Fig. 2: Inhibition of IGFBP5 impairs GSCs invasion and tumorigenesis.

a RT-qPCR analysis of IGFBP5 mRNA expression in X01 GSCs infected with lentivirus expressing shIGFBP5 or shCtrl. Data are presented as mean ± SEM (n = 3 independent experiments), two-tailed Student’s t-test (left to right, ^***P = 0.0008, ^***P = 0.0007). b ELISA analysis of IGFBP5 in CM from 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, ^****P = 0.00001, ^****P = 0.00001). c, d Invasion assays with X01 GSCs infected with shCtrl, shIGFBP5-1, or shIGFBP5-2 lentivirus. c Images taken after 48 h of invasion are representative of three independent experiments (scale bar, 100 μm; n = 3), and d the graph shows the mean number of invasive cells ± SEM, two-tailed Student’s t-test (left to right, ^**P = 0.003, ^**P = 0.007). e RT-qPCR analysis of IGFBP5 mRNA expression in 448 GSCs infected with shCtrl, shIGFBP5-1, and shIGFBP5-2 lentivirus. Data are presented as mean ± SEM (n = 3 independent experiments), two-tailed Student’s t-test (left to right, ^***P = 0.0006, ^**P = 0.002). f ELISA analysis of IGFBP5 in CM from 448 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, ^***P = 0.0002, ^***P = 0.0002). g, h Invasion assays using 448 GSCs infected with shCtrl, shIGFBP5-1, or shIGFBP5-2 lentivirus. g Images taken after 48 h of invasion are representative of three independent experiments (scale bar, 100 μm; n = 3), and h the graph shows the mean number of invasive cells ± SEM, two-tailed Student’s t-test (left to right, ^***P = 0.0004, ^***P = 0.0004). i H&E staining of the whole brains of mice bearing orthotopic xenografts of X01 GSCs infected with shCtrl, shIGFBP5-1, or shIGFBP5-2 lentivirus. Scale bar, 100 μm. j Kaplan–Meier survival curves of mice implanted with X01 GSCs infected with shCtrl (n = 10), shIGFBP5-1 (n = 8), or shIGFBP5-2 (n = 8) lentivirus (1 × 10⁴ cells/mouse). P < 0.0001, log-rank test. Source data are provided as the Source Data file.