三氧化二砷诱导人类恶性淋巴瘤细胞凋亡及机制探讨

目的研究三氧化二砷(As2O3)在体外对人类伯基特氏淋巴瘤细胞凋亡的影响,并探讨其作用机制。方法分别采用来源于人类伯基特氏淋巴瘤的EB病毒阳性细胞Raji和EB病毒阴性细胞BJAB为模型,利用细胞形态学检测、DNA凝胶电泳和蛋白质Western blotting分析等方法,从细胞形态、DNA水平和蛋白质水平探讨As2O3诱导恶性淋巴瘤凋亡及作用机制。结果分别采用2, 5和10 mol/L的As2O3与Raji和BJAB细胞作用24 h后,DNA凝胶电泳证实As2O3通过诱导细胞凋亡而抑制细胞的增殖。BJAB和Raji细胞对应于上述浓度As2O3的凋亡率分别47.6%±4.8% (Mean±SD, n=3), 66.4%±5.1% , 87.0%±7.3% 和35.5%±3.8%, 51.5%±6.2%, 62.2%±7.9,BJAB细胞对As2O3的敏感性要高于Raji细胞(P<0.05)。Western blotting蛋白质检测表明,As2O3通过下调抗凋亡蛋白Bcl-xL的表达和激活凋亡分子caspase-3诱导细胞凋亡。结论As2O3通过下调Bcl-xL蛋白的表达和激活caspase-3诱导人类恶性淋巴瘤细胞的凋亡;本研究可望为临床应用砷剂治疗恶性淋巴瘤提供实验依据。

Arsenic trioxide-induced apoptosis of human malignant lymphoma cell lines and its mechanisms

Objective To investigate the responses of human Burkitt lymphoma cells to arsenic trioxide (As2O3) and thepossible mechanisms. Methods Epstein-Barr virus (EBV)-positive human B-lymphoma Raji cell line and EBV-negative humanB-lymphoma B JAB cell line were used as in vitro models to assess the cell apoptosis by morphology and DNA agarose gelelectrophoresis. Protein expression was analyzed using Western blotting. Results After 24-hour treatment with the 2, 5 and 10μmol/L As2O3, the concentrations of As2O3 achievable in vivo, cell apoptosis was induced in human Burkitt lymphoma B JABcells at the rates of47.6%±4.8% (Mean±SD, n=3), 66.4%±5.1%, 87.0%±7.3% and at 35.5%±3.8%, 51.5%±6.2%, 62.2%±7.9% respectively in Raji cells, corresponding to the concentration of As2O3. EBV-infected Raji cell line was less sensitive toAs2O3 than EBV-negative BJAB cell line (P＜0.05). As2O3-induced apoptosis was accompanied by down-regulation of Bcl-xLprotein expression and activation ofapoptosis protein caspase-3, as identified by Western blotting. Conclusion As2O3 exertsapoptosis-inducing effects on human Burkitt lymphoma cells through down-regulation of Bcl-xL protein expression andactivation of apoptosis protein caspase-3, and may serve as a candidate therapeutic agent against malignant lymphoma for bothsystemic and local therapies.