【摘要】 目的探讨铁螯合剂去铁胺(DFO)诱导白血病细胞凋亡的分子机制。方法实验分为DFO组(终浓度分别为10、50、100μM)、DFO+FeCl3(各10μmol/L)组及空白对照组。用钙黄绿素检测K562细胞可变铁池。锥虫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方法检测K562细胞凋亡;比色法检测caspase-3活性。结果 (1)DFO作用于K562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;而DFO+FeCl3组细胞凋亡率与空白对照组差异无统计学意义。(2)50μmo/L、100μmol/L DFO作用于K562细胞24 h时,caspase-3酶活性升高明显,与对照组相比,差异有统计学意义(P<0.01);相关分析结果显示,K562细胞铁池的荧光改变与caspase-3活性变化呈负相关(r=-0.894,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,降低细胞可变铁池,激活caspase-3有关。更多还原

【Abstract】 Objective To study the molecular mechanism of apoptosis of leukemic cells(K562 cells) induced by iron chelating agent deferoxamine(DFO). Methods The exponentially growing K562 cells were used(1×106/mL) in this study.The K562 cells were treated with different concentrations of DFO(10,50 and 100 mmol/L),DFO+FeCl3(10 μmol/L each) or normal saline(blank control).The cellular labile iron pool was measured with a fluorimetric assay using the metalsensitive probe calcein-AM.The viable count and cell viability were determined by typanblue assay.Cell apoptosis was determined by morphological study and flow cytometry assay.Caspase-3 activity in K562 cells was detected by colorimetry. Results After DFO treatment,the cellular labile iron pool and the viability of K562 cells were reduced and the cell apoptosis increased in a time-and dose-dependent manner compared with the blank control group.The apoptosis rate of K562 cells in the DFO+FeCl3 treatment group was not significantly different from that in the blank control group.The caspase-3 activity in K562 cells increased significantly 24 hrs after 50 and 100 μmmol DFO treatment when compared with the blank control group(P<0.01).There was a negative correlation between cellular labile iron pool and caspase-3 activity of K562 cells(r=-0.894,P<0.05). Conclusions DFO induces apoptosis of leukemic cells possibly through decreasing cellular labile iron pool and increasing caspase-3 activity of the cells.更多还原