Fig. 5

Control experiments to show the effects of trastuzumab on EGFR phosphorylation in CHO-EGFR cells and the effects of CP-724714 on HER2 phosphorylation in CHO-K6 cells. a The effects of trastuzumab on EGFR phosphorylation or EGF-induced EGFR phosphorylation in CHO-EGFR cells. Cells were treated with EGF and/or trastuzumab at various concentrations as indicated. The phosphorylation of EGFR was determined by immunoblotting with antibody to EGFR pY1068. b The effects of chemical inhibitor of HER2, CP-724714 on HER2 phosphorylation in CHO-K6 cells. Cells were treated with CP-724714 at various concentrations as indicated for 1 h. The phosphorylation of HER2 was examined by immunoblotting with antibodies against HER2 pY1005 and pY1139