451
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Endometrial Cancer and Hypermethylation: Regulation of DNA and MicroRNA by Epigenetics. Biochem Res Int 2012; 2012:738274. [PMID: 22548175 PMCID: PMC3324134 DOI: 10.1155/2012/738274] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2011] [Accepted: 02/02/2012] [Indexed: 01/02/2023] Open
Abstract
Endometrial cancer is the seventh most common cancer in women worldwide. Therefore elucidation of the pathogenesis and development of effective treatment for endometrial cancer are important. However, several aspects of the mechanism of carcinogenesis in the endometrium remain unclear. Associations with genetic variation and mutations of cancer-related genes have been shown, but these do not provide a complete explanation. Therefore, in recent years, epigenetic mechanisms that do not involve changes in DNA sequences have been examined. Studies aimed at detection of aberrant DNA hypermethylation in cancer cells present in microscopic amounts in vivo and application of the results to cancer diagnosis have also started. Breakdown of the DNA mismatch repair mechanism is thought to play a large role in the development of endometrial cancer, with changes in the expression of the hMLH1 gene being particularly important. Silencing of genes such as APC and CHFR, Sprouty 2, RASSF1A, GPR54, CDH1, and RSK4 by DNA hypermethylation, onset of Lynch syndrome due to hereditary epimutation of hMLH1 and hMSH2 mismatch repair genes, and regulation of gene expression by microRNAs may also underlie the carcinogenic mechanisms of endometrial cancer. Further understanding of these issues may permit development of new therapies.
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452
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Adonizio C, Gazzillo M, Knezetic J, Snyder C, Lynch HT, Rybak C, Hall MJ, Lowstuter K, Eggington J, Morris GJ. Thirty-Nine-Year-Old With Familial Colon Cancer, and Variant of Undetermined Significance in MSH6. Semin Oncol 2012; 39:125-31. [DOI: 10.1053/j.seminoncol.2012.01.013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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453
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Foulkes WD. Epigenetic modification and cancer: mark or stamp? Endocr Relat Cancer 2012; 19:C23-7. [PMID: 22291435 DOI: 10.1530/erc-12-0003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Hypotheses are built upon data, but data require hypotheses before they can be understood. The development of the 'two-hit' hypothesis of carcinogenesis was a key event in cancer genetics because it provided a testable model of how tumours develop. In this commentary on 'Promoter hypermethylation patterns in Fallopian tube epithelium of BRCA1 and BRCA2 germline mutation carriers' by Bijron et al. published in the February 2012 issue of Endocrine-Related Cancer, the need for new grammar and some new hypotheses in epigenetics is discussed. Meanwhile, data suggesting an important role of epigenetic modification in the cause, progression and treatment of cancer continues to accumulate.
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Affiliation(s)
- William D Foulkes
- Department of Oncology, McGill University, Montreal, Quebec, Canada.
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454
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Xicola RM, Llor X. [DNA methylation defects in sporadic and hereditary colorectal cancer]. GASTROENTEROLOGIA Y HEPATOLOGIA 2012; 35:480-7. [PMID: 22459641 DOI: 10.1016/j.gastrohep.2012.01.010] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/19/2012] [Accepted: 01/20/2012] [Indexed: 12/17/2022]
Abstract
DNA methylation is a fundamental epigenetic mechanism in regulating the expression of genes controlling crucial cell functions in cancer development. Methylation defects (both global hypomethylation and hypermethylation of CpG islands) are implicated in colorectal carcinogenesis. Some nutrients have a clear effect on methylation, suggesting that some dietary-associated differences in the incidence of colorectal cancer could be due to the effect of diet on methylation. The presence of methylation defects has clear diagnostic and prognostic implications. Thus, several tests are being used for colorectal cancer screening based on methylated gene analysis, whether in feces or blood. In addition, the reversibility of methylation processes allows the development of chemotherapies that regulate this process through their antineoplastic activity.
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Affiliation(s)
- Rosa M Xicola
- Univerisity of Illinois at Chicago, Digestive Disease and Nutrition, Chicago, IL, USA.
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455
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Lee MP. Allele-specific gene expression and epigenetic modifications and their application to understanding inheritance and cancer. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2012; 1819:739-42. [PMID: 22366057 DOI: 10.1016/j.bbagrm.2012.02.007] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/07/2011] [Revised: 01/31/2012] [Accepted: 02/09/2012] [Indexed: 01/04/2023]
Abstract
Epigenetic information is characterized by its plasticity during development and differentiation as well as its stable transmission during mitotic cell divisions in somatic tissues. This duality contrasts to genetic information, which is essentially static and identical in every cell in an organism with only a few exceptions such as immunoglobulin genes in lymphocytes. Epigenetics is traditionally perceived as a means to regulate gene expression without a change in DNA sequence. This, however, does not exclude a potential role for genetic variations in providing differential backgrounds on which epigenetic modulations and their regulatory consequences are achieved. An effective approach to investigating the interplay between genetic variations and epigenetic variations is through allele-specific analysis of epigenetics and gene expression. Such studies have generated many new insights into functions of genetic variations, mechanisms of gene expression regulation, and the role of mutations and epigenetic alterations in human cancer. This article is part of a Special Issue entitled: Chromatin in time and space.
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Affiliation(s)
- Maxwell P Lee
- The Laboratory of Population Genetics, Center for Cancer Research, National Cancer Institute, USA.
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456
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Abstract
Lynch syndrome is a hereditary cancer predisposition syndrome caused by germline loss of a DNA mismatch repair gene. In a significant proportion of cases, loss of function of the MSH2 mismatch repair gene is caused by large heterogeneous deletions involving MSH2 and/or the adjacent EPCAM gene. These deletions usually result from homologous malrecombination events between Alu elements, a family of short interspersed nuclear elements (SINE). Recent recognition that the extent of these deletions influences phenotypic outcome provided new impetus for fine-mapping the breakpoints. In doing so, Pérez-Cabornero and colleagues uncovered new evidence for Alu-mediated ancestral founder deletions within MSH2 in the Spanish Lynch syndrome population (as reported beginning on pages 1546 and 1556 in this issue of the journal). This is the first such finding to date and prompted a revisitation of the role of Alu elements in the causation of Lynch syndrome. Whether Alu density is a danger sign for genomic regions prone to rearrangement and what additional factors may be required to actuate these events remain to be discovered.
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Affiliation(s)
- Megan P Hitchins
- Medical Epigenetics Laboratory, Lowy Cancer Research Centre, Prince of Wales Clinical School, Faculty of Medicine, University of New South Wales, Sydney, Australia.
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457
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Understanding transgenerational epigenetic inheritance via the gametes in mammals. Nat Rev Genet 2012; 13:153-62. [PMID: 22290458 DOI: 10.1038/nrg3188] [Citation(s) in RCA: 430] [Impact Index Per Article: 35.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
It is known that information that is not contained in the DNA sequence - epigenetic information - can be inherited from the parent to the offspring. However, many questions remain unanswered regarding the extent and mechanisms of such inheritance. In this Review, we consider the evidence for transgenerational epigenetic inheritance via the gametes, including cases of environmentally induced epigenetic changes. The molecular basis of this inheritance remains unclear, but recent evidence points towards diffusible factors, in particular RNA, rather than DNA methylation or chromatin. Interestingly, many cases of epigenetic inheritance seem to involve repeat sequences.
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458
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de Miranda NFCC, Hes FJ, van Wezel T, Morreau H. Role of the microenvironment in the tumourigenesis of microsatellite unstable and MUTYH-associated polyposis colorectal cancers. Mutagenesis 2012; 27:247-53. [DOI: 10.1093/mutage/ger077] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
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459
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van Lier MGF, Leenen CHM, Wagner A, Ramsoekh D, Dubbink HJ, van den Ouweland AMW, Westenend PJ, de Graaf EJR, Wolters LMM, Vrijland WW, Kuipers EJ, van Leerdam ME, Steyerberg EW, Dinjens WNM. Yield of routine molecular analyses in colorectal cancer patients ≤70 years to detect underlying Lynch syndrome. J Pathol 2012; 226:764-74. [PMID: 22081473 DOI: 10.1002/path.3963] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2011] [Revised: 11/01/2011] [Accepted: 11/04/2011] [Indexed: 01/26/2023]
Abstract
Although early detection of Lynch syndrome (LS) is important, a considerable proportion of patients with LS remains unrecognized. We aimed to study the yield of LS detection by routine molecular analyses in colorectal cancer (CRC) patients until 70 years of age. We prospectively included consecutive CRC patients ≤70 years. Tumour specimens were analysed for microsatellite instability (MSI), immunohistochemical mismatch-repair protein expression and MLH1-promoter methylation. Tumours were classified as either: (a) likely caused by LS; (b) sporadic microsatellite-unstable (MSI-H); or (c) microsatellite-stable (MSS). Predictors of LS were determined by multivariable logistic regression. A total of 1117 CRC patients (57% males, median age 61 years) were included. Fifty patients (4.5%, 95% CI 3.4-5.9) were likely to have LS, and 71 had a sporadic MSI-H tumour (6.4%, 95% CI 5.1-8.0). Thirty-five patients likely to have LS (70%) were aged > 50 years. A molecular profile compatible with LS was detected in 10% (15/144) of patients aged ≤50, in 4% (15/377) of those aged 51-60 and in 3% (20/596) of patients > 61 years. Compared to MSS cases, patients likely to have LS were significantly younger (OR 3.9, 95% CI 1.7-8.7) and more often had right-sided CRCs (OR 14, 95% CI 6.0-34). In conclusion, molecular screening for LS in CRC patients ≤70 years leads to identification of a molecular profile compatible with LS in 4.5% of patients, with most of them not fulfilling the age criterion (≤50 years) routinely used for LS assessment. Routine use of MSI testing may be considered in CRC patients up to the age of 70 years, with a central role for the pathologist in the selection of patients.
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Affiliation(s)
- Margot G F van Lier
- Department of Gastroenterology and Hepatology, Erasmus MC, University Medical Centre, Rotterdam, The Netherlands.
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460
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Abstract
Epigenetic silencing of genes is now recognized to be an important mechanism for inactivation of tumor suppressor genes in carcinogenesis. Because the role of genetic alterations in colorectal carcinogenesis has been well studied, colorectal cancer also offers an excellent model for elucidation of epigenetic mechanisms involved in carcinogenesis. DNA methylation and histone modification are involved in a complex network to maintain gene silencing and cause carcinogenesis. DNA methylation of cancer-related gene promoters generally begins early in the process of tumorigenesis, affecting various types of colorectal cancer to differing degrees. These advances in the understanding of the biology of tumorigenesis can be expected to provide distinct biomarkers that will aid future diagnosis, risk assessment, and treatment methods for patients with colorectal cancer.
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461
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Galetzka D, Hansmann T, El Hajj N, Weis E, Irmscher B, Ludwig M, Schneider-Rätzke B, Kohlschmidt N, Beyer V, Bartsch O, Zechner U, Spix C, Haaf T. Monozygotic twins discordant for constitutive BRCA1 promoter methylation, childhood cancer and secondary cancer. Epigenetics 2012; 7:47-54. [PMID: 22207351 PMCID: PMC3329502 DOI: 10.4161/epi.7.1.18814] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
We describe monozygotic twins discordant for childhood leukemia and secondary thyroid carcinoma. We used bisulfite pyrosequencing to compare the constitutive promoter methylation of BRCA1 and several other tumor suppressor genes in primary fibroblasts. The affected twin displayed an increased BRCA1 methylation (12%), compared with her sister (3%). Subsequent bisulfite plasmid sequencing demonstrated that 13% (6 of 47) BRCA1 alleles were fully methylated in the affected twin, whereas her sister displayed only single CpG errors without functional implications. This between-twin methylation difference was also found in irradiated fibroblasts and untreated saliva cells. The BRCA1 epimutation may have originated by an early somatic event in the affected twin: approximately 25% of her body cells derived from different embryonic cell lineages carry one epigenetically inactivated BRCA1 allele. This epimutation was associated with reduced basal protein levels and a higher induction of BRCA1 after DNA damage. In addition, we performed a genome-wide microarray analysis of both sisters and found several copy number variations, i.e., heterozygous deletion and reduced expression of the RSPO3 gene in the affected twin. This monozygotic twin pair represents an impressive example of epigenetic somatic mosaicism, suggesting a role for constitutive epimutations, maybe along with de novo genetic alterations in recurrent tumor development.
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Affiliation(s)
- Danuta Galetzka
- Institute of Human Genetics, University Medical Center, Mainz, Germany
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462
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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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463
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Berg M, Søreide K. Genetic and epigenetic traits as biomarkers in colorectal cancer. Int J Mol Sci 2011; 12:9426-39. [PMID: 22272141 PMCID: PMC3257138 DOI: 10.3390/ijms12129426] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2011] [Revised: 11/28/2011] [Accepted: 12/07/2011] [Indexed: 02/08/2023] Open
Abstract
Colorectal cancer is a major health burden, and a leading cause of cancer-related deaths in industrialized countries. The steady improvements in surgery and chemotherapy have improved survival, but the ability to identify high- and low-risk patients is still somewhat poor. Molecular biology has, over the years, given insight into basic principles of colorectal cancer initiation and development. These findings include aberrations increasing risk of tumor development, genetic changes associated with the stepwise progression of the disease, and errors predicting response to a specific treatment. Potential biomarkers in colorectal cancer are extensively studied, and how the molecular aberrations relate to clinical features. Yet, little of this knowledge has been possible to transfer into clinical practice. In this review, an overview of colorectal cancer genetics will be given, as well as how aberrations found in this tumor type are proposed as biomarkers for risk prediction, as diagnostic tools, for prognosis or prediction of treatment outcome.
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Affiliation(s)
- Marianne Berg
- Department of Surgery, Stavanger University Hospital, P O Box 8100, N-4068 Stavanger, Norway
- Author to whom correspondence should be addressed; E-Mail: ; Tel.: +47-51-51-80-00; Fax: +47-51-88-08-95
| | - Kjetil Søreide
- Department of Surgery, Stavanger University Hospital, P O Box 8100, N-4068 Stavanger, Norway
- Department of Surgical Sciences, University of Bergen, 5021 Bergen, Norway; E-Mail:
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464
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Affiliation(s)
- Denise P. Barlow
- CeMM, Research Center for Molecular Medicine of the Austrian Academy of Sciences, Vienna, Austria;
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465
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Weissman SM, Burt R, Church J, Erdman S, Hampel H, Holter S, Jasperson K, Kalady MF, Haidle JL, Lynch HT, Palaniappan S, Wise PE, Senter L. Identification of individuals at risk for Lynch syndrome using targeted evaluations and genetic testing: National Society of Genetic Counselors and the Collaborative Group of the Americas on Inherited Colorectal Cancer joint practice guideline. J Genet Couns 2011; 21:484-93. [PMID: 22167527 DOI: 10.1007/s10897-011-9465-7] [Citation(s) in RCA: 97] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2011] [Accepted: 11/30/2011] [Indexed: 12/18/2022]
Abstract
Identifying individuals who have Lynch syndrome (LS) involves a complex diagnostic work up that includes taking a detailed family history and a combination of various genetic and immunohistochemical tests. The National Society of Genetic Counselors (NSGC) and the Collaborative Group of the Americas on Inherited Colorectal Cancer (CGA-ICC) have come together to publish this clinical practice testing guideline for the evaluation of LS. The purpose of this practice guideline is to provide guidance and a testing algorithm for LS as well as recommendations on when to offer testing. This guideline does not replace a consultation with a genetics professional. This guideline includes explanations in support of this and a summary of background data. While this guideline is not intended to serve as a review of LS, it includes a discussion of background information on LS, and cites a number of key publications which should be reviewed for a more in-depth understanding of LS. These guidelines are intended for genetic counselors, geneticists, gastroenterologists, surgeons, medical oncologists, obstetricians and gynecologists, nurses and other healthcare providers who evaluate patients for LS.
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Affiliation(s)
- Scott M Weissman
- Center for Medical Genetics, NorthShore University HealthSystem, Evanston, IL, USA.
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466
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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: 55] [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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467
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Riley BD, Culver JO, Skrzynia C, Senter LA, Peters JA, Costalas JW, Callif-Daley F, Grumet SC, Hunt KS, Nagy RS, McKinnon WC, Petrucelli NM, Bennett RL, Trepanier AM. Essential elements of genetic cancer risk assessment, counseling, and testing: updated recommendations of the National Society of Genetic Counselors. J Genet Couns 2011; 21:151-61. [PMID: 22134580 DOI: 10.1007/s10897-011-9462-x] [Citation(s) in RCA: 222] [Impact Index Per Article: 17.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2011] [Accepted: 11/16/2011] [Indexed: 12/28/2022]
Abstract
Updated from their original publication in 2004, these cancer genetic counseling recommendations describe the medical, psychosocial, and ethical ramifications of counseling at-risk individuals through genetic cancer risk assessment with or without genetic testing. They were developed by members of the Practice Issues Subcommittee of the National Society of Genetic Counselors Familial Cancer Risk Counseling Special Interest Group. The information contained in this document is derived from extensive review of the current literature on cancer genetic risk assessment and counseling as well as the personal expertise of genetic counselors specializing in cancer genetics. The recommendations are intended to provide information about the process of genetic counseling and risk assessment for hereditary cancer disorders rather than specific information about individual syndromes. Essential components include the intake, cancer risk assessment, genetic testing for an inherited cancer syndrome, informed consent, disclosure of genetic test results, and psychosocial assessment. These recommendations should not be construed as dictating an exclusive course of management, nor does use of such recommendations guarantee a particular outcome. These recommendations do not displace a health care provider's professional judgment based on the clinical circumstances of a client.
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468
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469
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Wojdacz TK, Thestrup BB, Cold S, Overgaard J, Hansen LL. No difference in the frequency of locus-specific methylation in the peripheral blood DNA of women diagnosed with breast cancer and age-matched controls. Future Oncol 2011; 7:1451-5. [DOI: 10.2217/fon.11.123] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
There is no doubt that aberrant somatic (tumor-specific) methylation significantly contributes to the carcinogenic process. However, the question of the relevance of methylation pattern changes, acquired by individuals during their development and lifetime or inherited through the germline, to the pathology of different diseases, remains open. Recently, a number of studies addressed the question of the prevalence of aberrant methylation of cancer-related genes in peripheral blood leukocyte (PBL) DNA and indicated a strong possibility that the presence of constitutional methylation of different genes might predispose for cancer development. Here, we have used the methlyation-sensitive high-resolution melting approach to examine the methylation status of the BRCA1, BRCA2, APC, RASSF1A and RARβ2 genes in PBLs of a group of women diagnosed with breast cancer, and an age-matched control group with no signs of breast cancer. No significant differences in the frequency of methylation of the above genes were found between cases and controls in our study. Hence, testing for the presence of methylation of cancer-related genes in PBL DNA from women diagnosed with sporadic breast cancer and classified for testing without any pathological or clinical selection criteria does not seem to have clinical applicability.
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Affiliation(s)
- Tomasz K Wojdacz
- The Lundbeck Foundation Centre for International Research in Radiation Oncology (CIRRO), Nørrebrogade 44, DK-8000 Aarhus C, Denmark
| | - Britta B Thestrup
- Institute of Human Genetics, University of Aarhus, Wilhelm Meyers Alle 4, The Bartholin Building, DK-8000 Aarhus C, Denmark
| | - Søren Cold
- Department of Oncology R Odense University Hospital, DK-5000 Odense C, Denmark
| | - Jens Overgaard
- Department of Experimental Clinical Oncology, Aarhus University Hospital, Nørrebrogade 44, DK-8000 Aarhus C, Denmark
| | - Lise L Hansen
- Institute of Human Genetics, University of Aarhus, Wilhelm Meyers Alle 4, The Bartholin Building, DK-8000 Aarhus C, Denmark
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470
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Wojdacz TK, Thestrup BB, Overgaard J, Hansen LL. Methylation of cancer related genes in tumor and peripheral blood DNA from the same breast cancer patient as two independent events. Diagn Pathol 2011; 6:116. [PMID: 22129206 PMCID: PMC3253685 DOI: 10.1186/1746-1596-6-116] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2011] [Accepted: 11/30/2011] [Indexed: 12/16/2022] Open
Abstract
Background Recently it has been suggested that acquisition of methylation of the BRCA1 promoter detectable in peripheral blood (PB) DNA, could give raise to development of breast cancer. In this study, we aimed to investigate a relationship between methylation of three breast cancer related genes in PB DNA, and tumor specific (somatic) methylation of these genes in the same individual. Findings We have examined methylation status of the BRCA1, APC and RASSF1A promoter regions in a panel of 75 breast tumor and PB DNA samples from the same individual. In our study group, 4.0% of the patients displayed methylation of BRCA1 and APC in both tumor and the corresponding PB DNA. At the same time despite of marked methylation in tumor DNA, no methylation of BRCA1 and APC was seen in PB DNA of 4.3% and 2.7% of the patients respectively. The RASSF1A promoter did not show methylation in PB DNA. Conclusions Our results show that for at least a subset of cancer patients methylation of certain cancer related genes in PB DNA does not seem to be directly linked to somatic methylation of the same genes in tumor DNA, and therefore may only be specific to PB DNA.
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Affiliation(s)
- Tomasz K Wojdacz
- The Lundbeck Foundation Centre for International Research in Radiation Oncology, Nørrebrogade 44, Building no, 5, Aarhus University Hospital, DK-8000 Aarhus C, Denmark.
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471
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Abstract
CONTEXT About 15% of colorectal cancers are characterized by genomic microsatellite instability, and of these, about 1 in 5 (2%-4% overall) are due to Lynch syndrome, a dominantly inherited condition predisposing the patient to cancers of multiple organ systems, including the gastrointestinal tract. Identification of individuals with Lynch syndrome allows for increased surveillance of the affected individual and of potentially affected family members. OBJECTIVE To review the literature on microsatellite instability in colorectal cancer and current laboratory diagnostic testing strategies for the detection of Lynch syndrome. DATA SOURCES This review is based on peer-reviewed literature, published guidelines from professional organizations (Evaluation of Genomic Applications in Practice and Prevention Working Group, National Comprehensive Cancer Network), and information from clinical laboratories performing microsatellite instability testing. CONCLUSIONS Universal screening for Lynch syndrome in all individuals affected with colorectal cancer has been recommended by the Evaluation of Genomic Applications in Practice and Prevention Working Group. Preliminary screening tests can identify individuals unlikely to be affected by Lynch syndrome, thereby reducing the need for full gene analysis. Immunohistochemistry and polymerase chain reaction-based tests for microsatellite instability have similar clinical sensitivity and specificity, and each method has advantages and limitations. BRAF and MLH1 methylation testing are useful reflex tests for those with a defect in MLH1 identified by immunohistochemistry. Emerging technologies, such as high-throughput sequencing, may substantially affect diagnostic algorithms in the future.
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Affiliation(s)
- Katherine B Geiersbach
- Department of Pathology, University of Utah School of Medicine, Salt Lake City, UT 84108, USA.
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472
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Crépin M, Dieu MC, Lejeune S, Escande F, Boidin D, Porchet N, Morin G, Manouvrier S, Mathieu M, Buisine MP. Evidence of constitutional MLH1 epimutation associated to transgenerational inheritance of cancer susceptibility. Hum Mutat 2011; 33:180-8. [PMID: 21953887 DOI: 10.1002/humu.21617] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2011] [Accepted: 09/07/2011] [Indexed: 12/19/2022]
Abstract
Constitutional epimutations of DNA mismatch repair (MMR) genes have been recently reported as a possible cause of Lynch syndrome. However, little is known about their prevalence, the risk of transmission through the germline and the risk for carriers to develop cancers. In this study, we evaluated the contribution of constitutional epimutations of MMR genes in Lynch syndrome. A cohort of 134 unrelated Lynch syndrome-suspected patients without MMR germline mutation was screened for constitutional epimutations of MLH1 and MSH2 by quantitative bisulfite pyrosequencing. Patients were also screened for the presence of EPCAM deletions, a possible cause of MSH2 methylation. Tumors from patients with constitutional epimutations were extensively analyzed. We identified a constitutional MLH1 epimutation in two proband patients. For one of them, we report for the first time evidence of transmission to two children who also developed early colonic tumors, indicating that constitutional MLH1 epimutations are associated to a real risk of transgenerational inheritance of cancer susceptibility. Moreover, a somatic BRAF mutation was detected in one affected child, indicating that tumors from patients carrying constitutional MLH1 epimutation can mimic MSI-high sporadic tumors. These findings may have important implications for future diagnostic strategies and genetic counseling.
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Affiliation(s)
- Michel Crépin
- Oncologie et Génétique Moléculaires, Service de Biochimie et Biologie Moléculaire HMNO, CHRU de Lille, France
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473
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Vilar E, Tabernero J, Gruber SB. Micromanaging the classification of colon cancer: the role of the microRNAome. Clin Cancer Res 2011; 17:7207-9. [PMID: 22019515 DOI: 10.1158/1078-0432.ccr-11-2440] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Recent advances in our understanding of the microRNAome (miRNAome) have provided further insights into the molecular pathogenesis of colorectal cancer and shown a potential role for miRNAs in distinguishing molecular subtypes. The mucosa-adenoma-carcinoma model can now integrate miRNAs into the known genetic alterations that drive the progression of colorectal neoplasia.
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Affiliation(s)
- Eduardo Vilar
- Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, USA.
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474
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Clendenning M, Buchanan DD, Walsh MD, Nagler B, Rosty C, Thompson B, Spurdle AB, Hopper JL, Jenkins MA, Young JP. Mutation deep within an intron of MSH2 causes Lynch syndrome. Fam Cancer 2011; 10:297-301. [PMID: 21360204 DOI: 10.1007/s10689-011-9427-0] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Lynch syndrome, a heritable form of cancer predisposition, is caused by germline mutations within genes of the DNA mismatch repair family, and can be rapidly identified in young onset cancer patients through the detection of loss of expression of at least one of these genes in tumour samples. To date, such causative mutations have only been identified within exonic and splice site regions. Though this approach has been successful in the majority of families, a considerable number remain in which no mutation has been found. To address this situation, we used an alternative mutation discovery procedure which involved haplotype analysis of the locus containing the gene lost in the tumour and delineation of segregating haplotypes, followed by an investigation of splicing aberrations to uncover cryptic splice sites which lay outside the genomic regions routinely examined for mutations. In this report, we show that an intronic mutation 478 bp upstream of exon 2 in the MSH2 gene causes Lynch syndrome through creation of a novel splice donor site with subsequent pseudoexon activation, thus highlighting the need for more extensive sequencing approaches in families where routine procedures fail to find a mutation.
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Affiliation(s)
- Mark Clendenning
- Familial Cancer Laboratory, Queensland Institute of Medical Research, 300 Herston Road, Herston, QLD, Australia.
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475
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Lynch HT, Riegert-Johnson DL, Snyder C, Lynch JF, Hagenkord J, Boland CR, Rhees J, Thibodeau SN, Boardman LA, Davies J, Kuiper RP, Hoogerbrugge N, Ligtenberg MJ. Lynch syndrome-associated extracolonic tumors are rare in two extended families with the same EPCAM deletion. Am J Gastroenterol 2011; 106:1829-36. [PMID: 21769135 PMCID: PMC3805505 DOI: 10.1038/ajg.2011.203] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
OBJECTIVES The Lynch syndrome (LS) is an inherited cancer syndrome showing a preponderance of colorectal cancer (CRC) in context with endometrial cancer and several other extracolonic cancers, which is due to pathogenic mutations in the mismatch repair (MMR) genes, MLH1, MSH2, MSH6, and PMS2. Some families were found to show a LS phenotype without an identified MMR mutation, although there was microsatellite instability and absence of MSH2 expression by immunohistochemistry. Studies of a subset of these families found a deletion at the 3' end of the epithelial cell adhesion molecule (EPCAM) gene, causing transcription read-through resulting in silencing of MSH2 through hypermethylation of its promoter. The tumor spectrum of such families appears to differ from classical LS. METHODS Our study of two large families (USA Family R and Dutch Family A) with an EPCAM deletion was carried out using each institution's standard family study protocol. DNA was extracted from peripheral blood and EPCAM deletion analysis was performed. RESULTS Both families were found to harbor the same deletion at the 3' end of EPCAM. Analysis showed that the deletion originated from a common ancestor. Family R and Family A members showed segregation of CRC with the presence of this EPCAM mutation. Compared with classic LS, there were almost no extracolonic cancers. CONCLUSIONS Members of Family R and Family A, all with the same EPCAM deletion, predominantly presented with CRC but no LS-associated endometrial cancer, confirming findings seen in other, smaller, LS families with EPCAM mutations. In these EPCAM mutation carriers, cancer surveillance should be focused on CRC.
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Affiliation(s)
- Henry T. Lynch
- Department of Preventive Medicine, Creighton University, Omaha, Nebraska, USA
| | | | - Carrie Snyder
- Department of Preventive Medicine, Creighton University, Omaha, Nebraska, USA
| | - Jane F. Lynch
- Department of Preventive Medicine, Creighton University, Omaha, Nebraska, USA
| | - Jill Hagenkord
- Department of Pathology, Creighton University, Omaha, Nebraska, USA
| | - C. Richard Boland
- Division of Gastroenterology, Baylor University Medical Center, Dallas, Texas, USA
| | - Jennifer Rhees
- Division of Gastroenterology, Baylor University Medical Center, Dallas, Texas, USA
| | | | | | - Janine Davies
- GI Oncology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Roland P. Kuiper
- Department of Human Genetics, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands
| | - Nicoline Hoogerbrugge
- Department of Human Genetics, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands
| | - Marjolijn J.L. Ligtenberg
- Department of Human Genetics, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands,Department of Pathology, Radboud University Nijmegen Medical Centre, Mijmegen, The Netherlands
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476
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Somatic deletions of genes regulating MSH2 protein stability cause DNA mismatch repair deficiency and drug resistance in human leukemia cells. Nat Med 2011; 17:1298-303. [PMID: 21946537 PMCID: PMC3192247 DOI: 10.1038/nm.2430] [Citation(s) in RCA: 99] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2010] [Accepted: 07/05/2011] [Indexed: 12/14/2022]
Abstract
DNA mismatch repair enzymes (e.g., MSH2) maintain genomic integrity, and their deficiency predisposes to several human cancers and to drug resistance. We found that leukemia cells from a substantial proportion of patients (~11%) with newly diagnosed acute lymphoblastic leukemia (ALL) have low or undetectable MSH2 protein levels (MSH2-L), despite abundant wild-type MSH2 mRNA. MSH2-L leukemia cells contained partial or complete somatic deletions of 1–4 genes that regulate MSH2 degradation (FRAP1, HERC1, PRKCZ, PIK3C2B); these deletions were also found in adult ALL (16%) and sporadic colorectal cancer (13.5%). Knockdown of these genes in human leukemia cells recapitulated the MSH2 protein deficiency by enhancing MSH2-degradation, leading to significant reduction in DNA mismatch repair (MMR) and increased resistance to thiopurines. These findings reveal a previously unrecognized mechanism whereby somatic deletions of genes regulating MSH2 degradation result in undetectable levels of MSH2 protein in leukemia cells, MMR deficiency and drug resistance.
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477
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Abstract
The past decade has highlighted the central role of epigenetic processes in cancer causation, progression and treatment. Next-generation sequencing is providing a window for visualizing the human epigenome and how it is altered in cancer. This view provides many surprises, including linking epigenetic abnormalities to mutations in genes that control DNA methylation, the packaging and the function of DNA in chromatin, and metabolism. Epigenetic alterations are leading candidates for the development of specific markers for cancer detection, diagnosis and prognosis. The enzymatic processes that control the epigenome present new opportunities for deriving therapeutic strategies designed to reverse transcriptional abnormalities that are inherent to the cancer epigenome.
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Affiliation(s)
- Stephen B. Baylin
- The Sidney Kimmel Comprehensive Cancer Center at Johns Hopkins, Baltimore, Maryland 21231, USA
| | - Peter A. Jones
- The USC Norris Comprehensive Cancer Center, Keck School of Medicine, University of Southern California, Los Angeles, California 90089, USA
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478
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Canard G, Lefevre JH, Colas C, Coulet F, Svrcek M, Lascols O, Hamelin R, Shields C, Duval A, Fléjou JF, Soubrier F, Tiret E, Parc Y. Screening for Lynch syndrome in colorectal cancer: are we doing enough? Ann Surg Oncol 2011; 19:809-16. [PMID: 21879275 DOI: 10.1245/s10434-011-2014-7] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2010] [Indexed: 11/18/2022]
Abstract
PURPOSE The purpose of this study was to assess the efficacy of screening for the detection of Lynch syndrome (LS) in an unselected population undergoing surgery for a colorectal cancer. METHODS A total of 1,040 patients were prospectively included between 2005 and 2009. LS screening modalities included the Bethesda criteria, immunochemistry (IHC) for MLH1, MSH2, and MSH6, and microsatellite instability (MSI) by using pentaplex markers. Promoter methylation was assessed in tumors with a loss of MLH1 expression. Gene sequencing was offered to patients with abnormal IHC or MSI status without promoter methylation. RESULTS A total of 105 patients had an abnormal result: 102 (9.8%) exhibited a loss of protein on IHC and 98 (9.4%) had MSI. A discordant result was observed in 10 patients with eventual proven LS in 6 patients. Loss of MLH1 (n = 64) was due to promoter methylation in 43 patients (67.2%). Overall, of 62 patients with an abnormal result, 38 had genetic sequencing leading to 25 (65.8%) identified with a germ-line mutation. Loss of MSH2 on IHC was associated with a mutation in 78.3% (18 of 23) of cases. Among the 62 patients with abnormal results, 23 (37.1%) did not meet the Bethesda criteria. CONCLUSIONS Strict application of the Bethesda criteria does not lead to identification of all patients with LS. IHC and MSI testing are complementary methods and should be used in association to identify potential LS patients.
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Affiliation(s)
- Guillaume Canard
- Department of Digestive Surgery, Hôpital Saint-Antoine, Université Pierre et Marie Curie, Paris, France
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479
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Hitchins MP, Rapkins RW, Kwok CT, Srivastava S, Wong JJL, Khachigian LM, Polly P, Goldblatt J, Ward RL. Dominantly inherited constitutional epigenetic silencing of MLH1 in a cancer-affected family is linked to a single nucleotide variant within the 5'UTR. Cancer Cell 2011; 20:200-13. [PMID: 21840485 DOI: 10.1016/j.ccr.2011.07.003] [Citation(s) in RCA: 106] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/23/2011] [Revised: 05/16/2011] [Accepted: 07/05/2011] [Indexed: 10/17/2022]
Abstract
Constitutional epimutations of tumor suppressor genes manifest as promoter methylation and transcriptional silencing of a single allele in normal somatic tissues, thereby predisposing to cancer. Constitutional MLH1 epimutations occur in individuals with young-onset cancer and demonstrate non-Mendelian inheritance through their reversal in the germline. We report a cancer-affected family showing dominant transmission of soma-wide highly mosaic MLH1 methylation and transcriptional repression linked to a particular genetic haplotype. The epimutation was erased in spermatozoa but reinstated in the somatic cells of the next generation. The affected haplotype harbored two single nucleotide substitutions in tandem; c.-27C > A located near the transcription initiation site and c.85G > T. The c.-27C > A variant significantly reduced transcriptional activity in reporter assays and is the probable cause of this epimutation.
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Affiliation(s)
- Megan P Hitchins
- Adult Cancer Program, Lowy Cancer Research Centre, Prince of Wales Clinical School, Faculty of Medicine at the University of New South Wales, NSW 2052, Australia
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480
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Pérez-Cabornero L, Infante Sanz M, Velasco Sampedro E, Lastra Aras E, Acedo Becares A, Miner Pino C, Durán Domínguez M. Frequency of rearrangements in Lynch syndrome cases associated with MSH2: characterization of a new deletion involving both EPCAM and the 5' part of MSH2. Cancer Prev Res (Phila) 2011; 4:1556-62. [PMID: 21791569 DOI: 10.1158/1940-6207.capr-11-0080] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Lynch syndrome is caused by germline mutations in MSH2, MLH1, MSH6, and PMS2 mismatch repair genes and leads to a high risk of colorectal and endometrial cancer. It was recently shown that constitutional 3' end deletions of EPCAM could cause Lynch syndrome in tissues with MSH2 deficiency. We aim to establish the spectrum of mutations in MSH2-associated Lynch syndrome cases and their clinical implications. Probands from 159 families suspected of having Lynch syndrome were enrolled in the study. Immunohistochemistry and microsatellite instability (MSI) analyses were used on the probands of all families. Eighteen cases with MSH2 loss were identified: eight had point mutations in MSH2. In 10 Lynch syndrome families without MSH2 mutations, EPCAM-MSH2genomic rearrangement screening was carried out with the use of multiplex ligation-dependent probe amplification and reverse transcriptase PCR. We report that large germline deletions, encompassing one or more exons of the MSH2 gene, cosegregate with the Lynch syndrome phenotype in 23% (8 of 35) of MSI families tested. A new combined deletion EPCAM-MSH2 was identified and characterized by break point analysis, encompassing from the 3' end region of EPCAM to the 5' initial sequences of the MSH2 (c.859-1860_MSH2:646-254del). EPCAM-MSH2 fusion transcript was isolated. The tumors of the carriers show high-level MSI and MSH2 protein loss. The clinical correlation provided evidence that the type of mutation and the extension of the deletions involving the MSH2 gene could have different implications in cancer predisposition. Thus, the identification of EPCAM-MSH2 rearrangements and their comprehensive characterization should be included in the routine mutation screening protocols for Lynch syndrome.
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Affiliation(s)
- Lucia Pérez-Cabornero
- Cancer Genetics Laboratory, Instituto de Biología y Genética Molecular, University of Valladolid, Spain
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481
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Tresallet C, Brouquet A, Julié C, Beauchet A, Vallot C, Ménégaux F, Mitry E, Radvanyi F, Malafosse R, Rougier P, Nordlinger B, Laurent-Puig P, Boileau C, Emile JF, Muti C, Penna C, Hofmann-Radvanyi H. Evaluation of predictive models in daily practice for the identification of patients with Lynch syndrome. Int J Cancer 2011; 130:1367-77. [DOI: 10.1002/ijc.26144] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2010] [Accepted: 03/25/2011] [Indexed: 11/11/2022]
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482
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Zaina S, Pérez-Luque EL, Lund G. Genetics talks to epigenetics? The interplay between sequence variants and chromatin structure. Curr Genomics 2011; 11:359-67. [PMID: 21286314 PMCID: PMC2945002 DOI: 10.2174/138920210791616662] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2010] [Revised: 06/12/2010] [Accepted: 06/15/2010] [Indexed: 12/29/2022] Open
Abstract
Transcription is regulated by two major mechanisms. On the one hand, changes in DNA sequence are responsible for genetic gene regulation. On the other hand, chromatin structure regulates gene activity at the epigenetic level. Given the fundamental participation of these mechanisms in transcriptional regulation of virtually any gene, they are likely to co-regulate a significant proportion of the genome. The simple concept behind this idea is that a mutation may have a significant impact on local chromatin structure by modifying DNA methylation patterns or histone type recruitment. Yet, the relevance of these interactions is poorly understood. Elucidating how genetic and epigenetic mechanisms co-participate in regulating transcription may assist in some of the unresolved cases of genetic variant-phenotype association. One example is loci that have biologically predictable functions but genotypes that fail to correlate with phenotype, particularly disease outcome. Conversely, a crosstalk between genetics and epigenetics may provide a mechanistic explanation for cases in which a convincing association between phenotype and a genetic variant has been established, but the latter does not lie in a promoter or protein coding sequence. Here, we review recently published data in the field and discuss their implications for genetic variant-phenotype association studies.
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Affiliation(s)
- Silvio Zaina
- Department of Medical Research, Division of Health Sciences, Leon Campus, University of Guanajuato, Leon, Mexico
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483
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Jensen LH, Kuramochi H, Crüger DG, Lindebjerg J, Kolvraa S, Danenberg P, Danenberg K, Jakobsen A. Gene expression of the mismatch repair gene MSH2 in primary colorectal cancer. Tumour Biol 2011; 32:977-83. [PMID: 21732224 DOI: 10.1007/s13277-011-0199-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2011] [Accepted: 05/30/2011] [Indexed: 12/26/2022] Open
Abstract
Microsatellite instability (MSI) is caused by defective mismatch repair (MMR) and is one of the very few molecular markers with proven clinical importance in colorectal cancer with respect to heredity, prognosis, and treatment effect. The gene expression of the MMR gene MSH2 may be a quantitative marker for the level of MMR and a potential molecular marker with clinical relevance. The aim was to investigate the gene expression of MSH2 in primary operable colorectal cancer in correlation with MSI, protein expression, and promoter hypermethylation. In a cohort of 210 patients, the primary tumor and lymphnode metastases were analyzed with immunohistochemistry, methylation and MSI analyses, and quantitative polymerase chain reaction (PCR). The median gene expression of MSH2 was 1.00 (range 0.16-11.2, quartiles 0.70-1.51) and there was good agreement between the gene expression in primary tumor and lymph node metastasis (Spearman's rho = 0.57, p < 0.001, n = 73). The validity of gene expression analysis was made probable by a significant correlation to protein expression (p = 0.005). MSI was most often caused by deficient MLH1 and was not correlated to MSH2 expression. Hypermethylation of the MSH2 gene promoter was only detected in 14 samples and only at a low level with no correlation to gene expression. MSH2 gene expression was not a prognostic factor for overall survival in univariate or multivariate analysis. The gene expression of MSH2 is a potential quantitative marker ready for further clinical validation.
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Affiliation(s)
- Lars Henrik Jensen
- Danish Colorectal Cancer Group South, University of Southern Denmark and Vejle Hospital, Vejle, Denmark.
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484
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Edwards QT, Maradiegue A, Seibert D, Jasperson K. Pre- and postassessment of nurse practitioners' knowledge of hereditary colorectal cancer. ACTA ACUST UNITED AC 2011; 23:361-9. [PMID: 21696485 DOI: 10.1111/j.1745-7599.2011.00625.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
PURPOSE This study was part of an educational program conducted to describe nurse practitioners' (NPs') knowledge and perceived comfort level regarding the identification of hereditary colorectal cancer (CRC), specifically Lynch syndrome, also referred to as hereditary nonpolyposis CRC. DATA SOURCES A 3-h workshop was developed that included a pretest to evaluate NPs' knowledge of hereditary CRC syndromes, educational program focusing on Lynch syndrome, and a posttest knowledge evaluation. Knowledge of hereditary CRC syndromes was assessed via a nine-item multiple choice self-report survey. Forty-two NPs participated in the study. CONCLUSION Few NPs (39%) reported "comfortable" in identifying red flags "suspect" for Lynch syndrome. Percentage of NPs who responded correctly on each of the pretest items ranged from 17.0% to 57.1% (M = 26.2%; SD = 13.5%; 95% confidence intervals [CI] 14.9%, -37.5%). NPs who responded correctly to the same items after the educational program (posttest) ranged from 53.8% to 95% (M = 80.5%; SD = 15.3%; 95% CI 67.8%, -93.4%). IMPLICATIONS FOR PRACTICE Genetic testing is widely available for Lynch syndrome. It is important that NPs are cognizant of the syndrome and identify patients at risk for hereditary cancer syndromes so appropriate referral and management can be instituted.
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Affiliation(s)
- Quannetta T Edwards
- College of Graduate Nursing, Western University of Health Sciences, Pomona, California 91766-1854, USA.
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485
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How helpful is age at colorectal cancer onset in finding hereditary nonpolyposis colorectal cancer? Clin Gastroenterol Hepatol 2011; 9:458-60. [PMID: 21440092 DOI: 10.1016/j.cgh.2011.03.016] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/13/2010] [Revised: 03/14/2011] [Accepted: 03/14/2011] [Indexed: 02/07/2023]
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486
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Limburg PJ, Harmsen WS, Chen HH, Gallinger S, Haile RW, Baron JA, Casey G, Woods MO, Thibodeau SN, Lindor NM. Prevalence of alterations in DNA mismatch repair genes in patients with young-onset colorectal cancer. Clin Gastroenterol Hepatol 2011; 9:497-502. [PMID: 21056691 PMCID: PMC3058119 DOI: 10.1016/j.cgh.2010.10.021] [Citation(s) in RCA: 55] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/13/2010] [Revised: 09/17/2010] [Accepted: 10/12/2010] [Indexed: 12/11/2022]
Abstract
BACKGROUND & AIMS Direct germline analysis could be used to screen high-risk patients for mutations in DNA mismatch repair genes associated with Lynch Syndrome. We examined the prevalence of mutations in MLH1, MSH2, and MSH6 in a population-based sample of patients with young-onset (age <50 years) colorectal cancer (CRC). METHODS Young-onset CRC cases were randomly selected from 3 Colon Cancer Family Registry sites. DNA was extracted from peripheral blood leukocytes; MLH1, MSH2, and MSH6 were sequenced, and duplication and deletion analyses was performed for MLH1 and MSH2. Results were reported as deleterious or suspected deleterious, likely neutral, variant of uncertain significance, or no alteration detected. Germline data were compared to Amsterdam II criteria (ACII) and immunohistochemistry results in secondary analyses. RESULTS Among 195 subjects, 11 had deleterious/suspected deleterious mutations (5.6%; 95% confidence interval [CI], 2.8%-9.9%), 12 had likely neutral alterations (6.2%; 95% CI, 3.2%-10.5%), 14 had variants of uncertain significance (7.2%; 95% CI, 4.0%-11.8%), 2 had a likely neutral alteration and a variant of uncertain significance (1.0%; 95% CI, 0.1%-3.7%), and 156 had no alteration detected (80.0%; 95% CI, 73.7%-85.4%). Sensitivity, specificity, and positive and negative predictive values for detecting deleterious/suspected deleterious mutations, based on ACII, were 36.4% (4/11), 96.7% (178/184), 40.0% (4/10), and 96.2% (178/185), respectively; based on immunohistochemistry these values were 85.7% (6/7), 91.9% (136/148), 33.3% (6/18), and 99.3% (136/137), respectively. CONCLUSIONS In a population-based sample of young-onset CRC cases, germline mutations in MLH1, MSH, and/or MSH6 were more prevalent than reported for CRC patients overall. Because only about 5% of young-onset CRC cases had confirmed deleterious or suspected deleterious mutations, further comparative effectiveness research is needed to determine the most appropriate screening strategy for Lynch Syndrome in this high-risk group.
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Affiliation(s)
- Paul J. Limburg
- Division of Gastroenterology & Hepatology (PJL), Division of Biomedical Statistics and Informatics (WHS), Department of Laboratory Medicine (SNT) and Department of Medical Genetics (HHC, NML), Rochester, Minnesota
| | - William S. Harmsen
- Division of Gastroenterology & Hepatology (PJL), Division of Biomedical Statistics and Informatics (WHS), Department of Laboratory Medicine (SNT) and Department of Medical Genetics (HHC, NML), Rochester, Minnesota
| | - Helen H. Chen
- Division of Gastroenterology & Hepatology (PJL), Division of Biomedical Statistics and Informatics (WHS), Department of Laboratory Medicine (SNT) and Department of Medical Genetics (HHC, NML), Rochester, Minnesota
| | - Steven Gallinger
- Cancer Care Ontario, Mount Sinai Hospital, Samuel Lunenfeld Research Institute, University of Toronto, Toronto, Ontario, Canada
| | - Robert W. Haile
- Department of Preventive Medicine, Keck School of Medicine, University of Southern California, Los Angeles, CA
| | - John A. Baron
- Department of Community and Family Medicine, Dartmouth Medical School, Hanover, New Hamsphire
| | - Graham Casey
- Department of Preventive Medicine, Keck School of Medicine, University of Southern California, Los Angeles, CA
| | - Michael O. Woods
- Department of Genetics, Faculty of Medicine, Memorial University, St John's, Newfoundland, Canada
| | - Stephen N. Thibodeau
- Division of Gastroenterology & Hepatology (PJL), Division of Biomedical Statistics and Informatics (WHS), Department of Laboratory Medicine (SNT) and Department of Medical Genetics (HHC, NML), Rochester, Minnesota
| | - Noralane M. Lindor
- Division of Gastroenterology & Hepatology (PJL), Division of Biomedical Statistics and Informatics (WHS), Department of Laboratory Medicine (SNT) and Department of Medical Genetics (HHC, NML), Rochester, Minnesota
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487
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Hitchins MP, Owens SE, Kwok CT, Godsmark G, Algar UF, Ramesar RS. Identification of new cases of early-onset colorectal cancer with an MLH1 epimutation in an ethnically diverse South African cohort. Clin Genet 2011; 80:428-34. [PMID: 21375527 DOI: 10.1111/j.1399-0004.2011.01660.x] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Lynch syndrome, characterized by young-onset microsatellite unstable colorectal, endometrial and other cancers, is caused by germline mutations of the mismatch repair genes, most commonly MLH1, MSH2 and MSH6. Constitutional MLH1 epimutations, which manifest as soma-wide methylation and transcriptional silencing of a single allele, have been identified in a subset of patients with a Lynch syndrome phenotype in the absence of a mismatch repair mutation. This study aimed to determine if MLH1 epimutations predispose to the development of young-onset colorectal cancer in an ethnically diverse population of South African subjects. A total of 122 index cases with a diagnosis of colorectal cancer below 50 years of age, who had tested negative for a definitive pathogenic mutation of the key mismatch repair genes, were screened for constitutional MLH1 methylation in their leukocyte DNA. Monoallelic MLH1 epimutations were identified in two sporadic cases (1.6%): a male of black African descent and an Asian Indian female. Few alleles were affected by methylation in the female, indicating mosaicism. These cases provide further evidence of the aetiological role for MLH1 epimutations in cancer development and the requirement for sensitive molecular screening techniques to identify mosaic epimutations. Furthermore, while this mechanism is rare, it affects patients of multiple ethnic origins.
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Affiliation(s)
- M P Hitchins
- Medical Epigenetics Laboratory, Adult Cancer Program, Lowy Cancer Research Centre, University of New South Wales, Sydney, Australia
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488
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Abstract
Many patients develop cancers that have clinical features of inherited syndromes (e.g., young age of onset and unique pathology) but lack mutations in the genes characteristic of the disease. In this issue of the journal, Wong et al. report that somatic epigenetic inactivation could explain some such cases in the setting of BRCA1-associated breast cancer. Here, we discuss the implications of this work in terms of the etiology, risk, and potential prevention of cancer.
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Affiliation(s)
- Jean-Pierre J Issa
- Department of Leukemia, The University of Texas MD Anderson Cancer Center, 1515 Holcombe Boulevard, Box 428, Houston, TX 77030, USA.
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489
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Venkatachalam R, Verwiel ETP, Kamping EJ, Hoenselaar E, Görgens H, Schackert HK, van Krieken JHJM, Ligtenberg MJL, Hoogerbrugge N, van Kessel AG, Kuiper RP. Identification of candidate predisposing copy number variants in familial and early-onset colorectal cancer patients. Int J Cancer 2011; 129:1635-42. [PMID: 21128281 DOI: 10.1002/ijc.25821] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2010] [Accepted: 11/16/2010] [Indexed: 12/21/2022]
Abstract
In the majority of colorectal cancers (CRCs) under clinical suspicion for a hereditary cause, the disease-causing genetic factors are still to be discovered. To identify such genetic factors we stringently selected a discovery cohort of 41 CRC index patients with microsatellite-stable tumors. All patients were below 40 years of age at diagnosis and/or exhibited an overt family history. We employed genome-wide copy number profiling using high-resolution SNP arrays on germline DNA, which resulted in the identification of novel copy number variants (CNVs) in six patients (15%) encompassing, among others, the cadherin gene CDH18, the bone morphogenetic protein antagonist family gene GREM1, and the breakpoint cluster region gene BCR. In addition, two genomic deletions were encountered encompassing two microRNA genes, hsa-mir-491/KIAA1797 and hsa-mir-646/AK309218. None of these CNVs has previously been reported in relation to CRC predisposition in humans, nor were they encountered in large control cohorts (>1,600 unaffected individuals). Since several of these newly identified candidate genes may be functionally linked to CRC development, our results illustrate the potential of this approach for the identification of novel candidate genes involved in CRC predisposition.
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Affiliation(s)
- Ramprasath Venkatachalam
- Department of Human Genetics, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands
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490
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Abstract
The number of known mutations in human nuclear genes, underlying or associated with human inherited disease, has now exceeded 100,000 in more than 3700 different genes (Human Gene Mutation Database). However, for a variety of reasons, this figure is likely to represent only a small proportion of the clinically relevant genetic variants that remain to be identified in the human genome (the 'mutome'). With the advent of next-generation sequencing, we are currently witnessing a revolution in medical genetics. In particular, whole-genome sequencing (WGS) has the potential to identify all disease-causing or disease-associated DNA variants in a given individual. Here, we use examples of recent advances in our understanding of mutational/pathogenic mechanisms to guide our thinking about possible locations outwith gene-coding sequences for those disease-causing or disease-associated variants that are likely so often to have been overlooked because of the inadequacy of current mutation screening protocols. Such considerations are important not only for improving mutation-screening strategies but also for enhancing the interpretation of findings derived from genome-wide association studies, whole-exome sequencing and WGS. An improved understanding of the human mutome will not only lead to the development of improved diagnostic testing procedures but should also improve our understanding of human genome biology.
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Affiliation(s)
- J M Chen
- Etablissement Français du Sang (EFS) - Bretagne, Brest, France.
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491
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Kuiper RP, Vissers LELM, Venkatachalam R, Bodmer D, Hoenselaar E, Goossens M, Haufe A, Kamping E, Niessen RC, Hogervorst FBL, Gille JJP, Redeker B, Tops CMJ, van Gijn ME, van den Ouweland AMW, Rahner N, Steinke V, Kahl P, Holinski-Feder E, Morak M, Kloor M, Stemmler S, Betz B, Hutter P, Bunyan DJ, Syngal S, Culver JO, Graham T, Chan TL, Nagtegaal ID, van Krieken JHJM, Schackert HK, Hoogerbrugge N, van Kessel AG, Ligtenberg MJL. Recurrence and variability of germline EPCAM deletions in Lynch syndrome. Hum Mutat 2011; 32:407-14. [PMID: 21309036 DOI: 10.1002/humu.21446] [Citation(s) in RCA: 118] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2010] [Accepted: 01/03/2011] [Indexed: 12/23/2022]
Abstract
Recently, we identified 3' end deletions in the EPCAM gene as a novel cause of Lynch syndrome. These truncating EPCAM deletions cause allele-specific epigenetic silencing of the neighboring DNA mismatch repair gene MSH2 in tissues expressing EPCAM. Here we screened a cohort of unexplained Lynch-like families for the presence of EPCAM deletions. We identified 27 novel independent MSH2-deficient families from multiple geographical origins with varying deletions all encompassing the 3' end of EPCAM, but leaving the MSH2 gene intact. Within The Netherlands and Germany, EPCAM deletions appeared to represent at least 2.8% and 1.1% of the confirmed Lynch syndrome families, respectively. MSH2 promoter methylation was observed in epithelial tissues of all deletion carriers tested, thus confirming silencing of MSH2 as the causative defect. In a total of 45 families, 19 different deletions were found, all including the last two exons and the transcription termination signal of EPCAM. All deletions appeared to originate from Alu-repeat mediated recombination events. In 17 cases regions of microhomology around the breakpoints were found, suggesting nonallelic homologous recombination as the most likely mechanism. We conclude that 3' end EPCAM deletions are a recurrent cause of Lynch syndrome, which should be implemented in routine Lynch syndrome diagnostics.
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Affiliation(s)
- Roland P Kuiper
- Department of Human Genetics, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands.
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492
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Abstract
Microsatellite instability (MSI) occurs in about 15% of gastrointestinal cancers and it is associated with specific clinic, pathologic, and molecular features of the tumors. MSI-high (MSI-H) carcinomas also follow specific tumor development pathways. This review is focused on the molecular profile of alterations in members of the KRAS signaling pathway (EGFR, KRAS, BRAF, PIK3CA, RASSF1A, and MLK3 genes) in MSI gastrointestinal carcinomas. Alterations in these genes characterize more than half of gastrointestinal cancers and frequently occur simultaneously in the same tumor, pinpointing the KRAS signaling pathway as one of the most frequently altered pathways in this subset of cancers. Nowadays, many and novel inhibitors targeting molecules of this signaling pathway are being described; therefore, it is worthwhile to test their efficacy in MSI gastrointestinal cancers in order to develop new and more directed targeted therapies for patients affected by this disease.
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493
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Migliore L, Migheli F, Spisni R, Coppedè F. Genetics, cytogenetics, and epigenetics of colorectal cancer. J Biomed Biotechnol 2011; 2011:792362. [PMID: 21490705 PMCID: PMC3070260 DOI: 10.1155/2011/792362] [Citation(s) in RCA: 172] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2010] [Accepted: 12/14/2010] [Indexed: 12/17/2022] Open
Abstract
Most of the colorectal cancer (CRC) cases are sporadic, only 25% of the patients have a family history of the disease, and major genes causing syndromes predisposing to CRC only account for 5-6% of the total cases. The following subtypes can be recognized: MIN (microsatellite instability), CIN (chromosomal instability), and CIMP (CpG island methylator phenotype). CIN occurs in 80-85% of CRC. Chromosomal instability proceeds through two major mechanisms, missegregation that results in aneuploidy through the gain or loss of whole chromosomes, and unbalanced structural rearrangements that lead to the loss and/or gain of chromosomal regions. The loss of heterozygosity that occur in the first phases of the CRC cancerogenesis (in particular for the genes on 18q) as well as the alteration of methylation pattern of multiple key genes can drive the development of colorectal cancer by facilitating the acquisition of multiple tumor-associated mutations and the instability phenotype.
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Affiliation(s)
- Lucia Migliore
- Department of Human and Environmental Sciences, University of Pisa, Street S. Giuseppe 22, 56126 Pisa, Italy.
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494
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Lynch HT, Lynch JF, Snyder CL, Riegert-Johnson D. EPCAM deletions, Lynch syndrome, and cancer risk. Lancet Oncol 2011; 12:5-6. [PMID: 21195320 DOI: 10.1016/s1470-2045(10)70291-6] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Affiliation(s)
- Henry T Lynch
- Department of Preventive Medicine and Public Health, Creighton University, 2500 California Plaza, Omaha, NE, USA.
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495
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Goel A, Nguyen TP, Leung HCE, Nagasaka T, Rhees J, Hotchkiss E, Arnold M, Banerji P, Koi M, Kwok CT, Packham D, Lipton L, Boland CR, Ward RL, Hitchins MP. De novo constitutional MLH1 epimutations confer early-onset colorectal cancer in two new sporadic Lynch syndrome cases, with derivation of the epimutation on the paternal allele in one. Int J Cancer 2011; 128:869-78. [PMID: 20473912 DOI: 10.1002/ijc.25422] [Citation(s) in RCA: 70] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Lynch syndrome is an autosomal dominant cancer predisposition syndrome classically caused by germline mutations of the mismatch repair genes, MLH1, MSH2, MSH6 and PMS2. Constitutional epimutations of the MLH1 gene, characterized by soma-wide methylation of a single allele of the promoter and allelic transcriptional silencing, have been identified in a subset of Lynch syndrome cases lacking a sequence mutation in MLH1. We report two individuals with no family history of colorectal cancer who developed that disease at age 18 and 20 years. In both cases, cancer had arisen because of the de novo occurrence of a constitutional MLH1 epimutation and somatic loss-of-heterozygosity of the functional allele in the tumors. We show for the first time that the epimutation in one case arose on the paternally inherited allele. Analysis of 13 tumors from seven individuals with constitutional MLH1 epimutations showed eight tumors had lost the second MLH1 allele, two tumors had a novel pathogenic missense mutation and three had retained heterozygosity. Only 1 of 12 tumors demonstrated the BRAF V600E mutation and 3 of 11 tumors harbored a mutation in KRAS. The finding that epimutations can originate on the paternal allele provides important new insights into the mechanism of origin of epimutations. It is clear that the second hit in MLH1 epimutation-associated tumors typically has a genetic not epigenetic basis. Individuals with mismatch repair-deficient cancers without the BRAF V600E mutation are candidates for germline screening for sequence or methylation changes in MLH1.
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Affiliation(s)
- Ajay Goel
- Gastrointestinal Cancer Research Laboratory, Baylor University Medical Center, Dallas, TX, USA
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496
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Manders P, Spruijt L, Kets CM, Willems HW, Bodmer D, Hebeda KM, Nagtegaal ID, van Krieken JHJM, Ligtenberg MJL, Hoogerbrugge N. Young age and a positive family history of colorectal cancer are complementary selection criteria for the identification of Lynch syndrome. Eur J Cancer 2011; 47:1407-13. [PMID: 21273057 DOI: 10.1016/j.ejca.2010.12.024] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2010] [Revised: 12/16/2010] [Accepted: 12/22/2010] [Indexed: 11/28/2022]
Abstract
Families at high risk for Lynch syndrome can effectively be recognised by microsatellite instability (MSI) testing. The aim of the present study is to compare the effectiveness of a MSI test for the identification of Lynch syndrome in patients selected by a pathologist mainly based on young age at diagnosis (MSI-testing-indicated-by-a-Pathologist; MIPA), with that of patients selected by a clinical geneticist mainly based on family history (MSI-testing-indicated-by-Family-History; MIFH). Patients with a Lynch syndrome associated tumour were selected using MIPA (n=362) or MIFH (n=887). Germline DNA mutation testing was performed in 171 out of 215 patients (80%) with a MSI positive tumour. MSI was tested positive in 20% of the MIPA-group group compared to 16% in the MIFH-group (P=0.291). In 91 of 171 patients with MSI positive tumours tested for germline mutations were identified as Lynch syndrome patients: 42% in the MIPA-group and 56% in the MIFH-group (P=0.066). Colorectal cancer (CRC) or endometrial cancer (EC) presenting at an age below 50 years would have led to the diagnosis of Lynch syndrome in 89% of these families (CRC below 50 years: 88% and EC below 50 years: 12%). Families detected by MIPA were characterised more often by extracolonic Lynch syndrome associated malignancies, especially EC (P<0.001). Our results indicate that recognition of Lynch syndrome by CRC or EC below 50 years is as effective as a positive family history. Families from patients selected by individual criteria more often harbour extracolonic Lynch syndrome associated malignancies.
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Affiliation(s)
- P Manders
- Department of Human Genetics, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands
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497
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Power DG, Gloglowski E, Lipkin SM. Clinical genetics of hereditary colorectal cancer. Hematol Oncol Clin North Am 2011; 24:837-59. [PMID: 20816577 DOI: 10.1016/j.hoc.2010.06.006] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Colorectal cancer (CRC) is a common disease, and approximately 25% of patients have a familial component. High-penetrance singlegene germline mutations conferring a true hereditary susceptibility account for around 5% to 6% of all cases. Lynch syndrome is the most common hereditary form of colorectal cancer. Much of the hereditary component in the remaining familial cases of CRC is likely polygenic, and many of the genetic changes involved are as yet unidentified. This article addresses the most clinically important CRC genetic syndromes.
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Affiliation(s)
- Derek G Power
- Clinical Genetics, Department of Medicine, Memorial Sloan-Kettering Cancer Center, New York, NY 10065, USA
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498
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Yoo KH, Park YK, Kim HS, Jung WW, Chang SG. Epigenetic inactivation of HOXA5 and MSH2 gene in clear cell renal cell carcinoma. Pathol Int 2011; 60:661-6. [PMID: 20846263 DOI: 10.1111/j.1440-1827.2010.02578.x] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The high-throughput method using microarray is an easy and fast way to analyze the methylation status of hundreds of preselected genes and to screen them for signatures in methylation. The aim of our study is to detect hypermethylated genes and to analyze the association between methylation status and clinicopathological parameters of clear cell renal cell carcinoma. The genetic substrate included 62 cancer tissues and 62 matched adjacent normal kidney tissues. We adapted the GoldenGate genotyping assay to determine the methylation state of 1505 specific CpG sites in 807 genes. We identified two genes (HOXA5 and MSH2) with β-value differences of more than 0.3 between cancer and normal tissues. The high methylation group in HOXA5 had high Fuhrman's nuclear grade (P= 0.041). Other data in HOXA5 and MSH2 were not significant with methylation status (P > 0.05). Survival curve of the high methylation group in HOXA5 was slightly lower than that of the low methylation group. However, the statistical significances of overall survival in HOXA5 and MSH2 were low (P > 0.05). We report the hypermethylation of two genes in clear cell renal cell carcinoma. The data we obtained could provide the basis for a diagnostic test pathological assessment, or prognosis in clear cell renal cell carcinoma.
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Affiliation(s)
- Koo Han Yoo
- Department of Urology, School of Medicine, Kyung Hee University, Seoul, Korea
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499
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van Engeland M, Derks S, Smits KM, Meijer GA, Herman JG. Colorectal cancer epigenetics: complex simplicity. J Clin Oncol 2011; 29:1382-91. [PMID: 21220596 DOI: 10.1200/jco.2010.28.2319] [Citation(s) in RCA: 147] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Colorectal cancer (CRC) has predominantly been considered a genetic disease, characterized by sequential accumulation of genetic alterations. Growing evidence indicates that epigenetic alterations add an additional layer of complexity to the pathogenesis of CRC, and characterize a subgroup of colorectal cancers with a distinct etiology and prognosis. Epigenetic dysregulation in colorectal cancer is organized at multiple levels, involving DNA methylation, histone modifications, nucleosomal occupancy and remodeling, chromatin looping, and noncoding RNAs. Interactions between these processes and complex associations with genetic alterations have recently been unraveled. It appears that CRC epigenetics will be the paradigm for multistep carcinogenesis, as CRC genetics has been for the past three decades. This review integrates recent data on epigenetic regulation of gene expression in CRC and describes how the understanding of these processes will alter the management of CRC.
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Affiliation(s)
- Manon van Engeland
- GROW-School for Oncology and Developmental Biology, PO Box 616, 6200 Maastricht, The Netherlands.
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500
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Long Noncoding RNA and Epigenomics. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2011; 722:174-95. [DOI: 10.1007/978-1-4614-0332-6_11] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
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