Effect of aclacinomycin-A on survival and progression of mouse L cells through the cell cycle.

The survival of cultured mouse L cells and the progression of the cells through the cell cycle after exposure to aclacinomycin-A (ACM-A) were studied. At low drug concentrations, there was a slight depression in survival of S phase cells, while at high concentrations, cells at late G1 and late S-G2 were very sensitive to the drug. The dose-survival curve of synchronous cells was similar to that of asynchronous cells. Initially, there was a small reduction in survival, but as the dose was increased no additional killing occurred until a certain level was exceeded, after which an exponential decline in survival resulted. The age-response with high concentrations of the drug reflected the differences in the size of the shoulder of the dose-response curve, while that with low drug concentrations reflected the presence or absence of the initial small decrease in survival. ACM-A inhibition of cell progression was greatest for cells in mid G1 followed by cells in late S and finally by cells in G2.