miR-187-3p negatively regulated FGF9 expression and the Wnt signaling pathway downstream. (A) Compared with those transfected with the miR-NC mimic, miR-187-3p mimic transfection significantly reduced FGF9 mRNA expression in MDA-MB-231 cells. ***P<0.001 as indicated. (B) Compared with those transfected with the miR-NC mimic, miR-187-3p mimic transfection reduced FGF9 protein expression in MDA-MB-231 cells. (C) Quantified data from (B) demonstrating that miR-187-3p mimic transfection significantly reduced FGF9 protein expression in MDA-MB-231 breast cancer cells. (D) β-catenin, c-Myc and Cyclin D1 protein expression were all lower in MDA-MB-231 cells transfected with miR-187-3p mimic compared with those transfected with the miR-NC mimic. (E) Quantified data of (D) demonstrating that miR-187-3p mimic transfection significantly reduced β-catenin, c-Myc and Cyclin D1 expression in MDA-MB-231 breast cancer cells. (F) Gemcitabine treatment did not alter FGF9 protein expression in MDA-MB-231 cells. (G) Quantitative analysis of FGF9 protein expression displayed in (F) Data are presented as the mean ± standard deviation. *P<0.05, **P<0.01, ***P<0.001. FGF9. fibroblast growth factor 9; miR, microRNA; NC, negative control.