Inhibition or activation of PI3K/Akt signaling

The PI3K inhibitor LY294002 and the PI3K-specific agonist IGF-1 were used to suppress or activate the PI3K/Akt signaling pathway, respectively, in A549/T cells. Cells (1×104 cells/well) were incubated with the following: DMSO; 30 µM FKA for 24 h; LY294002 (10 µM) for 1 h; IGF-1 (12.5 nM) (15) for 1 h; 30 µM FKA for 24 h, followed by LY294002 for 1 h; or 30 µM FKA for 24 h, followed by IGF-1 for 1 h. The protein expression levels of p-Akt (Ser 473) and P-gp were measured by western blot analysis. Each experiment was conducted in triplicates to determine the means and standard deviations (SDs).