Qualitative and quantitative differences in intracellular protein patterns of normal immature myeloid and non-lymphocytic leukemic bone marrow cells

Polyacrylamide gel analysis of de novo synthesized polypeptides from non-lymphocytic leukemic blasts and normal immature myeloid bone marrow cells with comparable proliferating activity showed quantitative and qualitative differences, particularly in the high molecular weight region. Leukemic blast cells synthesized polypeptides between 94,000 and 200,000 Mr, not demonstrable in normal immature myeloid cells. Pulse-chase experiments revealed no further processing of these high molecular weight polypeptides nor excretion of such polypeptides out of the cells. Comparable high molecular weight polypeptides were present however in those normal bone marrow subpopulations which contain mainly mature myeloid cells. The presence of these high molecular weight polypeptides in leukemic cells, may reflect the activation of genome regions quiescent in normal immature cells and may represent a set of proteins comparable to those present in the maturing myeloid series of the normal bone marrow.