Review
Copyright ©2009 Baishideng. All rights reserved.
World J Gastrointest Oncol. Oct 15, 2009; 1(1): 41-46
Published online Oct 15, 2009. doi: 10.4251/wjgo.v1.i1.41
Hypermethylation of tumor suppressor and tumor-related genes in neoplastic and non-neoplastic gastric epithelia
Gen Tamura
Gen Tamura, Department of Pathology and Laboratory Medicine, Yamagata Prefectural Central Hospital, 1800 Aoyagi, Yamagata 990-2292, Japan
Author contributions: Tamura G is the sole contributer to this paper.
Correspondence to: Gen Tamura, MD, PhD, Department of Pathology and Laboratory Medicine, Yamagata Prefectural Central Hospital, 1800 Aoyagi, Yamagata 990-2292, Japan. gtamura@ypch.gr.jp
Telephone: +81-23-6852626 Fax: +81-23-6852708
Received: May 20, 2009
Revised: July 15, 2009
Accepted: July 22, 2009
Published online: October 15, 2009
Abstract

A number of tumor suppressor and tumor-related genes exhibit promoter hypermethylation with resultant gene silencing in human cancers. The frequencies of methylation differ among genes and genomic regions within CpG islands in different tissue types. Hypermethylation initially occurs at the edge of CpG islands and spreads to the transcription start site before ultimately shutting down gene expression. When the degree of methylation was quantitatively evaluated in neoplastic and non-neoplastic gastric epithelia using DNA microarray analysis, high-level methylation around the transcription start site appeared to be a tumor-specific phenomenon, although multiple tumor suppressor genes became increasingly methylated with patient age in non-neoplastic gastric epithelia. Quantitative analysis of DNA methylation is a promising method for both cancer diagnosis and risk assessment.

Keywords: Hypermethylation, DNA microarray, Tumor suppressor gene, Gastric cancer