Abstract:Objective To investigate the regulative effect of miRNA-138 on chemo-sensitivity of ovarian epithelial cancer to platinum and potential mechanism. Methods Totally 80 cases of patients with ovarian epithelial cancer admitted into Mudanjiang Medical College Hongqi Hospital from January 2014 to January 2017 were included in this study. Patients were divided into two groups: platinum-sensitive group and platinum-resistant group.Quantitative real-time PCR (RT-qPCR) and Western Blot were performed to detect the expression of miRNA-138 and SIRT1 in ovarian epithelial carcinoma. SKOV3 cell line were transfected with miRNA-138 analogs (miRNA-138 mimic group) and inhibitor (miRNA-138 inhibitor group). Expression of SIRT1 mRNA was measured by RT-qPCR.MTT assay was utilized for determination of sensitivity to platinum. SIRT1 mRNA 3'-UTR wild type and mutant type luciferase reporter plasmids were co-transfected with miRNA-138mimic, and double luciferase reporter system was used to analyze luciferase activity. Results The concentration of miRNA-138 in platinum-sensitive group was significantly higher than that in platinum-resistant group, while levels of SIRT1 was significantly decreased compared with platinum-resistant group (P < 0.05). Overexpression of miRNA-138 decreased the expression of SIRT1 and increased the sensitivity of tumor cells to platinum (P < 0.05), which was reversed by inhibition of miRNA-138(P < 0.05). Luciferase activity was significantly reduced in group with transfection of SIRT1 mRNA 3’-UTR wildtype plasmids, while no significant changes in luciferase activity were observed in transfected SIRT1 mRNA 3’-UTR mutant plasmid (P > 0.05). Conclusion MiRNA-138 may regulate the sensitivity of ovarian epithelial cancer cells to platinum through SIRT1 activity, which can be a potential therapeutic target of ovarian epithelial cancer.