Fig. 5. Interplay between MET and HER2 requires kinase activities.

a–c Isogenic H2170 MET^N375S-tGFP cells were treated with vehicle (0.1% DMSO), MET inhibitor crizotinib (1 µM), HER2 inhibitor lapatinib (0.3 µM), or crizotinib/lapatinib combination. a Interaction of ectopic MET and endogenous HER2 was detected with immunoprecipitation and immunoblotting. Total MET and HER2 band intensities, relative to vehicle treated group, are shown below. Values represent average of three independent experiments. Left, input controls. b Detection of MET/HER2 co-localization (red) in MET^N375S-tGFP cells with proximity ligation assay (PLA). Representative images are shown. Scale bar, 20 µm. c The PLA signals were quantified and expressed as number of signals/cell ± SD (n > 3). Crizo, crizotinib; Lapa, lapatinib. d MET/HER2 interaction in H2170 MET^N375S-tGFP tumors from Supplementary Fig. 3J was detected with immunoprecipitation and immunoblotting after crizotinib treatment. Left, input controls. Cells were harvested 48 h after treatment, β-Actin was used as a loading control. e–h Immunohistochemistry staining of H2170 MET^wt-tGFP and MET^N375S-tGFP tumors from Supplementary Fig. 3J, K. Representative images for p-MET (e) and p-HER2 (g) staining are shown. Expression of p-MET (f) and p-HER2 (h) were quantified and expressed as mean of positive-staining/100 cells ± SD (n = 5). Scale bar, 50 µm. Two-tailed Student’s t test; *P < 0.05.