Research Paper Volume 12, Issue 11 pp 10983—11003

The circRNA circIFI30 promotes progression of triple-negative breast cancer and correlates with prognosis

Figure 6. circIFI30 functions as a sponge for miR-520b-3p. (A) The miR-520b-3p binding site on circIFI30 was predicted by targetScan and miRanda. (B) FISH was performed to observe the cellular location of circIFI30 in TNBC cells (magnification, × 200, scale bar, 50 μm) and tissues (magnification, × 100, scale bar, 50 μm). (C) Relative expression of miR-520b-3p in TNBC tissues and adjacent non-tumor tissues was determined by qRT-PCR (n = 38). (D) Schematic illustration of circIFI30-WT and circIFI30-Mut luciferase reporter vectors was shown. (E) The relative luciferase activities were detected in 293 T cells after transfection with circIFI30-WT or circIFI30-Mut and miR-520b-3p mimics or miR-NC, respectively. (F, G) Anti-AGO2 RIP was executed in MDA-MB-231 cells after transfection with miR-520b-3p mimic or miR-NC, followed by western blot and qRT-PCR to detect AGO2 protein, circIFI30 and miR-520b-3p, respectively. (H) RNA pull-down with a biotin-labeled circIFI30 probe was executed in MDA-MB-231 cells, followed by qRT-PCR and RT-PCR to detect the enrichment of circIFI30 and miR-520b-3p. (I) The relative expression of miR-520b-3p was detected by qRT-PCR after transfection with indicated vectors. Data were indicated as mean ± SD, *P < 0.05, **P < 0.01, ***P < 0.001.