Delayed growth inhibition of human leukaemic cells in culture following treatment with aminonucleoside of puromycin.

The effects of the aminonucleoside analogue of puromycin (AMS) on the growth of the CCRF-CEM human leukaemic lymphoblast cell line have been studied. CEM lymphoblasts are capable of growth in the presence of AMS for a limited period of time, in a manner similar to other transformed cell lines in culture. However, a delayed effect of AMS was found to take place at the time of the third cell division after application of the drug. This phenomenon of delayed growth inhibition has not yet been described for any other type of cell. The delayed inhibition of CEM cells caused by AMS manifests regardless of the subsequent presence or absence of the drug. The magnitude of the delayed inhibition is linearly dependent on the concentration of AMS during the initial incubation period. Cell proliferation during drug application is not necessary for establishing the inhibition. Following the inhibition period, the cells resume a normal rate of growth.