The Role of miRNA-15a/16 in Regulating Bmi-1 Protein in Ovarian Cancer Resistance to Cisplatin Chemotherapy / 昆明医科大学学报

ABSTRACT

Objective To investigate the mechanisms of miRNA-15a and miRNA-16 in the process of reversing cisplatin resistance in ovarian cancer.Methods Human ovarian cancer cisplatin-resistant cell lines CoC1/DDP were transfected with miRNA-15a and miRNA-16 mimics and treated with cisplatin.qRT-PCR was used to detect the expression levels of miRNA-15a and miRNA-16 in normal CoC1/DDP cell group,cisplatin treated group,negative control group,miRNA-15a transfected group,miRNA-16 transfected group and overexpressed Bmi-1 plasmid.Western blot was used to detect the expression level of Bmi-1 in each group,CCK-8 and Annexin V/PI were used to detect cell survival and apoptosis,and γ-H2AX immunofluorescence was used to detect cell apoptosis.Results The CoC1/DDP ovarian cancer cell line shows low expression of miRNA-15a and miRNA-16,and high expression of Bmi-1 protein,which makes it resistant to cisplatin.When the levels of miRNA-15a and miRNA-16 are overexpressed,the Bmi-1 protein decreases(P<0.05),leading to a decrease in cell survival rate(P<0.05),a significant increase in DNA apoptosis(P<0.05),and more severe DNA damage(P<0.05).Overexpression of Bmi-1 plasmid can increase cell viability(P<0.05)and reduce the rate of cell apoptosis(P<0.05).Conclusion The Bmi-1 protein may be a target for the regulation of miRNA-15a and miRNA-16,and overexpression of miRNA-15a and miRNA-16 can increase the sensitivity of ovarian cancer cells to cisplatin by reducing the Bmi-1 protein.This provides a new idea for predicting molecular markers of cisplatin resistance in ovarian cancer and overcoming drug resistance targets in ovarian cancer.