ESTABLISHMENT OF A NEW CELL-LINE WITH THE CHARACTERISTICS OF A MULTIPOTENTIAL PROGENITOR FROM A PATIENT WITH CHRONIC MYELOGENOUS LEUKEMIA IN EARLY ERYTHROBLASTIC CRISIS

A novel cell line (KH88) was established from a patient with chronic m yelogenous leukemia in blastic crisis. The leukemic blasts had the fea tures of undifferentiated blasts with basophilic agranular cytoplasm a nd they were focally positive for acid phosphatase and alpha-naphthyl acetate esterase. CD36, CD33, HLADR, and CD71 were expressed on the su rfaces of the blast cells. Most blasts were positive for platelet pero xidase activity, and some of them had granules containing aggregates o f ferritin molecules. These findings were compatible with those of 'ea rly' erythroblastic leukemia, this established cell line (KH88) having similar characteristics, and actually producing hemoglobin A and hemo globin F. Although the KH88 cells were negative for megakaryocytic mar kers, they were induced to express CD41 by phorbol ester. Further, a f ew KH88 cells were positive for myeloperoxidase. This cell line was th us revealed to have the capacity to differentiate into three lineages, providing a useful model for studying the differentiation of multipot ential stem cells. Moreover, a subline of KH88 had a peculiar chromoso me abnormality, del(3)(q21q25); it would be useful to study the signif icance of this chromosomal abnormality.