Further Evidence for Loss of Growth Potential during Mouse Myeloid Leukemia (Ml) Cell Differentiation

In order to investigate the relationship between mouse myeloid leukemia (M1) cell differentiation and growth potential, M1 cells were differ- entiated to various extents by treatment with 0-3 × 10-5 M dexamethasone. When the strength of the induced lysozyme or phagocytic activity was plotted as a function of DNA synthesis, a negative correlation was found. The induc- tion of differentiation depended more on the specific rate of DNA synthesis than on the concentration of dexamethasone The present work, together with previous results (8), suggests the high probability that differentiation-associated properties are almost exclusively expressed by non-replicating M1 cells.