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Quiñones OG, Mata dos Santos HA, Kibwila DM, Leitão Á, dos Santos Pyrrho A, Pádula MD, Rosas EC, Lara MG, Pierre MBR. In vitroandin vivoinfluence of penetration enhancers in the topical application of celecoxib. Drug Dev Ind Pharm 2013; 40:1180-9. [DOI: 10.3109/03639045.2013.809731] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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52
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Krifka S, Spagnuolo G, Schmalz G, Schweikl H. A review of adaptive mechanisms in cell responses towards oxidative stress caused by dental resin monomers. Biomaterials 2013; 34:4555-63. [DOI: 10.1016/j.biomaterials.2013.03.019] [Citation(s) in RCA: 200] [Impact Index Per Article: 18.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2013] [Accepted: 03/09/2013] [Indexed: 12/28/2022]
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Sacerdote C, Guarrera S, Ricceri F, Pardini B, Polidoro S, Allione A, Critelli R, Russo A, Andrew AS, Ye Y, Wu X, Kiemeney LA, Bosio A, Casetta G, Cucchiarale G, Destefanis P, Gontero P, Rolle L, Zitella A, Fontana D, Vineis P, Matullo G. Polymorphisms in the XRCC1 gene modify survival of bladder cancer patients treated with chemotherapy. Int J Cancer 2013; 133:2004-9. [PMID: 23553206 DOI: 10.1002/ijc.28186] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2012] [Accepted: 03/13/2013] [Indexed: 12/28/2022]
Abstract
Survival of bladder cancer patients depends on several factors including disease stage and grade at diagnosis, age, health status of the patient and the applied treatment. Several studies investigated the role of DNA repair genetic variants in cancer susceptibility, but only few studies investigated their role in survival and response to chemotherapy for bladder cancer. We genotyped 28 single nucleotide polymorphisms (SNP) in DNA repair genes in 456 bladder cancer patients, reconstructed haplotypes and calculated a score for combinations of the SNPs. We estimated Hazard Ratios (adjHR) for time to death. Among patients treated with chemotherapy, variant alleles of five SNPs in the XRCC1 gene conferred better survival (rs915927 adjHR 0.55 (95%CI 0.32-0.94); rs76507 adjHR 0.48 (95%CI 0.27-0.84); rs2854501 adjHR 0.25 (95%CI 0.12-0.52); rs2854509 adjHR 0.21 (95%CI 0.09-0.46); rs3213255 adjHR 0.46 (95%CI 0.26-0.80). In this group of patients, an increasing number of variant alleles in a XRCC1 gene score were associated with a better survival (26% decrease of risk of death for each additional variant allele in XRCC1). By functional analyses we demonstrated that the previous XRCC1 SNPs confer lower DNA repair capacity. This may support the hypothesis that survival in these patients may be modulated by the different DNA repair capacity determined by genetic variants. Chemotherapy treated cancer patients bearing an increasing number of "risky" alleles in XRCC1 gene had a better survival, suggesting that a proficient DNA repair may result in resistance to therapy and shorter survival. This finding may have clinical implications for the choice of therapy.
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Abstract
Histone deacetylase inhibitors (HDACis) increase gene expression through induction of histone acetylation. However, it remains unclear whether specific gene expression changes determine the apoptotic response following HDACis administration. Herein, we discuss evidence that HDACis trigger in cancer and leukemia cells not only widespread histone acetylation but also actual increases in reactive oxygen species (ROS) and DNA damage that are further increased following treatment with DNA-damaging chemotherapies. While the origins of ROS production are not completely understood, mechanisms, including inflammation and altered antioxidant signaling, have been reported. While the generation of ROS is an explanation, at least in part, for the source of DNA damage observed with HDACi treatment, DNA damage can also be independently induced by changes in the DNA repair activity and chromatin remodeling factors. Recent development of sirtuin inhibitors (SIRTis) has shown that, similar to HDACis, these drugs induce increases in ROS and DNA damage used singly, or in combination with HDACis and other drugs. Thus, induction of apoptosis by HDACis/SIRTis may result through oxidative stress and DNA damage mechanisms in addition to direct activation of apoptosis-inducing genes. Nevertheless, while DNA damage and stress responses could be of interest as markers for clinical responses, they have yet to be validated as markers for responses to HDACi treatment in clinical trials, alone, and in combination.
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Affiliation(s)
- Carine Robert
- Department of Radiation Oncology and Greenebaum Cancer Center, University of Maryland School of Medicine, Baltimore, Maryland, USA
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Lesecque Y, Mouchiroud D, Duret L. GC-biased gene conversion in yeast is specifically associated with crossovers: molecular mechanisms and evolutionary significance. Mol Biol Evol 2013; 30:1409-19. [PMID: 23505044 PMCID: PMC3649680 DOI: 10.1093/molbev/mst056] [Citation(s) in RCA: 79] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
GC-biased gene conversion (gBGC) is a process associated with recombination that favors the transmission of GC alleles over AT alleles during meiosis. gBGC plays a major role in genome evolution in many eukaryotes. However, the molecular mechanisms of gBGC are still unknown. Different steps of the recombination process could potentially cause gBGC: the formation of double-strand breaks (DSBs), the invasion of the homologous or sister chromatid, and the repair of mismatches in heteroduplexes. To investigate these models, we analyzed a genome-wide data set of crossovers (COs) and noncrossovers (NCOs) in Saccharomyces cerevisiae. We demonstrate that the overtransmission of GC alleles is specific to COs and that it occurs among conversion tracts in which all alleles are converted from the same donor haplotype. Thus, gBGC results from a process that leads to long-patch repair. We show that gBGC is associated with longer tracts and that it is driven by the nature (GC or AT) of the alleles located at the extremities of the tract. These observations invalidate the hypotheses that gBGC is due to the base excision repair machinery or to a bias in DSB formation and suggest that in S. cerevisiae, gBGC is caused by the mismatch repair (MMR) system. We propose that the presence of nicks on both DNA strands during CO resolution could be the cause of the bias in MMR activity. Our observations are consistent with the hypothesis that gBGC is a nonadaptive consequence of a selective pressure to limit the mutation rate in mitotic cells.
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Affiliation(s)
- Yann Lesecque
- Laboratoire de Biométrie et Biologie Evolutive, UMR CNRS 5558, Université de Lyon, Université Lyon 1, Villeurbanne, France
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Le Dû-Lacoste M, Akcha F, Dévier MH, Morin B, Burgeot T, Budzinski H. Comparative study of different exposure routes on the biotransformation and genotoxicity of PAHs in the flatfish species, Scophthalmus maximus. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2013; 20:690-707. [PMID: 23247530 DOI: 10.1007/s11356-012-1388-9] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/30/2012] [Accepted: 11/29/2012] [Indexed: 06/01/2023]
Abstract
In this study, laboratory experiments were carried out in order to come to a better understanding of the fate of polycyclic aromatic hydrocarbons (PAHs) in the marine environment and especially on their bioaccumulation, biotransformation and genotoxic effects in fish. Juveniles of turbot (Scophthalmus maximus) were exposed to PAHs through different routes via (1) a mixture of dissolved PAHs, (2) a PAH-polluted sediment and (3) an oil fuel elutriate. Fish were exposed 4 days followed by a 6-day depuration period. In each experiment, PAH concentrations in the seawater of the tanks were analysed regularly by gas chromatography coupled with mass spectrometry. Muscle and liver samples were also analysed for parent PAH levels and PAH bioconcentration factors were calculated. Biotransformation was evaluated by measuring the levels of PAH metabolites in fish bile. Genotoxicity was assessed by the alkaline comet assay. Regardless of exposure route, the parent PAH concentrations in the liver and muscle showed a peak level 1 day after the beginning of the exposure, followed by a decrease up to the background level towards the end of the experiment, except for the exposure to dissolved PAHs for which levels were relatively low throughout the study. As a consequence, no bioaccumulation was observed in fish tissues at the end of the experiment. In contrast, regardless of exposure routes, a rapid production of biliary metabolites was observed throughout the whole exposure experiment. This was especially true for 1-hydroxypyrene, the major metabolite of pyrene. After 6 days of recovery in clean water, a significant decrease in the total metabolite concentrations occurred in bile. Fish exposed through either route displayed a significant increase in DNA strand breaks after 4 days of exposure, and significant correlations were observed between the level of biliary PAH metabolites and the level of DNA lesions in fish erythrocytes. Overall results indicate that exposure to either a mixture of dissolved PAHs, a PAH-contaminated sediment or a dispersed oil fuel elutriate leads to biotransformation and increase in DNA damage in fish. The quantification of PAH metabolites in bile and DNA damage in erythrocytes appear to be suitable for environmental monitoring of marine pollution either in the case of accidental oil spills or sediment contamination.
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Affiliation(s)
- Marie Le Dû-Lacoste
- Oceanic and Continental Environments and Paleoenvironments, EPOC, UMR 5805, CNRS, Laboratory of Physico- and Toxico-Chemistry of the Environment, LPTC, Université de Bordeaux, 351 cours de la Libération, 33405 Talence cedex, France
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Odajima C, Nakamura T, Miura M, Yamazaki K, Honda G, Kikuchi Y, Yamamoto A, Sasaki YF. Can an Inhibitor of DNA Polymerase ^|^beta; Enhance the Formation of Comet Tail? Genes Environ 2013. [DOI: 10.3123/jemsge.35.46] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
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Adhikary S, Cato MC, McGary KL, Rokas A, Eichman BF. Non-productive DNA damage binding by DNA glycosylase-like protein Mag2 from Schizosaccharomyces pombe. DNA Repair (Amst) 2012; 12:196-204. [PMID: 23273506 DOI: 10.1016/j.dnarep.2012.12.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2012] [Revised: 12/03/2012] [Accepted: 12/03/2012] [Indexed: 11/15/2022]
Abstract
Schizosaccharomyces pombe contains two paralogous proteins, Mag1 and Mag2, related to the helix-hairpin-helix (HhH) superfamily of alkylpurine DNA glycosylases from yeast and bacteria. Phylogenetic analysis of related proteins from four Schizosaccharomyces and other fungal species shows that the Mag1/Mag2 duplication is unique to the genus Schizosaccharomyces and most likely occurred in its ancestor. Mag1 excises N3- and N7-alkylguanines and 1,N(6)-ethenoadenine from DNA, whereas Mag2 has been reported to have no detectible alkylpurine base excision activity despite high sequence and active site similarity to Mag1. To understand this discrepancy we determined the crystal structure of Mag2 bound to abasic DNA and compared it to our previously determined Mag1-DNA structure. In contrast to Mag1, Mag2 does not flip the abasic moiety into the active site or stabilize the DNA strand 5' to the lesion, suggesting that it is incapable of forming a catalytically competent protein-DNA complex. Subtle differences in Mag1 and Mag2 interactions with the DNA duplex illustrate how Mag2 can stall at damage sites without fully engaging the lesion. We tested our structural predictions by mutational analysis of base excision and found a single amino acid responsible at least in part for Mag2's lack of activity. Substitution of Mag2 Asp56, which caps the helix at the base of the DNA intercalation loop, with the corresponding serine residue in Mag1 endows Mag2 with ɛA excision activity comparable to Mag1. This work provides novel insight into the chemical and physical determinants by which the HhH glycosylases engage DNA in a catalytically productive manner.
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Affiliation(s)
- Suraj Adhikary
- Department of Biological Sciences, Vanderbilt University, Nashville, TN 37232, USA
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59
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Brooks SC, Adhikary S, Rubinson EH, Eichman BF. Recent advances in the structural mechanisms of DNA glycosylases. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2012; 1834:247-71. [PMID: 23076011 DOI: 10.1016/j.bbapap.2012.10.005] [Citation(s) in RCA: 128] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/27/2012] [Revised: 09/24/2012] [Accepted: 10/05/2012] [Indexed: 02/06/2023]
Abstract
DNA glycosylases safeguard the genome by locating and excising a diverse array of aberrant nucleobases created from oxidation, alkylation, and deamination of DNA. Since the discovery 28years ago that these enzymes employ a base flipping mechanism to trap their substrates, six different protein architectures have been identified to perform the same basic task. Work over the past several years has unraveled details for how the various DNA glycosylases survey DNA, detect damage within the duplex, select for the correct modification, and catalyze base excision. Here, we provide a broad overview of these latest advances in glycosylase mechanisms gleaned from structural enzymology, highlighting features common to all glycosylases as well as key differences that define their particular substrate specificities.
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Affiliation(s)
- Sonja C Brooks
- Department of Biological Sciences and Center for Structural Biology, Vanderbilt University, Nashville, TN 37232, USA
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Ashwell S. Strategies towards more effective anticancer therapies: targeting DNA damage response pathways. Expert Rev Clin Pharmacol 2012; 3:103-15. [PMID: 22111536 DOI: 10.1586/ecp.09.51] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The last decade has seen a tremendous increase in the understanding of the cellular mechanisms that underlie the detection and repair of DNA damage. This gave rise to the hypothesis that inhibition of DNA repair may result in increased efficacy of existing therapies and, more recently, to the idea that some tumor cells may carry additional defects that make them hypersensitive to DNA repair inhibitors as single agents. In order to minimize the potential to cause lesions in normal tissue, strategies have been directed to specific targets or pathways where selectivity for tumor over normal tissue is possible, thus to date most emphasis has been placed on a relatively small number of targets such as the poly(ADP-ribose) polymerase and the checkpoint kinases. Both of these approaches have yielded small molecule inhibitors that are currently in clinical trials.
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Affiliation(s)
- Susan Ashwell
- AstraZeneca R&D Boston, 35 Gatehouse Drive, Waltham, MA 02451, USA.
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Llopis S, Querol A, Heyken A, Hube B, Jespersen L, Fernández-Espinar MT, Pérez-Torrado R. Transcriptomics in human blood incubation reveals the importance of oxidative stress response in Saccharomyces cerevisiae clinical strains. BMC Genomics 2012; 13:419. [PMID: 22916735 PMCID: PMC3483181 DOI: 10.1186/1471-2164-13-419] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2012] [Accepted: 08/20/2012] [Indexed: 01/19/2023] Open
Abstract
Background In recent years an increasing number of yeast infections in humans have been related to certain clinical isolates of Saccharomyces cerevisiae. Some clinical strains showed in vivo and in vitro virulence traits and were able to cause death in mice whereas other clinical strains were avirulent. Results In this work, we studied the transcriptional profiles of two S. cerevisiae clinical strains showing virulent traits and two control non-virulent strains during a blood incubation model and detected a specific transcriptional response of clinical strains. This response involves an mRNA levels increase of amino acid biosynthesis genes and especially oxidative stress related genes. We observed that the clinical strains were more resistant to reactive oxygen species in vitro. In addition, blood survival of clinical isolates was high, reaching similar levels to pathogenic Candida albicans strain. Furthermore, a virulent strain mutant in the transcription factor Yap1p, unable to grow in oxidative stress conditions, presented decreased survival levels in human blood compared with the wild type or YAP1 reconstituted strain. Conclusions Our data suggest that this enhanced oxidative stress response in virulent clinical isolates, presumably induced in response to oxidative burst from host defense cells, is important to increase survival in human blood and can help to infect and even produce death in mice models.
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Affiliation(s)
- Silvia Llopis
- Instituto de Agroquímica y Tecnología de los Alimentos, IATA-CSIC, Burjassot, Spain
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Kuznetsov NA, Vorobjev YN, Krasnoperov LN, Fedorova OS. Thermodynamics of the multi-stage DNA lesion recognition and repair by formamidopyrimidine-DNA glycosylase using pyrrolocytosine fluorescence--stopped-flow pre-steady-state kinetics. Nucleic Acids Res 2012; 40:7384-92. [PMID: 22584623 PMCID: PMC3424566 DOI: 10.1093/nar/gks423] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Formamidopyrimidine-DNA glycosylase, Fpg protein from Escherichia coli, initiates base excision repair in DNA by removing a wide variety of oxidized lesions. In this study, we perform thermodynamic analysis of the multi-stage interaction of Fpg with specific DNA-substrates containing 7,8-dihydro-8-oxoguanosine (oxoG), or tetrahydrofuran (THF, an uncleavable abasic site analog) and non-specific (G) DNA-ligand based on stopped-flow kinetic data. Pyrrolocytosine, highly fluorescent analog of the natural nucleobase cytosine, is used to record multi-stage DNA lesion recognition and repair kinetics over a temperature range (10–30°C). The kinetic data were used to obtain the standard Gibbs energy, enthalpy and entropy of the specific stages using van’t Hoff approach. The data suggest that not only enthalpy-driven exothermic oxoG recognition, but also the desolvation-accompanied entropy-driven enzyme-substrate complex adjustment into the catalytically active state play equally important roles in the overall process.
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Affiliation(s)
- Nikita A Kuznetsov
- Institute of Chemical Biology and Fundamental Medicine, Siberian Branch of Russian Academy of Sciences, Novosibirsk, 630090, Russia
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63
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Pietanza MC, Rudin CM. Novel therapeutic approaches for small cell lung cancer: the future has arrived. Curr Probl Cancer 2012; 36:156-73. [PMID: 22495056 DOI: 10.1016/j.currproblcancer.2012.03.005] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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DNA repair in human pluripotent stem cells is distinct from that in non-pluripotent human cells. PLoS One 2012; 7:e30541. [PMID: 22412831 PMCID: PMC3295811 DOI: 10.1371/journal.pone.0030541] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2011] [Accepted: 12/19/2011] [Indexed: 11/19/2022] Open
Abstract
The potential for human disease treatment using human pluripotent stem cells, including embryonic stem cells and induced pluripotent stem cells (iPSCs), also carries the risk of added genomic instability. Genomic instability is most often linked to DNA repair deficiencies, which indicates that screening/characterization of possible repair deficiencies in pluripotent human stem cells should be a necessary step prior to their clinical and research use. In this study, a comparison of DNA repair pathways in pluripotent cells, as compared to those in non-pluripotent cells, demonstrated that DNA repair capacities of pluripotent cell lines were more heterogeneous than those of differentiated lines examined and were generally greater. Although pluripotent cells had high DNA repair capacities for nucleotide excision repair, we show that ultraviolet radiation at low fluxes induced an apoptotic response in these cells, while differentiated cells lacked response to this stimulus, and note that pluripotent cells had a similar apoptotic response to alkylating agent damage. This sensitivity of pluripotent cells to damage is notable since viable pluripotent cells exhibit less ultraviolet light-induced DNA damage than do differentiated cells that receive the same flux. In addition, the importance of screening pluripotent cells for DNA repair defects was highlighted by an iPSC line that demonstrated a normal spectral karyotype, but showed both microsatellite instability and reduced DNA repair capacities in three out of four DNA repair pathways examined. Together, these results demonstrate a need to evaluate DNA repair capacities in pluripotent cell lines, in order to characterize their genomic stability, prior to their pre-clinical and clinical use.
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Miller AS, Balakrishnan L, Buncher NA, Opresko PL, Bambara RA. Telomere proteins POT1, TRF1 and TRF2 augment long-patch base excision repair in vitro. Cell Cycle 2012; 11:998-1007. [PMID: 22336916 PMCID: PMC3323798 DOI: 10.4161/cc.11.5.19483] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2012] [Revised: 01/24/2012] [Accepted: 01/25/2012] [Indexed: 12/13/2022] Open
Abstract
Human telomeres consist of multiple tandem hexameric repeats, each containing a guanine triplet. Guanosine-rich clusters are highly susceptible to oxidative base damage, necessitating base excision repair (BER). Previous demonstration of enhanced strand displacement synthesis by the BER component DNA polymerase β in the presence of telomere protein TRF2 suggests that telomeres employ long-patch (LP) BER. Earlier analyses in vitro showed that efficiency of BER reactions is reduced in the DNA-histone environment of chromatin. Evidence presented here indicates that BER is promoted at telomeres. We found that the three proteins that contact telomere DNA, POT1, TRF1 and TRF2, enhance the rate of individual steps of LP-BER and stimulate the complete reconstituted LP-BER pathway. Thought to protect telomere DNA from degradation, these proteins still apparently evolved to allow selective access of repair proteins.
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Affiliation(s)
- Adam S Miller
- Department of Biochemistry and Biophysics, University of Rochester School of Medicine and Dentistry, Rochester, NY, USA
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66
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Aggarwal M, Brosh RM. Functional analyses of human DNA repair proteins important for aging and genomic stability using yeast genetics. DNA Repair (Amst) 2012; 11:335-48. [PMID: 22349084 DOI: 10.1016/j.dnarep.2012.01.013] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2012] [Accepted: 01/24/2012] [Indexed: 12/18/2022]
Abstract
Model systems have been extremely useful for studying various theories of aging. Studies of yeast have been particularly helpful to explore the molecular mechanisms and pathways that affect aging at the cellular level in the simple eukaryote. Although genetic analysis has been useful to interrogate the aging process, there has been both interest and debate over how functionally conserved the mechanisms of aging are between yeast and higher eukaryotes, especially mammalian cells. One area of interest has been the importance of genomic stability for age-related processes, and the potential conservation of proteins and pathways between yeast and human. Translational genetics have been employed to examine the functional roles of mammalian proteins using yeast as a pliable model system. In the current review recent advancements made in this area are discussed, highlighting work which shows that the cellular functions of human proteins in DNA repair and maintenance of genomic stability can be elucidated by genetic rescue experiments performed in yeast.
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Affiliation(s)
- Monika Aggarwal
- Laboratory of Molecular Gerontology, National Institute on Aging, National Institutes of Health, NIH Biomedical Research Center, Baltimore, MD 21224, United States
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Song F, Qureshi AA, Zhang J, Zhan J, Amos CI, Lee JE, Wei Q, Han J. Exonuclease 1 (EXO1) gene variation and melanoma risk. DNA Repair (Amst) 2012; 11:304-9. [PMID: 22230721 DOI: 10.1016/j.dnarep.2011.12.005] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2011] [Revised: 11/08/2011] [Accepted: 12/10/2011] [Indexed: 02/01/2023]
Abstract
OBJECTIVE DNA repair pathway genes play an important role in maintaining genomic integrity and protecting against cancer development. This study aimed to identify novel SNPs in the DNA repair-related genes associated with melanoma risk from a genome-wide association study (GWAS). METHODS A total of 8422 SNPs from the 165 DNA repair-related genes were extracted from a GWAS of melanoma risk, including 494 cases and 5628 controls from the Nurses' Health Study (NHS) and the Health Professionals Follow-up Study (HPFS). We further replicated the top SNPs in a GWAS of melanoma risk from the MD Anderson Cancer Center (1804 cases and 1026 controls). RESULTS A total of 3 SNPs with P value <0.001 were selected for in silico replication. One SNP was replicated: rs3902093 [A] in EXO1 promoter region (P(discovery)=6.6 × 10⁻⁴, P(replication)=0.039, P(joint)=2.5 × 10⁻⁴; OR(joint)=0.80, 95% CI: 0.71, 0.90). This SNP was associated with the expression of the EXO1; carriers of the A allele showed lower expression (P=0.002). CONCLUSION Our study found that a promoter region SNP in the editing and processing nucleases gene EXO1 was associated with decreased expression of EXO1 and decreased melanoma risk. Further studies are warranted to validate this association and to investigate the potential mechanisms.
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Affiliation(s)
- Fengju Song
- Department of Epidemiology, Tianjin Medical University Cancer Institute and Hospital, Tianjin, China
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68
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Swartzlander DB, Bauer NC, Corbett AH, Doetsch PW. Regulation of base excision repair in eukaryotes by dynamic localization strategies. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2012; 110:93-121. [PMID: 22749144 DOI: 10.1016/b978-0-12-387665-2.00005-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
This chapter discusses base excision repair (BER) and the known mechanisms defined thus far regulating BER in eukaryotes. Unlike the situation with nucleotide excision repair and double-strand break repair, little is known about how BER is regulated to allow for efficient and accurate repair of many types of DNA base damage in both nuclear and mitochondrial genomes. Regulation of BER has been proposed to occur at multiple, different levels including transcription, posttranslational modification, protein-protein interactions, and protein localization; however, none of these regulatory mechanisms characterized thus far affect a large spectrum of BER proteins. This chapter discusses a recently discovered mode of BER regulation defined in budding yeast cells that involves mobilization of DNA repair proteins to DNA-containing organelles in response to genotoxic stress.
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Affiliation(s)
- Daniel B Swartzlander
- Department of Biochemistry, Emory University School of Medicine, Atlanta, Georgia, USA
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69
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Adhikary S, Eichman BF. Analysis of substrate specificity of Schizosaccharomyces pombe Mag1 alkylpurine DNA glycosylase. EMBO Rep 2011; 12:1286-92. [PMID: 21960007 DOI: 10.1038/embor.2011.189] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2011] [Revised: 08/26/2011] [Accepted: 08/29/2011] [Indexed: 11/09/2022] Open
Abstract
DNA glycosylases specialized for the repair of alkylation damage must identify, with fine specificity, a diverse array of subtle modifications within DNA. The current mechanism involves damage sensing through interrogation of the DNA duplex, followed by more specific recognition of the target base inside the active site pocket. To better understand the physical basis for alkylpurine detection, we determined the crystal structure of Schizosaccharomyces pombe Mag1 (spMag1) in complex with DNA and performed a mutational analysis of spMag1 and the close homologue from Saccharomyces cerevisiae (scMag). Despite strong homology, spMag1 and scMag differ in substrate specificity and cellular alkylation sensitivity, although the enzymological basis for their functional differences is unknown. We show that Mag preference for 1,N(6)-ethenoadenine (ɛA) is influenced by a minor groove-interrogating residue more than the composition of the nucleobase-binding pocket. Exchanging this residue between Mag proteins swapped their ɛA activities, providing evidence that residues outside the extrahelical base-binding pocket have a role in identification of a particular modification in addition to sensing damage.
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Affiliation(s)
- Suraj Adhikary
- Department of Biological Sciences and Center for Structural Biology, Vanderbilt University, 465 21st Avenue South, Box 351634 Station B, 5270A MRBIII, Nashville, Tennessee 37235, USA
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70
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Martinez VD, Vucic EA, Adonis M, Gil L, Lam WL. Arsenic biotransformation as a cancer promoting factor by inducing DNA damage and disruption of repair mechanisms. Mol Biol Int 2011. [PMID: 22091411 DOI: 10.4061/2011/718974]] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Chronic exposure to arsenic in drinking water poses a major global health concern. Populations exposed to high concentrations of arsenic-contaminated drinking water suffer serious health consequences, including alarming cancer incidence and death rates. Arsenic is biotransformed through sequential addition of methyl groups, acquired from s-adenosylmethionine (SAM). Metabolism of arsenic generates a variety of genotoxic and cytotoxic species, damaging DNA directly and indirectly, through the generation of reactive oxidative species and induction of DNA adducts, strand breaks and cross links, and inhibition of the DNA repair process itself. Since SAM is the methyl group donor used by DNA methyltransferases to maintain normal epigenetic patterns in all human cells, arsenic is also postulated to affect maintenance of normal DNA methylation patterns, chromatin structure, and genomic stability. The biological processes underlying the cancer promoting factors of arsenic metabolism, related to DNA damage and repair, will be discussed here.
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Affiliation(s)
- Victor D Martinez
- Department of Integrative Oncology, BC Cancer Research Centre, 675 West 10th Avenue, Vancouver, BC, Canada V5Z 1L3
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71
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Histone H3 lysine 56 acetylation and the response to DNA replication fork damage. Mol Cell Biol 2011; 32:154-72. [PMID: 22025679 DOI: 10.1128/mcb.05415-11] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
In Saccharomyces cerevisiae, histone H3 lysine 56 acetylation (H3K56ac) occurs in newly synthesized histones that are deposited throughout the genome during DNA replication. Defects in H3K56ac sensitize cells to genotoxic agents, suggesting that this modification plays an important role in the DNA damage response. However, the links between histone acetylation, the nascent chromatin structure, and the DNA damage response are poorly understood. Here we report that cells devoid of H3K56ac are sensitive to DNA damage sustained during transient exposure to methyl methanesulfonate (MMS) or camptothecin but are only mildly affected by hydroxyurea. We demonstrate that, after exposure to MMS, H3K56ac-deficient cells cannot complete DNA replication and eventually segregate chromosomes with intranuclear foci containing the recombination protein Rad52. In addition, we provide evidence that these phenotypes are not due to defects in base excision repair, defects in DNA damage tolerance, or a lack of Rad51 loading at sites of DNA damage. Our results argue that the acute sensitivity of H3K56ac-deficient cells to MMS and camptothecin stems from a failure to complete the repair of specific types of DNA lesions by recombination and/or from defects in the completion of DNA replication.
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72
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Kim N, Mudrak SV, Jinks-Robertson S. The dCMP transferase activity of yeast Rev1 is biologically relevant during the bypass of endogenously generated AP sites. DNA Repair (Amst) 2011; 10:1262-71. [PMID: 22024240 DOI: 10.1016/j.dnarep.2011.09.017] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2011] [Revised: 09/27/2011] [Accepted: 09/28/2011] [Indexed: 11/18/2022]
Abstract
The bypass of AP sites in yeast requires the Rev1 protein in addition to the Pol ζ translesion synthesis DNA polymerase. Although Rev1 was originally characterized biochemically as a dCMP transferase during AP-site bypass, the relevance of this activity in vivo is unclear. The current study uses highly sensitive frameshift- and nonsense-reversion assays to monitor the bypass of AP sites created when uracil is excised from chromosomal DNA. In the frameshift-reversion assay, an unselected base substitution frequently accompanies the selected mutation, allowing the relative incorporation of each of the four dNMPs opposite endogenously created AP sites to be inferred. Results with this assay suggest that dCMP is the most frequent dNMP inserted opposite uracil-derived AP sites and demonstrate that dCMP insertion absolutely requires the catalytic activity of Rev1. In the complementary nonsense-reversion assay, dCMP insertion likewise depended on the dCMP transferase activity of Rev1. Because dAMP insertion opposite uracil-derived AP sites does not revert the nonsense allele and hence could not be detected, it also was possible to detect low levels of dGMP or dTMP insertion upon loss of Rev1 catalytic activity. These results demonstrate that the catalytic activity of Rev1 is biologically relevant and is required specifically for dCMP insertion during the bypass of endogenous AP sites.
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Affiliation(s)
- Nayun Kim
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, NC 27710, United States
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73
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Oxidative stress, mitochondrial dysfunction, and aging. JOURNAL OF SIGNAL TRANSDUCTION 2011; 2012:646354. [PMID: 21977319 PMCID: PMC3184498 DOI: 10.1155/2012/646354] [Citation(s) in RCA: 576] [Impact Index Per Article: 44.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 05/15/2011] [Accepted: 08/03/2011] [Indexed: 12/31/2022]
Abstract
Aging is an intricate phenomenon characterized by progressive decline in physiological functions and increase in mortality that is often accompanied by many pathological diseases. Although aging is almost universally conserved among all organisms, the underlying molecular mechanisms of aging remain largely elusive. Many theories of aging have been proposed, including the free-radical and mitochondrial theories of aging. Both theories speculate that cumulative damage to mitochondria and mitochondrial DNA (mtDNA) caused by reactive oxygen species (ROS) is one of the causes of aging. Oxidative damage affects replication and transcription of mtDNA and results in a decline in mitochondrial function which in turn leads to enhanced ROS production and further damage to mtDNA. In this paper, we will present the current understanding of the interplay between ROS and mitochondria and will discuss their potential impact on aging and age-related diseases.
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74
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Sanada U, Yonekura SI, Kikuchi M, Hashiguchi K, Nakamura N, Yonei S, Zhang-Akiyama QM. NDX-1 protein hydrolyzes 8-oxo-7, 8-dihydrodeoxyguanosine-5'-diphosphate to sanitize oxidized nucleotides and prevent oxidative stress in Caenorhabditis elegans. J Biochem 2011; 150:649-57. [PMID: 21873335 DOI: 10.1093/jb/mvr107] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
8-oxo-dGTP is generated in the nucleotide pool by direct oxidation of dGTP or phosphorylation of 8-oxo-dGDP. It can be incorporated into DNA during replication, which would result in mutagenic consequences. The frequency of spontaneous mutations remains low in cells owing to the action of enzymes degrading such mutagenic substrates. Escherichia coli MutT and human MTH1 hydrolyze 8-oxo-dGTP to 8-oxo-dGMP. Human NUDT5 as well as human MTH1 hydrolyze 8-oxo-dGDP to 8-oxo-dGMP. These enzymes prevent mutations caused by misincorporation of 8-oxo-dGTP into DNA. In this study, we identified a novel MutT homolog (NDX-1) of Caenorhabditis elegans that hydrolyzes 8-oxo-dGDP to 8-oxo-dGMP. NDX-1 did not hydrolyze 8-oxo-dGTP, 2-hydroxy-dATP or 2-hydroxy-dADP. Expression of NDX-1 significantly reduced spontaneous A:T to C:G transversions and mitigated the sensitivity to a superoxide-generating agent, methyl viologen, in an E. coli mutT mutant. In C. elegans, RNAi of ndx-1 did not affect the lifespan of the worm. However, the sensitivity to methyl viologen and menadione bisulfite of the ndx-1-RNAi worms was enhanced compared with that of the control worms. These facts indicate that NDX-1 is involved in sanitization of 8-oxo-dGDP and plays a critical role in defense against oxidative stress in C. elegans.
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Affiliation(s)
- U Sanada
- Laboratory of Stress Response Biology, Graduate School of Science, Kyoto University, Kitashirakawa-Oiwakecho, Sakyo-ku, Kyoto 606-8502, Japan
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75
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Martinez VD, Vucic EA, Adonis M, Gil L, Lam WL. Arsenic biotransformation as a cancer promoting factor by inducing DNA damage and disruption of repair mechanisms. Mol Biol Int 2011; 2011:718974. [PMID: 22091411 PMCID: PMC3200225 DOI: 10.4061/2011/718974] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2011] [Accepted: 06/06/2011] [Indexed: 11/20/2022] Open
Abstract
Chronic exposure to arsenic in drinking water poses a major global health concern. Populations exposed to high concentrations of arsenic-contaminated drinking water suffer serious health consequences, including alarming cancer incidence and death rates. Arsenic is biotransformed through sequential addition of methyl groups, acquired from s-adenosylmethionine (SAM). Metabolism of arsenic generates a variety of genotoxic and cytotoxic species, damaging DNA directly and indirectly, through the generation of reactive oxidative species and induction of DNA adducts, strand breaks and cross links, and inhibition of the DNA repair process itself. Since SAM is the methyl group donor used by DNA methyltransferases to maintain normal epigenetic patterns in all human cells, arsenic is also postulated to affect maintenance of normal DNA methylation patterns, chromatin structure, and genomic stability. The biological processes underlying the cancer promoting factors of arsenic metabolism, related to DNA damage and repair, will be discussed here.
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Affiliation(s)
- Victor D Martinez
- Department of Integrative Oncology, BC Cancer Research Centre, 675 West 10th Avenue, Vancouver, BC, Canada V5Z 1L3
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76
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Gomes MR, Guimarães ACR, de Miranda AB. Specific and nonhomologous isofunctional enzymes of the genetic information processing pathways as potential therapeutical targets for tritryps. Enzyme Res 2011; 2011:543912. [PMID: 21808726 PMCID: PMC3145330 DOI: 10.4061/2011/543912] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2011] [Revised: 03/22/2011] [Accepted: 05/05/2011] [Indexed: 12/03/2022] Open
Abstract
Leishmania major, Trypanosoma brucei, and Trypanosoma cruzi (Tritryps) are unicellular protozoa that cause leishmaniasis, sleeping sickness and Chagas' disease, respectively. Most drugs against them were discovered through the screening of large numbers of compounds against whole parasites. Nonhomologous isofunctional enzymes (NISEs) may present good opportunities for the identification of new putative drug targets because, though sharing the same enzymatic activity, they possess different three-dimensional structures thus allowing the development of molecules against one or other isoform. From public data of the Tritryps' genomes, we reconstructed the Genetic Information Processing Pathways (GIPPs). We then used AnEnPi to look for the presence of these enzymes between Homo sapiens and Tritryps, as well as specific enzymes of the parasites. We identified three candidates (ECs 3.1.11.2 and 6.1.1.-) in these pathways that may be further studied as new therapeutic targets for drug development against these parasites.
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Affiliation(s)
- Monete Rajão Gomes
- Laboratório de Biologia Computacional e Sistemas, Instituto Oswaldo Cruz/FIOCRUZ, 21045-900 Rio de Janeiro, RJ, Brazil
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77
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Genetic polymorphisms in DNA repair and oxidative stress pathways associated with malignant melanoma susceptibility. Eur J Cancer 2011; 47:2618-25. [PMID: 21641795 DOI: 10.1016/j.ejca.2011.05.011] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2011] [Revised: 04/28/2011] [Accepted: 05/06/2011] [Indexed: 11/23/2022]
Abstract
BACKGROUND Base excision repair (BER) and nucleotide excision repair (NER) pathways eliminate a wide variety of DNA damage, including UV photoproducts. The ability of each individual to repair DNA damage following different causes might explain at least in part the variability in cancer susceptibility. Moreover, inflammatory response to UV exposure may further contribute to skin carcinogenesis by oxidative stress mechanisms. Single nucleotide polymorphisms in genes encoding various DNA-repair enzymes and oxidative stress factors may be candidate low-penetrance variants with a role in susceptibility to different cancers, particularly in those with aetiologies linked to environmental exposure, such as malignant melanoma (MM). METHODS In this case-control study, 684 Spanish sporadic MM patients and 406 cancer-free control subjects were included and the role of 46 polymorphisms belonging to 16 BER and NER genes as well as 11 genes involved in oxidative stress processes were investigated. RESULTS One polymorphism was identified to be individually associated with MM in the Spanish population. The variant was found in the NOS1 oxidative stress gene (rs2682826; p-value=0.01). These results suggest a putative role of oxidative stress processes in the genetic predisposition to melanoma. CONCLUSION To the authors' knowledge, this is the largest DNA repair-related SNP study in melanoma risk conducted in the Spanish population up to now. Furthermore, it also represents a comprehensive genetic study of several oxidative stress polymorphisms tested in relation to MM susceptibility.
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78
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Fedorova OS, Kuznetsov NA, Koval VV, Knorre DG. Conformational dynamics and pre-steady-state kinetics of DNA glycosylases. BIOCHEMISTRY (MOSCOW) 2011; 75:1225-39. [PMID: 21166640 DOI: 10.1134/s0006297910100044] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Results of investigations of E. coli DNA glycosylases using pre-steady-state kinetics are considered. Special attention is given to the connection of conformational changes in the interacting biomolecules with kinetic mechanisms of the enzymatic processes.
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Affiliation(s)
- O S Fedorova
- Institute of Chemical Biology and Fundamental Medicine, Novosibirsk, Russia.
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79
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Calvert H, Azzariti A. The clinical development of inhibitors of poly(ADP-ribose) polymerase. Ann Oncol 2011; 22 Suppl 1:i53-9. [PMID: 21285153 DOI: 10.1093/annonc/mdq667] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
A number of inhibitors of DNA repair have been evaluated or are undergoing development as potential cancer treatments. Inhibitors of poly(ADP-ribose) polymerase (PARP) are of particular interest in treating hereditary breast cancers occurring in patients who are carriers of BRCA1 or BRCA2 mutations. In vitro PARP inhibitors are highly cytotoxic to cell lines carrying BRCA mutations while only minimally toxic to cell lines without these mutations. This is thought to be due to a phenomenon known as synthetic lethality where the accumulation of single-strand breaks consequent on PARP inhibition are converted to double-strand breaks on cell division. Cancer cells in BRCA carriers are uniquely unable to repair the consequent double-strand breaks that result during cell division. PARP inhibitors were initially developed as possible chemo-potentiating agents but have now been evaluated clinically in BRCA-related tumors, showing remarkable single-agent activity. The potential future development and use is reviewed.
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Affiliation(s)
- H Calvert
- Northern Institute for Cancer Research, Newcastle University, Newcastle upon Tyne, UK
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80
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Wongvijitsuk S, Navasumrit P, Vattanasit U, Parnlob V, Ruchirawat M. Low level occupational exposure to styrene: Its effects on DNA damage and DNA repair. Int J Hyg Environ Health 2011; 214:127-37. [PMID: 21030303 DOI: 10.1016/j.ijheh.2010.09.007] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2010] [Revised: 09/10/2010] [Accepted: 09/27/2010] [Indexed: 11/30/2022]
Affiliation(s)
- Sirilak Wongvijitsuk
- Laboratory of Environmental Toxicology, Chulabhorn Research Institute, Bangkok 10210, Thailand
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81
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Balakrishnan L, Bambara RA. Eukaryotic lagging strand DNA replication employs a multi-pathway mechanism that protects genome integrity. J Biol Chem 2010; 286:6865-70. [PMID: 21177245 DOI: 10.1074/jbc.r110.209502] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
In eukaryotic nuclear DNA replication, one strand of DNA is synthesized continuously, but the other is made as Okazaki fragments that are later joined. Discontinuous synthesis is inherently more complex, and fragmented intermediates create risks for disruptions of genome integrity. Genetic analyses and biochemical reconstitutions indicate that several parallel pathways evolved to ensure that the fragments are made and joined with integrity. An RNA primer is removed from each fragment before joining by a process involving polymerase-dependent displacement into a single-stranded flap. Evidence in vitro suggests that, with most fragments, short flaps are displaced and efficiently cleaved. Some flaps can become long, but these are also removed to allow joining. Rarely, a flap can form structure, necessitating displacement of the entire fragment. There is now evidence that post-translational protein modification regulates the flow through the pathways to favor protection of genomic information in regions of actively transcribed chromatin.
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Affiliation(s)
- Lata Balakrishnan
- Department of Biochemistry and Biophysics, University of Rochester School of Medicine and Dentistry, Rochester, New York 14642, USA
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82
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Hang B. Formation and repair of tobacco carcinogen-derived bulky DNA adducts. J Nucleic Acids 2010; 2010:709521. [PMID: 21234336 PMCID: PMC3017938 DOI: 10.4061/2010/709521] [Citation(s) in RCA: 67] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2010] [Revised: 07/16/2010] [Accepted: 09/17/2010] [Indexed: 01/08/2023] Open
Abstract
DNA adducts play a central role in chemical carcinogenesis. The analysis of formation and repair of smoking-related DNA adducts remains particularly challenging as both smokers and nonsmokers exposed to smoke are repetitively under attack from complex mixtures of carcinogens such as polycyclic aromatic hydrocarbons and N-nitrosamines. The bulky DNA adducts, which usually have complex structure, are particularly important because of their biological relevance. Several known cellular DNA repair pathways have been known to operate in human cells on specific types of bulky DNA adducts, for example, nucleotide excision repair, base excision repair, and direct reversal involving O6-alkylguanine DNA alkyltransferase or AlkB homologs. Understanding the mechanisms of adduct formation and repair processes is critical for the assessment of cancer risk resulting from exposure to cigarette smoke, and ultimately for developing strategies of cancer prevention. This paper highlights the recent progress made in the areas concerning formation and repair of bulky DNA adducts in the context of tobacco carcinogen-associated genotoxic and carcinogenic effects.
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Affiliation(s)
- Bo Hang
- Life Sciences Division, Department of Cancer and DNA Damage Responses, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
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83
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Chang DY, Shi G, Durand-Dubief M, Ekwall K, Lu AL. The role of MutY homolog (Myh1) in controlling the histone deacetylase Hst4 in the fission yeast Schizosaccharomyces pombe. J Mol Biol 2010; 405:653-65. [PMID: 21110984 DOI: 10.1016/j.jmb.2010.11.037] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2010] [Revised: 11/03/2010] [Accepted: 11/16/2010] [Indexed: 10/18/2022]
Abstract
The DNA glycosylase MutY homolog (Myh1) excises adenines misincorporated opposite guanines or 7,8-dihydro-8-oxo-guanines on DNA by base excision repair thereby preventing G:C to T:A mutations. Schizosaccharomyces pombe (Sp) Hst4 is an NAD(+)-dependent histone/protein deacetylase involved in gene silencing and maintaining genomic integrity. Hst4 regulates deacetylation of histone 3 Lys56 at the entry and exit points of the nucleosome core particle. Here, we demonstrate that the hst4 mutant is more sensitive to H(2)O(2) than wild-type cells. H(2)O(2) treatment results in an SpMyh1-dependent decrease in SpHst4 protein level and hyperacetylation of histone 3 Lys56. Furthermore, SpHst4 interacts with SpMyh1 and the cell cycle checkpoint Rad9-Rad1-Hus1 (9-1-1) complex. SpHst4, SpMyh1, and SpHus1 are physically bound to telomeres. Following oxidative stress, there is an increase in the telomeric association of SpMyh1. Conversely, the telomeric association of spHst4 is decreased. Deletion of SpMyh1 strongly abrogated telomeric association of SpHst4 and SpHus1. However, telomeric association of SpMyh1 is enhanced in hst4Δ cells in the presence of chronic DNA damage. These results suggest that SpMyh1 repair regulates the functions of SpHst4 and the 9-1-1 complex in maintaining genomic stability.
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Affiliation(s)
- Dau-Yin Chang
- Department of Biochemistry and Molecular Biology, School of Medicine, University of Maryland, 108 North Greene Street, Baltimore, MD 21201, USA
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84
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Tell G, Wilson DM. Targeting DNA repair proteins for cancer treatment. Cell Mol Life Sci 2010; 67:3569-72. [PMID: 20706767 PMCID: PMC2956794 DOI: 10.1007/s00018-010-0484-6] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2010] [Accepted: 07/28/2010] [Indexed: 01/23/2023]
Affiliation(s)
- Gianluca Tell
- Molecular Biology Section, Department of Biomedical Sciences and Technologies, School of Medicine, University of Udine, Piazzale Kolbe 4, 33100, Udine, Italy.
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85
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Wilson SH, Beard WA, Shock DD, Batra VK, Cavanaugh NA, Prasad R, Hou EW, Liu Y, Asagoshi K, Horton JK, Stefanick DF, Kedar PS, Carrozza MJ, Masaoka A, Heacock ML. Base excision repair and design of small molecule inhibitors of human DNA polymerase β. Cell Mol Life Sci 2010; 67:3633-47. [PMID: 20844920 PMCID: PMC3324036 DOI: 10.1007/s00018-010-0489-1] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2010] [Accepted: 07/28/2010] [Indexed: 10/19/2022]
Abstract
Base excision repair (BER) can protect a cell after endogenous or exogenous genotoxic stress, and a deficiency in BER can render a cell hypersensitive to stress-induced apoptotic and necrotic cell death, mutagenesis, and chromosomal rearrangements. However, understanding of the mammalian BER system is not yet complete as it is extraordinarily complex and has many back-up processes that complement a deficiency in any one step. Due of this lack of information, we are unable to make accurate predictions on therapeutic approaches targeting BER. A deeper understanding of BER will eventually allow us to conduct more meaningful clinical interventions. In this review, we will cover historical and recent information on mammalian BER and DNA polymerase β and discuss approaches toward development and use of small molecule inhibitors to manipulate BER. With apologies to others, we will emphasize results obtained in our laboratory and those of our collaborators.
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Affiliation(s)
- Samuel H Wilson
- Laboratory of Structural Biology, National Institute of Environmental Health Sciences, NIH, 111 T.W. Alexander Drive, Research Triangle Park, NC 27709, USA.
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86
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Rhee DB, Ghosh A, Lu J, Bohr VA, Liu Y. Factors that influence telomeric oxidative base damage and repair by DNA glycosylase OGG1. DNA Repair (Amst) 2010; 10:34-44. [PMID: 20951653 DOI: 10.1016/j.dnarep.2010.09.008] [Citation(s) in RCA: 97] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2010] [Revised: 09/08/2010] [Accepted: 09/17/2010] [Indexed: 12/15/2022]
Abstract
Telomeres are nucleoprotein complexes at the ends of linear chromosomes in eukaryotes, and are essential in preventing chromosome termini from being recognized as broken DNA ends. Telomere shortening has been linked to cellular senescence and human aging, with oxidative stress as a major contributing factor. 7,8-Dihydro-8-oxogaunine (8-oxodG) is one of the most abundant oxidative guanine lesions, and 8-oxoguanine DNA glycosylase (OGG1) is involved in its removal. In this study, we examined if telomeric DNA is particularly susceptible to oxidative base damage and if telomere-specific factors affect the incision of oxidized guanines by OGG1. We demonstrated that telomeric TTAGGG repeats were more prone to oxidative base damage and repaired less efficiently than non-telomeric TG repeats in vivo. We also showed that the 8-oxodG-incision activity of OGG1 is similar in telomeric and non-telomeric double-stranded substrates. In addition, telomere repeat binding factors TRF1 and TRF2 do not impair OGG1 incision activity. Yet, 8-oxodG in some telomere structures (e.g., fork-opening, 3'-overhang, and D-loop) were less effectively excised by OGG1, depending upon its position in these substrates. Collectively, our data indicate that the sequence context of telomere repeats and certain telomere configurations may contribute to telomere vulnerability to oxidative DNA damage processing.
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Affiliation(s)
- David B Rhee
- Laboratory of Molecular Gerontology, National Institute on Aging, National Institutes of Health, Baltimore, MD 21224, United States
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87
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Selenium: a double-edged sword for defense and offence in cancer. Arch Toxicol 2010; 84:919-38. [PMID: 20871980 DOI: 10.1007/s00204-010-0595-8] [Citation(s) in RCA: 233] [Impact Index Per Article: 16.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2010] [Accepted: 09/09/2010] [Indexed: 10/19/2022]
Abstract
Selenium (Se) is an essential dietary component for animals including humans and is regarded as a protective agent against cancer. Although the mode of anticancer action of Se is not fully understood yet, several mechanisms, such as antioxidant protection by selenoenzymes, specific inhibition of tumor cell growth by Se metabolites, modulation of cell cycle and apoptosis, and effect on DNA repair have all been proposed. Despite the unsupported results of the last SELECT trial, the cancer-preventing activity of Se was demonstrated in majority of the epidemiological studies. Moreover, recent studies suggest that Se has a potential to be used not only in cancer prevention but also in cancer treatment where in combination with other anticancer drugs or radiation, it can increase efficacy of cancer therapy. In combating cancer cells, Se acts as pro-oxidant rather than antioxidant, inducing apoptosis through the generation of oxidative stress. Thus, the inorganic Se compound, sodium selenite (SeL), due to its prooxidant character, represents a promising alternative for cancer therapy. However, this Se compound is highly toxic compared to organic Se forms. Thus, the unregulated intake of dietary or pharmacological Se supplements mainly in the form of SeL has a potential to expose the body tissues to the toxic levels of Se with subsequent negative consequences on DNA integrity. Hence, due to a broad interest to exploit the positive effects of Se on human health and cancer therapy, studies investigating the negative effects such as toxicity and DNA damage induction resulting from high Se intake are also highly required. Here, we review a role of Se in cancer prevention and cancer therapy, as well as mechanisms underlying Se-induced toxicity and DNA injury. Since Saccharomyces cerevisiae has proven a powerful tool for addressing some important questions regarding Se biology, a part of this review is devoted to this model system.
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88
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Zhang M, Qureshi AA, Guo Q, Han J. Genetic variation in DNA repair pathway genes and melanoma risk. DNA Repair (Amst) 2010; 10:111-6. [PMID: 20837404 DOI: 10.1016/j.dnarep.2010.08.005] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2010] [Revised: 07/22/2010] [Accepted: 08/16/2010] [Indexed: 12/15/2022]
Abstract
Reduced DNA repair capacity has been proposed as a predisposing factor for melanoma. We comprehensively evaluated 1463 genetic variants across 60 DNA repair-related pathway genes in relation to melanoma risk in a nested case-control study of 218 melanoma cases (20% on head and neck) and 218 matched controls within the Nurses' Health Study (NHS). We then genotyped the two variants with the smallest P value in two replication sets: 184 melanoma cases (28% on head and neck) and 184 matched controls in the Health Professionals Follow-Up Study (HPFS); and 183 melanoma cases (10% on head and neck) and 183 matched controls in the NHS. The SNP rs3219125 in the PARP1 gene was significantly associated with melanoma risk in the discovery set (odds ratio (OR) 3.14; 95% confidence interval (CI) 1.70-5.80) and in the HPFS replication set (OR, 1.92; 95% CI, 1.05-3.54) but not in the NHS replication set (OR, 1.07; 95% CI, 0.58-1.97). In the joint analysis, the OR was 1.89 (95% CI, 1.34-2.68) for this polymorphism, and this increased risk was more pronounced among patients with lesions in head/neck (OR, 3.19; 95% CI, 1.77-5.73 for head/neck, and OR, 1.54; 95% CI, 1.03-2.30 for other sites, P value for heterogeneity test=0.036). Our findings suggest the possible involvement of the PARP1 variant in melanoma development, especially for sites with high sun exposure. Further work on fine-mapping and on the functional characterization of this and linked SNPs in this region is required.
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Affiliation(s)
- Mingfeng Zhang
- Clinical Research Program, Department of Dermatology, Brigham and Women's Hospital, and Harvard Medical School, Boston, MA, USA
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89
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Hinz AK, Wang Y, Smerdon MJ. Base excision repair in a glucocorticoid response element: effect of glucocorticoid receptor binding. J Biol Chem 2010; 285:28683-90. [PMID: 20628060 PMCID: PMC2937895 DOI: 10.1074/jbc.m110.113530] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/05/2022] Open
Abstract
DNA repair takes place in the context of chromatin. Previous studies showed that histones impair base excision repair (BER) of modified bases at both the excision and synthesis steps. We examined BER of uracil in a glucocorticoid response element (GRE) complexed with the glucocorticoid receptor DNA binding domain (GR-DBD). Five substrates were designed, each containing a unique C→U substitution within the mouse mammary tumor virus promoter, one located within each GRE half-site and the others located outside the GRE. To examine distinct steps of BER, DNA cleavage by uracil-DNA glycosylase and Ape1 endonuclease was used to assess initiation, dCTP incorporation by DNA polymerase (pol) β was used to measure repair synthesis, and DNA ligase I was used to seal the nick. For uracil sites within the GRE, there was a reduced rate of uracil-DNA glycosylase/Ape1 activity following GR-DBD binding. Cleavage in the right half-site, with higher GR-DBD binding affinity, was reduced ∼5-fold, whereas cleavage in the left half-site was reduced ∼3.8-fold. Conversely, uracil-directed cleavage outside the GRE was unaffected by GR-DBD binding. Surprisingly, there was no reduction in the rate of pol β synthesis or DNA ligase activity on any of the fragments bound to GR-DBD. Indeed, we observed a small increase (∼1.5–2.2-fold) in the rate of pol β synthesis at uracil residues in both the GRE and one site six nucleotides downstream. These results highlight the potential for both positive and negative impacts of DNA-transcription factor binding on the rate of BER.
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Affiliation(s)
- Angela K Hinz
- Biochemistry and Biophysics, School of Molecular Biosciences, Washington State University, Pullman, Washington 99164-7520, USA
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90
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Monsees GM, Kraft P, Chanock SJ, Hunter DJ, Han J. Comprehensive screen of genetic variation in DNA repair pathway genes and postmenopausal breast cancer risk. Breast Cancer Res Treat 2010; 125:207-14. [PMID: 20496165 DOI: 10.1007/s10549-010-0947-3] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2010] [Accepted: 05/10/2010] [Indexed: 12/17/2022]
Abstract
Mistakes in DNA repair can result in sustained damage and genetic instability. We comprehensively evaluated common variants in DNA repair pathway genes for their association with postmenopausal breast cancer risk with and without respect to estrogen receptor (ER) and progesterone receptor (PR) subtypes. In this study of 1,145 prospectively ascertained breast cancer cases and 1,142 matched controls from the Nurses' Health Study Cancer Genetic Markers of Susceptibility project, we evaluated 1,314 common genetic variants in 68 candidate genes. These variants were chosen to represent five DNA repair pathways including base excision repair, nucleotide excision repair, double-strand break repair (homologous recombination and non-homologous end-joining), direct reversal repair, and mismatch repair, along with candidate DNA polymerases, Fanconi Anemia complementation groups, and other genes relevant to DNA damage recognition and response. Main effects, pathway effects, and pair-wise interactions were evaluated using Logistic Regression, and the Admixture Maximum Likelihood (AML) and Kernel Machine tests. Eight linked loci within XRCC4 were associated with susceptibility to PR- breast cancer (main effect p-values corrected for multiple testing at the within-gene level < 0.04). These loci drove the association between the non-homologous end-joining pathway, and PR- breast cancer (AML p-value for the full pathway = 0.002; p-value when the eight loci were removed = 0.86). A Kernel machine test of no linear or quadratic effects, or pairwise interaction, yielded a p-value of 0.85. Common variation alone in DNA repair genes plays at most a small role in determining postmenopausal breast cancer risk among women of European ancestry.
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Affiliation(s)
- Genevieve M Monsees
- Program in Molecular and Genetic Epidemiology, Department of Epidemiology, Harvard School of Public Health, 665 Huntington Ave., Boston, MA 02115, USA
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91
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High selenium status in individuals exposed to arsenic through coal-burning in Shaanxi (PR of China) modulates antioxidant enzymes, heme oxygenase-1 and DNA damage. Clin Chim Acta 2010; 411:1312-8. [PMID: 20478284 DOI: 10.1016/j.cca.2010.05.018] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2009] [Revised: 05/10/2010] [Accepted: 05/10/2010] [Indexed: 12/26/2022]
Abstract
BACKGROUND Although interactions of arsenite and selenite in mammalian organisms have been suggested by literature data, the antioxidant effects and biochemical mechanisms of dietary selenium on human populations exposed to inorganic arsenic are not fully understood. METHODS Total blood, urine and hair concentrations of arsenic and selenium were determined in all individuals by hydride generation atomic fluorescence spectrometry. The individuals with skin lesions were subsequently classified as "High As group" and "High Se/As group" and controls were classified as "High Se group" and "Control group" according to their blood selenium concentrations. RESULTS High selenium status was correlated with elevated activities of serum superoxide dismutase, glutathione peroxidase, catalase, and reduced levels of malondialdehyde, and increased RNA and protein expression of heme oxygenase-1 in peripheral blood mononuclear cells (PBMC) of individuals in the high arsenic group. Urinary 8-hydroxy-2'-deoxyguanosine levels were positively associated with blood arsenic, but inversely with blood and hair selenium among individuals with skin lesions, whereas mRNA are protein levels of 8-oxoganine DNA glycosylase 1 in PBMC increased in the "High Se/As group" compared to the "High As group". CONCLUSIONS Inorganic arsenic exposure is associated with oxidative stress, which may be prevented by high selenium status via its antioxidative activity and detoxification effect possibly through the formation of an arsenic and selenium containing metabolite, the seleno-bis(S-glutathionyl) arsinium ion.
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92
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Wang Z, Rhee DB, Lu J, Bohr CT, Zhou F, Vallabhaneni H, de Souza-Pinto NC, Liu Y. Characterization of oxidative guanine damage and repair in mammalian telomeres. PLoS Genet 2010; 6:e1000951. [PMID: 20485567 PMCID: PMC2869316 DOI: 10.1371/journal.pgen.1000951] [Citation(s) in RCA: 144] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2009] [Accepted: 04/13/2010] [Indexed: 12/15/2022] Open
Abstract
8-oxo-7,8-dihydroguanine (8-oxoG) and 2,6-diamino-4-hydroxy-5-formamidopyrimidine (FapyG) are among the most common oxidative DNA lesions and are substrates for 8-oxoguanine DNA glycosylase (OGG1)-initiated DNA base excision repair (BER). Mammalian telomeres consist of triple guanine repeats and are subject to oxidative guanine damage. Here, we investigated the impact of oxidative guanine damage and its repair by OGG1 on telomere integrity in mice. The mouse cells were analyzed for telomere integrity by telomere quantitative fluorescence in situ hybridization (telomere-FISH), by chromosome orientation-FISH (CO-FISH), and by indirect immunofluorescence in combination with telomere-FISH and for oxidative base lesions by Fpg-incision/Southern blot assay. In comparison to the wild type, telomere lengthening was observed in Ogg1 null (Ogg1(-/-)) mouse tissues and primary embryonic fibroblasts (MEFs) cultivated in hypoxia condition (3% oxygen), whereas telomere shortening was detected in Ogg1(-/-) mouse hematopoietic cells and primary MEFs cultivated in normoxia condition (20% oxygen) or in the presence of an oxidant. In addition, telomere length abnormalities were accompanied by altered telomere sister chromatid exchanges, increased telomere single- and double-strand breaks, and preferential telomere lagging- or G-strand losses in Ogg1(-/-) mouse cells. Oxidative guanine lesions were increased in telomeres in Ogg1(-/-) mice with aging and primary MEFs cultivated in 20% oxygen. Furthermore, oxidative guanine lesions persisted at high level in Ogg1(-/-) MEFs after acute exposure to hydrogen peroxide, while they rapidly returned to basal level in wild-type MEFs. These findings indicate that oxidative guanine damage can arise in telomeres where it affects length homeostasis, recombination, DNA replication, and DNA breakage repair. Our studies demonstrate that BER pathway is required in repairing oxidative guanine damage in telomeres and maintaining telomere integrity in mammals.
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Affiliation(s)
- Zhilong Wang
- Laboratory of Molecular Gerontology, National Institute on Aging, National Institutes of Health, Baltimore, Maryland, United States of America
| | - David B. Rhee
- Laboratory of Molecular Gerontology, National Institute on Aging, National Institutes of Health, Baltimore, Maryland, United States of America
- University of Tennessee–Oak Ridge National Laboratory Graduate School of Genome Science and Technology, Knoxville, Tennessee, United States of America
| | - Jian Lu
- Laboratory of Molecular Gerontology, National Institute on Aging, National Institutes of Health, Baltimore, Maryland, United States of America
| | - Christina T. Bohr
- Laboratory of Molecular Gerontology, National Institute on Aging, National Institutes of Health, Baltimore, Maryland, United States of America
| | - Fang Zhou
- Laboratory of Molecular Gerontology, National Institute on Aging, National Institutes of Health, Baltimore, Maryland, United States of America
| | - Haritha Vallabhaneni
- Laboratory of Molecular Gerontology, National Institute on Aging, National Institutes of Health, Baltimore, Maryland, United States of America
| | - Nadja C. de Souza-Pinto
- Laboratory of Molecular Gerontology, National Institute on Aging, National Institutes of Health, Baltimore, Maryland, United States of America
| | - Yie Liu
- Laboratory of Molecular Gerontology, National Institute on Aging, National Institutes of Health, Baltimore, Maryland, United States of America
- * E-mail:
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93
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Liu HM, Yang SZ, Sun FY. 1-Methyl-4-phenyl-pyridinium time-dependently alters expressions of oxoguanine glycosylase 1 and xeroderma pigmentosum group F protein in PC12 cells. Neurosci Bull 2010; 26:1-7. [PMID: 20101267 DOI: 10.1007/s12264-010-0922-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022] Open
Abstract
OBJECTIVE To determine if DNA excision repair enzymes oxoguanine glycosylase 1 (OGG1) and xeroderma pigmentosum group F protein (XPF) are involved in the pathogenesis of Parkinson's disease (PD) in a cell model. METHODS PC12 cells were treated with 1-Methyl-4-phenylpyridine ion (MPP(+)) for various periods of time to induce oxidative DNA damage. MTT assay was used to determine cell viability. Immunocytochemistry with antibody against 8-hydroxy-2'-deoxyguanosine (8-oxodG) was used to evaluate oxidative DNA damage. Immunoblotting was used to detect the protein levels of OGG1 and XPF. RESULTS MPP(+) treatment (1 mmol/L) for 18 h and 24 h reduced cell viability to 78.6% and 70.3% of the control, respectively, in a time-dependent way. MPP(+) increased the immunoreactivity of 8-oxodG in the cytoplasm at 3 h and in the nucleus at 24 h of treatment. With the treatment of MPP(+), the expression of OGG1 was significantly increased at 1 h, reaching a peak at 3 h, and then it was decreased at 24 h, as compared to that with vehicle treatment. The same effect was exerted on XPF level, except that the XPF level reached a peak at 18 h of MPP(+) treatment. Moreover, the maximally-increased protein level of OGG1 by MPP(+) was approximately 2-fold higher than that of XPF. CONCLUSION MPP(+) treatment could time-dependently induce increases in OGG1 and XPF expressions in PC12 cells. Also, this study indicates that the base and nucleotide excision repair pathways may be compensatory activated in the early stage of pathogenesis in the cells after MPP(+) treatment.
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Affiliation(s)
- Hong-Mei Liu
- Department of Neurobiology, Shanghai Medical College, Fudan University, Shanghai 200032, China
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94
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Gatzidou E, Michailidi C, Tseleni-Balafouta S, Theocharis S. An epitome of DNA repair related genes and mechanisms in thyroid carcinoma. Cancer Lett 2010; 290:139-47. [DOI: 10.1016/j.canlet.2009.08.007] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2009] [Revised: 07/31/2009] [Accepted: 08/02/2009] [Indexed: 01/18/2023]
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95
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Sedelnikova OA, Redon CE, Dickey JS, Nakamura AJ, Georgakilas AG, Bonner WM. Role of oxidatively induced DNA lesions in human pathogenesis. Mutat Res 2010; 704:152-9. [PMID: 20060490 PMCID: PMC3074954 DOI: 10.1016/j.mrrev.2009.12.005] [Citation(s) in RCA: 249] [Impact Index Per Article: 17.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2009] [Revised: 12/08/2009] [Accepted: 12/14/2009] [Indexed: 02/06/2023]
Abstract
Genome stability is essential for maintaining cellular and organismal homeostasis, but it is subject to many threats. One ubiquitous threat is from a class of compounds known as reactive oxygen species (ROS), which can indiscriminately react with many cellular biomolecules including proteins, lipids, and DNA to produce a variety of oxidative lesions. These DNA oxidation products are a direct risk to genome stability, and of particular importance are oxidative clustered DNA lesions (OCDLs), defined as two or more oxidative lesions present within 10 bp of each other. ROS can be produced by exposure of cells to exogenous environmental agents including ionizing radiation, light, chemicals, and metals. In addition, they are produced by cellular metabolism including mitochondrial ATP generation. However, ROS also serve a variety of critical cellular functions and optimal ROS levels are maintained by multiple cellular antioxidant defenses. Oxidative DNA lesions can be efficiently repaired by base excision repair or nucleotide excision repair. If ROS levels increase beyond the capacity of its antioxidant defenses, the cell's DNA repair capacity can become overwhelmed, leading to the accumulation of oxidative DNA damage products including OCDLs, which are more difficult to repair than individual isolated DNA damage products. Here we focus on the induction and repair of OCDLs and other oxidatively induced DNA lesions. If unrepaired, these lesions can lead to the formation of mutations, DNA DSBs, and chromosome abnormalities. We discuss the roles of these lesions in human pathologies including aging and cancer, and in bystander effects.
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Affiliation(s)
- Olga A Sedelnikova
- Laboratory of Molecular Pharmacology, Center for Cancer Research, National Cancer Institute, 9000 Rockville Pike, Bethesda, MD 20892, USA.
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96
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Sandhu SK, Yap TA, de Bono JS. Poly(ADP-ribose) polymerase inhibitors in cancer treatment: a clinical perspective. Eur J Cancer 2010; 46:9-20. [PMID: 19926276 DOI: 10.1016/j.ejca.2009.10.021] [Citation(s) in RCA: 92] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2009] [Revised: 10/09/2009] [Accepted: 10/15/2009] [Indexed: 12/22/2022]
Abstract
Inbuilt mechanisms of DNA surveillance and repair are integral to the maintenance of genomic stability. Poly(ADP-ribose) polymerase (PARP) is a nuclear enzyme that plays a critical role in DNA damage response processes. PARP inhibition has been successfully employed as a novel therapeutic strategy to enhance the cytotoxic effects of DNA-damaging agents. We have shown that PARP inhibition has substantial single agent antitumour activity with a wide therapeutic index in homologous DNA repair-defective tumours such as those arising in BRCA1 and BRCA2 mutation carriers. This is the first successful clinical application of a synthetic lethal approach to targeting cancer. Exploitation of defects in DNA repair pathways through targeted inhibition of salvage repair pathways is an exciting anticancer approach, with potentially broad clinical applicability. Several PARP inhibitors are now in clinical development. This review outlines the biological function and rationale of targeting PARP, details pre-clinical and clinical data and discusses the promises and challenges involved in developing these antitumour agents.
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Affiliation(s)
- Shahneen K Sandhu
- The Royal Marsden NHS Foundation Trust, Downs Road, Sutton, Surrey SM2 5PT, United Kingdom
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97
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García-Prieto F, Gómez-Raja J, Andaluz E, Calderone R, Larriba G. Role of the homologous recombination genes RAD51 and RAD59 in the resistance of Candida albicans to UV light, radiomimetic and anti-tumor compounds and oxidizing agents. Fungal Genet Biol 2010; 47:433-45. [PMID: 20206282 DOI: 10.1016/j.fgb.2010.02.007] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2009] [Revised: 02/22/2010] [Accepted: 02/23/2010] [Indexed: 12/28/2022]
Abstract
We have cloned and characterized the RAD51 and RAD59 orthologs of the pathogenic fungus Candida albicans. CaRad51 exhibited more than 50% identity with several other eukaryotes and the conserved the catalytic domain of a bacterial RecA. As compared to the parental strain, null strains of rad51 exhibited a filamentous morphology, had a decreased grow rate and exhibited a moderate sensitivity to UV light, oxidizing agents, and compounds that cause double-strand breaks (DSB), indicating a role in DNA repair. By comparison, the rad52 null had a higher percentage of filaments, a more severe growth defect and a greater sensitivity to DNA-damaging compounds. Null strains of rad59 showed a UV-sensitive phenotype but behaved similarly to the parental strain in the rest of the assays. As compared to Saccharomyces cerevisiae, C. albicans was much more resistant to bleomycin and the same was true for their respective homologous recombination (HR) mutants. These results indicate that, as described in S. cerevisiae, RAD52 plays a more prominent role than RAD51 in the repair of DSBs in C. albicans and suggest the existence of at least two Rad52-dependent HR pathways, one dependent and one independent of Rad51.
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Affiliation(s)
- Fátima García-Prieto
- Departamento de Microbiología, Facultad de Ciencias, Universidad de Extremadura, 06071 Badajoz, Spain
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98
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Koval VV, Kuznetsov NA, Ishchenko AA, Saparbaev MK, Fedorova OS. Real-time studies of conformational dynamics of the repair enzyme E. coli formamidopyrimidine-DNA glycosylase and its DNA complexes during catalytic cycle. Mutat Res 2010; 685:3-10. [PMID: 19751748 DOI: 10.1016/j.mrfmmm.2009.08.018] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2009] [Accepted: 08/20/2009] [Indexed: 05/28/2023]
Abstract
Fpg protein from Escherichia coli belongs to the class of DNA glycosylases/abasic site lyases excising several oxidatively damaged purines in the base excision repair pathway. In this review, we summarize the results of our studies of Fpg protein from E. coli, elucidating the intrinsic mechanism of recognition and excision of damaged bases in DNA.
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Affiliation(s)
- Vladimir V Koval
- Institute of Chemical Biology and Fundamental Medicine, Siberian Branch of the Russian Academy of Sciences, Lavrentyev Ave. 8, Novosibirsk 630090, Russia
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99
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Rotational dynamics of DNA on the nucleosome surface markedly impact accessibility to a DNA repair enzyme. Proc Natl Acad Sci U S A 2010; 107:4646-51. [PMID: 20176960 DOI: 10.1073/pnas.0914443107] [Citation(s) in RCA: 85] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Histones play a crucial role in the organization of DNA in the nucleus, but their presence can prevent interactions with DNA binding proteins responsible for repair of DNA damage. Uracil is an abundant mutagenic lesion recognized by uracil DNA glycosylase (UDG) in the first step of base excision repair (BER). In nucleosome core particles (NCPs), we find substantial differences in UDG-directed cleavage at uracils rotationally positioned toward (U-In) or away from (U-Out) the histone core, or midway between these orientations (U-Mid). Whereas U-Out NCPs show a cleavage rate just below that of naked DNA, U-In and U-Mid NCPs have markedly slower rates of cleavage. Crosslinking of U-In DNA to histones in NCPs yields a greater reduction in cleavage rate but, surprisingly, yields a higher rate of cleavage in U-Out NCPs compared with uncrosslinked NCPs. Moreover, the next enzyme in BER, APE1, stimulates the activity of human UDG in U-Out NCPs, suggesting these enzymes interact on the surface of histones in orientations accessible to UDG. These data indicate that the activity of UDG likely requires "trapping" transiently exposed states arising from the rotational dynamics of DNA on histones.
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100
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Mániková D, Vlasáková D, Loduhová J, Letavayová L, Vigašová D, Krascsenitsová E, Vlčková V, Brozmanová J, Chovanec M. Investigations on the role of base excision repair and non-homologous end-joining pathways in sodium selenite-induced toxicity and mutagenicity in Saccharomyces cerevisiae. Mutagenesis 2009; 25:155-62. [DOI: 10.1093/mutage/gep056] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
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