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MSH6 G39E polymorphism and CpG island methylator phenotype in colon cancer
Author(s) -
Curtin Karen,
Samowitz Wade S.,
Wolff Roger K.,
Caan Bette J.,
Ulrich Cornelia M.,
Potter John D.,
Slattery Martha L.
Publication year - 2009
Publication title -
molecular carcinogenesis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.254
H-Index - 97
eISSN - 1098-2744
pISSN - 0899-1987
DOI - 10.1002/mc.20566
Subject(s) - microsatellite instability , biology , msh6 , mlh1 , colorectal cancer , germline mutation , genetics , dna methylation , cancer research , cancer , microsatellite , dna mismatch repair , mutation , allele , gene , gene expression
Abstract The MSH6 G39E germline polymorphism is not associated with an increased risk of either microsatellite stable or unstable sporadic colorectal cancer. Other than microsatellite instability, however, most genetic and epigenetic changes of tumors associated with this common variant have not been studied. The objective of our investigation was to evaluate associations between the MSH6 G39E (116G>A) polymorphism and CpG island methylator phenotype (CIMP) and BRAF V600E mutations in tumors from a sample of 1048 individuals with colon cancer and 1964 controls from Utah, Northern California, and Minnesota. The G39E polymorphism (rs1042821) was determined by the five prime nuclease assay. CIMP was determined by methylation‐specific polymerase chain reaction (PCR) of CpG islands in MLH1 , methylated in tumors (MINT)1, MINT2, MINT31, and CDKN2A . The BRAF V600E mutation was determined by sequencing exon 15. In microsatellite stable tumors, homozygous carriers of the G39E polymorphism had an increased risk of CIMP+ colon cancer (odds ratio (OR) 2.2, 95% confidence interval (CI) 1.1, 4.2) and BRAF V600E mutation (OR 3.1, 95% CI 1.01, 9.7) in a case–control comparison. This finding was not observed in unstable tumors; however, power may have been low to detect an association. Age at diagnosis, family history, and alcohol use did not interact with MSH6 G39E and CIMP. The MSH6 G39E germline polymorphism may be associated with CIMP+ colon cancer. © 2009 Wiley‐Liss, Inc.