Fig. 5

Effect of EGFR inhibitor (EGFR inh) on growth factor mRNA levels. Primary basal cells (passage 3) from each of three non-smoking donors were plated in triplicate in the presence or absence of 1 μg/ml LPA, 10 µM EGFR inhibitor (AG1478), and a combination of LPA and EGFR inhibitor. a mRNA expression levels shown are mRNA levels of connective tissue growth factor (CTGF), endothelin-1(EDN1), transforming growth factor beta (TGFB1), and platelet derived growth factor B were determined after 3 h of LPA exposure with and without the inhibitor using qRT-PCR using 18S RNA to normalize the samples. b Protein levels in the conditioned media. After 3 h of LPA with and without EGFR inhibitor (AG1478) exposure, LPA with or without inhibitor was removed and cells were incubated with non-supplemented basal media for 24 h. Conditioned media was harvested and evaluated for growth factor content by ELISA. Data are expressed as the mean value of the 3 donors ± SEM. ND—not detected. *p < 0.05, **p < 0.01, ***p < 0.001