Effects of CircNRIP1 on proliferation,apoptosis and chemotherapy resistance of breast cancer cells through regulating miR-136-5p/RAC1 axis
Objective To investigate the effects of CircNRIP1 on the proliferation,apoptosis and chemotherapy resistance of breast cancer cells by regulating miR-136-5p/Ras related C3 botulinum toxin substrate 1(RAC1)axis.Methods The mRNA expression of CircNRIP1,miR-136-5p and RAC1 in normal breast epithelial cells of MCF10A,breast cancer cells of MCF-7 and paclitaxel(PTX)resistant cell line of MCF-7/PTX were detected by qRT-PCR.MCF-7/PTX cells were divided into the CK group(normal culture),the si-NC group(transfected with si-NC),the si-CircNRIP1 group(transfected with si-CircNRIP1),the si-CircNRIP1+inhibitor NC group(transfected with si-CircNRIP1 and inhibitor NC),and the si-CircNRIP1+miR-136-5p inhibitor group(transfected with si-CircNRIP1 and miR-136-5p inhibitor).The cell proliferation rate of each group was detected by CCK-8 method;the cell apoptosis of each group was detected by flow cytometry;the expression of CircNRIP1,miR-136-5p,and RAC1 mRNA of each group were detected by qRT-PCR;the expression of Ki-67,Bax,Bcl-2,and RAC1 proteins of each group were detected by Western blot;the relationships between miR-136-5p and CircNRIP1 and RAC1 were verified by dual luciferase experiment.Results Compared with the normal breast epithelial cells of MCF10A,the expression of CircNRIP1 and RAC1 in the MCF-7 and MCF-7/PTX cells were increased(P<0.05),the expression of miR-136-5p was decreased(P<0.05);compared with the MCF-7 cells,the expression of CircNRIP1 and RAC1 in the MCF-7/PTX cells were increased(P<0.05),while the expression of miR-136-5p was decreased(P<0.05).Compared with the CK group and the si-NC group,the cell proliferation rate,the expression of CircNRIP1 and RAC1 mRNA,and the protein expression of Ki-67,Bcl-2,and RAC1 in the si-CircNRIP1 group were decreased(P<0.05),the apoptosis rate,and the expression of miR-136-5p and Bax were increased(P<0.05).Knocking down the expression of miR-136-5p could weaken the inhibitory effect of silencing CircNRIP1 on MCF-7/PTX cells(P<0.05).The dual luciferase experiment verified that miR-136-5p had targeting relationships with CircNRIP1 and RAC1.Conclusion Silencing CircNRIP1 expression can inhibit the malignant biological behavior of MCF-7/PTX cells,and reduce their PTX resistance,which may be related to regulating the miR-136-5p/RAC1 axis.
国家科技期刊平台
NSTL
万方数据
维普
