Elevation of adenylate cyclase activity during leukemic cell differentiation

Exposure of the various human myeloid leukemic cell lines (HL60 and RDFD) to various compounds results in marked differentiation of the cells. This differentiation is associated with a marked increase in both basal and NaF-stimulated adenylate cyclase (AC) activity. The increase in AC activity occurs regardless of the differentiation inducer one has utilized (retinoic acid (RA), dimethyl formamide (DMF), hypoxanthine (HPX) or actinomycin D (actD) and is correlated with this process, as a variant of the HL60 cell (HL60-Blast) that does not differentiate upon exposure to the various inducers does not demonstrate this increase in AC activity. In addition, the differentiation process is associated with a rapid increase in intracellular cAMP within hours of adding the inducer, followed by a gradual decrease.