Rates of cholesterol biosynthesis are related to early differentiation in acute non-lymphocytic leukaemia cells.

Cholesterol synthesis from acetate was studied in leukaemic cells from 20 patients with acute nonlymphocytic leukaemia. Marked differences in the rates of cholesterol biosynthesis were noted among three morphologically distinct types of leukaemia. As leukaemic cells differentiated along myeloid (acute promyelocytic) or monocytoid (acute myelomonocytic) pathways, their cholesterol-synthetic rates diverged and approached those of their respective mature cellular counterparts, the neutrophil or the peripheral blood monocyte. Enhanced sterol synthesis in leukaemic cells could not be explained by more rapid efflux of membrane cholesterol to the environment. In addition, the different rates of cholesterol biosynthesis in leukaemic-cell subgroups did not correlate with differences in their rates of cellular DNA synthesis. The normal divergence of sterol-synthesizing capacity found between mature neutrophils and monocytes develops at an early stage of differentiation and is detectable even in leukaemic cells.