Fig. 5

Oncogenic miR-155-5p is a sponging target of circPPFIA1s. A Venn diagram showing miR-155-5p predicted as a putative sponging target of circPPFIA1s in four databases (Arraystar, Starbase, circInteractome, and RNA22). B To verify that miR-155-5p binds to circPPFIA1s, an ASO pulldown experiment was performed. The pulldown efficacies of circPPFIA1s ASO were examined by semi-qPCR (upper) and the level of miR-155-5p in pulldown materials was checked by RT-qPCR (lower). C Enrichment of circPPFIA1-L and -S in miRISC was analyzed by Ago2 RIP with KM12C cells transfected with pre-miR-155-5p. D The levels of circPPFIA1-L and -S were determined by semi-qPCR in KM12C and KM12L4 cells transfected with pre-miR-155-5p or anti-miR-155-5p, respectively. E To examine the direct interaction between circPPFIA1s and miR-155-5p, the luciferase reporter vectors containing the wild-type or mutant sequence of miR-155-5p MRE were constructed. Following overexpression of miR-155-5p, a luciferase activity assay was carried out in KM12C cells. F After transfection of circPPFIA1 siRNAs, the expression level of miR-155-5p was determined by RT-qPCR. G, H Following transfection of pre-miR-155-5p or anti-miR-155-5p into KM12C (G) and KM12L4 (H) cells, the Invasive and migratory abilities were measured by transwell invasion and migration assays, respectively. I To check whether miR-155-5p is required for increased metastatic potential by knockdown of circPPFIA1s, rescue experiments were conducted. Invasive and migratory abilities were examined by transwell invasion and migrations assays, respectively. Statistical analyses were performed using the Student’s t-test using three independent experiments (*p < 0.05). All data represent mean ± standard variation (SD)