Figure 6

Mechanism of Akt and AMPK regulation by resveratrol (RSV) and ionizing radiation (IR). A. and B. Inhibition of ATM blocks IR-induced activation of the Akt and AMPK signaling pathways: PC3 cells were treated or not with the ATM inhibitor KU55933 (10 μM) for 1 hour followed by 0 or 8 Gy IR treatment. Cells were lysed 1 hour after IR exposure and subjected to immunoblot analysis using the indicated antibodies. C. AMPK mediates the IR induction of p53 and p21^cip1: 22RV-1 cells were incubated with siRNA complexes against the α1 and α2 subunits of AMPK for 72 hours as described in Methods. Cells were then treated with 0 or 8 Gy IR and lysed 1 hour after IR exposure and subjected to immunoblot analysis. D. RSV enhances signalling along the ATM-AMPK-p21^cip1 pathway: Cells were pre-treated with RSV (5 μM) for 1 hour followed by IR of 8 Gy. Cells were lysed 1 hour after IR exposure and subjected to immunoblot analysis using the indicated antibodies. Shown are representative immunoblots of at least 3 independent experiments.