Neoplastic transformation of C3H mouse embryo cells, 10T1/2: cell-cycle dependence for 50 kV X-rays and UV-B light.
The variation of neoplastic transformation induced by 50 kV X-rays, and by solar-simulating UV-B light, was studied through the cell cycle of C3H mouse embryo cells designated 10T1/2. A mitotic shake-off method was used to harvest mitotic cells. The progression through the cell cycle of initially mitotic cells was followed as a function of time by flow cytometry, DNA labelling for passage through S-phase, and growth curves for cell number. At 2-3 h after shake-off, about 90% of the cells were in early G1-phase and by 15 h 60-70% of cells had reached S-phase. For 2.5 Gy, the transformation frequency per viable cell in M-phase was some five times higher than in S-phase. In contrast, at similar survival levels, UV-B light is less efficient in transforming mitotic cells. For both types of radiation, the frequency of neoplastic transformation per viable cell was roughly inversely proportional to survival.
Cao
J
J
Department of Radiological Health Sciences, Colorado State University, Fort Collins 80523.
Wells
R L
RL
Elkind
M M
MM
D000818:Animals; D002453:Cell Cycle / Q000502:physiology* / Q000528:radiation effects; D002471:Cell Transformation, Neoplastic / Q000528:radiation effects*; D004622:Embryo, Mammalian / Q000166:cytology; D051379:Mice; D008809:Mice, Inbred C3H; D014466:Ultraviolet Rays; D014965:X-Rays