Effects of antioxidants and calcium chelator on Bcl-2 and p53 expressions in As_2O_3 induced apoptosis in leukemia cell lines

AIM: To investigate the effects of antioxidants (NAC, CAT and NDMS) and calcium chelator (Quin 2) on Bcl 2 and p53 expressions in apoptosis induced by As 2O 3 in three leukemia cell lines. METHODS: Cells were cultured with Bcl 2 and p53 Ab for 20 min and measured by flow cytometry. RESULTS: 0.6, 2.7 and 8.1 μmol·L -1 of As 2O 3 could induce 0.45±0.04, 0.58±0.06 and 0.62±0.08 apoptosis in NB4, K562 and HL 60 cells respectively. At the above 3 concentrations, As 2O 3 down regulated Bcl 2 expressions: the mean florescence intensity decreased from 109±31 to 68±22 in NB4 cells, 101±32 to 54±33 in K562 cells, and 87±23 to 66±18 in HL 60 cells. On the contrary, it up regulated p53 protein expressions: The mean FL intensity of p53 increased from 18±5 to 30±9 in NB4 cells, 2±1 to 15± 6 in K562 cells, and 3±1 to 28±8 in HL 60 cells. NAC, CAT, NDMS and calcium chelator Quin 2 had no significant effects on the expression of Bcl 2 and p53 in the three tested cell lines but they could inhibit the up regulation of p53 expression induced by As 2O 3 and had different regulation effects on the decline of Bcl 2 expression induced by As 2O 3. CONCLUSION: The declines of Bcl 2 and up regulation of p53 play an important role in apoptosis induced by As 2O 3. Antioxidants and calcium chelator can inhibit the above processes.