The blast cells of acute myeloblastic leukaemia.

Cell culture methods are available that permit colony formation by the normal progenitors of myelopoiesis and lymphopoiesis. The blast cells of acute myeloblastic leukaemia may also form colonies under selective conditions in culture. It is feasible, therefore, to determine some of the properties of blast progenitors. These were found to be uniformly in active cell cycle. However, great patient-to-patient variation was seen in the sensitivity of blast progenitors to chemotherapeutic agents and in their capacity to undergo self-renewal. The latter attribute, but not the former, was correlated with clinical outcome. These culture findings were used to propose a model of AML that includes an increase in diversity with malignant transformation. The model finds further support from studies of the phenotypes of blast cells freshly obtained from AML patients.