Survival Kinetics of Cultured Human Lymphoma Cells Exposed to Adriamycin1

Cultured human lymphoma cells exposed to adriamycin exhibited extreme sensitivity to the drug. When these cells were exposed to adriamycin for 12 hr, a 5-log kill in terms of reproductive capacity was observed. Furthermore, under these conditions, adriamycin exerted an immediate (interphase) lethal effect on about 60% of the cells. Synchronized cells revealed that the S-G2 boundary region was the most sensitive stage of the cell cycle. Insofar as adriamycin can achieve a great killing effect at low doses and with short exposure times, we suggest that a superior clinical therapeutic index could be achieved by utilizing adequately spaced low doses of adri amycin in the treatment of human tumors.