Low concentrations of cytosine arabinoside, 6-thioguanine, actinomycin-D and aclacinomycin A stimulates the differentiation of normal human marrow myeloid progenitor cells.

Myelosuppression is the major side effect of most anticancer cytotoxic drugs. Low concentrations of cytosine arabinoside (Ara-C), 6-thioguanine (6-Th), actinomycin-D (Act-D) and aclacinomycin A (ACM) have been reported to induce differentiation of leukaemic cell lines. With the proposed clinical trials of low-dosage of these four drugs, their effect on the differentiation of normal human myeloid progenitor marrow cells was studied. The four cytotoxic anticancer drugs at low concentrations stimulated normal human myeloid differentiation. Low dosage Ara-C has been used with great success in several clinical trials. The results suggest a similar therapeutic role for the other three anticancer drugs.