DNA methylation changes in gastrointestinal disease.
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.
Toyota
Minoru
M
First Department of Internal Medicine, Cancer Research Institute, Sapporo Medical University, S-1, W-16, Chuo-ku, Sapporo 060-8543, Japan.
Itoh
Fumio
F
Kikuchi
Takefumi
T
Satoh
Ayumi
A
Obata
Toshiro
T
Suzuki
Hiromu
H
Ishii
Suguru
S
Endo
Takao
T
Tokino
Takashi
T
Imai
Kohzoh
K
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