MicroRNAs in Gastric Cancer

Abstract

MicroRNAs (miRNAs) are small non-coding RNAs that function as endogenous silencers of numerous target genes. Hundreds of human miRNAs have been identified in the human genome and are expressed in a tissue-specific manner, playing important roles in cell proliferation, apoptosis, and differentiation. Links between miRNAs and gastric cancer have become increasingly apparent, and the aberrant expression of miRNAs may contribute to the development and progression of human gastric cancer. Recent studies have shown that some miRNAs play roles as tumor suppressors or oncogenes in gastric cancer. For example, miR-21 (one of the major oncogenic miRNAs) is activated by Helicobacter pylori infection and is increased in gastric cancer. On the contrary, the miR-29 family is down-regulated in the malignancy, suggesting that it is a potential tumor suppressor of gastric cancer. MiRNA expression profiling may be a powerful clinical tool for diagnosis and the regulation of miRNA expression could be a novel therapeutic strategy for the disease. This chapter summarizes the biological importance of miRNAs in human gastric cancer.