PI-3K inhibition blocks IGF-I–mediated activation of PKC and RhoA. H929 cells starved in serum-free medium and then pretreated with indicated concentrations (5 μM to 80 μM) of PI-3K inhibitor LY294002 for 1 hour were not stimulated or stimulated with 100 ng/mL IGF-I for 10 minutes. (A) Cell lysates were directly subjected to SDS-PAGE or (B) precipitated (AP) with GST-RBD glutathione beads and then subjected to SDS-PAGE, transferred to membranes, and blotted with indicated antibodies. Blot in panel A was stripped and reprobed with anti-Akt.