Fig. 3

MiR-582-3p and miR-515-5p can bind with circGNB1 and mediated promoting function of circGNB1 on GSCs. a Target miRNAs of circGNB1 were deduced by Starbase and circinteractome. b, c Circular RNA interactome predicted the complementary sequence of circGNB1 as miR-515-5p/miR-582-3p. d QRT-PCR analysis showed that the expression of circGNB1 was increased after miR-515-5p/miR-582-3p inhibitor treatment, while decreased following miR-515-5p/miR-582-3p mimic. e QRT-PCR showed the expression of miR-515-5p and miR-582-3p after circGNB1 knockdown or overexpression treatment. f, g The dual luciferase reporter assay was performed in GSC27 and GSC23 co-transfected with reporter plasmid (or the relative mutant reporter of GNB1) and miR-515-5p/miR582-3p inhibitor (or miR-515-5p/miR-582-3p mimic). h, i The anti-AgO2 RNA immunoprecipitation (RIP) assay was performed after the miR-515-5p/miR-582-3p or negative control was transfected, followed by qPCR to measure the enrichment of circGNB1 or miR-515-5p/miR-582-3p. j, k MTS assays were performed to detect the cell viabilities of GSC23 after circGNB1 overexpression, the effects of which could be reversed following miR-515-5p/miR-582-3p mimic. l, m Edu assays showed that the increasing positive rates of GSCs after circGNB1 overexpression could be impaired by miR-515-5p/miR-582-3p mimic. n, o The transwell assays showed that the enhancing invasion capability after circGNB1 overexpression could be weakened following miR-515-5p/miR-582-3p mimic. p, q The neurosphere formation assays revealed circGNB1 overexpression could increase the size of the neurospheres of GSCs, whereas reversed by miR-515-5p/miR-582-3p mimic. r–u The limiting dilution assays demonstrated that circGNB1 overexpression promoted neurosphere-forming capacity of GSCs, which could be repressed following miR-515-5p/miR-582-3p mimic. Data represent mean ± SD (three independent experiments). *p < 0.05; **p < 0.01; ***p < 0.001