姜黄素改善肺癌A549细胞对肿瘤坏死因子相关凋亡诱导配体抵抗的机制

目的:观察中药提取物姜黄素联合肿瘤坏死因子相关凋亡诱导配体对肺癌细胞株A549生长抑制率和对细胞凋亡相关因子表达的影响,探索姜黄素改善肺癌A549细胞对肿瘤坏死因子相关凋亡诱导配体抵抗的机制。方法:实验于2003-10/2004-10在上海东方医院中心实验室完成。用购于中科院上海细胞所肺腺癌细胞株A549,将培养的A549细胞暴露于姜黄素、肿瘤坏死因子相关凋亡诱导配体及两者联合中,分4组,每组6孔,姜黄素组(40μmol/L姜黄素)、肿瘤坏死因子相关凋亡诱导配体组(25μg/L肿瘤坏死因子相关凋亡诱导配体)、联合组(40μmol/L姜黄素与25μg/L肿瘤坏死因子相关凋亡诱导配体联合)、对照组(RPMI1640细胞培养液)。①用四氮唑蓝法测定姜黄素组、肿瘤坏死因子相关凋亡诱导配体组以及联合组的吸光值,根据吸光度值计算肺癌细胞株A549细胞生长抑制率。②应用ApoAlert半胱氨酸天冬氨酸蛋白酶系列比色法凋亡相关蛋白半胱氨酸天冬氨酸蛋白酶3,半胱氨酸天冬氨酸蛋白酶8表达。③反转录聚合酶链反应测定凋亡调控蛋白bcl-2/bax的表达。结果:①抑制率:肿瘤坏死因子相关凋亡诱导配体对肺腺癌A549细胞的抑制明显低于姜黄素,25μg/L肿瘤坏死因子相关凋亡诱导配体作用24h细胞抑制率仅有(2.65±1.416)%;两药联合对肺腺癌A549细胞的抑制作用明显增加[高达(30.97±1.318)%,P<0.01]。②凋亡相关因子:联合组半胱氨酸天冬氨酸蛋白酶3、半胱氨酸天冬氨酸蛋白酶8表达明显高于姜黄素组、肿瘤坏死因子相关凋亡诱导配体组、对照组[联合组:(50.77±0.812),(73.31±0.730)μmol/L;姜黄素组:(23.61±0.398),(26.84±1.511)μmol/L;肿瘤坏死因子相关凋亡诱导配体组:(9.63±1.024),(14.21±0.138)μmol/L;对照组:(3.69±0.486),(2.87±0.633)μmol/L,P<0.01];联合组、姜黄素组的bcl-2/bax明显高于肿瘤坏死因子相关凋亡诱导配体组(2.55±0.138,2.24±0.197,0.58±0.046,P<0.01)。结论:肺癌A549细胞对肿瘤坏死因子相关凋亡诱导配体细胞耐受,姜黄素可能通过调整bcl-2/bax的表达,进而激活半胱氨酸天冬氨酸蛋白酶家族,增加肿瘤坏死因子相关凋亡诱导配体的敏感性。     

激素性股骨头坏死早期细胞凋亡相关基因表达及阿仑磷酸钠的干预

背景：近年研究发现激素性股骨头坏死病例中凋产的骨细胞增多，因此认为激素性股骨头坏死是骨细胞凋亡所致，而并非缺血性坏死。目的：观察大鼠激素性股骨头坏死早期bcl-2、半胱氨酸天冬氨酸蛋白酶3（cysteinyl aspartate specific protease3，caspase-3）的表达，以及阿仑磷酸钠的干预效果。设计、时间及地点：随机对照动物实验，于2006—03／200702在吉林大学基础医学院病理实验室完成。材料：健康Wister大鼠100只，随机分为正常对照组、激素模型组、藻酸双酯钠组、阿仑磷酸钠组、联合用药组，20只，组。藻酸双酯钠片为吉林东丰制药厂产品，阿仑磷酸钠为杭州默沙东制药有限公司产品。方法：除正常对照组外，其余4组大鼠均给予醋酸泼尼松龙臀肌注射建立激素性股骨头坏死模型。藻酸双酯钠组、阿仑磷酸钠组分别灌服对应药物，联合用药组灌服藻酸双酯钠＋阿仑磷酸钠。各组肌注用药1次／周，灌服药1次，d，实验持续6周。所有大鼠均强迫间断站立，4h／d。主要观察指标：光镜观察股骨头病理变化。S．P免疫组织化学染色法检测股骨头组织bcl-2、caspase．3的表达。结果：给药第4周与正常对照组比较，激素模型组股骨头坏死现象明显，骨小梁变细甚至断裂，空骨陷窝数量明显增多（t=-2．629，P〈0．01）；藻酸双酯钠组骨小梁和空骨陷窝数量介于前2组之间（t-=1．713，P〈O．01）；阿仑磷酸钠组、联合用药组骨小梁和空骨陷窝数量接近正常对照组忙1．462，t=-1．657，P〉0．05）。与激素模型组比较，藻酸双酯钠组、阿仑磷酸钠组、联合用药组股骨头组织bcl-2阳性细胞率均明显升高（t=-2．146，P〈0．05；t=-2．815，P〈0．01；t=-2．947，P〈0．01），caspase、3阳性细胞率均明显降低（t=-2．97，P〈0．叭；t=-2．462，P〈0．01；t=-I．854，P〈0．05），其中阿仑磷酸钠组圾联合用药组升高尤为明显（t=2．503，t=-1．959，P〈0．051。结论：大剂量激素可能通过抑制bcl-2表达和促进caspase-3表达引起股骨头坏死。阿仑磷酸钠可能通过与其相反的途径来防止骨细胞凋亡，从而预防早期激素性股骨头坏死。     

环氧化酶-2RNA干扰对肺癌A549细胞凋亡及caspase家族的影响

目的观察环氧化酶-2（COX-2）RNA干扰对肺癌细胞凋亡的影响,以及对凋亡调控蛋白caspase-8、caspase-9、caspase-3的调控作用。方法构建COX-2特异性干扰质粒,并转染至肺癌A549细胞株中,AnnexinV-FITC／PI联合流式细胞仪检测细胞凋亡,Western Blot检测caspase-8、caspase-9、caspase-3的活性。结果成功构建COX-2特异性干扰质粒并转染至肺癌A549细胞株中,获得抑制COX-2表达的肺癌细胞模型;干扰COX-2的A549细胞凋亡率[（24．3±2．46）％]较未干扰组[（6．52±0．13）％]明显升高（P〈0．01）。干扰COX-2的肺癌细胞．4549caspase．8蛋白表达（0．86±0．09）较未干扰组（0．12±0．01）明显升高（P〈0．01）,caspase-3蛋白表达（0．94±0．09）较未干扰组（0．16±0．02）明显升高（P〈0．01）,caspase-9蛋白表达（1．12±0．11）较未干扰组（0．13±0．01）明显升高（P〈0．01）。结论干扰COX-2可以促进肺癌A549细胞的凋亡,并且活化caspase-8及caspase-9,从而活化caspase-3。     

肿瘤坏死因子相关凋亡诱导配体对卵巢癌裸鼠移植瘤SKOV3细胞的促凋亡研究

目的 研究肿瘤坏死因子相关凋亡诱导配体(TRAIL)蛋白对SKOV3移植瘤细胞半胱天冬氨酸蛋白酶-3(Caspase-3)表达的影响及其与肿瘤细胞凋亡的关系.方法 建立雌性裸小鼠SKOV3移植瘤24只,随机分为4组,每组6只.TRAIL组单用重组人TRAIL蛋白(10μg/kg),顺铂(DDP)组单用DDP(3 mg/...     

肿瘤坏死因子凋亡诱导配体诱导白血病细胞凋亡中抵抗机制的初步探讨

目的初步探讨肿瘤坏死因子凋亡诱导配体(TRAIL)诱导白血病细胞发生凋亡过程中可能存在的抵抗机制。方法用流式细胞仪检测经 TRAIL 处理后,白血病细胞系 K562、CEM 凋亡情况及线粒体跨膜电位的改变;采用 Western blot 检测 TRAIL 处理后细胞凋亡相关蛋白 Bcl-xL、Bax 及内源性半胱天冬酶(caspase)-8表达情况;并用 ELISA 法检测核转录因子(NF)-kB 活性变化。结果经TRAIL 处理后,K562、CEM 细胞出现不同程度的凋亡,其凋亡指数分别为29.98%、14.1%,后者显著低于前者(P<0.001);线粒体跨膜电位下降,分别为73.25%、25.4%(P<0.01);CEM 细胞中内源性caspase-8的表达水平低于 K562细胞,并且两者均表现出 Bcl-xL 表达上升、Bax 表达下降,在 CEM 细胞中 Bcl-xL/Bax 比例为18.8,显著高于 K562细胞 Bcl-xL/Bax 的比值(5.1);并且在 TRAIL 处理 CEM细胞后早期(2 h)即表现出 NF-kB 活性增加(0.48 μmol·L~(-1)·mg~(-1)蛋白),高于 K562细胞(0.326μmol·L~(-1)·mg~(-1)蛋白(P<0.001)。结论 TRAIL 诱导白血病细胞凋亡过程中,CEM 细胞对药物抵抗原因可能与 CEM 细胞内源性 caspase-8表达水平较低、线粒体内膜敏感程度降低、NF-kB 活性早期增加以及 Bcl-2家族蛋白的表达变化有关。     

肿瘤坏死因子相关凋亡诱导配体对胶质瘤细胞的诱导凋亡作用

肿瘤坏死因子相关凋亡诱导配体（tumor necrosisfactor related apoptosis-inducingligand,TRAIL）可以诱导多种肿瘤细胞发生凋亡,并且对正常细胞没有明显的毒性作用,因此在美国已进入临床Ⅱ期药物开发阶段。     

脑缺血后细胞凋亡与凋亡相关基因

细胞凋亡是一种生理性的细胞死亡,但近年来的研究发现高温、激素、化学物质、营养因子缺乏等均可引起细胞凋亡。脑细胞凋亡不仅仅伴随脑的发育亦见于病理过程,如脑缺血、缺氧,脑损伤。脑缺血后细胞凋亡是近年来的研究热点,大量研究表明细胞凋亡是由相关的遗传基因控制的。细胞凋亡信号传递途径是由特殊的死亡信号激活半胱氨酸天冬氨酸蛋白酶系统来诱导细胞凋亡。当然,对凋亡在疾病发病机制中的作用及应用凋亡理论和实践来防治疾病方面也取得了较明显的进展。文章介绍了细胞凋亡的概述,脑缺血后细胞凋亡和相关基因的研究进展。     

维生素K2诱导K562细胞凋亡的机制研究

目的 对维生素K2(Vit K2)诱导慢性粒细胞白血病(CML)急变细胞株K562细胞凋亡进行检测.方法 取对数生长期细胞(1×108/L),对照组不加药,实验组分别加入不同浓度(5、10、20和40μmol/L)Vit K2后24、48、72和96 h收集细胞,采用透射电镜技术、流式细胞术、RT-PCR以及化学发光比色法等多参数分析细胞凋亡及其机制.结果 Vit K2作用K562细胞72 h后,电镜下可见典型的凋亡细胞的形态改变;流式细胞仪分析结果显示随着Vit K2浓度的增加和作用时间的延长,凋亡率逐渐增高并呈明显的浓度、时间依赖性;S期细胞逐渐减少,G0/G1期细胞逐渐增多,细胞被阻滞在G0/G1期.随着Vit K2浓度的增高抗凋亡基因bcl-2、survivin表达明显下调,而促凋亡基因bax表达无明显差异,半胱氨酸天冬氨酸蛋白酶3(caspase-3)的活性逐渐增强.结论 Vit K2可能是通过激活caspase-3途径诱导K562细胞发生凋亡,同时抗凋亡基因survivin、bcl-2也参与了凋亡调控过程.     

肿瘤坏死因子相关凋亡诱导配体联合三氧化二砷对急性髓系白血病细胞凋亡的影响

我们观察了肿瘤坏死因子相关凋亡诱导配体(TRAIL)和三氧化二砷(As2O3)分别和联合对急性髓系白血病(AML)细胞凋亡的影响，旨在探讨TRAIL与As2O3联合应用治疗白血病的临床价值。     

肿瘤坏死因子相关凋亡诱导配体对类风湿关节炎滑膜细胞的影响

目的探讨重组人肿瘤坏死因子相关凋亡诱导配体(hTRAIL)对类风湿关节炎滑膜成纤维细胞(RASF)的作用。方法原代培养RASF,不同浓度hTRAIL(0、100、200、400、800、1000 ng/ml)干预4 h,检测hTRAIL对RASF的增殖和凋亡及其相应受体DR5 mRNA和蛋白表达的影响。结果 100、200、400、800、1000 ng/ml hTRAIL干预可抑制RASF增殖;可上调DR5 mRNA(0.801±0.036、0.947±0.032、0.969±0.048、1.052±0.031、0.992±0.072)和蛋白(0.650±0.118、0.803±0.142、0.968±0.130、0.945±0.136、0.864±0.160)表达(F=78.478,F=18.627,均P<0.01);高浓度hTRAIL(400、800、1000 ng/ml)可诱导RASF发生凋亡[(5.82±0.43)%、(7.32±0.49)%、(8.78±0.81)%](F=304.573,P<0.01)。结论 hTRAIL可诱导类风湿关节炎滑膜成纤维细胞凋亡。     

The dietary flavonoid apigenin sensitizes malignant tumor cells to tumor necrosis factor-related apoptosis-inducing ligand

Dietary flavonoid apigenin is expected to have preventive and therapeutic potential against malignant tumors. In this report, we show for the first time that apigenin markedly induces the expression of death receptor 5 (DR5) and synergistically acts with exogenous soluble recombinant human tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) to induce apoptosis in malignant tumor cells. TRAIL is a promising candidate for cancer therapeutics due to its ability to selectively induce apoptosis in cancer cells. The combined use of apigenin and TRAIL at suboptimal concentrations induces Bcl-2-interacting domain cleavage and the activation of caspases-8, -10, -9, and -3. Furthermore, human recombinant DR5/Fc chimera protein and caspase inhibitors dramatically inhibit apoptosis induced by the combination of apigenin and TRAIL. On the other hand, apigenin-mediated induction of DR5 expression is not observed in normal human peripheral blood mononuclear cells. Moreover, apigenin does not sensitize normal human peripheral blood mononuclear cells to TRAIL-induced apoptosis. These results suggest that this combined treatment with apigenin and TRAIL might be promising as a new therapy against malignant tumors.     

Mifepristone pretreatment overcomes resistance of prostate cancer cells to tumor necrosis factor alpha-related apoptosis-inducing ligand (TRAIL)

Examination of the effects of TRAIL (tumor necrosis factor alpha-related apoptosis-inducing ligand) showed higher apoptotic response in LNCaP C4-2, whereas LNCaP were resistant. However, treatment of LNCaP with Mifepristone, an antiprogestin, before TRAIL induced significant apoptosis, similar to the levels observed in LNCaP C4-2. Experiments to determine the reasons for altered response of the cell lines showed no significant differences in death/decoy receptors and caspase-8 activity. However, treatment induced increased truncation of Bid and activation of caspases -9, -7, and -3 in LNCaP C4-2. Time course experiments showed that caspase-8 was activated before the involvement of mitochondrial pathway, and caspase-9 was responsible for activation of caspases -7 and -3. Use of specific caspase inhibitors demonstrated the presence of a short-loop feedback activation of Bid. Published reports suggested that increased phosphorylation of Akt was responsible for resistance of LNCaP to TRAIL. However, no significant differences were noticed in the levels of phosphorylated Akt in TRAIL-resistant LNCaP and TRAIL-sensitive LNCaP C4-2. On the basis of our results, it is suggested that the differences in response of the two cell lines to TRAIL is at the mitochondrial level.     

肿瘤坏死因子相关凋亡诱导配体对骨髓基质细胞的毒性作用

背景:已证实肿瘤坏死因子相关凋亡诱导配体(tumor necrosis factor-related apoptosis-inducing ligand,TRAIL)能选择性诱导白血病细胞凋亡,并且不影响正常造血干/祖细胞的功能。但TRAIL对作为造血微环境核心的骨髓基质细胞的毒性作用如何,据作者查新检索目前尚未见系统报道。目的:通过观察TRAIL对骨髓基质细胞的凋亡诱导效应及其造血支持功能的影响,继而评价TRAIL对骨髓基质细胞的毒性作用。设计、时间及地点:细胞学体外对照观察,于2006-03/10在解放军沈阳军区总医院中心实验室完成。材料:血常规、骨髓涂片细胞检查正常的骨髓标本11份,取自解放军沈阳军区总医院血液科。化疗药物柔红霉素为浙江海正药业股份有限公司产品,国药准字H33020925。方法:Percoll 贴壁法体外分离培养骨髓基质细胞,达80%融合时胰蛋白酶消化扩增,取处于对数生长期的细胞,分为4组,空白对照组不进行任何干预,柔红霉素组加入0.5μmol/L柔红霉素作用24h,TRAIL组加入200μg/L TRAIL作用18h,联合组加入0.5μmoL/L柔红霉素作用6h后再以200μg/L TRAIL作用18h。取第2代骨髓基质细胞,60Co射线照射消除内源性造血集落,接种后去除悬浮细胞,TRAIL组以200μg/L TRAIL作用基质细胞层18h,按1×105/孔将骨髓单个核细胞接种于基质细胞层,扩增5d后加入甲基纤维素培养体系,于37℃、体积分数为0.05的CO2饱和湿度条件下培养10d。主要观察指标:荧光显微镜观察诱骗受体在骨髓基质细胞的表达及定位,流式细胞仪检测柔红霉素对骨髓基质细胞诱骗受体表达的影响,AnnexinⅤ/PI标记TRAIL对骨髓基质细胞的凋亡诱导作用及对其造血支持功能的影响。结果:诱骗受体DcR1和DcR2在骨髓基质细胞中均有表达,主要定位于胞膜及胞浆。0.5μmol/L柔红霉素作用24h后,基本不影响诱骗受体DcR1和DcR2的表达水平。与空白对照组细胞凋亡率比较,TRAIL组无明显变化(t=0.973,P>0.05);柔红霉素组、联合组均显著升高(t=5.141,P=0.001;t=4.187,P=0.002),此两组间比较差异无显著性意义(t=1.222,P>0.05)。与空白对照组比较,TRAIL组骨髓单个核细胞数、粒-巨噬集落形成单位均无明显变化(t=1.313,P>0.05;t=1.172,P>0.05)结论:TRAIL的诱骗受体DcR1及DcR2在骨髓基质细胞均有表达,使骨髓基质细胞免于TRAIL的凋亡诱导效应,且TRAIL不增强柔红霉素对骨髓基质细胞的细胞毒性作用。     

肿瘤坏死因子α对人肺腺癌细胞耐顺铂的影响

目的研究肿瘤坏死因子OL（TNF-α）对人肺腺癌细胞系A549／顺铂（DDP）耐DDP的逆转作用,探讨其与肺耐药相关蛋白（LRP）表达之间的关系。方法以MTT法检0n,0TNF-α与顺铂联用对A549／DDP细胞的细胞毒性作用,以免疫细胞化学方法检测A549／DDP细胞LRP的表达情况。结果250、1000U／mlTNF-α可使顺铂对A549／DDP细胞的IC50从7．12ng／L分别降至5．02、4．41ng／L,能够逆转A549／DDP对顺铂的耐药,逆转倍数分别为1．42、1．62。A549／DDP细胞LRP呈强阳性表达,250、1000U／mlTN-α与顺铂联用可以下调LRP表达,LRP阳性表达率分别为（60．14-4-6．54）％、（57．234-5．98）％,同无药组和顺铂组LRP表达率（79．63±4．78）％、（75．97±5．32）％比较,差异具有统计学意义（P均〈0．01）。结论TNF-α能够逆转A549／DDP对顺铂的耐药,其机制可能与下调LRP表达有关。     

肝细胞生长因子在肿瘤坏死因子相关凋亡诱导配体作用下对原代肝星状细胞增殖及凋亡的影响

背景:活化的肝星状细胞是肝纤维化的关键因素,研究表明肝细胞生长因子能促进星状细胞凋亡,其具体机制可能与增强肿瘤坏死因子相关凋亡诱导配体(TRAIL)诱导星状细胞凋亡有关。目的:观察肿瘤坏死因子相关凋亡诱导配体作用下,肝细胞生长因子对原代肝星状细胞增殖、凋亡的影响并初步探讨其可能机制。方法:将SD大鼠原代肝星状细胞复苏、传代,细胞增殖明显时用于实验。实验分为4组:空白对照组为单纯肝星状细胞培养;肝细胞生长因子组:将100μg/L肝细胞生长因子作用于肝星状细胞;TRAIL组:将2mg/L的TRAIL作用于肝星状细胞;肝细胞生长因子+TRAIL组:将肝细胞生长因子预先刺激肝星状细胞24h,再加入2mg/LTRAIL。结果与结论:MTT检测显示肝细胞生长因子及TRAIL分别在50～200μg/L、0.5～1.5mg/L各浓度下对肝星状细胞增殖抑制率无影响,TRAIL在2mg/L作用下对肝星状细胞有抑制作用。流式细胞仪检测肝细胞生长因子+TRAIL组的中晚期凋亡率明显高于空白对照组及肝细胞生长因子组(P<0.05);肝细胞生长因子+TRAIL组DR5荧光强度明显高于其他3组(P<0.01)。提示在TRAIL作用下,肝细胞生长因子能促进肝星状细胞的凋亡、抑制其增殖。可能与肝细胞生长因子上调活化肝星状细胞表面DR5表达有关。     

Antitumor activity of human CD34+ cells expressing membrane-bound tumor necrosis factor-related apoptosis-inducing ligand

Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) selectively induces apoptosis in a variety of transformed cells while sparing normal cells. To enhance the therapeutic index of soluble (s)TRAIL, we used CD34+ cells transduced with a replication-deficient adenovirus encoding the human TRAIL gene (CD34-TRAIL+) for the systemic delivery of membrane-bound (m)TRAIL to lymphoid tumors. CD34-TRAIL+ cells were evaluated for their activity in vitro and in vivo in nonobese diabetic/severe combined immunodeficient (NOD/SCID) mice xenografted with sTRAIL-sensitive and -resistant tumors. In vitro, coculturing CD34-TRAIL+ cells with sTRAIL-sensitive or -resistant lymphoma cell lines induced significant levels of caspase-dependent tumor cell death. In vivo, CD34-TRAIL+ cells significantly increased the survival of NOD/SCID mice bearing sTRAIL-sensitive or -resistant lymphoid tumors at an early or advanced stage of disease. No obvious toxicity was observed on administration of CD34-TRAIL+ cells. Histological analysis revealed high-level expression of the agonistic receptor TRAIL-R2 by tumor endothelial cells, and efficient tumor homing of transduced cells. Injection of CD34-TRAIL+ cells resulted in extensive damage of tumor vasculature followed by hemorrhagic necrosis exhibiting a perivascular distribution. These results show that CD34-TRAIL+ cells might be an efficient vehicle for mTRAIL delivery to tumors, where they exert a potent antitumor effect possibly mediated by both direct tumor cell killing and indirect vascular-disrupting mechanisms.     

Human dendritic cells mediate cellular apoptosis via tumor necrosis factor-related apoptosis-inducing ligand (TRAIL).

TRAIL (TNF-related apoptosis-inducing ligand) is a member of the TNF family that induces apoptosis in a variety of cancer cells. In this study, we demonstrate that human CD11c(+) blood dendritic cells (DCs) express TRAIL after stimulation with either interferon (IFN)-gamma or -alpha and acquire the ability to kill TRAIL-sensitive tumor cell targets but not TRAIL-resistant tumor cells or normal cell types. The DC-mediated apoptosis was TRAIL specific, as soluble TRAIL receptor blocked target cell death. Moreover, IFN-stimulated interleukin (IL)-3 receptor (R)alpha(+) blood precursor (pre-)DCs displayed minimal cytotoxicity toward the same target cells, demonstrating a clear functional difference between the CD11c(+) DC and IL-3Ralpha(+) pre-DC subsets. These results indicate that TRAIL may serve as an innate effector molecule on CD11c(+) DCs for the elimination of spontaneously arising tumor cells and suggest a means by which TRAIL-expressing DCs may regulate or eliminate T cells responding to antigen presented by the DCs.     

携带肿瘤坏死因子相关细胞凋亡诱导配体重组腺相关病毒的构建及鉴定

目的:构建一种携带肿瘤坏死因子相关细胞凋亡诱导配体(tumor necrosis factor related apoptosis inducing ligand,TRAIL)基因的重组腺相关病毒(recombined adeo-associated virus,rAAV)载体。方法:实验于2005-09/2006-04在中山大学附属第一医院普通外科实验室完成。首先构建携带可溶性肿瘤坏死因子相关细胞凋亡诱导配体基因的穿梭质粒pAAV-sTRAIL,利用磷酸钙共沉淀法将穿梭质粒共转染入HEK293细胞中,采用细胞内质粒DNA同源重组法构建重组腺相关病毒rAAV-sTRAIL。以噬斑分析法筛选单克隆重组腺相关病毒;聚合酶链反应法鉴定阳性重组腺相关病毒;氯化铯密度梯度离心法纯化病毒;紫外分光光度仪测定病毒颗粒数及纯度,噬斑分析法测定病毒感染滴度;Western blot检测rAAV-sTRAIL在293细胞中的表达情况。结果:成功构建了重组腺相关病毒载体rAAV-sTRAIL,制备的病毒纯度好、滴度高,且在293转导细胞中能有效表达目的基因sTRAIL。结论:构建的重组腺相关病毒载体rAAV-sTRAIL,为组织工程相关细胞转基因构建及临床应用提供先进的载体系统。     

Nonhematopoietic cells selected for resistance to tumor necrosis factor produce tumor necrosis factor

TNF-resistant lines of L cells can be derived from TNF-sensitive populations by repeated exposure to TNF, and these resistant L cells, in contrast to sensitive L cells and other types of cells, lack demonstrable cell surface receptors for TNF. We have now found that TNF-resistant L cells produce a factor that is cytotoxic for L cells and has the following distinguishing characteristics of mouse TNF: it is a protein of 43 kD, composed of 16 kD subunits, that competes with TNF for receptor binding, induces hemorrhagic necrosis of the TNF-sensitive mouse sarcoma Meth A, has synergistic cytotoxic action with interferon, and its activity is neutralized by antibody to TNF. The two conclusions of this study are that cells selected for TNF resistance spontaneously produce a molecule resembling macrophage TNF, and that cells of nonhematopoietic origin are capable of producing TNF.