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Manils J, Marruecos L, Soler C. Exonucleases: Degrading DNA to Deal with Genome Damage, Cell Death, Inflammation and Cancer. Cells 2022; 11:2157. [PMID: 35883600 PMCID: PMC9316158 DOI: 10.3390/cells11142157] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2022] [Revised: 06/30/2022] [Accepted: 07/07/2022] [Indexed: 01/27/2023] Open
Abstract
Although DNA degradation might seem an unwanted event, it is essential in many cellular processes that are key to maintaining genomic stability and cell and organism homeostasis. The capacity to cut out nucleotides one at a time from the end of a DNA chain is present in enzymes called exonucleases. Exonuclease activity might come from enzymes with multiple other functions or specialized enzymes only dedicated to this function. Exonucleases are involved in central pathways of cell biology such as DNA replication, repair, and death, as well as tuning the immune response. Of note, malfunctioning of these enzymes is associated with immune disorders and cancer. In this review, we will dissect the impact of DNA degradation on the DNA damage response and its links with inflammation and cancer.
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Affiliation(s)
- Joan Manils
- Serra Húnter Programme, Immunology Unit, Department of Pathology and Experimental Therapy, School of Medicine, Universitat de Barcelona, Feixa Llarga s/n, 08907 L’Hospitalet de Llobregat, Spain;
- Immunity, Inflammation and Cancer Group, Oncobell Program, Institut d’Investigació Biomèdica de Bellvitge—IDIBELL, 08907 L’Hospitalet de Llobregat, Spain
| | - Laura Marruecos
- Breast Cancer Laboratory, Cancer Biology and Stem Cells Division, The Walter and Eliza Hall Institute of Medical Research, Parkville, VIC 3052, Australia;
| | - Concepció Soler
- Immunity, Inflammation and Cancer Group, Oncobell Program, Institut d’Investigació Biomèdica de Bellvitge—IDIBELL, 08907 L’Hospitalet de Llobregat, Spain
- Immunology Unit, Department of Pathology and Experimental Therapy, School of Medicine, Universitat de Barcelona, 08007 Barcelona, Spain
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2
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Kelm JM, Samarbakhsh A, Pillai A, VanderVere-Carozza PS, Aruri H, Pandey DS, Pawelczak KS, Turchi JJ, Gavande NS. Recent Advances in the Development of Non-PIKKs Targeting Small Molecule Inhibitors of DNA Double-Strand Break Repair. Front Oncol 2022; 12:850883. [PMID: 35463312 PMCID: PMC9020266 DOI: 10.3389/fonc.2022.850883] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2022] [Accepted: 02/22/2022] [Indexed: 01/09/2023] Open
Abstract
The vast majority of cancer patients receive DNA-damaging drugs or ionizing radiation (IR) during their course of treatment, yet the efficacy of these therapies is tempered by DNA repair and DNA damage response (DDR) pathways. Aberrations in DNA repair and the DDR are observed in many cancer subtypes and can promote de novo carcinogenesis, genomic instability, and ensuing resistance to current cancer therapy. Additionally, stalled or collapsed DNA replication forks present a unique challenge to the double-strand DNA break (DSB) repair system. Of the various inducible DNA lesions, DSBs are the most lethal and thus desirable in the setting of cancer treatment. In mammalian cells, DSBs are typically repaired by the error prone non-homologous end joining pathway (NHEJ) or the high-fidelity homology directed repair (HDR) pathway. Targeting DSB repair pathways using small molecular inhibitors offers a promising mechanism to synergize DNA-damaging drugs and IR while selective inhibition of the NHEJ pathway can induce synthetic lethality in HDR-deficient cancer subtypes. Selective inhibitors of the NHEJ pathway and alternative DSB-repair pathways may also see future use in precision genome editing to direct repair of resulting DSBs created by the HDR pathway. In this review, we highlight the recent advances in the development of inhibitors of the non-phosphatidylinositol 3-kinase-related kinases (non-PIKKs) members of the NHEJ, HDR and minor backup SSA and alt-NHEJ DSB-repair pathways. The inhibitors described within this review target the non-PIKKs mediators of DSB repair including Ku70/80, Artemis, DNA Ligase IV, XRCC4, MRN complex, RPA, RAD51, RAD52, ERCC1-XPF, helicases, and DNA polymerase θ. While the DDR PIKKs remain intensely pursued as therapeutic targets, small molecule inhibition of non-PIKKs represents an emerging opportunity in drug discovery that offers considerable potential to impact cancer treatment.
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Affiliation(s)
- Jeremy M. Kelm
- Department of Pharmaceutical Sciences, Eugene Applebaum College of Pharmacy and Health Sciences, Wayne State University, Detroit, MI, United States
| | - Amirreza Samarbakhsh
- Department of Pharmaceutical Sciences, Eugene Applebaum College of Pharmacy and Health Sciences, Wayne State University, Detroit, MI, United States
| | - Athira Pillai
- Department of Pharmaceutical Sciences, Eugene Applebaum College of Pharmacy and Health Sciences, Wayne State University, Detroit, MI, United States
| | | | - Hariprasad Aruri
- Department of Pharmaceutical Sciences, Eugene Applebaum College of Pharmacy and Health Sciences, Wayne State University, Detroit, MI, United States
| | - Deepti S. Pandey
- Department of Pharmaceutical Sciences, Eugene Applebaum College of Pharmacy and Health Sciences, Wayne State University, Detroit, MI, United States
| | | | - John J. Turchi
- Department of Medicine, Indiana University School of Medicine, Indianapolis, IN, United States,NERx Biosciences, Indianapolis, IN, United States,Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, IN, United States
| | - Navnath S. Gavande
- Department of Pharmaceutical Sciences, Eugene Applebaum College of Pharmacy and Health Sciences, Wayne State University, Detroit, MI, United States,Molecular Therapeutics Program, Barbara Ann Karmanos Cancer Institute, Wayne State University School of Medicine, Detroit, MI, United States,*Correspondence: Navnath S. Gavande, ; orcid.org/0000-0002-2413-0235
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3
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Sterrenberg JN, Folkerts ML, Rangel V, Lee SE, Pannunzio NR. Diversity upon diversity: linking DNA double-strand break repair to blood cancer health disparities. Trends Cancer 2022; 8:328-343. [PMID: 35094960 PMCID: PMC9248772 DOI: 10.1016/j.trecan.2022.01.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2021] [Revised: 12/20/2021] [Accepted: 01/03/2022] [Indexed: 10/19/2022]
Abstract
Chromosomal translocations arising from aberrant repair of multiple DNA double-strand breaks (DSBs) are a defining characteristic of many cancers. DSBs are an essential part of physiological processes in antibody-producing B cells. The B cell environment is poised to generate genome instability leading to translocations relevant to the pathology of blood cancers. These are a diverse set of cancers, but limited data from under-represented groups have pointed to health disparities associated with each. We focus on the DSBs that occur in developing B cells and propose the most likely mechanism behind the formation of translocations. We also highlight specific cancers in which these rearrangements occur and address the growing concern of health disparities associated with them.
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Hausmann M, Hildenbrand G, Pilarczyk G. Networks and Islands of Genome Nano-architecture and Their Potential Relevance for Radiation Biology : (A Hypothesis and Experimental Verification Hints). Results Probl Cell Differ 2022; 70:3-34. [PMID: 36348103 DOI: 10.1007/978-3-031-06573-6_1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
The cell nucleus is a complex biological system in which simultaneous reactions and functions take place to keep the cell as an individualized, specialized system running well. The cell nucleus contains chromatin packed in various degrees of density and separated in volumes of chromosome territories and subchromosomal domains. Between the chromatin, however, there is enough "free" space for floating RNA, proteins, enzymes, ATPs, ions, water molecules, etc. which are trafficking by super- and supra-diffusion to the interaction points where they are required. It seems that this trafficking works somehow automatically and drives the system perfectly. After exposure to ionizing radiation causing DNA damage from single base damage up to chromatin double-strand breaks, the whole system "cell nucleus" responds, and repair processes are starting to recover the fully functional and intact system. In molecular biology, many individual epigenetic pathways of DNA damage response or repair of single and double-strand breaks are described. How these responses are embedded into the response of the system as a whole is often out of the focus of consideration. In this article, we want to follow the hypothesis of chromatin architecture's impact on epigenetic pathways and vice versa. Based on the assumption that chromatin acts like an "aperiodic solid state within a limited volume," functionally determined networks and local topologies ("islands") can be defined that drive the appropriate repair process at a given damage site. Experimental results of investigations of the chromatin nano-architecture and DNA repair clusters obtained by means of single-molecule localization microscopy offer hints and perspectives that may contribute to verifying the hypothesis.
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Affiliation(s)
- Michael Hausmann
- Kirchhoff-Institute for Physics, Heidelberg University, Heidelberg, Germany.
| | - Georg Hildenbrand
- Kirchhoff-Institute for Physics, Heidelberg University, Heidelberg, Germany
| | - Götz Pilarczyk
- Kirchhoff-Institute for Physics, Heidelberg University, Heidelberg, Germany
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Usman S, Jamal A, Teh MT, Waseem A. Major Molecular Signaling Pathways in Oral Cancer Associated With Therapeutic Resistance. FRONTIERS IN ORAL HEALTH 2021; 1:603160. [PMID: 35047986 PMCID: PMC8757854 DOI: 10.3389/froh.2020.603160] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2020] [Accepted: 12/29/2020] [Indexed: 12/12/2022] Open
Abstract
Oral cancer is a sub-category of head and neck cancers that primarily initiates in the oral cavity. The primary treatment option for oral cancer remains surgery but it is associated with massive disfigurement, inability to carry out normal oral functions, psycho-social stress and exhaustive rehabilitation. Other treatment options such as chemotherapy and radiotherapy have their own limitations in terms of toxicity, intolerance and therapeutic resistance. Immunological treatments to enhance the body's ability to recognize cancer tissue as a foreign entity are also being used but they are new and underdeveloped. Although substantial progress has been made in the treatment of oral cancer, its complex heterogeneous nature still needs to be explored, to elucidate the molecular basis for developing resistance to therapeutic agents and how to overcome it, with the aim of improving the chances of patients' survival and their quality of life. This review provides an overview of up-to-date information on the complex role of the major molecules and associated signaling, epigenetic changes, DNA damage repair systems, cancer stem cells and micro RNAs in the development of therapeutic resistance and treatment failure in oral cancer. We have also summarized the current strategies being developed to overcome these therapeutic challenges. This review will help not only researchers but also oral oncologists in the management of the disease and in developing new therapeutic modalities.
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Affiliation(s)
| | | | | | - Ahmad Waseem
- Centre for Oral Immunobiology and Regenerative Medicine, Institute of Dentistry, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, London, United Kingdom
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Masumura K, Yatagai F, Ochiai M, Nakagama H, Nohmi T. Effects of the scid mutation on X-ray-induced deletions in the brain and spleen of gpt delta mice. Genes Environ 2020; 42:19. [PMID: 32489484 PMCID: PMC7247204 DOI: 10.1186/s41021-020-00158-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2020] [Accepted: 05/16/2020] [Indexed: 11/24/2022] Open
Abstract
Background DNA-dependent protein kinase (DNA-PK), consisting of a Ku heterodimer (Ku70/80) and a large catalytic subunit (DNA-PKcs), plays an important role in the repair of DNA double-strand breaks via non-homologous end-joining (NHEJ) in mammalian cells. Severe combined immunodeficient (scid) mice carry a mutation in the gene encoding DNA-PKcs and are sensitive to ionizing radiation. To examine the roles of DNA-PKcs in the generation of deletion mutations in vivo, we crossed scid mice with gpt delta transgenic mice for detecting mutations. Results The scid and wild-type (WT) gpt delta transgenic mice were irradiated with a single X-ray dose of 10 Gy, and Spi− mutant frequencies (MFs) were determined in the brain and spleen 2 days after irradiation. Irradiation with X-rays significantly enhanced Spi− MF in both organs in the scid and WT mice. The MFs in the brain of irradiated scid mice were significantly lower than those in WT mice, i.e., 2.9 ± 1.0 × 10− 6 versus 5.0 ± 1.1 × 10− 6 (P < 0.001), respectively. In the spleen, however, both mouse strains exhibited similar MFs, i.e., 4.1 ± 1.8 × 10− 6 versus 4.8 ± 1.4 × 10− 6. Unirradiated scid and WT mice did not exhibit significant differences in MFs in either organ. Conclusions DNA-PKcs is unessential for the induction of deletion mutations in the spleen, while it plays a role in this in the brain. Therefore, the contribution of DNA-PKcs to NHEJ may be organ-specific.
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Affiliation(s)
- Kenichi Masumura
- Division of Genetics and Mutagenesis, National Institute of Health Sciences, 3-25-26 Tonomachi, Kawasaki-ku, Kawasaki-shi, Kanagawa 210-9501 Japan
| | - Fumio Yatagai
- Center for Sustainable Resource Science, The Institute of Physical and Chemical Research, 2-1 Hirosawa, Wako-shi, Saitama, 351-0198 Japan
| | - Masako Ochiai
- Biochemistry Division, National Cancer Center Research Institute, 5-1-1 Tsukiji, Chuo-ku, Tokyo, 104-0045 Japan.,Present Address: Department of Animal Experimentation, National Cancer Center Research Institute, 5-1-1 Tsukiji, Chuo-ku, Tokyo, 104-0045 Japan
| | - Hitoshi Nakagama
- Biochemistry Division, National Cancer Center Research Institute, 5-1-1 Tsukiji, Chuo-ku, Tokyo, 104-0045 Japan.,Present Address: National Cancer Center, 5-1-1 Tsukiji, Chuo-ku, Tokyo, 104-0045 Japan
| | - Takehiko Nohmi
- Division of Genetics and Mutagenesis, National Institute of Health Sciences, 3-25-26 Tonomachi, Kawasaki-ku, Kawasaki-shi, Kanagawa 210-9501 Japan
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Liu H, Wang X, Huang A, Gao H, Sun Y, Jiang T, Shi L, Wu X, Dong Q, Sun X. Silencing Artemis Enhances Colorectal Cancer Cell Sensitivity to DNA-Damaging Agents. Oncol Res 2018; 27:29-38. [PMID: 29426373 PMCID: PMC7848410 DOI: 10.3727/096504018x15179694020751] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Artemis is a key protein of NHEJ (nonhomologous end joining), which is the major pathway for the repair of IR-induced DSBs in mammalian cells. However, the expression of Artemis in tumors and the influence of silencing Artemis on tumor sensitivity to radiation have not been investigated fully. In this study, we investigated how the expression levels of Artemis may affect the treatment outcome of radiotherapy and chemotherapy in colorectal cancer cells. First, we found that the expression of Artemis is strong in some human rectal cancer samples, being higher than in adjacent normal tissues using immunohistochemical staining. We then knocked down Artemis gene in a human colorectal cancer cell line (RKO) using lentivirus-mediated siRNAs. Compared to the control RKO cells, the Artemis knockdown cells showed significantly increased sensitivity to bleomycin, etoposide, camptothecin, and IR. Induced by DNA-damaging agents, delayed DNA repair kinetics was found by the γ-H2AX foci assay, and a significantly increased cell apoptosis occurred in the Artemis knockdown RKO cells through apoptosis detection methods and Western blot. We also found that the p53/p21 signaling pathway may be involved in the apoptosis process. Taken together, our study indicates that manipulating Artemis can enhance colorectal cancer cell sensitivity to DNA-damaging agents. Therefore, Artemis can serve as a therapeutic target in rectal cancer therapy.
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Affiliation(s)
- Hai Liu
- Department of Radiation Oncology, Sir Run Run Shaw Hospital, Sir Run Run Shaw Institute of Clinical Medicine of Zhejiang University, Hangzhou, P.R. China
| | - Xuanxuan Wang
- Department of Radiation Oncology, Sir Run Run Shaw Hospital, Sir Run Run Shaw Institute of Clinical Medicine of Zhejiang University, Hangzhou, P.R. China
| | - Aihua Huang
- Department of Pathology, Sir Run Run Shaw Hospital, School of Medicine, Zhejiang University, Hangzhou, P.R. China
| | - Huaping Gao
- Department of Pharmacy, Sir Run Run Shaw Hospital, School of Medicine, Zhejiang University, Hangzhou, P.R. China
| | - Yikan Sun
- Faculty of Medicine, University of New South Wales, Sydney, Australia
| | - Tingting Jiang
- Department of Radiation Oncology, Sir Run Run Shaw Hospital, Sir Run Run Shaw Institute of Clinical Medicine of Zhejiang University, Hangzhou, P.R. China
| | - Liming Shi
- Department of Radiation Oncology, Sir Run Run Shaw Hospital, Sir Run Run Shaw Institute of Clinical Medicine of Zhejiang University, Hangzhou, P.R. China
| | - Xianjie Wu
- Department of Dermatology, The Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, P.R. China
| | - Qinghua Dong
- Biomedical Research Center, Sir Run Run Shaw Hospital, School of Medicine, Zhejiang University, Hangzhou, P.R. China
| | - Xiaonan Sun
- Department of Radiation Oncology, Sir Run Run Shaw Hospital, Sir Run Run Shaw Institute of Clinical Medicine of Zhejiang University, Hangzhou, P.R. China
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Pannunzio NR, Watanabe G, Lieber MR. Nonhomologous DNA end-joining for repair of DNA double-strand breaks. J Biol Chem 2017; 293:10512-10523. [PMID: 29247009 DOI: 10.1074/jbc.tm117.000374] [Citation(s) in RCA: 326] [Impact Index Per Article: 46.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Nonhomologous DNA end-joining (NHEJ) is the predominant double-strand break (DSB) repair pathway throughout the cell cycle and accounts for nearly all DSB repair outside of the S and G2 phases. NHEJ relies on Ku to thread onto DNA termini and thereby improve the affinity of the NHEJ enzymatic components consisting of polymerases (Pol μ and Pol λ), a nuclease (the Artemis·DNA-PKcs complex), and a ligase (XLF·XRCC4·Lig4 complex). Each of the enzymatic components is distinctive for its versatility in acting on diverse incompatible DNA end configurations coupled with a flexibility in loading order, resulting in many possible junctional outcomes from one DSB. DNA ends can either be directly ligated or, if the ends are incompatible, processed until a ligatable configuration is achieved that is often stabilized by up to 4 bp of terminal microhomology. Processing of DNA ends results in nucleotide loss or addition, explaining why DSBs repaired by NHEJ are rarely restored to their original DNA sequence. Thus, NHEJ is a single pathway with multiple enzymes at its disposal to repair DSBs, resulting in a diversity of repair outcomes.
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Affiliation(s)
- Nicholas R Pannunzio
- From the Departments of Pathology, Biochemistry and Molecular Biology, and Molecular Microbiology and Immunology, Section of Molecular and Computational Biology, Department of Biological Sciences, Norris Comprehensive Cancer Center, University of Southern California Keck School of Medicine, Los Angeles, California 90033
| | - Go Watanabe
- From the Departments of Pathology, Biochemistry and Molecular Biology, and Molecular Microbiology and Immunology, Section of Molecular and Computational Biology, Department of Biological Sciences, Norris Comprehensive Cancer Center, University of Southern California Keck School of Medicine, Los Angeles, California 90033
| | - Michael R Lieber
- From the Departments of Pathology, Biochemistry and Molecular Biology, and Molecular Microbiology and Immunology, Section of Molecular and Computational Biology, Department of Biological Sciences, Norris Comprehensive Cancer Center, University of Southern California Keck School of Medicine, Los Angeles, California 90033
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Saito S, Kurosawa A, Adachi N. Mechanistic basis for increased human gene targeting by promoterless vectors-roles of homology arms and Rad54 paralogs. FEBS J 2017. [DOI: 10.1111/febs.14137] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Affiliation(s)
- Shinta Saito
- Graduate School of Nanobioscience; Yokohama City University; Japan
| | - Aya Kurosawa
- Graduate School of Nanobioscience; Yokohama City University; Japan
| | - Noritaka Adachi
- Graduate School of Nanobioscience; Yokohama City University; Japan
- Advanced Medical Research Center; Yokohama City University; Japan
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Non-homologous DNA end joining and alternative pathways to double-strand break repair. Nat Rev Mol Cell Biol 2017; 18:495-506. [PMID: 28512351 DOI: 10.1038/nrm.2017.48] [Citation(s) in RCA: 1006] [Impact Index Per Article: 143.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
DNA double-strand breaks (DSBs) are the most dangerous type of DNA damage because they can result in the loss of large chromosomal regions. In all mammalian cells, DSBs that occur throughout the cell cycle are repaired predominantly by the non-homologous DNA end joining (NHEJ) pathway. Defects in NHEJ result in sensitivity to ionizing radiation and the ablation of lymphocytes. The NHEJ pathway utilizes proteins that recognize, resect, polymerize and ligate the DNA ends in a flexible manner. This flexibility permits NHEJ to function on a wide range of DNA-end configurations, with the resulting repaired DNA junctions often containing mutations. In this Review, we discuss the most recent findings regarding the relative involvement of the different NHEJ proteins in the repair of various DNA-end configurations. We also discuss the shunting of DNA-end repair to the auxiliary pathways of alternative end joining (a-EJ) or single-strand annealing (SSA) and the relevance of these different pathways to human disease.
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Suzuki T, Grúz P, Honma M, Adachi N, Nohmi T. The role of DNA polymerase ζ in translesion synthesis across bulky DNA adducts and cross-links in human cells. Mutat Res 2016; 791-792:35-41. [PMID: 27591392 DOI: 10.1016/j.mrfmmm.2016.08.004] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2016] [Revised: 08/17/2016] [Accepted: 08/24/2016] [Indexed: 06/06/2023]
Abstract
Translesion DNA synthesis (TLS) is a cellular defense mechanism against genotoxins. Defects or mutations in specialized DNA polymerases (Pols) involved in TLS are believed to result in hypersensitivity to various genotoxic stresses. Here, DNA polymerase ζ (Pol ζ)-deficient (KO: knockout) and Pol ζ catalytically dead (CD) human cells were established and their sensitivity towards cytotoxic activities of various genotoxins was examined. The CD cells were engineered by altering the DNA sequence encoding two amino acids essential for the catalytic activity of Pol ζ, i.e., D2781 and D2783, to alanines. Both Pol ζ KO and CD cells displayed a prolonged cell cycle and higher incidence of micronuclei formation than the wild-type (WT) cells in the absence of exogenous genotoxic treatments, and the order of abnormality was CD>KO>WT cells. Both KO and CD cells exhibited higher sensitivity towards the killing effects of benzo[a]pyrene diol epoxide, mitomycin C, potassium bromate, N-methyl-N'-nitro-N-nitrosoguanidine, and ultraviolet C irradiation than WT cells, and there were no differences between the sensitivities of KO and CD cells. Interestingly, neither KO nor CD cells were sensitive to the cytotoxic effects of hydrogen peroxide. Since KO and CD cells displayed similar sensitivities to the genotoxins, we employed only KO cells to further examine their sensitivity to other genotoxic agents. KO cells were more sensitive to the cytotoxicity of 4-nitroquinoline N-oxide, styrene oxide, cisplatin, methyl methanesulfonate, and ethyl methanesulfonate than WT cells. However, the KO cells displayed sensitivity camptothecin, etoposide, bleomycin, hydroxyurea, crotonealdehyde, and methylglyoxal in a manner similar to the WT cells. Our results suggest that Pol ζ plays an important role in the protection of human cells by carrying out TLS across bulky DNA adducts and cross-links, but has no or limited role in the protection against strand-breaks in DNA.
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Affiliation(s)
- Tetsuya Suzuki
- Division of Genetics and Mutagenesis, National Institute of Health Sciences, 1-18-1 Kamiyoga, Setagaya-ku, Tokyo 158-8501, Japan.
| | - Petr Grúz
- Division of Genetics and Mutagenesis, National Institute of Health Sciences, 1-18-1 Kamiyoga, Setagaya-ku, Tokyo 158-8501, Japan
| | - Masamitsu Honma
- Division of Genetics and Mutagenesis, National Institute of Health Sciences, 1-18-1 Kamiyoga, Setagaya-ku, Tokyo 158-8501, Japan
| | - Noritaka Adachi
- Graduate School of Nanobioscience, Yokohama City University, 22-2 Seto, Kanazawa-ku, Yokohama 236-0027, Japan
| | - Takehiko Nohmi
- Division of Genetics and Mutagenesis, National Institute of Health Sciences, 1-18-1 Kamiyoga, Setagaya-ku, Tokyo 158-8501, Japan
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12
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Yan H, Tammaro M, Liao S. Collision of Trapped Topoisomerase 2 with Transcription and Replication: Generation and Repair of DNA Double-Strand Breaks with 5' Adducts. Genes (Basel) 2016; 7:genes7070032. [PMID: 27376333 PMCID: PMC4962002 DOI: 10.3390/genes7070032] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2016] [Revised: 06/17/2016] [Accepted: 06/24/2016] [Indexed: 11/23/2022] Open
Abstract
Topoisomerase 2 (Top2) is an essential enzyme responsible for manipulating DNA topology during replication, transcription, chromosome organization and chromosome segregation. It acts by nicking both strands of DNA and then passes another DNA molecule through the break. The 5′ end of each nick is covalently linked to the tyrosine in the active center of each of the two subunits of Top2 (Top2cc). In this configuration, the two sides of the nicked DNA are held together by the strong protein-protein interactions between the two subunits of Top2, allowing the nicks to be faithfully resealed in situ. Top2ccs are normally transient, but can be trapped by cancer drugs, such as etoposide, and subsequently processed into DSBs in cells. If not properly repaired, these DSBs would lead to genome instability and cell death. Here, I review the current understanding of the mechanisms by which DSBs are induced by etoposide, the unique features of such DSBs and how they are repaired. Implications for the improvement of cancer therapy will be discussed.
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Affiliation(s)
- Hong Yan
- Fox Chase Cancer Center, 333 Cottman Avenue, Philadelphia, PA 19111, USA.
| | - Margaret Tammaro
- Fox Chase Cancer Center, 333 Cottman Avenue, Philadelphia, PA 19111, USA.
| | - Shuren Liao
- Fox Chase Cancer Center, 333 Cottman Avenue, Philadelphia, PA 19111, USA.
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13
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End-processing nucleases and phosphodiesterases: An elite supporting cast for the non-homologous end joining pathway of DNA double-strand break repair. DNA Repair (Amst) 2016; 43:57-68. [PMID: 27262532 DOI: 10.1016/j.dnarep.2016.05.011] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2016] [Accepted: 05/05/2016] [Indexed: 11/20/2022]
Abstract
Nonhomologous end joining (NHEJ) is an error-prone DNA double-strand break repair pathway that is active throughout the cell cycle. A substantial fraction of NHEJ repair events show deletions and, less often, insertions in the repair joints, suggesting an end-processing step comprising the removal of mismatched or damaged nucleotides by nucleases and other phosphodiesterases, as well as subsequent strand extension by polymerases. A wide range of nucleases, including Artemis, Metnase, APLF, Mre11, CtIP, APE1, APE2 and WRN, are biochemically competent to carry out such double-strand break end processing, and have been implicated in NHEJ by at least circumstantial evidence. Several additional DNA end-specific phosphodiesterases, including TDP1, TDP2 and aprataxin are available to resolve various non-nucleotide moieties at DSB ends. This review summarizes the biochemical specificities of these enzymes and the evidence for their participation in the NHEJ pathway.
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14
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Chang HHY, Watanabe G, Lieber MR. Unifying the DNA end-processing roles of the artemis nuclease: Ku-dependent artemis resection at blunt DNA ends. J Biol Chem 2015; 290:24036-50. [PMID: 26276388 DOI: 10.1074/jbc.m115.680900] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2015] [Indexed: 11/06/2022] Open
Abstract
Artemis is a member of the metallo-β-lactamase protein family of nucleases. It is essential in vertebrates because, during V(D)J recombination, the RAG complex generates hairpins when it creates the double strand breaks at V, D, and J segments, and Artemis is required to open the hairpins so that they can be joined. Artemis is a diverse endo- and exonuclease, and creating a unified model for its wide range of nuclease properties has been challenging. Here we show that Artemis resects iteratively into blunt DNA ends with an efficiency that reflects the AT-richness of the DNA end. GC-rich ends are not cut by Artemis alone because of a requirement for DNA end breathing (and confirmed using fixed pseudo-Y structures). All DNA ends are cut when both the DNA-dependent protein kinase catalytic subunit and Ku accompany Artemis but not when Ku is omitted. These are the first biochemical data demonstrating a Ku dependence of Artemis action on DNA ends of any configuration. The action of Artemis at blunt DNA ends is slower than at overhangs, consistent with a requirement for a slow DNA end breathing step preceding the cut. The AT sequence dependence, the order of strand cutting, the length of the cuts, and the Ku-dependence of Artemis action at blunt ends can be reconciled with the other nucleolytic properties of both Artemis and Artemis·DNA-PKcs in a model incorporating DNA end breathing of blunt ends to form transient single to double strand boundaries that have structural similarities to hairpins and fixed 5' and 3' overhangs.
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Affiliation(s)
- Howard H Y Chang
- From the Departments of Pathology, Biochemistry and Molecular Biology, Biological Sciences, and Molecular Microbiology and Immunology, University of Southern California Keck School of Medicine, Norris Comprehensive Cancer Center, Los Angeles, California
| | - Go Watanabe
- From the Departments of Pathology, Biochemistry and Molecular Biology, Biological Sciences, and Molecular Microbiology and Immunology, University of Southern California Keck School of Medicine, Norris Comprehensive Cancer Center, Los Angeles, California
| | - Michael R Lieber
- From the Departments of Pathology, Biochemistry and Molecular Biology, Biological Sciences, and Molecular Microbiology and Immunology, University of Southern California Keck School of Medicine, Norris Comprehensive Cancer Center, Los Angeles, California
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15
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Role for Artemis nuclease in the repair of radiation-induced DNA double strand breaks by alternative end joining. DNA Repair (Amst) 2015; 31:29-40. [DOI: 10.1016/j.dnarep.2015.04.004] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2014] [Revised: 04/14/2015] [Accepted: 04/15/2015] [Indexed: 11/24/2022]
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16
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Wu J, Starr S. Low-fidelity compensatory backup alternative DNA repair pathways may unify current carcinogenesis theories. Future Oncol 2015; 10:1239-53. [PMID: 24947263 DOI: 10.2217/fon.13.272] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
The somatic mutation carcinogenesis theory has dominated for decades. The alternative theory, tissue organization field theory, argues that the development of cancer is determined by the surrounding microenvironment. However, neither theory can explain all features of cancer. As cancers share the features of uncontrolled proliferation and genomic instability, they are likely to have the same pathogenesis. It has been found that various DNA repair pathways within a cell crosstalk with one another, forming a DNA repair network. When one DNA repair pathways is defective, the others may work as compensatory backups. The latter pathways are explored for synthetic lethal anticancer therapy. In this article, we extend the concept of compensatory alternative DNA repair to unify the theories. We propose that the microenvironmental stress can activate low-fidelity compensatory alternative DNA repair, causing mutations. If the mutation occurs to a DNA repair gene, this secondarily mutated gene can lead to even more mutated genes, including those related to other DNA repair pathways, eventually destabilizing the genome. Therefore, the low-fidelity compensatory alternative DNA repair may mediate microenvironment-dependent carcinogenesis. The proposal seems consistent with the view of evolution: the environmental stress causes mutations to adapt to the changing environment.
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Affiliation(s)
- Jiaxi Wu
- Central Laboratories, Xuhui Central Hospital, Shanghai Clinical Research Center, Chinese Academy of Sciences, 966 Middle Huaihai Road, Shanghai 200031, China
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17
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Calugaru V, Nauraye C, Cordelières FP, Biard D, De Marzi L, Hall J, Favaudon V, Mégnin-Chanet F. Involvement of the Artemis protein in the relative biological efficiency observed with the 76-MeV proton beam used at the Institut Curie Proton Therapy Center in Orsay. Int J Radiat Oncol Biol Phys 2014; 90:36-43. [PMID: 25195988 DOI: 10.1016/j.ijrobp.2014.05.018] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2014] [Revised: 03/25/2014] [Accepted: 05/14/2014] [Indexed: 12/27/2022]
Abstract
PURPOSE Previously we showed that the relative biological efficiency for induced cell killing by the 76-MeV beam used at the Institut Curie Proton Therapy Center in Orsay increased with depth throughout the spread-out Bragg peak (SOBP). To investigate the repair pathways underlying this increase, we used an isogenic human cell model in which individual DNA repair proteins have been depleted, and techniques dedicated to precise measurements of radiation-induced DNA single-strand breaks (SSBs) and double-strand breaks (DSBs). METHODS AND MATERIALS The 3-Gy surviving fractions of HeLa cells individually depleted of Ogg1, XRCC1, and PARP1 (the base excision repair/SSB repair pathway) or of ATM, DNA-PKcs, XRCC4, and Artemis (nonhomologous end-joining pathway) were determined at the 3 positions previously defined in the SOBP. Quantification of incident SSBs and DSBs by the alkaline elution technique and 3-dimensional (3D) immunofluorescence of γ-H2AX foci, respectively, was performed in SQ20 B cells. RESULTS We showed that the amount of SSBs and DSBs depends directly on the particle fluence and that the increase in relative biological efficiency observed in the distal part of the SOBP is due to a subset of lesions generated under these conditions, leading to cell death via a pathway in which the Artemis protein plays a central role. CONCLUSIONS Because therapies like proton or carbon beams are now being used to treat cancer, it is even more important to dissect the mechanisms implicated in the repair of the lesions generated by these particles. Additionally, alteration of the expression or activity of the Artemis protein could be a novel therapeutic tool before high linear energy transfer irradiation treatment.
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Affiliation(s)
- Valentin Calugaru
- Institut Curie Centre de Protonthérapie d'Orsay, Centre Universitaire, Orsay, France; Institut Curie, Centre Universitaire, Orsay, France; INSERM U612, Centre Universitaire, Orsay, France
| | - Catherine Nauraye
- Institut Curie Centre de Protonthérapie d'Orsay, Centre Universitaire, Orsay, France
| | | | - Denis Biard
- Centre d'Etude Atomique, Direction des Sciences du Vivant, Institut des Maladies Emergentes et des Thérapies Innovantes, Service d'Etude des Prions et des Infections Atypiques, Fontenay-aux-Roses, France
| | - Ludovic De Marzi
- Institut Curie Centre de Protonthérapie d'Orsay, Centre Universitaire, Orsay, France
| | - Janet Hall
- Institut Curie, Centre Universitaire, Orsay, France; INSERM U612, Centre Universitaire, Orsay, France
| | - Vincent Favaudon
- Institut Curie, Centre Universitaire, Orsay, France; INSERM U612, Centre Universitaire, Orsay, France
| | - Frédérique Mégnin-Chanet
- Institut Curie, Centre Universitaire, Orsay, France; INSERM U612, Centre Universitaire, Orsay, France.
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18
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Non-homologous end joining often uses microhomology: implications for alternative end joining. DNA Repair (Amst) 2014; 17:74-80. [PMID: 24613510 DOI: 10.1016/j.dnarep.2014.02.006] [Citation(s) in RCA: 87] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2013] [Revised: 01/27/2014] [Accepted: 02/10/2014] [Indexed: 11/20/2022]
Abstract
Artemis and PALF (also called APLF) appear to be among the primary nucleases involved in non-homologous end joining (NHEJ) and responsible for most nucleolytic end processing in NHEJ. About 60% of NHEJ events show an alignment of the DNA ends that use 1 or 2bp of microhomology (MH) between the two DNA termini. Thus, MH is a common feature of NHEJ. For most naturally occurring human chromosomal deletions (e.g., after oxidative damage or radiation) and translocations, such as those seen in human neoplasms and as well as inherited chromosomal structural variations, MH usage occurs at a frequency that is typical of NHEJ, and does not suggest major involvement of alternative pathways that require more extensive MH. Though we mainly focus on human NHEJ at double-strand breaks, comparison on these points to other eukaryotes, primarily S. cerevisiae, is informative.
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19
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Álvarez-Quilón A, Serrano-Benítez A, Ariel Lieberman J, Quintero C, Sánchez-Gutiérrez D, Escudero LM, Cortés-Ledesma F. ATM specifically mediates repair of double-strand breaks with blocked DNA ends. Nat Commun 2014; 5:3347. [PMID: 24572510 PMCID: PMC3948078 DOI: 10.1038/ncomms4347] [Citation(s) in RCA: 77] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2013] [Accepted: 01/30/2014] [Indexed: 12/23/2022] Open
Abstract
Ataxia telangiectasia is caused by mutations in ATM and represents a paradigm for cancer predisposition and neurodegenerative syndromes linked to deficiencies in the DNA-damage response. The role of ATM as a key regulator of signalling following DNA double-strand breaks (DSBs) has been dissected in extraordinary detail, but the impact of this process on DSB repair still remains controversial. Here we develop novel genetic and molecular tools to modify the structure of DSB ends and demonstrate that ATM is indeed required for efficient and accurate DSB repair, preventing cell death and genome instability, but exclusively when the ends are irreversibly blocked. We therefore identify the nature of ATM involvement in DSB repair, presenting blocked DNA ends as a possible pathogenic trigger of ataxia telangiectasia and related disorders.
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Affiliation(s)
- Alejandro Álvarez-Quilón
- Centro Andaluz de Biología Molecular y Medicina Regenerativa (CABIMER), CSIC-Universidad de Sevilla (Departamento de Genética), Sevilla 41092, Spain
| | - Almudena Serrano-Benítez
- Centro Andaluz de Biología Molecular y Medicina Regenerativa (CABIMER), CSIC-Universidad de Sevilla (Departamento de Genética), Sevilla 41092, Spain
| | - Jenna Ariel Lieberman
- Centro Andaluz de Biología Molecular y Medicina Regenerativa (CABIMER), CSIC-Universidad de Sevilla (Departamento de Genética), Sevilla 41092, Spain
| | - Cristina Quintero
- Centro Andaluz de Biología Molecular y Medicina Regenerativa (CABIMER), CSIC-Universidad de Sevilla (Departamento de Genética), Sevilla 41092, Spain
| | - Daniel Sánchez-Gutiérrez
- Instituto Biomedicina Sevilla (IBiS), Hospital Virgen del Rocío-CSIC-Universidad de Sevilla (Departamento de Biología Celular), Sevilla 41013, Spain
| | - Luis M. Escudero
- Instituto Biomedicina Sevilla (IBiS), Hospital Virgen del Rocío-CSIC-Universidad de Sevilla (Departamento de Biología Celular), Sevilla 41013, Spain
| | - Felipe Cortés-Ledesma
- Centro Andaluz de Biología Molecular y Medicina Regenerativa (CABIMER), CSIC-Universidad de Sevilla (Departamento de Genética), Sevilla 41092, Spain
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20
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Li S, Chang HH, Niewolik D, Hedrick MP, Pinkerton AB, Hassig CA, Schwarz K, Lieber MR. Evidence that the DNA endonuclease ARTEMIS also has intrinsic 5'-exonuclease activity. J Biol Chem 2014; 289:7825-34. [PMID: 24500713 DOI: 10.1074/jbc.m113.544874] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
ARTEMIS is a member of the metallo-β-lactamase protein family. ARTEMIS has endonuclease activity at DNA hairpins and at 5'- and 3'-DNA overhangs of duplex DNA, and this endonucleolytic activity is dependent upon DNA-PKcs. There has been uncertainty about whether ARTEMIS also has 5'-exonuclease activity on single-stranded DNA and 5'-overhangs, because this 5'-exonuclease is not dependent upon DNA-PKcs. Here, we show that the 5'-exonuclease and the endonuclease activities co-purify. Second, we show that a point mutant of ARTEMIS at a putative active site residue (H115A) markedly reduces both the endonuclease activity and the 5'-exonuclease activity. Third, divalent cation effects on the 5'-exonuclease and the endonuclease parallel one another. Fourth, both the endonuclease activity and 5'-exonuclease activity of ARTEMIS can be blocked in parallel by small molecule inhibitors, which do not block unrelated nucleases. We conclude that the 5'-exonuclease is intrinsic to ARTEMIS, making it relevant to the role of ARTEMIS in nonhomologous DNA end joining.
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Affiliation(s)
- Sicong Li
- From the Departments of Pathology, Biochemistry and Molecular Biology, Biological Sciences, and Molecular Microbiology and Immunology, University of Southern California Keck School of Medicine, Norris Comprehensive Cancer Center, Los Angeles, California 90089-9176
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21
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Kurosawa A, Saito S, So S, Hashimoto M, Iwabuchi K, Watabe H, Adachi N. DNA ligase IV and artemis act cooperatively to suppress homologous recombination in human cells: implications for DNA double-strand break repair. PLoS One 2013; 8:e72253. [PMID: 23967291 PMCID: PMC3743779 DOI: 10.1371/journal.pone.0072253] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2013] [Accepted: 07/08/2013] [Indexed: 11/24/2022] Open
Abstract
Nonhomologous end-joining (NHEJ) and homologous recombination (HR) are two major pathways for repairing DNA double-strand breaks (DSBs); however, their respective roles in human somatic cells remain to be elucidated. Here we show using a series of human gene-knockout cell lines that NHEJ repairs nearly all of the topoisomerase II- and low-dose radiation-induced DNA damage, while it negatively affects survival of cells harbouring replication-associated DSBs. Intriguingly, we find that loss of DNA ligase IV, a critical NHEJ ligase, and Artemis, an NHEJ factor with endonuclease activity, independently contribute to increased resistance to replication-associated DSBs. We also show that loss of Artemis alleviates hypersensitivity of DNA ligase IV-null cells to low-dose radiation- and topoisomerase II-induced DSBs. Finally, we demonstrate that Artemis-null human cells display increased gene-targeting efficiencies, particularly in the absence of DNA ligase IV. Collectively, these data suggest that DNA ligase IV and Artemis act cooperatively to promote NHEJ, thereby suppressing HR. Our results point to the possibility that HR can only operate on accidental DSBs when NHEJ is missing or abortive, and Artemis may be involved in pathway switching from incomplete NHEJ to HR.
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Affiliation(s)
- Aya Kurosawa
- Graduate School of Nanobioscience, Yokohama City University, Yokohama, Japan
| | - Shinta Saito
- Graduate School of Nanobioscience, Yokohama City University, Yokohama, Japan
| | - Sairei So
- Graduate School of Nanobioscience, Yokohama City University, Yokohama, Japan
| | | | - Kuniyoshi Iwabuchi
- Department of Biochemistry, Kanazawa Medical University, Ishikawa, Japan
| | - Haruka Watabe
- Graduate School of Nanobioscience, Yokohama City University, Yokohama, Japan
| | - Noritaka Adachi
- Graduate School of Nanobioscience, Yokohama City University, Yokohama, Japan
- Advanced Medical Research Center, Yokohama City University, Yokohama, Japan
- * E-mail:
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22
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Suzuki T, Ukai A, Honma M, Adachi N, Nohmi T. Restoration of mismatch repair functions in human cell line Nalm-6, which has high efficiency for gene targeting. PLoS One 2013; 8:e61189. [PMID: 23596518 PMCID: PMC3626652 DOI: 10.1371/journal.pone.0061189] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2012] [Accepted: 03/07/2013] [Indexed: 12/23/2022] Open
Abstract
Gene targeting is a powerful approach in reverse genetics. The approach has been hampered in most of human cell lines, however, by the poor targeting efficiency. Nalm-6, a human pre-B acute lymphoblastic leukemia cell line, exhibits exceptionally high gene targeting efficiency and is used in DNA repair and the related research fields. Nonetheless, usage of the cell line is still limited partly because it lacks expression of MSH2, a component of mismatch repair complex, which leads to increased genome instability. Here, we report successful restoration of MSH2 expression in Nalm-6 cells and demonstrate that the recovery does not affect the high targeting efficiency. We recovered the expression by introduction of cDNA sequences corresponding to exons 9 to 16 at downstream of exon 8 of the MSH2 gene. Endogenous exons 9 to 16 were deleted in the cell line. The MSH2 expression substantially reduced spontaneous HPRT mutation frequency. Moreover, gene targeting efficiency in the MSH2-expressing cells was similar to that in the MSH2-lacking cells. In fact, we generated heterozygously REV3L knockout and the catalytically dead mutants in the MSH2-proficient Nalm-6 cells with efficiency of 20–30%. The established cell line, Nalm-6-MSH+, is useful for reverse genetics in human cells.
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Affiliation(s)
- Tetsuya Suzuki
- Division of Genetics and Mutagenesis, National Institute of Health Sciences, Setagaya-ku, Tokyo, Japan
| | - Akiko Ukai
- Division of Genetics and Mutagenesis, National Institute of Health Sciences, Setagaya-ku, Tokyo, Japan
| | - Masamitsu Honma
- Division of Genetics and Mutagenesis, National Institute of Health Sciences, Setagaya-ku, Tokyo, Japan
| | - Noritaka Adachi
- Graduate School of Nanobioscience, Yokohama City University, Yokohama, Kanagawa, Japan
| | - Takehiko Nohmi
- Division of Genetics and Mutagenesis, National Institute of Health Sciences, Setagaya-ku, Tokyo, Japan
- Biological Safety Research Center, National Institute of Health Sciences, Setagaya-ku, Tokyo, Japan
- * E-mail:
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23
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Gómez-Herreros F, Romero-Granados R, Zeng Z, Álvarez-Quilón A, Quintero C, Ju L, Umans L, Vermeire L, Huylebroeck D, Caldecott KW, Cortés-Ledesma F. TDP2-dependent non-homologous end-joining protects against topoisomerase II-induced DNA breaks and genome instability in cells and in vivo. PLoS Genet 2013; 9:e1003226. [PMID: 23505375 PMCID: PMC3592926 DOI: 10.1371/journal.pgen.1003226] [Citation(s) in RCA: 125] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2012] [Accepted: 11/21/2012] [Indexed: 01/03/2023] Open
Abstract
Anticancer topoisomerase "poisons" exploit the break-and-rejoining mechanism of topoisomerase II (TOP2) to generate TOP2-linked DNA double-strand breaks (DSBs). This characteristic underlies the clinical efficacy of TOP2 poisons, but is also implicated in chromosomal translocations and genome instability associated with secondary, treatment-related, haematological malignancy. Despite this relevance for cancer therapy, the mechanistic aspects governing repair of TOP2-induced DSBs and the physiological consequences that absent or aberrant repair can have are still poorly understood. To address these deficits, we employed cells and mice lacking tyrosyl DNA phosphodiesterase 2 (TDP2), an enzyme that hydrolyses 5'-phosphotyrosyl bonds at TOP2-associated DSBs, and studied their response to TOP2 poisons. Our results demonstrate that TDP2 functions in non-homologous end-joining (NHEJ) and liberates DSB termini that are competent for ligation. Moreover, we show that the absence of TDP2 in cells impairs not only the capacity to repair TOP2-induced DSBs but also the accuracy of the process, thus compromising genome integrity. Most importantly, we find this TDP2-dependent NHEJ mechanism to be physiologically relevant, as Tdp2-deleted mice are sensitive to TOP2-induced damage, displaying marked lymphoid toxicity, severe intestinal damage, and increased genome instability in the bone marrow. Collectively, our data reveal TDP2-mediated error-free NHEJ as an efficient and accurate mechanism to repair TOP2-induced DSBs. Given the widespread use of TOP2 poisons in cancer chemotherapy, this raises the possibility of TDP2 being an important etiological factor in the response of tumours to this type of agent and in the development of treatment-related malignancy.
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Affiliation(s)
| | - Rocío Romero-Granados
- Centro Andaluz de Biología Molecular y Medicina Regenerativa (CABIMER), CSIC–Universidad de Sevilla (Departamento de Genética), Sevilla, Spain
| | - Zhihong Zeng
- Genome Damage and Stability Centre, University of Sussex, Falmer, United Kingdom
| | - Alejandro Álvarez-Quilón
- Centro Andaluz de Biología Molecular y Medicina Regenerativa (CABIMER), CSIC–Universidad de Sevilla (Departamento de Genética), Sevilla, Spain
| | - Cristina Quintero
- Centro Andaluz de Biología Molecular y Medicina Regenerativa (CABIMER), CSIC–Universidad de Sevilla (Departamento de Genética), Sevilla, Spain
| | - Limei Ju
- Genome Damage and Stability Centre, University of Sussex, Falmer, United Kingdom
| | - Lieve Umans
- Laboratory of Molecular Biology (Celgen), Department of Development and Regeneration, University of Leuven, Leuven, Belgium
| | - Liesbeth Vermeire
- Laboratory of Molecular Biology (Celgen), Department of Development and Regeneration, University of Leuven, Leuven, Belgium
| | - Danny Huylebroeck
- Laboratory of Molecular Biology (Celgen), Department of Development and Regeneration, University of Leuven, Leuven, Belgium
| | - Keith W. Caldecott
- Genome Damage and Stability Centre, University of Sussex, Falmer, United Kingdom
- * E-mail: (KWC); (FC-L)
| | - Felipe Cortés-Ledesma
- Centro Andaluz de Biología Molecular y Medicina Regenerativa (CABIMER), CSIC–Universidad de Sevilla (Departamento de Genética), Sevilla, Spain
- * E-mail: (KWC); (FC-L)
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24
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Both CpG methylation and activation-induced deaminase are required for the fragility of the human bcl-2 major breakpoint region: implications for the timing of the breaks in the t(14;18) translocation. Mol Cell Biol 2012; 33:947-57. [PMID: 23263985 DOI: 10.1128/mcb.01436-12] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
The t(14;18) chromosomal translocation typically involves breakage at the bcl-2 major breakpoint region (MBR) to cause human follicular lymphoma. A theory to explain the striking propensity of the MBR breaks at three CpG clusters within the 175-bp MBR region invoked activation-induced deaminase (AID). In a test of that theory, we used here minichromosomal substrates in human pre-B cell lines. Consistent with the essential elements of the theory, we found that the MBR breakage process is indeed highly dependent on DNA methylation at the CpG sites and highly dependent on the AID enzyme to create lesions at peak locations within the MBR. Interestingly, breakage of the phosphodiester bonds at the AID-initiated MBR lesions is RAG dependent, but, unexpectedly, most are also dependent on Artemis. We found that Artemis is capable of nicking small heteroduplex structures and is even able to nick single-base mismatches. This raises the possibility that activated Artemis, derived from the unjoined D to J(H) DNA ends at the IgH locus on chromosome 14, nicks AID-generated TG mismatches at methyl CpG sites, and this would explain why the breaks at the chromosome 18 MBR occur within the same time window as those on chromosome 14.
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25
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Povirk LF. Processing of damaged DNA ends for double-strand break repair in mammalian cells. ISRN MOLECULAR BIOLOGY 2012; 2012. [PMID: 24236237 PMCID: PMC3825254 DOI: 10.5402/2012/345805] [Citation(s) in RCA: 60] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Most DNA double-strand breaks (DSBs)formed in a natural environment have chemical modifications at or near the ends that preclude direct religation and require removal or other processing so that rejoining can proceed. Free radical-mediated DSBs typically bear unligatable 3'-phosphate or 3'-phosphoglycolate termini and often have oxidized bases and/or abasic sites near the break. Topoisomerase-mediated DSBs are blocked by covalently bound peptide fragments of the topoisomerase. Enzymes capable of resolving damaged ends include polynucleotide kinase/phosphatase, which restores missing 5'-phosphates and removes 3'-phosphates; tyrosyl-DNA phosphodiesterases I and II (TDP1 and TDP2), which remove peptide fragments of topoisomerases I and II, respectively, and the Artemis and Metnase endonucleases, which can trim damaged overhangs of diverse structure. TDP1 as well as APE1 can remove 3'-phosphoglycolates and other 3' blocks, while CtIP appears to provide an alternative pathway for topoisomerase II fragment removal. Ku, a core DSB joining protein, can cleave abasic sites near DNA ends. The downstream processes of patching and ligation are tolerant of residual damage, and can sometimes proceed without complete damage removal. Despite these redundant pathways for resolution, damaged ends appear to be a significant barrier to rejoining, and their resolution may be a rate-limiting step in repair of some DSBs..
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Affiliation(s)
- Lawrence F Povirk
- Department of Pharmacology and Toxicology, and Massey Cancer Center, Virginia Commonwealth University, 401 College St. Richmond, VA 23298, USA, 804-828-9640
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26
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Malu S, De Ioannes P, Kozlov M, Greene M, Francis D, Hanna M, Pena J, Escalante CR, Kurosawa A, Erdjument-Bromage H, Tempst P, Adachi N, Vezzoni P, Villa A, Aggarwal AK, Cortes P. Artemis C-terminal region facilitates V(D)J recombination through its interactions with DNA Ligase IV and DNA-PKcs. ACTA ACUST UNITED AC 2012; 209:955-63. [PMID: 22529269 PMCID: PMC3348108 DOI: 10.1084/jem.20111437] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Interactions of Artemis with DNA Ligase IV and DNA-PKcs are required for efficient coding joint formation. Artemis is an endonuclease that opens coding hairpin ends during V(D)J recombination and has critical roles in postirradiation cell survival. A direct role for the C-terminal region of Artemis in V(D)J recombination has not been defined, despite the presence of immunodeficiency and lymphoma development in patients with deletions in this region. Here, we report that the Artemis C-terminal region directly interacts with the DNA-binding domain of Ligase IV, a DNA Ligase which plays essential roles in DNA repair and V(D)J recombination. The Artemis–Ligase IV interaction is specific and occurs independently of the presence of DNA and DNA–protein kinase catalytic subunit (DNA-PKcs), another protein known to interact with the Artemis C-terminal region. Point mutations in Artemis that disrupt its interaction with Ligase IV or DNA-PKcs reduce V(D)J recombination, and Artemis mutations that affect interactions with Ligase IV and DNA-PKcs show additive detrimental effects on coding joint formation. Signal joint formation remains unaffected. Our data reveal that the C-terminal region of Artemis influences V(D)J recombination through its interaction with both Ligase IV and DNA-PKcs.
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Affiliation(s)
- Shruti Malu
- Immunology Institute, Mount Sinai School of Medicine, New York, NY 10029, USA
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Liu H, Sun X, Zhang S, Ge W, Zhu Y, Zhang J, Zheng S. The dominant negative mutant Artemis enhances tumor cell radiosensitivity. Radiother Oncol 2011; 101:66-72. [PMID: 21641068 DOI: 10.1016/j.radonc.2011.05.034] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2010] [Revised: 04/10/2011] [Accepted: 05/11/2011] [Indexed: 12/26/2022]
Abstract
BACKGROUND Tumor radioresistance often leads to treatment failure during radiotherapy. New strategies like developing radiosensitizer are clinically important. Intervention with DNA double-strand break repair is an effective way to modulate tumor cell radiosensitivity. This study focused on the mutant Artemis fragment-enhanced radiosensitivity of human cervical cancer cells. MATERIAL AND METHODS We constructed two pEGFP-C1-based eukaryotic expression vectors encoding full-length and the mutant Artemis fragment (D37N-413aa), respectively. HeLa cells were stably transfected with these plasmids or vector. Cell survival was measured by the clonogenic assay. The γH2AX foci assay was used to monitor DNA repair after irradiation. Co-immunoprecipitation and Western blot analysis were performed to study protein interaction and phosphorylation of Artemis. RESULTS Expression of the mutant Artemis fragment (D37N-413aa) delayed DNA DSB rejoining after irradiation, thereby enhanced radiosensitivity of HeLa cell. Further experiments indicate that this mutant Artemis fragment bind to DNA-PKcs and ATM, inhibited phosphorylation of endogenous Artemis, the key molecule for DNA repair and cell radiosensitivity. CONCLUSIONS The dominant negative mutant Artemis fragment (D37N-413aa) enhanced tumor cell radiosensitivity through blocking activity of endogenous Artemis and DNA repair. It is the first time to modulate tumor cell radiosensitivity via targeting Artemis. This novel mechanism of radiosensitivity strongly suggests the potential role of Artemis in cancer therapy.
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Affiliation(s)
- Hai Liu
- Cancer Institute, Zhejiang University School of Medicine, The Second Affiliated Hospital, Hangzhou, China
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Yan Y, Akhter S, Zhang X, Legerski R. The multifunctional SNM1 gene family: not just nucleases. Future Oncol 2010; 6:1015-29. [PMID: 20528238 DOI: 10.2217/fon.10.47] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
The archetypical member of the SNM1 gene family was discovered 30 years ago in the budding yeast Saccharomyces cerevisiae. This small but ubiquitous gene family is characterized by metallo-beta-lactamase and beta-CASP domains, which together have been demonstrated to comprise a nuclease activity. Three mammalian members of this family, SNM1A, SNM1B/Apollo and Artemis, have been demonstrated to play surprisingly divergent roles in cellular metabolism. These pathways include variable (diversity) joining recombination, nonhomologous end-joining of double-strand breaks, DNA damage and mitotic cell cycle checkpoints, telomere maintenance and protein ubiquitination. Not all of these functions are consistent with a model in which these proteins act only as nucleases, and indicate that the SNM1 gene family encodes multifunctional products that can act in diverse biochemical pathways. In this article we discuss the various functions of SNM1A, SNM1B/Apollo and Artemis.
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Affiliation(s)
- Yiyi Yan
- Department of Genetics, University of Texas MD Anderson Cancer Center, 1515 Holcombe Boulevard, Houston, TX 77030, USA
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Apollo contributes to G overhang maintenance and protects leading-end telomeres. Mol Cell 2010; 39:606-17. [PMID: 20619712 DOI: 10.1016/j.molcel.2010.06.031] [Citation(s) in RCA: 115] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2010] [Revised: 06/14/2010] [Accepted: 06/24/2010] [Indexed: 12/19/2022]
Abstract
Mammalian telomeres contain a single-stranded 3' overhang that is thought to mediate telomere protection. Here we identify the TRF2-interacting factor Apollo as a nuclease that contributes to the generation/maintenance of this overhang. The function of mouse Apollo was determined using Cre-mediated gene deletion, complementation with Apollo mutants, and the TRF2-F120A mutant that cannot bind Apollo. Cells lacking Apollo activated the ATM kinase at their telomeres in S phase and showed leading-end telomere fusions. These telomere dysfunction phenotypes were accompanied by a reduction in the telomeric overhang signal. The telomeric functions of Apollo required its TRF2-interaction and nuclease motifs. Thus, TRF2 recruits the Apollo nuclease to process telomere ends synthesized by leading-strand DNA synthesis, thereby creating a terminal structure that avoids ATM activation and resists end-joining. These data establish that the telomeric overhang is required for the protection of telomeres from the DNA damage response.
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Kurosawa A, Adachi N. Functions and regulation of Artemis: a goddess in the maintenance of genome integrity. JOURNAL OF RADIATION RESEARCH 2010; 51:503-509. [PMID: 20543526 DOI: 10.1269/jrr.10017] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Artemis is a structure-specific endonuclease when associated with and phosphorylated by DNA-dependent protein kinase catalytic subunit. This structure-specific endonuclease is responsible for the resolution of hairpin coding ends in V(D)J recombination. In DNA double-strand break repair, Artemis is implicated in the end-processing step of the non-homologous end-joining (NHEJ) pathway. Recently, we have demonstrated that the involvement of Artemis in NHEJ depends on the type of DNA damage. Interestingly, recent evidence suggests that the end-processing activity is not the only function of Artemis. Indeed, Artemis is rapidly phosphorylated by ataxia telangiectasia mutated in response to DNA damage, and such phosphorylation of Artemis appears to be involved in the regulation of cell cycle checkpoints. These findings suggest that Artemis is a multifunctional protein participating in the maintenance of genome integrity at two distinct levels; one at the end processing step of NHEJ, and the other at the signaling pathway of cell cycle regulation. Therefore, understanding Artemis function may give us profound insights into the DNA repair network. In this review, we summarize the functions and regulation of Artemis.
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Affiliation(s)
- Aya Kurosawa
- Graduate School of Nanobioscience, Yokohama City University, Yokohama, Japan.
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Abstract
Recent molecular studies have expanded the biological contexts in which topoisomerase II (TOP2) has crucial functions, including DNA replication, transcription and chromosome segregation. Although the biological functions of TOP2 are important for ensuring genomic integrity, the ability to interfere with TOP2 and generate enzyme-mediated DNA damage is an effective strategy for cancer chemotherapy. The molecular tools that have allowed an understanding of the biological functions of TOP2 are also being applied to understanding the details of drug action. These studies promise refined targeting of TOP2 as an effective anticancer strategy.
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Affiliation(s)
- John L Nitiss
- Molecular Pharmacology Department, St Jude Children's Research Hospital, Memphis, TN 38105, USA.
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Fachin AL, Mello SS, Sandrin-Garcia P, Junta CM, Ghilardi-Netto T, Donadi EA, Passos GADS, Sakamoto-Hojo ET. Gene expression profiles in radiation workers occupationally exposed to ionizing radiation. JOURNAL OF RADIATION RESEARCH 2009; 50:61-71. [PMID: 19218781 DOI: 10.1269/jrr.08034] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Ionizing radiation (IR) imposes risks to human health and the environment. IR at low doses and low dose rates has the potency to initiate carcinogenesis. Genotoxic environmental agents such as IR trigger a cascade of signal transduction pathways for cellular protection. In this study, using cDNA microarray technique, we monitored the gene expression profiles in lymphocytes derived from radiation-exposed individuals (radiation workers). Physical dosimetry records on these patients indicated that the absorbed dose ranged from 0.696 to 39.088 mSv. Gene expression analysis revealed statistically significant transcriptional changes in a total of 78 genes (21 up-regulated and 57 down-regulated) involved in several biological processes such as ubiquitin cycle (UHRF2 and PIAS1), DNA repair (LIG3, XPA, ERCC5, RAD52, DCLRE1C), cell cycle regulation/proliferation (RHOA, CABLES2, TGFB2, IL16), and stress response (GSTP1, PPP2R5A, DUSP22). Some of the genes that showed altered expression profiles in this study can be used as biomarkers for monitoring the chronic low level exposure in humans. Additionally, alterations in gene expression patterns observed in chronically exposed radiation workers reinforces the need for defining the effective radiation dose that causes immediate genetic damage as well as the long-term effects on genomic instability, including cancer.
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Affiliation(s)
- Ana Lucia Fachin
- Departamento de Genética, Faculdade de Medicina de Ribeirão Preto-USP, Av Bandeirantes 3900, 14049-900 Ribeirão Preto, SP, Brasil
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Iiizumi S, Kurosawa A, So S, Ishii Y, Chikaraishi Y, Ishii A, Koyama H, Adachi N. Impact of non-homologous end-joining deficiency on random and targeted DNA integration: implications for gene targeting. Nucleic Acids Res 2008; 36:6333-42. [PMID: 18835848 PMCID: PMC2577324 DOI: 10.1093/nar/gkn649] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
In higher animal cells, the principal limitation of gene-targeting technology is the extremely low efficiency of targeted integration, which occurs three to four orders of magnitude less frequently than random integration. Assuming that random integration mechanistically involves non-homologous end-joining (NHEJ), inactivation of this pathway should reduce random integration and may enhance gene targeting. To test this possibility, we examined the frequencies of random and targeted integration in NHEJ-deficient chicken DT40 and human Nalm-6 cell lines. As expected, loss of NHEJ resulted in drastically reduced random integration in DT40 cells. Unexpectedly, however, this was not the case for Nalm-6 cells, indicating that NHEJ is not the sole mechanism of random integration. Nevertheless, we present evidence that NHEJ inactivation can lead to enhanced gene targeting through a reduction of random integration and/or an increase in targeted integration by homologous recombination. Most intriguingly, our results show that, in the absence of functional NHEJ, random integration of targeting vectors occurs more frequently than non-targeting vectors (harboring no or little homology to the host genome), implying that suppression of NHEJ-independent random integration events is needed to greatly enhance gene targeting in animal cells.
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Affiliation(s)
- Susumu Iiizumi
- International Graduate School of Arts and Sciences and Kihara Institute for Biological Research, Yokohama City University, Yokohama, Japan
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