Fig. 4.

Anchorage-independent cell growth in irradiated HTori-3 cells. A colony-forming assay was used to detect the anchorage-independent growth of transformed cells from the various experimental groups. HTori-3 cells were exposed to low-dose-rate (40 mGy/h) or high-dose-rate (4.68 Gy/min) radiation. After 8 weeks, cells were seeded into 6-well plates in duplicate (1 × 10³ cells per well) and incubated for 4 weeks. The resulting colonies were stained with nitroblue tetrazolium. The data shown represent three independent experiments, with standard error bars indicated. *P < 0.0001, using Student's t-test on the differences between control and irradiated groups.