加热对恶性胶质瘤细胞生物学特性的影响

目的：为探索加热治疗胶质瘤的机理，本文对加热引起恶性胶质瘤细胞的多重生物学效应做了研究。方法：用Ｍ．Ｔ．Ｔ．法测定胶质瘤细胞存活率；用Ｋｉ－６７抗增殖细胞核抗原单克隆抗体，通过免疫组织化学ＡＢＣ染色分析胶质瘤细胞的增殖活性；用划痕染料示踪技术观察胶质瘤细胞的细胞间隙连接通讯。结果：加热能抑制胶质瘤的存活率和增殖活性，并能促进细胞间隙连接通讯的增强。在４１℃～４５℃温度范围内，随着温度的升高，这些作用越明显。结论：恶性胶质瘤对加热有良好的敏感性，为加热治疗胶质瘤提供了有力的依据。     

人脑肿瘤转化生长因子β_2基因表达与其增殖活性相关性研究

目的探讨人脑肿瘤转化生长因子β２（ＴＧＦβ２）基因表达与其恶性进展及增殖活性的相关性。方法采用Ｎｏｒｔｈｅｒｎ杂交、免疫组化和Ｗｅｓｔｅｒｎ杂交法检测了５０例胶质瘤、３０例脑膜瘤、３个恶性胶质瘤体外细胞系和８例正常脑组织ＴＧＦβ２的表达水平。用Ｋｉ６７标记指数（Ｋｉ６７ＬＩ）检测肿瘤增殖活性。结果正常脑组织无ＴＧＦβ２表达，而脑肿瘤均表达２８ｋｂ和／或５１ｋｂＴＧＦβ２ｍＲＮＡ片段和约２５ｋｄ及３０ｋｄ的蛋白；其在胶质瘤中的表达显著高于脑膜瘤，而低恶度胶质瘤（Ⅰ、Ⅱ）、Ⅲ、Ⅳ级胶质瘤、体外细胞系四者表达水平也有显著性差异；ＴＧＦβ２表达水平与Ｋｉ６７ＬＩ呈正相关。结论ＴＧＦβ２表达水平有随肿瘤增殖活性增高而升高的趋势，提示其可能为胶质瘤恶性进展的重要原因之一。且有可能作为基因治疗的候选基因     

内抑制素对人脑胶质瘤细胞增殖的实验研究

目的观察内抑制素对人脑胶质瘤细胞增殖的影响。方法①细胞培养：体外培养人脑胶质瘤细胞并进行光镜观察；②抑制因子试验：设立对照组与内抑制素实验组，采用四甲基偶氮唑蓝（MTT）法来判定该抑制因子对人脑胶质瘤细胞有无抑制作用；③细胞内游离Ca2＋浓度测定：将特异性ca2＋荧光指示剂-Fluo-3用来负载人脑胶质瘤细胞，应用激光共聚焦显微镜检测细胞内游离钙的浓度。结果对照组光密度（OD）值明显高于各实验组（P〈0．05）；内抑制素能明显增加细胞内游离Ca2＋的浓度，并且随药物浓度的增加而增加。结论内抑制素能够抑制人脑胶质瘤细胞的增殖且呈剂量依赖性，同时也能够增加胶质瘤细胞内游离ca2＋的浓度。     

反转录病毒介导的HSV-tk基因治疗大鼠脑胶质瘤的实验研究

目的：进行Ｃ６大鼠脑胶质瘤的基因治疗实验研究。方法：采用反转录病毒介导的基因转移和ＡＣＶ体内治疗方法进行研究。结果：构建了带有ＨＳＶ－ｔｋ基因的反转录病毒载体ＧＩＮａＴＫ，应用脂质体转移方法将ＧＩＮａＴＫ导入反转录病毒包装细胞ＰＡ３１７，成为产病毒细胞ＰＡ３１７ＴＫ，用带有ＨＳＶ－ｔｋ基因的复制缺陷型反转录病毒感染Ｃ６细胞，命名为Ｃ６ＴＫ细胞，对ＧＣＶ和ＡＣＶ的敏感性分别高于亲本４５０倍和１０倍；成功地建立了大鼠脑胶质瘤模型，并证实转染细胞Ｃ６ＴＫ的成瘤效应未改变，存活期约为１５天；而经ＡＣＶ治疗后，含有Ｃ６ＴＫ细胞的肿瘤生长明显被抑制，大鼠生存期延长为５７．８±８．０７天，尤其是采用ＰＡ３１７ＴＫ细胞混和治疗组和原位治疗组，肿瘤基本消失，大鼠生存期显著延长，混和治疗组存活１２０天以上，原位治疗组存活至７１．４±３６．１天。ｔ检验，Ｐ值均小于０．００１。结论：ＨＳＶ－ｔｋ／ＡＣＶ系统基因治疗大鼠脑胶质瘤疗效显著。     

人脑胶质瘤免疫抑制因子研究

实验表明人脑胶质瘤原代培养细胞及４个人脑恶性胶质瘤体外细胞系细胞培养上清液（Ｓｕ－ｐｅｒｎａｔａｎｔ，ＳＮ）显著抑制植物血凝素ＰＨＡ－Ｐ刺激的正常人或胶质瘤患者自体和异体外周血淋巴细胞增殖。我们发现用抗转化生长因子－β_２（ＴＧＦ－β_２）单克隆抗体可显著降低胶质瘤ＳＮ的免疫抑制活性。４个人脑胶质瘤体外细胞系应用抗ＴＧＦ－β_２单抗免疫组化染色呈阳性反应，３例正常脑组织呈阴性反应。Ｎｏｒｔｈｅｒｎ杂交实验表明上述４个人脑胶质瘤体外细胞系均表达６ｋｂ的ＴＧＦ－β_２ｍＲＮＡ，而４例人胎脑则无表达。这些结果提示人脑胶质瘤细胞可以自体分泌免疫抑制因子抑制患者的免疫功能，而这抑制因子的主要成份是ＴＧＦ－β_２。     

NADPH氧化酶调节U251胶质瘤细胞的生长和凋亡

目的 研究NADPH氧化酶(NOX)对U251胶质瘤细胞存活、增殖和凋亡的影响.方法 RT-PCR检测U251胶质瘤细胞系NOX基因的表达.分别使用5、15、25 μmol/LNOX抑制剂DPI及10 mmol/L抗氧化剂Tiron处理U251细胞,24h后alamarBlue法检测U251细胞的增殖,流式细胞术检测细胞内活性氧的产生和U251细胞的凋亡情况,并与正常对照组(不做任何处理的1的U251细胞进行比较.结果 U251细胞系中明显表达NOX4 mRNA.各浓度DPI及10 mmol/Ltiron均能抑制U251胶质瘤细胞的生长,诱导U251细胞凋亡.与正常对照组比较,各浓度DPI处理组的U251细胞内的活性氧簇(ROS)均明显减少,差异有统计学意义(P<0.05); 结论 NOX4可能是胶质瘤细胞内ROS生产的主要来源.NOX4可能通过增加细胞内ROS水平并作用于其下游调节分子,对胶质瘤细胞的生长、存活和凋亡起着重要的调节作用.     

逆转录病毒载体介导中国单疱病毒TK基因转导脑胶质瘤细胞

目的：研究载中国单疱病毒胸苷激酶基因逆转录病毒重组体（ＲＶ－ＨＳＶ－ＴＫｃ）和羟甲基无环鸟苷（ＧＣＶ）体外转染和杀伤脑胶质瘤效果，探索应用该系统基因治疗脑胶质瘤。方法：ＲＶ－ＨＳＶ－ＴＫｃ重组体病毒感染胶质瘤细胞，Ｇ４１８筛选转染阳性胶质瘤细胞克隆。Ｎｏｒｔｈｅｒｎ杂交检测抗Ｇ４１８胶质瘤细胞中的ＴＫｃ基因表达。药物敏感实验观察ＴＫｃ胶质瘤细胞对ＧＣＶ的毒性反应。结果：１．０ｍｇ／ｍｌＧ４１８筛选１０～１４天获抗性胶质瘤细胞克隆；Ｎｏｒｔｈｅｒｎ杂交显示抗Ｇ４１８细胞ＴＫｃ基因明显表达；ＴＫｃ胶质瘤细胞对ＧＣＶ高度敏感，其ＥＤ５０为：Ｃ６ＴＫｃ０．０２μｇ／ｍｌ，Ｕ２５１ＴＫｃ０．００６μｇ／ｍｌ，Ｕ８７ＴＫｃ０．００４μｇ／ｍｌ，ＴＫｃ胶质瘤细胞对ＧＣＶ的敏感性是非转基因胶质瘤细胞的５００倍以上。结论：载中国ＴＫｃ基因逆转录病毒重组体可有效转染脑胶质瘤细胞并使其对ＧＣＶ高度敏感，该系统可望用于脑胶质瘤的基因治疗。     

脑肿瘤局部浸润单个核细胞亚群及其免疫功能的原位免疫组织化学观察

应用免疫组化方法对５１例脑肿瘤局部浸润的单个核细胞进行观察。发现主要是辅助／诱导（ＣＤ４）Ｔ细胞、抑制／细胞毒（ＣＤ８）Ｔ细胞和单核巨噬细胞参与肿瘤免疫。仅９例及７例分别有少许Ｂ细胞与ＮＫ细胞。ＣＤ４、ＣＤ８Ｔ细胞的密度与单核巨噬细胞密度呈正相关，与肿瘤体积呈负相关。各病理类型脑肿瘤中ＣＤ４亚群均受抑制，胶质瘤还选择性抑制ＣＤ８亚群。脑肿瘤局部免疫状态不受肿瘤发生部位和浸润Ｔ细胞标记增殖期淋巴细胞（Ｋｉ－６７）抗原、标记活化Ｔ细胞（ＨＬＡ－Ｄｒ）及标记白细胞介素－２－受体（ＣＤ２５）表达水平的影响。     

重组白细胞介素2及T细胞亚群对重症肌无力患者AChR—ab的影响

对１９例全身型重症肌无力（ＭＧ）患者周围血Ｂ细胞分化能力进行了研究，并观察重组白细胞介素２（ｒＩＬ－２）及Ｔ细胞亚群对其影响。方法分离外周血纯Ｂ细胞，体外与电鳗乙酰胆碱受体（ＡＣｈＲ）一起培养，并分别加入去ＣＤ４＋Ｔ细胞，去ＣＤ８＋Ｔ细胞及ｒＩＬ－２。用酶联免疫－生物素法检测其上清液的乙酰胆碱受体抗体（ＡＣｈＲ－ａｂ）。同时以１０例健康人为对照组。结果去ＣＤ８＋Ｔ细胞后ＡＣｈＲ－ａｂ的产生无明显增加；去ＣＤ４＋Ｔ细胞加入ｒＩＬ－２后ＡＣｈＲ－ａｂ产生减少。结论提示ｒＩＬ－２对ＭＧ患者有潜在治疗价值。     

TNF—α对大鼠C6胶质瘤细胞增殖和Bcl—2蛋白表达的影响

目的 研究ＴＮＦ－α对胶质瘤细胞的抑制作用及其对Ｂｃｌ－２蛋白表达的影响。方法 应用细胞计数法和ＭＴＴ法研究经ＴＮＦ－α处理的大鼠Ｃ６胶质瘤细胞的生长和增殖活性,研究了细胞的形态学变化及及用免疫细胞化学方法检测ＰＣＮＡ（增殖细胞核抗原）和Ｂｃｌ－２蛋白表达。结果 ＴＮＦ－α对体外培养Ｃ６胶质瘤细胞生长和增殖具有呈时间和剂量依赖性的抑制作用,下调ＰＣＮＡ的表达,并诱导细胞凋亡,但对抑调亡蛋白Ｂｃｌ－     

As2O3对不同p53表型的人胶质瘤细胞系细胞周期蛋白B1、D1表达的影响

目的研究三氧化二砷(As2O3)对两种不同p53表型的人胶质瘤细胞系(U87MG和T98G)细胞周期蛋白B1、D1表达及细胞周期的影响。方法应用激光扫描细胞计数分析仪(LSC),共聚焦显微镜以及Western印迹分析等方法检测As2O3对细胞周期蛋白B1、D1和p53及细胞周期的作用。结果As2O3能使两个胶质瘤细胞系的p53蛋白水平升高,细胞周期蛋白B1表达降低及G2/M期俘获,但仅U87MG细胞的细胞周期蛋白D1表达下降。As2O3还能诱导U87MG细胞凋亡。结论体外低浓度的As2O3能有效地抑制U87MG和T98G细胞增殖,提示As2O3有希望用于神经胶质瘤患者的治疗。     

Alterations in cytokinetics and heat shock protein (70 kDa) expression of glial cell by hyperthermia]

Expression of major heat shock and stress-induced protein, HSP70, is known to be under complex regulation in tumor cells. In this study, we investigated the alternations of cytokinetics and HSP70 expression by hyperthermia in the in vitro experimental systems, using two rat glioma cell lines, two human glioblastoma cell lines and rat glioblast cells. For hyperthermal treatment the flasks were placed in water baths warmed up at 41 -45 degrees C for 15 min. To determine the effect of hyperthermia on the cell cycle progression, the changes in the DNA distribution of the cell population were studied by flow cytometry (FCM). The levels of HSP70 protein were determined by immunoblot analysis. The relationship between cell cycle and HSP70 expression was investigated by FCM using PI and FITC-labelled HSP70 double staining technique. These results were as follows: 1) Compared with the control, hyperthermic treatment at 42 degrees C or 44 degrees C caused both 354A and T98G cells to accumulate in S phase 18 hours after treatment and G2/M phase after 6-18 hours. 2) Hyperthermic treatment at 42 degrees C caused C6 cells to accumulate in S phase 6 hours after treatment, whereas heat treatment at 44 degrees C caused C6 cells to accumulate in S phase after 18 hours and G2/M phase after 6 hours. 3) A172 cells were accumulated only in G2/M phase by hyperthermia. 4) Glioblast cells did not show the alterations of cytokinetics by heat treatment remarkably. 5) HSP70 protein synthesis were enhanced under hyperthermic conditions in all type of cells, whether primary glioblast or permanent glioma cell lines.(ABSTRACT TRUNCATED AT 250 WORDS)     

连接蛋白/缝隙连接细胞间通讯对大鼠肝卵圆细胞增殖调控作用

背景：缝隙连接蛋白介导的缝隙连接细胞间通讯(gap junction intercellular communication,GJIC)是细胞间最重要的信息交流形式。 目的：验证CX/GJIC对卵圆细胞的增殖调控作用。 方法：Wistar大鼠分为4组。对照组正常饮食;2-AAF/PH组按改良Solt-Farber法建立卵圆细胞增殖动物模型;苯巴比妥组予以苯巴比妥饮水7 d,第8天按2-AAF/PH组建模,苯巴比妥饮水持续至实验结束;三七总皂苷组按2-AAF/PH组建模时予以三七总皂苷25 mg/(kg•d)腹腔内注射,并持续实验结束。 结果与结论：造模后肝脏连接蛋白呈时空特异性表达,先下调后逐渐恢复,连接蛋白43表达于卵圆细胞,先升高后逐渐恢复;采用苯巴比妥改变大鼠2-AAF/PH模型肝脏的连接蛋白32、连接蛋白43时空表达模式后,可下调肝脏的GJIC,减少卵圆细胞与偶联细胞间GJIC,解除卵圆细胞生长抑制,促进卵圆细胞的增殖;三七总皂苷可以增加大鼠2-AAF/PH模型肝脏的连接蛋白32表达、滞后连接蛋白43的表达,增加卵圆细胞与偶联细胞间GJIC,使卵圆细胞增殖峰低、滞后、持续时间长;通过下调大鼠2-AAF/PH模型肝脏的GJIC,可使卵圆细胞增殖早、增殖水平高;上调GJIC使卵圆细胞增殖峰低、滞后、持续时间长,CX/GJIC可以调节体内卵圆细胞的增殖、分化过程。     

Nerve growth factor effects on pyridine nucleotides after oxidant injury of rat pheochromocytoma cells

Neurotrophic factors regulate neuronal survival and neurite growth in development and following injury. Oxidative stress produced in neurons as a consequence of primary injury, or during reperfusion following ischemia, may contribute to cell death. Here, the effects of nerve growth factor (NGF) on the response to H2O2 injury were examined in the PC12 rat pheochromocytoma cell line. Specifically, the effect of NGF on cell viability after H2O2 injury was measured. Pretreatment with NGF enhanced survival after H2O2 treatment, as measured by Trypan blue dye exclusion, radiolabeled amino acid incorporation, tetrazolium salt reduction, or cytoplasmic enzyme release. One early event associated with H2O2 treatment was a rapid decrease in NAD+. Although initial decreases in NAD+ levels were similar in control and NGF-treated cells, the latter recovered more rapidly and extensively. The decline in total NAD observed after NGF treatment was almost equal in magnitude to the measured increase in NADP. Inhibition of poly(ADP-ribose) polymerase also enhanced viability following H2O2 injury. Treatment with both NGF and an inhibitor of this enzyme resulted in a greater reduction of H2O2 toxicity than was observed with either agent alone. These data suggest that NGF protection is multifactorial and that a significant component of the NGF effect is due to its regulatory role in the metabolism of pyridine nucleotides.     

丙戊酸对胶质瘤细胞株T98-G体外作用实验研究

目的 研究抗癫痫常用药物丙戊酸(2-propylpentanoic acid,VPA)临床治疗浓度对人脑胶质瘤细胞株T98-G增殖抑制、细胞周期及组蛋白乙酰化的影响,并探讨其意义.方法 四甲基偶氮唑蓝(MTT)比色法检测VPA对胶质瘤细胞株T98-G的细胞毒性作用;流式细胞术检测其对细胞周期动力学及其对细胞凋亡的影响;Western blot法检测胶质瘤细胞株在VPA处理后乙酰化组氨酸H3(Acetyl-Histone H3)、乙酰化组氨酸H4(Acetyl-Histone H4)的表达量变化.结果 丙戊酸对胶质瘤细胞株T98-G具有抑制增殖作用,随着药物浓度的增加,抑制作用增强;临床常用浓度(1.0 mmol/L)VPA能够对细胞周期动力学产生影响,S期细胞减少,而G1期、G2/M期细胞增加;Aceyl-HistoneH3、Aceyl-HistoneH4蛋白表达量明显上调.结论 VPA能够抑制胶质瘤细胞生长,引起细胞周期阻滞,其作用可能与其抑制组蛋白去乙酰化酶活性有关.     

IL-4基因修饰抗人脑胶质瘤效应的体外研究

目的 探讨人ＩＬ－４基因修饰对人脑胶质瘤的抑瘤效应及可能机制。方法 以逆转录病毒载体将人ＩＬ－４基因导入人脑胶质瘤细胞系ＳＨＧ４４细胞，用３Ｈ掺入法及流式细胞仪分析ＩＬ－４基因转染对人脑胶质瘤细胞增殖及细胞周期的影响；＾３Ｈ掺入法、＾５１Ｃｒ释放法检测ＩＬ－４基因修饰瘤苗对健康人外周血单个核细胞（ＰＢＭＣ）增殖、细胞毒性Ｔ细胞（ＣＴＬ）反应的影响。结果 与野生型瘤细胞比较，ＩＬ－４基因修饰瘤细胞增     

Growth regulation of astrocytes and C6 cells by TGFbeta1: correlation with gap junctions

Transforming growth factor (TGF) beta1 enhanced in vitro [3H]thymidine incorporation into C6 cells and reduced that of astrocytes in the presence of a high serum concentration. It concomitantly raised the gap junction intercellular communication (GJIC) in normal astrocytes but reduced the coupling of C6 cells, and respectively increased or decreased the proportion of P2-phosphorylated connexin (Cx) 43 isoform in these cells. Finally, octanol, which inhibited GJIC in both cell types, increased the thymidine incorporation in C6 cells, but neither altered the proliferation of astrocytes nor their response to TGFbeta1. These data indicate that an inhibition of gap junction intercellular communication, due to an altered phosphorylation of connexin 43, may contribute to the proliferative response of C6 glioblastoma cells to TGFbeta1.     

Aspirin and indomethacin exhibit antiproliferative effects and induce apoptosis in T98G human glioblastoma cells

The in vitro antiproliferative and apoptosis inducing properties of the nonsteroidal anti-inflammatory drugs (NSAIDs) like acetyl salicylic acid (aspirin) and indomethacin were investigated in T98G human glioblastoma cells to explore their potential role in the chemoprevention of human glioma. The biological effects induced by aspirin and indomethacin on T98G cells, in which the expression of cyclooxygenase-1 (COX-1) and cyclooxygenase-2 (COX-2) were confirmed by RT-PCR and immunostaining, were investigated by studying cell proliferation and apoptosis assays. The antiproliferative effects occurred in a dose- and time-dependent manner on T98G cells by the treatment with 0.1 -2 mM aspirin and 25-100 microM indomethacin. Moreover, aspirin displayed the greatest growth inhibition within 24 h. Approximately 90% growth inhibition occurred following treatment either with 2 mM aspirin or 100 microM indomethacin by 72 h and induction of apoptosis was confirmed by DNA laddering and TUNEL assay. Our in vitro findings indicate that aspirin and indomethacin have an antiproliferative effect on T98G human glioblastoma cells at toxic concentrations.     

Impact of vegf on astrocytes: analysis of gap junctional intercellular communication, proliferation, and motility

The purpose of the present study was to investigate the effects of vascular endothelial growth factor (VEGF) on gap junctional intercellular communication (GJIC), cell proliferation, and cell dynamics in primary astrocytes. VEGF is known as a dimeric polypeptide that potentially binds to two receptors, VEGFR-1 and VEGFR-2, however many effects are mediated by VEGFR-2, for example, actin polymerization, forced cell migration, angiogenesis, and cell proliferation. Recently it has been shown that in case of hypoxia, ischemia or injury VEGF is upregulated to stimulate angiogenesis and cell proliferation. Besides this, VEGF reveals a potent therapeutical target for averting tumor vascularization, emerging in bevacizumab, the first humanized anti-VEGF-A antibody for treating recurrent Glioblastoma multiforme. To expand our knowledge about VEGF effects in glial cells, we cultivated rat astrocytes in medium containing VEGF for 1 and 2 days. To investigate the effects of VEGF on GJIC, we microinjected neurobiotin into a single cell and monitored dye-spreading into adjacent cells. These experiments showed that VEGF significantly enhances astrocytic GJIC compared with controls. Cell proliferation measured by BrdU-labeling also revealed a significant increase of astrocytic mitose rates subsequent to 1 day of VEGF exposure, whereas longer VEGF treatment for 2 days did not have additive effects. To study cell-dynamics of astrocytes subsequent to VEGF treatment, we additionally transfected astrocytes with LifeAct-RFP. Live-cell imaging and quantitative analysis of these cells with aid of confocal laser scanning microscopy revealed higher process movement of VEGF-treated astrocytes. In conclusion, VEGF strongly affects cell proliferation, GJIC, and motility in astrocytes.     

Thyroidal stimulation of tubulin and actin in primary cultures of neuronal and glial cells of rat brain

The influence of triiodothyronine (T3) on the level of tubulin and other proteins in primary cultures of neuronal (N) and glial (G) cells from rat brain has been investigated. Quantitation of tubulin by [3H]colchicine binding assay revealed that when cells from 1 day rat brain were cultured for 18 hr with physiological doses (0.5-5 nM) of T3, the hormone elicited 35-40% increase in the soluble (30,000 g supernatant) tubulin content of G cells only. This stimulation was age-dependent and occurred neonatally at a time corresponding to the onset of synaptogenesis. In mouse and chick brain also, [3H]colchicine binding assay showed a similar selective stimulation of the soluble tubulin content of G cells by T3 with virtually no effect on N cells. However, SDS-polyacrylamide gel electrophoresis of the total proteins in the 30,000 g supernatants from N and C cells of rat brain, labeled for 18 hr with [14C]leucine in the presence of T3, revealed that T3 elicited 2-3-fold enhancement of radiolabeled tubulin in the N cells which is relatively greater than the 1.5-fold increase seen in the G cells. Analysis of the autoradiograms of these labeled proteins also revealed that in addition to tubulin, T3 stimulated the accumulation of radiolabeled actin by 1.5- and 2-fold in N cells and G cells respectively. Similar electrophoretic analysis of the solubilized labeled proteins in the 30,000 g pellets from N and G cells indicated that the failure to detect the stimulation of tubulin in the 30,000 g supernatants from N cells by [3H]colchicine binding assay could be at least partly due to rapid translocation of the dimeric soluble tubulin into insoluble membrane fractions or due to presence of higher oligomeric forms of tubulin which are insensitive to [3H]colchicine binding assay.