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Andrianova MA, Seplyarskiy VB, Terradas M, Sánchez-Heras AB, Mur P, Soto JL, Aiza G, Borràs E, Kondrashov FA, Kondrashov AS, Bazykin GA, Valle L. Discovery of recessive effect of human polymerase δ proofreading deficiency through mutational analysis of POLD1-mutated normal and cancer cells. Eur J Hum Genet 2024:10.1038/s41431-024-01598-8. [PMID: 38658779 DOI: 10.1038/s41431-024-01598-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2023] [Revised: 02/16/2024] [Accepted: 03/18/2024] [Indexed: 04/26/2024] Open
Abstract
Constitutional heterozygous pathogenic variants in the exonuclease domain of POLE and POLD1, which affect the proofreading activity of the corresponding polymerases, cause a cancer predisposition syndrome characterized by increased risk of gastrointestinal polyposis, colorectal cancer, endometrial cancer and other tumor types. The generally accepted explanation for the connection between the disruption of the proofreading activity of polymerases epsilon and delta and cancer development is through an increase in the somatic mutation rate. Here we studied an extended family with multiple members heterozygous for the pathogenic POLD1 variant c.1421T>C p.(Leu474Pro), which segregates with the polyposis and cancer phenotypes. Through the analysis of mutational patterns of patient-derived fibroblasts colonies and de novo mutations obtained by parent-offspring comparisons, we concluded that heterozygous POLD1 L474P just subtly increases the somatic and germline mutation burden. In contrast, tumors developed in individuals with a heterozygous mutation in the exonuclease domain of POLD1, including L474P, have an extremely high mutation rate (>100 mut/Mb) associated with signature SBS10d. We solved this contradiction through the observation that tumorigenesis involves somatic inactivation of the wildtype POLD1 allele. These results imply that exonuclease deficiency of polymerase delta has a recessive effect on mutation rate.
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Affiliation(s)
- Maria A Andrianova
- Institute for Research in Biomedicine (IRB Barcelona), The Barcelona Institute of Science and Technology, Barcelona, Spain
| | - Vladimir B Seplyarskiy
- Department of Biomedical Informatics, Harvard Medical School, Boston, MA, USA
- Division of Genetics, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
| | - Mariona Terradas
- Hereditary Cancer Program, Catalan Institute of Oncology, Oncobell Program, IDIBELL, Hospitalet de Llobregat, Barcelona, Spain
| | - Ana Beatriz Sánchez-Heras
- Foundation for the Promotion of Health and Biomedical Research of Valencia Region (FISABIO), Elche Health Department, Elche, Spain
- Medical Oncology Department, Cancer Genetic Counseling Unit. Elche University Hospital, Elche, Spain
| | - Pilar Mur
- Hereditary Cancer Program, Catalan Institute of Oncology, Oncobell Program, IDIBELL, Hospitalet de Llobregat, Barcelona, Spain
- Department of Health of Catalonia, Catalan Cancer Plan, Barcelona, Spain
| | - José Luis Soto
- Foundation for the Promotion of Health and Biomedical Research of Valencia Region (FISABIO), Elche Health Department, Elche, Spain
- Molecular Genetics Unit, Elche University Hospital, Elche, Spain
| | - Gemma Aiza
- Hereditary Cancer Program, Catalan Institute of Oncology, Oncobell Program, IDIBELL, Hospitalet de Llobregat, Barcelona, Spain
| | - Emma Borràs
- Molecular Genetics Unit, Consorci Sanitari de Terrassa, Terrassa, Spain
| | - Fyodor A Kondrashov
- Institute of Science and Technology Austria, Klosterneuburg, Austria
- Evolutionary and Synthetic Biology Unit, Okinawa Institute of Science and Technology Graduate University, Okinawa, Japan
| | - Alexey S Kondrashov
- Department of Ecology and Evolutionary Biology, University of Michigan, Ann Arbor, MI, USA
| | - Georgii A Bazykin
- Department of Biomedical Informatics, Harvard Medical School, Boston, MA, USA
- Division of Genetics, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
| | - Laura Valle
- Hereditary Cancer Program, Catalan Institute of Oncology, Oncobell Program, IDIBELL, Hospitalet de Llobregat, Barcelona, Spain.
- Centro de Investigación Biomédica en Red de Cáncer (CIBERONC), Madrid, Spain.
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2
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Ostroverkhova D, Tyryshkin K, Beach AK, Moore EA, Masoudi-Sobhanzadeh Y, Barbari SR, Rogozin IB, Shaitan KV, Panchenko AR, Shcherbakova PV. DNA polymerase ε and δ variants drive mutagenesis in polypurine tracts in human tumors. Cell Rep 2024; 43:113655. [PMID: 38219146 PMCID: PMC10830898 DOI: 10.1016/j.celrep.2023.113655] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2023] [Revised: 11/07/2023] [Accepted: 12/19/2023] [Indexed: 01/16/2024] Open
Abstract
Alterations in the exonuclease domain of DNA polymerase ε cause ultramutated cancers. These cancers accumulate AGA>ATA transversions; however, their genomic features beyond the trinucleotide motifs are obscure. We analyze the extended DNA context of ultramutation using whole-exome sequencing data from 524 endometrial and 395 colorectal tumors. We find that G>T transversions in POLE-mutant tumors predominantly affect sequences containing at least six consecutive purines, with a striking preference for certain positions within polypurine tracts. Using this signature, we develop a machine-learning classifier to identify tumors with hitherto unknown POLE drivers and validate two drivers, POLE-E978G and POLE-S461L, by functional assays in yeast. Unlike other pathogenic variants, the E978G substitution affects the polymerase domain of Pol ε. We further show that tumors with POLD1 drivers share the extended signature of POLE ultramutation. These findings expand the understanding of ultramutation mechanisms and highlight peculiar mutagenic properties of polypurine tracts in the human genome.
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Affiliation(s)
- Daria Ostroverkhova
- Department of Pathology and Molecular Medicine, School of Medicine, Queen's University, Kingston, ON, Canada
| | - Kathrin Tyryshkin
- Department of Pathology and Molecular Medicine, School of Medicine, Queen's University, Kingston, ON, Canada
| | - Annette K Beach
- Eppley Institute for Research in Cancer and Allied Diseases, Fred & Pamela Buffett Cancer Center, University of Nebraska Medical Center, Omaha, NE, USA
| | - Elizabeth A Moore
- Eppley Institute for Research in Cancer and Allied Diseases, Fred & Pamela Buffett Cancer Center, University of Nebraska Medical Center, Omaha, NE, USA
| | - Yosef Masoudi-Sobhanzadeh
- Department of Pathology and Molecular Medicine, School of Medicine, Queen's University, Kingston, ON, Canada
| | - Stephanie R Barbari
- Eppley Institute for Research in Cancer and Allied Diseases, Fred & Pamela Buffett Cancer Center, University of Nebraska Medical Center, Omaha, NE, USA
| | - Igor B Rogozin
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, MD, USA
| | | | - Anna R Panchenko
- Department of Pathology and Molecular Medicine, School of Medicine, Queen's University, Kingston, ON, Canada.
| | - Polina V Shcherbakova
- Eppley Institute for Research in Cancer and Allied Diseases, Fred & Pamela Buffett Cancer Center, University of Nebraska Medical Center, Omaha, NE, USA.
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3
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Selves J, de Castro E Gloria H, Brunac AC, Saffi J, Guimbaud R, Brousset P, Hoffmann JS. Exploring the basis of heterogeneity of cancer aggressiveness among the mutated POLE variants. Life Sci Alliance 2024; 7:e202302290. [PMID: 37891003 PMCID: PMC10610022 DOI: 10.26508/lsa.202302290] [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: 07/25/2023] [Revised: 10/04/2023] [Accepted: 10/18/2023] [Indexed: 10/29/2023] Open
Abstract
Germline pathogenic variants in the exonuclease domain of the replicative DNA polymerase Pol ε encoded by the POLE gene, predispose essentially to colorectal and endometrial tumors by inducing an ultramutator phenotype. It is still unclear whether all the POLE alterations influence similar strength tumorigenesis, immune microenvironment, and treatment response. In this review, we summarize the current understanding of the mechanisms and consequences of POLE mutations in human malignancies; we highlight the heterogeneity of mutation rate and cancer aggressiveness among POLE variants, propose some mechanistic basis underlining such heterogeneity, and discuss novel considerations for the choice and efficacy of therapies of POLE tumors.
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Affiliation(s)
- Janick Selves
- Department of Pathology, Institut Universitaire du Cancer-Oncopole de Toulouse; Centre Hospitalier Universitaire (CHU), Toulouse, France
- Université Fédérale Toulouse Midi-Pyrénées, Université Toulouse III Paul Sabatier, INSERM, CRCT, Toulouse, France
| | - Helena de Castro E Gloria
- Laboratory of Genetic Toxicology, Federal University of Health Sciences of Porto Alegre, Porto Alegre, Brazil
| | - Anne-Cécile Brunac
- Department of Pathology, Institut Universitaire du Cancer-Oncopole de Toulouse; Centre Hospitalier Universitaire (CHU), Toulouse, France
| | - Jenifer Saffi
- Laboratory of Genetic Toxicology, Federal University of Health Sciences of Porto Alegre, Porto Alegre, Brazil
| | - Rosine Guimbaud
- Université Fédérale Toulouse Midi-Pyrénées, Université Toulouse III Paul Sabatier, INSERM, CRCT, Toulouse, France
- Department of Digestive Oncology, Centre Hospitalier Universitaire (CHU), Toulouse, France
- Department of Digestive Surgery, Centre Hospitalier Universitaire (CHU), Toulouse, France
| | - Pierre Brousset
- Department of Pathology, Institut Universitaire du Cancer-Oncopole de Toulouse; Centre Hospitalier Universitaire (CHU), Toulouse, France
- Université Fédérale Toulouse Midi-Pyrénées, Université Toulouse III Paul Sabatier, INSERM, CRCT, Toulouse, France
- Laboratoire d'Excellence Toulouse Cancer (TOUCAN), Toulouse, France
| | - Jean-Sébastien Hoffmann
- Department of Pathology, Institut Universitaire du Cancer-Oncopole de Toulouse; Centre Hospitalier Universitaire (CHU), Toulouse, France
- Laboratoire d'Excellence Toulouse Cancer (TOUCAN), Toulouse, France
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4
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Chung WH. Signification and Application of Mutator and Antimutator Phenotype-Induced Genetic Variations in Evolutionary Adaptation and Cancer Therapeutics. J Microbiol 2023; 61:1013-1024. [PMID: 38100001 DOI: 10.1007/s12275-023-00091-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2023] [Revised: 10/30/2023] [Accepted: 11/01/2023] [Indexed: 01/11/2024]
Abstract
Mutations present a dichotomy in their implications for cellular processes. They primarily arise from DNA replication errors or damage repair processes induced by environmental challenges. Cumulative mutations underlie genetic variations and drive evolution, yet also contribute to degenerative diseases such as cancer and aging. The mutator phenotype elucidates the heightened mutation rates observed in malignant tumors. Evolutionary adaptation, analogous to bacterial and eukaryotic systems, manifests through mutator phenotypes during changing environmental conditions, highlighting the delicate balance between advantageous mutations and their potentially detrimental consequences. Leveraging the genetic tractability of Saccharomyces cerevisiae offers unique insights into mutator phenotypes and genome instability akin to human cancers. Innovative reporter assays in yeast model organisms enable the detection of diverse genome alterations, aiding a comprehensive analysis of mutator phenotypes. Despite significant advancements, our understanding of the intricate mechanisms governing spontaneous mutation rates and preserving genetic integrity remains incomplete. This review outlines various cellular pathways affecting mutation rates and explores the role of mutator genes and mutation-derived phenotypes, particularly prevalent in malignant tumor cells. An in-depth comprehension of mutator and antimutator activities in yeast and higher eukaryotes holds promise for effective cancer control strategies.
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Affiliation(s)
- Woo-Hyun Chung
- College of Pharmacy, Duksung Women's University, Seoul, 01369, Republic of Korea.
- Innovative Drug Center, Duksung Women's University, Seoul, 01369, Republic of Korea.
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5
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Zhang Y, Wang X, Zhu Y, Liang C, Zhao L, Meng Q, Yin JC, Shi Y, Wang F, Qin F, Xuan J. Case Report: Cancer spectrum and genetic characteristics of a de novo germline POLD1 p.L606M variant-induced polyposis syndrome. Front Oncol 2023; 13:1222873. [PMID: 37746257 PMCID: PMC10516538 DOI: 10.3389/fonc.2023.1222873] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2023] [Accepted: 07/20/2023] [Indexed: 09/26/2023] Open
Abstract
Germline variations in the DNA polymerase genes, POLE and POLD1, can lead to a hereditary cancer syndrome that is characterized by frequent gastrointestinal polyposis and multiple primary malignant tumors. However, because of its rare occurrence, this disorder has not been extensively studied. In this report, we present the case of a 22-year-old female patient who had been diagnosed with gastrointestinal polyposis, breast fibroadenoma, multiple primary colorectal cancers, and glioblastoma (grade IV) within a span of 4 years. Next-generation sequencing analysis revealed a germline variant in POLD1 (c.1816C>A; p.L606M). In silico analysis using protein functional predicting software, including SIFT, Polyphen, GERP++, and CADD, further confirmed the pathogenicity of POLD1 p.L606M (classified as ACMG grade Class 4). In line with polymerase deficiency, both rectal cancer and glioblastoma tissues exhibited a high tumor mutation burden, with 16.9 muts/Mb and 347.1 muts/Mb, respectively. Interestingly, the patient has no family history of cancer, and gene examination of both parents confirms that this is a de novo germline variant. Therefore, molecular screening for POLD1 may be necessary for patients with such a cancer spectrum, regardless of their family history.
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Affiliation(s)
- Ying Zhang
- Department of Pathology, Jinling Hospital, Nanjing University School of Medicine, Nanjing, Jiangsu, China
| | - Xiaolu Wang
- Department of Oncology, The Affiliated Hospital, Nanjing University of Chinese Medicine, Nanjing, Jiangsu, China
| | - Yuning Zhu
- Department of Pathology, Jinling Hospital, Nanjing University School of Medicine, Nanjing, Jiangsu, China
| | - Chong Liang
- Department of Neurosurgery Jinling Hospital, Nanjing University School of Medicine, Nanjing, Jiangsu, China
| | - Lijun Zhao
- Medical Science Liaison, Genetron Health Inc., Beijing, China
| | - Qi Meng
- Geneseeq Research Institute, Nanjing Geneseeq Technology Inc., Nanjing, Jiangsu, China
| | - Jiani C. Yin
- Geneseeq Research Institute, Nanjing Geneseeq Technology Inc., Nanjing, Jiangsu, China
| | - Yuqian Shi
- Geneseeq Research Institute, Nanjing Geneseeq Technology Inc., Nanjing, Jiangsu, China
| | - Fufeng Wang
- Geneseeq Research Institute, Nanjing Geneseeq Technology Inc., Nanjing, Jiangsu, China
| | - Feng Qin
- Cancer Center, Jinling Hospital, Nanjing University School of Medicine, Nanjing, China
| | - Ji Xuan
- Department of Gastroenterology, Jinling Hospital, Nanjing University, School of Medicine, Nanjing, China
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6
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Strauss JD, Pursell ZF. Replication DNA polymerases, genome instability and cancer therapies. NAR Cancer 2023; 5:zcad033. [PMID: 37388540 PMCID: PMC10304742 DOI: 10.1093/narcan/zcad033] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2023] [Revised: 05/24/2023] [Accepted: 06/25/2023] [Indexed: 07/01/2023] Open
Abstract
It has been over a decade since the initial identification of exonuclease domain mutations in the genes encoding the catalytic subunits of replication DNA polymerases ϵ and δ (POLE and POLD1) in tumors from highly mutated endometrial and colorectal cancers. Interest in studying POLE and POLD1 has increased significantly since then. Prior to those landmark cancer genome sequencing studies, it was well documented that mutations in replication DNA polymerases that reduced their DNA synthesis accuracy, their exonuclease activity or their interactions with other factors could lead to increased mutagenesis, DNA damage and even tumorigenesis in mice. There are several recent, well-written reviews of replication DNA polymerases. The aim of this review is to gather and review in some detail recent studies of DNA polymerases ϵ and δ as they pertain to genome instability, cancer and potential therapeutic treatments. The focus here is primarily on recent informative studies on the significance of mutations in genes encoding their catalytic subunits (POLE and POLD1), mutational signatures, mutations in associated genes, model organisms, and the utility of chemotherapy and immune checkpoint inhibition in polymerase mutant tumors.
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Affiliation(s)
- Juliet D Strauss
- Department of Biochemistry and Molecular Biology, Tulane University School of Medicine, New Orleans, 70118 LA, USA
| | - Zachary F Pursell
- Department of Biochemistry and Molecular Biology, Tulane University School of Medicine, New Orleans, 70118 LA, USA
- Tulane Cancer Center, Tulane University School of Medicine, New Orleans, 70118 LA, USA
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7
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Bonjoch L, Soares de Lima Y, Díaz-Gay M, Dotti I, Muñoz J, Moreira L, Carballal S, Ocaña T, Cuatrecasas M, Ortiz O, Castells A, Pellisé M, Balaguer F, Salas A, Alexandrov LB, Castellví-Bel S. Unraveling the impact of a germline heterozygous POLD1 frameshift variant in serrated polyposis syndrome. Front Mol Biosci 2023; 10:1119900. [PMID: 36756361 PMCID: PMC9900627 DOI: 10.3389/fmolb.2023.1119900] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2022] [Accepted: 01/10/2023] [Indexed: 01/24/2023] Open
Abstract
Serrated polyposis syndrome (SPS) is one of the most frequent polyposis syndromes characterized by an increased risk for developing colorectal cancer (CRC). Although SPS etiology has been mainly associated with environmental factors, germline predisposition to SPS could also be relevant for cases with familial aggregation or a family history of SPS/CRC. After whole-exome sequencing of 39 SPS patients from 16 families, we identified a heterozygous germline frameshift variant in the POLD1 gene (c.1941delG, p.(Lys648fs*46)) in a patient with SPS and CRC. Tumor presented an ultra-hypermutated phenotype and microsatellite instability. The POLD1 germline variant segregated in three additional SPS-affected family members. We attempted to create yeast and cellular models for this variant but were no viable. Alternatively, we generated patient-derived organoids (PDOs) from healthy rectal tissue of the index case, as well as from a control donor. Then, we challenged PDOs with a DNA-damaging agent to induce replication stress. No significant differences were observed in the DNA damage response between control and POLD1-Lys648fs PDOs, nor specific mutational signatures were observed. Our results do not support the pathogenicity of the analyzed POLD1 frameshift variant. One possible explanation is that haplosufficiency of the wild-type allele may be compensating for the absence of expression of the frameshift allele. Overall, future work is required to elucidate if functional consequences could be derived from POLD1 alterations different from missense variants in their proofreading domain. To our knowledge, our study presents the first organoid model for germline POLD1 variants and establishes the basis for its use as a model for disease in SPS, CRC and other malignancies.
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Affiliation(s)
- Laia Bonjoch
- Gastroenterology Department, Institut d’Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBERehd), Hospital Clínic, Barcelona, Spain
| | - Yasmin Soares de Lima
- Gastroenterology Department, Institut d’Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBERehd), Hospital Clínic, Barcelona, Spain
| | - Marcos Díaz-Gay
- Department of Cellular and Molecular Medicine and Department of Bioengineering and Moores Cancer Center, UC San Diego, La Jolla, CA, United States
| | - Isabella Dotti
- Inflammatory Bowel Disease Unit, Gastroenterology Department, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS) Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBERehd), Hospital Clínic, Barcelona, Spain
| | - Jenifer Muñoz
- Gastroenterology Department, Institut d’Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBERehd), Hospital Clínic, Barcelona, Spain
| | - Leticia Moreira
- Gastroenterology Department, Institut d’Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBERehd), Hospital Clínic, Barcelona, Spain
| | - Sabela Carballal
- Gastroenterology Department, Institut d’Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBERehd), Hospital Clínic, Barcelona, Spain
| | - Teresa Ocaña
- Gastroenterology Department, Institut d’Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBERehd), Hospital Clínic, Barcelona, Spain
| | - Miriam Cuatrecasas
- Pathology Department, Institut d’Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBERehd) and Tumor Bank-Biobank, Hospital Clínic, Barcelona, Spain
| | - Oswaldo Ortiz
- Gastroenterology Department, Institut d’Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBERehd), Hospital Clínic, Barcelona, Spain
| | - Antoni Castells
- Gastroenterology Department, Institut d’Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBERehd), Hospital Clínic, Barcelona, Spain
| | - Maria Pellisé
- Gastroenterology Department, Institut d’Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBERehd), Hospital Clínic, Barcelona, Spain
| | - Francesc Balaguer
- Gastroenterology Department, Institut d’Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBERehd), Hospital Clínic, Barcelona, Spain
| | - Azucena Salas
- Inflammatory Bowel Disease Unit, Gastroenterology Department, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS) Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBERehd), Hospital Clínic, Barcelona, Spain
| | - Ludmil B. Alexandrov
- Department of Cellular and Molecular Medicine and Department of Bioengineering and Moores Cancer Center, UC San Diego, La Jolla, CA, United States
| | - Sergi Castellví-Bel
- Gastroenterology Department, Institut d’Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBERehd), Hospital Clínic, Barcelona, Spain
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8
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Barbari SR, Beach AK, Markgren JG, Parkash V, Moore EA, Johansson E, Shcherbakova PV. Enhanced polymerase activity permits efficient synthesis by cancer-associated DNA polymerase ϵ variants at low dNTP levels. Nucleic Acids Res 2022; 50:8023-8040. [PMID: 35822874 PMCID: PMC9371911 DOI: 10.1093/nar/gkac602] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2022] [Revised: 06/13/2022] [Accepted: 06/29/2022] [Indexed: 11/28/2022] Open
Abstract
Amino acid substitutions in the exonuclease domain of DNA polymerase ϵ (Polϵ) cause ultramutated tumors. Studies in model organisms suggested pathogenic mechanisms distinct from a simple loss of exonuclease. These mechanisms remain unclear for most recurrent Polϵ mutations. Particularly, the highly prevalent V411L variant remained a long-standing puzzle with no detectable mutator effect in yeast despite the unequivocal association with ultramutation in cancers. Using purified four-subunit yeast Polϵ, we assessed the consequences of substitutions mimicking human V411L, S459F, F367S, L424V and D275V. While the effects on exonuclease activity vary widely, all common cancer-associated variants have increased DNA polymerase activity. Notably, the analog of Polϵ-V411L is among the strongest polymerases, and structural analysis suggests defective polymerase-to-exonuclease site switching. We further show that the V411L analog produces a robust mutator phenotype in strains that lack mismatch repair, indicating a high rate of replication errors. Lastly, unlike wild-type and exonuclease-dead Polϵ, hyperactive variants efficiently synthesize DNA at low dNTP concentrations. We propose that this characteristic could promote cancer cell survival and preferential participation of mutator polymerases in replication during metabolic stress. Our results support the notion that polymerase fitness, rather than low fidelity alone, is an important determinant of variant pathogenicity.
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Affiliation(s)
- Stephanie R Barbari
- Eppley Institute for Research in Cancer and Allied Diseases, Fred & Pamela Buffett Cancer Center, University of Nebraska Medical Center, Omaha, NE 68198, USA
| | - Annette K Beach
- Eppley Institute for Research in Cancer and Allied Diseases, Fred & Pamela Buffett Cancer Center, University of Nebraska Medical Center, Omaha, NE 68198, USA
| | - Joel G Markgren
- Department of Medical Biochemistry and Biophysics, Umeå University, SE-90187 Umeå, Sweden
| | - Vimal Parkash
- Department of Medical Biochemistry and Biophysics, Umeå University, SE-90187 Umeå, Sweden
| | - Elizabeth A Moore
- Eppley Institute for Research in Cancer and Allied Diseases, Fred & Pamela Buffett Cancer Center, University of Nebraska Medical Center, Omaha, NE 68198, USA
| | - Erik Johansson
- Department of Medical Biochemistry and Biophysics, Umeå University, SE-90187 Umeå, Sweden
| | - Polina V Shcherbakova
- Eppley Institute for Research in Cancer and Allied Diseases, Fred & Pamela Buffett Cancer Center, University of Nebraska Medical Center, Omaha, NE 68198, USA
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9
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Lim YW, Mansfeld BN, Schläpfer P, Gilbert KB, Narayanan NN, Qi W, Wang Q, Zhong Z, Boyher A, Gehan J, Beyene G, Lin ZJD, Esuma W, Feng S, Chanez C, Eggenberger N, Adiga G, Alicai T, Jacobsen SE, Taylor NJ, Gruissem W, Bart RS. Mutations in DNA polymerase δ subunit 1 co-segregate with CMD2-type resistance to Cassava Mosaic Geminiviruses. Nat Commun 2022; 13:3933. [PMID: 35798722 PMCID: PMC9262879 DOI: 10.1038/s41467-022-31414-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2022] [Accepted: 06/16/2022] [Indexed: 11/28/2022] Open
Abstract
Cassava mosaic disease (CMD) suppresses cassava yields across the tropics. The dominant CMD2 locus confers resistance to cassava mosaic geminiviruses. It has been reported that CMD2-type landraces lose resistance after regeneration through de novo morphogenesis. As full genome bisulfite sequencing failed to uncover an epigenetic mechanism for this loss of resistance, whole genome sequencing and genetic variant analysis was performed and the CMD2 locus was fine-mapped to a 190 kilobase interval. Collectively, these data indicate that CMD2-type resistance is caused by a nonsynonymous, single nucleotide polymorphism in DNA polymerase δ subunit 1 (MePOLD1) located within this region. Virus-induced gene silencing of MePOLD1 in a CMD-susceptible cassava variety produced a recovery phenotype typical of CMD2-type resistance. Analysis of other CMD2-type cassava varieties identified additional candidate resistance alleles within MePOLD1. Genetic variation of MePOLD1, therefore, could represent an important genetic resource for resistance breeding and/or genome editing, and elucidating mechanisms of resistance to geminiviruses.
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Affiliation(s)
- Yi-Wen Lim
- Institute of Molecular Plant Biology, Department of Biology, ETH Zürich, Universitätsstrasse 2, 8092, Zürich, Switzerland
| | - Ben N Mansfeld
- Donald Danforth Plant Science Center, 975 North Warson Road, St. Louis, MO, 63132, USA
| | - Pascal Schläpfer
- Institute of Molecular Plant Biology, Department of Biology, ETH Zürich, Universitätsstrasse 2, 8092, Zürich, Switzerland
| | - Kerrigan B Gilbert
- Donald Danforth Plant Science Center, 975 North Warson Road, St. Louis, MO, 63132, USA
| | - Narayanan N Narayanan
- Donald Danforth Plant Science Center, 975 North Warson Road, St. Louis, MO, 63132, USA
| | - Weihong Qi
- Functional Genomics Center Zurich, ETH Zurich and University of Zurich, Winterthurerstrasse 190, 8057, Zurich, Switzerland
| | - Qi Wang
- Donald Danforth Plant Science Center, 975 North Warson Road, St. Louis, MO, 63132, USA
| | - Zhenhui Zhong
- Department of Molecular, Cell and Developmental Biology, University of California Los Angeles, Los Angeles, CA, USA
| | - Adam Boyher
- Donald Danforth Plant Science Center, 975 North Warson Road, St. Louis, MO, 63132, USA
| | - Jackson Gehan
- Donald Danforth Plant Science Center, 975 North Warson Road, St. Louis, MO, 63132, USA
| | - Getu Beyene
- Donald Danforth Plant Science Center, 975 North Warson Road, St. Louis, MO, 63132, USA
| | - Zuh-Jyh Daniel Lin
- Donald Danforth Plant Science Center, 975 North Warson Road, St. Louis, MO, 63132, USA
| | - Williams Esuma
- Root Crops Program, National Crops Resources Research Institute, P. O. Box 7084, Kampala, Uganda
| | - Suhua Feng
- Department of Molecular, Cell and Developmental Biology, University of California Los Angeles, Los Angeles, CA, USA
| | - Christelle Chanez
- Institute of Molecular Plant Biology, Department of Biology, ETH Zürich, Universitätsstrasse 2, 8092, Zürich, Switzerland
| | - Nadine Eggenberger
- Institute of Molecular Plant Biology, Department of Biology, ETH Zürich, Universitätsstrasse 2, 8092, Zürich, Switzerland
| | - Gerald Adiga
- Root Crops Program, National Crops Resources Research Institute, P. O. Box 7084, Kampala, Uganda
| | - Titus Alicai
- Root Crops Program, National Crops Resources Research Institute, P. O. Box 7084, Kampala, Uganda
| | - Steven E Jacobsen
- Department of Molecular, Cell and Developmental Biology, University of California Los Angeles, Los Angeles, CA, USA
- Howard Hughes Medical Institute University of California Los Angeles, Los Angeles, CA, USA
| | - Nigel J Taylor
- Donald Danforth Plant Science Center, 975 North Warson Road, St. Louis, MO, 63132, USA
| | - Wilhelm Gruissem
- Institute of Molecular Plant Biology, Department of Biology, ETH Zürich, Universitätsstrasse 2, 8092, Zürich, Switzerland.
- Biotechnology Center, National Chung Hsing University, 145 Xingda Road, Taichung City, 40227, Taiwan.
| | - Rebecca S Bart
- Donald Danforth Plant Science Center, 975 North Warson Road, St. Louis, MO, 63132, USA.
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10
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Scrutinizing Deleterious Nonsynonymous SNPs and Their Effect on Human POLD1 Gene. Genet Res (Camb) 2022; 2022:1740768. [PMID: 35620275 PMCID: PMC9117041 DOI: 10.1155/2022/1740768] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2022] [Revised: 03/17/2022] [Accepted: 04/08/2022] [Indexed: 11/17/2022] Open
Abstract
POLD1 (DNA polymerase delta 1, catalytic subunit) is a protein-coding gene that encodes the large catalytic subunit (POLD1/p125) of the DNA polymerase delta (Polδ) complex. The consequence of missense or nonsynonymous SNPs (nsSNPs), which occur in the coding region of a specific gene, is the replacement of single amino acid. It may also change the structure, stability, and/or functions of the protein. Mutation in the POLD1 gene is associated with autosomal dominant predisposition to colonic adenomatous polyps, colon cancer, endometrial cancer (EDMC), breast cancer, and brain tumors. These de novo mutations in the POLD1 gene also result in autosomal dominant MDPL syndrome (mandibular hypoplasia, deafness, progeroid features, and lipodystrophy). In this study, genetic variations of POLD1 which may affect the structure and/or function were analyzed using different types of bioinformatics tools. A total of 17038 nsSNPs for POLD1 were collected from the NCBI database, among which 1317 were missense variants. Out of all missense nsSNPs, 28 were found to be deleterious functionally and structurally. Among these deleterious nsSNPs, 23 showed a conservation scale of >5, 2 were predicted to be associated with binding site formation, and one acted as a posttranslational modification site. All of them were involved in coil, extracellular structures, or helix formation, and some cause the change in size, charge, and hydrophobicity.
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11
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Polymerase Epsilon-Associated Ultramutagenesis in Cancer. Cancers (Basel) 2022; 14:cancers14061467. [PMID: 35326618 PMCID: PMC8946778 DOI: 10.3390/cancers14061467] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Revised: 03/09/2022] [Accepted: 03/09/2022] [Indexed: 01/27/2023] Open
Abstract
With advances in next generation sequencing (NGS) technologies, efforts have been made to develop personalized medicine, targeting the specific genetic makeup of an individual. Somatic or germline DNA Polymerase epsilon (PolE) mutations cause ultramutated (>100 mutations/Mb) cancer. In contrast to mismatch repair-deficient hypermutated (>10 mutations/Mb) cancer, PolE-associated cancer is primarily microsatellite stable (MSS) In this article, we provide a comprehensive review of this PolE-associated ultramutated tumor. We describe its molecular characteristics, including the mutation sites and mutation signature of this type of tumor and the mechanism of its ultramutagenesis. We discuss its good clinical prognosis and elucidate the mechanism for enhanced immunogenicity with a high tumor mutation burden, increased neoantigen load, and enriched tumor-infiltrating lymphocytes. We also provide the rationale for immune checkpoint inhibitors in PolE-mutated tumors.
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12
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Probing altered enzyme activity in the biochemical characterization of cancer. Biosci Rep 2022; 42:230680. [PMID: 35048115 PMCID: PMC8819661 DOI: 10.1042/bsr20212002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2021] [Revised: 01/10/2022] [Accepted: 01/19/2022] [Indexed: 11/30/2022] Open
Abstract
Enzymes have evolved to catalyze their precise reactions at the necessary rates, locations, and time to facilitate our development, to respond to a variety of insults and challenges, and to maintain a healthy, balanced state. Enzymes achieve this extraordinary feat through their unique kinetic parameters, myriad regulatory strategies, and their sensitivity to their surroundings, including substrate concentration and pH. The Cancer Genome Atlas (TCGA) highlights the extraordinary number of ways in which the finely tuned activities of enzymes can be disrupted, contributing to cancer development and progression often due to somatic and/or inherited genetic alterations. Rather than being limited to the domain of enzymologists, kinetic constants such as kcat, Km, and kcat/Km are highly informative parameters that can impact a cancer patient in tangible ways—these parameters can be used to sort tumor driver mutations from passenger mutations, to establish the pathways that cancer cells rely on to drive patients’ tumors, to evaluate the selectivity and efficacy of anti-cancer drugs, to identify mechanisms of resistance to treatment, and more. In this review, we will discuss how changes in enzyme activity, primarily through somatic mutation, can lead to altered kinetic parameters, new activities, or changes in conformation and oligomerization. We will also address how changes in the tumor microenvironment can affect enzymatic activity, and briefly describe how enzymology, when combined with additional powerful tools, and can provide us with tremendous insight into the chemical and molecular mechanisms of cancer.
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13
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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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14
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Wang Y, Chen Y, Wang C, Yang M, Wang Y, Bao L, Wang JE, Kim B, Chan KY, Xu W, Capota E, Ortega J, Nijhawan D, Li GM, Luo W, Wang Y. MIF is a 3' flap nuclease that facilitates DNA replication and promotes tumor growth. Nat Commun 2021; 12:2954. [PMID: 34012010 PMCID: PMC8134555 DOI: 10.1038/s41467-021-23264-z] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2020] [Accepted: 04/20/2021] [Indexed: 11/13/2022] Open
Abstract
How cancer cells cope with high levels of replication stress during rapid proliferation is currently unclear. Here, we show that macrophage migration inhibitory factor (MIF) is a 3’ flap nuclease that translocates to the nucleus in S phase. Poly(ADP-ribose) polymerase 1 co-localizes with MIF to the DNA replication fork, where MIF nuclease activity is required to resolve replication stress and facilitates tumor growth. MIF loss in cancer cells leads to mutation frequency increases, cell cycle delays and DNA synthesis and cell growth inhibition, which can be rescued by restoring MIF, but not nuclease-deficient MIF mutant. MIF is significantly upregulated in breast tumors and correlates with poor overall survival in patients. We propose that MIF is a unique 3’ nuclease, excises flaps at the immediate 3’ end during DNA synthesis and favors cancer cells evading replication stress-induced threat for their growth. Replication stress is associated with cancer formation and progression. Here the authors reveal that the macrophage migration inhibitory factor (MIF) functions as 3’ flap nuclease involved in resolving replication stress affecting overall tumor progression.
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Affiliation(s)
- Yijie Wang
- Department of Pathology, UT Southwestern Medical Center, Dallas, TX, USA
| | - Yan Chen
- Department of Pathology, UT Southwestern Medical Center, Dallas, TX, USA
| | - Chenliang Wang
- Department of Pathology, UT Southwestern Medical Center, Dallas, TX, USA
| | - Mingming Yang
- Department of Pathology, UT Southwestern Medical Center, Dallas, TX, USA
| | - Yanan Wang
- Department of Pathology, UT Southwestern Medical Center, Dallas, TX, USA
| | - Lei Bao
- Department of Pathology, UT Southwestern Medical Center, Dallas, TX, USA
| | - Jennifer E Wang
- Department of Pathology, UT Southwestern Medical Center, Dallas, TX, USA
| | - BongWoo Kim
- Department of Pathology, UT Southwestern Medical Center, Dallas, TX, USA
| | - Kara Y Chan
- Department of Radiation Oncology, UT Southwestern Medical Center, Dallas, TX, USA
| | - Weizhi Xu
- Department of Radiation Oncology, UT Southwestern Medical Center, Dallas, TX, USA
| | - Emanuela Capota
- Department of Internal Medicine, UT Southwestern Medical Center, Dallas, TX, USA
| | - Janice Ortega
- Department of Radiation Oncology, UT Southwestern Medical Center, Dallas, TX, USA
| | - Deepak Nijhawan
- Department of Internal Medicine, UT Southwestern Medical Center, Dallas, TX, USA
| | - Guo-Min Li
- Department of Radiation Oncology, UT Southwestern Medical Center, Dallas, TX, USA
| | - Weibo Luo
- Department of Pathology, UT Southwestern Medical Center, Dallas, TX, USA.,Department of Pharmacology, UT Southwestern Medical Center, Dallas, TX, USA
| | - Yingfei Wang
- Department of Pathology, UT Southwestern Medical Center, Dallas, TX, USA. .,Department of Neurology, UT Southwestern Medical Center, Dallas, TX, USA.
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15
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Stepchenkova EI, Zhuk AS, Cui J, Tarakhovskaya ER, Barbari SR, Shcherbakova PV, Polev DE, Fedorov R, Poliakov E, Rogozin IB, Lada AG, Pavlov YI. Compensation for the absence of the catalytically active half of DNA polymerase ε in yeast by positively selected mutations in CDC28. Genetics 2021; 218:6222163. [PMID: 33844024 DOI: 10.1093/genetics/iyab060] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2020] [Accepted: 04/02/2021] [Indexed: 11/14/2022] Open
Abstract
Current eukaryotic replication models postulate that leading and lagging DNA strands are replicated predominantly by dedicated DNA polymerases. The catalytic subunit of the leading strand DNA polymerase ε, Pol2, consists of two halves made of two different ancestral B-family DNA polymerases. Counterintuitively, the catalytically active N-terminal half is dispensable, while the inactive C-terminal part is required for viability. Despite extensive studies of yeast Saccharomyces cerevisiae strains lacking the active N-terminal half, it is still unclear how these strains survive and recover. We designed a robust method for constructing mutants with only the C-terminal part of Pol2. Strains without the active polymerase part show severe growth defects, sensitivity to replication inhibitors, chromosomal instability, and elevated spontaneous mutagenesis. Intriguingly, the slow-growing mutant strains rapidly accumulate fast-growing clones. Analysis of genomic DNA sequences of these clones revealed that the adaptation to the loss of the catalytic N-terminal part of Pol2 occurs by a positive selection of mutants with improved growth. Elevated mutation rates help generate sufficient numbers of these variants. Single nucleotide changes in the cell cycle-dependent kinase gene, CDC28, improve the growth of strains lacking the N-terminal part of Pol2, and rescue their sensitivity to replication inhibitors and, in parallel, lower mutation rates. Our study predicts that changes in mammalian homologs of cyclin-dependent kinases may contribute to cellular responses to the leading strand polymerase defects.
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Affiliation(s)
- Elena I Stepchenkova
- Laboratory of Mutagenesis and Genetic Toxicology, Vavilov Institute of General Genetics, Saint-Petersburg Branch, Russian Academy of Sciences, Saint-Petersburg 199034, Russia.,Department of Genetics and Biotechnology, Saint-Petersburg State University, Saint-Petersburg 199034, Russia.,Eppley Institute for Research in Cancer and Allied Diseases, University of Nebraska Medical Center, Omaha, NE 68198, USA
| | - Anna S Zhuk
- ITMO University, Saint-Petersburg 191002, Russia
| | - Jian Cui
- Eppley Institute for Research in Cancer and Allied Diseases, University of Nebraska Medical Center, Omaha, NE 68198, USA
| | - Elena R Tarakhovskaya
- Laboratory of Mutagenesis and Genetic Toxicology, Vavilov Institute of General Genetics, Saint-Petersburg Branch, Russian Academy of Sciences, Saint-Petersburg 199034, Russia.,Department of Plant Physiology and Biochemistry, Saint-Petersburg State University, Saint-Petersburg 199034, Russia
| | - Stephanie R Barbari
- Eppley Institute for Research in Cancer and Allied Diseases, University of Nebraska Medical Center, Omaha, NE 68198, USA
| | - Polina V Shcherbakova
- Eppley Institute for Research in Cancer and Allied Diseases, University of Nebraska Medical Center, Omaha, NE 68198, USA
| | - Dmitrii E Polev
- Research Resource Center "Biobank," Research Park, Saint-Petersburg State University, Saint-Petersburg 198504, Russia
| | - Roman Fedorov
- Department of Mathematics, University of Pittsburgh, PA 15213, USA
| | - Eugenia Poliakov
- Laboratory of Retinal Cell and Molecular Biology, National Eye Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Igor B Rogozin
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, MD 20894, USA
| | - Artem G Lada
- Department of Microbiology and Molecular Genetics, University of California Davis, Davis, CA 92697, USA
| | - Youri I Pavlov
- Department of Genetics and Biotechnology, Saint-Petersburg State University, Saint-Petersburg 199034, Russia.,Eppley Institute for Research in Cancer and Allied Diseases, University of Nebraska Medical Center, Omaha, NE 68198, USA.,Department of Biochemistry and Molecular Biology, University of Nebraska Medical Center, Omaha, NE 68198, USA.,Department of Microbiology and Pathology, University of Nebraska Medical Center, Omaha, NE 68198, USA.,Department of Genetics Cell Biology and Anatomy, University of Nebraska Medical Center, Omaha, NE 68198, USA
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16
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Koussa NC, Smith DJ. Limiting DNA polymerase delta alters replication dynamics and leads to a dependence on checkpoint activation and recombination-mediated DNA repair. PLoS Genet 2021; 17:e1009322. [PMID: 33493195 PMCID: PMC7861531 DOI: 10.1371/journal.pgen.1009322] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2020] [Revised: 02/04/2021] [Accepted: 12/23/2020] [Indexed: 12/20/2022] Open
Abstract
DNA polymerase delta (Pol δ) plays several essential roles in eukaryotic DNA replication and repair. At the replication fork, Pol δ is responsible for the synthesis and processing of the lagging-strand. At replication origins, Pol δ has been proposed to initiate leading-strand synthesis by extending the first Okazaki fragment. Destabilizing mutations in human Pol δ subunits cause replication stress and syndromic immunodeficiency. Analogously, reduced levels of Pol δ in Saccharomyces cerevisiae lead to pervasive genome instability. Here, we analyze how the depletion of Pol δ impacts replication origin firing and lagging-strand synthesis during replication elongation in vivo in S. cerevisiae. By analyzing nascent lagging-strand products, we observe a genome-wide change in both the establishment and progression of replication. S-phase progression is slowed in Pol δ depletion, with both globally reduced origin firing and slower replication progression. We find that no polymerase other than Pol δ is capable of synthesizing a substantial amount of lagging-strand DNA, even when Pol δ is severely limiting. We also characterize the impact of impaired lagging-strand synthesis on genome integrity and find increased ssDNA and DNA damage when Pol δ is limiting; these defects lead to a strict dependence on checkpoint signaling and resection-mediated repair pathways for cellular viability.
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Affiliation(s)
- Natasha C. Koussa
- Department of Biology, New York University, New York City, New York, United State of America
| | - Duncan J. Smith
- Department of Biology, New York University, New York City, New York, United State of America
- * E-mail:
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17
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Job A, Tatura M, Schäfer C, Lutz V, Schneider H, Lankat-Buttgereit B, Zielinski A, Borgmann K, Bauer C, Gress TM, Buchholz M, Gallmeier E. The POLD1 R689W variant increases the sensitivity of colorectal cancer cells to ATR and CHK1 inhibitors. Sci Rep 2020; 10:18924. [PMID: 33144657 PMCID: PMC7641191 DOI: 10.1038/s41598-020-76033-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2020] [Accepted: 10/13/2020] [Indexed: 02/07/2023] Open
Abstract
Inhibition of the kinase ATR, a central regulator of the DNA damage response, eliminates subsets of cancer cells in certain tumors. As previously shown, this is at least partly attributable to synthetic lethal interactions between ATR and POLD1, the catalytic subunit of the polymerase δ. Various POLD1 variants have been found in colorectal cancer, but their significance as therapeutic targets for ATR pathway inhibition remains unknown. Using CRISPR/Cas9 in the colorectal cancer cell line DLD-1, which harbors four POLD1 variants, we established heterozygous POLD1-knockout clones with exclusive expression of distinct variants to determine the functional relevance of these variants individually by assessing their impact on ATR pathway activation, DNA replication, and cellular sensitivity to inhibition of ATR or its effector kinase CHK1. Of the four variants analyzed, only POLD1R689W affected POLD1 function, as demonstrated by compensatory ATR pathway activation and impaired DNA replication. Upon treatment with ATR or CHK1 inhibitors, POLD1R689W strongly decreased cell survival in vitro, which was attributable at least partly to S phase impairment and apoptosis. Similarly, treatment with the ATR inhibitor AZD6738 inhibited growth of murine xenograft tumors, harboring the POLD1R689W variant, in vivo. Our POLD1-knockout model thus complements algorithm-based models to predict the pathogenicity of tumor-specific variants of unknown significance and illustrates a novel and potentially clinically relevant therapeutic approach using ATR/CHK1 inhibitors in POLD1-deficient tumors.
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Affiliation(s)
- Albert Job
- Department of Gastroenterology, Endocrinology, Metabolism, and Infectiology, University Hospital of Marburg, Philipps-University Marburg, Baldingerstraße, 35043, Marburg, Germany
| | - Marina Tatura
- Department of Gastroenterology, Endocrinology, Metabolism, and Infectiology, University Hospital of Marburg, Philipps-University Marburg, Baldingerstraße, 35043, Marburg, Germany
| | - Cora Schäfer
- Department of Gastroenterology, Endocrinology, Metabolism, and Infectiology, University Hospital of Marburg, Philipps-University Marburg, Baldingerstraße, 35043, Marburg, Germany
| | - Veronika Lutz
- Department of Gastroenterology, Endocrinology, Metabolism, and Infectiology, University Hospital of Marburg, Philipps-University Marburg, Baldingerstraße, 35043, Marburg, Germany
| | - Hanna Schneider
- Department of Gastroenterology, Endocrinology, Metabolism, and Infectiology, University Hospital of Marburg, Philipps-University Marburg, Baldingerstraße, 35043, Marburg, Germany
| | - Brigitte Lankat-Buttgereit
- Department of Gastroenterology, Endocrinology, Metabolism, and Infectiology, University Hospital of Marburg, Philipps-University Marburg, Baldingerstraße, 35043, Marburg, Germany
| | - Alexandra Zielinski
- Lab of Radiobiology & Experimental Radiooncology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Kerstin Borgmann
- Lab of Radiobiology & Experimental Radiooncology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Christian Bauer
- Department of Gastroenterology, Endocrinology, Metabolism, and Infectiology, University Hospital of Marburg, Philipps-University Marburg, Baldingerstraße, 35043, Marburg, Germany
| | - Thomas M Gress
- Department of Gastroenterology, Endocrinology, Metabolism, and Infectiology, University Hospital of Marburg, Philipps-University Marburg, Baldingerstraße, 35043, Marburg, Germany
| | - Malte Buchholz
- Department of Gastroenterology, Endocrinology, Metabolism, and Infectiology, University Hospital of Marburg, Philipps-University Marburg, Baldingerstraße, 35043, Marburg, Germany
| | - Eike Gallmeier
- Department of Gastroenterology, Endocrinology, Metabolism, and Infectiology, University Hospital of Marburg, Philipps-University Marburg, Baldingerstraße, 35043, Marburg, Germany.
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18
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Hühns M, Nürnberg S, Kandashwamy KK, Maletzki C, Bauer P, Prall F. High mutational burden in colorectal carcinomas with monoallelic POLE mutations: absence of allelic loss and gene promoter methylation. Mod Pathol 2020; 33:1220-1231. [PMID: 31857678 DOI: 10.1038/s41379-019-0430-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2019] [Revised: 10/28/2019] [Accepted: 11/11/2019] [Indexed: 01/09/2023]
Abstract
Hypermutator-type colorectal carcinomas are microsatellite-stable and have point mutations of the exonuclease domain of the DNA polymerase ε or δ genes (POLE and POLD1, respectively), and an ultrahigh tumor mutational burden (TMB). These tumors may be associated with enhanced antitumor immunity and preferentially afflict younger patients, but this notion awaits validation by accrual of further cases for detailed correlative phenotypic and molecular study. We performed POLE and POLD1 exonuclease domain Sanger sequencing of 271 unselected colorectal carcinomas. We identified two microsatellite-stable tumors with somatic POLE p.P286R variants, both with ultrahigh TMBs as demonstrated by whole exome sequencing. A POLE p.V411L was found in another two microsatellite-stable tumors with ultrahigh TMBs. Two of these four tumors were from young patients (<50 years old, nonsyndromic), and there was seen a prominent T-cell infiltration in three of them. Furthermore, a somatic POLE p.A465T was found in a Lynch-associated tumor, which, hypothetically, might have enhanced TMB (which was the highest of all). In two tumors, a somatic POLE p.V411L and a POLD1 p.E279K, respectively, were found only focally, and TMBs were low. It is commonly assumed that compromise of one allele is sufficient, but this has not been specifically addressed. Therefore, resequencing of the POLE or POLD1 mutations was done with DNA from tumor cells isolated by laser-capture microdissection. This demonstrated that the mutations were monoallelic, and there was no evidence of a "second hit", neither by allelic loss (allelotyping with polymorphic microsatellite markers), nor by promoter methylation (Pyromark CpG assays). Taken together, including at least the more common DNA polymerase mutations in NGS panels allows for straightforward identification of hypermutator-type colorectal carcinomas which often may be "immunoreactive". This is important at least in young patients or when a metastasizing stage of disease has been reached and immune-checkpoint therapy enters deliberation.
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Affiliation(s)
- Maja Hühns
- Institute of Pathology, University Medicine of Rostock, Strempelstraße 14, 18057, Rostock, Germany
| | | | | | - Claudia Maletzki
- Clinic for Hematology, Oncology and Palliative Care, University Medical Center Rostock, University of Rostock, Ernst-Heydemann-Strasse 6, 18057, Rostock, Germany
| | - Peter Bauer
- Centogene AG, Am Strande 7, 18055, Rostock, Germany
| | - Friedrich Prall
- Institute of Pathology, University Medicine of Rostock, Strempelstraße 14, 18057, Rostock, Germany.
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19
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Cervelli T, Lodovichi S, Bellè F, Galli A. Yeast-based assays for the functional characterization of cancer-associated variants of human DNA repair genes. MICROBIAL CELL 2020; 7:162-174. [PMID: 32656256 PMCID: PMC7328678 DOI: 10.15698/mic2020.07.721] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Technological advances are continuously revealing new genetic variants that are often difficult to interpret. As one of the most genetically tractable model organisms, yeast can have a central role in determining the consequences of human genetic variation. DNA repair gene mutations are associated with many types of cancers, therefore the evaluation of the functional impact of these mutations is crucial for risk assessment and for determining therapeutic strategies. Owing to the evolutionary conservation of DNA repair pathways between human cells and the yeast Saccharomyces cerevisiae, several functional assays have been developed. Here, we describe assays for variants of human genes belonging to the major DNA repair pathways divided in functional assays for human genes with yeast orthologues and human genes lacking a yeast orthologue. Human genes with orthologues can be studied by introducing the correspondent human mutations directly in the yeast gene or expressing the human gene carrying the mutations; while the only possible approach for human genes without a yeast orthologue is the heterologous expression. The common principle of these approaches is that the mutated gene determines a phenotypic alteration that can vary according to the gene studied and the domain of the protein. Here, we show how the versatility of yeast can help in classifying cancer-associated variants.
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Affiliation(s)
- Tiziana Cervelli
- Yeast Genetics and Genomics Group, Laboratory of Functional Genetics and Genomics, Institute of Clinical Physiology CNR, Via Moruzzi 1, 56125 Pisa, Italy
| | - Samuele Lodovichi
- Yeast Genetics and Genomics Group, Laboratory of Functional Genetics and Genomics, Institute of Clinical Physiology CNR, Via Moruzzi 1, 56125 Pisa, Italy
| | - Francesca Bellè
- Yeast Genetics and Genomics Group, Laboratory of Functional Genetics and Genomics, Institute of Clinical Physiology CNR, Via Moruzzi 1, 56125 Pisa, Italy
| | - Alvaro Galli
- Yeast Genetics and Genomics Group, Laboratory of Functional Genetics and Genomics, Institute of Clinical Physiology CNR, Via Moruzzi 1, 56125 Pisa, Italy
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20
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Abstract
Polδ and Polε are the two major replicative polymerases in eukaryotes, but their precise roles at the replication fork remain a subject of debate. A bulk of data supports a model where Polε and Polδ synthesize leading and lagging DNA strands, respectively. However, this model has been difficult to reconcile with the fact that mutations in Polδ have much stronger consequences for genome stability than equivalent mutations in Polε. We provide direct evidence for a long-entertained idea that Polδ can proofread errors made by Polε in addition to its own errors, thus, making a more prominent contribution to mutation avoidance. This paper provides an essential advance in the understanding of the mechanism of eukaryotic DNA replication. During eukaryotic replication, DNA polymerases ε (Polε) and δ (Polδ) synthesize the leading and lagging strands, respectively. In a long-known contradiction to this model, defects in the fidelity of Polε have a much weaker impact on mutagenesis than analogous Polδ defects. It has been previously proposed that Polδ contributes more to mutation avoidance because it proofreads mismatches created by Polε in addition to its own errors. However, direct evidence for this model was missing. We show that, in yeast, the mutation rate increases synergistically when a Polε nucleotide selectivity defect is combined with a Polδ proofreading defect, demonstrating extrinsic proofreading of Polε errors by Polδ. In contrast, combining Polδ nucleotide selectivity and Polε proofreading defects produces no synergy, indicating that Polε cannot correct errors made by Polδ. We further show that Polδ can remove errors made by exonuclease-deficient Polε in vitro. These findings illustrate the complexity of the one-strand–one-polymerase model where synthesis appears to be largely divided, but Polδ proofreading operates on both strands.
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Lee M, Eng G, Barbari SR, Deshpande V, Shcherbakova PV, Gala MK. Homologous Recombination Repair Truncations Predict Hypermutation in Microsatellite Stable Colorectal and Endometrial Tumors. Clin Transl Gastroenterol 2020; 11:e00149. [PMID: 32352724 PMCID: PMC7145036 DOI: 10.14309/ctg.0000000000000149] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/18/2019] [Accepted: 02/13/2020] [Indexed: 01/10/2023] Open
Abstract
INTRODUCTION Somatic mutations in BRCA1/2 and other homologous recombination repair (HRR) genes have been associated with sensitivity to PARP inhibitors and/or platinum agents in several cancers, whereas hypermutant tumors caused by alterations in POLE or mismatch repair genes have demonstrated robust responses to immunotherapy. We investigated the relationship between somatic truncations in HRR genes and hypermutation in colorectal cancer (CRC) and endometrial cancer (EC). METHODS We analyzed the mutational spectra associated with somatic BRCA1/2 truncations in multiple genomic cohorts (N = 2,335). From these results, we devised a classifier incorporating HRR genes to predict hypermutator status among microsatellite stable (MSS) tumors. Using additional genomic cohorts (N = 1,439) and functional in vivo assays, we tested the classifier to disambiguate POLE variants of unknown significance and identify MSS hypermutators without somatic POLE exonuclease domain mutations. RESULTS Hypermutator phenotypes were prevalent among CRCs with somatic BRCA1/2 truncations (50/62, 80.6%) and ECs with such mutations (44/47, 93.6%). The classifier predicted MSS hypermutators with a cumulative true-positive rate of 100% in CRC and 98.0% in EC and a false-positive rate of 0.07% and 0.63%. Validated by signature analyses of tumor exomes and in vivo assays, the classifier accurately reassigned multiple POLE variants of unknown significance as pathogenic and identified MSS hypermutant samples without POLE exonuclease domain mutations. DISCUSSION Somatic truncations in HRR can accurately fingerprint MSS hypermutators with or without known pathogenic exonuclease domain mutations in POLE and may serve as a low-cost biomarker for immunotherapy decisions in MSS CRC and EC.
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Affiliation(s)
- Minyi Lee
- Gastrointestinal Unit, Harvard Medical School, Massachusetts General Hospital, Boston, Massachusetts, USA
| | - George Eng
- Gastrointestinal Unit, Harvard Medical School, Massachusetts General Hospital, Boston, Massachusetts, USA
- Department of Pathology, Harvard Medical School, Massachusetts General Hospital, Boston, Massachusetts, USA
| | - Stephanie R. Barbari
- Eppley Institute for Research in Cancer and Allied Diseases, Fred & Pamela Buffett Cancer Center, University of Nebraska Medical Center, Omaha, Nebraska, USA
| | - Vikram Deshpande
- Department of Pathology, Harvard Medical School, Massachusetts General Hospital, Boston, Massachusetts, USA
| | - Polina V. Shcherbakova
- Eppley Institute for Research in Cancer and Allied Diseases, Fred & Pamela Buffett Cancer Center, University of Nebraska Medical Center, Omaha, Nebraska, USA
| | - Manish K. Gala
- Gastrointestinal Unit, Harvard Medical School, Massachusetts General Hospital, Boston, Massachusetts, USA
- Clinical and Translational Epidemiology Unit, Harvard Medical School, Massachusetts General Hospital, Boston, Massachusetts, USA
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22
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Combined immunodeficiency caused by a loss-of-function mutation in DNA polymerase delta 1. J Allergy Clin Immunol 2019; 145:391-401.e8. [PMID: 31629014 DOI: 10.1016/j.jaci.2019.10.004] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2019] [Revised: 09/11/2019] [Accepted: 10/04/2019] [Indexed: 01/29/2023]
Abstract
BACKGROUND Mutations affecting DNA polymerases have been implicated in genomic instability and cancer development, but the mechanisms by which they can affect the immune system remain largely unexplored. OBJECTIVE We sought to establish the role of DNA polymerase δ1 catalytic subunit (POLD1) as the cause of a primary immunodeficiency in an extended kindred. METHODS We performed whole-exome and targeted gene sequencing, lymphocyte characterization, molecular and functional analyses of the DNA polymerase δ (Polδ) complex, and T- and B-cell antigen receptor repertoire analysis. RESULTS We identified a missense mutation (c. 3178C>T; p.R1060C) in POLD1 in 3 related subjects who presented with recurrent, especially herpetic, infections and T-cell lymphopenia with impaired T-cell but not B-cell proliferation. The mutation destabilizes the Polδ complex, leading to ineffective recruitment of replication factor C to initiate DNA replication. Molecular dynamics simulation revealed that the R1060C mutation disrupts the intramolecular interaction between the POLD1 CysB motif and the catalytic domain and also between POLD1 and the Polδ subunit POLD2. The patients exhibited decreased numbers of naive CD4 and especially CD8 T cells in favor of effector memory subpopulations. This skewing was associated with oligoclonality and restricted T-cell receptor β-chain V-J pairing in CD8+ but not CD4+ T cells, suggesting that POLD1R1060C differentially affects peripheral CD8+ T-cell expansion and possibly thymic selection. CONCLUSION These results identify gene defects in POLD1 as a novel cause of T-cell immunodeficiency.
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Natali F, Rancati G. The Mutator Phenotype: Adapting Microbial Evolution to Cancer Biology. Front Genet 2019; 10:713. [PMID: 31447882 PMCID: PMC6691094 DOI: 10.3389/fgene.2019.00713] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2018] [Accepted: 07/05/2019] [Indexed: 01/07/2023] Open
Abstract
The mutator phenotype hypothesis was postulated almost 40 years ago to reconcile the observation that while cancer cells display widespread mutational burden, acquisition of mutations in non-transformed cells is a rare event. Moreover, it also suggested that cancer evolution could be fostered by increased genome instability. Given the evolutionary conservation throughout the tree of life and the genetic tractability of model organisms, yeast and bacterial species pioneered studies to dissect the functions of genes required for genome maintenance (caretaker genes) or for cell growth control (gatekeeper genes). In this review, we first provide an overview of what we learned from model organisms about the roles of these genes and the genome instability that arises as a consequence of their dysregulation. We then discuss our current understanding of how mutator phenotypes shape the evolution of bacteria and yeast species. We end by bringing clinical evidence that lessons learned from single-cell organisms can be applied to tumor evolution.
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Affiliation(s)
- Federica Natali
- Institute of Medical Biology (IMB), Agency for Science, Technology and Research (ASTAR), Singapore, Singapore.,School of Biological Sciences, Nanyang Technological University, Singapore, Singapore
| | - Giulia Rancati
- Institute of Medical Biology (IMB), Agency for Science, Technology and Research (ASTAR), Singapore, Singapore
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Rogozin IB, Pavlov YI, Goncearenco A, De S, Lada AG, Poliakov E, Panchenko AR, Cooper DN. Mutational signatures and mutable motifs in cancer genomes. Brief Bioinform 2019; 19:1085-1101. [PMID: 28498882 DOI: 10.1093/bib/bbx049] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2017] [Indexed: 12/22/2022] Open
Abstract
Cancer is a genetic disorder, meaning that a plethora of different mutations, whether somatic or germ line, underlie the etiology of the 'Emperor of Maladies'. Point mutations, chromosomal rearrangements and copy number changes, whether they have occurred spontaneously in predisposed individuals or have been induced by intrinsic or extrinsic (environmental) mutagens, lead to the activation of oncogenes and inactivation of tumor suppressor genes, thereby promoting malignancy. This scenario has now been recognized and experimentally confirmed in a wide range of different contexts. Over the past decade, a surge in available sequencing technologies has allowed the sequencing of whole genomes from liquid malignancies and solid tumors belonging to different types and stages of cancer, giving birth to the new field of cancer genomics. One of the most striking discoveries has been that cancer genomes are highly enriched with mutations of specific kinds. It has been suggested that these mutations can be classified into 'families' based on their mutational signatures. A mutational signature may be regarded as a type of base substitution (e.g. C:G to T:A) within a particular context of neighboring nucleotide sequence (the bases upstream and/or downstream of the mutation). These mutational signatures, supplemented by mutable motifs (a wider mutational context), promise to help us to understand the nature of the mutational processes that operate during tumor evolution because they represent the footprints of interactions between DNA, mutagens and the enzymes of the repair/replication/modification pathways.
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Affiliation(s)
- Igor B Rogozin
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, USA
| | - Youri I Pavlov
- Eppley Institute for Cancer Research, University of Nebraska Medical Center, USA
| | | | | | - Artem G Lada
- Department Microbiology and Molecular Genetics, University of California, Davis, USA
| | - Eugenia Poliakov
- Laboratory of Retinal Cell and Molecular Biology, National Eye Institute, National Institutes of Health, USA
| | - Anna R Panchenko
- National Center for Biotechnology Information, National Institutes of Health, USA
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25
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Foley MC, Couto L, Rauf S, Boyke A. Insights into DNA polymerase δ’s mechanism for accurate DNA replication. J Mol Model 2019; 25:80. [DOI: 10.1007/s00894-019-3957-z] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2018] [Accepted: 02/05/2019] [Indexed: 11/28/2022]
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Mercatanti A, Lodovichi S, Cervelli T, Galli A. CRIMEtoYHU: a new web tool to develop yeast-based functional assays for characterizing cancer-associated missense variants. FEMS Yeast Res 2018; 17:4562592. [PMID: 29069390 DOI: 10.1093/femsyr/fox078] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2017] [Accepted: 09/25/2017] [Indexed: 12/13/2022] Open
Abstract
Evaluation of the functional impact of cancer-associated missense variants is more difficult than for protein-truncating mutations and consequently standard guidelines for the interpretation of sequence variants have been recently proposed. A number of algorithms and software products were developed to predict the impact of cancer-associated missense mutations on protein structure and function. Importantly, direct assessment of the variants using high-throughput functional assays using simple genetic systems can help in speeding up the functional evaluation of newly identified cancer-associated variants. We developed the web tool CRIMEtoYHU (CTY) to help geneticists in the evaluation of the functional impact of cancer-associated missense variants. Humans and the yeast Saccharomyces cerevisiae share thousands of protein-coding genes although they have diverged for a billion years. Therefore, yeast humanization can be helpful in deciphering the functional consequences of human genetic variants found in cancer and give information on the pathogenicity of missense variants. To humanize specific positions within yeast genes, human and yeast genes have to share functional homology. If a mutation in a specific residue is associated with a particular phenotype in humans, a similar substitution in the yeast counterpart may reveal its effect at the organism level. CTY simultaneously finds yeast homologous genes, identifies the corresponding variants and determines the transferability of human variants to yeast counterparts by assigning a reliability score (RS) that may be predictive for the validity of a functional assay. CTY analyzes newly identified mutations or retrieves mutations reported in the COSMIC database, provides information about the functional conservation between yeast and human and shows the mutation distribution in human genes. CTY analyzes also newly found mutations and aborts when no yeast homologue is found. Then, on the basis of the protein domain localization and functional conservation between yeast and human, the selected variants are ranked by the RS. The RS is assigned by an algorithm that computes functional data, type of mutation, chemistry of amino acid substitution and the degree of mutation transferability between human and yeast protein. Mutations giving a positive RS are highly transferable to yeast and, therefore, yeast functional assays will be more predictable. To validate the web application, we have analyzed 8078 cancer-associated variants located in 31 genes that have a yeast homologue. More than 50% of variants are transferable to yeast. Incidentally, 88% of all transferable mutations have a reliability score >0. Moreover, we analyzed by CTY 72 functionally validated missense variants located in yeast genes at positions corresponding to the human cancer-associated variants. All these variants gave a positive RS. To further validate CTY, we analyzed 3949 protein variants (with positive RS) by the predictive algorithm PROVEAN. This analysis shows that yeast-based functional assays will be more predictable for the variants with positive RS. We believe that CTY could be an important resource for the cancer research community by providing information concerning the functional impact of specific mutations, as well as for the design of functional assays useful for decision support in precision medicine.
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Affiliation(s)
- Alberto Mercatanti
- Yeast Genetics and Genomics Group, Laboratory of Functional Genetics and Genomics, Institute of Clinical Physiology CNR, via G. Moruzzi 1, 56124 Pisa, Italy
| | - Samuele Lodovichi
- Yeast Genetics and Genomics Group, Laboratory of Functional Genetics and Genomics, Institute of Clinical Physiology CNR, via G. Moruzzi 1, 56124 Pisa, Italy
- PhD program in Clinical and Translational Science, University of Pisa, Pisa, Italy
| | - Tiziana Cervelli
- Yeast Genetics and Genomics Group, Laboratory of Functional Genetics and Genomics, Institute of Clinical Physiology CNR, via G. Moruzzi 1, 56124 Pisa, Italy
| | - Alvaro Galli
- Yeast Genetics and Genomics Group, Laboratory of Functional Genetics and Genomics, Institute of Clinical Physiology CNR, via G. Moruzzi 1, 56124 Pisa, Italy
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27
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Barbari SR, Kane DP, Moore EA, Shcherbakova PV. Functional Analysis of Cancer-Associated DNA Polymerase ε Variants in Saccharomyces cerevisiae. G3 (BETHESDA, MD.) 2018; 8:1019-1029. [PMID: 29352080 PMCID: PMC5844290 DOI: 10.1534/g3.118.200042] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/25/2017] [Accepted: 01/17/2018] [Indexed: 01/17/2023]
Abstract
DNA replication fidelity relies on base selectivity of the replicative DNA polymerases, exonucleolytic proofreading, and postreplicative DNA mismatch repair (MMR). Ultramutated human cancers without MMR defects carry alterations in the exonuclease domain of DNA polymerase ε (Polε). They have been hypothesized to result from defective proofreading. However, modeling of the most common variant, Polε-P286R, in yeast produced an unexpectedly strong mutator effect that exceeded the effect of proofreading deficiency by two orders of magnitude and indicated the involvement of other infidelity factors. The in vivo consequences of many additional Polε mutations reported in cancers remain poorly understood. Here, we genetically characterized 13 cancer-associated Polε variants in the yeast system. Only variants directly altering the DNA binding cleft in the exonuclease domain elevated the mutation rate. Among these, frequently recurring variants were stronger mutators than rare variants, in agreement with the idea that mutator phenotype has a causative role in tumorigenesis. In nearly all cases, the mutator effects exceeded those of an exonuclease-null allele, suggesting that mechanisms distinct from loss of proofreading may drive the genome instability in most ultramutated tumors. All mutator alleles were semidominant, supporting the view that heterozygosity for the polymerase mutations is sufficient for tumor development. In contrast to the DNA binding cleft alterations, peripherally located variants, including a highly recurrent V411L, did not significantly elevate mutagenesis. Finally, the analysis of Polε variants found in MMR-deficient tumors suggested that the majority cause no mutator phenotype alone but some can synergize with MMR deficiency to increase the mutation rate.
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Affiliation(s)
- Stephanie R Barbari
- Eppley Institute for Research in Cancer and Allied Diseases, Fred & Pamela Buffett Cancer Center, University of Nebraska Medical Center, Omaha, Nebraska 68198
| | - Daniel P Kane
- Eppley Institute for Research in Cancer and Allied Diseases, Fred & Pamela Buffett Cancer Center, University of Nebraska Medical Center, Omaha, Nebraska 68198
| | - Elizabeth A Moore
- Eppley Institute for Research in Cancer and Allied Diseases, Fred & Pamela Buffett Cancer Center, University of Nebraska Medical Center, Omaha, Nebraska 68198
| | - Polina V Shcherbakova
- Eppley Institute for Research in Cancer and Allied Diseases, Fred & Pamela Buffett Cancer Center, University of Nebraska Medical Center, Omaha, Nebraska 68198
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28
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Campbell BB, Light N, Fabrizio D, Zatzman M, Fuligni F, de Borja R, Davidson S, Edwards M, Elvin JA, Hodel KP, Zahurancik WJ, Suo Z, Lipman T, Wimmer K, Kratz CP, Bowers DC, Laetsch TW, Dunn GP, Johanns TM, Grimmer MR, Smirnov IV, Larouche V, Samuel D, Bronsema A, Osborn M, Stearns D, Raman P, Cole KA, Storm PB, Yalon M, Opocher E, Mason G, Thomas GA, Sabel M, George B, Ziegler DS, Lindhorst S, Issai VM, Constantini S, Toledano H, Elhasid R, Farah R, Dvir R, Dirks P, Huang A, Galati MA, Chung J, Ramaswamy V, Irwin MS, Aronson M, Durno C, Taylor MD, Rechavi G, Maris JM, Bouffet E, Hawkins C, Costello JF, Meyn MS, Pursell ZF, Malkin D, Tabori U, Shlien A. Comprehensive Analysis of Hypermutation in Human Cancer. Cell 2017; 171:1042-1056.e10. [PMID: 29056344 PMCID: PMC5849393 DOI: 10.1016/j.cell.2017.09.048] [Citation(s) in RCA: 515] [Impact Index Per Article: 73.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2017] [Revised: 07/26/2017] [Accepted: 09/25/2017] [Indexed: 12/23/2022]
Abstract
We present an extensive assessment of mutation burden through sequencing analysis of >81,000 tumors from pediatric and adult patients, including tumors with hypermutation caused by chemotherapy, carcinogens, or germline alterations. Hypermutation was detected in tumor types not previously associated with high mutation burden. Replication repair deficiency was a major contributing factor. We uncovered new driver mutations in the replication-repair-associated DNA polymerases and a distinct impact of microsatellite instability and replication repair deficiency on the scale of mutation load. Unbiased clustering, based on mutational context, revealed clinically relevant subgroups regardless of the tumors' tissue of origin, highlighting similarities in evolutionary dynamics leading to hypermutation. Mutagens, such as UV light, were implicated in unexpected cancers, including sarcomas and lung tumors. The order of mutational signatures identified previous treatment and germline replication repair deficiency, which improved management of patients and families. These data will inform tumor classification, genetic testing, and clinical trial design.
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Affiliation(s)
- Brittany B Campbell
- Program in Genetics and Genome Biology, The Hospital for Sick Children, Toronto, ON, Canada; The Arthur and Sonia Labatt Brain Tumour Research Centre, The Hospital for Sick Children, Toronto, ON, Canada; Institute of Medical Science, Faculty of Medicine, University of Toronto, Toronto, ON, Canada
| | - Nicholas Light
- Program in Genetics and Genome Biology, The Hospital for Sick Children, Toronto, ON, Canada; Institute of Medical Science, Faculty of Medicine, University of Toronto, Toronto, ON, Canada
| | | | - Matthew Zatzman
- Program in Genetics and Genome Biology, The Hospital for Sick Children, Toronto, ON, Canada; Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, ON, Canada
| | - Fabio Fuligni
- Program in Genetics and Genome Biology, The Hospital for Sick Children, Toronto, ON, Canada
| | - Richard de Borja
- Program in Genetics and Genome Biology, The Hospital for Sick Children, Toronto, ON, Canada
| | - Scott Davidson
- Program in Genetics and Genome Biology, The Hospital for Sick Children, Toronto, ON, Canada; Department of Paediatric Laboratory Medicine, The Hospital for Sick Children, Toronto, ON, Canada
| | - Melissa Edwards
- Program in Genetics and Genome Biology, The Hospital for Sick Children, Toronto, ON, Canada
| | | | - Karl P Hodel
- Department of Biochemistry and Molecular Biology, Tulane Cancer Center, Tulane University School of Medicine, New Orleans, LA, USA
| | - Walter J Zahurancik
- The Ohio State Biochemistry Program, The Ohio State University, Columbus, OH, USA; Department of Chemistry and Biochemistry, The Ohio State University, Columbus, OH, USA
| | - Zucai Suo
- The Ohio State Biochemistry Program, The Ohio State University, Columbus, OH, USA; Department of Chemistry and Biochemistry, The Ohio State University, Columbus, OH, USA
| | - Tatiana Lipman
- Program in Genetics and Genome Biology, The Hospital for Sick Children, Toronto, ON, Canada
| | - Katharina Wimmer
- Division of Human Genetics, Medical University Innsbruck, Innsbruck, Austria
| | - Christian P Kratz
- Pediatric Hematology and Oncology, Hannover Medical School, Hannover, Germany
| | - Daniel C Bowers
- Department of Pediatrics and Harold C. Simmons Comprehensive Cancer Center, University of Texas Southwestern Medical Center, Dallas, TX, USA; Pauline Allen Gill Center for Cancer and Blood Disorders, Children's Health, Dallas, TX, USA
| | - Theodore W Laetsch
- Department of Pediatrics and Harold C. Simmons Comprehensive Cancer Center, University of Texas Southwestern Medical Center, Dallas, TX, USA; Pauline Allen Gill Center for Cancer and Blood Disorders, Children's Health, Dallas, TX, USA
| | - Gavin P Dunn
- Department of Neurological Surgery, Center for Human Immunology and Immunotherapy Programs, Washington University School of Medicine, St. Louis, MO, USA
| | - Tanner M Johanns
- Department of Neurological Surgery, Center for Human Immunology and Immunotherapy Programs, Washington University School of Medicine, St. Louis, MO, USA; Division of Oncology, Department of Medicine, Washington University School of Medicine, St. Louis, MO, USA
| | - Matthew R Grimmer
- Division of Oncology, Department of Medicine, Washington University School of Medicine, St. Louis, MO, USA
| | - Ivan V Smirnov
- Department of Neurological Surgery, University of California, San Francisco, San Francisco, CA, USA; Division of Neuroepidemiology, Department of Neurological Surgery, University of California, San Francisco, San Francisco, CA, USA
| | - Valérie Larouche
- Department of Pediatrics, Centre Mère-enfant Soleil du CHU de Québec, CRCHU de Québec, Université Laval, Quebec City, QC, Canada
| | - David Samuel
- Department of Hematology-Oncology, Valley Children's Hospital, Madera, CA, USA
| | - Annika Bronsema
- Department of Pediatric Hematology and Oncology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Michael Osborn
- Department of Haematology and Oncology, Women's and Children's Hospital, North Adelaide, SA, Australia
| | - Duncan Stearns
- Department of Pediatrics-Hematology and Oncology, UH Rainbow Babies and Children's Hospital, Cleveland, OH, USA
| | - Pichai Raman
- Division of Oncology and Center for Childhood Cancer Research, Children's Hospital of Philadelphia, Philadelphia, PA, USA; Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, USA
| | - Kristina A Cole
- Division of Oncology and Center for Childhood Cancer Research, Children's Hospital of Philadelphia, Philadelphia, PA, USA; Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, USA
| | - Phillip B Storm
- Division of Neurosurgery, Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | - Michal Yalon
- Department of Pediatric Hematology-Oncology, Sheba Medical Center, Tel Hashomer, Israel
| | - Enrico Opocher
- Pediatric Oncology & Hematology, Azienda Ospedaliera-Università degli Studi di Padova, Via Giustiniani n.1, Padova, Italy
| | - Gary Mason
- Department of Pediatric Hematology-Oncology, Children's Hospital of Pittsburgh of UPMC, Pittsburgh, PA, USA
| | - Gregory A Thomas
- Division of Pediatric Hematology-Oncology, Oregon Health & Science University, Portland, OR, USA
| | - Magnus Sabel
- Department of Pediatrics, Institute of Clinical Sciences, Sahlgrenska Academy, University of Gothenburg & Queen Silvia Children's Hospital, Sahlgrenska University Hospital, Gothenburg, Sweden
| | - Ben George
- Division of Hematology and Oncology, Medical College of Wisconsin, Milwaukee, WI, USA
| | - David S Ziegler
- Kids Cancer Centre, Sydney Children's Hospital, Randwick, NSW, Australia; Children's Cancer Institute, Lowy Cancer Research Centre, University of New South Wales, Randwick, NSW, Australia
| | - Scott Lindhorst
- Neuro-Oncology, Department of Neurosurgery, and Department of Medicine, Division of Hematology/Medical Oncology, Medical University of South Carolina, Charleston, SC, USA
| | - Vanan Magimairajan Issai
- Department of Pediatric Hematology-Oncology, Cancer Care Manitoba; Research Institute in Oncology and Hematology (RIOH), University of Manitoba, Winnipeg, MB, Canada
| | - Shlomi Constantini
- Department of Pediatric Neurosurgery, Tel Aviv Sourasky Medical Center, Tel Aviv University, Tel Aviv, Israel
| | - Helen Toledano
- Department of Pediatric Neurosurgery, Tel Aviv Sourasky Medical Center, Tel Aviv University, Tel Aviv, Israel
| | - Ronit Elhasid
- Department of Hematology-Oncology, Tel Aviv Sourasky Medical Center, Tel Aviv, Israel
| | - Roula Farah
- Department of Pediatrics, Saint George Hospital University Medical Center, Beirut, Lebanon
| | - Rina Dvir
- Department of Pediatric Hematology/Oncology, Schneider Children's Medical Center of Israel, Petach Tikva, Israel; Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Peter Dirks
- Department of Neurosurgery, The Hospital for Sick Children, Toronto, ON, Canada
| | - Annie Huang
- The Arthur and Sonia Labatt Brain Tumour Research Centre, The Hospital for Sick Children, Toronto, ON, Canada; Division of Hematology/Oncology, The Hospital for Sick Children, Toronto, ON, Canada; Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, ON, Canada
| | - Melissa A Galati
- Program in Genetics and Genome Biology, The Hospital for Sick Children, Toronto, ON, Canada
| | - Jiil Chung
- Program in Genetics and Genome Biology, The Hospital for Sick Children, Toronto, ON, Canada
| | - Vijay Ramaswamy
- Division of Hematology/Oncology, The Hospital for Sick Children, Toronto, ON, Canada
| | - Meredith S Irwin
- Division of Hematology/Oncology, The Hospital for Sick Children, Toronto, ON, Canada
| | - Melyssa Aronson
- Zane Cohen Centre for Digestive Diseases, Mount Sinai Hospital, Toronto, ON, Canada
| | - Carol Durno
- Zane Cohen Centre for Digestive Diseases, Mount Sinai Hospital, Toronto, ON, Canada; Division of Gastroenterology, Hepatology and Nutrition, The Hospital for Sick Children, Toronto, ON, Canada
| | - Michael D Taylor
- Department of Neurosurgery, The Hospital for Sick Children, Toronto, ON, Canada
| | - Gideon Rechavi
- Cancer Research Center and Wohl Institute for Translational Medicine, Sheba Medical Center, Tel Hashomer, Ramat Gan, Israel
| | - John M Maris
- Division of Oncology and Center for Childhood Cancer Research, Children's Hospital of Philadelphia, Philadelphia, PA, USA; Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, USA
| | - Eric Bouffet
- Division of Hematology/Oncology, The Hospital for Sick Children, Toronto, ON, Canada
| | - Cynthia Hawkins
- The Arthur and Sonia Labatt Brain Tumour Research Centre, The Hospital for Sick Children, Toronto, ON, Canada
| | - Joseph F Costello
- Department of Neurological Surgery, University of California, San Francisco, San Francisco, CA, USA
| | - M Stephen Meyn
- Department of Molecular Genetics, University of Toronto, Toronto, ON, Canada; Center for Human Genomics and Precision Medicine, University of Wisconsin, Madison, WI, USA
| | - Zachary F Pursell
- Department of Biochemistry and Molecular Biology, Tulane Cancer Center, Tulane University School of Medicine, New Orleans, LA, USA
| | - David Malkin
- Division of Hematology/Oncology, The Hospital for Sick Children, Toronto, ON, Canada; Department of Pediatrics, University of Toronto, Toronto, ON, Canada
| | - Uri Tabori
- Program in Genetics and Genome Biology, The Hospital for Sick Children, Toronto, ON, Canada; The Arthur and Sonia Labatt Brain Tumour Research Centre, The Hospital for Sick Children, Toronto, ON, Canada; Division of Hematology/Oncology, The Hospital for Sick Children, Toronto, ON, Canada.
| | - Adam Shlien
- Program in Genetics and Genome Biology, The Hospital for Sick Children, Toronto, ON, Canada; Department of Paediatric Laboratory Medicine, The Hospital for Sick Children, Toronto, ON, Canada; Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, ON, Canada.
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Abstract
The fidelity of DNA replication is determined by many factors, here simplified as the contribution of the DNA polymerase (nucleotide selectivity and proofreading), mismatch repair, a balanced supply of nucleotides, and the condition of the DNA template (both in terms of sequence context and the presence of DNA lesions). This review discusses the contribution and interplay between these factors to the overall fidelity of DNA replication.
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Affiliation(s)
- Rais A Ganai
- Department of Medical Biochemistry and Biophysics, Umeå University, SE 901 87 Umeå, Sweden; Howard Hughes Medical Institute, Department of Biochemistry and Molecular Pharmacology, New York University School of Medicine, NY 10016, USA
| | - Erik Johansson
- Department of Medical Biochemistry and Biophysics, Umeå University, SE 901 87 Umeå, Sweden.
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Mertz TM, Baranovskiy AG, Wang J, Tahirov TH, Shcherbakova PV. Nucleotide selectivity defect and mutator phenotype conferred by a colon cancer-associated DNA polymerase δ mutation in human cells. Oncogene 2017; 36:4427-4433. [PMID: 28368425 PMCID: PMC5542868 DOI: 10.1038/onc.2017.22] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2016] [Revised: 12/17/2016] [Accepted: 12/30/2016] [Indexed: 12/14/2022]
Abstract
Mutations in the POLD1 and POLE genes encoding DNA polymerases δ (Polδ) and ɛ (Polɛ) cause hereditary colorectal cancer (CRC) and have been found in many sporadic colorectal and endometrial tumors. Much attention has been focused on POLE exonuclease domain mutations, which occur frequently in hypermutated DNA mismatch repair (MMR)-proficient tumors and appear to be responsible for the bulk of genomic instability in these tumors. In contrast, somatic POLD1 mutations are seen less frequently and typically occur in MMR-deficient tumors. Their functional significance is often unclear. Here we demonstrate that expression of the cancer-associated POLD1-R689W allele is strongly mutagenic in human cells. The mutation rate increased synergistically when the POLD1-R689W expression was combined with a MMR defect, indicating that the mutator effect of POLD1-R689W results from a high rate of replication errors. Purified human Polδ-R689W has normal exonuclease activity, but the nucleotide selectivity of the enzyme is severely impaired, providing a mechanistic explanation for the increased mutation rate in the POLD1-R689W-expressing cells. The vast majority of mutations induced by the POLD1-R689W are GC→︀TA transversions and GC→︀AT transitions, with transversions showing a strong strand bias and a remarkable preference for polypurine/polypyrimidine sequences. The mutational specificity of the Polδ variant matches that of the hypermutated CRC cell line, HCT15, in which this variant was first identified. The results provide compelling evidence for the pathogenic role of the POLD1-R689W mutation in the development of the human tumor and emphasize the need to experimentally determine the significance of Polδ variants present in sporadic tumors.
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Affiliation(s)
- T M Mertz
- Eppley Institute for Research in Cancer and Allied Diseases, Fred and Pamela Buffett Cancer Center, University of Nebraska Medical Center, Omaha, NE, USA
| | - A G Baranovskiy
- Eppley Institute for Research in Cancer and Allied Diseases, Fred and Pamela Buffett Cancer Center, University of Nebraska Medical Center, Omaha, NE, USA
| | - J Wang
- Eppley Institute for Research in Cancer and Allied Diseases, Fred and Pamela Buffett Cancer Center, University of Nebraska Medical Center, Omaha, NE, USA
| | - T H Tahirov
- Eppley Institute for Research in Cancer and Allied Diseases, Fred and Pamela Buffett Cancer Center, University of Nebraska Medical Center, Omaha, NE, USA
| | - P V Shcherbakova
- Eppley Institute for Research in Cancer and Allied Diseases, Fred and Pamela Buffett Cancer Center, University of Nebraska Medical Center, Omaha, NE, USA
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31
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Replicative DNA polymerase defects in human cancers: Consequences, mechanisms, and implications for therapy. DNA Repair (Amst) 2017; 56:16-25. [PMID: 28687338 DOI: 10.1016/j.dnarep.2017.06.003] [Citation(s) in RCA: 71] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The fidelity of DNA replication relies on three error avoidance mechanisms acting in series: nucleotide selectivity of replicative DNA polymerases, exonucleolytic proofreading, and post-replicative DNA mismatch repair (MMR). MMR defects are well known to be associated with increased cancer incidence. Due to advances in DNA sequencing technologies, the past several years have witnessed a long-predicted discovery of replicative DNA polymerase defects in sporadic and hereditary human cancers. The polymerase mutations preferentially affect conserved amino acid residues in the exonuclease domain and occur in tumors with an extremely high mutation load. Thus, a concept has formed that defective proofreading of replication errors triggers the development of these tumors. Recent studies of the most common DNA polymerase variants, however, suggested that their pathogenicity may be determined by functional alterations other than loss of proofreading. In this review, we summarize our current understanding of the consequences of DNA polymerase mutations in cancers and the mechanisms of their mutator effects. We also discuss likely explanations for a high recurrence of some but not other polymerase variants and new ideas for therapeutic interventions emerging from the mechanistic studies.
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32
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Normally lethal amino acid substitutions suppress an ultramutator DNA Polymerase δ variant. Sci Rep 2017; 7:46535. [PMID: 28417960 PMCID: PMC5394481 DOI: 10.1038/srep46535] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2016] [Accepted: 03/22/2017] [Indexed: 02/06/2023] Open
Abstract
In yeast, the pol3-01,L612M double mutant allele, which causes defects in DNA polymerase delta (Pol δ) proofreading (pol3-01) and nucleotide selectivity (pol3-L612M), confers an “ultramutator” phenotype that rapidly drives extinction of haploid and diploid MMR-proficient cells. Here, we investigate antimutator mutations that encode amino acid substitutions in Pol δ that suppress this lethal phenotype. We find that most of the antimutator mutations individually suppress the pol3-01 and pol3-L612M mutator phenotypes. The locations of many of the amino acid substitutions in Pol δ resemble those of previously identified antimutator substitutions; however, two novel mutations encode substitutions (R674G and Q697R) of amino acids in the fingers domain that coordinate the incoming dNTP. These mutations are lethal without pol3-L612M and markedly change the mutation spectra produced by the pol3-01,L612M mutator allele, suggesting that they alter nucleotide selection to offset the pol3-L612M mutator phenotype. Consistent with this hypothesis, mutations and drug treatments that perturb dNTP pool levels disproportionately influence the viability of pol3-L612M,R674G and pol3-L612M,Q697R cells. Taken together, our findings suggest that mutation rate can evolve through genetic changes that alter the balance of dNTP binding and dissociation from DNA polymerases.
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33
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Risks at the DNA Replication Fork: Effects upon Carcinogenesis and Tumor Heterogeneity. Genes (Basel) 2017; 8:genes8010046. [PMID: 28117753 PMCID: PMC5295039 DOI: 10.3390/genes8010046] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2016] [Revised: 01/09/2017] [Accepted: 01/17/2017] [Indexed: 12/27/2022] Open
Abstract
The ability of all organisms to copy their genetic information via DNA replication is a prerequisite for cell division and a biological imperative of life. In multicellular organisms, however, mutations arising from DNA replication errors in the germline and somatic cells are the basis of genetic diseases and cancer, respectively. Within human tumors, replication errors additionally contribute to mutator phenotypes and tumor heterogeneity, which are major confounding factors for cancer therapeutics. Successful DNA replication involves the coordination of many large-scale, complex cellular processes. In this review, we focus on the roles that defects in enzymes that normally act at the replication fork and dysregulation of enzymes that inappropriately damage single-stranded DNA at the fork play in causing mutations that contribute to carcinogenesis. We focus on tumor data and experimental evidence that error-prone variants of replicative polymerases promote carcinogenesis and on research indicating that the primary target mutated by APOBEC (apolipoprotein B mRNA-editing enzyme catalytic polypeptide-like) cytidine deaminases is ssDNA present at the replication fork. Furthermore, we discuss evidence from model systems that indicate replication stress and other cancer-associated metabolic changes may modulate mutagenic enzymatic activities at the replication fork.
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Deshmukh AL, Kumar C, Singh DK, Maurya P, Banerjee D. Dynamics of replication proteins during lagging strand synthesis: A crossroads for genomic instability and cancer. DNA Repair (Amst) 2016; 42:72-81. [DOI: 10.1016/j.dnarep.2016.04.010] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2016] [Revised: 04/22/2016] [Accepted: 04/22/2016] [Indexed: 01/18/2023]
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36
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Colon cancer-associated mutator DNA polymerase δ variant causes expansion of dNTP pools increasing its own infidelity. Proc Natl Acad Sci U S A 2015; 112:E2467-76. [PMID: 25827231 DOI: 10.1073/pnas.1422934112] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
Defects in DNA polymerases δ (Polδ) and ε (Polε) cause hereditary colorectal cancer and have been implicated in the etiology of some sporadic colorectal and endometrial tumors. We previously reported that the yeast pol3-R696W allele mimicking a human cancer-associated variant, POLD1-R689W, causes a catastrophic increase in spontaneous mutagenesis. Here, we describe the mechanism of this extraordinary mutator effect. We found that the mutation rate increased synergistically when the R696W mutation was combined with defects in Polδ proofreading or mismatch repair, indicating that pathways correcting DNA replication errors are not compromised in pol3-R696W mutants. DNA synthesis by purified Polδ-R696W was error-prone, but not to the extent that could account for the unprecedented mutator phenotype of pol3-R696W strains. In a search for cellular factors that augment the mutagenic potential of Polδ-R696W, we discovered that pol3-R696W causes S-phase checkpoint-dependent elevation of dNTP pools. Abrogating this elevation by strategic mutations in dNTP metabolism genes eliminated the mutator effect of pol3-R696W, whereas restoration of high intracellular dNTP levels restored the mutator phenotype. Further, the use of dNTP concentrations present in pol3-R696W cells for in vitro DNA synthesis greatly decreased the fidelity of Polδ-R696W and produced a mutation spectrum strikingly similar to the spectrum observed in vivo. The results support a model in which (i) faulty synthesis by Polδ-R696W leads to a checkpoint-dependent increase in dNTP levels and (ii) this increase mediates the hypermutator effect of Polδ-R696W by facilitating the extension of mismatched primer termini it creates and by promoting further errors that continue to fuel the mutagenic pathway.
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37
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Pelosini C, Martinelli S, Ceccarini G, Magno S, Barone I, Basolo A, Fierabracci P, Vitti P, Maffei M, Santini F. Identification of a novel mutation in the polymerase delta 1 (POLD1) gene in a lipodystrophic patient affected by mandibular hypoplasia, deafness, progeroid features (MDPL) syndrome. Metabolism 2014; 63:1385-9. [PMID: 25131834 DOI: 10.1016/j.metabol.2014.07.010] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/26/2014] [Revised: 07/16/2014] [Accepted: 07/22/2014] [Indexed: 11/19/2022]
Abstract
OBJECTIVE Progressive lipodystrophy is one of the major features of the rare MDPL syndrome. Until now, 9 patients affected by this syndrome have been described and a recent study identified in 4 of them an in-frame deletion (Ser605del) of a single codon in the POLD1 gene. Sequence alterations of the POLD1 gene at different sites have been previously reported in human colorectal and endometrial carcinomas. MATERIALS/METHODS A 48-year-old woman was admitted to our department for the assessment of a previously diagnosed lipodystrophy. She did not report a family history of diabetes or other metabolic disorders. Hypertriglyceridemia was diagnosed incidentally when she was 25years old. At that time she was also diagnosed with sensorineural bilateral hearing loss. At physical examination she presented lipoatrophy affecting nearly the entire body, mandibular hypoplasia, bird-like face, beaked nose, progeroid facial features, with crowded teeth, small mouth and uvula. Abdominal ultrasound showed hepatomegaly and hepatosteatosis. Fat mass index measured with DXA was 4.59kg/m(2), indicating a fat deficit; the oral glucose tolerance test showed an impaired glucose tolerance. RESULTS Sequence analysis of the entire coding region of the POLD1 gene, disclosed a novel heterozygous mutation in exon 13 (R507C). CONCLUSION The MDPL patient herein described harbors a novel mutation in the exonuclease domain of POLD1. This new variant provides further evidence for a role of POLD1 in the pathogenesis of MDPL. The mechanisms that link changes at various sites of the protein with different diseases remain to be clarified.
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Affiliation(s)
- Caterina Pelosini
- Obesity Center, Endocrinology Unit, University Hospital of Pisa, Italy
| | - Silvia Martinelli
- Obesity Center, Endocrinology Unit, University Hospital of Pisa, Italy
| | | | - Silvia Magno
- Obesity Center, Endocrinology Unit, University Hospital of Pisa, Italy
| | | | - Alessio Basolo
- Obesity Center, Endocrinology Unit, University Hospital of Pisa, Italy
| | - Paola Fierabracci
- Obesity Center, Endocrinology Unit, University Hospital of Pisa, Italy
| | - Paolo Vitti
- Obesity Center, Endocrinology Unit, University Hospital of Pisa, Italy
| | - Margherita Maffei
- Obesity Center, Endocrinology Unit, University Hospital of Pisa, Italy; CNR, Institute of Clinical Physiology, Pisa, Italy
| | - Ferruccio Santini
- Obesity Center, Endocrinology Unit, University Hospital of Pisa, Italy.
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38
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Doublié S, Zahn KE. Structural insights into eukaryotic DNA replication. Front Microbiol 2014; 5:444. [PMID: 25202305 PMCID: PMC4142720 DOI: 10.3389/fmicb.2014.00444] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2014] [Accepted: 08/04/2014] [Indexed: 12/23/2022] Open
Abstract
Three DNA polymerases of the B family function at the replication fork in eukaryotic cells: DNA polymerases α, δ, and ε. DNA polymerase α, an heterotetramer composed of two primase subunits and two polymerase subunits, initiates replication. DNA polymerases δ and ε elongate the primers generated by pol α. The DNA polymerase from bacteriophage RB69 has served as a model for eukaryotic B family polymerases for some time. The recent crystal structures of pol δ, α, and ε revealed similarities but also a number of unexpected differences between the eukaryotic polymerases and their bacteriophage counterpart, and also among the three yeast polymerases. This review will focus on their shared structural elements as well as the features that are unique to each of these polymerases.
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Affiliation(s)
- Sylvie Doublié
- Department of Microbiology and Molecular Genetics, University of Vermont Burlington, VT, USA
| | - Karl E Zahn
- Department of Microbiology and Molecular Genetics, University of Vermont Burlington, VT, USA
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39
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Henninger EE, Pursell ZF. DNA polymerase ε and its roles in genome stability. IUBMB Life 2014; 66:339-51. [PMID: 24861832 DOI: 10.1002/iub.1276] [Citation(s) in RCA: 64] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2014] [Accepted: 05/02/2014] [Indexed: 12/14/2022]
Abstract
DNA Polymerase Epsilon (Pol ε) is one of three DNA Polymerases (along with Pol δ and Pol α) required for nuclear DNA replication in eukaryotes. Pol ε is comprised of four subunits, the largest of which is encoded by the POLE gene and contains the catalytic polymerase and exonuclease activities. The 3'-5' exonuclease proofreading activity is able to correct DNA synthesis errors and helps protect against genome instability. Recent cancer genome sequencing efforts have shown that 3% of colorectal and 7% of endometrial cancers contain mutations within the exonuclease domain of POLE and are associated with significantly elevated levels of single nucleotide substitutions (15-500 per Mb) and microsatellite stability. POLE mutations have also been found in other tumor types, though at lower frequency, suggesting roles in tumorigenesis more broadly in different tissue types. In addition to its proofreading activity, Pol ε contributes to genome stability through multiple mechanisms that are discussed in this review.
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Affiliation(s)
- Erin E Henninger
- Department of Biochemistry and Molecular Biology, Tulane University School of Medicine, New Orleans, LA, USA
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40
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Bashir T, Sailer C, Gerber F, Loganathan N, Bhoopalan H, Eichenberger C, Grossniklaus U, Baskar R. Hybridization alters spontaneous mutation rates in a parent-of-origin-dependent fashion in Arabidopsis. PLANT PHYSIOLOGY 2014; 165:424-37. [PMID: 24664208 PMCID: PMC4012600 DOI: 10.1104/pp.114.238451] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/24/2014] [Accepted: 03/22/2014] [Indexed: 05/18/2023]
Abstract
Over 70 years ago, increased spontaneous mutation rates were observed in Drosophila spp. hybrids, but the genetic basis of this phenomenon is not well understood. The model plant Arabidopsis (Arabidopsis thaliana) offers unique opportunities to study the types of mutations induced upon hybridization and the frequency of their occurrence. Understanding the mutational effects of hybridization is important, as many crop plants are grown as hybrids. Besides, hybridization is important for speciation and its effects on genome integrity could be critical, as chromosomal rearrangements can lead to reproductive isolation. We examined the rates of hybridization-induced point and frameshift mutations as well as homologous recombination events in intraspecific Arabidopsis hybrids using a set of transgenic mutation detector lines that carry mutated or truncated versions of a reporter gene. We found that hybridization alters the frequency of different kinds of mutations. In general, Columbia (Col)×Cape Verde Islands and Col×C24 hybrid progeny had decreased T→G and T→A transversion rates but an increased C→T transition rate. Significant changes in frameshift mutation rates were also observed in some hybrids. In Col×C24 hybrids, there is a trend for increased homologous recombination rates, except for the hybrids from one line, while in Col×Cape Verde Islands hybrids, this rate is decreased. The overall genetic distance of the parents had no influence on mutation rates in the progeny, as closely related accessions on occasion displayed higher mutation rates than accessions that are separated farther apart. However, reciprocal hybrids had significantly different mutation rates, suggesting parent-of-origin-dependent effects on the mutation frequency.
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41
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Kane DP, Shcherbakova PV. A common cancer-associated DNA polymerase ε mutation causes an exceptionally strong mutator phenotype, indicating fidelity defects distinct from loss of proofreading. Cancer Res 2014; 74:1895-901. [PMID: 24525744 DOI: 10.1158/0008-5472.can-13-2892] [Citation(s) in RCA: 99] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Exonucleolytic proofreading and DNA mismatch repair (MMR) act in series to maintain high-fidelity DNA replication and to avoid mutagenesis. MMR defects elevate the overall mutation rate and are associated with increased cancer incidence. Hypermutable colorectal and endometrial tumors with functional MMR were recently reported to carry amino acid substitutions in the exonuclease domain of DNA polymerase ε (Polε). This created a notion that loss of the proofreading activity of Polε is an initiating cause of some sporadic human cancers. In this study, we identified a somatic P286R substitution in the conserved ExoI motif of Polε in a collection of 52 sporadic colorectal tumor specimens. This change has been repeatedly observed in colorectal and endometrial tumors in previous studies despite many possible ways to inactivate Polε proofreading. To understand the reasons for the recurrent appearance of the P286R variant, we characterized its functional consequences using the yeast model system. An analogous substitution in the yeast Polε produced an unusually strong mutator phenotype exceeding that of proofreading-deficient mutants by two orders of magnitude. This argues that the P286R mutation acts at some level other than loss of exonuclease to elevate cancer risk. Heterozygosity for the variant allele caused a strong mutator effect comparable with that of complete MMR deficiency, providing an explanation for why loss of heterozygosity is not required for the development of Polε-mutant human tumors.
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Affiliation(s)
- Daniel P Kane
- Authors' Affiliation: Eppley Institute for Research in Cancer and Allied Diseases, University of Nebraska Medical Center, Omaha, Nebraska
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42
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Stevens K, Weynberg K, Bellas C, Brown S, Brownlee C, Brown MT, Schroeder DC. A novel evolutionary strategy revealed in the phaeoviruses. PLoS One 2014; 9:e86040. [PMID: 24465858 PMCID: PMC3897601 DOI: 10.1371/journal.pone.0086040] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2013] [Accepted: 12/04/2013] [Indexed: 11/18/2022] Open
Abstract
Phaeoviruses infect the brown algae, which are major contributors to primary production of coastal waters and estuaries. They exploit a Persistent evolutionary strategy akin to a K- selected life strategy via genome integration and are the only known representatives to do so within the giant algal viruses that are typified by r- selected Acute lytic viruses. In screening the genomes of five species within the filamentous brown algal lineage, here we show an unprecedented diversity of viral gene sequence variants especially amongst the smaller phaeoviral genomes. Moreover, one variant shares features from both the two major sub-groups within the phaeoviruses. These phaeoviruses have exploited the reduction of their giant dsDNA genomes and accompanying loss of DNA proofreading capability, typical of an Acute life strategist, but uniquely retain a Persistent life strategy.
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Affiliation(s)
- Kim Stevens
- Cell and Molecular Department, Marine Biological Association, Plymouth, Devon, United Kingdom
- School of Marine Science and Engineering, University of Plymouth, Plymouth, Devon, United Kingdom
| | - Karen Weynberg
- Cell and Molecular Department, Marine Biological Association, Plymouth, Devon, United Kingdom
- School of Marine Science and Engineering, University of Plymouth, Plymouth, Devon, United Kingdom
| | - Christopher Bellas
- Cell and Molecular Department, Marine Biological Association, Plymouth, Devon, United Kingdom
- School of Marine Science and Engineering, University of Plymouth, Plymouth, Devon, United Kingdom
| | - Sonja Brown
- Cell and Molecular Department, Marine Biological Association, Plymouth, Devon, United Kingdom
- School of Marine Science and Engineering, University of Plymouth, Plymouth, Devon, United Kingdom
| | - Colin Brownlee
- Cell and Molecular Department, Marine Biological Association, Plymouth, Devon, United Kingdom
- School of Marine Science and Engineering, University of Plymouth, Plymouth, Devon, United Kingdom
| | - Murray T. Brown
- School of Marine Science and Engineering, University of Plymouth, Plymouth, Devon, United Kingdom
| | - Declan C. Schroeder
- Cell and Molecular Department, Marine Biological Association, Plymouth, Devon, United Kingdom
- * E-mail:
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43
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Abstract
Genetic defects in DNA polymerase accuracy, proofreading, or mismatch repair (MMR) induce mutator phenotypes that accelerate adaptation of microbes and tumor cells. Certain combinations of mutator alleles synergistically increase mutation rates to levels that drive extinction of haploid cells. The maximum tolerated mutation rate of diploid cells is unknown. Here, we define the threshold for replication error-induced extinction (EEX) of diploid Saccharomyces cerevisiae. Double-mutant pol3 alleles that carry mutations for defective DNA polymerase-δ proofreading (pol3-01) and accuracy (pol3-L612M or pol3-L612G) induce strong mutator phenotypes in heterozygous diploids (POL3/pol3-01,L612M or POL3/pol3-01,L612G). Both pol3-01,L612M and pol3-01,L612G alleles are lethal in the homozygous state; cells with pol3-01,L612M divide up to 10 times before arresting at random stages in the cell cycle. Antimutator eex mutations in the pol3 alleles suppress this lethality (pol3-01,L612M,eex or pol3-01,L612G,eex). MMR defects synergize with pol3-01,L612M,eex and pol3-01,L612G,eex alleles, increasing mutation rates and impairing growth. Conversely, inactivation of the Dun1 S-phase checkpoint kinase suppresses strong pol3-01,L612M,eex and pol3-01,L612G,eex mutator phenotypes as well as the lethal pol3-01,L612M phenotype. Our results reveal that the lethal error threshold in diploids is 10 times higher than in haploids and likely determined by homozygous inactivation of essential genes. Pronounced loss of fitness occurs at mutation rates well below the lethal threshold, suggesting that mutator-driven cancers may be susceptible to drugs that exacerbate replication errors.
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44
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Northam MR, Moore EA, Mertz TM, Binz SK, Stith CM, Stepchenkova EI, Wendt KL, Burgers PMJ, Shcherbakova PV. DNA polymerases ζ and Rev1 mediate error-prone bypass of non-B DNA structures. Nucleic Acids Res 2013; 42:290-306. [PMID: 24049079 PMCID: PMC3874155 DOI: 10.1093/nar/gkt830] [Citation(s) in RCA: 71] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
DNA polymerase ζ (Pol ζ) and Rev1 are key players in translesion DNA synthesis. The error-prone Pol ζ can also participate in replication of undamaged DNA when the normal replisome is impaired. Here we define the nature of the replication disturbances that trigger the recruitment of error-prone polymerases in the absence of DNA damage and describe the specific roles of Rev1 and Pol ζ in handling these disturbances. We show that Pol ζ/Rev1-dependent mutations occur at sites of replication stalling at short repeated sequences capable of forming hairpin structures. The Rev1 deoxycytidyl transferase can take over the stalled replicative polymerase and incorporate an additional 'C' at the hairpin base. Full hairpin bypass often involves template-switching DNA synthesis, subsequent realignment generating multiply mismatched primer termini and extension of these termini by Pol ζ. The postreplicative pathway dependent on polyubiquitylation of proliferating cell nuclear antigen provides a backup mechanism for accurate bypass of these sequences that is primarily used when the Pol ζ/Rev1-dependent pathway is inactive. The results emphasize the pivotal role of noncanonical DNA structures in mutagenesis and reveal the long-sought-after mechanism of complex mutations that represent a unique signature of Pol ζ.
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Affiliation(s)
- Matthew R Northam
- Eppley Institute for Research in Cancer and Allied Diseases, University of Nebraska Medical Center, Omaha, NE 68118, USA and Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, St. Louis, MO 63110, USA
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45
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Lada AG, Stepchenkova EI, Waisertreiger ISR, Noskov VN, Dhar A, Eudy JD, Boissy RJ, Hirano M, Rogozin IB, Pavlov YI. Genome-wide mutation avalanches induced in diploid yeast cells by a base analog or an APOBEC deaminase. PLoS Genet 2013; 9:e1003736. [PMID: 24039593 PMCID: PMC3764175 DOI: 10.1371/journal.pgen.1003736] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2013] [Accepted: 07/05/2013] [Indexed: 11/23/2022] Open
Abstract
Genetic information should be accurately transmitted from cell to cell; conversely, the adaptation in evolution and disease is fueled by mutations. In the case of cancer development, multiple genetic changes happen in somatic diploid cells. Most classic studies of the molecular mechanisms of mutagenesis have been performed in haploids. We demonstrate that the parameters of the mutation process are different in diploid cell populations. The genomes of drug-resistant mutants induced in yeast diploids by base analog 6-hydroxylaminopurine (HAP) or AID/APOBEC cytosine deaminase PmCDA1 from lamprey carried a stunning load of thousands of unselected mutations. Haploid mutants contained almost an order of magnitude fewer mutations. To explain this, we propose that the distribution of induced mutation rates in the cell population is uneven. The mutants in diploids with coincidental mutations in the two copies of the reporter gene arise from a fraction of cells that are transiently hypersensitive to the mutagenic action of a given mutagen. The progeny of such cells were never recovered in haploids due to the lethality caused by the inactivation of single-copy essential genes in cells with too many induced mutations. In diploid cells, the progeny of hypersensitive cells survived, but their genomes were saturated by heterozygous mutations. The reason for the hypermutability of cells could be transient faults of the mutation prevention pathways, like sanitization of nucleotide pools for HAP or an elevated expression of the PmCDA1 gene or the temporary inability of the destruction of the deaminase. The hypothesis on spikes of mutability may explain the sudden acquisition of multiple mutational changes during evolution and carcinogenesis.
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Affiliation(s)
- Artem G. Lada
- Eppley Institute for Research in Cancer and Allied Diseases, University of Nebraska Medical Center, Omaha, Nebraska, United States of America
| | - Elena I. Stepchenkova
- Eppley Institute for Research in Cancer and Allied Diseases, University of Nebraska Medical Center, Omaha, Nebraska, United States of America
- Saint Petersburg Branch of Vavilov Institute of General Genetics, St. Petersburg, Russia
- Department of Genetics, Saint Petersburg University, St. Petersburg, Russia
| | - Irina S. R. Waisertreiger
- Eppley Institute for Research in Cancer and Allied Diseases, University of Nebraska Medical Center, Omaha, Nebraska, United States of America
| | - Vladimir N. Noskov
- J. Craig Venter Institute, Rockville, Maryland, United States of America
| | - Alok Dhar
- Department of Genetics, Cell Biology and Anatomy and Munroe-Meyer Institute, University of Nebraska Medical Center, Omaha, Nebraska, United States of America
| | - James D. Eudy
- Department of Genetics, Cell Biology and Anatomy and Munroe-Meyer Institute, University of Nebraska Medical Center, Omaha, Nebraska, United States of America
| | - Robert J. Boissy
- Department of Internal Medicine, University of Nebraska Medical Center, Omaha, Nebraska, United States of America
| | - Masayuki Hirano
- Emory Vaccine Center, Department of Pathology and Laboratory Medicine, Emory University, Atlanta, Georgia, United States of America
| | - Igor B. Rogozin
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Youri I. Pavlov
- Eppley Institute for Research in Cancer and Allied Diseases, University of Nebraska Medical Center, Omaha, Nebraska, United States of America
- Department of Genetics, Saint Petersburg University, St. Petersburg, Russia
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46
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Swett RJ, Elias A, Miller JA, Dyson GE, Andrés Cisneros G. Hypothesis driven single nucleotide polymorphism search (HyDn-SNP-S). DNA Repair (Amst) 2013; 12:733-40. [PMID: 23830898 DOI: 10.1016/j.dnarep.2013.06.001] [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] [Received: 02/08/2013] [Revised: 05/27/2013] [Accepted: 06/11/2013] [Indexed: 12/28/2022]
Abstract
The advent of complete-genome genotyping across phenotype cohorts has provided a rich source of information for bioinformaticians. However the search for SNPs from this data is generally performed on a study-by-study case without any specific hypothesis of the location for SNPs that are predictive for the phenotype. We have designed a method whereby very large SNP lists (several gigabytes in size), combining several genotyping studies at once, can be sorted and traced back to their ultimate consequence in protein structure. Given a working hypothesis, researchers are able to easily search whole genome genotyping data for SNPs that link genetic locations to phenotypes. This allows a targeted search for correlations between phenotypes and potentially relevant systems, rather than utilizing statistical methods only. HyDn-SNP-S returns results that are less data dense, allowing more thorough analysis, including haplotype analysis. We have applied our method to correlate DNA polymerases to cancer phenotypes using four of the available cancer databases in dbGaP. Logistic regression and derived haplotype analysis indicates that ~80SNPs, previously overlooked, are statistically significant. Derived haplotypes from this work link POLL to breast cancer and POLG to prostate cancer with an increase in incidence of 3.01- and 9.6-fold, respectively. Molecular dynamics simulations on wild-type and one of the SNP mutants from the haplotype of POLL provide insights at the atomic level on the functional impact of this cancer related SNP. Furthermore, HyDn-SNP-S has been designed to allow application to any system. The program is available upon request from the authors.
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Affiliation(s)
- Rebecca J Swett
- Department of Chemistry, Wayne State University, 5101 Cass Avenue, Detroit, MI 48202, USA
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47
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Briggs S, Tomlinson I. Germline and somatic polymerase ε and δ mutations define a new class of hypermutated colorectal and endometrial cancers. J Pathol 2013; 230:148-53. [PMID: 23447401 PMCID: PMC3709119 DOI: 10.1002/path.4185] [Citation(s) in RCA: 216] [Impact Index Per Article: 19.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2013] [Revised: 02/20/2013] [Accepted: 02/22/2013] [Indexed: 12/28/2022]
Abstract
Polymerases ε and δ are the main enzymes that replicate eukaryotic DNA. Accurate replication occurs through Watson-Crick base pairing and also through the action of the polymerases' exonuclease (proofreading) domains. We have recently shown that germline exonuclease domain mutations (EDMs) of POLE and POLD1 confer a high risk of multiple colorectal adenomas and carcinoma (CRC). POLD1 mutations also predispose to endometrial cancer (EC). These mutations are associated with high penetrance and dominant inheritance, although the phenotype can be variable. We have named the condition polymerase proofreading-associated polyposis (PPAP). Somatic POLE EDMs have also been found in sporadic CRCs and ECs, although very few somatic POLD1 EDMs have been detected. Both the germline and the somatic DNA polymerase EDMs cause an 'ultramutated', apparently microsatellite-stable, type of cancer, sometimes leading to over a million base substitutions per tumour. Here, we present the evidence for POLE and POLD1 as important contributors to the pathogenesis of CRC and EC, and highlight some of the key questions in this emerging field.
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Affiliation(s)
- Sarah Briggs
- Molecular and Population Genetics Laboratory, Wellcome Trust Centre for Human Genetics, University of OxfordRoosevelt Drive, Oxford, OX3 7BN, UK
| | - Ian Tomlinson
- Molecular and Population Genetics Laboratory, Wellcome Trust Centre for Human Genetics, University of OxfordRoosevelt Drive, Oxford, OX3 7BN, UK
- Oxford NIHR Comprehensive Biomedical Research Centre, Wellcome Trust Centre for Human Genetics, University of Oxford, Roosevelt DriveOxford, OX3 7BN, UK
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48
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Tosato V, Grüning NM, Breitenbach M, Arnak R, Ralser M, Bruschi CV. Warburg effect and translocation-induced genomic instability: two yeast models for cancer cells. Front Oncol 2013; 2:212. [PMID: 23346549 PMCID: PMC3548335 DOI: 10.3389/fonc.2012.00212] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2012] [Accepted: 12/20/2012] [Indexed: 11/13/2022] Open
Abstract
Yeast has been established as an efficient model system to study biological principles underpinning human health. In this review we focus on yeast models covering two aspects of cancer formation and progression (i) the activity of pyruvate kinase (PK), which recapitulates metabolic features of cancer cells, including the Warburg effect, and (ii) chromosome bridge-induced translocation (BIT) mimiking genome instability in cancer. Saccharomyces cerevisiae is an excellent model to study cancer cell metabolism, as exponentially growing yeast cells exhibit many metabolic similarities with rapidly proliferating cancer cells. The metabolic reconfiguration includes an increase in glucose uptake and fermentation, at the expense of respiration and oxidative phosphorylation (the Warburg effect), and involves a broad reconfiguration of nucleotide and amino acid metabolism. Both in yeast and humans, the regulation of this process seems to have a central player, PK, which is up-regulated in cancer, and to occur mostly on a post-transcriptional and post-translational basis. Furthermore, BIT allows to generate selectable translocation-derived recombinants ("translocants"), between any two desired chromosomal locations, in wild-type yeast strains transformed with a linear DNA cassette carrying a selectable marker flanked by two DNA sequences homologous to different chromosomes. Using the BIT system, targeted non-reciprocal translocations in mitosis are easily inducible. An extensive collection of different yeast translocants exhibiting genome instability and aberrant phenotypes similar to cancer cells has been produced and subjected to analysis. In this review, we hence provide an overview upon two yeast cancer models, and extrapolate general principles for mimicking human disease mechanisms in yeast.
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Affiliation(s)
- Valentina Tosato
- International Centre for Genetic Engineering and Biotechnology Trieste, Italy
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49
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Prindle MJ, Schmitt MW, Parmeggiani F, Loeb LA. A substitution in the fingers domain of DNA polymerase δ reduces fidelity by altering nucleotide discrimination in the catalytic site. J Biol Chem 2013; 288:5572-80. [PMID: 23283971 DOI: 10.1074/jbc.m112.436410] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
DNA polymerase δ (Pol δ) is one of the major replicative DNA polymerases in eukaryotic cells, catalyzing lagging strand synthesis as well as playing a role in many DNA repair pathways. The catalytic site for polymerization consists of a palm domain and mobile fingers domain that opens and closes each catalytic cycle. We explored the effect of amino acid substitutions in a region of the highly conserved sequence motif B in the fingers domain on replication fidelity. A novel substitution, A699Q, results in a marked increase in mutation rate at the yeast CAN1 locus, and is synthetic lethal with both proofreading deficiency and mismatch repair deficiency. Modeling the A699Q mutation onto the crystal structure of Saccharomyces cerevisiae Pol δ template reveals four potential contacts for A699Q but not for A699. We substituted alanine for each of these residues and determined that an interaction with multiple residues of the N-terminal domain is responsible for the mutator phenotype. The corresponding mutation in purified human Pol δ results in a similar 30-fold increase in mutation frequency when copying gapped DNA templates. Sequence analysis indicates that the most characteristic mutation is a guanine-to-adenine (G to A) transition. The increase in deoxythymidine 5'-triphosphate-G mispairs was confirmed by performing steady state single nucleotide addition studies. Our combined data support a model in which the Ala-to-Gln substitution in the fingers domain of Pol δ results in an interaction with the N-terminal domain that affects the base selectivity of the enzyme.
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Affiliation(s)
- Marc J Prindle
- Joseph Gottstein Memorial Laboratory, Department of Pathology, University of Washington, Seattle, Washington 98195, USA
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50
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Smith BN, Newhouse S, Shatunov A, Vance C, Topp S, Johnson L, Miller J, Lee Y, Troakes C, Scott KM, Jones A, Gray I, Wright J, Hortobágyi T, Al-Sarraj S, Rogelj B, Powell J, Lupton M, Lovestone S, Sapp PC, Weber M, Nestor PJ, Schelhaas HJ, Asbroek AALMT, Silani V, Gellera C, Taroni F, Ticozzi N, Van den Berg L, Veldink J, Van Damme P, Robberecht W, Shaw PJ, Kirby J, Pall H, Morrison KE, Morris A, de Belleroche J, Vianney de Jong JMB, Baas F, Andersen PM, Landers J, Brown RH, Weale ME, Al-Chalabi A, Shaw CE. The C9ORF72 expansion mutation is a common cause of ALS+/-FTD in Europe and has a single founder. Eur J Hum Genet 2013; 21:102-8. [PMID: 22692064 PMCID: PMC3522204 DOI: 10.1038/ejhg.2012.98] [Citation(s) in RCA: 170] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2012] [Revised: 04/12/2012] [Accepted: 04/24/2012] [Indexed: 11/08/2022] Open
Abstract
A massive hexanucleotide repeat expansion mutation (HREM) in C9ORF72 has recently been linked to amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD). Here we describe the frequency, origin and stability of this mutation in ALS+/-FTD from five European cohorts (total n=1347). Single-nucleotide polymorphisms defining the risk haplotype in linked kindreds were genotyped in cases (n=434) and controls (n=856). Haplotypes were analysed using PLINK and aged using DMLE+. In a London clinic cohort, the HREM was the most common mutation in familial ALS+/-FTD: C9ORF72 29/112 (26%), SOD1 27/112 (24%), TARDBP 1/112 (1%) and FUS 4/112 (4%) and detected in 13/216 (6%) of unselected sporadic ALS cases but was rare in controls (3/856, 0.3%). HREM prevalence was high for familial ALS+/-FTD throughout Europe: Belgium 19/22 (86%), Sweden 30/41 (73%), the Netherlands 10/27 (37%) and Italy 4/20 (20%). The HREM did not affect the age at onset or survival of ALS patients. Haplotype analysis identified a common founder in all 137 HREM carriers that arose around 6300 years ago. The haplotype from which the HREM arose is intrinsically unstable with an increased number of repeats (average 8, compared with 2 for controls, P<10(-8)). We conclude that the HREM has a single founder and is the most common mutation in familial and sporadic ALS in Europe.
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Affiliation(s)
- Bradley N Smith
- Department of Clinical Neurosciences, MRC Centre for Neurodegeneration Research, Institute of Psychiatry, Kings College London, London, UK
| | - Stephen Newhouse
- Department of Clinical Neurosciences, MRC Centre for Neurodegeneration Research, Institute of Psychiatry, Kings College London, London, UK
| | - Aleksey Shatunov
- Department of Clinical Neurosciences, MRC Centre for Neurodegeneration Research, Institute of Psychiatry, Kings College London, London, UK
| | - Caroline Vance
- Department of Clinical Neurosciences, MRC Centre for Neurodegeneration Research, Institute of Psychiatry, Kings College London, London, UK
| | - Simon Topp
- Department of Clinical Neurosciences, MRC Centre for Neurodegeneration Research, Institute of Psychiatry, Kings College London, London, UK
| | - Lauren Johnson
- Department of Clinical Neurosciences, MRC Centre for Neurodegeneration Research, Institute of Psychiatry, Kings College London, London, UK
| | - Jack Miller
- Department of Clinical Neurosciences, MRC Centre for Neurodegeneration Research, Institute of Psychiatry, Kings College London, London, UK
| | - Younbok Lee
- Department of Clinical Neurosciences, MRC Centre for Neurodegeneration Research, Institute of Psychiatry, Kings College London, London, UK
| | - Claire Troakes
- Department of Clinical Neurosciences, MRC Centre for Neurodegeneration Research, Institute of Psychiatry, Kings College London, London, UK
| | - Kirsten M Scott
- Department of Clinical Neurosciences, MRC Centre for Neurodegeneration Research, Institute of Psychiatry, Kings College London, London, UK
| | - Ashley Jones
- Department of Clinical Neurosciences, MRC Centre for Neurodegeneration Research, Institute of Psychiatry, Kings College London, London, UK
| | - Ian Gray
- Department of Clinical Neurosciences, MRC Centre for Neurodegeneration Research, Institute of Psychiatry, Kings College London, London, UK
| | - Jamie Wright
- Department of Clinical Neurosciences, MRC Centre for Neurodegeneration Research, Institute of Psychiatry, Kings College London, London, UK
| | - Tibor Hortobágyi
- Department of Clinical Neurosciences, MRC Centre for Neurodegeneration Research, Institute of Psychiatry, Kings College London, London, UK
| | - Safa Al-Sarraj
- Department of Clinical Neurosciences, MRC Centre for Neurodegeneration Research, Institute of Psychiatry, Kings College London, London, UK
| | - Boris Rogelj
- Department of Clinical Neurosciences, MRC Centre for Neurodegeneration Research, Institute of Psychiatry, Kings College London, London, UK
| | - John Powell
- Department of Clinical Neurosciences, MRC Centre for Neurodegeneration Research, Institute of Psychiatry, Kings College London, London, UK
| | - Michelle Lupton
- Department of Clinical Neurosciences, MRC Centre for Neurodegeneration Research, Institute of Psychiatry, Kings College London, London, UK
| | - Simon Lovestone
- Department of Clinical Neurosciences, MRC Centre for Neurodegeneration Research, Institute of Psychiatry, Kings College London, London, UK
| | - Peter C Sapp
- Department of Neurology, University of Massachusetts Medical Center, Worcester, MA, USA
| | - Markus Weber
- Kantonsspital St Gallen and University Hospital Basel, Basel, Switzerland
| | - Peter J Nestor
- Department of Clinical Neurosciences, University of Cambridge, Cambridge, UK
| | - Helenius J Schelhaas
- Department of Neurology, Radboud University Nijmegen Medical Centre, Donders Institute for Brain, Cognition and Behaviour, Centre for Neuroscience, Nijmegen, The Netherlands
| | | | - Vincenzo Silani
- Department of Neurology and Laboratory of Neuroscience, ‘Dino Ferrari' Center, Universita' degli Studi di Milano, IRCCS Istituto Auxologico Italiano, Milan, Italy
| | - Cinzia Gellera
- SOSD Genetics of Neurodegenerative and Metabolic Diseases, Fondazione-IRCCS, Istituto Neurologico ‘Carlo Besta', Milan, Italy
| | - Franco Taroni
- SOSD Genetics of Neurodegenerative and Metabolic Diseases, Fondazione-IRCCS, Istituto Neurologico ‘Carlo Besta', Milan, Italy
| | - Nicola Ticozzi
- Department of Neurology and Laboratory of Neuroscience, ‘Dino Ferrari' Center, Universita' degli Studi di Milano, IRCCS Istituto Auxologico Italiano, Milan, Italy
| | - Leonard Van den Berg
- Department of Neurology, Rudolf Magnus Institute of Neuroscience, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Jan Veldink
- Department of Neurology, Rudolf Magnus Institute of Neuroscience, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Phillip Van Damme
- Laboratory of Neurobiology, Department of Neurology, K.U. Leuven, Leuven, Belgium
| | - Wim Robberecht
- Laboratory of Neurobiology, Department of Neurology, K.U. Leuven, Leuven, Belgium
| | - Pamela J Shaw
- Academic Neurology Unit, Sheffield Institute for Translational Neuroscience, Department of Neuroscience, School of Medicine and Biomedical Sciences, University of Sheffield, Sheffield, UK
| | - Janine Kirby
- Academic Neurology Unit, Sheffield Institute for Translational Neuroscience, Department of Neuroscience, School of Medicine and Biomedical Sciences, University of Sheffield, Sheffield, UK
| | - Hardev Pall
- School of Clinical and Experimental Medicine, College of Medicine and Dentistry, University of Birmingham, and Neurosciences Division, University Hospitals Birmingham NHS Foundation Trust, Birmingham, UK
| | - Karen E Morrison
- School of Clinical and Experimental Medicine, College of Medicine and Dentistry, University of Birmingham, and Neurosciences Division, University Hospitals Birmingham NHS Foundation Trust, Birmingham, UK
| | - Alex Morris
- Neurogenetics Group, Centre for Neuroscience, Division of Experimental Medicine, Hammersmith Hospital Campus, London, UK
| | - Jacqueline de Belleroche
- Neurogenetics Group, Centre for Neuroscience, Division of Experimental Medicine, Hammersmith Hospital Campus, London, UK
| | - J M B Vianney de Jong
- Department of Neurogenetics and Neurology, Academic Medical Centre, Amsterdam, The Netherlands
| | - Frank Baas
- Department of Neurogenetics and Neurology, Academic Medical Centre, Amsterdam, The Netherlands
| | - Peter M Andersen
- Department of Pharmacology and Clinical Neuroscience, Umeå University, Umeå, Sweden
| | - John Landers
- Department of Neurology, University of Massachusetts Medical Center, Worcester, MA, USA
| | - Robert H Brown
- Department of Neurology, University of Massachusetts Medical Center, Worcester, MA, USA
| | - Michael E Weale
- King's College London, Department of Medical and Molecular Genetics, London, UK
| | - Ammar Al-Chalabi
- Department of Clinical Neurosciences, MRC Centre for Neurodegeneration Research, Institute of Psychiatry, Kings College London, London, UK
| | - Christopher E Shaw
- Department of Clinical Neurosciences, MRC Centre for Neurodegeneration Research, Institute of Psychiatry, Kings College London, London, UK
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