Relationship of uptake and binding of an antileukemic phthalanilide to its biochemical and chemotherapeutic effects on P388 lymphocytic leukemia cells.

An antileukemic phthalanilide, 2-chloro-4',4"-di(2-imidazolin2-yl)terephthalanilide (NSC 60339), was taken up by P388 lymphocytic leukemia cells growing in culture. The uptake was related to the extracellular concentration of drug and the length of exposure to drug. The drug was extracted from the cells in 3 forms: lipid-bound, hydrophilic-bound, and "free." The levels of both bound components correlated significantly with the chemotherapeutic response, and it was found by multiple regression analysis that the chemotherapeutic resixmse was related to the level of the lipid-bound com|x>nent, less related to the hydrophiliu-bound drug, and not related to the level of the "free" drug.