Figure 2.

Akt activation is required for GAPDH-dependent protection from CICD. (a) Mock or GAPDH-V5 HeLa cells were treated with 1 μM Akti for 48 h and analyzed by immunoblot. Akt inhibition led to a decrease in phospho-Akt and phospho-FoxO as expected. (b) Mock or GAPDH-V5 HeLa cells were treated with 1 μM Akti±the pan-caspase inhibitor Q-VD-OPh (20 μM). Inhibitors were added 30 min before a 12-Gy irradiation step and replaced periodically at 48-h intervals for 10 days. Colonies were stained and quantified as described in Figure 1d. (c) Mock or GAPDH-overexpressing HeLa cells were transiently transfected with a constitutively active form of Akt (myrAkt) and treated 48 h later as described in panel b. Typical pictures of the culture wells are shown on the left part and quantification of three independent experiments on the right part. *P<0.05. The immunoblots are representative of four independent experiments. Erk2 was used as a loading control