Figure 2. PI₃K inhibitors suppress pemetrexed-induced Akt and GSK3β activation, S-phase arrest, cell apoptosis and caspase-3 activation.A549 were pretreated with 10 µM Ly294002 or 3 µM wortmannin (inhibitors of PI₃K/Akt) for 2 h, and then 1 µM pemetrexed was added.

(A) the levels of Akt and GSK3β and (B) the cell cycle distribution were determined for 24 h after pemetrexed treatment. (C) Cell apoptosis and (D) the caspase-3 activity were examined after 72 h pemetrexed incubation. **P<0.01, ***P<0.001.