Fig. 1.

Response to EGFR-directed therapy in EGFR-amplified BS153. Erlotinib (A), gefitinib (B), and C225 (cetuximab; C) were applied to BS153 in different concentrations. Proliferation was assessed after 3 and 6 days. Erlotinib and gefitinib significantly inhibited BS153 growth in a dose-dependent manner (*P < .05, **P < .005, t-test), while C225 had no effect. Similar results were obtained when migration toward EGF (20 nM) was analyzed (D; RLU, relative luminescence units; hpf, high power fields); values are means ± SD from octuplicate determinations. One of 3 independent experiments is shown.