(a) Vorinostat inhibits radiation-induced EGFR phosphorylation. MiaPaCa-2 cells were exposed to vorinostat (2 μM; 48 hr), irradiated (6 Gy), and harvested at indicated time points post-irradiation for immunoblot analysis. (b) Vorinostat decreases radiation-induced expression of phospho (active) c-jun. Cells were treated with vorinostat (2 μM; 48 h), irradiated (6 Gy), and harvested at indicated time points post-irradiation for immunobloting. (c) Effect of vorinostat on NF-κB activation. Cells were treated with indicated concentrations of vorinostat for 48 h, irradiated (6 Gy), and harvested 3 h post-irradiation. NF-κB activity in the nuclear fraction was analyzed by EMSA.