Cancer Stem Cells from Tumor Cell Lines Activate the DNA Damage Response Pathway after Ionizing Radiation More Efficiently Than Noncancer Stem Cells

Figure 5

HeLa SP overexpress pATM and γH2A.X after ionizing radiation. Localization of pATM and γH2A.X expression after 0.5 h and 1 h exposure to ionizing radiation in HeLa SP and HeLa ML using anti-pATM antibody (green) and anti-γH2A.X antibody (green). Visualization of nuclei by DAPI (blue). The representative images of the microscopy analysis indicated that γH2A.X is activated always in SP cultures, while in ML cultures, the activation of γH2A.X began 1 h after exposure to 1.5 Gy IR dose. Objective 60x.