Increase or knockdown of endogenous MDM2 levels increases or reduces Akt phosphorylation. Western blot analysis of extracts prepared from lung cells derived from littermate (a) p53+/+ and p53+/+ MDM2 transgenic (MDM2 Tr), (b, c) p53−/− and p53−/− MDM2 transgenic (MDM2 Tr) mice, (d) OsACL cells transfected with plasmids expressing MDM2 shRNA (shMDM2-1 or -2) or luciferase shRNA (shLuc), (e) ABC1 cells stably expressing shRNA against MDM2 (shMDM2-2 or -5) or GFP shRNA (shGFP) and (f) A549 cells treated with Nutlin-3 or vehicle (DMSO). Migration of MDM2, p-Akt, Akt, GSK3β phosphorylated at Ser 9 (p-GSK3β), GSK3β and Erk2 are indicated. Differences in the p-Akt or p-GSK3β levels are shown by graphs at the right panel of each western blot