Fig. 2.

Glioma cells with PDGFRα activation are more responsive to SHP099. (A) Viability of GSC 1123, R83, 157, and AC17 cells with PDGF-A stimulation after SHP099 treatment. GSCs were pre-cultured for 24 h in Dulbecco’s modified Eagle’s medium/F12 with EGF (2 ng/mL) and basic fibroblast growth factor (2 ng/mL) and then followed by co-culturing with or without 100 ng/mL PDGF-A and the indicated SHP099 concentrations for 72 h. (B and G) Viability of LN444 cells with ectopic expression of an EV or PDGF-A (B) or Ink4a/Arf^−/− mAsts with overexpression of an EV or PDGFRα plus PDGF-A (G) at 72 h after treatment with SHP099. (C and H) Comparison of SHP099 IC₅₀ in (B) or (G). (D and I) WB assays of expression of PDGF-A, PDGFRα, and p-PDGFRα in LN444 or Ink4a/Arf^−/− mAsts. (E and J) Representative images of drug-resistant colony formation in LN444 cells (E) or Ink4a/Arf^−/− mAsts (J) at day 7 post SHP099 treatment. (F and K) Quantification of drug-resistant colony formation in (E) and (J), respectively. Scale bars, 400 μm. *P < 0.05, **P < 0.01, by one-way ANOVA or two-tailed Student’s t-test.