Abstract: Objective To investigate the effect of overexpression of miR-30b on the proliferation, cell cycle, apoptosis and invasion of gastric cancer cell line SGC- 7901 and AGS, and the inhibitory effect on the tumor formation in vivo.Methods SGC-7901 and AGS cells were transfected with miR-30b mimics and miR-control, and qRT-PCR was used to detect the expression levels of miR-30b. Western blot assay was used to detect the expression of eIF5A2 protein. CCK-8 assay was used to measure the cell proliferation. Flow cytometry was used to analyze cell cycle and apoptosis. Transwell assay was used to detect cell invasion. In addition, the SGC-7901 and AGS cells transfected with miR-30b mimics and miRcontrol were injected into nude mice to observe the tumor formation and the expression of eIF5A2 protein in vivo. Results Results of qRT-PCR showed that the relative expression of miR-30b was significantly higher than that of miR-control group (P ＜ 0.05). Western blot assay showed that the expression of eIF5A2 protein was decreased in miR- 30b mimics group.CCK-8 assay showed that cell proliferation was inhibited in miR-30b mimics group. The result of flow cytometry showed that the cell cycle decreased and the apoptosis increased in miR-30b group. Transwell assay showed that the cell invasion was significantly lower in miR-30b group than that of control group (P＜0.05). Overexpression of miR-30b inhibited the formation of tumor and decreased the expression of eIF5A2 protein in vivo. Conclusion Overexpression of miR- 30b inhibits the proliferation, invasion and tumor formation of gastric cancer cells, and reduces the expression of eIF5A2 protein,which provides a potential target for gastric cancer treatment.

Key words: microRNAs, cell proliferation, cell cycle, apoptosis, neoplasm invasiveness, miR-30b