Fig. 5

Effect of ERK phosphorylation by erlotinib or trastuzumab on proliferation in EC cell lines. a All cells were treated with either ERL (3 μM, 30 μM) or TRA (100 μg/mL, 1000 μg/mL). After a 2-h incubation with the drug, cells were treated EGF (1 ng/mL) for 10 min and harvested for western blot analysis. The blot is representative of three independent experiments. The expression levels of phosphorylated ERK were quantified by scanning the digital image and digitized data were analyzed with the Image J. Data represent the means ± SEMs of three independent experiments. *, decreased with the drug treatment compared to control, P < 0.001. b All cells were treated with either ERL (0.1–30 μM) or TRA (10–1000 μg/mL). After 2 h incubation with the drug, all cells were treated EGF (1 ng/mL). Cell proliferation was monitored after 96 h using WST-1 assay. *, decreased as compared to vehicle control, P < 0.01