RESUMEN
Objective To explore the effect of STI571 on the CD_~117 expression and differentiation of bone marrow mononuclear cells in patients with acute non-lymphocytic leukemia(ANLL). Methods CD_~117 expression before and after STI571 treatment in vitro was assayed by FACS, and the cell differentiation was observed by Giemsa and peroxidase staining. Results After different concentrations of STI571 treatment in vitro, there was different degrees of differentiation in granulocytes and monocytes from patients with ANLL. With the increase of STI571 concentration, the number of progranulocyte and promyelocyte gradually decreased, the number of myelocyte, metamyelocyte and monocyte increased, and the positive degree of peroxidase staining increased. CD_~117 expression significantly decreased after STI571 treatment compared with before it. Conclusion STI571 could induce leukemia cells of ANLL into terminal differentiation by inhibiting c-kit tyrosine kinase.