Fig. 5.

IR sensitivity and persistent activation of DDR after IR in iPSCs. (A) To determine cell sensitivity to IR exposure, colony formation assay was performed. Fibroblasts (NB1RGB) and iPSCs (NB1RGBC2 and 201B7) were used. Compared with fibroblasts, iPSCs showed hypersensitivity to IR exposure. Error bars represent the SEM. (B) After IR exposure, cell extracts were immunoblotted with ATM, p53, serine 15 phospho-p53, KAP1 and serine 824 phospho-KAP1 antibodies. GAPDH antibody was used as a loading control. Immunoblotting data were obtained using C-digit as digital data. Full scan data of each band are provided in Supplementary Fig. 4. DDR hyperactivation increased in a time-dependent manner in iPSCs but not in fibroblasts and NPCs. IR = ionizing radiation, DDR = DNA damage response, iPSCs = induced pluripotent stem cells, SEM = standard error of the mean, ATM = ataxia-telangiectasia-mutated, KAP1 = Kruppel-associated box domain (KRAB)-associated protein-1, GAPDH = glyceraldehyde 3-phosphate dehydrogenase.