Fig. 5

Bcan-Ntrk1-induced gliomas develop resistance to the TRK inhibitor entrectinib. a Cell proliferation assay performed on p53-null TVA-Cas9 NSCs, Bcan-Ntrk1 or PDGFB tumorspheres exposed for 96 h to increasing doses of entrectinib, a pan-TRK inhibitor. b Entrectinib treatment in Bcan-Ntrk1 tumorspheres induces an increase in apoptosis, as measured by Annexin V-positive cells, 48 h after treatment. Data from a representative of two experiments are presented as mean ± SD (n = 3); Student’s t test: ***P < 0.001; A.U. arbitrary unit. c Western blot analysis using the specified antibodies on Bcan-Ntrk1 or PDGFB tumorspheres grown for overnight in absence of growth factors and then treated with entrectinib (1 μM) for 16 h. d Schematic representation of the generation of entrectinib-resistant cell lines (see text for details). e Cell proliferation assay performed on parental Bcan-Ntrk1, R1 and R2 tumorspheres exposed for 96 h to increasing doses of entrectinib. f Absence of apoptosis induction in entrectinib-resistant cells, as measured by Annexin V-positive cells, 72 h after entrectinib treatment (100 nM). Data from a representative of two experiments are presented as mean ± SD (n = 3); Student’s t test: **P < 0.005, *P < 0.05; A.U. arbitrary unit. g Western blot analysis using the specified antibodies on parental Bcan-Ntrk1, R1 and R2 tumorspheres treated with entrectinib (1 μM) for the indicated timepoint. h Cell proliferation assay performed on parental Bcan-Ntrk1, R1 and R2 tumorspheres exposed for 96 h to increasing doses of trametinib