Fig 1: Resveratrol activates ATM in transformed human cell lines.(a, b) Human HEK293T cells were treated with 0.01 mM ATM inhibitor (KU-55933) or vehicle (DMSO) for 1 hour, followed by incubation in media also containing 0.1 mM resveratrol (or DMSO), as indicated. After 30 minutes incubation with resveratrol, H2O2 (0.1 mM) or bleomycin (1 µg/ml) was added as indicated for 30 minutes before harvesting. Western blotting was performed with with antibodies directed against ATM, phospho-ATM Ser-1981, p53, and phospho-p53 Ser-15 as indicated. (c, d) Human HEK293T cells were treated with resveratrol, bleomycin, or both as in (a) and probed for ?-H2AX foci by immunofluorescence. Cell images (291, 267, 216, and 260 cells, respectively) were analyzed for foci using Image J software, and the average number of foci per cell as well as the percentage of cells containing >5 foci were quantitated. (e, f) Human HCT116 cells were incubated with KU-55933, resveratrol, H2O2, and bleomycin as in (a, b) but additional phosphorylation targets were examined using antibodies directed against Smc1, phospho-Smc1 Ser-957, Kap1, phospho-Kap1 Ser-824, Nbs1, phospho-Nbs1 Ser-343, Chk2, and phospho-Chk2 Thr-68 as indicated.