MiRNA‐96‐5p impacts the progression of breast cancer through targeting FOXO3

BACKGROUND: Breast cancer is the most common malignant tumor in women worldwide, with a high mortality rate. MicroRNAs are small non‐coding RNAs that negatively regulate the expression of target genes by interacting with the target gene 3'‐UTR, and participate in cell differentiation, proliferation, apoptosis and metabolism. The function of miRNA‐96‐5p in the progression of breast cancer has not been reported. METHODS: We used the StarBase database to investigate the expression of miRNA‐96‐5p in breast cancer and adjacent normal tissues. FOXO3 3'‐UTR construct and luciferase reporter assays was performed for the target gene. Expression levels of miRNAs including its target were analyzed by qRT‐PCR and western blot. Cell proliferation was detected by CCK8 and colony formation, EdU assay. RESULTS: Luciferase reporter assays showed miRNA‐96‐5p directly targeted FOXO3. Abrogation of miRNA‐96‐5p by transfection with its inhibitors in breast cancer cells significantly suppressed miRNA‐96‐5p expression and breast cancer cells proliferation. Western blot revealed that overexpression of miRNA‐96‐5p substantially reduced FOXO3 protein expression. We used the GEPIA, UALCAN and KM‐plotter databases to investigate the expression of FOXO3 in human breast cancer and adjacent normal tissues, and its correlation with survival. In addition, we found that FOXO3 spoiled miR‐96‐5p induced breast cancer cell proliferation block effecting. CONCLUSIONS: miRNA‐96‐5p may exert a tumor promotion role through negatively regulating tumor suppressor gene FOXO3 and promoting cell proliferation.