Fig. 7

SRSF1 regulated the proliferation of GSCs by binding to circATP5B and upregulating circATP5B expression. a The relative expression of circATP5B after SRSF1 knockdown or overexpression was detected by qRT-PCR. (GSC406: p < 0.01; GSC201: p < 0.05; One-Way ANOVA). b, c The RIP assay was performed after SRSF1 knockdown (b) or overexpression (c), followed by qRT-PCR to detect the enrichment of circATP5B in GSCs. (GSC406: p < 0.001; GSC201: p < 0.01; One-Way ANOVA). d, e The RNA pull-down assays showed the SRSF1 protein immunoprecipitation with circATP5B as detected by western blotting. f MTS assays showed that SRSF1 knockdown or overexpression affected the cell viability of GSCs and was reversed by circATP5B overexpression or knockdown, respectively. (GSC406: p < 0.001; GSC201: p < 0.001; One-Way ANOVA). g The relative expression correlation between HOXB5 and SRSF1 in 70 cases of glioma patients were detected by qRT-PCR. (Total: r = 0.6606, p < 0.0001; Grade II: r = 0.4726, p = 0.0354; Grade III: r = 0.5013, p = 0.0107; Grade IV: r = 0.5526, p = 0.0042; Pearson’s correlation analyses). h The EDU assays showed that SRSF1 knockdown or overexpression affected the proliferation of GSCs and was reversed by circATP5B overexpression or knockdown, respectively. Scale bar = 100 μm. (GSC406: p < 0.01; GSC201: p < 0.01; One-Way ANOVA). j The neurospheres formation assays showed that SRSF1 knockdown or overexpression affected the relative size of the neurospheres of GSCs and was reversed by circATP5B overexpression or knockdown, respectively. Scale bar = 20 μm. (GSC406: p < 0.01; GSC201: p < 0.01; One-Way ANOVA). i and k Limiting dilution assays showed that SRSF1 knockdown or overexpression affected the neurosphere-forming capacity of GSCs and was reversed by circATP5B overexpression or knockdown, respectively (GSC406: p < 0.01; GSC201: p < 0.05; ELDA analysis; circles represent corresponding points, triangles mean the point is outside of the log fraction number wells). l Schematic diagram of the putative HOXB5 binding site in the 3′-UTR of SRSF1. m and n The luciferase reporter assays showed that HOXB5 knockdown or overexpression affected the luciferase activities of SRSF1 in GSCs. (GSC406: p < 0.001; GSC201: p < 0.001; One-Way ANOVA). o The ChIP qRT-PCR showed that HOXB5 bound to the promoter of SRSF1. (GSC406: p < 0.01; GSC201: p < 0.001; One-Way ANOVA). p, q, r qRT-PCR (p) and western blotting (q, r) showed the SRSF1 expression was affected after HOXB5 knockdown or overexpression in GSCs. (GSC406: p < 0.01; GSC201: p < 0.001; One-Way ANOVA). 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