Alteration of bcl-2 and bax expression in apoptosis of HL-60 cells induced by arsenic trioxide

Objective: To investigate the alteration of bcl-2 and bax experssion in apoptosis of HL-60 cells induced by As₂O₃(arsenic trioxide,ATO).Methods: HL-60 cells were treated with 7.5 μmol/L As₂O₃ for 12 and 24 hours,the expressions of bcl-2 and bax mRNA were examined by semi-quantitative RT-PCR,and the activities of bcl-2 and bax protein were determined by Western blot.Results: Treated with 7.5 μmol/L As₂O₃ for 12 and 24h,the relative expressions of bcl-2 mRNA in HL-60 cells were(65.02±4.69)% and(40.70±3.94)%,and the bax were(46.71±4.26)% and(95.65±5.57)%,respectively.Western blot indicated that the ratio of bcl-2 protein were(56.34±6.45)% and(42.01±3.01)%,and the bax were(50.65±4.50)% and(66.78±5.05)%,respectively.There was significant difference between control group and experience group(P<0.01).Conclusions: As₂O₃ could down-regulate the expression of bcl-2 mRNA and protein,and the same time up-regulate the expression bax mRNA and protein in apoptosis of HL-60 cells.It may be one of signal transduction in apoptosis of HL-60 cells induced by As₂O₃.