Epigenetic changes in gastrointestinal cancers

Abstract

Epigenetic alterations, including DNA methylation, histone modification, loss of genome imprinting, chromatin remodeling and noncoding RNAs, are associated with human carcinogenesis. Among them, DNA methylation is a fundamental epigenetic process to modulate gene expression. In cancer cells, altered DNA methylation includes hypermethylation of site-specific CpG island promoter and global DNA hypomethylation. Detection of aberrant gene promoter methylation has been applied to clinic to stratify risk in cancer development, detect early cancer and predict clinical outcomes. Environmental factors associated with carcinogenesis are also significantly related to aberrant DNA methylation. Importantly, epigenetic changes, including altered DNA methylation, are reversible and thus, used as targets for cancer therapy or chemoprevention. An increasing number of recent studies reported DNA methylation level to be a useful biomarker for diagnosis, risk assessment and prognosis prediction for gastrointestinal cancers. This review summarized the accumulated evidence for clinical application to use aberrant DNA methylation levels in gastrointestinal cancers, including colorectal, gastric and esophageal cancer.

Keywords

Colorectal cancer / DNA methylation / epigenetic alterations / esophageal cancer / gastric cancer

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