Abstract: Objective:To investigate the effect of miR-301 on cisplatin resistance in gastric cancer cells and to explore the mechanism of miR-301-induced cisplatin resistance in gastric cancer cells. Methods:The cisplatin-resistant gastric cancer cell line was established by concentration gradient doubling method,and the migration and invasion abilities of the parent cell line and the drug-resistant cell line were detected by scratch test and transwell test.Real-time fluorescence quantitative method was used to detect the expression of miR-301 in resistant cell line and their parental cell line,and the change of miR-301 expression after cell line transfection with miR-301mimics was also detected.CCK-8 assay was used to detect the sensitivity of cells to cisplatin after transfection.Cell function test was used again to detect cell migration and invasion before and after transfection.Flow cytometry was used to detect the anti-apoptotic ability of cells before and after transfection.Western blotting was used to detect the changes of epithelial-mesenchymal transition markers after transfection. Results: The migration and invasion abilities of resistant cell line were significantly higher than those of their parents (P<0.01),and the expression of miR-301 was significantly higher than that of their parents (P<0.01).After transfection with miR-301 mimics,the expression of miR-301 was decreased (P<0.01),the median lethal concentration of cisplatin was decreased (P<0.01),the cell migration and invasion ability were significantly decreased (P<0.01),the anti-apoptotic ability was increased (P<0.01),the expression of epithelial cell marker E-Cadherin was increased,and the expression of mesenchymal cell markers N-Cadherin and Vimentin was decreased. Conclusions: MiR-301 induces and enhances migration and invasion ability of gastric cencer cells,improves anti-apoptotic ability,promotes promotes epithelial-mesenchymal transition,and enhances cell resistance to cisplatin.