Telomerase activity in preleukemia and acute myelogenous leukemia

The development of acute leukemia from preleukemia involves the appearance of clones with increasing proliferative potential. The studies described he re demonstrate that telomerase activity progressively increases as the bone marrow cells acquire increasing proliferative potential. This was demonstr ated by measuring telomerase activity in normal bone marrow, in post-treatm ent lymphoma marrows with skewed Lyonization, and in MDS and AML marrows. T he greater telomerase activity in myelodysplastic marrow than in normal mar row is not due to a higher proportion of blast cells or to a higher prolife rative rate of the MDS marrow. These data demonstrate that the increasing p roliferative potential of the marrow which occurs during the development of AML is associated with a simultaneous increase in telomerase activity.