Synergism between the antiproliferative activities of arabinosyladenine and N6-benzyladenosine.

N6-Benzyladenosine is a competitive inhibitor of adenosine deaminase from L-1210 cells in axenic culture as well as a potent antiproliferative agent in vitro and in vivo. Potentiation of the growth inhibitory activity of 9-beta-D-arabinosyladenine (ara-A) was observed in the L-1210 system with maximum synergism with a mixture of 16 micron ara-A and 10 micron benzyladenosine. Kinetic studies with L-1210 cell lysates showed values for Km of 0.25 mM ara-A and Ki of 0.23 mM benzyladenosine. It is suggested that ara-A and benzyladenosine in suitable combination may be expected to demonstrate enhanced clinical chemotherapeutic effectiveness.