In vivo and in vitro effects of microRNA-27a on proliferation, migration and invasion of breast cancer cells through targeting of SFRP1 gene via Wnt/β-catenin signaling pathway

This study aims to explore the effects of microRNA-27a (miR-27a) targeting of SFRP1 on the proliferation, migration and invasion of breast cancer (BC) cells through the regulation of Wnt/β-catenin signaling pathway. BC and normal breast tissues were obtained from 396 female BC patients and 308 female patients with benign breast lesions respectively. Human normal mammary epithelial (MCF-10A) and BC cell lines (BT-20, MCF-7, T-47D and MDA-MB-231) were cultured. After cell transfection, BC cells were assigned to six groups: control, miR-27a mimics, miR-27a inhibitors, negative control (NC), si-SFRP1 and si-SFRP1 + miR-27a inhibitors groups. qRT-PCR assay and Western blot were employed to detect the expressions of miR-27a, SFRP1, Wnt, β-catenin and GSK3β. MTT assay, wound-healing test and Transwell assay were used to test cell proliferation, migration and invasion. BC tissues were found to have higher miR-27a expression and lower SFRP1 mRNA and protein expressions than MCF-10A cells and normal breast tissues. Compared with the control and NC groups, the miR-27a mimics and si-SFRP1 groups exhibited down-regulation of SFRP1, up-regulation of Wnt, β-catenin and GSK3β, and promotion of cell proliferation, migration and invasion. The miR-27a inhibitor group showed up-regulation of SFRP1 and inhibition of cell proliferation, migration and invasion in comparison to the miR-27a mimic group. The si-SFRP1 + miR-27a inhibitors group also exhibited up-regulation of SFRP1 and inhibition of cell proliferation, migration and invasion in comparison to the si-SFRP1 group. miR-27a may activate the Wnt/β-catenin signaling pathway by negatively regulating SFRP1 to promote the proliferation, migration and invasion of BC cells.