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Fummey E, Navarro P, Plazzer JP, Frayling IM, Knott S, Tenesa A. Estimating cancer risk in carriers of Lynch syndrome variants in UK Biobank. J Med Genet 2024:jmg-2023-109791. [PMID: 39004446 DOI: 10.1136/jmg-2023-109791] [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: 11/28/2023] [Accepted: 06/17/2024] [Indexed: 07/16/2024]
Abstract
BackgroundLynch syndrome (LS) is an inherited cancer predisposition syndrome caused by genetic variants affecting DNA mismatch repair (MMR) genes MLH1, MSH2, MSH6 and PMS2 Cancer risk in LS is estimated from cohorts of individuals ascertained by individual or family history of cancer, which may upwardly bias estimates. METHODS 830 carriers of pathogenic or likely pathogenic (path_MMR) MMR gene variants classified by InSiGHT were identified in 454 756 UK Biobank (UKB) participants using whole-exome sequence. Nelson-Aalen survival analysis was used to estimate cumulative incidence of colorectal, endometrial and breast cancer (BC). RESULTS Cumulative incidence of colorectal and endometrial cancer (EC) by age 70 years was elevated in path_MMR carriers compared with non-carriers (colorectal: 11.8% (95% confidence interval (CI): 9.5% to 14.6%) vs 1.7% (95% CI: 1.6% to 1.7%), endometrial: 13.4% (95% CI: 10.2% to 17.6%) vs 1.0% (95% CI: 0.9% to 1.0%)), but the magnitude of this increase differed between genes. Cumulative BC incidence by age 70 years was not elevated in path_MMR carriers compared with non-carriers (8.9% (95% CI: 6.3% to 12.4%) vs 7.5% (95% CI: 7.4% to 7.6%)). Cumulative cancer incidence estimates in UKB were similar to estimates from the Prospective Lynch Syndrome Database for all genes and cancers, except there was no evidence for elevated EC risk in carriers of pathogenic PMS2 variants in UKB. CONCLUSION These results support offering incidentally identified carriers of any path_MMR surveillance to manage colorectal cancer risk. Incidentally identified carriers of pathogenic variants in MLH1, MSH2 and MSH6 would also benefit from interventions to reduce EC risk. The results suggest that BC is not an LS-related cancer.
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Affiliation(s)
- Eilidh Fummey
- MRC Human Genetics Unit, Institute of Genetics and Cancer, University of Edinburgh, Edinburgh, UK
| | - Pau Navarro
- MRC Human Genetics Unit, Institute of Genetics and Cancer, University of Edinburgh, Edinburgh, UK
- The Roslin Institute, University of Edinburgh, Roslin, Midlothian, UK
| | - John-Paul Plazzer
- Colorectal Medicine and Genetics, The Royal Melbourne Hospital, Parkville, Victoria, Australia
| | - Ian M Frayling
- The Centre for Familial Intestinal Cancer, St Mark's the National Bowel Hospital and Academic Institute, London, UK
- Institute of Cancer & Genetics, Cardiff University, Cardiff, UK
| | - Sara Knott
- Institute of Ecology and Evolution, University of Edinburgh, Edinburgh, UK
| | - Albert Tenesa
- MRC Human Genetics Unit, Institute of Genetics and Cancer, University of Edinburgh, Edinburgh, UK
- The Roslin Institute, University of Edinburgh, Roslin, Midlothian, UK
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2
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Tan X, Fang Y, Fan X, Deng W, Huang J, Cai Y, Zou J, Chen Z, Lin H, Xu L, Wang G, Zhan H, Huang S, Fu X. Testing region selection and prognostic analysis of MLH1 promoter methylation in colorectal cancer in China. Gastroenterol Rep (Oxf) 2024; 12:goae011. [PMID: 38566849 PMCID: PMC10985700 DOI: 10.1093/gastro/goae011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/08/2023] [Revised: 11/09/2023] [Accepted: 01/31/2024] [Indexed: 04/04/2024] Open
Abstract
Background MLH1 promoter methylation analysis is recommended in screening for Lynch syndrome (LS) in patients with MLH1-deficient colorectal cancer (CRC). The study aims to identify specific methylation regions in the MLH1 promoter and to evaluate the clinicopathologic characteristics of and prognosis for patients with MLH1 methylation. Methods A total of 580 CRC cases were included. The DNA mismatch repair (MMR) protein expression was assessed by using immunohistochemistry (IHC). The methylation status of the Regions A, B, C, D, and E in the MLH1 promoter was tested by using bisulfite sequencing PCR. The specificities of the five regions were calculated. Associations between MLH1 methylation and clinicopathologic characteristics were evaluated. Kaplan-Meier analyses for overall survival (OS) were carried out. Results In 580 CRC cases, the specificities of the methylation test in Regions D and E were both 97.8%. In the MLH1-deficient CRCs, the frequencies of MLH1 methylation and BRAFV600E mutation were 52.6% and 14.6%, respectively; BRAFV600E mutation occurred in 27.7% of patients with MLH1-methylated CRC. In the MMR-deficient patients, compared with MLH1 unmethylation, MLH1 methylation was more common in patients who were aged ≥50 years, female, had no family history of LS-related tumors, and had tumors located at the right colon. In the MMR-deficient patients, the MLH1-methylated cases had lower OS rates than the unmethylated cases with a family history of LS-related tumors (P = 0.047). Conclusions Regions D and E in the MLH1 promoter are recommended for determining the MLH1 methylation status in screening for LS in MLH1-deficient CRC. In MMR-deficient patients, the MLH1-methylated cases had a worse OS than the unmethylated cases with a family history of LS-related cancer.
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Affiliation(s)
- Xiaoli Tan
- Department of Pathology, The Sixth Affiliated Hospital, Sun Yat-sen University, Guangzhou, Guangdong, P. R. China
| | - Yongzhen Fang
- Guangdong Provincial Key Laboratory of Colorectal and Pelvic Floor Diseases, The Sixth Affiliated Hospital, Sun Yat-sen University, Guangzhou, Guangdong, P. R. China
| | - Xinjuan Fan
- Department of Pathology, The Sixth Affiliated Hospital, Sun Yat-sen University, Guangzhou, Guangdong, P. R. China
| | - Weihao Deng
- Department of Pathology, The Sixth Affiliated Hospital, Sun Yat-sen University, Guangzhou, Guangdong, P. R. China
| | - Jinglin Huang
- Department of Pathology, The Sixth Affiliated Hospital, Sun Yat-sen University, Guangzhou, Guangdong, P. R. China
| | - Yacheng Cai
- Department of Pathology, The Sixth Affiliated Hospital, Sun Yat-sen University, Guangzhou, Guangdong, P. R. China
| | - Jiaxin Zou
- Guangdong Provincial Key Laboratory of Colorectal and Pelvic Floor Diseases, The Sixth Affiliated Hospital, Sun Yat-sen University, Guangzhou, Guangdong, P. R. China
- Department of General Surgery, The Sixth Affiliated Hospital, Sun Yat-sen University, Guangzhou, Guangdong, P. R. China
| | - Zhiting Chen
- Department of Pathology, The Sixth Affiliated Hospital, Sun Yat-sen University, Guangzhou, Guangdong, P. R. China
| | - Hanjie Lin
- Department of Pathology, The Sixth Affiliated Hospital, Sun Yat-sen University, Guangzhou, Guangdong, P. R. China
| | - Liang Xu
- Department of Pathology, The Sixth Affiliated Hospital, Sun Yat-sen University, Guangzhou, Guangdong, P. R. China
| | - Guannan Wang
- Guangdong Provincial Key Laboratory of Colorectal and Pelvic Floor Diseases, The Sixth Affiliated Hospital, Sun Yat-sen University, Guangzhou, Guangdong, P. R. China
| | - Huanmiao Zhan
- Department of Pathology, The Sixth Affiliated Hospital, Sun Yat-sen University, Guangzhou, Guangdong, P. R. China
| | - Shuhui Huang
- Department of Pathology, The Sixth Affiliated Hospital, Sun Yat-sen University, Guangzhou, Guangdong, P. R. China
| | - Xinhui Fu
- Department of Pathology, The Sixth Affiliated Hospital, Sun Yat-sen University, Guangzhou, Guangdong, P. R. China
- Biomedical Innovation Center, The Sixth Affiliated Hospital, Sun Yat-sen University, Guangzhou, Guangdong, P. R. China
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3
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Helderman NC, Andini KD, van Leerdam ME, van Hest LP, Hoekman DR, Ahadova A, Bajwa-Ten Broeke SW, Bosse T, van der Logt EMJ, Imhann F, Kloor M, Langers AMJ, Smit VTHBM, Terlouw D, van Wezel T, Morreau H, Nielsen M. MLH1 Promotor Hypermethylation in Colorectal and Endometrial Carcinomas from Patients with Lynch Syndrome. J Mol Diagn 2024; 26:106-114. [PMID: 38061582 DOI: 10.1016/j.jmoldx.2023.10.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2023] [Revised: 07/19/2023] [Accepted: 10/17/2023] [Indexed: 01/26/2024] Open
Abstract
Screening for Lynch syndrome (LS) in colorectal cancer (CRC) and endometrial cancer patients generally involves immunohistochemical staining of the mismatch repair (MMR) proteins. In case of MLH1 protein loss, MLH1 promotor hypermethylation (MLH1-PM) testing is performed to indirectly distinguish the constitutional MLH1 variants from somatic epimutations. Recently, multiple studies have reported that MLH1-PM and pathogenic constitutional MMR variants are not mutually exclusive. This study describes 6 new and 86 previously reported MLH1-PM CRCs or endometrial cancers in LS patients. Of these, methylation of the MLH1 gene promotor C region was reported in 30 MLH1, 6 MSH2, 6 MSH6, and 3 PMS2 variant carriers at a median age at diagnosis of 48.5 years [interquartile range (IQR), 39-56.75 years], 39 years (IQR, 29-51 years), 58 years (IQR, 53.5-67 years), and 68 years (IQR, 65.6-68.5 years), respectively. For 31 MLH1-PM CRCs in LS patients from the literature, only the B region of the MLH1 gene promotor was tested, whereas for 13 cases in the literature the tested region was not specified. Collectively, these data indicate that a diagnosis of LS should not be excluded when MLH1-PM is detected. Clinicians should carefully consider whether follow-up genetic MMR gene testing should be offered, with age <60 to 70 years and/or a positive family history among other factors being suggestive for a potential constitutional MMR gene defect.
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Affiliation(s)
- Noah C Helderman
- Department of Clinical Genetics, Leiden University Medical Center, Leiden, the Netherlands
| | - Katarina D Andini
- Department of Genetics, University Medical Center Groningen, University of Groningen, Groningen, the Netherlands
| | - Monique E van Leerdam
- Department of Gastroenterology and Hepatology, Leiden University Medical Center, Leiden, the Netherlands; Department of Gastrointestinal Oncology, Netherlands Cancer Institute, Amsterdam, the Netherlands
| | - Liselotte P van Hest
- Department of Human Genetics, Amsterdam University Medical Center, Vrije Universiteit Amsterdam and University of Amsterdam, Amsterdam, the Netherlands
| | - Daniël R Hoekman
- Department of Human Genetics, Amsterdam University Medical Center, Vrije Universiteit Amsterdam and University of Amsterdam, Amsterdam, the Netherlands
| | - Aysel Ahadova
- Department of Applied Tumor Biology, Heidelberg University Hospital, Clinical Cooperation Unit Applied Tumor Biology, German Cancer Research Centre, Heidelberg, Germany
| | - Sanne W Bajwa-Ten Broeke
- Department of Genetics, University Medical Center Groningen, University of Groningen, Groningen, the Netherlands
| | - Tjalling Bosse
- Department of Pathology, Leiden University Medical Center, Leiden, the Netherlands
| | | | - Floris Imhann
- Department of Genetics, University Medical Center Groningen, University of Groningen, Groningen, the Netherlands
| | - Matthias Kloor
- Department of Applied Tumor Biology, Heidelberg University Hospital, Clinical Cooperation Unit Applied Tumor Biology, German Cancer Research Centre, Heidelberg, Germany
| | - Alexandra M J Langers
- Department of Gastroenterology and Hepatology, Leiden University Medical Center, Leiden, the Netherlands
| | - Vincent T H B M Smit
- Department of Pathology, Leiden University Medical Center, Leiden, the Netherlands
| | - Diantha Terlouw
- Department of Clinical Genetics, Leiden University Medical Center, Leiden, the Netherlands; Department of Pathology, Leiden University Medical Center, Leiden, the Netherlands
| | - Tom van Wezel
- Department of Pathology, Leiden University Medical Center, Leiden, the Netherlands
| | - Hans Morreau
- Department of Pathology, Leiden University Medical Center, Leiden, the Netherlands
| | - Maartje Nielsen
- Department of Clinical Genetics, Leiden University Medical Center, Leiden, the Netherlands.
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Foda ZH, Dharwadkar P, Katona BW. Preventive strategies in familial and hereditary colorectal cancer. Best Pract Res Clin Gastroenterol 2023; 66:101840. [PMID: 37852714 DOI: 10.1016/j.bpg.2023.101840] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/14/2023] [Revised: 05/05/2023] [Accepted: 05/17/2023] [Indexed: 10/20/2023]
Abstract
Colorectal cancer is a leading cause of cancer-related deaths worldwide. While most cases are sporadic, a significant proportion of cases are associated with familial and hereditary syndromes. Individuals with a family history of colorectal cancer have an increased risk of developing the disease, and those with hereditary syndromes such as Lynch syndrome or familial adenomatous polyposis have a significantly higher risk. In these populations, preventive strategies are critical for reducing the incidence and mortality of colorectal cancer. This review provides an overview of current preventive strategies for individuals at increased risk of colorectal cancer due to familial or hereditary factors. The manuscript includes a discussion of risk assessment and genetic testing, highlighting the importance of identifying at-risk individuals and families. This review describes various preventive measures, including surveillance colonoscopy, chemoprevention, and prophylactic surgery, and their respective benefits and limitations. Together, this work highlights the importance of preventive strategies in familial and hereditary colorectal cancer.
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Affiliation(s)
- Zachariah H Foda
- The Sidney Kimmel Comprehensive Cancer Center and Department of Medicine, Division of Gastroenterology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Pooja Dharwadkar
- Division of Gastroenterology, Department of Medicine, University of California, San Francisco, CA, USA
| | - Bryson W Katona
- Division of Gastroenterology and Hepatology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA.
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Hitchins MP, Alvarez R, Zhou L, Aguirre F, Dámaso E, Pineda M, Capella G, Wong JJL, Yuan X, Ryan SR, Sathe DS, Baxter MD, Cannon T, Biswas R, DeMarco T, Grzelak D, Hampel H, Pearlman R. MLH1-methylated endometrial cancer under 60 years of age as the "sentinel" cancer in female carriers of high-risk constitutional MLH1 epimutation. Gynecol Oncol 2023; 171:129-140. [PMID: 36893489 PMCID: PMC10153467 DOI: 10.1016/j.ygyno.2023.02.017] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2023] [Revised: 02/22/2023] [Accepted: 02/26/2023] [Indexed: 03/11/2023]
Abstract
OBJECTIVE Universal screening of endometrial carcinoma (EC) for mismatch repair deficiency (MMRd) and Lynch syndrome uses presence of MLH1 methylation to omit common sporadic cases from follow-up germline testing. However, this overlooks rare cases with high-risk constitutional MLH1 methylation (epimutation), a poorly-recognized mechanism that predisposes to Lynch-type cancers with MLH1 methylation. We aimed to determine the role and frequency of constitutional MLH1 methylation among EC cases with MMRd, MLH1-methylated tumors. METHODS We screened blood for constitutional MLH1 methylation using pyrosequencing and real-time methylation-specific PCR in patients with MMRd, MLH1-methylated EC ascertained from (i) cancer clinics (n = 4, <60 years), and (ii) two population-based cohorts; "Columbus-area" (n = 68, all ages) and "Ohio Colorectal Cancer Prevention Initiative (OCCPI)" (n = 24, <60 years). RESULTS Constitutional MLH1 methylation was identified in three out of four patients diagnosed between 36 and 59 years from cancer clinics. Two had mono-/hemiallelic epimutation (∼50% alleles methylated). One with multiple primaries had low-level mosaicism in normal tissues and somatic "second-hits" affecting the unmethylated allele in all tumors, demonstrating causation. In the population-based cohorts, all 68 cases from the Columbus-area cohort were negative and low-level mosaic constitutional MLH1 methylation was identified in one patient aged 36 years out of 24 from the OCCPI cohort, representing one of six (∼17%) patients <50 years and one of 45 patients (∼2%) <60 years in the combined cohorts. EC was the first/dual-first cancer in three patients with underlying constitutional MLH1 methylation. CONCLUSIONS A correct diagnosis at first presentation of cancer is important as it will significantly alter clinical management. Screening for constitutional MLH1 methylation is warranted in patients with early-onset EC or synchronous/metachronous tumors (any age) displaying MLH1 methylation.
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Affiliation(s)
- Megan P Hitchins
- Department of Biomedical Sciences, Cedars-Sinai Cancer, Cedars-Sinai Medical Center, Los Angeles, CA, USA; Department of Medicine (Oncology), Stanford University, Stanford, CA, USA.
| | - Rocio Alvarez
- Department of Biomedical Sciences, Cedars-Sinai Cancer, Cedars-Sinai Medical Center, Los Angeles, CA, USA
| | - Lisa Zhou
- Department of Biomedical Sciences, Cedars-Sinai Cancer, Cedars-Sinai Medical Center, Los Angeles, CA, USA
| | - Francesca Aguirre
- Department of Biomedical Sciences, Cedars-Sinai Cancer, Cedars-Sinai Medical Center, Los Angeles, CA, USA
| | - Estela Dámaso
- Department of Medicine (Oncology), Stanford University, Stanford, CA, USA; Hereditary Cancer Program, Catalan Institute of Oncology, Institut d'Investigació Biomèdica de Bellvitge (IDIBELL), ONCOBELL Program, Av. Gran Via de l'Hospitalet, 199-203, 08908 L' Hospitalet de Llobregat, Barcelona, Spain; Molecular Genetics Unit, Elche University Hospital, Elche, Alicante. Foundation for the Promotion of Health and Biomedical Research of Valencia Region (FISABIO), FISABIO- Elche Health Department, Spain
| | - Marta Pineda
- Molecular Genetics Unit, Elche University Hospital, Elche, Alicante. Foundation for the Promotion of Health and Biomedical Research of Valencia Region (FISABIO), FISABIO- Elche Health Department, Spain; Consortium for Biomedical Research in Cancer - CIBERONC, Carlos III Institute of Health, Av. De Monforte de Lemos 5, 28029 Madrid, Spain
| | - Gabriel Capella
- Molecular Genetics Unit, Elche University Hospital, Elche, Alicante. Foundation for the Promotion of Health and Biomedical Research of Valencia Region (FISABIO), FISABIO- Elche Health Department, Spain; Consortium for Biomedical Research in Cancer - CIBERONC, Carlos III Institute of Health, Av. De Monforte de Lemos 5, 28029 Madrid, Spain
| | - Justin J-L Wong
- Epigenetics and RNA Biology Program Centenary Institute, and Faculty of Medicine and Health, The University of Sydney, Camperdown, New South Wales 2050, Australia
| | - Xiaopu Yuan
- Department of Pathology and Laboratory Medicine, Cedars-Sinai Cancer, Cedars-Sinai Medical Center, Los Angeles, CA, USA
| | - Shawnia R Ryan
- Hereditary Cancer Assessment Program, University of New Mexico Comprehensive Cancer Center, NM, USA
| | - Devika S Sathe
- Precision Medicine and Genetics, Frederick Health, MD, USA
| | | | - Timothy Cannon
- Cancer Genetics Program, Inova Schar Cancer Institute, Inova Fairfax Hospital, VA, USA
| | - Rakesh Biswas
- Cancer Genetics Program, Inova Schar Cancer Institute, Inova Fairfax Hospital, VA, USA
| | - Tiffani DeMarco
- Cancer Genetics Program, Inova Schar Cancer Institute, Inova Fairfax Hospital, VA, USA
| | | | - Heather Hampel
- Department of Internal Medicine and the Comprehensive Cancer Center, Ohio State University, Columbus, OH, USA; Division of Clinical Cancer Genomics, Department of Medical Oncology and Therapeutics Research, City of Hope National Medical Center, Duarte, CA, USA
| | - Rachel Pearlman
- Department of Internal Medicine and the Comprehensive Cancer Center, Ohio State University, Columbus, OH, USA
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Peltomäki P, Nyström M, Mecklin JP, Seppälä TT. Lynch Syndrome Genetics and Clinical Implications. Gastroenterology 2023; 164:783-799. [PMID: 36706841 DOI: 10.1053/j.gastro.2022.08.058] [Citation(s) in RCA: 19] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/04/2022] [Revised: 08/29/2022] [Accepted: 08/30/2022] [Indexed: 01/29/2023]
Abstract
Lynch syndrome (LS) is one of the most prevalent hereditary cancer syndromes in humans and accounts for some 3% of unselected patients with colorectal or endometrial cancer and 10%-15% of those with DNA mismatch repair-deficient tumors. Previous studies have established the genetic basis of LS predisposition, but there have been significant advances recently in the understanding of the molecular pathogenesis of LS tumors, which has important implications in clinical management. At the same time, immunotherapy has revolutionized the treatment of advanced cancers with DNA mismatch repair defects. We aim to review the recent progress in the LS field and discuss how the accumulating epidemiologic, clinical, and molecular information has contributed to a more accurate and complete picture of LS, resulting in genotype- and immunologic subtype-specific strategies for surveillance, cancer prevention, and treatment.
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Affiliation(s)
- Päivi Peltomäki
- Department of Medical and Clinical Genetics, University of Helsinki, Helsinki, Finland.
| | - Minna Nyström
- Faculty of Biological and Environmental Sciences, University of Helsinki, Helsinki, Finland
| | - Jukka-Pekka Mecklin
- Department of Education and Science, Nova Hospital, Central Finland Health Care District, Jyväskylä, Finland; Faculty of Sports and Health Sciences, University of Jyväskylä, Jyväskylä, Finland
| | - Toni T Seppälä
- Department of Surgery, Helsinki University Hospital, Helsinki, Finland; Applied Tumor Genomics Research Programs Unit, University of Helsinki, Helsinki, Finland; Faculty of Medicine and Health Technology, Tampere University and Tays Cancer Center, Tampere University Hospital, Tampere, Finland
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7
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Pasanen A, Loukovaara M, Kaikkonen E, Olkinuora A, Pylvänäinen K, Alhopuro P, Peltomäki P, Mecklin JP, Bützow R. Testing for Lynch Syndrome in Endometrial Carcinoma: From Universal to Age-Selective MLH1 Methylation Analysis. Cancers (Basel) 2022; 14:cancers14051348. [PMID: 35267656 PMCID: PMC8909331 DOI: 10.3390/cancers14051348] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2021] [Revised: 02/21/2022] [Accepted: 03/04/2022] [Indexed: 12/13/2022] Open
Abstract
International guidelines recommend universal screening of endometrial carcinoma (EC) patients for Lynch syndrome (LS). This screening is generally based on mismatch repair (MMR) protein immunohistochemistry followed by MLH1 methylation analysis of MLH1-negative cases to exclude the likely sporadic cases from germline testing. As LS-associated EC is uncommon in the elderly, age-selective methylation testing could improve cost-efficiency. We performed MMR immunohistochemistry on 821 unselected ECs (clinic-based cohort) followed by a MLH1 promoter methylation test of all MLH1/PMS2-negative tumors. Non-methylated MLH1-deficient cases underwent NGS and MLPA-based germline analyses to identify MLH1 mutation carriers. A reduction in the test burden and corresponding false negative rates for LS screening were investigated for various age cut-offs. In addition, the age distribution of 132 MLH1 mutation carriers diagnosed with EC (registry-based cohort) was examined. A germline MLH1 mutation was found in 2/14 patients with non-methylated MLH1-deficient EC. When compared to a universal methylation analysis, selective testing with a cut-off age of 65 years, would have reduced the testing effort by 70.7% with a false negative rate for LS detection of 0% and 3% in the clinic and registry-based cohorts, respectively. The use of age-selective methylation analysis is a feasible way of reducing the costs and laboratory burden in LS screening for EC patients.
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Affiliation(s)
- Annukka Pasanen
- Department of Pathology, Helsinki University Hospital, University of Helsinki, 00290 Helsinki, Finland;
- Correspondence:
| | - Mikko Loukovaara
- Department of Obstetrics and Gynecology, Helsinki University Hospital, University of Helsinki, 00290 Helsinki, Finland;
| | - Elina Kaikkonen
- Laboratory of Genetics, HUS Diagnostic Center, Helsinki University Hospital, University of Helsinki, 00209 Helsinki, Finland; (E.K.); (P.A.)
| | - Alisa Olkinuora
- Department of Medical and Clinical Genetics, University of Helsinki, 00014 Helsinki, Finland; (A.O.); (P.P.)
| | - Kirsi Pylvänäinen
- Department of Education and Science, Central Finland Health Care District, 40620 Jyväskylä, Finland;
| | - Pia Alhopuro
- Laboratory of Genetics, HUS Diagnostic Center, Helsinki University Hospital, University of Helsinki, 00209 Helsinki, Finland; (E.K.); (P.A.)
| | - Päivi Peltomäki
- Department of Medical and Clinical Genetics, University of Helsinki, 00014 Helsinki, Finland; (A.O.); (P.P.)
| | - Jukka-Pekka Mecklin
- Department of Surgery, Central Finland Health Care District; 40620 Jyväskylä, Finland;
- Department of Sport and Health Sciences, Jyväskylä University, 40014 Jyväskylä, Finland
| | - Ralf Bützow
- Department of Pathology, Helsinki University Hospital, University of Helsinki, 00290 Helsinki, Finland;
- Applied Tumor Genomics Research Program, University of Helsinki, 00290 Helsinki, Finland
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8
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Leite Rocha D, Ashton-Prolla P, Rosset C. Reviewing the occurrence of large genomic rearrangements in patients with inherited cancer predisposing syndromes: importance of a comprehensive molecular diagnosis. Expert Rev Mol Diagn 2022; 22:319-346. [PMID: 35234551 DOI: 10.1080/14737159.2022.2049247] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
INTRODUCTION Hereditary cancer predisposition syndromes are caused by germline pathogenic or likely pathogenic variants in cancer predisposition genes (CPG). The majority of pathogenic variants in CPGs are point mutations, but large gene rearrangements (LGRs) are present in several CPGs. LGRs can be much more difficult to characterize and perhaps they may have been neglected in molecular diagnoses. AREAS COVERED We aimed to evaluate the frequencies of germline LGRs in studies conducted in different populations worldwide through a qualitative systematic review based on an online literature research in PubMed. Two reviewers independently extracted data from published studies between 2009 and 2020. In total, 126 studies from 37 countries and 5 continents were included in the analysis. The number of studies in different continents ranged from 3 to 48 and for several countries there was an absolute lack of information. Asia and Europe represented most of the studies, and LGR frequencies varied from 3.04 to 15.06% in different continents. MLPA was one of the methods of choice in most studies (93%). EXPERT OPINION The LGR frequencies found in this review reinforce the need for comprehensive molecular testing regardless of the population of origin and should be considered by genetic counseling providers.
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Affiliation(s)
- Débora Leite Rocha
- Laboratório de Medicina Genômica, Serviço de Pesquisa Experimental, Hospital de Clínicas de Porto Alegre (HCPA), Rua Ramiro Barcelos, 2350, CEP: 90035-930, Porto Alegre, Rio Grande do Sul, Brazil
| | - Patrícia Ashton-Prolla
- Laboratório de Medicina Genômica, Serviço de Pesquisa Experimental, Hospital de Clínicas de Porto Alegre (HCPA), Rua Ramiro Barcelos, 2350, CEP: 90035-930, Porto Alegre, Rio Grande do Sul, Brazil.,Programa de Pós-Graduação em Genética e Biologia Molecular, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, Rio Grande do Sul, Brazil. Av. Bento Gonçalves, 9500 - Prédio 43312 M, CEP: 91501-970, Caixa Postal 1505, Porto Alegre, Rio Grande do Sul, Brazil.,Serviço de Genética Médica, HCPA, Rio Grande do Sul, Brazil. Rua Ramiro Barcelos, 2350, CEP: 90035-930, Porto Alegre, Rio Grande do Sul, Brazil
| | - Clévia Rosset
- Laboratório de Medicina Genômica, Serviço de Pesquisa Experimental, Hospital de Clínicas de Porto Alegre (HCPA), Rua Ramiro Barcelos, 2350, CEP: 90035-930, Porto Alegre, Rio Grande do Sul, Brazil
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9
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Ukkola I, Nummela P, Kero M, Tammio H, Tuominen J, Kairisto V, Kallajoki M, Haglund C, Peltomäki P, Kytölä S, Ristimäki A. Gene fusions and oncogenic mutations in MLH1 deficient and BRAFV600E wild-type colorectal cancers. Virchows Arch 2022; 480:807-817. [PMID: 35237889 PMCID: PMC9023403 DOI: 10.1007/s00428-022-03302-x] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2021] [Revised: 01/19/2022] [Accepted: 02/05/2022] [Indexed: 01/09/2023]
Abstract
Gene fusions can act as oncogenic drivers and offer targets for cancer therapy. Since fusions are rare in colorectal cancer (CRC), their universal screening seems impractical. Our aim was to investigate gene fusions in 62 CRC cases with deficient MLH1 (dMLH1) and BRAFV600E wild-type (wt) status from a consecutive real-life series of 2079 CRCs. First, gene fusions were analysed using a novel FusionPlex Lung v2 RNA-based next-generation sequencing (NGS) panel, and these results were compared to a novel Idylla GeneFusion assay and pan-TRK immunohistochemistry (IHC). NGS detected seven (7/62, 11%) NTRK1 fusions (TPM3::NTRK1, PLEKHA6::NTRK1 and LMNA::NTRK1, each in two cases, and IRF2BP2::NTRK1 in one case). In addition, two ALK, four RET and seven BRAF fusions were identified. Idylla detected seven NTRK1 expression imbalances, in line with the NGS results (overall agreement 100%). Furthermore, Idylla detected the two NGS-identified ALK rearrangements as one specific ALK fusion and one ALK expression imbalance, whilst only two of the four RET fusions were discovered. However, Idylla detected several expression imbalances of ALK (n = 7) and RET (n = 1) that were found to be fusion negative with the NGS. Pan-TRK IHC showed clearly detectable, fusion partner-dependent staining patterns in the seven NTRK1 fusion cases. Overall agreement for pan-TRK antibody clone EPR17341 was 98% and for A7H6R 100% when compared to the NGS. Of the 62 CRCs, 43 were MLH1 promoter hypermethylated (MLH1ph) and 39 were RASwt. All fusion cases were both MLH1ph and RASwt. Our results show that kinase fusions (20/30, 67%) and most importantly targetable NTRK1 fusions (7/30, 23%) are frequent in CRCs with dMLH1/BRAFV600Ewt/MLH1ph/RASwt. NGS was the most comprehensive method in finding the fusions, of which a subset can be screened by Idylla or IHC, provided that the result is confirmed by NGS.
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Affiliation(s)
- Iiris Ukkola
- Department of Pathology, HUSLAB, HUS Diagnostic Center, Helsinki University Hospital and University of Helsinki, P.O. Box 400, 00029, HUS, Helsinki, Finland
- Applied Tumor Genomics Research Program, Research Programs Unit, Faculty of Medicine, University of Helsinki, Helsinki, Finland
| | - Pirjo Nummela
- Applied Tumor Genomics Research Program, Research Programs Unit, Faculty of Medicine, University of Helsinki, Helsinki, Finland
| | - Mia Kero
- Department of Pathology, HUSLAB, HUS Diagnostic Center, Helsinki University Hospital and University of Helsinki, P.O. Box 400, 00029, HUS, Helsinki, Finland
| | - Hanna Tammio
- Department of Genetics, HUSLAB, HUS Diagnostic Center, Helsinki University Hospital and University of Helsinki, Helsinki, Finland
| | - Jenni Tuominen
- Department of Genomics, Laboratory of Molecular Haematology and Pathology, Turku University Central Hospital, Turku, Finland
| | - Veli Kairisto
- Department of Genomics, Laboratory of Molecular Haematology and Pathology, Turku University Central Hospital, Turku, Finland
| | - Markku Kallajoki
- Department of Pathology, University of Turku and Turku University Hospital, Turku, Finland
| | - Caj Haglund
- Department of Surgery, University of Helsinki and Helsinki University Hospital, Helsinki, Finland
- Translational Cancer Medicine Research Program, Research Programs Unit, Faculty of Medicine, University of Helsinki, Helsinki, Finland
| | - Päivi Peltomäki
- Department of Medical and Clinical Genetics, University of Helsinki, Helsinki, Finland
| | - Soili Kytölä
- Department of Genetics, HUSLAB, HUS Diagnostic Center, Helsinki University Hospital and University of Helsinki, Helsinki, Finland
| | - Ari Ristimäki
- Department of Pathology, HUSLAB, HUS Diagnostic Center, Helsinki University Hospital and University of Helsinki, P.O. Box 400, 00029, HUS, Helsinki, Finland.
- Applied Tumor Genomics Research Program, Research Programs Unit, Faculty of Medicine, University of Helsinki, Helsinki, Finland.
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Pavanello M, Chan IHY, Ariff A, Pharoah PDP, Gayther SA, Ramus SJ. Rare Germline Genetic Variants and the Risks of Epithelial Ovarian Cancer. Cancers (Basel) 2020; 12:E3046. [PMID: 33086730 PMCID: PMC7589980 DOI: 10.3390/cancers12103046] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2020] [Revised: 10/12/2020] [Accepted: 10/14/2020] [Indexed: 02/06/2023] Open
Abstract
A family history of ovarian or breast cancer is the strongest risk factor for epithelial ovarian cancer (EOC). Germline deleterious variants in the BRCA1 and BRCA2 genes confer EOC risks by age 80, of 44% and 17% respectively. The mismatch repair genes, particularly MSH2 and MSH6, are also EOC susceptibility genes. Several other DNA repair genes, BRIP1, RAD51C, RAD51D, and PALB2, have been identified as moderate risk EOC genes. EOC has five main histotypes; high-grade serous (HGS), low-grade serous (LGS), clear cell (CCC), endometrioid (END), and mucinous (MUC). This review examines the current understanding of the contribution of rare genetic variants to EOC, focussing on providing frequency data for each histotype. We provide an overview of frequency and risk for pathogenic variants in the known susceptibility genes as well as other proposed genes. We also describe the progress to-date to understand the role of missense variants and the different breast and ovarian cancer risks for each gene. Identification of susceptibility genes have clinical impact by reducing disease-associated mortality through improving risk prediction, with the possibility of prevention strategies, and developing new targeted treatments and these clinical implications are also discussed.
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Affiliation(s)
- Marina Pavanello
- School of Women’s and Children’s Health, Faculty of Medicine, University of New South Wales, Sydney 2052, Australia; (M.P.); (I.H.C.); (A.A.)
- Adult Cancer Program, Lowy Cancer Research Centre, University of New South Wales, Sydney 2052, Australia
| | - Isaac HY Chan
- School of Women’s and Children’s Health, Faculty of Medicine, University of New South Wales, Sydney 2052, Australia; (M.P.); (I.H.C.); (A.A.)
| | - Amir Ariff
- School of Women’s and Children’s Health, Faculty of Medicine, University of New South Wales, Sydney 2052, Australia; (M.P.); (I.H.C.); (A.A.)
- Adult Cancer Program, Lowy Cancer Research Centre, University of New South Wales, Sydney 2052, Australia
| | - Paul DP Pharoah
- Strangeways Research Laboratory, University of Cambridge, Cambridge CB1 8RN, UK;
| | - Simon A. Gayther
- Center for Cancer Prevention and Translational Genomics, Cedars Sinai Medical Center, Los Angeles, CA 90048, USA;
- Applied Genomics, Computation and Translational Core, Cedars Sinai Medical Center, Los Angeles, CA 90048, USA
| | - Susan J. Ramus
- School of Women’s and Children’s Health, Faculty of Medicine, University of New South Wales, Sydney 2052, Australia; (M.P.); (I.H.C.); (A.A.)
- Adult Cancer Program, Lowy Cancer Research Centre, University of New South Wales, Sydney 2052, Australia
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11
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Peltomäki P, Olkinuora A, Nieminen TT. Updates in the field of hereditary nonpolyposis colorectal cancer. Expert Rev Gastroenterol Hepatol 2020; 14:707-720. [PMID: 32755332 DOI: 10.1080/17474124.2020.1782187] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
INTRODUCTION Up to one third of colorectal cancers show familial clustering and 5% are hereditary single-gene disorders. Hereditary non-polyposis colorectal cancer comprises DNA mismatch repair-deficient and -proficient subsets, represented by Lynch syndrome (LS) and familial colorectal cancer type X (FCCTX), respectively. Accurate knowledge of molecular etiology and genotype-phenotype correlations are critical for tailored cancer prevention and treatment. AREAS COVERED The authors highlight advances in the molecular dissection of hereditary non-polyposis colorectal cancer, based on recent literature retrieved from PubMed. Future possibilities for novel gene discoveries are discussed. EXPERT COMMENTARY LS is molecularly well established, but new information is accumulating of the associated clinical and tumor phenotypes. FCCTX remains poorly defined, but several promising candidate genes have been discovered and share some preferential biological pathways. Multi-level characterization of specimens from large patient cohorts representing multiple populations, combined with proper bioinformatic and functional analyses, will be necessary to resolve the outstanding questions.
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Affiliation(s)
- Paivi Peltomäki
- Department of Medical and Clinical Genetics, University of Helsinki , Helsinki, Finland
| | - Alisa Olkinuora
- Department of Medical and Clinical Genetics, University of Helsinki , Helsinki, Finland
| | - Taina T Nieminen
- Department of Medical and Clinical Genetics, University of Helsinki , Helsinki, Finland
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12
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Olkinuora A, Gylling A, Almusa H, Eldfors S, Lepistö A, Mecklin JP, Nieminen TT, Peltomäki P. Molecular Basis of Mismatch Repair Protein Deficiency in Tumors from Lynch Suspected Cases with Negative Germline Test Results. Cancers (Basel) 2020; 12:cancers12071853. [PMID: 32660107 PMCID: PMC7408769 DOI: 10.3390/cancers12071853] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2020] [Revised: 06/26/2020] [Accepted: 07/06/2020] [Indexed: 11/25/2022] Open
Abstract
Some 10–50% of Lynch-suspected cases with abnormal immunohistochemical (IHC) staining remain without any identifiable germline mutation of DNA mismatch repair (MMR) genes. MMR proteins form heterodimeric complexes, giving rise to distinct IHC patterns when mutant. Potential reasons for not finding a germline mutation include involvement of an MMR gene not predicted by the IHC pattern, epigenetic mechanism of predisposition, primary mutation in another DNA repair or replication-associated gene, and double somatic MMR gene mutations. We addressed these possibilities by germline and tumor studies in 60 Lynch-suspected cases ascertained through diagnostics (n = 55) or research (n = 5). All cases had abnormal MMR protein staining in tumors but no point mutation or large rearrangement of the suspected MMR genes in the germline. In diagnostic practice, MSH2/MSH6 (MutS Homolog 2/MutS Homolog 6) deficiency prompts MSH2 mutation screening; in our study, 3/11 index individuals (27%) with this IHC pattern revealed pathogenic germline mutations in MSH6. Individuals with isolated absence of MSH6 are routinely screened for MSH6 mutations alone; we found a predisposing mutation in MSH2 in 1/7 such cases (14%). Somatic deletion of the MSH2-MSH6 region, joint loss of MSH6 and MSH3 (MutS Homolog 3) proteins, and hindered MSH2/MSH6 dimerization offered explanations to misleading IHC patterns. Constitutional epimutation hypothesis was pursued in the MSH2 and/or MSH6-deficient cases plus 38 cases with MLH1 (MutL Homolog 1)-deficient tumors; a primary MLH1 epimutation was identified in one case with an MLH1-deficient tumor. We conclude that both MSH2 and MSH6 should be screened in MSH2/6- and MSH6-deficient cases. In MLH1-deficient cases, constitutional epimutations of MLH1 warrant consideration.
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Affiliation(s)
- Alisa Olkinuora
- Department of Medical and Clinical Genetics, University of Helsinki, 00014 Helsinki, Finland; (A.G.); (T.T.N.); (P.P.)
- Correspondence:
| | - Annette Gylling
- Department of Medical and Clinical Genetics, University of Helsinki, 00014 Helsinki, Finland; (A.G.); (T.T.N.); (P.P.)
| | - Henrikki Almusa
- Institute for Molecular Medicine Finland (FIMM), University of Helsinki, 00014 Helsinki, Finland; (H.A.); (S.E.)
| | - Samuli Eldfors
- Institute for Molecular Medicine Finland (FIMM), University of Helsinki, 00014 Helsinki, Finland; (H.A.); (S.E.)
| | - Anna Lepistö
- Department of Gastrointestinal Surgery, Helsinki University Hospital and University of Helsinki, 00290 Helsinki, Finland;
| | - Jukka-Pekka Mecklin
- Department of Surgery, Jyväskylä Central Hospital, 40620 Jyväskylä, Finland;
- Faculty of Sports and Health Sciences, University of Jyväskylä, 40014 Jyväskylä, Finland
| | - Taina Tuulikki Nieminen
- Department of Medical and Clinical Genetics, University of Helsinki, 00014 Helsinki, Finland; (A.G.); (T.T.N.); (P.P.)
| | - Päivi Peltomäki
- Department of Medical and Clinical Genetics, University of Helsinki, 00014 Helsinki, Finland; (A.G.); (T.T.N.); (P.P.)
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13
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Rosa I, Silva P, da Mata S, Magro F, Carneiro F, Peixoto A, Silva M, Sousa HT, Roseira J, Parra J, Barosa R, Vieira A, Brito MJ, Lago P, Coelho A, Moleiro J, Pereira da Silva J, Fonseca R, Albuquerque C, Dias Pereira A. Methylation patterns in dysplasia in inflammatory bowel disease patients. Scand J Gastroenterol 2020; 55:646-655. [PMID: 32456486 DOI: 10.1080/00365521.2020.1766552] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Background and aims: Inflammatory Bowel Disease (IBD) with colonic involvement increases colorectal cancer risk. However, the distinction between IBD related and sporadic dysplasia in IBD patients is difficult. Some data favors the importance of abnormal DNA methylation in IBD-related carcinogenesis. We aimed to define methylation patterns in patients with colonic cancer or dysplasia diagnosis following an IBD diagnosis.Methods: Multicentric cross-sectional study-91 samples from colonic mucosa with/without dysplasia from 9 patients with IBD-related dysplasia/cancer and 26 patients with IBD and sporadic dysplasia/cancer were included. Methylation patterns of CpG islands in the promoter regions of 67 genes were studied by Methylation-specific Multiplex Ligation-dependent Probe Amplification.Results: Mean age at IBD diagnosis: 42 ± 16 years;at dysplasia diagnosis: 56 ± 14 years. Twenty-ninepatients had ulcerative colitis. Twenty-five patients had at least 1 lesion endoscopically described as adenoma-like, 4 at least 1 non-adenoma like, 3 had cancer and 3 had dysplasia in flat mucosa. No patient had both adenoma-like and non-adenoma-like lesions. Patients with an IBD-related lesion were significantly younger at IBD diagnosis (p = .003) and at dysplasia/cancer diagnosis (p = .039). Promoter methylation of IGF2, RARB, ESR1, CHFR, CDH13, WT1, GATA5, WIF1genes was significantly associated to dysplasia/cancer; methylation of MSH6, TIMP3 was significantly associated to IBD-related dysplasia/cancer. Promoter methylation of MSH6, MSH3, RUNX3, CRABP1, TP73, RARB, CDH13, PAX5, WT1, THBS1, TP53, SFRP1, WIF1, APAF1, BCL2 genes was significantly associated to active IBD.Conclusions: Methylation analysis, namely of MSH6, may contribute to the classification of dysplastic lesions in IBD- to be further tested in prospective studies.
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Affiliation(s)
- Isadora Rosa
- Gastroenterology Department, Instituto Português de Oncologia de Lisboa, Francisco Gentil, EPE, Lisboa, Portugal
| | - Patrícia Silva
- Molecular Pathobiology Investigation Unit, Instituto Português de Oncologia de Lisboa, Francisco Gentil, EPE, Lisboa, Portugal
| | - Sara da Mata
- Pathology Department, Instituto Português de Oncologia de Lisboa, Francisco Gentil, EPE, Lisboa, Portugal
| | - Fernando Magro
- Gastroenterology Department, Centro Hospitalar de São João, EPE, Porto, Portugal
| | - Fátima Carneiro
- Pathology Department, Centro Hospitalar de São João, EPE, Porto, Portugal
| | - Armando Peixoto
- Gastroenterology Department, Centro Hospitalar de São João, EPE, Porto, Portugal
| | - Marco Silva
- Gastroenterology Department, Centro Hospitalar de São João, EPE, Porto, Portugal
| | - Helena T Sousa
- Gastroenterology Department, Centro Hospitalar Universitário do Algarve, EPE, Unidade de Portimão, Portimão, Portugal.,Algarve Biomedical Center, Campus Gambelas - Universidade do Algarve, Faro, Portugal
| | - Joana Roseira
- Gastroenterology Department, Centro Hospitalar Universitário do Algarve, EPE, Unidade de Portimão, Portimão, Portugal.,Algarve Biomedical Center, Campus Gambelas - Universidade do Algarve, Faro, Portugal
| | - José Parra
- Pathology Department, Centro Hospitalar Universitário do Algarve, EPE, Unidade de Portimão, Portimão, Portugal
| | - Rita Barosa
- Gastroenterology Department, Hospital Garcia de Orta, EPE, Almada, Portugal
| | - Ana Vieira
- Gastroenterology Department, Hospital Garcia de Orta, EPE, Almada, Portugal
| | - Maria José Brito
- Pathology Department, Hospital Garcia de Orta, EPE, Almada, Portugal
| | - Paula Lago
- Gastroenterology Department, Centro Hospitalar do Porto, EPE - Hospital de Santo António, Porto, Portugal
| | - André Coelho
- Portuguese Inflammatory Bowel Diseases Study Group, Porto, Portugal
| | - Joana Moleiro
- Gastroenterology Department, Instituto Português de Oncologia de Lisboa, Francisco Gentil, EPE, Lisboa, Portugal
| | - João Pereira da Silva
- Gastroenterology Department, Instituto Português de Oncologia de Lisboa, Francisco Gentil, EPE, Lisboa, Portugal
| | - Ricardo Fonseca
- Pathology Department, Instituto Português de Oncologia de Lisboa, Francisco Gentil, EPE, Lisboa, Portugal
| | - Cristina Albuquerque
- Molecular Pathobiology Investigation Unit, Instituto Português de Oncologia de Lisboa, Francisco Gentil, EPE, Lisboa, Portugal
| | - A Dias Pereira
- Gastroenterology Department, Instituto Português de Oncologia de Lisboa, Francisco Gentil, EPE, Lisboa, Portugal
| | -
- Portuguese Inflammatory Bowel Diseases Study Group, Porto, Portugal
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14
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LaDuca H, Polley EC, Yussuf A, Hoang L, Gutierrez S, Hart SN, Yadav S, Hu C, Na J, Goldgar DE, Fulk K, Smith LP, Horton C, Profato J, Pesaran T, Gau CL, Pronold M, Davis BT, Chao EC, Couch FJ, Dolinsky JS. A clinical guide to hereditary cancer panel testing: evaluation of gene-specific cancer associations and sensitivity of genetic testing criteria in a cohort of 165,000 high-risk patients. Genet Med 2020; 22:407-415. [PMID: 31406321 PMCID: PMC7000322 DOI: 10.1038/s41436-019-0633-8] [Citation(s) in RCA: 118] [Impact Index Per Article: 29.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2019] [Accepted: 07/26/2019] [Indexed: 01/11/2023] Open
Abstract
PURPOSE Despite the rapid uptake of multigene panel testing (MGPT) for hereditary cancer predisposition, there is limited guidance surrounding indications for testing and genes to include. METHODS To inform the clinical approach to hereditary cancer MGPT, we comprehensively evaluated 32 cancer predisposition genes by assessing phenotype-specific pathogenic variant (PV) frequencies, cancer risk associations, and performance of genetic testing criteria in a cohort of 165,000 patients referred for MGPT. RESULTS We identified extensive genetic heterogeneity surrounding predisposition to cancer types commonly referred for germline testing (breast, ovarian, colorectal, uterine/endometrial, pancreatic, and melanoma). PV frequencies were highest among patients with ovarian cancer (13.8%) and lowest among patients with melanoma (8.1%). Fewer than half of PVs identified in patients meeting testing criteria for only BRCA1/2 or only Lynch syndrome occurred in the respective genes (33.1% and 46.2%). In addition, 5.8% of patients with PVs in BRCA1/2 and 26.9% of patients with PVs in Lynch syndrome genes did not meet respective testing criteria. CONCLUSION Opportunities to improve upon identification of patients at risk for hereditary cancer predisposition include revising BRCA1/2 and Lynch syndrome testing criteria to include additional clinically actionable genes with overlapping phenotypes and relaxing testing criteria for associated cancers.
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Affiliation(s)
| | - Eric C Polley
- Department of Health Sciences Research, Mayo Clinic, Rochester, MN, USA
| | | | | | | | - Steven N Hart
- Department of Health Sciences Research, Mayo Clinic, Rochester, MN, USA
| | | | - Chunling Hu
- Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, MN, USA
| | - Jie Na
- Department of Health Sciences Research, Mayo Clinic, Rochester, MN, USA
| | - David E Goldgar
- Department of Dermatology, University of Utah, Salt Lake City, UT, USA
| | | | | | | | | | | | | | | | | | - Elizabeth C Chao
- Ambry Genetics, Aliso Viejo, CA, USA
- Department of Pediatrics, Division of Genetic and Genomic Medicine, University of California-Irvine, Irvine, CA, USA
| | - Fergus J Couch
- Department of Health Sciences Research, Mayo Clinic, Rochester, MN, USA
- Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, MN, USA
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Factors associated with decision-making on prophylactic hysterectomy and attitudes towards gynecological surveillance among women with Lynch syndrome (LS): a descriptive study. Fam Cancer 2020; 19:177-182. [PMID: 31997047 PMCID: PMC7101284 DOI: 10.1007/s10689-020-00158-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2019] [Accepted: 01/13/2020] [Indexed: 12/26/2022]
Abstract
To prevent endometrial carcinoma in Lynch syndrome (LS), regular gynecological surveillance visits and prophylactic surgery are recommended. Previous data have shown that prophylactic hysterectomy is an effective means of cancer prevention, while the advantages and disadvantages of surveillance are somewhat unclear. We aimed to evaluate female LS carriers’ attitudes towards regular gynecological surveillance and factors influencing their decision-making on prophylactic surgery that have not been well documented. Pain experienced during endometrial biopsies was also evaluated. Postal questionnaires were sent to LS carriers undergoing regular gynecological surveillance. Questionnaires were sent to 112 women with LS, of whom 76 responded (68%). Forty-two (55%) had undergone prophylactic hysterectomy by the time of the study. The majority of responders (64/76; 84.2%) considered surveillance appointments beneficial. Pain level during endometrial biopsy was not associated with the decision to undergo prophylactic surgery. The level of satisfaction the women had with the information and advice provided during surveillance was significantly associated with the history of prophylactic hysterectomy (satisfaction rate of 73.2% versus 31.8% of nonoperated women, p = 0.003). The women who had undergone prophylactic surgery were older than the nonoperated women both at mutation testing (median of 42.3 years versus 31.6 years, p < 0.001) and at the time of the study (median of 56.9 years versus 46.0 years, respectively, p < 0.001). Women with LS pathogenic variants have positive experiences with gynecological surveillance visits, and their perception of the quality of the information and advice obtained plays an important role in their decision-making concerning prophylactic surgery.
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16
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Lønning PE, Eikesdal HP, Løes IM, Knappskog S. Constitutional Mosaic Epimutations - a hidden cause of cancer? Cell Stress 2019; 3:118-135. [PMID: 31225507 PMCID: PMC6551830 DOI: 10.15698/cst2019.04.183] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2019] [Revised: 03/04/2019] [Accepted: 03/05/2019] [Indexed: 12/11/2022] Open
Abstract
Silencing of tumor suppressor genes by promoter hypermethylation is a key mechanism to facilitate cancer progression in many malignancies. While promoter hypermethylation can occur at later stages of the carcinogenesis process, constitutional methylation of key tumor suppressors may be an initiating event whereby cancer is started. Constitutional BRCA1 methylation due to cis-acting germline genetic variants is associated with a high risk of breast and ovarian cancer. However, this seems to be a rare event, restricted to a very limited number of families. In contrast, mosaic constitutional BRCA1 methylation is detected in 4-7% of newborn females without germline BRCA1 mutations. While the cause of such methylation is poorly understood, mosaic normal tissue BRCA1 methylation is associated with a 2-3 fold increased risk of high-grade serous ovarian cancer (HGSOC). As such, BRCA1 methylation may be the cause of a significant number of ovarian cancers. Given the molecular similarities between HGSOC and basal-like breast cancer, the findings with respect to HGSOC suggest that constitutional BRCA1 methylation could be a risk factor for basal-like breast cancer as well. Similar to BRCA1, some specific germline variants in MLH1 and MSH2 are associated with promoter methylation and a high risk of colorectal cancers in rare hereditary cases of the disease. However, as many as 15% of all colorectal cancers are of the microsatellite instability (MSI) "high" subtype, in which commonly the tumors harbor MLH1 hypermethylation. Constitutional mosaic methylation of MLH1 in normal tissues has been detected but not formally evaluated as a potential risk factor for incidental colorectal cancers. However, the findings with respect to BRCA1 in breast and ovarian cancer raises the question whether mosaic MLH1 methylation is a risk factor for MSI positive colorectal cancer as well. As for MGMT, a promoter variant is associated with elevated methylation across a panel of solid cancers, and MGMT promoter methylation may contribute to an elevated cancer risk in several of these malignancies. We hypothesize that constitutional mosaic promoter methylation of crucial tumor suppressors may trigger certain types of cancer, similar to germline mutations inactivating the same particular genes. Such constitutional methylation events may be a spark to ignite cancer development, and if associated with a significant cancer risk, screening for such epigenetic alterations could be part of cancer prevention programs to reduce cancer mortality in the future.
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Affiliation(s)
- Per E. Lønning
- K.G.Jebsen Center for Genome Directed Cancer Therapy, Department of Clinical Science, University of Bergen, Norway
- Department of Oncology, Haukeland University Hospital, Bergen, Norway
| | - Hans P. Eikesdal
- K.G.Jebsen Center for Genome Directed Cancer Therapy, Department of Clinical Science, University of Bergen, Norway
- Department of Oncology, Haukeland University Hospital, Bergen, Norway
| | - Inger M. Løes
- K.G.Jebsen Center for Genome Directed Cancer Therapy, Department of Clinical Science, University of Bergen, Norway
- Department of Oncology, Haukeland University Hospital, Bergen, Norway
| | - Stian Knappskog
- K.G.Jebsen Center for Genome Directed Cancer Therapy, Department of Clinical Science, University of Bergen, Norway
- Department of Oncology, Haukeland University Hospital, Bergen, Norway
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17
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Abstract
BACKGROUND The methylator pathway of colorectal carcinogenesis, characterized by CpG island hypermethylation and BRAF mutations, accounts for ≈25% of colorectal cancers. Because these cancers tend to be right sided and because DNA methylation in the right colon increases with age, we expect an increasing proportion of right-sided cancer over time. Conversely, we expect young patients (age <50 y) to have less methylated and fewer right-sided cancers OBJECTIVE:: The purpose of this study was to analyze the distribution and genetic traits of colorectal cancer from different age groups. DESIGN This was a retrospective cohort study. SETTING The study was conducted at a high-volume tertiary referral center. PATIENTS Patient samples included those from our colorectal cancer biobank of resected colorectal cancer specimens. MAIN OUTCOME MEASURES Tumor CpG island hypermethylation, microsatellite instability, and mutations in KRAS and BRAF oncogenes were analyzed in resected specimens and stratified by age and tumor location. Comparisons included age >50 or <50 years and decade of diagnosis (≤50, 51-60, 61-70, 71-80, and >81 y). Patients with IBD or hereditary syndromes were excluded. RESULTS A total of 497 colorectal cancers were analyzed (266 men and 231 women); 57 patients (11.5%) were ≤50 years of age. No young cancers (0/57) were hypermethylated compared with 97 (22%) of 440 cancers of patients aged >50 years (p < 0.001). An increasing percentage of tumors were CpG island phenotype high with each decade of age at diagnosis. No cancers in patients <50 years of age were microsatellite unstable compared with 91 (23.6%) of 346 for those >50 years of age. No young cancers contained a BRAF mutation compared with 46 (10.6%) of 434 in older cancers (p < 0.001). KRAS mutations were less common in young cancers compared with older cancers (13/57 (22.8%) vs 126/410 (30.7%); p < 0.01). Eleven (19.3%) of 57 young cancers were proximal compared with 228 (51.8%) of 440 (p < 0.001) older cancers. LIMITATIONS This study was limited by its retrospective design. CONCLUSIONS The lack of CpG island methylator phenotype tumors in young patients is consistent with the dominant left-sided cancer distribution seen in the young and focuses efforts to understand and prevent cancer in this age group on causes of chromosomal instability. See Video Abstract at http://links.lww.com/DCR/A709.
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Dámaso E, Castillejo A, Arias MDM, Canet-Hermida J, Navarro M, Del Valle J, Campos O, Fernández A, Marín F, Turchetti D, García-Díaz JDD, Lázaro C, Genuardi M, Rueda D, Alonso Á, Soto JL, Hitchins M, Pineda M, Capellá G. Primary constitutional MLH1 epimutations: a focal epigenetic event. Br J Cancer 2018; 119:978-987. [PMID: 30283143 PMCID: PMC6203851 DOI: 10.1038/s41416-018-0019-8] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2017] [Revised: 11/20/2017] [Accepted: 11/27/2017] [Indexed: 12/15/2022] Open
Abstract
Background Constitutional MLH1 epimutations are characterised by monoallelic methylation of the MLH1 promoter throughout normal tissues, accompanied by allele-specific silencing. The mechanism underlying primary MLH1 epimutations is currently unknown. The aim of this study was to perform an in-depth characterisation of constitutional MLH1 epimutations targeting the aberrantly methylated region around MLH1 and other genomic loci. Methods Twelve MLH1 epimutation carriers, 61 Lynch syndrome patients, and 41 healthy controls, were analysed by Infinium 450 K array. Targeted molecular techniques were used to characterise the MLH1 epimutation carriers and their inheritance pattern. Results No nucleotide or structural variants were identified in-cis on the epimutated allele in 10 carriers, in which inter-generational methylation erasure was demonstrated in two, suggesting primary type of epimutation. CNVs outside the MLH1 locus were found in two cases. EPM2AIP1-MLH1 CpG island was identified as the sole differentially methylated region in MLH1 epimutation carriers compared to controls. Conclusion Primary constitutional MLH1 epimutations arise as a focal epigenetic event at the EPM2AIP1-MLH1 CpG island in the absence of cis-acting genetic variants. Further molecular characterisation is needed to elucidate the mechanistic basis of MLH1 epimutations and their heritability/reversibility.
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Affiliation(s)
- Estela Dámaso
- Hereditary Cancer Program, Catalan Institute of Oncology-Bellvitge Biomedical Research Institute (ICO-IDIBELL),ONCOBELL, CIBERONC, Av.Gran Via de l'Hospitalet 199-203, L'Hospitalet de Llobregat, 08908, Barcelona, Spain
| | - Adela Castillejo
- Hereditary Cancer Program Valencian Region, Molecular Genetics Laboratory, Elche University Hospital, Camino de la Almazara 11, Elche, 03203, Alicante, Spain
| | - María Del Mar Arias
- Genetics Service, Complejo Hospitalario de Navarra, Calle de Irunlarrea 3, Pamplona, 31008, Navarra, Spain
| | - Julia Canet-Hermida
- Hereditary Cancer Program, Catalan Institute of Oncology-Bellvitge Biomedical Research Institute (ICO-IDIBELL),ONCOBELL, CIBERONC, Av.Gran Via de l'Hospitalet 199-203, L'Hospitalet de Llobregat, 08908, Barcelona, Spain
| | - Matilde Navarro
- Hereditary Cancer Program, Catalan Institute of Oncology-Bellvitge Biomedical Research Institute (ICO-IDIBELL),ONCOBELL, CIBERONC, Av.Gran Via de l'Hospitalet 199-203, L'Hospitalet de Llobregat, 08908, Barcelona, Spain
| | - Jesús Del Valle
- Hereditary Cancer Program, Catalan Institute of Oncology-Bellvitge Biomedical Research Institute (ICO-IDIBELL),ONCOBELL, CIBERONC, Av.Gran Via de l'Hospitalet 199-203, L'Hospitalet de Llobregat, 08908, Barcelona, Spain
| | - Olga Campos
- Hereditary Cancer Program, Catalan Institute of Oncology-Bellvitge Biomedical Research Institute (ICO-IDIBELL),ONCOBELL, CIBERONC, Av.Gran Via de l'Hospitalet 199-203, L'Hospitalet de Llobregat, 08908, Barcelona, Spain
| | - Anna Fernández
- Hereditary Cancer Program, Catalan Institute of Oncology-Bellvitge Biomedical Research Institute (ICO-IDIBELL),ONCOBELL, CIBERONC, Av.Gran Via de l'Hospitalet 199-203, L'Hospitalet de Llobregat, 08908, Barcelona, Spain
| | - Fátima Marín
- Hereditary Cancer Program, Catalan Institute of Oncology-Bellvitge Biomedical Research Institute (ICO-IDIBELL),ONCOBELL, CIBERONC, Av.Gran Via de l'Hospitalet 199-203, L'Hospitalet de Llobregat, 08908, Barcelona, Spain
| | - Daniela Turchetti
- Dipartimento di Scienze Mediche e Chirurgiche, Alma Mater Studiorum - Università di Bologna, Via Massarenti 11, Bologna, 40138, Italy
| | - Juan de Dios García-Díaz
- Unidad de Genética Clínica, Servicio de Medicina Interna, Hospital Universitario Príncipe de Asturias, Carretera Alcalá-Meco, Alcalá de Henares, 28805, Madrid, Spain
| | - Conxi Lázaro
- Hereditary Cancer Program, Catalan Institute of Oncology-Bellvitge Biomedical Research Institute (ICO-IDIBELL),ONCOBELL, CIBERONC, Av.Gran Via de l'Hospitalet 199-203, L'Hospitalet de Llobregat, 08908, Barcelona, Spain
| | - Maurizio Genuardi
- Istituto di Medicina Genomica, Università Cattolica del Sacro Cuore - Fondazione Policlinico Universitario Agostino Gemelli, Largo Agostino Gemelli 8, Rome, 00168, Italy
| | - Daniel Rueda
- Hereditary Cancer Genetic Diagnostic Laboratory, Doce de Octubre University Hospital, Avenida de Córdoba, Madrid, Madrid, 28041, Spain
| | - Ángel Alonso
- Genetics Service, Complejo Hospitalario de Navarra, Calle de Irunlarrea 3, Pamplona, 31008, Navarra, Spain
| | - Jose Luis Soto
- Hereditary Cancer Program Valencian Region, Molecular Genetics Laboratory, Elche University Hospital, Camino de la Almazara 11, Elche, 03203, Alicante, Spain.,Alicante Institute for Health and Biomedical Research (ISABIAL-FISABIO Foundation), Alicante, Spain
| | - Megan Hitchins
- Department of Medicine, Division of Oncology, Stanford University, 1291 Welch Road, Stanford, 94305, California, USA
| | - Marta Pineda
- Hereditary Cancer Program, Catalan Institute of Oncology-Bellvitge Biomedical Research Institute (ICO-IDIBELL),ONCOBELL, CIBERONC, Av.Gran Via de l'Hospitalet 199-203, L'Hospitalet de Llobregat, 08908, Barcelona, Spain.
| | - Gabriel Capellá
- Hereditary Cancer Program, Catalan Institute of Oncology-Bellvitge Biomedical Research Institute (ICO-IDIBELL),ONCOBELL, CIBERONC, Av.Gran Via de l'Hospitalet 199-203, L'Hospitalet de Llobregat, 08908, Barcelona, Spain.
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19
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Diversity of genetic events associated with MLH1 promoter methylation in Lynch syndrome families with heritable constitutional epimutation. Genet Med 2018; 20:1589-1599. [DOI: 10.1038/gim.2018.47] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2017] [Accepted: 02/20/2018] [Indexed: 02/07/2023] Open
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20
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Morak M, Ibisler A, Keller G, Jessen E, Laner A, Gonzales-Fassrainer D, Locher M, Massdorf T, Nissen AM, Benet-Pagès A, Holinski-Feder E. Comprehensive analysis of the MLH1 promoter region in 480 patients with colorectal cancer and 1150 controls reveals new variants including one with a heritable constitutional MLH1 epimutation. J Med Genet 2018; 55:240-248. [PMID: 29472279 DOI: 10.1136/jmedgenet-2017-104744] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2017] [Revised: 10/27/2017] [Accepted: 10/30/2017] [Indexed: 01/28/2023]
Abstract
BACKGROUND Germline defects in MLH1, MSH2, MSH6 and PMS2 predisposing for Lynch syndrome (LS) are mainly based on sequence changes, whereas a constitutional epimutation of MLH1(CEM) is exceptionally rare. This abnormal MLH1 promoter methylation is not hereditary when arising de novo, whereas a stably heritable and variant-induced CEM was described for one single allele. We searched for MLH1 promoter variants causing a germline or somatic methylation induction or transcriptional repression. METHODS We analysed the MLH1 promoter sequence in five different patient groups with colorectal cancer (CRC) (n=480) composed of patients with i) CEM (n=16), ii) unsolved loss of MLH1 expression in CRC (n=37), iii) CpG-island methylator-phenotype CRC (n=102), iv) patients with LS (n=83) and v) MLH1-proficient CRC (n=242) as controls. 1150 patients with non-LS tumours also served as controls to correctly judge the results. RESULTS We detected 10 rare MLH1 promoter variants. One novel, complex MLH1 variant c.-63_-58delins18 is present in a patient with CRC with CEM and his sister, both showing a complete allele-specific promoter methylation and transcriptional silencing. The other nine promoter variants detected in 17 individuals were not associated with methylation. For four of these, a normal, biallelic MLH1 expression was found in the patients' cDNA. CONCLUSION We report the second promoter variant stably inducing a hereditary CEM. Concerning the classification of promoter variants, we discuss contradictory results from the literature for two variants, describe classification discrepancies between existing rules for five variants, suggest the (re-)classification of five promoter variants to (likely) benign and regard four variants as functionally unclear.
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Affiliation(s)
- Monika Morak
- Medizinische Klinik und Poliklinik IV, Klinikum der Universität München, Munich, Bavaria, Germany.,Center of Medical Genetics, Medizinisch Genetisches Zentrum, Munich, Bavaria, Germany
| | - Ayseguel Ibisler
- Department of Human Genetics, Ruhr University Bochum, Bochum, North Rhine-Westphalia, Germany
| | - Gisela Keller
- Institute of Pathology, Technical University Munich, Munich, Bavaria, Germany
| | - Ellen Jessen
- Praxis für Humangenetik, Praxis für Humangenetik, Hamburg, Hamburg, Germany
| | - Andreas Laner
- Center of Medical Genetics, Medizinisch Genetisches Zentrum, Munich, Bavaria, Germany
| | | | - Melanie Locher
- Center of Medical Genetics, Medizinisch Genetisches Zentrum, Munich, Bavaria, Germany
| | - Trisari Massdorf
- Medizinische Klinik und Poliklinik IV, Klinikum der Universität München, Munich, Bavaria, Germany
| | - Anke M Nissen
- Center of Medical Genetics, Medizinisch Genetisches Zentrum, Munich, Bavaria, Germany
| | - Anna Benet-Pagès
- Center of Medical Genetics, Medizinisch Genetisches Zentrum, Munich, Bavaria, Germany
| | - Elke Holinski-Feder
- Medizinische Klinik und Poliklinik IV, Klinikum der Universität München, Munich, Bavaria, Germany.,Center of Medical Genetics, Medizinisch Genetisches Zentrum, Munich, Bavaria, Germany
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21
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Dos Santos ES, Caputo SM, Castera L, Gendrot M, Briaux A, Breault M, Krieger S, Rogan PK, Mucaki EJ, Burke LJ, Bièche I, Houdayer C, Vaur D, Stoppa-Lyonnet D, Brown MA, Lallemand F, Rouleau E. Assessment of the functional impact of germline BRCA1/2 variants located in non-coding regions in families with breast and/or ovarian cancer predisposition. Breast Cancer Res Treat 2017; 168:311-325. [PMID: 29236234 DOI: 10.1007/s10549-017-4602-0] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2017] [Accepted: 11/28/2017] [Indexed: 12/19/2022]
Abstract
PURPOSE The molecular mechanism of breast and/or ovarian cancer susceptibility remains unclear in the majority of patients. While germline mutations in the regulatory non-coding regions of BRCA1 and BRCA2 genes have been described, screening has generally been limited to coding regions. The aim of this study was to evaluate the contribution of BRCA1/2 non-coding variants. METHODS Four BRCA1/2 non-coding regions were screened using high-resolution melting analysis/Sanger sequencing or next-generation sequencing on DNA extracted from index cases with breast and ovarian cancer predisposition (3926 for BRCA1 and 3910 for BRCA2). The impact of a set of variants on BRCA1/2 gene regulation was evaluated by site-directed mutagenesis, transfection, followed by Luciferase gene reporter assay. RESULTS We identified a total of 117 variants and tested twelve BRCA1 and 8 BRCA2 variants mapping to promoter and intronic regions. We highlighted two neighboring BRCA1 promoter variants (c.-130del; c.-125C > T) and one BRCA2 promoter variants (c.-296C > T) inhibiting significantly the promoter activity. In the functional assays, a regulating region within the intron 12 was found with the same enhancing impact as within the intron 2. Furthermore, the variants c.81-3980A > G and c.4186-2022C > T suppress the positive effect of the introns 2 and 12, respectively, on the BRCA1 promoter activity. We also found some variants inducing the promoter activities. CONCLUSION In this study, we highlighted some variants among many, modulating negatively the promoter activity of BRCA1 or 2 and thus having a potential impact on the risk of developing cancer. This selection makes it possible to conduct future validation studies on a limited number of variants.
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Affiliation(s)
- E Santana Dos Santos
- Department of Oncology, Center for Translational Oncology, Cancer Institute of the State of São Paulo - ICESP, São Paulo, Brazil
- Service de Génétique, Institut Curie, Paris, France
- A.C.Camargo Cancer Center, São Paulo, Brazil
| | - S M Caputo
- Service de Génétique, Institut Curie, Paris, France
| | - L Castera
- Laboratoire de Biologie et de Génétique du Cancer, CLCC François Baclesse, INSERM 1079 Centre Normand de Génomique et de MédecinePersonnalisée, Caen, France
| | - M Gendrot
- Service de Génétique, Institut Curie, Paris, France
| | - A Briaux
- Service de Génétique, Institut Curie, Paris, France
| | - M Breault
- Service de Génétique, Institut Curie, Paris, France
| | - S Krieger
- Laboratoire de Biologie et de Génétique du Cancer, CLCC François Baclesse, INSERM 1079 Centre Normand de Génomique et de MédecinePersonnalisée, Caen, France
| | - P K Rogan
- Department of Biochemistry, Schulich School of Medicine and Dentistry, University of Western Ontario, London, Canada
| | - E J Mucaki
- Department of Biochemistry, Schulich School of Medicine and Dentistry, University of Western Ontario, London, Canada
| | - L J Burke
- School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, Australia
| | - I Bièche
- Service de Génétique, Institut Curie, Paris, France
- Université Paris Descartes, Paris, France
| | - C Houdayer
- Service de Génétique, Institut Curie, Paris, France
- Université Paris Descartes, Paris, France
| | - D Vaur
- Laboratoire de Biologie et de Génétique du Cancer, CLCC François Baclesse, INSERM 1079 Centre Normand de Génomique et de MédecinePersonnalisée, Caen, France
| | - D Stoppa-Lyonnet
- Service de Génétique, Institut Curie, Paris, France
- Université Paris Descartes, Paris, France
| | - M A Brown
- School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, Australia
| | - F Lallemand
- Service de Génétique, Institut Curie, Paris, France.
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22
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Nejadtaghi M, Jafari H, Farrokhi E, Samani KG. Familial Colorectal Cancer Type X (FCCTX) and the correlation with various genes-A systematic review. Curr Probl Cancer 2017; 41:388-397. [PMID: 29096939 DOI: 10.1016/j.currproblcancer.2017.10.002] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2016] [Revised: 05/10/2017] [Accepted: 10/12/2017] [Indexed: 02/09/2023]
Abstract
Familial Colorectal Cancer Type X (FCCTX) is a type of hereditary nonpolyposis colorectal cancer in accordance to Amsterdam criteria-1 for Lynch syndrome, with no related mutation in mismatch repair gene. FCCTX is microsatellite stable and is accounted for 40% of families with Amsterdam criteria-1 with a high age of onset. Thus, the carcinogenesis of FCCTX is different compared to Lynch syndrome. In addition to the microsatellite stability and the presence of less predominant tumors in proximal colon, various clinical features have also been associated with FCCTX in comparison with Lynch syndrome such as no increased risk of extra-colonic cancers, older age of diagnosis and higher adenoma/carcinoma rate. Genetic etiology of this type of cancer which is autosomal dominant is unknown. In this review, we focus on the genes and their variants identified in this type of CRC. In order to find out the correlation between FCCTX and various genes database such as PubMed and PMC, search engine such as Google scholar and portals such as Springer and Elsevier have been searched. Based on our literature search, several studies suggest that FCCTX is a heterogeneous type of disease with different genetic variants. Recent studies describe the correlation between FCCTX and genes such as BRCA2, SEMA4, NTS, RASSF9, GALNT12, KRAS, BRAF, APC, BMPR1A, and RPS20. Considering the fact that BRCA2 has the highest mutation rate (60%) and is one of the most crucial DNA repair genes, it will be considered as a big role player in this type of cancer in comparison with other genes.
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Affiliation(s)
- Mahdieh Nejadtaghi
- Cellular and Molecular Research Center, Shahrekord University of Medical Science, Shahrekord, Iran
| | - Hamideh Jafari
- Cellular and Molecular Research Center, Shahrekord University of Medical Science, Shahrekord, Iran
| | - Effat Farrokhi
- Cellular and Molecular Research Center, Shahrekord University of Medical Science, Shahrekord, Iran.
| | - Keihan Ghatreh Samani
- Clinical Biochemistry Research Center, Shahrekord University of Medical Science, Shahrekord, Iran
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23
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Tse JWT, Jenkins LJ, Chionh F, Mariadason JM. Aberrant DNA Methylation in Colorectal Cancer: What Should We Target? Trends Cancer 2017; 3:698-712. [PMID: 28958388 DOI: 10.1016/j.trecan.2017.08.003] [Citation(s) in RCA: 73] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2017] [Revised: 08/10/2017] [Accepted: 08/11/2017] [Indexed: 12/16/2022]
Abstract
Colorectal cancers (CRCs) are characterized by global hypomethylation and promoter-specific DNA methylation. A subset of CRCs with extensive and co-ordinate patterns of promoter methylation has also been identified, termed the CpG-island methylator phenotype. Some genes methylated in CRC are established tumor suppressors; however, for the majority, direct roles in disease initiation or progression have not been established. Herein, we examine functional evidence of specific methylated genes contributing to CRC pathogenesis, focusing on components of commonly deregulated signaling pathways. We also review current knowledge of the mechanisms underpinning promoter methylation in CRC, including genetic events, altered transcription factor binding, and DNA damage. Finally, we summarize clinical trials of DNA methyltransferase inhibitors in CRC, and propose strategies for enhancing their efficacy.
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Affiliation(s)
- Janson W T Tse
- Olivia Newton-John Cancer Research Institute, Melbourne, Australia; These authors contributed equally
| | - Laura J Jenkins
- Olivia Newton-John Cancer Research Institute, Melbourne, Australia; School of Cancer Medicine, La Trobe University, Melbourne, Australia; These authors contributed equally
| | - Fiona Chionh
- Olivia Newton-John Cancer Research Institute, Melbourne, Australia
| | - John M Mariadason
- Olivia Newton-John Cancer Research Institute, Melbourne, Australia; School of Cancer Medicine, La Trobe University, Melbourne, Australia.
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24
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Abstract
Four main DNA mismatch repair (MMR) genes have been identified, MLH1, MSH2, MSH6, and PMS2, which when mutated cause susceptibility to Lynch syndrome (LS). LS is one of the most prevalent hereditary cancer syndromes in man and accounts for 1–3 % of unselected colorectal carcinomas and some 15 % of those with microsatellite instability and/or absent MMR protein. The International Society for Gastrointestinal Hereditary Tumours (InSiGHT) maintains a database for LS-associated mutations since 1996. The database was recently reorganized to efficiently gather published and unpublished data and to classify the variants according to a five-tiered scheme linked to clinical recommendations. This review provides an update of germline mutations causing susceptibility to LS based on information available in the InSiGHT database and the latest literature. MMR gene mutation profiles, correlations between genotype and phenotype, and possible mechanisms leading to the characteristic spectrum of tumors in LS are discussed in light of the different functions of MMR proteins, many of which directly serve cancer avoidance.
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25
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Bartosch C, Lopes JM, Jerónimo C. Epigenetics in endometrial carcinogenesis - part 2: histone modifications, chromatin remodeling and noncoding RNAs. Epigenomics 2017; 9:873-892. [PMID: 28523964 DOI: 10.2217/epi-2016-0167] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Carcinogenesis is a multistep multifactorial process that involves the accumulation of genetic and epigenetic alterations. In the past two decades, there has been an exponential growth of knowledge establishing the importance of epigenetic changes in cancer. Our work focused on reviewing the main role of epigenetics in the pathogenesis of endometrial carcinoma, highlighting the reported results concerning each epigenetic mechanistic layer. In a previous review, we assessed DNA methylation alterations. The present review examines the contribution of histone modifications, chromatin remodeling and noncoding RNA alterations for endometrial carcinogenesis.
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Affiliation(s)
- Carla Bartosch
- Department of Pathology, Portuguese Oncology Institute of Porto (IPO-Porto), Porto, Portugal.,Cancer Biology & Epigenetics Group, Research Center (CI-IPOP), Portuguese Oncology Institute of Porto, Porto, Portugal.,Department of Pathology & Oncology, Medical Faculty, University of Porto, Porto, Portugal.,Porto Comprehensive Cancer Center (P.ccc), Porto, Portugal
| | - José Manuel Lopes
- Department of Pathology & Oncology, Medical Faculty, University of Porto, Porto, Portugal.,Department of Pathology, Centro Hospitalar São João (CHSJ), Porto, Portugal.,IPATIMUP (Institute of Molecular Pathology & Immunology, University of Porto); I3S-Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal
| | - Carmen Jerónimo
- Cancer Biology & Epigenetics Group, Research Center (CI-IPOP), Portuguese Oncology Institute of Porto, Porto, Portugal.,Porto Comprehensive Cancer Center (P.ccc), Porto, Portugal.,Department of Pathology & Molecular Immunology, Institute of Biomedical Sciences Abel Salazar (ICBAS), University of Porto, Porto, Portugal
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26
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Takeda T, Banno K, Yanokura M, Adachi M, Iijima M, Kunitomi H, Nakamura K, Iida M, Nogami Y, Umene K, Masuda K, Kobayashi Y, Yamagami W, Hirasawa A, Tominaga E, Susumu N, Aoki D. Methylation Analysis of DNA Mismatch Repair Genes Using DNA Derived from the Peripheral Blood of Patients with Endometrial Cancer: Epimutation in Endometrial Carcinogenesis. Genes (Basel) 2016; 7:genes7100086. [PMID: 27754426 PMCID: PMC5083925 DOI: 10.3390/genes7100086] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2016] [Revised: 08/28/2016] [Accepted: 10/06/2016] [Indexed: 01/28/2023] Open
Abstract
Germline mutation of DNA mismatch repair (MMR) genes is a cause of Lynch syndrome. Methylation of MutL homolog 1 (MLH1) and MutS homolog 2 (MSH2) has been detected in peripheral blood cells of patients with colorectal cancer. This methylation is referred to as epimutation. Methylation of these genes has not been studied in an unselected series of endometrial cancer cases. Therefore, we examined methylation of MLH1, MSH2, and MSH6 promoter regions of peripheral blood cells in 206 patients with endometrial cancer using a methylation-specific polymerase chain reaction (MSP). Germline mutation of MMR genes, microsatellite instability (MSI), and immunohistochemistry (IHC) were also analyzed in each case with epimutation. MLH1 epimutation was detected in a single patient out of a total of 206 (0.49%)-1 out of 58 (1.72%) with an onset age of less than 50 years. The patient with MLH1 epimutation showed high level MSI (MSI-H), loss of MLH1 expression and had developed endometrial cancer at 46 years old, complicated with colorectal cancer. No case had epimutation of MSH2 or MSH6. The MLH1 epimutation detected in a patient with endometrial cancer may be a cause of endometrial carcinogenesis. This result indicates that it is important to check epimutation in patients with endometrial cancer without a germline mutation of MMR genes.
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Affiliation(s)
- Takashi Takeda
- Department of Obstetrics and Gynecology, Keio University School of Medicine, Tokyo 160-8582, Japan.
| | - Kouji Banno
- Department of Obstetrics and Gynecology, Keio University School of Medicine, Tokyo 160-8582, Japan.
| | - Megumi Yanokura
- Department of Obstetrics and Gynecology, Keio University School of Medicine, Tokyo 160-8582, Japan.
| | - Masataka Adachi
- Department of Obstetrics and Gynecology, Keio University School of Medicine, Tokyo 160-8582, Japan.
| | - Moito Iijima
- Department of Obstetrics and Gynecology, Keio University School of Medicine, Tokyo 160-8582, Japan.
| | - Haruko Kunitomi
- Department of Obstetrics and Gynecology, Keio University School of Medicine, Tokyo 160-8582, Japan.
| | - Kanako Nakamura
- Department of Obstetrics and Gynecology, Keio University School of Medicine, Tokyo 160-8582, Japan.
| | - Miho Iida
- Department of Obstetrics and Gynecology, Keio University School of Medicine, Tokyo 160-8582, Japan.
| | - Yuya Nogami
- Department of Obstetrics and Gynecology, Keio University School of Medicine, Tokyo 160-8582, Japan.
| | - Kiyoko Umene
- Department of Obstetrics and Gynecology, Keio University School of Medicine, Tokyo 160-8582, Japan.
| | - Kenta Masuda
- Department of Obstetrics and Gynecology, Keio University School of Medicine, Tokyo 160-8582, Japan.
| | - Yusuke Kobayashi
- Department of Obstetrics and Gynecology, Keio University School of Medicine, Tokyo 160-8582, Japan.
| | - Wataru Yamagami
- Department of Obstetrics and Gynecology, Keio University School of Medicine, Tokyo 160-8582, Japan.
| | - Akira Hirasawa
- Department of Obstetrics and Gynecology, Keio University School of Medicine, Tokyo 160-8582, Japan.
| | - Eiichiro Tominaga
- Department of Obstetrics and Gynecology, Keio University School of Medicine, Tokyo 160-8582, Japan.
| | - Nobuyuki Susumu
- Department of Obstetrics and Gynecology, Keio University School of Medicine, Tokyo 160-8582, Japan.
| | - Daisuke Aoki
- Department of Obstetrics and Gynecology, Keio University School of Medicine, Tokyo 160-8582, Japan.
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27
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Staff S, Aaltonen M, Huhtala H, Pylvänäinen K, Mecklin JP, Mäenpää J. Endometrial cancer risk factors among Lynch syndrome women: a retrospective cohort study. Br J Cancer 2016; 115:375-81. [PMID: 27336600 PMCID: PMC4973157 DOI: 10.1038/bjc.2016.193] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2016] [Revised: 05/18/2016] [Accepted: 05/24/2016] [Indexed: 12/21/2022] Open
Abstract
BACKGROUND Lynch syndrome (LS) is associated with a significant lifetime risk of endometrial cancer (EC). There are limited data on factors modifying the EC risk in LS patients. METHODS The study cohort included 136 LS mutation-positive women. Exposure data were collected by postal questionnaires. Cox regression model was used to estimate the associations between lifestyle, hormonal, reproductive and medical factors and the risk of EC. RESULTS Increased EC risk was associated with type II diabetes and hypercholesterolaemia in univariable (HR 3.21, (95% CI 1.34-7.78), P=0.009 and HR 2.08, (95% CI 1.11-3.90), P=0.02; respectively) and with diabetes and duration of hormone replacement therapy (HRT) in multivariable analysis (HR 4.18 (95% CI 1.52-11.52), P=0.006 and HR 1.07 (95% CI 1.02-1.13), P=0.010; respectively). CONCLUSIONS Prevention of diabetes and avoiding long-duration HRT are potential targets for reduction of EC risk in women with LS.
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Affiliation(s)
- Synnöve Staff
- Department of Obstetrics and Gynecology, Tampere University Hospital, Tampere, Finland
- Laboratory of Cancer Biology, BioMediTech, University of Tampere, Tampere, Finland
| | - Mari Aaltonen
- Department of Obstetrics and Gynecology, Tampere University Hospital, Tampere, Finland
| | - Heini Huhtala
- School of Health Sciences, University of Tampere, Tampere, Finland
| | - Kirsi Pylvänäinen
- Department of Education and Research, Jyväskylä Central Hospital, Jyväskylä, Finland
| | - Jukka-Pekka Mecklin
- Department of Surgery, Jyväskylä Central Hospital and University of Eastern Finland, Jyväskylä, Finland
| | - Johanna Mäenpää
- Department of Obstetrics and Gynecology, Tampere University Hospital, Tampere, Finland
- School of Medicine, University of Tampere, Tampere, Finland
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28
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Silva P, Albuquerque C, Lage P, Fontes V, Fonseca R, Vitoriano I, Filipe B, Rodrigues P, Moita S, Ferreira S, Sousa R, Claro I, Nobre Leitão C, Chaves P, Dias Pereira A. Serrated polyposis associated with a family history of colorectal cancer and/or polyps: The preferential location of polyps in the colon and rectum defines two molecular entities. Int J Mol Med 2016; 38:687-702. [PMID: 27430658 PMCID: PMC4990292 DOI: 10.3892/ijmm.2016.2666] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2015] [Accepted: 03/11/2016] [Indexed: 12/25/2022] Open
Abstract
Serrated polyposis (SPP) is characterized by the development of multiple serrated polyps and an increased predisposition to colorectal cancer (CRC). In the present study, we aimed to characterize, at a clinical and molecular level, a cohort of SPP patients with or without a family history of SPP and/or polyps/CRC (SPP-FHP/CRC). Sixty-two lesions from 12 patients with SPP-FHP/CRC and 6 patients with sporadic SPP were included. The patients with SPP-FHP/CRC presented with an older mean age at diagnosis (p=0.027) and a more heterogeneous histological pattern of lesions (p=0.032) than the patients with sporadic SPP. We identified two molecular forms of SPP-FHP/CRC, according to the preferential location of the lesions: proximal/whole-colon or distal colon. Mismatch repair (MMR) gene methylation [mutS homolog 6 (MSH6)/mutS homolog 3 (MSH3)] or loss of heterozygosity (LOH) of D2S123 (flanking MSH6) were detected exclusively in the former (p=3.0×10−7), in most early lesions. Proximal/whole-colon SPP-FHP/CRC presented a higher frequency of O-6-methylguanine-DNA methyltransferase (MGMT) methylation/LOH, microsatel-lite instability (MSI) and Wnt mutations (19/29 vs. 7/17; 16/23 vs. 1/14, p=2.2×10−4; 15/26 vs. 2/15, p=0.006; 14/26 vs. 4/20, p=0.02) but a lower frequency of B-raf proto-oncogene, serine/threonine kinase (BRAF) mutations (7/30 vs. 12/20, p=0.0089) than the distal form. CRC was more frequent in cases of Kirsten rat sarcoma viral oncogene homolog (KRAS)-associated proximal/whole-colon SPP-FHP/CRC than in the remaining cases (4/4 vs. 1/8, p=0.01). Thus, SPP-FHP/CRC appears to be a specific entity, presenting two forms, proximal/whole-colon and distal, which differ in the underlying tumor initiation pathways. Early MGMT and MMR gene deficiency in the former may underlie an inherited susceptibility to genotoxic stress.
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Affiliation(s)
- Patrícia Silva
- Molecular Pathobiology Research Unit (UIPM), Portuguese Institute of Oncology of Lisbon Francisco Gentil, E.P.E. (IPOLFG, EPE), Lisbon, Portugal
| | - Cristina Albuquerque
- Molecular Pathobiology Research Unit (UIPM), Portuguese Institute of Oncology of Lisbon Francisco Gentil, E.P.E. (IPOLFG, EPE), Lisbon, Portugal
| | - Pedro Lage
- Gastroenterology Service, Portuguese Institute of Oncology of Lisbon Francisco Gentil, E.P.E. (IPOLFG, EPE), Lisbon, Portugal
| | - Vanessa Fontes
- Molecular Pathobiology Research Unit (UIPM), Portuguese Institute of Oncology of Lisbon Francisco Gentil, E.P.E. (IPOLFG, EPE), Lisbon, Portugal
| | - Ricardo Fonseca
- Pathology Service, Portuguese Institute of Oncology of Lisbon Francisco Gentil, E.P.E. (IPOLFG, EPE), Lisbon, Portugal
| | - Inês Vitoriano
- Molecular Pathobiology Research Unit (UIPM), Portuguese Institute of Oncology of Lisbon Francisco Gentil, E.P.E. (IPOLFG, EPE), Lisbon, Portugal
| | - Bruno Filipe
- Molecular Pathobiology Research Unit (UIPM), Portuguese Institute of Oncology of Lisbon Francisco Gentil, E.P.E. (IPOLFG, EPE), Lisbon, Portugal
| | - Paula Rodrigues
- Familial Cancer Risk Clinic, Portuguese Institute of Oncology of Lisbon Francisco Gentil, E.P.E. (IPOLFG, EPE), Lisbon, Portugal
| | - Susana Moita
- Molecular Pathobiology Research Unit (UIPM), Portuguese Institute of Oncology of Lisbon Francisco Gentil, E.P.E. (IPOLFG, EPE), Lisbon, Portugal
| | - Sara Ferreira
- Gastroenterology Service, Portuguese Institute of Oncology of Lisbon Francisco Gentil, E.P.E. (IPOLFG, EPE), Lisbon, Portugal
| | - Rita Sousa
- Gastroenterology Service, Portuguese Institute of Oncology of Lisbon Francisco Gentil, E.P.E. (IPOLFG, EPE), Lisbon, Portugal
| | - Isabel Claro
- Gastroenterology Service, Portuguese Institute of Oncology of Lisbon Francisco Gentil, E.P.E. (IPOLFG, EPE), Lisbon, Portugal
| | - Carlos Nobre Leitão
- Gastroenterology Service, Portuguese Institute of Oncology of Lisbon Francisco Gentil, E.P.E. (IPOLFG, EPE), Lisbon, Portugal
| | - Paula Chaves
- Pathology Service, Portuguese Institute of Oncology of Lisbon Francisco Gentil, E.P.E. (IPOLFG, EPE), Lisbon, Portugal
| | - António Dias Pereira
- Gastroenterology Service, Portuguese Institute of Oncology of Lisbon Francisco Gentil, E.P.E. (IPOLFG, EPE), Lisbon, Portugal
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29
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Li J, Dai H, Feng Y, Tang J, Chen S, Tian X, Gorman E, Schmitt ES, Hansen TAA, Wang J, Plon SE, Zhang VW, Wong LJC. A Comprehensive Strategy for Accurate Mutation Detection of the Highly Homologous PMS2. J Mol Diagn 2016; 17:545-53. [PMID: 26320870 DOI: 10.1016/j.jmoldx.2015.04.001] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2015] [Revised: 04/07/2015] [Accepted: 04/29/2015] [Indexed: 10/23/2022] Open
Abstract
Germline mutations in the DNA mismatch repair gene PMS2 underlie the cancer susceptibility syndrome, Lynch syndrome. However, accurate molecular testing of PMS2 is complicated by a large number of highly homologous sequences. To establish a comprehensive approach for mutation detection of PMS2, we have designed a strategy combining targeted capture next-generation sequencing (NGS), multiplex ligation-dependent probe amplification, and long-range PCR followed by NGS to simultaneously detect point mutations and copy number changes of PMS2. Exonic deletions (E2 to E9, E5 to E9, E8, E10, E14, and E1 to E15), duplications (E11 to E12), and a nonsense mutation, p.S22*, were identified. Traditional multiplex ligation-dependent probe amplification and Sanger sequencing approaches cannot differentiate the origin of the exonic deletions in the 3' region when PMS2 and PMS2CL share identical sequences as a result of gene conversion. Our approach allows unambiguous identification of mutations in the active gene with a straightforward long-range-PCR/NGS method. Breakpoint analysis of multiple samples revealed that recurrent exon 14 deletions are mediated by homologous Alu sequences. Our comprehensive approach provides a reliable tool for accurate molecular analysis of genes containing multiple copies of highly homologous sequences and should improve PMS2 molecular analysis for patients with Lynch syndrome.
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Affiliation(s)
- Jianli Li
- Baylor Miraca Genetics Laboratories, Houston, Texas
| | | | - Yanming Feng
- Baylor Miraca Genetics Laboratories, Houston, Texas
| | - Jia Tang
- Baylor Miraca Genetics Laboratories, Houston, Texas
| | - Stella Chen
- Baylor Miraca Genetics Laboratories, Houston, Texas
| | - Xia Tian
- Baylor Miraca Genetics Laboratories, Houston, Texas
| | | | | | - Terah A A Hansen
- Central Washington Genetics Program, Yakima Valley Memorial Hospital, Yakima, Washington
| | - Jing Wang
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas
| | - Sharon E Plon
- Department of Pediatrics, Baylor College of Medicine, Houston, Texas
| | - Victor Wei Zhang
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas.
| | - Lee-Jun C Wong
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas.
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30
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Ribi S, Baumhoer D, Lee K, Edison, Teo ASM, Madan B, Zhang K, Kohlmann WK, Yao F, Lee WH, Hoi Q, Cai S, Woo XY, Tan P, Jundt G, Smida J, Nathrath M, Sung WK, Schiffman JD, Virshup DM, Hillmer AM. TP53 intron 1 hotspot rearrangements are specific to sporadic osteosarcoma and can cause Li-Fraumeni syndrome. Oncotarget 2016; 6:7727-40. [PMID: 25762628 PMCID: PMC4480712 DOI: 10.18632/oncotarget.3115] [Citation(s) in RCA: 50] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2014] [Accepted: 01/08/2015] [Indexed: 12/05/2022] Open
Abstract
Somatic mutations of TP53 are among the most common in cancer and germline mutations of TP53 (usually missense) can cause Li-Fraumeni syndrome (LFS). Recently, recurrent genomic rearrangements in intron 1 of TP53 have been described in osteosarcoma (OS), a highly malignant neoplasm of bone belonging to the spectrum of LFS tumors. Using whole-genome sequencing of OS, we found features of TP53 intron 1 rearrangements suggesting a unique mechanism correlated with transcription. Screening of 288 OS and 1,090 tumors of other types revealed evidence for TP53 rearrangements in 46 (16%) OS, while none were detected in other tumor types, indicating this rearrangement to be highly specific to OS. We revisited a four-generation LFS family where no TP53 mutation had been identified and found a 445 kb inversion spanning from the TP53 intron 1 towards the centromere. The inversion segregated with tumors in the LFS family. Cancers in this family had loss of heterozygosity, retaining the rearranged allele and resulting in TP53 expression loss. In conclusion, intron 1 rearrangements cause p53-driven malignancies by both germline and somatic mechanisms and provide an important mechanism of TP53 inactivation in LFS, which might in part explain the diagnostic gap of formerly classified “TP53 wild-type” LFS.
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Affiliation(s)
- Sebastian Ribi
- Cancer Therapeutics & Stratified Oncology, Genome Institute of Singapore, Singapore 138672, Singapore
| | - Daniel Baumhoer
- Bone Tumor Reference Center at The Institute of Pathology, University Hospital Basel, CH-4003 Basel, Switzerland.,Clinical Cooperation Group Osteosarcoma, Helmholtz Zentrum Muenchen, German Research Center for Environmental Health, 85764 Neuherberg, Germany
| | - Kristy Lee
- Department of Pediatrics and Oncological Sciences, Huntsman Cancer Institute, University of Utah, Salt Lake City, UT 84112, USA
| | - Edison
- Duke-NUS Graduate Medical School Singapore, Singapore 169857, Singapore
| | - Audrey S M Teo
- Cancer Therapeutics & Stratified Oncology, Genome Institute of Singapore, Singapore 138672, Singapore
| | - Babita Madan
- Duke-NUS Graduate Medical School Singapore, Singapore 169857, Singapore
| | - Kang Zhang
- Institute for Genomic Medicine, UC San Diego, La Jolla, CA 92830, USA
| | - Wendy K Kohlmann
- Huntsman Cancer Institute, University of Utah Health Care, Utah, UT 84112, USA
| | - Fei Yao
- Cancer Therapeutics & Stratified Oncology, Genome Institute of Singapore, Singapore 138672, Singapore
| | - Wah Heng Lee
- Computational & Systems Biology, Genome Institute of Singapore, Singapore 138672, Singapore
| | - Qiangze Hoi
- Computational & Systems Biology, Genome Institute of Singapore, Singapore 138672, Singapore
| | - Shaojiang Cai
- Computational & Systems Biology, Genome Institute of Singapore, Singapore 138672, Singapore
| | - Xing Yi Woo
- Personal Genomics Solutions, Genome Institute of Singapore, Singapore 138672, Singapore
| | - Patrick Tan
- Cancer Therapeutics & Stratified Oncology, Genome Institute of Singapore, Singapore 138672, Singapore.,Duke-NUS Graduate Medical School Singapore, Singapore 169857, Singapore.,Cancer Science Institute of Singapore, National University of Singapore, Singapore 117599, Singapore
| | - Gernot Jundt
- Bone Tumor Reference Center at The Institute of Pathology, University Hospital Basel, CH-4003 Basel, Switzerland
| | - Jan Smida
- Clinical Cooperation Group Osteosarcoma, Helmholtz Zentrum Muenchen, German Research Center for Environmental Health, 85764 Neuherberg, Germany.,Department of Pediatrics and Wilhelm Sander Sarcoma Treatment Unit, Technische Universität München and Pediatric Oncology Center, 81675 Munich, Germany
| | - Michaela Nathrath
- Clinical Cooperation Group Osteosarcoma, Helmholtz Zentrum Muenchen, German Research Center for Environmental Health, 85764 Neuherberg, Germany.,Department of Pediatrics and Wilhelm Sander Sarcoma Treatment Unit, Technische Universität München and Pediatric Oncology Center, 81675 Munich, Germany
| | - Wing-Kin Sung
- Computational & Systems Biology, Genome Institute of Singapore, Singapore 138672, Singapore.,School of Computing, National University of Singapore, Singapore 117417, Singapore
| | - Joshua D Schiffman
- Department of Pediatrics and Oncological Sciences, Huntsman Cancer Institute, University of Utah, Salt Lake City, UT 84112, USA
| | - David M Virshup
- Duke-NUS Graduate Medical School Singapore, Singapore 169857, Singapore
| | - Axel M Hillmer
- Cancer Therapeutics & Stratified Oncology, Genome Institute of Singapore, Singapore 138672, Singapore
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31
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Abstract
Colorectal cancer (CRC) is the second most common cancer in women and the third most common in men globally. CRC arises from one or a combination of chromosomal instability, CpG island methylator phenotype, and microsatellite instability. Genetic instability is usually caused by aneuploidy and loss of heterozygosity. Mutations in the tumor suppressor or cell cycle genes may also lead to cellular transformation. Similarly, epigenetic and/or genetic alterations resulting in impaired cellular pathways, such as DNA repair mechanism, may lead to microsatellite instability and mutator phenotype. Non-coding RNAs, more importantly microRNAs and long non-coding RNAs have also been implicated at various CRC stages. Understanding the specific mechanisms of tumorigenesis and the underlying genetic and epigenetic traits is critical in comprehending the disease phenotype. This paper reviews these mechanisms along with the roles of various non-coding RNAs in CRCs.
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Affiliation(s)
- Kanwal Tariq
- Department of Biological and Biomedical Sciences, Aga Khan University, Karachi 74800, Pakistan
| | - Kulsoom Ghias
- Department of Biological and Biomedical Sciences, Aga Khan University, Karachi 74800, Pakistan
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32
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Abstract
Colorectal cancer (CRC) is the second most common cancer in women and the third most common in men globally. CRC arises from one or a combination of chromosomal instability, CpG island methylator phenotype, and microsatellite instability. Genetic instability is usually caused by aneuploidy and loss of heterozygosity. Mutations in the tumor suppressor or cell cycle genes may also lead to cellular transformation. Similarly, epigenetic and/or genetic alterations resulting in impaired cellular pathways, such as DNA repair mechanism, may lead to microsatellite instability and mutator phenotype. Non-coding RNAs, more importantly microRNAs and long non-coding RNAs have also been implicated at various CRC stages. Understanding the specific mechanisms of tumorigenesis and the underlying genetic and epigenetic traits is critical in comprehending the disease phenotype. This paper reviews these mechanisms along with the roles of various non-coding RNAs in CRCs.
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Affiliation(s)
- Kanwal Tariq
- Department of Biological and Biomedical Sciences, Aga Khan University, Karachi 74800, Pakistan
| | - Kulsoom Ghias
- Department of Biological and Biomedical Sciences, Aga Khan University, Karachi 74800, Pakistan
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33
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Hitchins MP. Finding the needle in a haystack: identification of cases of Lynch syndrome with MLH1 epimutation. Fam Cancer 2016; 15:413-22. [DOI: 10.1007/s10689-016-9887-3] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
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34
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Metcalf AM, Spurdle AB. Endometrial tumour BRAF mutations and MLH1 promoter methylation as predictors of germline mismatch repair gene mutation status: a literature review. Fam Cancer 2015; 13:1-12. [PMID: 23880961 DOI: 10.1007/s10689-013-9671-6] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Colorectal cancer (CRC) that displays high microsatellite instability (MSI-H) can be caused by either germline mutations in mismatch repair (MMR) genes, or non-inherited transcriptional silencing of the MLH1 promoter. A correlation between MLH1 promoter methylation, specifically the 'C' region, and BRAF V600E status has been reported in CRC studies. Germline MMR mutations also greatly increase risk of endometrial cancer (EC), but no systematic review has been undertaken to determine if these tumour markers may be useful predictors of MMR mutation status in EC patients. Endometrial cancer cohorts meeting review inclusion criteria encompassed 2675 tumours from 20 studies for BRAF V600E, and 447 tumours from 11 studies for MLH1 methylation testing. BRAF V600E mutations were reported in 4/2675 (0.1%) endometrial tumours of unknown MMR mutation status, and there were 7/823 (0.9%) total sequence variants in exon 11 and 27/1012 (2.7%) in exon 15. Promoter MLH1 methylation was not observed in tumours from 32 MLH1 mutation carriers, or for 13 MSH2 or MSH6 mutation carriers. MMR mutation-negative individuals with tumour MLH1 and PMS2 IHC loss displayed MLH1 methylation in 48/51 (94%) of tumours. We have also detailed specific examples that show the importance of MLH1 promoter region, assay design, and quantification of methylation. This review shows that BRAF mutations occurs so infrequently in endometrial tumours they can be discounted as a useful marker for predicting MMR-negative mutation status, and further studies of endometrial cohorts with known MMR mutation status are necessary to quantify the utility of tumour MLH1 promoter methylation as a marker of negative germline MMR mutation status in EC patients.
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Affiliation(s)
- Alexander M Metcalf
- Department of Genetics and Computational Biology, Queensland Institute of Medical Research, Herston, QLD, 4006, Australia
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35
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Cini G, Carnevali I, Quaia M, Chiaravalli AM, Sala P, Giacomini E, Maestro R, Tibiletti MG, Viel A. Concomitant mutation and epimutation of the MLH1 gene in a Lynch syndrome family. Carcinogenesis 2015; 36:452-8. [DOI: 10.1093/carcin/bgv015] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2014] [Accepted: 02/24/2015] [Indexed: 12/30/2022] Open
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36
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Rhees J, Arnold M, Boland CR. Inversion of exons 1-7 of the MSH2 gene is a frequent cause of unexplained Lynch syndrome in one local population. Fam Cancer 2015; 13:219-25. [PMID: 24114314 DOI: 10.1007/s10689-013-9688-x] [Citation(s) in RCA: 68] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Germline mutations in DNA mismatch repair (MMR) genes, such as MSH2, cause Lynch syndrome, an autosomal dominant predisposition to colorectal as well as other cancers. Our research clinic focuses on hereditary colorectal cancer, and over the past 9 years we have identified germline mutations in DNA MMR genes in 101 patients using commercial genetic reference laboratories. We also collected samples from twelve patients with absent MSH2 protein expression and microsatellite instability in tumor tissue, with a family history suggestive of Lynch syndrome, but negative germline test results. The most likely explanation for this set of results is that the germline testing did not detect true germline mutations in these patients. Two of our patients with failed commercial testing were later found to have deletions in the 3' region of EPCAM, the gene just upstream of MSH2, but no explanation could be found for inactivation of MSH2 in the other ten patients. We used allelic dropout in long PCR to look for potential regions of rearrangement in the MSH2 gene. This method detected a potential rearrangement breakpoint in the same region of MSH2 where one breakpoint of a 10 Mb inversion was reported previously. We tested these ten patients for this inversion. Six of 10 patients had the inversion, indicating the importance of including testing for this inversion in patients suspected of having MSH2-type Lynch syndrome in our population. Additionally, this method could be further developed to look for inversions in other genes where current methods of testing fail to find a causative mutation.
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Affiliation(s)
- Jennifer Rhees
- Gastrointestinal Cancer Research Laboratory, Division of Gastroenterology, Department of Internal Medicine, Baylor University Medical Center, Dallas, TX, USA,
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37
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Hitchins MP, Lynch HT. Dawning of the epigenetic era in hereditary cancer. Clin Genet 2014; 85:413-6. [PMID: 24588205 DOI: 10.1111/cge.12369] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2014] [Accepted: 02/27/2014] [Indexed: 12/12/2022]
Affiliation(s)
- M P Hitchins
- Department of Medicine, Stanford Cancer Institute, Stanford University, Stanford, CA, USA
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38
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Abstract
Recognition by Warthin of the familial clustering of colorectal and gynaecological cancers a century ago laid the foundation for the recognition of familial cancer. By tracking afflicted pedigrees, Lynch defined the clinical characteristics and argued for a heritable genetic component to this autosomal dominant cancer susceptibility condition, now termed Lynch syndrome. This was proven in the 1990s, with the discovery of deleterious germline mutations of the mismatch repair genes as its cause. Yet despite the genetic revolution at the turn of the twenty-first century, no pathogenic mutation was identifiable in approximately one-third of cases with suspected Lynch syndrome. In the past decade, the alternative mechanism of constitutional epimutation of the two major mismatch repair genes, MLH1 and MSH2, was identified in a proportion of these outstanding cases. This epigenetic defect, characterized by methylation and transcriptional inactivation of a single genetic allele within normal tissues, predisposes to the development of Lynch-type cancers. MSH2 and some MLH1 epimutations have been linked to genetic alterations within their vicinity and demonstrate dominant inheritance, whilst other MLH1 epimutations are reversible between generations and demonstrate non-Mendelian inheritance. This review charts the discovery of mismatch repair epimutations, their aetiological role in Lynch syndrome and the mechanistic basis for their variable inheritance patterns.
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Affiliation(s)
- Megan P Hitchins
- Adult Cancer Program, Medical Epigenetics Laboratory, Lowy Cancer Research Centre, Prince of Wales Clinical School, University of New South Wales, Randwick, NSW, Australia.
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39
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Peltomäki P. Epigenetic mechanisms in the pathogenesis of Lynch syndrome. Clin Genet 2014; 85:403-12. [PMID: 24443998 DOI: 10.1111/cge.12349] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2013] [Revised: 01/16/2014] [Accepted: 01/16/2014] [Indexed: 01/03/2023]
Abstract
Inherited defects in the DNA mismatch repair (MMR) system, MLH1, MSH2, MSH6, and PMS2 genes, underlie Lynch syndrome, one of the most prevalent cancer syndromes in man. The syndrome offers a model for cancers arising through MMR defects and microsatellite instability, which applies to ~ 15% of all colorectal, endometrial, and other cancers. Lynch syndrome also illustrates the significance of the epigenetic component in cancer development. Inactivation of tumor suppressor genes by epigenetic mechanisms is an acquired property of many tumors developing in Lynch syndrome. Furthermore, constitutional epimutations of MMR genes may explain a proportion of mutation-negative families lacking MLH1 or MSH2 protein expression in tumor tissue. This review provides an update of the molecular basis of Lynch syndrome by focusing on the role of epigenetic mechanisms in the pathogenesis of the disease.
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Affiliation(s)
- P Peltomäki
- Department of Medical Genetics, Haartman Institute, University of Helsinki, Helsinki, Finland
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40
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Frequency and variability of genomic rearrangements on MSH2 in Spanish Lynch Syndrome families. PLoS One 2013; 8:e72195. [PMID: 24039744 PMCID: PMC3770653 DOI: 10.1371/journal.pone.0072195] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2013] [Accepted: 07/06/2013] [Indexed: 11/29/2022] Open
Abstract
Large genomic rearrangements (LGRs) in DNA-mismatch-repair (MMR) genes, particularly among MSH2 gene, are frequently involved in the etiology of Lynch syndrome (LS). The Multiplex Ligation and Probe Amplification assay (MLPA) is commonly used to identify such alterations. However, in most cases, the MLPA-identified alteration is not characterized at the molecular level, which might be important to identify recurrent alterations and to analyze the molecular mechanisms underlying these mutational events. Probands from a cohort of Lynch Syndrome families were screened for point mutation in MMR genes, subsequently the MLPA assay was used for LGR screening. The identified MLPA alteration was confirmed by cDNA, CGH-microarrays or massive parallel sequencing. In this study, we have delimited the region of 11 LGRs variants on MSH2 locus. Six of them were fully characterized the breakpoints and 9 of them were considered pathogenic. According to our data, LGR on MSH2 locus constituted the 10.8% (9 out of 83) of pathogenic germline alterations found in LS. The frequency of colorectal cancer (CRC) and endometrial cancer (EC) in LGR carriers was 55% and 11% respectively. Analysis of the breakpoint sequences revealed that in 3 cases, deletions appeared to originate from Alu-mediated recombination events. In the remaining cases, sequence alignment failed to detect microhomology around the breakpoints. The present study provides knowledge on the molecular characterization of MSH2 LGRs, which may have important implications in LS diagnosis and Genetic Counseling. In addition, our data suggests that nonhomologous events would be more frequently involved in the etiology of MSH2 LGRs than expected.
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41
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Thiel A, Heinonen M, Kantonen J, Gylling A, Lahtinen L, Korhonen M, Kytölä S, Mecklin JP, Orpana A, Peltomäki P, Ristimäki A. BRAF mutation in sporadic colorectal cancer and Lynch syndrome. Virchows Arch 2013; 463:613-21. [DOI: 10.1007/s00428-013-1470-9] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2013] [Revised: 07/31/2013] [Accepted: 08/02/2013] [Indexed: 02/08/2023]
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42
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Contribution of large genomic rearrangements in Italian Lynch syndrome patients: characterization of a novel alu-mediated deletion. BIOMED RESEARCH INTERNATIONAL 2012; 2013:219897. [PMID: 23484096 PMCID: PMC3591251 DOI: 10.1155/2013/219897] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/10/2012] [Accepted: 11/20/2012] [Indexed: 11/18/2022]
Abstract
Lynch syndrome is associated with germ-line mutations in the DNA mismatch repair (MMR) genes, mainly MLH1 and MSH2. Most of the mutations reported in these genes to date are point mutations, small deletions, and insertions. Large genomic rearrangements in the MMR genes predisposing to Lynch syndrome also occur, but the frequency varies depending on the population studied on average from 5 to 20%. The aim of this study was to examine the contribution of large rearrangements in the MLH1 and MSH2 genes in a well-characterised series of 63 unrelated Southern Italian Lynch syndrome patients who were negative for pathogenic point mutations in the MLH1, MSH2, and MSH6 genes. We identified a large novel deletion in the MSH2 gene, including exon 6 in one of the patients analysed (1.6% frequency). This deletion was confirmed and localised by long-range PCR. The breakpoints of this rearrangement were characterised by sequencing. Further analysis of the breakpoints revealed that this rearrangement was a product of Alu-mediated recombination. Our findings identified a novel Alu-mediated rearrangement within MSH2 gene and showed that large deletions or duplications in MLH1 and MSH2 genes are low-frequency mutational events in Southern Italian patients with an inherited predisposition to colon cancer.
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43
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Frequency of mutations in mismatch repair genes in a population-based study of women with ovarian cancer. Br J Cancer 2012; 107:1783-90. [PMID: 23047549 PMCID: PMC3493867 DOI: 10.1038/bjc.2012.452] [Citation(s) in RCA: 64] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
Background: Mutations in genes for hereditary non-polyposis colorectal cancer (HNPCC) in ovarian cancer patients remains poorly defined. We sought to estimate the frequency and characteristics of HNPCC gene mutations in a population-based sample of women with epithelial ovarian cancer. Methods: The analysis included 1893 women with epithelial ovarian cancer ascertained from three population-based studies. Full-germline DNA sequencing of the coding regions was performed on three HNPCC genes, MLH1, MSH2 and MSH6. Collection of demographic, clinical and family history information was attempted in all women. Results: Nine clearly pathogenic mutations were identified, including five in MSH6, two each in MLH1 and MSH2. In addition, 28 unique predicted pathogenic missense variants were identified in 55 patients. Pathogenic mutation carriers had an earlier mean age at diagnosis of ovarian cancer, overrepresentation of cancers with non-serous histologies and a higher number of relatives with HNPCC-related cancers. Conclusions: Our findings suggest that fewer than 1% of women with ovarian cancer harbour a germline mutation in the HNPCC genes, with overrepresentation of MSH6 mutations. This represents a lower-range estimate due to the large number of predicted pathogenic variants in which pathogenicity could not definitively be determined. Identification of mismatch repair gene mutations has the potential to impact screening and treatment decisions in these women.
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Vaughn CP, Baker CL, Samowitz WS, Swensen JJ. The frequency of previously undetectable deletions involving 3' Exons of the PMS2 gene. Genes Chromosomes Cancer 2012; 52:107-12. [PMID: 23012243 DOI: 10.1002/gcc.22011] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2012] [Revised: 07/11/2012] [Accepted: 08/16/2012] [Indexed: 12/30/2022] Open
Abstract
Lynch syndrome is characterized by mutations in one of four mismatch repair genes, MLH1, MSH2, MSH6, or PMS2. Clinical mutation analysis of these genes includes sequencing of exonic regions and deletion/duplication analysis. However, detection of deletions and duplications in PMS2 has previously been confined to Exons 1-11 due to gene conversion between PMS2 and the pseudogene PMS2CL in the remaining 3' exons (Exons 12-15). We have recently described an MLPA-based method that permits detection of deletions of PMS2 Exons 12-15; however, the frequency of such deletions has not yet been determined. To address this question, we tested for 3' deletions in 58 samples that were reported to be negative for PMS2 mutations using previously available methods. All samples were from individuals whose tumors exhibited loss of PMS2 immunohistochemical staining without concomitant loss of MLH1 immunostaining. We identified seven samples in this cohort with deletions in the 3' region of PMS2, including three previously reported samples with deletions of Exons 13-15 (two samples) and Exons 14-15. Also detected were deletions of Exons 12-15, Exon 13, and Exon 14 (two samples). Breakpoint analysis of the intragenic deletions suggests they occurred through Alu-mediated recombination. Our results indicate that ∼12% of samples suspected of harboring a PMS2 mutation based on immunohistochemical staining, for which mutations have not yet been identified, would benefit from testing using the new methodology.
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Affiliation(s)
- Cecily P Vaughn
- ARUP Institute for Clinical and Experimental Pathology, Salt Lake City, UT 84108, USA
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Mismatch repair deficiency: a temozolomide resistance factor in medulloblastoma cell lines that is uncommon in primary medulloblastoma tumours. Br J Cancer 2012; 107:1399-408. [PMID: 22976800 PMCID: PMC3494444 DOI: 10.1038/bjc.2012.403] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
BACKGROUND Tumours are responsive to temozolomide (TMZ) if they are deficient in O(6)-methylguanine-DNA methyltransferase (MGMT), and mismatch repair (MMR) proficient. METHODS The effect of TMZ on medulloblastoma (MB) cell killing was analysed with clonogenic survival assays. Expression of DNA repair genes and enzymes was investigated using microarrays, western blot, and immunohistochemistry. DNA sequencing and promoter methylation analysis were employed to investigate the cause of loss of the expression of MMR gene MLH1. RESULTS Temozolomide exhibited potent cytotoxic activity in D425Med (MGMT deficient, MLH1 proficient; IC(50)=1.7 μM), moderate activity against D341Med (MGMT proficient, MLH1 deficient), and DAOY MB cells (MGMT proficient, MLH1 proficient). MGMT inhibitor O(6)-benzylguanine sensitised DAOY, but not D341Med cells to TMZ. Of 12 MB cell lines, D341Med, D283Med, and 1580WÜ cells exhibited MMR deficiency due to MLH1 promoter hypermethylation. DNA sequencing of these cells provided no evidence for somatic genetic alterations in MLH1. Expression analyses of MMR and MGMT in MB revealed that all patient specimens (n=74; expression array, n=61; immunostaining, n=13) are most likely MMR proficient, whereas some tumours had low MGMT expression levels (according to expression array) or were totally MGMT deficient (3 out of 13 according to immunohistochemistry). CONCLUSION A subset of MB may respond to TMZ as some patient specimens are MGMT deficient, and tumours appear to be MMR proficient.
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Identification of constitutional MLH1 epimutations and promoter variants in colorectal cancer patients from the Colon Cancer Family Registry. Genet Med 2012; 15:25-35. [PMID: 22878509 PMCID: PMC3908650 DOI: 10.1038/gim.2012.91] [Citation(s) in RCA: 70] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
PURPOSE Constitutional MLH1 epimutations manifest as promoter methylation and silencing of the affected allele in normal tissues, predisposing to Lynch syndrome-associated cancers. This study investigated their frequency and inheritance. METHODS A total of 416 individuals with a colorectal cancer showing loss of MLH1 expression and without deleterious germline mutations in MLH1 were ascertained from the Colon Cancer Family Registry (C-CFR). Constitutive DNA samples were screened for MLH1 methylation in all 416 subjects and for promoter sequence changes in 357 individuals. RESULTS Constitutional MLH1 epimutations were identified in 16 subjects. Of these, seven (1.7%) had mono- or hemi-allelic methylation and eight had low-level methylation (2%). In one subject the epimutation was linked to the c.-27C>A promoter variant. Testing of 37 relatives from nine probands revealed paternal transmission of low-level methylation segregating with a c.+27G>A variant in one case. Five additional probands had a promoter variant without an MLH1 epimutation, with three showing diminished promoter activity in functional assays. CONCLUSION Although rare, sequence changes in the regulatory region of MLH1 and aberrant methylation may alone or together predispose to the development of cancer. Screening for these changes is warranted in individuals who have a negative germline sequence screen of MLH1 and loss of MLH1 expression in their tumor.Genet Med 2013:15(1):25-35.
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MLH1 methylation screening is effective in identifying epimutation carriers. Eur J Hum Genet 2012; 20:1256-64. [PMID: 22763379 DOI: 10.1038/ejhg.2012.136] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Recently, constitutional MLH1 epimutations have been identified in a subset of Lynch syndrome (LS) cases. The aim of this study was the identification of patients harboring constitutional MLH1 epimutations in a set of 34 patients with a clinical suspicion of LS, MLH1-methylated tumors and non-detected germline mutations in mismatch repair (MMR) genes. MLH1 promoter methylation was analyzed in lymphocyte DNA samples by MS-MLPA (Methylation-specific multiplex ligation-dependent probe amplification). Confirmation of MLH1 constitutional methylation was performed by MS-MCA (Methylation-specific melting curve analysis), bisulfite sequencing and pyrosequencing in different biological samples. Allelic expression was determined using heterozygous polymorphisms. Vertical transmission was evaluated by MS-MLPA and haplotype analyses. MS-MLPA analysis detected constitutional MLH1 methylation in 2 of the 34 individuals whose colorectal cancers showed MLH1 methylation (5.9%). These results were confirmed by bisulfite-based methods. Both epimutation carriers had developed metachronous early-onset LS tumors, with no family history of LS-associated cancers in their first-degree relatives. In one of the cases, the identified MLH1 constitutional methylation was monoallelic and results in MLH1 and EPM2AIP1 allele-specific transcriptional silencing. It was present in normal somatic tissues and absent in spermatozoa. The methylated MLH1 allele was maternally transmitted and methylation was reversed in a daughter who inherited the same allele. MLH1 methylation screening in lymphocyte DNA from patients with early-onset MLH1-methylated LS-associated tumors allows the identification of epimutation carriers. The present study adds further evidence to the emerging entity of soma-wide MLH1 epimutation and its heritability.
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Abstract
In a fraction of families fulfilling the Amsterdam criteria for hereditary non-polyposis colorectal cancer, colorectal cancers are microsatellite stable and DNA mismatch repair gene (MMR) mutations are not found. These families were designated as familial colorectal cancer type X (FCCTX). We aimed to characterise a group of FCCTX families defined by the Amsterdam criteria and MSS tumours at clinical and molecular level. Twenty-four tumours from 15 FCCTX families were analysed for loss of known tumour suppressor gene (TSG) loci (APC, TP53, SMAD4 and DCC), MGMT and MMR genes promoter methylation, and also APC and KRAS somatic mutations. FCCTX families presented specific clinical features: absence of endometrial tumours, high adenoma/carcinoma ratio (1.91) and prevalence of rectal cancers (13/27, 48%). New molecular features were found: the majority of FCCTX tumours (13/18; 72%) presented TSG loss. TSG loss positive tumours presented frequent APC and KRAS somatic mutations and MGMT methylation [10/13 (77%), 7/13 (54%) and 6/11 (54%), respectively]. In TSG loss negative tumours (5/18; 28%), the same molecular events were found in 2/5 (40%), 2/5 (40%) and 1/3 (33%) tumours, respectively. Transition mutations in KRAS were more frequent among MGMT methylated tumours than in unmethylated [5/8 (63%) vs. 1/10 (10%), P = 0.03]. Although sharing similar clinical features, at least two different molecular entities should exist among FCCTX families, one whose tumours present frequent TSG loss, APC and KRAS somatic mutations, and MGMT promoter methylation, and a second, lesser predominant, with no evidence of TSG loss and rarely presenting promoter methylation.
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Brennan K, Flanagan JM. Epigenetic epidemiology for cancer risk: harnessing germline epigenetic variation. Methods Mol Biol 2012; 863:439-465. [PMID: 22359310 DOI: 10.1007/978-1-61779-612-8_27] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Genetic epidemiology aims to use the natural variation in the genome, namely single nucleotide polymorphisms and copy number variants to look for associations between particular genotypes and disease risk or prognosis. Recent work is now aiming to look further into the genome at the natural variation present in the epigenome, in DNA methylation as well as histone modifications, which both regulate gene expression. Epigenetic epidemiology aims to address the same questions about disease risk and prognosis using the normal epigenetic variability. Some examples of rare "epimutations" that can be detected in peripheral blood DNA have been reported in the genes MLH1, MSH2 and IGF2. Other studies have reported increased cancer risk with skewed distributions of the normal pattern in cancer cases compared to controls, showing the promise of harnessing the normal variation in the epigenome. However, some confounding factors need to be considered including the relationship between the epigenome and increasing age and tissue heterogeneity. Future studies using genome-wide approaches will likely find many more novel epigenetic biomarkers for cancer risk and prognosis.
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Affiliation(s)
- Kevin Brennan
- Division of Surgery and Cancer, Imperial College, London, UK
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Mutations and epimutations in the origin of cancer. Exp Cell Res 2011; 318:299-310. [PMID: 22182599 DOI: 10.1016/j.yexcr.2011.12.001] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2011] [Revised: 12/02/2011] [Accepted: 12/03/2011] [Indexed: 12/12/2022]
Abstract
Cancer is traditionally viewed as a disease of abnormal cell proliferation controlled by a series of mutations. Mutations typically affect oncogenes or tumor suppressor genes thereby conferring growth advantage. Genomic instability facilitates mutation accumulation. Recent findings demonstrate that activation of oncogenes and inactivation of tumor suppressor genes, as well as genomic instability, can be achieved by epigenetic mechanisms as well. Unlike genetic mutations, epimutations do not change the base sequence of DNA and are potentially reversible. Similar to genetic mutations, epimutations are associated with specific patterns of gene expression that are heritable through cell divisions. Knudson's hypothesis postulates that inactivation of tumor suppressor genes requires two hits, with the first hit occurring either in somatic cells (sporadic cancer) or in the germline (hereditary cancer) and the second one always being somatic. Studies on hereditary and sporadic forms of colorectal carcinoma have made it evident that, apart from genetic mutations, epimutations may serve as either hit or both. Furthermore, recent next-generation sequencing studies show that epigenetic genes, such as those encoding histone modifying enzymes and subunits for chromatin remodeling systems, are themselves frequent targets of somatic mutations in cancer and can act like tumor suppressor genes or oncogenes. This review discusses genetic vs. epigenetic origin of cancer, including cancer susceptibility, in light of recent discoveries. Situations in which mutations and epimutations occur to serve analogous purposes are highlighted.
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