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1.
为了探讨EB病毒潜伏膜蛋白1(LMP1)的致瘤机制,对鼻咽癌中LMP1激活重要的核转录因子NF-κB机制进行了研究.首先,采用免疫共沉淀-蛋白质印迹在稳定表达LMP1的鼻咽癌细胞系HNE2-LMP1中证实LMP1与TRAF1,2,3结合形成免疫共沉淀复合物,进一步以野生型LMP1及其三种突变体的鼻咽癌细胞系LMP1(野生型,wt)、HNE2-LMP1 del187~351(CTAR1缺失型)、HNE2-LMP1(1~231)(CTAR2缺失型)、HNE2-LMP1(1~187)(羧基端胞浆区缺失型)、HNE2-pSG5(空白载体型)为材料,结合NF-κB报道基因质粒(pGL2-NF-κB-luc)的荧光素酶活性表达分析NF-κB的活性,证实:较之母细胞, 野生型LMP1活化NF-κB达13.8倍, LMP1(1~187)几乎不活化NF-κB,LMP1(1~231)活化NF-κB达4.9倍, LMP1(del187~351)活化NF-κB达9.1倍;TRAF1过表达升高LMP1(wt)及LMP1(1~231)介导的NF-κB活性,而对LMP1(del 187~351)活化NF-κB无影响;TRAF3过表达或TRAF3负显性突变体抑制LMP1(wt)及LMP1(1~231)介导的NF-κB活性,而不影响LMP1(del 187~351)活化NF-κB; TRAF2过表达升高LMP1(wt)、LMP1 (1~231)及LMP1(del 187~351)介导的NF-κB活性.这些结果表明:鼻咽癌中LMP1通过TRAF1、TRAF2或TRAF3调控NF-κB,TRAF1和TRAF3主要通过CTAR1发挥作用,TRAF2的作用主要是通过CTAR1和CTAR2介导的.  相似文献   

2.
EB病毒潜伏膜蛋白1通过TRAF/TRADD激活JNK信号途径   总被引:12,自引:3,他引:9  
为了探讨在鼻咽癌细胞中EB病毒编码的潜伏膜蛋白1(LMP1)激活c-Jun氨基端激酶(JNK)信号途径的分子机制,利用可调控表达LMP1的鼻咽癌细胞系L7,蛋白质印迹检测,发现LMP1能够促进JNK的活化;利用稳定表达LMP1的鼻咽癌细胞系HNE2-LMP1及其三种突变体HNE2-LMP1ΔCTAR1、HNE2-LMP1ΔCTAR2、HNE2-LMP1ΔCTAR1,2及LMP1阴性的HNE2为材料,采用蛋白质印迹和报告基因法分析JNK和活化蛋白1(AP1)活化情况,结果显示HNE2-LMP1和HNE2-LMP1ΔCTAR1中磷酸化JNK蛋白表达量和AP1活性都无显著差异,而与HNE2-LMP1ΔCTAR2、HNE2-LMP1ΔCTAR1,2、阴性对照HNE2及空白载体转染细胞的JNK蛋白表达和AP1活性具有显著差异;进一步比较转染TRAF、TRADD显性负性突变体鼻咽癌细胞系HNE2-LMP1中磷酸化的JNK量和AP1活性,结果显示:TRAF-DN和TRADD-DN的导入使活化的JNK蛋白和AP-1活性显著降低,二者间无显著差异,提示TRAF和TRADD可能参与了LMP1对JNK和AP-1的活化.以上结果提示在鼻咽癌细胞系中LMP1功能结构域CTAR2通过结合TRAF/TRADD激活JNK从而活化重要的转录因子AP1.  相似文献   

3.
在EB病毒潜伏膜蛋白LMP1介导的信号传导通路中,TRAFs作为LMP1活化的第一位信号分子,可能扮演着重要的分子开关角色。令人关注的是,在上皮性肿瘤NPC的发生中,EB病毒LMP1能否激活重要的TRAFs信号分子?究竟激活何种TRAFs信号分子,激活的机制何在?将LMP1cDNA导入LMP1表达阴性的HNE2中,建立稳定表达LMP1的鼻咽癌细胞系HNE2-LMP1。以此为材料,应用差异RT-PCR和Western blotting法证实,无论在RNA水平,还是蛋白水平上,TRAF1在HNE2-LMP1中表达较HNE2强,而TRAF2及TRAF3在HNE2-LMP1与HNE2细胞中表达无明显差异;进一步用免疫共沉淀-Western blotting证实LMP1可使TRAF1、TRAF2、TRAF3磷酸化而被活化。这些结果提示在鼻咽癌中,LMP1可能诱导TRAF1表达,而对TRAF2及TRAF3并不影响,但LMP1可磷酸化TRAF1、TRAF2、TRAF3而使其功能性活化。q  相似文献   

4.
为了探讨在鼻咽癌细胞(NPC)中是否存在EB病毒潜伏膜蛋白1(LMP1)/JAK3/STAT信号传导途径,首先采用RT-PCR方法对NPC JAK家族4种成员检测,发现在两株鼻咽癌细胞株CNE1和HNE2中该家族4种成员均有表达.选择最有可能与LMP1相互作用的JAK家族成员JAK3作为我们的研究对象.利用已建立的一株受四环素衍生物强力霉素(doxycycline,Dox)调控的LMP1表达的鼻咽癌细胞系(Tet-on-LMP1 HNE2),诱导Tet-on-LMP1 HNE2细胞LMP1动态表达,蛋白质印迹发现JAK3的表达方式呈剂量和时间依赖性.采用瞬间转染方法将STAT报告基因质粒(GRR-Luc)转染入pTet-on-LMP1 HNE2细胞中,不同剂量的Dox促使LMP1的表达可以激活STAT报告基因活性,在0.06mg/L Dox诱导36 h时,STAT活性最高.在该条件下,加入3 μmol/L JAK3特异性抑制剂WHI-P131时,可抑制STAT的活性.结果表明:JAK3的表达在NPC细胞中受LMP1的调控,LMP1可以通过调控JAK3的表达参与STAT的活化.在鼻咽癌细胞中存在LMP1/JAK3/STAT信号途径并可能在其发生发展过程中起重要作用.  相似文献   

5.
EB病毒LMP1 CTAR1、CTAR2的表达促使人鼻咽癌细胞HNE2增殖   总被引:1,自引:0,他引:1  
探讨EB病毒LMP1不同结构域在鼻咽癌中的致瘤作用,为阐明鼻咽癌分子发病机理,寻找治疗鼻咽癌的分子靶提供实验依据。以转染空白载体为对照,利用电穿孔转染方法,建立稳定表达LMP1不同突变体的鼻咽癌细胞系HNE2-LMP1(1~815)、HNE2-LMP1(1~231)、HNE2-LMP1△187~351,并以这些细胞系为材料,用MTT法检测增殖期活细胞,BrdU掺入法检测细胞增殖状况,比较各组细胞的软琼脂集落形成率和裸鼠成瘤能力,以观察LMP1不同的结构域对鼻咽癌细胞生长的影响。LMP1(1~231)和LMP1△187~351在体外明显促进HNE2细胞增殖,HNE2-LMP1(1~231)、HNE2-LMP1△187~351平均吸光度(A)比值、BrdU掺入率、软琼脂集落形成率均高于HNE2-pSG5与HNE2(P<0 01),而HNE2-LMP1(1~187)与HNE2-pSG5、HNE2相比,这些指标无明显差别。HNE2-LMP1△187~351和HNE2-LMP1(1~231)的裸鼠成瘤潜伏期、倍增时间与平均瘤重明显高于HNE2-pSG5鼻咽癌细胞系,其差异有显著的统计学意义(P<0 05)。而HNE2-LMP1(1~187)、HNE2-pSG5和HNE2鼻咽癌细胞系在潜伏期、倍增时间与平均瘤重方面两两比较,差异无显著的统计学意义(P>0 05)。EB病毒LMP1CTAR1和CTAR2对HNE2细胞生长有明显促进作用,提示EB病毒LMP1可能在鼻咽癌的发生发展中起着重要的作用。  相似文献   

6.
EB病毒LMP1及其CTAR1、CTAR2导入人HNE2鼻咽癌细胞的研究   总被引:4,自引:2,他引:2  
用电穿孔转染法,建立稳定表达野生型LMP1及其不同突变体的鼻咽癌细胞系,并以这些细胞系为材料,用MTT法检测增殖期活细胞,观察LMP1及其不同的结构域对鼻咽癌细胞生长的影响。结果得到了LMP1及其三种突变体、空白载体表达的鼻咽癌细胞系;HNE2-LMP1(野生型)、HNE2-LMP1△185-351(CTAR1缺失型)、HNE2-LMP1(1-231)(CTAR2缺失型)、HNE2-LMP1(1-185)(羧基端胸浆区缺失型)、HNE2-pSG5(空载体型)。进一步证实HNE2-LMP1、HNE2-LMP1(1-231)、HNE2-LMP1△185-351平均吸光度(A)比值高于对照组HNE2-pSG5及HNE2(P<0.01)。这提示:EB病毒LMP1及其LMP1(1-231)和LMP1△185-351在体外明显促进HNE2细胞增殖。结果表明EB病毒LMP1可能在鼻咽癌中发挥着重要的作用。  相似文献   

7.
在EB病毒潜伏膜蛋白LMP1介导的信号传导通路中,TRAFs作为LMP1活化的第一位信号分子,可能扮演着重要的分子开关角色,令人关注的是,在上皮性肿瘤NPC的发生中,EB病毒LMP1能否激活重要的TRAFs信号分子?究竟激活何种TRAFs信号分子,激活的机制何在?将LMP1 cDNA导入LMP1表达阴性的HNE2中,建立稳定表达LMP1的劓咽癌细胞系:HNE2-LMP1。以此为材料,应用差异RT-PCR和Western blotting法证实,无论在RNA水平,还是蛋白水平上,TRAF1在HNE2-LMP1中表达较HNE2强,而TRAF2及TRAF3在HNE2-LMP1与HNE2细胞中表达无明显差异;进一步用免疫共沉淀-Western blotting证实LMP1可使TRAF1、TRAF2、TRAF3磷酸化耐被活化,这些结果提示在鼻咽癌中,LMP1可能诱导TRAF1表达,而对TRAF2及TRAF3并不影响,但LMP1可磷酸化TRAF1、TRAF2、TRAF3面使其功能性活化。  相似文献   

8.
EB病毒潜伏膜蛋白1通过结合TRAFs调控NF-κB   总被引:2,自引:1,他引:1  
为了探讨EB病毒潜伏膜蛋白1(LMP1)的致瘤机制,对鼻咽癌中LMP1激活重要的核转录因子NF-κB机制进行了研究,首先,采用免疫共沉淀-蛋白质印迹在稳定表达LMP1的鼻咽癌细胞系HNE2-LMP1中证实LMP1与TRAF1,2,3结合形成免疫共沉淀复合物,进一步以野生型LMP1及其三种突变体的鼻咽癌细胞系LMP1(野生型, wt),HNE2-LMP1 del187-351(CTAR1缺失型),HNE2-LMP1(1-231),(CTAR2缺失型),HNE2-LMP1(1-187)(羰基端胞浆区缺失型),HNE2-pSG5(空白载体型)为材料,结合NF-κB报道基因质粒(pG12-NF-B-luc)的荧光素酶活性表达分析NF-κB的活性,证实:较之母细胞,野生型LMP1活化NF-B达13.8倍,LMP1(1-187)几乎不活化NF-kb,LMP1(1-231)活化NF-kB 达4.9倍,LMP1(del187-351)活化NFκB达9.1倍,TRAF1过表达升高LMP1( wt)及LMP1(1-231)介导的NF-κB活性,而对LMP1(del187-351)活化NFκB无影响,TRAF3过表达或TRAF3负显性突变体抑,制LMP1(wt)及LMP1(1-231)介导的NF-κB活性而不影响LMP1(del187-351)活化NF-κB,TRAF2过表达升高LMP1(wt),LMP1(1-231)及LMP1(del 187-351)介导的NF-kB活性,这些结果表明:鼻咽癌中LMP1通过TRAF1,TRAF2或TRAF3调控NF-kB,TRAF1和TRAF3主要通过CTAR1发挥作用,TRAF2的作用主要是通过CTAR1和CTAR2介导的。  相似文献   

9.
EBV LMP1通过诱导c-myc表达活化端粒酶hTERT   总被引:4,自引:0,他引:4  
杨静  邓锡云  邓琳  丁琳  顾焕华  易薇  曹亚 《病毒学报》2003,19(3):240-244
利用原代人胚鼻咽上皮细胞和Tet on LMP1HNE2等良好的细胞体系,采用报道基因法和Westernblot法等,分别检测Epstein Barr病毒(EBV)潜伏膜蛋白1(LMP1)诱导的c myc反式激活活性和蛋白表达水平,从LMP1诱导细胞内c myc表达的角度,探讨LMP1诱导端粒酶表达的分子机制。结果表明,LMP1促使细胞内c myc反式激活活性增强,c Myc蛋白表达量升高;导入反义LMP1表达质粒阻断LMP1表达后,c myc反式激活活性下降。将端粒酶hTERT启动子上c myc结合位点突变后,LMP1不能诱导端粒酶hTERT表达。因而认为,EB病毒LMP1通过诱导c myc表达而活化端粒酶hTERT。  相似文献   

10.
EB病毒潜伏膜蛋白1在鼻咽癌中结合磷酸化的TRAFs   总被引:1,自引:0,他引:1  
 对鼻咽癌中潜伏膜蛋白 1 (LMP1 )是否结合磷酸化的肿瘤坏死因子受体相关因子 (tumornecrosis factor receptor- associated factors,TRAFs)信号分子进行探讨 .首先应用 CSA/SP双染色法在 30例鼻咽癌活检组织中发现 1 6例 (52 % ) LMP1与 TRAF1、TRAF2和 TRAF3共表达于癌细胞胞膜及胞浆同一部位 .这提示 EB病毒 LMP1在鼻咽癌中可能结合 TRAF1、TRAF2或TRAF3发挥作用 .进一步以导入载体 p SG5的鼻咽癌细胞系 HNE2 - p SG5为对照 ,建立了稳定表达 LMP1的鼻咽癌细胞系 HNE2 - LMP1 ,利用这两种细胞系 ,以免疫共沉淀 - Western印迹方法 ,证实了 LMP1可与磷酸化的 TRAF1、TRAF2或 TRAF3直接或间接作用形成免疫共沉淀复合物 .  相似文献   

11.

Background  

MiR-1 (microRNA-1) has been used as a positive control in some microRNA experiments. We found that miR-1 transfection of nasopharyngeal carcinoma cells reveals a typical apoptotic process as shown by time-lapse microscopy so we investigated the mechanisms of miR-1 inducing apoptosis.  相似文献   

12.
胆管癌是一种起病隐匿、侵袭性强、致死率高的原发性恶性肿瘤。多聚嘧啶区结合蛋白1(polypyrimidine tract-binding protein 1, PTBP1)已被报道,在多种类型肿瘤组织中异常高表达并参与癌症进展,但其在胆管癌中的作用仍未见报道。该研究旨在探讨PTBP1在胆管癌中的生物学功能,并初步解析其分子机制。本文利用公开的癌症基因组图谱(the cancer genome atlas, TCGA)数据,分析了胆管癌及癌旁组织中的PTBP1 mRNA表达水平。结果显示,PTBP1在胆管癌组织中的表达水平显著高于癌旁组织(P < 0.05)。随后,在胆管癌细胞系RBE和HuH28中,通过CCK-8和细胞平板克隆实验,评价了PTBP1对胆管癌细胞生长能力的影响。结果显示,过表达PTBP1可显著促进胆管癌细胞的生长(P < 0.01),而敲低PTBP1显著抑制胆管癌细胞的生长(P < 0.001)。Transwell和Invasion实验结果显示,过表达PTBP1可显著促进胆管癌细胞的迁移和侵袭(P < 0.001),而敲低PTBP1显著抑制胆管癌细胞的迁移和侵袭(P < 0.001)。转录物组测序和通路富集分析结果显示,在胆管癌细胞中,敲低PTBP1后上调表达的基因显著富集于p53信号通路;而下调表达的基因显著富集于胆固醇代谢、Rho GTPase和TGF-β等信号通路。基于上述转录物组测序数据,本文还分析发现,敲低PTBP1可导致一系列基因发生异常的mRNA可变剪接事件,例如参与TGF-β调控的TGIF1及与p53活性相关的GNAS基因等。综上所述,PTBP1可能通过调控一系列基因的可变剪接而影响多个癌症相关的信号通路,从而促进胆管癌的进展。  相似文献   

13.
Cysteine-rich FGF receptor (CFR) was originally identified as a FGF2 receptor and found to be identical to Golgi complex-localized glycoprotein-1 (GLG1), also known as MG-160, and to a murine E-selectin ligand-1 (ESL-1). Although CFR is a 150-kDa integral membrane glycoprotein that is primarily located in the cis-medial Golgi complex, a substantial proportion of CFR is secreted but the underlying mechanism is unknown. CFR contains several possible furin-like proprotein convertase (PC) and matrix metalloproteinase cleavage sites. Cells expressing CFR were treated with the furin protease inhibitor decanoyl-Arg-Val-Lys-Arg-chloromethylketone (decCMK) or the MMP-inhibitor GM6001. In the presence of furin-like PC inhibitor, secretion of CFR was almost completely inhibited. Secretion was not affected by the GM6001 inhibitor. The secreted forms were further characterized by creating different mutant CFR proteins with N-terminal and C-terminal tags. Immunoblot analysis and immunofluorescence indicated, that successive endoproteolytical processing of CFR which takes place in the Golgi complex is essential for secretion. Secreted CFR bound to heparan sulphate proteoglycan (HSPG) could trap FGFs and thereby directly competing with tyrosine kinase receptors for FGF binding.  相似文献   

14.
15.
Summary Alveolar macrophages, which play a central role in lung defense, produce cytokines that help orchestrate local inflammatory responses. In sepsis and other pathological conditions, bacterial lipopolysaccharide endotoxin can induce alveolar macrophages (AM) to release proinflammatory cytokines, including tumor necrosis factor-alpha, interleukin-1, and interleukin-6. Studying the mechanisms that control alveolar macrophage cytokine production may lead to better therapies for conditions involving inflammatory lung injury. We and others have noted significant differences between alveolar macrophages and peritoneal macrophages, but large numbers of human or murine alveolar macrophages are rarely available for detailed mechanistic studies. We have obtained three murine alveolar macrophage cell lines (AMJ2C8, AMJ2C11, and AMJ2C20) and have begun to characterize their cytokine responses to proinflammatory stimuli. We measured the effects of endotoxin, interferon gamma, and the combination of the two on production of tumor necrosis factor, interleukin-1 beta, and interleukin-6 in each line. We also studied the expression of the endotoxin receptor CD14 by these cells, and investigated the effect of serum on their endotoxin responsiveness. We show here that all three of the cell lines responded in a manner comparable to that of primary murine alveolar macrophages. Observed variations between these lines may reflect the documented heterogeneity seen in populations of primary alveolar macrophages. These cell lines should expand the repertoire of tools available to investigators studying regulation of murine alveolar macrophage responses.  相似文献   

16.
Intracellular ascorbate (vitamin C) has previously been shown to tighten the endothelial barrier and maintain barrier integrity during acute inflammation in vitro. However, the downstream effectors of ascorbate in the regulation of endothelial permeability remain unclear. In this study, we evaluated ascorbate as a mediator of thrombin-induced barrier permeabilization in human umbilical vein endothelial cells and their immortalized hybridoma line, EA.hy926. We found that the vitamin fully prevented increased permeability to the polysaccharide inulin by thrombin in a dose-dependent manner, and it took effect both before and after subjection to thrombin. Thrombin exposure consumed intracellular ascorbate but not the endogenous antioxidant GSH. Likewise, the antioxidants dithiothreitol and tempol did not reverse permeabilization. We identified a novel role for ascorbate in preserving cAMP during thrombin stimulation, resulting in two downstream effects. First, ascorbate maintained the cortical actin cytoskeleton in a Rap1- and Rac1-dependent manner, thus preserving stable adherens junctions between adjacent cells. Second, ascorbate prevented actin polymerization and formation of stress fibers by reducing the activation of RhoA and phosphorylation of myosin light chain. Although ascorbate and thrombin both required calcium for their respective effects, ascorbate did not prevent thrombin permeabilization by obstructing calcium influx. However, preservation of cAMP by ascorbate was found to depend on both the production of nitric oxide by endothelial nitric-oxide synthase, which ascorbate is known to activate, and the subsequent generation cGMP by guanylate cyclase. Together, these data implicate ascorbate in the prevention of inflammatory endothelial barrier permeabilization and explain the underlying signaling mechanism.  相似文献   

17.
Alpha-synuclein (α-Syn) is a major component of Lewy bodies, a pathological feature of Parkinson's and other neurodegenerative diseases collectively known as synucleinopathies. Among the possible mechanisms of α-Syn-mediated neurotoxicity is interference with cytoprotective pathways such as insulin signaling. Insulin receptor substrate (IRS)-1 is a docking protein linking IRs to downstream signaling pathways such as phosphatidylinositol 3-kinase/Akt and mammalian target of rapamycin (mTOR)/ribosomal protein S6 kinase (S6K)1; the latter exerts negative feedback control on insulin signaling, which is impaired in Alzheimer's disease. Our previous study found that α-Syn overexpression can inhibit protein phosphatase (PP)2A activity, which is involved in the protective mechanism of insulin signaling. In this study, we found an increase in IRS-1 phosphorylation at Ser636 and decrease in tyrosine phosphorylation, which accelerated IRS-1 turnover and reduced insulin-Akt signaling in α-Syn-overexpressing SK-N-SH cells and transgenic mice. The mTOR complex (C)1/S6K1 blocker rapamycin inhibited the phosphorylation of IRS-1 at Ser636 in cells overexpressing α-Syn, suggesting that mTORC1/S6K1 activation by α-Syn causes feedback inhibition of insulin signaling via suppression of IRS-1 function. α-Syn overexpression also inhibited PP2A activity, while the PP2A agonist C2 ceramide suppressed both S6K1 activation and IRS-1 Ser636 phosphorylation upon α-Syn overexpression. Thus, α-Syn overexpression negatively regulated IRS-1 via mTORC1/S6K1 signaling while activation of PP2A reverses this process. These results provide evidence for a link between α-Syn and IRS-1 that may represent a novel mechanism for α-Syn-associated pathogenesis.  相似文献   

18.
利用透射电子显微镜(TEM)和原子力显微镜(AFM)观察流感病毒(H1N1),探讨AFM在病毒形态研究中的应用,为病毒形态学研究提供一种新型、简便、快捷的工具.TEM采用磷钨酸负染方法,AFM采用轻敲模式在大气常温下扫描成像,并对主要指标长度(直径)、Ra、Rq等进行测量.两种方法最终得到相似的形态学结果,流感病毒呈球状、丝状,并有一些形状介于两者之间.TEM提供了流感病毒二维图像,可见钉状突起,AFM则呈现了流感病毒三维图像,且可见病毒表面有凹凸不平的特征和边缘有齿轮状的突起,同时获得表面粗糙度等可以量化指标.与TEM观察相比,原子力显微镜是一种制样简单、观察直观的新型病毒形态学研究工具,其表征参数可以作为病毒形态学研究的量化指标.  相似文献   

19.
间充质干细胞(mesenchymal stem cells, MSCs)是再生医学中临床使用最多的干细胞之一。外周血间充质干细胞(peripheral blood mesenchymal stem cells, PBMSCs)以其获取简便、创伤小和具有多向分化能力等优势,在人类缺血性疾病的治疗方面具有重要应用前景。但尚未建立在缺氧环境下,使PBMSCs高存活和高扩增培养方法。本研究旨在探讨HIF-1α(hypoxia-inducible factor -1α, HIF-1α)通过调节叉头框蛋白1(forkhead box C1, FoxC1)表达,促进PBMSCs缺氧存活和扩增的作用。采取SD大鼠外周血,分离出单个核细胞(mononuclear cells, MNCs),培养第3代后得到MSCs,随机将细胞进行以下3种处理,并分组:未处理组(Control, CON)、HIF-1α激动剂组(dimethyloxallyl glycine, DMOG,0.1 mmol/L,DMOG组)和HIF-1α抑制剂组(BAY87-2243,50 nmol/L,BAY组),进行缺氧培养PBMSCs,观察各组不同时间点(1 h、10 h、20 h、30 h、40 h、50 h、60 h、70 h、80 h)PBMSCs凋亡和增殖情况。应用qRT-PCR和Western 印迹观察细胞FoxC1表达情况,及抗凋亡分子Bcl2和凋亡信号分子Bax和胱天蛋白酶3(caspase3)表达情况。MNCs经过3代培养后,可得到纯度较高的PBMSCs。但是,这些细胞在体外缺氧培养30 h即发生凋亡,但经HIF-1α激动剂DMOG能抑制其凋亡,能使PBMSCs缺氧延长到60 h以上。与CON组比较,DMOG处理使DMOG组PBMSCs活力升高2.6倍(P<0.001),细胞老化率(SA-β-gal阳性细胞百分率)降低70.1%(P<0.001),细胞凋亡率(Annexin V+PI+细胞百分率)减少64.6%(P<0.001)。加入HIF-1α抑制剂BAY87-2243则引起相反的变化:培养20 h后细胞增殖能力明显减弱,与CON组比较,BAY组细胞活力明显下降(P<0.001),老化率增加35.6%(P<0.001),细胞凋亡率增加38.1%(P<0.001)。进一步研究发现,DMOG可上调HIF-1α表达,促进FoxC1表达(DMOG组较CON组升高2.3倍,P<0.001),上调抗凋亡蛋白Bcl2(DMOG组较CON组升高3.8倍,P<0.001)、下调凋亡蛋白Bax和胱天蛋白酶3表达(各下降86.5%和85.0%,均P<0.001),而加入BAY87-2243显著降低HIF-1α、FoxC1和Bcl2表达,上调Bax和胱天蛋白酶3表达(与CON组比较,均P<0.001)。由此可见,HIF-1α-FoxC1是影响MSCs缺氧存活和增殖的重要信号途径,这有助于提高PBMSCs在缺氧环境中存活和扩增。  相似文献   

20.
The function of ten-eleven translocation methylcytosine dioxygenase 1 (TET1) in cancer is background dependent and may be involved in the initial step of active DNA demethylation, while there is little research to decipher the role of TET1 in DNA methylation-sensitive colon cancer. Downregulated TET1 expression assayed by quantitative real-time PCR (qRT-PCR) was observed in both colon cancer samples and cancer cell lines of HT29, HCT116, and SW48. Such downregulation could promote colon cancer cells proliferation as indicated by the fact that shTET1 could increase the viability of HT29 and HCT116 cells determined by the 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide and cell count assay accompanied with upregulation of β-catenin (CTNNB1) and WNT luciferase activity, which was further confirmed as shTET1 could increase the tumor volume and tumor weight, and decrease the body weight in HT29 cells inoculated BALB/C nude mice. The CTNNB1 transfection could rescue the cell growth diminished by normal expression of TET1. shTET1 could promote axis inhibition protein1 (AXIN1) expression and the cell proliferation effect induced by TET1 short hairpin RNA was attenuated by co-inhibition of AXIN1. All of these indicate that TET1 can suppress colon cancer proliferation and the inhibition of the β-catenin pathway is AXIN1 dependent.  相似文献   

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