p38MAK基因诱导胶质瘤细胞凋亡机制的初步研究

目的 初步探讨p38MAPK基因诱导大鼠胶质瘤细胞C6发生凋亡的机制。方法 利用脂质体介导法将p38MAPK基因导入C6细胞中,用夹心法ELISA检测细胞培养液中sTNF-α水平的变化,用流式细胞仪检测膜TNF-α和膜TNFRI水平的变化。结果 转染pCMV5-p38MAPK后,细胞培养液中sTNF-α水平明显升高,膜TNF-α水平无明显变化,膜TNFRI表达升高。结论 p38MAPK可能通过上调sTNF-α和膜TNFRI水平而诱导C6细胞凋亡。     

转录因子FoxM1与颅内胶质瘤治疗的研究进展

胶质瘤是中枢神经系统最常见的原发性肿瘤,高级别胶质瘤具有高度侵袭性,术后复发快,并对放疗和化疗表现出内在抗性,患者预后不佳[1]。尽管临床医生不断探索和革新手术切除以及化学治疗和放射治疗方案,在一定程度上提高了患者术后生活质量,但一般的抗肿瘤药物,由于难以通过血脑屏障等因素的影响,治疗的效果欠佳,寻找到一个能有效治疗胶质瘤的药物就成为了研究的关键。     

FasL基因诱导胶质瘤细胞凋亡和抑制增殖作用的研究

目的 :探讨FasL基因诱导胶质瘤细胞凋亡和抑制增殖的作用。方法 :脂质体介导FasL基因转染TJ90 5胶质瘤细胞系 ,原位杂交 ,FasL免疫组化鉴定转染成功 ,应用MTT法、Ki 67免疫组化检测TJ90 5细胞的增殖变化 ,TUNEL法检测细胞凋亡。结果 :FasL基因转染成功后 ,肿瘤细胞内FasL表达增加 ,细胞增殖率降低 ,而凋亡细胞数增多。结论 :FasL基因诱导的细胞凋亡可能成为胶质瘤治疗的新途径之一     

肿瘤坏死因子相关凋亡诱导配体诱导胶质瘤细胞凋亡机制研究

目的 探讨肿瘤坏死因子相关凋亡诱导配体(TRAIL)诱导胶质瘤细胞凋亡的机制.方法 以人重组可溶性TRAIL蛋白(rsTRAIL)处理人胶质瘤细胞U87;AnnexinV-FITC/PI双染色流式细胞术检测细胞凋亡;DiOC6荧光染色流式细胞术检测细胞线粒体跨膜电位(△ψm);比色法测定细胞caspase-3、8、9活性的变化;ELISA法检测胞浆cytC浓度;观察caspase-8阻断剂(Z-IETD-fmk)对U87细胞凋亡、△ψm和caspase-3、8、9活性变化的影响. 结果 rsTRAIL以时间依赖方式诱导U87细胞凋亡.同时导致U87细胞△ψm进行性下降,caspase-3、8、9活性及胞浆内cyt C浓度升高:caspase-8阻断剂可明显减弱rsTRAIL对U87细胞的上述生物学效应. 结论 TRAU通过激活caspase-8间接启动线粒体凋亡途径诱导恶性胶质瘤细胞U87凋亡.     

氯喹通过抑制自噬促进TRAIL诱导的胶质瘤细胞凋亡

目的探讨氯喹对肿瘤坏死因子相关凋亡诱导配体(TRAIL)诱导的胶质瘤细胞凋亡的影响。方法体外培养人脑胶质瘤细胞U251和Hela细胞,分为对照组、氯喹组、重组人TRAIL蛋白(rhTRAIL)组和联用组(氯喹与rhTRAIL联合应用);MTT法检测细胞活力,Annexin V-FITC/PI凋亡检测试剂盒检测细胞凋亡,共聚焦显微镜检测GFP-LC3的分布判断细胞自噬水平,Western Blot检测cleaved caspase-8的表达水平。结果氯喹和rhTRAIL均显著增加U251细胞和Hela细胞自噬水平,而且联用较单独应用自噬水平更高,Hela细胞自噬水平明显高于U251细胞。U251细胞和Hela细胞增殖抑制率和细胞凋亡率:氯喹组与对照组均无统计学差异(P0.05),rhTRAIL和联用组均明显高于氯喹组(P0.05),联用组明显高于rhTRAIL组(P0.05)。氯喹组和对照组Cleaved caspases-8水平无统计学差异(P0.05),rhTRAIL和联用组均明显增高(P0.05),联用组明显高于rhTRAIL组(P0.05)。结论氯喹能通过抑制细胞自噬,增强TRAIL诱导的U251细胞凋亡。     

海葵毒素对神经胶质瘤细胞的凋亡诱导作用

目的 研究从海葵组织中提取的海葵毒素(Phyllodiscus semonii toxin,PsTX)对人神经胶质瘤细胞(U251)凋亡的诱导作用及其可能机制.方法 MTT法检测PsTX对肿瘤细胞的增殖抑制率;原位末端脱氧核糖苷肽转移酶分析法(TUNEL)及DNA Ladder法检测PsTX对肿瘤细胞的凋亡诱导作用;免疫组织化学染色显示Fas蛋白在U251细胞中的表达.结果 PsTX对人神经胶质瘤细胞具有明显的生长抑制及促凋亡作用,PsTX诱导Fas在人神经胶质瘤细胞膜上表达增高.结论 PsTX可能通过Fas途径诱导人神经胶质瘤细胞凋亡.     

p16基因抑制脑胶质瘤细胞恶性增殖并诱导细胞凋亡

目的：探索p16基因在脑胶质瘤发生过程中的作用及其与脑胶质瘤细胞凋亡的关系。方法：采用脂质体,磷酸钙＋DMSO休克转染的方法,分别将外源野生型p16基因导入胶质瘤细胞株U251,SWO,观察p16基因短暂转染与长期稳定转染对胶质瘤细胞的作用,并筛选阳性克隆。同时以空载体质粒pCDNA3为对照,免疫组化,Northern杂交检测p16基因表达,对转染后细胞生长的抑制,细胞周期,凋亡及裸鼠致瘤能力的变化进行分析,结果：外源p16基因的高水平表达显著抑制了胶质瘤U251,SWO细胞的生长,克隆形成率减少,肿瘤细胞发生了G1期阻滞,p16基因短暂转染可诱导胶质瘤细胞凋亡,而长期稳定转染无明显的凋亡诱导作用。结论：外源野生型p16基因可抑制胶质瘤细胞恶性增殖并诱导细胞凋亡,肿瘤细胞的异质性特点与p16基因转染后的“自然选择”作用可能是p16基因长期稳定转染无明显凋亡诱导作用的主要机制。     

FLIP蛋白抑制顺铂诱导大鼠C6胶质瘤细胞凋亡

目的探讨自杀相关因子（Fas）相关死亡结构域样白介素1（IL-1）β转化酶抑制蛋白（FLIP）对于顺铂（CDDP）诱导大鼠脑胶质瘤细胞（C6细胞株）凋亡的抑制作用,为进一步研究胶质瘤的耐药性奠定分子生物学基础。方法利用由Ad—Max腺病毒包装系统成功构建的携载大鼠FLIP基因的腺病毒表达载体Ad—FLIP感染大鼠C6胶质瘤细胞,24h后经逆转录酶一多聚酶链反应（RT—PCR）及Westernblot检测感染组及对照组细胞中FLIP基因的mRNA及蛋白表达水平;分别给予Ad—FLIP感染组及对照组细胞不同浓度的CDDP（0,1,2,4,8mg／ml）,药物处理48h后,经流式细胞仪（FCM）分析细胞凋亡状况;四唑蓝显色法（MTF）测定并比较两组细胞活力。结果Ad—FLIP感染组细胞与对照组细胞相比,FLIPmRNA和蛋白表达水平明显增高;流式细胞仪检测结果显示Ad—FLIP感染组细胞凋亡率明显低于对照组。MTT法结果提示经CDDP处理后,Ad—FLIP感染组与对照组细胞活力均有下降,但FLIP蛋白具有明显的抑制作用。结论FLIP蛋白在大鼠c6胶质瘤细胞中具有抵抗化疗药物的作用。     

抑制血红素加氧酶-1对三氧化二砷抗胶质瘤的增敏作用

目的 探讨抑制血红素加氧酶-1(HO-1)是否可以增强三氧化二砷(ATO)对胶质瘤细胞的氧化损伤作用.方法 分别用HO-1激动剂钴原卟啉IX(CoPPIX)和HO-1抑制剂锌原卟啉IX(ZnPPIX)预处理细胞后,用ATO处理胶质瘤细胞系U251MG,通过检测细胞死亡、线粒体膜电位的下降、SubG1等评价ATO对胶质瘤细胞的损伤作用,并使用流式细胞技术检测ATO诱导的活性氧蓄积,用Western blot分析HO-1的诱导、P38和JNK的磷酸化情况.结果 ATO可以诱导U251MG细胞出现明显的细胞死亡、线粒体膜电位(MMP)下降、活性氧蓄积以及HO-1蛋白表达,这些指标均可被活性氧抑制剂L-N-乙酰半胱氨酸(LANC)抑制.HO-1诱导剂CoPPIX可以明显抑制As2O3诱导的细胞死亡和活性氧生成,而HO-1抑制剂ZnPPIX则可以显著增强上述作用.结论 抑制胶质瘤细胞HO-1的表达能显著增强ATO的抗胶质瘤作用,考虑到HO-1在胶质瘤内高表达,ATO联合HO-1抑制剂可能是一种有效治疗胶质瘤的新方法.     

脑胶质瘤热休克蛋白抗原肽复合物抑瘤作用的研究

目的提纯大鼠脑胶质瘤C6细胞热休克蛋白抗原肽复合物(HAC),免疫大鼠,观察HAC的抑瘤作用。方法采用免疫亲和层析方法提纯鼠脑胶质瘤C6细胞HAC,免疫20只大鼠为实验组,以另20只大鼠作为对照组,于免疫后一周,采用立体定向脑内接种方法,以C6细胞攻击两组大鼠,于肿瘤细胞攻击后第二周,进行外周静脉血淋巴细胞计数,和血清INF、IL-2、TNF的浓度测定,并于正常对照。观察四周后动物的存活率。进行HE染色,并用免疫组化方法分析脑胶质瘤浸润区T淋巴细胞分布情况。结果实验组大鼠外周血淋巴细胞计数和IFN、IL-2、TNF浓度均显著高于对照组(P<0.01)。实验组胶质瘤局部浸润的CD3+和CD4+细胞数均显著高于对照组(P<0.01),CD8+细胞数与对照组比较无显著差异(P>0.05),T淋巴细胞CD4+/CD8+显著高于对照组(P<0.01)。结论C6细胞中HAC可以诱导大鼠产生对C6细胞的细胞免疫,抑制肿瘤生长,提高接种大鼠存活率。     

土贝母苷甲通过上调FADD/caspase-8/caspase-3的表达促进人胶质瘤U251细胞凋亡

目的研究土贝母苷甲(TBMSⅠ)诱导人胶质瘤U251细胞凋亡及其可能的内在机制。方法四甲基偶氮唑蓝比色法(MTT法)检测不同浓度的土贝母苷甲对U251细胞增殖的影响。Hoechst 33258荧光染色观察不同浓度土贝母苷甲处理U251细胞后细胞核形态的变化。流式细胞仪检测细胞的凋亡率。Western blot分析土贝母苷甲对FADD、caspase-8和caspase-3蛋白表达水平的影响。结果土贝母苷甲以剂量依赖方式抑制U251细胞的增殖。土贝母苷甲处理后,U251细胞的细胞核表现出固缩浓染等凋亡特征,且随着药物浓度的增加,细胞数目逐渐减少。与对照组相比较,土贝母处理组(10、20、25μg/ml)的早期和晚期凋亡率均显著增加,差异有统计学意义(P﹤0.05)。10、20、25μg/ml土贝母苷甲处理组上调了FADD、caspase-8和caspase-3蛋白的表达水平,差异有统计学意义(P﹤0.05)。结论土贝母苷甲在体外能够明显的抑制U251细胞的增殖,其机制可能与上调FADD、caspase-8和caspase-3蛋白表达从而诱导细胞凋亡有关。     

下调磷酸甘油酸激酶1增强胶质瘤U251细胞的放射敏感性

目的研究磷酸甘油酸激酶1(PGK1)对胶质瘤U251细胞放射敏感性的影响。方法建立放射抵抗的U251(RR-U251)细胞;LipofectamineTM2000方法将抑制PGK1表达的shRNA-PGK1质粒或对照shRNANC转染至U251细胞;荧光定量PCR及Western Blot检测PGK1的表达;MTT检测细胞相对存活率,划痕实验检测细胞迁移能力,Transwell小室实验检测细胞侵袭能力。结果与正常U251细胞相比,RR-U251细胞中PGK1的表达明显增高;放射处理后,RR-U251细胞的相对存活率升高,迁移能力及侵袭能力增强。转染shRNA-PGK1的细胞接受放射处理后,与对照组相比,细胞的相对存活率降低,迁移能力以及侵袭能力减弱。结论下调U251细胞中PGK1的表达可增加其放射敏感性,提示PGK1可能成为增强放射敏感性的调控靶点。     

Targeting X box-binding protein-1 (XBP1) enhances sensitivity of glioma cells to oxidative stress

Y. Liu, X. Zhang, Y. Liang, H. Yu, X. Chen, T. Zheng, B. Zheng, L. Wang, L. Zhao, C. Shi and S. Zhao (2011) Neuropathology and Applied Neurobiology 37, 395–405
Targeting X box‐binding protein‐1 (XBP1) enhances sensitivity of glioma cells to oxidative stress Aims: Reactive oxygen species (ROS) and oxidative stress are tightly linked with cancers including gliomas. We previously reported the protective role of X box‐binding protein‐1 (XBP1) against oxidative stress in both mouse embryofibroblasts and human Hela cells. This study was to investigate XBP1‐mediated protection against oxidative stress in the treatment of gliomas. Materials and methods: XBP1 expression levels were knocked down by siRNA transfection in the U251MG cell line. After exposure to hydrogen peroxide (H₂O₂) or the ROS inducer arsenic trioxide (As₂O₃), cell death, mitochondrial membrane potential (MMP) loss, ROS levels and the expression of several antioxidant molecules were examined. Expression of XBP1 and antioxidant molecules was also detected in surgically excised specimens from 30 patients with glioma, and 10 normal brain control specimens obtained at autopsy. Results: XBP1 knockdown significantly enhanced the cell death fraction, MMP loss and ROS levels in H₂O₂‐ or As₂O₃‐treated glioma cells, concomitant with a decrease of several antioxidant molecules including catalase. Moreover, the abundant expression of XBP1 and antioxidant molecules was also observed in human glioma specimens, as compared with normal brain tissues. Conclusions: XBP1 confers an important role in protection against oxidative stress in gliomas, potentially via up‐regulation of antioxidant molecules such as catalase. Targeting XBP1 may have synergistic effects with ROS inducers on glioma treatment.     

NUSAP1在脑胶质瘤中的表达以及对胶质瘤细胞LN229功能的影响

目的探讨核仁纺锤体相关蛋白1(NUSAP1)在脑胶质瘤样本的高表达,以及沉默NUSAP1对胶质瘤细胞系LN229细胞功能的影响。方法收集南京医科大学附属脑科医院30例胶质瘤手术标本以及10例癫痫病灶手术样本,采用荧光实时定量(qRT-PCR)和Western blot技术检测40例样本中NUSAP1的表达情况,用lentivirus和siRNA干扰LN229细胞系中NUSAP1表达后,采用CCK-8法、流式细胞仪法检测其对细胞增殖、凋亡、细胞周期的影响。结果 NUSAP1在胶质瘤组表达量明显高于癫痫组(对照)。NUSAP1表达被干扰后。脑胶质细胞LN229功能降低。结论 NUSAP1在脑胶质瘤中高表达,干扰其在LN229细胞株表达后,LN229增殖能力下降,细胞G2/M期停滞。提示NUSAP1可能成为一个新的胶质瘤治疗靶点。     

Pattern of heat shock factor and heat shock protein expression in lymphocytes of bipolar patients: Increased HSP70-glucocorticoid receptor heterocomplex

Bipolar disorder (BD), a stress-related disease, is characterized by altered glucocorticoid receptor (GR) signalling. Stress response includes activation of heat shock factor (HSF) and subsequent heat shock protein (HSP) synthesis which regulate GR folding and function. The objective of this study was to investigate the possible role of HSFs, HSPs and their interaction with GR in BD. We applied immunoprecipitation, SDS-PAGE/Western blot analysis and electrophoretic mobility shift assay (EMSA) in lymphocytes (whole cell or nuclear extracts) from BD patients and healthy subjects and determined the HSPs (HSP90 and HSP70), the heterocomplexes HSP90-GR and HSP70-GR, the HSFs (HSF1 and HSF4) as well as the HSF-DNA binding. The HSP70-GR heterocomplex was elevated (p < 0.05) in BD patients vs healthy subjects, and nuclear HSP70 was reduced (p ≤ 0.01) in bipolar manic patients. Protein levels of HSF1, HSF4, HSP90, HSP90-GR heterocomplex, and HSF-DNA binding remained unaltered in BD patients vs healthy subjects. The corresponding effect sizes (ES) indicated a large ES for HSP70-GR, HSP70, HSF-DNA binding and HSF4, and a medium ES for HSP90, HSF1 and HSP90-GR between healthy subjects and bipolar patients. Significant correlations among HSFs, HSPs, GR and HSP70-GR heterocomplex were observed in healthy subjects, which were abrogated in bipolar patients. The higher interaction between GR and HSP70 and the disturbances in the relations among heat shock response parameters and GR as observed in our BD patients may provide novel insights into the contribution of these factors in BD aetiopathogenesis.     

吴茱萸碱对人胶质瘤U251细胞增殖及凋亡影响的研究

目的研究吴茱萸碱(evodiamine)对人胶质瘤U251细胞增殖和凋亡的影响及其可能的作用机制。方法体外培养人胶质瘤U251细胞,并将其分为空白对照组及25、50、100μg/mL吴茱萸碱4组。应用MTT法检测吴茱萸碱对U251细胞的增殖抑制作用;Hoechst33258荧光染色法检测吴茱萸碱诱导胶质瘤U251细胞凋亡;采用Annexin V-FITC/PI双染法检测各组早期凋亡率;Western blot法分析凋亡相关蛋白的变化。结果与空白对照组同期比较,25、50、100μg/mL吴茱萸碱组生长抑制率在24、48、72 h均增加,差异有统计学意义。Hoechst 33258荧光染色显示吴茱萸碱作用24 h后U251细胞出现典型的细胞凋亡特征,各处理组均可见凋亡小体。与空白对照组自发早期凋亡率3.12%比较,25、50、100μg/mL吴茱萸碱组早期凋亡率分别为8.65%、19.47%及28.97%,差异均有统计学意义。Western blot实验显示,与空白对照组同期比较,25、50、100μg/mL吴茱萸碱上调了FAS、FADD、Caspase-8及Caspase-3蛋白表达,Bcl-2蛋白表达明显下降,Bax蛋白表达明显上升,差异均有统计学意义。上述指标均呈时间和剂量依赖性。结论吴茱萸碱对U251细胞具有明显的抑制细胞增殖和促进细胞凋亡的作用,其机制可能与上调Fas途径和下调Bcl-2/Bax有关。     

E2F1蛋白在胶质瘤中的表达及其对胶质瘤细胞生长的影响

目的探讨E2F1蛋白在胶质瘤中的表达及其对胶质瘤细胞生长的影响。方法用实时荧光定量PCR法检测E2F1mRNA在各级别胶质瘤组织中的表达水平。应用RNA干扰技术降低E2F1表达后,采用Western印迹法验证E2F1蛋白的变化。采用四甲基偶氮唑盐(MTT)微量酶反应比色法和糖检测分析试剂盒检测干扰E2F1表达后胶质瘤细胞的增殖和糖代谢的变化。结果胶质瘤组织中E2F1的表达高于正常脑组织,其表达随着级别的增高而升高;抑制E2F1的表达后,U87细胞生长受抑制,细胞的葡萄糖消耗量明显降低。结论 E2F1在胶质瘤中的表达随着肿瘤恶性程度的增高而升高;抑制E2F1表达可以明显抑制胶质瘤细胞增殖及代谢能力。     

Characterization of phenothiazine-induced apoptosis in neuroblastoma and glioma cell lines

In this study we aimed to (1) screen phenothiazines for cytotoxic activity in glioma, neuroblastoma, and primary mouse brain tissue; and (2) determine the mechanism of the cytotoxic effect (apoptosis, necrosis) and the roles of calmodulin inhibition and σ receptor modulation. Rat glioma (C6) and human neuroblastoma (SHSY-5Y) cell lines were treated with different phenothiazines. All agents induced a dose-dependent decrease in viability and proliferation, with the highest activity elicited by thioridazine. Sensitivity to thioridazine of glioma and neuroblastoma cells was significantly higher (p<0.05) than that of primary mouse brain culture (IC₅₀ 11.2 and 15.1 μM vs 41.3 μM, respectively). The N-mustard fluphenazine induced significantly lower cytotoxicity in glioma cells, compared to fluphenazine. The σ receptor selective ligand (+)-SK&F10047 increased viability slightly while combined with fluphenazine; SK&F10047 did not alter fluphenazine activity. Flow cytometry of propidium iodide (PI)-stained glioma cells treated with thioridazine, fluphenazine, or perphenazine (6–50 μM) resulted in a concentration-dependent increase of fragmented DNA up to 94% vs 3% in controls by all agents. Thioridazine (12.5 μM)-treated glioma cells costained with PI and Hoechst 33342 revealed a red fluorescence of fragmented nuclei in treated cells and a blue fluorescence of intact control nuclei. After 4-h exposure to thioridazine (25 and 50 μM), a 25- to 30-fold increase in caspase-3 activity in neuroblastoma cells was noted. Overall, the marked apoptotic effect of phenothiazines in brain-derived cancer cells, and the low sensitivity of primary brain tissue suggest the potential use of selected agents as therapeutic modalities in brain cancer.