铁螯合剂诱导白血病细胞凋亡中caspase-3的变化

目的探讨铁螯合剂去铁胺（DFO）对诱导白血病细胞HL-60的分子机制。方法 2003年712月用钙黄绿素（calcein）检测HL-60细胞LIP。台盼蓝活细胞拒染实验进行活细胞计数及细胞存活率测定;光镜形态学观察及流式细胞仪（FCM）等方法检测HL-60细胞凋亡;比色法检测caspase-3（基于pNA标记底物的比色法）活性。结果①不同浓度的DFO作用于HL-60细胞后,随培养时间延长及DFO浓度的增加,动态铁池降低,细胞生存率逐渐下降,凋亡率增加,显示一定的时间剂量依赖性。②HL-60细胞在不同浓度的DFO作用下,caspase-3的活性逐渐升高。50、100μmol/LDFO作用于HL-60细胞24h,caspase-3酶活性升高明显,与对照组相比,有统计学意义（P〈0.001）;相关分析结果显示,HL-60细胞LIP的改变与caspase-3活性变化呈负相关系（r=-0.887,P〈0.05）。结论 DFO诱导白血病细胞凋亡的作用可能与螯合细胞内铁,降低细胞LIP,激活caspase-3,最终实施细胞凋亡密切相关。

Changes of Caspase-3 in Deferoxamine-Induced Apoptosis of HL-60 Cells

Objective To observe the changes of caspase-3activity during apoptosis of HL-60cells induced by an iron deferoxamine（DFO）.Methods Exponentially growing HL-60cells（1×106/mL）were used in this experiment from July 2003to December 2003.The study groups were divided as follows：DFO group,iron＋DFO group and control group.The viability was detected by typanblue,apoptosis was assessed by morphological study and flow cy-tometry（FCM）assay,and the caspase-3activity was detected by melorimetry.The intracellular label iron pool（LIP） was measured with a fluorimetric assay using the metalsensitive probe calcein-AM.Results ①When HL-60cells were incubated with different concentrations of DFO,viability assay was lower than that in the control group at the 12th,24th and 48th hour（P0.05）.②The cells incubated with different concentrations of DFO showed dose-time dependence and was much higher than that in the control group（P0.01）.③The caspase-3activity was significantly higher in the apoptotic cells than that in the control cells.Conclusions The apoptosis of HL-60cells induced by DFO may be correlated with the decrease of cellular LIP and activity of caspase-3.