miR-205-3p promotes proliferation and reduces apoptosis of breast cancer MCF-7 cells and is associated with poor prognosis of breast cancer patients.

BACKGROUND: To study the expression of microribonucleic acid (miR)-205 in breast cancer and its effects on the proliferation and apoptosis of breast cancer cells. METHODS: Breast cancer cell line MCF-7 cells with stable expression of miR-205-3p were constructed. Cell proliferation, invasion, and apoptosis were detected via MTT assay, transwell assay, and flow cytometry, respectively. The expressions of Ezrin, LaminA/C, cleaved caspase-3, Bcl-2, and Bax were detected via Western blotting. The expressions of miR-205-3p in breast cancer tissues and para-carcinoma tissues were detected via quantitative PCR (qPCR). RESULTS: In transfection group, cell proliferation and invasion capacities were increased significantly (P < 0.01), but apoptotic cells were significantly reduced (P < 0.01). In addition, the expressions of Ezrin, LaminA/C, and cleaved caspase-3 in the transfection group were significantly decreased (P < 0.01), but the Bcl-2/Bax ratio was significantly increased (P < 0.01). The miR-205-3p expression in tumor tissues of breast cancer patients was significantly higher than that in para-carcinoma tissue, but Ezrin, LaminA/C, and cleaved caspase-3 expressions in tumor tissues were remarkably declined (P < 0.01), while the Bcl-2/Bax ratio was remarkably increased (P < 0.01). Moreover, the 5-year survival of patients with high expression of miR-205-3p was significantly shorter than patients with normal or low expression (P < 0.01). CONCLUSION: Highly expressed miR-205-3p can promote the proliferation and invasion and reduce the apoptosis of breast cancer cells, and the high expression of miR-205-3p can significantly reduce the survival time of patients.