miRNA-15a/16调控Bmi-1蛋白在卵巢癌顺铂化疗耐药中的作用

The Role of miRNA-15a/16 in Regulating Bmi-1 Protein in Ovarian Cancer Resistance to Cisplatin Chemotherapy

目的探讨miRNA-15a和miRNA-16在逆转卵巢癌顺铂化疗耐药过程中的作用机制。方法使用miRNA-15a和miRNA-16模拟物转染人卵巢癌顺铂耐药细胞株CoC1/DDP,予顺铂处理,qRT-PCR检测正常培养CoC1/DDP细胞组、顺铂处理组、阴性对照组、转染miRNA-15a组、转染miRNA-16组和过表达的Bmi-1质粒的转染miRNA-15a和miRNA-16组的miRNA-15a、miRNA-16的表达水平,同时应用Western blot检测各组细胞中Bmi-1的表达水平,CCK-8法、Annexin V/PI法检测每组细胞的存活及凋亡情况、γ-H2AX免疫荧光检测细胞凋亡情况。结果卵巢癌顺铂耐药细胞株CoC1/DDP中miRNA-15a和miRNA-16低表达,Bmi-1蛋白高表达。过表达miRNA-15a、miRNA-16水平,Bmi-1蛋白下降(P<0.05),细胞存活率下降(P<0.05),DNA凋亡明显增加(P<0.05),DNA损伤程度更严重(P<0.05)。过表达Bmi-1质粒可提高细胞活度(P<0.05),降低细胞凋亡率(P<0.05)。结论Bmi-1蛋白可能是miRNA-15a和miRNA-16的调节蛋白靶点,高表达miRNA-15a和miRNA-16可以通过降低Bmi-1蛋白来提高顺铂对卵巢癌细胞的敏感性。通过对卵巢癌顺铂化疗耐药性分子标记的预测和对卵巢癌肿耐药性目标的攻克提供了新的思路。

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,andγ-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.