Influence of harringtonine on human leukemia cell differentiation.

The influence of low doses of harringtonine (Ht) on differentiation of blood cells from acute myeloblastic (AML) and lymphoblastic leukemia (ALL) patients diagnosed according to FAB classification was tested. Out of five cases of ALL only in one case differentiation into mature lymphocytes appeared. In two cases out of four of AML differentiation was seen in one case into more mature granulocytic series and in another one into monocytes. Two out of 3 acute myelomonocytic leukemias (AMMOL) differentiated, one into more mature granulocyte cells and one into monocytes. One of our patients with AML (M2) in relapse was treated with ht using HOAP (harringtonine, oncovin, adriblastine, prednisone) schedule with good but transient effect. Prior to therapy in vitro tests performed with ht showed differentiation of leukemic cells into more mature granulocyte cells.