Acycloguanosine and herbimycin A co-operatively inhibit proliferation and induce erythrodifferentiation of human myeloid leukemia K562 cells.

Acycloguanosine (9-[(2-hydroxyethoxy)methyl]guanosine) induced human erythroleukemia K562 cells to differentiate into hemoglobin-producing cells, and cell growth was highly sensitive to this nucleoside analog. Herbimycin A also induced erythrodifferentiation of the cells, and selectively inhibited proliferation of the cells. Selective inhibition of the proliferation in K562 cells was greatly enhanced by combined treatment with acycloguanosine and herbimycin A, while the growth of another erythroleukemia cell line without bcr/abl gene (HEL) and normal mouse bone marrow cells was hardly affected by the treatment.