ABSTRACT
@#[Abstract] Objective: To investigate the effects of miR-361-5p on the oxaliplatin (OXA) resistance of gastric cancer SGC-7901 cells and its mechanism. Methods: The expression of miR-361-5p in gastric cancer cells (MKN-45, MGC80-3 and SGC-7901) and drug-resistant SGC-7901/OXA cells was detected by qPCR. The SGC-7901/OXA cells were transfected with miR-361-5p mimics/inhibitor or sh-CCND1 by using Liposome transfection technology. Then, cell proliferation, apoptosis and cell cycle of SGC-7901/OXA cells were measured by CCK-8 assay and Flow cytometry, respectively. The targeting relationship between miR-361-5p and CCND1 was examined by Dual luciferase report gene assay. The expression level of CCND1 in SGC-7901/OXA cells was detected by WB. Results: miR-361-5p was down-regulated in multiple gastric cancer cells and SGC-7901/OXA cells (P<0.05 or P<0.01). Over-expression of miR-361-5p significantly promoted the apoptosis, induced G0/G1 cell cycle arrest and inhibited cell proliferation of SGC-7901/OXA cells (P<0.05 or P<0.01). Dual luciferase reporter gene results verified that miR-361-5p targeted CCND1 and negatively regulated its expression (P<0.01). Further experiments showed that targeted down-regulation of CCND1 induced apoptosis and G0/G1 cell cycle arrest and inhibited CCND1 expression and proliferation of SGC-7901/OXA cells (P<0.05 or P<0.01). Over-expression of miR-361-5p targetedly down-regulated CCND1 and further promoted cell apoptosis, induced G0/G1 cell cycle arrest and inhibited cell proliferation of SGC-7901/OXA cells (P<0.05 or P<0.01). Conclusion: miR-361-5p over-expression can reverse the resistance of SGC-7901/OXA cells to OXA, and the mechanism may be related to its targeted down-regulation of CCND1 expression.