HEMATOTOXICITY OF 5-FLUOROURACIL AND ALPHA-INTERFERON ON THE HUMAN NORMAL HEMATOPOIETIC PROGENITORS

The toxic effects of a combination of 5 fluorouracil (5-FU) and interf eron a on normal human hemopoietic progenitors were assessed in vitro. CFU-GM growth was evaluated following 1 h incubation of bone marrow c ell suspension with 5-FU 100 mug/ml or IFN-alpha2a 1000 U/ml, or with both drugs, either simultaneously or sequentially added. IFN-alpha did not show toxic effects on normal human hemopoietic progenitors and th e severe toxicity of 5-FU on the latter was not modified by IFN-alpha. These results suggest that the changes observed in vivo of 5-FU toxic ity induced by IFN-alpha should be attributed to indirect effects of t he latter.