The therapeutic potential of recombinant interferon γ (IFN γ) alone or in combination with two cytotoxic drugs - 5-fluorouracil (5-FU) and cytosine arabinoside (Ara-C) - was studied in vitro on two myeloid leukemia systems: HL60 promyelocytic cell line and chronic granulocytic leukemia (CGL) progenitor cells. When applied individually, IFN γ and the drugs inhibited in a dose-dependent manner HL60 cell colony formation in semisolid culture. Moreover, IFN γ or the cytotoxic drugs dose-dependently reduced the colony formation of CGL progenitor cell in agar. When added in combination, IFN γ potentiated synergistically the inhibitory action of 5-FU in both systems. The most pronounced potentiation was detected at concentrations of 0.5 μg/ml 5-FU and 50 U/ml IFN γ. On the contrary, the antiproliferative effect of Ara-C was enhanced only subadditively when combined with IFN γ. In view of the present findings, which are supported by new evidence from the literature, the use of 5-FU in leukemia should be reconsidered. The results further imply the potential value of combined treatment of 5-FU and IFN γ in leukemia.
|Number of pages||4|
|State||Published - 1 Jan 1989|
ASJC Scopus subject areas
- Cancer Research