Fig. 5: IGFBP5 activates transcription of ETV5 and FBXW9 via CREB.

a Venn diagram showing the overlap of upregulated DEGs in invasive vs non-invasive GSCs and downregulated DEGs in 448 and X01 GSCs infected with shIGFBP5 versus GSCs infected with shCtrl based on RNA-seq data. The 22 selected genes are putative invasion-related target genes of IGFBP5. b Heatmap of the log2-fold change in putative invasion-related target genes of IGFBP5 identified by RNA-seq analysis of invasive GSCs infected with shIGFBP5 or shCtrl. c Kaplan–Meier survival curves for LGG patients with high or low ETV5 (left, P = 0.0004) or FBXW9 expression (right, P = 0.0005), log-rank test. d, e RT-qPCR analysis of ETV5 and FBXW9 expression in 83 GSCs infected with vector control or IGFBP5 lentivirus. Data are presented as mean ± SEM (n = 3 independent experiments), two-tailed Student’s t-test (d, e, ^**P = 0.008, ^****P = 0.00004). f, g RT-qPCR analysis of ETV5 and FBXW9 expression in X01 GSCs infected with shCtrl, shIGFBP5-1, or shIGFBP5-2 lentivirus. Data are presented as mean ± SEM (n = 3 independent experiments), two-tailed Student’s t-test (left to right, (f) ^**P = 0.001, ^**P = 0.008; (g) ^***P = 0.0003, ^***P = 0.0002). h, i RT-qPCR analysis of ETV5 and FBXW9 expression in invasive GSCs (X01 and 448) and non-invasive GSCs (131 and 83). Data are presented as mean ± SEM (n = 3 independent experiments), two-tailed Student’s t-test (compare with 131 group, left to right, ^***P = 0.0002, ^****P = 0.00001, ^*P = 0.03; ^***P = 0.0006, ^***P = 0.0001, ^**P = 0.003). j ChIP-qPCR analysis of CREB binding to the FBXW9 TSS in 448 GSCs infected with shCtrl or shIGFBP5-1 lentivirus. Data are presented as mean ± SEM (n = 3 independent experiments), two-tailed Student’s t-test (^**P = 0.002). k, l ChIP-qPCR analysis of CREB binding to the ETV5 promoter in 448 GSCs infected with shCtrl or shIGFBP5-1 lentivirus or in 83 GSCs infected with vector control or IGFBP5 lentivirus. Data are presented as mean ± SEM (n = 3 independent experiments), two-tailed Student’s t-test (k, l, ^*P = 0.02, ^**P = 0.006). m Kaplan–Meier survival curves for LGG patients stratified by IGFBP5 and ETV5 (left, P = 0.00000006) or IGFBP5 and FBXW9 expression (right, P = 0.00004), log-rank test. Source data are provided as the Source Data file.