Effects of miR-362 in Regulating the Proliferation, Invasion and Apoptosis of Gastric Cancer by Inhibiting the Expression of Tumor-Promoting Factor PRDM2.

Purpose - The high expression of positive regulatory domain zinc finger protein2 (PRDM2) is an important factor in inducing the formation and progression of gastric cancer. The current study was performed to explore the effect of micro-RNA-362 (miR-362) targeting PRDM2 on the proliferation and apoptosis of gastric cancer cells. Methods - The expression of miR-362 in gastric adenocarcinoma and normal gastric mucosa was detected by real-time fluorescence quantitative PCR (qPCR), and the expression of PRDM2 in gastric adenocarcinoma was detected by im-munohistochemical method. Gastric cancer cell line MGC-803 and human normal gastric mucosal epithelial cell line (GES-1) were selected for study. Blank control group, empty vector transfection group, miR-362 transfection group, and miR-362 and PRDM2 co-transfection group were established. CCK-8 assay was utilized to detect cell activity, flow cytometry was used to detect cell cycle and apoptosis, and invasion capability of cells was observed through transwell experiment. The expression of Cyclin D1 and Caspases-3 was detected by western blot method. Results - The expression of miR-362 in gastric adenocarcinoma was significantly lower than that in normal gastric mucosa. The expression of miR-362 in gastric adenocarcinoma was significantly different in the maximum diameter, depth of invasion, and different TNM stages. The expression of miR-362 was linked to prognosis. In addition, there was a negative correlation between miR-362 and PRDM2. The expression of miR-362 in gastric cancer cell line MGC-803 was significantly lower than that in GES-1. Compared with the blank control group and empty vector transfection group, the proliferation level of gastric cancer cells in miR-362 transfection group was remarkably decreased, the cells in S phase and G2/M phase were significantly decreased, the capability for invasion was evidently decreased, while the apoptosis was significantly increased. The expression of Caspases-3 increased significantly and the expression of Cyclin D1 decreased significantly. MiR-362 and PRDM2 co-transfection groups could reverse the abovementioned expression levels. Conclusion - MiR-362 can regulate the proliferation, invasion and apoptosis of gastric cancer by inhibiting the expression of tumor-promoting factor PRDM2. The expression of miR-362 in gastric adenocarcinoma is significantly decreased, which can regulate the formation and development of gastric adenocarcinoma by promoting the expression of PRDM2. Moreover, low expression of miR-362 in gastric adenocarcinoma is an important risk factor for tumor progression and poor prognosis.