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Oliveira GAR, Ferraz ERA, Souza AO, Lourenço RA, Oliveira DP, Dorta DJ. Evaluation of the mutagenic activity of chrysin, a flavonoid inhibitor of the aromatization process. JOURNAL OF TOXICOLOGY AND ENVIRONMENTAL HEALTH. PART A 2012; 75:1000-1011. [PMID: 22852850 DOI: 10.1080/15287394.2012.696517] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Chrysin is one of the natural flavonoids present in plants, and large amounts are present in honey and propolis. In addition to anticancer, antioxidation, and anti-inflammatory activities, chrysin has also been reported to be an inhibitor of aromatase, an enzyme converting testosterone into estrogen. The present study evaluated the mutagenicity of this flavonoid using micronucleus (MN) with HepG2 cells and Salmonella. Cell survival after exposure to different concentrations of chrysin was also determined using sulforhodamine B (SRB) colorimetric assay in HepG2 cells and the influence of this flavonoid on growth of cells in relation to the cell cycle and apoptosis. The MN test showed that from 1 to 15 μM of this flavonoid mutagenic activity was noted in HepG2 cells. The Salmonella assay demonstrated a positive response to the TA100 Salmonella strain in the presence or absence of S9, suggesting that this compound acted on DNA, inducing base pair substitution before or after metabolism via cytochrome P-450. The SRB assay illustrated that chrysin promoted growth inhibition of HepG2 cells in both periods studied (24 and 48 h). After 24 h of exposure it was noted that the most significant results were obtained with a concentration of 50 μM, resulting in 83% inhibition and SubG0 percentage of 12%. After 48 h of incubation cell proliferation inhibition rates (97% at 50 μM) were significantly higher. Our results showed that chrysin is a mutagenic and cytotoxic compound in cultured human HepG2 cells and Salmonella typhimurium. Although it is widely accepted that flavonoids are substances beneficial to health, one must evaluate the risk versus benefit relationship and concentrations of these substances to which an individual may be exposed.
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Affiliation(s)
- G A R Oliveira
- USP, Departamento de Análises Clínicas, Toxicológicas e Bromatológicas, Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP, Brazil.
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Jaceosidin Induces Apoptosis in U87 Glioblastoma Cells through G2/M Phase Arrest. EVIDENCE-BASED COMPLEMENTARY AND ALTERNATIVE MEDICINE 2011; 2012:703034. [PMID: 22216058 PMCID: PMC3246879 DOI: 10.1155/2012/703034] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/14/2011] [Revised: 09/08/2011] [Accepted: 09/15/2011] [Indexed: 01/11/2023]
Abstract
Artemisia argyi is a widely used medicinal plant in China. The present study was designed to identify the bioactive constituents with antiglioma activity from leaves of Artemesia argyi. A bioactivity guided approach based on MTT assay for cells growth inhibition led to the isolation of a flavonoid, “jaceosidin” from ethanol extract of leaves of Artemesia argyi. The growth inhibitory effect of jaceosidin was explored using flow cytometry and Western blot studies. Our results showed that jaceosidin exerts growth inhibitory effect by arresting the cells at G2/M phase and induction of apoptosis. Furthermore, our study revealed that induction of apoptosis was associated with cell cycle arrest at G2/M phase, upregulation of p53 and Bax, decrease in mitochondrial membrane potential, release of cytochrome c, and activation of caspase 3. This mitochondrial-caspase-3-dependent apoptosis pathway was confirmed by pretreatment with caspase 3 inhibitor, Ac-DEVD-CHO. Our findings suggested that jaceosidin induces mitochondrial-caspase-3-dependent apoptosis in U87 cells by arresting the cell cycle at G2/M phase.
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53
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Wu CL, Huang AC, Yang JS, Liao CL, Lu HF, Chou ST, Ma CY, Hsia TC, Ko YC, Chung JG. Benzyl isothiocyanate (BITC) and phenethyl isothiocyanate (PEITC)-mediated generation of reactive oxygen species causes cell cycle arrest and induces apoptosis via activation of caspase-3, mitochondria dysfunction and nitric oxide (NO) in human osteogenic sarcoma U-2 OS cells. J Orthop Res 2011; 29:1199-209. [PMID: 21374707 DOI: 10.1002/jor.21350] [Citation(s) in RCA: 89] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/14/2010] [Accepted: 12/10/2010] [Indexed: 02/04/2023]
Abstract
Benzyl isothiocyanate (BITC) and phenethyl isothiocyanate (PEITC), a member of the isothiocyanate family, have been shown to exhibit antineoplastic ability against many human cancer cells. In this study, we found that exposure of human osteogenic sarcoma U-2 OS cells to BITC and PEITC led to induce morphological changes and to decrease the percentage of viable cells in a time- and dose-dependent manner. BITC and PEITC induced cell cycle arrest at G2/M phase at 48 h treatment and inhibited the levels of cell cycle regulatory proteins such as cyclin A and B1 in U-2 OS cells but promoted the level of Chk1 and p53 that led to G2/M arrest. BITC and PEITC induced a marked increase in apoptosis (DNA fragmentation) and poly(ADP-ribose)polymerase (PARP) cleavage, which was associated with mitochondrial dysfunction and the activation of caspase-9 and -3. BITC and PEITC also promoted the ROS production in U-2 OS cells and the N-acetylcysteine (NAC, an antoxidant agent) was pretreated and then treated with both compounds which led to decrease the levels of ROS and increase the cell viability. Interestingly, BITC and PEITC promoted the levels of NO production and increased the iNOS enzyme. Confocal laser microscope also demonstrated that BITC and PEITC promoted the release of cytochrome c and AIF, suggesting that both compounds induced apoptosis through ROS, caspase-3 and mitochondrial, and NO signaling pathways. Taken together, these molecular alterations and signaling pathways offer an insight into BITC and PEITC-caused growth inhibition, G2/M arrest, and apoptotic death of U-2 OS cells.
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Affiliation(s)
- Chang-Lin Wu
- Department of Biological Science and Technology, China Medical University, Taichung 404, Taiwan
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54
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MUC16 induced rapid G2/M transition via interactions with JAK2 for increased proliferation and anti-apoptosis in breast cancer cells. Oncogene 2011; 31:805-17. [PMID: 21785467 DOI: 10.1038/onc.2011.297] [Citation(s) in RCA: 112] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
MUC16/CA125 is a tumor marker currently used in clinics for the follow-up of patients with ovarian cancer. However, MUC16 expression is not entirely restricted to ovarian malignancies and has been reported in other cancers including breast cancer. Although it is well established as a biomarker, function of MUC16 in cancer remains to be elucidated. In the present study, we investigated the role of MUC16 in breast cancer and its underlying mechanisms. Interestingly, our results showed that MUC16 is overexpressed in breast cancer tissues whereas not expressed in non-neoplastic ducts. Further, stable knockdown of MUC16 in breast cancer cells (MDA MB 231 and HBL100) resulted in significant decrease in the rate of cell growth, tumorigenicity and increased apoptosis. In search of a mechanism for breast cancer cell proliferation we found that MUC16 interacts with the ezrin/radixin/moesin domain-containing protein of Janus kinase (JAK2) as demonstrated by the reciprocal immunoprecipitation method. These interactions mediate phosphorylation of STAT3 (Tyr705), which might be a potential mechanism for MUC16-induced proliferation of breast cancer cells by a subsequent co-transactivation of transcription factor c-Jun. Furthermore, silencing of MUC16 induced G2/M arrest in breast cancer cells through downregulation of Cyclin B1 and decreased phosphorylation of Aurora kinase A. This in turn led to enhanced apoptosis in the MUC16-knockdown breast cancer cells through Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL)-mediated extrinsic apoptotic pathway with the help of c-Jun N-terminal kinase signaling. Collectively, our results suggest that MUC16 has a dual role in breast cancer cell proliferation by interacting with JAK2 and by inhibiting the apoptotic process through downregulation of TRAIL.
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55
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Franek F, Holý A, Votruba I, Eckschlager T. Modulation of cell cycle progression and of antibody production in mouse hybridomas by a nucleotide analogue. Cytotechnology 2011; 28:65-72. [PMID: 19003408 DOI: 10.1023/a:1008017328061] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
The nucleotide analogue 9-[2-(phosphonomethoxy)ethyl]guanine (PMEG) has been identified as a powerful antiproliferative substance when acting on hybridoma cells. In the range of 10 nM to 100 nM concentrations this agent reduces cell growth rate, while its apoptosis-inducing activity is marginal. Marked induction of apoptosis can be observed at micromolar and higher order concentrations. In PMEG-supplemented media the cell cycle progression is perturbed, the flow-cytometric DNA profile shows a higher proportion of cells in the S and G2/M phases of the cell cycle. Concomitantly with the reduction of the growth rate, the specific monoclonal antibody production rate may rise by 20-27%. Addition of PMEG at the end of the exponential phase of a batch culture results in an enhancement of the final monoclonal antibody concentration.
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Affiliation(s)
- F Franek
- Academy of Sciences, Institute of Molecular Genetics, Videnska 1083, CZ-14220, Praha 4, Czech Republic,
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56
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Su JC, Lin KL, Chien CM, Tseng CH, Chen YL, Chang LS, Lin SR. Furano-1,2-naphthoquinone inhibits EGFR signaling associated with G2/M cell cycle arrest and apoptosis in A549 cells. Cell Biochem Funct 2011; 28:695-705. [PMID: 21104938 DOI: 10.1002/cbf.1710] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Furano-1,2-naphthoquinone (FNQ), prepared from 2-hydroxy-1,4-naphthoquinone and chloroacetaldehyde in an efficient one-pot reaction, exhibits an anti-carcinogenic effect. FNQ exerted anti-proliferative activity with the G(2)/M cell cycle arrest and apoptosis in A549 cells. FNQ-induced G(2)/M arrest was correlated with a marked decrease in the expression levels of cyclin A and cyclin B, and their activating partner cyclin-dependent kinases (Cdk) 1 and 2 with concomitant induction of p53, p21, and p27. FNQ-induced apoptosis was accompanied with Bax up-regulation and the down-regulation of Bcl-2, X-linked inhibitor of apoptosis (XIAP), and survivin, resulting in cytochrome c release and sequential activation of caspase-9 and caspase-3. Western blot analysis revealed that FNQ suppressed EGFR phosphorylation and JAK2, STAT3, and STAT5 activation, but increased in activation of p38 MAPK and c-Jun NH2-terminal kinase (JNK) stress signal. The combined treatment of FNQ with AG1478 (a specific EGFR inhibitor) significantly enhanced the G(2)/M arrest and apoptosis, and also led to up-regulation in Bax, p53, p21, p27, release of mitochondrial cytochrome c, and down-regulation of Bcl-2, XIAP, survivin, cyclin A, cyclin B, Cdk1, and Cdk2 in A549 cells. These findings suggest that FNQ-mediated cytotoxicity of A549 cell related with the G(2)/M cell cycle arrest and apoptosis via inactivation of EGFR-mediated signaling pathway.
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Affiliation(s)
- J C Su
- Department of Medicinal and Applied Chemistry, Kaohsiung Medical University, Kaohsiung, Taiwan, ROC
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57
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Yan X, Yan X, Morrison A, Han T, Chen Q, Li J, Wang J. Fluoride induces apoptosis and alters collagen I expression in rat osteoblasts. Toxicol Lett 2011; 200:133-8. [DOI: 10.1016/j.toxlet.2010.11.005] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2010] [Revised: 11/09/2010] [Accepted: 11/11/2010] [Indexed: 11/30/2022]
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58
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Normalizing effect of plant-originated glycoprotein (116 kDa) on G0/G1 arrest in cadmium chloride-induced primary cultured mouse myelocytes. Naunyn Schmiedebergs Arch Pharmacol 2010; 383:109-18. [DOI: 10.1007/s00210-010-0580-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2010] [Accepted: 11/07/2010] [Indexed: 02/04/2023]
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59
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Semenyuk A, Darian E, Liu J, Majumdar A, Cuenoud B, Miller PS, MacKerell AD, Seidman MM. Targeting of an interrupted polypurine:polypyrimidine sequence in mammalian cells by a triplex-forming oligonucleotide containing a novel base analogue. Biochemistry 2010; 49:7867-78. [PMID: 20701359 PMCID: PMC2935506 DOI: 10.1021/bi100797z] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
The DNA triple helix consists of a third strand of nucleic acid lying in the major groove of an intact DNA duplex. The most stable triplexes form on polypurine:polypyrimidine sequences, and pyrimidine interruptions in the purine strand are destabilizing. Sequence stringency is imparted by specific Hoogsteen hydrogen bonds between third strand bases and the purine bases in the duplex. Appropriate base and sugar modifications of triple helix-forming oligonucleotides (TFOs) confer chromosome targeting activity in living cells. However, broad utilization of TFOs as gene targeting reagents in mammalian cells has been limited by the requirement for homopurine target sequences. Although there have been a number of base analogues described that appear to be promising as candidates for triplex target expansion, none has been examined in a biological system. We have employed a postsynthetic strategy to prepare a collection of TFOs with base analogues at a defined position. Following assessment of affinity for a triplex target with a single C:G inversion, TFOs with a second generation of analogues were synthesized. One of these, TFO-5a, with 2'-OMe-guanidinylethyl-5-methylcytosine at the position corresponding to the C:G interruption in the target sequence, was further modified to confer bioactivity. The activity of this TFO, linked to psoralen, was measured in a mammalian cell line that was engineered by directed sequence conversion to carry a triplex target with a single C:G interruption. TFO-5a was active against this target and inactive against the corresponding target with an uninterrupted polypurine:polypyrimidine sequence.
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Affiliation(s)
- A. Semenyuk
- National Institute on Aging, National Institutes of Health, Baltimore, Maryland 21224
| | - E. Darian
- School of Pharmacy, University of Maryland, 20 Penn Street, Baltimore, Maryland 21201
| | - J. Liu
- National Institute on Aging, National Institutes of Health, Baltimore, Maryland 21224
| | - A. Majumdar
- National Institute on Aging, National Institutes of Health, Baltimore, Maryland 21224
| | - B. Cuenoud
- Merck Serono S.A., Chemin des mines 9, 1202 Geneva, Switzerland
| | - P. S. Miller
- Bloomberg School of Public Health, Johns Hopkins School of Medicine, Baltimore, Maryland 21205
| | - A. D. MacKerell
- School of Pharmacy, University of Maryland, 20 Penn Street, Baltimore, Maryland 21201
| | - M. M. Seidman
- National Institute on Aging, National Institutes of Health, Baltimore, Maryland 21224
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60
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Cui J, Xing L, Li Z, Wu S, Wang J, Liu J, Wang J, Yan X, Zhang X. Ochratoxin A induces G2 phase arrest in human gastric epithelium GES-1 cells in vitro. Toxicol Lett 2010; 193:152-8. [PMID: 20060447 DOI: 10.1016/j.toxlet.2009.12.019] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2009] [Revised: 12/23/2009] [Accepted: 12/30/2009] [Indexed: 12/28/2022]
Affiliation(s)
- Jinfeng Cui
- Department of Pathology, The Second Hospital, Hebei Medical University, Shijiazhuang, China
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61
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Lin KL, Su JC, Chien CM, Tseng CH, Chen YL, Chang LS, Lin SR. Naphtho[1,2-b]furan-4,5-dione induces apoptosis and S-phase arrest of MDA-MB-231 cells through JNK and ERK signaling activation. Toxicol In Vitro 2010; 24:61-70. [DOI: 10.1016/j.tiv.2009.09.002] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2009] [Revised: 08/10/2009] [Accepted: 09/04/2009] [Indexed: 11/25/2022]
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2'-epi-2'-O-Acetylthevetin B extracted from seeds of Cerbera manghas L. induces cell cycle arrest and apoptosis in human hepatocellular carcinoma HepG2 cells. Chem Biol Interact 2010; 183:142-53. [PMID: 19874809 DOI: 10.1016/j.cbi.2009.10.012] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2009] [Revised: 10/12/2009] [Accepted: 10/16/2009] [Indexed: 11/24/2022]
Abstract
2'-epi-2'-O-Acetylthevetin B (GHSC-74) is a cardiac glycoside isolated from the seeds of Cerbera manghas L. We have demonstrated that GHSC-74 reduced the viability of HepG2 cells in a time- and dose-dependent manner. The present study was designed to explore cellular mechanisms whereby GHSC-74 led to cell cycle arrest and apoptosis in HepG2 cells. Cell cycle flow cytometry demonstrated that HepG2 cells treated with GHSC-74 (4microM) resulted in S and G2 phase arrest in a time-dependent manner, as confirmed by mitotic index analysis. G2 phase arrest was accompanied with down-regulation of CDC2 and Cyclin B1 protein. Furthermore, GHSC-74-induced apoptotic killing, as demonstrated by DNA fragmentation, DAPI staining, and flow cytometric detection of sub-G1 DNA content in HepG2 cells. GHSC-74 treatment resulted in a significant increase in reactive oxygen species, activation of caspase-9, dissipation of mitochondrial membrane potential, and translocation of apoptosis-inducing factor (AIF) from the mitochondrion to the nucleus in HepG2 cells. Nevertheless, after GHSC-74 exposure, no significant Fas and FasL up-regulation was observed in HepG2 cells by flow cytometry. In addition, treatment with antioxidant N-acetyl-l-cysteine (NAC) and broad-spectrum caspase inhibitor z-VAD-fmk partially prevented apoptosis but did not abrogate GHSC-74-induced nuclear translocation of AIF. In conclusion, we have demonstrated that GHSC-74 inhibited growth of HepG2 cells by inducing S and G2 phase arrest of the cell cycle and by triggering apoptosis via mitochondrial disruption including both caspase-dependent and -independent pathways, and ROS generation.
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63
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Novel indoloquinoline derivative, IQDMA, induces G2/M phase arrest and apoptosis in A549 cells through JNK/p38 MAPK signaling activation. Life Sci 2009; 85:505-16. [DOI: 10.1016/j.lfs.2009.08.006] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2009] [Revised: 07/27/2009] [Accepted: 08/05/2009] [Indexed: 11/19/2022]
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64
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Haykal J, Geara F, Haddadin MJ, Smith CA, Gali-Muhtasib H. The radiosensitizer 2-benzoyl-3-phenyl-6,7-dichloroquinoxaline 1,4-dioxide induces DNA damage in EMT-6 mammary carcinoma cells. Radiat Oncol 2009; 4:25. [PMID: 19594955 PMCID: PMC2716350 DOI: 10.1186/1748-717x-4-25] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2009] [Accepted: 07/14/2009] [Indexed: 11/13/2022] Open
Abstract
Background DCQ (2-benzoyl-3-phenyl-6,7-dichloroquinoxaline 1,4-dioxide), a synthetic quinoxaline 1,4-dioxide, enhances the cytotoxic effect of ionizing radiation (IR) in vivo and in vitro. We sought to clarify whether increased radiation-induced DNA damage, decreased rate of damage repair, and the generation of reactive oxygen species (ROS) contribute to DCQ enhancement of IR. Methods Murine mammary adenocarcinoma EMT-6 cells were treated with DCQ for 4 h before exposure to 10 Gy IR. Treated cells were monitored for modulations in cell cycle, induction of DNA damage, and generation of ROS. Results Combined DCQ and IR treatments (DCQ+IR) induced rapid cell-cycle arrests in EMT-6 cells, particularly in S and G2/M phases. Alkaline comet assays revealed high levels of DNA damage in cells after exposure to DCQ+IR, consistent with damage-induced arrest. Unlike IR-only and DCQ-only treated cells, the damage induced by combined DCQ+IR was repaired at a slower rate. Combined treatment, compared to separate DCQ and IR treatments, activated DNA-protein kinase and induced more p-ATM, supporting a role for double strand breaks (DSBs), which are more toxic and difficult to repair than single strand breaks (SSBs). Contributing factors to DCQ radiosensitization appear to be the induction of ROS and DSBs. Conclusion Collectively, our findings indicate that radiosensitization by DCQ is mediated by DNA damage and decreased repair and that ROS are at least partially responsible.
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Affiliation(s)
- Joelle Haykal
- Department of Biology, American University of Beirut, Beirut, Lebanon.
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65
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Effects of fluoride on DNA damage, S-phase cell-cycle arrest and the expression of NF-κB in primary cultured rat hippocampal neurons. Toxicol Lett 2008; 179:1-5. [DOI: 10.1016/j.toxlet.2008.03.002] [Citation(s) in RCA: 132] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2008] [Revised: 02/28/2008] [Accepted: 03/03/2008] [Indexed: 11/20/2022]
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66
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Chaudhry MA. Base excision repair of ionizing radiation-induced DNA damage in G1 and G2 cell cycle phases. Cancer Cell Int 2007; 7:15. [PMID: 17892593 PMCID: PMC2063494 DOI: 10.1186/1475-2867-7-15] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2007] [Accepted: 09/24/2007] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Major genomic surveillance mechanisms regulated in response to DNA damage exist at the G1/S and G2/M checkpoints. It is presumed that these delays provide time for the repair of damaged DNA. Cells have developed multiple DNA repair pathways to protect themselves from different types of DNA damage. Oxidative DNA damage is processed by the base excision repair (BER) pathway. Little is known about the BER of ionizing radiation-induced DNA damage and putative heterogeneity of BER in the cell cycle context. We measured the activities of three BER enzymes throughout the cell cycle to investigate the cell cycle-specific repair of ionizing radiation-induced DNA damage. We further examined BER activities in G2 arrested human cells after exposure to ionizing radiation. RESULTS Using an in vitro incision assay involving radiolabeled oligonucleotides with specific DNA lesions, we examined the activities of several BER enzymes in the whole cell extracts prepared from synchronized human HeLa cells irradiated in G1 and G2 phase of the cell cycle. The activities of human endonuclease III (hNTH1), a glycosylase/lyase that removes several damaged bases from DNA including dihydrouracil (DHU), 8-oxoguanine-DNA glycosylase (hOGG1) that recognizes 7,8-dihydro-8-oxo-2'-deoxyguanosine (8-oxoG) lesion and apurinic/apyrimidinic endonuclease (hAPE1) that acts on abasic sites including synthetic analog furan were examined. CONCLUSION Overall the repair activities of hNTH1 and hAPE1 were higher in the G1 compared to G2 phase of the cell cycle. The percent cleavages of oligonucleotide substrate with furan were greater than substrate with DHU in both G1 and G2 phases. The irradiation of cells enhanced the cleavage of substrates with furan and DHU only in G1 phase. The activity of hOGG1 was much lower and did not vary within the cell cycle. These results demonstrate the cell cycle phase dependence on the BER of ionizing radiation-induced DNA damage. Interestingly no evidence of enhanced BER activities was found in irradiated cells arrested in G2 phase.
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Affiliation(s)
- M Ahmad Chaudhry
- Department of Medical Laboratory and Radiation Sciences, University of Vermont, Burlington, VT 05405, USA.
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67
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Yang SH, Chien CM, Chang LS, Lin SR. Involvement of c-jun N-terminal kinase in G2/M arrest and caspase-mediated apoptosis induced by cardiotoxin III (Naja naja atra) in K562 leukemia cells. Toxicon 2007; 49:966-74. [PMID: 17368702 DOI: 10.1016/j.toxicon.2007.01.005] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2006] [Revised: 01/12/2007] [Accepted: 01/15/2007] [Indexed: 11/21/2022]
Abstract
Cardiotoxin III (CTX III), a basic polypeptide with 60 amino acid residues isolated from Naja naja atra venom, may have a potentiality as a structural template for rational drug design in killing cancer cells. Treatment of K562 cells with 0.3 microM of CTX III resulted in G2/M phase cell cycle arrest that was associated with a marked decline in protein levels of G2/M regulatory proteins including cyclin A, cyclin B1, Cdk2 and Cdc25C. In contrast to no effect on the phosphorylation of ERK, p38 MAPK and Akt, an activation of JNK was noted when K562 cells were exposed to CTX III. CTX III-mediated G2/M phase arrest and apoptosis were reduced by treatment with the JNK-specific inhibitor SP600125, but not by ERK and p38MAPK inhibitors. Further investigation showed that the specific JNK inhibitor, SP600125, reduced the activation of caspase-3, caspase-9, and reversed the decline in the expression of cyclin B1. Taken together, our data show for the first time that JNK, but not ERK, p38MAPK or Akt signaling, plays an important role in CTX III-mediated G2/M arrest and apoptosis in K562 cancer cells.
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Affiliation(s)
- Sheng-Huei Yang
- Faculty of Medicinal and Applied Chemistry, Kaohsiung Medical University, Kaohsiung 807, Taiwan, ROC
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68
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Lu YJ, Yang SH, Chien CM, Lin YH, Hu XW, Wu ZZ, Wu MJ, Lin SR. Induction of G2/M phase arrest and apoptosis by a novel enediyne derivative, THDB, in chronic myeloid leukemia (HL-60) cells. Toxicol In Vitro 2007; 21:90-8. [PMID: 17064874 DOI: 10.1016/j.tiv.2006.09.008] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2006] [Revised: 08/01/2006] [Accepted: 09/11/2006] [Indexed: 11/16/2022]
Abstract
(Z)-2-(6-(Thieanisyl-2-yl)hexa-3-en-1,5-diynyl)benzenamine (THDB), an enediyne compound, was identified in our laboratory as a novel antineoplastic agent with broad spectrum of antitumor activities against many human cancer cells. THDB was found to inhibit the growth of HL-60 cells in a time-and dose-dependent manner. Cell cycle analysis showed G2/M phase arrest in HL-60 cells following 48 h exposure to THDB. Analysis of the cell cycle regulatory proteins demonstrated that THDB did not change the steady-state levels of cyclin B1, cyclin E, Cdk1 and Cdc25C, but decreased the protein levels of Cdk2 and cyclin A. THDB also caused a marked increase in apoptosis, as characterized by DNA fragmentation (DNA ladder and sub G1 formation), and poly (ADP-ribose) polymerase (PARP) cleavage, which was associated with activation of caspase-3, caspase-8 and caspase-9. Moreover, the THDB-induced apoptosis was significantly attenuated in the presence of specific inhibitors of caspase-3, -8 and -9. These molecular alterations provide an insight into THDB-caused growth inhibition, G2/M arrest and apoptotic death of HL-60 cells.
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Affiliation(s)
- Yu-Jhang Lu
- Faculty of Medicinal and Applied Chemistry, Kaohsiung Medical University, 100 Shi-Chuan 1st Road, Kaohsiung 807, Taiwan, ROC
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69
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Yang SH, Tsai CH, Lu MC, Yang YN, Chien CM, Lin SF, Lin SR. Effects of cardiotoxin III on expression of genes and proteins related to G2/M arrest and apoptosis in K562 cells. Mol Cell Biochem 2006; 300:185-90. [PMID: 17149543 DOI: 10.1007/s11010-006-9382-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2006] [Accepted: 11/07/2006] [Indexed: 10/23/2022]
Abstract
Cardiotoxin III (CTX III) is a basic polypeptide of 60-amino acid residues isolated from Naja naja atra venom, exerts its anti-proliferative activity in human leukemia K562 cells. In the present study, the expression of mRNAs and proteins related to cell cycle and apoptosis in human leukemia K562 cells induced by CTX III was investigated by semi-quantitative reverse transcription-polymerase chain reaction (RT-PCR) and Western blot analysis. Flow cytometric analysis revealed that CTX III resulted in G2/M phase arrest in the cell cycle progression, which was associated with a marked decrease in the mRNA and protein expressions of cyclin A, cyclin B1, and Cdk 2, with no detectable changes in the levels of Cdk 1, cyclin D1, and cyclin E. Moreover, the increase in apoptosis was associated with the Bax gene and protein levels significantly increased as treatment durations of CTX III increased, while the Bcl-2 mRNA and protein levels exhibited no changes. We also observed that caspase-9 and caspase-3 genes remained unchanged up to 12 h with 2 microg/ml CTX III. These molecular alterations provide an insight into CTX III-caused growth inhibition, G2/M arrest, and apoptotic death of K562 cells.
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Affiliation(s)
- Sheng-Huei Yang
- Faculty of Medicinal and Applied Chemistry, Kaohsiung Medical University, Kaohsiung, Taiwan 807, ROC
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70
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Kommajosyula N, Rhind N. Cdc2 tyrosine phosphorylation is not required for the S-phase DNA damage checkpoint in fission yeast. Cell Cycle 2006; 5:2495-500. [PMID: 17102632 PMCID: PMC2562503 DOI: 10.4161/cc.5.21.3423] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
The S-phase DNA damage checkpoint slows replication when damage occurs during S phase. Cdc25, which activates Cdc2 by dephosphorylating tyrosine-15, has been shown to be a downstream target of the checkpoint in metazoans, but its role is not clear in fission yeast. The dephosphorylation of Cdc2 has been assumed not to play a role in S-phase regulation because cells replicate in the absence of Cdc25, demonstrating that tyrosine-15 phosphorylated dc2 is sufficient for S phase. However, it has been reported recently that Cdc25 is involved in the slowing of S phase in response to damage in fission yeast, suggesting a modulatory role for Cdc2 dephosphorylation in S phase. We have investigated the role of Cdc25 and the tyrosine phosphorylation of Cdc2 in the S-phase damage checkpoint, and our results show that Cdc2 phosphorylation is not a target of the checkpoint. The checkpoint was not compromised in a Cdc25 overexpressing strain, a strain carrying nonphosphorylatable form of Cdc2, or in a strain lacking Cdc25. Our results are consistent with a strictly Cdc2-Y15 phosphorylation-independent mechanism of the fission yeast S-phase DNA damage checkpoint.
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Affiliation(s)
| | - Nicholas Rhind
- Corresponding Author: (508) 856-8316:tel, (508) 856-6464:fax,
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71
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Hu XW, Chien CM, Yang SH, Lin YH, Lu CM, Chen YL, Lin SR. A novel indoloquinoline derivative, IQDMA, induces S-phase arrest and apoptosis in promyelocytic leukemia HL-60 cells. Cell Biol Toxicol 2006; 22:417-27. [PMID: 16906476 DOI: 10.1007/s10565-006-0098-9] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2006] [Accepted: 06/19/2006] [Indexed: 10/24/2022]
Abstract
N'-(11H-indolo[3,2-c]quinolin-6-yl)-N,N-dimethylethane-1,2-diamine (IQDMA), an indoloquinoline compound, was identified in our laboratory as a novel antineoplastic agent with a broad spectrum of antitumor activity against many human cancer cells. Cell cycle analysis showed S-phase arrest and induction of apoptosis in HL-60 cells following 24 h exposure to IQDMA. Analysis of the cell cycle regulatory proteins demonstrated that IQDMA did not change the steady-state levels of cyclin B1, cyclin D3, and p21, but decreased the protein levels of Cdk1, Cdk2, and cyclin A. IQDMA also caused a marked increase in apoptosis, which was accompanied by increased levels of Bax, activated caspase-3, -8, and -9, and cleaved PARP. These molecular alterations provide an insight into IQDMA-caused growth inhibition, S-phase arrest, and apoptotic death of HL-60 cells.
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Affiliation(s)
- Xiu-Wei Hu
- Faculty of Medicinal and Applied Chemistry, Kaohsiung Medical University, Kaohsiung, Taiwan, 807, ROC
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72
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Wu ZZ, Chien CM, Yang SH, Lin YH, Hu XW, Lu YJ, Wu MJ, Lin SR. Induction of G2/M phase arrest and apoptosis by a novel enediyne derivative, THDA, in chronic myeloid leukemia (K562) cells. Mol Cell Biochem 2006; 292:99-105. [PMID: 16733797 DOI: 10.1007/s11010-006-9222-7] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2006] [Accepted: 05/01/2006] [Indexed: 11/28/2022]
Abstract
We studied the effect of 2-(6-(2-thieanisyl)-3(Z)-hexen-1,5-diynyl)aniline(THDA), a newly developed anti-cancer agent, on cell proliferation, cell cycle progression, and induction of apoptosis in K562 cells. THDA was found to inhibit the growth of K562 cells in a time-and dose-dependent manner. Cell cycle analysis showed G2/M phase arrest and apoptosis in K562 cells following 24 h exposure to THDA. During the G2/M arrest, cyclin-dependent kinase inhibitors (CDKIs), p21 and p27 were increased in a time-dependent manner. Analysis of the cell cycle regulatory proteins demonstrated that THDA did not change the steady-state levels of cyclin B1, cyclin D3 and Cdc25C, but decreased the protein levels of Cdk1, Cdk2 and cyclin A. THDA also caused a marked increase in apoptosis, which was associated with activation of caspase-3 and proteolytic cleavage of poly (ADP-ribose) polymerase. These molecular alterations provide an insight into THDA-caused growth inhibition, G2/M arrest and apoptotic death of K562 cells.
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Affiliation(s)
- Zchong-Zcho Wu
- Faculty of Medicinal and Applied Chemistry, Kaohsiung Medical University, Kaohsiung 807, Taiwan, ROC
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73
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Li KS, Gu XF, Li P, Zhang Y, Zhao YS, Yao ZJ, Qu NQ, Wang BY. Effect of pseudolaric acid B on gastric cancer cells: inhibition of proliferation and induction of apoptosis. World J Gastroenterol 2006; 11:7555-9. [PMID: 16437677 PMCID: PMC4727228 DOI: 10.3748/wjg.v11.i48.7555] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
AIM To examine the effect of pseudolaric acid B on the growth of human gastric cancer cell line, AGS, and its possible mechanism of action. METHODS Growth inhibition by pseudolaric acid B was analyzed using MTT assay. Apoptotic cells were detected using Hoechst 33258 staining, and confirmed by DNA fragmentation analysis. Western blot was used to detect the expression of apoptosis-regulated gene Bcl-2, caspase 3, and cleavage of poly (ADP-ribose) polymerase-1 (PARP-1). RESULTS Pseudolaric acid B inhibited the growth of AGS cells in a time- and dose-dependent manner by arresting the cells at G(2)/M phase, which was accompanied with a decrease in the levels of cdc2. AGS cells treated with pseudolaric acid B showed typical characteristics of apoptosis including chromatin condensation and DNA fragmentation. Moreover, treatment of AGS cells with pseudolaric acid B was also associated with decreased levels of the anti-apoptotic protein Bcl-2, activation of caspase-3, and proteolytic cleavage of PARP-1. CONCLUSION Pseudolaric acid B can dramatically suppress the AGS cell growth by inducing apoptosis after G(2)/M phase arrest. These findings are consistent with the possibility that G(2)/M phase arrest is mediated by the down-regulation of cdc2 levels. The data also suggest that pseudolaric acid B can trigger apoptosis by decreasing Bcl-2 levels and activating caspase-3 protease.
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Affiliation(s)
- Ke-Shen Li
- Department of Epidemiology, Harbin Medical University, Harbin 150086, Heilongjiang Province, China
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74
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Lu MC, Yang SH, Hwang SL, Lu YJ, Lin YH, Wang SR, Wu YC, Lin SR. Induction of G2/M phase arrest by squamocin in chronic myeloid leukemia (K562) cells. Life Sci 2006; 78:2378-83. [PMID: 16310807 DOI: 10.1016/j.lfs.2005.09.048] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2005] [Accepted: 09/24/2005] [Indexed: 11/20/2022]
Abstract
Squamocin is one of the annonaceous acetogenins and has been reported to have anticancer activity. Squamocin was found to inhibit the growth of K562 cells in a time- and dose-dependent manner. Cell cycle analysis showed G2/M phase arrest in K562 cells following 24 h exposure to squamocin. During the G2/M arrest, cyclin-dependent kinase inhibitors (CDKIs), p21 and p27 were increased in a dose-dependent manner. Analysis of the cell cycle regulatory proteins demonstrated that squamocin did not change the steady-state levels of Cdk2, Cdk4, cyclin A, cyclin B1, cyclin D3 and cyclin E, but decreased the protein levels of Cdk1 and Cdc25C. These results suggest that squamocin inhibits the proliferation of K562 cells via G2/M arrest in association with the induction of p21, p27 and the reduction of Cdk1 and Cdc25C kinase activities.
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Affiliation(s)
- Mei-Chin Lu
- Graduate Institute of Natural Products, Kaohsiung Medical University, Kaohsiung 807, Taiwan, ROC
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75
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Lin YH, Yang SH, Chien CM, Hu XW, Huang YH, Lu CM, Chen YL, Lin SR. Induction of G2/M phase arrest and apoptosis by a novel indoloquinoline derivative, IQDMA, in K562 cells. Drug Dev Res 2006. [DOI: 10.1002/ddr.20113] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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76
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Li H, Chang TW, Tsai YC, Chu SF, Wu YY, Tzang BS, Liao CB, Liu YC. Colcemid inhibits the rejoining of the nucleotide excision repair of UVC-induced DNA damages in Chinese hamster ovary cells. Mutat Res 2005; 588:118-28. [PMID: 16290038 DOI: 10.1016/j.mrgentox.2005.09.005] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2005] [Revised: 09/13/2005] [Accepted: 09/16/2005] [Indexed: 11/16/2022]
Abstract
In our previous study, we found that colcemid, an inhibitor of mitotic spindle, promotes UVC-induced apoptosis in Chinese hamster ovary cells (CHO.K1). In this study, a brief treatment of colcemid on cells after but not before UV irradiation could synergistically reduce the cell viability. Although colcemid did not affect the excision of UV-induced DNA damages such as [6-4] photoproducts or cyclobutane pyrimidine dimers, colcemid accumulated the DNA breaks when it was added to cells following UV-irradiation. This colcemid effect required nucleotide excision repair (NER) since the same accumulation of DNA breaks was barely or not detected in two NER defective strains of CHO cells, UV5 or UV24. Furthermore, the colcemid effect was not due to semi-conservative DNA replication or mitosis since the colcemid-caused accumulation of DNA breaks was also seen in non-replicating cells. Moreover, colcemid inhibited rejoining of DNA breaks accumulated by hydroxyurea/cytosine arabinoside following UV irradiation. Nevertheless, colcemid did not affect the unscheduled DNA synthesis as assayed by the incorporation of bromodeoxyuridine. Taken together, our results suggest that colcemid might inhibit the step of ligation of NER pathways.
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Affiliation(s)
- Hsun Li
- Institute of Molecular Medicine, National Tsing-Hua University, Hsin-Chu 30043, Taiwan
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77
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Abid-Essefi S, Ouanes Z, Hassen W, Baudrimont I, Creppy E, Bacha H. Cytotoxicity, inhibition of DNA and protein syntheses and oxidative damage in cultured cells exposed to zearalenone. Toxicol In Vitro 2004; 18:467-74. [PMID: 15130604 DOI: 10.1016/j.tiv.2003.12.011] [Citation(s) in RCA: 201] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2003] [Accepted: 12/24/2003] [Indexed: 10/26/2022]
Abstract
Mycotoxins are toxic metabolites of various fungi commonly found in feed and foodstuff and can cause very serious health problems in animals as well as in humans. Zearalenone (ZEN), a mycotoxin produced by various Fusarium species has several adverse effects. Indeed, ZEN has strong estrogenic activity associated with hyperestrogenism and several physiological alterations of the reproductive tract. Moreover, ZEN was shown to be hepatotoxic, haematotoxic, immunotoxic and genotoxic. The exact mechanism of ZEN toxicity is not completely established. The observed strong estrogenic effect of ZEN resulting from its competition with 17beta-estradiol in the binding to estrogen receptors is generally considered to underline most toxic effects of ZEN, but estrogenic activity alone cannot explain the diverse and apparent adverse effects. The objective of the present study was to determine the involvement of other possible mechanisms in ZEN induced toxicity. Cytotoxicity, cell cycle perturbation, inhibition of protein and DNA synthesis as well as the presumed later marker of oxidative stress, malondialdehyde, were monitored in Vero and Caco-2 cells exposed to ZEN. Our results showed that ZEN reduces cell viability correlated to cell cycle perturbation, inhibits protein and DNA syntheses and increases MDA formation in both cell lines in concentration-dependant manner. We assumed that cytotoxicity and oxidative damage are additional mechanisms of ZEN mediated toxicity.
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Affiliation(s)
- S Abid-Essefi
- Laboratoire de Recherche sur les Substances Biologiquement Compatibles (LRSBC), Faculté de Médecine Dentaire, Rue Avicenne, 5019 Monastir, Tunisia
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78
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Hyun JW, Chung HS. Cyanidin and Malvidin from Oryza sativa cv. Heugjinjubyeo mediate cytotoxicity against human monocytic leukemia cells by arrest of G(2)/M phase and induction of apoptosis. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2004; 52:2213-2217. [PMID: 15080622 DOI: 10.1021/jf030370h] [Citation(s) in RCA: 82] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Oryza sativa cv. Heugjinjubyeo (Gramineae), anthocyanin-pigmented rice, having dark purple grains, is known broadly as enriched rice with an improved taste. Two bioactive compounds were isolated from the 0.5% HCl-ethyl alcohol soluble fraction of the aleurone layer of O. sativa cv. Heugjinjubyeo through an activity-monitored fractionation and isolation method. From spectral analysis, the cytotoxic components were the anthocyanidins cyanidin (1) and malvidin (2) The 50% growth inhibitory concentrations (IC(50)) of cyanidin and malvidin on U937, human monocytic leukemia cells, were 60 and 40 microg/mL, respectively. These compounds showed cytotoxicity through the arrest of the G(2)/M phase of cell cycle and induction of apoptosis.
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Affiliation(s)
- Jin Won Hyun
- Department of Biochemistry, College of Medicine, Cheju National University, Jeju 690-756, Korea
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79
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Kudo C, Wada K, Masuda T, Yonemura T, Shibuya A, Fujimoto Y, Nakajima A, Niwa H, Kamisaki Y. Nonylphenol induces the death of neural stem cells due to activation of the caspase cascade and regulation of the cell cycle. J Neurochem 2004; 88:1416-23. [PMID: 15009642 DOI: 10.1046/j.1471-4159.2003.02270.x] [Citation(s) in RCA: 68] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Endocrine disruptors (EDs) are a great concern throughout the world, because they have adverse effects on human health and wildlife. In the present study, we investigated the effects of EDs on the proliferation and survival of murine neural stem cells (NSCs). In contrast to bisphenol A, phthalic acid benzyl n-butyl ester, phthalic acid di-n-butyl ester and phthalic acid di(2-ethylhexyl) ester, the treatment of NSCs with 4-nonylphenol for 24 h inhibited cell growth in a concentration-dependent manner. In addition, treatment with 4-nonylphenol resulted in nuclear condensation and DNA fragmentation (morphological changes due to apoptosis) in NSCs after 12 h of exposure, and activated caspase-3 after 6 h and 9 h of exposure. Furthermore, an exposure to 4-nonylphenol led to the accumulation of cells at the G2/M phase interface and down-regulated the protein levels of cyclin A and B1, which are the major regulatory proteins at the G2 to M transition of the cell cycle. Together, these results indicate that, in contrast to other EDs, 4-nonylphenol may exhibit a potent cytotoxicity through apoptosis via the caspase cascade and cell cycle arrest at the G2/M phase, and suggest that 4-nonylphenol may affect neurogenesis in the CNS.
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Affiliation(s)
- Chiho Kudo
- Department of Pharmacology, Graduate School of Dentistry, Osaka University, Japan
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80
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Abid-Essefi S, Baudrimont I, Hassen W, Ouanes Z, Mobio TA, Anane R, Creppy EE, Bacha H. DNA fragmentation, apoptosis and cell cycle arrest induced by zearalenone in cultured DOK, Vero and Caco-2 cells: prevention by Vitamin E. Toxicology 2003; 192:237-48. [PMID: 14580790 DOI: 10.1016/s0300-483x(03)00329-9] [Citation(s) in RCA: 151] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Zearalenone (ZEN) is a non-steroidal oestrogenic mycotoxin produced by several Fusarium species growing on cereals. ZEN and its metabolites bind to human oestrogen receptors and hence display oestrogenic and anabolic properties. Several lines of investigation suggest that ZEN may be genotoxic in vivo. ZEN damages DNA in Bacillus subtilis recombination tests, and it induces sister chromatid exchange and chromosomal aberration in CHO cells. ZEN also induces DNA-adduct formation in mouse tissues and SOS repair process in lysogenic bacteria. In the present study, ZEN genotoxicity has been confirmed in three cell-lines, Vero, Caco-2 and DOK at concentrations of 10, 20 and 40 microM. Under these conditions, ZEN induces concentration-dependent DNA fragmentation resulting in DNA laddering patterns on agarose gel electrophoresis. This observation is consistent with apoptosis, which was confirmed by observations of formation of apoptotic bodies. Moreover, ZEN induces cell cycle arrest in the three cell-lines characterised by an increase of the number of cells in the G2/M phase of the cell cycle. Vitamin E (25 microM) added simultaneously with ZEN partially reduces DNA fragmentation and apoptotic body formation after 24h incubation. Vitamin E may act by maintaining prolonged cell cycle arrest during which time DNA repair takes place.
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Affiliation(s)
- Salwa Abid-Essefi
- Laboratoire de Recherche sur les Substances Biologiquement Compatibles (LRSBC), Faculté de Médecine Dentaire, Rue Avicenne, 5019 Monastir, Tunisia
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81
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Lim HK, Kang HK, Yoo ES, Kim BJ, Kim YW, Cho M, Lee JH, Lee YS, Chung MH, Hyun JW. Oxysterols induce apoptosis and accumulation of cell cycle at G(2)/M phase in the human monocytic THP-1 cell line. Life Sci 2003; 72:1389-99. [PMID: 12527036 DOI: 10.1016/s0024-3205(02)02377-9] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
The cytotoxic activity of oxysterols, 7 beta-hydroxycholesterol (7 beta-OHC) and 25-hydroxycholesterol (25-OHC), has been evaluated using various leukemia cell lines. Among the tested cell lines, both oxysterols showed the highest cytotoxicity to THP-1, human monocytic leukemia cell line. These oxysterols induced apoptosis through down-regulation of Bcl-2 expression and activation of caspases. Also, the oxysterols showed the accumulation at G(2)/M phase of cell cycle through down-regulation of cyclin B1 expression. Taken together, these results indicated that both 7 beta-OHC and 25-OHC inhibited the proliferation of THP-1 cells through apoptosis and cell cycle accumulation at G(2)/M phase.
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Affiliation(s)
- Hee-Kyoung Lim
- Department of Biochemistry, College of Medicine Cheju National University, 1 Ara 1-dong, Jeju, Jeju-do, 690-756, South Korea
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82
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Ohno S, Nishi T, Kojima Y, Haraoka J, Ito H, Mizuguchi J. Combined stimulation with interferon alpha and retinoic acid synergistically inhibits proliferation of the glioblastoma cell line GB12. Neurol Res 2002; 24:697-704. [PMID: 12392208 DOI: 10.1179/016164102101200609] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022]
Abstract
Since malignant glioma displays moderate resistance to conventional therapy, a new treatment modality is needed to improve the outcome of patients with these tumors. In this study, we examined whether combination stimulation with interferon alpha (IFN-alpha) and retinoic acid (RA) affected proliferation of the glioblastoma cell line GB 12 in vitro. Stimulation with IFN-alpha alone inhibited the GB 12 cell proliferation in a dose/time-dependent fashion, as assessed by WST-1 assay and uptake of 3H-thymidine, while RA limited it only slightly. The anti-proliferative action of IFN-alpha against glioblastoma cells was enhanced by the addition of RA. The IFN-alpha/RA combination also induced apoptosis in a substantial portion of the cells, compared with either reagent alone. Bcl-2 family proteins, regulating apoptosis, were altered by these stimuli: Bcl-2 was down-regulated, while Bax-alpha was up-regulated, especially by the combination. These findings suggest that the IFN-alpha/RA combination would synergistically affect glioblastoma cell growth, probably through apoptosis induction as well as a decreased cellular DNA synthesis.
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Affiliation(s)
- Shingo Ohno
- Department of Immunology and Intractable Diseases, Research Center, Tokyo Medical University, Japan
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83
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Smith DM, Kazi A, Smith L, Long TE, Heldreth B, Turos E, Dou QP. A novel beta-lactam antibiotic activates tumor cell apoptotic program by inducing DNA damage. Mol Pharmacol 2002; 61:1348-58. [PMID: 12021396 DOI: 10.1124/mol.61.6.1348] [Citation(s) in RCA: 58] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Many of the anticancer drugs in current use are toxic and thus limited in their efficacy. It therefore becomes essential to develop novel chemotherapeutic agents with lower levels of toxicity. The beta-lactam antibiotics have been used for many years to treat bacterial infections with limited or no toxicity. Until now, it has never been shown that beta-lactams could kill tumor cells. Here, for the first time, we have discovered and characterized the apoptosis-inducing properties of a family of novel beta-lactam antibiotics against human leukemia, breast, prostate, and head-and-neck cancer cells. We found that one particular lead compound (lactam 1) with an N-methylthio group was able to induce DNA damage and inhibit DNA replication in Jurkat T cells within a 2-h treatment. This was followed by p38 mitogen-activated protein kinase activation, S phase arrest, and apoptotic cell death. p38 was found to be a central player in beta-lactam-induced apoptosis and resided downstream of DNA damage but upstream of caspase activation. Accompanying caspase-8 activation was cleavage of the pro-apoptotic Bcl-2 family protein Bid, and release of the mitochondrial cytochrome c. This was also associated with activation of caspase-9 and -3. Analogs of lactam 1 in which the N-methylthio group was replaced with other organothio chains exhibited progressive decreased potencies to induce DNA damage, p38 kinase activation, S phase arrest, and apoptosis, demonstrating requirement of the N-methylthio group. Because of the ease of synthesis and structural manipulation, we believe these beta-lactams may have the potential to be developed into anticancer agents.
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Affiliation(s)
- David M Smith
- Drug Discovery Program, and the Department of Chemistry, College of Arts and Sciences, University of South Florida, Tampa, Florida 33612-9497, USA
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84
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Proietti De Santis L, Garcia CL, Balajee AS, Latini P, Pichierri P, Nikaido O, Stefanini M, Palitti F. Transcription coupled repair efficiency determines the cell cycle progression and apoptosis after UV exposure in hamster cells. DNA Repair (Amst) 2002; 1:209-23. [PMID: 12509253 DOI: 10.1016/s1568-7864(01)00017-9] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Nucleotide excision repair (NER) is a major pathway for the removal of bulky adducts and helix distorting lesions from the genomic DNA. NER is highly heterogeneous across the genome and operates principally at different levels of hierarchy. Transcription coupled repair (TCR), a special sub-pathway of NER and base excision repair (BER), is critical for cellular resistance after UV irradiation in mammalian cells. In this study, we have investigated the effects of UV-C irradiation on cell cycle progression and apoptosis in G1 synchronised isogenic hamster cell lines that are deficient in TCR and NER pathways. Our results revealed the existence of two apoptotic modes at low UV (2-4J/m2) doses in TCR deficient (UV61) and NER deficient (UV5) cells: one occurring in the first G1 and the other in the second G1-phase following the first division. At high UV doses (8-32J/m2), UV61 and UV5 cells underwent apoptosis without entry into S-phase after a permanent arrest in the initial G1. In contrast to repair deficient cells, parental TCR proficient AA8 cells did not show a significant G1 arrest and apoptosis at doses below 8J/m2. UV61 (proficient in repair of 6-4 photoproducts (PPs)) and UV5 (deficient in 6-4 PP repair) cells showed similar patterns of cell cycle progression and apoptosis. Taken together, these results suggest that the persistence of 6-4 PP and the replication inhibition may not be critical for apoptotic response in hamster cells. Instead, the extent of transcription blockage resulting from the TCR deficiency constitutes the major determining factor for G1 arrest and apoptosis.
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Affiliation(s)
- Luca Proietti De Santis
- Laboratory of Molecular Cytogenetic and Mutagenesis, DABAC, Università degli Studi della Tuscia, Via San Camillo de Lellis, 01100 Viterbo, Italy
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85
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Frydas S, Papaioannou N, Papazachariadou M, Xatzistilianou M, Vlemmas I, Merlitti D, Castellani ML, Schiavone C, Tulli A, Di Gioacchino M. A spectrum of antibody (IgG. IgG1, IgM) response in mice infected with trichinella spiralis treated with L-mimosine. Int J Immunopathol Pharmacol 2002; 15:19-26. [PMID: 12593784 DOI: 10.1177/039463200201500103] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
The purpose of this study was to demonstrate the anti-inflammatory effects of L-mimosine on chronic inflammation, by investigating its effect on the immunological response of BALB/c mice infected with the nematode parasite Trichinella spiralis. Specific anti-parasite immunoglobulins (IgG, IgG1 and IgM) were detected by the ELISA method in the serum of both the treated and the untreated animals at different periods of time for 60 days post infection. Two groups consisting of 18 mice each were used. The mice were 6 weeks of age. Both groups were infected with 220 larvae (L1-T. spiralis) per os: one group was administered an intraperitoneal injection of L-mimosine (200 &mgr;g/100 ml/dose) for 27 days (the first injection started 7 days before infection) and the second group was administered an intraperitoneal injection of saline solution (100 &mgr;l/dose). Parasite specific IgG, IgG1 and IgM levels were determined in the sera of infected, untreated mice. The levels of IgG and IgG1 were increased following infection and remained elevated throughout the experimental period, while IgM was significantly decreased on the 50th day post-infection. These levels were found to be lower in the L-mimosine treated infected mice, compared to the untreated mice. The inhibition started from day 10 and continued until day 60. In healthy animals, the production of immunoglobulins was not measurable. Non-infected animals treated with L-mimosine also showed no detectable anti-parasite specific immunoglobulins.
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Affiliation(s)
- S. Frydas
- Dept. Parasitology, Veterinary Faculty, Aristotle University, Thessaloniki, Greece
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86
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Conti P, Frydas S, Reale M, Barbacane RC, Di Gioacchino M, Felaco M, Trakatellis A. Inhibition of MCP-1 and MIP-2 transcription and translation by mimosine in muscle tissue infected with the parasite Trichinella spiralis. Mol Cell Biochem 2002; 229:129-37. [PMID: 11936838 DOI: 10.1023/a:1017989014906] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Mimosine is a non-toxic plant aminoacid which is an effective inhibitor of DNA replication by acting at the S-phase. In this study we infected mice with T. spiralis, a nematode parasite, and studied the inflammatory response through the determination of MIP-2, a C-X-C chemokine and MCP-1, a C-C chemokine in the inflamed area around the parasitic cyst. The animals were infected and their diaphragms were tested for inflammatory response. MCP-1 and MIP-2 was tested after 1, 10, 20, 30, and 40 days post inoculation, before and after mimosine treatment. The inflammatory index was calculated by counting the white blood cells around the nematode cysts, while expression of MIP-2 and MCP-1 was calculated by ELISA method and transcription by Northern blot and RT-PCR. Here we found that mimosine strongly inhibited the inflammatory index in the diaphragmatic tissue at 10, 20, 30 and 40 days post-treatment. In these experiments, mimosine had no effect on the number of cysts produced. In addition, we found that MCP-1 transcription and translation was completely inhibited by mimosine, while MIP-2 transcription and translation was partially inhibited at 30 and 40 days; yet it was totally inhibited after 10 and 20 days in encysted diaphragm tissue infected by T. spiralis. Our studies suggest that mimosine has an inhibitory effect through the inhibition of cytoplasmatic serine hydroxymethyltransferase altering the cell cycle of white blood cells. This study suggests for the first time the premise that mimosine acts as an anti-inflammatory compound.
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Affiliation(s)
- Pio Conti
- Department of Oncology and Neurosciences, University of Chieti, Italy.
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87
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Dunkern TR, Kaina B. Cell proliferation and DNA breaks are involved in ultraviolet light-induced apoptosis in nucleotide excision repair-deficient Chinese hamster cells. Mol Biol Cell 2002; 13:348-61. [PMID: 11809844 PMCID: PMC65093 DOI: 10.1091/mbc.01-05-0225] [Citation(s) in RCA: 68] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
UV light targets both membrane receptors and nuclear DNA, thus evoking signals triggering apoptosis. Although receptor-mediated apoptosis has been extensively investigated, the role of DNA damage in apoptosis is less clear. To analyze the importance of DNA damage induced by UV-C light in apoptosis, we compared nucleotide excision repair (NER)-deficient Chinese hamster ovary cells (lines 27-1 and 43-3B mutated for the repair genes ERCC3 and ERCC1, respectively) with the corresponding DNA repair-proficient fibroblasts (CHO-9 and ERCC1 complemented 43-3B cells). NER-deficient cells were hypersensitive as to the induction of apoptosis, indicating that apoptosis induced by UV-C light is due to unrepaired DNA base damage. Unrepaired lesions, however, do not activate the apoptotic pathway directly because apoptosis upon UV-C irradiation requires DNA replication and cell proliferation. It is also shown that in NER-deficient cells unrepaired lesions are converted into DNA double-strand breaks (DSBs) and chromosomal aberrations by a replication-dependent process that precedes apoptosis. We therefore propose that DSBs arising from replication of DNA containing nonrepaired lesions act as an ultimate trigger of UV-C-induced apoptosis. Induction of apoptosis by UV-C light was related to decline in the expression level of Bcl-2 and activation of caspases. Decline of Bcl-2 and subsequent apoptosis might also be caused, at least in part, by UV-C-induced blockage of transcription, which was more pronounced in NER-deficient than in wild-type cells. This is in line with experiments with actinomycin D, which provoked Bcl-2 decline and apoptosis. UV-C-induced apoptosis due to nonrepaired DNA lesions, replication-dependent formation of DSBs, and activation of the mitochondrial damage pathway is independent of functional p53 for which the cells are mutated.
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Affiliation(s)
- Torsten R Dunkern
- Institute of Toxicology, Division of Applied Toxicology, University of Mainz, D-55131 Mainz, Germany
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88
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Piao W, Yoo J, Lee DK, Hwang HJ, Kim JH. Induction of G(2)/M phase arrest and apoptosis by a new synthetic anti-cancer agent, DW2282, in promyelocytic leukemia (HL-60) cells. Biochem Pharmacol 2001; 62:1439-47. [PMID: 11728380 DOI: 10.1016/s0006-2952(01)00796-1] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
We studied the effect of DW2282-,[(S)-(+)-4-phenyl-1-[N-(4-aminobenzoyl)-indoline-5-sulfonyl-4,5-dihydro-2-imidazolone].hydrochloride], a newly developed anti-cancer agent, on cell proliferation, cell cycle progression, and induction of apoptosis in human promyelocytic leukemia (HL-60) cells. DW2282, a diarylsulfonylurea compound, was cytotoxic to HL-60 cells, with an IC(50) of 1.0 microg/mL. Treatment with DW2282 fragmented DNA in a concentration- and time-dependent manner, suggesting that these cells underwent apoptosis. Flow cytometric analysis further confirmed that DW2282-treated HL-60 cells were hypodiploid, in terms of DNA content, and were arrested at the G(2)/M phase. The cell cycle arrest was reversible upon the removal of DW2282. HL-60 cells also underwent distinct morphological changes in response to DW2282 treatment, including the appearance of elongated cells with conical tails and other apoptotic characteristics. G(2)/M phase cell cycle arrest was accompanied by a decrease in the levels of cdc2, a protein that plays a critical role for progression through the G(2)/M phase. Treatment of HL-60 cells with DW2282 was also associated with decreased levels of the anti-apoptotic protein Bcl-2, activation of caspase-3, and proteolytic cleavage of poly(ADP-ribose) polymerase. Taken together, these results demonstrate that DW2282 dramatically suppressed HL-60 cell growth by inducing apoptosis after G(2)/M phase arrest. These findings are consistent with the possibility that G(2)/M phase arrest was mediated by the down-regulation of cdc2 levels in HL-60 cells. The data also suggest that DW2282 triggered apoptosis by decreasing Bcl-2 levels and activating caspase-3 protease. These results provide important new information towards understanding the mechanisms by which DW2282 and other diarylsulfonylureas mediate their therapeutic effects.
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Affiliation(s)
- W Piao
- Department of Biochemistry, College of Dentistry, Kyung Hee University, 130-701, Seoul, South Korea
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89
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Fung H, Bennett RA, Demple B. Key role of a downstream specificity protein 1 site in cell cycle-regulated transcription of the AP endonuclease gene APE1/APEX in NIH3T3 cells. J Biol Chem 2001; 276:42011-7. [PMID: 11555653 DOI: 10.1074/jbc.m106423200] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Abasic (apurinic/apyrimidinic or AP) sites are a frequent type of DNA damage that threatens genetic stability. The predominant mammalian enzyme initiating repair of AP sites is the Ape1 AP endonuclease (also called Apex or Hap1), which also facilitates DNA binding by several transcription factors (Ref1 activity). We found that expression of the APE1 gene was coordinated with the cell cycle in murine NIH3T3 cells: APE1 mRNA levels rose after the G(1)-S transition and peaked approximately 4-fold higher in early to mid-S phase. The increased APE1 mRNA was the result of transcriptional activation rather than increased mRNA stability. Fusions of various APE1 promoter fragments to the chloramphenicol acetyltransferase CAT reporter gene indicated that APE1 expression depends on two transcription factor Sp1 binding sites within the promoter region. Mutation of these sites or of two CCAAT elements within the APE1 promoter, in conjunction with protein binding studies, demonstrated their specific roles. The Sp1 site upstream of the transcription start, together with an adjacent CCAAT element, establishes a protein-DNA complex required for basal transcription of APE1. The Sp1 site downstream of the transcription start was required for the response to cell growth. Because Ape1 is a dual function enzyme, its cell cycle-dependent expression might affect both DNA repair and the activity of various transcription factors as a function of the cell cycle.
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Affiliation(s)
- H Fung
- Department of Cancer Cell Biology, Harvard School of Public Health, Boston, Massachusetts 02115, USA
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90
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Chouinard N, Therrien JP, Mitchell DL, Robert M, Drouin R, Rouabhia M. Repeated exposures of human skin equivalent to low doses of ultraviolet-B radiation lead to changes in cellular functions and accumulation of cyclobutane pyrimidine dimers. Biochem Cell Biol 2001. [DOI: 10.1139/o01-133] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Chronic exposure to sunlight may induce skin damage such as photoaging and photocarcinogenesis. These harmful effects are mostly caused by ultraviolet-B (UVB) rays. Yet, less is known about the contribution of low UVB doses to skin damage. The aim of this study was to determine the tissue changes induced by repeated exposure to a suberythemal dose of UVB radiation. Human keratinocytes in monolayer cultures and in skin equivalent were irradiated daily with 8 mJ/cm2 of UVB. Then structural, ultrastructural, and biochemical alterations were evaluated. The results show that exposure to UVB led to a generalized destabilization of the epidermis structure. In irradiated skin equivalents, keratinocytes displayed differentiated morphology and a reduced capacity to proliferate. Ultrastructural analysis revealed, not only unusual aggregation of intermediate filaments, but also disorganized desmosomes and larger mitochondria in basal cells. UVB irradiation also induced the secretion of metalloproteinase-9, which may be responsible for degradation of type IV collagen at the basement membrane. DNA damage analysis showed that both single and repeated exposure to UVB led to formation of (64) photoproducts and cyclobutane pyrimidine dimers. Although the (64) photoproducts were repaired within 24 h after irradiation, cyclobutane pyrimidine dimers accumulated over the course of the experiment. These studies demonstrate that, even at a suberythemal dose, repeated exposure to UVB causes significant functional and molecular damage to keratinocytes, which might eventually predispose to skin cancer.Key words: UVB, keratinocytes, skin structure, DNA damage, photoproducts.
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91
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Frydas S, Papaioannou N, Hatzistilianou M, Merlitti D, Di Gioacchino M, Castellani M, Conti P. Generation of TNFα, IFNγ, IL-4, IL-6 and IL-10 in Trichinella spiralis infected mice: effect of the anti-inflammatory compound mimosine. Inflammopharmacology 2001. [DOI: 10.1163/156856001320290642] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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92
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Chiou CC, Chan CC, Sheu DL, Chen KT, Li YS, Chan EC. Helicobacter pylori infection induced alteration of gene expression in human gastric cells. Gut 2001; 48:598-604. [PMID: 11302954 PMCID: PMC1728271 DOI: 10.1136/gut.48.5.598] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
BACKGROUND Helicobacter pylori, a human pathogen responsible for many digestive disorders, induces complex changes in patterns of gene expression in infected tissues. cDNA expression arrays provide a useful tool for studying these complex phenomena. AIM To identify genes that showed altered expression after H pylori infection of human gastric cells compared with uninfected controls. METHODS The gastric adenocarcinoma cell line AGS was cocultivated with H pylori. Growth of infected cells was determined by trypan blue exclusion assay. Complementary DNA probes derived from H pylori treated and untreated cells were hybridised to two identical Atlas human cDNA expression arrays, and those genes with altered expression levels were identified. A real time quantitative reverse transcription-polymerase chain reaction assay was used to better define expression patterns of these genes in endoscopically gastric mucosal biopsies with and without H pylori infection. RESULTS Over 24 hours, coincubation with H pylori inhibited AGS cell growth but did not cause a noticeable degree of cell death. H pylori treatment altered the pattern of gene expression in AGS cells. We identified 21 overexpressed genes and 17 suppressed genes from the cDNA expression arrays. The majority of genes were transcription factors such as c-jun, BTEB2, and ETR101. Other genes were involved in signal transduction pathways, such as MAP kinase, interleukin 5, and insulin-like growth factor. Genes involved in cell cycle regulation and differentiation, such as CDC25B and NM23-H2, were also identified. In patients with H pylori infection (n=20), there was a significant difference for ERCC3, Id-2, and NM23-H2 mRNA levels in infected gastric mucosa compared with uninfected gastric mucosa in patients without peptic diseases (n=20) (ERCC3 4.75 molecules/10(4) beta-actin mRNA molecules v 13.65, p<0.001; Id-2 16.1 v 23.4, p<0.05; NM23-H2 17.5 v 45.5, p<0.001). There was no significant difference between mRNA levels of c-jun and CDC25B in H pylori colonised gastric mucosa and uninfected mucosa. CONCLUSION We demonstrated that H pylori infection caused alteration of gene expression in AGS cells. The differential hybridisation technique of Atlas human cDNA expression array is a useful method to identify host genes involved in pathogenic mechanisms in H pylori infection.
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Affiliation(s)
- C C Chiou
- School of Medical Technology, Chang Gung University, Taoyuan, Taiwan
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93
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Costa SL, Paillaud E, Fages C, Rochette-Egly C, Plassat JL, Jouault H, Perzelova A, Tardy M. Effects of a novel synthetic retinoid on malignant glioma in vitro: inhibition of cell proliferation, induction of apoptosis and differentiation. Eur J Cancer 2001; 37:520-30. [PMID: 11267863 DOI: 10.1016/s0959-8049(00)00430-5] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Among six synthetic retinoids tested, the retinoid 6-[3-(1-adamantyl)-4-hydroxyphenyl]-2-naphthalene carboxylic acid (CD437) was highly efficient in inducing growth inhibition of 8MG-BA and GL-15 human glioblastoma cell lines, with growth arrest at the S phase of the cell cycle. CD 437 also induced apoptosis in these cells, with 8MG-BA being the most sensitive. In these cells, induction of apoptosis by CD437 has been related to the downregulation of Bcl-2 expression and to CPP32 activation, but not to p53 expression. The remaining non-apoptotic cells presented a morphological pattern of astroglial differentiation with overexpression of glial fibrillary acidic protein (GFAP) and glutamine synthetase (GS). The mechanism of action of CD437, originally developed as a RARgamma agonist, is not yet elucidated. However, our results suggest that it acts through an increase of the expression of retinoid-inducible genes, such as RARbeta2 and/or RARalpha2.
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Affiliation(s)
- S L Costa
- INSERM U-421, Faculté de médicine, 8 rue du Général Sarrail, 94010 cedex, Créteil, France
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94
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Tommasi S, Oxyzoglou AB, Pfeifer GP. Cell cycle-independent removal of UV-induced pyrimidine dimers from the promoter and the transcription initiation domain of the human CDC2 gene. Nucleic Acids Res 2000; 28:3991-8. [PMID: 11024179 PMCID: PMC110792 DOI: 10.1093/nar/28.20.3991] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
To assess whether removal of UV-induced cyclobutane pyrimidine dimers (CPDs) occurs with equal efficiency at different stages of the cell cycle in a cell cycle-regulated gene, we have analyzed repair of CPDs, following a single dose of UV, in normal human fibroblasts that were synchronized in either G(0) or S phase. Based on a single nucleotide resolution analysis, we established a detailed map of DNA repair rates along the promoter region and the transcription initiation area of the human CDC2 gene. The promoter of this gene is covered by an array of sequence-specific transcription factors located between nt -280 and -9 relative to the major transcription start site. In both quiescent and S phase-synchronized fibroblasts the majority of these sequences were poorly repaired even after 24 h, probably as a result of the constitutive binding of transcription factors throughout the cell cycle. A domain of fast repair was found at sequences surrounding the transcription initiation site and continuing downstream for approximately 80 nt. CPD removal from this domain was preferential in both quiescent and proliferating fibroblasts, despite lower levels of global genome repair and a lack of CDC2 transcription in quiescent cells. We suggest that sequences involved in transcription initiation may be book-marked for efficient repair throughout the cell cycle, even when the gene is temporarily not expressed.
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Affiliation(s)
- S Tommasi
- Department of Biology, Beckman Research Institute, City of Hope National Medical Center, Duarte, CA 91010, USA.
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95
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Liu W, Ernst JD, Broaddus VC. Phagocytosis of crocidolite asbestos induces oxidative stress, DNA damage, and apoptosis in mesothelial cells. Am J Respir Cell Mol Biol 2000; 23:371-8. [PMID: 10970829 DOI: 10.1165/ajrcmb.23.3.4094] [Citation(s) in RCA: 68] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Phagocytosis of asbestos fibers may be a necessary step for asbestos-induced injury to mesothelial cells, but this has not been established because quantification of fiber uptake is difficult and ways to increase fiber phagocytosis without also increasing total dose were not available. We quantified phagocytosis by counting intracellular fibers after removing adherent fibers with trypsin; we selectively increased fiber phagocytosis by coating crocidolite asbestos fibers with the adhesive serum protein vitronectin (VN), which we have shown increases fiber uptake via integrins. We measured various aspects of asbestos-induced cytotoxicity: intracellular oxidation by the shift of fluorescence of cells loaded with an oxidative probe, DNA strand breakage by the alkaline unwinding ethidium bromide fluorometric assay, apoptosis by annexin V binding and by nuclear morphology, and cell-cycle progression. We found that, compared with control fibers or particles, asbestos increased intracellular oxidation, DNA strand breakage, and apoptosis. Selective increases in fiber uptake by VN-coating of the fibers further increased the oxidation, DNA strand breakage, and apoptosis, and induced a cell-cycle arrest in G2/M. Selective decreases in fiber uptake by cytochalasin or by integrin blockade with RGD peptides inhibited several of these measures of injury. We conclude that phagocytosis is important and perhaps necessary for asbestos-induced injury to mesothelial cells.
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Affiliation(s)
- W Liu
- Lung Biology Center and Rosalind Russell Arthritis Research Laboratory, Department of Medicine, San Francisco General Hospital, University of California, San Francisco, California, USA
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96
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Bataille V, Bykov VJ, Sasieni P, Harulow S, Cuzick J, Hemminki K. Photoadaptation to ultraviolet (UV) radiation in vivo: photoproducts in epidermal cells following UVB therapy for psoriasis. Br J Dermatol 2000; 143:477-83. [PMID: 10971317 DOI: 10.1111/j.1365-2133.2000.03698.x] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
BACKGROUND Ultraviolet (UV) radiation is mutagenic and induces specific DNA lesions in human skin that are often found at dipyrimidine sites. These photoproducts are likely to be biologically relevant regarding skin carcinogenesis, as p53 mutations in skin tumours are most often found at these UV radiation-specific sites within DNA. Psoriasis patients receiving long-term phototherapy are at an increased risk of non-melanoma skin cancers. OBJECTIVES The aim of this study was to quantify DNA photoproducts in human epidermis in vivo following consecutive doses of UVB and to investigate variations in DNA damage according to skin type, UVB dose and age. METHODS Eleven psoriasis patients receiving UVB phototherapy three times a week were recruited and underwent skin biopsies on a non-sun-exposed site before starting phototherapy and after three, nine and 18 UVB exposures. A biopsy was also taken at least 4 weeks after stopping phototherapy. DNA was extracted from separated epidermis and three types of photoproducts were quantified using a novel 32P high-performance liquid chromatographic technique. RESULTS The mean level of cyclobutane dipyrimidine dimers (CPDs) after three doses of UVB (dose range 0.03-0.15 J cm-2) was 3.2 (range 0.8-8.9) photoproducts per 106 normal nucleotides for TT=T dimers and 4.5 (range 0-14) per 106 normal nucleotides for TT=C dimers. The mean levels of TT-C 6-4 photoproducts after three doses of UVB were very low (0.2, range 0-1.8). Overall, the levels of TT=T and TT=C reached a plateau at three exposures and were found to decrease for subsequent exposures despite increasing UVB doses. Skin type was negatively associated with mean levels of CPDs. However, significant differences in levels of photoproducts were seen between individuals, even after adjusting for skin type. No association was found between challenge dose of UVB and photoproduct yield in this study. CONCLUSIONS This study showed a great individual variation in the accumulation of DNA photoproducts following exposure to repetitive doses of UVB. Photoadaptive responses of human skin involving DNA repair, tanning and epidermal thickening are likely to explain the overall lack of increase in DNA lesions throughout phototherapy. This in vivo study confirms that psoriasis patients produce a significant amount of DNA photolesions at suberythemal doses of UVB. Further work is needed to investigate which host factors are most likely to predict susceptibility to UV radiation-induced DNA damage.
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Affiliation(s)
- V Bataille
- Academic Department of Dermatology and ICRF Skin Tumour Laboratory, St Bartholomew's and Royal London School of Medicine and Dentistry, London E1 2AT, U.K.
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97
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Jeffy BD, Chen EJ, Gudas JM, Romagnolo DF. Disruption of cell cycle kinetics by benzo[a]pyrene: inverse expression patterns of BRCA-1 and p53 in MCF-7 cells arrested in S and G2. Neoplasia 2000; 2:460-70. [PMID: 11191113 PMCID: PMC1507983 DOI: 10.1038/sj.neo.7900104] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
The effects of a ligand of the aromatic hydrocarbon receptor (AhR), benzo[a] pyrene (B[ a]P), and its metabolite, BPDE (7r,8t-dihydroxy-9t,10t-epoxy-7,8,9,10-tetrahydro-benzo[a]pyrene), on BRCA-1 levels and cell cycle kinetics were determined in MCF-7 breast cancer cells. Exposure of asynchronous MCF-7 cells for 72 hours to a non-cytotoxic dose of 0.5 microM B[a]P triggered a three-fold reduction in BRCA-1 protein. In MCF-7 cells resistant (20% to 30%) to genotoxic concentrations of B[a]P (1 to 5 microM), the loss of BRCA-1 protein was coupled with pausing in S-phase and G2/M, and accumulation of p53, mdm2 and p21. Treatment of MCF-7 cells synchronized in S-phase (72%) with B[a]P prolonged the arrest in S-phase, although this checkpoint was transient since cells resumed to G2/M after 12 hours with reduced levels of BRCA-1. In these cells, levels of p53 were increased, whereas the cellular content of p21 remained unaltered. In contrast, the co-treatment with the AhR antagonist, alpha-naphthoflavone (ANF), abrogated the deleterious effects of B[a]P on BRCA-1 expression, while preventing the accumulation of p53 and disruption of cell cycle profile. These findings suggest that the AhR mediated the inverse expression patterns of BRCA-1 and p53 upon exposure to B[a]P. The treatment with BPDE induced S-phase arrest and reduced BRCA-1 mRNA levels. The negative effects of BPDE on BRCA-1 expression were not transient since removal of BPDE did not allow complete reversal of the repression. These cumulative data suggest that the B[a]P metabolite, BPDE, may play a key role in disruption of BRCA-1 expression and cell cycle kinetics in breast epithelial cells.
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MESH Headings
- 7,8-Dihydro-7,8-dihydroxybenzo(a)pyrene 9,10-oxide/pharmacology
- Adenocarcinoma/genetics
- Adenocarcinoma/pathology
- Aphidicolin/pharmacology
- BRCA1 Protein/biosynthesis
- BRCA1 Protein/genetics
- Benzo(a)pyrene/pharmacology
- Benzoflavones/pharmacology
- Breast Neoplasms/genetics
- Breast Neoplasms/pathology
- Cell Cycle/drug effects
- Colchicine/pharmacology
- Depression, Chemical
- Dose-Response Relationship, Drug
- Female
- G2 Phase/drug effects
- Gene Expression Regulation, Neoplastic/drug effects
- Genes, BRCA1
- Genes, p53
- Humans
- Neoplasm Proteins/biosynthesis
- Neoplasm Proteins/drug effects
- Neoplasm Proteins/genetics
- Neoplasm Proteins/physiology
- Receptors, Aryl Hydrocarbon/drug effects
- Receptors, Aryl Hydrocarbon/physiology
- S Phase/drug effects
- Tumor Cells, Cultured/drug effects
- Tumor Cells, Cultured/metabolism
- Tumor Suppressor Protein p53/biosynthesis
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Affiliation(s)
- B D Jeffy
- Cancer Biology Interdisciplinary Program, Arizona Cancer Center, The University of Arizona, Tucson, USA
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98
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Rodrigo G, Roumagnac S, Wold MS, Salles B, Calsou P. DNA replication but not nucleotide excision repair is required for UVC-induced replication protein A phosphorylation in mammalian cells. Mol Cell Biol 2000; 20:2696-705. [PMID: 10733572 PMCID: PMC85485 DOI: 10.1128/mcb.20.8.2696-2705.2000] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
Exposure of mammalian cells to short-wavelength light (UVC) triggers a global response which can either counteract the deleterious effect of DNA damage by enabling DNA repair or lead to apoptosis. Several stress-activated protein kinases participate in this response, making phosphorylation a strong candidate for being involved in regulating the cellular damage response. One factor that is phosphorylated in a UVC-dependent manner is the 32-kDa subunit of the single-stranded DNA-binding replication protein A (RPA32). RPA is required for major cellular processes like DNA replication, and removal of DNA damage by nucleotide excision repair (NER). In this study we examined the signal which triggers RPA32 hyperphosphorylation following UVC irradiation in human cells. Hyperphosphorylation of RPA was observed in cells from patients with either NER or transcription-coupled repair (TCR) deficiency (A, C, and G complementation groups of xeroderma pigmentosum and A and B groups of Cockayne syndrome, respectively). This exclude both NER intermediates and TCR as essential signals for RPA hyperphosphorylation. However, we have observed that UV-sensitive cells deficient in NER and TCR require lower doses of UV irradiation to induce RPA32 hyperphosphorylation than normal cells, indicating that persistent unrepaired lesions contribute to RPA phosphorylation. Finally, the results of UVC irradiation experiments on nonreplicating cells and S-phase-synchronized cells emphasize a major role for DNA replication arrest in the presence of UVC lesions in RPA UVC-induced hyperphosphorylation in mammalian cells.
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Affiliation(s)
- G Rodrigo
- Institut de Pharmacologie et de Biologie Structurale, CNRS UPR 9062, F-31077 Toulouse Cedex, France
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Johnson PA, Clements P, Hudson K, Caldecott KW. The mitotic spindle and DNA damage-induced apoptosis. Toxicol Lett 2000; 112-113:59-67. [PMID: 10720713 DOI: 10.1016/s0378-4274(99)00245-3] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
EM9 Chinese hamster ovary cells cannot rejoin DNA strand breaks induced by alkylating agents. Ethyl methanesulphonate (EMS)-treated EM9cells underwent G2 arrest for a prolonged period followed by entry into mitosis and apoptosis. EM9 cells treated with EMS in G1 entered mitosis 24-36 h after release from synchrony, approximately 12 h after untreated control cells, but the mitoses were morphologically abnormal. The spindle-poison nocodazole reduced apoptosis by greater than 60%, and allowed some cells to complete a second round of DNA replication. We conclude that the assembly of a mitotic spindle, or progression beyond the mitotic checkpoint, is important for apoptosis following DNA strand breakage.
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Affiliation(s)
- P A Johnson
- School of Biological Sciences, G.38 Stopford Building, University of Manchester, Oxford Road, Manchester, UK
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Balajee AS, Proietti De Santis L, Brosh RM, Selzer R, Bohr VA. Role of the ATPase domain of the Cockayne syndrome group B protein in UV induced apoptosis. Oncogene 2000; 19:477-89. [PMID: 10698517 DOI: 10.1038/sj.onc.1203372] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Cockayne syndrome (CS) is a human autosomal recessive disorder characterized by many neurological and developmental abnormalities. CS cells are defective in the transcription coupled repair (TCR) pathway that removes DNA damage from the transcribed strand of active genes. The individuals suffering from CS do not generally develop cancer but show increased neurodegeneration. Two genetic complementation groups (CS-A and CS-B) have been identified. The lack of cancer formation in CS may be due to selective elimination of cells containing DNA damage by a suicidal pathway. In this study, we have evaluated the role of the CSB gene in UV induced apoptosis in human and hamster cells. The hamster cell line UV61 carries a mutation in the homolog of the human CSB gene. We show that both human CS-B and hamster UV61 cells display increased apoptotic response following UV exposure compared with normal cells. The increased sensitivity of UV61 cells to apoptosis is complemented by the transfection of the wild type human CSB gene. In order to determine which functional domain of the CSB gene participates in the apoptotic pathway, we constructed stable cell lines with different CSB domain disruptions. UV61 cells were stably transfected with the human CSB cDNA containing a point mutation in the highly conserved glutamic acid residue in ATPase motif II. This cell line (UV61/ pc3.1-CSBE646Q) showed the same increased apoptosis as the UV61 cells. In contrast, cells containing a deletion in the acidic domain at the N-terminal end of the CSB protein had no effect on apoptosis. This indicates that the integrity of the ATPase domain of CSB protein is critical for preventing the UV induced apoptotic pathway. In primary human CS-B cells, the induction and stabilization of the p53 protein seems to correlate with their increased apoptotic potential. In contrast, no change in the level of either p53 or activation of mdm2 protein by p53 was observed in hamster UV61 cells after UV exposure. This suggests that the CSB dependent apoptotic pathway can occur independently of the transactivation potential of p53 in hamster cells.
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Affiliation(s)
- A S Balajee
- Laboratory of Molecular Genetics, National Institute on Aging, National Institutes of Health, Baltimore, Maryland 21224, USA
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