Low-dose Ara-C in the treatment of acute leukemia. Cytotoxicity or differentiation induction?
The differentiation inducing effect of low-dose Ara-C on human myeloid leukemic cells was studied in two patients with subacute myelocytic and subacute myelomonocytic leukemia in vivo and in vitro. By continuous i.v. administration of 10 mg Ara-C/m2 over 12 h daily for 12 or 20 days complete remissions were obtained in both patients with normalization of the incidence of the committed progenitor cells BFU-E and CFU-C in the marrow while the incidence of pluripotent CFU-GEMM remained subnormal. Parallel cultures of the patients' bone marrow cells in diffusion chambers (DC) implanted in mice demonstrated a clear cytotoxic effect of low-dose Ara-C. The greater increase of granulopoietic cells within DC in the Ara-C exposed group than in control mice after the end of drug administration is, in addition, an indication for differentiation induction by this kind of Ara-C therapy.
D000328:Adult; D002454:Cell Differentiation / Q000187:drug effects*; D003114:Colony-Forming Units Assay; D003561:Cytarabine / Q000627:therapeutic use*; D003603:Cytotoxins; D004305:Dose-Response Relationship, Drug; D005260:Female; D006801:Humans; D015470:Leukemia, Myeloid, Acute / Q000188:drug therapy*; D008875:Middle Aged
D003603:Cytotoxins; D003561:Cytarabine