Induction of FGFR2 and FGFR3 mRNA and protein in EGFR inhibitor treated NSCLC cells.

A. Quantitative RT-PCR assay for FGFR2 and FGFR3 mRNAs. Total RNA was purified from the indicated cell lines following a 3-day treatment with 1 µM gefitinib and submitted to quantitative RT-PCR analysis of FGFR2, FGFR3 and GAPDH. (Cell lines with EGFR autocrine signaling or gain-of-function EGFR mutations: open bars; cell lines lacking EGFR signaling: grey bars) The data are presented as fold expression over DMSO treated cells following normalization for GAPDH mRNA. B–C. Cell lysates from the indicated NSCLC cell lines treated 3 days with or without 1 µM gefitinib or 2 µg/mL Erbitux were immunoblotted for FGFR2, FGFR3, EGFR and the α-subunit of the NaK-ATPase as a loading control. Densitometry of FGFR2, FGFR3 and EGFR expression was normalized relative to NaK-ATPase expression and is indicated under each immunoblot.