Objective: To learn about the apoptosis role of HL-60 cells induced by DNR in vitro and the expression change of some protein. Methods: This study observed the apoptosis of HL-60 by optic microscope

flow cytometry (FCM) and DNA electrophoresis and detected changes of various apoptosis-associated proteins expression with immunocytochemistry (IC) and FCM assays. Results: When treated with 0.2μM～2μM DNR

the percentage of apoptotic HL-60 cells increased with the increase of dose and the extension of time

and there showed the typical apoptotic cells and the appearance of apoptotic DNA ladder . It was shown that after HL-60 cells were treated with 1uM DNR for 2h

the fluorescence intensity index(FI) of both bcl-2 and c-myc decreased

bax and caspase-3 increased; at 5h

the FI of bax and caspase-3 decreased on the contrary. Conclusion: It is suggested from the results that at the certain concentration

DNR can induce the apoptosis of HL-60 in vitro

and it can suppress the expression of bcl-2

c-myc and activate bax and caspase-3.