1
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Sugawara N, Towne MJ, Lovett ST, Haber JE. Spontaneous and double-strand break repair-associated quasipalindrome and frameshift mutagenesis in budding yeast: role of mismatch repair. Genetics 2024; 227:iyae068. [PMID: 38691577 DOI: 10.1093/genetics/iyae068] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2023] [Revised: 08/09/2023] [Accepted: 03/06/2024] [Indexed: 05/03/2024] Open
Abstract
Although gene conversion (GC) in Saccharomyces cerevisiae is the most error-free way to repair double-strand breaks (DSBs), the mutation rate during homologous recombination is 1,000 times greater than during replication. Many mutations involve dissociating a partially copied strand from its repair template and re-aligning with the same or another template, leading to -1 frameshifts in homonucleotide runs, quasipalindrome (QP)-associated mutations and microhomology-mediated interchromosomal template switches. We studied GC induced by HO endonuclease cleavage at MATα, repaired by an HMR::KI-URA3 donor. We inserted into HMR::KI-URA3 an 18-bp inverted repeat where one arm had a 4-bp insertion. Most GCs yield MAT::KI-ura3::QP + 4 (Ura-) outcomes, but template-switching produces Ura+ colonies, losing the 4-bp insertion. If the QP arm without the insertion is first encountered by repair DNA polymerase and is then (mis)used as a template, the palindrome is perfected. When the QP + 4 arm is encountered first, Ura+ derivatives only occur after second-end capture and second-strand synthesis. QP + 4 mutations are suppressed by mismatch repair (MMR) proteins Msh2, Msh3, and Mlh1, but not Msh6. Deleting Rdh54 significantly reduces QP mutations only when events creating Ura+ occur in the context of a D-loop but not during second-strand synthesis. A similar bias is found with a proofreading-defective DNA polymerase mutation (poI3-01). DSB-induced mutations differed in several genetic requirements from spontaneous events. We also created a + 1 frameshift in the donor, expanding a run of 4 Cs to 5 Cs. Again, Ura+ recombinants markedly increased by disabling MMR, suggesting that MMR acts during GC but favors the unbroken, template strand.
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Affiliation(s)
- Neal Sugawara
- Department of Biology and Rosenstiel Basic Medical Sciences Research Center MS029, Brandeis University, Waltham, MA 02454-9110, USA
| | - Mason J Towne
- Department of Biology and Rosenstiel Basic Medical Sciences Research Center MS029, Brandeis University, Waltham, MA 02454-9110, USA
| | - Susan T Lovett
- Department of Biology and Rosenstiel Basic Medical Sciences Research Center MS029, Brandeis University, Waltham, MA 02454-9110, USA
| | - James E Haber
- Department of Biology and Rosenstiel Basic Medical Sciences Research Center MS029, Brandeis University, Waltham, MA 02454-9110, USA
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2
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Vink-Börger E, den Bakker M, Voorham R, van Nederveen F, Nagtegaal I. Mismatch repair deficiency: how reliable is the two-antibody approach? A national real-life study. Histopathology 2024. [PMID: 38859771 DOI: 10.1111/his.15236] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2024] [Revised: 05/02/2024] [Accepted: 05/25/2024] [Indexed: 06/12/2024]
Abstract
AIMS Traditionally, mismatch repair (MMR) status is determined by a panel of four antibodies (MLH1, PMS2, MSH2, MSH6). If all proteins are retained, cases are MMR proficient (pMMR), while loss of one or more proteins is indicative of MMR deficiency (dMMR). This approach has been challenged in favour of a two-antibody approach, using PMS2 and MSH6 as a first screening. Their retainment is deemed sufficient to declare cases pMMR. In this study we aim to verify the validity of the two-antibody approach. METHODS AND RESULTS We performed a nationwide study in colorectal cancer (CRC) and endometrial cancer (EC) diagnosed between 2016 and 2023, including 47,657 patients to evaluate the two-antibody approach. In 0.17% and 0.4% of cases of CRC and EC, respectively, dMMR cases would be missed with the two-antibody approach. Subgroup analyses pointed towards slightly increased miss rates in younger patients (under the age of 50 years) in both groups and identified special subtypes (signet ring cell carcinoma, medullary carcinoma, and mucinous carcinoma in CRC and clear cell carcinoma in EC) with increased miss rates. For these specific subgroups, a low threshold should be used for further testing. In case of ambiguous or heterogeneous staining patterns, four antibodies should be used. CONCLUSION In general, the application of a two-antibody MMR testing strategy does not lead to considerable failure of dMMR identification and saves costs.
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Affiliation(s)
| | | | | | | | - Iris Nagtegaal
- Department of Pathology, Radboudumc, Nijmegen, The Netherlands
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3
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Jiang W, Lin T, Pan J, Rivera CE, Tincher C, Wang Y, Zhang Y, Gao X, Wang Y, Tsui HCT, Winkler ME, Lynch M, Long H. Spontaneous mutations and mutational responses to penicillin treatment in the bacterial pathogen Streptococcus pneumoniae D39. MARINE LIFE SCIENCE & TECHNOLOGY 2024; 6:198-211. [PMID: 38827133 PMCID: PMC11136922 DOI: 10.1007/s42995-024-00220-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/19/2023] [Accepted: 03/04/2024] [Indexed: 06/04/2024]
Abstract
Bacteria with functional DNA repair systems are expected to have low mutation rates due to strong natural selection for genomic stability. However, our study of the wild-type Streptococcus pneumoniae D39, a pathogen responsible for many common diseases, revealed a high spontaneous mutation rate of 0.02 per genome per cell division in mutation-accumulation (MA) lines. This rate is orders of magnitude higher than that of other non-mutator bacteria and is characterized by a high mutation bias in the A/T direction. The high mutation rate may have resulted from a reduction in the overall efficiency of selection, conferred by the tiny effective population size in nature. In line with this, S. pneumoniae D39 also exhibited the lowest DNA mismatch-repair (MMR) efficiency among bacteria. Treatment with the antibiotic penicillin did not elevate the mutation rate, as penicillin did not induce DNA damage and S. pneumoniae lacks a stress response pathway. Our findings suggested that the MA results are applicable to within-host scenarios and provide insights into pathogen evolution. Supplementary Information The online version contains supplementary material available at 10.1007/s42995-024-00220-6.
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Affiliation(s)
- Wanyue Jiang
- Institute of Evolution and Marine Biodiversity, KLMME, Ocean University of China, Qingdao, 266003 China
- Laboratory for Marine Biology and Biotechnology, Laoshan Laboratory, Qingdao, 266237 China
| | - Tongtong Lin
- Institute of Evolution and Marine Biodiversity, KLMME, Ocean University of China, Qingdao, 266003 China
| | - Jiao Pan
- Institute of Evolution and Marine Biodiversity, KLMME, Ocean University of China, Qingdao, 266003 China
| | - Caitlyn E. Rivera
- Department of Biology, Indiana University, Bloomington, IN 47405 USA
| | - Clayton Tincher
- Department of Biology, Indiana University, Bloomington, IN 47405 USA
| | - Yaohai Wang
- Institute of Evolution and Marine Biodiversity, KLMME, Ocean University of China, Qingdao, 266003 China
| | - Yu Zhang
- School of Mathematics Science, Ocean University of China, Qingdao, 266000 China
| | - Xiang Gao
- State Key Laboratory of Microbial Technology, Microbial Technology Institute, School of Life Science, Shandong University, Qingdao, 266237 China
| | - Yan Wang
- Institute of Evolution and Marine Biodiversity, KLMME, Ocean University of China, Qingdao, 266003 China
| | - Ho-Ching T. Tsui
- Department of Biology, Indiana University, Bloomington, IN 47405 USA
| | | | - Michael Lynch
- Biodesign Center for Mechanisms of Evolution, Arizona State University, Tempe, AZ 85281 USA
| | - Hongan Long
- Institute of Evolution and Marine Biodiversity, KLMME, Ocean University of China, Qingdao, 266003 China
- Laboratory for Marine Biology and Biotechnology, Laoshan Laboratory, Qingdao, 266237 China
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4
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Buckley CW, O’Reilly EM. Next-generation therapies for pancreatic cancer. Expert Rev Gastroenterol Hepatol 2024; 18:55-72. [PMID: 38415709 PMCID: PMC10960610 DOI: 10.1080/17474124.2024.2322648] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/23/2023] [Accepted: 02/20/2024] [Indexed: 02/29/2024]
Abstract
INTRODUCTION Pancreas ductal adenocarcinoma (PDAC) is a frequently lethal malignancy that poses unique therapeutic challenges. The current mainstay of therapy for metastatic PDAC (mPDAC) is cytotoxic chemotherapy. NALIRIFOX (liposomal irinotecan, fluorouracil, leucovorin, oxaliplatin) is an emerging standard of care in the metastatic setting. An evolving understanding of PDAC pathogenesis is driving a shift toward targeted therapy. Olaparib, a poly-ADP-ribose polymerase (PARP) inhibitor, has regulatory approval for maintenance therapy in BRCA-mutated mPDAC along with other targeted agents receiving disease-agnostic approvals including for PDAC with rare fusions and mismatch repair deficiency. Ongoing research continues to identify and evaluate an expanding array of targeted therapies for PDAC. AREAS COVERED This review provides a brief overview of standard therapies for PDAC and an emphasis on current and emerging targeted therapies. EXPERT OPINION There is notable potential for targeted therapies for KRAS-mutated PDAC with opportunity for meaningful benefit for a sizable portion of patients with this disease. Further, emerging approaches are focused on novel immune, tumor microenvironment, and synthetic lethality strategies.
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Affiliation(s)
- Conor W. Buckley
- Department of Medicine, Memorial Sloan Kettering Cancer Center, New York, USA
| | - Eileen M. O’Reilly
- Department of Medicine, Memorial Sloan Kettering Cancer Center, New York, USA
- Weill Cornell Medicine, New York, USA
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5
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Wang L, Yang S, Xue Y, Bo T, Xu J, Wang W. Mismatch Repair Protein Msh6 Tt Is Necessary for Nuclear Division and Gametogenesis in Tetrahymena thermophila. Int J Mol Sci 2023; 24:17619. [PMID: 38139447 PMCID: PMC10743813 DOI: 10.3390/ijms242417619] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2023] [Revised: 12/15/2023] [Accepted: 12/16/2023] [Indexed: 12/24/2023] Open
Abstract
DNA mismatch repair (MMR) improves replication accuracy by up to three orders of magnitude. The MutS protein in E. coli or its eukaryotic homolog, the MutSα (Msh2-Msh6) complex, recognizes base mismatches and initiates the mismatch repair mechanism. Msh6 is an essential protein for assembling the heterodimeric complex. However, the function of the Msh6 subunit remains elusive. Tetrahymena undergoes multiple DNA replication and nuclear division processes, including mitosis, amitosis, and meiosis. Here, we found that Msh6Tt localized in the macronucleus (MAC) and the micronucleus (MIC) during the vegetative growth stage and starvation. During the conjugation stage, Msh6Tt only localized in MICs and newly developing MACs. MSH6Tt knockout led to aberrant nuclear division during vegetative growth. The MSH6TtKO mutants were resistant to treatment with the DNA alkylating agent methyl methanesulfonate (MMS) compared to wild type cells. MSH6Tt knockout affected micronuclear meiosis and gametogenesis during the conjugation stage. Furthermore, Msh6Tt interacted with Msh2Tt and MMR-independent factors. Downregulation of MSH2Tt expression affected the stability of Msh6Tt. In addition, MSH6Tt knockout led to the upregulated expression of several MSH6Tt homologs at different developmental stages. Msh6Tt is involved in macronuclear amitosis, micronuclear mitosis, micronuclear meiosis, and gametogenesis in Tetrahymena.
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Affiliation(s)
- Lin Wang
- Key Laboratory of Chemical Biology and Molecular Engineering of Ministry of Education, Institute of Biotechnology, Shanxi University, Taiyuan 030006, China; (L.W.); (S.Y.); (Y.X.); (T.B.)
| | - Sitong Yang
- Key Laboratory of Chemical Biology and Molecular Engineering of Ministry of Education, Institute of Biotechnology, Shanxi University, Taiyuan 030006, China; (L.W.); (S.Y.); (Y.X.); (T.B.)
| | - Yuhuan Xue
- Key Laboratory of Chemical Biology and Molecular Engineering of Ministry of Education, Institute of Biotechnology, Shanxi University, Taiyuan 030006, China; (L.W.); (S.Y.); (Y.X.); (T.B.)
| | - Tao Bo
- Key Laboratory of Chemical Biology and Molecular Engineering of Ministry of Education, Institute of Biotechnology, Shanxi University, Taiyuan 030006, China; (L.W.); (S.Y.); (Y.X.); (T.B.)
- Shanxi Key Laboratory of Biotechnology, Taiyuan 030006, China
| | - Jing Xu
- Key Laboratory of Chemical Biology and Molecular Engineering of Ministry of Education, Institute of Biotechnology, Shanxi University, Taiyuan 030006, China; (L.W.); (S.Y.); (Y.X.); (T.B.)
- School of Life Science, Shanxi University, Taiyuan 030006, China
| | - Wei Wang
- Key Laboratory of Chemical Biology and Molecular Engineering of Ministry of Education, Institute of Biotechnology, Shanxi University, Taiyuan 030006, China; (L.W.); (S.Y.); (Y.X.); (T.B.)
- Shanxi Key Laboratory of Biotechnology, Taiyuan 030006, China
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6
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Li J, Wang H, Yang W. Tandem MutSβ binding to long extruded DNA trinucleotide repeats underpins pathogenic expansions. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.12.12.571350. [PMID: 38168405 PMCID: PMC10760016 DOI: 10.1101/2023.12.12.571350] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2024]
Abstract
Expansion of trinucleotide repeats causes Huntington's disease, Fragile X syndrome and over twenty other monogenic disorders1. How mismatch repair protein MutSβ and large repeats of CNG (N=A, T, C or G) cooperate to drive the expansion is poorly understood. Contrary to expectations, we find that MutSβ prefers to bind the stem of an extruded (CNG) hairpin rather than the hairpin end or hairpin-duplex junction. Structural analyses reveal that in the presence of MutSβ, CNG repeats with N:N mismatches adopt a B form-like pseudo-duplex, with one or two CNG repeats slipped out forming uneven bubbles that partly mimic insertion-deletion loops of mismatched DNA2. When the extruded hairpin exceeds 40-45 repeats, it can be bound by three or more MutSβ molecules, which are resistant to ATP-dependent dissociation. We envision that such MutSβ-CNG complexes recruit MutLγ endonuclease to nick DNA and initiate the repeat expansion process3,4. To develop drugs against the expansion diseases, we have identified lead compounds that prevent MutSβ binding to CNG repeats but not to mismatched DNA.
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Affiliation(s)
- Jun Li
- Laboratory of Molecular Biology, NIDDK, National Institutes of Health, Bethesda, MD 20892
| | - Huaibin Wang
- Laboratory of Cell and Molecular Biology, NIDDK, National Institutes of Health, Bethesda, MD 20892
| | - Wei Yang
- Laboratory of Molecular Biology, NIDDK, National Institutes of Health, Bethesda, MD 20892
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7
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Guan J, Li GM. DNA mismatch repair in cancer immunotherapy. NAR Cancer 2023; 5:zcad031. [PMID: 37325548 PMCID: PMC10262306 DOI: 10.1093/narcan/zcad031] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2023] [Revised: 05/08/2023] [Accepted: 06/07/2023] [Indexed: 06/17/2023] Open
Abstract
Tumors defective in DNA mismatch repair (dMMR) exhibit microsatellite instability (MSI). Currently, patients with dMMR tumors are benefitted from anti-PD-1/PDL1-based immune checkpoint inhibitor (ICI) therapy. Over the past several years, great progress has been made in understanding the mechanisms by which dMMR tumors respond to ICI, including the identification of mutator phenotype-generated neoantigens, cytosolic DNA-mediated activation of the cGAS-STING pathway, type-I interferon signaling and high tumor-infiltration of lymphocytes in dMMR tumors. Although ICI therapy shows great clinical benefits, ∼50% of dMMR tumors are eventually not responsive. Here we review the discovery, development and molecular basis of dMMR-mediated immunotherapy, as well as tumor resistant problems and potential therapeutic interventions to overcome the resistance.
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Affiliation(s)
- Junhong Guan
- Cuiying Biomedical Research Center, Lanzhou University Second Hospital, Lanzhou, Gansu 730030, China
| | - Guo-Min Li
- Department of Radiation Oncology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
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8
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Cox MM, Goodman MF, Keck JL, van Oijen A, Lovett ST, Robinson A. Generation and Repair of Postreplication Gaps in Escherichia coli. Microbiol Mol Biol Rev 2023; 87:e0007822. [PMID: 37212693 PMCID: PMC10304936 DOI: 10.1128/mmbr.00078-22] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/23/2023] Open
Abstract
When replication forks encounter template lesions, one result is lesion skipping, where the stalled DNA polymerase transiently stalls, disengages, and then reinitiates downstream to leave the lesion behind in a postreplication gap. Despite considerable attention in the 6 decades since postreplication gaps were discovered, the mechanisms by which postreplication gaps are generated and repaired remain highly enigmatic. This review focuses on postreplication gap generation and repair in the bacterium Escherichia coli. New information to address the frequency and mechanism of gap generation and new mechanisms for their resolution are described. There are a few instances where the formation of postreplication gaps appears to be programmed into particular genomic locations, where they are triggered by novel genomic elements.
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Affiliation(s)
- Michael M. Cox
- Department of Biochemistry, University of Wisconsin—Madison, Madison, Wisconsin, USA
| | - Myron F. Goodman
- Department of Biological Sciences, University of Southern California, University Park, Los Angeles, California, USA
- Department of Chemistry, University of Southern California, University Park, Los Angeles, California, USA
| | - James L. Keck
- Department of Biological Chemistry, University of Wisconsin—Madison School of Medicine, Madison, Wisconsin, USA
| | - Antoine van Oijen
- Molecular Horizons, University of Wollongong, Wollongong, New South Wales, Australia
- School of Chemistry and Molecular Bioscience, University of Wollongong, Wollongong, New South Wales, Australia
| | - Susan T. Lovett
- Department of Biology, Brandeis University, Waltham, Massachusetts, USA
| | - Andrew Robinson
- Molecular Horizons, University of Wollongong, Wollongong, New South Wales, Australia
- School of Chemistry and Molecular Bioscience, University of Wollongong, Wollongong, New South Wales, Australia
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9
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Wang L, Xue Y, Yang S, Bo T, Xu J, Wang W. Mismatch Repair Protein Msh2 Is Necessary for Macronuclear Stability and Micronuclear Division in Tetrahymena thermophila. Int J Mol Sci 2023; 24:10559. [PMID: 37445734 DOI: 10.3390/ijms241310559] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2023] [Revised: 06/20/2023] [Accepted: 06/22/2023] [Indexed: 07/15/2023] Open
Abstract
Mismatch repair (MMR) is a conserved mechanism that is primarily responsible for the repair of DNA mismatches during DNA replication. Msh2 forms MutS heterodimer complexes that initiate the MMR in eukaryotes. The function of Msh2 is less clear under different chromatin structures. Tetrahymena thermophila contains a transcriptionally active macronucleus (MAC) and a transcriptionally silent micronucleus (MIC) in the same cytoplasm. Msh2 is localized in the MAC and MIC during vegetative growth. Msh2 is localized in the perinuclear region around the MIC and forms a spindle-like structure as the MIC divides. During the early conjugation stage, Msh2 is localized in the MIC and disappears from the parental MAC. Msh2 is localized in the new MAC and new MIC during the late conjugation stage. Msh2 also forms a spindle-like structure with a meiotic MIC and mitotic gametic nucleus. MSH2 knockdown inhibits the division of MAC and MIC during vegetative growth and affects cellular proliferation. MSH2 knockdown mutants are sensitive to cisplatin treatment. MSH2 knockdown also affects micronuclear meiosis and gametogenesis during sexual development. Furthermore, Msh2 interacts with MMR-dependent and MMR-independent factors. Therefore, Msh2 is necessary for macronuclear stability, as well as micronuclear mitosis and meiosis in Tetrahymena.
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Affiliation(s)
- Lin Wang
- Key Laboratory of Chemical Biology and Molecular Engineering of Ministry of Education, Institute of Biotechnology, Shanxi University, Taiyuan 030006, China
| | - Yuhuan Xue
- Key Laboratory of Chemical Biology and Molecular Engineering of Ministry of Education, Institute of Biotechnology, Shanxi University, Taiyuan 030006, China
| | - Sitong Yang
- Key Laboratory of Chemical Biology and Molecular Engineering of Ministry of Education, Institute of Biotechnology, Shanxi University, Taiyuan 030006, China
| | - Tao Bo
- Key Laboratory of Chemical Biology and Molecular Engineering of Ministry of Education, Institute of Biotechnology, Shanxi University, Taiyuan 030006, China
- Shanxi Key Laboratory of Biotechnology, Taiyuan 030006, China
| | - Jing Xu
- Key Laboratory of Chemical Biology and Molecular Engineering of Ministry of Education, Institute of Biotechnology, Shanxi University, Taiyuan 030006, China
- School of Life Science, Shanxi University, Taiyuan 030006, China
| | - Wei Wang
- Key Laboratory of Chemical Biology and Molecular Engineering of Ministry of Education, Institute of Biotechnology, Shanxi University, Taiyuan 030006, China
- Shanxi Key Laboratory of Biotechnology, Taiyuan 030006, China
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10
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Kavun A, Veselovsky E, Lebedeva A, Belova E, Kuznetsova O, Yakushina V, Grigoreva T, Mileyko V, Fedyanin M, Ivanov M. Microsatellite Instability: A Review of Molecular Epidemiology and Implications for Immune Checkpoint Inhibitor Therapy. Cancers (Basel) 2023; 15:cancers15082288. [PMID: 37190216 DOI: 10.3390/cancers15082288] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2023] [Revised: 04/10/2023] [Accepted: 04/11/2023] [Indexed: 05/17/2023] Open
Abstract
Microsatellite instability (MSI) is one of the most important molecular characteristics of a tumor, which occurs among various tumor types. In this review article, we examine the molecular characteristics of MSI tumors, both sporadic and Lynch-associated. We also overview the risks of developing hereditary forms of cancer and potential mechanisms of tumor development in patients with Lynch syndrome. Additionally, we summarize the results of major clinical studies on the efficacy of immune checkpoint inhibitors for MSI tumors and discuss the predictive role of MSI in the context of chemotherapy and checkpoint inhibitors. Finally, we briefly discuss some of the underlying mechanisms causing therapy resistance in patients treated with immune checkpoint inhibitors.
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Affiliation(s)
| | - Egor Veselovsky
- OncoAtlas LLC, 119049 Moscow, Russia
- Department of Evolutionary Genetics of Development, Koltzov Institute of Developmental Biology of the Russian Academy of Sciences, 119334 Moscow, Russia
| | | | - Ekaterina Belova
- OncoAtlas LLC, 119049 Moscow, Russia
- Faculty of Physics, Lomonosov Moscow State University, 119991 Moscow, Russia
| | - Olesya Kuznetsova
- OncoAtlas LLC, 119049 Moscow, Russia
- N.N. Blokhin Russian Cancer Research Center, 115478 Moscow, Russia
| | - Valentina Yakushina
- OncoAtlas LLC, 119049 Moscow, Russia
- Laboratory of Epigenetics, Research Centre for Medical Genetics, 115522 Moscow, Russia
| | - Tatiana Grigoreva
- OncoAtlas LLC, 119049 Moscow, Russia
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry of the Russian Academy of Sciences, 117997 Moscow, Russia
| | | | - Mikhail Fedyanin
- N.N. Blokhin Russian Cancer Research Center, 115478 Moscow, Russia
- State Budgetary Institution of Health Care of the City of Moscow "Moscow Multidisciplinary Clinical Center" "Kommunarka" of the Department of Health of the City of Moscow, 142770 Moscow, Russia
- Federal State Budgetary Institution "National Medical and Surgical Center named after N.I. Pirogov" of the Ministry of Health of the Russian Federation, 105203 Moscow, Russia
| | - Maxim Ivanov
- OncoAtlas LLC, 119049 Moscow, Russia
- Moscow Institute of Physics and Technology, 141701 Dolgoprudny, Russia
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11
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The radioresistant and survival mechanisms of Deinococcus radiodurans. RADIATION MEDICINE AND PROTECTION 2023. [DOI: 10.1016/j.radmp.2023.03.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/07/2023] Open
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12
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Trost H, Merkell A, Lopezcolorado FW, Stark J. Resolution of sequence divergence for repeat-mediated deletions shows a polarity that is mediated by MLH1. Nucleic Acids Res 2023; 51:650-667. [PMID: 36620890 PMCID: PMC9881173 DOI: 10.1093/nar/gkac1240] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2022] [Revised: 11/07/2022] [Accepted: 01/04/2023] [Indexed: 01/10/2023] Open
Abstract
Repeat-mediated deletions (RMDs) are a type of chromosomal rearrangement between two homologous sequences that causes loss of the sequence between the repeats, along with one of the repeats. Sequence divergence between repeats suppresses RMDs; the mechanisms of such suppression and of resolution of the sequence divergence remains poorly understood. We identified RMD regulators using a set of reporter assays in mouse cells that test two key parameters: repeat sequence divergence and the distances between one repeat and the initiating chromosomal break. We found that the mismatch repair factor MLH1 suppresses RMDs with sequence divergence in the same pathway as MSH2 and MSH6, and which is dependent on residues in MLH1 and its binding partner PMS2 that are important for nuclease activity. Additionally, we found that the resolution of sequence divergence in the RMD product has a specific polarity, where divergent bases that are proximal to the chromosomal break end are preferentially removed. Moreover, we found that the domain of MLH1 that forms part of the MLH1-PMS2 endonuclease is important for polarity of resolution of sequence divergence. We also identified distinctions between MLH1 versus TOP3α in regulation of RMDs. We suggest that MLH1 suppresses RMDs with sequence divergence, while also promoting directional resolution of sequence divergence in the RMD product.
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Affiliation(s)
- Hannah Trost
- Department of Cancer Genetics and Epigenetics, Beckman Research Institute of the City of Hope, Duarte, CA 91010, USA
- Irell and Manella Graduate School of Biological Sciences, Beckman Research Institute of the City of Hope, Duarte, CA 91010, USA
| | - Arianna Merkell
- Department of Cancer Genetics and Epigenetics, Beckman Research Institute of the City of Hope, Duarte, CA 91010, USA
| | | | - Jeremy M Stark
- To whom correspondence should be addressed. Tel: +1 626 218-6346; Fax: +1 626 218 8892;
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13
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Evolving DNA repair synthetic lethality targets in cancer. Biosci Rep 2022; 42:232162. [PMID: 36420962 PMCID: PMC9760629 DOI: 10.1042/bsr20221713] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2022] [Revised: 11/21/2022] [Accepted: 11/24/2022] [Indexed: 11/25/2022] Open
Abstract
DNA damage signaling response and repair (DDR) is a critical defense mechanism against genomic instability. Impaired DNA repair capacity is an important risk factor for cancer development. On the other hand, up-regulation of DDR mechanisms is a feature of cancer chemotherapy and radiotherapy resistance. Advances in our understanding of DDR and its complex role in cancer has led to several translational DNA repair-targeted investigations culminating in clinically viable precision oncology strategy using poly(ADP-ribose) polymerase (PARP) inhibitors in breast, ovarian, pancreatic, and prostate cancers. While PARP directed synthetic lethality has improved outcomes for many patients, the lack of sustained clinical response and the development of resistance pose significant clinical challenges. Therefore, the search for additional DDR-directed drug targets and novel synthetic lethality approaches is highly desirable and is an area of intense preclinical and clinical investigation. Here, we provide an overview of the mammalian DNA repair pathways and then focus on current state of PARP inhibitors (PARPi) and other emerging DNA repair inhibitors for synthetic lethality in cancer.
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Zhao W, Guo C, Yao W, Zhang L, Ding Y, Yang Z, Lin S. Comparative phylogenomic analyses and co-expression gene network reveal insights in flowering time and aborted meiosis in woody bamboo, Bambusa oldhamii 'Xia Zao' ZSX. FRONTIERS IN PLANT SCIENCE 2022; 13:1023240. [PMID: 36438131 PMCID: PMC9681927 DOI: 10.3389/fpls.2022.1023240] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/19/2022] [Accepted: 09/16/2022] [Indexed: 06/16/2023]
Abstract
Woody bamboos have peculiar flowering characteristics with intervals ranging from several years to more than 100 years. Elucidating flowering time and reproductive development in bamboo could be beneficial for both humans and wildlife. To identity the mechanisms responsible for flowering time and embryo abortion in Bambusa oldhamii 'Xia Zao' ZSX, a transcriptome sequencing project was initiated to characterize the genes involved in developing flowers in this bamboo species. Morphological studies showed that pollen abortion in this bamboo species was mainly caused by a delay in tapetum degradation and abnormal meiotic process. Differential expression (DE) and optimized hierarchical clustering analyses identified three of nine gene expression clusters with decreasing expression at the meiosis of flowering stages. Together with enriched Gene Ontology Biological Process terms for meiosis, this suggests that their expression pattern may be associated with aborted meiosis in B. oldhamii 'Xia Zao'. Moreover, our large-scale phylogenomic analyses comparing meiosis-related transcripts of B. oldhamii 'Xia Zao' with well annotated genes in 22 representative angiosperms and sequence evolution analyses reveal two core meiotic genes NO EXINE FORMATION 1 (NFE1) and PMS1 with nonsense mutations in their coding regions, likely providing another line of evidence supporting embryo abortion in B. oldhamii 'Xia Zao'. Similar analyses, however, reveal conserved sequence evolution in flowering pathways such as LEAFY (LFY) and FLOWERING LOCUS T (FT). Seventeen orthogroups associated with flowering were identified by DE analyses between nonflowering and flowering culm buds. Six regulators found primarily in several connected network nodes of the photoperiod pathway were confirmed by mapping to the flowering time network in rice, such as Heading date (Hd3a) and Rice FT-like 1 (RFT1) which integrate upstream signaling into the downstream effectors. This suggests the existence of an intact photoperiod pathway is likely the key regulators that switch on/off flowering in B. oldhamii 'Xia Zao'.
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Affiliation(s)
- Wanqi Zhao
- Co-Innovation Center for Sustainable Forestry in Southern China, Bamboo Research Institute, College of Biology and Environment, Nanjing Forestry University, Nanjing, China
| | - Chunce Guo
- Jiangxi Provincial Key Laboratory for Bamboo Germplasm Resources and Utilization, Forestry College, Jiangxi Agricultural University, Nanchang, China
| | - Wenjing Yao
- Co-Innovation Center for Sustainable Forestry in Southern China, Bamboo Research Institute, College of Biology and Environment, Nanjing Forestry University, Nanjing, China
| | - Li Zhang
- Co-Innovation Center for Sustainable Forestry in Southern China, Bamboo Research Institute, College of Biology and Environment, Nanjing Forestry University, Nanjing, China
| | - Yulong Ding
- Co-Innovation Center for Sustainable Forestry in Southern China, Bamboo Research Institute, College of Biology and Environment, Nanjing Forestry University, Nanjing, China
| | - Zhenzhen Yang
- Shanghai Institute for Advanced Immunochemical Studies (SIAIS), ShanghaiTech University, Shanghai, China
| | - Shuyan Lin
- Co-Innovation Center for Sustainable Forestry in Southern China, Bamboo Research Institute, College of Biology and Environment, Nanjing Forestry University, Nanjing, China
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15
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Britton BM, London JA, Martin-Lopez J, Jones ND, Liu J, Lee JB, Fishel R. Exploiting the distinctive properties of the bacterial and human MutS homolog sliding clamps on mismatched DNA. J Biol Chem 2022; 298:102505. [PMID: 36126773 PMCID: PMC9597889 DOI: 10.1016/j.jbc.2022.102505] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2021] [Revised: 09/13/2022] [Accepted: 09/15/2022] [Indexed: 12/30/2022] Open
Abstract
MutS homologs (MSHs) are highly conserved core components of DNA mismatch repair. Mismatch recognition provokes ATP-binding by MSH proteins that drives a conformational transition from a short-lived lesion-searching clamp to an extremely stable sliding clamp on the DNA. Here, we have expanded on previous bulk biochemical studies to examine the stability, lifetime, and kinetics of bacterial and human MSH sliding clamps on mismatched DNA using surface plasmon resonance and single-molecule analysis of fluorescently labeled proteins. We found that ATP-bound MSH complexes bound to blocked-end or very long mismatched DNAs were extremely stable over a range of ionic conditions. These observations underpinned the development of a high-throughput Förster resonance energy transfer system that specifically detects the formation of MSH sliding clamps on mismatched DNA. The Förster resonance energy transfer system is capable of distinguishing between HsMSH2-HsMSH3 and HsMSH2-HsMSH6 and appears suitable for chemical inhibitor screens. Taken together, our results provide additional insight into MSH sliding clamps as well as methods to distinguish their functions in mismatch repair.
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Affiliation(s)
- Brooke M Britton
- Department of Cancer Biology and Genetics, The Ohio State University Wexner Medical Center, Columbus, Ohio, USA
| | - James A London
- Department of Cancer Biology and Genetics, The Ohio State University Wexner Medical Center, Columbus, Ohio, USA
| | - Juana Martin-Lopez
- Department of Cancer Biology and Genetics, The Ohio State University Wexner Medical Center, Columbus, Ohio, USA
| | - Nathan D Jones
- Department of Cancer Biology and Genetics, The Ohio State University Wexner Medical Center, Columbus, Ohio, USA
| | - Jiaquan Liu
- Department of Cancer Biology and Genetics, The Ohio State University Wexner Medical Center, Columbus, Ohio, USA
| | - Jong-Bong Lee
- Department of Physics, Pohang University of Science and Technology (POSTECH), Pohang, Korea; Interdisciplinary Bioscience and Bioengineering, POSTECH, Pohang, Korea
| | - Richard Fishel
- Department of Cancer Biology and Genetics, The Ohio State University Wexner Medical Center, Columbus, Ohio, USA.
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Liu K, Chen E, Gu Z, Dai B, Wang A, Zhu Z, Feng Q, Zhou C, Zhu J, Shangguan Y, Wang Y, Li Z, Hou Q, Lv D, Wang C, Huang T, Wang Z, Huang X, Han B. A retrotransposon insertion in MUTL-HOMOLOG 1 affects wild rice seed set and cultivated rice crossover rate. PLANT PHYSIOLOGY 2022; 190:1747-1762. [PMID: 35976143 PMCID: PMC9614510 DOI: 10.1093/plphys/kiac378] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/29/2022] [Accepted: 07/12/2022] [Indexed: 06/06/2023]
Abstract
Wild rice (Oryza rufipogon) has a lower panicle seed setting rate (PSSR) and gamete fertility than domesticated rice (Oryza sativa), but the genetic mechanisms of this phenomenon remain unknown. Here, we cloned a null allele of OsMLH1, an ortholog of MutL-homolog 1 to yeast and mammals, from wild rice O. rufipogon W1943 and revealed a 5.4-kb retrotransposon insertion in OsMLH1 is responsible for the low PSSR in wild rice. In contrast to the wild-type, a near isogenic line NIL-mlh1 exhibits defective crossover (CO) formation during meiosis, resulting in reduced pollen viability, partial embryo lethality, and low PSSR. Except for the mutant of mismatch repair gene postmeiotic segregation 1 (Ospms1), all other MutL mutants from O. sativa indica subspecies displayed male and female semi-sterility similar to NIL-mlh1, but less severe than those from O. sativa japonica subspecies. MLH1 and MLH3 did not contribute in an additive fashion to fertility. Two types of MutL heterodimers, MLH1-PMS1 and MLH1-MLH3, were identified in rice, but only the latter functions in promoting meiotic CO formation. Compared to japonica varieties, indica cultivars had greater numbers of CO events per meiosis. Our results suggest that low fertility in wild rice may be caused by different gene defects, and indica and japonica subspecies have substantially different CO rates responsible for the discrepancy between the fertility of mlh1 and mlh3 mutants.
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Affiliation(s)
- Kun Liu
- College of Life Sciences, Anhui Normal University, Wuhu, 241000, China
- National Center for Gene Research, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, 200233, China
| | - Erwang Chen
- National Center for Gene Research, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, 200233, China
| | - Zhoulin Gu
- National Center for Gene Research, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, 200233, China
| | - Bingxin Dai
- National Center for Gene Research, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, 200233, China
- School of Life Science and Technology, Shanghai Tech University, Shanghai, 201210, China
| | - Ahong Wang
- National Center for Gene Research, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, 200233, China
| | - Zhou Zhu
- National Center for Gene Research, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, 200233, China
| | - Qi Feng
- National Center for Gene Research, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, 200233, China
| | - Congcong Zhou
- National Center for Gene Research, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, 200233, China
| | - Jingjie Zhu
- National Center for Gene Research, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, 200233, China
| | - Yingying Shangguan
- National Center for Gene Research, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, 200233, China
| | - Yongchun Wang
- National Center for Gene Research, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, 200233, China
| | - Zhen Li
- College of Life Sciences, Anhui Normal University, Wuhu, 241000, China
- National Center for Gene Research, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, 200233, China
| | - Qingqing Hou
- National Center for Gene Research, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, 200233, China
| | - Danfeng Lv
- National Center for Gene Research, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, 200233, China
| | - Changsheng Wang
- National Center for Gene Research, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, 200233, China
| | - Tao Huang
- National Center for Gene Research, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, 200233, China
| | - Zixuan Wang
- National Center for Gene Research, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, 200233, China
| | - Xuehui Huang
- College of Life Sciences, Shanghai Normal University, Shanghai, 200234, China
| | - Bin Han
- National Center for Gene Research, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, 200233, China
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Li Y, Liu X, Chang Y, Fan B, Shangguan C, Chen H, Zhang L. Identification and Validation of a DNA Damage Repair-Related Signature for Diffuse Large B-Cell Lymphoma. BIOMED RESEARCH INTERNATIONAL 2022; 2022:2645090. [PMID: 36281462 PMCID: PMC9587677 DOI: 10.1155/2022/2645090] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/18/2022] [Accepted: 09/27/2022] [Indexed: 10/06/2023]
Abstract
BACKGROUND Diffuse large B-cell lymphoma (DLBCL) is the most common subtype of non-Hodgkin's lymphoma in adults, whose prognostic scoring system remains to be improved. Dysfunction of DNA repair genes is closely associated with the development and prognosis of diffuse large B-cell lymphoma. The aim of this study was to establish and validate a DNA repair-related gene signature associated with the prognosis of DLBCL and to investigate the clinical predictive value of this signature. METHODS DLBCL cases were obtained from The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) databases. One hundred ninety-nine DNA repair-related gene sets were retrieved from the GeneCards database. The LASSO Cox regression was used to generate the DNA repair-related gene signature. Subsequently, the level of immune cell infiltration and the correlation between the gene signature and immune cells were analyzed using the CIBERSORT algorithm. Based on the Genomics of Drug Sensitivity in Cancer (GDSC) database, the relationship between the signature and drug sensitivity was analyzed, and together with the nomogram and gene set variation analysis (GSVA), the value of the signature for clinical application was evaluated. RESULTS A total of 14 DNA repair genes were screened out and included in the final risk model. Subgroup analysis of the training and validation cohorts showed that the risk model accurately predicted overall survival of DLBCL patients, with patients in the high-risk group having a worse prognosis than patients in the low-risk group. Subsequently, the risk score was confirmed as an independent prognostic factor by multivariate analysis. Furthermore, by CIBERSORT analysis, we discovered that immune cells, such as regulatory T cells (Tregs), activated memory CD4+ T cells, and gamma delta T cells showed significant differences between the high- and low-risk groups. In addition, we found some interesting associations of our signature with immune checkpoint genes (CD96, TGFBR1, and TIGIT). By analyzing drug sensitivity data in the GDSC database, we were able to identify potential therapeutics for DLBCL patients stratified according to our signature. CONCLUSIONS Our study identified and validated a 14-DNA repair-related gene signature for stratification and prognostic prediction of DLBCL patients, which might guide clinical personalization of treatment.
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Affiliation(s)
- Yang Li
- Department of Oncology, The First Affiliated Hospital of Zhengzhou University, No. 1 Jianshe East Road, Zhengzhou 450000, China
| | - Xiyang Liu
- Department of Oncology, The First Affiliated Hospital of Zhengzhou University, No. 1 Jianshe East Road, Zhengzhou 450000, China
| | - Yu Chang
- Department of Oncology, The First Affiliated Hospital of Zhengzhou University, No. 1 Jianshe East Road, Zhengzhou 450000, China
| | - Bingjie Fan
- Department of Oncology, The First Affiliated Hospital of Zhengzhou University, No. 1 Jianshe East Road, Zhengzhou 450000, China
| | - Chenxing Shangguan
- Department of Oncology, The First Affiliated Hospital of Zhengzhou University, No. 1 Jianshe East Road, Zhengzhou 450000, China
| | - Huan Chen
- Department of Oncology, The First Affiliated Hospital of Zhengzhou University, No. 1 Jianshe East Road, Zhengzhou 450000, China
| | - Lei Zhang
- Department of Oncology, The First Affiliated Hospital of Zhengzhou University, No. 1 Jianshe East Road, Zhengzhou 450000, China
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The mismatch recognition protein MutSα promotes nascent strand degradation at stalled replication forks. Proc Natl Acad Sci U S A 2022; 119:e2201738119. [PMID: 36161943 PMCID: PMC9546528 DOI: 10.1073/pnas.2201738119] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
DNA mismatch repair (MMR) is well known for its role in maintaining replication fidelity by correcting mispairs generated during replication. Here, we identify an unusual MMR function to promote genome instability in the replication stress response. Under replication stress, binding of the mismatch recognition protein MutSα to replication forks blocks the loading of fork protection factors FANCD2 and BRCA1 to replication forks and promotes the recruitment of exonuclease MRE11 onto DNA to nascent strand degradation. This MutSα-dependent MRE11-catalyzed DNA degradation causes DNA breaks and chromosome abnormalities, contributing to an ultramutator phenotype. Mismatch repair (MMR) is a replication-coupled DNA repair mechanism and plays multiple roles at the replication fork. The well-established MMR functions include correcting misincorporated nucleotides that have escaped the proofreading activity of DNA polymerases, recognizing nonmismatched DNA adducts, and triggering a DNA damage response. In an attempt to determine whether MMR regulates replication progression in cells expressing an ultramutable DNA polymerase ɛ (Polɛ), carrying a proline-to-arginine substitution at amino acid 286 (Polɛ-P286R), we identified an unusual MMR function in response to hydroxyurea (HU)-induced replication stress. Polɛ-P286R cells treated with hydroxyurea exhibit increased MRE11-catalyzed nascent strand degradation. This degradation by MRE11 depends on the mismatch recognition protein MutSα and its binding to stalled replication forks. Increased MutSα binding at replication forks is also associated with decreased loading of replication fork protection factors FANCD2 and BRCA1, suggesting blockage of these fork protection factors from loading to replication forks by MutSα. We find that the MutSα-dependent MRE11-catalyzed fork degradation induces DNA breaks and various chromosome abnormalities. Therefore, unlike the well-known MMR functions of ensuring replication fidelity, the newly identified MMR activity of promoting genome instability may also play a role in cancer avoidance by eliminating rogue cells.
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Kumari S, Sharma S, Advani D, Khosla A, Kumar P, Ambasta RK. Unboxing the molecular modalities of mutagens in cancer. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2022; 29:62111-62159. [PMID: 34611806 PMCID: PMC8492102 DOI: 10.1007/s11356-021-16726-w] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/24/2021] [Accepted: 09/22/2021] [Indexed: 04/16/2023]
Abstract
The etiology of the majority of human cancers is associated with a myriad of environmental causes, including physical, chemical, and biological factors. DNA damage induced by such mutagens is the initial step in the process of carcinogenesis resulting in the accumulation of mutations. Mutational events are considered the major triggers for introducing genetic and epigenetic insults such as DNA crosslinks, single- and double-strand DNA breaks, formation of DNA adducts, mismatched bases, modification in histones, DNA methylation, and microRNA alterations. However, DNA repair mechanisms are devoted to protect the DNA to ensure genetic stability, any aberrations in these calibrated mechanisms provoke cancer occurrence. Comprehensive knowledge of the type of mutagens and carcinogens and the influence of these agents in DNA damage and cancer induction is crucial to develop rational anticancer strategies. This review delineated the molecular mechanism of DNA damage and the repair pathways to provide a deep understanding of the molecular basis of mutagenicity and carcinogenicity. A relationship between DNA adduct formation and cancer incidence has also been summarized. The mechanistic basis of inflammatory response and oxidative damage triggered by mutagens in tumorigenesis has also been highlighted. We elucidated the interesting interplay between DNA damage response and immune system mechanisms. We addressed the current understanding of DNA repair targeted therapies and DNA damaging chemotherapeutic agents for cancer treatment and discussed how antiviral agents, anti-inflammatory drugs, and immunotherapeutic agents combined with traditional approaches lay the foundations for future cancer therapies.
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Affiliation(s)
- Smita Kumari
- Molecular Neuroscience and Functional Genomics Laboratory, Department of Biotechnology, Delhi Technological University, Shahbad Daulatpur, Bawana Road, Delhi, 110042, India
| | - Sudhanshu Sharma
- Molecular Neuroscience and Functional Genomics Laboratory, Department of Biotechnology, Delhi Technological University, Shahbad Daulatpur, Bawana Road, Delhi, 110042, India
| | - Dia Advani
- Molecular Neuroscience and Functional Genomics Laboratory, Department of Biotechnology, Delhi Technological University, Shahbad Daulatpur, Bawana Road, Delhi, 110042, India
| | - Akanksha Khosla
- Molecular Neuroscience and Functional Genomics Laboratory, Department of Biotechnology, Delhi Technological University, Shahbad Daulatpur, Bawana Road, Delhi, 110042, India
| | - Pravir Kumar
- Molecular Neuroscience and Functional Genomics Laboratory, Department of Biotechnology, Delhi Technological University, Shahbad Daulatpur, Bawana Road, Delhi, 110042, India
| | - Rashmi K Ambasta
- Molecular Neuroscience and Functional Genomics Laboratory, Department of Biotechnology, Delhi Technological University, Shahbad Daulatpur, Bawana Road, Delhi, 110042, India.
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Acurzio B, Cecere F, Giaccari C, Verma A, Russo R, Valletta M, Hay Mele B, Angelini C, Chambery A, Riccio A. The mismatch-repair proteins MSH2 and MSH6 interact with the imprinting control regions through the ZFP57-KAP1 complex. Epigenetics Chromatin 2022; 15:27. [PMID: 35918739 PMCID: PMC9344765 DOI: 10.1186/s13072-022-00462-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2022] [Accepted: 07/25/2022] [Indexed: 11/21/2022] Open
Abstract
Background Imprinting Control Regions (ICRs) are CpG-rich sequences acquiring differential methylation in the female and male germline and maintaining it in a parental origin-specific manner in somatic cells. Despite their expected high mutation rate due to spontaneous deamination of methylated cytosines, ICRs show conservation of CpG-richness and CpG-containing transcription factor binding sites in mammalian species. However, little is known about the mechanisms contributing to the maintenance of a high density of methyl CpGs at these loci. Results To gain functional insights into the mechanisms for maintaining CpG methylation, we sought to identify the proteins binding the methylated allele of the ICRs by determining the interactors of ZFP57 that recognizes a methylated hexanucleotide motif of these DNA regions in mouse ESCs. By using a tagged approach coupled to LC–MS/MS analysis, we identified several proteins, including factors involved in mRNA processing/splicing, chromosome organization, transcription and DNA repair processes. The presence of the post-replicative mismatch-repair (MMR) complex components MSH2 and MSH6 among the identified ZFP57 interactors prompted us to investigate their DNA binding profile by chromatin immunoprecipitation and sequencing. We demonstrated that MSH2 was enriched at gene promoters overlapping unmethylated CpG islands and at repeats. We also found that both MSH2 and MSH6 interacted with the methylated allele of the ICRs, where their binding to DNA was mediated by the ZFP57/KAP1 complex. Conclusions Our findings show that the MMR complex is concentrated on gene promoters and repeats in mouse ESCs, suggesting that maintaining the integrity of these regions is a primary function of highly proliferating cells. Furthermore, the demonstration that MSH2/MSH6 are recruited to the methylated allele of the ICRs through interaction with ZFP57/KAP1 suggests a role of the MMR complex in the maintenance of the integrity of these regulatory regions and evolution of genomic imprinting in mammalian species. Supplementary Information The online version contains supplementary material available at 10.1186/s13072-022-00462-7.
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Affiliation(s)
- Basilia Acurzio
- Department of Environmental Biological and Pharmaceutical Sciences and Technologies (DiSTABiF), Università Degli Studi Della Campania "Luigi Vanvitelli", 81100, Caserta, Italy.,Institute of Genetics and Biophysics (IGB) "Adriano Buzzati-Traverso", Consiglio Nazionale Delle Ricerche (CNR), 80131, Naples, Italy
| | - Francesco Cecere
- Department of Environmental Biological and Pharmaceutical Sciences and Technologies (DiSTABiF), Università Degli Studi Della Campania "Luigi Vanvitelli", 81100, Caserta, Italy.,Institute of Genetics and Biophysics (IGB) "Adriano Buzzati-Traverso", Consiglio Nazionale Delle Ricerche (CNR), 80131, Naples, Italy
| | - Carlo Giaccari
- Department of Environmental Biological and Pharmaceutical Sciences and Technologies (DiSTABiF), Università Degli Studi Della Campania "Luigi Vanvitelli", 81100, Caserta, Italy.,Institute of Genetics and Biophysics (IGB) "Adriano Buzzati-Traverso", Consiglio Nazionale Delle Ricerche (CNR), 80131, Naples, Italy
| | - Ankit Verma
- Department of Environmental Biological and Pharmaceutical Sciences and Technologies (DiSTABiF), Università Degli Studi Della Campania "Luigi Vanvitelli", 81100, Caserta, Italy.,Institute of Genetics and Biophysics (IGB) "Adriano Buzzati-Traverso", Consiglio Nazionale Delle Ricerche (CNR), 80131, Naples, Italy
| | - Rosita Russo
- Department of Environmental Biological and Pharmaceutical Sciences and Technologies (DiSTABiF), Università Degli Studi Della Campania "Luigi Vanvitelli", 81100, Caserta, Italy
| | - Mariangela Valletta
- Department of Environmental Biological and Pharmaceutical Sciences and Technologies (DiSTABiF), Università Degli Studi Della Campania "Luigi Vanvitelli", 81100, Caserta, Italy
| | - Bruno Hay Mele
- Department of Biology, Università Degli Studi Di Napoli "Federico II", 80126, Naples, Italy
| | - Claudia Angelini
- Istituto Per Le Applicazioni del Calcolo "Mauro Picone" (IAC), CNR, 80131, Naples, Italy
| | - Angela Chambery
- Department of Environmental Biological and Pharmaceutical Sciences and Technologies (DiSTABiF), Università Degli Studi Della Campania "Luigi Vanvitelli", 81100, Caserta, Italy
| | - Andrea Riccio
- Department of Environmental Biological and Pharmaceutical Sciences and Technologies (DiSTABiF), Università Degli Studi Della Campania "Luigi Vanvitelli", 81100, Caserta, Italy. .,Institute of Genetics and Biophysics (IGB) "Adriano Buzzati-Traverso", Consiglio Nazionale Delle Ricerche (CNR), 80131, Naples, Italy.
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Interplay between H3K36me3, methyltransferase SETD2, and mismatch recognition protein MutSα facilitates processing of oxidative DNA damage in human cells. J Biol Chem 2022; 298:102102. [PMID: 35667440 PMCID: PMC9241034 DOI: 10.1016/j.jbc.2022.102102] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2022] [Revised: 05/26/2022] [Accepted: 05/27/2022] [Indexed: 11/21/2022] Open
Abstract
Oxidative DNA damage contributes to aging and the pathogenesis of numerous human diseases including cancer. 8-hydroxyguanine (8-oxoG) is the major product of oxidative DNA lesions. Although OGG1-mediated base excision repair is the primary mechanism for 8-oxoG removal, DNA mismatch repair has also been implicated in processing oxidative DNA damage. However, the mechanism of the latter is not fully understood. Here, we treated human cells defective in various 8-oxoG repair factors with H2O2 and performed biochemical, live cell imaging, and chromatin immunoprecipitation sequencing analyses to determine their response to the treatment. We show that the mismatch repair processing of oxidative DNA damage involves cohesive interactions between mismatch recognition protein MutSα, histone mark H3K36me3, and H3K36 trimethyltransferase SETD2, which activates the ATM DNA damage signaling pathway. We found that cells depleted of MutSα or SETD2 accumulate 8-oxoG adducts and fail to trigger H2O2-induced ATM activation. Furthermore, we show that SETD2 physically interacts with both MutSα and ATM, which suggests a role for SETD2 in transducing DNA damage signals from lesion-bound MutSα to ATM. Consistently, MutSα and SETD2 are highly coenriched at oxidative damage sites. The data presented here support a model wherein MutSα, SETD2, ATM, and H3K36me3 constitute a positive feedback loop to help cells cope with oxidative DNA damage.
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22
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Nasrallah NA, Wiese BM, Sears CR. Xeroderma Pigmentosum Complementation Group C (XPC): Emerging Roles in Non-Dermatologic Malignancies. Front Oncol 2022; 12:846965. [PMID: 35530314 PMCID: PMC9069926 DOI: 10.3389/fonc.2022.846965] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2021] [Accepted: 03/09/2022] [Indexed: 11/13/2022] Open
Abstract
Xeroderma pigmentosum complementation group C (XPC) is a DNA damage recognition protein essential for initiation of global-genomic nucleotide excision repair (GG-NER). Humans carrying germline mutations in the XPC gene exhibit strong susceptibility to skin cancer due to defective removal via GG-NER of genotoxic, solar UV-induced dipyrimidine photoproducts. However, XPC is increasingly recognized as important for protection against non-dermatologic cancers, not only through its role in GG-NER, but also by participating in other DNA repair pathways, in the DNA damage response and in transcriptional regulation. Additionally, XPC expression levels and polymorphisms likely impact development and may serve as predictive and therapeutic biomarkers in a number of these non-dermatologic cancers. Here we review the existing literature, focusing on the role of XPC in non-dermatologic cancer development, progression, and treatment response, and highlight possible future applications of XPC as a prognostic and therapeutic biomarker.
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Affiliation(s)
- Nawar Al Nasrallah
- Division of Pulmonary, Critical Care, Sleep and Occupational Medicine, Department of Medicine, Indiana University School of Medicine, Indianapolis, IN, United States
| | - Benjamin M. Wiese
- Division of Pulmonary, Critical Care, Sleep and Occupational Medicine, Department of Medicine, Indiana University School of Medicine, Indianapolis, IN, United States
| | - Catherine R. Sears
- Division of Pulmonary, Critical Care, Sleep and Occupational Medicine, Department of Medicine, Indiana University School of Medicine, Indianapolis, IN, United States
- Division of Pulmonary Medicine, Richard L. Roudebush Veterans Affairs Medical Center, Indianapolis, IN, United States
- *Correspondence: Catherine R. Sears,
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Singh S, Singh N, Baranwal M, Sharma S. Polymorphisms in the MSH2 gene predict poor survival of North Indian lung cancer patients undergoing chemotherapy. Biomark Med 2022; 16:69-82. [PMID: 35081740 DOI: 10.2217/bmm-2021-0565] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Aim: To estimate if MSH2 polymorphisms, viz. rs63749993, rs2303425, rs2303426, rs4987188, rs2303428 and rs17217772, have any association with clinical outcomes in North Indian lung cancer patients. Materials & methods: PCR-RFLP was used for genotyping 500 cases. Logistic regression and survival analysis was performed by utilizing MedCalc software. Results & conclusion: Our study concluded, adenocarcinoma subjects having heterozygous genotype for rs2303425 have increased survival time (MST = 12.43, p = 0.03). In lung cancer patients undergoing paclitaxel therapy, heterozygous carriers for the rs17217772 polymorphism have reduced survival time (MST = 7.96 vs 2.63 months; HR = 2.09; p = 0.02). For rs63749993 polymorphism undergoing irinotecan therapy, subjects having mutant genotype showed poor survival (13.26 vs 6.06 months; HR = 5.37; p = 0.0004). The results suggest that MSH2 polymorphisms are involved in decreasing overall survival for patients undergoing platinum-based chemotherapy.
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Affiliation(s)
- Sidhartha Singh
- Department of Biotechnology, Thapar Institute of Engineering & Technology, Patiala, 147001, India
| | - Navneet Singh
- Department of Pulmonary Medicine, Post Graduate Institute of Medical Education & Research (PGIMER), Chandigarh, 160012, India
| | - Manoj Baranwal
- Department of Biotechnology, Thapar Institute of Engineering & Technology, Patiala, 147001, India
| | - Siddharth Sharma
- Department of Biotechnology, Thapar Institute of Engineering & Technology, Patiala, 147001, India
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24
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Wang M, Chen S, Ao D. Targeting DNA repair pathway in cancer: Mechanisms and clinical application. MedComm (Beijing) 2021; 2:654-691. [PMID: 34977872 PMCID: PMC8706759 DOI: 10.1002/mco2.103] [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: 11/06/2021] [Revised: 11/21/2021] [Accepted: 11/22/2021] [Indexed: 02/05/2023] Open
Abstract
Over the last decades, the growing understanding on DNA damage response (DDR) pathways has broadened the therapeutic landscape in oncology. It is becoming increasingly clear that the genomic instability of cells resulted from deficient DNA damage response contributes to the occurrence of cancer. One the other hand, these defects could also be exploited as a therapeutic opportunity, which is preferentially more deleterious in tumor cells than in normal cells. An expanding repertoire of DDR-targeting agents has rapidly expanded to inhibitors of multiple members involved in DDR pathways, including PARP, ATM, ATR, CHK1, WEE1, and DNA-PK. In this review, we sought to summarize the complex network of DNA repair machinery in cancer cells and discuss the underlying mechanism for the application of DDR inhibitors in cancer. With the past preclinical evidence and ongoing clinical trials, we also provide an overview of the history and current landscape of DDR inhibitors in cancer treatment, with special focus on the combination of DDR-targeted therapies with other cancer treatment strategies.
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Affiliation(s)
- Manni Wang
- Department of BiotherapyCancer CenterWest China HospitalSichuan UniversityChengduChina
| | - Siyuan Chen
- Department of BiotherapyCancer CenterWest China HospitalSichuan UniversityChengduChina
| | - Danyi Ao
- Department of BiotherapyCancer CenterWest China HospitalSichuan UniversityChengduChina
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25
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Yao S, Feng Y, Zhang Y, Feng J. DNA damage checkpoint and repair: From the budding yeast Saccharomyces cerevisiae to the pathogenic fungus Candida albicans. Comput Struct Biotechnol J 2021; 19:6343-6354. [PMID: 34938410 PMCID: PMC8645783 DOI: 10.1016/j.csbj.2021.11.033] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2021] [Revised: 11/16/2021] [Accepted: 11/20/2021] [Indexed: 01/09/2023] Open
Abstract
Cells are constantly challenged by internal or external genotoxic assaults, which may induce a high frequency of DNA lesions, leading to genome instability. Accumulation of damaged DNA is severe or even lethal to cells and can result in abnormal proliferation that can cause cancer in multicellular organisms, aging or cell death. Eukaryotic cells have evolved a comprehensive defence system termed the DNA damage response (DDR) to monitor and remove lesions in their DNA. The DDR has been extensively studied in the budding yeast Saccharomyces cerevisiae. Emerging evidence indicates that DDR genes in the pathogenic fungus Candida albicans show functional consistency with their orthologs in S. cerevisiae, but may act through distinct mechanisms. In particular, the DDR in C. albicans appears critical for resisting DNA damage stress induced by reactive oxygen species (ROS) produced from immune cells, and this plays a vital role in pathogenicity. Therefore, DDR genes could be considered as potential targets for clinical therapies. This review summarizes the identified DNA damage checkpoint and repair genes in C. albicans based on their orthologs in S. cerevisiae, and discusses their contribution to pathogenicity in C. albicans.
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Affiliation(s)
- Shuangyan Yao
- Department of Pathogen Biology, School of Medicine, Nantong University, Nantong 226001, Jiangsu, China
- Nantong Health College of Jiangsu Province, Nantong 226016, Jiangsu, China
| | - Yuting Feng
- Department of Pathogen Biology, School of Medicine, Nantong University, Nantong 226001, Jiangsu, China
| | - Yan Zhang
- Department of Pathogen Biology, School of Medicine, Nantong University, Nantong 226001, Jiangsu, China
| | - Jinrong Feng
- Department of Pathogen Biology, School of Medicine, Nantong University, Nantong 226001, Jiangsu, China
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26
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Ajjugal Y, Rathinavelan T. Conformational distortions induced by periodically recurring A…A in d(CAG).d(CAG) provide stereochemical rationale for the trapping of MSH2.MSH3 in polyQ disorders. Comput Struct Biotechnol J 2021; 19:4447-4455. [PMID: 34471491 PMCID: PMC8379282 DOI: 10.1016/j.csbj.2021.07.018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2021] [Revised: 07/16/2021] [Accepted: 07/21/2021] [Indexed: 11/25/2022] Open
Abstract
CAG repeat instability causes a number of neurodegenerative disorders. The unusual hairpin stem structure formed by the CAG repeats in DNA traps the human mismatch repair MSH2.MSH3 (Mutsβ) complex. To understand the mechanism behind the abnormal binding of Mutsβ with the imperfect hairpin stem structure formed by CAG repeats, molecular dynamics simulations have been carried out for Mutsβ-d(CAG)2(CAG)(CAG)2.d(CTG)2(CAG)(CTG)2 (1 A…A mismatch) and Mutsβ-d(CAG)5.d(CAG)5 (5 mismatches, wherein, A…A occurs periodically) complexes. The interaction of MSH3 residue Tyr245 at the minor groove side of A…A, an essential interaction responsible for the recognition by Mutsβ, are retained in both the cases. Nevertheless, the periodic unwinding caused by the nonisostericity of A…A with the flanking canonical base pairs in d(CAG)5.d(CAG)5 distorts the regular B-form geometry. Such an unwinding exposes one of the A…A mismatches (that interacts with Tyr245) at the major groove side and also facilitates the on and off hydrogen bonding interaction with Lys546 sidechain (MSH2-domain-IV). In contrast, kinking of the DNA towards the major groove in Mutsβ-d(CAG)2(CAG)(CAG)2.d(CTG)2(CAG)(CTG)2 doesn’t facilitate such an exposure of the bases at the major groove. Further, the unwinding of the helix in d(CAG)5.d(CAG)5 enhances the tighter binding between MSH2-domain-I and d(CAG)5.d(CAG)5 at the major groove side as well as between MSH3-domain-I and MSH3-domain-IV. Markedly, such enhanced interactions are absent in Mutsβ-d(CAG)2(CAG)(CAG)2.d(CTG)2(CAG)(CTG)2 that has a single A…A mismatch. Thus, the above-mentioned enhancement in intra- and inter- molecular interactions in Mutsβ-d(CAG)5.d(CAG)5 provide the stereochemical rationale for the trapping of Mutsβ in CAG repeat expansion disorders.
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Affiliation(s)
- Yogeeshwar Ajjugal
- Department of Biotechnology, Indian Institute of Technology Hyderabad, Kandi, Telangana State 502285, India
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27
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Jung KW, Jung JH, Park HY. Functional Roles of Homologous Recombination and Non-Homologous End Joining in DNA Damage Response and Microevolution in Cryptococcus neoformans. J Fungi (Basel) 2021; 7:jof7070566. [PMID: 34356945 PMCID: PMC8307084 DOI: 10.3390/jof7070566] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2021] [Revised: 07/12/2021] [Accepted: 07/13/2021] [Indexed: 11/16/2022] Open
Abstract
DNA double-strand breaks (DSBs) are the most deleterious type of DNA lesions because they cause loss of genetic information if not properly repaired. In eukaryotes, homologous recombination (HR) and non-homologous end joining (NHEJ) are required for DSB repair. However, the relationship of HR and NHEJ in DNA damage stress is unknown in the radiation-resistant fungus Cryptococcus neoformans. In this study, we found that the expression levels of HR- and NHEJ-related genes were highly induced in a Rad53-Bdr1 pathway-dependent manner under genotoxic stress. Deletion of RAD51, which is one of the main components in the HR, resulted in growth under diverse types of DNA damage stress, whereas perturbations of KU70 and KU80, which belong to the NHEJ system, did not affect the genotoxic stresses except when bleomycin was used for treatment. Furthermore, deletion of both RAD51 and KU70/80 renders cells susceptible to oxidative stress. Notably, we found that deletion of RAD51 induced a hypermutator phenotype in the fluctuation assay. In contrast to the fluctuation assay, perturbation of KU70 or KU80 induced rapid microevolution similar to that induced by the deletion of RAD51. Collectively, Rad51-mediated HR and Ku70/Ku80-mediated NHEJ regulate the DNA damage response and maintain genome stability.
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Affiliation(s)
- Kwang-Woo Jung
- Radiation Research Division, Advanced Radiation Technology Institute, Korea Atomic Energy Research Institute, Jeongeup-Si 56212, Jeollabuk-Do, Korea; (J.-H.J.); (H.-Y.P.)
- Correspondence: ; Tel.: +82-63-570-3337
| | - Jong-Hyun Jung
- Radiation Research Division, Advanced Radiation Technology Institute, Korea Atomic Energy Research Institute, Jeongeup-Si 56212, Jeollabuk-Do, Korea; (J.-H.J.); (H.-Y.P.)
- Department of Radiation Science and Technology, University of Science and Technology, Daejeon 34113, Korea
| | - Ha-Young Park
- Radiation Research Division, Advanced Radiation Technology Institute, Korea Atomic Energy Research Institute, Jeongeup-Si 56212, Jeollabuk-Do, Korea; (J.-H.J.); (H.-Y.P.)
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28
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Ortega J, Lee GS, Gu L, Yang W, Li GM. Mispair-bound human MutS-MutL complex triggers DNA incisions and activates mismatch repair. Cell Res 2021; 31:542-553. [PMID: 33510387 PMCID: PMC8089094 DOI: 10.1038/s41422-021-00468-y] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2020] [Accepted: 12/17/2020] [Indexed: 01/30/2023] Open
Abstract
DNA mismatch repair (MMR) relies on MutS and MutL ATPases for mismatch recognition and strand-specific nuclease recruitment to remove mispaired bases in daughter strands. However, whether the MutS-MutL complex coordinates MMR by ATP-dependent sliding on DNA or protein-protein interactions between the mismatch and strand discrimination signal is ambiguous. Using functional MMR assays and systems preventing proteins from sliding, we show that sliding of human MutSα is required not for MMR initiation, but for final mismatch removal. MutSα recruits MutLα to form a mismatch-bound complex, which initiates MMR by nicking the daughter strand 5' to the mismatch. Exonuclease 1 (Exo1) is then recruited to the nick and conducts 5' → 3' excision. ATP-dependent MutSα dissociation from the mismatch is necessary for Exo1 to remove the mispaired base when the excision reaches the mismatch. Therefore, our study has resolved a long-standing puzzle, and provided new insights into the mechanism of MMR initiation and mispair removal.
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Affiliation(s)
- Janice Ortega
- Department of Radiation Oncology, University of Texas Southwestern Medical Center, Dallas, TX USA
| | - Grace Sanghee Lee
- Department of Toxicology and Cancer Biology, University of Kentucky College of Medicine, Lexington, KY USA ,Present Address: Division of Viral Hepatitis, National Center for HIV/AIDS, Viral Hepatitis, STD and TB Prevention, Centers for Disease Control and Prevention, Atlanta, GA USA
| | - Liya Gu
- Department of Radiation Oncology, University of Texas Southwestern Medical Center, Dallas, TX USA
| | - Wei Yang
- Laboratory of Molecular Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD USA
| | - Guo-Min Li
- Department of Radiation Oncology, University of Texas Southwestern Medical Center, Dallas, TX USA ,Department of Toxicology and Cancer Biology, University of Kentucky College of Medicine, Lexington, KY USA
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29
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Rahman MM, Mohiuddin M, Shamima Keka I, Yamada K, Tsuda M, Sasanuma H, Andreani J, Guerois R, Borde V, Charbonnier JB, Takeda S. Genetic evidence for the involvement of mismatch repair proteins, PMS2 and MLH3, in a late step of homologous recombination. J Biol Chem 2021; 295:17460-17475. [PMID: 33453991 DOI: 10.1074/jbc.ra120.013521] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2020] [Revised: 09/28/2020] [Indexed: 12/15/2022] Open
Abstract
Homologous recombination (HR) repairs DNA double-strand breaks using intact homologous sequences as template DNA. Broken DNA and intact homologous sequences form joint molecules (JMs), including Holliday junctions (HJs), as HR intermediates. HJs are resolved to form crossover and noncrossover products. A mismatch repair factor, MLH3 endonuclease, produces the majority of crossovers during meiotic HR, but it remains elusive whether mismatch repair factors promote HR in nonmeiotic cells. We disrupted genes encoding the MLH3 and PMS2 endonucleases in the human B cell line, TK6, generating null MLH3-/- and PMS2-/- mutant cells. We also inserted point mutations into the endonuclease motif of MLH3 and PMS2 genes, generating endonuclease death MLH3DN/DN and PMS2EK/EK cells. MLH3-/- and MLH3DN/DN cells showed a very similar phenotype, a 2.5-fold decrease in the frequency of heteroallelic HR-dependent repair of restriction enzyme-induced double-strand breaks. PMS2-/- and PMS2EK/EK cells showed a phenotype very similar to that of the MLH3 mutants. These data indicate that MLH3 and PMS2 promote HR as an endonuclease. The MLH3DN/DN and PMS2EK/EK mutations had an additive effect on the heteroallelic HR. MLH3DN/DN/PMS2EK/EK cells showed normal kinetics of γ-irradiation-induced Rad51 foci but a significant delay in the resolution of Rad51 foci and a 3-fold decrease in the number of cisplatin-induced sister chromatid exchanges. The ectopic expression of the Gen1 HJ re-solvase partially reversed the defective heteroallelic HR of MLH3DN/DN/PMS2EK/EK cells. Taken together, we propose that MLH3 and PMS2 promote HR as endonucleases, most likely by processing JMs in mammalian somatic cells.
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Affiliation(s)
- Md Maminur Rahman
- Department of Radiation Genetics, Graduate School of Medicine, Kyoto University, Kyoto, Japan
| | - Mohiuddin Mohiuddin
- Department of Radiation Genetics, Graduate School of Medicine, Kyoto University, Kyoto, Japan
| | - Islam Shamima Keka
- Department of Radiation Genetics, Graduate School of Medicine, Kyoto University, Kyoto, Japan
| | - Kousei Yamada
- Department of Radiation Genetics, Graduate School of Medicine, Kyoto University, Kyoto, Japan
| | - Masataka Tsuda
- Department of Radiation Genetics, Graduate School of Medicine, Kyoto University, Kyoto, Japan
| | - Hiroyuki Sasanuma
- Department of Radiation Genetics, Graduate School of Medicine, Kyoto University, Kyoto, Japan
| | - Jessica Andreani
- Institute for Integrative Biology of the Cell (I2BC), Commissariat à l'Energie Atomique (CEA), CNRS, Université Paris-Saclay, Gif-sur-Yvette, France
| | - Raphael Guerois
- Institute for Integrative Biology of the Cell (I2BC), Commissariat à l'Energie Atomique (CEA), CNRS, Université Paris-Saclay, Gif-sur-Yvette, France
| | - Valerie Borde
- Institut Curie, CNRS, UMR3244, PSL Research University, Paris, France
| | - Jean-Baptiste Charbonnier
- Institute for Integrative Biology of the Cell (I2BC), Commissariat à l'Energie Atomique (CEA), CNRS, Université Paris-Saclay, Gif-sur-Yvette, France
| | - Shunichi Takeda
- Department of Radiation Genetics, Graduate School of Medicine, Kyoto University, Kyoto, Japan.
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30
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Liang Y, Cai X, Zheng X, Yin H. Analysis of the Clinicopathological Characteristics of Stage I-III Colorectal Cancer Patients Deficient in Mismatch Repair Proteins. Onco Targets Ther 2021; 14:2203-2212. [PMID: 33814918 PMCID: PMC8010427 DOI: 10.2147/ott.s278029] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2020] [Accepted: 03/04/2021] [Indexed: 01/10/2023] Open
Abstract
Purpose To investigate the clinicopathological characteristics of stage I–III colorectal cancer (CRC) patients with deficient mismatch repair (dMMR) protein. Patients and Methods A retrospective analysis of 61 patients with stage I–III CRC confirmed by immunohistochemistry as dMMR after radical resection at Shenjing Hospital of China Medical University from May 2017 to June 2019 was performed. A total of 183 stage I–III CRC patients with proficient mismatch repair (pMMR) protein from the same period were randomly selected as a control group. The clinicopathological data of the two groups were investigated. Results There were significant differences between the two groups in age, sex, site of onset, maximum diameter of tumor, T stage, tumor differentiation, and histological type (P < 0.05). No significant difference was detected in nerve vessel invasion, cancer nodules, the N stage or the TNM stage. In the dMMR group, 41 patients (66.13%) showed PMS2/MLH1 deletion, and the number of MSH2/MSH6 deletion is 21 patients (33.87%). Among them, 34 patients (54.84%) had PMS2 and MLH1 deficiency. In total, 16 patients (25.81%) had MSH2 and MSH6 deficiency. A total of 5 patients (8.06%) showed simply PMS2 deletion and 5 patients (8.06%) showed simply MSH6 deletion. In total, 2 patients (3.23%) showed concurrent loss of PMS2, MLH1 and MSH2. No significant difference were found (P > 0.05) in the above factors among dMMR CRC patients with different MMR proteins deletions. Conclusion Our results show that dMMR status may be more likely exist in female and younger (≤55 years) patients with a greater tumor burden (>5cm), right colon, T4 stage disease, poor differentiation and mucinous adenocarcinoma. Loss of PMS2 and MLH1 is the most common pattern of MMR protein expression deficiency, followed by concurrent deletion of MSH2 and MSH6.
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Affiliation(s)
- Yichao Liang
- Department of General Surgery, Shengjing Hospital of China Medical University, Shenyang, Liaoning, People's Republic of China
| | - Xinling Cai
- Department of Clinical Oncology, Shengjing Hospital of China Medical University, Shenyang, Liaoning, People's Republic of China
| | - Xu Zheng
- Department of Clinical Oncology, Shengjing Hospital of China Medical University, Shenyang, Liaoning, People's Republic of China
| | - Hongzhuan Yin
- Department of General Surgery, Shengjing Hospital of China Medical University, Shenyang, Liaoning, People's Republic of China
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31
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Wu Q, Huang Y, Gu L, Chang Z, Li GM. OTUB1 stabilizes mismatch repair protein MSH2 by blocking ubiquitination. J Biol Chem 2021; 296:100466. [PMID: 33640455 PMCID: PMC8042173 DOI: 10.1016/j.jbc.2021.100466] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2020] [Revised: 02/19/2021] [Accepted: 02/23/2021] [Indexed: 12/12/2022] Open
Abstract
DNA mismatch repair (MMR) maintains genome stability primarily by correcting replication errors. MMR deficiency can lead to cancer development and bolsters cancer cell resistance to chemotherapy. However, recent studies have shown that checkpoint blockade therapy is effective in MMR-deficient cancers, thus the ability to identify cancer etiology would greatly benefit cancer treatment. MutS homolog 2 (MSH2) is an obligate subunit of mismatch recognition proteins MutSα (MSH2-MSH6) and MutSβ (MSH2-MSH3). Precise regulation of MSH2 is critical, as either over- or underexpression of MSH2 results in an increased mutation frequency. The mechanism by which cells maintain MSH2 proteostasis is unknown. Using functional ubiquitination and deubiquitination assays, we show that the ovarian tumor (OTU) family deubiquitinase ubiquitin aldehyde binding 1 (OTUB1) inhibits MSH2 ubiquitination by blocking the E2 ligase ubiquitin transfer activity. Depleting OTUB1 in cells promotes the ubiquitination and subsequent degradation of MSH2, leading to greater mutation frequency and cellular resistance to genotoxic agents, including the common chemotherapy agents N-methyl-N'-nitro-N-nitrosoguanidine and cisplatin. Taken together, our data identify OTUB1 as an important regulator of MSH2 stability and provide evidence that OTUB1 is a potential biomarker for cancer etiology and therapy.
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Affiliation(s)
- Qiong Wu
- Department of Basic Medical Sciences, Tsinghua University School of Medicine, Beijing, China
| | - Yaping Huang
- Department of Radiation Oncology, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Liya Gu
- Department of Radiation Oncology, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Zhijie Chang
- Department of Basic Medical Sciences, Tsinghua University School of Medicine, Beijing, China.
| | - Guo-Min Li
- Department of Radiation Oncology, University of Texas Southwestern Medical Center, Dallas, Texas, USA.
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32
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The Amazing Acrobat: Yeast's Histone H3K56 Juggles Several Important Roles While Maintaining Perfect Balance. Genes (Basel) 2021; 12:genes12030342. [PMID: 33668997 PMCID: PMC7996553 DOI: 10.3390/genes12030342] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2021] [Revised: 02/22/2021] [Accepted: 02/23/2021] [Indexed: 01/16/2023] Open
Abstract
Acetylation on lysine 56 of histone H3 of the yeast Saccharomyces cerevisiae has been implicated in many cellular processes that affect genome stability. Despite being the object of much research, the complete scope of the roles played by K56 acetylation is not fully understood even today. The acetylation is put in place at the S-phase of the cell cycle, in order to flag newly synthesized histones that are incorporated during DNA replication. The signal is removed by two redundant deacetylases, Hst3 and Hst4, at the entry to G2/M phase. Its crucial location, at the entry and exit points of the DNA into and out of the nucleosome, makes this a central modification, and dictates that if acetylation and deacetylation are not well concerted and executed in a timely fashion, severe genomic instability arises. In this review, we explore the wealth of information available on the many roles played by H3K56 acetylation and the deacetylases Hst3 and Hst4 in DNA replication and repair.
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33
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Kayser S, Hills RK, Langova R, Kramer M, Guijarro F, Sustkova Z, Estey EH, Shaw CM, Ráčil Z, Mayer J, Zak P, Baer MR, Brunner AM, Szotkowski T, Cetkovsky P, Grimwade D, Walter RB, Burnett AK, Ho AD, Ehninger G, Müller-Tidow C, Platzbecker U, Thiede C, Röllig C, Schulz A, Warsow G, Brors B, Esteve J, Russell NH, Schlenk RF, Levis MJ. Characteristics and outcome of patients with acute myeloid leukaemia and t(8;16)(p11;p13): results from an International Collaborative Study. Br J Haematol 2021; 192:832-842. [PMID: 33529373 DOI: 10.1111/bjh.17336] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2020] [Accepted: 12/03/2020] [Indexed: 02/06/2023]
Abstract
In acute myeloid leukaemia (AML) t(8;16)(p11;p13)/MYST3-CREBBP is a very rare abnormality. Previous small series suggested poor outcome. We report on 59 patients with t(8;16) within an international, collaborative study. Median age was 52 (range: 16-75) years. AML was de novo in 58%, therapy-related (t-AML) in 37% and secondary after myelodysplastic syndrome (s-AML) in 5%. Cytogenetics revealed a complex karyotype in 43%. Besides MYST3-CREBBP, whole-genome sequencing on a subset of 10 patients revealed recurrent mutations in ASXL1, BRD3, FLT3, MLH1, POLG, TP53, SAMD4B (n = 3, each), EYS, KRTAP9-1 SPTBN5 (n = 4, each), RUNX1 and TET2 (n = 2, each). Complete remission after intensive chemotherapy was achieved in 84%. Median follow-up was 5·48 years; five-year survival rate was 17%. Patients with s-/t-AML (P = 0·01) and those with complex karyotype (P = 0·04) had an inferior prognosis. Allogeneic haematopoietic cell transplantation (allo-HCT) was performed in 21 (36%) patients, including 15 in first complete remission (CR1). Allo-HCT in CR1 significantly improved survival (P = 0·04); multivariable analysis revealed that allo-HCT in CR1 was effective in de novo AML but not in patients with s-AML/t-AML and less in patients exhibiting a complex karyotype. In summary, outcomes of patients with t(8;16) are dismal with chemotherapy, and may be substantially improved with allo-HCT performed in CR1.
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Affiliation(s)
- Sabine Kayser
- Medical Clinic and Policlinic I, Hematology and Cellular Therapy, University Hospital Leipzig, Leipzig, Germany.,NCT Trial Center, National Center of Tumor Diseases, German Cancer Research Center (DKFZ), Heidelberg, Germany.,Department of Internal Medicine V, Heidelberg University Hospital, Heidelberg, Germany
| | | | - Ralitsa Langova
- Division Applied Bioinformatics, German Cancer Research Center (DKFZ), Heidelberg, Germany.,Faculty of Bioscience, University of Heidelberg, Heidelberg, Germany
| | - Michael Kramer
- Department of Medicine I, University Hospital Carl-Gustav-Carus, Dresden, Germany
| | | | - Zuzana Sustkova
- Department of Internal Medicine, Hematology and Oncology, Masaryk University and University Hospital Brno, Brno, Czech Republic
| | - Elihu H Estey
- Clinical Research Division, Fred Hutchinson Cancer Research Center, Seattle, WA, USA.,Division of Hematology/Department of Medicine, University of Washington, Seattle, WA, USA
| | - Carole M Shaw
- Clinical Research Division, Fred Hutchinson Cancer Research Center, Seattle, WA, USA.,Division of Hematology/Department of Medicine, University of Washington, Seattle, WA, USA
| | - Zdeněk Ráčil
- Department of Internal Medicine, Hematology and Oncology, Masaryk University and University Hospital Brno, Brno, Czech Republic.,Institute of Hematology and Blood Transfusion, Prague, Czech Republic
| | - Jiri Mayer
- Department of Internal Medicine, Hematology and Oncology, Masaryk University and University Hospital Brno, Brno, Czech Republic
| | - Pavel Zak
- 4th Department of Internal Medicine-Hematology, Faculty of Medicine, Charles University and University Hospital Hradec Králové, Hradec Králové, Czech Republic
| | - Maria R Baer
- University of Maryland Greenebaum Comprehensive Cancer Center, Baltimore, MD, USA.,Department of Medicine, University of Maryland School of Medicine, Baltimore, MD, USA
| | | | - Tomas Szotkowski
- Department of Hemato-Oncology, Faculty of Medicine and Dentistry, Palacky University Olomouc and University Hospital Olomouc, Olomouc, Czech Republic
| | - Petr Cetkovsky
- Institute of Hematology and Blood Transfusion, Prague, Czech Republic
| | - David Grimwade
- Department of Medical & Molecular Genetics, Faculty of Life Sciences and Medicine, King's College London, London, UK
| | - Roland B Walter
- Clinical Research Division, Fred Hutchinson Cancer Research Center, Seattle, WA, USA.,Division of Hematology/Department of Medicine, University of Washington, Seattle, WA, USA.,Department of Epidemiology, University of Washington, Seattle, WA, USA
| | - Alan K Burnett
- Department of Haematology, School of Medicine, Cardiff University, Cardiff, UK
| | - Anthony D Ho
- Department of Internal Medicine V, Heidelberg University Hospital, Heidelberg, Germany
| | - Gerhard Ehninger
- Department of Medicine I, University Hospital Carl-Gustav-Carus, Dresden, Germany
| | - Carsten Müller-Tidow
- Department of Internal Medicine V, Heidelberg University Hospital, Heidelberg, Germany
| | - Uwe Platzbecker
- Medical Clinic and Policlinic I, Hematology and Cellular Therapy, University Hospital Leipzig, Leipzig, Germany
| | - Christian Thiede
- Department of Medicine I, University Hospital Carl-Gustav-Carus, Dresden, Germany
| | - Christoph Röllig
- Department of Medicine I, University Hospital Carl-Gustav-Carus, Dresden, Germany
| | - Angela Schulz
- Genomics and Proteomics Core Facility High Throughput Sequencing, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Gregor Warsow
- Omics IT and Data Management, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Benedikt Brors
- Division Applied Bioinformatics, German Cancer Research Center (DKFZ), Heidelberg, Germany.,Department of Medical Oncology, National Center for Tumor Diseases (NCT), Heidelberg University Hospital, Heidelberg, Germany.,German Cancer Consortium (DKTK), Core Center Heidelberg, Heidelberg, Germany
| | | | - Nigel H Russell
- Department of Haematology, Nottingham University Hospitals NHS Trust, Nottingham, UK
| | - Richard F Schlenk
- NCT Trial Center, National Center of Tumor Diseases, German Cancer Research Center (DKFZ), Heidelberg, Germany.,Department of Internal Medicine V, Heidelberg University Hospital, Heidelberg, Germany.,Department of Medical Oncology, National Center for Tumor Diseases (NCT), Heidelberg University Hospital, Heidelberg, Germany
| | - Mark J Levis
- Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins University, Baltimore, MD, USA
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Guan J, Lu C, Jin Q, Lu H, Chen X, Tian L, Zhang Y, Ortega J, Zhang J, Siteni S, Chen M, Gu L, Shay JW, Davis AJ, Chen ZJ, Fu YX, Li GM. MLH1 Deficiency-Triggered DNA Hyperexcision by Exonuclease 1 Activates the cGAS-STING Pathway. Cancer Cell 2021; 39:109-121.e5. [PMID: 33338427 PMCID: PMC8666006 DOI: 10.1016/j.ccell.2020.11.004] [Citation(s) in RCA: 106] [Impact Index Per Article: 35.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/07/2020] [Revised: 09/22/2020] [Accepted: 11/13/2020] [Indexed: 12/15/2022]
Abstract
Tumors with defective mismatch repair (dMMR) are responsive to immunotherapy because of dMMR-induced neoantigens and activation of the cGAS-STING pathway. While neoantigens result from the hypermutable nature of dMMR, it is unknown how dMMR activates the cGAS-STING pathway. We show here that loss of the MutLα subunit MLH1, whose defect is responsible for ~50% of dMMR cancers, results in loss of MutLα-specific regulation of exonuclease 1 (Exo1) during DNA repair. This leads to unrestrained DNA excision by Exo1, which causes increased single-strand DNA formation, RPA exhaustion, DNA breaks, and aberrant DNA repair intermediates. Ultimately, this generates chromosomal abnormalities and the release of nuclear DNA into the cytoplasm, activating the cGAS-STING pathway. In this study, we discovered a hitherto unknown MMR mechanism that modulates genome stability and has implications for cancer therapy.
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Affiliation(s)
- Junhong Guan
- Department of Radiation Oncology, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Changzheng Lu
- Department of Pathology, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Qihuang Jin
- Department of Radiation Oncology, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Huiming Lu
- Department of Radiation Oncology, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Xiang Chen
- Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, TX, USA; Howard Hughes Medical Institute, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Lei Tian
- Department of Cancer Biology, Basser Center for BRCA, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Yanbin Zhang
- Department of Biochemistry & Molecular Biology, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Janice Ortega
- Department of Radiation Oncology, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Junqiu Zhang
- Department of Radiation Oncology, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Silvia Siteni
- Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Mingyi Chen
- Department of Pathology, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Liya Gu
- Department of Radiation Oncology, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Jerry W Shay
- Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Anthony J Davis
- Department of Radiation Oncology, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Zhijian J Chen
- Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, TX, USA; Howard Hughes Medical Institute, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Yang-Xin Fu
- Department of Pathology, University of Texas Southwestern Medical Center, Dallas, TX, USA.
| | - Guo-Min Li
- Department of Radiation Oncology, University of Texas Southwestern Medical Center, Dallas, TX, USA.
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35
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Reyes GX, Kolodziejczak A, Devakumar LJPS, Kubota T, Kolodner RD, Putnam CD, Hombauer H. Ligation of newly replicated DNA controls the timing of DNA mismatch repair. Curr Biol 2021; 31:1268-1276.e6. [PMID: 33417883 PMCID: PMC8281387 DOI: 10.1016/j.cub.2020.12.018] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2020] [Revised: 11/10/2020] [Accepted: 12/14/2020] [Indexed: 11/23/2022]
Abstract
Mismatch repair (MMR) safeguards genome stability through recognition and excision of DNA replication errors.1–4 How eukaryotic MMR targets the newly replicated strand in vivo has not been established. MMR reactions reconstituted in vitro are directed to the strand containing a preexisting nick or gap,5–8 suggesting that strand discontinuities could act as discrimination signals. Another candidate is the proliferating cell nuclear antigen (PCNA) that is loaded at replication forks and is required for the activation of Mlh1-Pms1 endonuclease.7–9 Here, we discovered that overexpression of DNA ligase I (Cdc9) in Saccharomyces cerevisiae causes elevated mutation rates and increased chromatin-bound PCNA levels and accumulation of Pms1 foci that are MMR intermediates, suggesting that premature ligation of replication-associated nicks interferes with MMR. We showed that yeast Pms1 expression is mainly restricted to S phase, in agreement with the temporal coupling between MMR and DNA replication.10 Restricting Pms1 expression to the G2/M phase caused a mutator phenotype that was exacerbated in the absence of the exonuclease Exo1. This mutator phenotype was largely suppressed by increasing the lifetime of replication-associated DNA nicks, either by reducing or delaying Cdc9 ligase activity in vivo. Therefore, Cdc9 dictates a window of time for MMR determined by transient DNA nicks that direct the Mlh1-Pms1 in a strand-specific manner. Because DNA nicks occur on both newly synthesized leading and lagging strands,11 these results establish a general mechanism for targeting MMR to the newly synthesized DNA, thus preventing the accumulation of mutations that underlie the development of human cancer. The correction of DNA replication errors by the mismatch repair (MMR) machinery requires the discrimination between parental and daughter DNA strands. Reyes et al. provide evidence that DNA replication-associated nicks are used as MMR strand discrimination signals and that DNA ligase I (Cdc9) activity dictates a window of time for MMR.
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Affiliation(s)
- Gloria X Reyes
- DNA Repair Mechanisms and Cancer, German Cancer Research Center (DKFZ), Heidelberg 69120, Germany
| | - Anna Kolodziejczak
- DNA Repair Mechanisms and Cancer, German Cancer Research Center (DKFZ), Heidelberg 69120, Germany; Faculty of Bioscience, Heidelberg University, Heidelberg 69120, Germany
| | - Lovely Jael Paul Solomon Devakumar
- Institute of Medical Sciences, School of Medicine, Medical Sciences & Nutrition, University of Aberdeen, Foresterhill, Aberdeen, Scotland AB25 2ZD, UK
| | - Takashi Kubota
- Institute of Medical Sciences, School of Medicine, Medical Sciences & Nutrition, University of Aberdeen, Foresterhill, Aberdeen, Scotland AB25 2ZD, UK
| | - Richard D Kolodner
- Ludwig Institute for Cancer Research, University of California, San Diego, School of Medicine, La Jolla, CA 92093-0669, USA; Department of Cellular and Molecular Medicine, University of California, San Diego, School of Medicine, La Jolla, CA 92093-0669, USA; Moores Cancer Center at UC San Diego Health, University of California, San Diego, School of Medicine, La Jolla, CA 92093-0669, USA; Institute of Genomic Medicine, University of California, San Diego, School of Medicine, La Jolla, CA 92093-0669, USA
| | - Christopher D Putnam
- Ludwig Institute for Cancer Research, University of California, San Diego, School of Medicine, La Jolla, CA 92093-0669, USA; Department of Medicine, University of California, San Diego, School of Medicine, La Jolla, CA 92093-0669, USA
| | - Hans Hombauer
- DNA Repair Mechanisms and Cancer, German Cancer Research Center (DKFZ), Heidelberg 69120, Germany; Zentrum für Molekulare Biologie der Universität Heidelberg (ZMBH), Heidelberg 69120, Germany.
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36
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Lee KC, Yen CK, Chen CN, Chang SF, Lu YC, Huang WS. Drug Resistance of CPT-11 in Human DLD-1 Colorectal Cancer Cells through MutS Homolog 2 Upregulation. Int J Med Sci 2021; 18:1269-1276. [PMID: 33526988 PMCID: PMC7847627 DOI: 10.7150/ijms.52620] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/31/2020] [Accepted: 12/18/2020] [Indexed: 11/20/2022] Open
Abstract
Colorectal cancers (CRCs) is the most commonly diagnosed and deadly cancer types in the world. Despite advances in chemotherapy for CRCs, drug resistance remains a major challenge to high incurable and eventually deadly rates for patients. CPT-11 is one of the current chemotherapy agents for CRC patients and the CPT-11 resistance development of CRCs is also inevitable. Recently, accumulating data has suggested that DNA repair system might be an inducer of chemotherapy resistance in cancer cells. Thus, this study was aimed to examine whether MutS homolog (MSH) 2, one member of DNA repair system, plays a role to affect the cytotoxicity of CPT-11 to CRCs. Human DLD-1 CRC cells were used in this study. It was shown that MSH2 gene and protein expression could be upregulated in DLD-1 cells under CPT-11 treatment and this upregulation subsequently attenuates the sensitivity of DLD-1 cells to CPT-11. Moreover, ERK1/2 and Akt signaling and AP-1 transcription factor have been found to modulate these effects. These results elucidate the drug resistance role of MSH2 upregulation in the CPT-11-treated DLD-1 CRC cells. Our findings may provide a useful thought for new adjuvant drug development by controlling the DNA repair system.
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Affiliation(s)
- Ko-Chao Lee
- Department of Colorectal Surgery, Department of Surgery, Chang Gung Memorial Hospital; Kaohsiung Medical Center, Kaohsiung 833, Taiwan
| | - Chia-Kung Yen
- Department of Food Science, National Chiayi University, Chiayi 600, Taiwan
| | - Cheng-Nan Chen
- Department of Biochemical Science and Technology, National Chiayi University, Chiayi 600, Taiwan
| | - Shun-Fu Chang
- Department of Medical Research and Development, Chiayi Chang Gung Memorial Hospital, Chiayi 613, Taiwan
| | - Ying-Chen Lu
- Department of Food Science, National Chiayi University, Chiayi 600, Taiwan
| | - Wen-Shih Huang
- Graduate Institute of Clinical Medical Sciences, College of Medicine, Chang Gung University, Taoyuan 333, Taiwan.,Division of Colon and Rectal Surgery, Department of Surgery, Chiayi Chang Gung Memorial Hospital, Chiayi 613, Taiwan
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Abstract
Through novel methodologies, including both basic and clinical research, progress has been made in the therapy of solid cancer. Recent innovations in anticancer therapies, including immune checkpoint inhibitor biologics, therapeutic vaccines, small drugs, and CAR-T cell injections, mark a new epoch in cancer research, already known for faster (epi-)genomics, transcriptomics, and proteomics. As the long-sought after personalization of cancer therapies comes to fruition, the need to evaluate all current therapeutic possibilities and select the best for each patient is of paramount importance. This is a novel task for medical care that deserves prominence in therapeutic considerations in the future. This is because cancer is a complex genetic disease. In its deadly form, metastatic cancer, it includes altered genes (and their regulators) that encode ten hallmarks of cancer-independent growth, dodging apoptosis, immortalization, multidrug resistance, neovascularization, invasiveness, genome instability, inflammation, deregulation of metabolism, and avoidance of destruction by the immune system. These factors have been known targets for many anticancer drugs and treatments, and their modulation is a therapeutic goal, with the hope of rendering solid cancer a chronic rather than deadly disease. In this article, the current therapeutic arsenal against cancers is reviewed with a focus on immunotherapies.
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Affiliation(s)
- Zlatko Dembic
- Molecular Genetics Laboratory, Department of Oral Biology, Faculty of Dentistry, University of Oslo, 0316 Oslo, Norway
- Molecular Genetics Laboratory, Department of Oral Biology, Faculty of Dentistry, University of Oslo, 0316 Oslo, Norway
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38
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Gupta A, George R, Aboobacker FN, ThamaraiSelvi B, Priscilla AJ. Pilomatricomas and café au lait macules as herald signs of constitutional mismatch repair deficiency (CMMRD) syndrome-A case report. Pediatr Dermatol 2020; 37:1139-1141. [PMID: 32876971 DOI: 10.1111/pde.14332] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Constitutional mismatch repair deficiency (CMMRD) syndrome results from bi-allelic mutations in DNA mismatch repair genes-MLH1, MSH2, MSH6, or PMS2. We present two siblings with CMMRD having p.Arg802Ter (c.2404C >T) homozygous mutations in PMS2 exon 14 with typical cutaneous features. This case report highlights the role of the dermatologist in early diagnosis of this condition.
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Affiliation(s)
- Ankan Gupta
- Department of Dermatology, CMC Hospital, Vellore, India
| | - Renu George
- Department of Dermatology, CMC Hospital, Vellore, India
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Kirstein A, Schmid TE, Combs SE. The Role of miRNA for the Treatment of MGMT Unmethylated Glioblastoma Multiforme. Cancers (Basel) 2020; 12:cancers12051099. [PMID: 32354046 PMCID: PMC7281574 DOI: 10.3390/cancers12051099] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2020] [Revised: 04/23/2020] [Accepted: 04/26/2020] [Indexed: 12/12/2022] Open
Abstract
Glioblastoma multiforme (GBM) is the most common high-grade intracranial tumor in adults. It is characterized by uncontrolled proliferation, diffuse infiltration due to high invasive and migratory capacities, as well as intense resistance to chemo- and radiotherapy. With a five-year survival of less than 3% and an average survival rate of 12 months after diagnosis, GBM has become a focus of current research to urgently develop new therapeutic approaches in order to prolong survival of GBM patients. The methylation status of the promoter region of the O6-methylguanine–DNA methyltransferase (MGMT) is nowadays routinely analyzed since a methylated promoter region is beneficial for an effective response to temozolomide-based chemotherapy. Furthermore, several miRNAs were identified regulating MGMT expression, apart from promoter methylation, by degrading MGMT mRNA before protein translation. These miRNAs could be a promising innovative treatment approach to enhance Temozolomide (TMZ) sensitivity in MGMT unmethylated patients and to increase progression-free survival as well as long-term survival. In this review, the relevant miRNAs are systematically reviewed.
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Affiliation(s)
- Anna Kirstein
- Institute of Radiation Medicine (IRM), Department of Radiation Sciences (DRS), Helmholtz Zentrum München, 85764 Neuherberg, Germany
- Department of Radiation Oncology, Technical University of Munich (TUM), Klinikum Rechts der Isar, 81675 Munich, Germany
| | - Thomas E. Schmid
- Institute of Radiation Medicine (IRM), Department of Radiation Sciences (DRS), Helmholtz Zentrum München, 85764 Neuherberg, Germany
- Department of Radiation Oncology, Technical University of Munich (TUM), Klinikum Rechts der Isar, 81675 Munich, Germany
| | - Stephanie E. Combs
- Institute of Radiation Medicine (IRM), Department of Radiation Sciences (DRS), Helmholtz Zentrum München, 85764 Neuherberg, Germany
- Department of Radiation Oncology, Technical University of Munich (TUM), Klinikum Rechts der Isar, 81675 Munich, Germany
- Deutsches Konsortium für Translationale Krebsforschung (DKTK), Partner Site Munich, 81675 Munich, Germany
- Correspondence: ; Tel.: +49-89-4140-4501
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40
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Fan Z, Pei R, Sha K, Chen L, Wang T, Lu Y. Comprehensive characterization of driver genes in diffuse large B cell lymphoma. Oncol Lett 2020; 20:382-390. [PMID: 32565964 PMCID: PMC7285964 DOI: 10.3892/ol.2020.11552] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2019] [Accepted: 03/09/2020] [Indexed: 01/08/2023] Open
Abstract
Diffuse large B cell lymphoma (DLBCL) is the most common hematological malignancy and is one of the most frequent non-Hodgkin lymphomas. Large-scale genomic studies have defined genetic drivers of DLBCL and their association with functional and clinical outcomes. However, the lymphomagenesis of DLBCL is yet to be fully understood. In the present study, four computational tools OncodriveFM, OncodriveCLUST, integrated Cancer Genome Score and Driver Genes and Pathways were used to detect driver genes and driver pathways involved in DLBCL. The aforementioned tools were also used to perform an integrative investigation of driver genes, including co-expression network, protein-protein interaction, copy number variation and survival analyses. The present study identified 208 driver genes and 31 driver pathways in DLBCL. IGLL5, MLL2, BTG2, B2M, PIM1, CARD11 were the top five frequently mutated genes in DLBCL. NOTCH3, LAMC1, COL4A1, PDGFRB and KDR were the 5 hub genes in the blue module that were associated with patient age. TP53, MYC, EGFR, PTEN, IL6, STAT3, MAPK8, TNF and CDH1 were at the core of the protein-protein interaction network. PRDM1, CDKN2A, CDKN2B, TNFAIP3, RSPO3 were the top five frequently deleted driver genes in DLBCL, while ACTB, BTG2, PLET1, CARD11, DIXDC1 were the top five frequently amplified driver genes in DLBCL. High EIF3B, MLH1, PPP1CA and RECQL4 expression was associated with decreased overall survival rate of patients with DLBCL. High XPO1 and LYN expression were associated with increased overall survival rate of patients with DLBCL. The present study improves the understanding of the biological processes and pathways involved in lymphomagenesis. The driver genes, EIF3B, MLH1, PPP1CA, RECQL4, XPO1 and LYN, pave the way for developing prognostic biomarkers and new therapeutic strategies for DLBCL.
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Affiliation(s)
- Zheng Fan
- Department of Hematology, Yinzhou Hospital Affiliated to Medical School of Ningbo University, Ningbo, Zhejiang 315000, P.R. China
| | - Renzhi Pei
- Department of Hematology, Yinzhou Hospital Affiliated to Medical School of Ningbo University, Ningbo, Zhejiang 315000, P.R. China
| | - Keya Sha
- Department of Hematology, Yinzhou Hospital Affiliated to Medical School of Ningbo University, Ningbo, Zhejiang 315000, P.R. China
| | - Lieguang Chen
- Department of Hematology, Yinzhou Hospital Affiliated to Medical School of Ningbo University, Ningbo, Zhejiang 315000, P.R. China
| | - Tiantian Wang
- Department of Hematology, Yinzhou Hospital Affiliated to Medical School of Ningbo University, Ningbo, Zhejiang 315000, P.R. China
| | - Ying Lu
- Department of Hematology, Yinzhou Hospital Affiliated to Medical School of Ningbo University, Ningbo, Zhejiang 315000, P.R. China
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41
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Biocompatible superparamagnetic nanoparticles with ibuprofen as potential drug carriers. SN APPLIED SCIENCES 2020. [DOI: 10.1007/s42452-020-2265-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
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42
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Kreidieh M, Mukherji D, Temraz S, Shamseddine A. Expanding the Scope of Immunotherapy in Colorectal Cancer: Current Clinical Approaches and Future Directions. BIOMED RESEARCH INTERNATIONAL 2020; 2020:9037217. [PMID: 32090113 PMCID: PMC7008242 DOI: 10.1155/2020/9037217] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/26/2019] [Accepted: 08/16/2019] [Indexed: 12/14/2022]
Abstract
The success of immune checkpoint inhibitors (ICIs) in an increasing range of heavily mutated tumor types such as melanoma has culminated in their exploration in different subsets of patients with metastatic colorectal cancer (mCRC). As a result of their dramatic and durable response rates in patients with chemorefractory, mismatch repair-deficient-microsatellite instability-high (dMMR-MSI-H) mCRC, ICIs have become potential alternatives to classical systemic therapies. The anti-programmed death-1 (PD-1) agents, Pembrolizumab and Nivolumab, have been granted FDA approval for this subset of patients. Unfortunately, however, not all CRC cases with the dMMR-MSI-H phenotype respond well to ICIs, and ongoing studies are currently exploring biomarkers that can predict good response to them. Another challenge lies in developing novel treatment strategies for the subset of patients with the mismatch repair-proficient-microsatellite instability-low (pMMR-MSI-L) phenotype that comprises 95% of all mCRC cases in whom treatment with currently approved ICIs has been largely unsuccessful. Approaches aiming at overcoming the resistance of tumors in this subset of patients are being developed including combining different checkpoint inhibitors with either chemotherapy, anti-angiogenic agents, cancer vaccines, adoptive cell transfer (ACT), or bispecific T-cell (BTC) antibodies. This review describes the rationale behind using immunotherapeutics in CRC. It sheds light on the progress made in the use of immunotherapy in the treatment of patients with dMMR-MSI-H CRC. It also discusses emerging approaches and proposes potential strategies for targeting the immune microenvironment in patients with pMMR-MSI-L CRC tumors in an attempt to complement immune checkpoint inhibition.
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Affiliation(s)
- Malek Kreidieh
- Division of Hematology and Oncology, Department of Internal Medicine, American University of Beirut, Beirut, Lebanon
| | - Deborah Mukherji
- Division of Hematology and Oncology, Department of Internal Medicine, American University of Beirut, Beirut, Lebanon
| | - Sally Temraz
- Division of Hematology and Oncology, Department of Internal Medicine, American University of Beirut, Beirut, Lebanon
| | - Ali Shamseddine
- Division of Hematology and Oncology, Department of Internal Medicine, American University of Beirut, Beirut, Lebanon
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43
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Mitra S, Bodor DL, David AF, Abdul-Zani I, Mata JF, Neumann B, Reither S, Tischer C, Jansen LET. Genetic screening identifies a SUMO protease dynamically maintaining centromeric chromatin. Nat Commun 2020; 11:501. [PMID: 31980633 PMCID: PMC6981222 DOI: 10.1038/s41467-019-14276-x] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2019] [Accepted: 12/18/2019] [Indexed: 12/27/2022] Open
Abstract
Centromeres are defined by a self-propagating chromatin structure based on stable inheritance of CENP-A containing nucleosomes. Here, we present a genetic screen coupled to pulse-chase labeling that allow us to identify proteins selectively involved in deposition of nascent CENP-A or in long-term transmission of chromatin-bound CENP-A. These include factors with known roles in DNA replication, repair, chromatin modification, and transcription, revealing a broad set of chromatin regulators that impact on CENP-A dynamics. We further identify the SUMO-protease SENP6 as a key factor, not only controlling CENP-A stability but virtually the entire centromere and kinetochore. Loss of SENP6 results in hyper-SUMOylation of CENP-C and CENP-I but not CENP-A itself. SENP6 activity is required throughout the cell cycle, suggesting that a dynamic SUMO cycle underlies a continuous surveillance of the centromere complex that in turn ensures stable transmission of CENP-A chromatin.
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Affiliation(s)
- Sreyoshi Mitra
- Department of Biochemistry, University of Oxford, South Parks Road, Oxford, OX1 3QU, UK
- Instituto Gulbenkian de Ciência, 2780-156, Oeiras, Portugal
| | - Dani L Bodor
- Instituto Gulbenkian de Ciência, 2780-156, Oeiras, Portugal
- MRC-Laboratory for Molecular Cell Biology, UCL, London, WC1E 6BT, UK
| | - Ana F David
- Instituto Gulbenkian de Ciência, 2780-156, Oeiras, Portugal
- Institute of Molecular Biotechnology, Dr. Bohr-Gasse 3, 1030, Vienna, Austria
| | - Izma Abdul-Zani
- Department of Biochemistry, University of Oxford, South Parks Road, Oxford, OX1 3QU, UK
| | - João F Mata
- Instituto Gulbenkian de Ciência, 2780-156, Oeiras, Portugal
| | - Beate Neumann
- European Molecular Biology Laboratory (EMBL), Meyerhofstrasse 1, D-69117, Heidelberg, Germany
| | - Sabine Reither
- European Molecular Biology Laboratory (EMBL), Meyerhofstrasse 1, D-69117, Heidelberg, Germany
| | - Christian Tischer
- European Molecular Biology Laboratory (EMBL), Meyerhofstrasse 1, D-69117, Heidelberg, Germany
| | - Lars E T Jansen
- Department of Biochemistry, University of Oxford, South Parks Road, Oxford, OX1 3QU, UK.
- Instituto Gulbenkian de Ciência, 2780-156, Oeiras, Portugal.
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44
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Paul Solomon Devakumar LJ, Gaubitz C, Lundblad V, Kelch BA, Kubota T. Effective mismatch repair depends on timely control of PCNA retention on DNA by the Elg1 complex. Nucleic Acids Res 2020; 47:6826-6841. [PMID: 31114918 PMCID: PMC6648347 DOI: 10.1093/nar/gkz441] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2018] [Revised: 05/06/2019] [Accepted: 05/09/2019] [Indexed: 11/14/2022] Open
Abstract
Proliferating cell nuclear antigen (PCNA) is a sliding clamp that acts as a central co-ordinator for mismatch repair (MMR) as well as DNA replication. Loss of Elg1, the major subunit of the PCNA unloader complex, causes over-accumulation of PCNA on DNA and also increases mutation rate, but it has been unclear if the two effects are linked. Here we show that timely removal of PCNA from DNA by the Elg1 complex is important to prevent mutations. Although premature unloading of PCNA generally increases mutation rate, the mutator phenotype of elg1Δ is attenuated by PCNA mutants PCNA-R14E and PCNA-D150E that spontaneously fall off DNA. In contrast, the elg1Δ mutator phenotype is exacerbated by PCNA mutants that accumulate on DNA due to enhanced electrostatic PCNA–DNA interactions. Epistasis analysis suggests that PCNA over-accumulation on DNA interferes with both MMR and MMR-independent process(es). In elg1Δ, over-retained PCNA hyper-recruits the Msh2–Msh6 mismatch recognition complex through its PCNA-interacting peptide motif, causing accumulation of MMR intermediates. Our results suggest that PCNA retention controlled by the Elg1 complex is critical for efficient MMR: PCNA needs to be on DNA long enough to enable MMR, but if it is retained too long it interferes with downstream repair steps.
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Affiliation(s)
- Lovely Jael Paul Solomon Devakumar
- Institute of Medical Sciences, School of Medicine, Medical Sciences & Nutrition, University of Aberdeen, Foresterhill, Aberdeen AB25 2ZD, Scotland, UK
| | - Christl Gaubitz
- Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, MA 01605, USA
| | | | - Brian A Kelch
- Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, MA 01605, USA
| | - Takashi Kubota
- Institute of Medical Sciences, School of Medicine, Medical Sciences & Nutrition, University of Aberdeen, Foresterhill, Aberdeen AB25 2ZD, Scotland, UK
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SMARCAD1-mediated recruitment of the DNA mismatch repair protein MutLα to MutSα on damaged chromatin induces apoptosis in human cells. J Biol Chem 2020. [DOI: 10.1016/s0021-9258(17)49915-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
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Takeishi Y, Fujikane R, Rikitake M, Obayashi Y, Sekiguchi M, Hidaka M. SMARCAD1-mediated recruitment of the DNA mismatch repair protein MutLα to MutSα on damaged chromatin induces apoptosis in human cells. J Biol Chem 2019; 295:1056-1065. [PMID: 31843968 DOI: 10.1074/jbc.ra119.008854] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2019] [Revised: 12/12/2019] [Indexed: 12/12/2022] Open
Abstract
The mismatch repair (MMR) complex is composed of MutSα (MSH2-MSH6) and MutLα (MLH1-PMS2) and specifically recognizes mismatched bases during DNA replication. O 6-Methylguanine is produced by treatment with alkylating agents, such as N-methyl-N-nitrosourea (MNU), and during DNA replication forms a DNA mismatch (i.e. an O 6-methylguanine/thymine pair) and induces a G/C to A/T transition mutation. To prevent this outcome, cells carrying this DNA mismatch are eliminated by MMR-dependent apoptosis, but the underlying molecular mechanism is unclear. In this study, we provide evidence that the chromatin-regulatory and ATP-dependent nucleosome-remodeling protein SMARCAD1 is involved in the induction of MMR-dependent apoptosis in human cells. Unlike control cells, SMARCAD1-knockout cells (ΔSMARCAD1) were MNU-resistant, and the appearance of a sub-G1 population and caspase-9 activation were significantly suppressed in the ΔSMARCAD1 cells. Furthermore, the MNU-induced mutation frequencies were increased in these cells. Immunoprecipitation analyses revealed that the recruitment of MutLα to chromatin-bound MutSα, observed in SMARCAD1-proficient cells, is suppressed in ΔSMARCAD1 cells. Of note, the effect of SMARCAD1 on the recruitment of MutLα exclusively depended on the ATPase activity of the protein. On the basis of these findings, we propose that SMARCAD1 induces apoptosis via its chromatin-remodeling activity, which helps recruit MutLα to MutSα on damaged chromatin.
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Affiliation(s)
- Yukimasa Takeishi
- Advanced Science Research Center, Fukuoka Dental College, Fukuoka 814-0193, Japan
| | - Ryosuke Fujikane
- Department of Physiological Science and Molecular Biology, Fukuoka Dental College, Fukuoka 814-0193, Japan
| | - Mihoko Rikitake
- Department of Physiological Science and Molecular Biology, Fukuoka Dental College, Fukuoka 814-0193, Japan.,Department of Oral Growth and Development, Fukuoka Dental College, Fukuoka 814-0193, Japan
| | - Yuko Obayashi
- Department of Physiological Science and Molecular Biology, Fukuoka Dental College, Fukuoka 814-0193, Japan.,Department of Oral and Maxillofacial Surgery, Fukuoka Dental College, Fukuoka 814-0193, Japan
| | - Mutsuo Sekiguchi
- Advanced Science Research Center, Fukuoka Dental College, Fukuoka 814-0193, Japan
| | - Masumi Hidaka
- Department of Physiological Science and Molecular Biology, Fukuoka Dental College, Fukuoka 814-0193, Japan
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47
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Lorca V, Garre P. Current status of the genetic susceptibility in attenuated adenomatous polyposis. World J Gastrointest Oncol 2019; 11:1101-1114. [PMID: 31908716 PMCID: PMC6937445 DOI: 10.4251/wjgo.v11.i12.1101] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/16/2019] [Revised: 08/18/2019] [Accepted: 10/14/2019] [Indexed: 02/05/2023] Open
Abstract
Adenomatous polyposis (AP) is classified according to cumulative adenoma number in classical AP (CAP) and attenuated AP (AAP). Genetic susceptibility is the major risk factor in CAP due to mutations in the known high predisposition genes APC and MUTYH. However, the contribution of genetic susceptibility to AAP is lower and less understood. New predisposition genes have been recently proposed, and some of them have been validated, but their scarcity hinders accurate risk estimations and prevalence calculations. AAP is a heterogeneous condition in terms of severity, clinical features and heritability. Therefore, clinicians do not have strong discriminating criteria for the recommendation of the genetic study of known predisposition genes, and the detection rate is low. Elucidation and knowledge of new AAP high predisposition genes are of great importance to offer accurate genetic counseling to the patient and family members. This review aims to update the genetic knowledge of AAP, and to expound the difficulties involved in the genetic analysis of a highly heterogeneous condition such as AAP.
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Affiliation(s)
- Víctor Lorca
- Laboratorio de Oncología Molecular, Grupo de Investigación Clínica y Traslacional en Oncología, Hospital Clínico San Carlos, Madrid 28040, Spain
| | - Pilar Garre
- Laboratorio de Oncología Molecular, Servicio de Oncología, Hospital Clínico San Carlos, Madrid 28040, Spain
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48
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Defects in the GINS complex increase the instability of repetitive sequences via a recombination-dependent mechanism. PLoS Genet 2019; 15:e1008494. [PMID: 31815930 PMCID: PMC6922473 DOI: 10.1371/journal.pgen.1008494] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2019] [Revised: 12/19/2019] [Accepted: 10/25/2019] [Indexed: 12/16/2022] Open
Abstract
Faithful replication and repair of DNA lesions ensure genome maintenance. During replication in eukaryotic cells, DNA is unwound by the CMG helicase complex, which is composed of three major components: the Cdc45 protein, Mcm2-7, and the GINS complex. The CMG in complex with DNA polymerase epsilon (CMG-E) participates in the establishment and progression of the replisome. Impaired functioning of the CMG-E was shown to induce genomic instability and promote the development of various diseases. Therefore, CMG-E components play important roles as caretakers of the genome. In Saccharomyces cerevisiae, the GINS complex is composed of the Psf1, Psf2, Psf3, and Sld5 essential subunits. The Psf1-1 mutant form fails to interact with Psf3, resulting in impaired replisome assembly and chromosome replication. Here, we show increased instability of repeat tracts (mononucleotide, dinucleotide, trinucleotide and longer) in yeast psf1-1 mutants. To identify the mechanisms underlying this effect, we analyzed repeated sequence instability using derivatives of psf1-1 strains lacking genes involved in translesion synthesis, recombination, or mismatch repair. Among these derivatives, deletion of RAD52, RAD51, MMS2, POL32, or PIF1 significantly decreased DNA repeat instability. These results, together with the observed increased amounts of single-stranded DNA regions and Rfa1 foci suggest that recombinational mechanisms make important contributions to repeat tract instability in psf1-1 cells. We propose that defective functioning of the CMG-E complex in psf1-1 cells impairs the progression of DNA replication what increases the contribution of repair mechanisms such as template switch and break-induced replication. These processes require sequence homology search which in case of a repeated DNA tract may result in misalignment leading to its expansion or contraction. Processes that ensure genome stability are crucial for all organisms to avoid mutations and decrease the risk of diseases. The coordinated activity of mechanisms underlying the maintenance of high-fidelity DNA duplication and repair is critical to deal with the malfunction of replication forks or DNA damage. Repeated sequences in DNA are particularly prone to instability; these sequences undergo expansions or contractions, leading in humans to various neurological, neurodegenerative, and neuromuscular disorders. A mutant form of one of the noncatalytic subunits of active DNA helicase complex impairs DNA replication. Here, we show that this form also significantly increases the instability of mononucleotide, dinucleotide, trinucleotide and longer repeat tracts. Our results suggest that in cells that harbor a mutated variant of the helicase complex, continuation of DNA replication is facilitated by recombination processes, and this mechanism can be highly mutagenic during repair synthesis through repetitive regions, especially regions that form secondary structures. Our results indicate that proper functioning of the DNA helicase complex is crucial for maintenance of the stability of repeated DNA sequences, especially in the context of recently described disorders in which mutations or deregulation of the human homologs of genes encoding DNA helicase subunits were observed.
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Bakhtiari E, Monfared AS, Niaki HA, Borzoueisileh S, Niksirat F, Fattahi S, Monfared MK, Gorji KE. The expression of MLH1 and MSH2 genes among inhabitants of high background radiation area of Ramsar, Iran. JOURNAL OF ENVIRONMENTAL RADIOACTIVITY 2019; 208-209:106012. [PMID: 31323602 DOI: 10.1016/j.jenvrad.2019.106012] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/13/2018] [Revised: 06/16/2019] [Accepted: 07/03/2019] [Indexed: 06/10/2023]
Abstract
Previous studies evidenced the critical role of the mismatch repair system in DNA damage recognition, cell cycle arrest, apoptosis and DNA repair. MLH1 and MSH2 genes belong to repairing complexes of mismatch repair system. The side effects of ionizing radiation on the human health were proved, but researches on the inhabitants of high background radiation areas, with extra-ordinary radiation exposure, showed that the prevalence of cancer or radiation-related diseases is not significantly higher than normal background areas. The city of Ramsar, in northern Iran, has the highest level of natural background radiation in the world and in this study, we aimed to evaluate the expression of MLH1 and MSH2 genes among the inhabitants of high background radiation areas of Ramsar compared to normal background radiation areas. In the present study, 60 blood sample from high and normal background inhabitants were collected and we MLH1, and MSH2 genes expressions in residents of high background radiation area compared with normal background radiation area were evaluated by Quantitative Real-Time PCR. Our results showed a significant upregulation of MLH1 in residents of high background radiation area. Also, there is a significant association between MLH1 and MSH2 gene expression in both sexes. Also, the increased expression of MLH1 in HBRA is notable. There is an increased expression of MLH1 in age above 50 and a decreased expression of MSH2 in ages under 50 years (P < 0.0001). These findings are suggesting the triggering of Mismatch Repair system in response to high-level of natural background radiation.
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Affiliation(s)
- Elahe Bakhtiari
- Student Research Committee, Babol University of Medical Sciences, Babol, I.R Iran; Cellular and Molecular Biology Research Center, Health Research Institute, Babol University of Medical Sciences, Babol, I.R.Iran
| | - Ali Shabestani Monfared
- Cancer Research Center, Health Research Institute, Babol University of Medical Sciences, Babol, I.R.Iran
| | - Hale Akhavan Niaki
- Department of Genetics, School of Medicine, Babol University of Medical Sciences, Babol, I.R Iran
| | - Sajad Borzoueisileh
- Cellular and Molecular Biology Research Center, Health Research Institute, Babol University of Medical Sciences, Babol, I.R.Iran
| | - Fatemeh Niksirat
- Department of Medical Physics Radiobiology and Radiation Protection, School of Medicine, Babol University of Medical Sciences, Babol, I.R Iran
| | - Sadegh Fattahi
- Cellular and Molecular Biology Research Center, Health Research Institute, Babol University of Medical Sciences, Babol, I.R.Iran; North Research Centre of Pasteur Institute, Amol, I.R.Iran
| | - Mohadese Kosari Monfared
- Cellular and Molecular Biology Research Center, Health Research Institute, Babol University of Medical Sciences, Babol, I.R.Iran
| | - Kourosh Ebrahimnejad Gorji
- Department of Medical Physics Radiobiology and Radiation Protection, School of Medicine, Babol University of Medical Sciences, Babol, I.R Iran.
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Goellner EM. Chromatin remodeling and mismatch repair: Access and excision. DNA Repair (Amst) 2019; 85:102733. [PMID: 31698199 DOI: 10.1016/j.dnarep.2019.102733] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2019] [Revised: 09/06/2019] [Accepted: 10/09/2019] [Indexed: 01/03/2023]
Abstract
DNA mismatch repair (MMR) increases replication fidelity and genome stability by correcting DNA polymerase errors that remain after replication. Defects in MMR result in the accumulation of mutations and lead to human tumor development. Germline mutations in MMR cause the hereditary cancer syndrome, Lynch syndrome. After replication, DNA is reorganized into its chromatin structure and wrapped around histone octamers. DNA MMR is thought to be less efficient in recognizing and repairing mispairs packaged in chromatin, in which case MMR must either compete for access to naked DNA before histone deposition or actively move nucleosomes to access the mispair. This article reviews studies into the mechanistic and physical interactions between MMR and various chromatin-associated factors, including the histone deposition complex CAF1. Recent Xenopus and Saccharomyces cerevisiae studies describe a physical interaction between Msh2 and chromatin-remodeling ATPase Fun30/SMARCAD1, with potential mechanistic roles for SMARCAD1 in moving histones for both mispair access and excision tract elongation. The RSC complex, another histone remodeling complex, also potentially influences excision tract length. Deletion mutations of RSC2 point to mechanistic interactions with the MMR pathways. Together, these studies paint a picture of complex interactions between MMR and the chromatin environment that will require numerous additional genetic, biochemical, and cell biology experiments to fully understand. Understanding how these pathways interconnect is essential in fully understanding eukaryotic MMR and has numerous implications in human tumor formation and treatment.
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Affiliation(s)
- Eva M Goellner
- Department of Toxicology and Cancer Biology, Markey Cancer Center, University of Kentucky College of Medicine, Lexington, KY, 40536, USA.
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