雷公藤红素对U937细胞Notch 1、NF-κB信号蛋白通路的调控作用  

Effects of Celastrol on growth inhibition of U937 leukemia cells through the regulation of the Notch1/NF-κB signaling pathway in vitro

作　　者：王晓南[1] 吴青[2] 杨旭[1] 张连生[1] 吴一品[2] 卢聪[2] 

机构地区：[1]武汉科技大学医学院,湖北武汉430000 [2]华中科技大学同济医学院附属协和医院,湖北武汉430022

出　　处：《癌症》2010年第4期422-428,共7页Chinese Journal of Cancer

摘　　要：背景与目的:白血病是高度依赖NF-κB的恶性肿瘤,NF-κB与肿瘤的发生和转移以及肿瘤细胞的增殖、凋亡、耐药相关,现已证实NF-κB家族是Notch信号通路的一个靶基因。本研究探讨雷公藤红素对白血病U937细胞凋亡和细胞中Notch1、NF-κB表达水平的影响。方法:以不同浓度雷公藤红素(0.25～16.0μmol/L)分别作用于U937细胞12～60h,MTT法检测细胞增殖活性,透射电子显微镜、流式细胞术观察雷公藤红素对U937细胞凋亡的影响,Western blot、RT-PCR法分别检测雷公藤红素对U937细胞内Notch1通路蛋白、基因表达水平的调控作用,激光共聚焦显微技术检测细胞凋亡时NF-κB的核浆分布变化。结果:雷公藤红素能明显抑制U937细胞增殖,具有浓度依赖和时间依赖性。此外,雷公藤红素以浓度依赖性方式诱导U937细胞凋亡,并伴随明显的凋亡细胞形态学改变,而雷公藤红素的凋亡诱导效应可能与其将细胞阻滞于G0/G1期有关。雷公藤红素对Notch1通路蛋白及基因表达水平均有不同程度的抑制作用,该抑制作用呈明显的量效关系。NF-κB在胞核表达减少,胞浆表达增多。与对照组相比差异具有统计学意义(P<0.05)。结论:雷公藤红素明显抑制U937细胞的增殖,并诱导其凋亡,其抗白血病效应可能与下调Notch1信号通路以及NF-κB蛋白表达有关。Background and Objective：Leukemia is a malignant tumor highly dependent on nuclear factor kappa-light-chain-enhancer of activated B cells （NF-κB）,which is relevant for the occurrence,metastasis,proliferation,apoptosis,and drug resistance of tumor cells. Research has confirmed that the NF-κB family is one of the target genes in the Notch signaling pathway. This study investigated the effects of Celastrol on the apoptosis of U937 cells and the expression levels of Notch1 and NF-κB in these cells. Methods：U937 cells were treated with various concentrations Celastrol （0.5-16.0） μmol/L for 12-60 h. MTT assay was performed to examine the effect of Celastrol on growth inhibition of U937 cells. Cell apoptosis was detected through both Annexin-V FITC/PI double-labeled cytometry and transmission electron microscopy （TEM）. Cell cycle regulation was studied by propidium iodide. Western blot analysis and reverse transcription-polymerase chain reaction （RT-PCR） technologies were applied to assess the expression level of hERG in K562 cells and to assess the expression level of Notch1 in U937 cells. Subcellular distributions of NF-κB/p65 were detected through confocal microscopy. Results：Celastrol presented striking growth inhibition and apoptosis induction potency on U937 cells in vitro in a time-and dose-dependent manner. The IC50 value of Celastrol for 24 h was （6.21± 0.24） μmol/L. Moreover,Celastrol induced apoptosis in U937 cells in a cell-cycle dependent manner,which means that Celastrol could arrest U937 cells in the G0/G1 phase. Through TEM,apoptotic bodies containing nuclear fragments were found in Celastrol-treated U937 cells. Overexpression of Notch1 was found in U937 cells,while Celastrol could downregulate it at both the protein and mRNA level in a dose-dependent manner,and expression of NF-κB decreased in nuclei and increased in the cytoplasm （ P 〈0.05）. Conclusions：Celastrol inhibited cell proliferation and induced apoptosis in U937 cells in a concentration-dependent manne

关 键 词：雷公藤红素 U937细胞 NOTCH1 NF-ΚB 凋亡 

分 类 号：R73-3[医药卫生—肿瘤]