Knockdown of miR-194-5p inhibits cell proliferation, migration and invasion in breast cancer by regulating the Wnt/β-catenin signaling pathway

Breast cancer is a major public health concern, due to its increasing incidence and limited effective treatment. The present study aimed to investigate the expression of microRNA (miR)-194-5p and its roles in breast cancer. The expression levels of miR-194-5p and SRY-box 17 (SOX17) mRNA were detected in breast cancer tissues and cell lines by reverse transcription-quantitative polymerase chain reaction. The protein expression levels were determined by western blotting. In addition, MTT, colony formation, scratch and Transwell assays were use to evaluate the characteristics of MCF-7 cells with miR-194-5p knockdown. The target verification of miR-194-5p was determined by luciferase reporter assay. Furthermore, tumor-bearing nude mice with miR-194-5p knockdown were used to assess the effects of miR-194-5p on tumor activity. In breast cancer tissues, miR-194-5p was upregulated, whereas SOX17 was downregulated. In addition, the expression levels of SOX17 and phosphorylated (p)-β-catenin in the cytosol and nucleus were increased in the miR-194-5p inhibitor group. In addition, cell proliferation, migration and invasion were inhibited in response to miR-194-5p knockdown. The luciferase reporter assay confirmed that SOX17 was a target gene of miR-194-5p. In the mouse studies, knockdown of miR-194-5p suppressed tumor growth and promoted SOX17 expression in nude mice with breast cancer. These findings suggested that knockdown of miR-194-5p may increase the expression of SOX17 and regulate the Wnt/β-catenin signaling pathway in breast cancer cells; therefore, miR-194-5p may be considered a potential target for breast cancer prevention.