[Cell-kinetics of the human uterine cervical carcinoma cells during radium irradiation].
HeLa cells grown in a monolayer culture and in nude mice were exposed to graded dose rates (37, 55 or 200 rad/hour) and doses (500-2,000 rad) of radiation and analyzed in terms of their cell cycle distribution using flow-microfluorometry. In the case of the cultured HeLa cells, dose-survival curves were constructed using colony formation as the end-point. The HeLa cells, both in vitro and in vivo, accumulated in G2-M phases after both acute and chronic irradiation. The dose rate of 37 rad/hour proved to be the most effective in producing G2-M accumulation, which is the sensitive phase of the cell cycle. In comparing the G2-M accumulation to the irradiation time, 55 and 37 rad/hour proved to be similarly efficient in producing G2-M accumulation, both in vitro and in vivo. When survival of HeLa cells in vitro was studied, the radiation-induced changes in cell distribution correlated with cell survival and accounted for the change in the dose rate effect above 1,000 rads. In the case of in vivo HeLa cells, the decrease in the number of G0+G1 stage cells was demonstrated during chronic irradiation (37 and 55 rad/hour). The two low dose rates were equally efficient in producing a decrease in the number of G0 + G1 cells. These data indicate that chronic irradiation induces redistribution and recruitment more effectively than acute irradiation.
D000818:Animals; D002453:Cell Cycle / Q000528:radiation effects*; D002470:Cell Survival / Q000528:radiation effects; D004247:DNA / Q000032:analysis; D004307:Dose-Response Relationship, Radiation; D005260:Female; D006367:HeLa Cells / Q000528:radiation effects; D006801:Humans; D051379:Mice; D008819:Mice, Nude; D008938:Mitosis / Q000528:radiation effects; D009368:Neoplasm Transplantation; D011829:Radiation Dosage; D011883:Radium; D002583:Uterine Cervical Neoplasms / Q000473:pathology*
D004247:DNA; D011883:Radium