Effect of arsenic trioxide or ATRA on primary APL cell or HL-60 cells and their value analysis in hyperleukocytosis

Objective: To detect the effect of arsenic trioxide or ATRA on APL cells or HL-60 cells and to investigate the mechanism of the hyperleukocytosis and detect the cross resistance between ATRA and arsenic trioxide. Methods: The number of promyelocytes or more matured granulocytes were counted by regular method, MTT test was used to measure the proliferation of HL-60 cells or APL cells, flow cytometry analysis to measure the apoptosis, NBT method to detect the differentiation of HL-60 cells or APL cells. Results: The proliferation of primary APL cells or HL-60 cells could be inhibited in vitro by either arsenic trioxide or ATRA, which could induce obvious apoptosis or obvious differentiation of primary APL cells or HL-60 cells. Inhibition of proliferation or apoptosis of ATRA resistant HL-60 cells were achieved by exposure to arsenic trioxide in vitro. On the other hand, the results of in vivo treatment showed that arsenic trioxide also induce of hyperleukocytosis. Conclusion: The results indicated that the hyperleukocytosis induced by ATRA is not contributed to the mechanism of more differentiation than apoptosis, there was not cross resistance between ATRA and arsenic trioxide.