FIG. 4.

Elevated Akt phosphorylation in caveolin-overexpressing cells is likely due to elevated PI3K activity and not to diminished PTEN expression. (A) Western blot analysis of p-Akt expression in 293-V and 293-Cav25 cells following either no treatment or treatment for 1 h with an inhibitor of growth factor receptors (20 μM AG1296, 1 μM AG1478, or 300 μM suramin), the MEK1/2 inhibitor U0126 (20 μM), or the PI3K inhibitor LY294002 (25 μM). (B) Western blot analysis of PTEN levels in 293-V, 293-Cav25, and 293-Cav31 cells treated with 25 μM arsenite for the times indicated.