Fig. 4

CircATP5B promoted the proliferation of GSCs through miRNA sponging of miR-185-5p. a Graphical illustration showing the predicted position of the circATP5B target on the miR-185-5p sequence. b and c qRT-PCR showed the relative expression of circATP5B in GSCs after miR-185-5p mimic or inhibitor treatment (b), and the relative expression of miR-185-5p in GSCs following circATP5B knockdown or overexpression (c). (b: GSC406: p < 0.0001; GSC201: p < 0.001; Student’s t-test; c: GSC406: p < 0.001; GSC201: p < 0.0001; One-Way ANOVA). d The luciferase reporter assays showed that miR-185-5p mimic or inhibitor affected the luciferase activities of circATP5B in GSCs. (GSC406: p < 0.0001; GSC201: p < 0.001; Student’s t-test). e The RNA immunoprecipitation (RIP) assay was performed in GSC406 after the miR-185-5p mimic or negative control was transfected, followed by qRT-PCR to detect the enrichment of circATP5B and miR-185-5p. (p < 0.01; One-Way ANOVA). f MTS assays showed that circATP5B knockdown or overexpression affected the cell viability of GSCs and was reversed by the miR-185-5p inhibitor or mimic treatment, respectively. (GSC406: p < 0.001; GSC201: p < 0.0001; One-Way ANOVA). g The relative expression correlation between circATP5B and miR-185-5p in 70 cases of glioma patients were detected by qRT-PCR. (Total: r = − 0.6057, p < 0.0001; Grade II: r = − 0.4505, p = 0.0462; Grade III: r = − 0.4809, p = 0.0150; Grade IV: r = − 0.4943, p = 0.0120; Pearson’s correlation analyses). h The EDU assays showed that circATP5B knockdown or overexpression affected the proliferation of GSCs and was reversed by miR-185-5p inhibitor or mimic treatment, respectively. Scale bar = 100 μm. (GSC406: p < 0.01; GSC201: p < 0.01; One-Way ANOVA). j The neurospheres formation assays showed that circATP5B knockdown or overexpression affected the relative size of the neurospheres of GSCs and was reversed by miR-185-5p inhibitor or mimic treatment, respectively. Scale bar = 20 μm. (GSC406: p < 0.01; GSC201: p < 0.01; One-Way ANOVA). i and k Limiting dilution assays showed that circATP5B knockdown or overexpression affected the neurosphere-forming capacity of GSCs and was reversed by miR-185-5p inhibitor or mimic treatment, respectively (GSC406: p < 0.001; GSC201: p < 0.01; ELDA analysis; circles represent corresponding points, triangles mean the point is outside of the log fraction number wells). EV: empty vector, OE: overexpression, NC: negative control, KD: knockdown. All data were expressed as the mean ± SD (three independent experiments). *p < 0.05; **p < 0.01; ***p < 0.001