Fig. 1.

BMP‐4 induces differentiation of GIC and upregulates the expression of PRRX1. TGS‐01 and TGS‐04 cells were treated with or without BMP‐4 (30 ng·mL⁻¹) for 72 h, except for panel (A). (A) Failure of sphere formation of TGS‐01 cells in the presence of BMP‐4 for 5 days. Scale bars: 200 µm. (B) Downregulation of glioma stem cell markers (n = 3 biological replicates). (C) A scheme of the splice isoforms of PRRX1. (D) Induction of the expression of two splice isoforms of PRRX1 in TGS‐01 and TGS‐04 cells by BMP‐4 stimulation (n = 3 biological replicates). (E) ChIP‐qPCR analysis of the binding of pmx‐1a and pmx‐1b on the PROM1 promoter in TGS‐01 cells stably expressing FLAG‐tagged PRRX1 proteins (n = 4 biological replicates). (F) Relative promoter activity measured in TGS‐01 cells treated with or without BMP‐4 by dual‐luciferase assay (n = 3 biological replicates). The PROM1 promoter was subcloned, and the AT‐rich sequence of PRRX1‐binding sites was deleted or converted into a GC‐rich sequence. The graphs in panels (B) and (D–F) represent mean ± SD of biological replicates. The P‐values were determined by Student’s t‐test (B) or Tukey’s test (D–F).