1
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Kadyrova LY, Mieczkowski PA, Kadyrov FA. MutLα suppresses error-prone DNA mismatch repair and preferentially protects noncoding DNA from mutations. J Biol Chem 2024; 300:107406. [PMID: 38782208 PMCID: PMC11231602 DOI: 10.1016/j.jbc.2024.107406] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2024] [Revised: 05/15/2024] [Accepted: 05/16/2024] [Indexed: 05/25/2024] Open
Abstract
The DNA mismatch repair (MMR) system promotes genome stability and protects humans from certain types of cancer. Its primary function is the correction of DNA polymerase errors. MutLα is an important eukaryotic MMR factor. We have examined the contributions of MutLα to maintaining genome stability. We show here that loss of MutLα in yeast increases the genome-wide mutation rate by ∼130-fold and generates a genome-wide mutation spectrum that consists of small indels and base substitutions. We also show that loss of yeast MutLα leads to error-prone MMR that produces T > C base substitutions in 5'-ATA-3' sequences. In agreement with this finding, our examination of human whole-genome DNA sequencing data has revealed that loss of MutLα in induced pluripotent stem cells triggers error-prone MMR that leads to the formation of T > C mutations in 5'-NTN-3' sequences. Our further analysis has shown that MutLα-independent MMR plays a role in suppressing base substitutions in N3 homopolymeric runs. In addition, we describe that MutLα preferentially protects noncoding DNA from mutations. Our study defines the contributions of MutLα-dependent and independent mechanisms to genome-wide MMR.
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Affiliation(s)
- Lyudmila Y Kadyrova
- Division of Biochemistry and Molecular Biology, Department of Biomedical Sciences, Southern Illinois University School of Medicine, Carbondale, Illinois, USA
| | - Piotr A Mieczkowski
- Department of Genetics, Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, North Carolina, USA
| | - Farid A Kadyrov
- Division of Biochemistry and Molecular Biology, Department of Biomedical Sciences, Southern Illinois University School of Medicine, Carbondale, Illinois, USA.
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2
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Kadyrova LY, Mieczkowski PA, Kadyrov FA. MutLα suppresses error-prone DNA mismatch repair and preferentially protects noncoding DNA from mutations. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.04.01.587563. [PMID: 38617288 PMCID: PMC11014525 DOI: 10.1101/2024.04.01.587563] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/16/2024]
Abstract
The DNA mismatch repair (MMR) system promotes genome stability and protects humans from certain types of cancer. Its primary function is the correction of DNA polymerase errors. MutLα is an important eukaryotic MMR factor. We have examined the contributions of MutLα to maintaining genome stability. We show here that loss of MutLα in yeast increases the genome-wide mutation rate by ~130-fold and generates a genome-wide mutation spectrum that consists of small indels and base substitutions. We also show that loss of yeast MutLα leads to error-prone MMR that produces T>C base substitutions in 5'-ATA-3' sequences. In agreement with this finding, our examination of human whole genome DNA sequencing data has revealed that loss of MutLα in induced pluripotent stem cells triggers error-prone MMR that leads to the formation of T>C mutations in 5'-NTN-3' sequences. Our further analysis has shown that MutLα-independent MMR plays a role in suppressing base substitutions in N3 homopolymeric runs. In addition, we describe that MutLα preferentially defends noncoding DNA from mutations. Our study defines the contributions of MutLα-dependent and independent mechanisms to genome-wide MMR.
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Affiliation(s)
- Lyudmila Y. Kadyrova
- Division of Biochemistry and Molecular Biology, Department of Biomedical Sciences, Southern Illinois University School of Medicine, Carbondale, IL 62901, USA
| | - Piotr A. Mieczkowski
- Department of Genetics, Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, North Carolina 27599, USA
| | - Farid A. Kadyrov
- Division of Biochemistry and Molecular Biology, Department of Biomedical Sciences, Southern Illinois University School of Medicine, Carbondale, IL 62901, USA
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3
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Pretta A, Ziranu P, Giampieri R, Pinna G, Randon G, Donisi C, Ravarino A, Loi F, Deias G, Palmas E, Pretta G, Morano F, Semonella F, Mariani S, Deidda MA, Pusceddu V, Puzzoni M, Lai E, Solinas C, Restivo A, Zorcolo L, Barbara R, Berardi R, Faa G, Pietrantonio F, Scartozzi M. Mismatch Repair system protein deficiency as a resistance factor for locally advanced rectal adenocarcinoma patients receiving neoadjuvant chemo-radiotherapy. Br J Cancer 2023; 129:1619-1624. [PMID: 37749283 PMCID: PMC10646038 DOI: 10.1038/s41416-023-02444-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2023] [Accepted: 09/14/2023] [Indexed: 09/27/2023] Open
Abstract
BACKGROUND Available data on Mismatch Repair system (MMR) deficiency are conflicting and derived from small studies. Our study aimed to evaluate the therapeutic implications of MMR status in patients with locally advanced rectal cancer (LARC). METHODS We retrospectively collected data from 318 patients affected by LARC treated in Italy at the Medical Oncology Units of the University Hospital of Cagliari, Istituto Nazionale dei Tumori Milan, and AOU Ospedali Riuniti Ancona. All patients underwent neoadjuvant chemoradiotherapy. The primary objective was major TRG while secondary objectives were pathological complete response, disease-free survival (DFS) and overall survival (OS). RESULTS One hundred sixty patients (148 pMMR and 12 dMMR) were included in the exploratory cohort and 158 (146 pMMR and 12 dMMR) were included in the validation cohort. A major TRG has been shown in 42.6% and 43.1% patients with pMMR in exploratory and validation cohort, respectively; while no major TRG have been shown in dMMR patients in both cohorts. Exploratory and validation cohorts showed a statistically significant higher mDFS in pMMR patients compared to dMMR: NR vs. 14 months and NR vs. 17 months, respectively. CONCLUSION Our results indicated an association between dMMR and poor response to preoperative chemoradiotherapy and they represent a hypothesis-generating data for new neoadjuvant strategies.
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Affiliation(s)
- Andrea Pretta
- Medical Oncology Unit, University Hospital and University of Cagliari, Cagliari, Italy.
| | - Pina Ziranu
- Medical Oncology Unit, University Hospital and University of Cagliari, Cagliari, Italy
| | - Riccardo Giampieri
- Medical Oncology Unit, Azienda Ospedaliera Universitaria delle Marche, Ancona, Italy
| | - Giovanna Pinna
- Medical Oncology Unit, University Hospital and University of Cagliari, Cagliari, Italy
| | - Giovanni Randon
- Medical Oncology Department, Fondazione IRCCS Istituto Nazionale dei Tumori, Milano, Italy
| | - Clelia Donisi
- Medical Oncology Unit, University Hospital and University of Cagliari, Cagliari, Italy
| | - Alberto Ravarino
- UOC Anatomia Patologica, AOU Cagliari, University of Cagliari, Cagliari, Italy
| | - Francesco Loi
- Medical Oncology Unit, University Hospital and University of Cagliari, Cagliari, Italy
| | - Giulia Deias
- Medical Oncology Unit, University Hospital and University of Cagliari, Cagliari, Italy
| | - Enrico Palmas
- Medical Oncology Unit, University Hospital and University of Cagliari, Cagliari, Italy
| | - Gianluca Pretta
- Science Department, King's School Hove, Hangleton Way, Hangleton, East Sussex, BN3 8BN, UK
| | - Federica Morano
- Medical Oncology Department, Fondazione IRCCS Istituto Nazionale dei Tumori, Milano, Italy
| | - Francesca Semonella
- Medical Oncology Unit, University Hospital and University of Cagliari, Cagliari, Italy
| | - Stefano Mariani
- Medical Oncology Unit, University Hospital and University of Cagliari, Cagliari, Italy
| | | | - Valeria Pusceddu
- Medical Oncology Unit, University Hospital and University of Cagliari, Cagliari, Italy
| | - Marco Puzzoni
- Medical Oncology Unit, University Hospital and University of Cagliari, Cagliari, Italy
| | - Eleonora Lai
- Medical Oncology Unit, University Hospital and University of Cagliari, Cagliari, Italy
| | - Cinzia Solinas
- Medical Oncology Unit, University Hospital and University of Cagliari, Cagliari, Italy
| | - Angelo Restivo
- Department of General Surgery, University Hospital and University of Cagliari, Cagliari, Italy
| | - Luigi Zorcolo
- Department of General Surgery, University Hospital and University of Cagliari, Cagliari, Italy
| | - Raffaele Barbara
- UOC Radioterapia Oncologica, Azienda Ospedaliera "Brotzu", Cagliari, Italy
| | - Rossana Berardi
- Medical Oncology Unit, Azienda Ospedaliera Universitaria delle Marche, Ancona, Italy
| | - Gavino Faa
- UOC Anatomia Patologica, AOU Cagliari, University of Cagliari, Cagliari, Italy
| | - Filippo Pietrantonio
- Medical Oncology Department, Fondazione IRCCS Istituto Nazionale dei Tumori, Milano, Italy
| | - Mario Scartozzi
- Medical Oncology Unit, University Hospital and University of Cagliari, Cagliari, Italy
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4
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Wolf K, Kosinski J, Gibson TJ, Wesch N, Dötsch V, Genuardi M, Cordisco EL, Zeuzem S, Brieger A, Plotz G. A conserved motif in the disordered linker of human MLH1 is vital for DNA mismatch repair and its function is diminished by a cancer family mutation. Nucleic Acids Res 2023; 51:6307-6320. [PMID: 37224528 PMCID: PMC10325900 DOI: 10.1093/nar/gkad418] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2022] [Revised: 04/26/2023] [Accepted: 05/17/2023] [Indexed: 05/26/2023] Open
Abstract
DNA mismatch repair (MMR) is essential for correction of DNA replication errors. Germline mutations of the human MMR gene MLH1 are the major cause of Lynch syndrome, a heritable cancer predisposition. In the MLH1 protein, a non-conserved, intrinsically disordered region connects two conserved, catalytically active structured domains of MLH1. This region has as yet been regarded as a flexible spacer, and missense alterations in this region have been considered non-pathogenic. However, we have identified and investigated a small motif (ConMot) in this linker which is conserved in eukaryotes. Deletion of the ConMot or scrambling of the motif abolished mismatch repair activity. A mutation from a cancer family within the motif (p.Arg385Pro) also inactivated MMR, suggesting that ConMot alterations can be causative for Lynch syndrome. Intriguingly, the mismatch repair defect of the ConMot variants could be restored by addition of a ConMot peptide containing the deleted sequence. This is the first instance of a DNA mismatch repair defect conferred by a mutation that can be overcome by addition of a small molecule. Based on the experimental data and AlphaFold2 predictions, we suggest that the ConMot may bind close to the C-terminal MLH1-PMS2 endonuclease and modulate its activation during the MMR process.
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Affiliation(s)
- Karla Wolf
- Department of Internal Medicine 1, University Hospital, Goethe University, Frankfurt am Main, 60590, Germany
| | - Jan Kosinski
- European Molecular Biology Laboratory (EMBL), Centre for Structural Systems Biology (CSSB), Hamburg, 22607, Germany
| | - Toby J Gibson
- European Molecular Biology Laboratory (EMBL), Structural and Computational Biology Unit, Heidelberg, 69117, Germany
| | - Nicole Wesch
- Institute of Biophysical Chemistry and Center for Biomolecular Magnetic Resonance, Goethe University, Frankfurt am Main, 60438, Germany
| | - Volker Dötsch
- Institute of Biophysical Chemistry and Center for Biomolecular Magnetic Resonance, Goethe University, Frankfurt am Main, 60438, Germany
| | - Maurizio Genuardi
- UOC Genetica Medica, Fondazione Policlinico Universitario A. Gemelli IRCCS, Rome00168, Italy
| | - Emanuela Lucci Cordisco
- Dipartimento di Scienze della Vita e di Sanità Pubblica, Università Cattolica del Sacro Cuore, Rome00168, Italy
| | - Stefan Zeuzem
- Department of Internal Medicine 1, University Hospital, Goethe University, Frankfurt am Main, 60590, Germany
| | - Angela Brieger
- Department of Internal Medicine 1, University Hospital, Goethe University, Frankfurt am Main, 60590, Germany
| | - Guido Plotz
- Department of Internal Medicine 1, University Hospital, Goethe University, Frankfurt am Main, 60590, Germany
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5
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Park JC, Kim YJ, Han JH, Kim D, Park MJ, Kim J, Jang HK, Bae S, Cha HJ. MutSα and MutSβ as size-dependent cellular determinants for prime editing in human embryonic stem cells. MOLECULAR THERAPY. NUCLEIC ACIDS 2023; 32:914-922. [PMCID: PMC10280094 DOI: 10.1016/j.omtn.2023.05.015] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/04/2022] [Accepted: 05/10/2023] [Indexed: 06/22/2023]
Abstract
Precise genome editing in human pluripotent stem cells (hPSCs) has potential applications in isogenic disease modeling and ex vivo stem cell therapy, necessitating diverse genome editing tools. However, unlike differentiated somatic cells, hPSCs have unique cellular properties that maintain genome integrity, which largely determine the overall efficiency of an editing tool. Considering the high demand for prime editors (PEs), it is imperative to characterize the key molecular determinants of PE outcomes in hPSCs. Through homozygous knockout (KO) of MMR pathway key proteins MSH2, MSH3, and MSH6, we reveal that MutSα and MutSβ determine PE efficiency in an editing size-dependent manner. Notably, MSH2 perturbation disrupted both MutSα and MutSβ complexes, dramatically escalating PE efficiency from base mispair to 10 bases, up to 50 folds. Similarly, impaired MutSα by MSH6 KO improved editing efficiency from single to three base pairs, while defective MutSβ by MSH3 KO heightened efficiency from three to 10 base pairs. Thus, the size-dependent effect of MutSα and MutSβ on prime editing implies that MMR is a vital PE efficiency determinant in hPSCs and highlights the distinct roles of MutSα and MutSβ in its outcome.
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Affiliation(s)
- Ju-Chan Park
- College of Pharmacy, Seoul National University, Seoul, Republic of Korea
| | - Yun-Jeong Kim
- College of Pharmacy, Seoul National University, Seoul, Republic of Korea
| | - Jun Hee Han
- Department of Chemistry, Hanyang University, Seoul, Republic of Korea
| | - Dayeon Kim
- College of Pharmacy, Seoul National University, Seoul, Republic of Korea
| | - Mihn Jeong Park
- College of Pharmacy, Seoul National University, Seoul, Republic of Korea
| | - Jumee Kim
- College of Pharmacy, Seoul National University, Seoul, Republic of Korea
| | - Hyeon-Ki Jang
- Division of Chemical Engineering and Bioengineering, College of Art Culture and Engineering, Kangwon National University, Chuncheon, South Korea
| | - Sangsu Bae
- College of Medicine, Seoul National University, Seoul, Republic of Korea
| | - Hyuk-Jin Cha
- College of Pharmacy, Seoul National University, Seoul, Republic of Korea
- Research Institute of Pharmaceutical Sciences, Seoul National University, Seoul, Republic of Korea
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6
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Kadyrova LY, Mieczkowski PA, Kadyrov FA. Genome-wide contributions of the MutSα- and MutSβ-dependent DNA mismatch repair pathways to the maintenance of genetic stability in S. cerevisiae. J Biol Chem 2023; 299:104705. [PMID: 37059180 DOI: 10.1016/j.jbc.2023.104705] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2023] [Revised: 04/07/2023] [Accepted: 04/08/2023] [Indexed: 04/16/2023] Open
Abstract
The DNA mismatch repair (MMR) system is a major DNA repair system that suppresses inherited and sporadic cancers in humans. In eukaryotes the MutSα-dependent and MutSβ-dependent MMR pathways correct DNA polymerase errors. Here, we investigated these two pathways on a whole-genome level in S. cerevisiae. We found that inactivation of MutSα-dependent MMR by deletion of the MSH6 gene increases the genome-wide mutation rate by ∼17-fold, and loss of MutSβ-dependent MMR via deletion of MSH3 elevates the genome-wide mutation rate by ∼4-fold. We also found that MutSα-dependent MMR does not show a preference for protecting coding or noncoding DNA from mutations, whereas MutSβ-dependent MMR preferentially protects noncoding DNA from mutations. The most frequent mutations in the msh6Δ strain are C>T transitions, whereas 1-6-bp deletions are the most common genetic alterations in the msh3Δ strain. Strikingly, MutSα-dependent MMR is more important than MutSβ-dependent MMR for protection from 1-bp insertions, while MutSβ-dependent MMR has a more critical role in the defense against 1-bp deletions and 2-6-bp indels. We also determined that a mutational signature of yeast MSH6 loss is similar to mutational signatures of human MMR deficiency. Furthermore, our analysis showed that compared to other 5'-NCN-3' trinucleotides, 5'-GCA-3' trinucleotides are at the highest risk of accumulating C>T transitions at the central position in the msh6Δ cells and that the presence of a G/A base at the -1 position is important for the efficient MutSα-dependent suppression of C>T transitions. Our results highlight key differences between the roles of the MutSα-dependent and MutSβ-dependent MMR pathways.
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Affiliation(s)
- Lyudmila Y Kadyrova
- Department of Biochemistry and Molecular Biology, Southern Illinois University School of Medicine, Carbondale, IL 62901, USA
| | - Piotr A Mieczkowski
- Department of Genetics, Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, North Carolina 27599, USA
| | - Farid A Kadyrov
- Department of Biochemistry and Molecular Biology, Southern Illinois University School of Medicine, Carbondale, IL 62901, USA.
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7
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Stoler-Barak L, Harris E, Peres A, Hezroni H, Kuka M, Di Lucia P, Grenov A, Gurwicz N, Kupervaser M, Yip BH, Iannacone M, Yaari G, Crispino JD, Shulman Z. B cell class switch recombination is regulated by DYRK1A through MSH6 phosphorylation. Nat Commun 2023; 14:1462. [PMID: 36927854 PMCID: PMC10020581 DOI: 10.1038/s41467-023-37205-5] [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: 06/21/2022] [Accepted: 03/06/2023] [Indexed: 03/18/2023] Open
Abstract
Protection from viral infections depends on immunoglobulin isotype switching, which endows antibodies with effector functions. Here, we find that the protein kinase DYRK1A is essential for B cell-mediated protection from viral infection and effective vaccination through regulation of class switch recombination (CSR). Dyrk1a-deficient B cells are impaired in CSR activity in vivo and in vitro. Phosphoproteomic screens and kinase-activity assays identify MSH6, a DNA mismatch repair protein, as a direct substrate for DYRK1A, and deletion of a single phosphorylation site impaired CSR. After CSR and germinal center (GC) seeding, DYRK1A is required for attenuation of B cell proliferation. These findings demonstrate DYRK1A-mediated biological mechanisms of B cell immune responses that may be used for therapeutic manipulation in antibody-mediated autoimmunity.
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Affiliation(s)
- Liat Stoler-Barak
- Department of Systems Immunology, Weizmann Institute of Science, Rehovot, 7610001, Israel
| | - Ethan Harris
- Department of Hematology, St. Jude Children's Research Hospital, Memphis, TN, 38105, USA
| | - Ayelet Peres
- Faculty of Engineering, Bar Ilan University, Ramat Gan, 52900, Israel
| | - Hadas Hezroni
- Department of Systems Immunology, Weizmann Institute of Science, Rehovot, 7610001, Israel
| | - Mirela Kuka
- Vita-Salute San Raffaele University and Division of Immunology, Transplantation and Infectious Diseases, IRCCS San Raffaele Scientific Institute, Milan, Italy
| | - Pietro Di Lucia
- Vita-Salute San Raffaele University and Division of Immunology, Transplantation and Infectious Diseases, IRCCS San Raffaele Scientific Institute, Milan, Italy
| | - Amalie Grenov
- Department of Systems Immunology, Weizmann Institute of Science, Rehovot, 7610001, Israel
| | - Neta Gurwicz
- Department of Systems Immunology, Weizmann Institute of Science, Rehovot, 7610001, Israel
| | - Meital Kupervaser
- De Botton Institute for Proteomics, Grand Israel National Center for Personalized Medicine, Weizmann Institute of Science, Rehovot, Israel
| | - Bon Ham Yip
- Department of Hematology, St. Jude Children's Research Hospital, Memphis, TN, 38105, USA
| | - Matteo Iannacone
- Vita-Salute San Raffaele University and Division of Immunology, Transplantation and Infectious Diseases, IRCCS San Raffaele Scientific Institute, Milan, Italy.,Experimental Imaging Center, IRCCS San Raffaele Scientific Institute, Milan, Italy
| | - Gur Yaari
- Faculty of Engineering, Bar Ilan University, Ramat Gan, 52900, Israel
| | - John D Crispino
- Department of Hematology, St. Jude Children's Research Hospital, Memphis, TN, 38105, USA
| | - Ziv Shulman
- Department of Systems Immunology, Weizmann Institute of Science, Rehovot, 7610001, Israel.
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8
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Ovejero-Sánchez M, González-Sarmiento R, Herrero AB. DNA Damage Response Alterations in Ovarian Cancer: From Molecular Mechanisms to Therapeutic Opportunities. Cancers (Basel) 2023; 15:448. [PMID: 36672401 PMCID: PMC9856346 DOI: 10.3390/cancers15020448] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2022] [Revised: 01/03/2023] [Accepted: 01/04/2023] [Indexed: 01/12/2023] Open
Abstract
The DNA damage response (DDR), a set of signaling pathways for DNA damage detection and repair, maintains genomic stability when cells are exposed to endogenous or exogenous DNA-damaging agents. Alterations in these pathways are strongly associated with cancer development, including ovarian cancer (OC), the most lethal gynecologic malignancy. In OC, failures in the DDR have been related not only to the onset but also to progression and chemoresistance. It is known that approximately half of the most frequent subtype, high-grade serous carcinoma (HGSC), exhibit defects in DNA double-strand break (DSB) repair by homologous recombination (HR), and current evidence indicates that probably all HGSCs harbor a defect in at least one DDR pathway. These defects are not restricted to HGSCs; mutations in ARID1A, which are present in 30% of endometrioid OCs and 50% of clear cell (CC) carcinomas, have also been found to confer deficiencies in DNA repair. Moreover, DDR alterations have been described in a variable percentage of the different OC subtypes. Here, we overview the main DNA repair pathways involved in the maintenance of genome stability and their deregulation in OC. We also recapitulate the preclinical and clinical data supporting the potential of targeting the DDR to fight the disease.
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Affiliation(s)
- María Ovejero-Sánchez
- Institute of Biomedical Research of Salamanca (IBSAL), 37007 Salamanca, Spain
- Molecular Medicine Unit, Department of Medicine, University of Salamanca, 37007 Salamanca, Spain
- Institute of Molecular and Cellular Biology of Cancer (IBMCC), University of Salamanca-Spanish National Research Council, 37007 Salamanca, Spain
| | - Rogelio González-Sarmiento
- Institute of Biomedical Research of Salamanca (IBSAL), 37007 Salamanca, Spain
- Molecular Medicine Unit, Department of Medicine, University of Salamanca, 37007 Salamanca, Spain
- Institute of Molecular and Cellular Biology of Cancer (IBMCC), University of Salamanca-Spanish National Research Council, 37007 Salamanca, Spain
| | - Ana Belén Herrero
- Institute of Biomedical Research of Salamanca (IBSAL), 37007 Salamanca, Spain
- Molecular Medicine Unit, Department of Medicine, University of Salamanca, 37007 Salamanca, Spain
- Institute of Molecular and Cellular Biology of Cancer (IBMCC), University of Salamanca-Spanish National Research Council, 37007 Salamanca, Spain
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9
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Abstract
Roughly 3% of the human genome consists of microsatellites or tracts of short tandem repeats (STRs). These STRs are often unstable, undergoing high-frequency expansions (increases) or contractions (decreases) in the number of repeat units. Some microsatellite instability (MSI) is seen at multiple STRs within a single cell and is associated with certain types of cancer. A second form of MSI is characterised by expansion of a single gene-specific STR and such expansions are responsible for a group of 40+ human genetic disorders known as the repeat expansion diseases (REDs). While the mismatch repair (MMR) pathway prevents genome-wide MSI, emerging evidence suggests that some MMR factors are directly involved in generating expansions in the REDs. Thus, MMR suppresses some forms of expansion while some MMR factors promote expansion in other contexts. This review will cover what is known about the paradoxical effect of MMR on microsatellite expansion in mammalian cells.
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10
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Vali-Pour M, Park S, Espinosa-Carrasco J, Ortiz-Martínez D, Lehner B, Supek F. The impact of rare germline variants on human somatic mutation processes. Nat Commun 2022; 13:3724. [PMID: 35764656 PMCID: PMC9240060 DOI: 10.1038/s41467-022-31483-1] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2021] [Accepted: 06/17/2022] [Indexed: 02/07/2023] Open
Abstract
Somatic mutations are an inevitable component of ageing and the most important cause of cancer. The rates and types of somatic mutation vary across individuals, but relatively few inherited influences on mutation processes are known. We perform a gene-based rare variant association study with diverse mutational processes, using human cancer genomes from over 11,000 individuals of European ancestry. By combining burden and variance tests, we identify 207 associations involving 15 somatic mutational phenotypes and 42 genes that replicated in an independent data set at a false discovery rate of 1%. We associate rare inherited deleterious variants in genes such as MSH3, EXO1, SETD2, and MTOR with two phenotypically different forms of DNA mismatch repair deficiency, and variants in genes such as EXO1, PAXIP1, RIF1, and WRN with deficiency in homologous recombination repair. In addition, we identify associations with other mutational processes, such as APEX1 with APOBEC-signature mutagenesis. Many of the genes interact with each other and with known mutator genes within cellular sub-networks. Considered collectively, damaging variants in the identified genes are prevalent in the population. We suggest that rare germline variation in diverse genes commonly impacts mutational processes in somatic cells.
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Affiliation(s)
- Mischan Vali-Pour
- Centre for Genomic Regulation (CRG), The Barcelona Institute of Science and Technology (BIST), Barcelona, Spain
- Universitat Pompeu Fabra (UPF), Barcelona, Spain
| | - Solip Park
- Centro Nacional de Investigaciones Oncológicas (CNIO), Madrid, Spain
| | - Jose Espinosa-Carrasco
- Institute for Research in Biomedicine (IRB Barcelona), The Barcelona Institute of Science and Technology (BIST), Barcelona, Spain
| | - Daniel Ortiz-Martínez
- Institute for Research in Biomedicine (IRB Barcelona), The Barcelona Institute of Science and Technology (BIST), Barcelona, Spain
| | - Ben Lehner
- Centre for Genomic Regulation (CRG), The Barcelona Institute of Science and Technology (BIST), Barcelona, Spain.
- Universitat Pompeu Fabra (UPF), Barcelona, Spain.
- Catalan Institution for Research and Advanced Studies (ICREA), Barcelona, Spain.
| | - Fran Supek
- Institute for Research in Biomedicine (IRB Barcelona), The Barcelona Institute of Science and Technology (BIST), Barcelona, Spain.
- Catalan Institution for Research and Advanced Studies (ICREA), Barcelona, Spain.
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11
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The nuclease activity of DNA2 promotes exonuclease 1-independent mismatch repair. J Biol Chem 2022; 298:101831. [PMID: 35300981 PMCID: PMC9036127 DOI: 10.1016/j.jbc.2022.101831] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2021] [Revised: 03/09/2022] [Accepted: 03/10/2022] [Indexed: 12/03/2022] Open
Abstract
The DNA mismatch repair (MMR) system is a major DNA repair system that corrects DNA replication errors. In eukaryotes, the MMR system functions via mechanisms both dependent on and independent of exonuclease 1 (EXO1), an enzyme that has multiple roles in DNA metabolism. Although the mechanism of EXO1-dependent MMR is well understood, less is known about EXO1-independent MMR. Here, we provide genetic and biochemical evidence that the DNA2 nuclease/helicase has a role in EXO1-independent MMR. Biochemical reactions reconstituted with purified human proteins demonstrated that the nuclease activity of DNA2 promotes an EXO1-independent MMR reaction via a mismatch excision-independent mechanism that involves DNA polymerase δ. We show that DNA polymerase ε is not able to replace DNA polymerase δ in the DNA2-promoted MMR reaction. Unlike its nuclease activity, the helicase activity of DNA2 is dispensable for the ability of the protein to enhance the MMR reaction. Further examination established that DNA2 acts in the EXO1-independent MMR reaction by increasing the strand-displacement activity of DNA polymerase δ. These data reveal a mechanism for EXO1-independent mismatch repair.
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12
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Prime editing efficiency and fidelity are enhanced in the absence of mismatch repair. Nat Commun 2022; 13:760. [PMID: 35140211 PMCID: PMC8828784 DOI: 10.1038/s41467-022-28442-1] [Citation(s) in RCA: 69] [Impact Index Per Article: 34.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2021] [Accepted: 01/26/2022] [Indexed: 02/07/2023] Open
Abstract
Prime editing (PE) is a powerful genome engineering approach that enables the introduction of base substitutions, insertions and deletions into any given genomic locus. However, the efficiency of PE varies widely and depends not only on the genomic region targeted, but also on the genetic background of the edited cell. Here, to determine which cellular factors affect PE efficiency, we carry out a focused genetic screen targeting 32 DNA repair factors, spanning all reported repair pathways. We show that, depending on cell line and type of edit, ablation of mismatch repair (MMR) affords a 2–17 fold increase in PE efficiency, across several human cell lines, types of edits and genomic loci. The accumulation of the key MMR factors MLH1 and MSH2 at PE sites argues for direct involvement of MMR in PE control. Our results shed new light on the mechanism of PE and suggest how its efficiency might be optimised. Prime Editing is a versatile genome engineering tool. Here, the authors identify the DNA repair pathway known as mismatch repair as inhibitory for Prime Editing, thus, loss of mismatch repair enhances the efficiency of Prime Editing.
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13
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Olkinuora AP, Peltomäki PT, Aaltonen LA, Rajamäki K. From APC to the genetics of hereditary and familial colon cancer syndromes. Hum Mol Genet 2021; 30:R206-R224. [PMID: 34329396 PMCID: PMC8490010 DOI: 10.1093/hmg/ddab208] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2021] [Revised: 07/01/2021] [Accepted: 07/05/2021] [Indexed: 11/12/2022] Open
Abstract
Hereditary colorectal cancer (CRC) syndromes attributable to high penetrance mutations represent 9-26% of young-onset CRC cases. The clinical significance of many of these mutations is understood well enough to be used in diagnostics and as an aid in patient care. However, despite the advances made in the field, a significant proportion of familial and early-onset cases remains molecularly uncharacterized and extensive work is still needed to fully understand the genetic nature of CRC susceptibility. With the emergence of next-generation sequencing and associated methods, several predisposition loci have been unraveled, but validation is incomplete. Individuals with cancer-predisposing mutations are currently enrolled in life-long surveillance, but with the development of new treatments, such as cancer vaccinations, this might change in the not so distant future for at least some individuals. For individuals without a known cause for their disease susceptibility, prevention and therapy options are less precise. Herein, we review the progress achieved in the last three decades with a focus on how CRC predisposition genes were discovered. Furthermore, we discuss the clinical implications of these discoveries and anticipate what to expect in the next decade.
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Affiliation(s)
- Alisa P Olkinuora
- Department of Medical and Clinical Genetics, Medicum, University of Helsinki, 00014 Helsinki, Finland
- iCAN Digital Precision Cancer Medicine Flagship, University of Helsinki, 00014 Helsinki, Finland
| | - Päivi T Peltomäki
- Department of Medical and Clinical Genetics, Medicum, University of Helsinki, 00014 Helsinki, Finland
- iCAN Digital Precision Cancer Medicine Flagship, University of Helsinki, 00014 Helsinki, Finland
| | - Lauri A Aaltonen
- Department of Medical and Clinical Genetics, Medicum, University of Helsinki, 00014 Helsinki, Finland
- iCAN Digital Precision Cancer Medicine Flagship, University of Helsinki, 00014 Helsinki, Finland
- Applied Tumor Genomics Research Program, Research Programs Unit, University of Helsinki, 00014 Helsinki, Finland
| | - Kristiina Rajamäki
- Department of Medical and Clinical Genetics, Medicum, University of Helsinki, 00014 Helsinki, Finland
- Applied Tumor Genomics Research Program, Research Programs Unit, University of Helsinki, 00014 Helsinki, Finland
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14
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Shioi S, Shimamoto A, Song Y, Hidaka K, Nakamura M, Take A, Hayashi N, Takiguchi S, Fujikane R, Hidaka M, Oda S, Nakatsu Y. DNA polymerase delta Exo domain stabilizes mononucleotide microsatellites in human cells. DNA Repair (Amst) 2021; 108:103216. [PMID: 34530183 DOI: 10.1016/j.dnarep.2021.103216] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2021] [Revised: 08/19/2021] [Accepted: 08/26/2021] [Indexed: 01/16/2023]
Abstract
In prokaryotes and yeasts, DNA polymerase proofreading (PPR) and DNA mismatch repair (MMR) cooperatively counteracts replication errors leading to repeat sequence destabilization (i.e. insertions/deletions of repeat units). However, PPR has not thus far been regarded as a mechanism stabilizing repeat sequences in higher eukaryotic cells. In a human cancer cell line, DLD-1, which carries mutations in both MSH6 and the Exo domain of POLD1, we previously observed that mononucleotide microsatellites were markedly destabilized whereas being stable in the simple MMR-defective backgrounds. In this study, we introduced the Exo domain mutation found in DLD-1 cells into MSH2-null HeLa cell clones, using CRISPR/Cas9 system. In the established Exo-/MMR-mutated HeLa clones, mononucleotide repeat sequences were remarkably destabilized as in DLD-1 cells. In contrast, dinucleotide microsatellites were readily destabilized in the parental MMR-deficient backgrounds, and the instability was not notably increased in the genome-edited HeLa clones. Here, we show an involvement of the Exo domain functions of DNA polymerase delta in mononucleotide repeat stabilization in human cells, which also suggests a possible role division between DNA polymerase and MMR in repeat maintenance in the human genome.
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Affiliation(s)
- Seijiro Shioi
- Cancer Genetics Laboratory, Clinical Research Institute, National Hospital Organization Kyushu Cancer Center, Fukuoka, Japan
| | - Akiyoshi Shimamoto
- Cancer Genetics Laboratory, Clinical Research Institute, National Hospital Organization Kyushu Cancer Center, Fukuoka, Japan
| | - Yingxia Song
- Department of Medical Biophysics and Radiation Biology, Faculty of Medical Sciences, Kyushu University, Japan
| | - Kyoko Hidaka
- Centre for Fundamental Education, University of Kitakyushu, Kitakyushu, Japan
| | - Maki Nakamura
- Cancer Genetics Laboratory, Clinical Research Institute, National Hospital Organization Kyushu Cancer Center, Fukuoka, Japan
| | - Ayumi Take
- Cancer Genetics Laboratory, Clinical Research Institute, National Hospital Organization Kyushu Cancer Center, Fukuoka, Japan
| | - Namiko Hayashi
- Cancer Genetics Laboratory, Clinical Research Institute, National Hospital Organization Kyushu Cancer Center, Fukuoka, Japan
| | - Soichi Takiguchi
- Cancer Genetics Laboratory, Clinical Research Institute, National Hospital Organization Kyushu Cancer Center, Fukuoka, Japan
| | - Ryosuke Fujikane
- Department of Physiological Science and Molecular Biology, Fukuoka Dental College, Fukuoka, Japan
| | - Masumi Hidaka
- Department of Physiological Science and Molecular Biology, Fukuoka Dental College, Fukuoka, Japan
| | - Shinya Oda
- Cancer Genetics Laboratory, Clinical Research Institute, National Hospital Organization Kyushu Cancer Center, Fukuoka, Japan.
| | - Yoshimichi Nakatsu
- Department of Medical Biophysics and Radiation Biology, Faculty of Medical Sciences, Kyushu University, Japan.
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15
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Kratz K, Artola-Borán M, Kobayashi-Era S, Koh G, Oliveira G, Kobayashi S, Oliveira A, Zou X, Richter J, Tsuda M, Sasanuma H, Takeda S, Loizou JI, Sartori AA, Nik-Zainal S, Jiricny J. FANCD2-Associated Nuclease 1 Partially Compensates for the Lack of Exonuclease 1 in Mismatch Repair. Mol Cell Biol 2021; 41:e0030321. [PMID: 34228493 PMCID: PMC8384067 DOI: 10.1128/mcb.00303-21] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2021] [Accepted: 06/28/2021] [Indexed: 11/20/2022] Open
Abstract
Germline mutations in the mismatch repair (MMR) genes MSH2, MSH6, MLH1, and PMS2 are linked to cancer of the colon and other organs, characterized by microsatellite instability and a large increase in mutation frequency. Unexpectedly, mutations in EXO1, encoding the only exonuclease genetically implicated in MMR, are not linked to familial cancer and cause a substantially weaker mutator phenotype. This difference could be explained if eukaryotic cells possessed additional exonucleases redundant with EXO1. Analysis of the MLH1 interactome identified FANCD2-associated nuclease 1 (FAN1), a novel enzyme with biochemical properties resembling EXO1. We now show that FAN1 efficiently substitutes for EXO1 in MMR assays and that this functional complementation is modulated by its interaction with MLH1. FAN1 also contributes to MMR in vivo; cells lacking both EXO1 and FAN1 have an MMR defect and display resistance to N-methyl-N-nitrosourea (MNU) and 6-thioguanine (TG). Moreover, FAN1 loss amplifies the mutational profile of EXO1-deficient cells, suggesting that the two nucleases act redundantly in the same antimutagenic pathway. However, the increased drug resistance and mutator phenotype of FAN1/EXO1-deficient cells are less prominent than those seen in cells lacking MSH6 or MLH1. Eukaryotic cells thus apparently possess additional mechanisms that compensate for the loss of EXO1.
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Affiliation(s)
- Katja Kratz
- Institute of Molecular Cancer Research, University of Zurich, Zurich, Switzerland
| | - Mariela Artola-Borán
- Institute of Molecular Cancer Research, University of Zurich, Zurich, Switzerland
| | - Saho Kobayashi-Era
- Institute of Molecular Cancer Research, University of Zurich, Zurich, Switzerland
- Institute of Biochemistry of the ETH Zurich, Zurich, Switzerland
| | - Gene Koh
- Wellcome Sanger Institute, Wellcome Genome Campus, Hinxton, United Kingdom
- Academic Department of Medical Genetics, The Clinical School, University of Cambridge, Cambridge, United Kingdom
- MRC Cancer Unit, The Clinical School, University of Cambridge, Cambridge, United Kingdom
| | - Goncalo Oliveira
- Institute of Cancer Research, Department of Medicine I, Comprehensive Cancer Centre, Medical University of Vienna, Vienna, Austria
| | - Shunsuke Kobayashi
- Institute of Molecular Cancer Research, University of Zurich, Zurich, Switzerland
- Institute of Biochemistry of the ETH Zurich, Zurich, Switzerland
| | - Andreia Oliveira
- Institute of Molecular Cancer Research, University of Zurich, Zurich, Switzerland
- Institute of Biochemistry of the ETH Zurich, Zurich, Switzerland
| | - Xueqing Zou
- Wellcome Sanger Institute, Wellcome Genome Campus, Hinxton, United Kingdom
- Academic Department of Medical Genetics, The Clinical School, University of Cambridge, Cambridge, United Kingdom
- MRC Cancer Unit, The Clinical School, University of Cambridge, Cambridge, United Kingdom
| | - Julia Richter
- Institute of Biochemistry of the ETH Zurich, Zurich, Switzerland
| | - 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
| | - Shunichi Takeda
- Department of Radiation Genetics, Graduate School of Medicine, Kyoto University, Kyoto, Japan
| | - Joanna I. Loizou
- Institute of Cancer Research, Department of Medicine I, Comprehensive Cancer Centre, Medical University of Vienna, Vienna, Austria
| | | | - Serena Nik-Zainal
- Academic Department of Medical Genetics, The Clinical School, University of Cambridge, Cambridge, United Kingdom
- MRC Cancer Unit, The Clinical School, University of Cambridge, Cambridge, United Kingdom
| | - Josef Jiricny
- Institute of Molecular Cancer Research, University of Zurich, Zurich, Switzerland
- Institute of Biochemistry of the ETH Zurich, Zurich, Switzerland
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16
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Zou X, Koh GCC, Nanda AS, Degasperi A, Urgo K, Roumeliotis TI, Agu CA, Badja C, Momen S, Young J, Amarante TD, Side L, Brice G, Perez-Alonso V, Rueda D, Gomez C, Bushell W, Harris R, Choudhary JS, Jiricny J, Skarnes WC, Nik-Zainal S. A systematic CRISPR screen defines mutational mechanisms underpinning signatures caused by replication errors and endogenous DNA damage. NATURE CANCER 2021; 2:643-657. [PMID: 34164627 PMCID: PMC7611045 DOI: 10.1038/s43018-021-00200-0] [Citation(s) in RCA: 76] [Impact Index Per Article: 25.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/04/2020] [Accepted: 03/17/2021] [Indexed: 02/02/2023]
Abstract
Mutational signatures are imprints of pathophysiological processes arising through tumorigenesis. We generated isogenic CRISPR-Cas9 knockouts (Δ) of 43 genes in human induced pluripotent stem cells, cultured them in the absence of added DNA damage, and performed whole-genome sequencing of 173 subclones. ΔOGG1, ΔUNG, ΔEXO1, ΔRNF168, ΔMLH1, ΔMSH2, ΔMSH6, ΔPMS1, and ΔPMS2 produced marked mutational signatures indicative of being critical mitigators of endogenous DNA modifications. Detailed analyses revealed mutational mechanistic insights, including how 8-oxo-dG elimination is sequence-context-specific while uracil clearance is sequence-context-independent. Mismatch repair (MMR) deficiency signatures are engendered by oxidative damage (C>A transversions), differential misincorporation by replicative polymerases (T>C and C>T transitions), and we propose a 'reverse template slippage' model for T>A transversions. ΔMLH1, ΔMSH6, and ΔMSH2 signatures were similar to each other but distinct from ΔPMS2. Finally, we developed a classifier, MMRDetect, where application to 7,695 WGS cancers showed enhanced detection of MMR-deficient tumors, with implications for responsiveness to immunotherapies.
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Affiliation(s)
- Xueqing Zou
- Academic Department of Medical Genetics, School of Clinical Medicine, University of Cambridge, Cambridge, UK
- MRC Cancer Unit, University of Cambridge, Cambridge, UK
- Wellcome Sanger Institute, Hinxton, UK
| | - Gene Ching Chiek Koh
- Academic Department of Medical Genetics, School of Clinical Medicine, University of Cambridge, Cambridge, UK
- MRC Cancer Unit, University of Cambridge, Cambridge, UK
- Wellcome Sanger Institute, Hinxton, UK
| | - Arjun Scott Nanda
- Academic Department of Medical Genetics, School of Clinical Medicine, University of Cambridge, Cambridge, UK
- MRC Cancer Unit, University of Cambridge, Cambridge, UK
| | - Andrea Degasperi
- Academic Department of Medical Genetics, School of Clinical Medicine, University of Cambridge, Cambridge, UK
- MRC Cancer Unit, University of Cambridge, Cambridge, UK
- Wellcome Sanger Institute, Hinxton, UK
| | | | | | | | - Cherif Badja
- Academic Department of Medical Genetics, School of Clinical Medicine, University of Cambridge, Cambridge, UK
- MRC Cancer Unit, University of Cambridge, Cambridge, UK
- Wellcome Sanger Institute, Hinxton, UK
| | - Sophie Momen
- Academic Department of Medical Genetics, School of Clinical Medicine, University of Cambridge, Cambridge, UK
- MRC Cancer Unit, University of Cambridge, Cambridge, UK
| | - Jamie Young
- Academic Department of Medical Genetics, School of Clinical Medicine, University of Cambridge, Cambridge, UK
| | - Tauanne Dias Amarante
- Academic Department of Medical Genetics, School of Clinical Medicine, University of Cambridge, Cambridge, UK
- MRC Cancer Unit, University of Cambridge, Cambridge, UK
| | - Lucy Side
- UCL Institute for Women's Health, Great Ormond Street Hospital, London, UK
- Wessex Clinical Genetics Service, Princess Anne Hospital, Southampton, UK
| | - Glen Brice
- Southwest Thames Regional Genetics Service, St George's University of London, London, UK
| | - Vanesa Perez-Alonso
- Pediatrics Department, Doce de Octubre University Hospital, i+12 Research Institute, Madrid, Spain
| | - Daniel Rueda
- Hereditary Cancer Laboratory, Doce de Octubre University Hospital, i+12 Research Institute, Madrid, Spain
| | | | | | - Rebecca Harris
- Academic Department of Medical Genetics, School of Clinical Medicine, University of Cambridge, Cambridge, UK
- Wellcome Sanger Institute, Hinxton, UK
| | - Jyoti S Choudhary
- The Institute of Cancer Research, Chester Beatty Laboratories, London, UK
| | - Josef Jiricny
- Institute of Molecular Life Sciences, University of Zurich, Zurich, Switzerland
- Institute of Biochemistry, ETH Zurich, Zurich, Switzerland
| | - William C Skarnes
- Wellcome Sanger Institute, Hinxton, UK
- William Harvey Research Institute, Queen Mary University of London, London, UK
| | - Serena Nik-Zainal
- Academic Department of Medical Genetics, School of Clinical Medicine, University of Cambridge, Cambridge, UK.
- MRC Cancer Unit, University of Cambridge, Cambridge, UK.
- Wellcome Sanger Institute, Hinxton, UK.
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17
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Tamura K, Kaneda M, Futagawa M, Takeshita M, Kim S, Nakama M, Kawashita N, Tatsumi-Miyajima J. Genetic and genomic basis of the mismatch repair system involved in Lynch syndrome. Int J Clin Oncol 2019; 24:999-1011. [PMID: 31273487 DOI: 10.1007/s10147-019-01494-y] [Citation(s) in RCA: 45] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2019] [Accepted: 06/17/2019] [Indexed: 12/11/2022]
Abstract
Lynch syndrome is a cancer-predisposing syndrome inherited in an autosomal-dominant manner, wherein colon cancer and endometrial cancer develop frequently in the family, it results from a loss-of-function mutation in one of four different genes (MLH1, MSH2, MSH6, and PMS2) encoding mismatch repair proteins. Being located immediately upstream of the MSH2 gene, EPCAM abnormalities can affect MSH2 and cause Lynch syndrome. Mismatch repair proteins are involved in repairing of incorrect pairing (point mutations and deletion/insertion of simple repetitive sequences, so-called microsatellites) that can arise during DNA replication. MSH2 forms heterodimers with MSH6 or MSH3 (MutSα, MutSβ, respectively) and is involved in mismatch-pair recognition and initiation of repair. MLH1 forms a complex with PMS2, and functions as an endonuclease. If the mismatch repair system is thoroughly working, genome integrity is maintained completely. Lynch syndrome is a state of mismatch repair deficiency due to a monoallelic abnormality of any mismatch repair genes. The phenotype indicating the mismatch repair deficiency can be frequently shown as a microsatellite instability in tumors. Children with germline biallelic mismatch repair gene abnormalities were reported to develop conditions such as gastrointestinal polyposis, colorectal cancer, brain cancer, leukemia, etc., and so on, demonstrating the need to respond with new concepts in genetic counseling. In promoting cancer genome medicine in a new era, such as by utilizing immune checkpoints, it is important to understand the genetic and genomic molecular background, including the status of mismatch repair deficiency.
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Affiliation(s)
- Kazuo Tamura
- Division of Medical Genetics, Master of Science, Graduate School of Science and Engineering Research, Kindai University, Higashiosaka, Japan.
| | - Motohide Kaneda
- Division of Medical Genetics, Master of Science, Graduate School of Science and Engineering Research, Kindai University, Higashiosaka, Japan
| | - Mashu Futagawa
- Division of Medical Genetics, Master of Science, Graduate School of Science and Engineering Research, Kindai University, Higashiosaka, Japan
| | - Miho Takeshita
- Division of Medical Genetics, Master of Science, Graduate School of Science and Engineering Research, Kindai University, Higashiosaka, Japan
| | - Sanghyuk Kim
- Division of Medical Genetics, Master of Science, Graduate School of Science and Engineering Research, Kindai University, Higashiosaka, Japan
| | - Mina Nakama
- Division of Clinical Genetics, Gifu University Hospital, Gifu, Japan
| | - Norihito Kawashita
- Division of Medical Genetics, Master of Science, Graduate School of Science and Engineering Research, Kindai University, Higashiosaka, Japan
| | - Junko Tatsumi-Miyajima
- Division of Medical Genetics, Master of Science, Graduate School of Science and Engineering Research, Kindai University, Higashiosaka, Japan
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18
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Torshizi Esfahani A, Seyedna SY, Nazemalhosseini Mojarad E, Majd A, Asadzadeh Aghdaei H. MSI-L/EMAST is a predictive biomarker for metastasis in colorectal cancer patients. J Cell Physiol 2018; 234:13128-13136. [PMID: 30549036 DOI: 10.1002/jcp.27983] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2018] [Accepted: 11/21/2018] [Indexed: 12/12/2022]
Abstract
BACKGROUND Microsatellite instability (MSI) is a prognostic marker in colorectal cancer (CRC). The biological significance of MSI-low (MSI-L) phenotype and its differences with microsatellite stable (MSS) phenotype remains unclear. The aim of this study is indicating the role of mononucleotide repeat in identifying MSI-L and revealing the association of MSI-L with elevated microsatellite alterations at selected tetranucleotide repeats (EMAST) and oncologic outcome in CRC patients. METHODS MSI and EMAST status were analyzed using three quasimonomorphic panel (BAT-25, BAT-26, and NR-27) and five tetranucleotide repeats (D20S82, D20S85, D9S242, D8S321, and MYCL1), respectively, by capillary electrophoresis method without the need to fluorescent primers. The associations of MSI status with clinicopathological features, EMAST status, metastasis, and overall survival (OS) were investigated. RESULTS Among 159 CRC patient 22.0% were MSI-H, 40.3% were MSS, 37.7% were MSI-L, and 41.5% showed EMAST + phenotype. MSI-L were associated with advanced stages, EMAST+ tumors and worse OS ( p ≤ 0.001). Metastasis was relatively common in MSI-L/EMAST + CRCs and BAT-25 were the most unstable marker in these tumors. CONCLUSIONS MSI-L tumors have different clinicopathological features from MSS and MSI-H tumors. The MSI-L phenotype is a worse prognostic biomarker in CRC and when accompanied by EMAST could be a predictor for metastasis.
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Affiliation(s)
- Amir Torshizi Esfahani
- Department of Biology, Faculty of Biological Sciences, Islamic Azad University, North Tehran Branch, Tehran, Iran
| | - Seyed Yoosef Seyedna
- Department of Biology, Faculty of Biological Sciences, Islamic Azad University, North Tehran Branch, Tehran, Iran
| | - Ehsan Nazemalhosseini Mojarad
- Department of Cancer, Gastroenterology and Liver Diseases Research Center, Research Institute for Gastroenterology and Liver Diseases, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Ahmad Majd
- Department of Molecular Medicine, Department of Cellular and Molecular Biology, Faculty of Biological Sciences, Islamic Azad University, North Tehran Branch, Tehran, Iran
| | - Hamid Asadzadeh Aghdaei
- Basic and Molecular Epidemiology of Gastrointestinal Disorders Research Center, Research Institute for Gastroenterology and Liver Diseases, Shahid Beheshti University of Medical Sciences, Tehran, Iran
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19
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Duan FX, Gu GL, Yang HR, Yu PF, Zhang Z. Must Peutz-Jeghers syndrome patients have the LKB1/STK11 gene mutation? A case report and review of the literature. World J Clin Cases 2018; 6:224-232. [PMID: 30148152 PMCID: PMC6107527 DOI: 10.12998/wjcc.v6.i8.224] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/21/2018] [Revised: 04/23/2018] [Accepted: 05/13/2018] [Indexed: 02/05/2023] Open
Abstract
Peutz-Jeghers syndrome (PJS) is an autosomal dominant inherited disease, which is characterized by mucocutaneous pigmentation and multiple gastrointestinal hamartoma polyps. The germline mutation of LKB1/STK11 gene on chromosome 19p13.3 is considered to be the hereditary cause of PJS. However, must a patient with PJS have the LKB1/STK11 gene mutation? We here report a case of a male patient who had typical manifestations of PJS and a definite family history, but did not have LKB1/STK11 gene mutation. By means of high-throughput sequencing technology, only mutations in APC gene (c.6662T > C: p.Met2221Thr) and MSH6 gene (c.3488A > T: p.Glu1163Val) were detected. The missense mutations in APC and MSH6 gene may lead to abnormalities in structure and function of their expression products, and may result in the occurrence of PJS. This study suggests that some other genetic disorders may cause PJS besides LKB1/STK11 gene mutation.
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Affiliation(s)
- Fu-Xiao Duan
- Department of General Surgery, Air Force General Hospital of Chinese PLA, Beijing 100142, China
| | - Guo-Li Gu
- Department of General Surgery, Air Force General Hospital of Chinese PLA, Beijing 100142, China
| | - Hai-Rui Yang
- Department of General Surgery, Air Force General Hospital of Chinese PLA, Beijing 100142, China
| | - Peng-Fei Yu
- Department of General Surgery, Air Force General Hospital of Chinese PLA, Beijing 100142, China
| | - Zhi Zhang
- Department of General Surgery, Air Force General Hospital of Chinese PLA, Beijing 100142, China
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20
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Cama A, Genuardi M, Guanti G, Radice P, Varesco L. Molecular Genetics of Hereditary Non-Polyposis Colorectal Cancer (HNPCC). TUMORI JOURNAL 2018; 82:122-35. [PMID: 8644374 DOI: 10.1177/030089169608200206] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
The story of the molecular genetics of HNPCC is one of astonishingly rapid achievements. In just 16 months, from May 1993 to September 1994, four different genes, namely hMSH2, hMLH1, hPMS1 and hPMS2 have been identified and demonstrated to be associated with the disease. Their cloning was facilitated by the finding that tumor cells in HNPCC patients display a hypermutability of DNA short tandem repeats (microsatellite instability). In fact, HNPCC associated genes are the human counterparts of genetic elements known to control the fidelity of DNA replication in lower organisms. So far, more than 50 germline mutations of hMSH2 and hMLH1 genes have been reported in HNPCC kindreds. In addition, somatic mutations have been documented in hereditary as well as sporadic cancers. Unfortunately, the molecular diagnosis of HNPCC is hampered by the lack of mutational “hot spots” and of clearly defined genotype-phenotype correlations and different screening methods are to be employed for the analysis of affected and at-risk individuals.
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Affiliation(s)
- A Cama
- Cattedra di Patologia Generale, Università Gabriele D'Annuzio, Chieti,Italy
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21
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Koi M, Tseng-Rogenski SS, Carethers JM. Inflammation-associated microsatellite alterations: Mechanisms and significance in the prognosis of patients with colorectal cancer. World J Gastrointest Oncol 2018; 10:1-14. [PMID: 29375743 PMCID: PMC5767788 DOI: 10.4251/wjgo.v10.i1.1] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/26/2017] [Revised: 11/29/2017] [Accepted: 12/06/2017] [Indexed: 02/05/2023] Open
Abstract
Microsatellite alterations within genomic DNA frameshift as a result of defective DNA mismatch repair (MMR). About 15% of sporadic colorectal cancers (CRCs) manifest hypermethylation of the DNA MMR gene MLH1, resulting in mono- and di-nucleotide frameshifts to classify it as microsatellite instability-high (MSI-H) and hypermutated, and due to frameshifts at coding microsatellites generating neo-antigens, produce a robust protective immune response that can be enhanced with immune checkpoint blockade. More commonly, approximately 50% of sporadic non-MSI-H CRCs demonstrate frameshifts at di- and tetra-nucleotide microsatellites to classify it as MSI-low/elevated microsatellite alterations at selected tetranucleotide repeats (EMAST) as a result of functional somatic inactivation of the DNA MMR protein MSH3 via a nuclear-to-cytosolic displacement. The trigger for MSH3 displacement appears to be inflammation and/or oxidative stress, and unlike MSI-H CRC patients, patients with MSI-L/EMAST CRCs show poor prognosis. These inflammatory-associated microsatellite alterations are a consequence of the local tumor microenvironment, and in theory, if the microenvironment is manipulated to lower inflammation, the microsatellite alterations and MSH3 dysfunction should be corrected. Here we describe the mechanisms and significance of inflammatory-associated microsatellite alterations, and propose three areas to deeply explore the consequences and prevention of inflammation's effect upon the DNA MMR system.
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Affiliation(s)
- Minoru Koi
- Division of Gastroenterology, Department of Internal Medicine and Comprehensive Cancer Center, University of Michigan, Ann Arbor, MI 48109-5368, United States
| | - Stephanie S Tseng-Rogenski
- Division of Gastroenterology, Department of Internal Medicine and Comprehensive Cancer Center, University of Michigan, Ann Arbor, MI 48109-5368, United States
| | - John M Carethers
- Division of Gastroenterology, Department of Internal Medicine and Comprehensive Cancer Center, University of Michigan, Ann Arbor, MI 48109-5368, United States
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22
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Yuan Y, Zhao Y, Chen L, Wu J, Chen G, Li S, Zou J, Chen R, Wang J, Jiang F, Tang Z. Selective tumor cell death induced by irradiated riboflavin through recognizing DNA G-T mismatch. Nucleic Acids Res 2017; 45:8676-8683. [PMID: 28911109 PMCID: PMC5587794 DOI: 10.1093/nar/gkx602] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2017] [Accepted: 07/04/2017] [Indexed: 12/04/2022] Open
Abstract
Riboflavin (vitamin B2) has been thought to be a promising antitumoral agent in photodynamic therapy, though the further application of the method was limited by the unclear molecular mechanism. Our work reveals that riboflavin was able to recognize G–T mismatch specifically and induce single-strand breaks in duplex DNA targets efficiently under irradiation. In the presence of riboflavin, the photo-irradiation could induce the death of tumor cells that are defective in mismatch repair system selectively, highlighting the G–T mismatch as potential drug target for tumor cells. Moreover, riboflavin is a promising leading compound for further drug design due to its inherent specific recognition of the G–T mismatch.
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Affiliation(s)
- Yi Yuan
- Natural Products Research Center, Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu 610041, PR China.,College of pharmacy, Chengdu University of Traditional Chinese Medicine, Chengdu 611137, PR China
| | - Yongyun Zhao
- Natural Products Research Center, Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu 610041, PR China
| | - Lianqi Chen
- Natural Products Research Center, Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu 610041, PR China
| | - Jiasi Wu
- College of pharmacy, Chengdu University of Traditional Chinese Medicine, Chengdu 611137, PR China
| | - Gangyi Chen
- Natural Products Research Center, Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu 610041, PR China
| | - Sheng Li
- Natural Products Research Center, Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu 610041, PR China
| | - Jiawei Zou
- Natural Products Research Center, Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu 610041, PR China
| | - Rong Chen
- Natural Products Research Center, Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu 610041, PR China
| | - Jian Wang
- College of pharmacy, Chengdu University of Traditional Chinese Medicine, Chengdu 611137, PR China
| | - Fan Jiang
- Laboratory of Computational Chemistry and Drug Design, Laboratory of Chemical Genomics, Peking University Shenzhen Graduate School, Shenzhen 518055, PR China
| | - Zhuo Tang
- Natural Products Research Center, Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu 610041, PR China
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23
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Dahal BK, Kadyrova LY, Delfino KR, Rogozin IB, Gujar V, Lobachev KS, Kadyrov FA. Involvement of DNA mismatch repair in the maintenance of heterochromatic DNA stability in Saccharomyces cerevisiae. PLoS Genet 2017; 13:e1007074. [PMID: 29069084 PMCID: PMC5673234 DOI: 10.1371/journal.pgen.1007074] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2017] [Revised: 11/06/2017] [Accepted: 10/15/2017] [Indexed: 11/30/2022] Open
Abstract
Heterochromatin contains a significant part of nuclear DNA. Little is known about the mechanisms that govern heterochromatic DNA stability. We show here that in the yeast Saccharomyces cerevisiae (i) DNA mismatch repair (MMR) is required for the maintenance of heterochromatic DNA stability, (ii) MutLα (Mlh1-Pms1 heterodimer), MutSα (Msh2-Msh6 heterodimer), MutSβ (Msh2-Msh3 heterodimer), and Exo1 are involved in MMR at heterochromatin, (iii) Exo1-independent MMR at heterochromatin frequently leads to the formation of Pol ζ-dependent mutations, (iv) MMR cooperates with the proofreading activity of Pol ε and the histone acetyltransferase Rtt109 in the maintenance of heterochromatic DNA stability, (v) repair of base-base mismatches at heterochromatin is less efficient than repair of base-base mismatches at euchromatin, and (vi) the efficiency of repair of 1-nt insertion/deletion loops at heterochromatin is similar to the efficiency of repair of 1-nt insertion/deletion loops at euchromatin. Eukaryotic mismatch repair is an important intracellular process that defends DNA against mutations. Inactivation of mismatch repair in human cells strongly increases the risk of cancer initiation and development. Although significant progress has been made in understanding mismatch repair at euchromatin, mismatch repair at heterochromatin is not well understood. Baker’s yeast is a key model organism to study mismatch repair. We determined that in baker’s yeast (1) mismatch repair protects heterochromatic DNA from mutations, (2) the MutLα, MutSα, MutSβ, and Exo1 proteins play important roles in mismatch repair at heterochromatin, (3) Exo1-independent mismatch repair at heterochromatin is an error-prone process; (4) mismatch repair cooperates with two other intracellular processes to protect the stability of heterochromatic DNA; and (5) the efficiency of repair of base-base mismatches at heterochromatin is lower than the efficiency of repair of base-base mismatches at euchromatin, but the efficiency of 1-nt insertion/deletion loop repair at heterochromatin is similar to the efficiency of 1-nt insertion/deletion loop repair at euchromatin.
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Affiliation(s)
- Basanta K. Dahal
- Department of Biochemistry and Molecular Biology, Southern Illinois University School of Medicine, Carbondale, IL, United States of America
| | - Lyudmila Y. Kadyrova
- Department of Biochemistry and Molecular Biology, Southern Illinois University School of Medicine, Carbondale, IL, United States of America
| | - Kristin R. Delfino
- Center for Clinical Research, Southern Illinois University School of Medicine, Springfield, IL, United States of America
| | - Igor B. Rogozin
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, MD, United States of America
| | - Vaibhavi Gujar
- Department of Biochemistry and Molecular Biology, Southern Illinois University School of Medicine, Carbondale, IL, United States of America
| | - Kirill S. Lobachev
- School of Biological Sciences and Institute for Bioengineering and Bioscience, Georgia Institute of Technology, Atlanta, GA, United States of America
| | - Farid A. Kadyrov
- Department of Biochemistry and Molecular Biology, Southern Illinois University School of Medicine, Carbondale, IL, United States of America
- * E-mail:
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24
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Houlleberghs H, Goverde A, Lusseveld J, Dekker M, Bruno MJ, Menko FH, Mensenkamp AR, Spaander MCW, Wagner A, Hofstra RMW, te Riele H. Suspected Lynch syndrome associated MSH6 variants: A functional assay to determine their pathogenicity. PLoS Genet 2017; 13:e1006765. [PMID: 28531214 PMCID: PMC5460888 DOI: 10.1371/journal.pgen.1006765] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2016] [Revised: 06/06/2017] [Accepted: 04/18/2017] [Indexed: 12/14/2022] Open
Abstract
Lynch syndrome (LS) is a hereditary cancer predisposition caused by inactivating mutations in DNA mismatch repair (MMR) genes. Mutations in the MSH6 DNA MMR gene account for approximately 18% of LS cases. Many LS-associated sequence variants are nonsense and frameshift mutations that clearly abrogate MMR activity. However, missense mutations whose functional implications are unclear are also frequently seen in suspected-LS patients. To conclusively diagnose LS and enroll patients in appropriate surveillance programs to reduce morbidity as well as mortality, the functional consequences of these variants of uncertain clinical significance (VUS) must be defined. We present an oligonucleotide-directed mutagenesis screen for the identification of pathogenic MSH6 VUS. In the screen, the MSH6 variant of interest is introduced into mouse embryonic stem cells by site-directed mutagenesis. Subsequent selection for MMR-deficient cells using the DNA damaging agent 6-thioguanine (6TG) allows the identification of MMR abrogating VUS because solely MMR-deficient cells survive 6TG exposure. We demonstrate the efficacy of the genetic screen, investigate the phenotype of 26 MSH6 VUS and compare our screening results to clinical data from suspected-LS patients carrying these variant alleles. The colorectal and endometrial cancer predisposition Lynch syndrome (LS) is caused by an inherited heterozygous defect in one of four DNA mismatch repair (MMR) genes. Deleterious mutations (e.g., protein-deleting or -truncating) in DNA MMR genes unambiguously allow for the clinical diagnosis LS and hence enable appropriate surveillance measures to be taken to reduce cancer risk and ensure early detection of tumors. However, currently about one-third of detected MMR gene variants are subtle with less clear functional consequences: missense mutations affecting a single amino acid may be innocuous, hence not causing LS, or partially or fully destroy protein function. As long as uncertainty exists about their pathogenicity, such mutations are labeled ‘variants of uncertain (clinical) significance’ (VUS). VUS hamper genetic counseling and therefore the need for functional testing of VUS is widely recognized. To functionally annotate MMR gene VUS, we have developed a high content cellular assay in which the VUS is introduced in a cell culture by oligonucleotide-directed gene modification. Should the VUS be deleterious for MMR, the modified cells survive exposure to the guanine analog 6-thioguanine (6TG) and 6TG-resistant colonies appear. Should the mutation not affect MMR, no colonies appear. Here we present the adaptation and application of this protocol to the functional annotation of variants of the MMR gene MSH6. Implementation of our assay in clinical genetics laboratories will provide clinicians with information for proper counseling of mutation carriers and treatment of their of tumors.
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Affiliation(s)
- Hellen Houlleberghs
- Division of Biological Stress Response, The Netherlands Cancer Institute, Amsterdam, The Netherlands
| | - Anne Goverde
- Department of Clinical Genetics, Erasmus University Medical Center, Rotterdam, The Netherlands
| | - Jarnick Lusseveld
- Division of Biological Stress Response, The Netherlands Cancer Institute, Amsterdam, The Netherlands
| | - Marleen Dekker
- Division of Biological Stress Response, The Netherlands Cancer Institute, Amsterdam, The Netherlands
| | - Marco J. Bruno
- Department of Gastroenterology and Hepatology, Erasmus University Medical Center, Rotterdam, The Netherlands
| | - Fred H. Menko
- Family Cancer Clinic, The Netherlands Cancer Institute, Amsterdam, The Netherlands
| | - Arjen R. Mensenkamp
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Manon C. W. Spaander
- Department of Gastroenterology and Hepatology, Erasmus University Medical Center, Rotterdam, The Netherlands
| | - Anja Wagner
- Department of Clinical Genetics, Erasmus University Medical Center, Rotterdam, The Netherlands
| | - Robert M. W. Hofstra
- Department of Clinical Genetics, Erasmus University Medical Center, Rotterdam, The Netherlands
| | - Hein te Riele
- Division of Biological Stress Response, The Netherlands Cancer Institute, Amsterdam, The Netherlands
- * E-mail:
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25
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Liccardo R, De Rosa M, Rossi GB, Carlomagno N, Izzo P, Duraturo F. Incomplete Segregation of MSH6 Frameshift Variants with Phenotype of Lynch Syndrome. Int J Mol Sci 2017; 18:ijms18050999. [PMID: 28481244 PMCID: PMC5454912 DOI: 10.3390/ijms18050999] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2017] [Revised: 04/21/2017] [Accepted: 05/02/2017] [Indexed: 12/23/2022] Open
Abstract
Lynch syndrome (LS), the most frequent form of hereditary colorectal cancer, involves mutations in mismatch repair genes. The aim of this study was to identify mutations in MSH6 from 97 subjects negative for mutations in MLH1 and MSH2. By direct sequencing, we identified 27 MSH6 variants, of which, nine were novel. To verify the pathogenicity of these novel variants, we performed in silico and segregation analyses. Three novel variants were predicted by in silico analysis as damaging mutations and segregated with the disease phenotype; while a novel frameshift deletion variant that was predicted to yield a premature stop codon did not segregate with the LS phenotype in three of four cases in the family. Interestingly, another frame-shift variant identified in this study, already described in the literature, also did not segregate with the LS phenotype in one of two affected subjects in the family. In all affected subjects of both families, no mutation was detected in other MMR genes. Therefore, it is expected that within these families, other genetic factors contribute to the disease either alone or in combination with MSH6 variants. We conclude that caution should be exercised in counseling for MSH6-associated LS family members.
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Affiliation(s)
- Raffaella Liccardo
- Department of Molecular Medicine and Medical Biotechnology, Federico II University Medical School, 80131 Naples, Italy.
| | - Marina De Rosa
- Department of Molecular Medicine and Medical Biotechnology, Federico II University Medical School, 80131 Naples, Italy.
| | - Giovanni Battista Rossi
- Endoscopy Unit, Fondazione Pascale National Institute for Study and Care of Tumors, 80131 Naples, Italy.
| | - Nicola Carlomagno
- General Surgery Unit-Advanced Biomedical Science Department, Federico II University Medical School, 80131 Naples, Italy.
| | - Paola Izzo
- Department of Molecular Medicine and Medical Biotechnology, Federico II University Medical School, 80131 Naples, Italy.
- CEINGE-Biotecnologie Avanzate, 80145 Naples, Italy.
| | - Francesca Duraturo
- Department of Molecular Medicine and Medical Biotechnology, Federico II University Medical School, 80131 Naples, Italy.
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26
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Melvin RL, Thompson WG, Godwin RC, Gmeiner WH, Salsbury FR. MutS α's Multi-Domain Allosteric Response to Three DNA Damage Types Revealed by Machine Learning. FRONTIERS IN PHYSICS 2017; 5:10. [PMID: 31938712 PMCID: PMC6959842 DOI: 10.3389/fphy.2017.00010] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
MutSα is a key component in the mismatch repair (MMR) pathway. This protein is responsible for initiating the signaling pathways for DNA repair or cell death. Herein we investigate this heterodimer's post-recognition, post-binding response to three types of DNA damage involving cytotoxic, anti-cancer agents-carboplatin, cisplatin, and FdU. Through a combination of supervised and unsupervised machine learning techniques along with more traditional structural and kinetic analysis applied to all-atom molecular dynamics (MD) calculations, we predict that MutSα has a distinct response to each of the three damage types. Via a binary classification tree (a supervised machine learning technique), we identify key hydrogen bond motifs unique to each type of damage and suggest residues for experimental mutation studies. Through a combination of a recently developed clustering (unsupervised learning) algorithm, RMSF calculations, PCA, and correlated motions we predict that each type of damage causes MutSα to explore a specific region of conformation space. Detailed analysis suggests a short range effect for carboplatin-primarily altering the structures and kinetics of residues within 10 angstroms of the damaged DNA-and distinct longer-range effects for cisplatin and FdU. In our simulations, we also observe that a key phenylalanine residue-known to stack with a mismatched or unmatched bases in MMR-stacks with the base complementary to the damaged base in 88.61% of MD frames containing carboplatinated DNA. Similarly, this Phe71 stacks with the base complementary to damage in 91.73% of frames with cisplatinated DNA. This residue, however, stacks with the damaged base itself in 62.18% of trajectory frames with FdU-substituted DNA and has no stacking interaction at all in 30.72% of these frames. Each drug investigated here induces a unique perturbation in the MutSα complex, indicating the possibility of a distinct signaling event and specific repair or death pathway (or set of pathways) for a given type of damage.
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Affiliation(s)
- Ryan L. Melvin
- Salsbury Group, Department of Physics, Wake Forest University, Winston-Salem, NC, USA
| | - William G. Thompson
- Salsbury Group, Department of Physics, Wake Forest University, Winston-Salem, NC, USA
| | - Ryan C. Godwin
- Salsbury Group, Department of Physics, Wake Forest University, Winston-Salem, NC, USA
| | - William H. Gmeiner
- Gmeiner Laboratory, Department of Cancer Biology, Wake Forest University School of Medicine, Winston-Salem, NC, USA
| | - Freddie R. Salsbury
- Salsbury Group, Department of Physics, Wake Forest University, Winston-Salem, NC, USA
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27
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Walter D, Döring C, Feldhahn M, Battke F, Hartmann S, Winkelmann R, Schneider M, Bankov K, Schnitzbauer A, Zeuzem S, Hansmann ML, Peveling-Oberhag J. Intratumoral heterogeneity of intrahepatic cholangiocarcinoma. Oncotarget 2017; 8:14957-14968. [PMID: 28146430 PMCID: PMC5362457 DOI: 10.18632/oncotarget.14844] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2016] [Accepted: 01/16/2017] [Indexed: 02/06/2023] Open
Abstract
No personalized therapy regimens could demonstrate a benefit in survival of intrahepatic cholangiocarcinoma (iCCA). Since genetic heterogeneity might influence single biopsy based targeted therapy or the outcome of clinical trials, aim of the present study was to investigate intratumoral heterogeneity of iCCA by whole exome sequencing. Therefore, samples from tumor center and tumor periphery of large iCCA lesions as well as a control from healthy liver tissue were obtained from four patients and whole exome sequencing was performed. Mutations that occurred only in the tumor center or periphery were defined as private, whereas mutations present in both samples were regarded as common. A mean of 3 non-synonymous private mutations (range 0-14) per sample compared to 33,3 common mutations per sample (range 24-41) was identified. Mean percentage of non-synonymous private mutations per sample was 12% (range 0-58). In all samples of patient 1-3 as well as the central sample of patient 4 ≤ 10% private mutations were found, whereas 58% of private mutations were identified in the peripheral sample of patient 4. In this sample a private mutation in the DNA mismatch repair protein MSH6 could be identified most likely causing the high amount of private mutations. No substantial intratumoral heterogeneity was found in copy number variation analysis. In conclusion, iCCA show a small but distinct intratumoral heterogeneity. Somatic mutations in mismatch repair proteins might contribute significantly to increased spatial tumor burden and thereby may influence clinical management.
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Affiliation(s)
- Dirk Walter
- Department of Internal Medicine I, Johann Wolfgang Goethe-University Hospital, 60590 Frankfurt, Germany
- Dr. Senckenberg Institute of Pathology, Johann Wolfgang Goethe-University Hospital, 60590 Frankfurt, Germany
| | - Claudia Döring
- Dr. Senckenberg Institute of Pathology, Johann Wolfgang Goethe-University Hospital, 60590 Frankfurt, Germany
| | | | | | - Sylvia Hartmann
- Dr. Senckenberg Institute of Pathology, Johann Wolfgang Goethe-University Hospital, 60590 Frankfurt, Germany
| | - Ria Winkelmann
- Dr. Senckenberg Institute of Pathology, Johann Wolfgang Goethe-University Hospital, 60590 Frankfurt, Germany
| | - Markus Schneider
- Dr. Senckenberg Institute of Pathology, Johann Wolfgang Goethe-University Hospital, 60590 Frankfurt, Germany
| | - Katrin Bankov
- Department of Internal Medicine I, Johann Wolfgang Goethe-University Hospital, 60590 Frankfurt, Germany
| | - Andreas Schnitzbauer
- Department of General and Visceral Surgery, Johann Wolfgang Goethe-University Hospital, 60590 Frankfurt, Germany
| | - Stefan Zeuzem
- Department of Internal Medicine I, Johann Wolfgang Goethe-University Hospital, 60590 Frankfurt, Germany
| | - Martin Leo Hansmann
- Dr. Senckenberg Institute of Pathology, Johann Wolfgang Goethe-University Hospital, 60590 Frankfurt, Germany
| | - Jan Peveling-Oberhag
- Department of Internal Medicine I, Johann Wolfgang Goethe-University Hospital, 60590 Frankfurt, Germany
- Dr. Senckenberg Institute of Pathology, Johann Wolfgang Goethe-University Hospital, 60590 Frankfurt, Germany
- Department for Gastroenterology, Hepatology and Endocrinology, Robert-Bosch Hospital, 70376 Stuttgart, Germany
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28
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Kadyrova LY, Dahal BK, Kadyrov FA. The Major Replicative Histone Chaperone CAF-1 Suppresses the Activity of the DNA Mismatch Repair System in the Cytotoxic Response to a DNA-methylating Agent. J Biol Chem 2016; 291:27298-27312. [PMID: 27872185 DOI: 10.1074/jbc.m116.760561] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2016] [Revised: 11/15/2016] [Indexed: 11/06/2022] Open
Abstract
The DNA mismatch repair (MMR) system corrects DNA mismatches in the genome. It is also required for the cytotoxic response of O6-methylguanine-DNA methyltransferase (MGMT)-deficient mammalian cells and yeast mgt1Δ rad52Δ cells to treatment with Sn1-type methylating agents, which produce cytotoxic O6-methylguanine (O6-mG) DNA lesions. Specifically, an activity of the MMR system causes degradation of irreparable O6-mG-T mispair-containing DNA, triggering cell death; this process forms the basis of treatments of MGMT-deficient cancers with Sn1-type methylating drugs. Recent research supports the view that degradation of irreparable O6-mG-T mispair-containing DNA by the MMR system and CAF-1-dependent packaging of the newly replicated DNA into nucleosomes are two concomitant processes that interact with each other. Here, we studied whether CAF-1 modulates the activity of the MMR system in the cytotoxic response to Sn1-type methylating agents. We found that CAF-1 suppresses the activity of the MMR system in the cytotoxic response of yeast mgt1Δ rad52Δ cells to the prototypic Sn1-type methylating agent N-methyl-N'-nitro-N-nitrosoguanidine. We also report evidence that in human MGMT-deficient cell-free extracts, CAF-1-dependent packaging of irreparable O6-mG-T mispair-containing DNA into nucleosomes suppresses its degradation by the MMR system. Taken together, these findings suggest that CAF-1-dependent incorporation of irreparable O6-mG-T mispair-containing DNA into nucleosomes suppresses its degradation by the MMR system, thereby defending the cell against killing by the Sn1-type methylating agent.
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Affiliation(s)
- Lyudmila Y Kadyrova
- From the Department of Biochemistry and Molecular Biology, Southern Illinois University, School of Medicine, Carbondale, Illinois 62901
| | - Basanta K Dahal
- From the Department of Biochemistry and Molecular Biology, Southern Illinois University, School of Medicine, Carbondale, Illinois 62901
| | - Farid A Kadyrov
- From the Department of Biochemistry and Molecular Biology, Southern Illinois University, School of Medicine, Carbondale, Illinois 62901
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29
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Affiliation(s)
- Guo-Min Li
- Department of Biochemistry and Molecular Biology, Norris Comprehensive Cancer Center, University of Southern California Keck School of Medicine, University of Southern California, Los Angeles, CA 90033.
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30
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Abstract
: More than 1.6 million new cases of cancer will be diagnosed in the U.S. in 2016, resulting in more than 500,000 deaths. Although chemotherapy has been the mainstay of treatment in advanced cancers, immunotherapy development, particularly with PD-1 inhibitors, has changed the face of treatment for a number of tumor types. One example is the subset of tumors characterized by mismatch repair deficiency and microsatellite instability that are highly sensitive to PD-1 blockade. Hereditary forms of cancer have been noted for more than a century, but the molecular changes underlying mismatch repair-deficient tumors and subsequent microsatellite unstable tumors was not known until the early 1990s. In this review article, we discuss the history and pathophysiology of mismatch repair, the process of testing for mismatch repair deficiency and microsatellite instability, and the role of immunotherapy in this subset of cancers. IMPLICATIONS FOR PRACTICE Mismatch repair deficiency has contributed to our understanding of carcinogenesis for the past 2 decades and now identifies a subgroup of traditionally chemotherapy-insensitive solid tumors as sensitive to PD-1 blockade. This article seeks to educate oncologists regarding the nature of mismatch repair deficiency, its impact in multiple tumor types, and its implications for predicting the responsiveness of solid tumors to immune checkpoint blockade.
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31
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Lee V, Murphy A, Le DT, Diaz LA. Mismatch Repair Deficiency and Response to Immune Checkpoint Blockade. Oncologist 2016; 21:1200-1211. [PMID: 27412392 DOI: 10.1634/theoncologist.2016-0046] [Citation(s) in RCA: 186] [Impact Index Per Article: 23.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2016] [Accepted: 05/04/2016] [Indexed: 02/06/2023] Open
Abstract
: More than 1.6 million new cases of cancer will be diagnosed in the U.S. in 2016, resulting in more than 500,000 deaths. Although chemotherapy has been the mainstay of treatment in advanced cancers, immunotherapy development, particularly with PD-1 inhibitors, has changed the face of treatment for a number of tumor types. One example is the subset of tumors characterized by mismatch repair deficiency and microsatellite instability that are highly sensitive to PD-1 blockade. Hereditary forms of cancer have been noted for more than a century, but the molecular changes underlying mismatch repair-deficient tumors and subsequent microsatellite unstable tumors was not known until the early 1990s. In this review article, we discuss the history and pathophysiology of mismatch repair, the process of testing for mismatch repair deficiency and microsatellite instability, and the role of immunotherapy in this subset of cancers. IMPLICATIONS FOR PRACTICE Mismatch repair deficiency has contributed to our understanding of carcinogenesis for the past 2 decades and now identifies a subgroup of traditionally chemotherapy-insensitive solid tumors as sensitive to PD-1 blockade. This article seeks to educate oncologists regarding the nature of mismatch repair deficiency, its impact in multiple tumor types, and its implications for predicting the responsiveness of solid tumors to immune checkpoint blockade.
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Affiliation(s)
- Valerie Lee
- Johns Hopkins Kimmel Cancer Center, Baltimore, Maryland, USA
| | - Adrian Murphy
- Johns Hopkins Kimmel Cancer Center, Baltimore, Maryland, USA
| | - Dung T Le
- Johns Hopkins Kimmel Cancer Center, Baltimore, Maryland, USA
| | - Luis A Diaz
- The Swim Across America Laboratory, Baltimore, Maryland, USA the Ludwig Center for Cancer Genetics and Therapeutics, Johns Hopkins Kimmel Cancer Center, Baltimore, Maryland, USA
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32
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Extended Abstracts. Toxicol Pathol 2016. [DOI: 10.1177/019262339702500633] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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33
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Simonelli V, Leuzzi G, Basile G, D'Errico M, Fortini P, Franchitto A, Viti V, Brown AR, Parlanti E, Pascucci B, Palli D, Giuliani A, Palombo F, Sobol RW, Dogliotti E. Crosstalk between mismatch repair and base excision repair in human gastric cancer. Oncotarget 2016; 8:84827-84840. [PMID: 29156686 PMCID: PMC5689576 DOI: 10.18632/oncotarget.10185] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2015] [Accepted: 05/23/2016] [Indexed: 12/05/2022] Open
Abstract
DNA repair gene expression in a set of gastric cancers suggested an inverse association between the expression of the mismatch repair (MMR) gene MLH1 and that of the base excision repair (BER) gene DNA polymerase β (Polβ). To gain insight into possible crosstalk of these two repair pathways in cancer, we analysed human gastric adenocarcinoma AGS cells over-expressing Polβ or Polβ active site mutants, alone or in combination with MLH1 silencing. Next, we investigated the cellular response to the alkylating agent methyl methanesulfonate (MMS) and the purine analogue 6-thioguanine (6-TG), agents that induce lesions that are substrates for BER and/or MMR. AGS cells over-expressing Polβ were resistant to 6-TG to a similar extent as when MLH1 was inactivated while inhibition of O6-methylguanine-DNA methyltransferase (MGMT) was required to detect resistance to MMS. Upon either treatment, the association with MLH1 down-regulation further amplified the resistant phenotype. Moreover, AGS cells mutated in Polβ were hypersensitive to both 6-TG and MMS killing and their sensitivity was partially rescued by MLH1 silencing. We provide evidence that the critical lethal lesions in this new pathway are double strand breaks that are exacerbated when Polβ is defective and relieved when MLH1 is silenced. In conclusion, we provide evidence of crosstalk between MLH1 and Polβ that modulates the response to alkylation damage. These studies suggest that the Polβ/MLH1 status should be taken into consideration when designing chemotherapeutic approaches for gastric cancer.
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Affiliation(s)
- Valeria Simonelli
- Department of Environment and Primary Prevention, Istituto Superiore di Sanità, Rome, Italy
| | - Giuseppe Leuzzi
- Department of Environment and Primary Prevention, Istituto Superiore di Sanità, Rome, Italy
| | - Giorgia Basile
- Department of Environment and Primary Prevention, Istituto Superiore di Sanità, Rome, Italy
| | - Mariarosaria D'Errico
- Department of Environment and Primary Prevention, Istituto Superiore di Sanità, Rome, Italy
| | - Paola Fortini
- Department of Environment and Primary Prevention, Istituto Superiore di Sanità, Rome, Italy
| | - Annapaola Franchitto
- Department of Environment and Primary Prevention, Istituto Superiore di Sanità, Rome, Italy
| | - Valentina Viti
- Istituto di Ricerche Biologia Molecolare P. Angeletti (IRBM), Pomezia (Rome), Italy
| | - Ashley R Brown
- University of Pittsburgh Cancer Institute, Hillman Cancer Center, Pittsburgh, PA, USA
| | - Eleonora Parlanti
- Department of Environment and Primary Prevention, Istituto Superiore di Sanità, Rome, Italy
| | - Barbara Pascucci
- Institute of Cristallography, Consiglio Nazionale delle Ricerche, Monterotondo Stazione, Rome, Italy
| | - Domenico Palli
- Molecular and Nutritional Epidemiology Unit, CSPO, Scientific Institute of Tuscany, Florence, Italy
| | - Alessandro Giuliani
- Department of Environment and Primary Prevention, Istituto Superiore di Sanità, Rome, Italy
| | | | - Robert W Sobol
- University of Pittsburgh Cancer Institute, Hillman Cancer Center, Pittsburgh, PA, USA.,Department of Pharmacology and Chemical Biology, University of Pittsburgh, Pittsburgh, PA, USA.,Department of Oncologic Sciences, Mitchell Cancer Institute, University of South Alabama, Mobile, AL, USA
| | - Eugenia Dogliotti
- Department of Environment and Primary Prevention, Istituto Superiore di Sanità, Rome, Italy
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Negureanu L, Salsbury FR. Insights into protein - DNA interactions, stability and allosteric communications: a computational study of mutSα-DNA recognition complexes. J Biomol Struct Dyn 2016; 29:757-76. [PMID: 22208277 DOI: 10.1080/07391102.2012.10507412] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
DNA mismatch repair proteins (MMR) maintain genetic stability by recognizing and repairing mismatched bases and insertion/deletion loops mistakenly incorporated during DNA replication, and initiate cellular response to certain types of DNA damage. Loss of MMR in mammalian cells has been linked to resistance to certain DNA damaging chemotherapeutic agents, as well as to increase risk of cancer. Mismatch repair pathway is considered to involve the concerted action of at least 20 proteins. The most abundant MMR mismatch-binding factor in eukaryotes, MutSα, recognizes and initiates the repair of base-base mismatches and small insertion/deletion. We performed molecular dynamics simulations on mismatched and damaged MutSα-DNA complexes. A comprehensive DNA binding site analysis of relevant conformations shows that MutSα proteins recognize the mismatched and platinum cross-linked DNA substrates in significantly different modes. Distinctive conformational changes associated with MutSα binding to mismatched and damaged DNA have been identified and they provide insight into the involvement of MMR proteins in DNA-repair and DNA-damage pathways. Stability and allosteric interactions at the heterodimer interface associated with the mismatch and damage recognition step allow for prediction of key residues in MMR cancer-causing mutations. A rigorous hydrogen bonding analysis for ADP molecules at the ATPase binding sites is also presented. Due to extended number of known MMR cancer causing mutations among the residues proved to make specific contacts with ADP molecules, recommendations for further studies on similar mutagenic effects were made.
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Oligonucleotide-directed mutagenesis screen to identify pathogenic Lynch syndrome-associated MSH2 DNA mismatch repair gene variants. Proc Natl Acad Sci U S A 2016; 113:4128-33. [PMID: 26951660 DOI: 10.1073/pnas.1520813113] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
Single-stranded DNA oligonucleotides can achieve targeted base-pair substitution with modest efficiency but high precision. We show that "oligo targeting" can be used effectively to study missense mutations in DNA mismatch repair (MMR) genes. Inherited inactivating mutations in DNA MMR genes are causative for the cancer predisposition Lynch syndrome (LS). Although overtly deleterious mutations in MMR genes can clearly be ascribed as the cause of LS, the functional implications of missense mutations are often unclear. We developed a genetic screen to determine the pathogenicity of these variants of uncertain significance (VUS), focusing on mutator S homolog 2 (MSH2). VUS were introduced into the endogenous Msh2 gene of mouse embryonic stem cells by oligo targeting. Subsequent selection for MMR-deficient cells using the guanine analog 6-thioguanine allowed the detection of MMR-abrogating VUS. The screen was able to distinguish weak and strong pathogenic variants from polymorphisms and was used to investigate 59 Msh2 VUS. Nineteen of the 59 VUS were identified as pathogenic. Functional assays revealed that 14 of the 19 detected variants fully abrogated MMR activity and that five of the detected variants attenuated MMR activity. Implementation of the screen in clinical practice allows proper counseling of mutation carriers and treatment of their tumors.
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36
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Rodriges Blanko E, Kadyrova LY, Kadyrov FA. DNA Mismatch Repair Interacts with CAF-1- and ASF1A-H3-H4-dependent Histone (H3-H4)2 Tetramer Deposition. J Biol Chem 2016; 291:9203-17. [PMID: 26945061 DOI: 10.1074/jbc.m115.713271] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2015] [Indexed: 01/07/2023] Open
Abstract
DNA mismatch repair (MMR) is required for the maintenance of genome stability and protection of humans from several types of cancer. Human MMR occurs in the chromatin environment, but little is known about the interactions between MMR and the chromatin environment. Previous research has suggested that MMR coincides with replication-coupled assembly of the newly synthesized DNA into nucleosomes. The first step in replication-coupled nucleosome assembly is CAF-1-dependent histone (H3-H4)2 tetramer deposition, a process that involves ASF1A-H3-H4 complex. In this work we used reconstituted human systems to investigate interactions between MMR and CAF-1- and ASF1A-H3-H4-dependent histone (H3-H4)2 tetramer deposition. We have found that MutSα inhibits CAF-1- and ASF1A-H3-H4-dependent packaging of a DNA mismatch into a tetrasome. This finding supports the idea that MMR occurs before the DNA mismatch is packaged into the tetrasome. Our experiments have also revealed that CAF-1- and ASF1A-H3-H4-dependent deposition of the histone (H3-H4)2 tetramers does not interfere with MMR reactions. In addition, we have established that unnecessary degradation of the discontinuous strand that takes place in both DNA polymerase δ (Pol δ)- and DNA polymerase ϵ (Pol ϵ)-dependent MMR reactions is suppressed by CAF-1- and ASF1A-H3-H4-dependent deposition of the histone (H3-H4)2 tetramers. These data suggest that CAF-1- and ASF1A-H3-H4-dependent deposition of the histone (H3-H4)2 tetramers is compatible with MMR and protects the discontinuous daughter strand from unnecessary degradation by MMR machinery.
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Affiliation(s)
- Elena Rodriges Blanko
- From the Department of Biochemistry and Molecular Biology, Southern Illinois University, School of Medicine, Carbondale, Illinois 62901
| | - Lyudmila Y Kadyrova
- From the Department of Biochemistry and Molecular Biology, Southern Illinois University, School of Medicine, Carbondale, Illinois 62901
| | - Farid A Kadyrov
- From the Department of Biochemistry and Molecular Biology, Southern Illinois University, School of Medicine, Carbondale, Illinois 62901
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Kolodner RD. A personal historical view of DNA mismatch repair with an emphasis on eukaryotic DNA mismatch repair. DNA Repair (Amst) 2016; 38:3-13. [PMID: 26698650 PMCID: PMC4740188 DOI: 10.1016/j.dnarep.2015.11.009] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2015] [Revised: 10/30/2015] [Accepted: 11/30/2015] [Indexed: 01/12/2023]
Affiliation(s)
- Richard D Kolodner
- Ludwig Institute for Cancer Research, Department of Cellular and Molecular Medicine, Moores-UCSD Cancer Center and Institute for Molecular Medicine, University of CA, San Diego School of Medicine, La Jolla, CA 92093-0669, United States.
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Kadyrova LY, Kadyrov FA. Endonuclease activities of MutLα and its homologs in DNA mismatch repair. DNA Repair (Amst) 2016; 38:42-49. [PMID: 26719141 PMCID: PMC4820397 DOI: 10.1016/j.dnarep.2015.11.023] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2015] [Revised: 08/26/2015] [Accepted: 11/30/2015] [Indexed: 12/28/2022]
Abstract
MutLα is a key component of the DNA mismatch repair system in eukaryotes. The DNA mismatch repair system has several genetic stabilization functions. Of these functions, DNA mismatch repair is the major one. The loss of MutLα abolishes DNA mismatch repair, thereby predisposing humans to cancer. MutLα has an endonuclease activity that is required for DNA mismatch repair. The endonuclease activity of MutLα depends on the DQHA(X)2E(X)4E motif which is a part of the active site of the nuclease. This motif is also present in many bacterial MutL and eukaryotic MutLγ proteins, DNA mismatch repair system factors that are homologous to MutLα. Recent studies have shown that yeast MutLγ and several MutL proteins containing the DQHA(X)2E(X)4E motif possess endonuclease activities. Here, we review the endonuclease activities of MutLα and its homologs in the context of DNA mismatch repair.
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Affiliation(s)
- Lyudmila Y Kadyrova
- Department of Biochemistry and Molecular Biology, Southern Illinois University School of Medicine, Carbondale, IL 62901, USA
| | - Farid A Kadyrov
- Department of Biochemistry and Molecular Biology, Southern Illinois University School of Medicine, Carbondale, IL 62901, USA.
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39
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Chen Y, Huang C, Bai C, Du C, Liao J, Dong Q. In vivo DNA mismatch repair measurement in zebrafish embryos and its use in screening of environmental carcinogens. JOURNAL OF HAZARDOUS MATERIALS 2016; 302:296-303. [PMID: 26476317 DOI: 10.1016/j.jhazmat.2015.09.056] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/01/2015] [Revised: 09/24/2015] [Accepted: 09/26/2015] [Indexed: 06/05/2023]
Abstract
Impairment of DNA mismatch repair (MMR) function leads to the development and progression of certain cancers. Many environmental contaminants can target DNA MMR system. Currently, measurement of MMR activity is limited to in vitro or in vivo methods at the cell line level, and reports on measurement of MMR activity at the live organism level are lacking. Here, we report an efficient method to measure DNA MMR activity in zebrafish embryos. A G-T mismatch was introduced into enhanced green fluorescent protein (EGFP) gene. Repair of the G-T mismatch to G-C in the heteroduplex plasmid generates a functional EGFP expression. The heteroduplex plasmid and a similarly constructed homoduplex plasmid were injected in parallel into the same batch of embryos at 1-cell stage and EGFP expression in EGFP positive embryos was quantified at 24 h after injection. MMR efficiency was calculated as the total fluorescence intensity of embryos injected with the heteroduplex construct divided by that of embryos injected with the homoduplex construct. Our results showed 73% reduction of MMR activity in embryos derived from MMR-deficient mlh1 mutant fish (positive control) when compared with embryos from MMR-competent wild type AB line fish, indicating feasibility of in vivo MMR activity measurement in zebrafish embryos. We further applied this novel assay for measurement of MMR efficiency in embryos exposed to environmental chemicals such as cadmium chloride (CdCl2), benzo[a]pyrene (BaP), and perfluorooctanesulphonic acid (PFOS) from 6 hpf to 24 hpf. We observed significant reductions of MMR efficiency in embryos exposed to 0.1 μM CdCl2 (52%) and 0.5 μM BaP (34%), but no effect in embryos exposed to PFOS. Our study for the first time provides a model system for in vivo measurement of DNA MMR activity at the organism level, which has important implications in risk assessment of various environmental carcinogens.
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Affiliation(s)
- Yuanhong Chen
- Institute of Environmental Safety and Human Health, Wenzhou Medical University, Wenzhou 325035, PR China
| | - Changjiang Huang
- Institute of Environmental Safety and Human Health, Wenzhou Medical University, Wenzhou 325035, PR China.
| | - Chenglian Bai
- Institute of Environmental Safety and Human Health, Wenzhou Medical University, Wenzhou 325035, PR China
| | - Changchun Du
- Institute of Environmental Safety and Human Health, Wenzhou Medical University, Wenzhou 325035, PR China
| | - Junhua Liao
- Institute of Environmental Safety and Human Health, Wenzhou Medical University, Wenzhou 325035, PR China
| | - Qiaoxiang Dong
- Institute of Environmental Safety and Human Health, Wenzhou Medical University, Wenzhou 325035, PR China; School of Laboratory Medicine and Life Science, Wenzhou Medical University, Wenzhou 325035, PR China.
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40
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Kadyrova LY, Dahal BK, Kadyrov FA. Evidence that the DNA mismatch repair system removes 1-nucleotide Okazaki fragment flaps. J Biol Chem 2015. [PMID: 26224637 DOI: 10.1074/jbc.m115.660357] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
The DNA mismatch repair (MMR) system plays a major role in promoting genome stability and suppressing carcinogenesis. In this work, we investigated whether the MMR system is involved in Okazaki fragment maturation. We found that in the yeast Saccharomyces cerevisiae, the MMR system and the flap endonuclease Rad27 act in overlapping pathways that protect the nuclear genome from 1-bp insertions. In addition, we determined that purified yeast and human MutSα proteins recognize 1-nucleotide DNA and RNA flaps. In reconstituted human systems, MutSα, proliferating cell nuclear antigen, and replication factor C activate MutLα endonuclease to remove the flaps. ATPase and endonuclease mutants of MutLα are defective in the flap removal. These results suggest that the MMR system contributes to the removal of 1-nucleotide Okazaki fragment flaps.
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Affiliation(s)
- Lyudmila Y Kadyrova
- From the Department of Biochemistry and Molecular Biology, Southern Illinois University School of Medicine, Carbondale, Illinois 62901
| | - Basanta K Dahal
- From the Department of Biochemistry and Molecular Biology, Southern Illinois University School of Medicine, Carbondale, Illinois 62901
| | - Farid A Kadyrov
- From the Department of Biochemistry and Molecular Biology, Southern Illinois University School of Medicine, Carbondale, Illinois 62901
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41
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Du X, Lan T, Yuan B, Chen J, Hu J, Ren W, Chen Z. Cadmium-induced microsatellite instability in the kidneys and leukocytes of C57BL/6J mice. ENVIRONMENTAL TOXICOLOGY 2015; 30:683-692. [PMID: 24391048 DOI: 10.1002/tox.21946] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/05/2013] [Revised: 12/15/2013] [Accepted: 12/21/2013] [Indexed: 06/03/2023]
Abstract
Cadmium is a cytotoxic, carcinogenic, and mutagenic industrial product or byproduct. The correlation between metal exposure and microsatellite instability (MSI) has been reported by several groups. In the present study, 50 C57BL/6J mice at 6 weeks of age were divided into five groups and intraperitoneally injected with 0, 0.25, 0.5, 1, or 2 mg/kg cadmium chloride quaque die alterna for 4 weeks. Then, the liver, kidney, testis, leukocytes, bone marrow, and small intestine were collected from the treated mice and weighed. Portions of these tissues were fixed for further histological analysis, and the remaining tissues were subjected to genomic DNA extraction for the analysis of a panel of 42 microsatellite markers. The liver and testis weight coefficients were significantly changed in the 1 and 2 mg/kg cadmium chloride-treated groups compared with the control group. Simultaneously, severe histopathologic changes in the liver and kidneys, along with a complete disorganization of testicular structure and obvious severe necrosis in the testes were observed in the cadmium-treated group. The cadmium accumulated in the liver and kidneys of the mice in all cadmium-treated groups; the tissue cadmium concentrations were significantly higher than those in the control group. After STR scanning, MSI was found at three loci (D15Mit5, D10Mit266, and DxMit172) in the kidneys and leukocytes of mice in the lower dose groups (0.25 and 0.5 mg/kg). In summary, we have successfully established a sub-chronic cadmium exposure model and confirmed that cadmium exposure can induce MSI in mice. We also identified two loci that could be regarded as "hotspots" of microsatellite mutation in mice.
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Affiliation(s)
- Xiaoyan Du
- Department of Laboratory Animal Science, School of Basic Medical Science, Capital Medical University, Beijing, 100069, China
| | - Tianfeng Lan
- Laboratory Animal Center, Jilin University, Changchun, Jilin, 130062, China
| | - Bao Yuan
- Department of Laboratory Animal Science, School of Basic Medical Science, Capital Medical University, Beijing, 100069, China
| | - Jian Chen
- Department of Laboratory Animal Science, School of Basic Medical Science, Capital Medical University, Beijing, 100069, China
| | - Jinping Hu
- Department of Laboratory Animal Science, School of Basic Medical Science, Capital Medical University, Beijing, 100069, China
| | - Wenzhi Ren
- Department of Laboratory Animal Science, School of Basic Medical Science, Capital Medical University, Beijing, 100069, China
| | - Zhenwen Chen
- Laboratory Animal Center, Jilin University, Changchun, Jilin, 130062, China
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Abstract
Lynch syndrome, which is now recognized as the most common hereditary colorectal cancer condition, is characterized by the predisposition to a spectrum of cancers, primarily colorectal cancer and endometrial cancer. We chronicle over a century of discoveries that revolutionized the diagnosis and clinical management of Lynch syndrome, beginning in 1895 with Warthin's observations of familial cancer clusters, through the clinical era led by Lynch and the genetic era heralded by the discovery of causative mutations in mismatch repair (MMR) genes, to ongoing challenges.
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Affiliation(s)
- Henry T Lynch
- Department of Preventive Medicine and Public Health, Creighton University, 2500 California Plaza, Omaha, Nebraska 68178, USA
| | - Carrie L Snyder
- Department of Preventive Medicine and Public Health, Creighton University, 2500 California Plaza, Omaha, Nebraska 68178, USA
| | - Trudy G Shaw
- Department of Preventive Medicine and Public Health, Creighton University, 2500 California Plaza, Omaha, Nebraska 68178, USA
| | - Christopher D Heinen
- Center for Molecular Medicine, University of Connecticut Health Center, 263 Farmington Avenue, Farmington, Connecticut 06030-3101, USA
| | - Megan P Hitchins
- Department of Medicine (Oncology), Stanford Cancer Institute, Stanford University, Grant Building S169, 1291 Welch Road, Stanford, California 94305, USA
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43
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Abstract
DNA mismatch repair is a conserved antimutagenic pathway that maintains genomic stability through rectification of DNA replication errors and attenuation of chromosomal rearrangements. Paradoxically, mutagenic action of mismatch repair has been implicated as a cause of triplet repeat expansions that cause neurological diseases such as Huntington disease and myotonic dystrophy. This mutagenic process requires the mismatch recognition factor MutSβ and the MutLα (and/or possibly MutLγ) endonuclease, and is thought to be triggered by the transient formation of unusual DNA structures within the expanded triplet repeat element. This review summarizes the current knowledge of DNA mismatch repair involvement in triplet repeat expansion, which encompasses in vitro biochemical findings, cellular studies, and various in vivo transgenic animal model experiments. We present current mechanistic hypotheses regarding mismatch repair protein function in mediating triplet repeat expansions and discuss potential therapeutic approaches targeting the mismatch repair pathway.
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Affiliation(s)
- Ravi R Iyer
- Teva Branded Pharmaceutical Products R&D, Inc., West Chester, Pennsylvania 19380;
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Abstract
Genomic instability is a hallmark of cancer that leads to an increase in genetic alterations, thus enabling the acquisition of additional capabilities required for tumorigenesis and progression. Substantial heterogeneity in the amount and type of instability (nucleotide, microsatellite, or chromosomal) exists both within and between cancer types, with epithelial tumors typically displaying a greater degree of instability than hematological cancers. While high-throughput sequencing studies offer a comprehensive record of the genetic alterations within a tumor, detecting the rate of instability or cell-to-cell viability using this and most other available methods remains a challenge. Here, we discuss the different levels of genomic instability occurring in human cancers and touch on the current methods and limitations of detecting instability. We have applied one such approach to the surveying of public tumor data to provide a cursory view of genome instability across numerous tumor types.
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Affiliation(s)
- Larissa Pikor
- Department of Integrative Oncology, BC Cancer Research Centre, 675 West 10th Ave, Vancouver, BC, Canada, V5Z 1L3,
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45
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Erie DA, Weninger KR. Single molecule studies of DNA mismatch repair. DNA Repair (Amst) 2014; 20:71-81. [PMID: 24746644 DOI: 10.1016/j.dnarep.2014.03.007] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2013] [Revised: 03/21/2014] [Accepted: 03/22/2014] [Indexed: 11/30/2022]
Abstract
DNA mismatch repair, which involves is a widely conserved set of proteins, is essential to limit genetic drift in all organisms. The same system of proteins plays key roles in many cancer related cellular transactions in humans. Although the basic process has been reconstituted in vitro using purified components, many fundamental aspects of DNA mismatch repair remain hidden due in part to the complexity and transient nature of the interactions between the mismatch repair proteins and DNA substrates. Single molecule methods offer the capability to uncover these transient but complex interactions and allow novel insights into mechanisms that underlie DNA mismatch repair. In this review, we discuss applications of single molecule methodology including electron microscopy, atomic force microscopy, particle tracking, FRET, and optical trapping to studies of DNA mismatch repair. These studies have led to formulation of mechanistic models of how proteins identify single base mismatches in the vast background of matched DNA and signal for their repair.
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Affiliation(s)
- Dorothy A Erie
- Department of Chemistry and Curriculum in Applied Sciences and Engineering, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, United States.
| | - Keith R Weninger
- Department of Physics, North Carolina State University, Raleigh, NC 27695, United States
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Whiffin N, Houlston RS. Architecture of inherited susceptibility to colorectal cancer: a voyage of discovery. Genes (Basel) 2014; 5:270-84. [PMID: 24705330 PMCID: PMC4094933 DOI: 10.3390/genes5020270] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2013] [Revised: 03/07/2014] [Accepted: 03/10/2014] [Indexed: 01/29/2023] Open
Abstract
This review looks back at five decades of research into genetic susceptibility to colorectal cancer (CRC) and the insights these studies have provided. Initial evidence of a genetic basis of CRC stems from epidemiological studies in the 1950s and is further provided by the existence of multiple dominant predisposition syndromes. Genetic linkage and positional cloning studies identified the first high-penetrance genes for CRC in the 1980s and 1990s. More recent genome-wide association studies have identified common low-penetrance susceptibility loci and provide support for a polygenic model of disease susceptibility. These observations suggest a high proportion of CRC may arise in a group of susceptible individuals as a consequence of the combined effects of common low-penetrance risk alleles and rare variants conferring moderate CRC risks. Despite these advances, however, currently identified loci explain only a small fraction of the estimated heritability to CRC. It is hoped that a new generation of sequencing projects will help explain this missing heritability.
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Affiliation(s)
- Nicola Whiffin
- Molecular and Population Genetics Team, Genetics and Epidemiology, The Institute of Cancer Research, Sutton, SM2 5NG, UK.
| | - Richard S Houlston
- Molecular and Population Genetics Team, Genetics and Epidemiology, The Institute of Cancer Research, Sutton, SM2 5NG, UK.
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48
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Srivatsan A, Bowen N, Kolodner RD. Mispair-specific recruitment of the Mlh1-Pms1 complex identifies repair substrates of the Saccharomyces cerevisiae Msh2-Msh3 complex. J Biol Chem 2014; 289:9352-64. [PMID: 24550389 DOI: 10.1074/jbc.m114.552190] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
DNA mismatch repair is initiated by either the Msh2-Msh6 or the Msh2-Msh3 mispair recognition heterodimer. Here we optimized the expression and purification of Saccharomyces cerevisiae Msh2-Msh3 and performed a comparative study of Msh2-Msh3 and Msh2-Msh6 for mispair binding, sliding clamp formation, and Mlh1-Pms1 recruitment. Msh2-Msh3 formed sliding clamps and recruited Mlh1-Pms1 on +1, +2, +3, and +4 insertion/deletions and CC, AA, and possibly GG mispairs, whereas Msh2-Msh6 formed mispair-dependent sliding clamps and recruited Mlh1-Pms1 on 7 of the 8 possible base:base mispairs, the +1 insertion/deletion mispair, and to a low level on the +2 but not the +3 or +4 insertion/deletion mispairs and not on the CC mispair. The mispair specificity of sliding clamp formation and Mlh1-Pms1 recruitment but not mispair binding alone correlated best with genetic data on the mispair specificity of Msh2-Msh3- and Msh2-Msh6-dependent mismatch repair in vivo. Analysis of an Msh2-Msh6/Msh3 chimeric protein and mutant Msh2-Msh3 complexes showed that the nucleotide binding domain and communicating regions but not the mispair binding domain of Msh2-Msh3 are responsible for the extremely rapid dissociation of Msh2-Msh3 sliding clamps from DNA relative to that seen for Msh2-Msh6, and that amino acid residues predicted to stabilize Msh2-Msh3 interactions with bent, strand-separated mispair-containing DNA are more critical for the recognition of small +1 insertion/deletions than larger +4 insertion/deletions.
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49
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Wang Y, Zhou X, Song Y, Ji X, Zhang A, Zhang G, Gao Z. The mismatch repair gene hPMS1 (human postmeiotic segregation1) is down regulated in oral squamous cell carcinoma. Gene 2013; 524:28-34. [DOI: 10.1016/j.gene.2013.04.030] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2012] [Revised: 03/29/2013] [Accepted: 04/01/2013] [Indexed: 11/27/2022]
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Burton AM, Hovick SR, Peterson SK. Health behaviors in patients and families with hereditary colorectal cancer. Clin Colon Rectal Surg 2013; 25:111-7. [PMID: 23730226 DOI: 10.1055/s-0032-1313782] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
It is estimated that 5 to 10% of all colorectal cancer (CRC) cases are attributed to a hereditary cause. The primary hereditary cancer syndromes that confer an increased risk for colorectal cancers are Lynch syndrome/hereditary nonpolyposis colorectal cancer (HNPCC) and familial adenomatous polyposis (FAP). Through genetic testing, health care providers can identify patients and families who carry gene mutations and subsequently are at a substantially greater risk for developing colorectal cancer than the general population. Genetic testing provides risk information not only about an individual patient, but also his or her biological relatives. A variety of risk-reduction behaviors (including screening, surgery, and health and lifestyle behaviors) have been examined in Lynch syndrome and FAP populations. The research indicates that screening behaviors are less than optimal, although the rates vary from study to study. Prophylactic colectomy is the primary course of treatment for individuals who test positive for a FAP mutation, but the results are inconclusive for cancer-unaffected Lynch syndrome mutation carriers. Although research suggests that the adoption of healthy lifestyles and behaviors (e.g., diet, physical activity, weight control, smoking cessation, limited alcohol consumption) could have a favorable impact on colon cancer burden, there is minimal data on how these behaviors may moderate cancer risk among those at risk of hereditary colon cancer. To date, we know very little about the actual health and lifestyle behaviors of those at risk of hereditary colon cancer. Genetic testing and counseling at risk individuals may resolve uncertainty about their personal and familial cancer risk and provide information to guide and personalize decisions about their future health care.
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Affiliation(s)
- Allison M Burton
- Department of Behavioral Science, The University of Texas MD Anderson Cancer Center, Houston, Texas
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