Figure 4. circIQCH functions as a sponge for miR-145. (A) Predicted binding sites of miR-145 within the circIQCH. (B) The relative expression level of miR-145 in breast cancer cell lines. (C, D) U6, GAPDH and circIQCH in nuclear and cytoplasmic fractions analyzed by qRT-PCR. (E, F) Luciferase reporter assay of SKBR3 and BT474 cells co-transfected with miR-145 mimics and circIQCH wild type or mutant luciferase reporter. The putative miRNA binding site of circIQCH was mutated. (G) MS2-based RIP assay transfected with MS2bs-circIQCH, MS2bs-circIQCH-mt or control. *P<0.05; **P<0.01.