Down-regulation of microRNA-205 promotes gastric cancer cell proliferation.

OBJECTIVE Increasing evidence indicates that MicroRNAs, a class of small RNA molecules, play crucial roles in tumorigenesis, through affecting cell proliferation, apoptosis and metastasis. The present study aimed to investigate the effect of miR-205 on gastric cancer cell proliferation. MATERIALS AND METHODS The expression of miR-205 was examined in the gastric cancer tissues and cell lines. BrdU incorporation assay was used to measure the cell proliferation. Western blot was performed to determine the protein expression. RESULTS miR-205 is significantly down-regulated in gastric cancer tissues, compared with adjacent normal tissues. Besides, miR-205 expression is associated with clinical and pathological characteristics of patients. In vitro studies further found that inhibition of miR-205 significantly promoted gastric cancer cell proliferation via cell-cycle progression. Further analyses indicated that miR-205 was able to repress oncoprotein Yin Yang 1 expression, through targeting its 3'-untranlated region. CONCLUSIONS Our data suggest that down-regulation of miR-205 may represent an important mechanism for the development of gastric cancer.