Figure 3

The dose and time responses of caffeine and wortmannin inhibition of the GAA-induced H2AX phosphorylation in MEC-1 cells. MEC-1 cells were pretreated with 8 m mol/l caffeine and 20 n mol/l wortmannin for 1 h and then were exposed to different doses of GAA. γH2AX foci formation was observed by immunofluorescent microscopy. (A) Dose responses of GAA-induced H2AX phosphorylation (GAA treated for 24 h); (B) Time responses of 20 μ mol/l GAA-induced H2AX phosphorylation(. *: P < 0.05, **: P < 0.01 vs GAA treated alone.