Histone Acetylation and Retinoic Acid Receptor beta DNA Methylation as Novel Targets for Gastric Cancer Therapy.

: Multiple genetic and epigenetic alterations in oncogenes, tumor-suppressor genes, cell-cycle regulators, cell adhesion molecules and DNA repair genes, as well as genetic instability and telomerase activation, are responsible for tumor genesis and progression of gastric cancer. The scenario of these epigenetic alterations found in gastric cancer differs, depending on the two types of gastric cancer, indicating that there are at least two types of CpG (cytidine phosphate guanosine) island methylator phenotypes in the intestinal-type and diffuse-type of gastric cancer. In addition to promoter methylation, acetylated histone H4 is obviously reduced in a majority of gastric carcinoma. Histone H4 is progressively deacetylated from the early stage (precancerous lesions) to the late stage (invasion and metastasis) in gastric carcinogenesis. Since there is no difference in the level of acetylated histone H4 between the intestinal-type and diffuse-type of gastric cancer, histone H4 deacetylation may be involved in both types of gastric cancer. This article proposes histone acetylation and retinoic acid receptor beta DNA methylation as novel targets for gastric cancer therapy. (c) 2002 Prous Science. All rights reserved.