title: DNA methylation changes in gastrointestinal disease.
abstract: DNA methylation of the 5' region of genes is often associated with gene silencing in X-chromosome inactivation and imprinting. Recent studies have indicated that altered DNA methylation plays a role in the inactivation of multiple tumor suppressor genes and DNA repair genes such as p16INK4A and hMLH1. Colorectal adenomas have a relatively high frequency of methylation, and aberrant methylation is an early event during tumorigenesis. In aging patients, even colon epithelium which appears to be normal showed a significant amount of methylation in a subset of the genes. Colon mucosa from patients with inflammatory bowel disease also showed a high level of methylation. DNA methylation can be a specific diagnostic marker in gastrointestinal cancer and inflammatory bowel disease, for which there is no perfect marker for a noninvasive diagnosis.
authors.affiliation: First Department of Internal Medicine, Cancer Research Institute, Sapporo Medical University, S-1, W-16, Chuo-ku, Sapporo 060-8543, Japan.
authors.forename: Minoru
authors.initials: M
authors.lastname: Toyota
authors.forename: Fumio
authors.initials: F
authors.lastname: Itoh
authors.forename: Takefumi
authors.initials: T
authors.lastname: Kikuchi
authors.forename: Ayumi
authors.initials: A
authors.lastname: Satoh
authors.forename: Toshiro
authors.initials: T
authors.lastname: Obata
authors.forename: Hiromu
authors.initials: H
authors.lastname: Suzuki
authors.forename: Suguru
authors.initials: S
authors.lastname: Ishii
authors.forename: Takao
authors.initials: T
authors.lastname: Endo
authors.forename: Takashi
authors.initials: T
authors.lastname: Tokino
authors.forename: Kohzoh
authors.initials: K
authors.lastname: Imai
mesh_terms: D018899:CpG Islands / Q000235:genetics*; D019175:DNA Methylation; D005260:Female; D005770:Gastrointestinal Neoplasms / Q000235:genetics* / Q000503:physiopathology; D020022:Genetic Predisposition to Disease; D006801:Humans; D015212:Inflammatory Bowel Diseases / Q000235:genetics* / Q000503:physiopathology; D007413:Intestinal Mucosa / Q000473:pathology; D008297:Male; D011237:Predictive Value of Tests; D011379:Prognosis; D018570:Risk Assessment; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index