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Zhang Z, Ma S, Li S, Chen Z, Song R, Wang Z. MSH6 germline mutations leading to Lynch syndrome-associated cholangiocarcinoma: a case report. Front Oncol 2024; 14:1414665. [PMID: 39161380 PMCID: PMC11330888 DOI: 10.3389/fonc.2024.1414665] [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: 04/09/2024] [Accepted: 07/22/2024] [Indexed: 08/21/2024] Open
Abstract
Lynch syndrome, a hereditary cancer susceptibility syndrome, arises from pathogenic mutations in mismatch repair genes. This syndrome is strongly linked to colorectal and endometrial cancers, as well as an elevated risk for other cancers such as gastric, ovarian, renal pelvis/ureter, and prostate. Notably, Lynch syndrome is rarely associated with cholangiocarcinoma (CCA). In this case study, we present a unique instance of Lynch syndrome-related CCA resulting from a singular MSH6 mutation. Notably, our findings reveal discrepancies between immunohistochemistry (IHC) and microsatellite stability results compared to genetic testing outcomes. This discrepancy underscores the limitations of solely relying on IHC analysis and microsatellite stability testing for the detection of hereditary tumors, emphasizing the crucial role of genetic testing in such cases. This insight enhances our comprehension of the mechanisms involved in cancer development and underscores the significance of thorough analysis integrating immunohistochemistry and genetic testing for diagnosing Lynch syndrome-related cancers.
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Affiliation(s)
| | | | | | | | | | - Zhanpeng Wang
- Department of hepatobiliary and pancreatic surgery, China-Japan Union Hospital, Jilin University, Changchun, China
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2
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Mendiola M, Heredia-Soto V, Ruz-Caracuel I, Baillo A, Ramon-Patino JL, Escudero FJ, Miguel M, Pelaez-Garcia A, Hernandez A, Feliu J, Hardisson D, Redondo A. Comparison of Methods for Testing Mismatch Repair Status in Endometrial Cancer. Int J Mol Sci 2023; 24:14468. [PMID: 37833916 PMCID: PMC10572657 DOI: 10.3390/ijms241914468] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2023] [Revised: 09/19/2023] [Accepted: 09/20/2023] [Indexed: 10/15/2023] Open
Abstract
Approximately 20-30% of endometrial carcinomas (EC) are characterized by mismatch repair (MMR) deficiency (dMMR) or microsatellite instability (MSI), and their testing has become part of the routine diagnosis. The aim of this study was to establish and compare the MMR status using various approaches. Immunohistochemistry (IHC), PCR-based MSI, and the detection of defects in the four key MMR genes (MLH1, PMS2, MSH2, and MSH6) via methylation-specific multiplex ligation-dependent probe amplification (MLPA) and targeted next-generation sequencing (NGS) were performed. MSH3 expression was also evaluated. A set of 126 early-stage EC samples were analyzed, 53.2% of which were dMMR and 46.8% of which were proficient MMR (pMMR) as determined using IHC, whereas 69.3% were classified as microsatellite stable, while 8.8% and 21.9% were classified MSI-low (MSI-L) and MSI-high (MSI-H), respectively. In total, 44.3% of the samples showed genetic or epigenetic alterations in one or more genes; MLH1 promoter methylation was the most common event. Although acceptable concordance was observed, there were overall discrepancies between the three testing approaches, mainly associated with the dMMR group. IHC had a better correlation with MMR genomic status than the MSI status determined using PCR. Further studies are needed to establish solid conclusions regarding the best MMR assessment technique for EC.
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Affiliation(s)
- Marta Mendiola
- Molecular Pathology and Therapeutic Targets Group, Hospital La Paz Institute for Health Research (IdiPAZ), 28046 Madrid, Spain; (M.M.); (A.P.-G.); (D.H.)
- Center for Biomedical Research in the Cancer Network (CIBERONC), Instituto de Salud Carlos III, 28029 Madrid, Spain; (V.H.-S.); (J.F.)
| | - Victoria Heredia-Soto
- Center for Biomedical Research in the Cancer Network (CIBERONC), Instituto de Salud Carlos III, 28029 Madrid, Spain; (V.H.-S.); (J.F.)
- Translational Oncology Research Laboratory, Hospital La Paz Institute for Health Research (IdiPAZ), 28046 Madrid, Spain
| | - Ignacio Ruz-Caracuel
- Center for Biomedical Research in the Cancer Network (CIBERONC), Instituto de Salud Carlos III, 28029 Madrid, Spain; (V.H.-S.); (J.F.)
- Department of Pathology, La Paz University Hospital, 28046 Madrid, Spain
| | - Amparo Baillo
- Mathematics Department, Autonomous University of Madrid, 28049 Madrid, Spain;
| | | | - Francisco Javier Escudero
- Translational Oncology Research Laboratory, Hospital La Paz Institute for Health Research (IdiPAZ), 28046 Madrid, Spain
| | - Maria Miguel
- Molecular Pathology and Therapeutic Targets Group, Hospital La Paz Institute for Health Research (IdiPAZ), 28046 Madrid, Spain; (M.M.); (A.P.-G.); (D.H.)
| | - Alberto Pelaez-Garcia
- Molecular Pathology and Therapeutic Targets Group, Hospital La Paz Institute for Health Research (IdiPAZ), 28046 Madrid, Spain; (M.M.); (A.P.-G.); (D.H.)
| | - Alicia Hernandez
- Department of Obstetrics and Gynecology, La Paz University Hospital, 28046 Madrid, Spain;
- Faculty of Medicine, Autonomous University of Madrid, 28046 Madrid, Spain
| | - Jaime Feliu
- Center for Biomedical Research in the Cancer Network (CIBERONC), Instituto de Salud Carlos III, 28029 Madrid, Spain; (V.H.-S.); (J.F.)
- Translational Oncology Research Laboratory, Hospital La Paz Institute for Health Research (IdiPAZ), 28046 Madrid, Spain
- Department of Medical Oncology, La Paz University Hospital, 28046 Madrid, Spain;
- Faculty of Medicine, Autonomous University of Madrid, 28046 Madrid, Spain
- Cátedra UAM-ANGEM, Faculty of Medicine, Autonomous University of Madrid, 28046 Madrid, Spain
| | - David Hardisson
- Molecular Pathology and Therapeutic Targets Group, Hospital La Paz Institute for Health Research (IdiPAZ), 28046 Madrid, Spain; (M.M.); (A.P.-G.); (D.H.)
- Center for Biomedical Research in the Cancer Network (CIBERONC), Instituto de Salud Carlos III, 28029 Madrid, Spain; (V.H.-S.); (J.F.)
- Department of Pathology, La Paz University Hospital, 28046 Madrid, Spain
- Faculty of Medicine, Autonomous University of Madrid, 28046 Madrid, Spain
| | - Andres Redondo
- Translational Oncology Research Laboratory, Hospital La Paz Institute for Health Research (IdiPAZ), 28046 Madrid, Spain
- Department of Medical Oncology, La Paz University Hospital, 28046 Madrid, Spain;
- Faculty of Medicine, Autonomous University of Madrid, 28046 Madrid, Spain
- Cátedra UAM-ANGEM, Faculty of Medicine, Autonomous University of Madrid, 28046 Madrid, Spain
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Biswas K, Mohammed A, Sharan SK, Shoemaker RH. Genetically engineered mouse models for hereditary cancer syndromes. Cancer Sci 2023; 114:1800-1815. [PMID: 36715493 PMCID: PMC10154891 DOI: 10.1111/cas.15737] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2022] [Revised: 01/21/2023] [Accepted: 01/25/2023] [Indexed: 01/31/2023] Open
Abstract
Advances in molecular diagnostics have led to improved diagnosis and molecular understanding of hereditary cancers in the clinic. Improving the management, treatment, and potential prevention of cancers in carriers of predisposing mutations requires preclinical experimental models that reflect the key pathogenic features of the specific syndrome associated with the mutations. Numerous genetically engineered mouse (GEM) models of hereditary cancer have been developed. In this review, we describe the models of Lynch syndrome and hereditary breast and ovarian cancer syndrome, the two most common hereditary cancer predisposition syndromes. We focus on Lynch syndrome models as illustrative of the potential for using mouse models to devise improved approaches to prevention of cancer in a high-risk population. GEM models are an invaluable tool for hereditary cancer models. Here, we review GEM models for some hereditary cancers and their potential use in cancer prevention studies.
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Affiliation(s)
- Kajal Biswas
- Chemopreventive Agent Development Research Group, Division of Cancer Prevention, National Cancer Institute, Rockville, Maryland, USA
| | - Altaf Mohammed
- Chemopreventive Agent Development Research Group, Division of Cancer Prevention, National Cancer Institute, Rockville, Maryland, USA
| | - Shyam K Sharan
- Mouse Cancer Genetics Program, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Frederick, Maryland, USA
| | - Robert H Shoemaker
- Chemopreventive Agent Development Research Group, Division of Cancer Prevention, National Cancer Institute, Rockville, Maryland, USA
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4
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Tanaka T, Takehara K, Yamashita N, Okazawa-Sakai M, Kuraoka K, Teramoto N, Taguchi K, Yamashiro K, Kato H, Mizunoe T, Suzuki R, Yamamoto D, Ueki A, Saito T. Frequency and clinical features of deficient mismatch repair in ovarian clear cell and endometrioid carcinoma. J Gynecol Oncol 2022; 33:e67. [PMID: 36032025 PMCID: PMC9428302 DOI: 10.3802/jgo.2022.33.e67] [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: 05/17/2021] [Revised: 04/20/2022] [Accepted: 06/12/2022] [Indexed: 11/30/2022] Open
Abstract
Objective To clarify the frequency of deficient mismatch repair (dMMR) in Japanese ovarian cancer patients, we examined microsatellite instability (MSI) status and immunohistochemistry (IHC) subtypes, including endometrioid carcinoma (EMC), clear cell carcinoma (CCC), or a mixture of both (Mix). Methods We registered 390 patients who were diagnosed with EMC/CCC/Mix between 2006 and 2015 and treated at seven participating facilities. For 339 patients confirmed eligible by the Central Pathological Review Board, MSI, IHC, and MutL homolog 1 methylation analyses were conducted. The tissues of patients with Lynch syndrome (LS)-related cancer histories, such as colorectal and endometrial cancer, were also investigated. Results MSI-high (MSI-H) status was observed in 2/217 CCC (0.9%), 10/115 EMC (8.7%), and 1/4 Mix (25%). Additionally, loss of MMR protein expression (LoE-MMR) was observed in 5/219 (2.3%), 16/115 (14.0%), and 1/4 (25%) patients with CCC, EMC, and Mix, respectively. Both MSI-H and LoE-MMR were found significantly more often in EMC (p<0.001). The median (range) ages of patients with MMR expression and LoE-MMR were 54 (30–90) and 46 (22–76) (p=0.002), respectively. In the multivariate analysis, advanced stage and histological type were identified as prognostic factors. Conclusion The dMMR rate for EMC/CCC was similar to that reported in Western countries. In Japan, it is assumed that the dMMR frequency is higher because of the increased proportion of CCC. The deficient mismatch repair (dMMR) rate in Japanese patients is currently unknown. This study determined the frequency of dMMR in Japanese ovarian cancer patients. The dMMR rate was similar to that reported in Western countries. We identified potential criteria for implementing microsatellite instability and immunohistochemistry analyses in Lynch syndrome screening.
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Affiliation(s)
- Tamaki Tanaka
- Department of Perinatology and Gynecology, Kagawa University Graduate School of Medicine, Kida, Japan.,Department of Gynecologic Oncology, National Hospital Organization Shikoku Cancer Center, Matsuyama, Japan
| | - Kazuhiro Takehara
- Department of Gynecologic Oncology, National Hospital Organization Shikoku Cancer Center, Matsuyama, Japan.
| | - Natsumi Yamashita
- Department of Clinical Research Center, National Hospital Organization Shikoku Cancer Center, Matsuyama, Japan
| | - Mika Okazawa-Sakai
- Department of Gynecologic Oncology, National Hospital Organization Shikoku Cancer Center, Matsuyama, Japan
| | - Kazuya Kuraoka
- Department of Diagnostic Pathology, National Hospital Organization Kure Medical Center and Chugoku Cancer Center, Kure, Japan
| | - Norihiro Teramoto
- Department of Pathology, National Hospital Organization Shikoku Cancer Center, Matsuyama, Japan
| | - Kenichi Taguchi
- Department of Pathology, National Hospital Organization Kyushu Cancer Center, Fukuoka, Japan
| | | | - Hidenori Kato
- Department of Gynecologic Oncology, National Hospital Organization Hokkaido Cancer Center, Sapporo, Japan
| | - Tomoya Mizunoe
- Department of Obstetrics and Gynecology, National Hospital Organization Kure Medical Center and Chugoku Cancer Center, Kure, Japan
| | - Rie Suzuki
- Department of Obstetrics and Gynecology, National Defense Medical Collage Hospital, Tokorozawa, Japan
| | - Dan Yamamoto
- Department of Gynecology, National Hospital Organization Fukuyama Medical Center, Fukuyama, Japan
| | - Arisa Ueki
- Department of Clinical Genetic Oncology, Cancer Institute Hospital of JFCR, Tokyo, Japan
| | - Toshiaki Saito
- Gynecology Service, National Hospital Organization Kyushu Cancer Center, Fukuoka, Japan
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5
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Wieland J, Buchan S, Sen Gupta S, Mantzouratou A. Genomic instability and the link to infertility: A focus on microsatellites and genomic instability syndromes. Eur J Obstet Gynecol Reprod Biol 2022; 274:229-237. [PMID: 35671666 DOI: 10.1016/j.ejogrb.2022.06.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2022] [Revised: 05/25/2022] [Accepted: 06/01/2022] [Indexed: 12/01/2022]
Abstract
Infertility is associated to multiple types of different genomic instabilities and is a genetic feature of genomic instability syndromes. While the mismatch repair machinery contributes to the maintenance of genome integrity, surprisingly its potential role in infertility is overlooked. Defects in mismatch repair mechanisms contribute to microsatellite instability and genomic instability syndromes, due to the inability to repair newly replicated DNA. This article reviews the literature to date to elucidate the contribution of microsatellite instability to genomic instability syndromes and infertility. The key findings presented reveal microsatellite instability is poorly researched in genomic instability syndromes and infertility.
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Affiliation(s)
- Jack Wieland
- Department of Life and Environmental Sciences, Faculty of Science and Technology, Bournemouth University, Poole BH12 5BB, UK.
| | - Sarah Buchan
- Department of Life and Environmental Sciences, Faculty of Science and Technology, Bournemouth University, Poole BH12 5BB, UK.
| | - Sioban Sen Gupta
- Institute for Women's Health, 86-96 Chenies Mews, University College London, London WC1E 6HX, UK.
| | - Anna Mantzouratou
- Department of Life and Environmental Sciences, Faculty of Science and Technology, Bournemouth University, Poole BH12 5BB, UK.
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Spectrum of DNA mismatch repair failures viewed through the lens of cancer genomics and implications for therapy. Clin Sci (Lond) 2022; 136:383-404. [PMID: 35274136 PMCID: PMC8919091 DOI: 10.1042/cs20210682] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2021] [Revised: 02/02/2022] [Accepted: 02/28/2022] [Indexed: 12/15/2022]
Abstract
Genome sequencing can be used to detect DNA repair failures in tumors and learn about underlying mechanisms. Here, we synthesize findings from genomic studies that examined deficiencies of the DNA mismatch repair (MMR) pathway. The impairment of MMR results in genome-wide hypermutation and in the ‘microsatellite instability’ (MSI) phenotype—occurrence of indel mutations at short tandem repeat (microsatellite) loci. The MSI status of tumors was traditionally assessed by molecular testing of a selected set of MS loci or by measuring MMR protein expression levels. Today, genomic data can provide a more complete picture of the consequences on genomic instability. Multiple computational studies examined somatic mutation distributions that result from failed DNA repair pathways in tumors. These include analyzing the commonly studied trinucleotide mutational spectra of single-nucleotide variants (SNVs), as well as of other features such as indels, structural variants, mutation clusters and regional mutation rate redistribution. The identified mutation patterns can be used to rigorously measure prevalence of MMR failures across cancer types, and potentially to subcategorize the MMR deficiencies. Diverse data sources, genomic and pre-genomic, from human and from experimental models, suggest there are different ways in which MMR can fail, and/or that the cell-type or genetic background may result in different types of MMR mutational patterns. The spectrum of MMR failures may direct cancer evolution, generating particular sets of driver mutations. Moreover, MMR affects outcomes of therapy by DNA damaging drugs, antimetabolites, nonsense-mediated mRNA decay (NMD) inhibitors, and immunotherapy by promoting either resistance or sensitivity, depending on the type of therapy.
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7
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Fraune C, Burandt E, Simon R, Hube-Magg C, Makrypidi-Fraune G, Kluth M, Büscheck F, Höflmayer D, Blessin NC, Mandelkow T, Li W, Perez D, Izbicki JR, Wilczak W, Sauter G, Schrader J, Neipp M, Mofid H, Daniels T, Isbert C, Clauditz TS, Steurer S. MMR Deficiency is Homogeneous in Pancreatic Carcinoma and Associated with High Density of Cd8-Positive Lymphocytes. Ann Surg Oncol 2020; 27:3997-4006. [PMID: 32108923 PMCID: PMC7471097 DOI: 10.1245/s10434-020-08209-y] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2019] [Indexed: 12/19/2022]
Abstract
BACKGROUND Microsatellite instability (MSI) has emerged as a predictive biomarker for immune checkpoint inhibitor therapy. Cancer heterogeneity represents a potential obstacle for the analysis of predicitive biomarkers. MSI has been reported in pancreatic cancer, but data on the possible extent of intratumoral heterogeneity are lacking. METHODS To study MSI heterogeneity in pancreatic cancer, a tissue microarray (TMA) comprising 597 tumors was screened by immunohistochemistry with antibodies for the mismatch repair (MMR) proteins MLH1, PMS2, MSH2, and MSH6. RESULTS In six suspicious cases, large section immunohistochemistry and microsatellite analysis (Bethesda panel) resulted in the identification of 4 (0.8%) validated MSI cases out of 480 interpretable pancreatic ductal adenocarcinomas. MSI was absent in 55 adenocarcinomas of the ampulla of Vater and 7 acinar cell carcinomas. MMR deficiency always involved MSH6 loss, in three cases with additional loss of MSH2 expression. Three cancers were MSI-high and one case with isolated MSH6 loss was MSS in PCR analysis. The analysis of 44 cancer-containing tumor blocks revealed that the loss of MMR protein expression was always homogeneous in affected tumors. Automated digital image analysis of CD8 immunostaining demonstrated markedly higher CD8 + tumor infiltrating lymphocytes in tumors with (mean = 685, median = 626) than without (mean = 227; median = 124) MMR deficiency (p < 0.0001), suggesting a role of MSI for immune response. CONCLUSIONS Our data suggest that MSI occurs early in a small subset of ductal adenocarcinomas of the pancreas and that immunohistochemical MMR analysis on limited biopsy or cytology material may be sufficient to estimate MMR status of the entire cancer mass.
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Affiliation(s)
- Christoph Fraune
- Institute of Pathology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Eike Burandt
- Institute of Pathology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Ronald Simon
- Institute of Pathology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.
| | - Claudia Hube-Magg
- Institute of Pathology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | | | - Martina Kluth
- Institute of Pathology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Franziska Büscheck
- Institute of Pathology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Doris Höflmayer
- Institute of Pathology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Niclas Ch Blessin
- Institute of Pathology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Tim Mandelkow
- Institute of Pathology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Wenchao Li
- Institute of Pathology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Daniel Perez
- General, Visceral and Thoracic Surgery Department and Clinic, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Jakob R Izbicki
- General, Visceral and Thoracic Surgery Department and Clinic, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Waldemar Wilczak
- Institute of Pathology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Guido Sauter
- Institute of Pathology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Jörg Schrader
- General, Visceral and Thoracic Surgery Department and Clinic, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
- I. Medical Department - Gastroenterology and Hepatology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Michael Neipp
- General, Vascular and Visceral Surgery Clinic, Itzehoe Medical Center, Itzehoe, Germany
| | - Hamid Mofid
- General, Visceral Thoracic and Vascular Surgery Clinic, Regio Clinic Pinneberg, Pinneberg, Germany
| | - Thies Daniels
- General, Visceral and Tumor Sugery Clinic, Albertinen Hospital, Hamburg, Germany
| | - Christoph Isbert
- Department of General, Gastrointestinal and Colorectal Surgery, Amalie Sieveking Hospital, Hamburg, Germany
| | - Till S Clauditz
- Institute of Pathology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Stefan Steurer
- Institute of Pathology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
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Kazmi S, Wagner S, Heintzelman R, Corbman M. Malignant phyllodes tumor in Lynch syndrome: a case report. J Med Case Rep 2019; 13:216. [PMID: 31307558 PMCID: PMC6631613 DOI: 10.1186/s13256-019-2138-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2019] [Accepted: 05/29/2019] [Indexed: 01/13/2023] Open
Abstract
BACKGROUND Lynch syndrome, or hereditary nonpolyposis colorectal cancer, is an autosomal dominant genetic syndrome that predisposes individuals to multiple cancer types. The known cancers associated with Lynch syndrome include colorectal and endometrial cancers as well as cancers of the stomach, ovary, urinary tract, hepatobiliary tract, pancreas, small bowel, and brain. There are no searchable cases of malignant phyllodes of the breast associated with Lynch syndrome. CASE PRESENTATION Our patient was a 43-year-old Caucasian woman who felt a lump in her left breast and was found to have a spindle cell neoplasm. Definitive surgery revealed a malignant phyllodes tumor. On the basis of her cancer diagnosis and family history of multiple cancers, a Myriad myRisk Hereditary Cancer® test panel of 25 genes was performed. This testing revealed that she had a heterozygous MSH6 mutation as part of the Lynch syndrome panel. Due to positive margins, the patient received adjuvant chemotherapy with doxorubicin and ifosfamide. She also had a subsequent total abdominal hysterectomy and a bilateral salpingo-oophorectomy for risk reduction. She remains in a high-risk surveillance program. Her family members have been tested, which revealed that her two brothers and daughter also carry the genetic mutation. CONCLUSIONS This case highlights the importance of genetic testing with rare malignancies because the full scope of phenotypic sequelae for known hereditary syndromes has not been mapped.
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Affiliation(s)
- Shayma Kazmi
- Cancer Treatment Centers of America, Comprehensive Care and Research Center, 1331 East Wyoming Avenue, Philadelphia, PA 19124 USA
| | - Steven Wagner
- Cancer Treatment Centers of America, Comprehensive Care and Research Center, 1331 East Wyoming Avenue, Philadelphia, PA 19124 USA
| | - Rebecca Heintzelman
- Cancer Treatment Centers of America, Comprehensive Care and Research Center, 1331 East Wyoming Avenue, Philadelphia, PA 19124 USA
| | - Melanie Corbman
- Cancer Treatment Centers of America, Comprehensive Care and Research Center, 1331 East Wyoming Avenue, Philadelphia, PA 19124 USA
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AbdelGawwad MR, Marić A, Al-Ghamdi AA, Hatamleh AA. Interactome Analysis and Docking Sites of MutS Homologs Reveal New Physiological Roles in Arabidopsis thaliana. Molecules 2019; 24:molecules24132493. [PMID: 31288414 PMCID: PMC6651420 DOI: 10.3390/molecules24132493] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2019] [Revised: 06/25/2019] [Accepted: 06/26/2019] [Indexed: 11/16/2022] Open
Abstract
Due to their sedentary lifestyle, plants are constantly exposed to different stress stimuli. Stress comes in variety of forms where factors like radiation, free radicals, “replication errors, polymerase slippage”, and chemical mutagens result in genotoxic or cytotoxic damage. In order to face “the base oxidation or DNA replication stress”, plants have developed many sophisticated mechanisms. One of them is the DNA mismatch repair (MMR) pathway. The main part of the MMR is the MutS homologue (MSH) protein family. The genome of Arabidopsis thaliana encodes at least seven homologues of the MSH family: AtMSH1, AtMSH2, AtMSH3, AtMSH4, AtMSH5, AtMSH6, and AtMSH7. Despite their importance, the functions of AtMSH homologs have not been investigated. In this work, bioinformatics tools were used to obtain a better understanding of MSH-mediated DNA repair mechanisms in Arabidopsis thaliana and to understand the additional biological roles of AtMSH family members. In silico analysis, including phylogeny tracking, prediction of 3D structure, interactome analysis, and docking site prediction, suggested interactions with proteins were important for physiological development of A. thaliana. The MSH homologs extensively interacted with both TIL1 and TIL2 (DNA polymerase epsilon catalytic subunit), proteins involved in cell fate determination during plant embryogenesis and involved in flowering time repression. Additionally, interactions with the RECQ protein family (helicase enzymes) and proteins of nucleotide excision repair pathway were detected. Taken together, the results presented here confirm the important role of AtMSH proteins in mismatch repair and suggest important new physiological roles.
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Affiliation(s)
- Mohamed Ragab AbdelGawwad
- Genetics and Bioengineering, Faculty of Engineering and Natural Sciences, International University of Sarajevo, 71210 Sarajevo, Bosnia and Herzegovina.
| | - Aida Marić
- Centre for Research in Agricultural Genomics, UAB-Edifici CRAG, Cerdanyola, 08193 Barcelona, Spain
| | - Abdullah Ahmed Al-Ghamdi
- Department of Botany and Microbiology, College of Sciences, King Saud University, Riyadh 11451, Saudi Arabia
| | - Ashraf A Hatamleh
- Department of Botany and Microbiology, College of Sciences, King Saud University, Riyadh 11451, Saudi Arabia
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10
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Lu H, Yang S, Zhu H, Tong X, Xie F, Qin J, Han N, Wu X, Fan Y, Shao YW, Mao W. Targeted next generation sequencing identified clinically actionable mutations in patients with esophageal sarcomatoid carcinoma. BMC Cancer 2018; 18:251. [PMID: 29506494 PMCID: PMC5838991 DOI: 10.1186/s12885-018-4159-2] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2017] [Accepted: 02/21/2018] [Indexed: 02/08/2023] Open
Abstract
Background Esophageal sarcomatoid carcinoma (ESC) is a rare disease with a mixture of both carcinomatous and sarcomatous components in the tumor. Its genetic background and mechanisms of oncogenesis remain largely unknown. Methods Here we performed targeted next generation sequencing (NGS) on a pan-cancer gene panel in 15 ESC tumors to explore their genetic alterations, and aimed to identify clinically actionable mutations for future treatment instructions. Results TP53 alterations were identified in all patients. Alterations in receptor tyrosine kinases (RTK) were identified in 10 out of 15 patients. Members of downstream RAS and PI3-kinase pathways are also mutated in 10 patients, and PIK3CA is the top mutated gene in these pathways. In addition, we identified mutations on histone modification genes in 5 patients, including histone acetyltransferase gene EP300 and its homologue CREBBP, lysine methyltransferase genes KMT2A and KMT2B, and lysine demethylase gene KDM5A. Finally, mismatch repair (MMR) genes and proofreading gene POLE all together were mutated in one third of the ESC patients. Conclusions This is the first study to unravel the mutational profile of ESC tumors. Our findings could match 9 patients to the targeted therapies currently available in clinical practice or in active clinical trials, suggesting the potential utility of targeted therapies for this rare disease in the future. Electronic supplementary material The online version of this article (10.1186/s12885-018-4159-2) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Hongyang Lu
- Zhejiang Key Laboratory of Diagnosis & Treatment Technology on Thoracic Oncology (lung and esophagus), Zhejiang Cancer Hospital, NO.1 East Banshan Road, Gongshu District, Hangzhou, 310022, People's Republic of China.,Department of Thoracic Medical Oncology, Zhejiang Cancer Hospital, Hangzhou, 310022, People's Republic of China
| | - Shifeng Yang
- Department of Pathology, Zhejiang Cancer Hospital, Hangzhou, 310022, People's Republic of China
| | - Huineng Zhu
- Department of Pathology, Zhejiang Cancer Hospital, Hangzhou, 310022, People's Republic of China
| | - Xiaoling Tong
- Translational Medicine Research Institute, Geneseeq Technology Inc, Suite 300, MaRS Centre, South Tower, 101 College Street, Toronto, ON, M5G 1L7, Canada
| | - Fajun Xie
- Department of Thoracic Medical Oncology, Zhejiang Cancer Hospital, Hangzhou, 310022, People's Republic of China
| | - Jing Qin
- Department of Thoracic Medical Oncology, Zhejiang Cancer Hospital, Hangzhou, 310022, People's Republic of China
| | - Na Han
- Department of Thoracic Medical Oncology, Zhejiang Cancer Hospital, Hangzhou, 310022, People's Republic of China
| | - Xue Wu
- Translational Medicine Research Institute, Geneseeq Technology Inc, Suite 300, MaRS Centre, South Tower, 101 College Street, Toronto, ON, M5G 1L7, Canada
| | - Yun Fan
- Zhejiang Key Laboratory of Diagnosis & Treatment Technology on Thoracic Oncology (lung and esophagus), Zhejiang Cancer Hospital, NO.1 East Banshan Road, Gongshu District, Hangzhou, 310022, People's Republic of China.,Department of Thoracic Medical Oncology, Zhejiang Cancer Hospital, Hangzhou, 310022, People's Republic of China
| | - Yang W Shao
- Translational Medicine Research Institute, Geneseeq Technology Inc, Suite 300, MaRS Centre, South Tower, 101 College Street, Toronto, ON, M5G 1L7, Canada.
| | - Weimin Mao
- Zhejiang Key Laboratory of Diagnosis & Treatment Technology on Thoracic Oncology (lung and esophagus), Zhejiang Cancer Hospital, NO.1 East Banshan Road, Gongshu District, Hangzhou, 310022, People's Republic of China.
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11
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Chen ML, Chen JY, Hu J, Chen Q, Yu LX, Liu BR, Qian XP, Yang M. Comparison of microsatellite status detection methods in colorectal carcinoma. INTERNATIONAL JOURNAL OF CLINICAL AND EXPERIMENTAL PATHOLOGY 2018; 11:1431-1438. [PMID: 31938240 PMCID: PMC6958115] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 01/15/2018] [Accepted: 02/23/2018] [Indexed: 06/10/2023]
Abstract
There are two commonly accepted methods for detecting microsatellite status. One is to detect amplified microsatellite loci by polymerase chain reaction (PCR) and the other is to detect mismatch repair gene (MMR) protein expression by immunohistochemistry (IHC). PCR detection is considered to be accurate in clinical operations while IHC is widely used due to ease of operation and lesser expense. In order to compare IHC with PCR in detecting microsatellite status in colorectal carcinoma, a total of 569 samples of colorectal carcinoma resection were collected in the Department of Pathology, Nanjing Drum Tower Hospital, between June 2014 and June 2017. In all samples, IHC and PCR was used to detect microsatellite status and the consistency of results between the two methods was compared. We found that 48 cases of microsatellite instability (MSI) were detected by PCR including 37 cases of microsatellite instability high (MSI-H), 11 cases of microsatellite instability low (MSI-L), and 521 cases of MSS. MSI accounted for 8.44% of all cases and MSI-H accounted for 6.50%. IHC results of the 569 patients showed that 69 cases were deficient mismatch repair (dMMR) and 500 cases were proficient mismatch repair (pMMR). dMMR accounted for 12.13% of all cases. Loss expression of PMS2 protein was the most common while MSH6 was rare. The coincidence rate of the two methods for detecting microsatellite states was 91.92%. IHC and the PCR method had high consistency in microsatellite status. Compared with PCR, the IHC method is more economical and more convenient for clinical operations. When the 4 repair proteins were without deficiency detected by IHC, it could be diagnosed as MSS/MSI-L and further PCR was not necessary. When any repair protein was found to be deficient, PCR detection was needed to determine whether MSI existed. Our conclusion will save a lot of time and costs in clinical work.
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Affiliation(s)
- Mei-Li Chen
- The Comprehensive Cancer Center of Drum Tower Hospital, Medical School of Nanjing University and Clinical Cancer Institute of Nanjing UniversityNanjing 210008, China
- Medical School of Southeast UniversityNanjing, Jiangsu, China
| | - Jie-Yu Chen
- Department of Pathology, Drum Tower Hospital, The Affiliated Hospital of Nanjing University Medical SchoolNanjing, China
| | - Jing Hu
- The Comprehensive Cancer Center of Drum Tower Hospital, Medical School of Nanjing University and Clinical Cancer Institute of Nanjing UniversityNanjing 210008, China
| | - Qian Chen
- Nanjing Drum Tower Hospital Group Suqian People’s HospitalSuqian, China
| | - Li-Xia Yu
- The Comprehensive Cancer Center of Drum Tower Hospital, Medical School of Nanjing University and Clinical Cancer Institute of Nanjing UniversityNanjing 210008, China
| | - Bao-Rui Liu
- The Comprehensive Cancer Center of Drum Tower Hospital, Medical School of Nanjing University and Clinical Cancer Institute of Nanjing UniversityNanjing 210008, China
| | - Xiao-Ping Qian
- The Comprehensive Cancer Center of Drum Tower Hospital, Medical School of Nanjing University and Clinical Cancer Institute of Nanjing UniversityNanjing 210008, China
| | - Mi Yang
- The Comprehensive Cancer Center of Drum Tower Hospital, Medical School of Nanjing University and Clinical Cancer Institute of Nanjing UniversityNanjing 210008, China
- Medical School of Southeast UniversityNanjing, Jiangsu, China
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12
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Metcalfe MJ, Petros FG, Rao P, Mork ME, Xiao L, Broaddus RR, Matin SF. Universal Point of Care Testing for Lynch Syndrome in Patients with Upper Tract Urothelial Carcinoma. J Urol 2017; 199:60-65. [PMID: 28797715 DOI: 10.1016/j.juro.2017.08.002] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/01/2017] [Indexed: 10/19/2022]
Abstract
PURPOSE Patients with Lynch syndrome are at risk for upper tract urothelial carcinoma. We sought to identify the incidence and most reliable means of point of care screening for Lynch syndrome in patients with upper tract urothelial carcinoma. MATERIALS AND METHODS A total of 115 consecutive patients with upper tract urothelial carcinoma without a history of Lynch syndrome were universally screened during followup from January 2013 through July 2016. We evaluated patient and family history using AMS (Amsterdam criteria) I and II, and tumor immunohistochemistry for mismatch repair proteins and microsatellite instability. Patients who were positive for AMS I/II, microsatellite instability or immunohistochemistry were classified as potentially having Lynch syndrome and referred for clinical genetic analysis and counseling. Patients with known Lynch syndrome served as positive controls. RESULTS Of the 115 patients 16 (13.9%) screened positive for potential Lynch syndrome. Of these patients 7.0% met AMS II criteria, 11.3% had loss of at least 1 mismatch repair protein and 6.0% had high microsatellite instability. All 16 patients were referred for germline testing, 9 completed genetic analysis and counseling, and 6 were confirmed to have Lynch syndrome. All 7 patients with upper tract urothelial carcinoma who had a known history of Lynch syndrome were positive for AMS II criteria and at least a single mismatch repair protein loss while 5 of 6 had high microsatellite instability. CONCLUSIONS We identified 13.9% of upper tract urothelial carcinoma cases as potential Lynch syndrome and 5.2% as confirmed Lynch syndrome at the point of care. These findings have important implications for universal screening of upper tract urothelial carcinoma, representing one of the highest rates of undiagnosed genetic disease in a urological cancer.
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Affiliation(s)
- Michael J Metcalfe
- Department of Urology, University of Texas M. D. Anderson Cancer Center, Houston, Texas
| | - Firas G Petros
- Department of Urology, University of Texas M. D. Anderson Cancer Center, Houston, Texas
| | - Priya Rao
- Department of Pathology, University of Texas M. D. Anderson Cancer Center, Houston, Texas
| | - Maureen E Mork
- Clinical Cancer Genetics Program, University of Texas M. D. Anderson Cancer Center, Houston, Texas
| | - Lianchun Xiao
- Department of Biostatistics, University of Texas M. D. Anderson Cancer Center, Houston, Texas
| | - Russell R Broaddus
- Department of Pathology, University of Texas M. D. Anderson Cancer Center, Houston, Texas
| | - Surena F Matin
- Department of Urology, University of Texas M. D. Anderson Cancer Center, Houston, Texas.
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13
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Wielders E, Delzenne-Goette E, Dekker R, van der Valk M, Te Riele H. Truncation of the MSH2 C-terminal 60 amino acids disrupts effective DNA mismatch repair and is causative for Lynch syndrome. Fam Cancer 2016; 16:221-229. [PMID: 27873144 DOI: 10.1007/s10689-016-9945-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
Missense variants of DNA mismatch repair (MMR) genes pose a problem in clinical genetics as long as they cannot unambiguously be assigned as the cause of Lynch syndrome (LS). To study such variants of uncertain clinical significance, we have developed a functional assay based on direct measurement of MMR activity in mouse embryonic stem cells expressing mutant protein from the endogenous alleles. We have applied this protocol to a specific truncation mutant of MSH2 that removes 60 C-terminal amino acids and has been found in suspected LS families. We show that the stability of the MSH2/MSH6 heterodimer is severely perturbed, causing attenuated MMR in in vitro assays and cancer predisposition in mice. This mutation can therefore unambiguously be considered as deleterious and causative for LS.
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Affiliation(s)
- Eva Wielders
- Division of Biological Stress Response, The Netherlands Cancer Institute/Antoni van Leeuwenhoek, Plesmanlaan 121, 1066 CX, Amsterdam, The Netherlands
| | - Elly Delzenne-Goette
- Division of Biological Stress Response, The Netherlands Cancer Institute/Antoni van Leeuwenhoek, Plesmanlaan 121, 1066 CX, Amsterdam, The Netherlands
| | - Rob Dekker
- Division of Biological Stress Response, The Netherlands Cancer Institute/Antoni van Leeuwenhoek, Plesmanlaan 121, 1066 CX, Amsterdam, The Netherlands
| | - Martin van der Valk
- Division of Biological Stress Response, The Netherlands Cancer Institute/Antoni van Leeuwenhoek, Plesmanlaan 121, 1066 CX, Amsterdam, The Netherlands
| | - Hein Te Riele
- Division of Biological Stress Response, The Netherlands Cancer Institute/Antoni van Leeuwenhoek, Plesmanlaan 121, 1066 CX, Amsterdam, The Netherlands.
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14
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Modrich P. Mechanismen der Fehlpaarungsreparatur in E. coliund im Menschen (Nobel-Aufsatz). Angew Chem Int Ed Engl 2016. [DOI: 10.1002/ange.201601412] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Paul Modrich
- Howard Hughes Medical Institute and Department of Biochemistry; Duke University, Medical Center; Durham NC 27710 USA
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15
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Modrich P. Mechanisms in E. coli and Human Mismatch Repair (Nobel Lecture). Angew Chem Int Ed Engl 2016; 55:8490-501. [PMID: 27198632 PMCID: PMC5193110 DOI: 10.1002/anie.201601412] [Citation(s) in RCA: 64] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2016] [Indexed: 11/11/2022]
Abstract
DNA molecules are not completely stable, they are subject to chemical or photochemical damage and errors that occur during DNA replication resulting in mismatched base pairs. Through mechanistic studies Paul Modrich showed how replication errors are corrected by strand-directed mismatch repair in Escherichia coli and human cells.
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Affiliation(s)
- Paul Modrich
- Howard Hughes Medical Institute and Department of Biochemistry, Duke University, Medical Center, Durham, NC, 27710, USA.
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16
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Suzuki S, Iwaizumi M, Tseng-Rogenski S, Hamaya Y, Miyajima H, Kanaoka S, Sugimoto K, Carethers JM. Production of truncated MBD4 protein by frameshift mutation in DNA mismatch repair-deficient cells enhances 5-fluorouracil sensitivity that is independent of hMLH1 status. Cancer Biol Ther 2016; 17:760-8. [PMID: 27115207 DOI: 10.1080/15384047.2016.1178430] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
Methyl-CpG binding domain protein 4 (MBD4) is a DNA glycosylase that can remove 5-fluorodeoxyuracil from DNA as well as repair T:G or U:G mismatches. MBD4 is a target for frameshift mutation with DNA mismatch repair (MMR) deficiency, creating a truncated MBD4 protein (TruMBD4) that lacks its glycosylase domain. Here we show that TruMBD4 plays an important role for enhancing 5-fluorouracil (5FU) sensitivity in MMR-deficient colorectal cancer cells. We found biochemically that TruMBD4 binds to 5FU incorporated into DNA with higher affinity than MBD4. TruMBD4 reduced the 5FU affinity of the MMR recognition complexes that determined 5FU sensitivity by previous reports, suggesting other mechanisms might be operative to trigger cytotoxicity. To analyze overall 5FU sensitivity with TruMBD4, we established TruMBD4 overexpression in hMLH1-proficient or -deficient colorectal cancer cells followed by treatment with 5FU. 5FU-treated TruMBD4 cells demonstrated diminished growth characteristics compared to controls, independently of hMLH1 status. Flow cytometry revealed more 5FU-treated TruMBD4 cells in S phase than controls. We conclude that patients with MMR-deficient cancers, which show characteristic resistance to 5FU therapy, may be increased for 5FU sensitivity via secondary frameshift mutation of the base excision repair gene MBD4.
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Affiliation(s)
- Satoshi Suzuki
- a First Department of Medicine , Hamamatsu University School of Medicine , Hamamatsu , Shizuoka , Japan
| | - Moriya Iwaizumi
- a First Department of Medicine , Hamamatsu University School of Medicine , Hamamatsu , Shizuoka , Japan.,b Division of Gastroenterology, Department of Internal Medicine and Department of Human Genetics, University of Michigan , Ann Arbor , MA , USA
| | - Stephanie Tseng-Rogenski
- b Division of Gastroenterology, Department of Internal Medicine and Department of Human Genetics, University of Michigan , Ann Arbor , MA , USA
| | - Yasushi Hamaya
- a First Department of Medicine , Hamamatsu University School of Medicine , Hamamatsu , Shizuoka , Japan.,b Division of Gastroenterology, Department of Internal Medicine and Department of Human Genetics, University of Michigan , Ann Arbor , MA , USA
| | - Hiroaki Miyajima
- a First Department of Medicine , Hamamatsu University School of Medicine , Hamamatsu , Shizuoka , Japan
| | - Shigeru Kanaoka
- c Department of Gastroenterology , Hamamatsu Medical Center , Shizuoka , Japan
| | - Ken Sugimoto
- a First Department of Medicine , Hamamatsu University School of Medicine , Hamamatsu , Shizuoka , Japan
| | - John M Carethers
- b Division of Gastroenterology, Department of Internal Medicine and Department of Human Genetics, University of Michigan , Ann Arbor , MA , USA
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17
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The polymorphisms of MSH6 gene are associated with AIDS progression in a northern Chinese population. INFECTION GENETICS AND EVOLUTION 2016; 42:9-13. [PMID: 27090025 DOI: 10.1016/j.meegid.2016.04.016] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/19/2016] [Revised: 04/12/2016] [Accepted: 04/14/2016] [Indexed: 01/09/2023]
Abstract
It has been reported that DNA repair genes play an important role in HIV-1 infection and AIDS progression. One DNA repair pathway, the mismatch repair (MMR) is associated with a wide variety of tumors. However, the role of single nucleotide polymorphisms (SNPs) in the MMR genes and their importance in HIV-1 infection and AIDS progression remain unclear. In the present study, 479 HIV-1-infected and 487 healthy individuals from northern China were genotyped for nine SNPs in the MSH2 gene (rs13019654, rs4608577, rs4952887, rs6726691, rs10191478, rs12999145, rs1981929, rs2042649, rs2303428) and five SNPs in the MSH6 gene (rs2348244, rs3136245, rs3136329, rs2072447, rs7562048). Our results showed that the rs7562048 G allele frequency was significantly higher in the cases with the CD4(+) T-lymphocyte count <200cells/μl than those with >200cells/μl (P=0.001, OR=1.811, 95% CI 1.255-2.614), which is in agreement with the result of the Bonferroni correction. The frequencies of the rs2348244 C allele and rs3136245 T allele were higher in the cases at clinical phase IV than those at clinical phase I+II+III (P=0.026, OR=1.591, 95% CI 1.056-2.398 and P=0.019, OR=1.749, 95% CI 1.096-2.791, respectively); however, this difference is not supported by the Bonferroni correction. There were no significant differences in the frequency of allele, genotype and haplotype of the 14 SNPs between HIV-1-infected individuals and healthy controls (P>0.05). These results suggest that the rs7562048 is associated with the clinical features and that the MSH6 gene polymorphisms likely play an important role in the progression of AIDS in the northern Chinese population.
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18
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Perez RE, Shen H, Duan L, Kim RH, Kim T, Park NH, Maki CG. Modeling the Etiology of p53-mutated Cancer Cells. J Biol Chem 2016; 291:10131-47. [PMID: 27022024 DOI: 10.1074/jbc.m116.724781] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2016] [Indexed: 12/23/2022] Open
Abstract
p53 gene mutations are among the most common alterations in cancer. In most cases, missense mutations in one TP53 allele are followed by loss-of-heterozygosity (LOH), so tumors express only mutant p53. TP53 mutations and LOH have been linked, in many cases, with poor therapy response and worse outcome. Despite this, remarkably little is known about how TP53 point mutations are acquired, how LOH occurs, or the cells involved. Nutlin-3a occupies the p53-binding site in MDM2 and blocks p53-MDM2 interaction, resulting in the stabilization and activation of p53 and subsequent growth arrest or apoptosis. We leveraged the powerful growth inhibitory activity of Nutlin-3a to select p53-mutated cells and examined how TP53 mutations arise and how the remaining wild-type allele is lost or inactivated. Mismatch repair (MMR)-deficient colorectal cancer cells formed heterozygote (p53 wild-type/mutant) colonies when cultured in low doses of Nutlin-3a, whereas MMR-corrected counterparts did not. Placing these heterozygotes in higher Nutlin-3a doses selected clones in which the remaining wild-type TP53 was silenced. Our data suggest silencing occurred through a novel mechanism that does not involve DNA methylation, histone methylation, or histone deacetylation. These data indicate MMR deficiency in colorectal cancer can give rise to initiating TP53 mutations and that TP53 silencing occurs via a copy-neutral mechanism. Moreover, the data highlight the use of MDM2 antagonists as tools to study mechanisms of TP53 mutation acquisition and wild-type allele loss or silencing in cells with defined genetic backgrounds.
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Affiliation(s)
- Ricardo E Perez
- From the Department of Anatomy and Cell Biology, Rush University Medical Center, Chicago, Illinois 60612 and
| | - Hong Shen
- From the Department of Anatomy and Cell Biology, Rush University Medical Center, Chicago, Illinois 60612 and
| | - Lei Duan
- From the Department of Anatomy and Cell Biology, Rush University Medical Center, Chicago, Illinois 60612 and
| | - Reuben H Kim
- The Shapiro Family Laboratory of Viral Oncology and Aging Research, UCLA School of Dentistry and David Geffen School of Medicine at UCLA, Los Angeles, California 90095
| | - Terresa Kim
- The Shapiro Family Laboratory of Viral Oncology and Aging Research, UCLA School of Dentistry and David Geffen School of Medicine at UCLA, Los Angeles, California 90095
| | - No-Hee Park
- The Shapiro Family Laboratory of Viral Oncology and Aging Research, UCLA School of Dentistry and David Geffen School of Medicine at UCLA, Los Angeles, California 90095
| | - Carl G Maki
- From the Department of Anatomy and Cell Biology, Rush University Medical Center, Chicago, Illinois 60612 and
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19
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Kolodner RD. A personal historical view of DNA mismatch repair with an emphasis on eukaryotic DNA mismatch repair. DNA Repair (Amst) 2016; 38:3-13. [PMID: 26698650 PMCID: PMC4740188 DOI: 10.1016/j.dnarep.2015.11.009] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2015] [Revised: 10/30/2015] [Accepted: 11/30/2015] [Indexed: 01/12/2023]
Affiliation(s)
- Richard D Kolodner
- Ludwig Institute for Cancer Research, Department of Cellular and Molecular Medicine, Moores-UCSD Cancer Center and Institute for Molecular Medicine, University of CA, San Diego School of Medicine, La Jolla, CA 92093-0669, United States.
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20
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Exome Sequencing and Epigenetic Analysis of Twins Who Are Discordant for Congenital Cataract. Twin Res Hum Genet 2015; 18:393-8. [PMID: 26045100 DOI: 10.1017/thg.2015.34] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
PURPOSE To further understand genetic factors that contribute to congenital cataracts, we sought to identify early post-twinning mutational and epigenetic events that may account for the discordant phenotypes of a twin pair. METHODS A patient with a congenital cataract and her twin sister were assessed for genetic factors that might contribute to their discordant phenotypes by mutation screening of 11 candidate genes (CRYGC, CRYGD, CRYAA, CRYAB, CRYBA1, CRYBB1, CRYBB2, MIP, HSF4, GJA3, and GJA8), exome analysis followed by Sanger sequencing of 10 additional candidate genes (PLEKHO2, FRYL, RBP3, P2RX2, GSR, TRAM1, VEGFA, NARS2, CADPS, and TEKT4), and promoter methylation analysis of five representative genes (TRAM1, CRYAA, HSF4, VEGFA, GJA3, DCT) plus one additional candidate gene (FTL). RESULTS Mutation screening revealed no gene mutation differences between the patient and her twin sister for the 11 candidate genes. Exome sequencing analysis revealed variations between the twins in 442 genes, 10 of which are expressed in the eye. However, these differential variants could not be confirmed by Sanger sequencing. Furthermore, epigenetic discordance was not detected in the twin pair. CONCLUSIONS The genomic DNA mutational and epigenetic events assessed in this study could not explain the discordance in the development of phenotypic differences between the twin pair, suggesting the possible involvement of somatic mutations or environmental factors. Identification of possible causes requires further research.
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Tosti E, Katakowski JA, Schaetzlein S, Kim HS, Ryan CJ, Shales M, Roguev A, Krogan NJ, Palliser D, Keogh MC, Edelmann W. Evolutionarily conserved genetic interactions with budding and fission yeast MutS identify orthologous relationships in mismatch repair-deficient cancer cells. Genome Med 2014; 6:68. [PMID: 25302077 PMCID: PMC4189729 DOI: 10.1186/s13073-014-0068-4] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2013] [Accepted: 08/28/2014] [Indexed: 12/13/2022] Open
Abstract
Background The evolutionarily conserved DNA mismatch repair (MMR) system corrects base-substitution and insertion-deletion mutations generated during erroneous replication. The mutation or inactivation of many MMR factors strongly predisposes to cancer, where the resulting tumors often display resistance to standard chemotherapeutics. A new direction to develop targeted therapies is the harnessing of synthetic genetic interactions, where the simultaneous loss of two otherwise non-essential factors leads to reduced cell fitness or death. High-throughput screening in human cells to directly identify such interactors for disease-relevant genes is now widespread, but often requires extensive case-by-case optimization. Here we asked if conserved genetic interactors (CGIs) with MMR genes from two evolutionary distant yeast species (Saccharomyces cerevisiae and Schizosaccharomyzes pombe) can predict orthologous genetic relationships in higher eukaryotes. Methods High-throughput screening was used to identify genetic interaction profiles for the MutSα and MutSβ heterodimer subunits (msh2Δ, msh3Δ, msh6Δ) of fission yeast. Selected negative interactors with MutSβ (msh2Δ/msh3Δ) were directly analyzed in budding yeast, and the CGI with SUMO-protease Ulp2 further examined after RNA interference/drug treatment in MSH2-deficient and -proficient human cells. Results This study identified distinct genetic profiles for MutSα and MutSβ, and supports a role for the latter in recombinatorial DNA repair. Approximately 28% of orthologous genetic interactions with msh2Δ/msh3Δ are conserved in both yeasts, a degree consistent with global trends across these species. Further, the CGI between budding/fission yeast msh2 and SUMO-protease Ulp2 is maintained in human cells (MSH2/SENP6), and enhanced by Olaparib, a PARP inhibitor that induces the accumulation of single-strand DNA breaks. This identifies SENP6 as a promising new target for the treatment of MMR-deficient cancers. Conclusion Our findings demonstrate the utility of employing evolutionary distance in tractable lower eukaryotes to predict orthologous genetic relationships in higher eukaryotes. Moreover, we provide novel insights into the genome maintenance functions of a critical DNA repair complex and propose a promising targeted treatment for MMR deficient tumors. Electronic supplementary material The online version of this article (doi:10.1186/s13073-014-0068-4) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Elena Tosti
- Department of Cell Biology, Albert Einstein College of Medicine, New York, USA
| | - Joseph A Katakowski
- Department of Microbiology & Immunology, Albert Einstein College of Medicine, New York, USA
| | - Sonja Schaetzlein
- Department of Cell Biology, Albert Einstein College of Medicine, New York, USA
| | - Hyun-Soo Kim
- Department of Cell Biology, Albert Einstein College of Medicine, New York, USA
| | - Colm J Ryan
- Department of Cellular & Molecular Pharmacology, UCSF, San Francisco, USA ; California Institute for Quantitative Biosciences, San Francisco, USA ; School of Medicine and Medical Science, University College Dublin, Dublin, Ireland
| | - Michael Shales
- Department of Cellular & Molecular Pharmacology, UCSF, San Francisco, USA
| | - Assen Roguev
- Department of Cellular & Molecular Pharmacology, UCSF, San Francisco, USA
| | - Nevan J Krogan
- Department of Cellular & Molecular Pharmacology, UCSF, San Francisco, USA ; California Institute for Quantitative Biosciences, San Francisco, USA ; J. David Gladstone Institutes, San Francisco, USA
| | - Deborah Palliser
- Department of Microbiology & Immunology, Albert Einstein College of Medicine, New York, USA
| | | | - Winfried Edelmann
- Department of Cell Biology, Albert Einstein College of Medicine, New York, USA
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22
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Wielders EAL, Hettinger J, Dekker R, Kets CM, Ligtenberg MJ, Mensenkamp AR, van den Ouweland AMW, Prins J, Wagner A, Dinjens WNM, Dubbink HJ, van Hest LP, Menko F, Hogervorst F, Verhoef S, te Riele H. Functional analysis of MSH2 unclassified variants found in suspected Lynch syndrome patients reveals pathogenicity due to attenuated mismatch repair. J Med Genet 2014; 51:245-53. [PMID: 24501230 DOI: 10.1136/jmedgenet-2013-101987] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
BACKGROUND Lynch syndrome, an autosomal-dominant disorder characterised by high colorectal and endometrial cancer risks, is caused by inherited mutations in DNA mismatch repair (MMR) genes. Mutations fully abrogating gene function are unambiguously disease causing. However, missense mutations often have unknown functional implications, hampering genetic counselling. We have applied a novel approach to study three MSH2 unclassified variants (UVs) found in Dutch families with suspected Lynch syndrome. METHODS The three mutations were recreated in the endogenous Msh2 gene in mouse embryonic stem cells by oligonucleotide-directed gene modification. The effect of the UVs on MMR activity was then tested using a set of functional assays interrogating the main MMR functions. RESULTS We recreated and functionally tested three MSH2 UVs: MSH2-Y165D (c.493T>G), MSH2-Q690E (c.2068C>G) and MSH2-M813V (c.2437A>G). We observed reduced levels of MSH2-Y165D and MSH2-Q690E but not MSH2-M813V proteins. MSH2-M813V was able to support all MMR functions similar to wild-type MSH2, whereas MSH2-Y165D and MSH2-Q690E showed partial defects. CONCLUSIONS Based on the results from our functional assays, we conclude that the MSH2-M813V variant is not disease causing. The MSH2-Y165D and MSH2-Q690E variants affect MMR function and are therefore likely the underlying cause of familial cancer predisposition. Since the MMR defect is partial, these variants may represent low penetrance alleles.
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Affiliation(s)
- Eva A L Wielders
- Division of Biological Stress Response, The Netherlands Cancer Institute, Amsterdam, The Netherlands
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Li R, Montpetit A, Rousseau M, Wu SYM, Greenwood CMT, Spector TD, Pollak M, Polychronakos C, Richards JB. Somatic point mutations occurring early in development: a monozygotic twin study. J Med Genet 2013; 51:28-34. [DOI: 10.1136/jmedgenet-2013-101712] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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Mutation rates, spectra, and genome-wide distribution of spontaneous mutations in mismatch repair deficient yeast. G3-GENES GENOMES GENETICS 2013; 3:1453-65. [PMID: 23821616 PMCID: PMC3755907 DOI: 10.1534/g3.113.006429] [Citation(s) in RCA: 84] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
DNA mismatch repair is a highly conserved DNA repair pathway. In humans, germline mutations in hMSH2 or hMLH1, key components of mismatch repair, have been associated with Lynch syndrome, a leading cause of inherited cancer mortality. Current estimates of the mutation rate and the mutational spectra in mismatch repair defective cells are primarily limited to a small number of individual reporter loci. Here we use the yeast Saccharomyces cerevisiae to generate a genome-wide view of the rates, spectra, and distribution of mutation in the absence of mismatch repair. We performed mutation accumulation assays and next generation sequencing on 19 strains, including 16 msh2 missense variants implicated in Lynch cancer syndrome. The mutation rate for DNA mismatch repair null strains was approximately 1 mutation per genome per generation, 225-fold greater than the wild-type rate. The mutations were distributed randomly throughout the genome, independent of replication timing. The mutation spectra included insertions/deletions at homopolymeric runs (87.7%) and at larger microsatellites (5.9%), as well as transitions (4.5%) and transversions (1.9%). Additionally, repeat regions with proximal repeats are more likely to be mutated. A bias toward deletions at homopolymers and insertions at (AT)n microsatellites suggests a different mechanism for mismatch generation at these sites. Interestingly, 5% of the single base pair substitutions might represent double-slippage events that occurred at the junction of immediately adjacent repeats, resulting in a shift in the repeat boundary. These data suggest a closer scrutiny of tumor suppressors with homopolymeric runs with proximal repeats as the potential drivers of oncogenesis in mismatch repair defective cells.
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Abstract
Normal cell function requires strict control over the repair of DNA damage, which prevents excessive mutagenesis. An enhanced accumulation of mutations results in the multistep process generally known as carcinogenesis. Defects in repair pathways fuel such mutagenesis by allowing reiterative cycles of mutation, selection, and clonal expansion that drive cancer progression. The repair of mismatches is an important mechanism in the prevention of such genetic instability. In addition, proteins of this pathway have the unique ability to function in DNA damage response by inducing apoptosis when irreparable damage is encountered. Though originally identified primarily in association with a predisposition to hereditary colon cancer, mismatch repair defects have been identified in many other cancer types, including prostate cancer. From the first discovery of microsatellite instability in prostate cancer cell lines and tumor samples, variations in protein levels and a possible association with recurrence and aggression of disease have been described. Current results suggest that the involvement of mismatch repair proteins in prostate cancer may differ from that found in colorectal cancer, in the type of proteins and protein defects involved and the type of causative mutations. Additional work is clearly needed to investigate this involvement and the possibility that such defects may affect treatment response and androgen independence.
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Affiliation(s)
- John Jarzen
- Department of Biology, College of Science and Technology, Georgia Southern University, Statesboro, Georgia, USA
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Iwaizumi M, Tseng-Rogenski S, Carethers JM. Acidic tumor microenvironment downregulates hMLH1 but does not diminish 5-fluorouracil chemosensitivity. Mutat Res 2013; 747-748:19-27. [PMID: 23643670 DOI: 10.1016/j.mrfmmm.2013.04.006] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2012] [Revised: 03/31/2013] [Accepted: 04/17/2013] [Indexed: 12/12/2022]
Abstract
Human DNA mismatch repair (MMR) recognizes and binds 5-fluorouracil (5FU) incorporated into DNA and triggers a MMR-dependent cell death. Absence of MMR in a patient's colorectal tumor abrogates 5FU's beneficial effects on survival. Changes in the tumor microenvironment like low extracellular pH (pHe) may diminish DNA repair, increasing genomic instability. Here, we explored if low pHe modifies MMR recognition of 5FU, as 5FU can exist in ionized and non-ionized forms depending on pH. We demonstrate that MMR-proficient cells at low pHe show downregulation of hMLH1, whereas expression of TDG and MBD4, known DNA glycosylases for base excision repair (BER) that can remove 5FU from DNA, were unchanged. We show in vitro that 5FU within DNA pairs with adenine (A) at high and low pH (in absence of MMR and BER). Surprisingly, 5FdU:G was repaired to C:G in hMLH1-deficient cells cultured at both low and normal pHe, similar to MMR-proficient cells. Moreover, both hMSH6 and hMSH3, components of hMutSα and hMutSβ, respectively, bound 5FU within DNA (hMSH6>hMSH3) but is influenced by hMLH1. We conclude that an acidic tumor microenvironment triggers downregulation of hMLH1, potentially removing the execution component of MMR for 5FU cytotoxicity, whereas other mechanisms remain stable to implement overall 5FU sensitivity.
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Affiliation(s)
- Moriya Iwaizumi
- Division of Gastroenterology, Department of Internal Medicine, University of Michigan, Ann Arbor, MI, United States
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Campregher C, Schmid G, Ferk F, Knasmüller S, Khare V, Kortüm B, Dammann K, Lang M, Scharl T, Spittler A, Roig AI, Shay JW, Gerner C, Gasche C. MSH3-deficiency initiates EMAST without oncogenic transformation of human colon epithelial cells. PLoS One 2012; 7:e50541. [PMID: 23209772 PMCID: PMC3507781 DOI: 10.1371/journal.pone.0050541] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2012] [Accepted: 10/25/2012] [Indexed: 12/16/2022] Open
Abstract
BACKGROUND/AIM Elevated microsatellite instability at selected tetranucleotide repeats (EMAST) is a genetic signature in certain cases of sporadic colorectal cancer and has been linked to MSH3-deficiency. It is currently controversial whether EMAST is associated with oncogenic properties in humans, specifically as cancer development in Msh3-deficient mice is not enhanced. However, a mutator phenotype is different between species as the genetic positions of repetitive sequences are not conserved. Here we studied the molecular effects of human MSH3-deficiency. METHODS HCT116 and HCT116+chr3 (both MSH3-deficient) and primary human colon epithelial cells (HCEC, MSH3-wildtype) were stably transfected with an EGFP-based reporter plasmid for the detection of frameshift mutations within an [AAAG]17 repeat. MSH3 was silenced by shRNA and changes in protein expression were analyzed by shotgun proteomics. Colony forming assay was used to determine oncogenic transformation and double strand breaks (DSBs) were assessed by Comet assay. RESULTS Despite differential MLH1 expression, both HCT116 and HCT116+chr3 cells displayed comparable high mutation rates (about 4×10(-4)) at [AAAG]17 repeats. Silencing of MSH3 in HCECs leads to a remarkable increased frameshift mutations in [AAAG]17 repeats whereas [CA]13 repeats were less affected. Upon MSH3-silencing, significant changes in the expression of 202 proteins were detected. Pathway analysis revealed overexpression of proteins involved in double strand break repair (MRE11 and RAD50), apoptosis, L1 recycling, and repression of proteins involved in metabolism, tRNA aminoacylation, and gene expression. MSH3-silencing did not induce oncogenic transformation and DSBs increased 2-fold. CONCLUSIONS MSH3-deficiency in human colon epithelial cells results in EMAST, formation of DSBs and significant changes of the proteome but lacks oncogenic transformation. Thus, MSH3-deficiency alone is unlikely to drive human colon carcinogenesis.
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Affiliation(s)
- Christoph Campregher
- Christian Doppler Laboratory for Molecular Cancer Chemoprevention, Division of Gastroenterology and Hepatology, Department of Medicine 3, Medical University of Vienna, Vienna, Austria
| | - Gerald Schmid
- Christian Doppler Laboratory for Molecular Cancer Chemoprevention, Division of Gastroenterology and Hepatology, Department of Medicine 3, Medical University of Vienna, Vienna, Austria
| | - Franziska Ferk
- Institute of Cancer Research, Department of Medicine I, Medical University of Vienna, Vienna, Austria
| | - Siegfried Knasmüller
- Institute of Cancer Research, Department of Medicine I, Medical University of Vienna, Vienna, Austria
| | - Vineeta Khare
- Christian Doppler Laboratory for Molecular Cancer Chemoprevention, Division of Gastroenterology and Hepatology, Department of Medicine 3, Medical University of Vienna, Vienna, Austria
| | - Benedikt Kortüm
- Christian Doppler Laboratory for Molecular Cancer Chemoprevention, Division of Gastroenterology and Hepatology, Department of Medicine 3, Medical University of Vienna, Vienna, Austria
| | - Kyle Dammann
- Christian Doppler Laboratory for Molecular Cancer Chemoprevention, Division of Gastroenterology and Hepatology, Department of Medicine 3, Medical University of Vienna, Vienna, Austria
| | - Michaela Lang
- Christian Doppler Laboratory for Molecular Cancer Chemoprevention, Division of Gastroenterology and Hepatology, Department of Medicine 3, Medical University of Vienna, Vienna, Austria
| | - Theresa Scharl
- ACIB GmbH, c/o Department of Biotechnology, University of Natural Resources and Life Sciences, Vienna, Austria
- Department of Statistics and Probability Theory, University of Technology, Vienna, Austria
| | - Andreas Spittler
- Department of Surgery, Research Laboratories & Core Facility Flow Cytometry, Medical University of Vienna, Vienna, Austria
| | - Andres I. Roig
- Department of Cell Biology, Division of Digestive and Liver Diseases, University of Texas Southwestern Medical Center, Dallas, Texas, United States of America
| | - Jerry W. Shay
- Department of Cell Biology, Division of Digestive and Liver Diseases, University of Texas Southwestern Medical Center, Dallas, Texas, United States of America
| | - Christopher Gerner
- Department of Medicine I, Comprehensive Cancer Center, Medical University of Vienna, Vienna, Austria
| | - Christoph Gasche
- Christian Doppler Laboratory for Molecular Cancer Chemoprevention, Division of Gastroenterology and Hepatology, Department of Medicine 3, Medical University of Vienna, Vienna, Austria
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Vageli DP, Giannopoulos S, Doukas SG, Kalaitzis C, Giannakopoulos S, Giatromanolaki A, Koukoulis GK, Touloupidis S. Mismatch repair hMSH2, hMLH1, hMSH6 and hPMS2 mRNA expression profiles in precancerous and cancerous urothelium. Oncol Lett 2012; 5:283-294. [PMID: 23255936 DOI: 10.3892/ol.2012.979] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2012] [Accepted: 09/26/2012] [Indexed: 01/15/2023] Open
Abstract
Changes in the expression of the mismatch repair (MMR) genes hMSH2, hMLH1, hMSH6 and hPMS2 reflect dysfunction of the DNA repair system that may allow the malignant transformation of tissue cells. The aim of the present study was to address the mRNA expression profiles of the mismatch DNA repair system in cancerous and precancerous urothelium. This is the first study to quantify MMR mRNA expression by applying quantitative real-time PCR (qPCR) and translate the results to mRNA phenotypic profiles (r, reduced; R, regular or elevated) in bladder tumors [24 urothelial cell carcinomas (UCCs) and 1 papillary urothelial neoplasm of low malignant potential (PUNLMP)] paired with their adjacent normal tissues (ANTs). Genetic instability analysis was applied at polymorphic sites distal or close to the hMSH2 and hMLH1 locus. Presenting our data, reduced hMSH2, hMSH6 and hPMS2 mRNA expression profiles were observed in cancerous and precancerous urothelia. Significantly, the ANTs of UCCs revealed the highest percentages of reduced hMSH2 (r(2)), hMSH6 (r(6)) and hPMS2 (p(2)) mRNA phenotypes relative to their tumors (P<0.03). In particular, combined r(2)r(6) (P<0.02) presented a greater difference between ANTs of low-grade UCCs vs. their tumors compared with ANTs of high-grade UCCs (P= 0.000). Reduced hMLH1 (r(1)) phenotype was not expressed in precancerous or cancerous urothelia. The hMSH6 mRNA was the most changed in UCCs (47.8%), while hMSH2, hMLH1 and hPMS2 showed overexpression (47.8, 35 and 30%, respectively) that was associated with gender and histological tumor grading or staging. Genetic instability was rare in polymorphic regions distal to hMLH1. Our data reveal a previously unrecognized hMSH2 and hMSH6 mRNA combined phenotype (r(2)r(6)) correlated with a precancerous urothelium and show that hMLH1 is transcriptionally activated in precancerous or cancerous urothelium. In the present study, it is demonstrated that reduction of hMSH6 mRNA is a frequent event in bladder tumorigenesis and reflects a common mechanism of suppression with hMSH2, while alterations of hMSH2 or hMLH1 mRNA expression in UCCs does not correlate with the allelic imbalance of polymorphic regions harboring the genes.
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Affiliation(s)
- Dimitra P Vageli
- Department of Pathology, Medical School, University of Thessaly, Larissa, Thessaly 41110
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The Changes in MGMT Promoter Methylation Status in Initial and Recurrent Glioblastomas. Transl Oncol 2012; 5:393-7. [PMID: 23066447 DOI: 10.1593/tlo.12253] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2012] [Revised: 08/07/2012] [Accepted: 08/07/2012] [Indexed: 01/26/2023] Open
Abstract
To evaluate the mechanism of the development of therapeutic resistance after temozolomide treatment, we focused on changes in O(6)-methylguanine DNA methyltransferase (MGMT) and mismatch repair (MMR) between initial and recurrent glioblastomas. Tissue samples obtained from 24 paired histologically confirmed initial and recurrent adult glioblastoma patients who were initially treated with temozolomide were used for MGMT and MMR gene promoter methylation status and protein expression analysis using methylation-specific multiplex ligation probe amplification (MS-MLPA), methylation-specific polymerase chain reaction (MSP), and immunohistochemical staining. There was a significant decrease in the methylation ratio of the MGMT promoter determined by MS-MLPA, which was not detectable with MSP, and MGMT protein expression changes were not remarkable. However, there was no epigenetic variability in MMR genes, and a relatively homogeneous expression of MMR proteins was observed in initial and recurrent tumors. We conclude that the development of reduced methylation in the MGMT promoter is one of the mechanisms for acquiring therapeutic resistance after temozolomide treatment in glioblastomas.
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Plaschke J, Preußler M, Ziegler A, Schackert HK. Aberrant protein expression and frequent allelic loss of MSH3 in colorectal cancer with low-level microsatellite instability. Int J Colorectal Dis 2012; 27:911-9. [PMID: 22249440 DOI: 10.1007/s00384-011-1408-0] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 12/22/2011] [Indexed: 02/04/2023]
Abstract
PURPOSE High level of microsatellite instability (MSI-H) in colorectal cancer (CRC) is caused by the inactivation of mismatch repair (MMR) genes; however, it is unknown for tumors with low level MSI (MSI-L). The protein complex involving MSH3 preferentially recognizes insertion/deletion loops (IDLs) of two to eight bases and di- and tetranucleotide repeats are affected in the majority of MSI-L CRC. METHODS We selected 10 and eight MSI-L CRCs from 228 and 204 patients with sporadic and hereditary disease, respectively. The tumors were analyzed for protein expression of MSH3, MSH2, MSH6, MLH1, and PMS2, and for mutations and loss of heterozygosity (LOH) in MSH3. RESULTS Four tumors showed a markedly reduced MSH3 expression, whereas all 18 tumors had normal expression of the remaining MMR proteins. Twenty-five different sequence variants were identified. None of these results in a truncated protein, though L902W represents the first constitutional missense mutation in MSH3 predicted to be functional based on conservation among mutS homologues. All variants have also been found in normal DNA of the patients and in controls. LOH intragenic to MSH3 was evident for 12 of 16 (75%) informative tumors. CONCLUSIONS Occurrence of sequence variants in normal DNA of the patients and in controls excludes somatic mutations and mutations specific to the CRC patient population, respectively. In contrast, the high frequency of LOH as well as the aberrant protein expression in some tumors indicates an involvement of MSH3 impairment in MSI-L CRC.
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Affiliation(s)
- Jens Plaschke
- Department of Surgical Research, Carl Gustav Carus Klinikum, Technical University Dresden, Fetscherstr. 74, 01307 Dresden, Germany.
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Laghi L, Bianchi P, Delconte G, Celesti G, Di Caro G, Pedroni M, Chiaravalli AM, Jung B, Capella C, de Leon MP, Malesci A. MSH3 protein expression and nodal status in MLH1-deficient colorectal cancers. Clin Cancer Res 2012; 18:3142-53. [PMID: 22496206 DOI: 10.1158/1078-0432.ccr-12-0175] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
PURPOSE Patients with colorectal cancers (CRC) and high microsatellite instability (MSI) have a better outcome than their chromosome-unstable counterpart. Given the heterogeneity of microsatellite-unstable CRCs, we wanted to see whether any MSI-associated molecular features are specifically associated with prognosis. EXPERIMENTAL DESIGN One hundred and nine MSI-high CRCs were typed for primary mismatch repair (MMR) defect and for secondary loss of MMR proteins. Frameshifts at seven target genes, mutations in the RAS pathway, and methylation at MLH1/CDKN2A promoters were also searched. The interplay of molecular findings with clinicopathologic features and patient survival was analyzed. RESULTS Of 84 MLH1-deficient CRCs, 31 (36.9%) had MSH3 and 11 (13.1%) had MSH6 loss (P < 0.001), biallelic frameshift mutations at mononucleotide repeats accounting for most (78%) MSH3 losses. As compared with MSH3-retaining cancers, MLH1-deficient tumors with MSH3 loss showed a higher number of mutated target genes (3.94 ± 1.56 vs. 2.79 ± 1.75; P = 0.001), absence of nodal involvement at pathology [N0; OR, 0.11; 95% confidence interval (CI), 0.04-0.43, P < 0.001], and better disease-free survival (P = 0.06). No prognostic value was observed for KRAS status and for MLH1/CDKN2A promoter methylation. The association between MSH3 loss and N0 was confirmed in an independent cohort of 71 MLH1-deficient CRCs (OR, 0.23; 95% CI, 0.06-0.83, P = 0.02). CONCLUSIONS MLH1-deficient CRCs not expressing MSH3 have a more severe MSI, a lower rate of nodal involvement, and a better postsurgical outcome.
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Affiliation(s)
- Luigi Laghi
- Laboratory of Molecular Gastroenterology, Department of Gastroenterology, IRCCS Istituto Clinico Humanitas - Rozzano, Milano, Italy.
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Tajima A, Iwaizumi M, Tseng-Rogenski S, Cabrera BL, Carethers JM. Both hMutSα and hMutSß DNA mismatch repair complexes participate in 5-fluorouracil cytotoxicity. PLoS One 2011; 6:e28117. [PMID: 22164234 PMCID: PMC3229514 DOI: 10.1371/journal.pone.0028117] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2011] [Accepted: 11/01/2011] [Indexed: 01/12/2023] Open
Abstract
BACKGROUND Patients with advanced microsatellite unstable colorectal cancers do not show a survival benefit from 5-fluorouracil (5-FU)-based chemotherapy. We and others have shown that the DNA mismatch repair (MMR) complex hMutSα binds 5-FU incorporated into DNA. Although hMutSß is known to interact with interstrand crosslinks (ICLs) induced by drugs such as cisplatin and psoralen, it has not been demonstrated to interact with 5-FU incorporated into DNA. Our aim was to examine if hMutSß plays a role in 5-FU recognition. METHODS We compared the normalized growth of 5-FU treated cells containing either or both mismatch repair complexes using MTT and clonogenic assays. We utilized oligonucleotides containing 5-FU and purified baculovirus-synthesized hMutSα and hMutSß in electromobility shift assays (EMSA) and further analyzed binding using surface plasmon resonance. RESULTS MTT and clonogenic assays after 5-FU treatment demonstrated the most cytotoxicity in cells with both hMutSα and hMutSß, intermediate cytotoxicity in cells with hMutSα alone, and the least cytotoxicity in cells with hMutSß alone, hMutSß binds 5-FU-modified DNA, but its relative binding is less than the binding of 5-FU-modified DNA by hMutSα. CONCLUSION Cytotoxicity induced by 5-FU is dependent on intact DNA MMR, with relative cell death correlating directly with hMutSα and/or hMutSß 5-FU binding ability (hMutSα>hMutSß). The MMR complexes provide a hierarchical chemosensitivity for 5-FU cell death, and may have implications for treatment of patients with certain MMR-deficient tumors.
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Affiliation(s)
- Akihiro Tajima
- Division of Gastroenterology, Department of Medicine, University of California San Diego, La Jolla, California, United States of America
| | - Moriya Iwaizumi
- Division of Gastroenterology, Department of Internal Medicine, University of Michigan, Ann Arbor, Michigan, United States of America
- Division of Gastroenterology, Department of Medicine, University of California San Diego, La Jolla, California, United States of America
| | - Stephanie Tseng-Rogenski
- Division of Gastroenterology, Department of Internal Medicine, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Betty L. Cabrera
- Division of Gastroenterology, Department of Medicine, University of California San Diego, La Jolla, California, United States of America
| | - John M. Carethers
- Division of Gastroenterology, Department of Internal Medicine, University of Michigan, Ann Arbor, Michigan, United States of America
- Division of Gastroenterology, Department of Medicine, University of California San Diego, La Jolla, California, United States of America
- Moores Comprehensive Cancer Center, University of California San Diego, La Jolla, California, United States of America
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Abstract
Despite substantial attention from theoreticians, the evolutionary mechanisms that drive intra- and interspecific variation in the mutation rate remain unclear. It has often been argued that mutation rates associated with the major replicative polymerases have been driven down to their physiological limits, defined as the point at which further enhancement in replication fidelity incurs a cost in terms of reproductive output, but no evidence in support of this argument has emerged for cellular organisms. Here, it is suggested that the lower barrier to mutation rate evolution may ultimately be defined not by molecular limitations but by the power of random genetic drift. As the mutation rate is reduced to a very low level, a point will eventually be reached at which the small advantage of any further reduction is overwhelmed by the power of drift. This hypothesis is consistent with a number of observations, including the inverse relationship between the per-site mutation rate and genome size in microbes, the negative scaling between the per-site mutation rate and effective population size in eukaryotes, and the elevated error rates associated with less frequently deployed polymerases and repair pathways.
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Gassman NR, Clodfelter JE, McCauley AK, Bonin K, Salsbury FR, Scarpinato KD. Cooperative nuclear localization sequences lend a novel role to the N-terminal region of MSH6. PLoS One 2011; 6:e17907. [PMID: 21437237 PMCID: PMC3060103 DOI: 10.1371/journal.pone.0017907] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2011] [Accepted: 02/14/2011] [Indexed: 01/08/2023] Open
Abstract
Human mismatch repair proteins MSH2-MSH6 play an essential role in maintaining genetic stability and preventing disease. While protein functions have been extensively studied, the substantial amino-terminal region (NTR*) of MSH6 that is unique to eukaryotic proteins, has mostly evaded functional characterization. We demonstrate that a cluster of three nuclear localization signals (NLS) in the NTR direct nuclear import. Individual NLSs are capable of partially directing cytoplasmic protein into the nucleus; however only cooperative effects between all three NLSs efficiently transport MSH6 into the nucleus. In striking contrast to yeast and previous assumptions on required heterodimerization, human MSH6 does not determine localization of its heterodimeric partner, MSH2. A cancer-derived mutation localized between two of the three NLS significantly decreases nuclear localization of MSH6, suggesting altered protein localization can contribute to carcinogenesis. These results clarify the pending speculations on the functional role of the NTR in human MSH6 and identify a novel, cooperative nuclear localization signal.
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Affiliation(s)
- Natalie R. Gassman
- Department of Cancer Biology, Wake Forest University School of Medicine, Winston Salem, North Carolina, United States of America
| | - Jill E. Clodfelter
- Department of Cancer Biology, Wake Forest University School of Medicine, Winston Salem, North Carolina, United States of America
| | - Anita K. McCauley
- Department of Biology, Wake Forest University, Winston Salem, North Carolina, United States of America
| | - Keith Bonin
- Department of Physics, Wake Forest University, Winston Salem, North Carolina, United States of America
| | - Freddie R. Salsbury
- Department of Physics, Wake Forest University, Winston Salem, North Carolina, United States of America
- Comprehensive Cancer Center, Wake Forest University School of Medicine, Winston Salem, North Carolina, United States of America
| | - Karin D. Scarpinato
- Department of Cancer Biology, Wake Forest University School of Medicine, Winston Salem, North Carolina, United States of America
- Comprehensive Cancer Center, Wake Forest University School of Medicine, Winston Salem, North Carolina, United States of America
- * E-mail:
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Peled JU, Sellers RS, Iglesias-Ussel MD, Shin DM, Montagna C, Zhao C, Li Z, Edelmann W, Morse HC, Scharff MD. Msh6 protects mature B cells from lymphoma by preserving genomic stability. THE AMERICAN JOURNAL OF PATHOLOGY 2010; 177:2597-608. [PMID: 20934970 DOI: 10.2353/ajpath.2010.100234] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Most human B-cell non-Hodgkin's lymphomas arise from germinal centers. Within these sites, the mismatch repair factor MSH6 participates in antibody diversification. Reminiscent of the neoplasms arising in patients with Lynch syndrome III, mice deficient in MSH6 die prematurely of lymphoma. In this study, we characterized the B-cell tumors in MSH6-deficient mice and describe their histological, immunohistochemical, and molecular features, which include moderate microsatellite instability. Based on histological markers and gene expression, the tumor cells seem to be at or beyond the germinal center stage. The simultaneous loss of MSH6 and of activation-induced cytidine deaminase did not appreciably affect the survival of these animals, suggesting that these germinal center-like tumors arose by an activation-induced cytidine deaminase-independent pathway. We conclude that MSH6 protects B cells from neoplastic transformation by preserving genomic stability.
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Affiliation(s)
- Jonathan U Peled
- Cell Biology Department, Chanin 403, Albert Einstein College of Medicine, 1300 Morris Park Ave., Bronx, NY 10461, USA
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Preston BD, Albertson TM, Herr AJ. DNA replication fidelity and cancer. Semin Cancer Biol 2010; 20:281-93. [PMID: 20951805 PMCID: PMC2993855 DOI: 10.1016/j.semcancer.2010.10.009] [Citation(s) in RCA: 105] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2010] [Accepted: 10/07/2010] [Indexed: 12/14/2022]
Abstract
Cancer is fueled by mutations and driven by adaptive selection. Normal cells avoid deleterious mutations by replicating their genomes with extraordinary accuracy. Here we review the pathways governing DNA replication fidelity and discuss evidence implicating replication errors (point mutation instability or PIN) in carcinogenesis.
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Affiliation(s)
- Bradley D Preston
- Department of Pathology, University of Washington, Seattle, WA 98195, USA.
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Martin SA, McCarthy A, Barber LJ, Burgess DJ, Parry S, Lord CJ, Ashworth A. Methotrexate induces oxidative DNA damage and is selectively lethal to tumour cells with defects in the DNA mismatch repair gene MSH2. EMBO Mol Med 2010; 1:323-37. [PMID: 20049736 PMCID: PMC3378145 DOI: 10.1002/emmm.200900040] [Citation(s) in RCA: 127] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Mutations in the MSH2 gene predispose to a number of tumourigenic conditions, including hereditary non-polyposis colon cancer (HNPCC). MSH2 encodes a protein in the mismatch repair (MMR) pathway which is involved in the removal of mispairs originating during replication or from damaged DNA. To identify new therapeutic strategies for the treatment of cancer arising from MMR deficiency, we screened a small molecule library encompassing previously utilized drugs and drug-like molecules to identify agents selectively lethal to cells lacking functional MSH2. This approach identified the drug methotrexate as being highly selective for cells with MSH2 deficiency. Methotrexate treatment caused the accumulation of potentially lethal 8-hydroxy-2'-deoxyguanosine (8-OHdG) oxidative DNA lesions in both MSH2 deficient and proficient cells. In MSH2 proficient cells, these lesions were rapidly cleared, while in MSH2 deficient cells 8-OHdG lesions persisted, potentially explaining the selectivity of methotrexate. Short interfering (si)RNA mediated silencing of the target of methotrexate, dihydrofolate reductase (DHFR), was also selective for MSH2 deficiency and also caused an accumulation of 8-OHdG. This suggested that the ability of methotrexate to modulate folate synthesis via inhibition of DHFR, may explain MSH2 selectivity. Consistent with this hypothesis, addition of folic acid to culture media substantially rescued the lethal phenotype caused by methotrexate. While methotrexate has been used for many years as a cancer therapy, our observations suggest that this drug may have particular utility for the treatment of a subset of patients with tumours characterized by MSH2 mutations.
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Affiliation(s)
- Sarah A Martin
- Cancer Research UK Gene Function and Regulation Group, The Breakthrough Breast Cancer Research Centre, The Institute of Cancer Research, London, UK
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Kantelinen J, Kansikas M, Korhonen MK, Ollila S, Heinimann K, Kariola R, Nyström M. MutSbeta exceeds MutSalpha in dinucleotide loop repair. Br J Cancer 2010; 102:1068-73. [PMID: 20160730 PMCID: PMC2844022 DOI: 10.1038/sj.bjc.6605531] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
BACKGROUND The target substrates of DNA mismatch recognising factors MutSalpha (MSH2+MSH6) and MutSbeta (MSH2+MSH3) have already been widely researched. However, the extent of their functional redundancy and clinical substance remains unclear. Mismatch repair (MMR)-deficient tumours are strongly associated with microsatellite instability (MSI) and the degree and type of MSI seem to be dependent on the MMR gene affected, and is linked to its substrate specificities. Deficiency in MSH2 and MSH6 is associated with both mononucleotide and dinucleotide repeat instability. Although no pathogenic MSH3 mutations have been reported, its deficiency is also suggested to cause low dinucleotide repeat instability. METHODS To assess the substrate specificities and functionality of MutSalpha and MutSbeta we performed an in vitro MMR assay using three substrate constructs, GT mismatch, 1 and 2 nucleotide insertion/deletion loops (IDLs) in three different cell lines. RESULTS Our results show that though MutSalpha alone seems to be responsible for GT and IDL1 repair, MutSalpha and MutSbeta indeed have functional redundancy in IDL2 repair and in contrast with earlier studies, MutSbeta seems to exceed MutSalpha. CONCLUSION The finding is clinically relevant because the strong role of MutSbeta in IDL2 repair indicates MSH3 deficiency in tumours with low dinucleotide and no mononucleotide repeat instability.
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Affiliation(s)
- J Kantelinen
- Department of Biological and Environmental Sciences, University of Helsinki, Viikinkaari 5, Helsinki, Finland
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39
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Abstract
Although mutation provides the fuel for phenotypic evolution, it also imposes a substantial burden on fitness through the production of predominantly deleterious alleles, a matter of concern from a human-health perspective. Here, recently established databases on de novo mutations for monogenic disorders are used to estimate the rate and molecular spectrum of spontaneously arising mutations and to derive a number of inferences with respect to eukaryotic genome evolution. Although the human per-generation mutation rate is exceptionally high, on a per-cell division basis, the human germline mutation rate is lower than that recorded for any other species. Comparison with data from other species demonstrates a universal mutational bias toward A/T composition, and leads to the hypothesis that genome-wide nucleotide composition generally evolves to the point at which the power of selection in favor of G/C is approximately balanced by the power of random genetic drift, such that variation in equilibrium genome-wide nucleotide composition is largely defined by variation in mutation biases. Quantification of the hazards associated with introns reveals that mutations at key splice-site residues are a major source of human mortality. Finally, a consideration of the long-term consequences of current human behavior for deleterious-mutation accumulation leads to the conclusion that a substantial reduction in human fitness can be expected over the next few centuries in industrialized societies unless novel means of genetic intervention are developed.
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Affiliation(s)
- Michael Lynch
- Department of Biology, Indiana University, Bloomington, IN 47405, USA.
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40
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Topping RP, Wilkinson JC, Scarpinato KD. Mismatch repair protein deficiency compromises cisplatin-induced apoptotic signaling. J Biol Chem 2009; 284:14029-39. [PMID: 19286655 DOI: 10.1074/jbc.m809303200] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Mismatch repair (MMR) proteins participate in cytotoxicity induced by certain DNA damage-inducing agents, including cisplatin (cis-diamminedichloroplatinum(II), CDDP), a cancer chemotherapeutic drug utilized clinically to treat a variety of malignancies. MMR proteins have been demonstrated to bind to CDDP-DNA adducts and initiate MMR protein-dependent cell death in cells treated with CDDP; however, the molecular events underlying this death remain unclear. As MMR proteins have been suggested to be important in clinical responses to CDDP, a clear understanding of MMR protein-dependent, CDDP-induced cell death is critical. In this report, we demonstrate MMR protein-dependent relocalization of cytochrome c to the cytoplasm and cleavage of caspase-9, caspase-3, and poly(ADP-ribose) polymerase upon treatment of cells with CDDP. Chemical inhibition of caspases specifically attenuates CDDP/MMR protein-dependent cytotoxicity, suggesting that a caspase-dependent signaling mechanism is required for the execution of this cell death. p53 protein levels were up-regulated independently of MMR protein status, suggesting that p53 is not a mediator of MMR-dependent, CDDP-induced death. This work is the first indication of a required signaling mechanism in CDDP-induced, MMR protein-dependent cytotoxicity, which can be uncoupled from other CDDP response pathways, and defines a critical contribution of MMR proteins to the control of cell death.
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Affiliation(s)
- Ryan P Topping
- Departments of Cancer Biology and Biochemistry and Comprehensive Cancer Center, Wake Forest University School of Medicine, Winston-Salem, North Carolina 27157, USA
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41
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Abstract
Genetically engineered mice are essential tools in both mechanistic studies and drug development in colon cancer research. Mice with mutations in the Apc gene, as well as in genes that modify or interact with Apc, are important models of familial adenomatous polyposis. Mice with mutations in the beta-catenin signaling pathway have also revealed important information about colon cancer pathogenesis, along with models for hereditary nonpolyposis colon cancer and inflammatory bowel diseases associated with colon cancer. Finally, transplantation models (xenografts)have been useful in the study of metastasis and for testing potential therapeutics. This review discusses what models have been developed most recently and what they have taught us about colon cancer formation, progression, and possible treatment strategies.
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Affiliation(s)
- Makoto Mark Taketo
- Department of Cell Biology, Albert Einstein College of Medicine, Bronx, New York, USA
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42
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Haugen AC, Goel A, Yamada K, Marra G, Nguyen TP, Nagasaka T, Kanazawa S, Koike J, Kikuchi Y, Zhong X, Arita M, Shibuya K, Oshimura M, Hemmi H, Boland CR, Koi M. Genetic instability caused by loss of MutS homologue 3 in human colorectal cancer. Cancer Res 2008; 68:8465-72. [PMID: 18922920 DOI: 10.1158/0008-5472.can-08-0002] [Citation(s) in RCA: 121] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Microsatellite instability (MSI) is a hallmark of mismatch repair (MMR) deficiency. High levels of MSI at mononucleotide and dinucleotide repeats in colorectal cancer (CRC) are attributed to inactivation of the MMR genes, hMLH1 and hMSH2. CRC with low levels of MSI (MSI-L) exists; however, its molecular basis is unclear. There is another type of MSI--elevated microsatellite alterations at selected tetranucleotide repeats (EMAST)--where loci containing [AAAG](n) or [ATAG](n) repeats are unstable. EMAST is frequent in non-CRCs; however, the incidence of EMAST and its cause in CRC is not known. Here, we report that MutS homologue 3 (MSH3) knockdown or MSH3-deficient cells exhibit the EMAST phenotype and low levels of mutations at dinucleotide repeats. About 60% of 117 sporadic CRC cases exhibit EMAST. All of the cases defined as MSI-H (16 cases) exhibited high levels of EMAST. Among 101 non-MSI-H cases, all 19 cases of MSI-L and 35 of 82 cases of MSS exhibited EMAST. Although non-MSI-H CRC tissues contained MSH3-negative tumor cells ranging from 2% to 50% of the total tumor cell population, the tissues exhibiting EMAST contained more MSH3-negative cells (average, 31.5%) than did the tissues not exhibiting EMAST (8.4%). Taken together, our results support the concept that MSH3 deficiency causes EMAST or EMAST with low levels of MSI at loci with dinucleotide repeats in CRC.
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Affiliation(s)
- Astrid C Haugen
- Laboratory of Molecular Genetics, National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina, USA
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Maxwell JA, Johnson SP, McLendon RE, Lister DW, Horne KS, Rasheed A, Quinn JA, Ali-Osman F, Friedman AH, Modrich PL, Bigner DD, Friedman HS. Mismatch repair deficiency does not mediate clinical resistance to temozolomide in malignant glioma. Clin Cancer Res 2008; 14:4859-68. [PMID: 18676759 DOI: 10.1158/1078-0432.ccr-07-4807] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
PURPOSE A major mechanism of resistance to methylating agents, including temozolomide, is the DNA repair protein O(6)-alkylguanine-DNA alkyltransferase (AGT). Preclinical data indicates that defective DNA mismatch repair (MMR) results in tolerance to temozolomide regardless of AGT activity. The purpose of this study was to determine the role of MMR deficiency in mediating resistance in samples from patients with both newly diagnosed malignant gliomas and those who have failed temozolomide therapy. EXPERIMENTAL DESIGN The roles of AGT and MMR deficiency in mediating resistance in glioblastoma multiforme were assessed by immunohistochemistry and microsatellite instability (MSI), respectively. The mutation status of the MSH6 gene, a proposed correlate of temozolomide resistance, was determined by direct sequencing and compared with data from immunofluorescent detection of MSH6 protein and reverse transcription-PCR amplification of MSH6 RNA. RESULTS Seventy percent of newly diagnosed and 78% of failed-therapy glioblastoma multiforme samples expressed nuclear AGT protein in > or = 20% of cells analyzed, suggesting alternate means of resistance in 20% to 30% of cases. Single loci MSI was observed in 3% of patient samples; no sample showed the presence of high MSI. MSI was not shown to correlate with MSH6 mutation or loss of MSH6 protein expression. CONCLUSIONS Although high AGT levels may mediate resistance in a portion of these samples, MMR deficiency does not seem to be responsible for mediating temozolomide resistance in adult malignant glioma. Accordingly, the presence of a fraction of samples exhibiting both low AGT expression and MMR proficiency suggests that additional mechanisms of temozolomide resistance are operational in the clinic.
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Affiliation(s)
- Jill A Maxwell
- Department of Surgery, Duke University Medical Center, Durham, North Carolina 27710, USA
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Shia J. Immunohistochemistry versus microsatellite instability testing for screening colorectal cancer patients at risk for hereditary nonpolyposis colorectal cancer syndrome. Part I. The utility of immunohistochemistry. J Mol Diagn 2008; 10:293-300. [PMID: 18556767 PMCID: PMC2438196 DOI: 10.2353/jmoldx.2008.080031] [Citation(s) in RCA: 463] [Impact Index Per Article: 28.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/28/2008] [Indexed: 01/26/2023] Open
Abstract
The utility of immunohistochemical detection of DNA mismatch repair (MMR) protein in screening colorectal tumors for hereditary nonpolyposis colorectal cancer (HNPCC) syndrome has been the focus of much intensive research over the last 10 years. Particular attention has been given to the relative usefulness of immunohistochemistry (IHC) versus testing of tumor microsatellite instability (MSI). Earlier work that focused on mutL homolog 1 (MLH1) and mutS homolog 2 (MSH2) has created a false impression that IHC has a lower sensitivity than MSI testing in predicting germline mutation. More recent studies that included postmeiotic segregation increased 2 (PMS2) and MSH6, on the other hand, have demonstrated an IHC predictive value that is virtually equivalent to that of MSI testing. Such added value of PMS2 and MSH6 can be explained by the biological and biochemical properties of the MMR proteins. On the premise that IHC with PMS2 and MSH6 is as sensitive as MSI testing, given that IHC is easily available and generally inexpensive and, importantly, identifies the affected gene, it is reasonable to regard IHC as a more optimal first-line screening tool than MSI testing for identifying HNPCC. MSI testing can provide a fallback position in equivocal situations, while remaining an important research tool. However, for IHC to be used as a first-line screening test requires that both pathologists and clinicians be aware that IHC results may be construed as "genetic information," and that appropriate procedures should be established to ensure patient understanding and consent.
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Affiliation(s)
- Jinru Shia
- Department of Pathology, Memorial Sloan-Kettering Cancer Center, New York, NY 10065, USA.
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Hirata H, Hinoda Y, Kawamoto K, Kikuno N, Suehiro Y, Okayama N, Tanaka Y, Dahiya R. Mismatch repair gene MSH3 polymorphism is associated with the risk of sporadic prostate cancer. J Urol 2008; 179:2020-4. [PMID: 18355840 DOI: 10.1016/j.juro.2008.01.009] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2007] [Indexed: 11/19/2022]
Abstract
PURPOSE The mismatch repair system is a DNA repair mechanism that corrects mispaired bases during DNA replication errors. Cancer cells deficient in MMR proteins have a 10(2) to 10(3)-fold increase in the mutation rate. Single nucleotide polymorphisms of mismatch repair genes have been shown to cause a decrease in DNA repair activity. We hypothesized that mismatch repair gene polymorphism could be a risk factor for prostate cancer and p53 Pro/Pro genotype carriers could influence MSH3 and MSH6 polymorphisms. MATERIALS AND METHODS DNA samples from 110 patients with prostate cancer and 110 healthy controls were analyzed by single strand conformational polymorphism and polymerase chain reaction-restriction fragment length polymorphism to determine the genotypic frequency of 5 polymorphic loci on 2 MMR genes (MSH3 and MSH6) and p53 codon72. The chi-square test was applied to compare genotype frequency between patients and controls. RESULTS A significant increase in the G/A+A/A genotype of MSH3 Pro222Pro was observed in patients compared to controls (OR 1.87, 95% CI 1.0-3.5). The frequency of A/G + G/G genotypes of MSH3 exon23 Thr1036Ala also tended to increase in patients (OR 1.57, 95% CI 0.92-2.72). In p53 codon72 Arg/Pro + Pro/Pro carriers the frequency of the AG + GG genotype of MSH3 exon23 was significantly increased in patients compared to controls (OR 2.1, 95% CI 1.05-4.34). CONCLUSIONS To our knowledge this is the first report of the association of MSH3 gene polymorphisms in prostate cancer. These results suggest that the MSH3 polymorphism may be a risk factor for prostate cancer.
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Affiliation(s)
- Hiroshi Hirata
- Department of Urology, Veterans Affairs Medical Center and University of California at San Francisco, San Francisco, California 94121, USA
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46
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Seifert M, Reichrath J. The role of the human DNA mismatch repair gene hMSH2 in DNA repair, cell cycle control and apoptosis: implications for pathogenesis, progression and therapy of cancer. J Mol Histol 2006; 37:301-7. [PMID: 17080293 DOI: 10.1007/s10735-006-9062-5] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2006] [Accepted: 09/26/2006] [Indexed: 01/12/2023]
Abstract
The cellular DNA mismatch repair (MMR) pathway, involving the DNA mismatch repair genes MLH1 and MSH2, detects and repairs DNA replication errors. Defects in MSH2 and MLH1 account for most cases of hereditary non-polyposis colorectal cancer as well as for sporadic colorectal tumors. Additionally, increased expression of MSH2 RNA and/or protein has been reported in various malignancies. Loss of DNA MMR in mammalian cells has been linked to resistance to certain DNA damaging agents including clinically important cytotoxic chemotherapeutics. Due to other functions besides its role in DNA repair, that include regulation of cell proliferation and apoptosis, MSH2 has recently been shown to be of importance for pathogenesis and progression of cancer. This review summarizes our present understanding of the function of MSH2 for DNA repair, cell cycle control, and apoptosis and discusses its importance for pathogenesis, progression and therapy of cancer.
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Affiliation(s)
- Markus Seifert
- Department of Dermatology, The Saarland University Hospital, Building 18, Kirrberger Strasse, 66421 Homburg, Germany.
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47
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Dekker M, Brouwers C, Aarts M, van der Torre J, de Vries S, van de Vrugt H, te Riele H. Effective oligonucleotide-mediated gene disruption in ES cells lacking the mismatch repair protein MSH3. Gene Ther 2006; 13:686-94. [PMID: 16437133 DOI: 10.1038/sj.gt.3302689] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
We have previously demonstrated that site-specific insertion, deletion or substitution of one or two nucleotides in mouse embryonic stem cells (ES cells) by single-stranded deoxyribo-oligonucleotides is several hundred-fold suppressed by DNA mismatch repair (MMR) activity. Here, we have investigated whether compound mismatches and larger insertions escape detection by the MMR machinery and can be effectively introduced in MMR-proficient cells. We identified several compound mismatches that escaped detection by the MMR machinery to some extent, but could not define general rules predicting the efficacy of complex base-pair substitutions. In contrast, we found that four-nucleotide insertions were largely subject to suppression by the MSH2/MSH3 branch of MMR and could be effectively introduced in Msh3-deficient cells. As these cells have no overt mutator phenotype and Msh3-deficient mice do not develop cancer, Msh3-deficient ES cells can be used for oligonucleotide-mediated gene disruption. As an example, we present disruption of the Fanconi anemia gene Fancf.
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Affiliation(s)
- M Dekker
- Division of Molecular Biology, The Netherlands Cancer Institute, 1066 CX Amsterdam, The Netherlands
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Plotz G, Zeuzem S, Raedle J. DNA mismatch repair and Lynch syndrome. J Mol Histol 2006; 37:271-83. [PMID: 16821093 DOI: 10.1007/s10735-006-9038-5] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2006] [Accepted: 06/06/2006] [Indexed: 01/31/2023]
Abstract
The evolutionary conserved mismatch repair proteins correct a wide range of DNA replication errors. Their importance as guardians of genetic integrity is reflected by the tremendous decrease of replication fidelity (two to three orders of magnitude) conferred by their loss. Germline mutations in mismatch repair genes, predominantly MSH2 and MLH1, have been found to underlie the Lynch syndrome (also called hereditary non-polyposis colorectal cancer, HNPCC), a hereditary predisposition for cancer. Lynch syndrome affects predominantly the colon and accounts for 2-5% of all colon cancer cases. During more than 30 years of biochemical, crystallographic and clinical research, deep insight has been achieved in the function of mismatch repair and the diseases that are associated with its loss. We review the biochemistry of mismatch repair and also introduce the clinical, diagnostic and genetic aspects of Lynch syndrome.
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Affiliation(s)
- Guido Plotz
- Klinik für Innere Medizin II, Universitätsklinikum des Saarlandes, Kirrberger Strasse, Gebäude 41, D-66421 Homburg, Germany.
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Song H, Ramus SJ, Quaye L, DiCioccio RA, Tyrer J, Lomas E, Shadforth D, Hogdall E, Hogdall C, McGuire V, Whittemore AS, Easton DF, Ponder BAJ, Kjaer SK, Pharoah PDP, Gayther SA. Common variants in mismatch repair genes and risk of invasive ovarian cancer. Carcinogenesis 2006; 27:2235-42. [PMID: 16774946 DOI: 10.1093/carcin/bgl089] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Mismatch repair (MMR) is important for repairing of nucleotide mismatches during DNA replication. Germline mutations in MMR genes are associated with hereditary non-polyposis colorectal cancer (HNPCC). Ovarian cancer occurs as part of the HNPCC phenotype, and so common variants in MMR genes are candidates for ovarian cancer susceptibility. We performed a large multicentre case-control study to investigate associations of common variations in MMR genes and ovarian cancer using a single nucleotide polymorphism (SNP) tagging approach. A total of 2570 controls and 1531 cases from three separate studies were genotyped for 44 tagging SNPs (stSNP) in seven MMR genes (MLH1, MLH3, MSH2, MSH3, MSH6, PMS1 and PMS2). Genotype frequencies were marginally different between cases and controls for PMS2 rs7797466 (P(2df) = 0.046) with a 1.17-fold (95% CI 1.03-1.33) increase in risk for each 'a' allele carried (P-trend = 0.013). Haplotype analysis of PMS2 also showed significant differences in frequencies between cases and controls (P(7df) = 0.005), with one haplotype accounting for most of the effect. There was also marginal evidence for a recessive protective effect with common homozygote as the baseline comparator for two SNPs--MSH6 rs3136245 (OR 0.67; 95% CI 0.46-0.98) and MSH3 rs6151662 (OR 0.28; 95% CI 0.08-0.91)--but the comparisons of genotype frequencies for these variants were not significant (P = 0.10 and 0.054). In conclusion, it is unlikely that common variants in MLH1, MLH3, PMS1, MSH2, MSH3 and MSH6 contribute significantly to ovarian cancer susceptibility. The observed association of PMS2 rs7797466 with ovarian cancer warrants confirmation in an independent study.
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Affiliation(s)
- Honglin Song
- CR-UK Department of Oncology, University of Cambridge Strangeways Research Laboratory, Cambridge, UK.
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50
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Abstract
The molecular mechanisms of the DNA mismatch repair (MMR) system have been uncovered over the last decade, especially in prokaryotes. The results obtained for prokaryotic MMR proteins have provided a framework for the study of the MMR system in eukaryotic organisms, such as yeast, mouse and human, because the functions of MMR proteins have been conserved during evolution from bacteria to humans. However, mutations in eukaryotic MMR genes result in pleiotropic phenotypes in addition to MMR defects, suggesting that eukaryotic MMR proteins have evolved to gain more diverse and specific roles in multicellular organisms. Here, we summarize recent advances in the understanding of both prokaryotic and eukaryotic MMR systems and describe various new functions of MMR proteins that have been intensively researched during the last few years, including DNA damage surveillance and diversification of antibodies.
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Affiliation(s)
- Sung-Hoon Jun
- Department of Chemistry and Division of Molecular & Life Science, Pohang University of Science and Technology, Korea
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