Figure 1.

Correlation of gefitinib sensitivity with expression levels of EGFR and HER2. (A) Cellular protein levels of EGFR and HER2 were determined by western blotting using 30 µg total cell lysates of each cell type. MTT assays were performed for cells incubated for 48 h with various concentrations of gefitinib. All experiments were performed in duplicate and averaged. (B) Protein expression of HER2 in H1975 and H1299 cell lines, and in their HER2 transfectants. Comparison of HER2 protein expression status in the H1975 and H1299 cells transfected with HER2 or mock vector. EGFR, epidermal growth factor receptor; HER, human EGRF.