Different responsiveness of normal and leukemic hemopoietic cells to esorubicin.

The effect of different Esorubicin concentrations (10(-7) M to 10(-10) M) has been tested on the in vitro growth of human normal hemopoietic progenitor cells and of three leukemic cell lines (K562, U 937, HL60). The highest drug concentration completely abolished both normal and leukemic proliferation. Lower doses of Esorubicin failed to induce any morphological or phenotypic differentiation of leukemic cell lines. A 24h pretreatment of the cells with 10(-9) M Esorubicin enhanced the in vitro proliferation of normal early myeloid progenitor cells, whereas it did not affect leukemic, myelomonocytic cell proliferation.