Parallel studies of clonogenic leukaemia cells and the leukaemia cell population as a whole in acute myelogenous leukaemia

The clonogenic cells in patients with acute myelogenous leukaemia (AML) were evaluated with respect to the relationship between primary and secondary cloning capacity and the proliferative and molecular biological characteristics of the leukaemia cell population as a whole. Secondary cloning capacity was correlated with primary cloning efficiency, and with the ability of the clonogenic cells to produce large sized clones. The cloning capacity of AML cells was unrelated to the cell cycle characteristics of the leukaemia cell population in vivo or to the level of myc, myb, fms, or interleukin (IL)1β expression. The sensitivities of the clonogenic cells to cytosine arabinoside and daunorubicin were inversely correlated with the ability of the leukaemia cells to produce large sized clones in vitro. This latter observation may explain the reported relationships between the clonogenic capacity of AML cells and response to chemotherapy.