Figure 1.

MiR-152 targeted β-catenin in breast cancer cells. (A) The relative expression levels of miR-152 (normalized to U6) in normal and breast cancer tissues were detected by qRT-PCR. (B) Expression levels of miR-152 in MCF-10A, MCF7, T47D, MDA-MB-453 and MDA-MB-231 cells were determined by qRT-PCR assay and normalized to the U6 levels. Results represent mean ± SEM from three independent experiments. *Indicates p < 0.05 when compared with miR-152 level in MCF-10A. (C) The sequence of miR-152 binding sites at 3′-UTR of β-catenin. The wild type (WT) and mutated (Mut) reporter constructs of the β-catenin 3′-UTR sequence are shown in left schematic diagram. Both constructs were verified by sequencing. Luciferase reporter assay was performed to detect the relative luciferase activities of WT and Mut β-catenin reporters, respectively. (D) Overexpression of miR-152 inhibited β-catenin expressions at protein level. Negative control (miR-NC) or miR-152 mimics (200 μM and 400 μM) were transiently transfected into MCF7 and MDA-MB-231 cells for 48 hours. Immunoblotting analysis was performed to detect the expression of β-catenin and β-actin. (E) MCF7 cells were co-transfected with TOP-FLASH/FOP-FLASH plasmids and negative control, miR-152 mimics or anti-miR-152. Luciferase activities were determined by the dual-luciferase reporter assay system. Data represent the means ± SEM of three independent experiments and * indicates p < 0.05 when compared with miR-NC group.