Proliferative response of clonal acute myelogenous leukemia cells in localized grafts of normal bone marrow stroma to in vivo stimulation of myelopoiesis.

Bone marrow from inbred Wistar/Furth (W/Fu) rats, normal and 90% replaced by acute myelogenous leukemia (AML), was transplanted, respectively, to the left and right kidneys of adult W/Fu rats. After a transient period of hypocellularity, AML grafts repopulated to pre-transplant cellularity by day 9, whereas normal bone marrow (NBM) grafts required 25 days for repopulation to pre-transplant cellularity. Grafted leukemia cells remained localized to the kidney for 17 days. In NBM grafts phlebotomy accelerated erythroid proliferation, and intrathoracic inoculation of live Escherichia coli accelerated myeloid proliferation; in AML grafts only E. coli injection increased bone marrow proliferation. There was no morphologically detectable differentiation of W/Fu AML cells. These studies provide evidence of a myelopoietic response of AML blast cells in vivo and present a transplantation technique for comparison of localized grafts of leukemic and normal bone marrow in the same animal.