LEUKEMIC CELL PROLIFERATION AS DETERMINED BY IN VITRO DEOXYRIBONUCLEIC ACID SYNTHESIS*

Abstract

Correlation of DNA synthesis as determined by quantitative uptake of P32 and tritiated thymidine (H3TDR) and radioautographic studies indicate the following differences in the various leukemias. Chronic granulocytic and chronic lymphocytic cells show a small proportion of proliferating cells, relative to total numbers circulating, which are actively synthesizing DNA at a rate comparable to normal granulocytic and lymphocytic precursors, respectively. The acute leukemias ofter show a pattern compatible with a prolonged generation time, slow DNA synthesis rate, and long survival of a variable percentage of the population. The data demand a re-evaluation of the proliferative rate of the precursor cells in the various leukemias.