Figure 6

Detection by western blotting of the effect of epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor (AG1478) and mitogen-activated protein kinase kinase (MEK) inhibitor (U0126) on cytokine-induced extracellular signal-regulated kinases (ERK)1/2 phosphorylation. (a) Representative western blots for total (Tot-ERK1/2) and phosphorylated ERK1/2 (P-ERK1/2) levels in Calu-3 cultured with medium alone (Medium) or exposed to TNF-α, IL-4 and INF-γ for 5 min, in the presence of AG1478, 1 μM or U0126, 25 μM. (b) Densitometric analysis of P-ERK1/2 data, normalized to Tot-ERK1/2 and plotted as means ± s.e.m.. Dotted line represents P-ERK/Tot-ERK ratio under basal conditions (Control). The results shown are representative of five independent experiments. ^***P<0.001 versus cells exposed to cytokines in cultures without AG1478 or U0126.