiation alone showed significant increase in DNA damage and micronuclei frequency. But animals treated with UMB prior to the radiation exposure showed significant decrease

  18. DNA Tetrahedron Delivery Enhances Doxorubicin-Induced Apoptosis of HT-29 Colon Cancer Cells

    Science.gov (United States)

    Zhang, Guiyu; Zhang, Zhiyong; Yang, Junen

    2017-08-01

    As a nano-sized drug carrier with the advantage of modifiability and proper biocompatibility, DNA tetrahedron (DNA tetra) delivery is hopeful to enhance the inhibitory efficiency of nontargeted anticancer drugs. In this investigation, doxorubicin (Dox) was assembled to a folic acid-modified DNA tetra via click chemistry to prepare a targeted antitumor agent. Cellular uptake efficiency was measured via fluorescent imaging. Cytotoxicity, inhibition efficiency, and corresponding mechanism on colon cancer cell line HT-29 were evaluated by MTT assay, cell proliferation curve, western blot, and flow cytometry. No cytotoxicity was induced by DNA tetra, but the cellular uptake ratio increased obviously resulting from the DNA tetra-facilitated penetration through cellular membrane. Accordingly, folic acid-DNA tetra-Dox markedly increased the antitumor efficiency with increased apoptosis levels. In details, 100 μM was the effective concentration and a 6-h incubation period was needed for apoptosis induction. In conclusion, nano-sized DNA tetrahedron was a safe and effective delivery system for Dox and correspondingly enhanced the anticancer efficiency.

  19. Docosahexaenoic Acid Induces Oxidative DNA Damage and Apoptosis, and Enhances the Chemosensitivity of Cancer Cells

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    Eun Ah Song

    2016-08-01

    Full Text Available The human diet contains low amounts of ω-3 polyunsaturated fatty acids (PUFAs and high amounts of ω-6 PUFAs, which has been reported to contribute to the incidence of cancer. Epidemiological studies have shown that a high consumption of fish oil or ω-3 PUFAs reduced the risk of colon, pancreatic, and endometrial cancers. The ω-3 PUFA, docosahexaenoic acid (DHA, shows anticancer activity by inducing apoptosis of some human cancer cells without toxicity against normal cells. DHA induces oxidative stress and oxidative DNA adduct formation by depleting intracellular glutathione (GSH and decreasing the mitochondrial function of cancer cells. Oxidative DNA damage and DNA strand breaks activate DNA damage responses to repair the damaged DNA. However, excessive DNA damage beyond the capacity of the DNA repair processes may initiate apoptotic signaling pathways and cell cycle arrest in cancer cells. DHA shows a variable inhibitory effect on cancer cell growth depending on the cells’ molecular properties and degree of malignancy. It has been shown to affect DNA repair processes including DNA-dependent protein kinases and mismatch repair in cancer cells. Moreover, DHA enhanced the efficacy of anticancer drugs by increasing drug uptake and suppressing survival pathways in cancer cells. In this review, DHA-induced oxidative DNA damage, apoptotic signaling, and enhancement of chemosensitivity in cancer cells will be discussed based on recent studies.

  20. Docosahexaenoic Acid Induces Oxidative DNA Damage and Apoptosis, and Enhances the Chemosensitivity of Cancer Cells.

    Science.gov (United States)

    Song, Eun Ah; Kim, Hyeyoung

    2016-08-03

    The human diet contains low amounts of ω-3 polyunsaturated fatty acids (PUFAs) and high amounts of ω-6 PUFAs, which has been reported to contribute to the incidence of cancer. Epidemiological studies have shown that a high consumption of fish oil or ω-3 PUFAs reduced the risk of colon, pancreatic, and endometrial cancers. The ω-3 PUFA, docosahexaenoic acid (DHA), shows anticancer activity by inducing apoptosis of some human cancer cells without toxicity against normal cells. DHA induces oxidative stress and oxidative DNA adduct formation by depleting intracellular glutathione (GSH) and decreasing the mitochondrial function of cancer cells. Oxidative DNA damage and DNA strand breaks activate DNA damage responses to repair the damaged DNA. However, excessive DNA damage beyond the capacity of the DNA repair processes may initiate apoptotic signaling pathways and cell cycle arrest in cancer cells. DHA shows a variable inhibitory effect on cancer cell growth depending on the cells' molecular properties and degree of malignancy. It has been shown to affect DNA repair processes including DNA-dependent protein kinases and mismatch repair in cancer cells. Moreover, DHA enhanced the efficacy of anticancer drugs by increasing drug uptake and suppressing survival pathways in cancer cells. In this review, DHA-induced oxidative DNA damage, apoptotic signaling, and enhancement of chemosensitivity in cancer cells will be discussed based on recent studies.

  1. Requirement for aspartate-cleaved bid in apoptosis signaling by DNA-damaging anti-cancer regimens

    NARCIS (Netherlands)

    Werner, Arlette B.; Tait, Stephen W. G.; de Vries, Evert; Eldering, Eric; Borst, Jannie

    2004-01-01

    Lymphoid malignancies can escape from DNA-damaging anti-cancer drugs and gamma-radiation by blocking apoptosis-signaling pathways. How these regimens induce apoptosis is incompletely defined, especially in cells with nonfunctional p53. We report here that the BH3-only Bcl-2 family member Bid is

  2. RhoB promotes cancer initiation by protecting keratinocytes from UVB-induced apoptosis but limits tumor aggressiveness.

    Science.gov (United States)

    Meyer, Nicolas; Peyret-Lacombe, Alexis; Canguilhem, Bruno; Médale-Giamarchi, Claire; Mamouni, Kenza; Cristini, Agnese; Monferran, Sylvie; Lamant, Laurence; Filleron, Thomas; Pradines, Anne; Sordet, Olivier; Favre, Gilles

    2014-01-01

    The role of UVB-induced apoptosis in the formation of squamous cell carcinoma (SCC) is recognized. We previously identified the small RhoB (Ras homolog gene family, member B) GTPase, an early response gene to cellular stress, as a critical protein controlling apoptosis of human keratinocytes after UVB exposure. Here we generated SKH1 (hairless immunocompetent mouse) mice invalidated for RhoB to evaluate its role in UVB-induced skin carcinogenesis in vivo. We show that rhob-/- mice have a lower risk of developing UVB-induced keratotic tumors and actinic keratosis that is associated with a higher sensitivity of UVB-exposed keratinocytes to apoptosis. We extend this observation to primary cultures of normal human keratinocytes in which RhoB was downregulated with small interfering RNA (siRNA) and further show that the hypersensitivity to apoptosis depends on B-cell lymphoma 2 (Bcl-2) downregulation. In rhob-/- mice, the UVB-induced tumors were preferentially undifferentiated and highly proliferative. Finally, we show in humans an almost constant loss of RhoB expression in undifferentiated SCCs. These undifferentiated and RhoB-deficient tumors have elevated phosphorylated histone H2AX (γH2AX) and 53BP1, two markers of DNA double-strand breaks. Together, our results indicate that UVB-induced RhoB expression participates in in vivo SCC initiation by increasing keratinocyte survival. Conversely, RhoB may limit tumor aggressiveness as loss of RhoB expression in tumor cells is associated with tumor progression.

  3. Ruthenium(II) complexes as apoptosis inducers by stabilizing c-myc G-quadruplex DNA.

    Science.gov (United States)

    Zhang, Zhao; Wu, Qiong; Wu, Xiao-Hui; Sun, Fen-Yong; Chen, Lan-Mei; Chen, Jin-Chan; Yang, Shu-Ling; Mei, Wen-Jie

    2014-06-10

    Two ruthenium(II) complexes, [Ru(L)2(p-tFMPIP)](ClO4)2 (L = bpy, 1; phen, 2; p-tFMPIP = 2-(4-(trifluoromethyphenyl)-1H-imidazo[4,5f][1,10] phenanthroline)), were prepared by microwave-assisted synthesis technology. The inhibitory activity evaluated by MTT assay shown that 2 can inhibit the growth of MDA-MB-231 cells with inhibitory activity (IC50) of 16.3 μM, which was related to the induction of apoptosis. Besides, 2 exhibit low toxicity against normal HAcat cells. The inhibitory growth activity of both complexes related to the induction of apoptosis was also confirmed. Furthermore, the studies on the interaction of both complexes with c-myc G4 DNA shown that 1 and 2 can stabilize the conformation of c-myc G4 DNA in groove binding mode, which has been rational explained by using DFT theoretical calculation methods. In a word, this type of ruthenium(II) complexes can act as potential apoptosis inducers with low toxicity in clinic by stabilizing c-myc G4 DNA. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

  4. Early-stage apoptosis is associated with DNA-damage-independent ATM phosphorylation and chromatin decondensation in NIH3T3 fibroblasts

    DEFF Research Database (Denmark)

    Schou, Kenneth Bødtker; Schneider, Linda; Christensen, Søren Tvorup

    2008-01-01

    Chromatin condensation and degradation of DNA into internucleosomal DNA fragments are key hallmarks of apoptosis. The phosphorylation of protein kinase ataxia telangiectasia mutated (ATM) and histone H2A.X was recently shown to occur concurrently with apoptotic DNA fragmentation. We have used...... independently of DNA damage signaling pathways during the very early stages of apoptosis....

  5. DNA apoptosis and stability in B-cell chronic lymphoid leukaemia: implication of the DNA double-strand breaks repair system by non homologous recombination

    International Nuclear Information System (INIS)

    Deriano, L.

    2005-01-01

    After an introduction presenting the diagnosis and treatment of chronic lymphoid leukaemia, its molecular and genetic characteristics, and its cellular origin and clonal evolution, this research thesis describes the apoptosis (definition and characteristics, cancer and chemotherapy, apoptotic ways induced by gamma irradiation), the genotoxic stresses, the different repair mechanisms for different damages, and the DNA repair processes. It reports how human chronic lymphocytic leukaemia B cells can escape DNA damage-induced apoptosis through the non-homologous end-joining DNA repair pathway, and presents non-homologous end-joining DNA repair as a potent mutagenic process in human chronic lymphocytic leukaemia B cells

  6. Baculovirus DNA Replication-Specific Expression Factors Trigger Apoptosis and Shutoff of Host Protein Synthesis during Infection▿

    Science.gov (United States)

    Schultz, Kimberly L. W.; Friesen, Paul D.

    2009-01-01

    Apoptosis is an important antivirus defense. To define the poorly understood pathways by which invertebrates respond to viruses by inducing apoptosis, we have identified replication events that trigger apoptosis in baculovirus-infected cells. We used RNA silencing to ablate factors required for multiplication of Autographa californica multicapsid nucleopolyhedrovirus (AcMNPV). Transfection with double-stranded RNA (dsRNA) complementary to the AcMNPV late expression factors (lefs) that are designated as replicative lefs (lef-1, lef-2, lef-3, lef-11, p143, dnapol, and ie-1/ie-0) blocked virus DNA synthesis and late gene expression in permissive Spodoptera frugiperda cells. dsRNAs specific to designated nonreplicative lefs (lef-8, lef-9, p47, and pp31) blocked late gene expression without affecting virus DNA replication. Thus, both classes of lefs functioned during infection as defined. Silencing the replicative lefs prevented AcMNPV-induced apoptosis of Spodoptera cells, whereas silencing the nonreplicative lefs did not. Thus, the activity of replicative lefs or virus DNA replication is sufficient to trigger apoptosis. Confirming this conclusion, AcMNPV-induced apoptosis was suppressed by silencing the replicative lefs in cells from a divergent species, Drosophila melanogaster. Silencing replicative but not nonreplicative lefs also abrogated AcMNPV-induced shutdown of host protein synthesis, suggesting that virus DNA replication triggers inhibition of host biosynthetic processes and that apoptosis and translational arrest are linked. Our findings suggest that baculovirus DNA replication triggers a host cell response similar to the DNA damage response in vertebrates, which causes translational arrest and apoptosis. Pathways for detecting virus invasion and triggering apoptosis may therefore be conserved between insects and mammals. PMID:19706708

  7. Baculovirus DNA replication-specific expression factors trigger apoptosis and shutoff of host protein synthesis during infection.

    Science.gov (United States)

    Schultz, Kimberly L W; Friesen, Paul D

    2009-11-01

    Apoptosis is an important antivirus defense. To define the poorly understood pathways by which invertebrates respond to viruses by inducing apoptosis, we have identified replication events that trigger apoptosis in baculovirus-infected cells. We used RNA silencing to ablate factors required for multiplication of Autographa californica multicapsid nucleopolyhedrovirus (AcMNPV). Transfection with double-stranded RNA (dsRNA) complementary to the AcMNPV late expression factors (lefs) that are designated as replicative lefs (lef-1, lef-2, lef-3, lef-11, p143, dnapol, and ie-1/ie-0) blocked virus DNA synthesis and late gene expression in permissive Spodoptera frugiperda cells. dsRNAs specific to designated nonreplicative lefs (lef-8, lef-9, p47, and pp31) blocked late gene expression without affecting virus DNA replication. Thus, both classes of lefs functioned during infection as defined. Silencing the replicative lefs prevented AcMNPV-induced apoptosis of Spodoptera cells, whereas silencing the nonreplicative lefs did not. Thus, the activity of replicative lefs or virus DNA replication is sufficient to trigger apoptosis. Confirming this conclusion, AcMNPV-induced apoptosis was suppressed by silencing the replicative lefs in cells from a divergent species, Drosophila melanogaster. Silencing replicative but not nonreplicative lefs also abrogated AcMNPV-induced shutdown of host protein synthesis, suggesting that virus DNA replication triggers inhibition of host biosynthetic processes and that apoptosis and translational arrest are linked. Our findings suggest that baculovirus DNA replication triggers a host cell response similar to the DNA damage response in vertebrates, which causes translational arrest and apoptosis. Pathways for detecting virus invasion and triggering apoptosis may therefore be conserved between insects and mammals.

  8. DNA Damage, Cell Cycle Arrest, and Apoptosis Induction Caused by Lead in Human Leukemia Cells

    Directory of Open Access Journals (Sweden)

    Clement G. Yedjou

    2015-12-01

    Full Text Available In recent years, the industrial use of lead has been significantly reduced from paints and ceramic products, caulking, and pipe solder. Despite this progress, lead exposure continues to be a significant public health concern. The main goal of this research was to determine the in vitro mechanisms of lead nitrate [Pb(NO32] to induce DNA damage, apoptosis, and cell cycle arrest in human leukemia (HL-60 cells. To reach our goal, HL-60 cells were treated with different concentrations of Pb(NO32 for 24 h. Live cells and necrotic death cells were measured by the propidium idiode (PI assay using the cellometer vision. Cell apoptosis was measured by the flow cytometry and DNA laddering. Cell cycle analysis was evaluated by the flow cytometry. The result of the PI demonstrated a significant (p < 0.05 increase of necrotic cell death in Pb(NO32-treated cells, indicative of membrane rupture by Pb(NO32 compared to the control. Data generated from the comet assay indicated a concentration-dependent increase in DNA damage, showing a significant increase (p < 0.05 in comet tail-length and percentages of DNA cleavage. Data generated from the flow cytometry assessment indicated that Pb(NO32 exposure significantly (p < 0.05 increased the proportion of caspase-3 positive cells (apoptotic cells compared to the control. The flow cytometry assessment also indicated Pb(NO32 exposure caused cell cycle arrest at the G0/G1 checkpoint. The result of DNA laddering assay showed presence of DNA smear in the agarose gel with little presence of DNA fragments in the treated cells compared to the control. In summary, Pb(NO32 inhibits HL-60 cells proliferation by not only inducing DNA damage and cell cycle arrest at the G0/G1 checkpoint but also triggering the apoptosis through caspase-3 activation and nucleosomal DNA fragmentation accompanied by secondary necrosis. We believe that our study provides a new insight into the mechanisms of Pb(NO32 exposure and its associated adverse

  9. The beetroot component betanin modulates ROS production, DNA damage and apoptosis in human polymorphonuclear neutrophils.

    Science.gov (United States)

    Zielińska-Przyjemska, Małgorzata; Olejnik, Anna; Kostrzewa, Artur; Łuczak, Michał; Jagodziński, Paweł P; Baer-Dubowska, Wanda

    2012-06-01

    The aim of this study was to evaluate the effect of betanin, one of the beetroot major components, on ROS production, DNA damage and apoptosis in human resting and stimulated with phorbol 12-myristate13-acetate polymorphonuclear neutrophils, one of the key elements of the inflammatory response. Incubation of neutrophils with betanin in the concentration range 2-500 µM resulted in significant inhibition of ROS production (by 15-46%, depending on the ROS detection assay). The antioxidant capacity of betanin was most prominently expressed in the chemiluminescence measurements. This compound decreased also the percentage of DNA in comet tails in stimulated neutrophils, but only at the 24 h time point. In resting neutrophils an increased level of DNA in comet tails was observed. Betanin did not affect the activity of caspase-3, in resting neutrophils, but significantly enhanced the enzyme activity in stimulated neutrophils. The western blot analysis showed, however, an increased level of caspase-3 cleavage products as a result of betanin treatment both in resting and stimulated neutrophils. The results indicate that betanin may be responsible for the effect of beetroot products on neutrophil oxidative metabolism and its consequences, DNA damage and apoptosis. The dose and time dependent effects on these processes require further studies. Copyright © 2011 John Wiley & Sons, Ltd.

  10. 10-Acetylirciformonin B, A Sponge Furanoterpenoid, Induces DNA Damage and Apoptosis in Leukemia Cells

    Directory of Open Access Journals (Sweden)

    Fu-Wen Kuo

    2012-10-01

    Full Text Available 10-Acetylirciformonin B, a furanoterpenoid derived from irciformonin B found in a marine sponge, has been reported to possess potent cytotoxic activity against several cancer cell lines. However, the mechanism of its apoptotic activity against human leukemia cells has never been reported. The purpose of this study was to investigate the cytotoxic effects of 10-acetylirciformonin B and its possible mechanism of action against leukemia HL 60 cells. We found that 10-acetylirciformonin B decreased cell viability through the inhibition of cell growth as well as the induction of DNA damage and apoptosis in a dose-dependent manner. The induction of DNA damage was mediated by the increase of p-CHK2 and γ-H2A.X, which was suggested from the increase of tail movement in the neutral Comet assay. Induction of apoptosis was mediated with the increase in caspases 8, 9 and 3 activation as well as PARP cleavage. In summary, our resultsindicate that 10-acetylirciformonin B treatment causes apoptosis in leukaemia cells; probably through a caspase-dependent regulatory pathway.

  11. Stress-induced DNA Damage biomarkers: Applications and limitations

    Science.gov (United States)

    Nikitaki, Zacharenia; Hellweg, Christine; Georgakilas, Alexandros; Ravanat, Jean-Luc

    2015-06-01

    A variety of environmental stresses like chemicals, UV and ionizing radiation and organism’s endogenous processes like replication stress and metabolism can lead to the generation of reactive oxygen and nitrogen species (ROS/RNS) that can attack cellular vital components like DNA, proteins and lipid membranes. Among them, much attention has been focused on DNA since DNA damages play a role in several biological disorders and aging processes. Thus, DNA damage can be used as a biomarker in a reliable and accurate way to quantify for example radiation exposure and can indicate its possible long term effects and cancer risk. Based on the type of DNA lesions detected one can hypothesize on the most probable mechanisms involved in the formation of these lesions for example in the case of UV and ionizing radiation (e.g. X- or α-, γ-rays, energetic ions, neutrons). In this review we describe the most accepted chemical pathways for DNA damage induction and the different types of DNA lesions, i.e. single, complex DNA lesions etc. that can be used as biomarkers. We critically compare DNA damage detection methods and their limitations. In addition to such DNA damage products, we suggest possible gene inductions that can be used to characterize responses to different types of stresses i.e. radiation, oxidative and replication stress, based on bioinformatic approaches and stringent meta-analysis of literature data.

  12. Radon-induced DNA damage and apoptosis analyzed by flow cytometry

    International Nuclear Information System (INIS)

    Meenakshi, C.; Mohankumar, Mary N.

    2012-01-01

    Natural radiation is the major source of human exposure to ionizing radiation and its largest contributing component to effective doses arises from inhalation of 222 Rn and its radioactive progeny. 222 Rn, a chemically inert gas produced naturally from radium in rocks and soil is a proven source of lung cancer especially in closed environments such as mines and in poorly ventilated homes. Much of the data on the effect of radon in humans comes from epidemiological studies, often masked by confounding factors such as age, smoking and lifestyle. Radiation carcinogenesis is initiated by DNA damage and flow cytometry is a versatile, fast and accurate technique for the analysis of DNA damage as it offers the analysis of high number of individual cells in few minutes. An attempt was made to detect DNA damage and apoptosis after exposing human blood cells in vitro to radon by flow cytometry. Blood samples were collected from apparently healthy individuals and exposed in vitro to radon ranging between 1-5 mGy using a simple, portable irradiation assembly designed and tested at the Radiological Safety Division of Indira Gandhi Centre for Atomic Research. Cultures were initiated by the addition of phytohemagglutinin and cells were processed stained and analyzed for DNA damage and apoptosis by flow cytometry. CV values indicative of DNA damage were plotted against dose and were observed to increase in a dose dependent manner 3h after of irradiation. However no such response was observed at 24h and 48h. Nevertheless, the percentage of apoptotic cells increased steadily with dose after 24 and 48h post exposure. DNA breaks appear to be rejoined after about 24h of irradiation. However apoptotic cells increased with time and dose, suggesting elimination of highly damaged cells. Further experiments are needed to identify apoptotic cells as a biomarker of radiation exposure and risk. (author)

  13. Quantification of cell-free DNA in blood plasma and DNA damage degree in lymphocytes to evaluate dysregulation of apoptosis in schizophrenia patients.

    Science.gov (United States)

    Ershova, E S; Jestkova, E M; Chestkov, I V; Porokhovnik, L N; Izevskaya, V L; Kutsev, S I; Veiko, N N; Shmarina, G; Dolgikh, O; Kostyuk, S V

    2017-04-01

    Oxidative DNA damage has been proposed as one of the causes of schizophrenia (SZ), and post mortem data indicate a dysregulation of apoptosis in SZ patients. To evaluate apoptosis in vivo we quantified the concentration of plasma cell-free DNA (cfDNA index, determined using fluorescence), the levels of 8-oxodG in cfDNA (immunoassay) and lymphocytes (FL1-8-oxodG index, flow cytometry) of male patients with acute psychotic disorders: paranoid SZ (total N = 58), schizophreniform (N = 11) and alcohol-induced (N = 14) psychotic disorder, and 30 healthy males. CfDNA in SZ (N = 58) does not change compared with controls. In SZ patients. Elevated levels of 8-oxodG were found in cfDNA (N = 58) and lymphocytes (n = 45). The main sources of cfDNA are dying cells with oxidized DNA. Thus, the cfDNA/FL1-8-oxodG ratio shows the level of apoptosis in damaged cells. Two subgroups were identified among the SZ patients (n = 45). For SZ-1 (31%) and SZ-2 (69%) median values of cfDNA/FL1-8-oxodG index are related as 1:6 (p DNA in the patient's body tissues and may be a contributing cause of acute psychotic disorder. Copyright © 2016 Elsevier Ltd. All rights reserved.

  14. Novel insights into the apoptosis mechanism of DNA topoisomerase I inhibitor isoliquiritigenin on HCC tumor cell

    Energy Technology Data Exchange (ETDEWEB)

    Li, Ze-xin; Li, Jian; Li, Yan; You, Kun; Xu, Hongwei; Wang, Jianguo, E-mail: wangjianguoxx@163.com

    2015-08-21

    The inhibitory effect of DNA topoisomerase (Top I) by isoliquiritigenin(ISO) were investigated and their interaction mechanism was evaluated using methods including UV–vis absorption, fluorescence, coupled with molecular simulation, and using the MTT method of inhibition rate of HCC tumor cell SNU475 proliferation assay, finally, the interaction of ISO with calf thymus DNA was investigated by melting measurements and molecular docking studies. It was found that isoliquiritigenin reversibly inhibited DNA Top I in a competitive manner with the concentrations of ISO resulting in 50% activity lost (IC{sub 50}) were estimated to be 0.178 ± 0.12 mM. Isoliquiritigenin exhibited a strong ability to quench the intrinsic fluorescence of Top I through a static quenching procedure. The positive values of enthalpy change and entropy change suggested that the binding of isoliquiritigenin to Top I was driven mainly by hydrophobic interactions. The molecular docking results revealed isoliquiritigenin actually interacted with the primary amino acid residues on the active site of Top I, and the detection results of fluorescence staining and the inhibitory effect on the growth of HCC SUN475 showed that isoliquiritigenin induced the apoptosis cells increased gradually. The interaction of ISO with DNA can cause the denaturation temperature to be increased, which indicated that the stabilization of the DNA helix was increased in the presence of ISO, which indicated that the results provide strong evidence for intercalative binding of ISO with DNA. - Highlights: • ISO reversibly inhibits TOP I activity in an A dose dependent manner. • Hydrophobic interactions play a major role in ISO–TOP I interaction. • ISO has a high affinity close to the active site pocket of TOP I. • The binding of ISO to DNA induces the stability of the structure of DNA.

  15. Relationship between radiation induced activation of DNA repair genes and radiation induced apoptosis in human cell line A431

    International Nuclear Information System (INIS)

    Bom, Hee Seung; Min, Jung Jun; Kim, Kyung Keun; Choi, Keun Hee

    2000-01-01

    The purpose of this study was to evaluate the relationship between radiation-induced acivation of DNA repair genes and radiation induced apoptosis in A431 cell line. Five and 25 Gys of gamma radiation were given to A431 cells by a Cs-137 cell irradiator. Apoptosis was evaluated by flow cytometry using annexin V-fluorescein isothiocyanate and propidium iodide staining. The expression of DNA repair genes was evaluated by both Northern and Western blot analyses. The number of apoptotic cells increased with the increased radiation dose. It increased most significantly at 12 hours after irradiation. Expression of p53, p21, and ℎRAD50 reached the highest level at 12 hours after 5 Gy irradiation. In response to 25 Gy irradiation, ℎRAD50 and p21 were expressed maximally at 12 hours, but p53 and GADD45 genes showed the highest expression level after 12 hours. Induction of apoptosis and DNA repair by ionizing radiation were closely correlated. The peak time of inducing apoptosis and DNA repair was 12 hours in this study model. ℎRAD50, a recently discovered DNA repair gene, was also associated with radiation-induced apoptosis.=20

  16. Molecular adjuvants for malaria DNA vaccines based on the modulation of host-cell apoptosis.

    Science.gov (United States)

    Bergmann-Leitner, Elke S; Leitner, Wolfgang W; Duncan, Elizabeth H; Savranskaya, Tatyana; Angov, Evelina

    2009-09-18

    Malaria represents a major global health problem but despite extensive efforts, no effective vaccine is available. Various vaccine candidates have been developed that provide protection in animal models, such as a gene gun-delivered DNA vaccine encoding the circumsporozoite protein (CSP) of Plasmodium berghei. A common shortcoming of most malaria vaccines is the requirement for multiple immunizations leaving room for improvement even for established vaccine candidates such as the CSP-DNA vaccine. In this study, we explored whether regulating apoptosis in DNA vaccine transfected host cells could accelerate the onset of protective immunity and provide significant protection after a single immunization. A pro-apoptotic gene (Bax) was used as a molecular adjuvant in an attempt to mimic the immunostimulatory apoptosis triggered by viral or virus-derived vaccines, while anti-apoptotic genes such as Bcl-XL may increase the life span of transfected cells thus prolonging antigen production. Surprisingly, co-delivery of either Bax or Bcl-XL greatly reduced CSP-DNA vaccine efficacy after a single immunization. Co-delivery of Bax for three immunizations still had a detrimental effect on protective immunity, while repeated co-delivery of Bcl-XL had no negative impact. The fine characterization of humoral and cellular immune response modulated by these two molecular adjuvants revealed a previously unknown effect, i.e., a shift in the Th-profile. These results demonstrate that pro- or anti-apoptotic molecules should not be used as molecular adjuvants without careful evaluation of the resulting immune response. This finding represents yet another example that strategies to enhance vaccine efficacy developed for other model systems such as viral diseases cannot easily be applied to any vaccine.

  17. Cadmium Chloride Induces DNA Damage and Apoptosis of Human Liver Carcinoma Cells via Oxidative Stress

    Directory of Open Access Journals (Sweden)

    Anthony Skipper

    2016-01-01

    Full Text Available Cadmium is a heavy metal that has been shown to cause its toxicity in humans and animals. Many documented studies have shown that cadmium produces various genotoxic effects such as DNA damage and chromosomal aberrations. Ailments such as bone disease, renal damage, and several forms of cancer are attributed to overexposure to cadmium.  Although there have been numerous studies examining the effects of cadmium in animal models and a few case studies involving communities where cadmium contamination has occurred, its molecular mechanisms of action are not fully elucidated. In this research, we hypothesized that oxidative stress plays a key role in cadmium chloride-induced toxicity, DNA damage, and apoptosis of human liver carcinoma (HepG2 cells. To test our hypothesis, cell viability was determined by MTT assay. Lipid hydroperoxide content stress was estimated by lipid peroxidation assay. Genotoxic damage was tested by the means of alkaline single cell gel electrophoresis (Comet assay. Cell apoptosis was measured by flow cytometry assessment (Annexin-V/PI assay. The result of MTT assay indicated that cadmium chloride induces toxicity to HepG2 cells in a concentration-dependent manner, showing a 48 hr-LD50 of 3.6 µg/mL. Data generated from lipid peroxidation assay resulted in a significant (p < 0.05 increase of hydroperoxide production, specifically at the highest concentration tested. Data obtained from the Comet assay indicated that cadmium chloride causes DNA damage in HepG2 cells in a concentration-dependent manner. A strong concentration-response relationship (p < 0.05 was recorded between annexin V positive cells and cadmium chloride exposure. In summary, these in vitro studies provide clear evidence that cadmium chloride induces oxidative stress, DNA damage, and programmed cell death in human liver carcinoma (HepG2 cells.

  18. Withaferin A Induces Oxidative Stress-Mediated Apoptosis and DNA Damage in Oral Cancer Cells

    Science.gov (United States)

    Chang, Hsueh-Wei; Li, Ruei-Nian; Wang, Hui-Ru; Liu, Jing-Ru; Tang, Jen-Yang; Huang, Hurng-Wern; Chan, Yu-Hsuan; Yen, Ching-Yu

    2017-01-01

    Withaferin A (WFA) is one of the most active steroidal lactones with reactive oxygen species (ROS) modulating effects against several types of cancer. ROS regulation involves selective killing. However, the anticancer and selective killing effects of WFA against oral cancer cells remain unclear. We evaluated whether the killing ability of WFA is selective, and we explored its mechanism against oral cancer cells. An MTS tetrazolium cell proliferation assay confirmed that WFA selectively killed two oral cancer cells (Ca9-22 and CAL 27) rather than normal oral cells (HGF-1). WFA also induced apoptosis of Ca9-22 cells, which was measured by flow cytometry for subG1 percentage, annexin V expression, and pan-caspase activity, as well as western blotting for caspases 1, 8, and 9 activations. Flow cytometry analysis shows that WFA-treated Ca9-22 oral cancer cells induced G2/M cell cycle arrest, ROS production, mitochondrial membrane depolarization, and phosphorylated histone H2A.X (γH2AX)-based DNA damage. Moreover, pretreating Ca9-22 cells with N-acetylcysteine (NAC) rescued WFA-induced selective killing, apoptosis, G2/M arrest, oxidative stress, and DNA damage. We conclude that WFA induced oxidative stress-mediated selective killing of oral cancer cells. PMID:28936177

  19. Concordant and opposite roles of DNA-PK and the "facilitator of chromatin transcription" (FACT in DNA repair, apoptosis and necrosis after cisplatin

    Directory of Open Access Journals (Sweden)

    Calkins Anne S

    2011-06-01

    Full Text Available Abstract Background Platinum-containing chemotherapy produces specific DNA damage and is used to treat several human solid tumors. Tumors initially sensitive to platinum-based drugs frequently become resistant. Inhibition of DNA repair is a potential strategy to enhance cisplatin effectiveness. After cisplatin treatment, a balance between repair and apoptosis determines whether cancer cells proliferate or die. DNA-dependent protein kinase (DNA-PK binds to DNA double strand breaks (DSBs through its Ku subunits and initiates non-homologous end joining. Inhibition of DNA-PK sensitizes cancer cells to cisplatin killing. The goal of this study is to elucidate the mechanism underlying the effects of DNA-PK on cisplatin sensitivity. Results Silencing the expression of the catalytic subunit of DNA-PK (DNA-PKcs increased sensitivity to cisplatin and decreased the appearance of γH2AX after cisplatin treatment. We purified DNA-PK by its Ku86 subunit and identified interactors by tandem mass spectrometry before and after cisplatin treatment. The structure specific recognition protein 1 (SSRP1, Spt16 and γH2AX appeared in the Ku86 complex 5 hours after cisplatin treatment. SSRP1 and Spt16 form the facilitator of chromatin transcription (FACT. The cisplatin-induced association of FACT with Ku86 and γH2AX was abrogated by DNase treatment. In living cells, SSRP1 and Ku86 were recruited at sites of DSBs induced by laser beams. Silencing SSRP1 expression increased sensitivity to cisplatin and decreased γH2AX appearance. However, while silencing SSRP1 in cisplatin-treated cells increased both apoptosis and necrosis, DNA-PKcs silencing, in contrast, favored necrosis over apoptosis. Conclusions DNA-PK and FACT both play roles in DNA repair. Therefore both are putative targets for therapeutic inhibition. Since DNA-PK regulates apoptosis, silencing DNA-PKcs redirects cells treated with cisplatin toward necrosis. Silencing FACT however, allows both apoptosis and

  20. Administration of the optimized β-Lapachone-poloxamer-cyclodextrin ternary system induces apoptosis, DNA damage and reduces tumor growth in a human breast adenocarcinoma xenograft mouse model.

    Science.gov (United States)

    Seoane, Samuel; Díaz-Rodríguez, Patricia; Sendon-Lago, Juan; Gallego, Rosalia; Pérez-Fernández, Román; Landin, Mariana

    2013-08-01

    β-Lapachone (β-Lap) is a 1,2-orthonaphthoquinone that selectively induces cell death in human cancer cells through NAD(P)H:quinone oxidoreductase-1 (NQO1). NQO1 is overexpressed in a variety of tumors, as compared to normal adjacent tissue. However, the low solubility and non-specific distribution of β-Lap limit its suitability for clinical assays. We formulated β-Lap in an optimal random methylated-β-cyclodextrin/poloxamer 407 mixture (i.e., β-Lap ternary system) and, using human breast adenocarcinoma MCF-7 cells and immunodeficient mice, performed in vitro and in vivo evaluation of its anti-tumor effects on proliferation, cell cycle, apoptosis, DNA damage, and tumor growth. This ternary system is fluid at room temperature, gels over 29 °C, and provides a significant amount of drug, thus facilitating intratumoral delivery, in situ gelation, and the formation of a depot for time-release. Administration of β-Lap ternary system to MCF-7 cells induces an increase in apoptosis and DNA damage, while producing no changes in cell cycle. Moreover, in a mouse xenograft tumor model, intratumoral injection of the system significantly reduces tumor volume, while increasing apoptosis and DNA damage without visible toxicity to liver or kidney. These anti-tumoral effects and lack of visible toxicity make this system a promising new therapeutic agent for breast cancer treatment. Copyright © 2013 Elsevier B.V. All rights reserved.

  1. Electron microscopic observations and DNA chain fragmentation studies on apoptosis in bone tumor cells induced by 153Sm-EDTMP

    International Nuclear Information System (INIS)

    Zhu Shoupeng; Xiao Dong; Han Xiaofeng

    1997-01-01

    The morphological changes observed by electron microscopy indicate that after internal irradiation with 153 Sm-EDTMP bone tumor cells displayed feature of apoptosis, such as margination of condensed chromatin, chromatin fragmentation, as well as the membrane bounded apoptotic bodies formation. The quantification analysis of fragmentation DNA for bone tumor cells induced by 153 Sm-EDTMP shows that the DNA fragmentation is enhanced with the prolongation of internally irradiated time. These characteristics suggest that 153 Sm-EDTMP internal irradiation could induce bone tumor cells to go to apoptosis

  2. DNA damage signaling and apoptosis in preinvasive tubal lesions of ovarian carcinoma.

    Science.gov (United States)

    Chene, Gautier; Ouellet, Veronique; Rahimi, Kurosh; Barres, Veronique; Caceres, Katia; Meunier, Liliane; Cyr, Louis; De Ladurantaye, Manon; Provencher, Diane; Mes Masson, Anne Marie

    2015-06-01

    High-grade serous ovarian cancer (HGSC) is the most life-threatening gynecological malignancy despite surgery and chemotherapy. A better understanding of the molecular basis of the preinvasive stages might be helpful in early detection and diagnosis. Genetic instability is 1 of the characteristics shared by most human cancers, and its level is variable through precancerous lesions to advanced cancer. Because DNA damage response (DDR) has been described as 1 of the first phases in genomic instability, we investigated the level of DDR activation and the apoptosis pathway in serous tubal intraepithelial carcinoma (STIC), the potential precursor of HGSC. A tissue microarray including 21 benign fallopian tubes, 21 STICs, 17 HGSCs from patients with STICs (associated ovarian cancer [AOC]) from the same individuals, and 30 HGSCs without STICs (non-AOC) was used in this study.Immunohistochemistry was performed to evaluate the level of DDR proteins (pATM, pChk2, γH2AX, 53BP1, and TRF2), apoptosis proteins (Bcl2, BAX, and BIM), and cyclin E. The expression of all DDR proteins increased from benign fallopian tubes to STICs. The level of expression of pATM, pChk2, γH2AX, and TRF2 was also increased in STICs in comparison with AOC. BAX, BIM, and cyclin E expressions were high in STICs, whereas Bcl2 expression was low. Immunohistochemical profiles of AOC and non-AOC were also different. These results suggest an activation of the DDR and apoptosis pathways in STICs, indicating that genomic instability may occur early in the precancerous lesions of HGSC.

  3. Conformational changes in DNA gyrase revealed by limited proteolysis

    DEFF Research Database (Denmark)

    Kampranis, S C; Maxwell, A

    1998-01-01

    We have used limited proteolysis to identify conformational changes in DNA gyrase. Gyrase exhibits a proteolytic fingerprint dominated by two fragments, one of approximately 62 kDa, deriving from the A protein, and another of approximately 25 kDa from the B protein. Quinolone binding to the enzyme......-DNA intermediate by calcium ions does not reveal any protection, suggesting that the quinolone-induced conformational change is different from an "open-gate" state of the enzyme. A quinolone-resistant mutant of gyrase fails to give the characteristic quinolone-associated proteolytic signature. The ATP...... does not prevent dimerization since incubation of the enzyme-DNA complex with both ADPNP and quinolones gives rise to a complex whose proteolytic pattern retains the characteristic signature of dimerization but has lost the quinolone-induced protection. As a result, the quinolone-gyrase complex can...

  4. Transient p53 suppression increases reprogramming of human fibroblasts without affecting apoptosis and DNA damage

    DEFF Research Database (Denmark)

    Rasmussen, Mikkel Aabech; Holst, Bjørn; Tümer, Zeynep

    2014-01-01

    The discovery of human-induced pluripotent stem cells (iPSCs) has sparked great interest in the potential treatment of patients with their own in vitro differentiated cells. Recently, knockout of the Tumor Protein 53 (p53) gene was reported to facilitate reprogramming but unfortunately also led...... to genomic instability. Here, we report that transient suppression of p53 during nonintegrative reprogramming of human fibroblasts leads to a significant increase in expression of pluripotency markers and overall number of iPSC colonies, due to downstream suppression of p21, without affecting apoptosis...... and DNA damage. Stable iPSC lines generated with or without p53 suppression showed comparable expression of pluripotency markers and methylation patterns, displayed normal karyotypes, contained between 0 and 5 genomic copy number variations and produced functional neurons in vitro. In conclusion...

  5. The centella asiatica juice effects on DNA damage, apoptosis and gene expression in hepatocellular carcinoma (HCC).

    Science.gov (United States)

    Hussin, Faridah; Eshkoor, Sima Ataollahi; Rahmat, Asmah; Othman, Fauziah; Akim, Abdah

    2014-01-20

    This paper is to investigate the effects of Centella asiatica on HepG2 (human hepatocellular liver carcinoma cell line). Centella asiatica is native to the Southeast Asia that is used as a traditional medicine. This study aims to determine the chemopreventive effects of the Centella asiatica juice on human HepG2 cell line. Different methods including flow cytometry, comet assay and reverse transcription-polymerase chain reaction (RT-PCR) were used to show the effects of juice exposure on the level of DNA damage and the reduction of cancerous cells. MTT assay is a colorimetric method applied to measure the toxic effects of juice on cells. The Centella asiatica juice was not toxic to normal cells. It showed cytotoxic effects on tumor cells in a dose dependent manner. Apoptosis in cells was started after being exposed for 72 hr of dose dependent. It was found that the higher percentage of apoptotic cell death and DNA damage was at the concentration above 0.1%. In addition, the juice exposure caused the reduction of c-myc gene expression and the enhancement of c-fos and c-erbB2 gene expressions in tumor cells. It was concluded that the Centella asiatica juice reduced liver tumor cells. Thus, it has the potential to be used as a chemopreventive agent to prevent and treat liver cancer.

  6. Regulation of apoptosis through bcl-2/bax proteins expression and DNA damage by Zanthoxylum alatum.

    Science.gov (United States)

    Karmakar, Indrajit; Haldar, Sagnik; Chakraborty, Mainak; Chaudhury, Keya; Dewanjee, Saikat; Haldar, Pallab Kanti

    2016-01-01

    Many of the major chemotherapeutic agents are secondary metabolites found in nature. Zanthoxylum alatum Roxb. (Rutaceae) is traditionally used in the treatment of various diseases. The present study evaluates the apoptotic activity of methanol extract of Z. alatum (MEZA) on Ehrlich ascites tumor (EAT) in Swiss albino mice. The presence of flavonoids in MEZA was standardized by HPLC. The in vitro cytotoxicity of MEZA was measured by the MTT assay. The in vivo antitumor activity of MEZA (100 and 200 mg/kg b.w., i.p. for 9 days) was also evaluated. On the 10th day, EAT tumor volume, cell viability, and hematological parameters were assayed. Apoptotic morphology was determined by acredine orange/ethedium bromide using fluorescence microscopy. Apoptosis percentage was measured by flow cytometric analysis using annexine-V-FITC. Also, DNA damage and bcl-2/bax were estimated by UV-method and western blot, respectively. HPLC analysis revealed presence of three flavonoids, rutin, myricetin, and quercetin. MEZA showed satisfactory cytotoxicity in MTT assay (IC50 = 111.50 µg/ml). The extract significantly (p < 0.01) changed the tumor volume, viable, non-viable cell count, and hematological parameters towards the normal. Apoptotic activity of MEZA was confirmed by acridine orange/ethidium bromide staining, annexin-V-FITC staining, DNA fragmentation, and Bcl-2/Bax ratio. The study showed that MEZA has antitumor activity which may be due to the presence of flavonoids in the extract.

  7. Oxidative stress, cell cycle arrest, DNA damage and apoptosis in adult zebrafish (Danio rerio) induced by tris(1,3-dichloro-2-propyl) phosphate.

    Science.gov (United States)

    Chen, Hanyan; Wang, Pingping; Du, Zhongkun; Wang, Guowei; Gao, Shixiang

    2018-01-01

    Tris(1,3-dichloro-2-propyl)phosphate (TDCPP) is an additive flame retardant of high production volume, and frequently detected in biota and environment. However, knowledge on its potential risk and toxicological mechanism still remains limited. In this study, DNA damage, transcriptomic responses and biochemical changes in the liver of zebrafish (Danio rerio) induced by TDCPP were investigated. Zebrafish was exposed to 45.81μg/L (1/100 (96h-LC 50 )) and 229.05μg/L (1/20 (96h-LC 50 )) TDCPP for 7 d. The reactive oxygen species (ROS) and GSH contents, in addition to antioxidant enzyme activities in the liver changed significantly, and the mRNA levels of genes related to oxidative stress were alerted in a dose-dependent and/or sex-dependent manner after exposure to TDCPP. Significant DNA damage in zebrafish liver was found, and olive tail moment increased in a concentration-dependent manner. Moreover, exposure of TDCPP at 45.81μg/L level activated the cell cycle arrest, DNA repair system and apoptosis pathway in male zebrafish, and 229.05μg/L TDCPP exposure inhibited those pathways in both male and female zebrafish. The cell apoptosis was confirmed in TUNEL assay as higher incidence of TUNEL-positive cells were observed in zebrafish exposed to 229.05μg/L TDCPP. Our results also indicated that males were more sensitive to TDCPP exposure compared with females. Taken together, our results showed that TDCPP could induce oxidative stress, cell cycle arrest, DNA damage and apoptosis in adult zebrafish liver in sex- and concentration-dependent manners. Copyright © 2017 Elsevier B.V. All rights reserved.

  8. Hydroxychavicol, a betel leaf component, inhibits prostate cancer through ROS-driven DNA damage and apoptosis

    Energy Technology Data Exchange (ETDEWEB)

    Gundala, Sushma Reddy; Yang, Chunhua [Department of Biology, Georgia State University, Atlanta, GA 30303 (United States); Mukkavilli, Rao [Advinus Therapeutics, Karnataka (India); Paranjpe, Rutugandha; Brahmbhatt, Meera; Pannu, Vaishali; Cheng, Alice [Department of Biology, Georgia State University, Atlanta, GA 30303 (United States); Reid, Michelle D. [Department of Pathology, Emory University School of Medicine, Atlanta, GA (United States); Aneja, Ritu, E-mail: raneja@gsu.edu [Department of Biology, Georgia State University, Atlanta, GA 30303 (United States)

    2014-10-01

    Dietary phytochemicals are excellent ROS-modulating agents and have been shown to effectively enhance ROS levels beyond toxic threshold in cancer cells to ensure their selective killing while leaving normal cells unscathed. Here we demonstrate that hydroxychavicol (HC), extracted and purified from Piper betel leaves, significantly inhibits growth and proliferation via ROS generation in human prostate cancer, PC-3 cells. HC perturbed cell-cycle kinetics and progression, reduced clonogenicity and mediated cytotoxicity by ROS-induced DNA damage leading to activation of several pro-apoptotic molecules. In addition, HC treatment elicited a novel autophagic response as evidenced by the appearance of acidic vesicular organelles and increased expression of autophagic markers, LC3-IIb and beclin-1. Interestingly, quenching of ROS with tiron, an antioxidant, offered significant protection against HC-induced inhibition of cell growth and down regulation of caspase-3, suggesting the crucial role of ROS in mediating cell death. The collapse of mitochondrial transmembrane potential by HC further revealed the link between ROS generation and induction of caspase-mediated apoptosis in PC-3 cells. Our data showed remarkable inhibition of prostate tumor xenografts by ∼ 72% upon daily oral administration of 150 mg/kg bw HC by quantitative tumor volume measurements and non-invasive real-time bioluminescent imaging. HC was well-tolerated at this dosing level without any observable toxicity. This is the first report to demonstrate the anti-prostate cancer efficacy of HC in vitro and in vivo, which is perhaps attributable to its selective prooxidant activity to eliminate cancer cells thus providing compelling grounds for future preclinical studies to validate its potential usefulness for prostate cancer management. - Highlights: • HC perturbs cell-cycle progression by induction of reactive oxygen species (ROS). • HC mediated cytotoxicity by ROS-induced DNA damage leading to

  9. Cholesterol Exchange, DNA Damages, Apoptosis and Necrosis of Blood Cells in Severe Concomitant Injury

    Directory of Open Access Journals (Sweden)

    V. V. Moroz

    2008-01-01

    -density lipoproteins were characterized by their decreased plasma levels throughout the observation of the victims. In both groups, the activity of alkaline phosphatase increased over time and was 1.5—2 times higher than the normal values on days 15. In the survivors, the admission activity of y-glutamyltransferase (y-GT was in the normal range. The activity of the enzyme in this group tended to increase, so did the plasma level of total protein in these patients. Conclusion. In severe concomitant injury, there is an increase in DNA damage processes, which is associated with the enhanced cell death. The time course of changes in the levels of total cholesterol, LDL cholesterol, and total protein and in the activities of y-GT and 8-hydroxy-2-deoxyguanosine may be used as predictors. Key words: apoptosis, necrosis, DNA damage, 8-hydroxy-2-deoxyguanosine, cholesterol exchange, injury.

  10. DNA damage and apoptosis of endometrial cells cause loss of the early embryo in mice exposed to carbon disulfide

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Bingzhen [Department of Epidemiology and Health Statistics, School of Public Health, Shandong University, Jinan (China); Shen, Chunzi [Centers for Disease Control and Prevention, Zibo (China); Yang, Liu; Li, Chunhui; Yi, Anji [Department of Epidemiology and Health Statistics, School of Public Health, Shandong University, Jinan (China); Wang, Zhiping, E-mail: zhipingw@sdu.edu.cn [Department of Epidemiology and Health Statistics, School of Public Health, Shandong University, Jinan (China)

    2013-12-01

    Carbon disulfide (CS{sub 2}) may lead to spontaneous abortion and very early pregnancy loss in women exposed in the workplace, but the mechanism remains unclear. We designed an animal model in which gestating Kunming strain mice were exposed to CS{sub 2} via i.p. on gestational day 4 (GD4). We found that the number of implanted blastocysts on GD8 was significantly reduced by each dose of 0.1 LD{sub 50} (157.85 mg/kg), 0.2 LD{sub 50} (315.7 mg/kg) and 0.4 LD{sub 50} (631.4 mg/kg). In addition, both the level of DNA damage and apoptosis rates of endometrial cells on GD4.5 were increased, showed definite dose–response relationships, and inversely related to the number of implanted blastocysts. The expressions of mRNA and protein for the Bax and caspase-3 genes in the uterine tissues on GD4.5 were up-regulated, while the expressions of mRNA and protein for the Bcl-2 gene were dose-dependently down-regulated. Our results indicated that DNA damage and apoptosis of endometrial cells were important reasons for the loss of implanted blastocysts induced by CS{sub 2}. - Highlights: • We built an animal model of CS2 exposure during blastocyst implantation. • Endometrial cells were used in the comet assay to detect DNA damage. • CS2 exposure caused DNA damage and endometrial cell apoptosis. • DNA damage and endometrial cell apoptosis were responsible for embryo loss.

  11. Soluble histone H2AX is induced by DNA replication stress and sensitizes cells to undergo apoptosis

    Directory of Open Access Journals (Sweden)

    Duensing Stefan

    2008-07-01

    Full Text Available Abstract Background Chromatin-associated histone H2AX is a key regulator of the cellular responses to DNA damage. However, non-nucleosomal functions of histone H2AX are poorly characterized. We have recently shown that soluble H2AX can trigger apoptosis but the mechanisms leading to non-chromatin-associated H2AX are unclear. Here, we tested whether stalling of DNA replication, a common event in cancer cells and the underlying mechanism of various chemotherapeutic agents, can trigger increased soluble H2AX. Results Transient overexpression of H2AX was found to lead to a detectable fraction of soluble H2AX and was associated with increased apoptosis. This effect was enhanced by the induction of DNA replication stress using the DNA polymerase α inhibitor aphidicolin. Cells manipulated to stably express H2AX did not contain soluble H2AX, however, short-term treatment with aphidicolin (1 h resulted in detectable amounts of H2AX in the soluble nuclear fraction and enhanced apoptosis. Similarly, soluble endogenous H2AX was detected under these conditions. We found that excessive soluble H2AX causes chromatin aggregation and inhibition of ongoing gene transcription as evidenced by the redistribution and/or loss of active RNA polymerase II as well as the transcriptional co-activators CBP and p300. Conclusion Taken together, these results show that DNA replication stress rapidly leads to increased soluble H2AX and that non-chromatin-associated H2AX can sensitize cells to undergo apoptosis. Our findings encourage further studies to explore H2AX and the cellular pathways that control its expression as anti-cancer drug targets.

  12. Chalcone-imidazolone conjugates induce apoptosis through DNA damage pathway by affecting telomeres

    Directory of Open Access Journals (Sweden)

    Kamal Ahmed

    2011-04-01

    Full Text Available Abstract Background Breast cancer is one of the most prevalent cancers in the world and more than one million women are diagnosed leading to 410,000 deaths every year. In our previous studies new chalcone-imidazolone conjugates were prepared and evaluated for their anticancer activity in a panel of 53 human tumor cell lines and the lead compounds identified were 6 and 8. This prompted us to investigate the mechanism of apoptotic event. Results Involvement of pro-apoptotic protein (Bax, active caspase-9 and cleavage of retinoblastoma protein was studied. Interestingly, the compounds caused upregulation of p21, check point proteins (Chk1, Chk2 and as well as their phosphorylated forms which are known to regulate the DNA damage pathway. Increased p53BP1 foci by immunolocalisation studies and TRF1 suggested the possible involvement of telomere and associated proteins in the apoptotic event. The telomeric protein such as TRF2 which is an important target for anticancer therapy against human breast cancer was extensively studied along with proteins involved in proper functioning of telomeres. Conclusions The apoptotic proteins such as Bax, active caspase-9 and cleaved RB are up-regulated in the compound treated cells revealing the apoptotic nature of the compounds. Down regulation of TRF2 and upregulation of the TRF1 as well as telomerase assay indicated the decrease in telomeric length revealing telomeric dysfunction and thereby controlling the rapid rate of cell proliferation. In summary, chalcone-imidazolone conjugates displayed significant DNA damage activity particularly at telomeres and caused both apoptosis and senescence-like growth arrest which suggested that these compounds have potential activity against breast carcinoma.

  13. [Construction of subtractive cDNA library of apoptosis-related genes in NB4 cells treated by arsenic trioxide].

    Science.gov (United States)

    Di, Chunhong; Gu, Shaohua; Tan, Xiaohua; Xian, Lingling; Wu, Qihan; Yang, Lei

    2009-02-01

    Construct the gene library of apoptosis related genes in acute promyelocytic leukemia (APL) cell line NB4 cells treated by arsenic trioxide to clarify the apoptotic mechanism of NB4 cells. APL cell line NB4 cells treated with or without arsenic trioxide for 24 hours. Total RNA was extracted and suppress subtractive hybridization (SSH) was conducted according to the manual. With the cDNA of the apoptosis cells as the tester and that of control cells as the driver, forward and reverse hybridization was performed. Differentially expressed genes were linked with pGEM-Teasy cloning vector and transformed into E. coli DH5alpha. The positive clones were screened by blue and white spot. PCR were used to amplify these genes. The subtractive cDNA libraries related with apoptosis of NB4 cells were successfully constructed. The constructed subtractive libraries are suitable for further study on the functional genes associated with apoptosis ofNB4 cells induced by arsenic trioxide.

  14. Urinary metabolites of polycyclic aromatic hydrocarbons, sperm DNA damage and spermatozoa apoptosis.

    Science.gov (United States)

    Yang, Pan; Wang, Yi-Xin; Sun, Li; Chen, Ying-Jun; Liu, Chong; Huang, Li-Li; Lu, Wen-Qing; Zeng, Qiang

    2017-05-05

    Inconsistent results between polycyclic aromatic hydrocarbons (PAHs) exposure and adverse male reproductive health have been reported in humans. To assess whether PAH exposure is associated with declined sperm function. Ten monohydroxylated PAHs (OH-PAHs) metabolites were analyzed in repeated urine samples from an infertility clinic. We used multivariable linear models to estimate the associations of urinary OH-PAH metabolites with sperm DNA damage (n=405) and spermatozoa apoptosis (n=366). The shapes of dose-dependent associations of exposure measurements with outcomes were further evaluated by restricted cubic splines. Multiple comparisons were adjusted by false discovery rate (FDR). We found that urinary 9-hydroxyfluorene (9-OHFlu) was associated with increased tail length and comet length (p for trend=0.05 and 0.01, respectively), and that urinary 9-hydroxyphenanthrene (9-OHPh) was associated with decreased percentage of Annexin V - /PI - spermatozoa (p for trend=0.04). Also, suggestive associations of urinary 9-OHPh and ∑OHFlu with increased comet length, and urinary 9-OHFlu and 2-OHPh with decreased percentage of Annexin V - /PI - spermatozoa were observed (all p for trends cubic splines. Our results suggest that environmental exposure to fluorene and phenanthrene are associated with declined sperm function. Copyright © 2017 Elsevier B.V. All rights reserved.

  15. Mitochondrial DNA depletion promotes impaired oxidative status and adaptive resistance to apoptosis in T47D breast cancer cells.

    Science.gov (United States)

    Yu, Man; Shi, Yurong; Wei, Xiyin; Yang, Yi; Zang, Fenglin; Niu, Ruifang

    2009-11-01

    The mutation and reduction of mitochondrial DNA (mtDNA) have been extensively detected in human cancers. The effects of mitochondrial dysfunction are particularly important in breast cancer, because estrogen-mediated metabolites generate large quantities of local reactive oxygen species in the breast, which directly bind to mtDNA and facilitate neoplastic transformation. To further elucidate the molecular roles of mtDNA in breast cancer, we determined the oxidative status of a breast tumor cell line lacking mtDNA (T47D ρ⁰) and analyzed its susceptibility after exposure to various anticancer drugs as well as different proapoptotic signals. Our data showed that T47D ρ⁰ cells generated significantly increased levels of lactate with concomitantly reduced oxygen consumption and ATP production compared with the wild-type (WT). The amount of reactive oxygen species generation in ρ cells was lowered to approximately 12% that of parental cells, as evidenced by the oxidation of redox-sensitive probes. Although mtDNA depletion did not affect the expression of superoxide dismutase or its activity, the activities of antioxidant enzymes, catalase and glutathione peroxidase, were significantly higher in ρ⁰ cells compared with WT cells. In addition, mtDNA-depleted cells displayed a decreased sensitivity and accumulation of chemotherapeutic drugs (doxorubicin, vincristine, and paclitaxel), potentially because of the upregulated expression of multidrug resistance 1 (MDR1) gene and its product P-glycoprotein. When compared with their WT counterparts, T47D ρ⁰ cells were also more resistant to apoptosis induced by varying concentrations of staurosporine and anti-Fas antibody. Altogether, our results indicate the importance of intact mtDNA for maintaining the proper intracellular oxidative status. These data provide evidence for a possible role of mtDNA content reduction in acquiring an apoptosis-resistant phenotype during breast tumor progression and might contribute to

  16. Ginsenoside Rg3 induces DNA damage in human osteosarcoma cells and reduces MNNG-induced DNA damage and apoptosis in normal human cells.

    Science.gov (United States)

    Zhang, Yue-Hui; Li, Hai-Dong; Li, Bo; Jiang, Sheng-Dan; Jiang, Lei-Sheng

    2014-02-01

    Panax ginseng is a Chinese medicinal herb. Ginsenosides are the main bioactive components of P. ginseng, and ginsenoside Rg3 is the primary ginsenoside. Ginsenosides can potently kill various types of cancer cells. The present study was designed to evaluate the potential genotoxicity of ginsenoside Rg3 in human osteosarcoma cells and the protective effect of ginsenoside Rg3 with respect to N-methyl-N'-nitro-N-nitrosoguanidine (MNNG)-induced DNA damage and apoptosis in a normal human cell line (human fibroblasts). Four human osteosarcoma cell lines (MG-63, OS732, U-2OS and HOS cells) and a normal human cell line (human fibroblasts) were employed to investigate the cytotoxicity of ginsenosides Rg3 by MTT assay. Alkaline comet assay and γH2AX focus staining were used to detect the DNA damage in MG-63 and U-2OS cells. The extent of cell apoptosis was determined by flow cytometry and a DNA ladder assay. Our results demonstrated that the cytotoxicity of ginsenoside Rg3 was dose-dependent in the human osteosarcoma cell lines, and MG-63 and U-2OS cells were the most sensitive to ginsenoside Rg3. As expected, compared to the negative control, ginsenoside Rg3 significantly increased DNA damage in a concentration-dependent manner. In agreement with the comet assay data, the percentage of γH2AX-positive MG-63 and U-2OS cells indicated that ginsenoside Rg3 induced DNA double-strand breaks in a concentration-dependent manner. The results also suggest that ginsenoside Rg3 reduces the extent of MNNG-induced DNA damage and apoptosis in human fibroblasts.

  17. Forskolin protects keratinocytes from ultraviolet (UV) B-induced apoptosis and increases DNA repair independent of its effects on melanogenesis

    Science.gov (United States)

    Passeron, Thierry; Namiki, Takeshi; Passeron, Hélène; Le Pape, Elodie; Hearing, Vincent J.

    2009-01-01

    Melanin pigments provide efficient protection against ultraviolet (UV) B radiation but DNA repair also plays a key role in eliminating UV-induced damage and preventing the development of skin cancers. In this study, we demonstrate that forskolin, an agent that increases intracellular levels of cAMP, protects keratinocytes from UVB-induced apoptosis independently from the amount of melanin in the skin. Forskolin enhances the removal of the two major types of UVB-induced DNA damage, cyclobutane pyrimidine dimers and 6,4-photoproducts, by facilitating DNA repair. These findings suggest new preventive approaches with topical formulations of forskolin or other bioactive agents that could be applied to the skin before sun exposure to increase its ability to repair DNA damage. PMID:18580960

  18. Forskolin protects keratinocytes from UVB-induced apoptosis and increases DNA repair independent of its effects on melanogenesis.

    Science.gov (United States)

    Passeron, Thierry; Namiki, Takeshi; Passeron, Hélène J; Le Pape, Elodie; Hearing, Vincent J

    2009-01-01

    Melanin pigments provide efficient protection against ultraviolet B (UVB) radiation but DNA repair also plays a key role in eliminating UV-induced damage and preventing the development of skin cancers. In this study, we demonstrate that forskolin (FSK), an agent that increases intracellular levels of cAMP, protects keratinocytes from UVB-induced apoptosis independently from the amount of melanin in the skin. FSK enhances the removal of the two major types of UVB-induced DNA damage, cyclobutane pyrimidine dimers and 6,4-photoproducts, by facilitating DNA repair. These findings suggest new preventive approaches with topical formulations of FSK or other bioactive agents that could be applied to the skin before sun exposure to increase its ability to repair DNA damage.

  19. Hydroxychavicol, a betel leaf component, inhibits prostate cancer through ROS-driven DNA damage and apoptosis.

    Science.gov (United States)

    Gundala, Sushma Reddy; Yang, Chunhua; Mukkavilli, Rao; Paranjpe, Rutugandha; Brahmbhatt, Meera; Pannu, Vaishali; Cheng, Alice; Reid, Michelle D; Aneja, Ritu

    2014-10-01

    Dietary phytochemicals are excellent ROS-modulating agents and have been shown to effectively enhance ROS levels beyond toxic threshold in cancer cells to ensure their selective killing while leaving normal cells unscathed. Here we demonstrate that hydroxychavicol (HC), extracted and purified from Piper betel leaves, significantly inhibits growth and proliferation via ROS generation in human prostate cancer, PC-3 cells. HC perturbed cell-cycle kinetics and progression, reduced clonogenicity and mediated cytotoxicity by ROS-induced DNA damage leading to activation of several pro-apoptotic molecules. In addition, HC treatment elicited a novel autophagic response as evidenced by the appearance of acidic vesicular organelles and increased expression of autophagic markers, LC3-IIb and beclin-1. Interestingly, quenching of ROS with tiron, an antioxidant, offered significant protection against HC-induced inhibition of cell growth and down regulation of caspase-3, suggesting the crucial role of ROS in mediating cell death. The collapse of mitochondrial transmembrane potential by HC further revealed the link between ROS generation and induction of caspase-mediated apoptosis in PC-3 cells. Our data showed remarkable inhibition of prostate tumor xenografts by ~72% upon daily oral administration of 150mg/kg bw HC by quantitative tumor volume measurements and non-invasive real-time bioluminescent imaging. HC was well-tolerated at this dosing level without any observable toxicity. This is the first report to demonstrate the anti-prostate cancer efficacy of HC in vitro and in vivo, which is perhaps attributable to its selective prooxidant activity to eliminate cancer cells thus providing compelling grounds for future preclinical studies to validate its potential usefulness for prostate cancer management. Copyright © 2014 Elsevier Inc. All rights reserved.

  20. Plumericin inhibits the viability of cervical cancer cells by induction of apoptosis through degradation of DNA structure

    Directory of Open Access Journals (Sweden)

    Jing Sun

    2016-06-01

    Full Text Available The current study demonstrates the effect of plumericin on the viability and induction of apoptosis through degradation of double helical DNA structure in Bu25TK and HeLa cervical carcinoma cell lines. Plumericin treatment exhibited concentration- and time-dependent effect on the viability of Bu25TK and HeLa cells. Incubation of Bu25TK and HeLa cells with 40 µM concentration of plumericin decreased cell viability to 24 and 29%, respectively after 48 hours. Plumericin treatment also caused significant increase in the proportion of apoptotic cells in both the cell lines at 40 µM concentration compared to the control cells. Examination of the DNA double helical structure after 48 hours of treatment with plumericin at 40 µM concentration showed DNA degradation and formation of comets. Thus, plumericin exhibits inhibitory effect on the viability of Bu25TK and HeLa cells and induced apoptosis through DNA degradation. Therefore, plumericin is a potent candidate for the treatment of cervical carcinoma.

  1. DNA damage and apoptosis induced by Pteridium aquilinum aqueous extract in the oral cell lines HSG and OSCC-3.

    Science.gov (United States)

    Pereira, Luciana Oliveira; Bicalho, Leandro Santos; Campos-da-Paz Lopes, Mariana; de Sousa, Thiago Machado Mello; Báo, Sônia Nair; de Fátima Menezes Almeida Santos, Maria; Fonseca, Marcio José Poças

    2009-05-01

    Bracken fern (Pteridium aquilinum) has been consumed by humans and animals for centuries. However, its consumption is associated with a high incidence of cancer in the upper digestory tract of different species. Although the oral cavity is the first site of contact with ingested toxic substances, the interaction of bracken fern composites with oral cell lines has not yet been studied. In order to study the biological responses of oral cells exposed to bracken fern, we evaluated the genotoxic and cytotoxic effects of a bracken fern aqueous extract in oral cell lines. Human submandibular gland (HSG) and human oral epithelium cells (OSCC-3) cells were treated with three different concentrations of the extract. DNA damage was determined by the comet assay, and cellular morphology was examined by light microscopy. Apoptotic changes were evaluated by transmission electron microscopy and TUNEL assay. The comet assay revealed that the extract was genotoxic for both cell lines but the results were not dose-dependent. The morphological and ultrastructural analyses showed that the extract caused conspicuous alterations in both cell types: uncommon chromatin condensation, nuclear picnosis, cellular volume decrease, nuclear envelope disruption, formation of numerous vacuoles of different sizes and apoptotic bodies. The TUNEL assay confirmed apoptosis induction. These results demonstrate that the extract was cytotoxic to HSG and OSCC-3 cells, and that cellular degeneration occurred mainly by apoptosis. We believe that oral cells could trigger apoptosis after bracken fern induced DNA damage, in order to avoid the malignant transformation.

  2. Epidermal Rac1 regulates the DNA damage response and protects from UV-light-induced keratinocyte apoptosis and skin carcinogenesis

    Science.gov (United States)

    Deshmukh, Jayesh; Pofahl, Ruth; Haase, Ingo

    2017-01-01

    Non-melanoma skin cancer (NMSC) is the most common type of cancer. Increased expression and activity of Rac1, a small Rho GTPase, has been shown previously in NMSC and other human cancers; suggesting that Rac1 may function as an oncogene in skin. DMBA/TPA skin carcinogenesis studies in mice have shown that Rac1 is required for chemically induced skin papilloma formation. However, UVB radiation by the sun, which causes DNA damage, is the most relevant cause for NMSC. A potential role of Rac1 in UV-light-induced skin carcinogenesis has not been investigated so far. To investigate this, we irradiated mice with epidermal Rac1 deficiency (Rac1-EKO) and their controls using a well-established protocol for long-term UV-irradiation. Most of the Rac1-EKO mice developed severe skin erosions upon long-term UV-irradiation, unlike their controls. These skin erosions in Rac1-EKO mice healed subsequently. Surprisingly, we observed development of squamous cell carcinomas (SCCs) within the UV-irradiation fields. This shows that the presence of Rac1 in the epidermis protects from UV-light-induced skin carcinogenesis. Short-term UV-irradiation experiments revealed increased UV-light-induced apoptosis of Rac1-deficient epidermal keratinocytes in vitro as well as in vivo. Further investigations using cyclobutane pyrimidine dimer photolyase transgenic mice revealed that the observed increase in UV-light-induced keratinocyte apoptosis in Rac1-EKO mice is DNA damage dependent and correlates with caspase-8 activation. Furthermore, Rac1-deficient keratinocytes showed reduced levels of p53, γ-H2AX and p-Chk1 suggesting an attenuated DNA damage response upon UV-irradiation. Taken together, our data provide direct evidence for a protective role of Rac1 in UV-light-induced skin carcinogenesis and keratinocyte apoptosis probably through regulating mechanisms of the DNA damage response and repair pathways. PMID:28277539

  3. Enterolactone: A novel radiosensitizer for human breast cancer cell lines through impaired DNA repair and increased apoptosis

    International Nuclear Information System (INIS)

    Bigdeli, Bahareh; Goliaei, Bahram; Masoudi-Khoram, Nastaran; Jooyan, Najmeh; Nikoofar, Alireza; Rouhani, Maryam; Haghparast, Abbas; Mamashli, Fatemeh

    2016-01-01

    Introduction: Radiotherapy is a potent treatment against breast cancer, which is the most commonly diagnosed cancer among women. However, the emergence of radioresistance due to increased DNA repair leads to radiotherapeutic failure. Applying polyphenols combined with radiation is a more promising method leading to better survival. Enterolactone, a phytoestrogenic polyphenol, has been reported to inhibit an important radioresistance signaling pathway, therefore we conjectured that enterolactone could enhance radiosensitivity in breast cancer. To assess this hypothesis, radiation response of enterolactone treated MDA-MB-231 and T47D cell lines and corresponding cellular mechanisms were investigated. Methods: Cytotoxicity of enterolactone was measured via MTT assay. Cells were treated with enterolactone before X-irradiation, and clonogenic assay was used to evaluate radiosensitivity. Cell cycle distribution and apoptosis were measured by flow cytometric analysis. In addition, DNA damages and corresponding repair, chromosomal damages, and aberrations were assessed by comet, micronucleus, and cytogenetic assays, respectively. Results: Enterolactone decreased the viability of cells in a concentration- and time dependent manner. Enterolactone significantly enhanced radiosensitivity of cells by abrogating G2/M arrest, impairing DNA repair, and increasing radiation-induced apoptosis. Furthermore, increased chromosomal damages and aberrations were detected in cells treated with enterolactone combined with X-rays than X-ray alone. These effects were more prominent in T47D than MDA-MB-231 cells. Discussion: To our knowledge, this is the first report that enterolactone is a novel radiosensitizer for breast cancer irrespective of estrogen receptor status. Authors propose enterolactone as a candidate for combined therapy to decrease the radiation dose delivered to patients and subsequent side effects. - Highlights: • Enterolactone is proposed to be a novel radiosensitizer for

  4. Mutagen Sensitivity, Apoptosis, and Polymorphism in DNA Repair as Measures of Prostate Cancer Risk

    National Research Council Canada - National Science Library

    Goldman, Radoslav

    2006-01-01

    .... We also created a computerized database of the samples in Microsoft Access. We developed assays for mutagen sensitivity, comet assay, and apoptosis in white blood cells exposed to bleomycin and ionizing radiation to evaluate...

  5. Antioxidative Dietary Compounds Modulate Gene Expression Associated with Apoptosis, DNA Repair, Inhibition of Cell Proliferation and Migration

    Directory of Open Access Journals (Sweden)

    Likui Wang

    2014-09-01

    Full Text Available Many dietary compounds are known to have health benefits owing to their antioxidative and anti-inflammatory properties. To determine the molecular mechanism of these food-derived compounds, we analyzed their effect on various genes related to cell apoptosis, DNA damage and repair, oxidation and inflammation using in vitro cell culture assays. This review further tests the hypothesis proposed previously that downstream products of COX-2 (cyclooxygenase-2 called electrophilic oxo-derivatives induce antioxidant responsive elements (ARE, which leads to cell proliferation under antioxidative conditions. Our findings support this hypothesis and show that cell proliferation was inhibited when COX-2 was down-regulated by polyphenols and polysaccharides. Flattened macrophage morphology was also observed following the induction of cytokine production by polysaccharides extracted from viili, a traditional Nordic fermented dairy product. Coix lacryma-jobi (coix polysaccharides were found to reduce mitochondrial membrane potential and induce caspase-3- and 9-mediated apoptosis. In contrast, polyphenols from blueberries were involved in the ultraviolet-activated p53/Gadd45/MDM2 DNA repair system by restoring the cell membrane potential. Inhibition of hypoxia-inducible factor-1 by saponin extracts of ginsenoside (Ginsen and Gynostemma and inhibition of S100A4 by coix polysaccharides inhibited cancer cell migration and invasion. These observations suggest that antioxidants and changes in cell membrane potential are the major driving forces that transfer signals through the cell membrane into the cytosol and nucleus, triggering gene expression, changes in cell proliferation and the induction of apoptosis or DNA repair.

  6. Copper complexes based on chiral Schiff-base ligands: DNA/BSA binding ability, DNA cleavage activity, cytotoxicity and mechanism of apoptosis.

    Science.gov (United States)

    Zhou, Xue-Quan; Li, Yang; Zhang, Dong-Yan; Nie, Yan; Li, Zong-Jin; Gu, Wen; Liu, Xin; Tian, Jin-Lei; Yan, Shi-Ping

    2016-05-23

    Four copper(II) complexes with chiral Schiff-base ligands, [Cu(R-L(1))2]·EtOAc (1) and [Cu(S-L(1))2]·EtOAc (2), [Cu(R-L(2))2]·EtOAc (3) and [Cu(S-L(2))2]·EtOAc (4), (R/S-HL(1) = (R/S)-(1-naththyl)-salicylaldimine, R/S-HL(2) = (R/S)-(1-naththyl)-3-methoxysalicylaldimine, EtOAc = ethyl acetate) were synthesized to serve as artificial nucleases and anticancer drugs. All complexes and R/S-HL(1) ligands were structurally characterized by X-ray crystallography. The interaction of these complexes with CT-DNA was researched via several spectroscopy methods, which indicates that complexes bind to CT-DNA by moderate intercalation binding mode. Moreover, DNA cleavage experiments revealed that the complexes exhibited remarkable DNA cleavage activities in the presence of H2O2via the generation of hydroxyl radical. Particularly, complex 4 also could nick DNA with the production of (1)O2. And all complexes exhibited excellent cytotoxicity to MDA-MB-231, A549 and Hela human cancer cells in micromole magnitude. Furthermore, complex 4 exhibited comparable cytotoxic effect to cisplatin against the proliferation of MDA-MB-231 and A549 cancer cells, as well as showed better anticancer ability to the three cancer cells than the other complexes. The results of cell cycle analysis indicated that complexes 3-4 could induce G2/M phase cell cycle arrest. Furthermore, MDA-MB-231 cells treated with 3 and 4 were subjected to apoptosis and death by generation of ROS and the activation of caspase-3. Interestingly, the chiral complexes 3 and 4 may induce cell apoptosis through extrinsic and mitochondrial intrinsic pathway, respectively. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  7. The content of DNA and RNA in microparticles released by Jurkat and HL-60 cells undergoing in vitro apoptosis.

    Science.gov (United States)

    Reich, Charles F; Pisetsky, David S

    2009-03-10

    Microparticles are small membrane-bound vesicles that are released from apoptotic cells during blebbing. These particles contain DNA and RNA and display important functional activities, including immune system activation. Furthermore, nucleic acids inside the particle can be analyzed as biomarkers in a variety of disease states. To elucidate the nature of microparticle nucleic acids, DNA and RNA released in microparticles from the Jurkat T and HL-60 promyelocytic cell lines undergoing apoptosis in vitro were studied. Microparticles were isolated from culture media by differential centrifugation and characterized by flow cytometry and molecular approaches. In these particles, DNA showed laddering by gel electrophoresis and was present in a form that allowed direct binding by a monoclonal anti-DNA antibody, suggesting antigen accessibility even without fixation. Analysis of RNA by gel electrophoresis showed intact 18s and 28s ribosomal RNA bands, although lower molecular bands consistent with 28s ribosomal RNA degradation products were also present. Particles also contained messenger RNA as shown by RT-PCR amplification of sequences for beta-actin and GAPDH. In addition, gel electrophoresis showed the presence of low molecular weight RNA in the size range of microRNA. Together, these results indicate that microparticles from apoptotic Jurkat and HL-60 cells contain diverse nucleic acid species, indicating translocation of both nuclear and cytoplasmic DNA and RNA as particle release occurs during death.

  8. The content of DNA and RNA in microparticles released by Jurkat and HL-60 cells undergoing in vitro apoptosis

    International Nuclear Information System (INIS)

    Reich, Charles F.; Pisetsky, David S.

    2009-01-01

    Microparticles are small membrane-bound vesicles that are released from apoptotic cells during blebbing. These particles contain DNA and RNA and display important functional activities, including immune system activation. Furthermore, nucleic acids inside the particle can be analyzed as biomarkers in a variety of disease states. To elucidate the nature of microparticle nucleic acids, DNA and RNA released in microparticles from the Jurkat T and HL-60 promyelocytic cell lines undergoing apoptosis in vitro were studied. Microparticles were isolated from culture media by differential centrifugation and characterized by flow cytometry and molecular approaches. In these particles, DNA showed laddering by gel electrophoresis and was present in a form that allowed direct binding by a monoclonal anti-DNA antibody, suggesting antigen accessibility even without fixation. Analysis of RNA by gel electrophoresis showed intact 18s and 28s ribosomal RNA bands, although lower molecular bands consistent with 28s ribosomal RNA degradation products were also present. Particles also contained messenger RNA as shown by RT-PCR amplification of sequences for β-actin and GAPDH. In addition, gel electrophoresis showed the presence of low molecular weight RNA in the size range of microRNA. Together, these results indicate that microparticles from apoptotic Jurkat and HL-60 cells contain diverse nucleic acid species, indicating translocation of both nuclear and cytoplasmic DNA and RNA as particle release occurs during death

  9. Chk2 regulates transcription-independent p53-mediated apoptosis in response to DNA damage

    International Nuclear Information System (INIS)

    Chen Chen; Shimizu, Shigeomi; Tsujimoto, Yoshihide; Motoyama, Noboru

    2005-01-01

    The tumor suppressor protein p53 plays a central role in the induction of apoptosis in response to genotoxic stress. The protein kinase Chk2 is an important regulator of p53 function in mammalian cells exposed to ionizing radiation (IR). Cells derived from Chk2-deficient mice are resistant to the induction of apoptosis by IR, and this resistance has been thought to be a result of the defective transcriptional activation of p53 target genes. It was recently shown, however, that p53 itself and histone H1.2 translocate to mitochondria and thereby induces apoptosis in a transcription-independent manner in response to IR. We have now examined whether Chk2 also regulates the transcription-independent induction of apoptosis by p53 and histone H1.2. The reduced ability of IR to induce p53 stabilization in Chk2-deficient thymocytes was associated with a marked impairment of p53 and histone H1 translocation to mitochondria. These results suggest that Chk2 regulates the transcription-independent mechanism of p53-mediated apoptosis by inducing stabilization of p53 in response to IR

  10. Silver nanoparticles protect human keratinocytes against UVB radiation-induced DNA damage and apoptosis: potential for prevention of skin carcinogenesis

    Science.gov (United States)

    Arora, Sumit; Tyagi, Nikhil; Bhardwaj, Arun; Rusu, Lilia; Palanki, Rohan; Vig, Komal; Singh, Shree R.; Singh, Ajay P.; Palanki, Srinivas; Miller, Michael E.; Carter, James E.; Singh, Seema

    2015-01-01

    Ultraviolet (UV)-B radiation from the sun is an established etiological cause of skin cancer, which afflicts more than a million lives each year in the United States alone. Here, we tested the chemopreventive efficacy of silver-nanoparticles (AgNPs) against UVB-irradiation-induced DNA damage and apoptosis in human immortalized keratinocytes (HaCaT). AgNPs were synthesized by reduction-chemistry and characterized for their physicochemical properties. AgNPs were well tolerated by HaCaT cells and their pretreatment protected them from UVB-irradiation-induced apoptosis along with significant reduction in cyclobutane-pyrimidine-dimer formation. Moreover, AgNPs pre-treatment led to G1-phase cell-cycle arrest in UVB-irradiated HaCaT cells. AgNPs were efficiently internalized in UVB-irradiated cells and localized into cytoplasmic and nuclear compartments. Furthermore, we observed an altered expression of various genes involved in cell-cycle, apoptosis and nucleotide-excision repair in HaCaT cells treated with AgNPs prior to UVB-irradiation. Together, these findings provide support for potential utility of AgNPs as novel chemopreventive agents against UVB-irradiation-induced skin carcinogenesis. PMID:25804413

  11. Ternary copper(II) complexes with amino acid chains and heterocyclic bases: DNA binding, cytotoxic and cell apoptosis induction properties.

    Science.gov (United States)

    Ma, Tieliang; Xu, Jun; Wang, Yuan; Yu, Hao; Yang, Yong; Liu, Yang; Ding, Weiliang; Zhu, Wenjiao; Chen, Ruhua; Ge, Zhijun; Tan, Yongfei; Jia, Lei; Zhu, Taofeng

    2015-03-01

    Nowadays, chemotherapy is a common means of oncology. However, it is difficult to find excellent chemotherapy drugs. Here we reported three new ternary copper(II) complexes which have potential chemotherapy characteristics with reduced Schiff base ligand and heterocyclic bases (TBHP), [Cu(phen)(TBHP)]H2O (1), [Cu(dpz)(TBHP)]H2O (2) and [Cu(dppz)(TBHP)]H2O (3) (phen=1,10-phenanthroline, dpz=dipyrido [3,2:2',3'-f]quinoxaline, dppz=dipyrido [3,2-a:2',3'-c]phenazine, H2TBHP=2-(3,5-di-tert-butyl-2-hydroxybenzylamino)-2-benzyl-acetic acid). The DNA-binding properties of the complexes were investigated by spectrometric titrations, ethidium bromide displacement experiments and viscosity measurements. The results indicated that the three complexes, especially the complex 13, can strongly bind to calf-thymus DNA (CT-DNA). The intrinsic binding constants Kb of the ternary copper(II) complexes with CT-DNA were 1.37×10(5), 1.81×10(5) and 3.21×10(5) for 1, 2 and 3 respectively. Comparative cytotoxic activities of the copper(II) complexes were also determined by 3-(4,5-dimethylthiazol-2yl)-2,5-diphenyltetrazolium bromide (MTT) assay. The results showed that the ternary copper(II) complexes had significant cytotoxic activity against the human lung cancer (A549), human esophageal cancer (Eca109) and human gastric cancer (SGC7901) cell lines. Cell apoptosis were detected by AnnexinV/PI flow cytometry and by Western blotting with the protein expression of p53, Bax and Bcl-2. All the three copper complexes can effectively induce apoptosis of the three human tumor cells. Copyright © 2014 Elsevier Inc. All rights reserved.

  12. The prevention of radiation-induced DNA damage and apoptosis in human intestinal epithelial cells by salvianic acid A

    Directory of Open Access Journals (Sweden)

    Yanjun Zhang

    2014-07-01

    Full Text Available The topic of radiation always provokes public debate, and the uses of radiation for therapeutic and other purposes have always been associated with some anxiety. Salvia miltiorrhiza Bunge has been widely used for the treatment of various diseases including cerebrovascular diseases, coronary artery diseases, and myocardial infarction. Salvianolic acid A (SAA d (+-(3,4-dihydroxyphenyl lactic acid is the principal effective, watersoluble constituent of Salvia miltiorrhiza Bunge. In our present study, radiation-induced DNA damage and apoptosis in human intestinal epithelial cells (HIEC in the presence and absence of SAA were examined. We investigated the effects of SAA on ROS formation and the activity of enzymatic antioxidants (SOD, the lipid peroxidative index and the levels of non-enzymatic antioxidant (GSH. Finally, we investigated whether the reduction of radiation-induced cell death caused by SAA might be related to mitochondria-dependent apoptosis. Present findings indicate that SAA is a promising radioprotective agent with a strong antioxidant activity. SAA exerted its protective action on the proliferative activity of HIEC cells as evidenced by decreased cytotoxicity after exposure to γ-radiation. It is possible that SAA achieved its radioprotective action, at least in part, by enhancing DNA repair and the activity of antioxidant enzymes, by scavenging ROS and by inhibiting the mitochondria-dependent apoptotic pathway.

  13. miR-520 promotes DNA-damage-induced trophoblast cell apoptosis by targeting PARP1 in recurrent spontaneous abortion (RSA).

    Science.gov (United States)

    Dong, Xiujuan; Yang, Long; Wang, Hui

    2017-04-01

    The establishment and maintenance of successful pregnancy mainly depends on trophoblast cells. Their dysfunction has been implicated in recurrent spontaneous abortion (RSA), a major complication of pregnancy. However, the underlying mechanisms of trophoblasts dysfunction remain unclear. DNA-damage-induced cell apoptosis has been reported to play a vital role in cell death. In this study, we identified a novel microRNA (miR-520) in RSA progression via regulating trophoblast cell apoptosis. Microarray analysis showed that miR-520 was highly expressed in villus of RSA patients. By using flow cytometry analysis, we observed miR-520 expression was correlated with human trophoblast cell apoptosis in vitro, along with decreased poly (ADP-ribose) polymerase-1 (PARP1) expression. With the analysis of clinic samples, we observed that miR-520 level was negatively correlated with PARP1 level in RSA villus. In addition, overexpression of PARP1 restored the miR-520-induced trophoblast cell apoptosis in vitro. The status of chromosome in trophoblast implied that miR-520-promoted DNA-damage-induced cell apoptosis to regulate RSA progression. These results indicated that the level of miR-520 might associate with RSA by prompting trophoblast cell apoptosis via PARP1 dependent DNA-damage pathway.

  14. Modulation of DNA methylation levels sensitizes doxorubicin-resistant breast adenocarcinoma cells to radiation-induced apoptosis

    Energy Technology Data Exchange (ETDEWEB)

    Luzhna, Lidia [Department of Biological Sciences, University of Lethbridge, AB, Canada T1K 3M4 (Canada); Kovalchuk, Olga, E-mail: olga.kovalchuk@uleth.ca [Department of Biological Sciences, University of Lethbridge, AB, Canada T1K 3M4 (Canada)

    2010-02-05

    Chemoresistant tumors often fail to respond to other cytotoxic treatments such as radiation therapy. The mechanisms of chemo- and radiotherapy cross resistance are not fully understood and are believed to be epigenetic in nature. We hypothesize that MCF-7 cells and their doxorubicin-resistant variant MCF-7/DOX cells may exhibit different responses to ionizing radiation due to their dissimilar epigenetic status. Similar to previous studies, we found that MCF-7/DOX cells harbor much lower levels of global DNA methylation than MCF-7 cells. Furthermore, we found that MCF-7/DOX cells had lower background apoptosis levels and were less responsive to radiation than MCF-7 cells. Decreased radiation responsiveness correlated to significant global DNA hypomethylation in MCF-7/DOX cells. Here, for the first time, we show that the radiation resistance of MCF-7/DOX cells can be reversed by an epigenetic treatment - the application of methyl-donor SAM. SAM-mediated reversal of DNA methylation led to elevated radiation sensitivity in MCF-7/DOX cells. Contrarily, application of SAM on the radiation sensitive and higher methylated MCF-7 cells resulted in a decrease in their radiation responsiveness. This data suggests that a fine balance of DNA methylation is needed to insure proper radiation and drug responsiveness.

  15. Effect of stainless steel manual metal arc welding fume on free radical production, DNA damage, and apoptosis induction.

    Science.gov (United States)

    Antonini, James M; Leonard, Stephen S; Roberts, Jenny R; Solano-Lopez, Claudia; Young, Shih-Houng; Shi, Xianglin; Taylor, Michael D

    2005-11-01

    Questions exist concerning the potential carcinogenic effects after welding fume exposure. Welding processes that use stainless steel (SS) materials can produce fumes that may contain metals (e.g., Cr, Ni) known to be carcinogenic to humans. The objective was to determine the effect of in vitro and in vivo welding fume treatment on free radical generation, DNA damage, cytotoxicity and apoptosis induction, all factors possibly involved with the pathogenesis of lung cancer. SS welding fume was collected during manual metal arc welding (MMA). Elemental analysis indicated that the MMA-SS sample was highly soluble in water, and a majority (87%) of the soluble metal was Cr. Using electron spin resonance (ESR), the SS welding fume had the ability to produce the biologically reactive hydroxyl radical (*OH), likely as a result of the reduction of Cr(VI) to Cr(V). In vitro treatment with the MMA-SS sample caused a concentration-dependent increase in DNA damage and lung macrophage death. In addition, a time-dependent increase in the number of apoptotic cells in lung tissue was observed after in vivo treatment with the welding fume. In summary, a soluble MMA-SS welding fume was found to generate reactive oxygen species and cause DNA damage, lung macrophage cytotoxicity and in vivo lung cell apoptosis. These responses have been shown to be involved in various toxicological and carcinogenic processes. The effects observed appear to be related to the soluble component of the MMA-SS sample that is predominately Cr. A more comprehensive in vivo animal study is ongoing in the laboratory that is continuing these experiments to try to elucidate the potential mechanisms that may be involved with welding fume-induced lung disease.

  16. DNA damage and DNA damage response in human bronchial epithelial BEAS-2B cells following exposure to 2-nitrobenzanthrone and 3-nitrobenzanthrone: role in apoptosis.

    Science.gov (United States)

    Oya, Elisabeth; Ovrevik, Johan; Arlt, Volker M; Nagy, Eszter; Phillips, David H; Holme, Jørn A

    2011-11-01

    Nitro-polycyclic aromatic hydrocarbons (nitro-PAHs) are mutagenic and carcinogenic environmental pollutants found in diesel exhaust and on urban air pollution particles. In the present study, human bronchial epithelial BEAS-2B cells were exposed to 2-nitrobenzanthrone (2-NBA) and 3-nitrobenzanthrone (3-NBA). DNA damage responses were compared to those observed after exposure to 1-nitropyrene (1-NP) and benzo[a]pyrene (B[a]P). Examination by microscopy revealed that 3-NBA was the most potent toxic compound while weaker responses were observed with 1-NP and B[a]P. Most interestingly, 2-NBA did not induce cell death or any other stress-related responses. 3-NBA induced a typical apoptotic cell death judged by nuclear condensation and little plasma membrane damage as well as cleavage of caspase 3 and poly-(ADP-ribose) polymerase (PARP). Exposure to 3-NBA resulted in an accumulation of cells in S-phase, and further analysis by Western blotting, immunocytochemistry and flow cytometry revealed that 3-NBA induced a DNA damage response characterized by phosphorylation of ATM (ataxia-telangiectasia mutated), checkpoint kinase (Chk) 2/Chk1, H2AX and p53. The p53 inhibitor pifithrin-α inhibited 3-NBA-induced apoptosis while small effects were seen using pifithrin-μ, suggesting that 3-NBA-induced cell death is a result of transcriptional activation of p53. In conclusion, 3-NBA is a potent inducer of apoptosis, which seemed to be triggered by the DNA damage response. Furthermore, a change of the nitro-group to the second position (i.e. 2-NBA) dramatically changed the cellular reactivity of the compound.

  17. Common genomic signaling among initial DNA damage and radiation-induced apoptosis in peripheral blood lymphocytes from locally advanced breast cancer patients

    DEFF Research Database (Denmark)

    Henríquez-Hernández, Luis Alberto; Pinar, Beatriz; Carmona-Vigo, Ruth

    2013-01-01

    PURPOSE: To investigate the genomic signaling that defines sensitive lymphocytes to radiation and if such molecular profiles are consistent with clinical toxicity; trying to disclose the radiobiology mechanisms behind these cellular processes. PATIENTS AND METHODS: Twelve consecutive patients...... suffering from locally advanced breast cancer and treated with high-dose hyperfractionated radiotherapy were recruited. Initial DNA damage was measured by pulsed-field gel electrophoresis and radiation-induced apoptosis was measured by flow cytometry. Gene expression was assessed by DNA microarray. RESULTS...

  18. The limits of de novo DNA motif discovery.

    Directory of Open Access Journals (Sweden)

    David Simcha

    Full Text Available A major challenge in molecular biology is reverse-engineering the cis-regulatory logic that plays a major role in the control of gene expression. This program includes searching through DNA sequences to identify "motifs" that serve as the binding sites for transcription factors or, more generally, are predictive of gene expression across cellular conditions. Several approaches have been proposed for de novo motif discovery-searching sequences without prior knowledge of binding sites or nucleotide patterns. However, unbiased validation is not straightforward. We consider two approaches to unbiased validation of discovered motifs: testing the statistical significance of a motif using a DNA "background" sequence model to represent the null hypothesis and measuring performance in predicting membership in gene clusters. We demonstrate that the background models typically used are "too null," resulting in overly optimistic assessments of significance, and argue that performance in predicting TF binding or expression patterns from DNA motifs should be assessed by held-out data, as in predictive learning. Applying this criterion to common motif discovery methods resulted in universally poor performance, although there is a marked improvement when motifs are statistically significant against real background sequences. Moreover, on synthetic data where "ground truth" is known, discriminative performance of all algorithms is far below the theoretical upper bound, with pronounced "over-fitting" in training. A key conclusion from this work is that the failure of de novo discovery approaches to accurately identify motifs is basically due to statistical intractability resulting from the fixed size of co-regulated gene clusters, and thus such failures do not necessarily provide evidence that unfound motifs are not active biologically. Consequently, the use of prior knowledge to enhance motif discovery is not just advantageous but necessary. An implementation of

  19. DNA damage-induced primordial follicle oocyte apoptosis and loss of fertility require TAp63-mediated induction of Puma and Noxa

    Science.gov (United States)

    Kerr, Jeffrey B.; Hutt, Karla J.; Michalak, Ewa M.; Cook, Michele; Vandenberg, Cassandra J.; Liew, Seng H.; Bouillet, Philippe; Mills, Alea; Scott, Clare L.; Findlay, Jock K.; Strasser, Andreas

    2012-01-01

    SUMMARY Trp63, a transcription factor related to the tumor suppressor p53, is activated by diverse stimuli and can initiate a range of cellular responses. TAp63 is the predominant Trp53 family member in primordial follicle oocytes and essential for their apoptosis triggered by DNA damage in vivo. Following γ-irradiation, induction of the pro-apoptotic BH3-only members Puma and Noxa was observed in primordial follicle oocytes from wt and Trp53−/− mice but not in those from TAp63 deficient mice. Primordial follicle oocytes from mice lacking Puma or both Puma and Noxa were protected from γ-irradiation-induced apoptosis and, remarkably, could produce healthy offspring. Hence, PUMA and NOXA are critical for DNA damage-induced, TAp63-mediated primordial follicle oocyte apoptosis. Thus, blockade of PUMA may protect fertility during cancer therapy and prevent premature menopause, improving women’s health. PMID:23000175

  20. 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

  1. Complexation of DNA with ruthenium organometallic compounds: the high complexation ratio limit.

    Science.gov (United States)

    Despax, Stéphane; Jia, Fuchao; Pfeffer, Michel; Hébraud, Pascal

    2014-06-14

    Interactions between DNA and ruthenium organometallic compounds are studied by using visible light absorption and circular dichroism measurements. A titration technique allowing for the absolute determination of the advancement degree of the complexation, without any assumption about the number of complexation modes is developed. When DNA is in excess, complexation involves intercalation of one of the organometallic compound ligands between DNA base pairs. But, in the high complexation ratio limit, where organometallic compounds are in excess relative to the DNA base pairs, a new mode of interaction is observed, in which the organometallic compound interacts weakly with DNA. The weak interaction mode, moreover, develops when all the DNA intercalation sites are occupied. A regime is reached in which one DNA base pair is linked to more than one organometallic compound.

  2. UV Differentially Induces Oxidative Stress, DNA Damage and Apoptosis in BCR-ABL1-Positive Cells Sensitive and Resistant to Imatinib

    Science.gov (United States)

    Synowiec, Ewelina; Hoser, Grazyna; Wojcik, Katarzyna; Pawlowska, Elzbieta; Skorski, Tomasz; Błasiak, Janusz

    2015-01-01

    Chronic myeloid leukemia (CML) cells express the active BCR-ABL1 protein, which has been targeted by imatinib in CML therapy, but resistance to this drug is an emerging problem. BCR-ABL1 induces endogenous oxidative stress promoting genomic instability and imatinib resistance. In the present work, we investigated the extent of oxidative stress, DNA damage, apoptosis and expression of apoptosis-related genes in BCR-ABL1 cells sensitive and resistant to imatinib. The resistance resulted either from the Y253H mutation in the BCR-ABL1 gene or incubation in increasing concentrations of imatinib (AR). UV irradiation at a dose rate of 0.12 J/(m2·s) induced more DNA damage detected by the T4 pyrimidine dimers glycosylase and hOGG1, recognizing oxidative modifications to DNA bases in imatinib-resistant than -sensitive cells. The resistant cells displayed also higher susceptibility to UV-induced apoptosis. These cells had lower native mitochondrial membrane potential than imatinib-sensitive cells, but UV-irradiation reversed that relationship. We observed a significant lowering of the expression of the succinate dehydrogenase (SDHB) gene, encoding a component of the complex II of the mitochondrial respiratory chain, which is involved in apoptosis sensing. Although detailed mechanism of imatinib resistance in AR cells in unknown, we detected the presence of the Y253H mutation in a fraction of these cells. In conclusion, imatinib-resistant cells may display a different extent of genome instability than their imatinib-sensitive counterparts, which may follow their different reactions to both endogenous and exogenous DNA-damaging factors, including DNA repair and apoptosis. PMID:26251899

  3. Evaluation of the nuclear DNA Diffusion Assay to detect apoptosis and necrosis

    Czech Academy of Sciences Publication Activity Database

    Gichner, Tomáš; Mukherjee, A.; Wagner, E. D.; Plewa, M. J.

    2005-01-01

    Roč. 586, č. 1 (2005), s. 38-46 ISSN 1383-5718 R&D Projects: GA ČR GA521/05/0500 Institutional research plan: CEZ:AV0Z50380511 Keywords : DNa se-I * Ethyl methanesulphonate * Hydrogen peroxide Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 2.188, year: 2005

  4. PTEN counteracts FBXL2 to promote IP3R3- and Ca2+-mediated apoptosis limiting tumour growth.

    Science.gov (United States)

    Kuchay, Shafi; Giorgi, Carlotta; Simoneschi, Daniele; Pagan, Julia; Missiroli, Sonia; Saraf, Anita; Florens, Laurence; Washburn, Michael P; Collazo-Lorduy, Ana; Castillo-Martin, Mireia; Cordon-Cardo, Carlos; Sebti, Said M; Pinton, Paolo; Pagano, Michele

    2017-06-22

    In response to environmental cues that promote IP3 (inositol 1,4,5-trisphosphate) generation, IP3 receptors (IP3Rs) located on the endoplasmic reticulum allow the 'quasisynaptical' feeding of calcium to the mitochondria to promote oxidative phosphorylation. However, persistent Ca 2+ release results in mitochondrial Ca 2+ overload and consequent apoptosis. Among the three mammalian IP3Rs, IP3R3 appears to be the major player in Ca 2+ -dependent apoptosis. Here we show that the F-box protein FBXL2 (the receptor subunit of one of 69 human SCF (SKP1, CUL1, F-box protein) ubiquitin ligase complexes) binds IP3R3 and targets it for ubiquitin-, p97- and proteasome-mediated degradation to limit Ca 2+ influx into mitochondria. FBXL2-knockdown cells and FBXL2-insensitive IP3R3 mutant knock-in clones display increased cytosolic Ca 2+ release from the endoplasmic reticulum and sensitization to Ca 2+ -dependent apoptotic stimuli. The phosphatase and tensin homologue (PTEN) gene is frequently mutated or lost in human tumours and syndromes that predispose individuals to cancer. We found that PTEN competes with FBXL2 for IP3R3 binding, and the FBXL2-dependent degradation of IP3R3 is accelerated in Pten -/- mouse embryonic fibroblasts and PTEN-null cancer cells. Reconstitution of PTEN-null cells with either wild-type PTEN or a catalytically dead mutant stabilizes IP3R3 and induces persistent Ca 2+ mobilization and apoptosis. IP3R3 and PTEN protein levels directly correlate in human prostate cancer. Both in cell culture and xenograft models, a non-degradable IP3R3 mutant sensitizes tumour cells with low or no PTEN expression to photodynamic therapy, which is based on the ability of photosensitizer drugs to cause Ca 2+ -dependent cytotoxicity after irradiation with visible light. Similarly, disruption of FBXL2 localization with GGTi-2418, a geranylgeranyl transferase inhibitor, sensitizes xenotransplanted tumours to photodynamic therapy. In summary, we identify a novel molecular

  5. [Construction of anti-sense cDNA library of human breast cancer cells during apoptosis induced by trichostatin A and preliminary screening of essential genes].

    Science.gov (United States)

    Ma, Xiao-Li; Wang, Bei-Bei; Wu, Peng; Lu, Yun-Ping; Zhou, Jian-Feng; Ma, Ding

    2009-02-24

    To construct an anti-sense cDNA library of human breast cancer cells to screen essential genes with anti-tumor effects on apoptosis of human breast cancer cells induced by trichostatin A. Poly (A)(+)RNA was extracted from human breast cancer cells of the line MCF-7 treated by trichostatin A for 0, 12, 24, 36, 48, 60, or 72 h. cDNA were synthesized and inserted reversely into PCEP 4 vector to construct an anti-sense cDNA library. HeLa cells were transfected with the library DNA or blank PCEP 4 vector as control group. All the transfected cells were screened by 200 nmol/L trichostatin A and 200 microg/ml hygromycin B. Screening was stopped when the control cells died. Then the surviving cell clones were amplified and Hirt DNA was extracted. Several expressed sequence tags were thus obtained. The data were analyzed by bioinformatics and interested EST fragment was chosen for preliminary functional screening. An anti-sense cDNA library was constructed containing 2 x 10(6) independent clones with an insert efficiency of more than 90%; DNA sequencing and bioinformatic analysis suggested that the No.27 survival clone was zinc transporter LIV1 showing a strong resistance against trichostatin A-induced apoptosis during functional screening. An anti-sense cDNA library with high quantity and quality has been successfully constructed; LIV1 gene may be one of the essential genes with anti-tumor effects on apoptosis induced by trichostatin A.

  6. Opposed arsenite-mediated regulation of p53-survivin is involved in neoplastic transformation, DNA damage, or apoptosis in human keratinocytes

    International Nuclear Information System (INIS)

    Li, Yuan; Jiang, Rongrong; Zhao, Yue; Xu, Yuan; Ling, Min; Pang, Ying; Shen, Lu; Zhou, Yun; Zhang, Jianping; Zhou, Jianwei; Wang, Xinru; Liu, Qizhan

    2012-01-01

    Highlights: ► Different concentrations of arsenite cause biphasic effects in HaCaT cells. ► p53-survivin signal pathway plays a role in arsenite-induced biphasic effects. ► ERKs inactivate p53, but improve survivin expression by NF-κB/mot-2. ► JNKs block survivin expression by preventing p53 from mdm2-mediated degradation. ► ERKs and JNKs play roles in arsenite-induced biphasic effects. -- Abstract: Biphasic dose–response relationship induced by environmental agents is often characterized with the effect of low-dose stimulation and high dose inhibition. Some studies showed that arsenite may induce cell proliferation and apoptosis via biphasic dose–response relationship in human cells; however, mechanisms underlying this phenomenon are not well understood. Our present study shows that, for human keratinocytes (HaCaT) cells, a low concentration of arsenite activates extracellular signal-regulated kinases (ERKs), which leads to up-regulation of nuclear factor κB (NF-κB) binding to DNA and to elevated, NF-κB-dependent expression of mot-2 (a p53 inhibitor) and survivin (an inhibitor of apoptosis). Activation of p53 is blocked, and neoplastic transformation is enhanced. Inhibition of ERKs reduces cell proliferation and neoplastic transformation. In contrast, a high concentration of arsenite activates c-Jun N-terminal kinases (JNKs), positive regulators of p53, by binding to p53 and preventing its murine double minute 2 (mdm2)-mediated degradation. The elevated levels of p53 lead to repair of DNA damage and apoptosis. Inhibition of JNKs increases DNA damage but decreases apoptosis. By identifying a mechanism whereby ERKs and JNKs-mediated regulation of the p53-survivin signal pathway is involved in the biphasic effects of arsenite on human keratinocytes, our data expand understanding of arsenite-induced cell proliferation, neoplastic transformation, DNA damage, and apoptosis.

  7. JA, a new type of polyunsaturated fatty acid isolated from Juglans mandshurica Maxim, limits the survival and induces apoptosis of heptocarcinoma cells.

    Science.gov (United States)

    Gao, Xiu-Li; Lin, Hua; Zhao, Wei; Hou, Ya-Qin; Bao, Yong-Li; Song, Zhen-Bo; Sun, Lu-Guo; Tian, Shang-Yi; Liu, Biao; Li, Yu-Xin

    2016-03-01

    Juglans mandshurica Maxim (Juglandaceae) is a famous folk medicine for cancer treatment and some natural compounds isolated from it have been studied extensively. Previously we isolated a type of ω-9 polyunsaturated fatty acid (JA) from the bark of J. mandshurica, however little is known about its activity and the underlying mechanisms. In this study, we studied anti-tumor activity of JA on several human cancer cell lines. Results showed that JA is cytotoxic to HepG2, MDA-MB-231, SGC-7901, A549 and Huh7 cells at a concentration exerting minimal toxic effects on L02 cells. The selective toxicity of JA was better than other classical anti-cancer drugs. Further investigation indicated that JA could induce cell apoptosis, characterized by chromatin condensation, DNA fragmentation and activation of the apoptosis-associated proteins such as Caspase-3 and PARP-1. Moreover, we investigated the cellular apoptosis pathway involved in the apoptosis process in HepG2 cells. We found that proteins involved in mitochondrion (cleaved-Caspase-9, Apaf-1, HtrA2/Omi, Bax, and Mitochondrial Bax) and endocytoplasmic reticulum (XBP-1s, GRP78, cleaved-Caspase-7 and cleaved-Caspase-12) apoptotic pathways were up-regulated when cells were treated by JA. In addition, a morphological change in the mitochondrion was detected. Furthermore, we found that JA could inhibit DNA synthesis and induce G2/M cell cycle arrest. The expression of G2-to-M transition related proteins, such as CyclinB1 and phosphorylated-CDK1, were reduced. In contrast, the G2-to-M inhibitor p21 was increased in JA-treated cells. Overall, our results suggest that JA can induce mitochondrion- and endocytoplasmic reticulum-mediated apoptosis, and G2/M phase arrest in HepG2 cells, making it a promising therapeutic agent against hepatoma.

  8. DAZL Limits Pluripotency, Differentiation, and Apoptosis in Developing Primordial Germ Cells

    Directory of Open Access Journals (Sweden)

    Hsu-Hsin Chen

    2014-11-01

    Full Text Available The scarcity of primordial germ cells (PGCs in the developing mammalian embryo hampers robust biochemical analysis of the processes that underlie early germ cell formation. Here, we demonstrate that DAZL, a germ cell-specific RNA binding protein, is a robust PGC marker during in vitro germ cell development. Using Dazl-GFP reporter ESCs, we demonstrate that DAZL plays a central role in a large mRNA/protein interactive network that blocks the translation of core pluripotency factors, including Sox2 and Sall4, as well as of Suz12, a polycomb family member required for differentiation of pluripotent cells. Thus, DAZL limits both pluripotency and somatic differentiation in nascent PGCs. In addition, we observed that DAZL associates with mRNAs of key Caspases and similarly inhibits their translation. This elegant fail-safe mechanism ensures that, whereas loss of DAZL results in prolonged expression of pluripotency factors, teratoma formation is avoided due to the concomitant activation of the apoptotic cascade.

  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. Two coffins and a funeral: early or late caspase activation determines two types of apoptosis induced by DNA damaging agents.

    Science.gov (United States)

    Oropesa-Ávila, Manuel; de la Cruz-Ojeda, Patricia; Porcuna, Jesús; Villanueva-Paz, Marina; Fernández-Vega, Alejandro; de la Mata, Mario; de Lavera, Isabel; Rivero, Juan Miguel Suarez; Luzón-Hidalgo, Raquel; Álvarez-Córdoba, Mónica; Cotán, David; Zaderenko, Ana Paula; Cordero, Mario D; Sánchez-Alcázar, José A

    2017-03-01

    Cell cytoskeleton makes profound changes during apoptosis including the organization of an Apoptotic Microtubule Network (AMN). AMN forms a cortical structure which plays an important role in preserving plasma membrane integrity during apoptosis. Here, we examined the cytoskeleton rearrangements during apoptosis induced by camptothecin (CPT), a topoisomerase I inhibitor, in human H460 and porcine LLCPK-1α cells. Using fixed and living cell imaging, we showed that CPT induced two dose- and cell cycle-dependent types of apoptosis characterized by different cytoskeleton reorganizations, time-dependent caspase activation and final apoptotic cell morphology. In the one referred as "slow" (~h) or round-shaped, apoptosis was characterized by a slow contraction of the actinomyosin ring and late caspase activation. In "slow" apoptosis the γ-tubulin complexes were not disorganized and microtubules were not depolymerized at early stages. In contrast, "fast" (~min) or irregular-shaped apoptosis was characterized by early caspase activation followed by full contraction of the actinomyosin ring. In fast apoptosis γ-tubulin complexes were disorganized and microtubules were initially depolymerized. However, after actinomyosin contraction, microtubules were reformed adopting a cortical but irregular disposition near plasma membrane. In addition to distinctive cytoskeleton reorganization kinetics, round and irregular-shaped apoptosis showed different biological properties with respect to AMN maintenance, plasma membrane integrity and phagocytes response. Our results suggest that the knowledge and modulation of the type of apoptosis promoted by genotoxic agents may be important for deciding a better therapeutic option and predicting the immune response in cancer treatment.

  11. Sustained activation of DNA damage response in irradiated apoptosis-resistant cells induces reversible senescence associated with mTOR downregulation and expression of stem cell markers.

    Science.gov (United States)

    Chitikova, Zhanna V; Gordeev, Serguei A; Bykova, Tatiana V; Zubova, Svetlana G; Pospelov, Valery A; Pospelova, Tatiana V

    2014-01-01

    Cells respond to genotoxic stress by activating the DNA damage response (DDR). When injury is severe or irreparable, cells induce apoptosis or cellular senescence to prevent transmission of the lesions to the daughter cells upon cell division. Resistance to apoptosis is a hallmark of cancer that challenges the efficacy of cancer therapy. In this work, the effects of ionizing radiation on apoptosis-resistant E1A + E1B transformed cells were investigated to ascertain whether the activation of cellular senescence could provide an alternative tumor suppressor mechanism. We show that irradiated cells arrest cell cycle at G 2/M phase and resume DNA replication in the absence of cell division followed by formation of giant polyploid cells. Permanent activation of DDR signaling due to impaired DNA repair results in the induction of cellular senescence in E1A + E1B cells. However, irradiated cells bypass senescence and restore the population by dividing cells, which have near normal size and ploidy and do not express senescence markers. Reversion of senescence and appearance of proliferating cells were associated with downregulation of mTOR, activation of autophagy, mitigation of DDR signaling, and expression of stem cell markers.

  12. p53 protein or BID protein select the route to either apoptosis (programmed cell death) or to cell cycle arrest opposing carcinogenesis after DNA damage by ROS.

    Science.gov (United States)

    Wiseman, Alan

    2006-01-01

    p53 is a tumour-suppressor protein of human cells that prevents their entry into the route to carcinogenesis. Furthermore, p53 protein acts at the p53-response loci in genomic DNA to facilitate the switch-on of genes that can be expressed by the biosynthesis of routing-proteins for apoptosis or stalling of cellular proliferation (via cell cycle progression checkpoint arrests). Moreover, oxidative stress by reactive oxygen species (ROS) such as the hydroxyl radical (*OH) produced by ionizing radiation (carcinogenic) triggers p53 activation in response to the damage of DNA (followed by initiation of DNA-repair mechanisms). Phosphorylation of the BID protein may lead to the recovery from DNA-damage by ROS.

  13. Baculovirus DNA Replication-Specific Expression Factors Trigger Apoptosis and Shutoff of Host Protein Synthesis during Infection▿

    OpenAIRE

    Schultz, Kimberly L. W.; Friesen, Paul D.

    2009-01-01

    Apoptosis is an important antivirus defense. To define the poorly understood pathways by which invertebrates respond to viruses by inducing apoptosis, we have identified replication events that trigger apoptosis in baculovirus-infected cells. We used RNA silencing to ablate factors required for multiplication of Autographa californica multicapsid nucleopolyhedrovirus (AcMNPV). Transfection with double-stranded RNA (dsRNA) complementary to the AcMNPV late expression factors (lefs) that are des...

  14. ATM-deficient human fibroblast cells are resistant to low levels of DNA double-strand break induced apoptosis and subsequently undergo drug-induced premature senescence

    Energy Technology Data Exchange (ETDEWEB)

    Park, Jun; Jo, Yong Hwa; Cho, Chang Hoon; Choe, Wonchae; Kang, Insug; Baik, Hyung Hwan [Department of Biochemistry and Molecular Biology, School of Medicine, Kyung Hee University, 26 Kyunghee-daero, Dongdaemun-gu, Seoul 130-701 (Korea, Republic of); Yoon, Kyung-Sik, E-mail: sky9999@khu.ac.kr [Department of Biochemistry and Molecular Biology, School of Medicine, Kyung Hee University, 26 Kyunghee-daero, Dongdaemun-gu, Seoul 130-701 (Korea, Republic of)

    2013-01-04

    Highlights: Black-Right-Pointing-Pointer A-T cells were not hypersensitive to low levels of DNA DSBs. Black-Right-Pointing-Pointer A-T cells have enhanced Akt but defect in activation of p53 and apoptotic proteins. Black-Right-Pointing-Pointer A-T cells underwent premature senescence after DNA damage accumulated. Black-Right-Pointing-Pointer Chemotherapeutic effect in cancer therapy may be associated with premature senescence. -- Abstract: DNA DSBs are induced by IR or radiomimetic drugs such as doxorubicin. It has been indicated that cells from ataxia-telangiectasia patients are highly sensitive to radiation due to defects in DNA repair, but whether they have impairment in apoptosis has not been fully elucidated. A-T cells showed increased sensitivity to high levels of DNA damage, however, they were more resistant to low doses. Normal cells treated with combination of KU55933, a specific ATM kinase inhibitor, and doxorubicin showed increased resistance as they do in a similar manner to A-T cells. A-T cells have higher viability but more DNA breaks, in addition, the activations of p53 and apoptotic proteins (Bax and caspase-3) were deficient, but Akt expression was enhanced. A-T cells subsequently underwent premature senescence after treatment with a low dose of doxorubicin, which was confirmed by G2 accumulation, senescent morphology, and SA-{beta}-gal positive until 15 days repair incubation. Finally, A-T cells are radio-resistant at low doses due to its defectiveness in detecting DNA damage and apoptosis, but the accumulation of DNA damage leads cells to premature senescence.

  15. 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.

  16. Digital Droplet Multiple Displacement Amplification (ddMDA for Whole Genome Sequencing of Limited DNA Samples.

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    Minsoung Rhee

    Full Text Available Multiple displacement amplification (MDA is a widely used technique for amplification of DNA from samples containing limited amounts of DNA (e.g., uncultivable microbes or clinical samples before whole genome sequencing. Despite its advantages of high yield and fidelity, it suffers from high amplification bias and non-specific amplification when amplifying sub-nanogram of template DNA. Here, we present a microfluidic digital droplet MDA (ddMDA technique where partitioning of the template DNA into thousands of sub-nanoliter droplets, each containing a small number of DNA fragments, greatly reduces the competition among DNA fragments for primers and polymerase thereby greatly reducing amplification bias. Consequently, the ddMDA approach enabled a more uniform coverage of amplification over the entire length of the genome, with significantly lower bias and non-specific amplification than conventional MDA. For a sample containing 0.1 pg/μL of E. coli DNA (equivalent of ~3/1000 of an E. coli genome per droplet, ddMDA achieves a 65-fold increase in coverage in de novo assembly, and more than 20-fold increase in specificity (percentage of reads mapping to E. coli compared to the conventional tube MDA. ddMDA offers a powerful method useful for many applications including medical diagnostics, forensics, and environmental microbiology.

  17. Benefits and Limitations of DNA Barcoding and Metabarcoding in Herbal Product Authentication

    Science.gov (United States)

    Raclariu, Ancuta Cristina; Heinrich, Michael; Ichim, Mihael Cristin

    2017-01-01

    Abstract Introduction Herbal medicines play an important role globally in the health care sector and in industrialised countries they are often considered as an alternative to mono‐substance medicines. Current quality and authentication assessment methods rely mainly on morphology and analytical phytochemistry‐based methods detailed in pharmacopoeias. Herbal products however are often highly processed with numerous ingredients, and even if these analytical methods are accurate for quality control of specific lead or marker compounds, they are of limited suitability for the authentication of biological ingredients. Objective To review the benefits and limitations of DNA barcoding and metabarcoding in complementing current herbal product authentication. Method Recent literature relating to DNA based authentication of medicinal plants, herbal medicines and products are summarised to provide a basic understanding of how DNA barcoding and metabarcoding can be applied to this field. Results Different methods of quality control and authentication have varying resolution and usefulness along the value chain of these products. DNA barcoding can be used for authenticating products based on single herbal ingredients and DNA metabarcoding for assessment of species diversity in processed products, and both methods should be used in combination with appropriate hyphenated chemical methods for quality control. Conclusions DNA barcoding and metabarcoding have potential in the context of quality control of both well and poorly regulated supply systems. Standardisation of protocols for DNA barcoding and DNA sequence‐based identification are necessary before DNA‐based biological methods can be implemented as routine analytical approaches and approved by the competent authorities for use in regulated procedures. © 2017 The Authors. Phytochemical Analysis Published by John Wiley & Sons Ltd. PMID:28906059

  18. 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

  19. Reaching for the limits in continuous-flow dielectrophoretic DNA analysis.

    Science.gov (United States)

    Täuber, Sarah; Kunze, Lena; Grauberger, Oleg; Grundmann, Armin; Viefhues, Martina

    2017-12-04

    The efficient purification and analysis of topological DNA variants is mandatory for many state-of-the-art molecular medicine technologies, like gene- and cancer-therapy as well as plasmid vaccination. In this work, we exploit dielectrophoresis (DEP) for a fast and efficient continuous-flow separation and analysis that goes beyond the standard methods of gel electrophoresis and capillary electrophoresis. The aim of this work was to reach for the limits in dielectrophoretic analysis of DNA regarding the size resolution and the topological conformation. A continuous-flow analytical separation of analyte mixtures of small linear DNA-fragments (10.0 kbp, 8.0 kbp, 6.0 kbp, and 5.0 kbp) and topological DNA variants (linear and supercoiled conformation) was investigated. We present a world record in the minimal size difference of 16.7% of DNA samples that can be resolved in a dielectrophoretic continuous-flow separation. Moreover, we demonstrate for the first time a microfluidic continuous-flow separation of DNA molecules based on their topological conformation. Since dielectrophoresis is virtually label-free, it offers a fast in-process quality control with low consumption, e.g. for the production of gene vaccines.

  20. Threshold Dose of Three Types of Quantum Dots (QDs) Induces Oxidative Stress Triggers DNA Damage and Apoptosis in Mouse Fibroblast L929 Cells.

    Science.gov (United States)

    Zhang, Ting; Wang, Yiqing; Kong, Lu; Xue, Yuying; Tang, Meng

    2015-10-26

    Although it has been reported that fluorescent quantum dots (QDs) have obvious acute toxic effects in vitro, their toxic effects at low doses or threshold doses are still unknown. Therefore, we evaluated the biological histocompatibility and in vitro toxicity of three types of QDs at threshold doses. Also, we compared the toxic effects of QDs with different raw chemical compositions and sizes. The results showed that low concentrations of QDs (≤7 μg/mL) had no obvious effect on cell viability and cell membrane damage, oxidative damage, cell apoptosis or DNA damage. However, QD exposure led to a significant cytotoxicity at higher doses (≥14 μg/mL) and induced abnormal cellular morphology. In addition, when comparing the three types of QDs, 2.2 nm CdTe QDs exposure showed a significantly increased proportion of apoptotic cells and significant DNA damage, suggesting that size and composition contribute to the toxic effects of QDs. Based on these discussions, it was concluded that the concentration (7 μg/mL) may serve as a threshold level for these three types of QDs only in L929 fibroblasts, whereas high concentrations (above 14 μg/mL) may be toxic, resulting in inhibition of proliferation, induction of apoptosis and DNA damage in L929 fibroblasts.

  1. DNA binding, cytotoxicity and apoptosis induction activity of a mixed-ligand copper(II) complex with taurine Schiff base and imidazole

    Science.gov (United States)

    Li, Mei; kong, Lin Lin; Gou, Yi; Yang, Feng; Liang, Hong

    2014-07-01

    A novel binuclear copper(II) complex (complex 1) with taurine Schiff base and imidazole has been synthesized and structurally characterized by single crystal X-ray diffraction, elemental analysis, ESI-MS spectrometry, UV-vis and IR spectroscopy. Single-crystal analysis revealed that 1 displays the sulfonate-bridged dinuclear copper(II) centers. Both copper atoms are five-coordinated and exhibit slightly distorted square pyramidal geometries. Each of copper atom is surrounded by three oxygen atoms and one nitrogen atom from different taurine Schiff base ligands, and one nitrogen atom from one imidazole ligand. The interaction between 1 and calf thymus DNA (CT-DNA) was investigated by UV-vis, fluorescence, circular dichroism (CD) spectra and agarose gel electrophoresis. The experimental results indicated that 1 could bind to CT-DNA via an intercalative mode and show efficient cleavage activity. In addition, 1 showed an antitumor effect on cell cycle and apoptosis. Flow cytometric analysis revealed that MGC-803 cells were arrested in the S phase after treatment with 1. Fluorescence microscopic observation indicated that 1 could induce apoptosis of MGC-803 cells.

  2. Microwave-Assisted Synthesis of Imidazo[4,5-f][1,10]phenanthroline Derivatives as Apoptosis Inducers in Chemotherapy by Stabilizing Bcl-2 G-quadruplex DNA

    Directory of Open Access Journals (Sweden)

    Li Li

    2017-05-01

    Full Text Available Herein, a series of imidazo[4,5-f][1,10] phenanthroline derivatives RPIP (PIP = imidazo [4,5-f][1,10] phenanthroline, R = NO2, 1; CF3, 2; Cl, 3; OH, 4 have been synthesized in yields of 82.3–94.7% at 100 °C under the irradiation of microwave. MTT assay has been utilized to evaluate the inhibitory activity (IC50 of these compounds against the growth of various tumor cells, and the results revealed that these compounds, especially 1, exhibited excellent inhibitory activity against the growth of A549 cells with IC50 of 15.03 μM. Moreover, it’s also confirmed that 1 can penetrate into the membrane of tumor cells and distribute in mitochondria when observed under microscopy, resulting apoptosis of tumor cells. The further studies showed that 1 can bind to bcl-2 G-quadruplex DNA, which demonstrated by the increase of melting point of bcl-2 G4 DNA in the presence of 1, as well as electronic titration and emission spectra. In a word, this kind of compound may develop as a potential apoptosis inducer in cancer chemotherapy via binding and stabilizing to the bcl-2 G-quadruplex DNA.

  3. Bienzymatic-based electrochemical DNA biosensors: a way to lower the detection limit of hybridization assays.

    Science.gov (United States)

    Rochelet-Dequaire, Murielle; Djellouli, Naïma; Limoges, Benoît; Brossier, Pierre

    2009-02-01

    The use of the alkaline phosphatase (AP) as an enzyme label and the amplification of its analytical response with a diaphorase (DI) secondary enzyme were investigated in an electrochemical hybridization assay involving arrays of carbon screen-printed DNA biosensors for the sensitive quantification of an amplified 406-base pair human cytomegalovirus DNA sequence (HCMV DNA). For this purpose, PCR-amplified biotinylated HCMV DNA targets were simultaneously bound to a monolayer of neutravidin irreversibly adsorbed on the surface of the electrodes and hybridized to complementary digoxigenin-labeled detection probes. The amount of hybrids immobilized on the electrode surface was labeled with an anti-digoxigenin AP conjugate and quantified electrochemically by measuring the activity of the AP label through the hydrolysis of the electroinactive p-aminophenylphosphate (PAPP) substrate into the p-aminophenol (PAP) product. The intensity of the cyclic voltammetric anodic peak current resulting from the oxidation of PAP into p-quinoneimine (PQI) was related to the number of viral amplified DNA targets present in the sample, and a detection limit of 10 pM was thus achieved. The electrochemical response of the AP label product was further enhanced by adding the diaphorase enzymatic amplifier in the solution. In the presence of the auxiliary enzyme DI, the PQI was reduced back to PAP and the resulting oxidized form of DI was finally regenerated in its reduced native state by its natural substrate, NADH. Such a bienzymatic amplification scheme enabled a 100-fold lowering of the HCMV DNA detection limit obtained with the monoenzymatic system.

  4. SF Treg cells transcribing high levels of Bcl-2 and microRNA-21 demonstrate limited apoptosis in RA

    NARCIS (Netherlands)

    van der Geest, Kornelis S. M.; Smigielska, Katarzyna; Park, Ji-Ah; Abdulahad, Wayel H.; Kim, Hye-Won; Kroesen, Bart-Jan; van den Berg, Anke; Boots, Annemieke M. H.; Lee, Eun-Bong; Brouwer, Elisabeth

    Objective. The aim of this study was to investigate the turnover of Treg cells in the SF of RA patients. Methods. Treg cells were enumerated in peripheral blood and SF of RA patients and analysed by flow cytometry for expression of the proliferation marker Ki-67 and binding of the apoptosis marker

  5. DNA damage and apoptosis in blood neutrophils of inflammatory bowel disease patients and in Caco-2 cells in vitro exposed to betanin.

    Science.gov (United States)

    Zielińska-Przyjemska, Małgorzata; Olejnik, Anna; Dobrowolska-Zachwieja, Agnieszka; Łuczak, Michał; Baer-Dubowska, Wanda

    2016-04-06

    Inflammatory bowel diseases (IBD) are chronic, relapsing, inflammatory disorders of the gastrointestinal tract, and continuing colonic inflammation is considered an important risk factor in the development of colorectal cancer. Our previous studies showed that beetroot (Beta vulgaris var. rubra) products and their major component betanin modulate the reactive oxygen species (ROS) production and DNA damage in 12-O-tetradecanoylphorbol 13-acetate (TPA) stimulated human polymorphonuclear neutrophils of healthy volunteers. The aim of the present study was to evaluate the effects of betanin on the oxidative DNA damage and apoptosis in neutrophils isolated from blood of patients with inflammatory bowel disease--ulcerative colitis (UC) and Crohn's disease (CD). The results were compared with those obtained in colon carcinoma-derived Caco-2 cells. Betanin treatment at the concentration of 100 μM for 24 h increased DNA damage assessed by comet assay in IBD patients' neutrophils. A similar effect although less pronounced was observed in Caco-2 cells. Treatment of Caco-2 cells with H2O2 caused a 4-fold increase of DNA strand breaks in comparison to untreated cells, but pre-treatment with betanin reduced DNA damage in these cells. Betanin also induced procaspase-3 cleavage and caspase-3 activity accompanied by the loss of mitochondrial transmembrane potential, indicating its pro-apoptotic activity. These results suggest that betanin may support mechanisms that lead to the release of ROS and apoptotic cell death. In this way betanin may exert anti-inflammatory and potentially cancer preventive activity.

  6. DNA damage and apoptosis in blood neutrophils of inflammatory bowel disease patients and in Caco-2 cells in vitro exposed to betanin

    Directory of Open Access Journals (Sweden)

    Małgorzata Zielińska-Przyjemska

    2016-04-01

    Full Text Available Inflammatory bowel diseases (IBD are chronic, relapsing, inflammatory disorders of the gastrointestinal tract, and continuing colonic inflammation is considered an important risk factor in the development of colorectal cancer. Our previous studies showed that beetroot (Beta vulgaris var. rubra products and their major component betanin modulate the reactive oxygen species (ROS production and DNA damage in 12-O-tetradecanoylphorbol 13-acetate (TPA stimulated human polymorphonuclear neutrophils of healthy volunteers. The aim of the present study was to evaluate the effects of betanin on the oxidative DNA damage and apoptosis in neutrophils isolated from blood of patients with inflammatory bowel disease– ulcerative colitis (UC and Crohn’s disease (CD. The results were compared with those obtained in colon carcinoma-derived Caco-2 cells. Betanin treatment at the concentration of 100 μM for 24 h increased DNA damage assessed by comet assay in IBD patients’ neutrophils. A similar effect although less pronounced was observed in Caco-2 cells. Treatment of Caco-2 cells with H2O2 caused a 4-fold increase of DNA strand breaks in comparison to untreated cells, but pre-treatment with betanin reduced DNA damage in these cells. Betanin also induced procaspase-3 cleavage and caspase-3 activity accompanied by the loss of mitochondrial transmembrane potential, indicating its pro-apoptoticactivity. These results suggest that betanin may support mechanisms that lead to the release of ROS and apoptotic cell death. In this way betanin may exert anti-inflammatory and potentially cancer preventive activity.

  7. Increased apoptosis and DNA double-strand breaks in the embryonic mouse brain in response to very low-dose X-rays but not 50 Hz magnetic fields.

    Science.gov (United States)

    Saha, Shreya; Woodbine, Lisa; Haines, Jackie; Coster, Margaret; Ricket, Nicole; Barazzuol, Lara; Ainsbury, Elizabeth; Sienkiewicz, Zenon; Jeggo, Penny

    2014-11-06

    The use of X-rays for medical diagnosis is enhancing exposure to low radiation doses. Exposure to extremely low-frequency electromagnetic or magnetic fields is also increasing. Epidemiological studies show consistent associations of childhood leukaemia with exposure to magnetic fields but any causal relationship is unclear. A limitation in assessing the consequence of such exposure is the availability of sensitive assays. The embryonic neuronal stem and progenitor cell compartments are radiosensitive tissues. Using sensitive assays, we report a statistically significant increase in DNA double-strand break (DSB) formation and apoptosis in the embryonic neuronal stem cell compartment following in utero exposure to 10-200 mGy X-rays. Both endpoints show a linear response. We also show that DSB repair is delayed following exposure to doses below 50 mGy compared with 100 mGy. Thus, we demonstrate in vivo consequences of low-dose radiation. In contrast to these impacts, we did not observe any significant induction of DSBs or apoptosis following exposure to 50 Hz magnetic fields (100 or 300 µT). We conclude that any DSB induction by treatment with magnetic fields is lower than following exposure to 10 mGy X-rays. For comparison, certain procedures involving computed tomography scanning are equivalent to 1-5 mGy X-rays.

  8. USP22 Induces Cisplatin Resistance in Lung Adenocarcinoma by Regulating γH2AX-Mediated DNA Damage Repair and Ku70/Bax-Mediated Apoptosis

    Directory of Open Access Journals (Sweden)

    Aman Wang

    2017-05-01

    Full Text Available Resistance to platinum-based chemotherapy is one of the most important reasons for treatment failure in advanced non-small cell lung cancer, but the underlying mechanism is extremely complex and unclear. The present study aimed to investigate the correlation of ubiquitin-specific peptidase 22 (USP22 with acquired resistance to cisplatin in lung adenocarcinoma. In this study, we found that overexpression of USP22 could lead to cisplatin resistance in A549 cells. USP22 and its downstream proteins γH2AX and Sirt1 levels are upregulated in the cisplatin- resistant A549/CDDP cell line. USP22 enhances DNA damage repair and induce cisplatin resistance by promoting the phosphorylation of histone H2AX via deubiquitinating histone H2A. In addition, USP22 decreases the acetylation of Ku70 by stabilizing Sirt1, thus inhibiting Bax-mediated apoptosis and inducing cisplatin resistance. The cisplatin sensitivity in cisplatin-resistant A549/CDDP cells was restored by USP22 inhibition in vivo and vitro. In summary, our findings reveal the dual mechanism of USP22 involvement in cisplatin resistance that USP22 can regulate γH2AX-mediated DNA damage repair and Ku70/Bax-mediated apoptosis. USP22 is a potential target in cisplatin-resistant lung adenocarcinoma and should be considered in future therapeutic practice.

  9. Juvenile hormone effect on DNA synthesis and apoptosis in caste-specific differentiation of the larval honey bee (Apis mellifera L.) ovary.

    Science.gov (United States)

    Capella, Ines C. Schmidt; Hartfelder, Klaus

    1998-05-01

    Caste-specific differentiation of the honey bee ovary commences in the last larval instar. In this process, formation of germ cell clusters by synchronous and incomplete mitoses occurs in the queen ovary, whereas in the worker ovary programmed cell death is the dominant feature. BrdU and TUNEL labeling were used to study dynamics of cell proliferation and apoptosis-dependent DNA degradation in ovaries of naturally developing queens and workers, as well as in juvenile hormone-treated worker larvae. Cell proliferation in ovaries of last-instar queen larvae generally exceeded that in workers, except for the late feeding phase. This inversion in cell proliferation patterns coincided with the onset of apoptosis in worker ovaries, as evidenced by TUNEL labeling. Juvenile hormone application to early-fifth-instar worker larvae had two noticeable effects. First, it diminished the number of S-phase nuclei in ovaries of late feeding-phase workers, bringing them to queen-like levels. Second, it prevented the induction of apoptotic DNA degradation. Caste-specific regulation of cell division in connection with programmed cell death can thus be attributed to the previously described differences in juvenile hormone titer in queen and worker larvae, adding a new facet to this hormone's multiple functions.

  10. Effect of PEG Grafting Density and Hydrodynamic Volume on Gold Nanoparticle-Cell Interactions: An Investigation on Cell Cycle, Apoptosis, and DNA Damage.

    Science.gov (United States)

    Uz, Metin; Bulmus, Volga; Alsoy Altinkaya, Sacide

    2016-06-14

    In this study, interactions of polyethylene glycol (PEG)-coated gold nanoparticles (AuNPs) with cells were investigated with particular focus on the relationship between the PEG layer properties (conformation, grafting density, and hydrodynamic volume) and cell cycle arrest, apoptosis, and DNA damage. Steric hindrance and PEG hydrodynamic volume controlled the protein adsorption, whereas the AuNP core size and PEG hydrodynamic volume were primary factors for cell uptake and viability. At all PEG grafting densities, the particles caused significant cell cycle arrest and DNA damage against CaCo2 and PC3 cells without apoptosis. However, at a particular PEG grafting density (∼0.65 chains/nm(2)), none of these severe damages were observed on 3T3 cells indicating discriminating behavior of the healthy (3T3) and cancer (PC3 and CaCo2) cells. It was concluded that the PEG grafting density and hydrodynamic volume, tuned with the PEG concentration and AuNP size, played an important role in particle-cell interactions.

  11. Genomic sequence of Spodoptera frugiperda Ascovirus 1a, an enveloped, double-stranded DNA insect virus that manipulates apoptosis for viral reproduction.

    Science.gov (United States)

    Bideshi, Dennis K; Demattei, Marie-Véronique; Rouleux-Bonnin, Florence; Stasiak, Karine; Tan, Yeping; Bigot, Sylvie; Bigot, Yves; Federici, Brian A

    2006-12-01

    Ascoviruses (family Ascoviridae) are double-stranded DNA viruses with circular genomes that attack lepidopterans, where they produce large, enveloped virions, 150 by 400 nm, and cause a chronic, fatal disease with a cytopathology resembling that of apoptosis. After infection, host cell DNA is degraded, the nucleus fragments, and the cell then cleaves into large virion-containing vesicles. These vesicles and virions circulate in the hemolymph, where they are acquired by parasitic wasps during oviposition and subsequently transmitted to new hosts. To develop a better understanding of ascovirus biology, we sequenced the genome of the type species Spodoptera frugiperda ascovirus 1a (SfAV-1a). The genome consisted of 156,922 bp, with a G+C ratio of 49.2%, and contained 123 putative open reading frames coding for a variety of enzymes and virion structural proteins, of which tentative functions were assigned to 44. Among the most interesting enzymes, due to their potential role in apoptosis and viral vesicle formation, were a caspase, a cathepsin B, several kinases, E3 ubiquitin ligases, and especially several enzymes involved in lipid metabolism, including a fatty acid elongase, a sphingomyelinase, a phosphate acyltransferase, and a patatin-like phospholipase. Comparison of SfAV-1a proteins with those of other viruses showed that 10% were orthologs of Chilo iridescent virus proteins, the highest correspondence with any virus, providing further evidence that ascoviruses evolved from a lepidopteran iridovirus. The SfAV-1a genome sequence will facilitate the determination of how ascoviruses manipulate apoptosis to generate the novel virion-containing vesicles characteristic of these viruses and enable study of their origin and evolution.

  12. Seasonal variability in the persistence of dissolved environmental DNA (eDNA in a marine system: The role of microbial nutrient limitation.

    Directory of Open Access Journals (Sweden)

    Ian Salter

    Full Text Available Environmental DNA (eDNA can be defined as the DNA pool recovered from an environmental sample that includes both extracellular and intracellular DNA. There has been a significant increase in the number of recent studies that have demonstrated the possibility to detect macroorganisms using eDNA. Despite the enormous potential of eDNA to serve as a biomonitoring and conservation tool in aquatic systems, there remain some important limitations concerning its application. One significant factor is the variable persistence of eDNA over natural environmental gradients, which imposes a critical constraint on the temporal and spatial scales of species detection. In the present study, a radiotracer bioassay approach was used to quantify the kinetic parameters of dissolved eDNA (d-eDNA, a component of extracellular DNA, over an annual cycle in the coastal Northwest Mediterranean. Significant seasonal variability in the biological uptake and turnover of d-eDNA was observed, the latter ranging from several hours to over one month. Maximum uptake rates of d-eDNA occurred in summer during a period of intense phosphate limitation (turnover <5 hrs. Corresponding increases in bacterial production and uptake of adenosine triphosphate (ATP demonstrated the microbial utilization of d-eDNA as an organic phosphorus substrate. Higher temperatures during summer may amplify this effect through a general enhancement of microbial metabolism. A partial least squares regression (PLSR model was able to reproduce the seasonal cycle in d-eDNA persistence and explained 60% of the variance in the observations. Rapid phosphate turnover and low concentrations of bioavailable phosphate, both indicative of phosphate limitation, were the most important parameters in the model. Abiotic factors such as pH, salinity and oxygen exerted minimal influence. The present study demonstrates significant seasonal variability in the persistence of d-eDNA in a natural marine environment that can

  13. The cyclin-dependent kinase inhibitor 5, 6-dichloro-1-beta-D-ribofuranosylbenzimidazole induces nongenotoxic, DNA replication-independent apoptosis of normal and leukemic cells, regardless of their p53 status

    International Nuclear Information System (INIS)

    Turinetto, Valentina; Porcedda, Paola; Orlando, Luca; De Marchi, Mario; Amoroso, Antonio; Giachino, Claudia

    2009-01-01

    Current chemotherapy of human cancers focuses on the DNA damage pathway to induce a p53-mediated cellular response leading to either G1 arrest or apoptosis. However, genotoxic treatments may induce mutations and translocations that result in secondary malignancies or recurrent disease. In addition, about 50% of human cancers are associated with mutations in the p53 gene. Nongenotoxic activation of apoptosis by targeting specific molecular pathways thus provides an attractive therapeutic approach. Normal and leukemic cells were evaluated for their sensitivity to 5, 6-dichloro-1-beta-D-ribofuranosylbenzimidazole (DRB) through cell viability and caspase activation tests. The apoptotic pathway induced by DRB was analysed by immunfluorescence and immunoblot analysis. H2AX phosphorylation and cell cycle analysis were performed to study the dependance of apoptosis on DNA damage and DNA replication, respectively. To investigate the role of p53 in DRB-induced apoptosis, specific p53 inhibitors were used. Statistical analysis on cell survival was performed with the test of independence. Here we report that DRB, an inhibitor of the transcriptional cyclin-dependent kinases (CDKs) 7 and 9, triggers DNA replication-independent apoptosis in normal and leukemic human cells regardless of their p53 status and without inducing DNA damage. Our data indicate that (i) in p53-competent cells, apoptosis induced by DRB relies on a cytosolic accumulation of p53 and subsequent Bax activation, (ii) in the absence of p53, it may rely on p73, and (iii) it is independent of ATM and NBS1 proteins. Notably, even apoptosis-resistant leukemic cells such as Raji were sensitive to DRB. Our results indicate that DRB represents a potentially useful cancer chemotherapeutic strategy that employs both the p53-dependent and -independent apoptotic pathways without inducing genotoxic stress, thereby decreasing the risk of secondary malignancies

  14. Dioxin-like (PCB 126) and non dioxin-like (PCB 153) action on DNA damage and apoptosis in granulosa cells. Preliminary data

    Energy Technology Data Exchange (ETDEWEB)

    Gregoraszczuk, E.L.; Wojtowicz, A. [Lab. of Physiology and Toxicology of Reproduction, Inst. of Zoology, Jagiellonian Univ., Krakow (Poland); Kapiszewska, M.; Magnowska, Z. [Dept. of General Biochemistry, Jagiellonian Univ., Krakow (Poland)

    2004-09-15

    Introduction Approximately 60-90% of all cancer cases are now generally believed to be due to environmental factors, to which humans are exposed by taking food, and water or inhaling air. These chemicals, including polycyclic aromatic hydrocarbons (PAHs), can be subdivided into different classes. TCDD was classified as group (documented carcinogen in humans) Benzo [a] pyrene and benzo [a] anthracene were included into group 2A (probably carcinogen in humans). PCB is not mentioned in this list. The International Agency for Research on Cancer (IARC) maintains a register of human carcinogens and suspected human carcinogens. The capacity of PCBs to induce DNA strand breaks has been studied to a lesser degree and is quite controversial. DNA strand breaks are the potentially mutagenic lesions that have been proposed as a genotoxicity biomarker for the biomonitoring of environmental pollutants. The mutations induced by these lesions in pollutant-exposed populations are believed to be induced by chemical carcinogens. The formation of PCB adducts has been demonstrated and measured in vitro and in vivo 3. The capacity of PCBs to form DNA adducts depends on their metabolic rate, which is determined by the degree of chlorination. The aim of the presented preliminary data was to evaluate the follicular stage-specific action of PCB 126 and PCB 153 on DNA damage and apoptosis in granulosa cells.

  15. DNA double-strand break and apoptosis induction in human lymphocytes in different cycle cell phases by 60Co gamma rays and Bragg peak protons of a medical beam

    International Nuclear Information System (INIS)

    Khachenkova, A.A.; Boreyko, A.V.; Mozhaeva, A.V.; Chausov, V.N.; Ravnachka, I.I.; Amov, I.; Tiunchik, S.I.

    2009-01-01

    A comparative analysis is made of the regularities in the formation of DNA double-strand break and apoptosis induction in peripheral human blood lymphocytes in different cell cycle phases after 60 Co gamma and extended Bragg peak proton irradiation. It is shown that the formation of apoptotic cells in a lymphocyte population increases linearly in all the cell cycle stages after proton irradiation. The maximal DNA double-strand break and apoptosis yield in lymphocytes is observed in the S phase of the cell cycle

  16. Study on potential antitumor mechanism of a novel Schiff base copper(II) complex: synthesis, crystal structure, DNA binding, cytotoxicity and apoptosis induction activity.

    Science.gov (United States)

    Qiao, Xin; Ma, Zhong-Ying; Xie, Cheng-Zhi; Xue, Fei; Zhang, Yan-Wen; Xu, Jing-Yuan; Qiang, Zhao-Yan; Lou, Jian-Shi; Chen, Gong-Jun; Yan, Shi-Ping

    2011-05-01

    A new cytotoxic copper(II) complex with Schiff base ligand [Cu(II)(5-Cl-pap)(OAc)(H(2)O)]·2H(2)O (1) (5-Cl-pap=N-2-pyridiylmethylidene-2-hydroxy-5-chloro-phenylamine), was synthesized and structurally characterized by X-ray diffraction. Single-crystal analysis revealed that the copper atom shows a 4+1 pyramidal coordination, a water oxygen appears in the apical position, and three of the basal positions are occupied by the NNO tridentate ligand and the fourth by an acetate oxygen. The interaction of Schiff base copper(II) complex 1 with DNA was investigated by UV-visible spectra, fluorescence spectra and agarose gel electrophoresis. The apparent binding constant (K(app)) value of 6.40×10(5) M(-1) for 1 with DNA suggests moderate intercalative binding mode. This copper(II) complex displayed efficient oxidative cleavage of supercoiled DNA, which might indicate that the underlying mechanism involve hydroxyl radical, singlet oxygen-like species, and hydrogen peroxide as reactive oxygen species. In addition, our present work showed the antitumor effect of 1 on cell cycle and apoptosis. Flow cytometric analysis revealed that HeLa cells were arrested in the S phase after treatment with 1. Fluorescence microscopic observation indicated that complex 1 can induce apoptosis of HeLa cells, whose process was mediated by intrinsic mitochondrial apoptotic pathway owing to the activation of caspase-9 and caspase-3. Copyright © 2011 Elsevier Inc. All rights reserved.

  17. Microwave-Assisted Synthesis of Arene Ru(II Complexes Induce Tumor Cell Apoptosis Through Selectively Binding and Stabilizing bcl-2 G-Quadruplex DNA

    Directory of Open Access Journals (Sweden)

    Yanhua Chen

    2016-05-01

    Full Text Available A series of arene Ru(II complexes coordinated with phenanthroimidazole derivatives, [(η6-C6H6Ru(lCl]Cl(1b L = p-ClPIP = 2-(4-Chlorophenylimidazole[4,5f] 1,10-phenanthroline; 2b L = m-ClPIP = 2-(3-Chlorophenylimidazole[4,5f] 1,10-phenanthroline; 3b L = p-NPIP = 2-(4-Nitrophenylimidazole[4,5f] 1,10-phenanthroline; 4b L = m-NPIP = 2-(3-Nitrophenyl imidazole [4,5f] 1,10-phenanthroline were synthesized in yields of 89.9%–92.7% under conditions of microwave irradiation heating for 30 min to liberate four arene Ru(II complexes (1b, 2b, 3b, 4b. The anti-tumor activity of 1b against various tumor cells was evaluated by MTT assay. The results indicated that this complex blocked the growth of human lung adenocarcinoma A549 cells with an IC50 of 16.59 μM. Flow cytometric analysis showed that apoptosis of A549 cells was observed following treatment with 1b. Furthermore, the in vitro DNA-binding behaviors that were confirmed by spectroscopy indicated that 1b could selectively bind and stabilize bcl-2 G-quadruplex DNA to induce apoptosis of A549 cells. Therefore, the synthesized 1b has impressive bcl-2 G-quadruplex DNA-binding and stabilizing activities with potential applications in cancer chemotherapy.

  18. The SMAC mimetic BV6 sensitizes colorectal cancer cells to ionizing radiation by interfering with DNA repair processes and enhancing apoptosis

    International Nuclear Information System (INIS)

    Hehlgans, Stephanie; Oppermann, Julius; Reichert, Sebastian; Fulda, Simone; Rödel, Claus; Rödel, Franz

    2015-01-01

    In the present study, we aimed to investigate the effect of counteracting inhibitor of apoptosis (IAP) proteins using the small molecule Second Mitochondria-derived Activator of Caspase (SMAC) mimetic BV6 in combination with ionizing radiation on apoptosis, cell cycle regulation, DNA double-strand break (DSB) repair, three-dimensional (3D) clonogenic survival and expression of IAPs in colorectal carcinoma cells. Colorectal cancer cell lines (HCT-15, HT-29, SW480) were subjected to BV6 treatment (0–4 μM) with or without irradiation (2–8 Gy, single dose) followed by MTT, Caspase 3/7 activity, γH2AX/53BP1 foci assays, AnnexinV staining, cell cycle analysis, 3D colony forming assays and Western blotting (cellular IAP1 (cIAP1) and cIAP2, Survivin, X-linked IAP (XIAP)). BV6 treatment decreased cell viability and significantly increased irradiation-induced apoptosis as analyzed by Caspase 3/7 activity, AnnexinV-positive and subG1 phase cells. While basal 3D clonogenic survival was decreased in a cell line-dependent manner, BV6 significantly enhanced cellular radiosensitivity of all cell lines in a concentration-dependent manner and increased the number of radiation-induced γH2AX/53BP1-positive foci. Western blot analysis revealed a markedly reduced cIAP1 expression at 4 h after BV6 treatment in all cell lines, a substantial reduction of XIAP expression in SW480 and HT-29 cells at 24 h and a slightly decreased cIAP2 expression in HCT-15 cells at 48 h after treatment. Moreover, single or double knockdown of cIAP1 and XIAP resulted in significantly increased residual γH2AX/53BP1-positive foci 24 h after 2 Gy and radiosensitization relative to control small interfering RNA (siRNA)-treated cells. The SMAC mimetic BV6 induced apoptosis and hampered DNA damage repair to radiosensitize 3D grown colorectal cancer cells. Our results demonstrate IAP targeting as a promising strategy to counteract radiation resistance of colorectal cancer cells. The online version of this

  19. Limited clinical relevance of mitochondrial DNA mutation and gene expression analyses in ovarian cancer

    International Nuclear Information System (INIS)

    Bragoszewski, Piotr; Kupryjanczyk, Jolanta; Bartnik, Ewa; Rachinger, Andrea; Ostrowski, Jerzy

    2008-01-01

    In recent years, numerous studies have investigated somatic mutations in mitochondrial DNA in various tumours. The observed high mutation rates might reflect mitochondrial deregulation; consequently, mutation analyses could be clinically relevant. The purpose of this study was to determine if mutations in the mitochondrial D-loop region and/or the level of mitochondrial gene expression could influence the clinical course of human ovarian carcinomas. We sequenced a 1320-base-pair DNA fragment of the mitochondrial genome (position 16,000-750) in 54 cancer samples and in 44 corresponding germline control samples. In addition, six transcripts (MT-ATP6, MT-CO1, MT-CYB, MT-ND1, MT-ND6, and MT-RNR1) were quantified in 62 cancer tissues by real-time RT-PCR. Somatic mutations in the D-loop sequence were found in 57% of ovarian cancers. Univariate analysis showed no association between mitochondrial DNA mutation status or mitochondrial gene expression and any of the examined clinicopathologic parameters. A multivariate logistic regression model revealed that the expression of the mitochondrial gene RNR1 might be used as a predictor of tumour sensitivity to chemotherapy. In contrast to many previously published papers, our study indicates rather limited clinical relevance of mitochondrial molecular analyses in ovarian carcinomas. These discrepancies in the clinical utility of mitochondrial molecular tests in ovarian cancer require additional large, well-designed validation studies

  20. Limited clinical relevance of mitochondrial DNA mutation and gene expression analyses in ovarian cancer

    Directory of Open Access Journals (Sweden)

    Rachinger Andrea

    2008-10-01

    Full Text Available Abstract Background In recent years, numerous studies have investigated somatic mutations in mitochondrial DNA in various tumours. The observed high mutation rates might reflect mitochondrial deregulation; consequently, mutation analyses could be clinically relevant. The purpose of this study was to determine if mutations in the mitochondrial D-loop region and/or the level of mitochondrial gene expression could influence the clinical course of human ovarian carcinomas. Methods We sequenced a 1320-base-pair DNA fragment of the mitochondrial genome (position 16,000-750 in 54 cancer samples and in 44 corresponding germline control samples. In addition, six transcripts (MT-ATP6, MT-CO1, MT-CYB, MT-ND1, MT-ND6, and MT-RNR1 were quantified in 62 cancer tissues by real-time RT-PCR. Results Somatic mutations in the D-loop sequence were found in 57% of ovarian cancers. Univariate analysis showed no association between mitochondrial DNA mutation status or mitochondrial gene expression and any of the examined clinicopathologic parameters. A multivariate logistic regression model revealed that the expression of the mitochondrial gene RNR1 might be used as a predictor of tumour sensitivity to chemotherapy. Conclusion In contrast to many previously published papers, our study indicates rather limited clinical relevance of mitochondrial molecular analyses in ovarian carcinomas. These discrepancies in the clinical utility of mitochondrial molecular tests in ovarian cancer require additional large, well-designed validation studies.

  1. Treatment with MAPKAP2 (MK2) inhibitor and DNA methylation inhibitor, 5-aza dC, synergistically triggers apoptosis in hepatocellular carcinoma (HCC) via tristetraprolin (TTP).

    Science.gov (United States)

    Tran, Doan Duy Hai; Koch, Alexandra; Allister, Aldrige; Saran, Shashank; Ewald, Florian; Koch, Martina; Nashan, Björn; Tamura, Teruko

    2016-12-01

    Over 100 putative driver genes that are associated with multiple recurrently altered pathways were detected in hepatocellular carcinoma (HCC), suggesting that multiple pathways will need to be inhibited for any therapeutic method to be effective. In this context, functional modification of the RNA regulating protein, tristetraprolin (TTP) that regulates approximately 2500 genes represents a promising strategy in HCC therapy. Since overexpression of TTP induces cell death in all cell types, it would be useful to target the regulator of TTP. In this study, we applied an inhibitor to MAPKAP2 (MK2) that suppresses TTP function. Importantly, cBIOportal for HCC genomics shows that expression level of the MK2 gene correlates with clinical outcome of HCC. We show that upon treatment with MK2 inhibitor, all 5 HCC cell lines, namely HepG2, Huh7, Hep3B, HLE and HLF, reduced cell growth, especially HepG2 and Hep3B cells underwent apoptosis. Simultaneously, TTP target genes such as c-Myc, IER3 or AKT-1 were downregulated. Depletion of the TTP gene rescued cells from apoptosis and restored the TTP-target mRNA expression in the presence of MK2 inhibitor. Furthermore, MK2 was activated in primary HCC that express TTP at high level. The TTP gene was induced upon treatment with DNA methylation inhibitor, 5-aza dC or interferon in three other cell lines, Huh7, HLE or HLF. Upon treatment with MK2 inhibitor and 5-aza dC or interferon these cells underwent apoptosis. The depletion of TTP in these cells partially rescued them from apoptosis, suggesting that the MK2/TTP pathway plays a role in proliferation and maintenance of HCCs. Notably, under the same conditions human hepatocyte cells (THLE-2) did not undergo apoptosis. These data also suggest that MK2 inhibitor with 5-aza dC or interferon may be a useful tool for therapy against HCC. Copyright © 2016 Elsevier Inc. All rights reserved.

  2. DNA isolation protocols affect the detection limit of PCR approaches of bacteria in samples from the human gastrointestinal tract

    NARCIS (Netherlands)

    Zoetendal, E.G.; Ben-Amor, K.; Akkermans, A.D.L.; Abee, T.; Vos, de W.M.

    2001-01-01

    A major concern in molecular ecological studies is the lysis efficiency of different bacteria in a complex ecosystem. We used a PCR-based 16S rDNA approach to determine the effect of two DNA isolation protocols (i.e. the bead beating and Triton-X100 method) on the detection limit of seven

  3. Limited ability of DNA polymerase kappa to suppress benzo[a]pyrene-induced genotoxicity in vivo.

    Science.gov (United States)

    Masumura, Kenichi; Toyoda-Hokaiwado, Naomi; Niimi, Naoko; Grúz, Petr; Wada, Naoko A; Takeiri, Akira; Jishage, Kou-Ichi; Mishima, Masayuki; Nohmi, Takehiko

    2017-12-01

    DNA polymerase kappa (Polk) is a specialized DNA polymerase involved in translesion DNA synthesis. To understand the protective roles against genotoxins in vivo, we established inactivated Polk knock-in gpt delta (inactivated Polk KI) mice that possessed reporter genes for mutations and expressed inactive Polk. In this study, we examined genotoxicity of benzo[a]pyrene (BP) to determine whether Polk actually suppressed BP-induced genotoxicity as predicted by biochemistry and in vitro cell culture studies. Seven-week-old inactivated Polk KI and wild-type (WT) mice were treated with BP at doses of 5, 15, or 50 mg/(kg·day) for three consecutive days by intragastric gavage, and mutations in the colon and micronucleus formation in the peripheral blood were examined. Surprisingly, no differences were observed in the frequencies of mutations and micronucleus formation at 5 or 50 mg/kg doses. Inactivated Polk KI mice exhibited approximately two times higher gpt mutant frequency than did WT mice only at the 15 mg/kg dose. The frequency of micronucleus formation was slightly higher in inactivated Polk KI than in WT mice at the same dose, but it was statistically insignificant. The results suggest that Polk has a limited ability to suppress BP-induced genotoxicity in the colon and bone marrow and also that the roles of specialized DNA polymerases in mutagenesis and carcinogenesis should be examined not only by in vitro assays but also by in vivo mouse studies. We also report the spontaneous mutagenesis in inactivated Polk KI mice at young and old ages. Environ. Mol. Mutagen. 58:644-653, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

  4. DNA damage stress and inhibition of Jak2-V617F cause its degradation and synergistically induce apoptosis through activation of GSK3β.

    Directory of Open Access Journals (Sweden)

    Toshikage Nagao

    Full Text Available The cytoplasmic tyrosine kinase Jak2 plays a crucial role in cytokine receptor signaling in hematopoietic cells. The activated Jak2-V617F mutant is present in most cases of BCR/ABL-negative myeloproliferative neoplasms and constitutively activates downstream signals from homodimeric cytokine receptors, such as the erythropoietin receptor (EpoR. Here we examine the effects of DNA damage stress on Jak2 or Jak2-V617F and on induction of apoptosis in hematopoietic cells. Etoposide or doxorubicin dose-dependently decreased the expression level of Jak2 in UT7 or 32D cells expressing EpoR in the absence of Epo and that of exogenously expressed Jak2-V617F in UT7 cells when cotreated with the Jak2 inhibitor JakI-1 or AG490. Studies with pharmacological inhibitors and genetic manipulations further showed that downregulation of the PI3K/Akt pathway leading to the activation of GSK3β may be involved in downregulation of Jak2 or Jak2-V617F as well as in synergistic induction of Bax activation and apoptosis. The downregulation of Jak2 was inhibited by the proteasome inhibitor MG132 or by expression of both of loss-of-function mutants of c-Cbl and Cbl-b, E3 ubiquitin ligases which facilitated ubiquitination of Jak2-V617F when co-expressed in 293T cells. The pan-caspase inhibitor Boc-d-fmk also inhibited the Jak2 downregulation as well as appearance of a 100-kDa fragment that contained the N-terminal portion of Jak2 in response to DNA damage. Together, these data suggest that DNA damage stress with simultaneous inhibition of the kinase activity causes degradation of Jak2 or Jak2-V617F by caspase cleavage and proteasomal degradation through GSK3β activation, which is closely involved in synergistic induction of apoptosis in hematopoietic cells.

  5. Ecotoxicological assessment of cobalt using Hydra model: ROS, oxidative stress, DNA damage, cell cycle arrest, and apoptosis as mechanisms of toxicity.

    Science.gov (United States)

    Zeeshan, Mohammed; Murugadas, Anbazhagan; Ghaskadbi, Surendra; Ramaswamy, Babu Rajendran; Akbarsha, Mohammad Abdulkader

    2017-05-01

    The mechanisms underlying cobalt toxicity in aquatic species in general and cnidarians in particular remain poorly understood. Herein we investigated cobalt toxicity in a Hydra model from morphological, histological, developmental, and molecular biological perspectives. Hydra, exposed to cobalt (0-60 mg/L), were altered in morphology, histology, and regeneration. Exposure to standardized sublethal doses of cobalt impaired feeding by affecting nematocytes, which in turn affected reproduction. At the cellular level, excessive ROS generation, as the principal mechanism of action, primarily occurred in the lysosomes, which was accompanied by the upregulation of expression of the antioxidant genes SOD, GST, GPx, and G6PD. The number of Hsp70 and FoxO transcripts also increased. Interestingly, the upregulations were higher in the 24-h than in the 48-h time-point group, indicating that ROS overwhelmed the cellular defense mechanisms at the latter time-point. Comet assay revealed DNA damage. Cell cycle analysis indicated the induction of apoptosis accompanied or not by cell cycle arrest. Immunoblot analyses revealed that cobalt treatment triggered mitochondria-mediated apoptosis as inferred from the modulation of the key proteins Bax, Bcl-2, and caspase-3. From this data, we suggest the use of Hydra as a model organism for the risk assessment of heavy metal pollution in aquatic ecosystems. Copyright © 2016 Elsevier Ltd. All rights reserved.

  6. Detection limits of quantitative and digital PCR assays and their influence in presence-absence surveys of environmental DNA

    Science.gov (United States)

    Hunter, Margaret; Dorazio, Robert M.; Butterfield, John S.; Meigs-Friend, Gaia; Nico, Leo; Ferrante, Jason A.

    2017-01-01

    A set of universal guidelines is needed to determine the limit of detection (LOD) in PCR-based analyses of low concentration DNA. In particular, environmental DNA (eDNA) studies require sensitive and reliable methods to detect rare and cryptic species through shed genetic material in environmental samples. Current strategies for assessing detection limits of eDNA are either too stringent or subjective, possibly resulting in biased estimates of species’ presence. Here, a conservative LOD analysis grounded in analytical chemistry is proposed to correct for overestimated DNA concentrations predominantly caused by the concentration plateau, a nonlinear relationship between expected and measured DNA concentrations. We have used statistical criteria to establish formal mathematical models for both quantitative and droplet digital PCR. To assess the method, a new Grass Carp (Ctenopharyngodon idella) TaqMan assay was developed and tested on both PCR platforms using eDNA in water samples. The LOD adjustment reduced Grass Carp occupancy and detection estimates while increasing uncertainty – indicating that caution needs to be applied to eDNA data without LOD correction. Compared to quantitative PCR, digital PCR had higher occurrence estimates due to increased sensitivity and dilution of inhibitors at low concentrations. Without accurate LOD correction, species occurrence and detection probabilities based on eDNA estimates are prone to a source of bias that cannot be reduced by an increase in sample size or PCR replicates. Other applications also could benefit from a standardized LOD such as GMO food analysis, and forensic and clinical diagnostics.

  7. Cohesin Is limiting for the suppression of DNA damage-induced recombination between homologous chromosomes.

    Directory of Open Access Journals (Sweden)

    Shay Covo

    2010-07-01

    Full Text Available Double-strand break (DSB repair through homologous recombination (HR is an evolutionarily conserved process that is generally error-free. The risk to genome stability posed by nonallelic recombination or loss-of-heterozygosity could be reduced by confining HR to sister chromatids, thereby preventing recombination between homologous chromosomes. Here we show that the sister chromatid cohesion complex (cohesin is a limiting factor in the control of DSB repair and genome stability and that it suppresses DNA damage-induced interactions between homologues. We developed a gene dosage system in tetraploid yeast to address limitations on various essential components in DSB repair and HR. Unlike RAD50 and RAD51, which play a direct role in HR, a 4-fold reduction in the number of essential MCD1 sister chromatid cohesion subunit genes affected survival of gamma-irradiated G(2/M cells. The decreased survival reflected a reduction in DSB repair. Importantly, HR between homologous chromosomes was strongly increased by ionizing radiation in G(2/M cells with a single copy of MCD1 or SMC3 even at radiation doses where survival was high and DSB repair was efficient. The increased recombination also extended to nonlethal doses of UV, which did not induce DSBs. The DNA damage-induced recombinants in G(2/M cells included crossovers. Thus, the cohesin complex has a dual role in protecting chromosome integrity: it promotes DSB repair and recombination between sister chromatids, and it suppresses damage-induced recombination between homologues. The effects of limited amounts of Mcd1and Smc3 indicate that small changes in cohesin levels may increase the risk of genome instability, which may lead to genetic diseases and cancer.

  8. JS-K, a nitric oxide prodrug, induces DNA damage and apoptosis in HBV-positive hepatocellular carcinoma HepG2.2.15 cell.

    Science.gov (United States)

    Liu, Zhengyun; Li, Guangmin; Gou, Ying; Xiao, Dongyan; Luo, Guo; Saavedra, Joseph E; Liu, Jie; Wang, Huan

    2017-08-01

    Hepatocellular carcinoma (HCC) is the most important cause of cancer-related death, and 85% of HCC is caused by chronic HBV infection, the prognosis of patients and the reduction of HBV DNA levels remain unsatisfactory. JS-K, a nitric oxide-releasing diazeniumdiolates, is effective against various tumors, but little is known on its effects on HBV positive HCC. We found that JS-K reduced the expression of HBsAg and HBeAg in HBV-positive HepG2.2.15 cells. This study aimed to further examine anti-tumor effects of JS-K on HepG2.2.15 cells. The MTT assay and colony forming assay were used to study the cell growth inhibition of JS-K; scratch assay and transwell assay were performed to detect cell migration. The cell cycle was detected by flow cytometry. The immunofluorescence, flow cytometry analysis, and western blot were used to study DNA damage and cell apoptosis. JS-K inhibited HepG2.2.15 cell growth in a dose-dependent manner, suppressed cell colony formation and migration, arrested cells gather in the G2 phase. JS-K (1-20μM) increased the expression of DNA damage-associated protein phosphorylation H 2 AX (γH 2 AX), phosphorylation of checkpoint kinase 1 (p-Chk1), phosphorylation of checkpoint kinase 2 (p-Chk2), ataxia-telangiectasia mutated (ATM), phosphorylation of ataxia-telangiectasia mutated rad3-related (p-ATR) and apoptotic-associated proteins cleaved caspase-3, cleaved caspase-7, cleaved poly ADP-ribose polymerase (cleaved PARP). The study demonstrated JS-K is effective against HBV-positive HepG2.2.15 cells, the mechanisms are not only related to inhibition of HBsAg and HBeAg secretion, but also related with induction of DNA damage and apoptosis. JS-K is a promising anti-cancer candidate against HBV-positive HCC. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  9. The chemopreventive activity of the histone deacetylase inhibitor tributyrin in colon carcinogenesis involves the induction of apoptosis and reduction of DNA damage

    Energy Technology Data Exchange (ETDEWEB)

    Heidor, Renato [Laboratory of Diet, Nutrition and Cancer, Department of Food and Experimental Nutrition, Faculty of Pharmaceutical Sciences, University of São Paulo (Brazil); Advanced Research Center in Food Science and Nutrition (NAPAN) and Food Research Center (FoRC), Faculty of Pharmaceutical Sciences, University of São Paulo (Brazil); Furtado, Kelly Silva; Ortega, Juliana Festa [Laboratory of Diet, Nutrition and Cancer, Department of Food and Experimental Nutrition, Faculty of Pharmaceutical Sciences, University of São Paulo (Brazil); Oliveira, Tiago Franco de [Department of Clinical and Toxicological Analyses, Faculty of Pharmaceutical Sciences, University of São Paulo (Brazil); Tavares, Paulo Eduardo Latorre Martins; Vieira, Alessandra; Miranda, Mayara Lilian Paulino [Laboratory of Diet, Nutrition and Cancer, Department of Food and Experimental Nutrition, Faculty of Pharmaceutical Sciences, University of São Paulo (Brazil); Purgatto, Eduardo [Laboratory of Food Chemistry and Biochemistry, Department of Food and Experimental Nutrition, Faculty of Pharmaceutical Sciences, University of São Paulo (Brazil); Advanced Research Center in Food Science and Nutrition (NAPAN) and Food Research Center (FoRC), Faculty of Pharmaceutical Sciences, University of São Paulo (Brazil); Moreno, Fernando Salvador, E-mail: rmoreno@usp.br [Laboratory of Diet, Nutrition and Cancer, Department of Food and Experimental Nutrition, Faculty of Pharmaceutical Sciences, University of São Paulo (Brazil); Advanced Research Center in Food Science and Nutrition (NAPAN) and Food Research Center (FoRC), Faculty of Pharmaceutical Sciences, University of São Paulo (Brazil)

    2014-04-15

    The chemopreventive activity of the histone deacetylase inhibitor (HDACi) tributyrin (TB), a prodrug of butyric acid (BA), was evaluated in a rat model of colon carcinogenesis. The animals were treated with TB (TB group: 200 mg/100 g of body weight, b.w.) or maltodextrin (MD isocaloric control group: 300 mg/100 g b.w.) daily for 9 consecutive weeks. In the 3rd and 4th weeks of treatment, the rats in the TB and MD groups were given DMH (40 mg/kg b.w.) twice a week. After 9 weeks, the animals were euthanized, and the distal colon was examined. Compared with the control group (MD group), TB treatment reduced the total number of aberrant crypt foci (ACF; p < 0.05) as well as the ACF with ≥ 4 crypts (p < 0.05), which are considered more aggressive, but not inhibited the formation of DMH-induced O6-methyldeoxyguanosine DNA adducts. The TB group also showed a higher apoptotic index (p < 0.05) and reduced DNA damage (p < 0.05) compared with MD group. TB acted as a HDACi, as rats treated with the prodrug of BA had higher levels of histone H3K9 acetylation compared with the MD group (p < 0.05). TB administration resulted in increased colonic tissue concentrations of BA (p < 0.05) compared with the control animals. These results suggest that TB can be considered a promising chemopreventive agent for colon carcinogenesis because it reduced the number of ACF, including those that were more aggressive. Induction of apoptosis and reduction of DNA damage are cellular mechanisms that appear to be involved in the chemopreventive activity of TB. - Highlights: • Tributyrin is a chemopreventive agent for rat colon aberrant crypt foci. • Tributyrin increased apoptosis in an experimental rat colon carcinogenesis model. • Tributyrin treatment in a rat colon carcinogenesis model decreased DNA damage. • Tributyrin treatment induced H3K9 acetylation in a rat colon carcinogenesis model.

  10. The chemopreventive activity of the histone deacetylase inhibitor tributyrin in colon carcinogenesis involves the induction of apoptosis and reduction of DNA damage

    International Nuclear Information System (INIS)

    Heidor, Renato; Furtado, Kelly Silva; Ortega, Juliana Festa; Oliveira, Tiago Franco de; Tavares, Paulo Eduardo Latorre Martins; Vieira, Alessandra; Miranda, Mayara Lilian Paulino; Purgatto, Eduardo; Moreno, Fernando Salvador

    2014-01-01

    The chemopreventive activity of the histone deacetylase inhibitor (HDACi) tributyrin (TB), a prodrug of butyric acid (BA), was evaluated in a rat model of colon carcinogenesis. The animals were treated with TB (TB group: 200 mg/100 g of body weight, b.w.) or maltodextrin (MD isocaloric control group: 300 mg/100 g b.w.) daily for 9 consecutive weeks. In the 3rd and 4th weeks of treatment, the rats in the TB and MD groups were given DMH (40 mg/kg b.w.) twice a week. After 9 weeks, the animals were euthanized, and the distal colon was examined. Compared with the control group (MD group), TB treatment reduced the total number of aberrant crypt foci (ACF; p < 0.05) as well as the ACF with ≥ 4 crypts (p < 0.05), which are considered more aggressive, but not inhibited the formation of DMH-induced O6-methyldeoxyguanosine DNA adducts. The TB group also showed a higher apoptotic index (p < 0.05) and reduced DNA damage (p < 0.05) compared with MD group. TB acted as a HDACi, as rats treated with the prodrug of BA had higher levels of histone H3K9 acetylation compared with the MD group (p < 0.05). TB administration resulted in increased colonic tissue concentrations of BA (p < 0.05) compared with the control animals. These results suggest that TB can be considered a promising chemopreventive agent for colon carcinogenesis because it reduced the number of ACF, including those that were more aggressive. Induction of apoptosis and reduction of DNA damage are cellular mechanisms that appear to be involved in the chemopreventive activity of TB. - Highlights: • Tributyrin is a chemopreventive agent for rat colon aberrant crypt foci. • Tributyrin increased apoptosis in an experimental rat colon carcinogenesis model. • Tributyrin treatment in a rat colon carcinogenesis model decreased DNA damage. • Tributyrin treatment induced H3K9 acetylation in a rat colon carcinogenesis model

  11. DNA Double Strand Break Response and Limited Repair Capacity in Mouse Elongated Spermatids

    Directory of Open Access Journals (Sweden)

    Emad A. Ahmed

    2015-12-01

    Full Text Available Spermatids are extremely sensitive to genotoxic exposures since during spermiogenesis only error-prone non homologous end joining (NHEJ repair pathways are available. Hence, genomic damage may accumulate in sperm and be transmitted to the zygote. Indirect, delayed DNA fragmentation and lesions associated with apoptotic-like processes have been observed during spermatid elongation, 27 days after irradiation. The proliferating spermatogonia and early meiotic prophase cells have been suggested to retain a memory of a radiation insult leading later to this delayed fragmentation. Here, we used meiotic spread preparations to localize phosphorylate histone H2 variant (γ-H2AX foci marking DNA double strand breaks (DSBs in elongated spermatids. This technique enabled us to determine the background level of DSB foci in elongated spermatids of RAD54/RAD54B double knockout (dko mice, severe combined immunodeficiency SCID mice, and poly adenosine diphosphate (ADP-ribose polymerase 1 (PARP1 inhibitor (DPQ-treated mice to compare them with the appropriate wild type controls. The repair kinetics data and the protein expression patterns observed indicate that the conventional NHEJ repair pathway is not available for elongated spermatids to repair the programmed and the IR-induced DSBs, reflecting the limited repair capacity of these cells. However, although elongated spermatids express the proteins of the alternative NHEJ, PARP1-inhibition had no effect on the repair kinetics after IR, suggesting that DNA damage may be passed onto sperm. Finally, our genetic mutant analysis suggests that an incomplete or defective meiotic recombinational repair of Spo11-induced DSBs may lead to a carry-over of the DSB damage or induce a delayed nuclear fragmentation during the sensitive programmed chromatin remodeling occurring in elongated spermatids.

  12. Determination of apoptosis, proliferation status and O6-methylguanine DNA methyltransferase methylation profiles in different immunophenotypic profiles of diffuse large B-cell lymphoma

    Directory of Open Access Journals (Sweden)

    Nilay Şen Türk

    2011-03-01

    Full Text Available Objective: Our aim was to investigate the expression of apoptosis-associated proteins (bcl-2, bcl-xl, bax, bak, bid, apoptotic index (AI and proliferation index (PI in germinal center B-cell-like immunophenotypic profile (GCB and non-GCB of diffuse large B-cell lymphoma (DLBCL. Materials and Methods: The methylation status of the promoter region of O6-methylguanine-DNA yerine O6-methylguanine-DNA methyltransferase (MGMT gene and its relation with immunophenotypic differentiation of DLBCLs were also investigated. 101 cases were classified as GCB (29 cases or non-GCB (72 cases. Apoptosis-associated proteins and PI were determined by IHC, and TUNEL method was used to determine AI. MGMT methylation analysis was performed by real-time PCR. Results: The PI was significantly higher in GCB compared with non-GCB (p=0.011. Percentage of cells stained with bcl-6 was positively correlated with the percentage of cells expressing bcl-2 (p=0.023, AI (p=0.006 and PI (p<0.001, while a significant negative correlation was observed with the percentage of cells expressing bax (p=0.027. The percentage of cells stained with MUM1 showed a significantly positive correlation with the percentage of cells expressing bcl-xl (p=0.003, bid (p=0.002, AI (p<0.001, and PI (p=0.001. MGMT methylation analysis was performed in 95 samples, and methylated profile was found in 31 cases (32.6%. GCB was found in 6 cases (22.2% and non-GCB was determined in 25 cases (36.8% out of 31 with MGMT methylated samples. There was no significant association between MGMT methylation status and immunophenotypic profiles (p=0.173. Conclusion: These results suggest that bcl-6 protein expression may be responsible for the high PI in GCB. Additionally, we found that apoptosis-associated proteins were not significantly associated with immunophenotypic profiles.

  13. Effects of Cinnamon (C. zeylanicum) Bark Oil Against Taxanes-Induced Damages in Sperm Quality, Testicular and Epididymal Oxidant/Antioxidant Balance, Testicular Apoptosis, and Sperm DNA Integrity.

    Science.gov (United States)

    Sariözkan, Serpil; Türk, Gaffari; Güvenç, Mehmet; Yüce, Abdurrauf; Özdamar, Saim; Cantürk, Fazile; Yay, Arzu Hanım

    2016-01-01

    The aim of this study was to investigate whether cinnamon bark oil (CBO) has protective effect on taxanes-induced adverse changes in sperm quality, testicular and epididymal oxidant/antioxidant balance, testicular apoptosis, and sperm DNA integrity. For this purpose, 88 adult male rats were equally divided into 8 groups: control, CBO, docetaxel (DTX), paclitaxel (PTX), DTX+PTX, DTX+CBO, PTX+CBO, and DTX+PTX+CBO. CBO was given by gavage daily for 10 weeks at the dose of 100 mg/kg. DTX and PTX were administered by intraperitoneal injection at the doses of 5 and 4 mg/kg/week, respectively, for 10 weeks. DTX+PTX and DTX+PTX+CBO groups were treated with DTX during first 5 weeks and PTX during next 5 weeks. DTX, PTX, and their mixed administrations caused significant decreases in absolute and relative weights of all reproductive organs, testosterone level, sperm motility, concentration, glutathione level, and catalase activity in testicular and epididymal tissues. They also significantly increased abnormal sperm rate, testicular and epididymal malondialdehyde level, apoptotic germ cell number, and sperm DNA fragmentation and significantly damaged the histological structure of testes. CBO consumption by DTX-, PTX-, and DTX+PTX-treated rats provided significant ameliorations in decreased relative weights of reproductive organs, decreased testosterone, decreased sperm quality, imbalanced oxidant/antioxidant system, increased apoptotic germ cell number, rate of sperm with fragmented DNA, and severity of testicular histopathological lesions induced by taxanes. In conclusion, taxanes cause impairments in sperm quality, testicular and epididymal oxidant/antioxidant balance, testicular histopathological structure, and sperm DNA integrity, and long-term CBO consumption protects male reproductive system of rats.

  14. Apoptosis in oral erythema multiforme.

    Science.gov (United States)

    Chrysomali, E; Lozada-Nur, F; Dekker, N P; Papanicolaou, S I; Regezi, J A

    1997-02-01

    Cell death was evaluated in oral erythema multiforme to test the hypothesis that apoptosis may be a mechanism by which keratinocytes die in this condition. Ten erythema multiforme and five control oral mucosa biopsy specimens were evaluated in immunohistochemically stained sections for apoptosis-regulating proteins Bcl-2, Bcl-x, Bax, p53, Fas, and Fas-ligand. Apoptotic keratinocytes, determined by a detection method for DNA fragmentation (TUNEL) and by conventional morphologic criteria were counted per high power field. Keratinocyte staining for Bcl-2 protein was comparable in erythema multiforme and controls. Bcl-x expression was reduced in five erythema multiforme cases. Staining for Bax protein differed in six erythema multiforme cases and showed variable intensity in layers under the parakeratin. Only slight differences in staining patterns of Fas and Fas-ligand proteins were noted between erythema multiforme and controls. The number of apoptotic keratinocytes evaluated by morphologic examination was significantly higher in erythema multiforme (mean per high power field, 0.90 +/- 0.2; controls, 0.06 +/- 0.04; p < 0.05, Mann-Whitney test) and was limited in significance by the TUNEL method (erythema multiforme, 0.43 +/- 0.1; controls, 0.02 +/- 0.02). Overexpression of p53 protein was seen in basal keratinocytes in five erythema multiforme specimens (mean, 17.5 +/- 4.03 per high power field; controls 1.2 +/- 0.3). There is evidence that cell death in erythema multiforme is at least in part due to apoptosis. The apoptotic mechanism may be related to an altered expression of apoptosis-regulating proteins. Although measurable alterations in the phenotypic expression of Fas and Fas-ligand proteins were not apparent, activation of Fas/Fas-ligand system could still be involved in the induction of apoptosis in erythema multiforme.

  15. Dual electrochemical and physiological apoptosis assay detection of in vivo generated nickel chloride induced DNA damage in Caenorhabditis elegans.

    Science.gov (United States)

    Huffnagle, Ian M; Joyner, Alyssa; Rumble, Blake; Hysa, Sherif; Rudel, David; Hvastkovs, Eli G

    2014-08-19

    Environmental nickel exposure is known to cause allergic reactions, respiratory illness, and may be responsible for some forms of cancer in humans. Nematodes are an excellent model organism to test for environmental toxins, as they are prevalent in many different environments. Nickel exposure has previously been shown to impact nematode life processes. In this study, Caenorhabditis elegans nematodes exposed to NiCl2 featured high levels of programmed cell death (PCD) in a concentration-dependent manner as measured by counting apoptotic corpses in the nematode germ line. A green fluorescent protein (GFP) reporter transgene was used that highlights cell corpse engulfment by fluorescence microscopy. Analysis of the reporter in a p53 mutant strain putatively indicates that the PCDs are a result of genomic DNA damage. In order to assay the potential genotoxic actions of NiCl2, DNA was extracted from nematodes exposed to increasing concentrations of NiCl2 and electrochemically assayed. In vivo damaged DNA was immobilized on pyrolytic graphite electrodes using the layer-by-layer (LbL) technique. Square-wave voltammograms were obtained in the presence of redox mediator, ruthenium trisbipyridine (Ru(bpy)3(2+)), that catalytically oxidizes guanines in DNA. Oxidative peak currents were shown to increase as a function of NiCl2 exposure, which further suggests that the extracted DNA from nematodes exposed to the nickel was damaged. This report demonstrates that our electrochemical biosensor can detect damage at lower Ni concentrations than our physiological PCD assay and that the results are predictive of physiological responses at higher concentrations. Thus, a biological model for toxicity and animal disease can be assayed using an electrochemical approach.

  16. Inactivation of PNKP by mutant ATXN3 triggers apoptosis by activating the DNA damage-response pathway in SCA3.

    Directory of Open Access Journals (Sweden)

    Rui Gao

    2015-01-01

    Full Text Available Spinocerebellar ataxia type 3 (SCA3, also known as Machado-Joseph disease (MJD, is an untreatable autosomal dominant neurodegenerative disease, and the most common such inherited ataxia worldwide. The mutation in SCA3 is the expansion of a polymorphic CAG tri-nucleotide repeat sequence in the C-terminal coding region of the ATXN3 gene at chromosomal locus 14q32.1. The mutant ATXN3 protein encoding expanded glutamine (polyQ sequences interacts with multiple proteins in vivo, and is deposited as aggregates in the SCA3 brain. A large body of literature suggests that the loss of function of the native ATNX3-interacting proteins that are deposited in the polyQ aggregates contributes to cellular toxicity, systemic neurodegeneration and the pathogenic mechanism in SCA3. Nonetheless, a significant understanding of the disease etiology of SCA3, the molecular mechanism by which the polyQ expansions in the mutant ATXN3 induce neurodegeneration in SCA3 has remained elusive. In the present study, we show that the essential DNA strand break repair enzyme PNKP (polynucleotide kinase 3'-phosphatase interacts with, and is inactivated by, the mutant ATXN3, resulting in inefficient DNA repair, persistent accumulation of DNA damage/strand breaks, and subsequent chronic activation of the DNA damage-response ataxia telangiectasia-mutated (ATM signaling pathway in SCA3. We report that persistent accumulation of DNA damage/strand breaks and chronic activation of the serine/threonine kinase ATM and the downstream p53 and protein kinase C-δ pro-apoptotic pathways trigger neuronal dysfunction and eventually neuronal death in SCA3. Either PNKP overexpression or pharmacological inhibition of ATM dramatically blocked mutant ATXN3-mediated cell death. Discovery of the mechanism by which mutant ATXN3 induces DNA damage and amplifies the pro-death signaling pathways provides a molecular basis for neurodegeneration due to PNKP inactivation in SCA3, and for the first time offers

  17. Glucose transporter 1-mediated glucose uptake is limiting for B-cell acute lymphoblastic leukemia anabolic metabolism and resistance to apoptosis.

    Science.gov (United States)

    Liu, T; Kishton, R J; Macintyre, A N; Gerriets, V A; Xiang, H; Liu, X; Abel, E D; Rizzieri, D; Locasale, J W; Rathmell, J C

    2014-10-16

    The metabolic profiles of cancer cells have long been acknowledged to be altered and to provide new therapeutic opportunities. In particular, a wide range of both solid and liquid tumors use aerobic glycolysis to supply energy and support cell growth. This metabolic program leads to high rates of glucose consumption through glycolysis with secretion of lactate even in the presence of oxygen. Identifying the limiting events in aerobic glycolysis and the response of cancer cells to metabolic inhibition is now essential to exploit this potential metabolic dependency. Here, we examine the role of glucose uptake and the glucose transporter Glut1 in the metabolism and metabolic stress response of BCR-Abl+ B-cell acute lymphoblastic leukemia cells (B-ALL). B-ALL cells were highly glycolytic and primary human B-ALL samples were dependent on glycolysis. We show B-ALL cells express multiple glucose transporters and conditional genetic deletion of Glut1 led to a partial loss of glucose uptake. This reduced glucose transport capacity, however, was sufficient to metabolically reprogram B-ALL cells to decrease anabolic and increase catabolic flux. Cell proliferation decreased and a limited degree of apoptosis was also observed. Importantly, Glut1-deficient B-ALL cells failed to accumulate in vivo and leukemic progression was suppressed by Glut1 deletion. Similarly, pharmacologic inhibition of aerobic glycolysis with moderate doses of 2-deoxyglucose (2-DG) slowed B-ALL cell proliferation, but extensive apoptosis only occurred at high doses. Nevertheless, 2-DG induced the pro-apoptotic protein Bim and sensitized B-ALL cells to the tyrosine kinase inhibitor Dasatinib in vivo. Together, these data show that despite expression of multiple glucose transporters, B-ALL cells are reliant on Glut1 to maintain aerobic glycolysis and anabolic metabolism. Further, partial inhibition of glucose metabolism is sufficient to sensitize cancer cells to specifically targeted therapies, suggesting

  18. Effect of etodolac hydrazone, a new compound synthesised from etodolac, on spermatozoon quality, testicular lipid peroxidation, apoptosis and spermatozoon DNA integrity.

    Science.gov (United States)

    Sarıözkan, S; Türk, G; Çıkla-Süzgün, P; Güvenç, M; Yüce, A; Yay, A H; Cantürk, F; Küçükgüzel, Ş G

    2016-03-01

    The aim of this study was to investigate the effect of etodolac hydrazone (EH), a new compound synthesised from etodolac, on spermatozoon quality, testicular lipid peroxidation, apoptosis and spermatozoon DNA integrity in rats. Group 1 (n = 8) received 1 ml dimethyl sulfoxide (DMSO) daily (Control); group 2 (n = 8) was treated with 5 mg kg(-1)  day(-1) EH, dissolved in 1 ml DMSO (EH-5); and group 3 (n = 8) was treated with 10 mg kg(-1)  day(-1) EH, dissolved in 1 ml DMSO (EH-10). All administrations were performed by gavage and maintained for 8 weeks. Both doses of EH administration caused significant decreases in absolute and relative weights of testis, whole epididymis, right cauda epididymis, and spermatozoon motility, spermatozoon count in comparison with the control group. Only 10 mg kg(-1)  day(-1) EH administration caused significant decreases in absolute and relative weights of seminal vesicles and serum testosterone level, and significant increases in testicular lipid peroxidation level, and numbers of TUNEL+ apoptotic germ cells and spermatozoa with damaged DNA along with some histopathological damages when compared to the control group. However, body and ventral prostate weight, and testicular antioxidant markers (glutathione, glutathione-peroxidase and catalase), were unaffected significantly by both doses of EH administration. In conclusion, two different doses of EH, in particular its high dose, damage to testicular spermatogenic cells and spermatozoon DNA and, it decreases spermatozoon motility, count and testosterone level in healthy rats. © 2015 Blackwell Verlag GmbH.

  19. Mutation of a Nopp140 gene dao-5 alters rDNA transcription and increases germ cell apoptosis in C. elegans.

    Science.gov (United States)

    Lee, C-C; Tsai, Y-T; Kao, C-W; Lee, L-W; Lai, H-J; Ma, T-H; Chang, Y-S; Yeh, N-H; Lo, S J

    2014-04-10

    Human diseases of impaired ribosome biogenesis resulting from disruption of rRNA biosynthesis or loss of ribosomal components are collectively described as 'ribosomopathies'. Treacher Collins syndrome (TCS), a representative human ribosomopathy with craniofacial abnormalities, is attributed to mutations in the tcof1 gene that has a homologous gene called nopp140. Previous studies demonstrated that the dao-5 (dauer and aged animal overexpression gene 5) of Caenorhabditis elegans is a member of nopp140 gene family and plays a role in nucleogenesis in the early embryo. Here, we established a C. elegans model for studying Nopp140-associated ribosomopathy. A null dao-5 mutant ok542 with a semi-infertile phenotype showed a delay in gonadogenesis, as well as a higher incidence of germline apoptosis. These phenotypes in dao-5(ok542) are likely resulted from inefficient rDNA transcription that was observed by run-on analyses and chromatin immunoprecipitation (ChIP) assays measuring the RNA Pol I occupancy on the rDNA promoter. ChIP assays further showed that the modifications of acetylated histone 4 (H4Ac) and dimethylation at the lysine 9 of histone 3 (H3K9me2) around the rDNA promoter were altered in dao-5 mutants compared with the N2 wild type. In addition, activated CEP-1 (a C. elegans p53 homolog) activity was also linked to the loss of DAO-5 in terms of the transcriptional upregulation of two CEP-1 downstream effectors, EGL-1 and CED-13. We propose that the dao-5 mutant of C. elegans can be a valuable model for studying human Nopp140-associated ribosomopathy at the cellular and molecular levels.

  20. Lichen metabolites prevent UV light and nitric oxide-mediated plasmid DNA damage and induce apoptosis in human melanoma cells.

    Science.gov (United States)

    Russo, A; Piovano, M; Lombardo, L; Garbarino, J; Cardile, V

    2008-09-26

    In humans both UV-A and UV-B can cause gene mutations and suppress immunity, which leads to skin cancer, including melanoma. Inhibition of reactive oxygen species (ROS) and reactive nitrogen species (RNS) appears particularly promising as ROS and RNS production by both UV-A and UV-B contributes to inflammation, immunosuppression, gene mutation and carcinogenesis. We evaluated the effect of two lichen compounds, sphaerophorin (depside) and pannarin (depsidone) on pBR322 DNA cleavage induced by hydroxyl radicals (()OH), and by nitric oxide (NO), and their superoxide anion (O(2)(-)) scavenging capacity. In addition, we investigated the growth inhibitory activity of these compounds against human melanoma cells (M14 cell line). Sphaerophorin and pannarin showed a protective effect on plasmid DNA and exhibited a superoxide dismutase like effect. The data obtained in cell culture show that these lichen metabolites inhibit the growth of melanoma cells, inducing an apoptotic cell death, demonstrated by the fragmentation of genomic DNA (COMET and TUNEL Assays) and by a significant increase of caspase-3 activity, and correlated, at least in part, to the increase of ROS generation, These results confirm the promising biological properties of sphaerophorin and pannarin and encourage further investigations on their molecular mechanisms.

  1. Melatonin sensitizes human cervical cancer HeLa cells to cisplatin-induced cytotoxicity and apoptosis: effects on oxidative stress and DNA fragmentation.

    Science.gov (United States)

    Pariente, Roberto; Pariente, José A; Rodríguez, Ana B; Espino, Javier

    2016-01-01

    Melatonin has antitumor activity via several mechanisms including its antiproliferative and pro-apoptotic effects as well as its potent antioxidant actions, although recent evidence has indicated that melatonin may perform pro-oxidant actions in tumor cells. Therefore, melatonin may be useful in the treatment of tumors in association with chemotherapy drugs. This study was intended to evaluate the in vitro effect of melatonin on the cytotoxic and pro-apoptotic actions of various chemotherapeutic agents in cervical cancer HeLa cells. Herein, we found that both melatonin and three of the chemotherapeutic drugs tested, namely cisplatin (CIS), 5-fluorouracil (5-FU), and doxorubicin, induced a decrease in HeLa cell viability. Furthermore, melatonin significantly increased the cytotoxic effect of such chemotherapeutic agents. Consistently, costimulation of HeLa cells with any chemotherapeutic agent in the presence of melatonin further increased caspase-3 activation, particularly in CIS- and 5-FU-challenged cells. Likewise, concomitant treatments with melatonin and CIS significantly enhanced the ratio of cells entering mitochondrial apoptosis due to reactive oxygen species (ROS) overproduction, substantially augmented the population of apoptotic cells, and markedly enlarged DNA fragmentation compared to the treatments with CIS alone. Nonetheless, melatonin only displayed moderate chemosensitizing effects in 5-FU-stimulated HeLa cells, as suggested by slight increments in the percentage of cells stimulated for ROS production and in the proportion of early apoptotic cells compared to the treatments with 5-FU alone. In summary, our findings provided evidence that in vitro melatonin strongly enhances CIS-induced cytotoxicity and apoptosis in HeLa cells and, hence, the indoleamine could be potentially applied to cervical cancer treatment as a powerful synergistic agent. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  2. Response of thyroid follicular cells to gamma irradiation compared to proton irradiation. I. Initial characterization of DNA damage, micronucleus formation, apoptosis, cell survival, and cell cycle phase redistribution

    Science.gov (United States)

    Green, L. M.; Murray, D. K.; Bant, A. M.; Kazarians, G.; Moyers, M. F.; Nelson, G. A.; Tran, D. T.

    2001-01-01

    The RBE of protons has been assumed to be equivalent to that of photons. The objective of this study was to determine whether radiation-induced DNA and chromosome damage, apoptosis, cell killing and cell cycling in organized epithelial cells was influenced by radiation quality. Thyroid-stimulating hormone-dependent Fischer rat thyroid cells, established as follicles, were exposed to gamma rays or proton beams delivered acutely over a range of physical doses. Gamma-irradiated cells were able to repair DNA damage relatively rapidly so that by 1 h postirradiation they had approximately 20% fewer exposed 3' ends than their counterparts that had been irradiated with proton beams. The persistence of free ends of DNA in the samples irradiated with the proton beam implies that either more initial breaks or a quantitatively different type of damage had occurred. These results were further supported by an increased frequency of chromosomal damage as measured by the presence of micronuclei. Proton-beam irradiation induced micronuclei at a rate of 2.4% per gray, which at 12 Gy translated to 40% more micronuclei than in comparable gamma-irradiated cultures. The higher rate of micronucleus formation and the presence of larger micronuclei in proton-irradiated cells was further evidence that a qualitatively more severe class of damage had been induced than was induced by gamma rays. Differences in the type of damage produced were detected in the apoptosis assay, wherein a significant lag in the induction of apoptosis occurred after gamma irradiation that did not occur with protons. The more immediate expression of apoptotic cells in the cultures irradiated with the proton beam suggests that the damage inflicted was more severe. Alternatively, the cell cycle checkpoint mechanisms required for recovery from such damage might not have been invoked. Differences based on radiation quality were also evident in the alpha components of cell survival curves (0.05 Gy(-1) for gamma rays, 0

  3. The novel curcumin analog FLLL32 decreases STAT3 DNA binding activity and expression, and induces apoptosis in osteosarcoma cell lines

    International Nuclear Information System (INIS)

    Fossey, Stacey L; London, Cheryl A; Bear, Misty D; Lin, Jiayuh; Li, Chenglong; Schwartz, Eric B; Li, Pui-Kai; Fuchs, James R; Fenger, Joelle; Kisseberth, William C

    2011-01-01

    Curcumin is a naturally occurring phenolic compound shown to have a wide variety of antitumor activities; however, it does not attain sufficient blood levels to do so when ingested. Using structure-based design, a novel compound, FLLL32, was generated from curcumin. FLLL32 possesses superior biochemical properties and more specifically targets STAT3, a transcription factor important in tumor cell survival, proliferation, metastasis, and chemotherapy resistance. In our previous work, we found that several canine and human osteosarcoma (OSA) cell lines, but not normal osteoblasts, exhibit constitutive phosphorylation of STAT3. Compared to curcumin, we hypothesized that FLLL32 would be more efficient at inhibiting STAT3 function in OSA cells and that this would result in enhanced downregulation of STAT3 transcriptional targets and subsequent death of OSA cells. Human and canine OSA cells were treated with vehicle, curcumin, or FLLL32 and the effects on proliferation (CyQUANT ® ), apoptosis (SensoLyte ® Homogeneous AMC Caspase- 3/7 Assay kit, western blotting), STAT3 DNA binding (EMSA), and vascular endothelial growth factor (VEGF), survivin, and matrix metalloproteinase-2 (MMP2) expression (RT-PCR, western blotting) were measured. STAT3 expression was measured by RT-PCR, qRT- PCR, and western blotting. Our data showed that FLLL32 decreased STAT3 DNA binding by EMSA. FLLL32 promoted loss of cell proliferation at lower concentrations than curcumin leading to caspase-3- dependent apoptosis, as evidenced by PARP cleavage and increased caspase 3/7 activity; this could be inhibited by treatment with the pan-caspase inhibitor Z-VAD-FMK. Treatment of OSA cells with FLLL32 decreased expression of survivin, VEGF, and MMP2 at both mRNA and protein levels with concurrent decreases in phosphorylated and total STAT3; this loss of total STAT3 occurred, in part, via the ubiquitin-proteasome pathway. These data demonstrate that the novel curcumin analog FLLL32 has biologic activity

  4. Lipophilic ester and amide derivatives of rosmarinic acid protect cells against H2O2-induced DNA damage and apoptosis: The potential role of intracellular accumulation and labile iron chelation

    Directory of Open Access Journals (Sweden)

    Paraskevi S. Gerogianni

    2018-05-01

    Full Text Available Phenolic acids represent abundant components contained in human diet. However, the negative charge in their carboxylic group limits their capacity to diffuse through biological membranes, thus hindering their access to cell interior. In order to promote the diffusion of rosmarinic acid through biological membranes, we synthesized several lipophilic ester- and amide-derivatives of this compound and evaluated their capacity to prevent H2O2-induced DNA damage and apoptosis in cultured human cells. Esterification of the carboxylic moiety with lipophilic groups strongly enhanced the capacity of rosmarinic acid to protect cells. On the other hand, the amide-derivatives were somewhat less effective but exerted less cytotoxicity at high concentrations. Cell uptake experiments, using ultra-high performance liquid chromatography coupled with tandem mass spectrometry (UHPLC-MS/MS, illustrated different levels of intracellular accumulation among the ester- and amide-derivatives, with the first being more effectively accumulated, probably due to their extensive hydrolysis inside the cells. In conclusion, these results highlight the hitherto unrecognized fundamental importance of derivatization of diet-derived phenolic acids to unveil their biological potential.

  5. Translocation of the papillomavirus L2/vDNA complex across the limiting membrane requires the onset of mitosis.

    Science.gov (United States)

    Calton, Christine M; Bronnimann, Matthew P; Manson, Ariana R; Li, Shuaizhi; Chapman, Janice A; Suarez-Berumen, Marcela; Williamson, Tatum R; Molugu, Sudheer K; Bernal, Ricardo A; Campos, Samuel K

    2017-05-01

    The human papillomavirus type 16 (HPV16) L2 protein acts as a chaperone to ensure that the viral genome (vDNA) traffics from endosomes to the trans-Golgi network (TGN) and eventually the nucleus, where HPV replication occurs. En route to the nucleus, the L2/vDNA complex must translocate across limiting intracellular membranes. The details of this critical process remain poorly characterized. We have developed a system based on subcellular compartmentalization of the enzyme BirA and its cognate substrate to detect membrane translocation of L2-BirA from incoming virions. We find that L2 translocation requires transport to the TGN and is strictly dependent on entry into mitosis, coinciding with mitotic entry in synchronized cells. Cell cycle arrest causes retention of L2/vDNA at the TGN; only release and progression past G2/M enables translocation across the limiting membrane and subsequent infection. Microscopy of EdU-labeled vDNA reveals a rapid and dramatic shift in vDNA localization during early mitosis. At late G2/early prophase vDNA egresses from the TGN to a pericentriolar location, accumulating there through prometaphase where it begins to associate with condensed chromosomes. By metaphase and throughout anaphase the vDNA is seen bound to the mitotic chromosomes, ensuring distribution into both daughter nuclei. Mutations in a newly defined chromatin binding region of L2 potently blocked translocation, suggesting that translocation is dependent on chromatin binding during prometaphase. This represents the first time a virus has been shown to functionally couple the penetration of limiting membranes to cellular mitosis, explaining in part the tropism of HPV for mitotic basal keratinocytes.

  6. Translocation of the papillomavirus L2/vDNA complex across the limiting membrane requires the onset of mitosis.

    Directory of Open Access Journals (Sweden)

    Christine M Calton

    2017-05-01

    Full Text Available The human papillomavirus type 16 (HPV16 L2 protein acts as a chaperone to ensure that the viral genome (vDNA traffics from endosomes to the trans-Golgi network (TGN and eventually the nucleus, where HPV replication occurs. En route to the nucleus, the L2/vDNA complex must translocate across limiting intracellular membranes. The details of this critical process remain poorly characterized. We have developed a system based on subcellular compartmentalization of the enzyme BirA and its cognate substrate to detect membrane translocation of L2-BirA from incoming virions. We find that L2 translocation requires transport to the TGN and is strictly dependent on entry into mitosis, coinciding with mitotic entry in synchronized cells. Cell cycle arrest causes retention of L2/vDNA at the TGN; only release and progression past G2/M enables translocation across the limiting membrane and subsequent infection. Microscopy of EdU-labeled vDNA reveals a rapid and dramatic shift in vDNA localization during early mitosis. At late G2/early prophase vDNA egresses from the TGN to a pericentriolar location, accumulating there through prometaphase where it begins to associate with condensed chromosomes. By metaphase and throughout anaphase the vDNA is seen bound to the mitotic chromosomes, ensuring distribution into both daughter nuclei. Mutations in a newly defined chromatin binding region of L2 potently blocked translocation, suggesting that translocation is dependent on chromatin binding during prometaphase. This represents the first time a virus has been shown to functionally couple the penetration of limiting membranes to cellular mitosis, explaining in part the tropism of HPV for mitotic basal keratinocytes.

  7. Chitosan-Dextran sulfate coated doxorubicin loaded PLGA-PVA-nanoparticles caused apoptosis in doxorubicin resistance breast cancer cells through induction of DNA damage.

    Science.gov (United States)

    Siddharth, Sumit; Nayak, Anmada; Nayak, Deepika; Bindhani, Birendra Kumar; Kundu, Chanakya Nath

    2017-05-19

    To overcome the toxicity, pharmacokinetics and drug resistance associated with doxorubicin (DOX), a strategy was developed by encapsulating DOX- loaded-PLGA-PVA- nanoparticles within chitosan-dextran sulfate nanoparticles (CS-DS) [CS-DS-coated-DOX-loaded -PLGA-PVA-NP] and study the sensitivity against DOX- resistance- breast cancer cells (MCF-7-DOX-R). These CS-DS and PLGA-PVA double coated DOX are spherical, stable, polydispersed and have zeta potential +2.89 mV. MCF-7- DOX-R cells were derived by exposing increasing doses of DOX in MCF-7 cells. These cells were resistance to 500 nM of DOX while parental cells were susceptible at 150 nM. The double coated NP caused more cytotoxicity in cancer and MCF-7-DOX-R cells without affecting the normal cells in comparison to DOX-loaded-PLGA-PVA-NP. These NP enhances the uptake of DOX in MCF-7-DOX-R cells and caused apoptosis by increasing apoptotic nuclei, Bax/Bcl-xL ratio, cleaved product PARP-1, tumor suppressor gene p21, p53, topoisomerase inhibition activity, DNA damage and decreasing the migratory potential of cells. An increased S phase arrest was noted in DOX and DOX- loaded- PLGA-PVA-NP treated cells but reduction of S phase and simultaneous increase of Sub-G1 was observed in double coated-NP. Thus, data revealed that CS-DS- DOX- loaded PLGA-PVA- NP caused DOX-resistance cell death by inducing inhibition of topoisomerase activity followed by DNA damage.

  8. Limiter

    Science.gov (United States)

    Cohen, S.A.; Hosea, J.C.; Timberlake, J.R.

    1984-10-19

    A limiter with a specially contoured front face is provided. The front face of the limiter (the plasma-side face) is flat with a central indentation. In addition, the limiter shape is cylindrically symmetric so that the limiter can be rotated for greater heat distribution. This limiter shape accommodates the various power scrape-off distances lambda p, which depend on the parallel velocity, V/sub parallel/, of the impacting particles.

  9. Limitations and recommendations for successful DNA extraction from forensic soil samples: a review.

    Science.gov (United States)

    Young, Jennifer M; Rawlence, Nicolas J; Weyrich, Laura S; Cooper, Alan

    2014-05-01

    Soil is commonly used in forensic casework to provide discriminatory power to link a suspect to a crime scene. Standard analyses examine the intrinsic properties of soils, including mineralogy, geophysics, texture and colour; however, soils can also support a vast amount of organisms, which can be examined using DNA fingerprinting techniques. Many previous genetic analyses have relied on patterns of fragment length variation produced by amplification of unidentified taxa in the soil extract. In contrast, the development of advanced DNA sequencing technologies now provides the ability to generate a detailed picture of soil microbial communities and the taxa present, allowing for improved discrimination between samples. However, DNA must be efficiently extracted from the complex soil matrix to achieve accurate and reproducible DNA sequencing results, and extraction efficacy is highly dependent on the soil type and method used. As a result, a consideration of soil properties is important when estimating the likelihood of successful DNA extraction. This would include a basic understanding of soil components, their interactions with DNA molecules and the factors that affect such interactions. This review highlights some important considerations required prior to DNA extraction and discusses the use of common chemical reagents in soil DNA extraction protocols to achieve maximum efficacy. Together, the information presented here is designed to facilitate informed decisions about the most appropriate sampling and extraction methodology, relevant both to the soil type and the details of a specific forensic case, to ensure sufficient DNA yield and enable successful analysis. Copyright © 2014 Forensic Science Society. Published by Elsevier Ireland Ltd. All rights reserved.

  10. Physician Education: Apoptosis.

    Science.gov (United States)

    Kataoka; Tsuruo

    1996-01-01

    We have come to understand apoptosis as not merely a single form of cell death, but as a fundamental theme in cell biology that has far-reaching implications in the fields of physiology and pathology. At the present time, however, the mechanism of apoptosis is not clearly understood, as research into apoptosis is still at the initial stages. Nevertheless, the links between apoptosis and a variety of pathological conditions are gradually becoming clearer. In this article, we will provide a simple explanation of apoptosis and its mechanism as a novel concept of cell death and discuss the way in which apoptosis has been linked to a variety of pathological conditions. WHAT IS APOPTOSIS?: In normal tissue, cells that are no longer needed are rapidly eliminated without affecting the overall function of the tissue. In this process cells undergo an active and spontaneous suicide called programmed cell death. In fact, the majority of physiological cell deaths take the form of apoptosis. The word apoptosis is used, in contrast to necrosis, to describe the situation in which a cell actively pursues a course toward death upon receiving certain stimuli [1]. The morphological changes of apoptosis found in most cell types first involve contraction in cell volume and condensation of the nucleus. When this happens the intracellular organelles such as the mitochondria retain their normal morphology. As apoptosis proceeds, blebbing of the plasma membrane occurs, and the nucleus becomes fragmented. Finally, the cell itself fragments to form apoptotic bodies that are engulfed by nearby phagocytes. With respect to biochemical changes, it is known that the chromosomes become fragmented into nucleosome units, and DNA forms characteristic ladder patterns when subjected to agarose gel electrophoresis. MECHANISM OF APOPTOSIS: It has been reported that apoptosis is induced in various cells by many kinds of irritations, but the precise mechanism is still unclear. Cell injuries that induce

  11. Artifactual mutations resulting from DNA lesions limit detection levels in ultrasensitive sequencing applications

    Science.gov (United States)

    Arbeithuber, Barbara; Makova, Kateryna D.; Tiemann-Boege, Irene

    2016-01-01

    The need in cancer research or evolutionary biology to detect rare mutations or variants present at very low frequencies (DNA lesions introduce important error sources in ultrasensitive technologies such as single molecule PCR (smPCR) applications (e.g. droplet-digital PCR), or next-generation sequencing (NGS) based methods. Using templates with known amplifiable lesions (8-oxoguanine, deaminated 5-methylcytosine, uracil, and DNA heteroduplexes), we assessed with smPCR and duplex sequencing that templates with these lesions were amplified very efficiently by proofreading polymerases (except uracil), leading to G->T, and to a lesser extent, to unreported G->C substitutions at 8-oxoguanine lesions, and C->T transitions in amplified uracil containing templates. Long heat incubations common in many DNA extraction protocols significantly increased the number of G->T substitutions. Moreover, in ∼50-80% smPCR reactions we observed the random amplification preference of only one of both DNA strands explaining the known ‘PCR jackpot effect’, with the result that a lesion became indistinguishable from a true mutation or variant. Finally, we showed that artifactual mutations derived from uracil and 8-oxoguanine could be significantly reduced by DNA repair enzymes. PMID:27477585

  12. Spaceflight Associated Apoptosis

    Science.gov (United States)

    Ichiki, Albert T.; Gibson, Linda A.; Allebban, Zuhair

    1996-01-01

    Lymphoid tissues have been shown to atrophy in rats flown on Russian spaceflights. Histological examination indicated evidence for cell degradation. Lymphoid tissues from rats flown on Spacelab Life Sciences-2 mission were analyzed for apoptosis by evidence of fragmented lymphocytes, which could be engulfed by macrophages, or DNA strand breaks using the terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling (TUNEL) assay. Apoptosis was not detected in the thymus and spleen collected inflight or from the synchronous ground rats but was detected in the thymus, spleen and inguinal lymph node of the flight animals on recovery. These results indicate that the apoptosis observed in the lymphatic tissues of the rats on recovery could have been induced by the gravitational stress of reentry, corroborating the findings from the early space-flight observations.

  13. Prophylactic role of B vitamins against bulk and zinc oxide nano-particles toxicity induced oxidative DNA damage and apoptosis in rat livers.

    Science.gov (United States)

    Yousef, Jehad Mustafa; Mohamed, Azza Mostafa

    2015-01-01

    The aim of this work is to explore the protective of B vitamins (B(3), B(6) and B(12)) against the hepatotoxic potency of either bulk zinc oxide (ZnO-bulk) or its nanoparticles (ZnO-NPs)-induced liver damage in rats. ZnO- bulk or its NPs were administered orally (500 mg/kg b.w.) for 10 successive days. The results revealed that oral co-administration of combination of B vitamins (250 mg B(3), 60 mg B(6) and 0.6 mg B(12)/Kg body weight) daily for 3 weeks to rats intoxicated by either ZnO- bulk or its NPs markedly ameliorated increases in serum of alanine aminotransferase (ALT), aspartate aminotransferase (AST) and lactate dehdrogenase (LDH). The B vitamins also down-regulated increases in serum glucose level as well as increases in immuno-inflammatory biomarkers, including tumor necrosis factor-α (TNF-α) and C-reactive protein compared with intoxicated, untreated rats. Beside, the used agent successfully modulated the alterations in serum vascular endothelial growth factor (VEGF), attenuated liver oxidative DNA damage compared with ZnO intoxicated groups. We showed that the used B complex mitigated increased malondialdehyde (MDA), decrease in glutathione peroxidase (GPx) and increase in the apoptosis marker caspase 3 of liver tissue in response to either ZnO-bulk or its NP toxicity. In conclusion, early treatment with vitamin B complex may protect liver tissue from deleterious damage induced by the toxic effects of ZnO-bulk or its NPs.

  14. Apoptosis in Pneumovirus Infection

    Directory of Open Access Journals (Sweden)

    Reinout A. Bem

    2013-01-01

    Full Text Available Pneumovirus infections cause a wide spectrum of respiratory disease in humans and animals. The airway epithelium is the major site of pneumovirus replication. Apoptosis or regulated cell death, may contribute to the host anti-viral response by limiting viral replication. However, apoptosis of lung epithelial cells may also exacerbate lung injury, depending on the extent, the timing and specific location in the lungs. Differential apoptotic responses of epithelial cells versus innate immune cells (e.g., neutrophils, macrophages during pneumovirus infection can further contribute to the complex and delicate balance between host defense and disease pathogenesis. The purpose of this manuscript is to give an overview of the role of apoptosis in pneumovirus infection. We will examine clinical and experimental data concerning the various pro-apoptotic stimuli and the roles of apoptotic epithelial and innate immune cells during pneumovirus disease. Finally, we will discuss potential therapeutic interventions targeting apoptosis in the lungs.

  15. Viruses and apoptosis.

    Science.gov (United States)

    Roulston, A; Marcellus, R C; Branton, P E

    1999-01-01

    Successful viral replication requires not only the efficient production and spread of progeny, but also evasion of host defense mechanisms that limit replication by killing infected cells. In addition to inducing immune and inflammatory responses, infection by most viruses triggers apoptosis or programmed cell death of the infected cell. This cell response often results as a compulsory or unavoidable by-product of the action of critical viral replicative functions. In addition, some viruses seem to use apoptosis as a mechanism of cell killing and virus spread. In both cases, successful replication relies on the ability of certain viral products to block or delay apoptosis until sufficient progeny have been produced. Such proteins target a variety of strategic points in the apoptotic pathway. In this review we summarize the great amount of recent information on viruses and apoptosis and offer insights into how this knowledge may be used for future research and novel therapies.

  16. Bortezomib-induced sensitization of malignant human glioma cells to vorinostat-induced apoptosis depends on reactive oxygen species production, mitochondrial dysfunction, Noxa upregulation, Mcl-1 cleavage, and DNA damage.

    Science.gov (United States)

    Premkumar, Daniel R; Jane, Esther P; Agostino, Naomi R; DiDomenico, Joseph D; Pollack, Ian F

    2013-02-01

    Glioblastomas are invasive tumors with poor prognosis despite current therapies. Histone deacetylase inhibitors (HDACIs) represent a class of agents that can modulate gene expression to reduce tumor growth, and we and others have noted some antiglioma activity from HDACIs, such as vorinostat, although insufficient to warrant use as monotherapy. We have recently demonstrated that proteasome inhibitors, such as bortezomib, dramatically sensitized highly resistant glioma cells to apoptosis induction, suggesting that proteasomal inhibition may be a promising combination strategy for glioma therapeutics. In this study, we examined whether bortezomib could enhance response to HDAC inhibition in glioma cells. Although primary cells from glioblastoma multiforme (GBM) patients and established glioma cell lines did not show significant induction of apoptosis with vorinostat treatment alone, the combination of vorinostat plus bortezomib significantly enhanced apoptosis. The enhanced efficacy was due to proapoptotic mitochondrial injury and increased generation of reactive oxygen species. Our results also revealed that combination of bortezomib with vorinostat enhanced apoptosis by increasing Mcl-1 cleavage, Noxa upregulation, Bak and Bax activation, and cytochrome c release. Further downregulation of Mcl-1 using shRNA enhanced cell killing by the bortezomib/vorinostat combination. Vorinostat induced a rapid and sustained phosphorylation of histone H2AX in primary GBM and T98G cells, and this effect was significantly enhanced by co-administration of bortezomib. Vorinostat/bortezomib combination also induced Rad51 downregulation, which plays an important role in the synergistic enhancement of DNA damage and apoptosis. The significantly enhanced antitumor activity that results from the combination of bortezomib and HDACIs offers promise as a novel treatment for glioma patients. Copyright © 2011 Wiley Periodicals, Inc.

  17. Drug-induced reactivation of apoptosis abrogates HIV-1 infection.

    Directory of Open Access Journals (Sweden)

    Hartmut M Hanauske-Abel

    Full Text Available HIV-1 blocks apoptosis, programmed cell death, an innate defense of cells against viral invasion. However, apoptosis can be selectively reactivated in HIV-infected cells by chemical agents that interfere with HIV-1 gene expression. We studied two globally used medicines, the topical antifungal ciclopirox and the iron chelator deferiprone, for their effect on apoptosis in HIV-infected H9 cells and in peripheral blood mononuclear cells infected with clinical HIV-1 isolates. Both medicines activated apoptosis preferentially in HIV-infected cells, suggesting that the drugs mediate escape from the viral suppression of defensive apoptosis. In infected H9 cells, ciclopirox and deferiprone enhanced mitochondrial membrane depolarization, initiating the intrinsic pathway of apoptosis to execution, as evidenced by caspase-3 activation, poly(ADP-ribose polymerase proteolysis, DNA degradation, and apoptotic cell morphology. In isolate-infected peripheral blood mononuclear cells, ciclopirox collapsed HIV-1 production to the limit of viral protein and RNA detection. Despite prolonged monotherapy, ciclopirox did not elicit breakthrough. No viral re-emergence was observed even 12 weeks after drug cessation, suggesting elimination of the proviral reservoir. Tests in mice predictive for cytotoxicity to human epithelia did not detect tissue damage or activation of apoptosis at a ciclopirox concentration that exceeded by orders of magnitude the concentration causing death of infected cells. We infer that ciclopirox and deferiprone act via therapeutic reclamation of apoptotic proficiency (TRAP in HIV-infected cells and trigger their preferential elimination. Perturbations in viral protein expression suggest that the antiretroviral activity of both drugs stems from their ability to inhibit hydroxylation of cellular proteins essential for apoptosis and for viral infection, exemplified by eIF5A. Our findings identify ciclopirox and deferiprone as prototypes of

  18. DNA polymerase ζ limits chromosomal damage and promotes cell survival following aflatoxin exposure.

    Science.gov (United States)

    Lin, Ying-Chih; Owen, Nichole; Minko, Irina G; Lange, Sabine S; Tomida, Junya; Li, Liang; Stone, Michael P; Wood, Richard D; McCullough, Amanda K; Lloyd, R Stephen

    2016-11-29

    Routine dietary consumption of foods that contain aflatoxins is the second leading cause of environmental carcinogenesis worldwide. Aflatoxin-driven mutagenesis is initiated through metabolic activation of aflatoxin B 1 (AFB 1 ) to its epoxide form that reacts with N7 guanine in DNA. The resulting AFB 1 -N7-dG adduct undergoes either spontaneous depurination or imidazole-ring opening yielding formamidopyrimidine AFB 1 (AFB 1 -Fapy-dG). Because this latter adduct is known to persist in human tissues and contributes to the high frequency G-to-T mutation signature associated with many hepatocellular carcinomas, we sought to establish the identity of the polymerase(s) involved in processing this lesion. Although our previous biochemical analyses demonstrated the ability of polymerase ζ (pol ζ) to incorporate an A opposite AFB 1 -Fapy-dG and extend from this mismatch, biological evidence supporting a unique role for this polymerase in cellular tolerance following aflatoxin exposure has not been established. Following challenge with AFB 1 , survival of mouse cells deficient in pol ζ (Rev3L -/- ) was significantly reduced relative to Rev3L +/- cells or Rev3L -/- cells complemented through expression of the wild-type human REV3L. Furthermore, cell-cycle progression of Rev3L -/- mouse embryo fibroblasts was arrested in late S/G2 following AFB 1 exposure. These Rev3L -/- cells showed an increase in replication-dependent formation of γ-H2AX foci, micronuclei, and chromosomal aberrations (chromatid breaks and radials) relative to Rev3L +/- cells. These data suggest that pol ζ is essential for processing AFB 1 -induced DNA adducts and that, in its absence, cells do not have an efficient backup polymerase or a repair/tolerance mechanism facilitating survival.

  19. Soil DNA metabarcoding and high-throughput sequencing as a forensic tool: considerations, potential limitations and recommendations.

    Science.gov (United States)

    Young, J M; Austin, J J; Weyrich, L S

    2017-02-01

    Analysis of physical evidence is typically a deciding factor in forensic casework by establishing what transpired at a scene or who was involved. Forensic geoscience is an emerging multi-disciplinary science that can offer significant benefits to forensic investigations. Soil is a powerful, nearly 'ideal' contact trace evidence, as it is highly individualistic, easy to characterise, has a high transfer and retention probability, and is often overlooked in attempts to conceal evidence. However, many real-life cases encounter close proximity soil samples or soils with low inorganic content, which cannot be easily discriminated based on current physical and chemical analysis techniques. The capability to improve forensic soil discrimination, and identify key indicator taxa from soil using the organic fraction is currently lacking. The development of new DNA sequencing technologies offers the ability to generate detailed genetic profiles from soils and enhance current forensic soil analyses. Here, we discuss the use of DNA metabarcoding combined with high-throughput sequencing (HTS) technology to distinguish between soils from different locations in a forensic context. Specifically, we provide recommendations for best practice, outline the potential limitations encountered in a forensic context and describe the future directions required to integrate soil DNA analysis into casework. © FEMS 2016. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  20. Inhibition of the epidermal growth factor receptor in bladder cancer cells treated with the DNA-damaging drug etoposide markedly increases apoptosis

    DEFF Research Database (Denmark)

    Munk, Mathias; Memon, Ashfaque Ahmed; Nexo, Ebba

    2007-01-01

    : The bladder cancer cell lines RT4 and T24, representing low- and high-malignancy grades respectively, were treated with VP16 (10 or 50 microM) and the level of apoptosis determined using a commercial kit. EGFR receptor activity was determined by western blotting using antibodies against phosphorylated EGFR...... of apoptotic cells with VP16 alone. This was found in both T24 and RT4 cells. Gefitinib used alone (1 and 5 microM) generated no apoptosis in the cells. Treatment of T24 cells with Z-VAD showed that apoptosis induced by both VP16 alone and VP16 with gefitinib was caspase-mediated. CONCLUSION: These results...

  1. Using DNA metabarcoding to investigate honey bee foraging reveals limited flower use despite high floral availability

    Science.gov (United States)

    de Vere, Natasha; Jones, Laura E.; Gilmore, Tegan; Moscrop, Jake; Lowe, Abigail; Smith, Dan; Hegarty, Matthew J.; Creer, Simon; Ford, Col R.

    2017-01-01

    Understanding which flowers honey bees (Apis mellifera) use for forage can help us to provide suitable plants for healthy honey bee colonies. Accordingly, honey DNA metabarcoding provides a valuable tool for investigating pollen and nectar collection. We investigated early season (April and May) floral choice by honey bees provided with a very high diversity of flowering plants within the National Botanic Garden of Wales. There was a close correspondence between the phenology of flowering and the detection of plants within the honey. Within the study area there were 437 genera of plants in flower during April and May, but only 11% of these were used. Thirty-nine plant taxa were recorded from three hives but only ten at greater than 1%. All three colonies used the same core set of native or near-native plants, typically found in hedgerows and woodlands. The major plants were supplemented with a range of horticultural species, with more variation in plant choice between the honey bee colonies. We conclude that during the spring, honey bees need access to native hedgerows and woodlands to provide major plants for foraging. Gardens provide supplementary flowers that may increase the nutritional diversity of the honey bee diet. PMID:28205632

  2. Up regulation of serum tumor necrosis factor-related apoptosis inducing ligand in juvenile-onset systemic lupus erythematosus: relations with disease activity, antibodies to double -stranded DNA, nephritis and neutropenia.

    Science.gov (United States)

    Ezzat, Mohamed H M; El-Gammasy, Tarek M A; Shaheen, Kareem Y A; El-Mezdawi, Ramzi A M; Youssef, Mervat S M

    2013-06-01

    Apoptosis is induced by binding of death receptor ligands, members of the tumor necrosis factor (TNF) superfamily, to their cognate receptors. It is suggested that TNF-related apoptosis inducing ligand (TRAIL) is involved in pathogenesis of juvenile-onset systemic lupus erythematosus (JSLE). This study aimed to assess TRAIL concentrations in sera of JSLE children and to determine their potential relationship with disease activity, anti-double-stranded DNA (anti-dsDNA) levels, neutropenia and renal involvement. Circulating levels of TRAIL were measured by enzyme-linked immunosorbent assay (ELISA) in serum samples obtained from 40 JSLE patients (20 with active and 20 with inactive disease) and 20 controls. The mean (SEM) serum TRAIL concentration in JSLE was 1750.7 (440.2) pg/mL. Serum TRAIL concentrations in patients were higher than those in controls (P nephritis compared to classes I and II nephritis (1970 [512] vs. 1330 [331] pg/mL; P lupus nephritis. © 2013 The Authors International Journal of Rheumatic Diseases © 2013 Asia Pacific League of Associations for Rheumatology and Wiley Publishing Asia Pty Ltd.

  3. An ELISA for detection of apoptosis.

    OpenAIRE

    Salgame, P; Varadhachary, A S; Primiano, L L; Fincke, J E; Muller, S; Monestier, M

    1997-01-01

    We describe a simple and convenient enzyme-linked immunosorbent assay (ELISA) for the detection of apoptosis in tissue culture. An early event in apoptosis is DNA fragmentation followed by release of nucleosomes into the cytoplasm. Our sandwich assay uses a pair of monoclonal antibodies specific for two nucleosomal epitopes to capture and detect cytoplasmic nucleosomes onto the ELISA plate. Our assay is about 500 times more sensitive than the detection of apoptotic DNA ladder by agarose elect...

  4. A need for standardization in drinking water analysis – an investigation of DNA extraction procedure, primer choice and detection limit of 16S rRNA amplicon sequencing

    DEFF Research Database (Denmark)

    Brandt, Jakob; Nielsen, Per Halkjær; Albertsen, Mads

    have been made to illuminate the effects specifically related to bacterial communities in drinking water. In this study, we investigated the impact of the DNA extraction and primer choice on the observed community structure, and we also estimated the detection limit of the 16S rRNA amplicon sequencing....... The PowerWater DNA Isolation Kit resulted in significantly higher amounts of isolated DNA compared to the FastDNA SPIN Kit for Soil. Furthermore, extraction with the PowerWater kit lead to detection of a significantly higher number of OTUs. Likewise, the primer experiment revealed great discrepancies in OTU....... coli could be detected in all samples. However, samples with 101 cells/mL had several contaminating OTUs, constituting approximately 8% of the read abundances. For 16S rRNA gene analysis in drinking water samples, we recommend using the PowerWater DNA Isolation Kit for DNA extraction in combination...

  5. Universal and blocking primer mismatches limit the use of high-throughput DNA sequencing for the quantitative metabarcoding of arthropods.

    Science.gov (United States)

    Piñol, J; Mir, G; Gomez-Polo, P; Agustí, N

    2015-07-01

    The quantification of the biological diversity in environmental samples using high-throughput DNA sequencing is hindered by the PCR bias caused by variable primer-template mismatches of the individual species. In some dietary studies, there is the added problem that samples are enriched with predator DNA, so often a predator-specific blocking oligonucleotide is used to alleviate the problem. However, specific blocking oligonucleotides could coblock nontarget species to some degree. Here, we accurately estimate the extent of the PCR biases induced by universal and blocking primers on a mock community prepared with DNA of twelve species of terrestrial arthropods. We also compare universal and blocking primer biases with those induced by variable annealing temperature and number of PCR cycles. The results show that reads of all species were recovered after PCR enrichment at our control conditions (no blocking oligonucleotide, 45 °C annealing temperature and 40 cycles) and high-throughput sequencing. They also show that the four factors considered biased the final proportions of the species to some degree. Among these factors, the number of primer-template mismatches of each species had a disproportionate effect (up to five orders of magnitude) on the amplification efficiency. In particular, the number of primer-template mismatches explained most of the variation (~3/4) in the amplification efficiency of the species. The effect of blocking oligonucleotide concentration on nontarget species relative abundance was also significant, but less important (below one order of magnitude). Considering the results reported here, the quantitative potential of the technique is limited, and only qualitative results (the species list) are reliable, at least when targeting the barcoding COI region. © 2014 John Wiley & Sons Ltd.

  6. Hyperglycemia-induced oxidative stress induces apoptosis by inhibiting PI3-kinase/Akt and ERK1/2 MAPK mediated signaling pathway causing downregulation of 8-oxoG-DNA glycosylase levels in glial cells.

    Science.gov (United States)

    Kumar, Premranjan; Rao, G Nageswar; Pal, Bibhuti Bhusan; Pal, Arttatrana

    2014-08-01

    Glial cells are very important for normal brain function and alterations in their activity due to hyperglycemia, could contribute to diabetes-related cognitive dysfunction. Oxidative insults often cause rapid changes in almost all cells including glial cells. However, pathophysiologic mechanisms that lead to diabetic complications are not completely elucidated. Therefore, we examined whether elevated glucose levels directly or indirectly disrupt antioxidant defense mechanisms causing alterations in signaling pathways, cell cycle dysregulation, and reactive oxygen/nitrogen species-mediated apoptosis in glial cells. Findings of this study demonstrated that exposure of glial cells to high glucose markedly induces cellular and molecular injuries, as evidenced by elevated levels of reactive oxygen/nitrogen species, biomolecules damage, cell cycle dysregulation, decrease in antioxidant enzymes, and decrease in cell viability. Pretreatment of cells with N-acetyl-L-cysteine reduced high glucose-induced cytotoxicity by increasing the levels of antioxidant enzymes, and decreasing the number of apoptotic cells. Further, at molecular level high glucose treatment resulted in a significant increase in phosphorylation of Akt, MAPKs, tuberin, down regulation of 8-oxoG-DNA glycosylase and increase in 8-hydroxydeoxyguanosine accumulations. Pretreatment of cells with N-acetyl-L-cysteine, phosphatidylinositol3-kinase/Akt and ERK1/2 inhibitors completely abolished the apoptotic effects of high glucose. Moreover, N-acetyl-L-cysteine significantly inhibited reactive oxygen/nitrogen species generation, elevated antioxidants levels, inhibited Akt, ERK1/2, tuberin phosphorylation, decreased 8-hydroxydeoxyguanosine accumulation and upregulated 8-oxoG-DNA glycosylase expression. Our results demonstrate that high glucose induces apoptosis and inhibits proliferation of glial cells, which may be mediated by the phosphorylation of tuberin, down regulation of 8-oxoG-DNA glycosylase and 8

  7. Radiation response and regulation of apoptosis induced by a combination of TRAIL and CHX in cells lacking mitochondrial DNA: A role for NF-{kappa}B-STAT3-directed gene expression

    Energy Technology Data Exchange (ETDEWEB)

    Ivanov, Vladimir N., E-mail: vni3@columbia.edu; Ghandhi, Shanaz A.; Zhou, Hongning; Huang, Sarah X.; Chai, Yunfei; Amundson, Sally A.; Hei, Tom K.

    2011-07-01

    Mitochondrial DNA depleted ({rho}{sup 0}) human skin fibroblasts (HSF) with suppressed oxidative phosphorylation were characterized by significant changes in the expression of 2100 nuclear genes, encoding numerous protein classes, in NF-{kappa}B and STAT3 signaling pathways, and by decreased activity of mitochondrial death pathway, compared to the parental {rho}{sup +} HSF. In contrast, the extrinsic TRAIL/TRAIL-Receptor mediated death pathway remained highly active, and exogenous TRAIL in a combination with cycloheximide (CHX) induced higher levels of apoptosis in {rho}{sup 0} cells compared to {rho}{sup +} HSF. Global gene expression analysis using microarray and qRT-PCR demonstrated that mRNA expression levels of many growth factors and their adaptor proteins (FGF13, HGF, IGFBP4, IGFBP6, and IGFL2), cytokines (IL6, {Oota}L17{Beta}, {Oota}L18, {Oota}L19, and {Oota}L28{Beta}) and cytokine receptors (IL1R1, IL21R, and IL31RA) were substantially decreased after mitochondrial DNA depletion. Some of these genes were targets of NF-{kappa}B and STAT3, and their protein products could regulate the STAT3 signaling pathway. Alpha-irradiation further induced expression of several NF-{kappa}B/STAT3 target genes, including IL1A, IL1B, IL6, PTGS2/COX2 and MMP12, in {rho}{sup +} HSF, but this response was substantially decreased in {rho}{sup 0} HSF. Suppression of the IKK-NF-{kappa}B pathway by the small molecular inhibitor BMS-345541 and of the JAK2-STAT3 pathway by AG490 dramatically increased TRAIL-induced apoptosis in the control and irradiated {rho}{sup +} HSF. Inhibitory antibodies against IL6, the main activator of JAK2-STAT3 pathway, added into the cell media, also increased TRAIL-induced apoptosis in HSF, especially after alpha-irradiation. Collectively, our results indicated that NF-{kappa}B activation was partially lost in {rho}{sup 0} HSF resulting in downregulation of the basal or radiation-induced expression of numerous NF-{kappa}B targets, further suppressing IL6

  8. Diphtheria toxin- and Pseudomonas A toxin-mediated apoptosis. ADP ribosylation of elongation factor-2 is required for DNA fragmentation and cell lysis and synergy with tumor necrosis factor-alpha.

    Science.gov (United States)

    Morimoto, H; Bonavida, B

    1992-09-15

    We have reported that diphtheria toxin (DTX) mediates target cell lysis and intranucleosomal DNA fragmentation (apoptosis) and also synergizes with TNF-alpha. In this paper, we examined which step in the pathway of DTX-mediated inhibition of protein synthesis was important for induction of cytolytic activity and for synergy. Using a DTX-sensitive tumor cell line, we first examined the activity of the mutant CRM 197, which does not catalyze the ADP ribosylation of elongation factor-2 (EF-2). CRM 197 was not cytolytic for target cells and did not mediate intranucleosomal DNA fragmentation of viable cells. The failure of CRM 197 to mediate target cell lysis suggested that the catalytic activity of DTX is prerequisite for target cell lysis. This was corroborated by demonstrating that MeSAdo, which blocks the biosynthesis of diphthamide, inhibited DTX-mediated protein synthesis inhibition and also blocked target cell lysis. Furthermore, the addition of nicotinamide, which competes with NAD+ on the DTX action site of EF-2, also blocked DTX-mediated lysis. These findings suggest that ADP-ribosylation of EF-2 may be a necessary step in the pathway leading to target cell lysis. In contrast to the sensitive line, the SKOV-3 tumor cell line is sensitive to protein synthesis inhibition by DTX but is not susceptible to cytolysis and apoptosis by DTX. Thus, protein synthesis inhibition by DTX is not sufficient to mediate target cell lysis. The synergy in cytotoxicity obtained with the combination of DTX and TNF-alpha was examined in order to determine the pathway mediated by DTX in synergy. Like the direct lysis by DTX, synergy was significantly reduced by MeSAdo and by nicotinamide. Furthermore, synergy was not observed with combination of CRM 197 and TNF-alpha. These results demonstrate that, in synergy, DTX may utilize the same pathway required for its cytolytic activity. Pseudomonas aeruginosa exotoxin shared most the properties shown for DTX. Altogether, these findings

  9. Exogenous DNA Loading into Extracellular Vesicles via Electroporation is Size-Dependent and Enables Limited Gene Delivery.

    Science.gov (United States)

    Lamichhane, Tek N; Raiker, Rahul S; Jay, Steven M

    2015-10-05

    Extracellular vesicles (EVs) hold immense promise for utilization as biotherapeutics and drug delivery vehicles due to their nature as biological nanoparticles that facilitate intercellular molecular transport. Specifically, EVs have been identified as natural carriers of nucleic acids, sparking interest in their use for gene therapy and RNA interference applications. So far, small RNAs (siRNA and miRNA) have been successfully loaded into EVs for a variety of delivery applications, but the potential use of EVs for DNA delivery has scarcely been explored. Here, we report that exogenous linear DNA can be associated with EVs via electroporation in quantities sufficient to yield an average of hundreds of DNA molecules per vesicle. We determined that loading efficiency and capacity of DNA in EVs is dependent on DNA size, with linear DNA molecules less than 1000 bp in length being more efficiently associated with EVs compared to larger linear DNAs and plasmid DNAs using this approach. We further showed that EV size is also determinant with regard to DNA loading, as larger microvesicles encapsulated more linear and plasmid DNA than smaller, exosome-like EVs. Additionally, we confirmed the ability of EVs to transfer foreign DNA loaded via electroporation into recipient cells, although functional gene delivery was not observed. These results establish critical parameters that inform the potential use of EVs for gene therapy and, in agreement with other recent results, suggest that substantial barriers must be overcome to establish EVs as broadly applicable DNA delivery vehicles.

  10. Resveratrol-3-O-glucuronide and resveratrol-4’-O-glucuronide reduce DNA strand breakage but not apoptosis in Jurkat T cells treated with camptothecin

    Science.gov (United States)

    Resveratrol has been reported to inhibit or induce DNA damage depending upon the type of cell and experimental conditions. Dietary resveratrol is present in the body mostly as metabolites and little is known about the activities of these metabolic products. We evaluated physiologically obtainable ...

  11. Genotoxic polycyclic aromatic hydrocarbons fail to induce the p53-dependent DNA damage response, apoptosis or cell-cycle arrest in human prostate carcinoma LNCaP cells

    Czech Academy of Sciences Publication Activity Database

    Hrubá, E.; Trilecová, L.; Marvanová, S.; Krčmář, P.; Vykopalová, L.; Milcová, Alena; Líbalová, Helena; Topinka, Jan; Staršíchová, Andrea; Souček, Karel; Vondráček, Jan; Machala, M.

    2010-01-01

    Roč. 198, č. 3 (2010), s. 227-235 ISSN 0378-4274 Grant - others:GA ČR(CZ) GA310/07/0961 Program:GA Institutional research plan: CEZ:AV0Z50040507; CEZ:AV0Z50040702; CEZ:AV0Z50390512; CEZ:AV0Z50390703 Keywords : prostate epithelial cells * DNA adducts * carcinogenesis Subject RIV: BO - Biophysics Impact factor: 3.581, year: 2010

  12. [Effect of SET deficiency on the trichloroethylene-induced alteration of cell proliferation and cell apoptosis and DNA methylation in human hepatic L-02 cells].

    Science.gov (United States)

    Xie, G S; Liu, J J; Hong, W X; Zhang, H; Sun, Y; Zhu, W G

    2016-03-20

    To compare the trichloroethylene (TCE) -induced alteration in cell proliferation, cell apoptosis, histone deacetylase activity and expression levels in human hepatic L-02 cells (L-02 cells) and SET deficient cells, and reveal the TCE-induced effect in histone modification and the role of SET on epigenetic pathway. The L-02 cells and preestablished SET deficient cells were treated with different TCE concentrations. For the changes of cell proliferation level and apoptosis rate, The L-02 cells and SET deficiency cells without TCE treatment were served as the control group, the TCE treatment was in the concentration of 2.0 and 8.0 mmol/L for 24 h. For histone deacetylase activity and expression levels, the TCE treatment was in the concentration of 0.25, 0.50, 1.0, 2.0, 4.0, and 8.0 mmol/L for 24 h. After treatment with TCE for 24 h, the cell proliferation level was significantly decreased and the apoptotic rate was significantly increased in both cell lines. When concentration of TCE were reached to 8.0 mmol/L, the difference of cell proliferation level and apoptotic rate between two groups was statistically significant (t=-4.362 for proliferation level and t=23.950 for apoptotic rate, both Pcell lines. When the TCE concentration were high than 0.50 mmol/L, compared with control group of L-02 cells, the enzymes activity were significantly increased (F=403.26, Pcells, the enzyme activity was significantly increased when TCE concentration was reached 1.00 mmol/L (F=44.01, Pcells, TCE exposure can induced a significant increased expression level of HDAC2 in TCE-treated L-02 cells (F values were 79.99, Pcells was not significant. TCE exposure can induce a significant alteration on cell proliferation, apoptotic rate and, the activity and expression on histone deacetylases. SET deficiency can attenuate the TCE-induced alteration in histone modification in L-02 cells. Our results indicated that SET is involved in the mechanism of TCE-induced cytotoxicity and epigenetic

  13. Biological Sexing of a 4000-Year-Old Egyptian Mummy Head to Assess the Potential of Nuclear DNA Recovery from the Most Damaged and Limited Forensic Specimens.

    Science.gov (United States)

    Loreille, Odile; Ratnayake, Shashikala; Bazinet, Adam L; Stockwell, Timothy B; Sommer, Daniel D; Rohland, Nadin; Mallick, Swapan; Johnson, Philip L F; Skoglund, Pontus; Onorato, Anthony J; Bergman, Nicholas H; Reich, David; Irwin, Jodi A

    2018-03-01

    High throughput sequencing (HTS) has been used for a number of years in the field of paleogenomics to facilitate the recovery of small DNA fragments from ancient specimens. Recently, these techniques have also been applied in forensics, where they have been used for the recovery of mitochondrial DNA sequences from samples where traditional PCR-based assays fail because of the very short length of endogenous DNA molecules. Here, we describe the biological sexing of a ~4000-year-old Egyptian mummy using shotgun sequencing and two established methods of biological sex determination (R X and R Y ), by way of mitochondrial genome analysis as a means of sequence data authentication. This particular case of historical interest increases the potential utility of HTS techniques for forensic purposes by demonstrating that data from the more discriminatory nuclear genome can be recovered from the most damaged specimens, even in cases where mitochondrial DNA cannot be recovered with current PCR-based forensic technologies. Although additional work remains to be done before nuclear DNA recovered via these methods can be used routinely in operational casework for individual identification purposes, these results indicate substantial promise for the retrieval of probative individually identifying DNA data from the most limited and degraded forensic specimens.

  14. Biological Sexing of a 4000-Year-Old Egyptian Mummy Head to Assess the Potential of Nuclear DNA Recovery from the Most Damaged and Limited Forensic Specimens

    Directory of Open Access Journals (Sweden)

    Odile Loreille

    2018-03-01

    Full Text Available High throughput sequencing (HTS has been used for a number of years in the field of paleogenomics to facilitate the recovery of small DNA fragments from ancient specimens. Recently, these techniques have also been applied in forensics, where they have been used for the recovery of mitochondrial DNA sequences from samples where traditional PCR-based assays fail because of the very short length of endogenous DNA molecules. Here, we describe the biological sexing of a ~4000-year-old Egyptian mummy using shotgun sequencing and two established methods of biological sex determination (RX and RY, by way of mitochondrial genome analysis as a means of sequence data authentication. This particular case of historical interest increases the potential utility of HTS techniques for forensic purposes by demonstrating that data from the more discriminatory nuclear genome can be recovered from the most damaged specimens, even in cases where mitochondrial DNA cannot be recovered with current PCR-based forensic technologies. Although additional work remains to be done before nuclear DNA recovered via these methods can be used routinely in operational casework for individual identification purposes, these results indicate substantial promise for the retrieval of probative individually identifying DNA data from the most limited and degraded forensic specimens.

  15. Advantages and Limitations of Ribosomal RNA PCR and DNA Sequencing for Identification of Bacteria in Cardiac Valves of Danish Patients

    DEFF Research Database (Denmark)

    Kemp, Michael; Bangsborg, Jette; Kjerulf, Anne

    2013-01-01

    of direct molecular identification should also address weaknesses, their relevance in the given setting, and possible improvements. In this study cardiac valves from 56 Danish patients referred for surgery for infective endocarditis were analysed by microscopy and culture as well as by PCR targeting part...... of the bacterial 16S rRNA gene followed by DNA sequencing of the PCR product. PCR and DNA sequencing identified significant bacteria in 49 samples from 43 patients, including five out of 13 culture-negative cases. No rare, exotic, or intracellular bacteria were identified. There was a general agreement between...... bacterial identity obtained by ribosomal PCR and DNA sequencing from the valves and bacterial isolates from blood culture. However, DNA sequencing of the 16S rRNA gene did not discriminate well among non-haemolytic streptococci, especially within the Streptococcus mitis group. Ribosomal PCR with subsequent...

  16. Activity on non-methylated DNA limits the use of endonuclease MspJI for epigenetic analyses

    Directory of Open Access Journals (Sweden)

    María Belén Jerez

    2018-03-01

    Full Text Available Cytosine methylation of DNA in mammals has been associated with both physiological and pathological changes in gene-expression. DNA treatment with methylation sensitive and/or dependent restriction enzymes, followed by PCR amplification is a widely used approach to test CpG methylation. Recently, restriction endonuclease MspJI has been proposed as a promising tool for epigenetic analyses. In this paper, we have tested MspJI as a tool for detecting CpG methylation on mammalian genomic DNA. For this experiment mouse genomic sequences harboring or lacking CpG sites were selected. The extent of degradation was evaluated by PCR using primers flanking the chosen genomic regions. Digestion of mouse genomic DNA, in combination with end-point and real-time PCR reactions, revealed that MspJI treatment reduced the amplification of genomic regions either containing or lacking of CpG motifs. In addition, treatment of bona fide non-methylated (in vitro amplified DNA samples definitely demonstrated that MspJI shows significant activity against non-methylated DNA. These results show that star activity can be an important concern when using MspJI, even under standard conditions. Therefore, we conclude that (in contrast to classical restriction enzymes, careful case by case evaluation of reaction conditions is mandatory for optimizing the usefulness of MspJI in epigenetic studies.

  17. Absence of zero-temperature transmission rate of a double-chain tight-binding model for DNA with random sequence of nucleotides in thermodynamic limit

    International Nuclear Information System (INIS)

    Xiong Gang; Wang, X.R.

    2005-01-01

    The zero-temperature transmission rate spectrum of a double-chain tight-binding model for real DNA is calculated. It is shown that a band of extended-like states exists only for finite chain length with strong inter-chain coupling. While the whole spectrum tends to zero in thermodynamic limit, regardless of the strength of inter-chain coupling. It is also shown that a more faithful model for real DNA with periodic sugar-phosphate chains in backbone structures can be mapped into the above simple double-chain tight-binding model. Combined with above results, the transmission rate of real DNA with long random sequence of nucleotides is expected to be poor

  18. Analysis of DNA Methylation in Young People: Limited Evidence for an Association Between Victimization Stress and Epigenetic Variation in Blood.

    Science.gov (United States)

    Marzi, Sarah J; Sugden, Karen; Arseneault, Louise; Belsky, Daniel W; Burrage, Joe; Corcoran, David L; Danese, Andrea; Fisher, Helen L; Hannon, Eilis; Moffitt, Terrie E; Odgers, Candice L; Pariante, Carmine; Poulton, Richie; Williams, Benjamin S; Wong, Chloe C Y; Mill, Jonathan; Caspi, Avshalom

    2018-01-12

    DNA methylation has been proposed as an epigenetic mechanism by which early-life experiences become "embedded" in the genome and alter transcriptional processes to compromise health. The authors sought to investigate whether early-life victimization stress is associated with genome-wide DNA methylation. The authors tested the hypothesis that victimization is associated with DNA methylation in the Environmental Risk (E-Risk) Longitudinal Study, a nationally representative 1994-1995 birth cohort of 2,232 twins born in England and Wales and assessed at ages 5, 7, 10, 12, and 18 years. Multiple forms of victimization were ascertained in childhood and adolescence (including physical, sexual, and emotional abuse; neglect; exposure to intimate-partner violence; bullying; cyber-victimization; and crime). Epigenome-wide analyses of polyvictimization across childhood and adolescence revealed few significant associations with DNA methylation in peripheral blood at age 18, but these analyses were confounded by tobacco smoking and/or did not survive co-twin control tests. Secondary analyses of specific forms of victimization revealed sparse associations with DNA methylation that did not replicate across different operationalizations of the same putative victimization experience. Hypothesis-driven analyses of six candidate genes in the stress response (NR3C1, FKBP5, BDNF, AVP, CRHR1, SLC6A4) did not reveal predicted associations with DNA methylation in probes annotated to these genes. Findings from this epidemiological analysis of the epigenetic effects of early-life stress do not support the hypothesis of robust changes in DNA methylation in victimized young people. We need to come to terms with the possibility that epigenetic epidemiology is not yet well matched to experimental, nonhuman models in uncovering the biological embedding of stress.

  19. The benefits and limitations of cell-free DNA screening for 22q11.2 deletion syndrome.

    Science.gov (United States)

    Dugoff, Lorraine; Mennuti, Michael T; McDonald-McGinn, Donna M

    2017-01-01

    Cell-free DNA testing is increasingly being used to screen pregnant women for fetal aneuploidy. This technology may also identify microdeletion syndromes, including 22q11.2 deletion syndrome, the most common microdeletion syndrome, and the 22q11.2 duplication syndrome. The purpose of this paper is to provide an overview of the 22q11.2 deletion syndrome, to review the early experience with cell-free DNA screening for this deletion and to consider the potential benefits that may be associated with prenatal detection of the deletion. © 2016 John Wiley & Sons, Ltd. © 2016 John Wiley & Sons, Ltd.

  20. Cellular response after irradiation: Cell cycle control and apoptosis

    International Nuclear Information System (INIS)

    Siles, E.; Valenzuela, M.T.; Nunez, M.I.; Guerrero, R.; Villalobos, M.; Ruiz de Almodovar, J.M.

    1997-01-01

    The importance of apoptotic death was assessed in a set of experiments, involving eight human tumour cell lines (breast cancer, bladder carcinoma, medulloblastoma). Various aspects of the quantitative study of apoptosis and methods based on the detection of DNA fragmentation (in situ tailing and comet assay) are described and discussed. Data obtained support the hypothesis that apoptosis is not crucial for cellular radiosensitivity and that the relationship between p53 functionality or clonogenic survival and apoptosis may bee cell type specific. (author)

  1. Between the Balkans and the Baltic: Phylogeography of a Common Vole Mitochondrial DNA Lineage Limited to Central Europe.

    Science.gov (United States)

    Stojak, Joanna; McDevitt, Allan D; Herman, Jeremy S; Kryštufek, Boris; Uhlíková, Jitka; Purger, Jenő J; Lavrenchenko, Leonid A; Searle, Jeremy B; Wójcik, Jan M

    2016-01-01

    The common vole (Microtus arvalis) has been a model species of small mammal for studying end-glacial colonization history. In the present study we expanded the sampling from central and eastern Europe, analyzing contemporary genetic structure to identify the role of a potential 'northern glacial refugium', i.e. a refugium at a higher latitude than the traditional Mediterranean refugia. Altogether we analyzed 786 cytochrome b (cytb) sequences (representing mitochondrial DNA; mtDNA) from the whole of Europe, adding 177 new sequences from central and eastern Europe, and we conducted analyses on eight microsatellite loci for 499 individuals (representing nuclear DNA) from central and eastern Europe, adding data on 311 new specimens. Our new data fill gaps in the vicinity of the Carpathian Mountains, the potential northern refugium, such that there is now dense sampling from the Balkans to the Baltic Sea. Here we present evidence that the Eastern mtDNA lineage of the common vole was present in the vicinity of this Carpathian refugium during the Last Glacial Maximum and the Younger Dryas. The Eastern lineage expanded from this refugium to the Baltic and shows low cytb nucleotide diversity in those most northerly parts of the distribution. Analyses of microsatellites revealed a similar pattern but also showed little differentiation between all of the populations sampled in central and eastern Europe.

  2. Polymyxin B Induces Apoptosis in Kidney Proximal Tubular Cells.

    Science.gov (United States)

    Azad, Mohammad A K; Finnin, Ben A; Poudyal, Anima; Davis, Kathryn; Li, Jinhua; Hill, Prue A; Nation, Roger L; Velkov, Tony; Li, Jian

    2013-09-01

    The nephrotoxicity of polymyxins is a major dose-limiting factor for treatment of infections caused by multidrug-resistant Gram-negative pathogens. The mechanism(s) of polymyxin-induced nephrotoxicity is not clear. This study aimed to investigate polymyxin B-induced apoptosis in kidney proximal tubular cells. Polymyxin B-induced apoptosis in NRK-52E cells was examined by caspase activation, DNA breakage, and translocation of membrane phosphatidylserine using Red-VAD-FMK [Val-Ala-Asp(O-Me) fluoromethyl ketone] staining, a terminal deoxynucleotidyltransferase-mediated dUTP-biotin nick end labeling (TUNEL) assay, and double staining with annexin V-propidium iodide (PI). The concentration dependence (50% effective concentration [EC 50 ]) and time course for polymyxin B-induced apoptosis were measured in NRK-52E and HK-2 cells by fluorescence-activated cell sorting (FACS) with annexin V and PI. Polymyxin B-induced apoptosis in NRK-52E cells was confirmed by positive labeling from Red-VAD-FMK staining, TUNEL assay, and annexin V-PI double staining. The EC 50 (95% confidence interval [CI]) of polymyxin B for the NRK-52E cells was 1.05 (0.91 to 1.22) mM and was 0.35 (0.29 to 0.42) mM for HK-2 cells. At lower concentrations of polymyxin B, minimal apoptosis was observed, followed by a sharp rise in the apoptotic index at higher concentrations in both cell lines. After treatment of NRK-52E cells with 2.0 mM polymyxin B, the percentage of apoptotic cells (mean ± standard deviation [SD]) was 10.9% ± 4.69% at 6 h and reached plateau (>80%) at 24 h, whereas treatment with 0.5 mM polymyxin B for 24 h led to 93.6% ± 5.57% of HK-2 cells in apoptosis. Understanding the mechanism of polymyxin B-induced apoptosis will provide important information for discovering less nephrotoxic polymyxin-like lipopeptides. Copyright © 2013, American Society for Microbiology. All Rights Reserved.

  3. Dopamine induces neutrophil apoptosis through a dopamine D-1 receptor-independent mechanism.

    LENUS (Irish Health Repository)

    Sookhai, S

    2012-02-03

    BACKGROUND: For the normal resolution of an acute inflammatory response, neutrophil (PMN) apoptosis is essential to maintain immune homeostasis and to limit inappropriate host tissue damage. A delay in PMN apoptosis has been implicated in the pathogenesis of the systemic inflammatory response syndrome (SIRS). Dopamine, a biogenic amine with known cardiovascular and neurotransmitter properties, is used in patients with SIRS to maintain hemodynamic stability. We sought to determine whether dopamine may also have immunoregulatory properties capable of influencing PMN apoptosis, function, and activation state in patients with SIRS. METHODS: PMNs were isolated from healthy volunteers and patients with SIRS and treated with varying doses of dopamine and a dopamine D-1 receptor agonist, fenoldopam. PMN apoptosis was assessed every 6 hours with use of propidium iodide DNA staining and PMN function was assessed with use of respiratory burst activity, phagocytosis ability, and CD11a, CD11b, and CD18 receptor expression as functional markers. RESULTS: There was a significant delay in PMN apotosis in patients with SIRS compared with controls. Treatment of isolated PMNs from both healthy controls and patients with SIRS with 10 and 100 mumol\\/L dopamine induced apoptosis. PMN ingestive and cytocidal capacity were both decreased in patients with SIRS compared with controls. Treatment with dopamine significantly increased phagocytic function. Fenoldopam did not induce PMN apoptosis. CONCLUSION: Our data demonstrate for the first time that dopamine induces PMN apoptosis and modulates PMN function both in healthy controls and in patients with SIRS. These results indicate that dopamine may be beneficial during SIRS through a nonhemodynamic PMN-dependent proapoptotic mechanism.

  4. Apoptosis in Acanthamoeba castellanii belonging to the T4 genotype.

    Science.gov (United States)

    Baig, Abdul M; Lalani, Salima; Khan, Naveed A

    2017-07-01

    Here we describe features of apoptosis in unicellular Acanthamoeba castellanii belonging to the T4 genotype. When exposed to apoptosis-inducing compounds such as doxorubicin, A. castellanii trophozoites exhibited cell shrinkage and membrane blebbing as observed microscopically, DNA fragmentation using agarose gel electrophoresis, and phosphatidylserine (PS) externalization using annexin V immunostaining. Overall, these findings suggest the existence of apoptosis in A. castellanii possibly mediated by intrinsic apoptotic cascade. Further research in this field could provide avenues to selectively induce apoptosis in A. castellanii by triggering intrinsic apoptotic cascade. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. Detection of T cell apoptosis after major operations.

    Science.gov (United States)

    Sasajima, K; Inokuchi, K; Onda, M; Miyashita, M; Okawa, K I; Matsutani, T; Takubo, K

    1999-11-01

    To detect T cell apoptosis in reduced peripheral lymphocyte counts in patients having major operations. Prospective study. University hospital, Japan. 11 patients having oesophagectomy and 5 having laparoscopic cholecystectomy. To investigate T cell apoptosis we detected DNA fragmentation using electrophoresis, and T-cell receptor-gamma (TCR-gamma) gene amplification using polymerase chain reaction (PCR) in serum. Peripheral lymphocyte count and DNA extracted from the serum preoperatively and on postoperative days 1, 3, 5, and 7. The lymphocyte count decreased significantly until day 5 and then increased in the patients who had had oesophagectomy. DNA fragmentation and PCR products for the TCRgamma variable region gene were found in the serum DNA of 10 patients until day 5. No DNA fragmentation or PCR products were found in the serum of patients who had had laparoscopic cholecystectomy. These results suggest that transient T cell apoptosis occurs after major operations.

  6. Endoplasmic reticulum stress and IRE-1 signaling cause apoptosis in colon cancer cells in response to andrographolide treatment.

    Science.gov (United States)

    Banerjee, Aditi; Ahmed, Hafiz; Yang, Peixin; Czinn, Steven J; Blanchard, Thomas G

    2016-07-05

    The plant metabolite andrographolide induces cell cycle arrest and apoptosis in cancer cells. The mechanism(s) by which andrographolide induces apoptosis however, have not been elucidated. The present study was performed to determine the molecular events that promote apoptosis in andrographolide treated cells using T84, HCT116 and COLO 205 colon cancer cell lines. Andrographolide was determined to limit colony formation and Ki67 expression, alter nuclear morphology, increase cytoplasmic histone-associated-DNA-fragments, and increase cleaved caspase-3 levels. Andrographolide also induced significantly higher expression of endoplasmic reticulum (ER) stress proteins GRP-78 and IRE-1 by 48 h but not PERK or ATF6. Apoptosis signaling molecules BAX, spliced XBP-1 and CHOP were also significantly increased. Moreover, chemical inhibition of ER stress or IRE-1 depletion with siRNA in andrographolide treated cells significantly limited expression of IRE-1 and CHOP as determined by immunofluorescence staining, real time PCR, or immunobloting. This was accompanied by a decreased BAX/Bcl-2 ratio. Andrographolide significantly promotes cancer cell death compared to normal cells. These data demonstrate that andrographolide associated ER stress contributes to apoptosis through the activation of a pro-apoptotic GRP-78/IRE-1/XBP-1/CHOP signaling pathway.

  7. Screening mitochondrial DNA sequence variation as an alternative method for tracking established and outbreak populations of Queensland fruit fly at the species southern range limit.

    Science.gov (United States)

    Blacket, Mark J; Malipatil, Mali B; Semeraro, Linda; Gillespie, Peter S; Dominiak, Bernie C

    2017-04-01

    Understanding the relationship between incursions of insect pests and established populations is critical to implementing effective control. Studies of genetic variation can provide powerful tools to examine potential invasion pathways and longevity of individual pest outbreaks. The major fruit fly pest in eastern Australia, Queensland fruit fly Bactrocera tryoni (Froggatt), has been subject to significant long-term quarantine and population reduction control measures in the major horticulture production areas of southeastern Australia, at the species southern range limit. Previous studies have employed microsatellite markers to estimate gene flow between populations across this region. In this study, we used an independent genetic marker, mitochondrial DNA (mtDNA) sequences, to screen genetic variation in established and adjacent outbreak populations in southeastern Australia. During the study period, favorable environmental conditions resulted in multiple outbreaks, which appeared genetically distinctive and relatively geographically localized, implying minimal dispersal between simultaneous outbreaks. Populations in established regions were found to occur over much larger areas. Screening mtDNA (female) lineages proved to be an effective alternative genetic tool to assist in understanding fruit fly population dynamics and provide another possible molecular method that could now be employed for better understanding of the ecology and evolution of this and other pest species.

  8. Ubiquitin-dependent system controls radiation induced apoptosis

    International Nuclear Information System (INIS)

    Delic, J.; Magdelenat, H.; Glaisner, S.; Magdelenat, H.; Maciorowski, Z.

    1997-01-01

    The selective proteolytic pathway, dependent upon 'N-end rule' protein recognition/ubiquitination and on the subsequent proteasome dependent processing of ubiquitin conjugates, operates in apoptosis induced by γ-irradiation. The proteasome inhibitor peptide aldehyde, MG132, efficiently induced apoptosis and was also able (at doses lower than those required for apoptosis induction) to potentiate apoptosis induced by DNA damage. Its specificity is suggested by the induction of the ubiquitin (UbB and UbC) and E1 (ubiquitin activating enzyme) genes and by an altered ubiquitination pattern. More selectively, a di-peptide competitor of the 'N-end rule' of ubiquitin dependent protein processing inhibited radiation induced apoptosis. This inhibition is also followed by an altered ubiquitination pattern and by activation of Poly (ADP-ribose) polymerase (PARP). These data strongly suggest that early apoptosis radiation induced events are controlled by ubiquitin-dependent proteolytic processing. (author)

  9. Role of the nucleus in apoptosis: signaling and execution.

    Science.gov (United States)

    Prokhorova, Evgeniia A; Zamaraev, Alexey V; Kopeina, Gelina S; Zhivotovsky, Boris; Lavrik, Inna N

    2015-12-01

    Since their establishment in the early 1970s, the nuclear changes upon apoptosis induction, such as the condensation of chromatin, disassembly of nuclear scaffold proteins and degradation of DNA, were, and still are, considered as the essential steps and hallmarks of apoptosis. These are the characteristics of the execution phase of apoptotic cell death. In addition, accumulating data clearly show that some nuclear events can lead to the induction of apoptosis. In particular, if DNA lesions resulting from deregulation during the cell cycle or DNA damage induced by chemotherapeutic drugs or viral infection cannot be efficiently eliminated, apoptotic mechanisms, which enable cellular transformation to be avoided, are activated in the nucleus. The functional heterogeneity of the nuclear organization allows the tight regulation of these signaling events that involve the movement of various nuclear proteins to other intracellular compartments (and vice versa) to initiate and govern apoptosis. Here, we discuss how these events are coordinated to execute apoptotic cell death.

  10. Molecular Mechanism of Apoptosis and Necrosis

    Directory of Open Access Journals (Sweden)

    Gulfidan Coskun

    2011-06-01

    Full Text Available Organismal homeostasis depends on an intricate balance between cell death and renewal. Apoptosis is a process of programmed cell death that plays a critical role in some normal and pathologic conditions beginning from embryologic development and ends at death. Apoptosis is initiated by morphological changes at the cell membrane, surface organels and nucleus. Apoptosis starts with death signals coming from outside or inside of the cell and continue to activate the mechanisms of apoptosis via cell death receptor or mitochondrial pathways. During apoptosis a group proteases are activated which cause DNA fragmentation, cytoplasmic shrinkage and membrane blebbing. Apoptotic cells divide into apoptotic bodies and then these apoptotic bodies are removed from tissue by phagocytes and adjacent cells In contrast to the “programmed” nature of apoptosis, necrotic cell death has always been believed to be a random, uncontrolled process that leads to death of the cell. Also necrosis, which is an other type of cell death, came to be used to describe pathologic cell death which cause inflamation. [Archives Medical Review Journal 2011; 20(3.000: 145-158

  11. Homeostatic imbalance between apoptosis and cell renewal in the liver of premature aging Xpd mice.

    Directory of Open Access Journals (Sweden)

    Jung Yoon Park

    2008-06-01

    Full Text Available Unrepaired or misrepaired DNA damage has been implicated as a causal factor in cancer and aging. Xpd(TTD mice, harboring defects in nucleotide excision repair and transcription due to a mutation in the Xpd gene (R722W, display severe symptoms of premature aging but have a reduced incidence of cancer. To gain further insight into the molecular basis of the mutant-specific manifestation of age-related phenotypes, we used comparative microarray analysis of young and old female livers to discover gene expression signatures distinguishing Xpd(TTD mice from their age-matched wild type controls. We found a transcription signature of increased apoptosis in the Xpd(TTD mice, which was confirmed by in situ immunohistochemical analysis and found to be accompanied by increased proliferation. However, apoptosis rate exceeded the rate of proliferation, resulting in homeostatic imbalance. Interestingly, a metabolic response signature was observed involving decreased energy metabolism and reduced IGF-1 signaling, a major modulator of life span. We conclude that while the increased apoptotic response to endogenous DNA damage contributes to the accelerated aging phenotypes and the reduced cancer incidence observed in the Xpd(TTD mice, the signature of reduced energy metabolism is likely to reflect a compensatory adjustment to limit the increased genotoxic stress in these mutants. These results support a general model for premature aging in DNA repair deficient mice based on cellular responses to DNA damage that impair normal tissue homeostasis.

  12. ATM promotes apoptosis and suppresses tumorigenesis in response to Myc

    Science.gov (United States)

    Pusapati, Raju V.; Rounbehler, Robert J.; Hong, Sungki; Powers, John T.; Yan, Mingshan; Kiguchi, Kaoru; McArthur, Mark J.; Wong, Paul K.; Johnson, David G.

    2006-01-01

    Overexpression of the c-myc oncogene contributes to the development of a significant number of human cancers. In response to deregulated Myc activity, the p53 tumor suppressor is activated to promote apoptosis and inhibit tumor formation. Here we demonstrate that p53 induction in response to Myc overexpression requires the ataxia-telangiectasia mutated (ATM) kinase, a major regulator of the cellular response to DNA double-strand breaks. In a transgenic mouse model overexpressing Myc in squamous epithelial tissues, inactivation of Atm suppresses apoptosis and accelerates tumorigenesis. Deregulated Myc expression induces DNA damage in primary transgenic keratinocytes and the formation of H2AX and phospho-SMC1 foci in transgenic tissue. These findings suggest that Myc overexpression causes DNA damage in vivo and that the ATM-dependent response to this damage is critical for p53 activation, apoptosis, and the suppression of tumor development. p53 | DNA damage

  13. Proanthocyanidin and fish oil potent activity against cisplatin-induced renal cell cycle arrest and apoptosis in rats.

    Science.gov (United States)

    Hassan, Hanaa A; Edrees, Gamal M; El-Gamel, Ezz M; El-Sayed, Elsamra A

    2015-01-01

    Cisplatin is an effective chemotherapeutic agent that displays dose-limiting nephrotoxicity. In the present study, the efficacy of grape seed proanthocyanidin extract (GSPE: 100 mg/kg/day) and fish oil (FO: 5 mL/kg/day) against cisplatin-induced nephrotoxicity was evaluated in terms of DNA damage, histopathological changes and expression levels of molecular markers of apoptosis. The administration of cisplatin (CP) (7 mg/kg) results in an increasing percentage of S-phase, G2/M and apoptosis. Furthermore, CP induces apoptosis as indicated by an elevation of renal caspase-3 and reduction in the expression of BCL-2. In addition to occurred renal histopathological changes as manifested by tubular degeneration, degenerative glomerulus, necrotic tubular cells, and cell debris. On the other hand, the administration of GSPE or FO pre-cisplatin treatment can be ameliorated the current DNA cell cycle alterations by the restoration of expression of proteins related to apoptosis and reduced the undesirable renal histopathological changes. So, it can be concluded that the consumption of GSPE or FO might be useful for minimizing nephrotoxicity caused by cisplatin chemotherapy through their anti-apoptotic and antioxidant properties.

  14. Mitochondrial respiratory pathways inhibition in Rhizopus oryzae potentiates activity of posaconazole and itraconazole via apoptosis.

    Directory of Open Access Journals (Sweden)

    Fazal Shirazi

    Full Text Available The incidence of mucormycosis has increased drastically in immunocompromised patients. Also the array of targets whose inhibition results in Mucorales death is limited. Recently, researchers identified mitochondria as important regulators of detoxification and virulence mechanisms in fungi. In this context, targeting the mitochondrial respiratory chain may provide a new platform for antifungal development. We hypothesized that targeting respiratory pathways potentiates triazoles activity via apoptosis. We found that simultaneous administration of antimycin A (AA and benzohydroxamate (BHAM, inhibitors of classical and alternative mitochondrial pathways respectively, resulted in potent activity of posaconazole (PCZ and itraconazole (ICZ against Rhizopus oryzae. We observed cellular changes characteristic of apoptosis in R. oryzae cells treated with PCZ or ICZ in combination with AA and BHAM. The fungicidal activity of this combination against R. oryzae was correlated with intracellular reactive oxygen species accumulation (ROS, phosphatidylserine externalization, mitochondrial membrane depolarization, and increased caspase like activity. DNA fragmentation and condensation assays also revealed apoptosis of R. oryzae cells. These apoptotic features were prevented by the addition of the ROS scavenger N-acetyl-cysteine. Taken together, these findings suggest that the use of PCZ or ICZ in combination with AA and BHAM makes R. oryzae exquisitely sensitive to treatment with triazoles via apoptosis. This strategy may serve as a new model for the development of improved or novel antifungal agents.

  15. Mitochondrial Respiratory Pathways Inhibition in Rhizopus oryzae Potentiates Activity of Posaconazole and Itraconazole via Apoptosis

    Science.gov (United States)

    Shirazi, Fazal; Kontoyiannis, Dimitrios P.

    2013-01-01

    The incidence of mucormycosis has increased drastically in immunocompromised patients. Also the array of targets whose inhibition results in Mucorales death is limited. Recently, researchers identified mitochondria as important regulators of detoxification and virulence mechanisms in fungi. In this context, targeting the mitochondrial respiratory chain may provide a new platform for antifungal development. We hypothesized that targeting respiratory pathways potentiates triazoles activity via apoptosis. We found that simultaneous administration of antimycin A (AA) and benzohydroxamate (BHAM), inhibitors of classical and alternative mitochondrial pathways respectively, resulted in potent activity of posaconazole (PCZ) and itraconazole (ICZ) against Rhizopus oryzae. We observed cellular changes characteristic of apoptosis in R. oryzae cells treated with PCZ or ICZ in combination with AA and BHAM. The fungicidal activity of this combination against R. oryzae was correlated with intracellular reactive oxygen species accumulation (ROS), phosphatidylserine externalization, mitochondrial membrane depolarization, and increased caspase like activity. DNA fragmentation and condensation assays also revealed apoptosis of R. oryzae cells. These apoptotic features were prevented by the addition of the ROS scavenger N-acetyl-cysteine. Taken together, these findings suggest that the use of PCZ or ICZ in combination with AA and BHAM makes R. oryzae exquisitely sensitive to treatment with triazoles via apoptosis. This strategy may serve as a new model for the development of improved or novel antifungal agents. PMID:23696824

  16. Extremely Low Frequency Magnetic Fields Induce Spermatogenic Germ Cell Apoptosis: Possible Mechanism

    Directory of Open Access Journals (Sweden)

    Sang-Kon Lee

    2014-01-01

    Full Text Available The energy generated by an extremely low frequency electromagnetic field (ELF-EMF is too weak to directly induce genotoxicity. However, it is reported that an extremely low frequency magnetic field (ELF-MF is related to DNA strand breakage and apoptosis. The testes that conduct spermatogenesis through a dynamic cellular process involving meiosis and mitosis seem vulnerable to external stress such as heat, MF exposure, and chemical or physical agents. Nevertheless the results regarding adverse effects of ELF-EMF on human or animal reproductive functions are inconclusive. According to the guideline of the International Commission on Non-Ionizing Radiation Protection (ICNIRP; 2010 for limiting exposure to time-varying MF (1 Hz to 100 kHz, overall conclusion of epidemiologic studies has not consistently shown an association between human adverse reproductive outcomes and maternal or paternal exposure to low frequency fields. In animal studies there is no compelling evidence of causal relationship between prenatal development and ELF-MF exposure. However there is increasing evidence that EL-EMF exposure is involved with germ cell apoptosis in testes. Biophysical mechanism by which ELF-MF induces germ cell apoptosis has not been established. This review proposes the possible mechanism of germ cell apoptosis in testes induced by ELF-MF.

  17. Different mechanisms between premitotic apoptosis and postmitotic apoptosis in X-irradiated U937 cells

    International Nuclear Information System (INIS)

    Shinomiya, Nariyoshi; Kuno, Yukie; Yamamoto, Fuyumi; Fukasawa, Masashi; Okumura, Atsushi; Uefuji, Megumi; Rokutanda, Makoto

    2000-01-01

    Purpose: Apoptosis is currently being evaluated for its importance as a pathway of radiation-induced cell death. However, the difference in the mechanisms between premitotic and postmitotic apoptosis following X-irradiation remains not well understood. We show here that the human monoblastoid cell line U937 can be induced to undergo these two different types of apoptosis. Methods and Materials: U937 cells were irradiated at a dose of 5 or 20 Gy, and the DNA fragmentation rate was measured by both flow cytometric analysis and gel electrophoresis. Activation of caspase-3 was detected by Western blot analysis and fluorogenic assay using acetyl-Asp-Glu-Val-Asp-7-amino-4-methyl-coumarin (Ac-DEVD-AMC). Detection of mitochondrial transmembrane potential (no. DELTAno. no. PSIno. ) was performed by using Rho123. Chasing of S-phase fraction following X-irradiation was performed after labeling with 5-bromo-2'-deoxyuridine (BrdU). Thymidine was used for synchronization of the cells. Inhibition of caspase-3 activity was achieved by Acetyl-Asp-Glu-Val-Asp-aldehyde (Ac-DEVD-CHO). Results: Time courses of the apoptotic rates, caspase activation, and no. DELTAno. no. PSIno. indicated that two different types of cell death were induced by the different X-ray doses. High-dose X-ray (20 Gy) induced a rapid and strong apoptosis, whereas low-dose X-ray (5 Gy) induced a slow and mild apoptosis. Cell-cycle analyses revealed that there was cell death before cell division in the former apoptosis but the cells must be dying after cell division in the latter apoptosis. By means of cell-cycle synchronization, the S-phase cells proved to be the most sensitive fraction to premitotic apoptosis, but an obvious difference in the susceptibility to cell death among the cell-cycle phases was not observed in postmitotic apoptosis. Ac-DEVD-CHO treatment effectively blocked caspase activity and premitotic apoptosis, but it failed to block postmitotic apoptosis. Conclusions: Irradiation of U937 cells at

  18. Apoptosis of neutrophils

    NARCIS (Netherlands)

    Maianski, N. A.; Maianski, A. N.; Kuijpers, T. W.; Roos, D.

    2004-01-01

    Regulation of the neutrophil life span by apoptosis provides a fine balance between their function as effector cells of host defense and a safe turnover of these potentially harmful cells. Alterations of neutrophil apoptosis are associated with a number of diseases. As do other cell types,

  19. Ubiquitination in apoptosis signaling

    NARCIS (Netherlands)

    van de Kooij, L.W.

    2014-01-01

    The work described in this thesis focuses on ubiquitination and protein degradation, with an emphasis on how these processes regulate apoptosis signaling. More specifically, our aims were: 1. To increase the understanding of ubiquitin-mediated regulation of apoptosis signaling. 2. To identify the E3

  20. Hyperthermia-induced apoptosis

    NARCIS (Netherlands)

    Nijhuis, E.H.A.

    2008-01-01

    This thesis describes a number of studies that investigated several aspects of heat-induced apoptosis in human lymphoid malignancies. Cells harbour both pro- and anti-apoptotic proteins and the balance between these proteins determines whether a cell is susceptible to undergo apoptosis. In this

  1. Pre-Columbian origins of Native American dog breeds, with only limited replacement by European dogs, confirmed by mtDNA analysis.

    Science.gov (United States)

    van Asch, Barbara; Zhang, Ai-bing; Oskarsson, Mattias C R; Klütsch, Cornelya F C; Amorim, António; Savolainen, Peter

    2013-09-07

    Dogs were present in pre-Columbian America, presumably brought by early human migrants from Asia. Studies of free-ranging village/street dogs have indicated almost total replacement of these original dogs by European dogs, but the extent to which Arctic, North and South American breeds are descendants of the original population remains to be assessed. Using a comprehensive phylogeographic analysis, we traced the origin of the mitochondrial DNA lineages for Inuit, Eskimo and Greenland dogs, Alaskan Malamute, Chihuahua, xoloitzcuintli and perro sín pelo del Peru, by comparing to extensive samples of East Asian (n = 984) and European dogs (n = 639), and previously published pre-Columbian sequences. Evidence for a pre-Columbian origin was found for all these breeds, except Alaskan Malamute for which results were ambigous. No European influence was indicated for the Arctic breeds Inuit, Eskimo and Greenland dog, and North/South American breeds had at most 30% European female lineages, suggesting marginal replacement by European dogs. Genetic continuity through time was shown by the sharing of a unique haplotype between the Mexican breed Chihuahua and ancient Mexican samples. We also analysed free-ranging dogs, confirming limited pre-Columbian ancestry overall, but also identifying pockets of remaining populations with high proportion of indigenous ancestry, and we provide the first DNA-based evidence that the Carolina dog, a free-ranging population in the USA, may have an ancient Asian origin.

  2. Pre-Columbian origins of Native American dog breeds, with only limited replacement by European dogs, confirmed by mtDNA analysis

    Science.gov (United States)

    van Asch, Barbara; Zhang, Ai-bing; Oskarsson, Mattias C. R.; Klütsch, Cornelya F. C.; Amorim, António; Savolainen, Peter

    2013-01-01

    Dogs were present in pre-Columbian America, presumably brought by early human migrants from Asia. Studies of free-ranging village/street dogs have indicated almost total replacement of these original dogs by European dogs, but the extent to which Arctic, North and South American breeds are descendants of the original population remains to be assessed. Using a comprehensive phylogeographic analysis, we traced the origin of the mitochondrial DNA lineages for Inuit, Eskimo and Greenland dogs, Alaskan Malamute, Chihuahua, xoloitzcuintli and perro sín pelo del Peru, by comparing to extensive samples of East Asian (n = 984) and European dogs (n = 639), and previously published pre-Columbian sequences. Evidence for a pre-Columbian origin was found for all these breeds, except Alaskan Malamute for which results were ambigous. No European influence was indicated for the Arctic breeds Inuit, Eskimo and Greenland dog, and North/South American breeds had at most 30% European female lineages, suggesting marginal replacement by European dogs. Genetic continuity through time was shown by the sharing of a unique haplotype between the Mexican breed Chihuahua and ancient Mexican samples. We also analysed free-ranging dogs, confirming limited pre-Columbian ancestry overall, but also identifying pockets of remaining populations with high proportion of indigenous ancestry, and we provide the first DNA-based evidence that the Carolina dog, a free-ranging population in the USA, may have an ancient Asian origin. PMID:23843389

  3. The specific diagnosis of gastrointestinal nematode infections in livestock: larval culture technique, its limitations and alternative DNA-based approaches.

    Science.gov (United States)

    Roeber, Florian; Kahn, Lewis

    2014-10-15

    The specific diagnosis of gastrointestinal nematode infections in ruminants is routinely based on larval culture technique and on the morphological identification of developed third-stage larvae. However, research on the ecology and developmental requirements of different species suggests that environmental conditions (e.g., temperature and humidity) for optimal development to occur vary between the different species. Thus, employing a common culture protocol for all species will favour the development of certain species over others and can cause a biased result in particular when species proportions in a mixed infection are to be determined. Furthermore, the morphological identification of L3 larvae is complicated by a lack of distinctive, obvious features that would allow the identification of all key species. In the present paper we review in detail the potential limitations of larval culture technique and morphological identification and provide account to some modern molecular alternatives to the specific diagnosis of gastrointestinal nematode infection in ruminants. Copyright © 2014 Elsevier B.V. All rights reserved.

  4. Apoptosis – is it good or bad?

    Directory of Open Access Journals (Sweden)

    Bakir Mehić

    2012-08-01

    induced by TNF-α. The over expression of antiapoptotic proteins may allow injured cells to survive, and autophagy may assist by providing critical metabolites. Apoptotic cells induce anergy or an immunosuppressive phenotype, whereas necrotic cells augment inflammation, in part by binding the receptor C-type lectin domain family 9 on dendritic cells.Clinical implications of apoptosis are consist in more than 50% of neoplasm’s that have defects in the apoptotic machinery mutations in the tumor-suppressor gene TP53, that is called the “guardian of the genome,” initiates apoptosis in response to DNA damage induced by radiation, chemical agents, oxidative stress, and other agents.[3] Abnormalities in apoptosis can increase susceptibility to autoimmune diseases.[4] There is growing evidence that neuronal apoptosis plays a key role in neonatal brain disorders.[5] Hepatocytes are particularly prone to apoptosis in response to various types of stress, including infections.[6] Necrosis predominates in ischemic injury, but often there are apoptotic cells in the hypoxic penumbra in myocardial infarction and stroke and in globally hypoxic zones after reperfusion injury. Sepsis is perhaps the most remarkable clinical setting in which apoptosis occurs. Massive apoptosis of immune effectors’ cells and gastrointestinal epithelial cells develops in patients with sepsis.[7] The profound loss of immune effectors’ cells in sepsis inhibits the ability of the immune system to eradicate the primary infection and renders the patient susceptible to nosocomial infections. Finally, why apoptosis is good? Because without apoptosis, 2 tons of bone marrow and lymph nodes and a 16-km intestine would probably accumulate in a human by the age of 8o.[8

  5. miR-7-5p overexpression suppresses cell proliferation and promotes apoptosis through inhibiting the ability of DNA damage repair of PARP-1 and BRCA1 in TK6 cells exposed to hydroquinone.

    Science.gov (United States)

    Luo, Hao; Liang, Hairong; Chen, Yuting; Chen, Shaoyun; Xu, Yongchun; Xu, Longmei; Liu, Jiaxian; Zhou, Kairu; Peng, Jucheng; Guo, Guoqiang; Lai, Bei; Song, Li; Yang, Hui; Liu, Linhua; Peng, Jianming; Liu, Zhidong; Tang, Lin; Chen, Wen; Tang, Huanwen

    2018-03-01

    Hydroquinone (HQ), one of the major metabolic products of benzene, is a carcinogen, which induces apoptosis and inhibit proliferation in lymphoma cells. microRNA-7-5p (miR-7-5p), a tumor suppressor, participates in various biological processes including cell proliferation and apoptosis regulation by repressing expression of specific oncogenic target genes. To explore whether miR-7-5p is involved in HQ-induced cell proliferation and apoptosis, we assessed the effect of miR-7-5p overexpression on induction of apoptosis analyzed by FACSCalibur flow cytometer in transfection of TK6 cells with miR-7-5p mimic (TK6- miR-7-5p). We observed an increased apoptosis by 25.43% and decreased proliferation by 28.30% in TK6-miR-7-5p cells compared to those negative control cells (TK6-shNC) in response to HQ treatment. Furthermore, HQ might active the apoptotic pathway via partly downregulation the expression of BRCA1 and PARP-1, followed by p53 activation, in TK6-miR-7-5p cells. In contrast, attenuated p53 and BRCA1 expression was observed in shPARP-1 cells than in NC cells after HQ treatment. Therefore, we conclude that HQ may activate apoptotic signals via inhibiting the tumor suppressive effects of miR-7-5p, which may be mediated partly by upregulating the expression of PARP-1 and BRCA1 in control cells. The increase of miR-7-5p expression further intensified downregulation of PARP-1 and BRCA1 in TK6-miR-7-5p cells, resulting in an increase of apoptosis and proliferation inhibited. Copyright © 2018 Elsevier B.V. All rights reserved.

  6. Cyclin-dependent kinases regulate apoptosis of intestinal epithelial cells

    Science.gov (United States)

    Bhattacharya, Sujoy; Ray, Ramesh M.; Johnson, Leonard R.

    2014-01-01

    Homeostasis of the gastrointestinal epithelium is dependent upon a balance between cell proliferation and apoptosis. Cyclin-dependent kinases (Cdks) are well known for their role in cell proliferation. Previous studies from our group have shown that polyamine-depletion of intestinal epithelial cells (IEC-6) decreases cyclin-dependent kinase 2 (Cdk2) activity, increases p53 and p21Cip1 protein levels, induces G1 arrest, and protects cells from camptothecin (CPT)-induced apoptosis. Although emerging evidence suggests that members of the Cdk family are involved in the regulation of apoptosis, their roles directing apoptosis of IEC-6 cells are not known. In this study, we report that inhibition of Cdk1, 2, and 9 (with the broad range Cdk inhibitor, AZD5438) in proliferating IEC-6 cells triggered DNA damage, activated p53 signaling, inhibited proliferation, and induced apoptosis. By contrast, inhibition of Cdk2 (with NU6140) increased p53 protein and activity, inhibited proliferation, but had no effect on apoptosis. Notably, AZD5438 sensitized, whereas, NU6140 rescued proliferating IEC-6 cells from CPT-induced apoptosis. However, in colon carcinoma (Caco2) cells with mutant p53, treatment with either AZD5438 or NU6140 blocked proliferation, albeit more robustly with AZD5438. Both Cdk inhibitors induced apoptosis in Caco2 cells in a p53-independent manner. In serum starved quiescent IEC-6 cells, both AZD5438 and NU6140 decreased TNF- /CPT-induced activation of p53 and, consequently, rescued cells from apoptosis, indicating that sustained Cdk activity is required for apoptosis of quiescent cells. Furthermore, AZD5438 partially reversed the protective effect of polyamine depletion whereas NU6140 had no effect. Together, these results demonstrate that Cdks possess opposing roles in the control of apoptosis in quiescent and proliferating cells. In addition, Cdk inhibitors uncouple proliferation from apoptosis in a p53-dependent manner. PMID:24242917

  7. The minus of a plus is a minus. Mass death of selected neuron populations in sporadic late-onset neurodegenerative disease may be due to a combination of subtly decreased capacity to repair oxidative DNA damage and increased propensity for damage-related apoptosis

    Directory of Open Access Journals (Sweden)

    Rumena Petkova

    2016-07-01

    Full Text Available Neurons in the adult central nervous system (CNS are subjected to high levels of oxidative damage that is usually promptly repaired. Transcribed genomic regions are repaired with priority over untranscribed regions. The prioritization of DNA repair in neurons results in modification of the input into the assessment of genomic integrity in order to delay or avoid damage-related apoptosis unless the damage interferes directly with the functioning of the neuron. CNS neurons may be replaced, albeit rarely. Over-stimulation of adult neural progenitor niche caused by accelerated neuronal loss may result in its premature depletion. The combination of the two pathologic mechanisms (increased rates of neuronal death and depletion of the progenitor niche may eventually result in irreversible loss of specific cell populations in the CNS and/or generalized neuronal loss. Here we propose that the risk of developing sporadic late-onset neurodegenerative disease (LONDD may be modulated by the individual capacity for detection and repair of DNA damage and the genetic propensity to repair moderate-degree damage or to assess it as irreparable and route the cell towards apoptosis. Thus, subtly deficient DNA damage repair coupled with a tendency to repair the damage rather than kill the damaged cell may be associated with increased risk of cancer, whereas deficient DNA repair coupled with a propensity to destroy damaged cells may increase the risk of LONDD. Extensive studies of individual repair capacity may be needed to test this hypothesis and, potentially, use the results in the assessment of the risk of common late-onset disease.

  8. Mitochondrial catalase overexpressed transgenic mice are protected against lung fibrosis in part via preventing alveolar epithelial cell mitochondrial DNA damage.

    Science.gov (United States)

    Kim, Seok-Jo; Cheresh, Paul; Jablonski, Renea P; Morales-Nebreda, Luisa; Cheng, Yuan; Hogan, Erin; Yeldandi, Anjana; Chi, Monica; Piseaux, Raul; Ridge, Karen; Michael Hart, C; Chandel, Navdeep; Scott Budinger, G R; Kamp, David W

    2016-12-01

    Alveolar epithelial cell (AEC) injury and mitochondrial dysfunction are important in the development of lung fibrosis. Our group has shown that in the asbestos exposed lung, the generation of mitochondrial reactive oxygen species (ROS) in AEC mediate mitochondrial DNA (mtDNA) damage and apoptosis which are necessary for lung fibrosis. These data suggest that mitochondrial-targeted antioxidants should ameliorate asbestos-induced lung. To determine whether transgenic mice that express mitochondrial-targeted catalase (MCAT) have reduced lung fibrosis following exposure to asbestos or bleomycin and, if so, whether this occurs in association with reduced AEC mtDNA damage and apoptosis. Crocidolite asbestos (100µg/50µL), TiO 2 (negative control), bleomycin (0.025 units/50µL), or PBS was instilled intratracheally in 8-10 week-old wild-type (WT - C57Bl/6J) or MCAT mice. The lungs were harvested at 21d. Lung fibrosis was quantified by collagen levels (Sircol) and lung fibrosis scores. AEC apoptosis was assessed by cleaved caspase-3 (CC-3)/Surfactant protein C (SFTPC) immunohistochemistry (IHC) and semi-quantitative analysis. AEC (primary AT2 cells from WT and MCAT mice and MLE-12 cells) mtDNA damage was assessed by a quantitative PCR-based assay, apoptosis was assessed by DNA fragmentation, and ROS production was assessed by a Mito-Sox assay. Compared to WT, crocidolite-exposed MCAT mice exhibit reduced pulmonary fibrosis as measured by lung collagen levels and lung fibrosis score. The protective effects in MCAT mice were accompanied by reduced AEC mtDNA damage and apoptosis. Similar findings were noted following bleomycin exposure. Euk-134, a mitochondrial SOD/catalase mimetic, attenuated MLE-12 cell DNA damage and apoptosis. Finally, compared to WT, asbestos-induced MCAT AT2 cell ROS production was reduced. Our finding that MCAT mice have reduced pulmonary fibrosis, AEC mtDNA damage and apoptosis following exposure to asbestos or bleomycin suggests an important role

  9. Caspases: An apoptosis mediator

    Directory of Open Access Journals (Sweden)

    Tapan Kumar Palai

    2015-03-01

    Full Text Available The process of programmed cell death, or apoptosis, is generally characterized by distinct morphological characteristics and energy - dependent biochemical mechanisms. Apoptosis is a widely conserved phenomenon helping many processes, including normal cell turnover, proper development and functioning of the immune system, hormone dependent atrophy etc. Inappropriate apoptosis (either low level or high level leads to many developmental abnormalities like, neurodegenerative diseases, ischemic damage, autoimmune disorders and many types of cancer. To use cells for therapeutic purposes through generating cell lines, it is critical to study the cell cycle machinery and signalling pathways that controls cell death and apoptosis. Apoptotic pathways provide a fundamental protective mechanism that decreases cellular sensitivity to damaging events and allow proper developmental process in multi-cellular organisms. Major mediator of apoptosis is a family of proteins known as caspases. There are mainly fourteen types of caspases but out of them only ten caspasese have got essential role in controlling the process of apoptosis. These ten caspases have been categorized into either initiator caspases (caspase 2, 8, 9, 10 or executioner caspases (caspase 3, 6, 7. Although various types of caspases have been identified so far, the exact mechanisms of action of these groups of proteins is still to be fully understood. The aim of this review is to provide a detail overview of role of different caspases in regulating the process of apoptosis.

  10. The role of death-associated protein 3 in apoptosis, anoikis and human cancer.

    Science.gov (United States)

    Wazir, Umar; Orakzai, Mona Maw; Khanzada, Zubair S; Jiang, Wen G; Sharma, Anup K; Kasem, Abdul; Mokbel, Kefah

    2015-01-01

    Death-associated protein 3 (DAP3) is a molecule with a significant role in the control of both apoptosis and anoikis. Apoptosis is the predominant type of programmed cell death (PCD) which may occur in response to irreparable damage to DNA, or in response to induction by inflammatory cells. Anoikis is subset of apoptosis which occurs in epithelial cells in response to detachment from the surrounding matrix. Both apoptosis and anoikis are of interest in the context of carcinogenesis. In this review, we shall discuss apoptosis and anoikis, and the recent literature regarding the role of DAP3 in both these pathways.

  11. DNA polymerase eta is a limiting factor for A:T mutations in Ig genes and contributes to antibody affinity maturation.

    Science.gov (United States)

    Masuda, Keiji; Ouchida, Rika; Yokoi, Masayuki; Hanaoka, Fumio; Azuma, Takachika; Wang, Ji-Yang

    2008-10-01

    DNA polymerase eta (POLH) is required for the generation of A:T mutations during the somatic hypermutation of Ig genes in germinal center B cells. It remains unclear, however, whether POLH is a limiting factor for A:T mutations and how the absence of POLH might affect antibody affinity maturation. We found that the heterozygous Polh+/- mice exhibited a significant reduction in the frequency of A:T mutations in Ig genes, with each type of base substitutions at a level intermediate between the Polh+/+ and Polh(-/-) mice. These observations suggest that Polh is haplo-insufficient for the induction of A:T mutations in Ig genes. Intriguingly, there was also a reduction of C to T and G to A transitions in Polh+/- mice as compared with WT mice. Polh(-/-) mice produced decreased serum titers of high-affinity antibodies against a T-dependent antigen, which was associated with a significant reduction in the number of plasma cells secreting high-affinity antibodies. Analysis of the V region revealed that aa substitutions caused by A:T mutations were greatly reduced in Polh(-/-) mice. These results demonstrate that POLH is a limiting factor for A:T mutations and contributes to the efficient diversification of Ig genes and affinity maturation of antibodies.

  12. HYPOXIA-INDUCED GROWTH LIMITATION OF JUVENILE FISHES IN AN ESTUARINE NURSERY: ASSESSMENT OF SMALL-SCALE TEMPORAL DYNAMICS USING RNA:DNA

    Science.gov (United States)

    The ratio of RNA to DNA (RNA:DNA) in white muscle tissue of juvenile summer flounder (Paralichthys dentatus) and weakfish (Cynoscion regalis) was used as a proxy for recent growth rate in an estuarine nursery. Variability in RNA:DNA was examined relative to temporal changes in te...

  13. Reaper-Induced Apoptosis

    National Research Council Canada - National Science Library

    Perry, Jennifer

    2005-01-01

    Reaper is a central regulator of apoptosis in the fly, Drosophila melanogaster. At the start of this proposal our laboratory identified what was believed to be a pro-apoptotic human homolog of Reaper...

  14. Apoptosis-induced lymphopenia in sepsis and other severe injuries.

    Science.gov (United States)

    Girardot, Thibaut; Rimmelé, Thomas; Venet, Fabienne; Monneret, Guillaume

    2017-02-01

    Sepsis and other acute injuries such as severe trauma, extensive burns, or major surgeries, are usually followed by a period of marked immunosuppression. In particular, while lymphocytes play a pivotal role in immune response, their functions and numbers are profoundly altered after severe injuries. Apoptosis plays a central role in this process by affecting immune response at various levels. Indeed, apoptosis-induced lymphopenia duration and depth have been associated with higher risk of infection and mortality in various clinical settings. Therapies modulating apoptosis represent an interesting approach to restore immune competence after acute injury, although their use in clinical practice still presents several limitations. After briefly describing the apoptosis process in physiology and during severe injuries, we will explore the immunological consequences of injury-induced lymphocyte apoptosis, and describe associations with clinically relevant outcomes in patients. Therapeutic perspectives targeting apoptosis will also be discussed.

  15. Limits of RNA 2'-OH Mimicry by Fluorine: Crystal Structure of Bacillus halodurans RNase H Bound to a 2'-FRNA:DNA Hybrid.

    Science.gov (United States)

    Pallan, Pradeep S; Prakash, Thazha P; de Leon, Arnie R; Egli, Martin

    2016-09-27

    RNase H1 cleaves the RNA strand of RNA:DNA hybrids. Replacement of RNA 2'-hydroxyls by fluorine (FRNA) is commonly used to stabilize aptamers and siRNAs. However, FRNA:DNA hybrids fail to elicit RNase H activity. The underlying reasons are unclear, as 2'-OH groups are not directly involved in cleavage. We determined the crystal structure of Bacillus halodurans RNase H bound to a FRNA:DNA hybrid. The structure points to dynamic (slippage of the FRNA:DNA hybrid relative to the enzyme), geometric (different curvatures of FRNA:DNA and RNA:DNA hybrids), and electronic reasons (Mg(2+) absent from the active site of the FRNA:DNA complex) for the loss of RNaseH activity.

  16. Picornaviruses and Apoptosis: Subversion of Cell Death.

    Science.gov (United States)

    Croft, Sarah N; Walker, Erin J; Ghildyal, Reena

    2017-09-19

    Infected cells can undergo apoptosis as a protective response to viral infection, thereby limiting viral infection. As viruses require a viable cell for replication, the death of the cell limits cellular functions that are required for virus replication and propagation. Picornaviruses are single-stranded RNA viruses that modify the host cell apoptotic response, probably in order to promote viral replication, largely as a function of the viral proteases 2A, 3C, and 3CD. These proteases are essential for viral polyprotein processing and also cleave cellular proteins. Picornavirus proteases cleave proapoptotic adaptor proteins, resulting in downregulation of apoptosis. Picornavirus proteases also cleave nucleoporins, disrupting the orchestrated manner in which signaling pathways use active nucleocytoplasmic trafficking, including those involved in apoptosis. In addition to viral proteases, the transmembrane 2B protein alters intracellular ion signaling, which may also modulate apoptosis. Overall, picornaviruses, via the action of virally encoded proteins, exercise intricate control over and subvert cell death pathways, specifically apoptosis, thereby allowing viral replication to continue. Copyright © 2017 Croft et al.

  17. Effect of cycloheximide and actinomycin D on radionuclide 235U-induced apoptosis

    International Nuclear Information System (INIS)

    Fu Qiang; Zhang Lansheng; Zhu Shoupeng

    1999-01-01

    Objective: The mechanism of apoptosis induced by radionuclide 235 U was studied. Methods: MTT and JAM assay were used to analyse the cell viability and quantification of fragmented DNA. Results: The inhibitor of protein cycloheximide (CHX), and the inhibitor of RNA synthesis, actinomycin D. cannot inhibit the apoptosis induced by 235 U, but CHX can partly inhibit apoptotic cells DNA fragmentation. Conclusion: The pathway of apoptosis induced by radionuclide 235 U is different from X-and γ-ray external irradiation, protein synthesis is not essential for it, but synthetic endonuclease is necessary for DNA fragmentation of apoptotic cells

  18. Reduced risk of apoptosis: mechanisms of stress responses.

    Science.gov (United States)

    Milisav, Irina; Poljšak, Borut; Ribarič, Samo

    2017-02-01

    Apoptosis signaling pathways are integrated into a wider network of interconnected apoptotic and anti-apoptotic pathways that regulate a broad range of cell responses from cell death to growth, development and stress responses. An important trigger for anti- or pro-apoptotic cell responses are different forms of stress including hypoxia, energy deprivation, DNA damage or inflammation. Stress duration and intensity determine whether the cell's response will be improved cell survival, due to stress adaptation, or cell death by apoptosis, necrosis or autophagy. Although the interplay between enhanced stress tolerance and modulation of apoptosis triggering is not yet fully understood, there is a substantial body of experimental evidence demonstrating that apoptosis and anti-apoptosis signaling pathways can be manipulated to trigger or delay apoptosis in vitro or in vivo. Anti-apoptotic strategies cover a broad range of approaches. These interventions include mediators that prevent apoptosis (trophic factors and cytokines), apoptosis inhibition (caspase inhibition, stimulation of anti-apoptotic or inhibition of pro-apoptotic proteins and elimination of apoptotic stimulus), adaptive stress responses (induction of maintenance and repair, caspase inactivation) and cell-cell interactions (blocking engulfment and modified micro environment). There is a consensus that preclinical efficacy and safety evaluations of anti-apoptotic strategies should be performed with protocols that simulate as closely as possible the effects of aging, gender, risk factors, comorbidities and co-medications.

  19. Decreased transcription-coupled nucleotide excision repair capacity is associated with increased p53- and MLH1-independent apoptosis in response to cisplatin

    International Nuclear Information System (INIS)

    Stubbert, Lawton J; Smith, Jennifer M; McKay, Bruce C

    2010-01-01

    One of the most commonly used classes of anti-cancer drugs presently in clinical practice is the platinum-based drugs, including cisplatin. The efficacy of cisplatin therapy is often limited by the emergence of resistant tumours following treatment. Cisplatin resistance is multi-factorial but can be associated with increased DNA repair capacity, mutations in p53 or loss of DNA mismatch repair capacity. RNA interference (RNAi) was used to reduce the transcription-coupled nucleotide excision repair (TC-NER) capacity of several prostate and colorectal carcinoma cell lines with specific defects in p53 and/or DNA mismatch repair. The effect of small inhibitory RNAs designed to target the CSB (Cockayne syndrome group B) transcript on TC-NER and the sensitivity of cells to cisplatin-induced apoptosis was determined. These prostate and colon cancer cell lines were initially TC-NER proficient and RNAi against CSB significantly reduced their DNA repair capacity. Decreased TC-NER capacity was associated with an increase in the sensitivity of tumour cells to cisplatin-induced apoptosis, even in p53 null and DNA mismatch repair-deficient cell lines. The present work indicates that CSB and TC-NER play a prominent role in determining the sensitivity of tumour cells to cisplatin even in the absence of p53 and DNA mismatch repair. These results further suggest that CSB represents a potential target for cancer therapy that may be important to overcome resistance to cisplatin in the clinic

  20. Apoptosis signaling and radiation protection

    International Nuclear Information System (INIS)

    Morita, Akinori; Suzuki, Norio; Hosoi, Yoshio

    2005-01-01

    Radiation protection by apoptosis control is the suppression of cell death in highly radiosensitive tissues. This paper describes the outline of radiation-induced apoptosis framework, apoptosis-concerned target molecules possibly related to apoptosis by radiation and their inhibitors. Although there are intrinsic (via mitochondria) and extrinsic (via death receptor) pathways in apoptosis, this review mainly mentions the former which is more important in radiation-induced apoptosis. Those molecules known at present in the apoptosis are caspase, Bcl-2 family and p53. Caspase, a group of cystein proteases, initiates apoptosis but its inhibition is known not always to result in apoptosis suppression, suggesting the existence of caspase-independent pathways. Bcl-2 family involves apoptosis-suppressing (possessing BH domains) and -promoting (lacking BH domains or possessing BH3 domain alone/BH3-only protein) groups. Two p53-transcription-dependent and one -independent pathways in p53-induced apoptosis are known and p53 can be a most possible target molecule since it positions at the start of apoptosis. Authors have found a vanadate inactivates p53. Inhibitors affecting upstream molecules of apoptosis will be the most useful candidate for apoptosis suppression/radiation protection. (S.I.) 106 refs

  1. A novel method for detection of apoptosis

    Energy Technology Data Exchange (ETDEWEB)

    Zagariya, Alexander M., E-mail: zagariya@uic.edu

    2012-04-15

    There are two different Angiotensin II (ANG II) peptides in nature: Human type (ANG II) and Bovine type (ANG II*). These eight amino acid peptides differ only at position 5 where Valine is replaced by Isoleucine in the Bovine type. They are present in all species studied so far. These amino acids are different by only one atom of carbon. This difference is so small, that it will allow any of ANG II, Bovine or Human antibodies to interact with all species and create a universal method for apoptosis detection. ANG II concentrations are found at substantially higher levels in apoptotic, compared to non-apoptotic, tissues. ANG II accumulation can lead to DNA damage, mutations, carcinogenesis and cell death. We demonstrate that Bovine antiserum can be used for universal detection of apoptosis. In 2010, the worldwide market for apoptosis detection reached the $20 billion mark and significantly increases each year. Most commercially available methods are related to Annexin V and TUNNEL. Our new method based on ANG II is more widely known to physicians and scientists compared to previously used methods. Our approach offers a novel alternative for assessing apoptosis activity with enhanced sensitivity, at a lower cost and ease of use.

  2. A novel method for detection of apoptosis

    International Nuclear Information System (INIS)

    Zagariya, Alexander M.

    2012-01-01

    There are two different Angiotensin II (ANG II) peptides in nature: Human type (ANG II) and Bovine type (ANG II*). These eight amino acid peptides differ only at position 5 where Valine is replaced by Isoleucine in the Bovine type. They are present in all species studied so far. These amino acids are different by only one atom of carbon. This difference is so small, that it will allow any of ANG II, Bovine or Human antibodies to interact with all species and create a universal method for apoptosis detection. ANG II concentrations are found at substantially higher levels in apoptotic, compared to non-apoptotic, tissues. ANG II accumulation can lead to DNA damage, mutations, carcinogenesis and cell death. We demonstrate that Bovine antiserum can be used for universal detection of apoptosis. In 2010, the worldwide market for apoptosis detection reached the $20 billion mark and significantly increases each year. Most commercially available methods are related to Annexin V and TUNNEL. Our new method based on ANG II is more widely known to physicians and scientists compared to previously used methods. Our approach offers a novel alternative for assessing apoptosis activity with enhanced sensitivity, at a lower cost and ease of use.

  3. Apoptosis-inducing factor (Aif1) mediates anacardic acid-induced apoptosis in Saccharomyces cerevisiae.

    Science.gov (United States)

    Muzaffar, Suhail; Chattoo, Bharat B

    2017-03-01

    Anacardic acid is a medicinal phytochemical that inhibits proliferation of fungal as well as several types of cancer cells. It induces apoptotic cell death in various cell types, but very little is known about the mechanism involved in the process. Here, we used budding yeast Saccharomyces cerevisiae as a model to study the involvement of some key elements of apoptosis in the anacardic acid-induced cell death. Plasma membrane constriction, chromatin condensation, DNA degradation, and externalization of phosphatidylserine (PS) indicated that anacardic acid induces apoptotic cell death in S. cerevisiae. However, the exogenous addition of broad-spectrum caspase inhibitor Z-VAD-FMK or deletion of the yeast caspase Yca1 showed that the anacardic acid-induced cell death is caspase independent. Apoptosis-inducing factor (AIF1) deletion mutant was resistant to the anacardic acid-induced cell death, suggesting a key role of Aif1. Overexpression of Aif1 made cells highly susceptible to anacardic acid, further confirming that Aif1 mediates anacardic acid-induced apoptosis. Interestingly, instead of the increase in the intracellular reactive oxygen species (ROS) normally observed during apoptosis, anacardic acid caused a decrease in the intracellular ROS levels. Quantitative real-time PCR analysis showed downregulation of the BIR1 survivin mRNA expression during the anacardic acid-induced apoptosis.

  4. Apoptosis signal-regulating kinase 1 mediates denbinobin-induced apoptosis in human lung adenocarcinoma cells

    Directory of Open Access Journals (Sweden)

    Pan Shiow-Lin

    2009-05-01

    Full Text Available Abstract In the present study, we explore the role of apoptosis signal-regulating kinase 1 (ASK1 in denbinobin-induced apoptosis in human lung adenocarcinoma (A549 cells. Denbinobin-induced cell apoptosis was attenuated by an ASK1 dominant-negative mutant (ASK1DN, two antioxidants (N-acetyl-L-cysteine (NAC and glutathione (GSH, a c-Jun N-terminal kinase (JNK inhibitor (SP600125, and an activator protein-1 (AP-1 inhibitor (curcumin. Treatment of A549 cells with denbinobin caused increases in ASK1 activity and reactive oxygen species (ROS production, and these effects were inhibited by NAC and GSH. Stimulation of A549 cells with denbinobin caused JNK activation; this effect was markedly inhibited by NAC, GSH, and ASK1DN. Denbinobin induced c-Jun phosphorylation, the formation of an AP-1-specific DNA-protein complex, and Bim expression. Bim knockdown using a bim short interfering RNA strategy also reduced denbinobin-induced A549 cell apoptosis. The denbinobin-mediated increases in c-Jun phosphorylation and Bim expression were inhibited by NAC, GSH, SP600125, ASK1DN, JNK1DN, and JNK2DN. These results suggest that denbinobin might activate ASK1 through ROS production to cause JNK/AP-1 activation, which in turn induces Bim expression, and ultimately results in A549 cell apoptosis.

  5. Studies on hematopoietic cell apoptosis and the relative gene expression in irradiated mouse bone marrow

    International Nuclear Information System (INIS)

    Peng Ruiyun; Wang Dewen; Xiong Chengqi; Gao Yabing; Yang Hong; Cui Yufang; Wang Baozhen

    2001-01-01

    Objective: To study apoptosis and expressions bcl-2 and p53 in irradiated mouse bone marrow. Methods: LACA mice were irradiated with 60 Co γ-rays. By means of in situ terminal labelling, in situ hybridization and image analysis, the authors studied radiation-induced apoptosis of hematopoietic cells and the expressions of bcl-2 and p53. Results: The characteristics of apoptosis appeared in hematopoietic cells at 6 hrs after irradiation. The expression of bcl-2 was obviously decreased when apoptosis of hematopoietic cells occurred, whereas it increased in the early recovery phase; p53 protein increased during both apoptosis of hematopoietic cells and the recovery phase, and mutant type p53 DNA was positive only in the recovery phase. Conclusion: Radiation may induced apoptosis of hematopoietic cells in a dose-dependent manner; Both bcl-2 and p53 genes play an important role in apoptosis and recovery phase

  6. Analysis of Residual DSBs in Ataxia-Telangiectasia Lymphoblast Cells Initiating Apoptosis

    Directory of Open Access Journals (Sweden)

    Teresa Anglada

    2016-01-01

    Full Text Available In order to examine the relationship between accumulation of residual DNA double-strand breaks (DSBs and cell death, we have used a control and an ATM (Ataxia-Telangiectasia Mutated defective cell line, as Ataxia-Telangiectasia (AT cells tend to accumulate residual DSBs at long times after damage infliction. After irradiation, AT cells showed checkpoint impairment and a fraction of cells displayed an abnormal centrosome number and tetraploid DNA content, and this fraction increased along with apoptosis rates. At all times analyzed, AT cells displayed a significantly higher rate of radiation-induced apoptosis than normal cells. Besides apoptosis, 70–85% of the AT viable cells (TUNEL-negative carried ≥10 γH2AX foci/cell, while only 12–27% of normal cells did. The fraction of AT and normal cells undergoing early and late apoptosis were isolated by flow cytometry and residual DSBs were concretely scored in these populations. Half of the γH2AX-positive AT cells undergoing early apoptosis carried ≥10 γH2AX foci/cell and this fraction increased to 75% in late apoptosis. The results suggest that retention of DNA damage-induced γH2AX foci is an indicative of lethal DNA damage, as cells undergoing apoptosis are those accumulating more DSBs. Scoring of residual γH2AX foci might function as a predictive tool to assess radiation-induced apoptosis.

  7. Apoptosis: A Four-Week Laboratory Investigation for Advanced Molecular and Cellular Biology Students

    Science.gov (United States)

    DiBartolomeis, Susan M.; Mone, James P.

    2003-01-01

    Over the past decade, apoptosis has emerged as an important field of study central to ongoing research in many diverse fields, from developmental biology to cancer research. Apoptosis proceeds by a highly coordinated series of events that includes enzyme activation, DNA fragmentation, and alterations in plasma membrane permeability. The detection…

  8. Pushing the limit: synthesis, photophysical and DNA binding studies of a NIR-emitting Ru(II)-polypyridyl probe with 'light switch' behaviour.

    Science.gov (United States)

    Elmes, Robert B P; Kitchen, Jonathan A; Williams, D Clive; Gunnlaugsson, Thorfinnur

    2012-06-14

    The new Ru(II) polypyridyl complex 1 was synthesised using microwave irradiation from the new polypyridyl ligand 2'DipyTAP', and its photophysical properties, and DNA binding abilities were investigated using various spectroscopic techniques; and 1 was shown to act as a 'NIR molecular light switch' for DNA with an emission window between 680 and 860 nm.

  9. Cl- channels in apoptosis

    DEFF Research Database (Denmark)

    Wanitchakool, Podchanart; Ousingsawat, Jiraporn; Sirianant, Lalida

    2016-01-01

    A remarkable feature of apoptosis is the initial massive cell shrinkage, which requires opening of ion channels to allow release of K(+), Cl(-), and organic osmolytes to drive osmotic water movement and cell shrinkage. This article focuses on the role of the Cl(-) channels LRRC8, TMEM16/anoctamin......, and cystic fibrosis transmembrane conductance regulator (CFTR) in cellular apoptosis. LRRC8A-E has been identified as a volume-regulated anion channel expressed in many cell types. It was shown to be required for regulatory and apoptotic volume decrease (RVD, AVD) in cultured cell lines. Its presence also...

  10. Nicotinamide "protects" resting lymphocytes exposed to hydrogen peroxide from necrosis but not from apoptosis.

    Science.gov (United States)

    Tronov, V A; Konstantinov, E M; Petrakou, E; Tsilimigaki, S; Piperakis, S M

    2002-01-01

    The aim of this work was to investigate the relationship between mechanisms of DNA repair and apoptosis induced by oxidative stress (H2O2) in human lymphocytes. Using the comet assay, fluorescent microscopy, and DNA electrophoresis, we studied the DNA damage induced by hydrogen peroxide (H2O2) treatment, the time and the amount of repair of strand breaks, the type of cell death, and the influence of inhibitors of repair (nicotinamide). When lymphocytes were treated with H2O2, we observed an increased in necrosis compared to apoptosis. However, when nicotinamide (which inhibits DNA repair) was added, the mode of death reversed to increased apoptosis. These results indicate that nicotinamide "protects" resting lymphocytes exposed to H2O2 from necrosis but not from apoptosis.

  11. Spermine inhibits Endoplasmic Reticulum Stress - induced Apoptosis: a New Strategy to Prevent Cardiomyocyte Apoptosis

    Directory of Open Access Journals (Sweden)

    Can Wei

    2016-02-01

    Full Text Available Background/Aims: Endoplasmic reticulum stress (ERS plays an important role in the progression of acute myocardial infarction (AMI, in part by mediating apoptosis. Polyamines, including putrescine, spermidine, and spermine, are polycations with anti-oxidative, anti-aging, and cell growth-promoting activities. This study aimed to determine the mechanisms by which spermine protects against ERS-induced apoptosis in rats following AMI. Methods and Results: AMI was established by ligation of the left anterior descending coronary artery (LAD in rats, and exogenous spermine was administered by intraperitoneal injection (2.5 mg/ml daily for 7 days pre-AMI. Spermine treatment limited infarct size, attenuated cardiac troponin I and creatinine kinase-MB release, improved cardiac function, and decreased ERS and apoptosis related protein expression. Isolated cardiomyocytes subjected to hypoxia showed significant increase in reactive oxygen species (ROS and the expression of apoptosis and ERS related proteins; these effects occurred through PERK and eIF2α phosphorylation. The addition of spermine attenuated cardiomyocyte apoptosis, suppressed the production of ROS, and inhibited ERS related pathways. Conclusions: Spermine was an effective pre-treatment strategy to attenuate cardiac ERS injury in rats, and the cardioprotective mechanism occurring through inhibition of ROS production and down regulation of the PERK-eIF2α pathway. These findings provide a novel target for the prevention of apoptosis in the setting of AMI.

  12. Leukocyte apoptosis as a predictor of radiosensitivity in Fanconi anemia

    International Nuclear Information System (INIS)

    Petrovic, Sandra; Leskovac, Andreja; Joksic, Ivana; Filipovic, Jelena; Joksic, Gordana; Vujic, Dragana; Guc-Scekic, Marija

    2013-01-01

    Fanconi anemia (FA) is a rare cancer-prone genetic disease characterized by impaired oxygen metabolism and defects in DNA damage repair. Response of FA cells to ionizing radiation has been an issue intensively debated in the literature. To study in vitro radiosensitivity in patients suffering from FA and their parents (heterozygous carriers), we determined radiation-induced leukocyte apoptosis using flow cytometry. As TP53 gene is involved in the control of apoptosis, we studied its status in FA lymphocytes using dual colour fluorescence in situ hybridization (FISH). FA patients and female heterozygous carriers display radiosensitive response to ionizing radiation seen as abnormal elimination of cells via apoptosis. By employment of FISH, the TP53 allele loss in FA lymphocytes was not observed. In diseases related to oxidative stress, determination of radiation-induced apoptosis is the method of choice for testing the radiosensitivity. (author)

  13. ING1 induces apoptosis through direct effects at the mitochondria

    DEFF Research Database (Denmark)

    Bose, P; Thakur, S; Thalappilly, S

    2013-01-01

    The ING family of tumor suppressors acts as readers and writers of the histone epigenetic code, affecting DNA repair, chromatin remodeling, cellular senescence, cell cycle regulation and apoptosis. The best characterized member of the ING family, ING1,interacts with the proliferating cell nuclear...... translocates to the mitochondria of primary fibroblasts and established epithelial cell lines in response to apoptosis inducing stimuli, independent of the cellular p53 status. The ability of ING1 to induce apoptosis in various breast cancer cell lines correlates well with its degree of translocation...... to the mitochondria after UV treatment. Endogenous ING1 protein specifically interacts with the pro-apoptotic BCL2 family member BAX, and colocalizes with BAX in a UV-inducible manner. Ectopic expression of a mitochondria-targeted ING1 construct is more proficient in inducing apoptosis than the wild type ING1 protein...

  14. The Bacteriophage lambdaDNA packaging enzyme: Identification of four structural domains of the gpNu1 subunit using limited proteolysis

    Directory of Open Access Journals (Sweden)

    PAMELA ARAYA

    2001-01-01

    Full Text Available Lambda DNA terminase, the enzyme that cleaves virion-length chromosomes from multigenomic concatemers and packages them into the bacteriophage head, is composed of two subunits, gpNu1 and gpA. Direct determination of the structure of gpNu1, the smaller subunit, has not been possible because of its insolubility in aqueous solutions. Therefore, to identify smaller and potentially water-soluble domains of gpNu1, we analyzed the nature of the products obtained by limited digestion of the protein with several proteases. The gpNu1 subunit was obtained from E.coli cells transfected with the plasmid pH6-Nu1 that overproduces the protein. Incubation of gpNu1 solubized in 2.5 M guanidinium chloride with chymotrypsin resulted in the formation of at least eight discrete protein bands, while treatment with endoproteinase glu-C and bromelain yielded three and one major bands, respectively. The peptides generated by digestion with the various proteases were separated by two-dimensional gel electrophoresis and transferred to Immobilon membranes. Amino acid sequencing of the peptides allowed for the precise assignment of their N-terminal amino acid, while their estimated molecular weights permitted the identification of their C-terminal ends. The results reveal that in the presence of 2.5 M guanidinium chloride, gpNu1 is partially folded in at least four distinct structural domains that correspond to functional domains as determined by previously reported genetic experiments. This information is key to design new plasmids to overproduce these domains for further structural analysis.

  15. Nonylphenol diethoxylate inhibits apoptosis induced in PC12 cells.

    Science.gov (United States)

    Liu, Chuang; Sun, Yongkun; Song, Yutong; Saito, Takeshi; Kurasaki, Masaaki

    2016-11-01

    Nonylphenol and short-chain nonylphenol ethoxylates such as NP 2 EO are present in aquatic environment as wastewater contaminants, and their toxic effects on aquatic species have been reported. Apoptosis has been shown to be induced by serum deprivation or copper treatment. To understand the toxicity of nonylphenol diethoxylate, we investigated the effects of NP 2 EO on apoptosis induced by serum deprivation and copper by using PC12 cell system. Nonylphenol diethoxylate itself showed no toxicity and recovered cell viability from apoptosis. In addition, nonylphenol diethoxylate decreased DNA fragmentation caused by apoptosis in PC12 cells. This phenomenon was confirmed after treating apoptotic PC12 cells with nonylphenol diethoxylate, whereas the cytochrome c release into the cytosol decreased as compared to that in apoptotic cells not treated with nonylphenol diethoxylates. Furthermore, Bax contents in apoptotic cells were reduced after exposure to nonylphenol diethoxylate. Thus, nonylphenol diethoxylate has the opposite effect on apoptosis in PC12 cells compared to nonylphenol, which enhances apoptosis induced by serum deprivation. The difference in structure of the two compounds is hypothesized to be responsible for this phenomenon. These results indicated that nonylphenol diethoxylate has capability to affect cell differentiation and development and has potentially harmful effect on organisms because of its unexpected impact on apoptosis. © 2015 Wiley Periodicals, Inc. Environ Toxicol 31: 1389-1398, 2016. © 2015 Wiley Periodicals, Inc.

  16. Roles of Apoptosis and Cellular Senescence in Cancer and Aging.

    Science.gov (United States)

    Cerella, Claudia; Grandjenette, Cindy; Dicato, Mario; Diederich, Marc

    2016-01-01

    Cancer and aging are two similar processes representing the final outcome of timedependent accumulation of various irreversible dysfunctions, mainly caused by stress-induced DNA and cellular damages. Apoptosis and senescence are two types of cellular response to damages that are altered in both cancer and aging, albeit through different mechanisms. Carcinogenesis is associated with a progressive reduction in the ability of the cells to trigger apoptosis and senescence. In contrast, in aging tissues, there is an increased accumulation of senescent cells, and the nature of apoptosis deregulation varies depending on the tissue. Thus, the prevailing model suggests that apoptosis and cellular senescence function as two essential tumor-suppressor mechanisms, ensuring the health of the individual during early and reproductive stages of life, but become detrimental and promote aging later in life. The recent discovery that various anticancer agents, including canonical inducers of apoptosis, act also as inducers of cellular senescence indicates that pro-senescence strategies may have applications in cancer prevention therapy. Therefore, dissection of the mechanisms mediating the delicate balance between apoptosis and cellular senescence will be beneficial in the therapeutic exploitation of both processes in the development of future anticancer and anti-aging strategies, including minimizing the side effects of such strategies. Here, we provide an overview of the roles of apoptosis and cellular senescence in cancer and aging.

  17. Mitochondria in neutrophil apoptosis

    NARCIS (Netherlands)

    van Raam, B. J.; Verhoeven, A. J.; Kuijpers, T. W.

    2006-01-01

    Central in the regulation of the short life span of neutrophils are their mitochondria. These organelles hardly contribute to the energy status of neutrophils but play a vital role in the apoptotic process. Not only do the mitochondria contain cytotoxic proteins that are released during apoptosis

  18. Aniline Induces Oxidative Stress and Apoptosis of Primary Cultured Hepatocytes

    Directory of Open Access Journals (Sweden)

    Yue Wang

    2016-11-01

    Full Text Available The toxicity and carcinogenicity of aniline in humans and animals have been well documented. However, the molecular mechanism involved in aniline-induced liver toxicity and carcinogenesis remains unclear. In our research, primary cultured hepatocytes were exposed to aniline (0, 1.25, 2.50, 5.0 and 10.0 μg/mL for 24 h in the presence or absence of N-acetyl-l-cysteine (NAC. Levels of reactive oxygen species (ROS, malondialdehyde (MDA, and glutathione (GSH, activities of superoxide dismutase (SOD and catalase (CAT, mitochondrial membrane potential, DNA damage, cell viability, and apoptosis were detected. Levels of ROS and MDA were significantly increased and levels of GSH and CAT, activity of SOD, and mitochondrial membrane potential in hepatocytes were significantly decreased by aniline compared with the negative control group. The tail moment and DNA content of the tail in exposed groups were significantly higher than those in the negative control group. Cell viability was reduced and apoptotic death was induced by aniline in a concentration-dependent manner. The phenomena of ROS generation, oxidative damage, loss of mitochondrial membrane potential, DNA damage and apoptosis could be prevented if ROS inhibitor NAC was added. ROS generation is involved in the loss of mitochondrial membrane potential and DNA injury, which may play a role in aniline-induced apoptosis in hepatocytes. Our study provides insight into the mechanism of aniline-induced toxicity and apoptosis of hepatocytes.

  19. The single-cell gel electrophoresis assay to determine apoptosis ...

    African Journals Online (AJOL)

    The aim of the present study was to determine if the pattern of DNA fragmentation determined by the single cell gel electrophoresis assay can be used to determine apoptosis induced by siRNA in Colo 320 cells. When the frequency of appearance of apoptotic cells following was observed over a period of time, there was a ...

  20. Radiation-induced apoptosis of chicken lymphocyte B-cell line DT40

    International Nuclear Information System (INIS)

    Furusawa, Y.; Aoki, M.; Takakura, K.

    2003-01-01

    Full text: Ionizing radiation causes lesions of DNA, cell cycle arrest, induced cell death, and apoptosis in the irradiated cells. Then it is easy to expect that those events would be increased in a cell line which is defective in DNA repair system. However, induction of apoptosis by irradiation takes so complicated process when the cells are defective of DNA repair system. Indeed by many recent studies it has been clarified that DNA repair gene is also concerned with apoptotic event and some study shows the contrary data. Thus, the relationship between the genetics of apoptosis and that of DNA repair is still unclear. In this study two kinds of DNA repair proteins, Rad54 and Ku70, were focused. Proteins of Rad54 and Ku70 have important role at two type of DNA repair systems called homologous recombination repair and non-homologous end joining repair, respectively. 4 phenotypes of DT40, parent type, ku70-/-, rad54-/- and ku70-/-/rad54-/- were used to study the radiation-induced apoptosis (Previous study shows that survival fraction of 4 phenotypes of DT40 is decreased in the cell line, in which DNA repair gene is defective). From the results in this study, two things are clarifies. One is that the dependence of apoptotic index on phenotypes is so different between at low dose and at high dose irradiation. The other is that Ku70 has effective role to induce apoptosis in DT40 irradiated with high dose X-rays

  1. Apoptosis and inflammation

    Directory of Open Access Journals (Sweden)

    C. Haanen

    1995-01-01

    Full Text Available During the last few decades it has been recognized that cell death is not the consequence of accidental injury, but is the expression of a cell suicide programme. Kerr et al. (1972 introduced the term apoptosis. This form of cell death is under the influence of hormones, growth factors and cytokines, which depending upon the receptors present on the target cells, may activate a genetically controlled cell elimination process. During apoptosis the cell membrane remains intact and the cell breaks into apoptotic bodies, which are phagocytosed. Apoptosis, in contrast to necrosis, is not harmful to the host and does not induce any inflammatory reaction. The principal event that leads to inflammatory disease is cell damage, induced by chemical/physical injury, anoxia or starvation. Cell damage means leakage of cell contents into the adjacent tissues, resulting in the capillary transmigration of granulocytes to the injured tissue. The accumulation of neutrophils and release of enzymes and oxygen radicals enhances the inflammatory reaction. Until now there has been little research into the factors controlling the accumulation and the tissue load of granulocytes and their histotoxic products in inflammatory processes. Neutrophil apoptosis may represent an important event in the control of intlamtnation. It has been assumed that granulocytes disintegrate to apoptotic bodies before their fragments are removed by local macrophages. Removal of neutrophils from the inflammatory site without release of granule contents is of paramount importance for cessation of inflammation. In conclusion, apoptotic cell death plays an important role in inflammatory processes and in the resolution of inflammatory reactions. The facts known at present should stimulate further research into the role of neutrophil, eosinophil and macrophage apoptosis in inflammatory diseases.

  2. LDL Receptor-Related Protein 1 Prevents Early Atherosclerosis by Limiting Lesional Apoptosis and Inflammatory Ly-6Chigh Monocytosis: Evidence that the Effects Are Not ApoE-Dependent

    Science.gov (United States)

    Yancey, Patricia G.; Ding, Yu; Fan, Daping; Blakemore, John L.; Zhang, Youmin; Ding, Lei; Zhang, Jiabao; Linton, MacRae F.; Fazio, Sergio

    2011-01-01

    Background We previously demonstrated that macrophage LRP1 deficiency increases atherosclerosis despite anti-atherogenic changes including decreased uptake of remnants and increased secretion of apoE. Thus, our objective was to determine whether the atheroprotective effects of LRP1 require interaction with apoE, one of its ligands with multiple beneficial effects. Methods and Results We examined atherosclerosis development in mice with specific deletion of macrophage LRP1 (apoE−/−MΦLRP1−/−) and in LDLR−/− mice reconstituted with apoE−/−MΦLRP1−/− bone marrow. The combined absence of apoE and LRP1 promoted atherogenesis more than did macrophage apoE deletion alone in both apoE-producing LDLR−/− (+88%) and apoE−/− mice (+163%). The lesions of both mouse models with apoE−/−LRP1−/− macrophages had increased macrophage content. In vitro, apoE and LRP1 additively inhibit macrophage apoptosis. Furthermore, there was excessive accumulation of apoptotic cells in lesions of both LDLR−/− (+110%) and apoE−/−MΦLRP1−/− mice (+252%). The apoptotic cell accumulation was partially due to decreased efferocytosis as the ratio of free to cell-associated apoptotic nuclei was 3.5-fold higher in lesions of apoE−/−MΦLRP1−/− versus apoE−/− mice. Lesion necrosis was also increased (6-fold) in apoE−/−MΦLRP1−/− versus apoE−/− mice. Compared to apoE−/− mice, the spleens of apoE−/−MΦLRP1−/− mice contained 1.6 – and 2.4 –fold more total and Ly6-Chigh monocytes. Finally, there were 3.6- and 2.4-fold increases in Ly6-Chigh and CCR2+ cells in lesions of apoE−/−MΦLRP1−/− versus apoE−/− mice, suggesting that accumulation of apoptotic cells enhances lesion development and macrophage content by promoting the recruitment of inflammatory monocytes. Conclusion LRP1 exerts anti-atherogenic effects via pathways independent of apoE involving macrophage apoptosis and monocyte recruitment. PMID:21730304

  3. On-site detection of Phytophthora spp.—single-stranded target DNA as the limiting factor to improve on-chip hybridization

    International Nuclear Information System (INIS)

    Schwenkbier, Lydia; Pollok, Sibyll; Popp, Jürgen; Weber, Karina; König, Stephan; Wagner, Stefan; Werres, Sabine; Weber, Jörg; Hentschel, Martin

    2014-01-01

    We report on a lab-on-a-chip approach for on-site detection of Phytophthora species that allows visual signal readout. The results demonstrate the significance of single-stranded DNA (ssDNA) generation in terms of improving the intensity of the hybridization signal and to improve the reliability of the method. Conventional PCR with subsequent heat denaturation, sodium hydroxide-based denaturation, lambda exonuclease digestion and two asymmetric PCR methods were investigated for the species P. fragariae, P. kernoviae, and P. ramorum. The positioning of the capture probe within the amplified yeast GTP-binding protein (YPT1) target DNA was also of interest because it significantly influences the intensity of the signal. Statistical tests were used to validate the impact of the ssDNA generation methods and the capture-target probe position. The single-stranded target DNA generated by Linear-After-The-Exponential PCR (LATE-PCR) was found to produce signal intensities comparable to post-PCR exonuclease treatment. The LATE-PCR is the best method for the on-site detection of Phytophthora because the enzymatic digestion after PCR is more laborious and time-consuming. (author)

  4. Inhibition of apoptosis by BCL2 prevents leukemic transformation of a murine myelodysplastic syndrome

    Science.gov (United States)

    Saw, Jesslyn; Jowett, Jeremy B. M.; Aplan, Peter D.; Strasser, Andreas; Jane, Stephen M.; Curtis, David J.

    2012-01-01

    Programmed cell death or apoptosis is a prominent feature of low-risk myelodysplastic syndromes (MDS), although the underlying mechanism remains controversial. High-risk MDS have less apoptosis associated with increased expression of the prosurvival BCL2-related proteins. To address the mechanism and pathogenic role of apoptosis and BCL2 expression in MDS, we used a mouse model resembling human MDS, in which the fusion protein NUP98-HOXD13 (NHD13) of the chromosomal translocation t(2;11)(q31;p15) is expressed in hematopoietic cells. Hematopoietic stem and progenitor cells from 3-month-old mice had increased rates of apoptosis associated with increased cell cycling and DNA damage. Gene expression profiling of these MDS progenitors revealed a specific reduction in Bcl2. Restoration of Bcl2 expression by a BCL2 transgene blocked apoptosis of the MDS progenitors, which corrected the macrocytic anemia. Blocking apoptosis also restored cell-cycle quiescence and reduced DNA damage in the MDS progenitors. We expected that preventing apoptosis would accelerate malignant transformation to acute myeloid leukemia (AML). However, contrary to expectations, preventing apoptosis of premalignant cells abrogated transformation to AML. In contrast to the current dogma that overcoming apoptosis is an important step toward cancer, this work demonstrates that gaining a survival advantage of premalignant cells may delay or prevent leukemic progression. PMID:22855610

  5. Fullerene and apoptosis

    Directory of Open Access Journals (Sweden)

    M. A. Orlova

    2013-01-01

    Full Text Available Fullerene derivatives superfamily attracts a serious attention as antiviral and anticancer agents and drug delivery carriers as well. A large number of such fullerene С60 derivatives obtained to date. However, there is an obvious deficit of information about causes and mechanisms of immediately and long-term consequences of their effects in vivo which is a true obstacle on the way leading to practical medical use of them. First, this concerns their impact on the proliferation, apoptosis and necrosis regulation. Fullerene nanoparticle functionalization type, their sizes and surface nanopathology are of great importance to further promoting of either cytoprotective or cytotoxic effects. This lecture provides modern concept analysis regarding fullerenes effects on apoptosis pathway in normal and tumor cells.

  6. Ancient DNA

    DEFF Research Database (Denmark)

    Willerslev, Eske; Cooper, Alan

    2004-01-01

    ancient DNA, palaeontology, palaeoecology, archaeology, population genetics, DNA damage and repair......ancient DNA, palaeontology, palaeoecology, archaeology, population genetics, DNA damage and repair...

  7. Hepatitis B viral DNA decline at loss of HBeAg is mainly explained by reduced cccDNA load--down-regulated transcription of PgRNA has limited impact.

    Science.gov (United States)

    Malmström, Sebastian; Larsson, Simon B; Hannoun, Charles; Lindh, Magnus

    2012-01-01

    Quantification of hepatitis B virus (HBV) DNA and surface antigen (HBsAg) serum levels have become increasingly important for the assessment of clinical stage and response to treatment for chronic hepatitis B. Effective immune clearance results in reduction of viremia by 4-5 log units and HBsAg levels by 2 log, but these processes are not well understood. Thus, it is uncertain to what extent mechanisms that inhibit transcription of the pregenomic RNA (pgRNA), an RNA intermediate, contribute to suppression of viremia. Likewise, it is unclear if transcriptional regulation is important for the excessive production of surface antigen (HBsAg) that is a hallmark of HBV infection. HBV RNA and cccDNA were quantified in 19 liver biopsies from patients with chronic HBV infection, as well as in transfected Huh7.5 cells and in PLC/PRF/5 cells carrying integrated HBV genome. Patients negative for HBeAg had 2.15 log lower levels of cccDNA in liver tissue, 4.84 log lower serum levels of HBV DNA and 1.45 log lower serum levels of HBsAg, than HBeAg-positive patients. The pgRNA in liver tissue correlated strongly with cccDNA (R(2) = 0.87, ploss of HBeAg was mainly explained by reduced cccDNA load in the liver, whereas the contribution of down-regulation of pgRNA transcription was relatively small. Enhanced transcription of S-RNA does not explain excessive production of HBsAg.

  8. Catalase inhibits ionizing radiation-induced apoptosis in hematopoietic stem and progenitor cells.

    Science.gov (United States)

    Xiao, Xia; Luo, Hongmei; Vanek, Kenneth N; LaRue, Amanda C; Schulte, Bradley A; Wang, Gavin Y

    2015-06-01

    Hematologic toxicity is a major cause of mortality in radiation emergency scenarios and a primary side effect concern in patients undergoing chemo-radiotherapy. Therefore, there is a critical need for the development of novel and more effective approaches to manage this side effect. Catalase is a potent antioxidant enzyme that coverts hydrogen peroxide into hydrogen and water. In this study, we evaluated the efficacy of catalase as a protectant against ionizing radiation (IR)-induced toxicity in hematopoietic stem and progenitor cells (HSPCs). The results revealed that catalase treatment markedly inhibits IR-induced apoptosis in murine hematopoietic stem cells and hematopoietic progenitor cells. Subsequent colony-forming cell and cobble-stone area-forming cell assays showed that catalase-treated HSPCs can not only survive irradiation-induced apoptosis but also have higher clonogenic capacity, compared with vehicle-treated cells. Moreover, transplantation of catalase-treated irradiated HSPCs results in high levels of multi-lineage and long-term engraftments, whereas vehicle-treated irradiated HSPCs exhibit very limited hematopoiesis reconstituting capacity. Mechanistically, catalase treatment attenuates IR-induced DNA double-strand breaks and inhibits reactive oxygen species. Unexpectedly, we found that the radioprotective effect of catalase is associated with activation of the signal transducer and activator of transcription 3 (STAT3) signaling pathway and pharmacological inhibition of STAT3 abolishes the protective activity of catalase, suggesting that catalase may protect HSPCs against IR-induced toxicity via promoting STAT3 activation. Collectively, these results demonstrate a previously unrecognized mechanism by which catalase inhibits IR-induced DNA damage and apoptosis in HSPCs.

  9. Ruthenium(II) Complexes as Potential Apoptosis Inducers in Chemotherapy.

    Science.gov (United States)

    Zheng, Kangdi; Wu, Qiong; Wang, Chengxi; Tan, Weijun; Mei, Wenjie

    2017-01-01

    Herein, the development of ruthenium complexes as potential apoptosis inducers, as well as their underlying mechanism has been reviewed. In recent years, various ruthenium complexes have been designed and their in vitro and in vivo inhibitory activities against various types of tumor cells have been evaluated extensively. It's demonstrated that ruthenium complexes can induce apoptosis of tumor cells through the signal pathway of mitochondria-mediated, death receptor-mediated, and/or endoplasmic reticulum (ER) stress pathways. Alternately, the binding behavior of these ruthenium(II) complexes with DNA, especially with Gquadruplex DNA may play a key role in the DNA damage of tumor cells, and thus provides a versatile tool to rational design novel ruthenium complexes with high activity and selectivity.

  10. Chronic Opium Treatment Can Differentially Induce Brain and Liver Cells Apoptosis in Diabetic and Non-diabetic Male and Female Rats

    OpenAIRE

    Asiabanha, Majid; Asadikaram, Gholamreza; Rahnema, Amir; Mahmoodi, Mehdi; Hasanshahi, Gholamhosein; Hashemi, Mohammad; Khaksari, Mohammad

    2011-01-01

    It has been shown that some opium derivatives promote cell death via apoptosis. This study was designed to examine the influence of opium addiction on brain and liver cells apoptosis in male and female diabetic and non-diabetic Wistar rats. This experimental study was performed on normal, opium-addicted, diabetic and diabetic opium-addicted male and female rats. Apoptosis was evaluated by TUNEL and DNA fragmentation assays. Results of this study showed that apoptosis in opium-addicted and dia...

  11. Systems biology approach identifies the kinase Csnk1a1 as a regulator of the DNA damage response in embryonic stem cells

    DEFF Research Database (Denmark)

    Carreras Puigvert, Jordi; von Stechow, Louise; Siddappa, Ramakrishnaiah

    2013-01-01

    damage repair, cell cycle and survival, and differentiation. Experimental probing of these networks identified a mode of DNA damage-induced Wnt signaling that limited apoptosis. Silencing or deleting the p53 gene demonstrated that genotoxic stress elicited Wnt signaling in a p53-independent manner....... Instead, this response occurred through reduced abundance of Csnk1a1 (CK1α), a kinase that inhibits β-catenin. Together, our findings reveal a balance between p53-mediated elimination of stem cells (through loss of pluripotency and apoptosis) and Wnt signaling that attenuates this response to tune...

  12. Apoptosis-associated markers in oral lichen planus.

    Science.gov (United States)

    Dekker, N P; Lozada-Nur, F; Lagenaur, L A; MacPhail, L A; Bloom, C Y; Regezi, J A

    1997-04-01

    Hypothesizing that loss of basal cells in oral lichen planus is due to apoptosis, we evaluated LP specimens for apoptosis-regulating proteins [positive regulators Bcl-xS, Bax, Fas/Fas-ligand, p53, and negative regulators (anti-apoptotic) Bcl-2, Bcl-xL and compared results with reactions in normal mucosa and chronically inflamed gingiva. Also, sections were evaluated with an in situ TUNEL assay that identifies apoptotic DNA fragments. Basal keratinocytes in normal buccal mucosa, nonspecific gingivitis, and LP were negative for Bcl-2 protein, but melanocytes and lymphoid cells were positive. Keratinocyte staining for Bcl-x was negative to weak in normal buccal mucosa and gingivitis, and moderate in LP. Keratinocytes (especially upper prickle cells) in all tissues stained similarly for Bax at weak to moderate levels. Also, no differences in Fas and Fas-ligand staining were evident. Prominent p53-positive staining was seen in all LP biopsies (10-100% of basal keratinocytes) but not in normal buccal mucosa and gingivitis. Few basal keratinocytes in 5/10 LP cases exhibited a positive in situ signal for DNA fragment-associated apoptosis. That the Bcl-2 family of proteins and Fas/Fas-ligand were detected in normal and diseased tissues, and were occasionally expressed differently in oral LP, supports the notion that apoptosis is a potential mechanism of keratinocyte loss, especially in LP. The pattern of p53 staining in oral LP suggests over-expression of wild-type protein; a phenomenon that would arrest the cell cycle to allow repair of damaged DNA, or trigger apoptosis. While immunohistochemical evidence for apoptosis-associated basal keratinocyte death in LP was slight, it appeared that it may be p53 protein, and possibly Bcl-x associated.

  13. The significance of intestinal apoptosis

    International Nuclear Information System (INIS)

    Potten, C.S.

    1997-01-01

    Apoptosis occurs at a low level spontaneously in the small intestine (SI). The levels can be raised by a variety of cytotoxic agents including radiation. The apoptosis induced by radiation, and some drugs and the spontaneous apoptosis, show some specificity for the stem cells in the small intestinal crypt. In the colon, these agents target transit cells in the mid crypt. p53 expression is elevated at the same time as apoptosis in the SI but not in the cells undergoing apoptosis. The expression of bcl-2, a survival gene, is largely absent in the SI, but is expressed, albeit weakly, in the stem cells in the colon. Spontaneous apoptosis is observed in p53 null mice which also develop normally suggesting that spontaneous and developmental apoptosis are p53 independent and that spontaneous apoptosis is part of the homeostatic mechanisms maintaining stem cell numbers. Radiation induced apoptosis is completely absent at these early times post-irradiation in p53 nulls. In bel-2 null mice, the levels of spontaneous and radiation induced apoptosis are elevated in the colon. Bax, a death gene, is expressed on the villus and inter-crypt table in the colon suggesting that cells at the end of their lifespan initiate apoptosis. It has been suggested that apoptosis in the SI is a protective mechanism against carcinogenesis in the stem cells of the SI which rarely develops cancer. Cells that possess genetic damage detected. In the large bowel, this mechanism is not effective due to the action of bcl-2. Thus stem cells may persist in this tissue with genetic damage resulting in a higher cancer risk. Furthermore, the lack of spontaneous apoptosis in the colon may result in a gradual increase of the stem cells with time resulting in more ells at risk. (author)

  14. A novel firefly luciferase biosensor enhances the detection of apoptosis induced by ESAT-6 family proteins of Mycobacterium tuberculosis

    International Nuclear Information System (INIS)

    Shi, Junwei; Zhang, Huan; Fang, Liurong; Xi, Yongqiang; Zhou, Yanrong; Luo, Rui; Wang, Dang; Xiao, Shaobo; Chen, Huanchun

    2014-01-01

    Highlights: • We developed a novel firefly luciferase based biosensor to detect apoptosis. • The novel biosensor 233-DnaE-DEVDG was reliable, sensitive and convenient. • 233-DnaE-DEVDG faithfully indicated ESAT-6 family proteins of Mycobacterium tuberculosis induced apoptosis. • EsxA, esxT and esxL in ESAT-6 family proteins induced apoptosis. • Activation of nuclear factor-κB (NF-κB) participated in esxT-induced apoptosis. - Abstract: The activation of caspase-3 is a key surrogate marker for detecting apoptosis. To quantitate caspase-3 activity, we constructed a biosensor comprising a recombinant firefly luciferase containing a caspase-3 cleavage site. When apoptosis was induced, caspase-3 cleavage of the biosensor activated firefly luciferase by a factor greater than 25. The assay conveniently detected apoptosis in real time, indicating that it will facilitate drug discovery. We screened ESAT-6 family proteins of Mycobacterium tuberculosis and found that esxA, esxT and esxL induced apoptosis. Further, activation of nuclear factor-κB (NF-κB) and the NF-κB-regulated genes encoding tumor necrosis factor-α (TNF-α) and tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) participated in esxT-induced apoptosis. We conclude that this assay is useful for high-throughput screening to identify and characterize proteins and drugs that regulate apoptosis

  15. A novel firefly luciferase biosensor enhances the detection of apoptosis induced by ESAT-6 family proteins of Mycobacterium tuberculosis

    Energy Technology Data Exchange (ETDEWEB)

    Shi, Junwei; Zhang, Huan; Fang, Liurong; Xi, Yongqiang; Zhou, Yanrong; Luo, Rui; Wang, Dang, E-mail: wangdang511@126.com; Xiao, Shaobo; Chen, Huanchun

    2014-10-03

    Highlights: • We developed a novel firefly luciferase based biosensor to detect apoptosis. • The novel biosensor 233-DnaE-DEVDG was reliable, sensitive and convenient. • 233-DnaE-DEVDG faithfully indicated ESAT-6 family proteins of Mycobacterium tuberculosis induced apoptosis. • EsxA, esxT and esxL in ESAT-6 family proteins induced apoptosis. • Activation of nuclear factor-κB (NF-κB) participated in esxT-induced apoptosis. - Abstract: The activation of caspase-3 is a key surrogate marker for detecting apoptosis. To quantitate caspase-3 activity, we constructed a biosensor comprising a recombinant firefly luciferase containing a caspase-3 cleavage site. When apoptosis was induced, caspase-3 cleavage of the biosensor activated firefly luciferase by a factor greater than 25. The assay conveniently detected apoptosis in real time, indicating that it will facilitate drug discovery. We screened ESAT-6 family proteins of Mycobacterium tuberculosis and found that esxA, esxT and esxL induced apoptosis. Further, activation of nuclear factor-κB (NF-κB) and the NF-κB-regulated genes encoding tumor necrosis factor-α (TNF-α) and tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) participated in esxT-induced apoptosis. We conclude that this assay is useful for high-throughput screening to identify and characterize proteins and drugs that regulate apoptosis.

  16. Spaceflight alters microtubules and increases apoptosis in human lymphocytes (Jurkat)

    Science.gov (United States)

    Lewis, M. L.; Reynolds, J. L.; Cubano, L. A.; Hatton, J. P.; Lawless, B. D.; Piepmeier, E. H.

    1998-01-01

    Alteration in cytoskeletal organization appears to underlie mechanisms of gravity sensitivity in space-flown cells. Human T lymphoblastoid cells (Jurkat) were flown on the Space Shuttle to test the hypothesis that growth responsiveness is associated with microtubule anomalies and mediated by apoptosis. Cell growth was stimulated in microgravity by increasing serum concentration. After 4 and 48 h, cells filtered from medium were fixed with formalin. Post-flight, confocal microscopy revealed diffuse, shortened microtubules extending from poorly defined microtubule organizing centers (MTOCs). In comparable ground controls, discrete microtubule filaments radiated from organized MTOCs and branched toward the cell membrane. At 4 h, 30% of flown, compared to 17% of ground, cells showed DNA condensation characteristic of apoptosis. Time-dependent increase of the apoptosis-associated Fas/ APO-1 protein in static flown, but not the in-flight 1 g centrifuged or ground controls, confirmed microgravity-associated apoptosis. By 48 h, ground cultures had increased by 40%. Flown populations did not increase, though some cells were cycling and actively metabolizing glucose. We conclude that cytoskeletal alteration, growth retardation, and metabolic changes in space-flown lymphocytes are concomitant with increased apoptosis and time-dependent elevation of Fas/APO-1 protein. We suggest that reduced growth response in lymphocytes during spaceflight is linked to apoptosis.

  17. Does atorvastatin induce aortic smooth muscle cell apoptosis in vivo?

    Science.gov (United States)

    Doyon, Marielle; Hale, Taben Mary; Huot-Marchand, Julie-Emilie; Wu, Rong; de Champlain, Jacques; DeBlois, Denis

    2011-01-01

    It has been reported that HMG-CoA reductase inhibitors such as atorvastatin induce vascular smooth muscle cell (SMC) apoptosis in vitro. However, this effect remains to be demonstrated in vivo. The present studies were designed to test the ability of atorvastatin to induce SMC apoptosis in vivo, using the spontaneously hypertensive rat (SHR) as a well-known reference model of SMC apoptosis induction in vivo by cardiovascular drugs including the calcium channel blocker amlodipine. Atorvastatin was administered to SHR for 3 or 6 weeks either alone or together with amlodipine, a drug combination clinically available to patients. Primary endpoints included aortic medial hypertrophy and aortic SMC hyperplasia, internucleosomal DNA fragmentation and expression of the apoptosis regulatory proteins Bax and Bcl-2. The SHR aorta showed no evidence of SMC apoptosis induction by atorvastatin, even at the high dose of 50 mg kg(-1) day(-1), although the statin significantly reduced oxidative stress after 3 weeks and blood pressure after 6 weeks of administration. Amlodipine-induced regression of aortic hypertophy and aortic SMC hyperplasia were dose- and time-dependent, but there was no interaction between atorvastatin and amlodipine in modulating the primary endpoints. These results do not support the notion that atorvastatin induces SMC apoptosis in the aortic media in vivo. Copyright © 2010. Published by Elsevier Inc.

  18. Effect of pH on radiation-induced apoptosis

    International Nuclear Information System (INIS)

    Chang, W. Song; Park, Heon J.; Lyons, John C.; Auger, Elizabeth A.; Lee, Hyung-Sik

    1996-01-01

    Purpose/Objective: The effect of environmental pH on the radiation-induced apoptosis in tumor cells in vitro was investigated. Materials and Methods: SCK mammary adenocarcinoma cells of A/J mice were irradiated with γ-rays using a 137 Cs irradiator and incubated in media of different pHs. After incubation at 37 degree sign C for 24-120 hrs., the extent of apoptosis was determined using agarose gel electrophoresis of DNA, in situ TUNEL staining, flow cytometry, and release of 3 H from 3 H-thymidine labeled cells. The membrane integrity, using the trypan blue exclusion method, and the clonogenicity of the cells were also determined. Results: Irradiation with 2-12 Gy of γ-rays induced apoptosis in pH 7.5 medium within 48 hrs. The radiation-induced apoptosis progressively declined as the medium pH was lowered so that little apoptosis occurred in 48 hrs. after irradiation with 12 Gy in pH 6.6 medium. However, when the cells were irradiated and incubated for 48 hrs. in pH 6.6 medium and then medium was replaced with pH 7.5 medium, apoptosis promptly occurred. Apoptosis also occurred even in pH 6.6 medium when the cells were irradiated and maintained in pH 7.5 medium for 8 hrs. or longer post-irradiation before incubation in pH 6.6 medium. Conclusion: An acidic environment markedly suppresses radiation-induced apoptosis probably by suppressing the expression of initial signals responsible for irradiation-induced apoptosis. Indications are that the signals persist in an acidic environment and trigger apoptosis when the environmental acidity is eased. Our results suggest that the acidic environment in human tumors may inhibit the apoptosis after irradiation. However, apoptosis may be triggered when reoxygenation occurs after irradiation, and thus, the intratumor environment becomes less acidic after irradiation. Not only the change in pO 2 but the change in pH during the course of fractionated radiotherapy may greatly influence the outcome of the treatment

  19. Butyrate down regulates BCL-XL and sensitizes human fibroblasts to radiation and chemotherapy induced apoptosis

    International Nuclear Information System (INIS)

    Chung, Diana H.; Ljungman, Mats; Zhang Fenfen; Chen Feng; McLaughlin, William P.

    1997-01-01

    Purpose/Objective: Butyrate is a short chain fatty acid that has been implicated in the induction of cell cycle arrest, cell differentiation and apoptosis. The purpose of this study was to determine if butyrate treatment sensitizes cells to radiation or chemotherapy induced apoptosis. Materials and Methods: Normal neonatal human diploid fibroblasts were used throughout this study. Apoptosis was scored and quantified using three different methods. First, cell morphology using propidium iodide and fluorescence microscopy was used to qualitatively determine apoptosis and to quantify the percentage of cells undergoing apoptosis. Second, apoptosis induced DNA degradation was scored by quantifying the amount of cells appearing in a sub-G1 peak using fixed and PI-stained cells and flow cytometry. Third, apoptosis-induced DNA degradation was examined by using an assay involving direct lysis of cells in the wells of agarose gels followed by conventional gel electrophoresis. Western blotting was used to quantify the cellular levels of the apoptosis regulators, Bcl-2, Bcl-XL and Bax. Results: Human diploid fibroblasts, which were resistant to radiation induced apoptosis, were found to undergo massive apoptosis when radiation was combined with butyrate treatment. Sensitization was obtained when butyrate was added before or after radiation although the combination of both pre and post-treatment was the most effective. Butyrate was also found to enhance UV light and cisplatin-induced apoptosis. These findings correlated with a reduction of the apoptosis antagonist Bcl-XL. Bcl-XL levels significantly dropped in a time and dose dependent manner. In addition, butyrate effectively blocked UV-induced accumulation of p53. Conclusion: Our results suggest that butyrate may be an attractive agent to use in combination with radiation or chemotherapy to lower the apoptotic threshold of tumor cells, regardless of the p53 status of the tumor cells

  20. A review and appraisal of the DNA damage theory of ageing.

    Science.gov (United States)

    Freitas, Alex A; de Magalhães, João Pedro

    2011-01-01

    Given the central role of DNA in life, and how ageing can be seen as the gradual and irreversible breakdown of living systems, the idea that damage to the DNA is the crucial cause of ageing remains a powerful one. DNA damage and mutations of different types clearly accumulate with age in mammalian tissues. Human progeroid syndromes resulting in what appears to be accelerated ageing have been linked to defects in DNA repair or processing, suggesting that elevated levels of DNA damage can accelerate physiological decline and the development of age-related diseases not limited to cancer. Higher DNA damage may trigger cellular signalling pathways, such as apoptosis, that result in a faster depletion of stem cells, which in turn contributes to accelerated ageing. Genetic manipulations of DNA repair pathways in mice further strengthen this view and also indicate that disruption of specific pathways, such as nucleotide excision repair and non-homologous end joining, is more strongly associated with premature ageing phenotypes. Delaying ageing in mice by decreasing levels of DNA damage, however, has not been achieved yet, perhaps due to the complexity inherent to DNA repair and DNA damage response pathways. Another open question is whether DNA repair optimization is involved in the evolution of species longevity, and we suggest that the way cells from different organisms respond to DNA damage may be crucial in species differences in ageing. Taken together, the data suggest a major role of DNA damage in the modulation of longevity, possibly through effects on cell dysfunction and loss, although understanding how to modify DNA damage repair and response systems to delay ageing remains a crucial challenge. Copyright © 2011 Elsevier B.V. All rights reserved.

  1. ex vivo DNA assembly

    Directory of Open Access Journals (Sweden)

    Adam B Fisher

    2013-10-01

    Full Text Available Even with decreasing DNA synthesis costs there remains a need for inexpensive, rapid and reliable methods for assembling synthetic DNA into larger constructs or combinatorial libraries. Advances in cloning techniques have resulted in powerful in vitro and in vivo assembly of DNA. However, monetary and time costs have limited these approaches. Here, we report an ex vivo DNA assembly method that uses cellular lysates derived from a commonly used laboratory strain of Escherichia coli for joining double-stranded DNA with short end homologies embedded within inexpensive primers. This method concurrently shortens the time and decreases costs associated with current DNA assembly methods.

  2. Knockdown of HIF-1α and IL-8 induced apoptosis of hepatocellular carcinoma triggers apoptosis of vascular endothelial cells.

    Science.gov (United States)

    Choi, Sung Hoon; Park, Jun Yong; Kang, Wonseok; Kim, Seung Up; Kim, Do Young; Ahn, Sang Hoon; Ro, Simon Wonsang; Han, Kwang-Hyub

    2016-01-01

    A local hypoxic microenvironment is one of the most important characteristics of solid tumors. Hypoxia inducible factor-1α (HIF-1α) and Interleukin-8 (IL-8) activate tumor survival from hypoxic-induced apoptosis in each pathway. This study aimed to evaluate whether knockdown of HIF-1α and IL-8 induced apoptosis of the hepatocellular carcinoma (HCC) and endothelial cell lines. HCC cell lines were infected with adenovirus-expressing shRNA for HIF-1α and IL-8 and maintained under hypoxic conditions (1% O2, 24 h). The expression levels of HIF-1α and both apoptotic and growth factors were examined by real-time quantitative PCR and western blot. We also investigated apoptosis by TUNEL assay (FACS and Immunofluorescence) and measured the concentration of cytochrome C. Inhibition of HIF-1α and IL-8 up-regulated the expression of apoptotic factors while downregulating anti-apoptotic factors simultaneously. Knockdown of HIF-1α and IL-8 increased the concentration of cytochrome C and enhanced DNA fragmentation in HCC cell lines. Moreover, culture supernatant collected from the knockdown of HIF-1α and IL-8 in HCC cell lines induced apoptosis in human umbilical vein endothelial cells under hypoxia, and the expression of variable apoptotic ligand increased from HCC cell lines, time-dependently. These data suggest that adenovirus-mediated knockdown of HIF-1α and IL-8 induced apoptosis in HCC cells and triggered apoptosis of vascular endothelial cells.

  3. DNA binding and photocleavage properties and apoptosis-inducing activities of a ruthenium porphyrin complex [(Py-3')TPP-Ru(phen)2Cl]Cl and its heterometallic derivatives.

    Science.gov (United States)

    Liu, Yanan; Chen, Tianfeng; Wong, Yum-Shing; Mei, Wen-Jie; Huang, Xiao-Mei; Yang, Fang; Liu, Jie; Zheng, Wen-Jie

    2010-02-12

    The interactions of a ruthenium porphyrin complex [(Py-3')TPP-Ru(phen)(2)Cl]Cl (phen=1,10-phenanthroline, (Py-3')TPP=5-(3'-pyridyl-10,15,20-triphenylporphyrin) (1) and its heterometallic derivatives, [Ni(Py-3')TPP-Ru(phen)(2)Cl][PF(6)] (2) and [Cu(Py-3')TPP-Ru(phen)(2)Cl][PF(6)] (3), with calf thymus DNA have been investigated by spectroscopic and viscosity measurements in this study. The results showed that these synthetic complexes can bind to double strand helix DNA in groove binding mode, and the intrinsic binding constants of complexes 1, 2 and 3, as calculated according to the decay of the Soret absorption, are (1.35+/-0.5) x10(5)M(-1) (s=4.2), (1.29+/-0.5)x10(5)M(-1) (s=5.6) and (1.22+/-0.5)x10(5)M(-1) (s=6.2) (s is the binding-site size), respectively, which are consistent with those obtained from ethidium bromide-quenching experiments. Further investigations on the photocleavage properties of these complexes on plasmid pBR 322 DNA showed that complexes 1, 2 and 3 could cleave single chain DNA and convert DNA molecules from supercoiled form to the nicked form. As determined by MTT assay, the complexes were also identified as potent antiproliferative agents against A375 human melanoma cells, MCF-7 human breast adrenocarcinoma cells, Colo201 human colon adenocarcinoma cells and HepG2 human liver cancer cells. Complex 1 inhibits the growth of A375 cells through induction of apoptotic cell death and G0/G1 cell cycle arrest. Further investigation on intracellular mechanisms indicated that Complex 1 induced depletion of mitochondrial membrane potential (DeltaPsi(m)) in A375 cells through regulating the expression of pro-survival and pro-apoptotic Bcl-2 family members. Our results suggest that ruthenium porphyrin complexes could be candidates for further evaluation as chemopreventive and chemotherapeutic agents for human cancers. Copyright (c) 2009 Elsevier Ireland Ltd. All rights reserved.

  4. Influence of Proton and Salt Concentration on the Chromonic Liquid Crystal Phase Diagram of Disodium Cromoglycate Solutions: Prospects and Limitations of a Host for DNA Nanostructures.

    Science.gov (United States)

    Zhang, Bingru; Kitzerow, Heinz-S

    2016-03-31

    Lyotropic chromonic liquid crystals have recently been suggested for use as a self-organized host for dispersing and aligning self-organized DNA origami nanostructures. However, an appropriate pH value and a suitable cation concentration are necessary to stabilize such nanostructures and to avoid unfolding of the DNA. The present study shows that the nematic and columnar liquid crystal phases appearing in aqueous solutions of disodium cromoglycate are robust against the replacement of deionized water by a neutral or alkaline buffer solution. However, disodium cromoglycate precipitates when an acidic buffer is used or when the concentration of magnesium cations exceeds a critical concentration of about 0.6-0.7 mmol/L.

  5. Avenanthramides Prevent Osteoblast and Osteocyte Apoptosis and Induce Osteoclast Apoptosis in Vitro in an Nrf2-Independent Manner

    Science.gov (United States)

    Pellegrini, Gretel G.; Morales, Cynthya C.; Wallace, Taylor C.; Plotkin, Lilian I.; Bellido, Teresita

    2016-01-01

    Oats contain unique bioactive compounds known as avenanthramides (AVAs) with antioxidant properties. AVAs might enhance the endogenous antioxidant cellular response by activation of the transcription factor Nrf2. Accumulation of reactive oxygen species plays a critical role in many chronic and degenerative diseases, including osteoporosis. In this disease, there is an imbalance between bone formation by osteoblasts and bone resorption by osteoclasts, which is accompanied by increased osteoblast/osteocyte apoptosis and decreased osteoclast apoptosis. We investigated the ability of the synthethic AVAs 2c, 2f and 2p, to 1-regulate gene expression in bone cells, 2-affect the viability of osteoblasts, osteocytes and osteoclasts, and the generation of osteoclasts from their precursors, and 3-examine the potential involvement of the transcription factor Nrf2 in these actions. All doses of AVA 2c and 1 and 5 µM dose of 2p up-regulated collagen 1A expression. Lower doses of AVAs up-regulated OPG (osteoprotegerin) in OB-6 osteoblastic cells, whereas 100 μM dose of 2f and all concentrations of 2c down-regulated RANKL gene expression in MLO-Y4 osteocytic cells. AVAs did not affect apoptosis of OB-6 osteoblastic cells or MLO-Y4 osteocytic cells; however, they prevented apoptosis induced by the DNA topoisomerase inhibitor etoposide, the glucocorticoid dexamethasone, and hydrogen peroxide. AVAs prevented apoptosis of both wild type (WT) and Nrf2 Knockout (KO) osteoblasts, demonstrating that AVAs-induced survival does not require Nrf2 expression. Further, KO osteoclast precursors produced more mature osteoclasts than WT; and KO cultures exhibited less apoptotic osteoclasts than WT cultures. Although AVAs did not affect WT osteoclasts, AVA 2p reversed the low apoptosis of KO osteoclasts. These in vitro results demonstrate that AVAs regulate, in part, the function of osteoblasts and osteocytes and prevent osteoblast/osteocyte apoptosis and increase osteoclast apoptosis; further

  6. Avenanthramides Prevent Osteoblast and Osteocyte Apoptosis and Induce Osteoclast Apoptosis in Vitro in an Nrf2-Independent Manner

    Directory of Open Access Journals (Sweden)

    Gretel G. Pellegrini

    2016-07-01

    Full Text Available Oats contain unique bioactive compounds known as avenanthramides (AVAs with antioxidant properties. AVAs might enhance the endogenous antioxidant cellular response by activation of the transcription factor Nrf2. Accumulation of reactive oxygen species plays a critical role in many chronic and degenerative diseases, including osteoporosis. In this disease, there is an imbalance between bone formation by osteoblasts and bone resorption by osteoclasts, which is accompanied by increased osteoblast/osteocyte apoptosis and decreased osteoclast apoptosis. We investigated the ability of the synthethic AVAs 2c, 2f and 2p, to 1-regulate gene expression in bone cells, 2-affect the viability of osteoblasts, osteocytes and osteoclasts, and the generation of osteoclasts from their precursors, and 3-examine the potential involvement of the transcription factor Nrf2 in these actions. All doses of AVA 2c and 1 and 5 µM dose of 2p up-regulated collagen 1A expression. Lower doses of AVAs up-regulated OPG (osteoprotegerin in OB-6 osteoblastic cells, whereas 100 μM dose of 2f and all concentrations of 2c down-regulated RANKL gene expression in MLO-Y4 osteocytic cells. AVAs did not affect apoptosis of OB-6 osteoblastic cells or MLO-Y4 osteocytic cells; however, they prevented apoptosis induced by the DNA topoisomerase inhibitor etoposide, the glucocorticoid dexamethasone, and hydrogen peroxide. AVAs prevented apoptosis of both wild type (WT and Nrf2 Knockout (KO osteoblasts, demonstrating that AVAs-induced survival does not require Nrf2 expression. Further, KO osteoclast precursors produced more mature osteoclasts than WT; and KO cultures exhibited less apoptotic osteoclasts than WT cultures. Although AVAs did not affect WT osteoclasts, AVA 2p reversed the low apoptosis of KO osteoclasts. These in vitro results demonstrate that AVAs regulate, in part, the function of osteoblasts and osteocytes and prevent osteoblast/osteocyte apoptosis and increase osteoclast

  7. THE LIMITS OF DNA TESTING USED AS EVIDENCE IN COURT. A REPORT BASED ON THE PRACTICE OF THE INSTITUTE OF LEGAL MEDICINE CLUJ-NAPOCA

    OpenAIRE

    Dan Perju-Dumbrava,; Ioana Mic; Ovidiu Sorin Chiroban

    2013-01-01

    The evaluation of the evidentiary value of scientific evidence is the assessment of thestrength of the link between a finding and a person. It is usually a statisticalassessment but its presentation is full of pitfalls. The evaluation of scientific evidencemust be based on an established methodology to both evaluate, expose and interpretthe evidence. The formidable expansion in the use of DNA has not only increased theextent of interaction between forensic scientists and lawyers but more impo...

  8. Structure of the Tetrameric p53 Tumor Suppressor Bound to DNA

    National Research Council Canada - National Science Library

    Marmorstein, Ronen

    2002-01-01

    The p53 tumor suppressor binds DNA as a tetramer to regulate the transcription of genes involved in cell cycle arrest and apoptosis, and alterations in the DNA-binding core domain of p53 are the most...

  9. DNA damage assessment by visualization and quantification of DNA damage response

    International Nuclear Information System (INIS)

    Matsuda, Shun; Matsuda, Tomonari; Ikura, Tsuyoshi

    2017-01-01

    DNA damage response (DDR) carries out signal transduction for DNA repair, activation of cell cycle checkpoint, and apoptosis to maintain genome integrity, in response to DNA damage. Many proteins and their post-translational modifications participate in the process. Especially, S139-phosphorylated histone H2AX (γH2AX), which is formed by DNA double-strand breaks (DSBs), is an important factor to bring and retain other DDR proteins to DSB sites, Thus, γH2AX is used as a good indicator of DSBs in clinical study and pharmacology for efficacy evaluation of chemotherapy and radiotherapy, detection of precancerous regions, and others. In regulatory science, γH2AX is also a useful biomarker of genotoxicity of chemicals, since a wide range of genotoxic chemicals induce γH2AX. However, conventional detection methods of γH2AX absolutely require anti-γH2AX antibody whose staining is burdensome and time-consuming, and some of these methods are not so superior in quantitativity. In this review, we introduce two new methods to overcome these limitations, involving an easy-to-use genotoxicity assay using DDR-visualizing cells and an absolute quantification method of γH2AX using liquid chromatography-tandem mass spectrometry (LC/MS/MS). (author)

  10. Reassessing apoptosis in plants.

    Science.gov (United States)

    Dickman, Martin; Williams, Brett; Li, Yurong; de Figueiredo, Paul; Wolpert, Thomas

    2017-10-01

    Cell death can be driven by a genetically programmed signalling pathway known as programmed cell death (PCD). In plants, PCD occurs during development as well as in response to environmental and biotic stimuli. Our understanding of PCD regulation in plants has advanced significantly over the past two decades; however, the molecular machinery responsible for driving the system remains elusive. Thus, whether conserved PCD regulatory mechanisms include plant apoptosis remains enigmatic. Animal apoptotic regulators, including Bcl-2 family members, have not been identified in plants but expression of such regulators can trigger or suppress plant PCD. Moreover, plants exhibit nearly all of the biochemical and morphological features of apoptosis. One difference between plant and animal PCD is the absence of phagocytosis in plants. Evidence is emerging that the vacuole may be key to removal of unwanted plant cells, and may carry out functions that are analogous to animal phagocytosis. Here, we provide context for the argument that apoptotic-like cell death occurs in plants.

  11. Study of progesterone mechanisms in radio-induced apoptosis prevention

    International Nuclear Information System (INIS)

    Vares, G.

    2004-10-01

    The purpose of this work was to study the modulation of radiation-induced cell death of human mammary tumoral cells by progesterone. On the one hand, we observed that progesterone protects cells against radiation-induced apoptosis and increases the proportion of surviving and proliferating damaged cells. On the other hand, a transcriptome analysis was undertaken in irradiated cells treated by progesterone, using DNA micro-arrays. This let us highlight several transcriptional dis-regulations that are likely to explain the protective effect of the hormone; in particular, we showed that progesterone regulates the expression of genes implicated in apoptosis signaling by death receptors. Knowing the crucial role of hormonal control and of apoptosis regulation in breast cancer initiation, our results may help to achieve a better understanding of the implication of progesterone in mammary carcinogenesis. (author)

  12. Cardiovascular molecular imaging of apoptosis

    International Nuclear Information System (INIS)

    Wolters, S.L.; Reutelingsperger, C.P.M.; Corsten, M.F.; Hofstra, L.; Narula, J.

    2007-01-01

    Molecular imaging strives to visualise processes at the molecular and cellular level in vivo. Understanding these processes supports diagnosis and evaluation of therapeutic efficacy on an individual basis and thereby makes personalised medicine possible. Apoptosis is a well-organised mode of cell suicide that plays a role in cardiovascular diseases (CVD). Apoptosis is associated with loss of cardiomyocytes following myocardial infarction, atherosclerotic plaque instability, congestive heart failure and allograft rejection of the transplanted heart. Thus, apoptosis constitutes an attractive target for molecular imaging of CVD. Our current knowledge about the molecular players and mechanisms underlying apoptosis offers a rich palette of potential molecular targets for molecular imaging. However, only a few have been successfully developed so far. This review highlights aspects of the molecular machinery and biochemistry of apoptosis relevant to the development of molecular imaging probes. It surveys the role of apoptosis in four major areas of CVD and portrays the importance and future perspectives of apoptosis imaging. The annexin A5 imaging protocol is emphasised since it is the most advanced protocol to measure apoptosis in both preclinical and clinical studies. (orig.)

  13. Cardiovascular molecular imaging of apoptosis

    Energy Technology Data Exchange (ETDEWEB)

    Wolters, S.L.; Reutelingsperger, C.P.M. [Maastricht University, Department of Biochemistry, Cardiovascular Research Institute Maastricht, Maastricht (Netherlands); Corsten, M.F.; Hofstra, L. [Maastricht University, Department of Cardiology, Cardiovascular Research Institute Maastricht, P.O. Box 616, Maastricht (Netherlands); Narula, J. [University of California Irvine, Department of Cardiology, Irvine (United States)

    2007-06-15

    Molecular imaging strives to visualise processes at the molecular and cellular level in vivo. Understanding these processes supports diagnosis and evaluation of therapeutic efficacy on an individual basis and thereby makes personalised medicine possible. Apoptosis is a well-organised mode of cell suicide that plays a role in cardiovascular diseases (CVD). Apoptosis is associated with loss of cardiomyocytes following myocardial infarction, atherosclerotic plaque instability, congestive heart failure and allograft rejection of the transplanted heart. Thus, apoptosis constitutes an attractive target for molecular imaging of CVD. Our current knowledge about the molecular players and mechanisms underlying apoptosis offers a rich palette of potential molecular targets for molecular imaging. However, only a few have been successfully developed so far. This review highlights aspects of the molecular machinery and biochemistry of apoptosis relevant to the development of molecular imaging probes. It surveys the role of apoptosis in four major areas of CVD and portrays the importance and future perspectives of apoptosis imaging. The annexin A5 imaging protocol is emphasised since it is the most advanced protocol to measure apoptosis in both preclinical and clinical studies. (orig.)

  14. Induction of apoptosis by eugenol in human breast cancer cells

    International Nuclear Information System (INIS)

    Vidhya, N.; Niranjali Devaraj, S.

    2011-01-01

    In the present study, potential anticancer effect of eugenol on inhibition of cell proliferation and induction of apoptosis in human MCF-7 breast cancer cells was investigated. Induction of cell death by eugenol was evaluated following MTT assay and monitoring lactate dehydrogenase released into the culture medium for cell viability and cytotoxicity, giemsa staining for morphological alterations, fluorescence microscopy analysis of cells using ethidium bromide and acridine orange and quantitation of DNA fragments for induction of apoptosis. Effect of eugenol on intracellular redox status of the human breast cancer cells was assessed by determining the level of glutathione and lipid peroxidation products (TBARS). Eugenol treatment inhibited the growth and proliferation of human MCF-7 breast cancer cells through induction of cell death, which was dose and time dependent. Microscopic examination of eugenol treated cells showed cell shrinkage, membrane blebbing and apoptotic body formation. Further, eugenol treatment also depleted the level of intracellular glutathione and increased the level of lipid peroxidation. The dose dependent increase in the percentage of apoptotic cells and DNA fragments suggested that apoptosis was involved in eugenol induced cell death and apoptosis might have played a role in the chemopreventive action of eugenol. (author)

  15. Prenatal irradiation: radioinduced apoptosis in developing central nervous system

    International Nuclear Information System (INIS)

    Gisone, P.; Dubner, D.; Michelin, S.; Perez, M.R.; Barboza, M.

    1998-01-01

    Severe mental retardation (SMR) is the most significant effect of prenatal irradiation. The high radiosensitivity of developing brain is related with the chronology of morpho genetic phenomena regarding neuroblast proliferation, neuronal differentiation and migration, synaptogenesis and dendritic arborization. Programmed cell death (apoptosis) normally occurs during development in central nervous system (CNS). Apoptosis is a direct result of the expression of specific genes with a final common pathway leading to a characteristic DNA fragmentation pattern. A wide variety of situations and toxic agents have been reported to result in apoptotic death in developing CNS. The aim of this work was the characterization and quantification of apoptosis using an in vitro model of prenatal irradiation. Primary cell cultures from rat brain cortex of 17 days g.a. were irradiated with a gamma source, with doses between 0.2 Gy to 2 Gy. Apoptosis was evaluated 4 hours and 20 hours after irradiation by hematoxylin/eosin, fluorescent microscopy, flow cytometry and DNA electrophoresis. It was also evaluated the neuro protective effect of L-NAME, SOD and glutathion. A dose-dependent increase in apoptotic cell fraction was observed. A protector effect related with the presence of glutathion was observed. (author) [es

  16. Involvement of the Extrinsic and Intrinsic Pathways in Ultraviolet B-Induced Apoptosis of Corneal Epithelial Cells

    Science.gov (United States)

    Ubels, John L.; Glupker, Courtney D.; Schotanus, Mark P.; Haarsma, Loren D.

    2015-01-01

    The goal of this study was to elucidate the pathway by which UVB initiates efflux of K+ and subsequently apoptosis in human corneal limbal epithelial (HCLE) cells. The initial focus of the study was on the extrinsic pathway involving Fas. HCLE cells transfected with Fas siRNA were exposed to 80–150 mJ/cm2 UVB and incubated in culture medium with 5.5 mM K+. Knock down of Fas resulted in limited reduction in UVB-induced caspase-8 and -3 activity. Patch-clamp recordings showed no difference in UVB-induced normalized K+ currents between Fas transfected and control cells. Knockdown of caspase-8 had no effect on the activation of caspase-3 following UVB exposure, while a caspase-8 inhibitor completely eliminated UVB activation of caspase-3. This suggests that caspase-8 is a robust enzyme, able to activate caspase-3 via residual caspase-8 present after knockdown, and that caspase-8 is directly involved in the UVB activation of caspase-3. Inhibition of caspase-9 significantly decreased the activation of caspases-8 and -3 in response to UVB. Knockdown of Apaf-1, required for activation of caspase-9, resulted in a significant reduction in UVB-induced activation of caspases-9, -8, and -3. Knockdown of Apaf-1 also inhibited intrinsic and UVB-induced levels of apoptosis, as determined by DNA fragmentation measured by TUNEL assay. In UVB exposed cultures treated with caspase-3 inhibitor, the percentage of apoptotic cells was reduced to control levels, confirming the necessity of caspase-3 activation in DNA fragmentation. The lack of effect of Fas knockdown on K+ channel activation, as well as the limited effect on activation of caspases-8 and -3, strongly suggest that Fas and the extrinsic pathway is not of primary importance in the initiation of apoptosis in response to UVB in HCLE cells. Inhibition of caspase-8 and -3 activation following inhibition of caspase-9, as well as reduction in activation of caspases-9, -8, and -3 and DNA fragmentation in response to Apaf-1

  17. Thymocyte apoptosis induced by p53-dependent and independent pathways

    Energy Technology Data Exchange (ETDEWEB)

    Clarke, A.R.; Purdie, C.A.; Harrison, D.J.; Morris, R.G.; Bird, C.C.; Hooper, M.L.; Wyllie, A.H. (Edinburgh Univ. Medical School (United Kingdom). Dept. of Pathology)

    1993-04-29

    The authors studied the dependence of apoptosis on p53 expression in cells from the thymus cortex. Short-term thymocyte cultures were prepared from mice constitutively heterozygous or homozygous for a deletion in the p53 gene introduced into the germ line after gene targeting. Wild-type thymocytes readily undergo apoptosis after treatment with ionizing radiation, the glucocorticoid methylprednisolone, or etoposide (an inhibitor of topoisomerase II), or after Ca[sup 2+]-dependent activation by phorbol ester and a calcium ionophore. In contrast, homozygous null p53 thymocytes are resistant to induction of apoptosis by radiation or etoposide, but retain normal sensitivity to glucocorticoid and calcium. The time- dependent apoptosis that occurs in untreated cultures is unaffected by p53 status. Cells heterozygous for p53 deletion are partially resistant to radiation and etoposide. Results show that p53 exerts a significant and dose-dependent effect in the initiation of apoptosis, but only when it is induced by agents that cause DNA-strand breakage. (Author).

  18. ARF and ATM/ATR cooperate in p53-mediated apoptosis upon oncogenic stress

    International Nuclear Information System (INIS)

    Pauklin, Siim; Kristjuhan, Arnold; Maimets, Toivo; Jaks, Viljar

    2005-01-01

    Induction of apoptosis is pivotal for eliminating cells with damaged DNA or deregulated proliferation. We show that tumor suppressor ARF and ATM/ATR kinase pathways cooperate in the induction of apoptosis in response to elevated expression of c-myc, β-catenin or human papilloma virus E7 oncogenes. Overexpression of oncogenes leads to the formation of phosphorylated H2AX foci, induction of Rad51 protein levels and ATM/ATR-dependent phosphorylation of p53. Inhibition of ATM/ATR kinases abolishes both induction of Rad51 and phosphorylation of p53, and remarkably reduces the level of apoptosis induced by co-expression of oncogenes and ARF. However, the induction of apoptosis is downregulated in p53-/- cells and does not depend on activities of ATM/ATR kinases, indicating that efficient induction of apoptosis by oncogene activation depends on coordinated action of ARF and ATM/ATR pathways in the regulation of p53

  19. ATR-p53 restricts homologous recombination in response to replicative stress but does not limit DNA interstrand crosslink repair in lung cancer cells.

    Directory of Open Access Journals (Sweden)

    Bianca M Sirbu

    Full Text Available Homologous recombination (HR is required for the restart of collapsed DNA replication forks and error-free repair of DNA double-strand breaks (DSB. However, unscheduled or hyperactive HR may lead to genomic instability and promote cancer development. The cellular factors that restrict HR processes in mammalian cells are only beginning to be elucidated. The tumor suppressor p53 has been implicated in the suppression of HR though it has remained unclear why p53, as the guardian of the genome, would impair an error-free repair process. Here, we show for the first time that p53 downregulates foci formation of the RAD51 recombinase in response to replicative stress in H1299 lung cancer cells in a manner that is independent of its role as a transcription factor. We find that this downregulation of HR is not only completely dependent on the binding site of p53 with replication protein A but also the ATR/ATM serine 15 phosphorylation site. Genetic analysis suggests that ATR but not ATM kinase modulates p53's function in HR. The suppression of HR by p53 can be bypassed under experimental conditions that cause DSB either directly or indirectly, in line with p53's role as a guardian of the genome. As a result, transactivation-inactive p53 does not compromise the resistance of H1299 cells to the interstrand crosslinking agent mitomycin C. Altogether, our data support a model in which p53 plays an anti-recombinogenic role in the ATR-dependent mammalian replication checkpoint but does not impair a cell's ability to use HR for the removal of DSB induced by cytotoxic agents.

  20. Contrast agents and renal cell apoptosis.

    Science.gov (United States)

    Romano, Giulia; Briguori, Carlo; Quintavalle, Cristina; Zanca, Ciro; Rivera, Natalia V; Colombo, Antonio; Condorelli, Gerolama

    2008-10-01

    Contrast media (CM) induce a direct toxic effect on renal tubular cells. This toxic effect may have a role in the pathophysiology of contrast nephropathy. We evaluated (i) the cytotoxicity of CM [both low-osmolality (LOCM) and iso-osmolality (IOCM)], of iodine alone, and of an hyperosmolar solution (mannitol 8%) on human embryonic kidney (HEK 293), porcine proximal renal tubular (LLC-PK1), and canine Madin-Darby distal tubular renal (MDCK) cells; and (ii) the effectiveness of various antioxidant compounds [n-acetylcysteine (NAC), ascorbic acid and sodium bicarbonate] in preventing CM cytotoxicity. The cytotoxicity of CM was assessed at different time points, with different methods: cell viability, DNA laddering, flow cytometry, and caspase activation. Both LOCM and IOCM produced a concentration- and time-dependent increase in cell death as assessed by the different methods. On the contrary, iodine alone and hyperosmolar solution did not induce any significant cytotoxic effect. There was not any significant difference in the cytotoxic effect between LOCM and IOCM. Furthermore, both LOCM and IOCM caused a marked increase in caspase-3 and -9 activities and poly(ADP-ribose) fragmentation, while no effect on caspase-8/-10 was observed, thus indicating that the CM activated apoptosis mainly through the intrinsic pathway. Both CM induced an increase in protein expression levels of pro-apoptotic members of the Bcl2 family (Bim and Bad). NAC and ascorbic acid but not sodium bicarbonate had a dose-dependent protective effect on renal cells after 3 h incubation with high dose (200 mg iodine/mL) of both LOCM and IOCM. Both LOCM and IOCM induce a dose-dependent renal cell apoptosis. NAC and ascorbic acid but not sodium bicarbonate prevent this contrast-induced apoptosis.

  1. Estimates of DNA strand breakage in bottlenose dolphin (Tursiops truncatus leukocytes measured with the Comet and DNA diffusion assays

    Directory of Open Access Journals (Sweden)

    Adriana Díaz

    2009-01-01

    Full Text Available The analysis of DNA damage by mean of Comet or single cell gel electrophoresis (SCGE assay has been commonly used to assess genotoxic impact in aquatic animals being able to detect exposure to low concentrations of contaminants in a wide range of species. The aims of this work were 1 to evaluate the usefulness of the Comet to detect DNA strand breakage in dolphin leukocytes, 2 to use the DNA diffusion assay to determine the amount of DNA strand breakage associated with apoptosis or necrosis, and 3 to determine the proportion of DNA strand breakage that was unrelated to apoptosis and necrosis. Significant intra-individual variation was observed in all of the estimates of DNA damage. DNA strand breakage was overestimated because a considerable amount (~29% of the DNA damage was derived from apoptosis and necrosis. The remaining DNA damage in dolphin leukocytes was caused by factors unrelated to apoptosis and necrosis. These results indicate that the DNA diffusion assay is a complementary tool that can be used together with the Comet assay to assess DNA damage in bottlenose dolphins.

  2. Flow cytofluorometric monitoring of leukocyte apoptosis in experimental cholera

    Science.gov (United States)

    Lotsmanova, Ekaterina Y.; Kravtsov, Alexander L.; Livanova, Ludmila F.; Kobkova, Irina M.; Kuznetsov, Oleg S.; Shchukovskaya, Tatyana N.; Smirnova, Nina I.; Kutyrev, Vladimir V.

    2003-10-01

    Flow cytofluorometric DNA analysis was applied to determine of the relative contents of proliferative (more then 2C DNA per cell) and apoptotic (less then 2C DNA per cell) leukocytes in blood of adult rabbits, challenged with 10,000 times the 50 % effective dose of Vibrio cholerae virulent strain by the RITARD technique. It has been shown that irreversible increase the percentage of cells carrying DNA in the degradation stage brings to disbalance between the genetically controlled cell proliferation and apoptosis that leads to animal death from the cholera infection. Such fatal changes were not observed in challenging of immunized animals that were not died. Thus received data show that the flow cytofluorometric measurements may be used for detection of transgressions in homeostasis during acute infection diseases, for outlet prognosis of the cholera infection.

  3. Biological dosimetry: the potential use of radiation-induced apoptosis in human T-lymphocytes

    International Nuclear Information System (INIS)

    Menz, R.; Andres, R.; Larsson, B.; Ozsahin, M.; Crompton, N.E.A.; Trott, K.

    1997-01-01

    An assay for biological dosimetry based on the induction of apoptosis in human T-lymphocytes is described. Radiation-induced apoptosis was assessed by flow cytometric identification of cells displaying apoptosis-associated DNA condensation. CD4 and CD8 T-lymphocytes were analysed. They were recognized on the basis of their cell-surface antigens. Four parameters were measured for both cell types: cell size, granularity, antigen immunofluorescence and DNA content. Apoptosis was quantified as the fraction of CD4-, or CD8-positive cells with a characteristic reduction of cell size and DNA content. At doses below 1 Gy, levels of radiation-induced apoptosis increased for up to 5 days after irradiation. Optimal dose discrimination was observed 4 days after irradiation, at which time the dose-response curves were linear, with a slope of 8% ± 0.5% per 0.1 Gy. In controlled, dose-response experiments the lowest dose level at which the radiation-induced apoptosis frequency was still significantly above control was 0.05 Gy. After 5 days post-irradiation incubation, intra- and interdonor variations were measured and found to be similar; thus, apoptotic levels depend more on the dose than on the donor. The results demonstrate the potential of this assay as a biological dosimeter. (orig.)

  4. Arsenic induced apoptosis in rat liver following repeated 60 days exposure

    International Nuclear Information System (INIS)

    Bashir, Somia; Sharma, Yukti; Irshad, M.; Nag, T.C.; Tiwari, Monica; Kabra, M.; Dogra, T.D.

    2006-01-01

    Background: Accumulation of the wide spread environmental toxin arsenic in liver results in hepatotoxcity. Exposure to arsenite and other arsenicals has been previously shown to induce apoptosis in certain tumor cell lines at low (1-3 μM) concentration. Aim: The present study was focused to elucidate the role of free radicals in arsenic toxicity and to investigate the nature of in vivo sodium arsenite induced cell death in liver. Methods: Male wistar rats were exposed to arsenite at three different doses of 0.05, 2.5 and 5 mg/l for 60 days. Oxidative stress in liver was measured by estimating pro-oxidant and antioxidant activity in liver. Histopathological examination of liver was carried out by light and transmission electron microscopy. Analysis of DNA fragmentation by gel electrophoresis was used to identify apoptosis after the exposure. Terminal deoxy-nucleotidyl transferase mediated dUTP Nick end-labeling (TUNEL) assay was used to qualify and quantify apoptosis. Results: A significant increase in cytochrome-P450 and lipid peroxidation accompanied with a significant alteration in the activity of many of the antioxidants was observed, all suggestive of arsenic induced oxidative stress. Histopathological examination under light and transmission electron microscope suggested a combination of ongoing necrosis and apoptosis. DNA-TUNEL showed an increase in apoptotic cells in liver. Agarose gel electrophoresis of DNA of hepatocytes resulted in a characteristic ladder pattern. Conclusion: Chronic arsenic administration induces a specific pattern of apoptosis called post-mitotic apoptosis

  5. Depletion of cdc-25.3, a Caenorhabditis elegans orthologue of cdc25, increases physiological germline apoptosis.

    Science.gov (United States)

    Sung, Minhee; Kawasaki, Ichiro; Shim, Yhong-Hee

    2017-07-01

    In Caenorhabditis elegans hermaphrodites, physiological germline apoptosis is higher in cdc-25.3 mutants than in wild-type. The elevated germline apoptosis in cdc-25.3 mutants seems to be induced by accumulation of double-stranded DNA breaks (DSBs). Both DNA damage and synapsis checkpoint genes are required to increase the germline apoptosis. Notably, the number of germ cells that lose P-granule components, PGL-1 and PGL-3, increase in cdc-25.3 mutants, and the increase in germline apoptosis requires the activity of SIR-2.1, a Sirtuin orthologue. These results suggest that elevation of germline apoptosis in cdc-25.3 mutants is induced by accumulation of DSBs, leading to a loss of PGL-1 and PGL-3 in germ cells, which promotes cytoplasmic translocation of SIR-2.1, and finally activates the core apoptotic machinery. © 2017 Federation of European Biochemical Societies.

  6. Apoptosis induced by pyrimidine dimer produced by ultraviolet irradiation in cultured cyprinodont cells. Analysis utilizing the evasion from photolysis

    International Nuclear Information System (INIS)

    Nishigaki, Reiko

    2000-01-01

    This is the review of author's investigations on the mechanism of apoptosis induced by UV irradiation in cultured cyprinodont cells highly expressing photolyases of cyclobutane pyrimidine dimer (CPD). Authors found out the evasion from photolysis by UV-induced apoptosis of which cascade had been thought irreversible: the cascade was reversible until the process of DNA fragmentation. In controlling the process, a mechanism to recognize CPD was found concerned. In those cells, morphological changes by UVC were reversible ones in apoptosis from which they evaded if CPD was repaired. Investigations on caspase, which playing important roles in apoptosis, revealed that the DEVD-cleaving enzyme activities were regulated by CPD quantity. However, differing from mammalian cells, elevation of caspase (-7, -3A and -3B) activities did not always induce the morphologic changes and DNA fragmentation. Further studies were thought necessary to elucidate the mechanism of apoptosis in those fish cells. (K.H.)

  7. γ-Tocotrienol Inhibits Proliferation and Induces Apoptosis Via the Mitochondrial Pathway in Human Cervical Cancer HeLa Cells.

    Science.gov (United States)

    Xu, Weili; Mi, Yaqing; He, Pan; He, Shenghua; Niu, Lingling

    2017-08-04

    γ-Tocotrienol, a kind of isoprenoid phytochemical, has antitumor activity. However, there is limited evidence that it has an effect on cervical cancer. In this study, the capacity to inhibit proliferation and induce apoptosis in human cervical cancer HeLa cells and the mechanism underlying these effects were examined. The results indicated that a γ-tocotrienol concentration over 30 μM inhibited the growth of HeLa cells with a 50% inhibitory concentration (IC 50 ) of 46.90 ± 3.50 μM at 24 h, and significantly down-regulated the expression of proliferative cell nuclear antigen (PCNA) and Ki-67. DNA flow cytometric analysis indicated that γ-tocotrienol arrested the cell cycle at G0/G1 phase and reduced the S phase in HeLa cells. γ-tocotrienol induced apoptosis of HeLa cells in a time- and dose-dependent manner. γ-tocotrienol-induced apoptosis in HeLa cells was accompanied by down-regulation of Bcl-2, up-regulation of Bax, release of cytochrome from mitochondria, activation of caspase-9 and caspase-3, and subsequent poly (ADP-ribose) polymerase (PARP) cleavage. These results suggested that γ-tocotrienol could significantly inhibit cell proliferation through G0/G1 cell cycle arrest, and induce apoptosis via the mitochondrial apoptotic pathway in human cervical cancer HeLa cells. Thus, our findings revealed that γ-tocotrienol may be considered as a potential agent for cervical cancer therapy.

  8. γ-Tocotrienol Inhibits Proliferation and Induces Apoptosis via the Mitochondrial Pathway in Human Cervical Cancer HeLa Cells

    Directory of Open Access Journals (Sweden)

    Weili Xu

    2017-08-01

    Full Text Available γ-Tocotrienol, a kind of isoprenoid phytochemical, has antitumor activity. However, there is limited evidence that it has an effect on cervical cancer. In this study, the capacity to inhibit proliferation and induce apoptosis in human cervical cancer HeLa cells and the mechanism underlying these effects were examined. The results indicated that a γ-tocotrienol concentration over 30 μM inhibited the growth of HeLa cells with a 50% inhibitory concentration (IC50 of 46.90 ± 3.50 μM at 24 h, and significantly down-regulated the expression of proliferative cell nuclear antigen (PCNA and Ki-67. DNA flow cytometric analysis indicated that γ-tocotrienol arrested the cell cycle at G0/G1 phase and reduced the S phase in HeLa cells. γ-tocotrienol induced apoptosis of HeLa cells in a time- and dose-dependent manner. γ-tocotrienol-induced apoptosis in HeLa cells was accompanied by down-regulation of Bcl-2, up-regulation of Bax, release of cytochrome from mitochondria, activation of caspase-9 and caspase-3, and subsequent poly (ADP-ribose polymerase (PARP cleavage. These results suggested that γ-tocotrienol could significantly inhibit cell proliferation through G0/G1 cell cycle arrest, and induce apoptosis via the mitochondrial apoptotic pathway in human cervical cancer HeLa cells. Thus, our findings revealed that γ-tocotrienol may be considered as a potential agent for cervical cancer therapy.

  9. Methylselenium and Prostate Cancer Apoptosis

    National Research Council Canada - National Science Library

    Lu, Junxuan

    2007-01-01

    The purpose of this research is to gain a better understanding of the biochemical pathways and molecular targets for the selective induction of apoptosis signaling and execution of prostate cancer (PCa...

  10. Methylselenium and Prostate Cancer Apoptosis

    National Research Council Canada - National Science Library

    Lu, Junxuan

    2005-01-01

    The purpose of this research is to gain a better understanding of the biochemical pathways and molecular targets for the selective induction of apoptosis signaling and execution of prostate cancer (PCa...

  11. Methylselenium and Prostate Cancer Apoptosis

    National Research Council Canada - National Science Library

    Lu, Junxuan

    2006-01-01

    The purpose of this research is to gain a better understanding of the biochemical pathways and molecular targets for the selective induction of apoptosis signaling and execution of prostate cancer (PCa...

  12. Methylselenium and Prostate Cancer Apoptosis

    National Research Council Canada - National Science Library

    Lu, Junxuan

    2004-01-01

    The purpose of this research is to gain a better understanding of the biochemical pathways and molecular targets for the selective induction of apoptosis signaling and execution of PCa cells by methyl selenium (Se)/selenol...

  13. Methylselenium and Prostate Cancer Apoptosis

    National Research Council Canada - National Science Library

    Lu, Junxuan

    2008-01-01

    The purpose of this research is to gain a better understanding of the biochemical pathways and molecular targets for the selective induction of apoptosis signaling and execution of prostate cancer (PCa...

  14. Methylselenium and Prostate Cancer Apoptosis

    National Research Council Canada - National Science Library

    Lu, Junxuan

    2003-01-01

    The purpose of this research is to gain a better understanding of the biochemical pathways and molecular targets for the selective induction of apoptosis signaling and execution of PCa cells by methyl selenium (Se...

  15. Lymphocytes from wasted mice express enhanced spontaneous and {gamma}-ray-induced apoptosis

    Energy Technology Data Exchange (ETDEWEB)

    Woloschak, G.E. [Argonne National Lab., IL (United States)]|[Loyola Univ. Medical Center, Maywood, IL (United States); Chang-Liu, Chin-Mei [Argonne National Lab., IL (United States); Chung, Jen; Libertin, C.R. [Loyola Univ. Medical Center, Maywood, IL (United States)

    1993-09-01

    Mice bearing the autosomal recessive mutation wasted (wst/wst) display a disease pattern including faulty repair of DNA damage in lymphocytes after radiation exposure, neurologic abnormalities, and immunodeficiency. Many of the features of this mouse model have suggested a premature or increased spontaneous frequency of apoptosis in thymocytes; past work has shown an inability to establish cultured T cell lines, an abnormally high death rate of stimulated T cells in culture, and an increased sensitivity of T cells to the killing effects of ionizing radiations in wst/wst mice relative to controls. The experiments reported here were designed to examine splenic and thymic lymphocytes from wasted and control mice for signs of early apoptosis. Our results revealed enhanced expression of Rp-8 mRNA (associated with apoptosis) in thymic lymphocytes and reduced expression in splenic lymphocytes of wst/wst mice relative to controls; expression of Rp-2 and Td-30 mRNA (induced during apoptosis) were not detectable in spleen or thymus. Higher spontaneous DNA fragmentation was observed in wasted mice than in controls; however, {gamma}-ray-induced DNA fragmentation peaked at a lower dose and occurred to a greater extent in wasted mice relative to controls. These results provide evidence for high spontaneous and {gamma}-ray-induced apoptosis in T cells of wasted mice as a mechanism underlying the observed lymphocyte and DNA repair abnormalities.

  16. Sensitization to UV-induced apoptosis by the histone deacetylase inhibitor trichostatin A (TSA)

    International Nuclear Information System (INIS)

    Kim, Myoung Sook; Baek, Jin Hyen; Chakravarty, Devulapalli; Sidransky, David; Carrier, France

    2005-01-01

    UV-induced apoptosis is a protective mechanism that is primarily caused by DNA damage. Cyclobutane pyrimidine dimers (CPD) and 6-4 photoproducts are the main DNA adducts triggered by UV radiation. Because the formation of DNA lesions in the chromatin is modulated by the structure of the nucleosomes, we postulated that modification of chromatin compaction could affect the formation of the lesions and consequently apoptosis. To verify this possibility we treated human colon carcinoma RKO cells with the histone deacetylase inhibitor trichostatin A (TSA) prior to exposure to UV radiation. Our data show that pre-treatment with TSA increased UV killing efficiency by more than threefold. This effect correlated with increased formation of CPDs and consequently apoptosis. On the other hand, TSA treatment after UV exposure rather than before had no more effect than UV radiation alone. This suggests that a primed (opened) chromatin status is required to sensitize the cells. Moreover, TSA sensitization to UV-induced apoptosis is p53 dependent. p53 and acetylation of the core histones may thus contribute to UV-induced apoptosis by modulating the formation of DNA lesions on chromatin

  17. Bile duct cell apoptosis is a rare event in primary biliary cirrhosis.

    Science.gov (United States)

    Ballardini, G; Guidi, M; Susca, M; Ghetti, S; Grassi, A; Lari, F; Fusconi, M; Zauli, D; Bianchi, F B

    2001-03-01

    The frequency of apoptosis in bile duct cells of primary biliary cirrhosis is still unclear spanning from rare to 50% in the various reports. To study bile duct cell apoptosis in stage I primary biliary cirrhosis lesions. Nine stage I-II biopsies with a total number of 26 bile ducts of different sizes, selected from a larger series on the basis of the expression on serial frozen sections of HLA-DR and Fas antigens. Apoptosis was evaluated by a DNA fragmentation assay on frozen sections, according to the manufacturer's protocol and by expression of apoptosis related cytokeratin neoepitopes. Bile duct cell proliferation was assessed by MIB1 (Ki-67) expression. Apoptosis was frequently found in inflammatory cells of portal tracts and sinusoids. Apoptosis of hepatocytes was also systematically observed. Only 4 positive bile duct cells were found in 3 bile ducts from 3 biopsies. Quantitative evaluation was not attempted. Cholangiocyte proliferation was observed in the same ducts and occasionally in other biopsies. These data suggest that cholangiocyte death by apoptosis at the level of typical primary biliary cirrhosis lesions is a rare event, at least in early stages of the disease. The observed rate of proliferation was consistent with the rate of apoptosis.

  18. Effects of topical vitamin E on keratocyte apoptosis after traditional photorefractive keratectomy.

    Science.gov (United States)

    Bilgihan, K; Adiguzel, U; Sezer, C; Akyol, G; Hasanreisoglu, B

    2001-01-01

    To evaluate the keratocyte apoptosis and effects of topical vitamin E on keratocyte apoptosis after photorefractive surgery. Rabbits were divided into 7 groups, and all groups were compared with controls after epithelial scraping, epithelial scrape and photorefractive keratectomy (PRK) (traditional PRK), transepithelial PRK, production of a corneal flap with microkeratome and laser-assisted in situ keratomileusis (LASIK). The effects of topical Vitamin E treatment were investigated in the traditional PRK group. The terminal deoxyribonucleotidyl transferase-mediated dUTP-digoxigenin nick-end labelling assay (to detect DNA fragmentation in situ) and light microscopy have been used to detect apoptosis in rabbit cornea. Transepithelial PRK induced minimal keratocyte apoptosis, less than in all other refractive surgical procedures. The greatest amount of keratocyte apoptosis was observed after traditional PRK (p = 0.001), therefore we tested the effects of topical vitamin E in this group. The number of apoptotic keratocytes significantly reduced after vitamin E therapy (p < 0.005). Keratocytes undergo apoptosis after refractive surgery in response to mechanical epithelial removal, preparing of corneal flap and excimer laser stromal photoablation. The topical application of vitamin E immediately after surgery can prevent keratocyte apoptosis, and this result suggests that free radicals may be partly responsible for keratocyte apoptosis after excimer laser keratectomy. Copyright 2001 S. Karger AG, Basel

  19. Keratocyte apoptosis and corneal antioxidant enzyme activities after refractive corneal surgery.

    Science.gov (United States)

    Bilgihan, K; Bilgihan, A; Adiguzel, U; Sezer, C; Yis, O; Akyol, G; Hasanreisoglu, B

    2002-01-01

    Refractive corneal surgery induces keratocyte apoptosis and generates reactive oxygen radicals (ROS) in the cornea. The purpose of the present study is to evaluate the correlation between keratocyte apoptosis and corneal antioxidant enzyme activities after different refractive surgical procedures in rabbits. Rabbits were divided into six groups. All groups were compared with the control group (Group 1), after epithelial scraping (Group 2), epithelial scrape and photorefractive keratectomy (PRK) (traditional PRK: Group 3), transepithelial PRK (Group 4), creation of a corneal flap with microkeratome (Group 5) and laser-assisted in situ keratomileusis (LASIK, Group 6). Terminal deoxyribonucleotidyl transferase-mediated dUTP-digoxigenin nick-end labelling assay (to detect DNA fragmentation in situ) and light microscopy were used to detect apoptosis in rabbit eyes. Glutathione peroxidase (Gpx) and superoxide dismutase (SOD) activities of the corneal tissues were measured with spectrophotometric methods. Corneal Gpx and SOD activities decreased significantly in all groups when compared with the control group (P<0.05) and groups 2, 3 and 6 showed a significantly higher amount of keratocyte apoptosis (P<0.05). Not only a negative correlation was observed between corneal SOD activity and keratocyte apoptosis (cc: -0.3648) but Gpx activity also showed negative correlation with keratocyte apoptosis (cc: -0.3587). The present study illustrates the negative correlation between keratocyte apoptosis and corneal antioxidant enzyme activities. This finding suggests that ROS may be partly responsible for keratocyte apoptosis after refractive surgery.

  20. Radiation-induced apoptosis of lymphocytes in peripheral blood

    International Nuclear Information System (INIS)

    Oh, Yoon Kyeong; Lee, Tae Bum; Nam, Taek Keun; Kee, Keun Hong; Choi, Cheol Hee

    2003-01-01

    This study quantitatively evaluated the apoptosis in human peripheral blood lymphocytes using flow cytometry, and investigated the possibility of using this method, with a small amount of blood, and the time and dose dependence of radiation-induced apoptosis. Peripheral blood lymphocytes were isolated from the heparinized venous blood of 11 healthy volunteers, 8 men and 3 women, with each 10 ml of blood being divided into 15 samples. The blood lymphocytes were irradiated using a linear accelerator at a dose rate of 2.4 Gy/min, to deliver doses of 0.5, 1, 2 and 5 Gy. The control samples, and irradiated cells, were maintained in culture medium for 24, 48 and 72 hours following the irradiation. The number of apoptotic cells after the in vitro X-irradiation was measured by flow cytometry after incubation periods of 24, 48 and 72 hours. We also observed the apoptotic cells using a DNA fragmentation assay and electron microscopy. The rate of spontaneous apoptosis increased in relation to the time interval following irradiation (1.761±0.161, 3.563±0.564, 11.098±2.849, at 24, 48, and 72 hours). The apoptotic cells also increased in the samples irradiated with 0.5, 1, 2 and 5 Gy, in a radiation dose and time interval after irradiation manner, with the apoptosis being too great at 72 hours after irradiation. The dose-response curves were characterized by an initial steep increase in the number of apoptotic cells for irradiation doses below 2 Gy, with a flattening of the curves as the dose approached towards 5 Gy. The flow cytometric assay technique yielded adequate data, and required less than 1 mL of blood. The time and dose dependence of the radiation-induced apoptosis, was also shown. It is suggested that the adequate time interval required for the evaluation of apoptosis would be 24 to 48 hours after blood sampling

  1. Origin of DNA in human serum and usefulness of serum as a material for DNA typing.

    Science.gov (United States)

    Takayama, T; Yamada, S; Watanabe, Y; Hirata, K; Nagai, A; Nakamura, I; Bunai, Y; Ohya, I

    2001-06-01

    The aims of this study were to clarify the origin of DNA in human serum and to investigate whether serum is a material available for DNA typing in routine forensic practice. Blood was donated from 10 healthy adult volunteers and stored for up to 8 days, at 4 degrees C and at room temperature. The serum DNA concentration at zero time was in the range of 5.6 to 21.8 ng/ml with a mean of 12.2+/-1.6 ng/ml. The concentrations increased with storage time. On agarose gel electrophoresis, all serum samples showed ladder patterns and the size of each band was an integer multiple of approximately 180 bp considered to be characteristic of apoptosis. DNA typing from DNA released by apoptosis was possible. Exact DNA typing of D1S80, HLA DQA1, PM, CSF1PO, TPOX, TH01 and vWA was possible for each sample. These results indicate that serum contains fragmented DNA derived from apoptosis of leukocytes, especially neutrophils, and that fragmented DNA is an appropriate material for DNA typing.

  2. Good news for conservation: mitochondrial and microsatellite DNA data detect limited genetic signatures of inter-basin fish transfer in Thymallus thymallus (Salmonidae from the Upper Drava River

    Directory of Open Access Journals (Sweden)

    Meraner A.

    2013-06-01

    Full Text Available In the last few decades, numerous populations of European grayling, Thymallus thymallus, have been suffering from stocking-induced genetic admixture of foreign strains into wild populations. Concordantly, genetic introgression was also reportedfor grayling stocks inhabiting the Upper Drava River, but all published genetic data based on specimens caught at least a decade ago, when stocking load was strong. Here, we applied mitochondrial control region sequencing and nuclear microsatellite genotyping to Upper Drava grayling fry collections and reference samples to update patterns and extent of human-mediated introgression. In contrast to previous data, we highlighted an almost genetic integrity of Drava grayling, evidencing limited genetic signatures of trans-basin stocking for grayling of Northern Alpine Danubian origin. Recent hybridisation was detected only twice among sixty-nine samples, while several cases of later-generation hybrids were disclosed by linking mitochondrial sequence to nuclear genetic data. The observed past, but very limited recent genetic introgression in grayling from Upper Drava seems to reflect shifting stocking trends, changing from massive introduction of trans-basin fish to more conservation-oriented strategies during the last 27 years. In a conservation context, we encourage pursuing the use of local wild grayling for supportive- and captive-breeding, but underline the need for genetic approaches in brood-stock selection programs. Finally, our integrated results from sibship reconstruction validate our strictly fry-based sampling scheme, thus offering a reasonable alternative also for other rheophilic fish species with similar life-history characteristics.

  3. Influence of vitamin D on cell cycle, apoptosis, and some apoptosis related molecules in systemic lupus erythematosus

    Directory of Open Access Journals (Sweden)

    Nafise Tabasi

    2015-11-01

    Full Text Available Objective(s:Genetic and environmental factors are involved in the pathogenesis of systemic lupus erythematosus (SLE. Autoreactive lymphocytes are cleared through apoptosis and any disturbance in the apoptosis or clearance of apoptotic cells may disturb tolerance and lead to autoimmunity. Vitamin D has anti-proliferative effects and controls cell cycle progression. In this study we investigated the effects of vitamin D on cell cycle and apoptosis induction in lupus patients. Materials and Methods:Isolated peripheral blood mononuclear cells (PBMCs from 25 SLE patients were cultured in the presence of 50 nM of 1,25(OH2D3; then one part of the cells were stained with FITC labeled Annexin V and PI and were analyzed for apoptosis determination. For gene expression assessment of FasL, Bcl-2 and Bax, RNA was extracted from one another part of the cells, cDNA was synthesized and gene expression analysis was performed using Real time PCR. An additional part of the cells were treated with PI and the cell cycle was analyzed using flowcytometer. Results: The mean number of early apoptotic cells in vitamin D treated cells decreased significantly (18.48±7.9% compared to untreated cells (22.02±9.4% (P=0.008. Cell cycle analysis showed a significant increase in G1 phase in vitamin D treated cells (67.33±5.2% compared to non treated ones (60.77±5.7% (P =0.02. Vitamin D up-regulated the expression levels of Bcl-2 by (18.87 fold increase, and down-regulated expression of Bax (23% and FasL (25%. Conclusion:Vitamin D has regulatory effects on cell cycle progression, apoptosis and apoptosis related molecules in lupus patients.

  4. Dose-effect relationship of apoptosis induced by fission-neutron in murine thymocytes

    International Nuclear Information System (INIS)

    Yuan Bin; Li Liang; Xue Wencheng; Sun Jianmin; Wang Baoqin

    2000-01-01

    Objective: To investigate the effectiveness of high LET fission-neutron to induce apoptosis in murine thymocytes and to compare it with that of low LET 60 Co γ-ray. Methods: Apoptosis induction was studied qualitatively by light and transmission electron microscopy and DNA gel electrophoresis,also quantitatively by flow cytometry(FCM) and diphenylamine (DPA)methods. Results: DNA ladders of murine thymocytes were detectable, the typical apoptosis of thymocytes could be observed morphologically by means of light and electron microscopy at 6 h after fission-neutron irradiation with doses ranging from 0.5 to 5.0 Gy, meanwhile the percentages of apoptosis increased with increasing doses. After exposure to γ-rays with doses ranging from 1.0 to 30 Gy, the experimental results were similar to those from neutron radiation. The incidence of apoptosis peaked at about 20 Gy, the percentages did not increase further when doses increased. Conclusion: Apoptosis of murine thymocytes can be induced when mice are exposed to either fission-neutron (0.5-5.0 Gy) or to γ-ray (1-30 Gy). Although the relationship between apoptosis and radiation doses is similar, the percentage of apoptosis induced by neutron irradiation is higher than that induced by γ-irradiation. The RBE values of fission-neutron for inducing apoptosis murine thymocytes are 2.09 (by FCM method) and 2.37 (by DPA method), respectively. These results also suggest that fission-neutron-induced murine immune tissue is more severe than that induced by γ-rays at several hours post-irradiation and this might be the basis for heavy damage to immune tissues induced by fission-neutron-irradiation in later period

  5. Involvement of Prohibitin Upregulation in Abrin-Triggered Apoptosis

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    Yu-Huei Liu

    2012-01-01

    Full Text Available Abrin (ABR, a protein purified from the seeds of Abrus precatorius, induces apoptosis in various types of cancer cells. However, the detailed mechanism remains largely uncharacterized. By using a cDNA microarray platform, we determined that prohibitin (PHB, a tumor suppressor protein, is significantly upregulated in ABR-triggered apoptosis. ABR-induced upregulation of PHB is mediated by the stress-activated protein kinase/c-Jun NH2-terminal kinase (SAPK/JNK pathway, as demonstrated by chemical inhibitors. In addition, ABR significantly induced the expression of Bax as well as the activation of caspase-3 and poly(ADP-ribose polymerase (PARP in Jurkat T cells, whereas the reduction of PHB by specific RNA interference delayed ABR-triggered apoptosis through the proapoptotic genes examined. Moreover, our results also indicated that nuclear translocation of the PHB-p53 complex may play a role in the transcription of Bax. Collectively, our data show that PHB plays a role in ABR-induced apoptosis, which may be helpful for the development of diagnostic or therapeutic agents.

  6. alpha-Amanitin induced apoptosis in primary cultured dog hepatocytes.

    Directory of Open Access Journals (Sweden)

    Adam Szelag

    2010-06-01

    Full Text Available Amatoxin poisoning is caused by mushroom species belonging to the genera Amanita, Galerina and Lepiota with the majority of lethal mushroom exposures attributable to Amanita phalloides. High mortality rate in intoxications with these mushrooms is principally a result of the acute liver failure following significant hepatocyte damage due to hepatocellular uptake of amatoxins. A wide variety of amatoxins have been isolated; however, alpha-amanitin (alpha-AMA appears to be the primary toxin. Studies in vitro and in vivo suggest that alpha-AMA does not only cause hepatocyte necrosis, but also may lead to apoptotic cell death. The objective of this study was to evaluate the complex hepatocyte apoptosis in alpha-AMA cytotoxicity. All experiments were performed on primary cultured canine hepatocytes. The cells were incubated for 12 h with alpha-AMA at a final concentration of 1, 5, 10 and 20 microM. Viability test (MTT assay, apoptosis evaluation (TUNEL reaction, detection of DNA laddering and electron microscopy were performed at 6 and 12 h of exposure to alpha-AMA. There was a clear correlation between hepatocyte viability, concentration of alpha-AMA and time of exposure to this toxin. The decline in cultured dog hepatocyte viability during the exposure to alpha-AMA is most likely preceded by enhanced cellular apoptosis. Our results demonstrate that apoptosis might contribute to pathogenesis of the severe liver injury in the course of amanitin intoxication, particularly during the early phase of poisoning.

  7. Apple polysaccharides induce apoptosis in colorectal cancer cells.

    Science.gov (United States)

    Zhang, Dian; Sun, Yang; Yue, Zhenggang; Li, Qian; Meng, Jin; Liu, Junajuan; Hekong, Xiang; Jiang, Fengliang; Mi, Man; Liu, Li; Mei, Qibing

    2012-07-01

    Certain components of apples have been shown to prevent cancer growth and impede cancer progression. We hypothesized that extracted apple polysaccharides (APs) might, therefore, have anticancer effects, through a mechanism involving the induction of apoptosis in cancer cells, partly via the NF-κB pathway. Two human colorectal cancer (CRC) cell lines, HT-29 and SW620, were exposed to different concentrations of APs (0.01, 0.1 or 1 mg/ml). Cell apoptosis was measured by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay by flow cytometry and incorporation of 5'-bromodeoxyuridine (BrdU) into DNA to identify the proliferating cell fraction, using fluorescence microscopy in vitro. The protein levels of NF-κB/p65, I-κBα, pI-κBα, Bax, Bcl-xl and Bcl-2 were evaluated by western blotting. The target sites of APs on CRC cells were assessed by flow cytometry. At concentrations of 0.1 and 1 mg/ml, APs showed apoptosis-inducing effects, increased expressions of Bax, nuclear p65 and cytoplasmic pI-κBα, and decreased expressions of Bcl-2, Bcl-xl and cytoplasmic I-κBα. APs induced apoptosis by slightly activating the NF-κB pathway; the AP target site could be the Toll-like receptor 4 on the cell membrane. These results demonstrate the potential of APs as agents for clinical prevention and treatment of CRC.

  8. Iron starvation induces apoptosis in Rhizopus oryzae in vitro.

    Science.gov (United States)

    Shirazi, Fazal; Kontoyiannis, Dimitrios P; Ibrahim, Ashraf S

    2015-01-01

    Mortality associated with mucormycosis remains high despite current antifungals. Iron-starvation strategies have been shown to have promising activity against Mucorales. We hypothesized that iron starvation enhances apoptosis in Rhizopus oryzae. Apoptosis was characterized in R. oryzae transformed with RNAi plasmid targeting FTR1 expression (iron permease mutant) or empty plasmid grown in iron rich (0.125% FeCl3) and iron depleted media (YNB+1mM ferrozine and 1 mM ascorbic acid). Increased apoptosis was observed with dihydrorhodamine-123 and rhodamine-123 staining in the iron starved mutant FTR1 when compared to empty plasmid, followed by increased extracellular ATP levels. In addition, DNA fragmentation and metacaspase activity were prominent in FTR1. In contrast, Rhizopus strains grown in iron-rich medium displayed minimal apoptosis. Our results demonstrate a metacaspase dependent apoptotic process in iron deprived condition and further support the role of iron starvation strategies as an adjunct treatment for mucormycosis, a mechanism by which iron starvation affects R. oryzae.

  9. WRN-targeted therapy using inhibitors NSC 19630 and NSC 617145 induce apoptosis in HTLV-1-transformed adult T-cell leukemia cells

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    R. Moles

    2016-11-01

    Full Text Available Abstract Background Human T-cell leukemia virus type 1 (HTLV-1 infection is associated with adult T-cell leukemia/lymphoma (ATLL, a lymphoproliferative malignancy with a dismal prognosis and limited therapeutic options. Recent evidence shows that HTLV-1-transformed cells present defects in both DNA replication and DNA repair, suggesting that these cells might be particularly sensitive to treatment with a small helicase inhibitor. Because the “Werner syndrome ATP-dependent helicase” encoded by the WRN gene plays important roles in both cellular proliferation and DNA repair, we hypothesized that inhibition of WRN activity could be used as a new strategy to target ATLL cells. Methods Our analysis demonstrates an apoptotic effect induced by the WRN helicase inhibitor in HTLV-1-transformed cells in vitro and ATL-derived cell lines. Inhibition of cellular proliferation and induction of apoptosis were demonstrated with cell cycle analysis, XTT proliferation assay, clonogenic assay, annexin V staining, and measurement of mitochondrial transmembrane potential. Results Targeted inhibition of the WRN helicase induced cell cycle arrest and apoptosis in HTLV-1-transformed leukemia cells. Treatment with NSC 19630 (WRN inhibitor induces S-phase cell cycle arrest, disruption of the mitochondrial membrane potential, and decreased expression of anti-apoptotic factor Bcl-2. These events were associated with activation of caspase-3-dependent apoptosis in ATL cells. We identified some ATL cells, ATL-55T and LMY1, less sensitive to NSC 19630 but sensitive to another WRN inhibitor, NSC 617145. Conclusions WRN is essential for survival of ATL cells. Our studies suggest that targeting the WRN helicase with small inhibitors is a novel promising strategy to target HTLV-1-transformed ATL cells.

  10. A large 28S rDNA-based phylogeny confirms the limitations of established morphological characters for classification of proteocephalidean tapeworms (Platyhelminthes, Cestoda

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    Alain de Chambrier

    2015-04-01

    Full Text Available Proteocephalidean tapeworms form a diverse group of parasites currently known from 315 valid species. Most of the diversity of adult proteocephalideans can be found in freshwater fishes (predominantly catfishes, a large proportion infects reptiles, but only a few infect amphibians, and a single species has been found to parasitize possums. Although they have a cosmopolitan distribution, a large proportion of taxa are exclusively found in South America. We analyzed the largest proteocephalidean cestode molecular dataset to date comprising more than 100 species (30 new, including representatives from 54 genera (80% and all subfamilies, thus significantly improving upon previous works to develop a molecular phylogeny for the group. The Old World origin of proteocephalideans is confirmed, with their more recent expansion in South America. The earliest diverging lineages are composed of Acanthotaeniinae and Gangesiinae but most of the presently recognized subfamilies (and genera appear not to be monophyletic; a deep systematic reorganization of the order is thus needed and the present subfamilial system should be abandoned. The main characters on which the classical systematics of the group has been built, such as scolex morphology or relative position of genital organs in relation to the longitudinal musculature, are of limited value, as demonstrated by the very weak support for morphologically-defined subfamilies. However, new characters, such as the pattern of uterus development, relative ovary size, and egg structure have been identified, which may be useful in defining phylogenetically well-supported subgroups. A strongly supported lineage infecting various snakes from a wide geographical distribution was found. Although several improvements over previous works regarding phylogenetic resolution and taxon coverage were achieved in this study, the major polytomy in our tree, composed largely of siluriform parasites from the Neotropics, remained

  11. A large 28S rDNA-based phylogeny confirms the limitations of established morphological characters for classification of proteocephalidean tapeworms (Platyhelminthes, Cestoda).

    Science.gov (United States)

    de Chambrier, Alain; Waeschenbach, Andrea; Fisseha, Makda; Scholz, Tomáš; Mariaux, Jean

    2015-01-01

    Proteocephalidean tapeworms form a diverse group of parasites currently known from 315 valid species. Most of the diversity of adult proteocephalideans can be found in freshwater fishes (predominantly catfishes), a large proportion infects reptiles, but only a few infect amphibians, and a single species has been found to parasitize possums. Although they have a cosmopolitan distribution, a large proportion of taxa are exclusively found in South America. We analyzed the largest proteocephalidean cestode molecular dataset to date comprising more than 100 species (30 new), including representatives from 54 genera (80%) and all subfamilies, thus significantly improving upon previous works to develop a molecular phylogeny for the group. The Old World origin of proteocephalideans is confirmed, with their more recent expansion in South America. The earliest diverging lineages are composed of Acanthotaeniinae and Gangesiinae but most of the presently recognized subfamilies (and genera) appear not to be monophyletic; a deep systematic reorganization of the order is thus needed and the present subfamilial system should be abandoned. The main characters on which the classical systematics of the group has been built, such as scolex morphology or relative position of genital organs in relation to the longitudinal musculature, are of limited value, as demonstrated by the very weak support for morphologically-defined subfamilies. However, new characters, such as the pattern of uterus development, relative ovary size, and egg structure have been identified, which may be useful in defining phylogenetically well-supported subgroups. A strongly supported lineage infecting various snakes from a wide geographical distribution was found. Although several improvements over previous works regarding phylogenetic resolution and taxon coverage were achieved in this study, the major polytomy in our tree, composed largely of siluriform parasites from the Neotropics, remained unresolved and

  12. A large 28S rDNA-based phylogeny confirms the limitations of established morphological characters for classification of proteocephalidean tapeworms (Platyhelminthes, Cestoda)

    Science.gov (United States)

    de Chambrier, Alain; Waeschenbach, Andrea; Fisseha, Makda; Scholz, Tomáš; Mariaux, Jean

    2015-01-01

    Abstract Proteocephalidean tapeworms form a diverse group of parasites currently known from 315 valid species. Most of the diversity of adult proteocephalideans can be found in freshwater fishes (predominantly catfishes), a large proportion infects reptiles, but only a few infect amphibians, and a single species has been found to parasitize possums. Although they have a cosmopolitan distribution, a large proportion of taxa are exclusively found in South America. We analyzed the largest proteocephalidean cestode molecular dataset to date comprising more than 100 species (30 new), including representatives from 54 genera (80%) and all subfamilies, thus significantly improving upon previous works to develop a molecular phylogeny for the group. The Old World origin of proteocephalideans is confirmed, with their more recent expansion in South America. The earliest diverging lineages are composed of Acanthotaeniinae and Gangesiinae but most of the presently recognized subfamilies (and genera) appear not to be monophyletic; a deep systematic reorganization of the order is thus needed and the present subfamilial system should be abandoned. The main characters on which the classical systematics of the group has been built, such as scolex morphology or relative position of genital organs in relation to the longitudinal musculature, are of limited value, as demonstrated by the very weak support for morphologically-defined subfamilies. However, new characters, such as the pattern of uterus development, relative ovary size, and egg structure have been identified, which may be useful in defining phylogenetically well-supported subgroups. A strongly supported lineage infecting various snakes from a wide geographical distribution was found. Although several improvements over previous works regarding phylogenetic resolution and taxon coverage were achieved in this study, the major polytomy in our tree, composed largely of siluriform parasites from the Neotropics, remained

  13. 16S rDNA-based analysis reveals cosmopolitan occurrence but limited diversity of two cyanobacterial lineages with contrasted patterns of intracellular carbonate mineralization

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    Marie eRagon

    2014-07-01

    Full Text Available Cyanobacteria are mainly thought to induce carbonate precipitation extracellularly via their photosynthetic activity combined with the nucleation potential of exopolymeric substances. The discovery in microbialites of the alkaline lake Alchichica (Mexico of Candidatus Gloeomargarita lithophora, a cyanobacterium forming large amounts of intracellular Mg-Ca-Sr-Ba carbonate spherules, showed that intracellular biomineralization in cyanobacteria is also possible. A second cyanobacterium isolated from the same environment, Candidatus Synechococcus calcipolaris G9, has been recently shown to also form intracellular calcium carbonates at the cell poles, a capability shared by all cultured species of the Thermosynechococcus clade, to which it belongs. To explore the diversity of these two distant cyanobacterial lineages representing two different patterns of intracellular calcification, we designed specific primers against their 16S rRNA genes and looked for their occurrence in a wide variety of samples. We identified the presence of members of the Gloeomargarita and Thermosynechococcus/S. calcipolaris lineages in microbialites collected from Lake Alchichica and three other neighboring Mexican lakes. The two clades also occurred in karstic areas and in some thermophilic or hypersaline microbial mats collected in South America and/or Southern Europe. Surprisingly, the within-group diversity in the two clades was low, especially within the S. calcipolaris clade, with all 16S rRNA gene sequences retrieved sharing more than 97% identity. This suggests that these clades are composed of a limited number of species with cosmopolitan distribution. Moreover, scanning electron microscopy coupled with energy dispersive x-ray spectrometry showed the presence of intracellularly calcifying Gloeomargarita-like cyanobacteria in fresh samples where this clade was relatively abundant, suggesting that these cyanobacteria do precipitate carbonates intracellularly under

  14. "Artifactual" arsenate DNA

    DEFF Research Database (Denmark)

    Nielsen, Peter E

    2012-01-01

    The recent claim by Wolfe-Simon et al. that the Halomonas bacterial strain GFAJ-1 when grown in arsenate-containing medium with limiting phosphate is able to substitute phosphate with arsenate in biomolecules including nucleic acids and in particular DNA(1) arose much skepticism, primarily due...... to the very limited chemical stability of arsenate esters (see ref. 2 and references therein). A major part of the criticisms was concerned with the insufficient (bio)chemical evidence in the Wolfe-Simon study for the actual chemical incorporation of arsenate in DNA (and/or RNA). Redfield et al. now present...... evidence that the identification of arsenate DNA was artifactual....

  15. Placental apoptosis in recurrent miscarriage

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    Tarek A. Atia

    2017-09-01

    Full Text Available Apoptosis is an interactive and dynamic biological process involved in all phases of embryogenesis. We aimed to study the effect of placental apoptosis on recurrent miscarriage (RM. Placental tissue samples were collected from 40 women with RM (study group and 30 women with sporadic spontaneous abortion (control group. Samples were prepared and stained immunohistochemically with markers for both the apoptotic protein (p53 and anti-apoptotic Bcl-2 antibodies. Our results showed that expression of the apoptotic (p53 protein was significantly increased in the placental tissues of the RM group (p = 0.003. By contrast, the expression of anti-apoptotic (Bcl-2 antibodies was significantly increased in the placental tissues of the control group (p = 0.025. We concluded that placental apoptosis plays a crucial role in pregnancy continuation. However, increased p53 expression in placental tissue in early pregnancy could negatively affect pregnancy continuation.

  16. Sonodynamically induced apoptosis and active oxygen generation by gallium-porphyrin complex, ATX-70.

    Science.gov (United States)

    Yumita, Nagahiko; Okudaira, Kazuho; Momose, Yasunori; Umemura, Shin-Ichiro

    2010-11-01

    In this study, we investigated the induction of apoptosis by ultrasound in the presence of the photochemically active gallium-porphyrin complex, 7,12-bis(1-decyloxyethyl)-Ga(III)-3,8,13,17-tetramethyl-porphyrin 2,18-dipropionyl diaspartic acid (ATX-70). HL-60 cells were exposed to ultrasound for up to 3 min in the presence and absence of ATX-70, and the induction of apoptosis was examined by analyzing cell morphology, DNA fragmentation, and caspase-3 activity. Cells treated with 80 μM ATX-70 and ultrasound clearly showed membrane blebbing and cell shrinkage, whereas significant morphologic changes were not observed in cells exposed to either ultrasound or ATX-70 alone. Also, DNA ladder formation and caspase-3 activation were observed in cells treated with both ultrasound and ATX-70 but not in cells treated with ultrasound or ATX-70 alone. In addition, the combination of ATX-70 and the same acoustical arrangement of ultrasound substantially enhanced nitroxide generation by the cells. Sonodynamically induced apoptosis, caspase-3 activation, and nitroxide generation were significantly suppressed by histidine. These results indicate that the combination of ultrasound and ATX-70 induces apoptosis in HL-60 cells. The significant reduction in sonodynamically induced apoptosis, nitroxide generation, and caspase-3 activation by histidine suggests that active species such as singlet oxygen are important in the sonodynamic induction of apoptosis.

  17. Human monocytes undergo excessive apoptosis following temozolomide activating the ATM/ATR pathway while dendritic cells and macrophages are resistant.

    Directory of Open Access Journals (Sweden)

    Martina Bauer

    Full Text Available Immunodeficiency is a severe therapy-limiting side effect of anticancer chemotherapy resulting from sensitivity of immunocompetent cells to DNA damaging agents. A central role in the immune system is played by monocytes that differentiate into macrophages and dendritic cells (DCs. In this study we compared human monocytes isolated from peripheral blood and cytokine matured macrophages and DCs derived from them and assessed the mechanism of toxicity of the DNA methylating anticancer drug temozolomide (TMZ in these cell populations. We observed that monocytes, but not DCs and macrophages, were highly sensitive to the killing effect of TMZ. Studies on DNA damage and repair revealed that the initial DNA incision was efficient in monocytes while the re-ligation step of base excision repair (BER can not be accomplished, resulting in an accumulation of DNA single-strand breaks (SSBs. Furthermore, monocytes accumulated DNA double-strand breaks (DSBs following TMZ treatment, while DCs and macrophages were able to repair DSBs. Monocytes lack the DNA repair proteins XRCC1, ligase IIIα and PARP-1 whose expression is restored during differentiation into macrophages and DCs following treatment with GM-CSF and GM-CSF plus IL-4, respectively. These proteins play a key role both in BER and DSB repair by B-NHEJ, which explains the accumulation of DNA breaks in monocytes following TMZ treatment. Although TMZ provoked an upregulation of XRCC1 and ligase IIIα, BER was not enhanced likely because PARP-1 was not upregulated. Accordingly, inhibition of PARP-1 did not sensitize monocytes, but monocyte-derived DCs in which strong PARP activation was observed. TMZ induced in monocytes the DNA damage response pathways ATM-Chk2 and ATR-Chk1 resulting in p53 activation. Finally, upon activation of the Fas-receptor and the mitochondrial pathway apoptosis was executed in a caspase-dependent manner. The downregulation of DNA repair in monocytes, resulting in their selective

  18. Autophagy in DNA Damage Response

    Directory of Open Access Journals (Sweden)

    Piotr Czarny

    2015-01-01

    Full Text Available DNA damage response (DDR involves DNA repair, cell cycle regulation and apoptosis, but autophagy is also suggested to play a role in DDR. Autophagy can be activated in response to DNA-damaging agents, but the exact mechanism underlying this activation is not fully understood, although it is suggested that it involves the inhibition of mammalian target of rapamycin complex 1 (mTORC1. mTORC1 represses autophagy via phosphorylation of the ULK1/2–Atg13–FIP200 complex thus preventing maturation of pre-autophagosomal structures. When DNA damage occurs, it is recognized by some proteins or their complexes, such as poly(ADPribose polymerase 1 (PARP-1, Mre11–Rad50–Nbs1 (MRN complex or FOXO3, which activate repressors of mTORC1. SQSTM1/p62 is one of the proteins whose levels are regulated via autophagic degradation. Inhibition of autophagy by knockout of FIP200 results in upregulation of SQSTM1/p62, enhanced DNA damage and less efficient damage repair. Mitophagy, one form of autophagy involved in the selective degradation of mitochondria, may also play role in DDR. It degrades abnormal mitochondria and can either repress or activate apoptosis, but the exact mechanism remains unknown. There is a need to clarify the role of autophagy in DDR, as this process may possess several important biomedical applications, involving also cancer therapy.

  19. N-acetylcysteine prevents cadmium-induced apoptosis in human breast cancer MDA-MB468 cell line.

    Science.gov (United States)

    Panjehpour, M; Alaie, S H

    2014-05-11

    Cadmium is a heavy metal posing severe risks and destructive effects on human health. Although cadmium was classified as a human carcinogen, it has been also shown to be a cytotoxic agent that induces cell death either by necrosis or apoptosis. In this study, we investigated the protective role of N-acetylcysteine, a free radical scavenger, on cadmium induced apoptosis in MDA-MB468 cells. The breast cancer cells were exposed to increasing concentrations of CdCl2 in the presence and absence of NAC and the cell viability was assessed using MTT assay. The microscopic studies of apoptosis were carried out with fluorescent staining. To investigate the induction of apoptosis, cellular DNA was isolated using DNA kit extraction and analyzed electrophoretically. The results showed significant decrease in cellular viability upon 48 hours exposure to CdCl2 in a dose-dependent manner (p cadmium cytotoxicity effects and protected cells from apoptotic death. DNA Hoechst staining showed the apoptotic bodies. The electrophoresis of extracted DNA identified a fragmentation pattern consistent with apoptosis mechanism. The results suggest that cytotoxic effects and induction of apoptosis caused by CdCl2 are mediated, by oxidative stress.

  20. Role of Smac in apoptosis of lung cancer cells A549 induced by Taxol.

    Science.gov (United States)

    Zhang, Ying; Hao, Yingtao; Sun, Qifeng; Peng, Chuanliang

    2015-01-01

    A series of structurally unique second mitochondria-derived activators of caspase (Smac) that act as antagonists of inhibitor of apoptosis proteins (IAPs) directly have been discovered and have been shown to promote chemotherapy-induced apoptosis. In this study, we investigate the role of Smac in Taxol-induced apoptosis of lung cancer cell in vitro. PcDNA3.1/Smac recombinants were transfected into the non-small cell lung cancer cell line A549. Smac expression was detected by RT-PCR and Western blot. The invasive ability of cells was examined. Flow cytometry was used to analyze apoptosis of cells induced by Taxol with Annexin V/PI double staining technique. Smac expression was significantly higher in the PcDNA3.1/Smac recombinant group than in the untransfected group at mRNA and protein level (p Smac group. There were significant differences compared to the empty vector group and control group. The apoptosis rate was significantly higher in PcDNA3.1/Smac + Taxol group than in other groups (p Smac can enhance the chemosensitivity of the non-small cell lung cancer cell line A549 to Taxol.

  1. PUMA promotes apoptosis of hematopoietic progenitors driving leukemic progression in a mouse model of myelodysplasia.

    Science.gov (United States)

    Guirguis, A A; Slape, C I; Failla, L M; Saw, J; Tremblay, C S; Powell, D R; Rossello, F; Wei, A; Strasser, A; Curtis, D J

    2016-06-01

    Myelodysplastic syndrome (MDS) is characterized by ineffective hematopoiesis with resultant cytopenias. Increased apoptosis and aberrantly functioning progenitors are thought to contribute to this phenotype. As is the case for other malignancies, overcoming apoptosis is believed to be important in progression toward acute myeloid leukemia (AML). Using the NUP98-HOXD13 (NHD13) transgenic mouse model of MDS, we previously reported that overexpression of the anti-apoptotic protein BCL2, blocked apoptosis and improved cytopenias, paradoxically, delaying leukemic progression. To further understand this surprising result, we examined the role of p53 and its pro-apoptotic effectors, PUMA and NOXA in NHD13 mice. The absence of p53 or PUMA but not NOXA reduced apoptosis and expanded the numbers of MDS-repopulating cells. Despite a similar effect on apoptosis and cell numbers, the absence of p53 and PUMA had diametrically opposed effects on progression to AML: absence of p53 accelerated leukemic progression, while absence of PUMA significantly delayed progression. This may be explained in part by differences in cellular responses to DNA damage. The absence of p53 led to higher levels of γ-H2AX (indicative of persistent DNA lesions) while PUMA-deficient NHD13 progenitors resolved DNA lesions in a manner comparable to wild-type cells. These results suggest that targeting PUMA may improve the cytopenias of MDS without a detrimental effect on leukemic progression thus warranting further investigation.

  2. Ultraviolet B irradiation of human leukaemia HL-60 cells in vitro induces apoptosis

    International Nuclear Information System (INIS)

    Martin, S.J.; Cotter, T.G.

    1991-01-01

    UV radiation is known to be a potent agent for the induction of programmed cell death (apoptosis) in human skin. However, the mechanistic aspects of UV-induced apoptosis remain ill-defined. In this study the effects of varying periods of UV-irradiation on the human leukaemia HL-60 cell line and on five other human cell lines were investigated.HL-60 cells were found to rapidly undergo apoptosis en masse after short periods of UV-irradiation whereas prolonged exposure of these cells to this form of radiation induced a more rapid form of cell death which was suggestive of necrosis, the pathological mode of cell death. UV-induced apoptosis in cell lines was characterized by morphological changes as well as DNA fragmentation into unit multiples of ∼ 200 bp, which was indicative of endogenous endonuclease activation. This DNA fragmentation pattern was not detected in cells immediately after UV-irradiation, and was therefore not the result of direct UV-induced DNA damage. UV-induced apoptosis of the HL-60 cell line was found to require extracellular calcium and to be inhibited in a dose-dependent way by zinc added to the culture medium. (author)

  3. DNA Nanotechnology for Cancer Therapy.

    Science.gov (United States)

    Kumar, Vinit; Palazzolo, Stefano; Bayda, Samer; Corona, Giuseppe; Toffoli, Giuseppe; Rizzolio, Flavio

    2016-01-01

    DNA nanotechnology is an emerging and exciting field, and represents a forefront frontier for the biomedical field. The specificity of the interactions between complementary base pairs makes DNA an incredible building material for programmable and very versatile two- and three-dimensional nanostructures called DNA origami. Here, we analyze the DNA origami and DNA-based nanostructures as a drug delivery system. Besides their physical-chemical nature, we dissect the critical factors such as stability, loading capability, release and immunocompatibility, which mainly limit in vivo applications. Special attention was dedicated to highlighting the boundaries to be overcome to bring DNA nanostructures closer to the bedside of patients.

  4. DNA Nanotechnology for Cancer Therapy

    Science.gov (United States)

    Kumar, Vinit; Palazzolo, Stefano; Bayda, Samer; Corona, Giuseppe; Toffoli, Giuseppe; Rizzolio, Flavio

    2016-01-01

    DNA nanotechnology is an emerging and exciting field, and represents a forefront frontier for the biomedical field. The specificity of the interactions between complementary base pairs makes DNA an incredible building material for programmable and very versatile two- and three-dimensional nanostructures called DNA origami. Here, we analyze the DNA origami and DNA-based nanostructures as a drug delivery system. Besides their physical-chemical nature, we dissect the critical factors such as stability, loading capability, release and immunocompatibility, which mainly limit in vivo applications. Special attention was dedicated to highlighting the boundaries to be overcome to bring DNA nanostructures closer to the bedside of patients. PMID:27022418

  5. Zinc finger protein 598 inhibits cell survival by promoting UV-induced apoptosis.

    Science.gov (United States)

    Yang, Qiaohong; Gupta, Romi

    2018-01-19

    UV is one of the major causes of DNA damage induced apoptosis. However, cancer cells adopt alternative mechanisms to evade UV-induced apoptosis. To identify factors that protect cancer cells from UV-induced apoptosis, we performed a genome wide short-hairpin RNA (shRNA) screen, which identified Zinc finger protein 598 (ZNF598) as a key regulator of UV-induced apoptosis. Here, we show that UV irradiation transcriptionally upregulates ZNF598 expression. Additionally, ZNF598 knockdown in cancer cells inhibited UV-induced apoptosis. In our study, we observe that ELK1 mRNA level as well as phosphorylated ELK1 levels was up regulated upon UV irradiation, which was necessary for UV irradiation induced upregulation of ZNF598. Cells expressing ELK1 shRNA were also resistant to UV-induced apoptosis, and phenocopy ZNF598 knockdown. Upon further investigation, we found that ZNF598 knockdown inhibits UV-induced apoptotic gene expression, which matches with decrease in percentage of annexin V positive cell. Similarly, ectopic expression of ZNF598 promoted apoptotic gene expression and also increased annexin V positive cells. Collectively, these results demonstrate that ZNF598 is a UV irradiation regulated gene and its loss results in resistance to UV-induced apoptosis.

  6. Coxsackievirus A16 infection induces neural cell and non-neural cell apoptosis in vitro.

    Directory of Open Access Journals (Sweden)

    Zhaolong Li

    Full Text Available Coxsackievirus A16 (CA16 is one of the main causative pathogens of hand, foot and mouth disease (HFMD. Viral replication typically results in host cell apoptosis. Although CA16 infection has been reported to induce apoptosis in the human rhabdomyosarcoma (RD cell line, it remains unclear whether CA16 induces apoptosis in diverse cell types, especially neural cells which have important clinical significance. In the current study, CA16 infection was found to induce similar apoptotic responses in both neural cells and non-neural cells in vitro, including nuclear fragmentation, DNA fragmentation and phosphatidylserine translocation. CA16 generally is not known to lead to serious neurological symptoms in vivo. In order to further clarify the correlation between clinical symptoms and cell apoptosis, two CA16 strains from patients with different clinical features were investigated. The results showed that both CA16 strains with or without neurological symptoms in infected patients led to neural and muscle cell apoptosis. Furthermore, mechanistic studies showed that CA16 infection induced apoptosis through the same mechanism in both neural and non-neural cells, namely via activation of both the mitochondrial (intrinsic pathway-related caspase 9 protein and the Fas death receptor (extrinsic pathway-related caspase 8 protein. Understanding the mechanisms by which CA16 infection induces apoptosis in both neural and non-neural cells will facilitate a better understanding of CA16 pathogenesis.

  7. Enhanced 15-HPETE production during oxidant stress induces apoptosis of endothelial cells.

    Science.gov (United States)

    Sordillo, Lorraine M; Weaver, James A; Cao, Yu-Zhang; Corl, Chris; Sylte, Matt J; Mullarky, Isis K

    2005-05-01

    Oxidant stress plays an important role in the etiology of vascular diseases by increasing rates of endothelial cell apoptosis, but few data exist on the mechanisms involved. Using a unique model of oxidative stress based on selenium deficiency (-Se), the effects of altered eicosanoid production on bovine aortic endothelial cells (BAEC) apoptosis was evaluated. Oxidant stress significantly increased the immediate oxygenation product of arachidonic acid metabolized by the 15-lipoxygenase pathway, 15-hydroxyperoxyeicosatetraenoic acid (15-HPETE). Treatment of -Se BAEC with TNFalpha/cyclohexamide (CHX) exhibited elevated levels of apoptosis, which was significantly reduced by the addition of a specific 15-lipoxygenase inhibitor PD146176. Furthermore, the addition of 15-HPETE to PD146176-treated BAEC, partially restored TNF/CHX-induced apoptosis. Increased exposure to 15-HPETE induced apoptosis, as determined by internucleosomal DNA fragmentation, chromatin condensation, caspase-3 activation, and caspase-9 activation, which suggests mitochondrial dysfunction. The expression of Bcl-2 protein also was decreased in -Se BAEC. Addition of a caspase-9 inhibitor (LEHD-fmk) completely blocked 15-HPETE-induced chromatin condensation in -Se BAEC, suggesting that 15-HPETE-induced apoptosis is caspase-9 dependent. Increased apoptosis of BAEC as a result of oxidant stress and subsequent production of 15-HPETE may play a critical role in a variety of inflammatory based diseases.

  8. Selected aspects of apoptosis in psoriasis

    Directory of Open Access Journals (Sweden)

    Hanna Myśliwiec

    2017-03-01

    Full Text Available Apoptosis is a physiological mechanism of programmed cell death, in contrast to necrosis, without eliciting an inflammatory response. It plays the key role in the functioning of different tissues and organs. The balance between proliferation and apoptosis of keratinocytes is important for epidermal maintenance of homeostasis. Dysfunctional apoptosis plays an important role in the development of several skin disorders. Diseases with an increase of apoptosis are usually acute, while those with inhibited apoptosis tend to be chronic. Psoriasis is an immune-mediated chronic inflammatory skin disease. It is characterized by keratinocyte hyperproliferation and abnormal differentiation. Psoriatic keratinocytes are resistant to apoptosis and this phenomenon can be the key event in psoriatic hyperplasia. Apoptosis disturbances can also affect immune cells involved in the pathogenesis of psoriasis. In this review, we describe the basic concept of apoptosis and its relevance in psoriatic pathogenesis.

  9. Effects of estradiol on radiation-induced apoptosis in immunocytes of mouse

    International Nuclear Information System (INIS)

    Wu Wei; Yang Rujun; Kong Xiantao; Zhang Lingzhen; Li Bolong; Cai Jianming

    2000-01-01

    Objective: To assess the effects of estradiol on 60 Co γ-radiation induced apoptosis of splenic lymphocytes and thymocytes, and surface molecule expression of splenic lymphocytes. Methods: Mice were whole body irradiated with 4.0 Gy γ-rays. By flow cytometry and electrophoretic analysis of DNA, the changes in apoptosis of mouse immunocytes were determined. The splenic lymphocytes were analyzed by flow cytometry with fluorescent monoclonal antibodies. Results: 10 days after administration of estradiol, the characteristic DNA ladder in mice 8h after irradiation was minor than in mice without estradiol administration,indicating that the apoptotic rate reduced on flow cytometry. CD4+ T cells, CD8+ T cells and IgM+ B cells up regulated Fas, CD25 and CD69 expression, but did not so in the estradiol treated mice. Conclusion: Estradiol can block CD25, CD69 and Fas overexpression, thereby inhibiting Fas mediated apoptosis induced by γ-irradiation

  10. Radiation Combined Injury: DNA Damage, Apoptosis, and Autophagy

    Science.gov (United States)

    2010-01-01

    potential for nuclear accidents and accidental exposures will become greater with the expected proliferation of nuclear power plant construction to meet...radiological weapons poses a seri- ous risk of mass casualties. The fact that more than 50% of cancer patients receive radiotherapy at some point during...alone. It is unrealistic however to assume that accidental radiation injury will occur in the absence of other injuries—especially when considering

  11. Impact of four antimutagens on apoptosis in genotoxically damaged lymphocytes in vitro.

    Science.gov (United States)

    Gasiorowski, K; Brokos, B; Kulma, A; Ogorzałek, A; Skórkowska, K

    2001-01-01

    An antimutagenic activity of fluphenazine, todralazine, anthocyanins and alkylresorcinols was established in a battery of short-term cytogenetic tests. One of the possible mechanisms of their antimutagenic action could be an increase in apoptotic elimination of heavily-damaged cells from a culture. In this paper we provide data on quantitative estimation of the antimutagens' impact on apoptosis in lymphocyte cultures exposed in the G(0)-phase to genotoxic agents: hydrogen peroxide (0.2mM, 20 min.) or benzo[a]pyrene (40 microM, 90 min.), and then cultured for 36 hrs in the presence of a lectin (PHA-M, 1% v/v) and each of the tested antimutagens. Apoptosis was estimated by means of microscopic examination of cell smears stained with a mixture of fluorochromes (ethidium bromide/acridine orange) as well as of the results of DNA separation with the field inversion gel electrophoresis. By microscopic examination we assessed that the frequencies of cells exhibiting morphological features of apoptosis considerably increased in the cultures containing the antimutagens. The FIGE separation of DNA from those cultures proved that the DNA content in the 30-50 kb domain was markedly elevated, as compared with the control cultures that did not contain antimutagens. It was established in the regression analysis that the apoptosis-enhancing effect significantly depended on the concentration of each tested antimutagen in a culture medium. However, marked differences of apoptosis-enhancing potency were noticed among the four antimutagens. The multicriterial analysis proved that the apoptosis-enhancing effects of fluphenazine and also, to a smaller extent, by alkylresorcinols, were many times stronger than those of anthocyanins and of todralazine. The results suggest that the enhancement of apoptosis by fluphenazine and by alkylresorcinols can explain a major part of their antimutagenic activity, whereas in the case of anthocyanins and of todralazine other mechanisms of antimutagenic

  12. Interdependence of Bad and Puma during ionizing-radiation-induced apoptosis.

    Directory of Open Access Journals (Sweden)

    Cristhian Toruno

    Full Text Available Ionizing radiation (IR-induced DNA double-strand breaks trigger an extensive cellular signaling response that involves the coordination of hundreds of proteins to regulate DNA repair, cell cycle arrest and apoptotic pathways. The cellular outcome often depends on the level of DNA damage as well as the particular cell type. Proliferating zebrafish embryonic neurons are highly sensitive to IR-induced apoptosis, and both p53 and its transcriptional target puma are essential mediators of the response. The BH3-only protein Puma has previously been reported to activate mitochondrial apoptosis through direct interaction with the pro-apoptotic Bcl-2 family proteins Bax and Bak, thus constituting the role of an "activator" BH3-only protein. This distinguishes it from BH3-only proteins like Bad that are thought to indirectly promote apoptosis through binding to anti-apoptotic Bcl-2 family members, thereby preventing the sequestration of activator BH3-only proteins and allowing them to directly interact with and activate Bax and Bak. We have shown previously that overexpression of the BH3-only protein Bad in zebrafish embryos supports normal embryonic development but greatly sensitizes developing neurons to IR-induced apoptosis. While Bad has previously been shown to play only a minor role in promoting IR-induced apoptosis of T cells in mice, we demonstrate that Bad is essential for robust IR-induced apoptosis in zebrafish embryonic neural tissue. Moreover, we found that both p53 and Puma are required for Bad-mediated radiosensitization in vivo. Our findings show the existence of a hierarchical interdependence between Bad and Puma whereby Bad functions as an essential sensitizer and Puma as an essential activator of IR-induced mitochondrial apoptosis specifically in embryonic neural tissue.

  13. Deltamethrin-induced testicular apoptosis in rats: the protective effect of nitric oxide synthase inhibitor.

    Science.gov (United States)

    El-Gohary, M; Awara, W M; Nassar, S; Hawas, S

    1999-01-01

    This study is the first to examine and characterize the testicular apoptosis which might be induced due to exposure of male rats to deltamethrin. Furthermore, the role which might be played by nitric oxide (NO), as well as the other reactive oxygen species (ROS) in controlling this testicular apoptosis was assessed. Apoptosis was evaluated by DNA fragmentation detected by agarose gel electrophoresis and cellular morphology on testicular tissue sections. It was found that administration of deltamethrin (1 mg/kg daily for 21 days) to animals resulted in characteristic DNA migration patterns (laddering), thereby providing evidence that apoptosis is the major mechanism of cell death in the testicular tissues. In addition, histopathological examination of testicular tissue sections showed that apoptosis was confined to the basal germ cells, primary and secondary spermatocytes. These changes, in addition to the appearance of Sertoli cell vacuoles in deltamethrin-intoxicated animals, indicates the suppression of spermatogenesis. At the same time, the plasma levels of both NO and lipid peroxides measured as malondialdehyde (MDA) were found to be significantly increased in deltamethrin-treated animals. Administration of NO synthase (NOS) inhibitors such as N(G)-nitro monomethyl L-arginine hydrochloride (L-NMMA, 1 mg/kg) to rats 2 h before exposure to deltamethrin was effective in the reduction of the typically testicular apoptotic DNA fragmentation pattern and the associated histopathological changes. These findings may suggest that deltamethrin-induced testicular apoptosis is mediated by NO. Therefore, the pharmacological manipulation of apoptosis by selective NOS inhibitors such as L-NMMA may offer new possibilities for the control of deltamethrin-induced testicular dysfunction and infertility in the future.

  14. DNA Microarrays

    Science.gov (United States)

    Nguyen, C.; Gidrol, X.

    Genomics has revolutionised biological and biomedical research. This revolution was predictable on the basis of its two driving forces: the ever increasing availability of genome sequences and the development of new technology able to exploit them. Up until now, technical limitations meant that molecular biology could only analyse one or two parameters per experiment, providing relatively little information compared with the great complexity of the systems under investigation. This gene by gene approach is inadequate to understand biological systems containing several thousand genes. It is essential to have an overall view of the DNA, RNA, and relevant proteins. A simple inventory of the genome is not sufficient to understand the functions of the genes, or indeed the way that cells and organisms work. For this purpose, functional studies based on whole genomes are needed. Among these new large-scale methods of molecular analysis, DNA microarrays provide a way of studying the genome and the transcriptome. The idea of integrating a large amount of data derived from a support with very small area has led biologists to call these chips, borrowing the term from the microelectronics industry. At the beginning of the 1990s, the development of DNA chips on nylon membranes [1, 2], then on glass [3] and silicon [4] supports, made it possible for the first time to carry out simultaneous measurements of the equilibrium concentration of all the messenger RNA (mRNA) or transcribed RNA in a cell. These microarrays offer a wide range of applications, in both fundamental and clinical research, providing a method for genome-wide characterisation of changes occurring within a cell or tissue, as for example in polymorphism studies, detection of mutations, and quantitative assays of gene copies. With regard to the transcriptome, it provides a way of characterising differentially expressed genes, profiling given biological states, and identifying regulatory channels.

  15. A Photosensitizer-Loaded DNA Origami Nanosystem for Photodynamic Therapy.

    Science.gov (United States)

    Zhuang, Xiaoxi; Ma, Xiaowei; Xue, Xiangdong; Jiang, Qiao; Song, Linlin; Dai, Luru; Zhang, Chunqiu; Jin, Shubin; Yang, Keni; Ding, Baoquan; Wang, Paul C; Liang, Xing-Jie

    2016-03-22

    Photodynamic therapy (PDT) offers an alternative for cancer treatment by using ultraviolet or visible light in the presence of a photosensitizer and molecular oxygen, which can produce highly reactive oxygen species that ultimately leading to the ablation of tumor cells by multifactorial mechanisms. However, this technique is limited by the penetration depth of incident light, the hypoxic environment of solid tumors, and the vulnerability of photobleaching reduces the efficiency of many imaging agents. In this work, we reported a cellular level dual-functional imaging and PDT nanosystem BMEPC-loaded DNA origami for photodynamic therapy with high efficiency and stable photoreactive property. The carbazole derivative BMEPC is a one- and two-photon imaging agent and photosensitizer with large two-photon absorption cross section, which can be fully excited by near-infrared light, and is also capable of destroying targets under anaerobic condition by generating reactive intermediates of Type I photodynamic reactions. However, the application of BMEPC was restricted by its poor solubility in aqueous environment and its aggregation caused quenching. We observed BMEPC-loaded DNA origami effectively reduced the photobleaching of BMEPC within cells. Upon binding to DNA origami, the intramolecular rotation of BMEPC became proper restricted, which intensify fluorescence emission and radicals production when being excited. After the BMEPC-loaded DNA origami are taken up by tumor cells, upon irradiation, BMEPC could generate free radicals and be released due to DNA photocleavage as well as the following partially degradation. Apoptosis was then induced by the generation of free radicals. This functional nanosystem provides an insight into the design of photosensitizer-loaded DNA origami for effective intracellular imaging and photodynamic therapy.

  16. Endoplasmic reticulum stress and IRE-1 signaling cause apoptosis in colon cancer cells in response to andrographolide treatment

    OpenAIRE

    Banerjee, Aditi; Ahmed, Hafiz; Yang, Peixin; Czinn, Steven J.; Blanchard, Thomas G.

    2016-01-01

    The plant metabolite andrographolide induces cell cycle arrest and apoptosis in cancer cells. The mechanism(s) by which andrographolide induces apoptosis however, have not been elucidated. The present study was performed to determine the molecular events that promote apoptosis in andrographolide treated cells using T84, HCT116 and COLO 205 colon cancer cell lines. Andrographolide was determined to limit colony formation and Ki67 expression, alter nuclear morphology, increase cytoplasmic histo...

  17. Apoptosis detection in histological sections

    Czech Academy of Sciences Publication Activity Database

    Matalová, Eva; Dubská, Lenka; Míšek, Ivan

    2003-01-01

    Roč. 72, č. 7 (2003), s. 18-19 ISSN 0001-7213. [Congress of the European Association of Veterinary Anatomists/24./. 21.07.2002-25.07.2002, Brno] R&D Projects: GA ČR GP204/02/P112 Institutional research plan: CEZ:AV0Z5045916 Keywords : apoptosis Subject RIV: FF - HEENT, Dentistry

  18. Intestinal epithelial apoptosis initiates gross bowel necrosis in an experimental rat model of neonatal necrotizing enterocolitis.

    Science.gov (United States)

    Jilling, Tamas; Lu, Jing; Jackson, Michele; Caplan, Michael S

    2004-04-01

    The histopathology of necrotizing enterocolitis (NEC) is characterized by destruction of the mucosal layer in initial stages and by transmural necrosis of the intestinal wall in advanced stages of the disease. To test the hypothesis that enhanced epithelial apoptosis is an initial event underlying the gross histologic changes, we analyzed epithelial apoptosis and tissue morphology in an animal model of NEC and evaluated the effect of caspase inhibition on the incidence of experimental NEC in this model. Apoptosis was analyzed with terminal deoxynucleotidyltransferase-mediated dUTP-FITC nick end labeling (TUNEL) staining in intestinal sections and by measuring caspase 3 activity from intestinal lysates of neonatal rats subjected to formula feeding and cold/asphyxia stress (FFCAS) and from mother-fed (MF) controls. Morphologic evaluation was based on hematoxylin and eosin staining of intestinal sections. FFCAS resulted in histologic changes consistent with NEC, which were absent from MF animals. FFCAS was also associated with a significantly increased rate of nuclear DNA fragmentation in the small intestinal epithelium compared with MF. Elevated tissue caspase 3 activity confirmed the presence of apoptosis in samples with increased DNA fragmentation. Analysis of the coincidence of morphologic damage and apoptosis in corresponding tissue sections indicated that apoptosis precedes gross morphologic changes in this model. Furthermore, supplementation of formula with 8 boc-aspartyl(OMe)-fluoromethylketone, a pan-caspase inhibitor, significantly reduced the incidences of apoptosis and experimental NEC. These findings indicate that in neonatal rats FFCAS induces epithelial apoptosis that serves as an underlying cause for subsequent gross tissue necrosis.

  19. Apoptosis induced by GanoPoly in human gastric cancer cell line ...

    African Journals Online (AJOL)

    In order to investigate polysaccharide effect on the cultured human gastric cancer cells (SGC7901), DNA ladder, flow cytometry and western blot were used to examine the morpholog, proliferation and apoptosis of human gastric cancer SGC-7901 cells when they were affected by polysaccharide. Results show that ...

  20. CIRRHOSIS INDUCES APOPTOSIS IN RENAL TISSUE THROUGH INTRACELLULAR OXIDATIVE STRESS

    Directory of Open Access Journals (Sweden)

    Keli Cristina Simões da SILVEIRA

    2015-03-01

    Full Text Available Background Renal failure is a frequent and serious complication in patients with decompensated cirrhosis. Objectives We aimed to evaluate the renal oxidative stress, cell damage and impaired cell function in animal model of cirrhosis. Methods Secondary biliary cirrhosis was induced in rats by ligation of the common bile duct. We measured TBARS, ROS and mitochondrial membrane potential in kidney as markers of oxidative stress, and activities of the antioxidant enzymes. Relative cell viability was determined by trypan blue dye-exclusion assay. Annexin V-PE was used with a vital dye, 7-AAD, to distinguish apoptotic from necrotic cells and comet assay was used for determined DNA integrity in single cells. Results In bile duct ligation animals there was significant increase in the kidney lipoperoxidation and an increase of the level of intracellular ROS. There was too an increase in the activity of all antioxidant enzymes evaluated in the kidney. The percentage viability was above 90% in the control group and in bile duct ligation was 64.66% and the dominant cell death type was apoptosis. DNA damage was observed in the bile duct ligation. There was a decreased in the mitochondrial membrane potential from 71.40% ± 6.35% to 34.48% ± 11.40% in bile duct ligation. Conclusions These results indicate that intracellular increase of ROS cause damage in the DNA and apoptosis getting worse the renal function in cirrhosis.

  1. Electrochemical DNA sensor-based strategy for sensitive detection of DNA demethylation and DNA demethylase activity.

    Science.gov (United States)

    Shen, Qingming; Fan, Mengxing; Yang, Yin; Zhang, Hui

    2016-08-31

    DNA demethylation and demethylase activity play important roles in DNA self-repair, and their detection is key to early diagnosis of fatal diseases. Herein, a facile electrochemical DNA (E-DNA) sensor was developed for the sensitive detection of DNA demethylation and demethylase activity based on an enzyme cleavage strategy. The thiol modified hemi-methylated hairpin probe DNA (pDNA) was self-assembled on a Au electrode surface through the formation of AuS bonds. The hemi-methylated pDNA served as the substrate of DNA demethylase (using methyl-CpG-binding domain protein 2 (MBD2) as an example). Following demethylation, the hairpin stem was then recognized and cleaved by BstUI endonuclease. The ferrocene carboxylic acid (FcA)-tagged pDNA strands were released into the buffer solution from the electrode surface, resulting in a significant decrease of electrochemical signal and providing a means to observe DNA demethylation. The activity of DNA demethylase was analyzed in the concentration ranging from 0.5 to 500 ng mL(-1) with a limit of detection as low as 0.17 ng mL(-1). With high specificity and sensitivity, rapid response, and low cost, this simple E-DNA sensor provides a unique platform for the sensitive detection of DNA demethylation, DNA demethylase activity, and related molecular diagnostics and drug screening. Copyright © 2016 Elsevier B.V. All rights reserved.

  2. Carbon ion beam triggers both caspase-dependent and caspase-independent pathway of apoptosis in HeLa and status of PARP-1 controls intensity of apoptosis.

    Science.gov (United States)

    Ghorai, Atanu; Sarma, Asitikantha; Bhattacharyya, Nitai P; Ghosh, Utpal

    2015-04-01

    High linear energy transfer (LET) carbon ion beam (CIB) is becoming very promising tool for various cancer treatments and is more efficient than conventional low LET gamma or X-rays to kill malignant or radio-resistant cells, although detailed mechanism of cell death is still unknown. Poly (ADP-ribose) polymerase-1 (PARP-1) is a key player in DNA repair and its inhibitors are well-known as radio-sensitizer for low LET radiation. The objective of our study was to find mechanism(s) of induction of apoptosis by CIB and role of PARP-1 in CIB-induced apoptosis. We observed overall higher apoptosis in PARP-1 knocked down HeLa cells (HsiI) compared with negative control H-vector cells after irradiation with CIB (0-4 Gy). CIB activated both intrinsic and extrinsic pathways of apoptosis via caspase-9 and caspase-8 activation respectively, followed by caspase-3 activation, apoptotic body, nucleosomal ladder formation and sub-G1 accumulation. Apoptosis inducing factor translocation into nucleus in H-vector but not in HsiI cells after CIB irradiation contributed caspase-independent apoptosis. Higher p53 expression was observed in HsiI cells compared with H-vector after exposure with CIB. Notably, we observed about 37 % fall of mitochondrial membrane potential, activation of caspase-9 and caspase-3 and mild activation of caspase-8 without any detectable apoptotic body formation in un-irradiated HsiI cells. We conclude that reduction of PARP-1 expression activates apoptotic signals via intrinsic and extrinsic pathways in un-irradiated cells. CIB irradiation further intensified both intrinsic and extrinsic pathways of apoptosis synergistically along with up-regulation of p53 in HsiI cells resulting overall higher apoptosis in HsiI than H-vector.

  3. Phorbol Esters Isolated from Jatropha Meal Induced Apoptosis-Mediated Inhibition in Proliferation of Chang and Vero Cell Lines

    Directory of Open Access Journals (Sweden)

    Syahida Ahmad

    2012-10-01

    Full Text Available The direct feeding of Jatropha meal containing phorbol esters (PEs indicated mild to severe toxicity symptoms in various organs of different animals. However, limited information is available on cellular and molecular mechanism of toxicity caused by PEs present in Jatropha meal. Thus, the present study was conducted to determine the cytotoxic and mode of action of PEs isolated from Jatropha meal using human hepatocyte (Chang and African green monkey kidney (Vero cell lines. The results showed that isolated PEs inhibited cell proliferation in a dose-dependent manner in both cell lines with the CC50 of 125.9 and 110.3 μg/mL, respectively. These values were compatible to that of phorbol 12-myristate 13-acetate (PMA values as positive control i.e., 124.5 and 106.3 μg/mL respectively. Microscopic examination, flow cytometry and DNA fragmentation results confirmed cell death due to apoptosis upon treatment with PEs and PMA at CC50 concentration for 24 h in both cell lines. The Western blot analysis revealed the overexpression of PKC-δ and activation of caspase-3 proteins which could be involved in the mechanism of action of PEs and PMA. Consequently, the PEs isolated form Jatropha meal caused toxicity and induced apoptosis-mediated proliferation inhibition toward Chang and Vero cell lines involving over-expression of PKC-δ and caspase-3 as their mode of actions.

  4. Modulation of the BRCA1 Protein and Induction of Apoptosis in Triple Negative Breast Cancer Cell Lines by the Polyphenolic Compound Curcumin

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    Danica L. Rowe

    2009-09-01

    Full Text Available In the current study, we sought to examine the effects of curcumin in a specific type of breast cancer called triple negative breast cancer. These cancers lack expression of the estrogen and progesterone receptors and do not over-express HER2. Current treatment for triple negative breast cancers is limited to cytotoxic chemotherapy, and upon relapse, there are not any therapies currently available. We demonstrate here that the bioactive food compound curcumin induces DNA damage in triple negative breast cancer cells in association with phosphorylation, increased expression, and cytoplasmic retention of the BRCA1 protein. In addition, curcumin promotes apoptosis and prevents anchorage-independent growth and migration of triple negative breast cancer cells. Apoptosis and BRCA1 modulation were not observed in non-transformed mammary epithelial cells, suggesting curcumin may have limited non-specific toxicity. This study suggests that curcumin and potentially curcumin analogues should be tested further in the context of triple negative breast cancer. These results are novel, having never been previously reported, and suggest that curcumin could provide a novel, non-toxic therapy, which could lead to improved survival for patients with triple negative breast cancer. Curcumin should be studied further in this subset of breast cancer patients, for whom treatment options are severely limited.

  5. Interference of Apoptosis by Hepatitis B Virus.

    Science.gov (United States)

    Lin, Shaoli; Zhang, Yan-Jin

    2017-08-18

    Hepatitis B virus (HBV) causes liver diseases that have been a consistent problem for human health, leading to more than one million deaths every year worldwide. A large proportion of hepatocellular carcinoma (HCC) cases across the world are closely associated with chronic HBV infection. Apoptosis is a programmed cell death and is frequently altered in cancer development. HBV infection interferes with the apoptosis signaling to promote HCC progression and viral proliferation. The HBV-mediated alteration of apoptosis is achieved via interference with cellular signaling pathways and regulation of epigenetics. HBV X protein (HBX) plays a major role in the interference of apoptosis. There are conflicting reports on the HBV interference of apoptosis with the majority showing inhibition of and the rest reporting induction of apoptosis. In this review, we described recent studies on the mechanisms of the HBV interference with the apoptosis signaling during the virus infection and provided perspective.

  6. Interference of Apoptosis by Hepatitis B Virus

    Science.gov (United States)

    2017-01-01

    Hepatitis B virus (HBV) causes liver diseases that have been a consistent problem for human health, leading to more than one million deaths every year worldwide. A large proportion of hepatocellular carcinoma (HCC) cases across the world are closely associated with chronic HBV infection. Apoptosis is a programmed cell death and is frequently altered in cancer development. HBV infection interferes with the apoptosis signaling to promote HCC progression and viral proliferation. The HBV-mediated alteration of apoptosis is achieved via interference with cellular signaling pathways and regulation of epigenetics. HBV X protein (HBX) plays a major role in the interference of apoptosis. There are conflicting reports on the HBV interference of apoptosis with the majority showing inhibition of and the rest reporting induction of apoptosis. In this review, we described recent studies on the mechanisms of the HBV interference with the apoptosis signaling during the virus infection and provided perspective. PMID:28820498

  7. Cyclopalladated Compound 7a Induces Apoptosis- and Autophagy-Like Mechanisms in Paracoccidioides and Is a Candidate for Paracoccidioidomycosis Treatment.

    Science.gov (United States)

    Arruda, Denise C; Matsuo, Alisson L; Silva, Luiz S; Real, Fernando; Leitão, Natanael P; Pires, Jhon H S; Caires, Antonio Carlos F; Garcia, Daniel M; Cunha, Fernanda F M; Puccia, Rosana; Longo, Larissa V G

    2015-12-01

    Paracoccidioidomycosis (PCM), caused by Paracoccidioides species, is the main cause of death due to systemic mycoses in Brazil and other Latin American countries. Therapeutic options for PCM and other systemic mycoses are limited and time-consuming, and there are high rates of noncompliance, relapses, toxic side effects, and sequelae. Previous work has shown that the cyclopalladated 7a compound is effective in treating several kinds of cancer and parasitic Chagas disease without significant toxicity in animals. Here we show that cyclopalladated 7a inhibited the in vitro growth of Paracoccidioides lutzii Pb01 and P. brasiliensis isolates Pb18 (highly virulent), Pb2, Pb3, and Pb4 (less virulent) in a dose-response manner. Pb18 was the most resistant. Opportunistic Candida albicans and Cryptococcus neoformans were also sensitive. BALB/c mice showed significantly lighter lung fungal burdens when treated twice a day for 20 days with a low cyclopalladated 7a dose of 30 μg/ml/day for 30 days after intratracheal infection with Pb18. Electron microscopy images suggested that apoptosis- and autophagy-like mechanisms are involved in the fungal killing mechanism of cyclopalladated 7a. Pb18 yeast cells incubated with the 7a compound showed remarkable chromatin condensation, DNA degradation, superoxide anion production, and increased metacaspase activity suggestive of apoptosis. Autophagy-related killing mechanisms were suggested by increased autophagic vacuole numbers and acidification, as indicated by an increase in LysoTracker and monodansylcadaverine (MDC) staining in cyclopalladated 7a-treated Pb18 yeast cells. Considering that cyclopalladated 7a is highly tolerated in vivo and affects yeast fungal growth through general apoptosis- and autophagy-like mechanisms, it is a novel promising drug for the treatment of PCM and other mycoses. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  8. The cephalostatin way of apoptosis.

    Science.gov (United States)

    Rudy, Anita; López-Antón, Nancy; Dirsch, Verena M; Vollmar, Angelika M

    2008-03-01

    The cephalostatins, bis-steroidal natural products from the marine tube worm Cephalodiscus gilchristi, were isolated by Dr. G. R. Pettit and his group. These compounds show a unique cytotoxicity profile in the in vitro screen of the National Cancer Institute, suggesting a novel mechanism of action. Indeed, cephalostatin 1 ( 1) is an extremely powerful agent that acts via an unusual apoptosis pathway. It induces selective Smac/DIABLO, but no cytochrome c release from mitochondria. Nevertheless, caspase-9 is required for apoptosis induction. Interestingly, caspase-9 is activated without the participation of the apoptosome, leading to the question of its mechanism of activation. We found that endoplasmic reticulum stress-associated caspase-4 contributes to nonclassical cephalostatin-mediated caspase-9 activation, additionally pointing out the unusual pathway used by this substance. Cephalostatin 1 ( 1), therefore, provides a very good tool to discover novel apoptotic pathways, which might be important in the understanding and treatment of chemo-resistant cancer.

  9. Methylselenium and Prostate Cancer Apoptosis

    Science.gov (United States)

    2003-02-01

    miethylselenol generated in cell-culture medium by described previously [12,15]. All cell-culture workwas performed without antibiotics . L-methionine-cL-deamino...Thompson HJ. Effect of 16. Datta SR, Brunet A, Greenberg ME. Cellular survival: A play an aqueous extract of selenium enriched garlic on in vitro in three... garlic on in vitro markers and relationship to caspase-mediated apoptosis execution. The in vivo efficacy in cancer prevention. Carcinogenesis (Lond.), 17

  10. Mitochondrial DNA.

    Science.gov (United States)

    Wright, Russell G.; Bottino, Paul J.

    1986-01-01

    Provides background information for teachers on mitochondrial DNA, pointing out that it may have once been a free-living organism. Includes a ready-to-duplicate exercise titled "Using Microchondrial DNA to Measure Evolutionary Distance." (JN)

  11. The novel NF-κB inhibitor IMD-0354 induces apoptosis in chronic lymphocytic leukemia

    International Nuclear Information System (INIS)

    Kanduri, M; Tobin, G; Åleskog, A; Nilsson, K; Rosenquist, R

    2011-01-01

    Nuclear factor-κB (NF-κB) is an important regulator of cell survival and has been shown to be constitutively active in chronic lymphocytic leukemia (CLL) cells. Recently, a novel NF-κB inhibitor, IMD-0354 (N-(3, 5-bis-trifluoromethyl-phenyl)-5-chloro-2-hydroxy-benzamide), was shown to specifically inhibit the phosphorylation of IκBα by IkB kinases, thus preventing NF-κB release. In this study, we investigated if IMD-0354 can inhibit NF-κB activation and induce apoptosis in CLL cells in vitro. The rate of increase in apoptosis, drug sensitivity and DNA-binding activity of NF-κB were studied using Annexin V stainings, the fluorometric microculture cytotoxicity assay and electrophoretic mobility shift assay, respectively. Finally, the impact of IMD-0354 treatment on the expression of a set of apoptosis-related genes was investigated. The results clearly show that IMD-0354 induced apoptosis (mean 26%, range 8–48%) in CLL cells, independent of immunoglobulin heavy variable (IGHV) gene mutational status, and showed a dose-dependent cytotoxic effect. IMD-0354 treatment also significantly lowered the DNA-binding activity of NF-κB in CLL cells. In addition, we identified differences in expression levels of pro- and antiapoptotic genes following IMD-0354 treatment. In summary, our novel findings show that IMD-0354 can induce apoptosis in CLL cells, and thus merits further investigation as an anticancer agent in vivo

  12. The novel NF-κB inhibitor IMD-0354 induces apoptosis in chronic lymphocytic leukemia

    Science.gov (United States)

    Kanduri, M; Tobin, G; Åleskog, A; Nilsson, K; Rosenquist, R

    2011-01-01

    Nuclear factor-κB (NF-κB) is an important regulator of cell survival and has been shown to be constitutively active in chronic lymphocytic leukemia (CLL) cells. Recently, a novel NF-κB inhibitor, IMD-0354 (N-(3, 5-bis-trifluoromethyl-phenyl)-5-chloro-2-hydroxy-benzamide), was shown to specifically inhibit the phosphorylation of IκBα by IkB kinases, thus preventing NF-κB release. In this study, we investigated if IMD-0354 can inhibit NF-κB activation and induce apoptosis in CLL cells in vitro. The rate of increase in apoptosis, drug sensitivity and DNA-binding activity of NF-κB were studied using Annexin V stainings, the fluorometric microculture cytotoxicity assay and electrophoretic mobility shift assay, respectively. Finally, the impact of IMD-0354 treatment on the expression of a set of apoptosis-related genes was investigated. The results clearly show that IMD-0354 induced apoptosis (mean 26%, range 8–48%) in CLL cells, independent of immunoglobulin heavy variable (IGHV) gene mutational status, and showed a dose-dependent cytotoxic effect. IMD-0354 treatment also significantly lowered the DNA-binding activity of NF-κB in CLL cells. In addition, we identified differences in expression levels of pro- and antiapoptotic genes following IMD-0354 treatment. In summary, our novel findings show that IMD-0354 can induce apoptosis in CLL cells, and thus merits further investigation as an anticancer agent in vivo. PMID:22829125

  13. Mitochondria-dependent apoptosis induced by nanoscale hydroxyapatite in human gastric cancer SGC-7901 cells.

    Science.gov (United States)

    Chen, Xiaojuan; Deng, Changsheng; Tang, Shengli; Zhang, Ming

    2007-01-01

    Nanoscale hydroxyapatite (nano-HAP) has been reported to exhibit anti-cancer effect on several human cancers, but the molecular mechanism of which remains unclear. The aim of this study was to explore the mechanisms by investigating the effects of nano-HAP on human gastric cancer SGC-7901 cells. Our results showed that nano-HAP significantly reduced cell viability, and induced apoptosis in SGC-7901 cells characterized by hypodiploid DNA contents, morphological changes and DNA fragmentation. The increase in apoptosis was accompanied with the increased expression of Bax, a pro-apoptotic protein, and decreased expression of Bcl-2, an anti-apoptotic protein, the decrease of mitochondrial membrane potential and the release of cytochrome c from mitochondria into cytosol. Furthermore, the activation of caspases-3, and -9, but not activation of caspases-8 was induced by nano-HAP. Z-VAD-fmk, a universal caspase inhibitor, dose-dependently inhibited nano-HAP-induced apoptosis. This study demonstrates that nano-HAP inhibits the proliferation of SGC-7901 cells by inducing apoptosis, and the apoptotic pathway of nano-HAP-induced apoptosis is mediated through the mitochondrial-dependent and caspase-dependent pathway.

  14. Study on apoptosis of prostate cancer cell induced by 125I seed irradiation

    International Nuclear Information System (INIS)

    Liao Anyan; Wang Junjie; Wang Jidong; Zhuang Hongqing; Zhao Yong

    2007-01-01

    Objective: To explore the mechanism of apoptosis induced by 125 I seed irradiation on PC3 cells. Methods: Human prostate cancer cell line PC3 was treated by irradiation of 125 I (2.77 cGy/h) with various dose. Agarose gel electrophoresis of DNA and flows cytometry were used to detect the apoptosis of PC3 cells and indirect immunofluorescence assay was used to detect the expression of Bcl-2. The activity of Caspase-3 was measured by Caspase Colorimetric Assay Kits. Results: Apoptosis of PC3 cells could be efficiently induced by 125 I seed irradiation. The apoptotic peaks were found by flow cytometry and DNA ladder appeared on 1.8% agarose gel. The activity of Caspase-3 on PC3 cells treated by 125 I seed irradiation was not changed significantly. Bcl-2 gene expression was down-regulated with the sample concentration increased. Conclusion: 125 I irradiation can induce the apoptosis of PC3 cells and the mechanism of apoptosis is related with down regulation of Bcl-2 gene expression and is not related with Caspase-3 activity. (authors)

  15. Cytoprotective effect of selective small-molecule caspase inhibitors against staurosporine-induced apoptosis

    Directory of Open Access Journals (Sweden)

    Wu J

    2014-05-01

    Full Text Available Jianghong Wu, Yuren Wang, Shuguang Liang, Haiching Ma Reaction Biology Corp, Malvern, PA, USA Abstract: Caspases are currently known as the central executioners of the apoptotic pathways. Inhibition of apoptosis and promotion of normal cell survival by caspase inhibitors would be a tremendous benefit for reducing the side effects of cancer therapy and for control of neurodegenerative disorders such as Parkinson's, Alzheimer's, and Huntington's diseases. The objective of this study was to discover small-molecule caspase inhibitors with which to achieve cytoprotective effect. We completed the high-throughput screening of Bionet's 37,500-compound library (Key Organics Limited, Camelford, Cornwall, UK against caspase-1, -3, and -9 and successfully identified 43 initial hit compounds. The 43 hit compounds were further tested for cytoprotective activity against staurosporine-induced cell death in NIH3T3 cells. Nineteen compounds were found to have significant cytoprotective effects in cell viability assays. One of the compounds, RBC1023, was demonstrated to protect NIH3T3 cells from staurosporine-induced caspase-3 cleavage and activation. RBC1023 was also shown to protect against staurosporine-induced impairment of mitochondrial membrane potential. DNA microarray analysis demonstrated that staurosporine treatment induced broad global gene expression alterations, and RBC1023 co-treatment significantly restored these changes, especially of the genes that are related to cell growth and survival signaling such as Egr1, Cdc25c, cdkn3, Rhob, Nek2, and Taok1. Collectively, RBC1023 protects NIH3T3 cells against staurosporine-induced apoptosis via inhibiting caspase activity, restoring mitochondrial membrane potential, and possibly upregulating some cell survival-related gene expressions and pathways. Keywords: cell death, caspase inhibition, mitochondria, RBC1023

  16. Mouse zygotes respond to severe sperm DNA damage by delaying paternal DNA replication and embryonic development.

    Directory of Open Access Journals (Sweden)

    Joanna E Gawecka

    Full Text Available Mouse zygotes do not activate apoptosis in response to DNA damage. We previously reported a unique form of inducible sperm DNA damage termed sperm chromatin fragmentation (SCF. SCF mirrors some aspects of somatic cell apoptosis in that the DNA degradation is mediated by reversible double strand breaks caused by topoisomerase 2B (TOP2B followed by irreversible DNA degradation by a nuclease(s. Here, we created zygotes using spermatozoa induced to undergo SCF (SCF zygotes and tested how they responded to moderate and severe paternal DNA damage during the first cell cycle. We found that the TUNEL assay was not sensitive enough to identify the breaks caused by SCF in zygotes in either case. However, paternal pronuclei in both groups stained positively for γH2AX, a marker for DNA damage, at 5 hrs after fertilization, just before DNA synthesis, while the maternal pronuclei were negative. We also found that both pronuclei in SCF zygotes with moderate DNA damage replicated normally, but paternal pronuclei in the SCF zygotes with severe DNA damage delayed the initiation of DNA replication by up to 12 hrs even though the maternal pronuclei had no discernable delay. Chromosomal analysis of both groups confirmed that the paternal DNA was degraded after S-phase while the maternal pronuclei formed normal chromosomes. The DNA replication delay caused a marked retardation in progression to the 2-cell stage, and a large portion of the embryos arrested at the G2/M border, suggesting that this is an important checkpoint in zygotic development. Those embryos that progressed through the G2/M border died at later stages and none developed to the blastocyst stage. Our data demonstrate that the zygote responds to sperm DNA damage through a non-apoptotic mechanism that acts by slowing paternal DNA replication and ultimately leads to arrest in embryonic development.

  17. Protective role of morin, a flavonoid, against high glucose induced oxidative stress mediated apoptosis in primary rat hepatocytes.

    Directory of Open Access Journals (Sweden)

    Radhika Kapoor

    Full Text Available Apoptosis is an early event of liver damage in diabetes and oxidative stress has been linked to accelerate the apoptosis in hepatocytes. Therefore, the compounds that can scavenge ROS may confer regulatory effects on high-glucose induced apoptosis. In the present study, primary rat hepatocytes were exposed to high concentration (40 mM of glucose. At this concentration decreased cell viability and enhanced ROS generation was observed. Depleted antioxidant status of hepatocytes under high glucose stress was also observed as evident from transcriptional level and activities of antioxidant enzymes. Further, mitochondrial depolarisation was accompanied by the loss of mitochondrial integrity and altered expression of Bax and Bcl-2. Increased translocation of apoptotic proteins like AIF (Apoptosis inducing factor & Endo-G (endonuclease-G from its resident place mitochondria to nucleus was also observed. Cyt-c residing in the inter-membrane space of mitochondria also translocated to cytoplasm. These apoptotic proteins initiated caspase activation, DNA fragmentation, chromatin condensation, increased apoptotic DNA content in glucose treated hepatocytes, suggesting mitochondria mediated apoptotic mode of cell death. Morin, a dietary flavonoid from Psidium guajava was effective in increasing the cell viability and decreasing the ROS level. It maintained mitochondrial integrity, inhibited release of apoptotic proteins from mitochondria, prevented DNA fragmentation, chromatin condensation and hypodiploid DNA upon exposure to high glucose. This study confirms the capacity of dietary flavonoid Morin in regulating apoptosis induced by high glucose via mitochondrial mediated pathway through intervention of oxidative stress.

  18. Molecular Cell Biology of Apoptosis and Necroptosis in Cancer.

    Science.gov (United States)

    Dillon, Christopher P; Green, Douglas R

    Cell death is a major mechanism to eliminate cells in which DNA is damaged, organelles are stressed, or oncogenes are overexpressed, all events that would otherwise predispose cells to oncogenic transformation. The pathways that initiate and execute cell death are complex, genetically encoded, and subject to significant regulation. Consequently, while these pathways are often mutated in malignancy, there is considerable interest in inducing cell death in tumor cells as therapy. This chapter addresses our current understanding of molecular mechanisms contributing to two cell death pathways, apoptotic cell death and necroptosis, a regulated form of necrotic cell death. Apoptosis can be induced by a wide variety of signals, leading to protease activation that dismantles the cell. We discuss the physiological importance of each apoptosis pathway and summarize their known roles in cancer suppression and the current efforts at targeting each pathway therapeutically. The intricate mechanistic link between death receptor-mediated apoptosis and necroptosis is described, as well as the potential opportunities for utilizing necroptosis in the treatment of malignancy.

  19. Modeling DNA

    Science.gov (United States)

    Robertson, Carol

    2016-01-01

    Deoxyribonucleic acid (DNA) is life's most amazing molecule. It carries the genetic instructions that almost every organism needs to develop and reproduce. In the human genome alone, there are some three billion DNA base pairs. The most difficult part of teaching DNA structure, however, may be getting students to visualize something as small as a…

  20. Cyclic GMP protects human macrophages against peroxynitrite-induced apoptosis

    Directory of Open Access Journals (Sweden)

    Rossi Adriano G

    2009-05-01

    Full Text Available Abstract Background Nitric oxide (NO can be both pro- and anti-apoptotic in various cell types, including macrophages. This apparent paradox may result from the actions of NO-related species generated in the microenvironment of the cell, for example the formation of peroxynitrite (ONOO-. In this study we have examined the ability of NO and ONOO- to evoke apoptosis in human monocyte-derived macrophages (MDMϕ, and investigated whether preconditioning by cyclic guanosine monophosphate (cGMP is able to limit apoptosis in this cell type. Methods Characterisation of the NO-related species generated by (Z-1- [2-(2-aminoethyl-N-(2-ammonioethylamino]diazen-1-ium-1,2-diolate (DETA/NO and 1,2,3,4-oxatriazolium, 5-amino-3-(3,4-dichlorophenyl-, chloride (GEA-3162 was performed by electrochemistry using an isolated NO electrode and electron paramagnetic resonance (EPR spectrometry. Mononuclear cells were isolated from peripheral blood of healthy volunteers and cultured to allow differentiation into MDMϕ. Resultant MDMϕ were treated for 24 h with DETA/NO (100 – 1000 μM or GEA-3162 (10 – 300 μM in the presence or absence of BAY 41–2272 (1 μM, isobutylmethylxanthine (IBMX; 1 μM, 1H- [1,2,4]oxadiazolo [4,3-a]quinoxalin-1-one (ODQ; 20 μM or 8-bromo-cGMP (1 mM. Apoptosis in MDMϕ was assessed by flow cytometric analysis of annexin V binding in combination with propidium iodide staining. Results Electrochemistry and EPR revealed that DETA/NO liberated free NO radical, whilst GEA-3162 concomitantly released NO and O2-, and is therefore a ONOO- generator. NO (DETA/NO had no effect on cell viability, but ONOO- (GEA-3162 caused a concentration-dependent induction of apoptosis in MDMϕ. Preconditioning of MDMϕ with NO in combination with the phosphodiesterase inhibitor, 3-Isobutyl-1-methylxanthine (IBMX, or the NO-independent stimulator of soluble guanylate cyclase, BAY 41–2272, significantly attenuated ONOO--induced apoptosis in a cGMP-dependent manner

  1. Canine distemper virus induces apoptosis in cervical tumor derived cell lines

    Directory of Open Access Journals (Sweden)

    Rajão Daniela S

    2011-06-01

    Full Text Available Abstract Apoptosis can be induced or inhibited by viral proteins, it can form part of the host defense against virus infection, or it can be a mechanism for viral spread to neighboring cells. Canine distemper virus (CDV induces apoptotic cells in lymphoid tissues and in the cerebellum of dogs naturally infected. CDV also produces a cytopathologic effect, leading to apoptosis in Vero cells in tissue culture. We tested canine distemper virus, a member of the Paramyxoviridae family, for the ability to trigger apoptosis in HeLa cells, derived from cervical cancer cells resistant to apoptosis. To study the effect of CDV infection in HeLa cells, we examined apoptotic markers 24 h post infection (pi, by flow cytometry assay for DNA fragmentation, real-time PCR assay for caspase-3 and caspase-8 mRNA expression, and by caspase-3 and -8 immunocytochemistry. Flow cytometry showed that DNA fragmentation was induced in HeLa cells infected by CDV, and immunocytochemistry revealed a significant increase in the levels of the cleaved active form of caspase-3 protein, but did not show any difference in expression of caspase-8, indicating an intrinsic apoptotic pathway. Confirming this observation, expression of caspase-3 mRNA was higher in CDV infected HeLa cells than control cells; however, there was no statistically significant change in caspase-8 mRNA expression profile. Our data suggest that canine distemper virus induced apoptosis in HeLa cells, triggering apoptosis by the intrinsic pathway, with no participation of the initiator caspase -8 from the extrinsic pathway. In conclusion, the cellular stress caused by CDV infection of HeLa cells, leading to apoptosis, can be used as a tool in future research for cervical cancer treatment and control.

  2. Elevated pressure, a novel cancer therapeutic tool for sensitizing cisplatin-mediated apoptosis in A549

    International Nuclear Information System (INIS)

    Oh, Sangnam; Kim, Yanghee; Kim, Joonhee; Kwon, Daeho; Lee, Eunil

    2010-01-01

    Research highlights: → Sensitized apoptosis in cancer cells stimulated by EP precondition with p53 dependence. → EP attenuates several CDDP-resistance mechanisms. → No harmful effect of EP on normal fibroblasts. -- Abstract: Intensive cancer therapy strategies have thus far focused on sensitizing cancer cells to anticancer drug-mediated apoptosis to overcome drug resistance, and this strategy has led to more effective cancer therapeutics. Cisplatin (cis-diamminedichloroplatinum(II), CDDP) is an effective anticancer drug used to treat many types of cancer, including non-small cell lung carcinoma (NSCLC), and can be used in combination with various chemicals to enhance cancer cell apoptosis. Here, we introduce the use of elevated pressure (EP) in combination with CDDP for cancer treatment and explore the effects of EP on CDDP-mediated apoptosis in NSCLC cells. Our findings demonstrate that preconditioning NSCLC cells with EP sensitizes cells for CDDP-induced apoptosis. Enhanced apoptosis was dependent on p53 and HO-1 expression, and was associated with increased DNA damage and down-regulation of genes involved in nucleotide excision repair. The transcriptional levels of transporter proteins indicated that the mechanism by which EP-induced CDDP sensitization was intracellular drug accumulation. The protein levels of some antioxidants, such as hemeoxygenase-1 (HO-1), glutathione (GSH) and glutathione peroxidase (Gpx), were decreased in A549 cells exposed to EP via the down-regulation of the transcription factor nuclear factor (erythroid-derived 2)-like 2 (Nrf-2). Furthermore, normal human fibroblasts were resistant to EP treatment, with no elevated DNA damage or apoptosis. Collectively, these data show that administration of EP is a potential adjuvant tool for CDDP-based chemosensitivity of lung cancer cells that may reduce drug resistance.

  3. Ursodeoxycholic acid induces apoptosis in hepatocellular carcinoma xenografts in mice.

    Science.gov (United States)

    Liu, Hui; Xu, Hong-Wei; Zhang, Yu-Zhen; Huang, Ya; Han, Guo-Qing; Liang, Tie-Jun; Wei, Li-Li; Qin, Cheng-Yong; Qin, Cheng-Kun

    2015-09-28

    To evaluate the efficacy of ursodeoxycholic acid (UDCA) as a chemotherapeutic agent for the treatment of hepatocellular carcinoma (HCC). BALB/c nude mice were randomized into four groups 24 h before subcutaneous injection of hepatocarcinoma BEL7402 cells suspended in phosphate buffered saline (PBS) into the right flank. The control group (n = 10) was fed a standard diet while treatment groups (n = 10 each) were fed a standard daily diet supplemented with different concentrations of UDCA (30, 50 and 70 mg/kg per day) for 21 d. Tumor growth was measured once each week, and tumor volume (V) was calculated with the following equation: V = (L × W(2)) × 0.52, where L is the length and W is the width of the xenograft. After 21 d, mice were killed under ether anesthesia, and tumors were excised and weighed. Apoptosis was evaluated through detection of DNA fragmentation with gel electrophoresis and the terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling (TUNEL) assay. Western blot analysis was performed to determine the expression of apoptosis-related proteins BAX, BCL2, APAF1, cleaved caspase-9, and cleaved caspase-3. UDCA suppressed tumor growth relative to controls. The mean tumor volumes were the following: control, 1090 ± 89 mm(3); 30 mg/kg per day, 612 ± 46 mm(3); 50 mg/kg per day, 563 ± 38 mm(3); and 70 mg/kg per day, 221 ± 26 mm(3). Decreased tumor volumes reached statistical significance relative to control xenografts (30 mg/kg per day, P < 0.05; 50 mg/kg per day, P < 0.05; 70 mg/kg per day, P < 0.01). Increasing concentrations of UDCA led to increased DNA fragmentation observed on gel electrophoresis and in the TUNEL assay (control, 1.6% ± 0.3%; 30 mg/kg per day, 2.9% ± 0.5%; 50 mg/kg per day, 3.15% ± 0.7%, and 70 mg/kg per day, 4.86% ± 0.9%). Western blot analysis revealed increased expression of BAX, APAF1, cleaved-caspase-9 and cleaved-caspase-3 proteins, which induce apoptosis, but decreased expression of BCL2 protein, which

  4. The ganglioside GM3 is associated with cisplatin-induced apoptosis in human colon cancer cells.

    Directory of Open Access Journals (Sweden)

    Tae-Wook Chung

    Full Text Available Cisplatin (cis-diamminedichloroplatinum, CDDP is a well-known chemotherapeutic agent for the treatment of several cancers. However, the precise mechanism underlying apoptosis of cancer cells induced by CDDP remains unclear. In this study, we show mechanistically that CDDP induces GM3-mediated apoptosis of HCT116 cells by inhibiting cell proliferation, and increasing DNA fragmentation and mitochondria-dependent apoptosis signals. CDDP induced apoptosis within cells through the generation of reactive oxygen species (ROS, regulated the ROS-mediated expression of Bax, Bcl-2, and p53, and induced the degradation of the poly (ADP-ribosyl polymerase (PARP. We also checked expression levels of different gangliosides in HCT116 cells in the presence or absence of CDDP. Interestingly, among the gangliosides, CDDP augmented the expression of only GM3 synthase and its product GM3. Reduction of the GM3 synthase level through ectopic expression of GM3 small interfering RNA (siRNA rescued HCT116 cells from CDDP-induced apoptosis. This was evidenced by inhibition of apoptotic signals by reducing ROS production through the regulation of 12-lipoxigenase activity. Furthermore, the apoptotic sensitivity to CDDP was remarkably increased in GM3 synthase-transfected HCT116 cells compared to that in controls. In addition, GM3 synthase-transfected cells treated with CDDP exhibited an increased accumulation of intracellular ROS. These results suggest the CDDP-induced oxidative apoptosis of HCT116 cells is mediated by GM3.

  5. Apoptosis and histological response of preoperative intraarterial chemotherapy infusion for colorectal carcinoma

    International Nuclear Information System (INIS)

    Yuan Jianhua; Hu Tingyang; Yu Wenqiang; Chen Fanghong; Luo Zuyan; Mao Yinmin; Zhao Zhongsheng; Ru Guoqing; Deng Gaoli; Dong Quanjin; Tu Shiliang

    2003-01-01

    Objective: To investigate apoptosis and histological response of preoperative intraarterial chemotherapy infusion for colorectal carcinoma. Methods: Fifty patients with colorectal carcinoma were treated by intraarterial infusion of anti-cancer drugs. Surgical resection of the tumor was performed 5-30 days after the intraarterial infusion (mean 12 days). The histological response was evaluated. The density and distribution of the apoptosis cells were observed by DNA nick end labelling technique. 22 biopsy specimens before the intraarterial chemotherapy and 25 normal mucosa (obtained from surgery specimen) were used as controls. Results: The total histological response rate was 100% with grade I in 20 cases, grade II in 21 cases, and grade III in 9 cases. The density of the apoptosis cells was 31.47±5.58 before and 76.69±17.12 after the intraarterial chemotherapy infusion, and 8.01±3.39 in normal mucosa, respectively. The density of the apoptosis cells after the intraarterial chemotherapy was significantly higher than that before the intraarterial chemotherapy (t=13.701, P 2 =4.696, P>0.30). The apoptosis of adenocarcinoma was significantly different with different histological response (F=7.73, P 0.05) and for adenocarcinoma with different pathological stages (F=0.001376, P>0.05). Conclusion: As an effective and safe procedure, preoperative transcatheter intraarterial chemotherapy infusion achieves a significant histological response and apoptosis in colorectal adenocarcinoma

  6. Radiation-induced apoptosis in different pH environments in vitro

    International Nuclear Information System (INIS)

    Lee, Hyung-Sik; Park, Heon J.; Lyons, John C.; Griffin, Robert J.; Auger, Elizabeth A.; Song, Chang W.

    1997-01-01

    Purpose: The effect of environmental pH on the radiation-induced apoptosis in tumor cells in vitro was investigated. Methods and Materials: Mammary adenocarcinoma cells of A/J mice (SCK cells) were irradiated with γ-rays using a 137 Cs irradiator and incubated in media of different pHs. After incubation at 37 deg. C for 24-120 h the extent of apoptosis was determined using agarose gel electrophoresis, TdT-mediated dUTP-biotin nick end labeling (TUNEL) staining, flow cytometry, and release of 3 H from 3 H-thymidine labeled cells. The clonogenicity of the cells irradiated in different pH medium was determined, and the progression of cells through the cell cycle after irradiation in different pHs was also determined with flow cytometry. Results: Irradiation with 2-12 Gy of γ-rays induced apoptosis in SCK cells in pH 7.5 medium within 48 h as judged from the results of four different assays mentioned. Radiation-induced apoptosis declined as the medium pH was lowered from 7.5 to 6.4. Specifically, the radiation-induced degradation of DNA including the early DNA breaks, as determined with the TUNEL method, progressively declined as the medium pH was lowered so that little DNA fragmentation occurred 48 h after irradiation with 12 Gy in pH 6.6 medium. When the cells were irradiated and incubated for 48 h in pH 6.6 medium and the medium was replaced with pH 7.5 medium, DNA fragmentation promptly occurred. DNA fragmentation also occurred even in pH 6.6 medium when the cells were irradiated and maintained in pH 7.5 medium for 8 h or longer post-irradiation before incubation in pH 6.6 medium. The radiation-induced G 2 arrest in pH 6.6 medium lasted markedly longer than that in pH 7.5 medium. Conclusion: Radiation-induced apoptosis in SCK cells in vitro is reversibly suppressed in an acidic environment. Taking the results of four different assays together, it was concluded that early step(s) in the apoptotic pathway, probably the DNA break or upstream of DNA break, is

  7. Dna Sequencing

    Science.gov (United States)

    Tabor, Stanley; Richardson, Charles C.

    1995-04-25

    A method for sequencing a strand of DNA, including the steps off: providing the strand of DNA; annealing the strand with a primer able to hybridize to the strand to give an annealed mixture; incubating the mixture with four deoxyribonucleoside triphosphates, a DNA polymerase, and at least three deoxyribonucleoside triphosphates in different amounts, under conditions in favoring primer extension to form nucleic acid fragments complementory to the DNA to be sequenced; labelling the nucleic and fragments; separating them and determining the position of the deoxyribonucleoside triphosphates by differences in the intensity of the labels, thereby to determine the DNA sequence.

  8. [Essential oil from Artemisia lavandulaefolia induces apoptosis and necrosis of HeLa cells].

    Science.gov (United States)

    Zhang, Lu-min; Lv, Xue-wei; Shao, Lin-xiang; Ma, Yan-fang; Cheng, Wen-zhao; Gao, Hai-tao

    2013-12-01

    To investigate the effects of Artemisia lavandulaefolia essential oil on apoptosis and necrosis of HeLa cells. Cell viability was assayed using MTT method. The morphological and structure alterations in HeLa cells were observed by microscopy. Furthermore, cell apoptosis was measured by DNA Ladder and flow cytometry. DNA damage was measured by comet assay, and the protein expression was examined by Western blot analysis. MTT assay displayed essential oil from Artemisia lavandulaefolia could inhibit the proliferation of HeLa cells in a dose-dependent manner. After treated with essential oil of Artemisia lavadulaefolia for 24 h, HeLa cells in 100 and 200 microg/mL experiment groups exhibited the typical morphology changes of undergoing apoptosis, such as cell shrinkage and nucleus chromatin condensed. However, the cells in the 400 microg/mL group showed the necrotic morphology changes including cytomembrane rupture and cytoplasm spillover. In addition, DNA Ladder could be demonstrated by DNA electrophoresis in each experiment group. Apoptosis peak was also evident in flow cytometry in each experiment group. After treating the HeLa cells with essential oil of Artemisia lavadulaefolia for 6 h, comet tail was detected by comet assay. Moreover, western blotting analysis showed that caspase-3 was activated and the cleavage of PARP was inactivated. Essential oil from Artemisia lavadulaefolia can inhibit the proliferation of HeLa cells in vitro. Low concentration of essential oil from Artemisia lavadulaefolia can induce apoptosis, whereas high concentration of the compounds result in necrosis of HeLa cells. And,the mechanism may be related to the caspase-3-mediated-PARP apoptotic signal pathway.

  9. Linear ubiquitin chain induces apoptosis and inhibits tumor growth.

    Science.gov (United States)

    Qin, Zhoushuai; Jiang, Wandong; Wang, Guifen; Sun, Ying; Xiao, Wei

    2018-01-01

    Ubiquitination of proliferating cell nuclear antigen (PCNA) plays an important role in DNA damage response. Ectopic expression of PCNA fused at either terminus with ubiquitin (Ub) lacking two C-terminal glycine residues induces translesion DNA synthesis which resembles synthesis mediated by PCNA monoubiquitination. PCNA fused with Ub containing the C-terminal Gly residues at the C-terminus can be further polyubiquitinated in a Gly-dependent manner, which inhibits cell proliferation and induces ATR-dependent replication checkpoint. In this study, we surprisingly found that PCNA fused to a head-to-tail linear Ub chain induces apoptosis in a Ub chain length-dependent manner. Further investigation revealed that the apoptotic effect is actually induced by the linear Ub chain independently from PCNA, as the Ub chain fused to GFP or an epitope tag still efficiently induces apoptosis. It is revealed that the artificial linear Ub chain differs from endogenously encoded linear Ub chains in that its Ubs contain a Ub-G76S substitution, making the Ub chain resistant to cleavage by deubiquitination enzymes. We demonstrated in this study that ectopic expression of the artificial Ub chain alone in cultured human cancer cells is sufficient to inhibit tumor growth in a xenograft mouse model, making the linear Ub chain a putative anti-cancer agent.

  10. DNA Damage and Pulmonary Hypertension

    Science.gov (United States)

    Ranchoux, Benoît; Meloche, Jolyane; Paulin, Roxane; Boucherat, Olivier; Provencher, Steeve; Bonnet, Sébastien

    2016-01-01

    Pulmonary hypertension (PH) is defined by a mean pulmonary arterial pressure over 25 mmHg at rest and is diagnosed by right heart catheterization. Among the different groups of PH, pulmonary arterial hypertension (PAH) is characterized by a progressive obstruction of distal pulmonary arteries, related to endothelial cell dysfunction and vascular cell proliferation, which leads to an increased pulmonary vascular resistance, right ventricular hypertrophy, and right heart failure. Although the primary trigger of PAH remains unknown, oxidative stress and inflammation have been shown to play a key role in the development and progression of vascular remodeling. These factors are known to increase DNA damage that might favor the emergence of the proliferative and apoptosis-resistant phenotype observed in PAH vascular cells. High levels of DNA damage were reported to occur in PAH lungs and remodeled arteries as well as in animal models of PH. Moreover, recent studies have demonstrated that impaired DNA-response mechanisms may lead to an increased mutagen sensitivity in PAH patients. Finally, PAH was linked with decreased breast cancer 1 protein (BRCA1) and DNA topoisomerase 2-binding protein 1 (TopBP1) expression, both involved in maintaining genome integrity. This review aims to provide an overview of recent evidence of DNA damage and DNA repair deficiency and their implication in PAH pathogenesis. PMID:27338373

  11. Cigarette smoke causes caspase-independent apoptosis of bronchial epithelial cells from asthmatic donors.

    Directory of Open Access Journals (Sweden)

    Fabio Bucchieri

    Full Text Available Epidemiologic studies have demonstrated important links between air pollution and asthma. Amongst these pollutants, environmental cigarette smoke is a risk factor both for asthma pathogenesis and exacerbation. As the barrier to the inhaled environment, the bronchial epithelium is a key structure that is exposed to cigarette smoke.Since primary bronchial epithelial cells (PBECs from asthmatic donors are more susceptible to oxidant-induced apoptosis, we hypothesized that they would be susceptible to cigarette smoke-induced cell death.PBECs from normal and asthmatic donors were exposed to cigarette smoke extract (CSE; cell survival and apoptosis were assessed by fluorescence-activated cell sorting, and protective effects of antioxidants evaluated. The mechanism of cell death was evaluated using caspase inhibitors and immunofluorescent staining for apoptosis-inducing factor (AIF.Exposure of PBEC cultures to CSE resulted in a dose-dependent increase in cell death. At 20% CSE, PBECs from asthmatic donors exhibited significantly more apoptosis than cells from non-asthmatic controls. Reduced glutathione (GSH, but not ascorbic acid (AA, protected against CSE-induced apoptosis. To investigate mechanisms of CSE-induced apoptosis, caspase-3 or -9 inhibitors were tested, but these failed to prevent apoptosis; in contrast, CSE promoted nuclear translocation of AIF from the mitochondria. GSH reduced the number of nuclear-AIF positive cells whereas AA was ineffective.Our results show that PBECs from asthmatic donors are more susceptible to CSE-induced apoptosis. This response involves AIF, which has been implicated in DNA damage and ROS-mediated cell-death. Epithelial susceptibility to CSE may contribute to the impact of environmental tobacco smoke in asthma.

  12. Autophagy and apoptosis in planarians.

    Science.gov (United States)

    González-Estévez, Cristina; Saló, Emili

    2010-03-01

    Adult planarians are capable of undergoing regeneration and body remodelling in order to adapt to physical damage or extreme environmental conditions. Moreover, most planarians can tolerate long periods of starvation and during this time, they shrink from an adult size to, and sometimes beyond, the initial size at hatching. Indeed, these properties have made them a classic model to study stem cells and regeneration. Under such stressful conditions, food reserves from the gastrodermis and parenchyma are first used up and later the testes, copulatory organs and ovaries are digested. More surprisingly, when food is again made available to shrunken individuals, they grow back to adult size and all their reproductive structures reappear. These cycles of growth and shrinkage may occur over long periods without any apparent impairment to the individual, or to its future maturation and breeding capacities. This plasticity resides in a mesoderm tissue known as the parenchyma, which is formed by several differentiated non-proliferating cell types and only one mitotically active cell type, the neoblasts, which represent approximately 20-30% of the cells in the parenchyma. Neoblasts are generally thought to be somatic stem-cells that participate in the normal continuous turnover of all cell types in planarians. Hence, planarians are organisms that continuously adapt their bodies (morphallaxis) to different environmental stresses (i.e.: injury or starvation). This adaptation involves a variety of processes including proliferation, differentiation, apoptosis and autophagy, all of which are perfectly orchestrated and tightly regulated to remodel or restore the body pattern. While neoblast biology and body re-patterning are currently the subject of intense research, apoptosis and autophagy remain much less studied. In this review we will summarize our current understanding and hypotheses regarding where and when apoptosis and autophagy occur and fulfil an essential role in

  13. Mechanisms of Neuronal Apoptosis In Vivo

    National Research Council Canada - National Science Library

    Martin, Lee J

    2004-01-01

    .... Neuronal cell death in the form of apoptosis or necrosis occurs after exposure to neurotoxins, chemical warfare agents, radiation, viruses, and after seizures, trauma, limb amputation, and hypoxic...

  14. Apoptosis in cancer: from pathogenesis to treatment

    Directory of Open Access Journals (Sweden)

    Wong Rebecca SY

    2011-09-01

    Full Text Available Abstract Apoptosis is an ordered and orchestrated cellular process that occurs in physiological and pathological conditions. It is also one of the most studied topics among cell biologists. An understanding of the underlying mechanism of apoptosis is important as it plays a pivotal role in the pathogenesis of many diseases. In some, the problem is due to too much apoptosis, such as in the case of degenerative diseases while in others, too little apoptosis is the culprit. Cancer is one of the scenarios where too little apoptosis occurs, resulting in malignant cells that will not die. The mechanism of apoptosis is complex and involves many pathways. Defects can occur at any point along these pathways, leading to malignant transformation of the affected cells, tumour metastasis and resistance to anticancer drugs. Despite being the cause of problem, apoptosis plays an important role in the treatment of cancer as it is a popular target of many treatment strategies. The abundance of literature suggests that targeting apoptosis in cancer is feasible. However, many troubling questions arise with the use of new drugs or treatment strategies that are designed to enhance apoptosis and critical tests must be passed before they can be used safely in human subjects.

  15. Mitochondrial Dynamics: Functional Link with Apoptosis

    Directory of Open Access Journals (Sweden)

    Hidenori Otera

    2012-01-01

    Full Text Available Mitochondria participate in a variety of physiologic processes, such as ATP production, lipid metabolism, iron-sulfur cluster biogenesis, and calcium buffering. The morphology of mitochondria changes dynamically due to their frequent fusion and division in response to cellular conditions, and these dynamics are an important constituent of apoptosis. The discovery of large GTPase family proteins that regulate mitochondrial dynamics, together with novel insights into the role of mitochondrial fusion and fission in apoptosis, has provided important clues to understanding the molecular mechanisms of cellular apoptosis. In this paper, we briefly summarize current knowledge of the role of mitochondrial dynamics in apoptosis and cell pathophysiology in mammalian cells.

  16. Mitochondrial dynamics: functional link with apoptosis.

    Science.gov (United States)

    Otera, Hidenori; Mihara, Katsuyoshi

    2012-01-01

    Mitochondria participate in a variety of physiologic processes, such as ATP production, lipid metabolism, iron-sulfur cluster biogenesis, and calcium buffering. The morphology of mitochondria changes dynamically due to their frequent fusion and division in response to cellular conditions, and these dynamics are an important constituent of apoptosis. The discovery of large GTPase family proteins that regulate mitochondrial dynamics, together with novel insights into the role of mitochondrial fusion and fission in apoptosis, has provided important clues to understanding the molecular mechanisms of cellular apoptosis. In this paper, we briefly summarize current knowledge of the role of mitochondrial dynamics in apoptosis and cell pathophysiology in mammalian cells.

  17. Mycobacterium tuberculosis effectors interfering host apoptosis signaling.

    Science.gov (United States)

    Liu, Minqiang; Li, Wu; Xiang, Xiaohong; Xie, Jianping

    2015-07-01

    Tuberculosis remains a serious human public health concern. The coevolution between its pathogen Mycobacterium tuberculosis and human host complicated the way to prevent and cure TB. Apoptosis plays subtle role in this interaction. The pathogen endeavors to manipulate the apoptosis via diverse effectors targeting key signaling nodes. In this paper, we summarized the effectors pathogen used to subvert the apoptosis, such as LpqH, ESAT-6/CFP-10, LAMs. The interplay between different forms of cell deaths, such as apoptosis, autophagy, necrosis, is also discussed with a focus on the modes of action of effectors, and implications for better TB control.

  18. Apoptosis and Molecular Targeting Therapy in Cancer

    Science.gov (United States)

    Hassan, Mohamed; Watari, Hidemichi; AbuAlmaaty, Ali; Ohba, Yusuke; Sakuragi, Noriaki

    2014-01-01

    Apoptosis is the programmed cell death which maintains the healthy survival/death balance in metazoan cells. Defect in apoptosis can cause cancer or autoimmunity, while enhanced apoptosis may cause degenerative diseases. The apoptotic signals contribute into safeguarding the genomic integrity while defective apoptosis may promote carcinogenesis. The apoptotic signals are complicated and they are regulated at several levels. The signals of carcinogenesis modulate the central control points of the apoptotic pathways, including inhibitor of apoptosis (IAP) proteins and FLICE-inhibitory protein (c-FLIP). The tumor cells may use some of several molecular mechanisms to suppress apoptosis and acquire resistance to apoptotic agents, for example, by the expression of antiapoptotic proteins such as Bcl-2 or by the downregulation or mutation of proapoptotic proteins such as BAX. In this review, we provide the main regulatory molecules that govern the main basic mechanisms, extrinsic and intrinsic, of apoptosis in normal cells. We discuss how carcinogenesis could be developed via defective apoptotic pathways or their convergence. We listed some molecules which could be targeted to stimulate apoptosis in different cancers. Together, we briefly discuss the development of some promising cancer treatment strategies which target apoptotic inhibitors including Bcl-2 family proteins, IAPs, and c-FLIP for apoptosis induction. PMID:25013758

  19. MicroRNA-1185 Induces Endothelial Cell Apoptosis by Targeting UVRAG and KRIT1

    Directory of Open Access Journals (Sweden)

    Haoyuan Deng

    2017-04-01

    Full Text Available Background/Aims: Atherosclerosis is a multifactorial chronic disease and is the main cause of death and impairment in the world. Endothelial injury and apoptosis play a crucial role in the onset and development of atherosclerosis. MicroRNAs (miRNAs have been proven to be involved in the pathogenesis of atherosclerosis. However, studies of the functional role of apoptosis-related miRNAs in the endothelium during atherogenesis are limited. Methods: Cell injury and apoptosis were measured in five types of cells transfected with miR-1185 or co-transfected with miR-1185 and its inhibitor. Bioinformatics analysis and a luciferase reporter assay were used to confirm the targets of miR-1185. The effects of the targets of miR-1185 on endothelial apoptosis were determined using small-interfering RNA. Results: In this study, we first report that miR-1185 significantly promoted apoptosis in endothelial cells but not in vascular smooth muscle cells and macrophages. A mechanistic analysis showed that ultraviolet irradiation resistance-associated gene (UVRAG and krev1 interaction trapped gene 1 (KRIT1, targets of miR-1185, mediated miR-1185-induced endothelial cell apoptosis. Conclusion: The results revealed the impact of miR-1185 on endothelial apoptosis, suggesting that miR-1185 may be a potential target for the prevention and treatment of atherosclerosis.

  20. DNA fusion gene vaccines

    DEFF Research Database (Denmark)

    Holst, Peter Johannes; Bassi, Maria Rosaria; Thomsen, Allan Randrup

    2010-01-01

    DNA vaccines are versatile and safe, but limited immunogenicity has prevented their use in the clinical setting. Experimentally, immunogenicity may be enhanced by the use of new delivery technologies, by coadministration of cytokines and pathogen-associated molecular patterns, or by fusion...... of antigens into molecular domains that enhance antigen presentation. More specifically, the immunogenicity of DNA vaccines may benefit from increased protein synthesis, increased T-cell help and MHC class I presentation, and the addition of a range of specific cytokines and pathogen-associated molecular...... with these modifications, it is likely that the primary use of DNA vaccines may be as primers for viral-vectored vaccines, rather than as single agents. This review discusses the approaches used to enhance DNA vaccine immunogenicity, with a primary focus on fusion strategies that enhance antigen presentation....

  1. Close encounters with DNA

    Science.gov (United States)

    Maffeo, C.; Yoo, J.; Comer, J.; Wells, D. B.; Luan, B.; Aksimentiev, A.

    2014-01-01

    Over the past ten years, the all-atom molecular dynamics method has grown in the scale of both systems and processes amenable to it and in its ability to make quantitative predictions about the behavior of experimental systems. The field of computational DNA research is no exception, witnessing a dramatic increase in the size of systems simulated with atomic resolution, the duration of individual simulations and the realism of the simulation outcomes. In this topical review, we describe the hallmark physical properties of DNA from the perspective of all-atom simulations. We demonstrate the amazing ability of such simulations to reveal the microscopic physical origins of experimentally observed phenomena and we review the frustrating limitations associated with imperfections of present atomic force fields and inadequate sampling. The review is focused on the following four physical properties of DNA: effective electric charge, response to an external mechanical force, interaction with other DNA molecules and behavior in an external electric field. PMID:25238560

  2. DNA from keratinous tissue

    DEFF Research Database (Denmark)

    Bengtsson, Camilla F.; Olsen, Maja E.; Brandt, Luise Ørsted

    2011-01-01

    Keratinous tissues such as nail, hair, horn, scales and feather have been used as a source of DNA for over 20 years. Particular benefits of such tissues include the ease with which they can be sampled, the relative stability of DNA in such tissues once sampled, and, in the context of ancient...... genetic analyses, the fact that sampling generally causes minimal visual damage to valuable specimens. Even when freshly sampled, however, the DNA quantity and quality in the fully keratinized parts of such tissues is extremely poor in comparison to other tissues such as blood and muscle – although little...... systematic research has been undertaken to characterize how such degradation may relate to sample source. In this review paper we present the current understanding of the quality and limitations of DNA in two key keratinous tissues, nail and hair. The findings indicate that although some fragments of nuclear...

  3. DNA fusion gene vaccines

    DEFF Research Database (Denmark)

    Holst, Peter Johannes; Bassi, Maria Rosaria; Thomsen, Allan Randrup

    2010-01-01

    DNA vaccines are versatile and safe, but limited immunogenicity has prevented their use in the clinical setting. Experimentally, immunogenicity may be enhanced by the use of new delivery technologies, by coadministration of cytokines and pathogen-associated molecular patterns, or by fusion...... of antigens into molecular domains that enhance antigen presentation. More specifically, the immunogenicity of DNA vaccines may benefit from increased protein synthesis, increased T-cell help and MHC class I presentation, and the addition of a range of specific cytokines and pathogen-associated molecular...... with viral-vectored vaccines, various synergistic components may need to be incorporated into DNA vaccines. From the perspective of the future clinical use of DNA vaccines, it has been suggested that antigen presentation should be improved and cytokine coadministration attempted. However, even...

  4. Mitogenomic analyses from ancient DNA

    DEFF Research Database (Denmark)

    Paijmans, Johanna L. A.; Gilbert, Tom; Hofreiter, Michael

    2013-01-01

    The analysis of ancient DNA is playing an increasingly important role in conservation genetic, phylogenetic and population genetic analyses, as it allows incorporating extinct species into DNA sequence trees and adds time depth to population genetics studies. For many years, these types of DNA...... analyses (whether using modern or ancient DNA) were largely restricted to the analysis of short fragments of the mitochondrial genome. However, due to many technological advances during the past decade, a growing number of studies have explored the power of complete mitochondrial genome sequences...... (mitogenomes). Such studies were initially limited to analyses of extant organisms, but developments in both DNA sequencing technologies and general methodological aspects related to working with degraded DNA have resulted in complete mitogenomes becoming increasingly popular for ancient DNA studies as well...

  5. Polo-like kinase (Plk)1 depletion induces apoptosis in cancer cells.

    Science.gov (United States)

    Liu, Xiaoqi; Erikson, Raymond L

    2003-05-13

    Elevated expression of mammalian polo-like kinase (Plk)1 occurs in many different types of cancers, and Plk1 has been proposed as a novel diagnostic marker for several tumors. We used the recently developed vector-based small interfering RNA technique to specifically deplete Plk1 in cancer cells. We found that Plk1 depletion dramatically inhibited cell proliferation, decreased viability, and resulted in cell-cycle arrest with 4 N DNA content. The formation of dumbbell-like chromatin structure suggests the inability of these cells to completely separate the sister chromatids at the onset of anaphase. Plk1 depletion induced apoptosis, as indicated by the appearance of subgenomic DNA in fluorescence-activated cell-sorter (FACS) profiles, the activation of caspase 3, and the formation of fragmented nuclei. Plk1-depletion-induced apoptosis was partially reversed by cotransfection of nondegradable mouse Plk1 constructs. In addition, the p53 pathway was shown to be involved in Plk1-depletion-induced apoptosis. DNA damage occurred in Plk1-depleted cells and inhibition of ATM strongly potentiated the lethality of Plk1 depletion. Although p53 is stabilized in Plk1-depleted cells, DNA damage also occurs in p53(-/-) cells. These data support the notion that disruption of Plk1 function could be an important application in cancer therapy.

  6. Methane rescues retinal ganglion cells and limits retinal mitochondrial dysfunction following optic nerve crush.

    Science.gov (United States)

    Wang, Ruobing; Sun, Qinglei; Xia, Fangzhou; Chen, Zeli; Wu, Jiangchun; Zhang, Yuelu; Xu, Jiajun; Liu, Lin

    2017-06-01

    Secondary degeneration is a common event in traumatic central nervous system disorders, which involves neuronal apoptosis and mitochondrial dysfunction. Exogenous methane exerts the therapeutic effects in many organ injury. Our study aims to investigate the potential neuroprotection of methane in a rat model of optic nerve crush (ONC). Adult male Sprague-Dawley rats were subjected to ONC and administrated intraperitoneally with methane-saturated or normal saline (10 ml/kg) once per day for one week after ONC. The retinal ganglion cells (RGCs) density was assessed by hematoxylin and eosin staining and Fluoro-Gold retrogradely labeling. Visual function was evaluated by flash visual evoked potentials (FVEP). The retinal apoptosis was measured by terminal-deoxy-transferase-mediated dUTP nick end labeling (TUNEL) assay and the expression of apoptosis-related factors, such as phosphorylated Bcl-2-associated death promoter (pBAD), phosphorylated glycogen synthase kinase-3β (pGSK-3β), Bcl-2 associated X protein (Bax) and Bcl-2 extra large (Bcl-xL). Retinal mitochondrial function was assessed by the mRNA expressions of peroxisome proliferator-activated receptor gamma coactivator-1α (PGC-1α), nuclear respiratory factor 1 (NRF1) and mitochondrial transcription factor A (TFAM), the mitochondrial DNA (mtDNA) copy number, citrate synthase activity and ATP content. Methane treatment significantly improved the RGC loss and visual dysfunction following ONC. As expected, methane also remarkably inhibited the retinal neural apoptosis, such as the fewer TUNEL-positive cells in ganglion cell layer, accompanied by the up-regulations of anti-apoptotic factors (pGSK-3β, pBAD, Bcl-xL) and the down-regulation of pro-apoptotic factor (Bax). Furthermore, methane treatment suppressed up-regulations of critical mitochondrial components (PGC-1α, NRF1 and TFAM) mRNA and mtDNA copy number, as well as improved the reduction of functional mitochondria markers, including citrate synthase

  7. An atmospheric-pressure cold plasma leads to apoptosis in Saccharomyces cerevisiae by accumulating intracellular reactive oxygen species and calcium

    Science.gov (United States)

    Ma, R. N.; Feng, H. Q.; Liang, Y. D.; Zhang, Q.; Tian, Y.; Su, B.; Zhang, J.; Fang, J.

    2013-07-01

    A non-thermal plasma is known to induce apoptosis of various cells but the mechanism is not yet clear. A eukaryotic model organism Saccharomyces cerevisiaewas used to investigate the cellular and biochemical regulations of cell apoptosis and cell cycle after an atmospheric-pressure cold plasma treatment. More importantly, intracellular calcium (Ca2+) was first involved in monitoring the process of plasma-induced apoptosis in this study. We analysed the cell apoptosis and cell cycle by flow cytometry and observed the changes in intracellular reactive oxygen species (ROS) and Ca2+ concentration, cell mitochondrial membrane potential (Δψm) as well as nuclear DNA morphology via fluorescence staining assay. All experimental results indicated that plasma-generated ROS leads to the accumulation of intracellular ROS and Ca2+ that ultimately contribute to apoptosis associated with cell cycle arrest at G1 phase through depolarization of Δψm and fragmenting nuclear DNA. This work provides a novel insight into the physical and biological mechanism of apoptosis induced by a plasma which could benefit for promoting the development of plasmas applied to cancer therapy.

  8. Bee venom induces apoptosis through intracellular Ca2+ -modulated intrinsic death pathway in human bladder cancer cells.

    Science.gov (United States)

    Ip, Siu-Wan; Chu, Yung-Lin; Yu, Chun-Shu; Chen, Po-Yuan; Ho, Heng-Chien; Yang, Jai-Sing; Huang, Hui-Ying; Chueh, Fu-Shin; Lai, Tung-Yuan; Chung, Jing-Gung

    2012-01-01

    To focus on bee venom-induced apoptosis in human bladder cancer TSGH-8301 cells and to investigate its signaling pathway to ascertain whether intracellular calcium iron (Ca(2+)) is involved in this effect. Bee venom-induced cytotoxic effects, productions of reactive oxygen species and Ca(2+) and the level of mitochondrial membrane potential (ΔΨm) were analyzed by flow cytometry. Apoptosis-associated proteins were examined by Western blot analysis and confocal laser microscopy. Bee venom-induced cell morphological changes and decreased cell viability through the induction of apoptosis in TSGH-8301 cell were found. Bee venom promoted the protein levels of Bax, caspase-9, caspase-3 and endonuclease G. The enhancements of endoplasmic reticulum stress-related protein levels were shown in bee venom-provoked apoptosis of TSGH-8301 cells. Bee venom promoted the activities of caspase-3, caspase-8, and caspase-9, increased Ca(2+) release and decreased the level of ΔΨm. Co-localization of immunofluorescence analysis showed the releases of endonuclease G and apoptosis-inducing factor trafficking to nuclei for bee venom-mediated apoptosis. The images revealed evidence of nuclear condensation and formation of apoptotic bodies by 4',6-diamidino-2-phenylindole staining and DNA gel electrophoresis showed the DNA fragmentation in TSGH-8301 cells. Bee venom treatment induces both caspase-dependent and caspase-independent apoptotic death through intracellular Ca(2+) -modulated intrinsic death pathway in TSGH-8301 cells. © 2011 The Japanese Urological Association.

  9. Mechanisms of dealing with DNA damage in terminally differentiated cells

    Energy Technology Data Exchange (ETDEWEB)

    Fortini, P. [Department of Environment and Primary Prevention, Istituto Superiore di Sanita, Viale Regina Elena 299, 00161 Rome (Italy); Dogliotti, E., E-mail: eugenia.dogliotti@iss.it [Department of Environment and Primary Prevention, Istituto Superiore di Sanita, Viale Regina Elena 299, 00161 Rome (Italy)

    2010-03-01

    To protect genomic integrity living cells that are continuously exposed to DNA-damaging insults are equipped with an efficient defence mechanism termed the DNA damage response. Its function is to eliminate DNA damage through DNA repair and to remove damaged cells by apoptosis. The DNA damage response has been investigated mainly in proliferating cells, in which the cell cycle machinery is integrated with the DNA damage signalling. The current knowledge of the mechanisms of DNA repair, DNA damage signalling and cell death of post-mitotic cells that have undergone irreversible cell cycle withdrawal will be reviewed. Evidence will be provided that the protection of the genome integrity in terminally differentiated cells is achieved by different strategies than in proliferating cells.

  10. Mechanisms of dealing with DNA damage in terminally differentiated cells

    International Nuclear Information System (INIS)

    Fortini, P.; Dogliotti, E.

    2010-01-01

    To protect genomic integrity living cells that are continuously exposed to DNA-damaging insults are equipped with an efficient defence mechanism termed the DNA damage response. Its function is to eliminate DNA damage through DNA repair and to remove damaged cells by apoptosis. The DNA damage response has been investigated mainly in proliferating cells, in which the cell cycle machinery is integrated with the DNA damage signalling. The current knowledge of the mechanisms of DNA repair, DNA damage signalling and cell death of post-mitotic cells that have undergone irreversible cell cycle withdrawal will be reviewed. Evidence will be provided that the protection of the genome integrity in terminally differentiated cells is achieved by different strategies than in proliferating cells.

  11. Demethoxycurcumin Retards Cell Growth and Induces Apoptosis in Human Brain Malignant Glioma GBM 8401 Cells

    Directory of Open Access Journals (Sweden)

    Tzuu-Yuan Huang

    2012-01-01

    Full Text Available Demethoxycurcumin (DMC; a curcumin-related demethoxy compound has been recently shown to display antioxidant and antitumor activities. It has also produced a potent chemopreventive action against cancer. In the present study, the antiproliferation (using the MTT assay, DMC was found to have cytotoxic activities against GBM 8401 cell with IC50 values at 22.71 μM and induced apoptosis effects of DMC have been investigated in human brain malignant glioma GBM 8401 cells. We have studied the mitochondrial membrane potential (MMP, DNA fragmentation, caspase activation, and NF-κB transcriptional factor activity. By these approaches, our results indicated that DMC has produced an inhibition of cell proliferation as well as the activation of apoptosis in GBM 8401 cells. Both effects were observed to increase in proportion with the dosage of DMC treatment, and the apoptosis was induced by DMC in human brain malignant glioma GBM 8401 cells via mitochondria- and caspase-dependent pathways.

  12. Effect of Uncaria tomentosa Extract on Apoptosis Triggered by Oxaliplatin Exposure on HT29 Cells.

    Science.gov (United States)

    de Oliveira, Liliane Z; Farias, Iria Luiza G; Rigo, Melânia L; Glanzner, Werner G; Gonçalves, Paulo Bayard D; Cadoná, Francine C; Cruz, Ivana B; Farias, Júlia G; Duarte, Marta M M F; Franco, Luzia; Bertol, Gustavo; Colpo, Elisangela; Brites, Patricia C; Rocha, João Batista T; Leal, Daniela B R

    2014-01-01

    Background/Aim. The use of herbal products as a supplement to minimize the effects of chemotherapy for cancer treatment requires further attention with respect to the activity and toxicity of chemotherapy. Uncaria tomentosa extract, which contains oxindole alkaloids, is one of these herbal products. The objective of this study was to evaluate whether Uncaria tomentosa extract modulates apoptosis induced by chemotherapy exposure. Materials and Methods. Colorectal adenocarcinoma cells (HT29 cells) were grown in the presence of oxaliplatin and/or Uncaria tomentosa extract. Results. The hydroalcoholic extract of Uncaria tomentosa enhanced chemotherapy-induced apoptosis, with an increase in the percentage of Annexin positive cells, an increase in caspase activities, and an increase of DNA fragments in culture of the neoplastic cells. Moreover, antioxidant activity may be related to apoptosis. Conclusion. Uncaria tomentosa extract has a role for cancer patients as a complementary therapy. Further studies evaluating these beneficial effects with other chemotherapy drugs are recommended.

  13. CD40-mediated apoptosis in murine B-lymphoma lines containing mutated p53

    DEFF Research Database (Denmark)

    Hollmann, Annette C; Gong, Qiaoke; Owens, Trevor

    2002-01-01

    Crosslinking CD40 induces normal B-cells to proliferate and differentiate but causes many tumor cell lines to undergo apoptosis. As p53 is required for many apoptotic pathways, we analyzed the effects of CD40 ligation and their correlation with p53 function in four murine B-lymphoma lines. A20...... of detectable p21 mRNA in A20 and M12 cells. P21 mRNA was increased to detectable levels in M12 cells upon CD40 ligation; however, blocking this effect with the p53 inhibitor pifithrin had no effect on CD40-mediated apoptosis. Sequencing showed that p53 in A20 and M12 cells contained point mutations leading...... to amino acid substitutions in DNA binding regions, but was unmutated in WEHI231 and WEHI 279. These results suggest that CD40-mediated apoptosis can occur in the absence of functional p53....

  14. Effect of Uncaria tomentosa Extract on Apoptosis Triggered by Oxaliplatin Exposure on HT29 Cells

    Directory of Open Access Journals (Sweden)

    Liliane Z. de Oliveira

    2014-01-01

    Full Text Available Background/Aim. The use of herbal products as a supplement to minimize the effects of chemotherapy for cancer treatment requires further attention with respect to the activity and toxicity of chemotherapy. Uncaria tomentosa extract, which contains oxindole alkaloids, is one of these herbal products. The objective of this study was to evaluate whether Uncaria tomentosa extract modulates apoptosis induced by chemotherapy exposure. Materials and Methods. Colorectal adenocarcinoma cells (HT29 cells were grown in the presence of oxaliplatin and/or Uncaria tomentosa extract. Results. The hydroalcoholic extract of Uncaria tomentosa enhanced chemotherapy-induced apoptosis, with an increase in the percentage of Annexin positive cells, an increase in caspase activities, and an increase of DNA fragments in culture of the neoplastic cells. Moreover, antioxidant activity may be related to apoptosis. Conclusion. Uncaria tomentosa extract has a role for cancer patients as a complementary therapy. Further studies evaluating these beneficial effects with other chemotherapy drugs are recommended.

  15. 2-aryl benzimidazole conjugate induced apoptosis in human breast cancer MCF-7 cells through caspase independent pathway.

    Science.gov (United States)

    Nayak, V Lakshma; Nagesh, Narayana; Ravikumar, A; Bagul, Chandrakant; Vishnuvardhan, M V P S; Srinivasulu, Vunnam; Kamal, Ahmed

    2017-01-01

    Apoptosis is a representative form of programmed cell death, which has been assumed to be critical for cancer prevention. Thus, any agent that can induce apoptosis may be useful for cancer treatment and apoptosis induction is arguably the most potent defense against cancer promotion. In our previous studies, 2-aryl benzimidazole conjugates were synthesized and evaluated for their antiproliferative activity and one of the new molecule (2f) was considered as a potential lead. This lead molecule showed significant antiproliferative activity against human breast cancer cell line, MCF-7. The results of the present study revealed that this compound arrested the cell cycle at G2/M phase. Topoisomerase II inhibition assay and Western blot analysis suggested that this compound effectively inhibits topoisomerase II activity which leads to apoptotic cell death. Apoptosis induction in MCF-7 cells was further confirmed by loss of mitochondrial membrane potential (∆Ψm), release of cytochrome c from mitochondria, an increase in the level of apoptosis inducing factor (AIF), generation of reactive oxygen species (ROS), up regulation of proapoptotic protein Bax and down regulation of anti apoptotic protein Bcl-2. Apoptosis assay using Annexin V-FITC assay also suggested that this compound induced cell death by apoptosis. However, compound 2f induced apoptosis could not be reversed by Z-VAD-FMK (a pan-caspase inhibitor) demonstrated that the 2f induced apoptosis was caspase independent. Further, 2f treatment did not activate caspase-7 and caspase-9 activity, suggesting that this compound induced apoptosis in breast cancer cells via a caspase independent pathway. Most importantly, this compound was less toxic towards non-tumorigenic breast epithelial cells, MCF-10A. Furthermore, docking studies also support the potentiality of this molecule to bind to the DNA topoisomerase II.

  16. Apelin-13 attenuates cisplatin-induced cardiotoxicity through inhibition of ROS-mediated DNA damage and regulation of MAPKs and AKT pathways.

    Science.gov (United States)

    Zhang, Pu; Yi, Lu-Hua; Meng, Guang-Yuan; Zhang, Huan-Yi; Sun, Hai-Hui; Cui, Lian-Qun

    2017-05-01

    Platinum-based chemotherapy represents one of the most effective ways in combating human cancers. However, the cardiotoxicity subsequent severely limited its clinical application. Increased evidences indicate that oxidative stress plays a crucial role in the pathological process of platinum-induced cardiotoxicity. It is reported that apelin-13 a bioactive peptide has the scavenging capacity of free radical, and it has the potential to regulate the cardiovascular system. Hence, the potential of apelin-13 to antagonize cisplatin-induced cardiotoxicity was evaluated in H9c2 rat myocardial cells in vitro and in C57 mice in vivo. The results showed that cisplatin indeed caused DNA damage in H9c2 cells by promoting the accumulation of intracellular reactive oxygen species (ROS) and superoxide anion, which led to cell apoptosis and resulted in overt cardiotoxicity. However, apelin-13 pre-treatment effectively attenuated the cisplatin-induced ROS and superoxide anion generation, inhibited DNA damage, and suppressed the PARP cleavage and caspases activation. Further investigation revealed that apelin-13 blocked cisplatin-induced H9c2 cells apoptosis involving the regulation of MAPKs and PI3K/Akt signaling pathway. Importantly, apelin-13 co-treatment also significantly attenuated cisplatin-induced cardiotoxicity in vivo by inhibiting myocardial cells apoptosis and improving angiogenesis in mice heart. Taken together, our results suggest that the use of apelin-13 may be an effective strategy for antagonizing the cardiotoxicity-induced by platinum-based chemotherapy.

  17. Radiation-induced apoptosis and developmental disturbance of the brain

    International Nuclear Information System (INIS)

    Inouye, Minoru

    1995-01-01

    The developing mammalian brain is highly susceptible to ionizing radiation. A significant increase in small head size and mental retardation has been noted in prenatally exposed survivors of the atomic bombing, with the highest risk in those exposed during 8-15 weeks after fertilization. This stage corresponds to day 13 of pregnancy for mice and day 15 for rats in terms of brain development. The initial damage produced by radiation at this stage is cell death in the ventricular zone (VZ) of the brain mantle, the radiosensitive germinal cell population. During histogenesis of the cerebellum the external granular layer (EGL) is also radiosensitive. Although extensive cell death results in microcephaly and histological abnormlity, both VZ and EGL have an ability to recover from a considerable cell loss and form the normal structure of the central nervous system. The number of cell deaths to induce tissue abnormalities in adult brain rises in the range of 15-25% of the germinal cell population; and the threshold doses are about 0.3 Gy for cerebral defects and 1 Gy for cerebellar anomalies in both mice and rats. A similar threshold level is suggested in human cases in induction of mental retardation. Radiation-induced cell death in the VZ and EGL has been revealed as apoptosis, by the nuclear and cytoplasmic condensation, transglutaminase activation, required macromolecular synthesis, and internucleosomal DNA cleavage. Apoptosis of the germinal cell is assumed to eliminate acquired genetic damage. Once an abnormality in DNA has been induced and fixed in a germinal cell, it would be greatly amplified during future proliferation. These cells would commit suicide when injured for replacement by healthy cells, rather than undertake DNA repair. In fact they show very slow repair of cellular damage. Thus the high sensitivity of undifferentiated neural cells to the lethal effect of radiation may constitute a biological defense mechanism. (author) 69 refs

  18. XIAP impairs Smac release from the mitochondria during apoptosis.

    Science.gov (United States)

    Flanagan, L; Sebastià, J; Tuffy, L P; Spring, A; Lichawska, A; Devocelle, M; Prehn, J H M; Rehm, M

    2010-06-03

    X-linked inhibitor of apoptosis protein (XIAP) is a potent inhibitor of caspases 3, 7 and 9, and mitochondrial Smac (second mitochondria-derived activator of caspase) release during apoptosis inhibits the activity of XIAP. In this study we show that cytosolic XIAP also feeds back to mitochondria to impair Smac release. We constructed a fluorescent XIAP-fusion protein by labelling NH(2)- and COOH-termini with Cerulean fluorescent protein (C-XIAP-C). Immunoprecipitation confirmed that C-XIAP-C retained the ability to interact with Smac and impaired extrinsically and intrinsically activated apoptosis in response to tumour necrosis factor-related apoptosis-inducing ligand/cycloheximide and staurosporine. In C-XIAP-C-expressing cells, cytochrome c release from mitochondria proceeded normally, whereas Smac release was significantly prolonged and incomplete. In addition, physiological expression of native XIAP prolonged or limited Smac release in HCT-116 colon cancer cells and primary mouse cortical neurons. The Smac-binding capacity of XIAP, but not caspase inhibition, was central for mitochondrial Smac retention, as evidenced in experiments using XIAP mutants that cannot bind to Smac or effector caspases. Similarly, the release of a Smac mutant that cannot bind to XIAP was not impaired by C-XIAP-C expression. Full Smac release could however be provoked by rapid cytosolic C-XIAP-C depletion upon digitonin-induced plasma membrane permeabilization. Our findings suggest that although mitochondria may already contain pores sufficient for cytochrome c release, elevated amounts of XIAP can selectively impair and limit the release of Smac.

  19. Host-pathogen interactions during apoptosis

    Indian Academy of Sciences (India)

    Unknown

    rity and tissue homeostasis in multicellular organisms. (Vaux and Strasser 1996). Apoptosis characteristically occurs in isolated single cells. Inappropriate apoptosis is linked to a number of parasitic infections as well as the cause and progression of diseases such as neurodegenera- tive disorders, aging and cancer.

  20. Crosstalk between apoptosis and inflammation in atherosclerosis

    NARCIS (Netherlands)

    Westra, Marijke Marianne

    2010-01-01

    In this thesis the role of several apoptosis regulating proteins in the development of atherosclerosis and atherosclerotic plaque stability is investigated. Apoptosis of different cell types in atherosclerotic plaques, such as macrophages and smooth muscle cells may inhibit or promote plaque

  1. Apoptosis in mammalian oocytes: a review.

    Science.gov (United States)

    Tiwari, Meenakshi; Prasad, Shilpa; Tripathi, Anima; Pandey, Ashutosh N; Ali, Irfan; Singh, Arvind K; Shrivastav, Tulsidas G; Chaube, Shail K

    2015-08-01

    Apoptosis causes elimination of more than 99% of germ cells from cohort of ovary through follicular atresia. Less than 1% of germ cells, which are culminated in oocytes further undergo apoptosis during last phases of oogenesis and depletes ovarian reserve in most of the mammalian species including human. There are several players that induce apoptosis directly or indirectly in oocytes at various stages of meiotic cell cycle. Premature removal of encircling granulosa cells from immature oocytes, reduced levels of adenosine 3',5'-cyclic monophosphate and guanosine 3',5'-cyclic monophosphate, increased levels of calcium (Ca(2+)) and oxidants, sustained reduced level of maturation promoting factor, depletion of survival factors, nutrients and cell cycle proteins, reduced meiotic competency, increased levels of proapoptotic as well as apoptotic factors lead to oocyte apoptosis. The BH3-only proteins also act as key regulators of apoptosis in oocyte within the ovary. Both intrinsic (mitochondria-mediated) as well as extrinsic (cell surface death receptor-mediated) pathways are involved in oocyte apoptosis. BID, a BH3-only protein act as a bridge between both apoptotic pathways and its cleavage activates cell death machinery of both the pathways inside the follicular microenvironment. Oocyte apoptosis leads to the depletion of ovarian reserve that directly affects reproductive outcome of various mammals including human. In this review article, we highlight some of the important players and describe the pathways involved during oocyte apoptosis in mammals.

  2. Fas-induced apoptosis in malnourished infants

    African Journals Online (AJOL)

    EL-HAKIM

    deprivation in animals, including man11. Factor of apoptosis signal (Fas) induces apoptosis in activated T cells when they are repeatedly stimulated by antigen and functions to maintain T cell tolerance by deleting auto reactive cells12. The functional role of Fas (CD95) in the immune system has been examined in a variety ...

  3. Apoptosis in mouse fetal and neonatal oocytes during meiotic prophase one

    Directory of Open Access Journals (Sweden)

    Hartshorne Geraldine M

    2007-07-01

    Full Text Available Abstract Background The vast majority of oocytes formed in the fetal ovary do not survive beyond birth. Possible reasons for their loss include the elimination of non-viable genetic constitutions arising through meiosis, however, the precise relationship between meiotic stages and prenatal apoptosis of oocytes remains elusive. We studied oocytes in mouse fetal and neonatal ovaries, 14.5–21 days post coitum, to examine the relationship between oocyte development and programmed cell death during meiotic prophase I. Results Microspreads of fetal and neonatal ovarian cells underwent immunocytochemistry for meiosis- and apoptosis-related markers. COR-1 (meiosis-specific highlighted axial elements of the synaptonemal complex and allowed definitive identification of the stages of meiotic prophase I. Labelling for cleaved poly-(ADP-ribose polymerase (PARP-1, an inactivated DNA repair protein, indicated apoptosis. The same oocytes were then labelled for DNA double strand breaks (DSBs using TUNEL. 1960 oocytes produced analysable results. Oocytes at all stages of meiotic prophase I stained for cleaved PARP-1 and/or TUNEL, or neither. Oocytes with fragmented (19.8% or compressed (21.2% axial elements showed slight but significant differences in staining for cleaved PARP-1 and TUNEL to those with intact elements. However, fragmentation of axial elements alone was not a good indicator of cell demise. Cleaved PARP-1 and TUNEL staining were not necessarily coincident, showing that TUNEL is not a reliable marker of apoptosis in oocytes. Conclusion Our data indicate that apoptosis can occur throughout meiotic prophase I in mouse fetal and early postnatal oocytes, with greatest incidence at the diplotene stage. Careful selection of appropriate markers for oocyte apoptosis is essential.

  4. p53 modulates the AMPK inhibitor compound C induced apoptosis in human skin cancer cells

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Shi-Wei [Institute of Biomedical Sciences, National Chung Hsing University, Taichung, Taiwan (China); Wu, Chun-Ying [Division of Gastroenterology and Hepatology, Taichung Veterans General Hospital, Taichung, Taiwan (China); Wang, Yen-Ting [Department of Medical Research and Education, Cheng Hsin General Hospital, Taipei, Taiwan (China); Kao, Jun-Kai [Institute of Biomedical Sciences, National Chung Hsing University, Taichung, Taiwan (China); Department of Pediatrics, Children' s Hospital, Changhua Christian Hospital, Changhua, Taiwan (China); Lin, Chi-Chen; Chang, Chia-Che; Mu, Szu-Wei; Chen, Yu-Yu [Institute of Biomedical Sciences, National Chung Hsing University, Taichung, Taiwan (China); Chiu, Husan-Wen [Institute of Biotechnology, National Cheng-Kung University, Tainan, Taiwan (China); Agricultural Biotechnology Research Center, Academia Sinica, Taipei, Taiwan (China); Chang, Chuan-Hsun [Department of Surgical Oncology, Cheng Hsin General Hospital, Taipei, Taiwan (China); Department of Nutrition Therapy, Cheng Hsin General Hospital, Taipei, Taiwan (China); School of Nutrition and Health Sciences, Taipei Medical University, Taipei, Taiwan (China); Liang, Shu-Mei [Institute of Biotechnology, National Cheng-Kung University, Tainan, Taiwan (China); Agricultural Biotechnology Research Center, Academia Sinica, Taipei, Taiwan (China); Chen, Yi-Ju [Department of Dermatology, Taichung Veterans General Hospital, Taichung, Taiwan (China); Huang, Jau-Ling [Department of Bioscience Technology, Chang Jung Christian University, Tainan, Taiwan (China); Shieh, Jeng-Jer, E-mail: shiehjj@vghtc.gov.tw [Institute of Biomedical Sciences, National Chung Hsing University, Taichung, Taiwan (China); Department of Education and Research, Taichung Veterans General Hospital, Taichung, Taiwan (China)

    2013-02-15

    Compound C, a well-known inhibitor of the intracellular energy sensor AMP-activated protein kinase (AMPK), has been reported to cause apoptotic cell death in myeloma, breast cancer cells and glioma cells. In this study, we have demonstrated that compound C not only induced autophagy in all tested skin cancer cell lines but also caused more apoptosis in p53 wildtype skin cancer cells than in p53-mutant skin cancer cells. Compound C can induce upregulation, phosphorylation and nuclear translocalization of the p53 protein and upregulate expression of p53 target genes in wildtype p53-expressing skin basal cell carcinoma (BCC) cells. The changes of p53 status were dependent on DNA damage which was caused by compound C induced reactive oxygen species (ROS) generation and associated with activated ataxia-telangiectasia mutated (ATM) protein. Using the wildtype p53-expressing BCC cells versus stable p53-knockdown BCC sublines, we present evidence that p53-knockdown cancer cells were much less sensitive to compound C treatment with significant G2/M cell cycle arrest and attenuated the compound C-induced apoptosis but not autophagy. The compound C induced G2/M arrest in p53-knockdown BCC cells was associated with the sustained inactive Tyr15 phosphor-Cdc2 expression. Overall, our results established that compound C-induced apoptosis in skin cancer cells was dependent on the cell's p53 status. - Highlights: ► Compound C caused more apoptosis in p53 wildtype than p53-mutant skin cancer cells. ► Compound C can upregulate p53 expression and induce p53 activation. ► Compound C induced p53 effects were dependent on ROS induced DNA damage pathway. ► p53-knockdown attenuated compound C-induced apoptosis but not autophagy. ► Compound C-induced apoptosis in skin cancer cells was dependent on p53 status.

  5. Withaferin A-induced apoptosis in human breast cancer cells is mediated by reactive oxygen species.

    Directory of Open Access Journals (Sweden)

    Eun-Ryeong Hahm

    Full Text Available Withaferin A (WA, a promising anticancer constituent of Ayurvedic medicinal plant Withania somnifera, inhibits growth of MDA-MB-231 and MCF-7 human breast cancer cells in culture and MDA-MB-231 xenografts in vivo in association with apoptosis induction, but the mechanism of cell death is not fully understood. We now demonstrate, for the first time, that WA-induced apoptosis is mediated by reactive oxygen species (ROS production due to inhibition of mitochondrial respiration. WA treatment caused ROS production in MDA-MB-231 and MCF-7 cells, but not in a normal human mammary epithelial cell line (HMEC. The HMEC was also resistant to WA-induced apoptosis. WA-mediated ROS production as well as apoptotic histone-associated DNA fragment release into the cytosol was significantly attenuated by ectopic expression of Cu,Zn-superoxide dismutase in both MDA-MB-231 and MCF-7 cells. ROS production resulting from WA exposure was accompanied by inhibition of oxidative phosphorylation and inhibition of complex III activity. Mitochondrial DNA-deficient Rho-0 variants of MDA-MB-231 and MCF-7 cells were resistant to WA-induced ROS production, collapse of mitochondrial membrane potential, and apoptosis compared with respective wild-type cells. WA treatment resulted in activation of Bax and Bak in MDA-MB-231 and MCF-7 cells, and SV40 immortalized embryonic fibroblasts derived from Bax and Bak double knockout mouse were significantly more resistant to WA-induced apoptosis compared with fibroblasts derived from wild-type mouse. In conclusion, the present study provides novel insight into the molecular circuitry of WA-induced apoptosis involving ROS production and activation of Bax/Bak.

  6. Apoptosis in ovarian cells in postmenopausal women.

    Directory of Open Access Journals (Sweden)

    Maria Laszczyńska

    2007-06-01

    Full Text Available Apoptosis is a natural process which accompanies human ovary from the moment of birth until old age. While it is a well-known process at the reproductive age, it still needs to be thoroughly examined when referring to the postmenopausal age. The study involved 30 postmenopausal women who had their ovaries removed by laparotomy due to nonneoplastic diseases of the uterus. The women were divided into 3 groups depending on the time that had passed since the last menstruation. Group A consisted of women who had their last menstruation no more than 5 years earlier. In group B menopause occurred 5 to 10 years earlier. Group C was composed of patients who had the last menstruation over 10 years earlier. In all the patients concentrations of follitropin (FSH and estradiol (E2 in blood plasma were measured. Ovarian tissue was obtained during surgery. For morphological studies, ovaries were fixed in Bouin's solution and 4% formalin and embedded in paraffin. Morphological analysis was carried out after hematoxylin-eosin (H-E staining. For histochemical detection of apoptotic cells (in situ localization of fragment DNA, the TUNEL method was used. The expression of caspase-3 positive cells was determined immunohistochemically in paraffin-embedded specimens. Comparing to groups A and B, the ovaries in group C contained small number of corpora albicantia located in the medullary part as well as thinned blood vessels and few lymphatic vessels and nerves. In contrast to group A where the number of TUNEL-positive cells was high and caspase-3 expression was observed, no TUNEL-positive nuclei and caspase-3 expression were found in the examined ovaries of group C women.

  7. Apoptosis induced by chlormethine and ionizing radiations in normal and tumoral lymphocytes: role of caspase-3

    International Nuclear Information System (INIS)

    Holl, V.P.

    2000-01-01

    Apoptosis can be induced by various stimuli like ionizing radiations or alkylating agents. Recent works have shown that apoptosis due to ionizing radiations can be initiated by DNA and cell membrane alterations, via radical species generation, implying the in fine activation of effector caspases, and in particular caspase-3. The main goal of this work is to clarify the role of caspase-3 in the radio-induced apoptosis mechanisms and to study the effects of apoptosis inhibition on the behaviour of the damaged cells. The effects of activation and caspase-3 activity inhibition on the progress of spontaneous, radio-induced or chlormethine-induced apoptosis have been evaluated for normal and tumoral lymphocytes. A chemical molecule, the ebselen, which can mime the action of the endogenous glutathione peroxidase, and a tetra-peptide inhibitor, AC-DEVD-CHO, selective of effector caspases, have been selected. The results indicate an inhibition by ebselen of all morphological and biochemical characteristics of chlormethine-induced apoptosis and a restoring of the cells viability. This seleno-organic compound also reduces the drop of the intra-cellular glutathione level and the loss of the trans-membrane potential (M) of the mitochondrion in the MOLT-4 tumoral cells treated with chlormethine. In parallel, the AC-DEVD-CHO effect on apoptosis induction has been tested. This inhibitor stops some chlormethine-induced criteria of apoptosis without affecting the final loss of the mitochondrial M and the cells proliferation. AC-DEVD-CHO has been also incubated just before the irradiation of the culture cells. The inhibition of the specific DEVD caspases prevents the inter-nucleosomal fragmentation of DNA and partially delays the externalization of phosphatidylserine without changing the viability of the irradiated cells. Moreover, the analysis of the AC-DEVD-CHO pre-treated irradiated cells floating on the surface shows a strong mitochondrial lactate dehydrogenase activity, which

  8. The effects of benzene exposure on apoptosis in epithelial lung cells: localization by terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling (TUNEL) and the immunocytochemical localization of apoptosis-related gene products.

    Science.gov (United States)

    Weaver, C V; Liu, S-P; Lu, J-F; Lin, B-S

    2007-05-01

    Although benzene, a well-known human carcinogen, has been shown to induce apoptosis in vitro, no studies have been carried out to confirm and characterize its role in activating apoptosis in vivo. The present study investigated the effects of benzene inhalation on the epithelial cells lining the respiratory tract including bronchioles, terminal bronchioles, respiratory bronchioles and alveoli of male Sprague-Dawley rats. Inhalation of benzene 300 ppm for 7 days induced apoptotic changes in the parenchymal components in the lung that significantly exceeded the events of programmed cell death in normal control tissues. Apoptosis was confirmed by the electrophoretic analysis of internucleosomal DNA fragmentation of benzene-exposed lung tissues, which exhibited 180-200 bp laddering subunits indicative of genomic DNA degradation. Furthermore, semi-quantitative analysis of intracellular localization of terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling TUNEL) showed a significant (p respiratory bronchiolar 60.8% segmental epithelial components as well as alveolar (55%) epithelia. Analysis of immunohistochemical expression of apoptosis-related gene products also supported the hypothesis that benzene can induce apoptosis in chemosensitive target cells in the lung parenchyma. Quantitative immunhistochemistry showed a statistically significant increase p respiratory system that demonstrates that benzene inhalation induces lung cell apoptosis as confirmed by DNA electrophoresis, in situ nick end labeling, and the upregulation of apoptosis-related gene products that facilitate caspase-cleaved enzymes which lead to cell degradation via programmed cell death. These responses may represent an important defense mechanism within the parenchymal cells of the respiratory system that reduce mutational hazard and the potential carcinogenic effects of benzene-initiated pathogenesis.

  9. DNA glue

    DEFF Research Database (Denmark)

    Filichev, Vyacheslav V; Astakhova, Irina V.; Malakhov, Andrei D.

    2008-01-01

    Significant alterations in thermal stability of parallel DNA triplexes and antiparallel duplexes were observed upon changing the attachment of ethynylpyrenes from para to ortho in the structure of phenylmethylglycerol inserted as a bulge into DNA (TINA). Insertions of two ortho-TINAs as a pseudo...

  10. DNA Vaccines

    Indian Academy of Sciences (India)

    DNA vaccine, immune response, antibodies, infectious diseases. GENERAL I ARTICLE. DNA Vaccines. P N Rangarajan. History of Vaccine Development. The year 1996 marked the 200th anniversary of the first vaccine developed against smallpox by Edward Jenner. In the now- famous 1796 experiment, Jenner scratched ...

  11. Hyperstretching DNA

    NARCIS (Netherlands)

    Schakenraad, Koen; Biebricher, Andreas S.; Sebregts, Maarten; Ten Bensel, Brian; Peterman, Erwin J.G.; Wuite, Gijs J L; Heller, Iddo; Storm, Cornelis; Van Der Schoot, Paul

    2017-01-01

    The three-dimensional structure of DNA is highly susceptible to changes by mechanical and biochemical cues in vivo and in vitro. In particular, large increases in base pair spacing compared to regular B-DNA are effected by mechanical (over)stretching and by intercalation of compounds that are widely

  12. Cancer Therapy Due to Apoptosis: Galectin-9

    Directory of Open Access Journals (Sweden)

    Koji Fujita

    2017-01-01

    Full Text Available Dysregulation of apoptosis is a major hallmark in cancer biology that might equip tumors with a higher malignant potential and chemoresistance. The anti-cancer activities of lectin, defined as a carbohydrate-binding protein that is not an enzyme or antibody, have been investigated for over a century. Recently, galectin-9, which has two distinct carbohydrate recognition domains connected by a linker peptide, was noted to induce apoptosis in thymocytes and immune cells. The apoptosis of these cells contributes to the development and regulation of acquired immunity. Furthermore, human recombinant galectin-9, hG9NC (null, which lacks an entire region of the linker peptide, was designed to resist proteolysis. The hG9NC (null has demonstrated anti-cancer activities, including inducing apoptosis in hematological, dermatological and gastrointestinal malignancies. In this review, the molecular characteristics, history and apoptosis-inducing potential of galectin-9 are described.

  13. Apoptosis in inner ear sensory hair cells

    Directory of Open Access Journals (Sweden)

    Seth Morrill

    2017-12-01

    Full Text Available Apoptosis, or controlled cell death, is a normal part of cellular lifespan. Cell death of cochlear hair cells causes deafness; an apoptotic process that is not well understood. Worldwide, 1.3 billion humans suffer some form of hearing loss, while 360 million suffer debilitating hearing loss as a direct result of the absence of these cochlear hair cells (Worldwide Hearing, 2014. Much is known about apoptosis in other systems and in other cell types thanks to studies done since the mid-20th century. Here we review current literature on apoptosis in general, and causes of deafness and cochlear hair cells loss as a result of apoptosis. The family of B-cell lymphoma (Bcl proteins are among the most studied and characterized. We will review current literature on the Bcl2 and Bcl6 protein interactions in relation to apoptosis and their possible roles in vulnerability and survival of cochlear hair cells.

  14. UVC-induced apoptosis in Dubca cells is independent of JNK activation and p53Ser-15 phosphorylation

    International Nuclear Information System (INIS)

    Chathoth, Shahanas; Thayyullathil, Faisal; Hago, Abdulkader; Shahin, Allen; Patel, Mahendra; Galadari, Sehamuddin

    2009-01-01

    Ultraviolet C (UVC) irradiation in mammalian cell lines activates a complex signaling network that leads to apoptosis. By using Dubca cells as a model system, we report the presence of a UVC-induced apoptotic pathway that is independent of c-Jun N-terminal kinases (JNKs) activation and p53 phosphorylation at Ser 15 . Irradiation of Dubca cells with UVC results in a rapid JNK activation and phosphorylation of its downstream target c-Jun, as well as, phosphorylation of activating transcription factor 2 (ATF2). Pre-treatment with JNK inhibitor, SP600125, inhibited UVC-induced c-Jun phosphorylation without preventing UVC-induced apoptosis. Similarly, inhibition of UVC-induced p53 phosphorylation did not prevent Dubca cell apoptosis, suggesting that p53 Ser-15 phosphorylation is not associated with UVC-induced apoptosis signaling. The pan-caspase inhibitor z-VAD-fmk inhibited UVC-induced PARP cleavage, DNA fragmentation, and ultimately apoptosis of Dubca cells. Altogether, our study clearly indicates that UVC-induced apoptosis is independent of JNK and p53 activation in Dubca cells, rather, it is mediated through a caspase dependent pathway. Our findings are not in line with the ascribed critical role for JNKs activation, and downstream phosphorylation of targets such as c-Jun and ATF2 in UVC-induced apoptosis.

  15. AICA-riboside induces apoptosis of pancreatic beta cells through stimulation of AMP-activated protein kinase.

    Science.gov (United States)

    Kefas, B A; Heimberg, H; Vaulont, S; Meisse, D; Hue, L; Pipeleers, D; Van de Casteele, M

    2003-02-01

    Prolonged exposure of beta cells to low glucose concentrations triggers their apoptosis and is known to activate AMP-activated protein kinase (AMPK) in beta cell lines. We examined whether prolonged activation of AMPK can trigger apoptosis in rodent beta cells. Primary beta cells were FACS-purified from rats, and from wild-type and AMPK(alpha2)-deficient mice. AMPK activation in beta cells was induced by the adenosine analog AICA-riboside and detected by immunoblotting using a phosphospecific antibody. Apoptosis of rodent beta cells was monitored by FACS analysis of beta cell DNA content, by direct counting of apoptotic cells using fluorescence microscopy, or by measurement of their caspase-3 activity. Dose-dependent and time-dependent apoptosis of the cells, concommittant with an activation of caspase-3, were suppressed by the caspase inhibitors zVAD-fmk and zDEVD-fmk. Apoptosis induction by AICA-riboside was also prevented by adding the MAPK-inhibitor SB203580 which blocked the AICA-riboside-induced phosphorylation of AMPK. Beta cells isolated from AMPK-(alpha2)-deficient mice were resistant against AICA-riboside induced apoptosis. Sustained activation of AMPK by AICA-riboside can trigger a caspase-dependent apoptosis of pancreatic beta cells.

  16. The p53-induced Siva-1 plays a significant role in cisplatin-mediated apoptosis

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    Barkinge John

    2009-01-01

    Full Text Available Background: The pro-apoptotic protein Siva-1 functions in both extrinsic and intrinsic cell death signaling; however, the exact contribution of the endogenous Siva-1 to DNA damage-induced apoptosis is unclear. Using cisplatin, a chemotherapeutic drug, to induce DNA damage and cell death, we determined the role of Siva-1. Methods: Cisplatin treated HCT116 colorectal carcinoma cells (p53+/+ and -/- were used in the study. With the help of recombinant lentivirus that can express siSiva (siRNA that specifically targets Siva-1, we also generated Siva-1 knockdown HCT116 cells. Apoptosis was determined by tetramethyl rhodamine methyl ester (TMRM staining and propidium iodide (PI staining. Results: Treatment with cisplatin induced Siva-1 expression in a p53 dependent manner. In Siva-1 knockdown p53+/+ HCT116 colorectal carcinoma cells, loss of Siva-1 expression conferred significant resistance to cisplatin-induced apoptosis. Although Siva-1 levels were positively regulated by p53, Siva-1-induced apoptosis did not require p53. Despite the fact that Siva-1 lacks even a minimal BH3 domain, similar to other proapoptotic Bcl2 family members induced by p53, we showed that Siva-1 mediated apoptosis is characterized by Bax oligomerization and cytochrome c leakage from mitochondria. The putative amphipathic helical region in Siva-1 (SAH appeared to function analogously to a BH3 domain. Conclusion: The p53 induced Siva-1 is one of the effector molecules, which plays a significant role in DNA damage-induced cell death.

  17. Fumonisins and Alternaria alternata lycopersici toxins: sphinganine analog mycotoxins induce apoptosis in monkey kidney cells.

    Science.gov (United States)

    Wang, W; Jones, C; Ciacci-Zanella, J; Holt, T; Gilchrist, D G; Dickman, M B

    1996-04-16

    Fusarium moniliforme toxins (fumonisins) and Alternaria alternata lycopersici (AAL) toxins are members of a new class of sphinganine analog mycotoxins that occur widely in the food chain. These mycotoxins represent a serious threat to human and animal health, inducing both cell death and neoplastic events in mammals. The mechanisms by which this family of chemical congeners induce changes in cell homeostasis were investigated in African green monkey kidney cells (CV-1) by assessing the appearance of apoptosis, cell cycle regulation, and putative components of signal transduction pathways involved in apoptosis. Structurally, these mycotoxins resemble the sphingoid bases, sphingosine and sphinganine, that are reported to play critical roles in cell communication and signal transduction. The addition of fumonisin B1 or AAL toxin, TA, to CV-1 cells induced the stereotypical hallmarks of apoptosis, including the formation of DNA ladders, compaction of nuclear DNA, and the subsequent appearance of apoptotic bodies. Neither mycotoxin induced cell death, DNA ladders, or apoptotic bodies in CV-1 cells expressing simian virus 40 large T antigen (COS-7) at toxin concentrations that readily killed CV-1 cells. Fumonisin B1 induced cell cycle arrest in the G1 phase in CV-1 cells but not in COS-7 cells. AAL toxin TA did not arrest cell cycle progression in either cell line. The induction of apoptosis combined with the widespread presence of these compounds in food crops and animal feed identifies a previously unrecognized health risk to humans and livestock. These molecules also represent a new class of natural toxicants that can be used as model compounds to further characterize the molecular and biochemical pathways leading to apoptosis.

  18. Reduced glutathione prevents camphorquinone-induced apoptosis in human oral keratinocytes.

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    Volk, Joachim; Leyhausen, Gabriele; Wessels, Miriam; Geurtsen, Werner

    2014-02-01

    Camphorquinone (CQ) is a widely used photoinitiator in dental visible light (VL)-cured resinous materials. However, little is known about the toxicity of CQ in human cells. This study was designed to investigate CQ induced oxidative strain and apoptosis in cultured human oral keratinocytes (OKF6/TERT 2). Furthermore, the effects of visible-light (VL)-irradiation and the reducing agent N,N-dimethyl-p-toluidine (DMT) were investigated. In addition, the preventive potential of the antioxidant glutathione (GSH) against CQ induced toxicity was analyzed as well. The fluorescent DNA-staining dye Hoechst 33342 was used to quantify total cell numbers. Intracellular levels of reactive oxygen species (ROS) were measured by the fluorescent probe 2',7'-dichlorofluorescein diacetate (DCFH-DA). Apoptosis was determined by FACS analysis (Annexin V-FITC/propidium iodide), by measuring caspase-3/7 activity (ELISA) and by DNA laddering. Our data show that CQ was dose-dependent cytotoxic and caused oxidative stress by inducing reactive oxygen species (ROS). The redistribution of phosphatidylserine (PS) to the outer layer of the plasma membrane, induction of caspase-3 enzyme activity and DNA fragmentation were also observed in CQ exposed cells. Interestingly, CQ-induced ROS generation enhanced by VL irradiation or a simultaneous treatment with DMT showed no quantitative effect on apoptosis. However, co-exposure of cells with GSH significantly reduced the intracellular ROS generation as well as apoptosis caused by CQ. This is the first report showing that ROS-induced apoptosis, which is caused by CQ, is prevented by GSH. Copyright © 2013 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

  19. Phytochemicals radiosensitize cancer cells by inhibiting DNA repair

    International Nuclear Information System (INIS)

    Singh, Rana P.

    2017-01-01

    Solid tumors are mostly treated with radiotherapy. Radiotherapy is toxic to normal tissues and also promote the invasiveness and radioresistance in cancer cells. The resistance against radiotherapy and adverse effects to normal cells reduce the overall therapeutic effects of the treatment. Radiosensitizing agents usually show limited success during clinical trials. Therefore, the search and development of new radiosensitizers showing selective response to only cancer cells is desirable. We analyzed the radiosensitizing effects including cell death effect of silibinin, a phytochemical on prostate cancer cells. Silibinin enhanced gamma radiation (2.5-10 Gy) induced inhibition in colony formation selectively in prostate cancer cells. In cell cycle progression, G2/M phase is the most sensitive phase for radiation-induced damage which was delayed by the compound treatment in radiation exposed cells. The lower concentrations of silibinin substantially enhanced radiation-induced apoptosis. A prolonged reactive oxygen species production was also observed in these treatments EGFR signaling pathway can contribute to radiation-induced pro-survival mechanisms and to the therapeutic resistance. Agent treatment reduced the IR-induced EGFR phosphorylation and consequently reversed the resistance mediating mechanisms within the cancer cell. Thus, inhibiting DNA repair in cancer cells would enhance therapeutic response of radiation in cancer cells. Silibinin affected the localization of EGFR and DNA-dependent protein kinase, the DNA-PK is known to be an important mediator of DSB repair in human cells, and showed increased number of pH2AX (ser139) foci, and thus indicating lower DNA repair in these cancer cells. This was also confirmed in the tumor xenograft study. Our findings suggest that a combination of silibinin with radiation could be an effective treatment of radioresistant human prostate cancer and warrants further investigation. (author)

  20. Transcutaneous application of carbon dioxide (CO2 induces mitochondrial apoptosis in human malignant fibrous histiocytoma in vivo.

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    Yasuo Onishi

    Full Text Available Mitochondria play an essential role in cellular energy metabolism and apoptosis. Previous studies have demonstrated that decreased mitochondrial biogenesis is associated with cancer progression. In mitochondrial biogenesis, peroxisome proliferator-activated receptor gamma coactivator-1 alpha (PGC-1α regulates the activities of multiple nuclear receptors and transcription factors involved in mitochondrial proliferation. Previously, we showed that overexpression of PGC-1α leads to mitochondrial proliferation and induces apoptosis in human malignant fibrous histiocytoma (MFH cells in vitro. We also demonstrated that transcutaneous application of carbon dioxide (CO(2 to rat skeletal muscle induces PGC-1α expression and causes an increase in mitochondrial proliferation. In this study, we utilized a murine model of human MFH to determine the effect of transcutaneous CO(2 exposure on PGC-1α expression, mitochondrial proliferation and cellular apoptosis. PGC-1α expression was evaluated by quantitative real-time PCR, while mitochondrial proliferation was assessed by immunofluorescence staining and the relative copy number of mitochondrial DNA (mtDNA was assessed by real-time PCR. Immunofluorescence staining and DNA fragmentation assays were used to examine mitochondrial apoptosis. We also evaluated the expression of mitochondrial apoptosis related proteins, such as caspases, cytochorome c and Bax, by immunoblot analysis. We show that transcutaneous application of CO(2 induces PGC-1α expression, and increases mitochondrial proliferation and apoptosis of tumor cells, significantly reducing tumor volume. Proteins involved in the mitochondrial apoptotic cascade, including caspase 3 and caspase 9, were elevated in CO(2 treated tumors compared to control. We also observed an enrichment of cytochrome c in the cytoplasmic fraction and Bax protein in the mitochondrial fraction of CO(2 treated tumors, highlighting the involvement of mitochondria in apoptosis

  1. Carnosol induces ROS-mediated beclin1-independent autophagy and apoptosis in triple negative breast cancer.

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    Yusra Al Dhaheri

    Full Text Available In this study we investigated the in vitro and in vivo anticancer effect of carnosol, a naturally occurring polyphenol, in triple negative breast cancer.We found that carnosol significantly inhibited the viability and colony growth induced G2 arrest in the triple negative MDA-MB-231. Blockade of the cell cycle was associated with increased p21/WAF1 expression and downregulation of p27. Interestingly, carnosol was found to induce beclin1-independent autophagy and apoptosis in MDA-MB-231 cells. The coexistence of both events, autophagy and apoptosis, was confirmed by electron micrography. Induction of autophagy was found to be an early event, detected within 3 h post-treatment, which subsequently led to apoptosis. Carnosol treatment also caused a dose-dependent increase in the levels of phosphorylated extracellular signal-regulated kinase 1 and 2 (pERK1/2. Moreover, we show that carnosol induced DNA damage, reduced the mitochondrial potential and triggered the activation of the intrinsic and extrinsic apoptotic pathway. Furthermore, we found that carnosol induced a dose-dependent generation of reactive oxygen species (ROS and inhibition of ROS by tiron, a ROS scavenger, blocked the induction of autophagy and apoptosis and attenuated DNA damage. To our knowledge, this is the first report to identify the induction of autophagy by carnosol.In conclusion our findings provide strong evidence that carnosol may be an alternative therapeutic candidate against the aggressive form of breast cancer and hence deserves more exploration.

  2. Depletion of Paraspeckle Protein 1 Enhances Methyl Methanesulfonate-Induced Apoptosis through Mitotic Catastrophe.

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    Xiangjing Gao

    Full Text Available Previously, we have shown that paraspeckle protein 1 (PSPC1, a protein component of paraspeckles that was involved in cisplatin-induced DNA damage response (DDR, probably functions at the G1/S checkpoint. In the current study, we further examined the role of PSPC1 in another DNA-damaging agent, methyl methanesulfonate (MMS-induced DDR, in particular, focusing on MMS-induced apoptosis in HeLa cells. First, it was found that MMS treatment induced the expression of PSPC1. While MMS treatment alone can induce apoptosis, depletion of PSPC1 expression using siRNA significantly increased the level of apoptosis following MMS exposure. In contrast, overexpressing PSPC1 decreased the number of apoptotic cells. Interestingly, morphological observation revealed that many of the MMS-treated PSPC1-knockdown cells contained two or more nuclei, indicating the occurrence of mitotic catastrophe. Cell cycle analysis further showed that depletion of PSPC1 caused more cells entering the G2/M phase, a prerequisite of mitosis catastrophe. On the other hand, over-expressing PSPC1 led to more cells accumulating in the G1/S phase. Taken together, these observations suggest an important role for PSPC1 in MMS-induced DDR, and in particular, depletion of PSPC1 can enhance MMS-induced apoptosis through mitotic catastrophe.

  3. Thymoquinone Induces Mitochondria-Mediated Apoptosis in Acute Lymphoblastic Leukaemia in Vitro

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    Bassem Y. Sheikh

    2013-09-01

    Full Text Available There has been a growing interest in naturally occurring compounds from traditional medicine with anti-cancer potential. Nigella sativa (black seed is one of the most widely studied plants. This annual herb grows in countries bordering the Mediterranean Sea and India. Thymoquinone (TQ is an active ingredient isolated from Nigella sativa. The anti-cancer effect of TQ, via the induction of apoptosis resulting from mitochondrial dysfunction, was assessed in an acute lymphocyte leukemic cell line (CEMss with an IC50 of 1.5 µg/mL. A significant increase in chromatin condensation in the cell nucleus was observed using fluorescence analysis. The apoptosis was then confirmed by Annexin V and an increased number of cellular DNA breaks in treated cells were observed as a DNA ladder. Treatment of CEMss cells with TQ encouraged apoptosis with cell death-transducing signals by a down-regulation of Bcl-2 and up-regulation of Bax. Moreover, the significant generation of cellular ROS, HSP70 and activation of caspases 3 and 8 were also observed in the treated cells. The mitochondrial apoptosis was clearly associated with the S phase cell cycle arrest. In conclusion, the results from the current study indicated that TQ could be a promising agent for the treatment of leukemia.

  4. Carnosol Induces ROS-Mediated Beclin1-Independent Autophagy and Apoptosis in Triple Negative Breast Cancer

    Science.gov (United States)

    Al Dhaheri, Yusra; Attoub, Samir; Ramadan, Gaber; Arafat, Kholoud; Bajbouj, Khuloud; Karuvantevida, Noushad; AbuQamar, Synan; Eid, Ali; Iratni, Rabah

    2014-01-01

    Background In this study we investigated the in vitro and in vivo anticancer effect of carnosol, a naturally occurring polyphenol, in triple negative breast cancer. Results We found that carnosol significantly inhibited the viability and colony growth induced G2 arrest in the triple negative MDA-MB-231. Blockade of the cell cycle was associated with increased p21/WAF1 expression and downregulation of p27. Interestingly, carnosol was found to induce beclin1-independent autophagy and apoptosis in MDA-MB-231 cells. The coexistence of both events, autophagy and apoptosis, was confirmed by electron micrography. Induction of autophagy was found to be an early event, detected within 3 h post-treatment, which subsequently led to apoptosis. Carnosol treatment also caused a dose-dependent increase in the levels of phosphorylated extracellular signal-regulated kinase 1 and 2 (pERK1/2). Moreover, we show that carnosol induced DNA damage, reduced the mitochondrial potential and triggered the activation of the intrinsic and extrinsic apoptotic pathway. Furthermore, we found that carnosol induced a dose-dependent generation of reactive oxygen species (ROS) and inhibition of ROS by tiron, a ROS scavenger, blocked the induction of autophagy and apoptosis and attenuated DNA damage. To our knowledge, this is the first report to identify the induction of autophagy by carnosol. Conclusion In conclusion our findings provide strong evidence that carnosol may be an alternative therapeutic candidate against the aggressive form of breast cancer and hence deserves more exploration. PMID:25299698

  5. DNA methylation dynamics in neurogenesis

    Science.gov (United States)

    Wang, Zhiqin; Tang, Beisha; He, Yuquan; Jin, Peng

    2016-01-01

    Neurogenesis is not limited to the embryonic stage, but continually proceeds in the adult brain throughout life. Epigenetic mechanisms, including DNA methylation, histone modification and noncoding RNA, play important roles in neurogenesis. For decades, DNA methylation was thought to be a stable modification, except for demethylation in the early embryo. In recent years, DNA methylation has proved to be dynamic during development. In this review, we summarize the latest understanding about DNA methylation dynamics in neurogenesis, including the roles of different methylation forms (5-methylcytosine, 5-hydroxymethylcytosine, 5-formylcytosine and 5-carboxylcytosine), as well as their ‘writers’, ‘readers’ and interactions with histone modifications. PMID:26950681

  6. Toward larger DNA origami.

    Science.gov (United States)

    Marchi, Alexandria N; Saaem, Ishtiaq; Vogen, Briana N; Brown, Stanley; LaBean, Thomas H

    2014-10-08

    Structural DNA nanotechnology, and specifically scaffolded DNA origami, is rapidly developing as a versatile method for bottom-up fabrication of novel nanometer-scale materials and devices. However, lengths of conventional single-stranded scaffolds, for example, 7,249-nucleotide circular genomic DNA from the M13mp18 phage, limit the scales of these uniquely addressable structures. Additionally, increasing DNA origami size generates the cost burden of increased staple-strand synthesis. We addressed this 2-fold problem by developing the following methods: (1) production of the largest to-date biologically derived single-stranded scaffold using a λ/M13 hybrid virus to produce a 51 466-nucleotide DNA in a circular, single-stranded form and (2) inexpensive DNA synthesis via an inkjet-printing process on a chip embossed with functionalized micropillars made from cyclic olefin copolymer. We have experimentally demonstrated very efficient assembly of a 51-kilobasepair origami from the λ/M13 hybrid scaffold folded by chip-derived staple strands. In addition, we have demonstrated two-dimensional, asymmetric origami sheets with controlled global curvature such that they land on a substrate in predictable orientations that have been verified by atomic force microscopy.

  7. Coordinate expression of apoptosis-associated proteins in human breast cancer before and during chemotherapy.

    Science.gov (United States)

    Parton, Marina; Krajewski, Stanislaw; Smith, Ian; Krajewska, Maryla; Archer, Caroline; Naito, Mihikito; Ahern, Roger; Reed, John; Dowsett, Mitchell

    2002-07-01

    Induction of apoptosis is a key factor in the response of tumors to chemotherapy. Laboratory studies have established many of the factors that regulate and execute apoptosis, but the significance of these in human tumors is poorly understood. Therefore, the relationship between key components of this machinery was examined in primary human breast carcinomas before and 24 h after the initiation of chemotherapy. Apoptosis was measured using the terminal deoxynucleotidyl transferase-mediated nick end labeling assay, and proliferation was assessed using the anti-Ki67 antibody MIB-1. Monospecific polyclonal antibodies were used for immunohistochemical detection of Bcl-2, Bax, XIAP, activated (cleaved) caspase 3 and 6, and cleaved DNA Fragmentation Factor-40 (DFF40) using paraffin-embedded tissues. Before treatment, a significant correlation was found between apoptosis and proliferation (r = 0.64, P apoptosis protein, XIAP, also correlated positively with cleaved caspase 3 (r = 0.64, P apoptosis and decreases in proliferation were observed, with the degree of increase in apoptosis inversely associated with decrease in proliferation. Chemotherapy-induced increases in Bax were correlated with increases in cleaved DFF40 (r = 0.54, P = 0.0008), but no other variables showed significant change at 24 h after initiation of chemotherapy. The pretreatment biomarker relationships suggest parallel cleavage and activation of these executioner proteins in breast cancer and that XIAP may maintain cell survival in the face of caspase activation. The findings provide in vivo evidence in human breast cancer that chemotherapy induces an apoptotic program characterized by up-regulation of Bax and cleavage of caspase substrate DFF40.

  8. Kinetics of radiation-induced apoptosis in neonatal urogenital tissues with and without protein synthesis inhibition

    International Nuclear Information System (INIS)

    Gobe, G.C.; Harmon, B.; Schoch, E.; Allan, D.J.

    1996-01-01

    The difference in incidence of radiation-induced apoptosis between two neonatal urogenital tissues, kidney and testis, was analysed over a 24h period. Concurrent administration of cycloheximide (10mg/kg body weight), a protein synthesis inhibitor, with radiation treatment was used to determine whether new protein synthesis had a role in induction of apoptosis in this in vivo model. Many chemotherapeutic drugs act via protein synthesis inhibition, and we believe that the results of this latter analysis may provide information for the planning of concurrent radio and chemotherapy. Apoptosis was quantified using morphological parameters, and verified by DNA gel electrophoresis for the typical banding pattern, and by electron microscopy. The proliferative index in tissues was studied, using [6- 3 H]-thymidine uptake ( 1h prior to euthanasia and collection of tissues) and autoradiography as indicators of cell proliferation (S-phase). Tissue was collected 2, 4, 6, 8, and 24h after radiation treatment. Expression of one of the apoptosis-associated genes, Bcl-2 (an apoptosis inhibitor/cell survival gene), was studied using immunohistochemistry. Apoptosis peaked at 4h in the testis and 6h in the kidney, emphasising the necessity of knowing tissue differences in radiation response if comparing changes at a particular time. A higher proportion (almost five fold) of the apoptotic cells died in S-phase in the kidney than the testis, over the 24h. Protein synthesis inhibition completely negated induction of apoptosis in both tissues. Necrosis was not identified at any time. Cycloheximide treatment greatly diminished Bcl-2 expression. The differences in response of the two tissues to irradiation relates to their innate cell (genetic) controls, which may be determined by their state of differentiation at time of treatment, or the tissue type. This in vivo study also suggests the model may be useful for analysis of other cancer therapies for example polychemotherapies or chemo

  9. Kinetics of radiation-induced apoptosis in neonatal urogenital tissues with and without protein synthesis inhibition

    Energy Technology Data Exchange (ETDEWEB)

    Gobe, G.C.; Harmon, B.; Schoch, E.; Allan, D.J. [Queensland Univ., St. Lucia, QLD (Australia). Dept. of Chemistry

    1996-12-31

    The difference in incidence of radiation-induced apoptosis between two neonatal urogenital tissues, kidney and testis, was analysed over a 24h period. Concurrent administration of cycloheximide (10mg/kg body weight), a protein synthesis inhibitor, with radiation treatment was used to determine whether new protein synthesis had a role in induction of apoptosis in this in vivo model. Many chemotherapeutic drugs act via protein synthesis inhibition, and we believe that the results of this latter analysis may provide information for the planning of concurrent radio and chemotherapy. Apoptosis was quantified using morphological parameters, and verified by DNA gel electrophoresis for the typical banding pattern, and by electron microscopy. The proliferative index in tissues was studied, using [6-{sup 3}H]-thymidine uptake ( 1h prior to euthanasia and collection of tissues) and autoradiography as indicators of cell proliferation (S-phase). Tissue was collected 2, 4, 6, 8, and 24h after radiation treatment. Expression of one of the apoptosis-associated genes, Bcl-2 (an apoptosis inhibitor/cell survival gene), was studied using immunohistochemistry. Apoptosis peaked at 4h in the testis and 6h in the kidney, emphasising the necessity of knowing tissue differences in radiation response if comparing changes at a particular time. A higher proportion (almost five fold) of the apoptotic cells died in S-phase in the kidney than the testis, over the 24h. Protein synthesis inhibition completely negated induction of apoptosis in both tissues. Necrosis was not identified at any time. Cycloheximide treatment greatly diminished Bcl-2 expression. The differences in response of the two tissues to irradiation relates to their innate cell (genetic) controls, which may be determined by their state of differentiation at time of treatment, or the tissue type. This in vivo study also suggests the model may be useful for analysis of other cancer therapies for example polychemotherapies or chemo

  10. Foxa2 may modulate hepatic apoptosis through the cIAP1 pathway.

    Science.gov (United States)

    Wang, Kewei; Brems, John J; Gamelli, Richard L; Holterman, Ai-Xuan

    2013-04-01

    Hepatocyte apoptosis is a ubiquitous feature of chronic liver injury, but the molecular mechanism remains to be determined. The liver-enriched Foxa2 transcription factor has been implicated in inflammation and neoplasia. Foxa2 may play a role in the regulation of apoptosis. This study aimed to investigate the relationship between Foxa2 and hepatic apoptosis. Apoptosis was induced with different causative factors as measured by caspase activity and TUNEL assay. Results showed that the apoptotic injury was associated with a downregulation of Foxa2. Foxa2-expressing vectors decreased apoptosis, whereas siRNA silencing of Foxa2 increased apoptosis in HepG2 cells. Foxa2 was correlated with expression profiling of anti-apoptotic genes cIAP1, cIAP2, XIAP, and survivin. Significantly, the cIAP1 expression was decreased by siRNA silencing of Foxa2, but increased by Foxa2-expressing vectors. The promoter of cIAP1 had specific DNA sequences that could be bound by Foxa2 nuclear protein as demonstrated by EMSA and gel supershift assay. The cIAP1 promoter was also occupied by Foxa2 nuclear factor through ChIP assay. Deletion of putative Foxa2 binding domains in cIAP1 promoter significantly reduced its promoter activity. A mechanism by which Foxa2 transcription factor modulates hepatic apoptosis may be through cIAP1 signaling pathway. Foxa2 can be a potential target for therapeutic intervention in liver diseases. Copyright © 2012 Elsevier Inc. All rights reserved.

  11. Centchroman induces redox-dependent apoptosis and cell-cycle arrest in human endometrial cancer cells.

    Science.gov (United States)

    Shyam, Hari; Singh, Neetu; Kaushik, Shweta; Sharma, Ramesh; Balapure, Anil K

    2017-04-01

    Centchroman (CC) or Ormeloxifene has been shown to induce apoptosis and cell cycle arrest in various types of cancer cells. This has, however, not been addressed for endometrial cancer cells where its (CC) mechanism of action remains unclear. This study focuses on the basis of antineoplasticity of CC by blocking the targets involved in the cell cycle, survival and apoptosis in endometrial cancer cells. Ishikawa Human Endometrial Cancer Cells were cultured under estrogen deprived medium, exposed to CC and analyzed for proliferation and apoptosis. Additionally, we also analyzed oxidative stress induced by CC. Cell viability studies confirmed the IC 50 of CC in Ishikawa cells to be 20 µM after 48 h treatment. CC arrests the cells in G0/G1 phase through cyclin D1 and cyclin E mediated pathways. Phosphatidylserine externalization, nuclear morphology changes, DNA fragmentation, PARP cleavage, and alteration of Bcl-2 family protein expression clearly suggest ongoing apoptosis in the CC treated cells. Activation of caspase 3 & 9, up-regulation of AIF and inhibition of apoptosis by z-VAD-fmk clearly explains the participation of the intrinsic pathway of programmed cell death. Further, the increase of ROS, loss of MMP, inhibition of antioxidant (MnSOD, Cu/Zn-SOD and GST) and inhibition of apoptosis with L-NAC suggests CC induced oxidative stress leading to apoptosis via mitochondria mediated pathway. Therefore, CC could be a potential therapeutic agent for the treatment of Endometrial Cancer adjunct to its utility as a contraceptive and an anti-breast cancer agent.

  12. HERG K+ channel-dependent apoptosis and cell cycle arrest in human glioblastoma cells.

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    Ingo Staudacher

    Full Text Available Glioblastoma (GB is associated with poor patient survival owing to uncontrolled tumor proliferation and resistance to apoptosis. Human ether-a-go-go-related gene K(+ channels (hERG; Kv11.1, KCNH2 are expressed in multiple cancer cells including GB and control cell proliferation and death. We hypothesized that pharmacological targeting of hERG protein would inhibit tumor growth by inducing apoptosis of GB cells. The small molecule hERG ligand doxazosin induced concentration-dependent apoptosis of human LNT-229 (EC50 = 35 µM and U87MG (EC50 = 29 µM GB cells, accompanied by cell cycle arrest in the G0/G1 phase. Apoptosis was associated with 64% reduction of hERG protein. HERG suppression via siRNA-mediated knock down mimicked pro-apoptotic effects of doxazosin. Antagonism of doxazosin binding by the non-apoptotic hERG ligand terazosin resulted in rescue of protein expression and in increased survival of GB cells. At the molecular level doxazosin-dependent apoptosis was characterized by activation of pro-apoptotic factors (phospho-erythropoietin-producing human hepatocellular carcinoma receptor tyrosine kinase A2, phospho-p38 mitogen-activated protein kinase, growth arrest and DNA damage inducible gene 153, cleaved caspases 9, 7, and 3, and by inactivation of anti-apoptotic poly-ADP-ribose-polymerase, respectively. In summary, this work identifies doxazosin as small molecule compound that promotes apoptosis and exerts anti-proliferative effects in human GB cells. Suppression of hERG protein is a crucial molecular event in GB cell apoptosis. Doxazosin and future derivatives are proposed as novel options for more effective GB treatment.

  13. Prodigiosin from the supernatant of Serratia marcescens induces apoptosis in haematopoietic cancer cell lines.

    Science.gov (United States)

    Montaner, B; Navarro, S; Piqué, M; Vilaseca, M; Martinell, M; Giralt, E; Gil, J; Pérez-Tomás, R

    2000-10-01

    The effects of supernatant from the bacterial strain Serratia marcescens 2170 (CS-2170) on the viability of different haematopoietic cancer cell lines (Jurkat, NSO, HL-60 and Ramos) and nonmalignant cells (NIH-3T3 and MDCK) was studied. We examined whether this cytotoxic effect was due to apoptosis, and we purified the molecule responsible for this effect and determined its chemical structure. Using an MTT assay we showed a rapid (4 h) decrease in the number of viable cells. This cytotoxic effect was due to apoptosis, according to the fragmentation pattern of DNA, Hoechst 33342 staining and FACS analysis of the phosphatidylserine externalization. This apoptosis was blocked by using the caspase inhibitor Z-VAD.fmk, indicating the involvement of caspases. Prodigiosin is a red pigment produced by various bacteria including S. marcescens. Using mutants of S. marcescens (OF, WF and 933) that do not synthesize prodigiosin, we further showed that prodigiosin is involved in this apoptosis. This evidence was corroborated by spectroscopic analysis of prodigiosin isolated from S. marcescens. These results indicate that prodigiosin, an immunosuppressor, induces apoptosis in haematopoietic cancer cells with no marked toxicity in nonmalignant cells, raising the possibility of its therapeutic use as an antineoplastic drug.

  14. Transmissible gastroenteritis virus infection induces apoptosis through FasL- and mitochondria-mediated pathways.

    Science.gov (United States)

    Ding, Li; Xu, Xingang; Huang, Yong; Li, Zhaocai; Zhang, Kuan; Chen, Guangda; Yu, Gaoshui; Wang, Zhisheng; Li, Wei; Tong, Dewen

    2012-07-06

    Transmissible gastroenteritis virus (TGEV) has been reported to induce apoptosis in swine testis (ST) cells. However, the mechanisms underlying TGEV-induced apoptosis are still unclear. In this study we observed that TGEV infection induced apoptosis in porcine kidney (PK-15) cells in a time- and dose-dependent manner. TGEV infection up-regulated FasL, activated FasL-mediated apoptotic pathway, leading to activation of caspase-8 and cleavage of Bid. In addition, TGEV infection down-regulated Bcl-2, up-regulated Bax expression, promoted translocation of Bax to mitochondria, activated mitochondria-mediated apoptotic pathway, which in turn caused the release of cytochrome c and the activation of caspase-9. Both extrinsic and intrinsic pathways activated downstream effector caspase-3, followed by the cleavage of PARP, resulting in cell apoptosis. Moreover, TGEV infection did not induce significant DNA fragmentation in ammonium chloride (NH(4)Cl) pretreated PK-15 cells or cells infected with UV-inactivated TGEV. In turn, block of caspases activation also did not affect TGEV replication. Taken together, this study demonstrates that TGEV-induced apoptosis is dependent on viral replication in PK-15 cells and occurs through activation of FasL- and mitochondria-mediated apoptotic pathways. Copyright © 2012 Elsevier B.V. All rights reserved.

  15. P53 is required for radiation-induced apoptosis in mouse thymocytes

    Energy Technology Data Exchange (ETDEWEB)

    Lowe, S.W.; Schmitt, E.M.; Jacks, Tyler (Massachusetts Inst. of Tech., Cambridge, MA (United States). Dept. of Biology); Smith, S.W.; Osborne, B.A. (Massachusetts Univ., Amherst, MA (United States))

    1993-04-29

    The p53 tumor suppressor gene is the most widely mutated gene in human tumorigenesis. p53 encodes a transcriptional activator whose targets may include genes that regulate genomic stability, the cellular response to DNA damage, and cell-cycle progression. Introduction of wild-type p53 into cell lines that have lost endogenous p53 function can cause growth arrest or induce a process of cell death known as apoptosis. During normal development, self- reactive thymocytes undergo negative selection by apoptosis, which can also be induced in immature thymocytes by other stimuli, including exposure to glucocorticoids and ionizing radiation. Although normal negative selection involves signalling through the T- cell receptor, the induction of apoptosis by other stimuli is poorly understood. The authors investigated the requirement for p53 during apoptosis in mouse thymocytes. They report here that immature thymocytes lacking p53 die normally when exposed to compounds that may mimic T-cell receptor engagement and to glucocorticoids but are resistant to the lethal effects of ionizing radiation. These results demonstrate that p53 is required for radiation-induced cell death in the thymus but is not necessary for all forms of apoptosis. (Author).

  16. Apoptosis in thymocytes and lymphoma cells induced by neutrons and X-rays

    International Nuclear Information System (INIS)

    Ohyama, Harumi; Koike, Sachiko; Ando, Kouichi

    1993-01-01

    Apoptosis is a distinctive mode of programmed cell death with characteristic morphological and biochemical features. The cells undergoing apoptosis display shrinkage, chromatin condensation and internucleosomal breakage of DNA. The cell death is a process through which organisms get rid of unwanted cells. Thymocytes are highly radiosensitive, and undergo typical apoptosis within a few hours after the exposure to X-ray. Also extremely radiosensitive thymic lymphoma cells have been found. The effect of 30 MeV NIRS fast neutrons on the induction of apoptosis in thymocytes and thymoma cells was examined in comparison with that of X-ray. Although apoptotic cells increased gradually with time, the apoptotic process proceeded rapidly in individual cells after the onset. By the measurement of cell size distribution, the appearance of a distinct apoptotic cell peak was observed. In the case of neutron irradiation on SCA1 thymic lymphoma cells, the method for counting apoptotic cells based on chromatin condensation was developed. The cell volume reduction of thymocytes, the dose survival curves and the induction of apoptosis in SCA1 are reported. (K.I.)

  17. Compound K, a metabolite of ginseng saponin, induces apoptosis via caspase-8-dependent pathway in HL-60 human leukemia cells

    International Nuclear Information System (INIS)

    Cho, Sung-Hee; Chung, Kyung-Sook; Choi, Jung-Hye; Kim, Dong-Hyun; Lee, Kyung-Tae

    2009-01-01

    Compound K [20-O-β-(D-glucopyranosyl)-20(S)-protopanaxadiol], a metabolite of the protopanaxadiol-type saponins of Panax ginseng C.A. Meyer, has been reported to possess anti-tumor properties to inhibit angiogenesis and to induce tumor apoptosis. In the present study, we investigated the effect of Compound K on apoptosis and explored the underlying mechanisms involved in HL-60 human leukemia cells. We examined the effect of Compound K on the viabilities of various cancer cell lines using MTT assays. DAPI assay, Annexin V and PI double staining, Western blot assay and immunoprecipitation were used to determine the effect of Compound K on the induction of apoptosis. Compound K was found to inhibit the viability of HL-60 cells in a dose- and time-dependent manner with an IC 50 of 14 μM. Moreover, this cell death had typical features of apoptosis, that is, DNA fragmentation, DNA ladder formation, and the externalization of Annexin V targeted phosphatidylserine residues in HL-60 cells. In addition, compound-K induced a series of intracellular events associated with both the mitochondrial- and death receptor-dependent apoptotic pathways, namely, (1) the activation of caspases-3, -8, and -9; (2) the loss of mitochondrial membrane potential; (3) the release of cytochrome c and Smac/DIABLO to the cytosol; (4) the translocation of Bid and Bax to mitochondria; and (5) the downregulations of Bcl-2 and Bcl-xL. Furthermore, a caspase-8 inhibitor completely abolished caspase-3 activation, Bid cleavage, and subsequent DNA fragmentation by Compound K. Interestingly, the activation of caspase-3 and -8 and DNA fragmentation were significantly prevented in the presence of cycloheximide, suggesting that Compound K-induced apoptosis is dependent on de novo protein synthesis. The results indicate that caspase-8 plays a key role in Compound K-stimulated apoptosis via the activation of caspase-3 directly or indirectly through Bid cleavage, cytochrome c release, and caspase-9 activation

  18. DNA probes

    International Nuclear Information System (INIS)

    Castelino, J.

    1992-01-01

    The creation of DNA probes for detection of specific nucleotide segments differs from ligand detection in that it is a chemical rather than an immunological reaction. Complementary DNA or RNA is used in place of the antibody and is labelled with 32 P. So far, DNA probes have been successfully employed in the diagnosis of inherited disorders, infectious diseases, and for identification of human oncogenes. The latest approach to the diagnosis of communicable and parasitic infections is based on the use of deoxyribonucleic acid (DNA) probes. The genetic information of all cells is encoded by DNA and DNA probe approach to identification of pathogens is unique because the focus of the method is the nucleic acid content of the organism rather than the products that the nucleic acid encodes. Since every properly classified species has some unique nucleotide sequences that distinguish it from every other species, each organism's genetic composition is in essence a finger print that can be used for its identification. In addition to this specificity, DNA probes offer other advantages in that pathogens may be identified directly in clinical specimens

  19. Current limiters

    Energy Technology Data Exchange (ETDEWEB)

    Loescher, D.H. [Sandia National Labs., Albuquerque, NM (United States). Systems Surety Assessment Dept.; Noren, K. [Univ. of Idaho, Moscow, ID (United States). Dept. of Electrical Engineering

    1996-09-01

    The current that flows between the electrical test equipment and the nuclear explosive must be limited to safe levels during electrical tests conducted on nuclear explosives at the DOE Pantex facility. The safest way to limit the current is to use batteries that can provide only acceptably low current into a short circuit; unfortunately this is not always possible. When it is not possible, current limiters, along with other design features, are used to limit the current. Three types of current limiters, the fuse blower, the resistor limiter, and the MOSFET-pass-transistor limiters, are used extensively in Pantex test equipment. Detailed failure mode and effects analyses were conducted on these limiters. Two other types of limiters were also analyzed. It was found that there is no best type of limiter that should be used in all applications. The fuse blower has advantages when many circuits must be monitored, a low insertion voltage drop is important, and size and weight must be kept low. However, this limiter has many failure modes that can lead to the loss of over current protection. The resistor limiter is simple and inexpensive, but is normally usable only on circuits for which the nominal current is less than a few tens of milliamperes. The MOSFET limiter can be used on high current circuits, but it has a number of single point failure modes that can lead to a loss of protective action. Because bad component placement or poor wire routing can defeat any limiter, placement and routing must be designed carefully and documented thoroughly.

  20. Honey and Apoptosis in Human Gastric Mucosa

    Directory of Open Access Journals (Sweden)

    Alireza Ostadrahimi

    2012-07-01

    Full Text Available Background: Gastric cancer is the fourth most common malignancy in the world. Honey is acomplex mixture of special biological active constituents. Honey possesses antioxidant and antitumorproperties. Nutritional studies have indicated that consumption of honey modulates therisk of developing gastric cancer. On the other hand, apoptosis has been reported to play a decisiverole in precancerous changes. Our chief study was conducted to assess the relationship betweenconsumption of honey and apoptosis in human gastric mucosa.Method: This cross-sectional study was conducted on 98 subjects over 18 years old, referred totwo hospitals in Tabriz, Iran. Subjects were undergone an upper gastrointestinal endoscopy, 62subjects were finally enrolled. Honey consumption was assessed by a Food Frequency Questionnaire(FFQ and apoptosis was detected by TUNEL technique. We tested polynomial curve tofind the best fit between honey consumption and apoptosis.Results: A positive relation between honey consumption and apoptosis was found (P=0.024.Our results indicated that the final and the best fit curve was: apoptosis = 1.714+1.648(honeyamount - 0.533(honey amount2 +1.833×10-5(honey amount7.Conclusion: Honey consumption had positive effects on gastric cancer by inducing apoptosis ingastric mucosa.

  1. Ascorbate induces apoptosis in melanoma cells by suppressing Clusterin expression.

    Science.gov (United States)

    Mustafi, Sushmita; Sant, David W; Liu, Zhao-Jun; Wang, Gaofeng

    2017-06-16

    Pharmacological levels of ascorbate have long been suggested as a potential treatment of cancer. However, we observed that EC50 of ascorbate was at a similar level for cultured healthy melanocytes and melanoma cells, suggesting a limit of pharmacological ascorbate in treating cancer. Loss of 5-hydroxymethylcytosine (5 hmC) is an epigenetic hallmark of cancer and ascorbate promotes 5 hmC generation by serving as a cofactor for TET methylcytosine dioxygenases. Our previous work demonstrated that ascorbate treatment at physiological level (100 μM) increased 5 hmC content in melanoma cells toward the level of healthy melanocytes. Here we show that 100 µM of ascorbate induced apoptosis in A2058 melanoma cells. RNA-seq analysis revealed that expression of the Clusterin (CLU) gene, which is related to apoptosis, was downregulated by ascorbate. The suppression of CLU was verified at transcript level in different melanoma cell lines, and at protein level in A2058 cells. The anti-apoptotic cytoplasmic CLU was decreased, while the pro-apoptotic nuclear CLU was largely maintained, after ascorbate treatment. These changes in CLU subcellular localization were also associated with Bax and caspases activation, Bcl-xL sequestration, and cytochrome c release. Taken together, this study establishes an impending therapeutic role of physiological ascorbate to potentiate apoptosis in melanoma.

  2. Involvement of cathepsin B in mitochondrial apoptosis by p-phenylenediamine under ambient UV radiation

    Energy Technology Data Exchange (ETDEWEB)

    Goyal, Shruti; Amar, Saroj Kumar [Photobiology Division, CSIR – Indian Institute of Toxicology Research, Post Box No. 80, M.G. Marg, Lucknow 226001, Uttar Pradesh (India); Academy of Scientific and Innovative Research, CSIR-IITR Campus, Lucknow (India); Dubey, Divya; Pal, Manish Kumar [Photobiology Division, CSIR – Indian Institute of Toxicology Research, Post Box No. 80, M.G. Marg, Lucknow 226001, Uttar Pradesh (India); Singh, Jyoti [Photobiology Division, CSIR – Indian Institute of Toxicology Research, Post Box No. 80, M.G. Marg, Lucknow 226001, Uttar Pradesh (India); Academy of Scientific and Innovative Research, CSIR-IITR Campus, Lucknow (India); Verma, Ankit; Kushwaha, Hari Narayan [Photobiology Division, CSIR – Indian Institute of Toxicology Research, Post Box No. 80, M.G. Marg, Lucknow 226001, Uttar Pradesh (India); Ray, Ratan Singh, E-mail: ratanray.2011@rediffmail.com [Photobiology Division, CSIR – Indian Institute of Toxicology Research, Post Box No. 80, M.G. Marg, Lucknow 226001, Uttar Pradesh (India)

    2015-12-30

    Highlights: • Photodegradation and formation of photoproduct. • Involvement of ROS in PPD phototoxicity. • Role of ROS in DNA damage, CPD and micronuclei formation. • PPD induced lysosomal destabilization and release of cathepsin B. • Cleavage of Bid and activation of mitochondrial apoptosis. - Abstract: Paraphenylenediamine (PPD), a derivative of paranitroaniline has been most commonly used as an ingredient of oxidative hair dye and permanent tattoos. We have studied the phototoxic potential of PPD under ambient ultraviolet radiation. PPD is photodegraded and form a novel photoproduct under UV A exposure. PPD shows a concentration dependent decrease in cell viability of human Keratinocyte cells (HaCaT) through MTT and NRU test. Significant intracellular ROS generation was measured by DCFDA assay. It caused an oxidative DNA damage via single stranded DNA breaks, micronuclei and CPD formation. Both lysosome and mitochondria is main target for PPD induced apoptosis which was proved through lysosomal destabilization and release of cathepsin B by immunofluorescence, real time PCR and western blot analysis. Cathepsin B process BID to active tBID which induces the release of cytochrome C from mitochondria. Mitochondrial depolarization was reported through transmission electron microscopy. The cathepsin inhibitor reduced the release of cytochrome C in PPD treated cells. Thus study suggests that PPD leads to apoptosis via the involvement of lysosome and mitochondria both under ambient UV radiation. Therefore, photosensitizing nature of hair dye ingredients should be tested before coming to market as a cosmetic product for the safety of human beings.

  3. Involvement of cathepsin B in mitochondrial apoptosis by p-phenylenediamine under ambient UV radiation

    International Nuclear Information System (INIS)

    Goyal, Shruti; Amar, Saroj Kumar; Dubey, Divya; Pal, Manish Kumar; Singh, Jyoti; Verma, Ankit; Kushwaha, Hari Narayan; Ray, Ratan Singh

    2015-01-01

    Highlights: • Photodegradation and formation of photoproduct. • Involvement of ROS in PPD phototoxicity. • Role of ROS in DNA damage, CPD and micronuclei formation. • PPD induced lysosomal destabilization and release of cathepsin B. • Cleavage of Bid and activation of mitochondrial apoptosis. - Abstract: Paraphenylenediamine (PPD), a derivative of paranitroaniline has been most commonly used as an ingredient of oxidative hair dye and permanent tattoos. We have studied the phototoxic potential of PPD under ambient ultraviolet radiation. PPD is photodegraded and form a novel photoproduct under UV A exposure. PPD shows a concentration dependent decrease in cell viability of human Keratinocyte cells (HaCaT) through MTT and NRU test. Significant intracellular ROS generation was measured by DCFDA assay. It caused an oxidative DNA damage via single stranded DNA breaks, micronuclei and CPD formation. Both lysosome and mitochondria is main target for PPD induced apoptosis which was proved through lysosomal destabilization and release of cathepsin B by immunofluorescence, real time PCR and western blot analysis. Cathepsin B process BID to active tBID which induces the release of cytochrome C from mitochondria. Mitochondrial depolarization was reported through transmission electron microscopy. The cathepsin inhibitor reduced the release of cytochrome C in PPD treated cells. Thus study suggests that PPD leads to apoptosis via the involvement of lysosome and mitochondria both under ambient UV radiation. Therefore, photosensitizing nature of hair dye ingredients should be tested before coming to market as a cosmetic product for the safety of human beings.

  4. Melatonin increases survival of HaCaT keratinocytes by suppressing UV-induced apoptosis.

    Science.gov (United States)

    Fischer, T W; Zbytek, B; Sayre, R M; Apostolov, E O; Basnakian, A G; Sweatman, T W; Wortsman, J; Elsner, P; Slominski, A

    2006-01-01

    Melatonin is a potent antioxidant and direct radical scavenger. As keratinocytes represent the major population in the skin and UV light causes damage to these cells, the possible protective effects of melatonin against UV-induced cell damage in HaCaT keratinocytes were investigated in vitro. Cells were preincubated with melatonin at graded concentrations from 10(-9) to 10(-3) m for 30 min prior to UV irradiation at doses of 25 and 50 mJ/cm2. Biological markers of cellular viability such as DNA synthesis and colony-forming efficiency as well as molecular markers of apoptosis were measured. DNA synthesis was determined by [3H]-thymidine incorporation into insoluble cellular fraction, clonogenicity through plating efficiency experiments and apoptosis by the terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL) assay. DNA synthesis experiments showed a strong protective effect by preincubation with melatonin at concentrations of 10(-4) m (P UV incubation protective effect. These results indicate that preincubation is a requirement for melatonin to exert its protective effects. The mechanism of melatonin's protective effect (10(-6) to 10(-3) m) includes inhibition of apoptosis as measured by TUNEL assay. Moreover, the biological significance of these effects is supported by clonogenic studies showing a significantly higher number of colonies in cultures treated with melatonin compared to controls. Thus, pretreatment with melatonin led to strong protection against UVB-induced damage in keratinocytes.

  5. Crataegus azarolus Leaves Induce Antiproliferative Activity, Cell Cycle Arrest, and Apoptosis in Human HT-29 and HCT-116 Colorectal Cancer Cells.

    Science.gov (United States)

    Mustapha, Nadia; Pinon, Aline; Limami, Youness; Simon, Alain; Ghedira, Kamel; Hennebelle, Thierry; Chekir-Ghedira, Leila

    2016-05-01

    Limited success has been achieved in extending the survival of patients with metastatic colorectal cancer (CRC). There is a strong need for novel agents in the treatment and prevention of CRC. Therefore, in the present study we evaluated the antiproliferative and pro-apoptotic potential of Crataegus azarolus ethyl acetate extract in HCT-116 and HT-29 human colorectal cancer cell lines. Moreover, we attempted to investigate the signaling pathways that should be involved in its cytotoxic effect. The Crataegus azarolus ethyl acetate extract-induced growth inhibitory effect was associated with DNA fragmentation, sub-G1 peak, loss of mitochondrial potential, and poly (ADP-ribose) polymerase (PARP) cleavage. In addition, ethyl acetate extract of Crataegus azarolus induced the cleavage of caspase-8. It has no effect on steady-state levels of total Bcl-2 protein. Whereas Bax levels decreased significantly in a dose-dependent manner in both tested cell lines. Taken together, these findings confirm the involvement of the extrinsic pathway of apoptosis. The apoptotic cell death induced by ethyl acetate extract of Crataegus azarolus was accompanied by an enhancement of the p21 expression but not through p53 activation in human colorectal cancer cells. The above-mentioned data provide insight into the molecular mechanisms of Crataegus azarolus ethyl acetate extract-induced apoptosis in CRC. Therefore, this compound should be a potential anticancer agent for the treatment of CRC. © 2015 Wiley Periodicals, Inc.

  6. Attenuation of endoplasmic reticulum stress-related myocardial apoptosis by SERCA2a gene delivery in ischemic heart disease.

    Science.gov (United States)

    Xin, Wei; Lu, Xiaochun; Li, Xiaoying; Niu, Kun; Cai, Jimei

    2011-01-01

    Previous studies suggested that endoplasmic reticulum (ER) stress-associated apoptosis plays an important role in the pathogenesis of ischemic heart disease. Gene transfer of sarco/endoplasmic reticulum Ca(2+) ATPase 2a (SERCA2a) attenuates myocardial apoptosis in a variety of heart failure models. This study is to investigate the effects of SERCA2a gene delivery on the myocardial apoptosis and ER stress pathway in a porcine ischemic heart disease model. Eighteen pigs were either subjected to ameroid implantation in the coronary artery or sham operation. Eight wks after gene delivery, the protein level and activity of SERCA2a were measured. Myocardial apoptosis was determined using terminal deoxynucleotidyl transferase-mediated DNA nick-end labeling assay. Regional myocardial perfusion and function were evaluated by (99m)Tc-sestamibi ((99m)Tc-MIBI) single photon emission computed tomography and echocardiography. The ER stress signaling was assessed by Western blot. SERCA2a protein level and activity were significantly decreased in the ischemic myocardium and restored to normal after SERCA2a gene transfer. Restoration of SERCA2a expression significantly improved the cardiac function, although no improvement of regional myocardial perfusion was detected. Restoration of SERCA2a significantly attenuated myocardial apoptosis and reversed the activation of unfolded protein response (UPR) pathway and the ER stress-associated apoptosis pathways. These findings demonstrate a robust role of SERCA2a in attenuation of ischemic myocardial apoptosis, correlating with reverse activation of the ER stress-associated apoptosis pathways, suggesting that the beneficial effects of SERCA2a gene transfer may involve the attenuation of ER stress-associated myocardial apoptosis.

  7. DNA data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Raw DNA chromatogram data produced by the ABI 373, 377, 3130 and 3730 automated sequencing machines in ABI format. These are from fish (primarily Sebastes spp.,...

  8. DNA methylation

    DEFF Research Database (Denmark)

    Williams, Kristine; Christensen, Jesper; Helin, Kristian

    2012-01-01

    DNA methylation is involved in key cellular processes, including X-chromosome inactivation, imprinting and transcriptional silencing of specific genes and repetitive elements. DNA methylation patterns are frequently perturbed in human diseases such as imprinting disorders and cancer. The recent...... discovery that the three members of the TET protein family can convert 5-methylcytosine (5mC) into 5-hydroxymethylcytosine (5hmC) has provided a potential mechanism leading to DNA demethylation. Moreover, the demonstration that TET2 is frequently mutated in haematopoietic tumours suggests that the TET...... proteins are important regulators of cellular identity. Here, we review the current knowledge regarding the function of the TET proteins, and discuss various mechanisms by which they contribute to transcriptional control. We propose that the TET proteins have an important role in regulating DNA methylation...

  9. DNA nanotechnology

    Science.gov (United States)

    Seeman, Nadrian C.; Sleiman, Hanadi F.

    2018-01-01

    DNA is the molecule that stores and transmits genetic information in biological systems. The field of DNA nanotechnology takes this molecule out of its biological context and uses its information to assemble structural motifs and then to connect them together. This field has had a remarkable impact on nanoscience and nanotechnology, and has been revolutionary in our ability to control molecular self-assembly. In this Review, we summarize the approaches used to assemble DNA nanostructures and examine their emerging applications in areas such as biophysics, diagnostics, nanoparticle and protein assembly, biomolecule structure determination, drug delivery and synthetic biology. The introduction of orthogonal interactions into DNA nanostructures is discussed, and finally, a perspective on the future directions of this field is presented.

  10. Possible role of apoptosis in pathogenesis of adenoid hypertrophy and chronic adenoiditis: Prospective case-control study.

    Science.gov (United States)

    Önal, Merih; Yılmaz, Taner; Bilgiç, Elif; Müftüoğlu, Sevda; Sözen, Tevfik; Bajin, Münir Demir

    2015-12-01

    Apoptosis is a programmed cell death; it provides an important balance between lymphocytes in adenoid tissue. The aim of this study is to investigate the role of apoptosis in chronic adenoiditis and adenoid hypertrophy. This is the first study in the literature about apoptosis in adenoid hypertrophy and chronic adenoiditis. Prospective case-control study in a tertiary referral university hospital was conducted. 46 patients who had chronic adenoiditis and adenoid hypertrophy underwent adenoidectomy. Adenoids were evaluated for apoptosis<