阿司匹林诱导EB病毒转化的人B淋巴细胞凋亡

摘要

目的：探讨阿司匹林诱导 EB 病毒转化的人 B 淋巴细胞凋亡及其机制。方法EB 病毒转化的人 B 淋巴细胞经一定浓度的阿司匹林处理后，首先通过 MTT 法分析细胞的增殖情况；然后用光学显微镜和电子显微镜、PI 染色和流式细胞术分析以及琼脂糖凝胶电泳等方法对细胞凋亡进行评价；最后，通过免疫印记法检测凋亡相关蛋白、mTOR 信号通路和 PU．1-Bim 信号通路蛋白表达情况。结果阿司匹林能抑制 EB 病毒转化的人 B 淋巴细胞增殖。形态学和超微结构观察发现，阿司匹林处理的细胞固缩变小、数目减少、细胞核畸形、染色质边缘化和细胞质空泡化。阿司匹林处理导致细胞膜通透性增加、细胞存活率明显下降和细胞 DNA 的弥散现象。免疫印迹分析显示，阿司匹林处理抑制了细胞的mTOR 信号和转录因子 PU．1的表达水平，激活了细胞凋亡相关蛋白 caspase-3、PARP 和 Bim。结论阿司匹林可能通过抑制 EB 病毒转化的人 B 淋巴细胞增殖和诱导细胞凋亡表现一定的抗淋巴瘤效应，mTOR 信号途径和 PU．1-Bim 轴可能参与了阿司匹林抗肿瘤作用机制。%Aim To investigate the effects of aspirin on Epstein-Barr virus (EBV)-transformed human B-lym-phocytes.Methods EBV-transformed human B-lym-phocytes were treated with certain concentrations of as-pirin.Cellular proliferation was analyzed by MTT as-say.Further evaluation of apoptosis of aspirin-treated cells was performed through light-field microscope, transmission electronic microscope(TEM),propidium iodide(PI)staining and flow cytometric analysis and DNA electrophoresis. Finally, immunoblot analysis was used to determine the expression levels of apopto-sis-associated proteins, proteins involved in mTOR pathway and PU.1 -Bim axis.Results Aspirin treat-ment inhibited proliferation of EBV-transformed human B-lymphocytes.We observed that aspirin treatment in-duced apoptosis in EBV-transformed human B-lympho-cytes,resulting in the decreased number and size of cells.Ultramicroscopic structural analysis via TEM in-dicated that aspirin treatment deformed the cellular nu-cleus,and led to peripheral chromatin and cytoplasmic vacuole.PI staining and flow cytometric analysis indi-cated that aspirin increased the permeability of cell membrane and decreased the viability of treated cells. Agarose electrophoresis revealed DNA smear in aspirin-treated cells.Mechanistically,mTOR signaling was in-hibited in aspirin-treated cells,as evidenced by the de-creased phosphorylation of S6K1 and S6 via immunob-lot analysis.Aspirin treatment led to the decrease of hematopoietic transcription factor PU.1 .Consequently, pro-apoptotic Bim, apoptosis-associated proteins caspase-3 and PARP were activated in aspirin-treated cells.Conclusion Aspirin may show anti-lymphoma effects via its inhibition of proliferation and induction of apoptosis of EBV-transformed human B-lymphocytes, in which mTOR signal pathway and PU.1 -Bim axis may be involved.