Effect of treatment with caffeine and NU7026 on ATM and H2AX phosphorylation. A549 cells were exposed to CS for 20 min either in the presence of PBS, 4 mM caffeine or 10 uM NU7026 or were collected in the absence of smoke treatment (mock exposure). Cells exposed to caffeine and NU7026 were also treated for one hour prior to exposure and one hour subsequent to cell harvest. Only treatment with caffeine lowered the level of expression of ATM-A1981P and γH2AX IF.
Tanaka et al. BMC Cell Biology 2007 8:26 doi:10.1186/1471-2121-8-26