Fig. 4

circPAPD4 inhibits growth and induces apoptosis of BC cells by sponging miR-1269a. (A) Venn diagram of potential sponged miRNAs of circPAPD4 in Starbase prediction and significantly up-regulated miRNAs in TCGA-BRCA. (B) After BC cells were treated with circPAPD4 specific probe (Bio-circPAPD4) or control probe (Bio-control), the enrichment of potential sponged miRNAs (miR-124-3p, miR-1269a, miR-138-5p, miR-1269b) were evaluated by RT-qPCR. (C) Schematic diagram demonstrated luciferase reporter vectors were inserted with wild-type (WT) or mutant (Mut) potential binding sequence between miR-1269a and circPAPD4. (D) Luciferase reporter vectors loaded with circPAPD4 wild-type (WT) or mutant (Mut) were co-transfected with miR-1269a mimics (miR-1269a mim) or mimics control (miR-NC), and then relative luciferase activity were assessed to verified the binding relationship between miR-1269a and circPAPD4 in BC cells. (E) The proliferation and apoptosis of MCF-7 and SKBR3 cells was measured by EdU and TUNEL assays after co-transfected with EV, OE-circPAPD4, OE-circPAPD4 + miR-NC, or OE-circPAPD4 + miR-1269a mim. (F) The expression of cyclin-D1, cyclin-E1, BCL-2, and BAX were evaluated by western blotting in MCF-7 and SKBR3 cells as indicated treatments. Data are presented as means ± SD. *p < 0.05; **p < 0.01; ***p < 0.001.