THE COMPARISON OF 2-CHLORODEOXYADENOSINE (2-CD-A) IN COMBINATION WITHINTERFERON-ALPHA (IFN-ALPHA) OR INTERFERON-GAMMA (IFN-GAMMA) ON GRANULOCYTE-MACROPHAGE PROGENITOR CELLS (CFU-GM) AND CLONOGENIC BLASTS IN (CFU-L) IN-VITRO CULTURES

In the present in vitro study we investigated the influence of 2-chlor odeoxyadenosine (2-CdA) and interferon gamma(IFN gamma) on the clonal growth of granulocyte macrophage progenitor (CFU-GM) cells from 10 nor mal individuals and from 10 patients with chronic myeloid leukemia (CM L) and on CFU-L blasts from 10 patients with acute myeloid leukemia (A ML). 2-CdA was added to the culture medium at 20 nM/l, 40nM/l and 80nM /l concentrations and IFN gamma at concentrations of 10(2)U/ml, 10(3)U /ml and 10(4)U/ml. Both agents were used alone and in combination with these different concentrations. We observed a decrease in the number of colonies formed by CML CFU-GM as well as by AML CFU-L in a dose-dep endent manner. The drugs used alone inhibited to a higher degree the g rowth of CML than of normal CFU-GM progenitors. 2-CdA and IFN gamma sh owed the greatest additive effect on the growth of CFU-L blasts at the concentrations of 80nM/l and 10(4)U/ml, respectively. We compared our results with previous in vitro studies in which we have demonstrated the synergistic inhibitory effect of 2-CdA and IFN alpha on both norma l and leukemic hematopoiesis. We suggest that the greatest inhibitory effect is observed when 2-CdA and IFN alpha at the highest concentrati on are added together to the culture of AML CFU-L blasts.