A study of irradiation-caused changes in cancerous cell kinetics

Irradiation-caused changes in L-1210 cellular morphology and the effect of irradiation on cell Kinetics were investigated. With respect to morphological changes, as exposure dose was raised, both cellular and nuclear diameters increased. Cells became giant, multinuclear, and finally, ghost cells. Thus, the progression to cell death was suggested. Nuclear DNA histograms disclosed accumulation to G2M phase as exposure dose was increased. G2 block was suggested in terms of both cellular morphology and nuclear DNA histogram. At the same time the amounts of BrdU and DNA were measured. One result of irradiation was decreased S phase fraction; that is, DNA synthetic rate. As exposure dose increased, accumulation was observed to a point which seemed to be late S phase and G2M phase, until at last DNA synthesis was discontinued. The process to discontinuance was revealed. (author)