The mechanism of apoptosis of acute promyelocytic leukemia cells induced by arsenic trioxide / 解放军医学杂志

ABSTRACT

Objective To investigate the effects and the gene expression of mitochondria on arsenic trioxide-induced apoptosis of acute promyelocytic leukemia (APL) NB4 cells. Methods NB4 cells were treated with As2O3. Fluorescent microscopy and flow cytometry were used and mitochondria membrane potential detection and RT-PCR were performed to observe the NB4 cell apoptosis, growth inhibitory effect and mitochondrial transmembrane potentials. Mitochondria genome primers were designed, and the expression of mitochondria genome at gene and protein levels was studied. Results Induced by As2O3, the NB4 cells showed typical morphological changes of apoptosis with a significant growth inhibitory effect. The ratios of NB4 cells apoptosis were 5.02%, 6.40%, 28.40% and 33.34%, respectively, when treated with As2O3 in concentrations of 0.5?mol/L, 1?mol/L, 2?mol/L and 3?mol/L. When treated with As2O3 in 0.5?mol/L, 1?mol/L, 2?mol/L, 4?mol/L and 8?mol/L at 48h, the mitochondria potential of NB4 cells was decreased by 12.8%, 21.6%, 66.9%, 83.7% and 83.8%, respectively. After the NB4 cell apoptosis was induced by As2O3, RT-PCR assay was used to detect the expression of 13 genes of mitochondria genome. The expression of COX2 gene was down-regulated in this process, while no change was found in the expression of other 12 genes. Conclusions As2O3 has shown to exert a significant effect on promoting apoptosis and growth inhibition on APL cells. The apoptotic effect induced by As2O3 on NB4 cells is closely related to a decrease of mitochondrial membrane potential. The expression change in the mitochondria gene COX2 is involved in the As2O3-induced apoptosis of NB4 cells.