PI3K and MEK inhibitors in NSCLC cell lines. NSCLC cell lines A549, HCC827 and H3122 were exposed to increasing concentrations of the PI3K inhibitors ZSTK474 and PI-103 and the MEK inhibitor CI-1040. (A) Western blot analysis of phosphorylated AKT (pAKT), S6 (pS6), and ERK1/2 (pERK1/2) and their corresponding total proteins (AKT, S6, ERK1/2) in response to the PI3K inhibitors. (B) Western blot analysis of phosphorylated ERK1/2 (pERK1/2) and AKT (pAKT) and their corresponding total proteins (ERK1/2, AKT) in response to the MEK inhibitor. (C) MTS assay for cytotoxicity in response to the PI3K inhibitors or MEK inhibitor. The cells were exposed to the inhibitors for 6h in the Western blot experiments and 72 h in MTS assays. Error bars show SD.