Fig. 7

Involvement of DNA damage-signaling pathway and p53 in compounds-induced cell death of A549 cells. a A549 cells cultured in the presence of 10 μM C1 for 48 h or C2 for 72 h were harvested, and intracellular phospho-ATM expression was analyzed. Representative histograms of three different experiments are shown. The dotted line histogram indicates cells stained with Alexa Fluor® 488-conjugated secondary antibody alone. The broken line and filled gray histograms indicate phosphor-ATM expression in cells treated with vehicle and compound, respectively. As a positive control, A549 cells were irradiated with 10 Gy X-ray and harvested 30 min after irradiation. b A549 cells preincubated with the caffeine (2 mM) were cultured in the presence of 10 μM C1 or C2 for 72 h. The cells were harvested, and annexin V/propidium iodide staining was performed. Percentages of annexin V(+) cells are presented as the mean ± SE of three independent experiments; * and ** indicate p < 0.05 and p < 0.01. c–d A549 cells treated with p53-targeting siRNA were cultured in the presence of 10 μM C1 for 48 h or C2 for 72 h. The cells were harvested, and then western blotting (c) and cell death analysis (d) were performed. Representative results of two different experiments are shown