Regulation of growth of mouse mastocytoma cells.

N6,O2'-Dibutyryladenosine cyclic 3',5'-phosphate plus theophylline inhibited the growth of the mouse mast cell tumor line PY 815 both in vivo and in vitro. The inhibitory effect on growth in vitro was rapidly reversed following removal of the drugs. Growth inhibition was accompanied by reduced cell surface activity and increased cell-cell adhesion. The drug-treated cells accumulated distinct membrane-bound granules, which are characteristic of more mature mast cells. Treated cells also developed increased amounts of surface-associated acidic mucopolysaccharides. These results suggest that increased intracellular cyclic adenosine 3':5'-monophosphate causes mouse mastocytoma cells to decrease growth and elicits the expression of a more differentiated mast cell phenotype. The effect of the antileukemia drug, 4'-(9-acridinylamino)methanesulfon-m-anisidine, on cyclic adenosine 3':5'-monophosphate and adenosine 5'-triphosphate in mastocytoma cells is also reported.