Neuroblastoma cells were infected with 25 pfu of Ad.5/3-Null or Ad.5/3-E1A or the indicated dose of Ad.5/3-CTV for 72 hours. (A) Cells were collected and western blotting was performed for γ–H2AX and H2AX using specific antibodies and β-Actin served as loading control. (B) Western blotting was performed for determining pATM and ATM protein levels using specific antibodies and β-Actin served as loading control. (C) Neuroblastoma cells were untreated or treated overnight with KU-60019 (3 μM) and infected with 25 pfu Ad.5/3-E1A or the indicated dose of Ad.5/3-CTV for 48 hours. Cells were collected and western blotting was performed for MDA-7/IL-24, pATM, γ–H2AX, AIF and PARP using specific antibodies and β-Actin served as loading control. Results are representative of three independent experiments. (D) Neuroblastoma cells were pre-treated with AIF inhibitor and infected with 25 pfu of Ad.5/3-E1A or the indicated dose of Ad.5/3-CTV for 48 hours. Cells were collected and western blotting analysis was performed for pATM using specific antibodies and β-Actin served as loading control. Results are representative of three independent experiments. (E) Neuroblastoma cells were untreated or treated over night with KU-60019 (3 μM) and infected with 25 pfu Ad.5/3-Null or Ad.5/3-E1A or the indicated dose of Ad.5/3-CTV for 48 hours. Cells were fixed and TUNEL assays were performed. TUNEL positive cells were counted and data presented as TUNEL positive cells per microscopic field in a graphical manner, columns, average of TUNEL positive cells per 5 different microscopic fields; bars, S.D. *, p<0.001 versus control; @, p<0.01 versus Ad.5/3-CTV alone at corresponding doses.