[Enhancement of all-trans retinoic acid-induced differentiation by bufalin in primary culture of acute promyelocytic leukemia cells].

Objective: To investigate the effect of bufalin combined with all-trans retinoic acid-induced (ATRA) differentiation of acute promyelocytic leukemia (APL) cells in primary culture.
Methods: Fresh leukemia cells were obtained from heparinized bone marrow aspirations of 12 newly diagnosed APL patients. Cell viability was determined by trypan blue dye exclusion. Apoptosis of APL cell was assessed by morphological analysis. Differentiation of APL cell was also assessed by morphological analysis. Nitro blue tetrazolium (NBT) reduction test and expression of the granulocyte/macrophage-specific antigen CD(11)b was carried out with flow cytometric assay.
Results: Bufalin combined with ATRA can induce differentiation of APL cells towards mature stages, NBT reduction was increased 15% - 52% and CD(11)b expression was also increased 16% - 69% in combination of bufalin and ATRA as compared with that of ATRA alone, while the concentration of ATRA needed in the combination group was reduced to 30% and the time of differentiation was reduced from 7 days to 4 days.
Conclusion: The combination of ATRA with bufalin can significantly enhance the differentiation of acute promyelocytic leukemia cells in primary culture by ATRA.