Expression of peripheral blood miRNA-134 in patients with breast cancer and mechanism of chemotherapy drug resistance / 重庆医学

ABSTRACT

Objective To explore the expression of peripheral blood miRNA-134 in the patients with breast cancer and chemotherapy drug resistance mechanism.Methods A total of 98 cases of newly diagnosed breast cancer were divided into the chemotherapy sensitive group(n=68) and chemotherapy drug resistant group(n=30).The expression of miRNA-134 in peripheral blood was measured by adopting RT-PCR.miRNA-mimics and miRNA-inhibitor were transfected into epirubicin and docetaxel resistant cell lines,the cell apoptosis and expression levels of Bax and Caspase-3 protein were detected.Results The level of serum miRNA134 expression in the chemotherapy sensitive group was significantly higher than that in the chemotherapy drug resistant group (P＜0.05);the proliferation capacity of epirubicin and docetaxel resistant cell lines was significantly lower than that in the MCF-7 cells(P＜0.05).Compared with normal MCF-7 cell line,the expression level of miRNA-134 in the epirubicin and docetaxel resistant cell lines was significantly decreased(P＜0.05).The apoptosis rate in the miRNA-mimics group was significantly higher than that in the control group and miRNA-inhibitor group(P＜0.05).The expression of Bax and Caspase-3 protein in the miRNA-mimics group was significantly higher than that in the control group and miRNA-inhibitor group(P＜0.05).Conclusion MiRNA-134 may enhance the sensitivity of breast cancer ceils to chemotherapy by promoting the expression of Bax and Caspase-3.