title: Enhancement of the cytotoxicity of cytosine arabinoside by interleukin-3.
abstract: We have evaluated the feasibility of enhancing the cytotoxic effect of cytosine arabinoside (ara-C) on acute myeloid leukemia (AML) cells by increasing the proliferative activity with hematopoietic growth factors. Leukemic cells from 8 persons with AML were tested. Preincubation with interleukin (IL)-3 (5 U/ml) for 3 days increased DNA synthesis as measured by tritiated thymidine incorporation and Ki67 expression in cells from 7 out of 8 persons with AML. Leukemic cells preincubated with IL-1 (10 U/ml) or IL-3 (5 U/ml) were subsequently exposed to ara-C (3 micrograms/ml) for the final 24 h and the activity of ara-C against clonogenic acute myeloid leukemia cells was evaluated in terms of the inhibition of colony formation in semisolid media. The exposure to ara-C inhibits the proliferation of a higher proportion of clonogenic cells in culture pretreated with IL-3 than in control or cells pretreated with IL-1. The enhanced cytotoxic effect of ara-C in the cells pretreated with IL-3 correlated with increased formation of intracellular ara-CTP. IL-3-induced recruitment of quiescent blasts into the proliferative compartment will lead to increased formation of ara-CTP in the cells, which would result in an enhanced leukemia cell kill.
authors.affiliation: Nagoya National Hospital, Hematological Disease Center.
authors.forename: M
authors.initials: M
authors.lastname: Tanaka
mesh_terms: D000208:Acute Disease; D001085:Arabinofuranosylcytosine Triphosphate / Q000378:metabolism; D001752:Blast Crisis / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology; D003561:Cytarabine / Q000378:metabolism / Q000494:pharmacology*; D004357:Drug Synergism; D005240:Feasibility Studies; D006801:Humans; D007375:Interleukin-1 / Q000494:pharmacology*; D007377:Interleukin-3 / Q000494:pharmacology*; D007951:Leukemia, Myeloid / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology; D014410:Tumor Stem Cell Assay
chemical_list: D007375:Interleukin-1; D007377:Interleukin-3; D003561:Cytarabine; D001085:Arabinofuranosylcytosine Triphosphate