刺梨汁促人急性单核细胞白血病U937细胞凋亡作用的研究

目的：探讨刺梨汁（RRTJ）促U937细胞凋亡作用和可能的机制。方法：不同浓度RRTJ在体外作用于人急性单核细胞白血病U937细胞株。应用光学显微镜观察细胞形态变化；细胞计数测定细胞生长情况；流式细胞仪分析细胞生长周期的变化；逆转录聚合酶链反应法（RT—PCR）观察凋亡相关基因bcl-2、bax表达的变化；硝酸还原酶法测定细胞一氧化氮（NO）分泌量；并通过测定细胞上清液乳酸脱氢酶（LDH）活性分析RRTJ对细胞的毒性作用。结果：刺梨汁显著抑制U937细胞生长，并表现出剂量依赖性。随RRTJ浓度增加，U937细胞凋亡率增高，baxmRNA表达量上升，而bcl-2mRNA表达水平明显下降。U937细胞NO释放量也随RRTJ浓度增加而增加。结论：RRTJ可能是通过影响细胞生长周期、降低bcl-2／bax比值，同时诱导NO分泌，促进U937细胞凋亡。

The effect of the rosa roxborghii tratt juice on the apoptosis of U937 cell line

Objective:To investigate the effects of rosa roxborghii tratt juice(RRTJ) on the apoptosis of U937 cells and possible mechanism in it. Methods:U937 cells were incubated with different concentrations of RRTJ.The inhibitory effect of RRTJ on the growth of cells was determined by counting viable cells.The effects of RRTJ on cells cycle were investigated with flow cytometry and the changes in the mRNA expression levels of bcl-2 and bax,both are apoptosis related genes,were measured by RT-PCR.Nitric oxide secreted from U937 cells to the medium was measured by nitric acid reductase method.In addition,LDH released from cells was measured to evaluate the virulence effect of RRTJ on the cells. Results:RRTJ exhibited markedly inhibitory effect on the growth of U937 cells.RRTJ induced the apoptosis of U937 cells in a dose-dependent manner.RRTJ was found to up-regulate the expression of bax mRNA and at the same time down-regulate the expression of bcl-2 mRNA.In addition,after exposure to RRTJ,the content of nitric oxide in the cellular medium was increased. Conclusion:RRTJ induces U937 cells apoptosis probably by influencing cell cycle,reducing the ratio of bcl-2 to bax in cells and stimulating the secretion of NO from cells.