Fig. 4

Hsa_circ_0043278 regulated and functioned as a sponge of miR-455-3p. A qRT–PCR analysis of miR-455-3p expression in MDA-MB-231 cells and MCF-7 cells with upregulation or downregulation of hsa_circ_0043278. B Verification of the relative expression of miR-455-3p in BC tissues (Tumour) and matched normal tissues (Normal) by qRT–PCR (n = 50). The middle horizontal lines in the scatter plot indicate the medians. C Pearson correlation analysis of miR-455-3p and hsa_circ_0043278 expression in BC tissues (n = 50). D The relative expression of miR-455-3p in cell lines was analysed by qRT–PCR. E and F Schematic illustration of the hsa_circ_0043278-WT and hsa_circ_0043278 mutant (Mut) luciferase reporter vectors with mutation of the two predicted binding sites of miR-455-3p. After transfection with the hsa_circ_0043278-WT (circ-WT) or hsa_circ_0043278-Mut (circ-Mut) vector and the miR-455-3p mimic or miR-455-3p NC into HEK 293T cells, relative luciferase activities were measured in each group. The data are presented as the mean ± standard deviation values (n = 3); ** P < 0.01, **** P < 0.0001. WT, wild-type; NC, negative control