ABSTRACT
AIM:To investigate the function of microRNA-125a-5p (miR-125a-5p) on epithelial-mesenchy-mal transition ( EMT) of breast cancer cells via GSK-3β/Snail signaling pathway. METHODS:The expression of miR-125a-5p in normal breast epithelial cells and breast cancer cells, as well as the transfection efficiency of miR-125a-5p plas-mid in MDA-MB-231 cells was detected by RT-qPCR. The chemotaxis ability and invasion ability were detected by chemo-taxis assay and Transwell invasion assay. The changes of EMT-related markers, the protein level of phosphorylated glycogen synthase kinase-3β (p-GSK-3β) and the nuclear translocation of Snail were determined by Western blot. RESULTS:The expression of miR-125a-5p in the breast cancer cells was significantly lower than that in the normal breast epithelial cells. The expression of miR-125a-5p was significantly higher in MDA-MB-231/miR-125a-5p cells than that in MDA-MB-231/NC cells. The ability of epithelial growth factor (EGF) at 10 μg/L to induce chemotaxis of MDA-MB-231 cells was the stron-gest. Compared with MDA-MB-231/NC group, stimulation of EGF decreased the invasion ability of MDA-MB-231/miR-125a-5p cells, and resulted in the increase in E-cadherin expression, while significantly decreased the protein levels of vi-mentin and p-GSK-3β. Meanwhile, the nuclear localization of Snail was significantly inhibited. The invasion capacity of MDA-MB-231/miR-125a-5p+GAB2 cells was significantly enhanced compared with MDA-MB-231/miR-125a-5p +Con cells, the expression of E-cadherin was decreased, and the protein levels of vimentin and p-GSK-3β were significantly in-creased, while the nuclear localization of Snail was promoted. CONCLUSION:miR-125a-5p suppresses EMT via GSK-3β/Snail signaling pathway, thus inhibiting the invasion ability of breast cancer cells.