Abstract: Objective To investigate the effect of miR-205-5p on the proliferation, migration and invasion of gastric cancer cells by targeting at RAS oncogene family (RAP2B). Methods RT-qPCR and Western blot were used to detect the expression of miR-205-5p and RAP2B in gastric cancer cell lines AGS, MGC803, MKN-28, SGC-7901 and normal gastric mucosal cell line GES-1. Over expressing miR-205-5p, inhibition of RAP2B, cell viability was detected by MTT assay; cell migration and invasion ability were detected by Transwell method; The expression of RAP2B, cyclin D1, MMP-2, MMP-9 GSK-3β and β-catenin proteins were detected by Western blot. The dual luciferase reporter gene assay was used to verify the targeting of miR-205-5p to RAP2B. Results Compared with normal gastric mucosal cells, the expression of miR-205-5p was significantly decreased in four gastric cancer cell lines, and the expression of RAP2B was significantly increased (P＜0.05). The over-expression of miR-205-5p or inhibition of RAP2B inhibited the proliferation, migration and invasion of AGS cells and inhibited the expression of cyclin D1, MMP-2 and MMP-9 proteins (P＜0.05). miR-205-5pnegatively regulated the expression of RAP2B. Conclusions miR-205-5p inhibits the proliferation, migration and invasion of gastric cancer cells in vitro by targeting at RAP2B.

Key words: miR-205-5p, RAP2B, gastric cancer, proliferation, migration