Development of sporadic microsatellite instability in colorectal tumors involves hypermethylation at methylated-in-tumor loci in adenoma.

ABSTRACT: Microsatellite instability (MSI) and genomic hypermethylation of methylated-in-tumor (MINT) loci are both strong prognostic indicators in a subgroup of patients with sporadic colorectal cancer (CRC). The present study was designed to determine whether the methylation of MINT loci during the progression of adenoma to CRC is related to MSI in CRC cases. Methylation index (MI) was measured by absolute quantitative assessment of methylated alleles at seven MINT loci in primary CRC with contiguous adenomatous and normal tissues of 79 patients. Results were then validated in primary CRC tissues from an independent group of 54 patients. Increased MI of both MINT loci 1 and 31 was significantly associated with MSI in CRC and was specific for adenoma. Total MI and the number of methylated loci were

SUBMITTER: de Maat MF 

PROVIDER: S-EPMC2966793 | biostudies-literature | 2010 Nov

REPOSITORIES: biostudies-literature