Fig. 1.

Effects of radiation on the enrichment of CD133+ populations in A549 and H157 human lung cancer cell cultures. a Percentage of CD133+ cells was increased after radiation. Flow cytometric analysis of CD133+ cells was performed at 7 days after 6 Gy Cs-137 gamma ray irradiation (non-irradiated cells as control). Percentage of CD133+ cells was calculated from the fluorescence distribution of anti-CD133 labeled cells. b Sphere formation was increased in irradiated cells. A549 and H157 cells were irradiated with 6 Gy, cultured for 7 days, and then analyzed for sphere formation (non-irradiated cells as control). Spheres with greater than 50 μm in diameter were counted at the end of incubation. *p < 0.05 c Expression of stem cell markers was increased after radiation in IF staining. The A549 and H157 cells were seeded on chamber slides and irradiated with 6 Gy. Seven days after irradiation, IF staining was performed using CSC marker anitbodies