Fig. 7. Effects of MEK inhibitor U0126 and PI3K inhibitor LY294002. (A) Filter-grown cells were stimulated with TGF-ß1 (10 ng/ml) or EGF (10 ng/ml) or both in the presence or absence of 25 µM U0126 for 24 hours, and then processed for western blot analysis of N-cadherin, occludin and claudin-1. ß-actin (ß-actin) was used as an internal control for equal protein loading. (B) Cells were exposed to EGF with or without TGF-ß1 in the presence or absence of U0126 for the indicated times and then analysed for the presence of phosphorylated Erk (P-Erk 1/2). Total Erk (Erk 1/2) indicates equal protein loading. (C) Cells were exposed to EGF and TGF-ß1 in the presence or absence of 5 µM LY294002. Cell lysates at equivalent protein concentrations were analysed for N-cadherin with SDS-PAGE and western blotting. ß-actin was used as an internal control for equal protein loading.