Elevation of microRNA-512-5p inhibits MUC1 to reduce radioresistance in cervical cancer.

Researches about the role of several microRNAs (miRNAs) in cervical cancer were performed by previous studies, but the function of miR-512-5p in cervical cancer is rare to see. Thus, we aimed to investigate the effect and mechanism of miR-512-5p on radiosensitivity in cervical cancer by regulating MUC1 expression. First, 111 patients with cervical cancer were divided into radiotherapy sensitive group and radiotherapy resistant group. After that, miR-512-5p expression in cancer tissues from two groups was detected. Next, RT-qPCR was used to detect miR-512-5p expression in radiotherapy resistant cervical cancer cells SiHa and radiotherapy sensitive cervical cancer cells Me180. Moreover, SiHa and Me180 cells were treated with miR-512-5p overexpression and MUC1 poor expression plasmids. With 0 Gy, 2 Gy, 4 Gy, 6 Gy and 8 Gy irradiation, proliferation, colony formation ability and apoptosis of cervical cancer cells were determined. Also, cell lines that overexpressed miR-512-5p and overexpressed MUC1 were then constructed to observe the changes in cell radiosensitivity. MiR-512-5p was down-regulated and MUC1 was up-regulated in radiotherapy resistant cervical cancer tissues and cells. Overexpression of miR-512-5p and down-regulation of MUC1 increased the apoptosis and reduced cell survival rate of cervical cancer cells after radiotherapy. Overexpression of miR-512-5p reversed the effect of MUC1 overexpression on decreasing cell apoptosis and elevating cell survival rate of cervical cancer cells. Our study provides evidence that elevation of miR-512-5p contributes to the reduction of radioresistance in cervical cancer cells by inhibiting MUC1 expression.