Influence of the poly (ADP-ribose) polymerase inhibitor 3-aminobenzamide on macrophage and granulocyte differentiation of HL-60 cells.

We investigated the influence of the poly(ADP-ribose) polymerase inhibitor 3-aminobenzamide (ABA) on induction of phenotypic markers of granulocyte differentiation by retinoic acid and markers of macrophage differentiation by TPA in HL-60 cells. The differentiation of HL-60 cells towards the granulocyte lineage was assessed by hexose monophosphate shunt activity, proportion of cells capable of reducing NBT dye, and the appearance of recognizable neutrophils and bands. The effect of ABA and retinoic acid on NBT dye reduction and appearance of mature neutrophils and bands was synergistic, whereas the effects of these agents on hexose monophosphate shunt activity were additive. The differentiation inducing capacity of ABA in the presence of retinoic acid was dose-related. The influence of ABA on TPA-induced markers of macrophage differentiation was assessed by determining the proportion of adherent cells produced after treatment and by measuring acid phosphatase activity in the adherent cell fraction. In the presence of ABA, the number of cells adhering to plastic declined after day 2 of exposure to TPA, and acid phosphatase activity in adherent cells was inhibited fourfold (p = 0.01). The influence of ABA on the phenotypic markers of granulocyte and macrophage differentiation was detectable at concentrations that were not cytotoxic. The influence of ABA on HL-60 differentiation is similar to that previously reported for human bone marrow CFU-GM. Our data suggest that poly(ADP-ribose) polymerase plays a role in differentiation of HL-60 cells and that HL-60 might provide a useful model for evaluating control mechanisms involved in the differentiation of CFU-GM.