Fas基因在高三尖杉酯碱诱导HL-60细胞凋亡中的作用

Effect of Fas on homoharringtonine induced apoptosis in HL 60 cell line

目的探讨高三尖杉酯碱诱导ＨＬ６０白血病细胞凋亡的机制。方法应用细胞形态学观察、ＤＮＡ琼脂糖凝胶电泳、免疫组织化学技术、Ｎｏｒｔｈｅｒｎ印迹杂交进行检测分析。结果ＨＬ６０白血病细胞在高三尖杉酯碱的作用下，出现典型的凋亡特征，细胞形态学表现出细胞核裂解、染色质聚集、核碎裂，胞浆浓缩、有空泡形成，琼脂糖电泳出现典型的ＤＮＡ梯带。免疫组织化学技术发现促凋亡蛋白Ｆａｓ在用药后明显增高，Ｆａｓ配体无明显变化，Ｎｏｒｔｈｅｒｎ印迹杂交分析发现ＦａｓｍＲＮＡ在用药后表达无明显改变，Ｆａｓ蛋白与ＦａｓｍＲＮＡ无相关性。结论高三尖杉酯碱诱导凋亡的机理之一是增加促凋亡蛋白Ｆａｓ水平，Ｆａｓ蛋白增高的原因可能是高三尖杉酯碱促进ＦａｓｍＲＮＡ转录为Ｆａｓ蛋白，而不是增加ＦａｓｍＲＮＡ的表达。

Objective To investigate the mechanism by which homoharringtonine induced apoptosis in HL 60 leukemia cells. Methods Cell morphology, DNA agarose gel electrophoresis, immunohistochemistry and Northern blot were performed. Results HL 60 leukemia cells treated with homoharringtonine underwent apoptosis. Apoptosis cells demonstrated compaction and segregation of the nuclear chromatin, condensation and vacuolus of the cytoplasm. Nuclear DNA of apoptosis cells displayed ladder bands characteristic of internucleosomal DNA fragmentation. Protein expression of Fas, inducer of apoptosis, was increased, while that of FasL did not change. mRNA expression of Fas, examined by Northern blot, did not change. Conclusion The mechanism by which homoharringtonine induces apoptosis in HL 60 cells involves increasing Fas protein expression. The cause of altered expression of Fas protein is probably that homoharringtonine promotes Fas mRNA translation but not Fas mRNA level.