Published in:
01-07-2011 | Original Article
miR-137 Is Frequently Down-Regulated in Gastric Cancer and Is a Negative Regulator of Cdc42
Published in: Digestive Diseases and Sciences | Issue 7/2011
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Introduction
MicroRNAs (miRNAs) are a class of small (19–25 nucleotides) noncoding RNAs that regulate the expressions of a wide variety of genes, including some involved in cancer development. Some recent studies show that DNA methylation contributes to down-regulation of microRNA-137 (miR-137) during tumorigenesis. Whether down-regulation of miR-137 also exists in gastric cancer is unknown.
Aim
Our aim was to test the hypothesis that down-regulation of miR-137 also exists in gastric cancer.
Methods
Expression of levels of miR-137 were examined using real-time PCR on paired gastric cancer and adjacent non-cancerous tissues. The methylation status is detected by MSP.
Results
Results show that miR-137 is downregulated by hypermethylation of the promoter in gastric cancer tissues. Epigenetic silencing of miR-137 induced an up-regulation of its targets, Cdc42. Restoration of the miR-137 expression in gastric cancer cell lines downregulated the Cdc42 expression. Restoration of the miR-137 and inactivation of Cdc42 induce apoptosis and cell cycle G1 arrest in gastric cancer cells. Furthermore, the miR-137 expression was found to be inversely correlated with CDC42 expression in gastric caner.
Conclusions
miR-137 is frequently down-regulated in gastric cancer and is a negative regulator of Cdc42.