Fig. 4.

Circ_0001667 sponged miR-125a-5p in breast cancer cells. a The predicted binding sites of miR-125a-5p within circ_0001667 were shown. b, c MiR-125a-5p expression in MDA-MB-468 and BT549 cells. Cells were transfected with miR-125a-5p mimic or miR-125a-5p inhibitor and qRT-PCR analysis was used to detect the transfection efficiency. d, e Luciferase activity of the cells. MDA-MB-468 cells were cotransfected with miR-125a-5p mimics or miR-125a-5p inhibitor and luciferase reporter containing circ_0001667 3′-UTR (wt) or mutant construct (mut). The luciferase activity was assayed by luciferase assay. f MiR-125a-5p expression in MDA-MB-468 and BT549 cells with circ_0001667 down-regulation. Cells were transfected with circ_0001667 shRNA or the control, and the expression of miR-125a-5p determined by qRT-PCR. **p < 0.01