Fig. 5: The xDFG mutation NTRK1G667C sensitizes the kinase to type II inhibitors.
From: NTRK kinase domain mutations in cancer variably impact sensitivity to type I and type II inhibitors
Dose response cell viability data comparing the activity of indicated inhibitors in Ba/F3 TPM3-NTRK1 (a) or TPM3-NTRK1G667C (b) cell lines after 72 h treatment. Data are representative of four independent experiments for larotrectinib, entrectinib, and altiratinib, and three independent experiments for cabozantinib and foretinib. Average ± SEM from three replicates shown. c Scatter plot compares IC50 of indicated inhibitor for Ba/F3 TPM3-NTRK1 wildtype versus G667C mutant cells. d Immunoblot analysis of TPM3-NTRK1wt (wildtype) TPM3-NTRK1G667C autophosphorylation (pNTRK) and effector protein, Erk1/2 phosphorylation (pErk1/2) and corresponding total NTRK (tNTRK) and total Erk1/2 (tErk1/2) as well as loading control (Gapdh) levels from Ba/F3 cells treated with indicated inhibitors. “Veh.” indicates vehicle (DMSO) treatment. Data are representative of three independent experiments. e Densitometry of pixel intensity to show relative auto-phosphorylation of TPM3-NTRK1 wildtype (red columns) and G667C (blue columns) mutant from three experiments. Average ± SEM are shown. Individual values are shown as symbols at the top of the column: wildtype—triangles and G667C—circles. f Immunoblot analysis from Ba/F3 allograft tumors with lysates harvested 3 h after a single dose of larotrectinib (100 mg/kg) or altiratinib (50 mg/kg) treatment. TPM3-NTRK1wt (wildtype) TPM3-NTRK1G667C autophosphorylation (pNTRK) and effector protein, Erk1/2 phosphorylation (pERK1/2) and corresponding total NTRK (tNTRK) and total Erk1/2 (tErk1/2) as well as Gapdh (loading control).
