Figure 5.

miR-15b potentiates the β-catenin signaling by targeting FOXO1 and transcriptionally activating CCND1. (A) Mapping of the binding sites between miR-15b and FOXO1 predicted by StarBase bioinformatics website; (B) the luciferase activity of FOXO1 in cells transfected with miR-15b mimic or mimic control; (C) FOXO1 expression in BC patients revealed by GEPIA website (http://gepia.cancer-pku.cn/index.html); (D) FOXO1 mRNA expression in T47D and MCF-7 cells under different treatments assessed by RT-qPCR; (E) FOXO1 protein expression in T47D and MCF-7 cells under different treatments assessed by Western blot analysis; (F) the promoter sequence binding sites of FOXO1 to CCND1 analyzed by JASPAR bioinformatics website (http://jaspar.genereg.net/); (G) FOXO1 binding sites to CCND1 promoter sequence confirmed by ChIP-qPCR; (H) CCND1 expression in BC patients revealed by GEPIA website (http://gepia.cancer-pku.cn/index.html); (I) the β-catenin and GSK3β expression as well as the extent of GSK3β phosphorylation in MCF-7 and T47D parents and resistant cells. Data are displayed in the form of mean ± SD. All experiments were repeated at least three times. In panel (B) two-way ANOVA along with Tukey’s multiple comparison was applied, while in panel (D, E and I) one-way ANOVA along with Tukey’s multiple comparison was used. *p < 0.05, **p < 0.01.

Abbreviations: miR, microRNA; FOXO1, forkhead box O1; CCND1, cyclin D1; SD, standard deviation; ANOVA, analysis of variance.