MiR-493 suppresses the proliferation and invasion of gastric cancer cells by targeting RhoC

OBJECTIVES MiRNAs have been proposed to be key regulators of tumorigenesis, progression and metastasis. However, their effect and prognostic value in gastric cancer is still poorly known. MATERIALS AND METHODS Gastric cancer cell lines were cultured. Tissue samples obtained from 36 gastric cancer patients were used for quantitative real-time PCR (qRT-PCR) analysis. The tissue microarrays (TMAs) consisted of 126 cases of gastric carcinoma that were used for In situ hybridisation (ISH). Lentivirus plasmids were co-transfected into 293FT cells. Cell migration was examined using wound-healing assays. Statistical analyses were performed using SPSS16.0 software. RESULTS In this study, we found that the expression levels of miR-493 were strongly down-regulated in gastric cancer and were associated with clinical stage and the presence of lymph node metastases. Moreover, miR-493 might independently predict OS and RFS in gastric cancer. We further found that up-regulation of miR-493 inhibited the proliferation and metastasis of gastric cancer cells, in vitro and in vivo. In addition, miR-493 directly targeted RhoC, which resulted in a marked reduction of the expression of mRNA and protein. This effect, in turn, led to a decreased ability of growth, invasion and metastasis in gastric cancer cells. CONCLUSION Taken together, our findings demonstrate that miR-493 is important for gastric cancer initiation and progression and holds promise as a prognostic biomarker to predict survival and relapse in gastric cancer. It is also a potential therapeutic tool to improve clinical outcomes in this disease.