Fig. 7

Selective BRAF inhibition induces EGFR family-dependent MAPK hyperactivation in Calu-3 cells. a and b The NSCLC cell line Calu-3 (HER2-amplified, KRAS-wt) was treated with increasing concentrations of dabrafenib (0.01–10 μM) alone a or in combination with trametinib (ratio 1:1000; b) for 4 h. The cells were lysed and analyzed by Western Blotting using antibodies specific for the proteins indicated. Western blot with Hsp70 specific antibody is shown as protein loading and blotting control. c Calu-3 cells were treated with increasing concentrations of dabrafenib (0.01–10 μM) and trametinib (0.01 nM–10 nM) alone or in combination for 72 h. Cell viability was assessed by Crystal violet assay and pharmacologic interactions were evaluated using the Calcusyn software. The results represent the average ± SD of three independent experiments. d Calu-3 and HCC827 (EGFR-mut) cells were treated with increasing concentrations of dabrafenib (0.1–10 μM) and lapatinib (0.1–10 μM) for 4 h. The proteins were subjected to Western Blotting and analyzed for the indicated antibodies. e MiaPaCa2, A549 and A427 cells were treated with dabrafenib (10 μM) and lapatinib (10 μM) alone or in combination for 4 h. The cells were lysed and analyzed by Western Blotting using antibodies specific for the protein above indicated