ATM and breast carcinoma: To evaluate if observed effects on ATM activity in the nuclear extracts were recapitulated upon treatment of intact cells, HT29 colon cancer cells and MDA-MB-436 breast cancer cells were treated with CC-115 for 2 or 12 hours in the presence or absence of the DSB inducer bleomycin and the total cell lysate was used for immunoblotting (Figure 3D).