两种不同方法建立脑胶质瘤裸鼠移植模型及组织学特征分析

采用C6型鼠胶质瘤细胞悬液接种至裸鼠皮下,同时用瘤组织块异体移植至裸鼠皮下,建立脑胶质瘤细胞裸鼠移植动物模型,分别观察裸鼠皮下移植瘤长出时间,并分析肿瘤的病理组织学及免疫组织化学特征.结果 两种方法所建肿瘤模型其成功率均为100%,均符合胶质瘤细胞的形态学特征.采用瘤组织块异体移植法建立的肿瘤模型,所需时间均明显短于细胞接种法,裸鼠肿瘤组织块生长速度基本相同.认为利用肿瘤组织块移植的方法可快速建立裸鼠皮下移植瘤模型,并能作为研究胶质瘤发病机制、生物学特性以及基因治疗的可靠动物模型.     

TRAIL真核表达质粒诱导胶质瘤细胞凋亡的实验研究

目的探讨肿瘤坏死因子相关凋亡诱导配体(tumornecrosis factor-related apoptosis-inducing ligand,TRAIL)真核表达质粒对U251胶质瘤细胞凋亡的诱导作用。方法构建人TRAIL基因114-281胞外段肽链相应基因序列(504bp)的真核表达质粒;构建荷U251胶质瘤裸鼠模型,随机分组给药后,观察肿瘤生长情况,应用透射电镜技术,分析TRAIL真核表达质粒抗肿瘤作用。结果质粒组和质粒 化疗组肿瘤生长受到抑制。超微结构提示为凋亡改变。结论TRAIL真核表达质粒可以诱导U251胶质瘤细胞凋亡,与化疗药物联合应用后作用更明显。     

辛伐他汀体外对人U251脑胶质瘤细胞增殖及凋亡的影响

目的观察辛伐他汀体外对人U251胶质瘤细胞增殖及诱导其凋亡的作用。方法对照组和实验组分别行辛伐他汀干预,培养24、48、72、96 h,采用MTT比色法和流式细胞仪检测不同浓度及不同时间干预后人U251胶质瘤细胞增殖活性和细胞周期的变化;采用TUNEL法检测干预后细胞凋亡的情况及RT-PCR检测对照组和实验组在干预48 h后检测Caspase-3的表达。结果辛伐他汀体外可明显降低人U251胶质瘤细胞增殖活性及诱导其凋亡,浓度到达1.0μmol/L时抑制作用明显,与对照组相比具有显著性差异(P0.05)。此外,辛伐他汀对人U251胶质瘤细胞的生长抑制呈明显的量-效关系。人U251胶质瘤细胞凋亡随药物浓度增加而显著,Caspase-3的表达亦呈剂量依赖关系。结论辛伐他汀在体外可一定程度上抑制人U251胶质瘤细胞的增殖及诱导其凋亡,Caspase-3参与细胞的凋亡过程。     

Bcl-2反义寡核苷酸对环已亚胺诱导U251细胞凋亡的影响

目的 探讨Bcl-2反义寡核苷酸对环已亚胺（CHX）诱导胶质瘤细胞U251凋亡的影响。方法在光镜下观察Bcl-2反义寡核苷酸、CHX及二者联合应用对U251凋亡的形态学改变;应用MTT法检测各组U251细胞的抑制率;通过DNA电泳检测CHX诱导U251细胞凋亡的情况。结果 Bcl-2反义寡核苷酸可明显促进CHX诱导的U251凋亡,对照组、SODN组与CHX组、AODN组、SODN＋CHX组及AODN＋CHX组的细胞抑制率相比P均〈0．01,AODN组、SODN＋CHX组和AODN＋CHX组的细胞抑制率相比P均〈0．01;Bcl-2反义寡核苷酸可促进细胞凋亡,呈现出特征性的DNA梯状带。结论Bcl-2反义寡核苷酸和CHX均可诱导胶质瘤细胞U251发生凋亡,且Bcl-2反义寡核苷酸可明显促进CHX诱导的胶质瘤细胞U251凋亡,提高胶质瘤细胞对CHX的敏感性。     

C6/IL-24对鼠脑胶质瘤治疗作用的研究

目的 观察C6/IL-24对大鼠脑胶质瘤的治疗作用.方法 建立SD大鼠脑胶质瘤模型,实验组皮下注射C6/IL-24细胞,对照组皮下注射同等体积的生理盐水,观察大鼠的生存期及颅内肿瘤的生长变化.结果 实验组肿瘤生长速度明显减慢,实验组大鼠各时段肿瘤体积明显小于对照组,实验组大鼠存活时间明显长于对照组.结论 通过逆转录病毒将IL-24导入C6细胞而形成的C6/IL-24细胞对鼠脑胶质瘤具有较好的治疗效果,建立稳定可靠的脑胶质瘤动物模型是进行各种脑胶质瘤在体实验研究的基础,治疗时间窗的选择应在肿瘤指数生长期以前.     

裸鼠肝癌模型中miR-20a的作用

目的探讨microRNA-20a(miR-20a)对人肝癌细胞系HepG2裸鼠皮下荷瘤模型中肿瘤生长的影响,并探讨其可能的机制。方法于瘤体内分别注射miR-20a agomir、阴性片段和生理盐水。观察荷瘤裸鼠体重变化、裸鼠皮下形成瘤体的大小并计算抑瘤率。接种35 d后处死裸鼠并取出肿瘤组织,计算肿瘤体积大小,并采用免疫组化法检测肿瘤组织中VEGFA的表达。结果 3组裸鼠皮下接种肿瘤细胞7 d后均有瘤体形成,实验组瘤体生长速度明显低于阴性对照组和空白对照组(P<0.01);实验结束时,实验组裸鼠体重显著高于阴性对照组和空白对照组(P<0.01);实验组肿瘤体积显著小于其他两组体积(P<0.01)。实验组肿瘤组织中VEGFA表达量显著低于其他两组(P<0.01)。结论 miR-20a可能通过抑制VEGFA表达,而抑制肝癌细胞HepG2裸鼠皮下移植瘤的生长。     

地喹氯铵对脑胶质瘤细胞凋亡的影响

目的探讨地喹氯铵对脑胶质瘤细胞增殖、凋亡及侵袭的影响。方法用50、100、200μmol/L的地喹氯铵作用于脑胶质瘤细胞U251、U87、C6,作用时间分别为12、24、48、72、96 h,MTT检测细胞增殖情况。流式细胞仪检测76μmol/L的地喹氯铵作用48 h后的脑胶质瘤细胞U251的细胞凋亡情况。Transwell小室检测地喹氯铵对脑胶质瘤细胞侵袭能力的影响。Western印迹检测细胞中PI3K、p-PI3K、Akt、p-Akt蛋白的表达水平。结果 50、100、200μmol/L的地喹氯铵对U251、U87、C6脑胶质瘤细胞增殖均具有抑制作用。地喹氯铵对脑胶质瘤细胞的增殖抑制作用随着作用时间的增加而增加,随着药物作用浓度的增加而增加。地喹氯铵作用胶质瘤U251、U87、C6细胞48 h的半数抑制浓度由大到小依次为:C6>U87>U251。76μmol/L的地喹氯铵作用后的脑胶质瘤细胞凋亡率明显高于对照组(P<0.01)。脑胶质瘤细胞经地喹氯铵作用后的侵袭细胞数明显低于对照组(P<0.01)。地喹氯铵作用后的脑胶质瘤细胞中PI3K、Akt的表达水平与对照组相比无明显差异,而p-PI3K、p-Akt的表达水平明显下降。结论地喹氯铵对脑胶质瘤细胞增殖、侵袭能力具有抑制作用,对脑胶质瘤细胞凋亡具有促进作用,作用机制与PI3K/Akt信号通路有关。     

Slug-siRNA干扰Slug基因表达对胰腺癌的抑制作用

目的: 研究携带Slug-siRNA的rAAV对裸鼠体内胰腺癌的作用.方法: 建立人胰腺癌裸鼠皮下移植瘤模型,2wk后随机将建模成功的裸鼠分为3组,每组6只. 构建携带Slug-siRNA的rAAV载体,采用瘤体内多点注射的方法,阴性对照组裸鼠按1×109 puf(50 μL)标准注射rAAV-EGFP,空白对照组裸鼠注射等量生理盐水,实验组裸鼠按1×109 puf(50 μL)标准注射rAAV2-EGFP-slugsiRNA,只注射1次. 观察裸鼠的一般情况,摄食,活动能力,每周用电子天平秤体质量,绘制裸鼠生长曲线. 治疗6 wk后二氧化碳吸入法处死裸鼠,切取肿瘤称质量;免疫组织化学SP法检测slug蛋白的表达,TUNEL检测皮下移植瘤细胞凋亡,透射电镜检测细胞超微结构.结果: 3组裸鼠分别接受不同的处理后,在开始的2 wk皮下移植瘤的生长无明显差别,2 wk以后,实验组裸鼠皮下移植瘤的体积增长明显滞后于阴性对照组和空白对照组,差异有统计学意义( P<0.05). 治疗6 wk后,实验组裸鼠皮下移植瘤的质量明显轻于阴性对照组和空白对照组差异有统计学意义(3.26±0.48 g vs7.56±1.25 g,7.50±1.23 g,均P<0.05). 实验组裸鼠皮下移植瘤的AI值明显高于阴性对照组和空白对照组,差异有统计学意义(0.27±0.06vs 0.024±0.01,0.025±0.01,均P<0.05);实验组的抑瘤率明显高于阴性对照组,差异有统计学差异(71.4% vs 0.04%,P<0.01). 透射电镜下,实验组肿瘤细胞可见细胞器结构模糊,核固缩,染色质边集等现象. 免疫组织化学检测示实验组Slug表达明显减少.结论: Slug基因被有效沉默,Slug基因沉默后促进细胞凋亡,抑制胰腺癌实体瘤增殖和生长.     

5-杂氮-2'-脱氧胞苷诱导裸鼠HepG2种植瘤细胞T-cadherin的表达及其对种植瘤的抑制作用

目的: 探讨去甲基化药物5-杂氮-2'-脱氧胞苷(5-Aza-CdR)在裸鼠体内诱导HepG2细胞T-cadherin的表达,及其对HepG2种植瘤生长的抑制作用.方法:皮下接种法建立HepG2细胞裸鼠种植瘤模型,随机分为实验组(11只)和对照组(10只).实验组裸鼠给予5-Aza-CdR注射,对照组裸鼠注射等量PBS.4wk后处死裸鼠,观察种植瘤的生长情况,用RT-PCR技术及免疫组织化学技术检测T-cadherin mRNA及蛋白的表达.结果:用药4wk后,实验组肿瘤组织的T-cadherin mRNA的表达水平显著高于对照组(t=6.613, P<0.05);对照组HepG2细胞几乎检测不到T-cadherin蛋白表达,而实验组裸鼠种植瘤细胞膜上可检测到T-cadherin蛋白表达;实验组肿瘤的平均体积明显小于对照组肿瘤平均体积(t=2.337,P=0.025).结论:5-Aza-CdR能诱导裸鼠皮下种植HepG2瘤细胞的T-cadherin表达,抑制HepG2种植瘤的生长,其机制可能为5-Aza-CdR使甲基化的T-cadherin启动子去甲基化,恢复T-cadherin的表达,从而抑制HepG2种植瘤生长.     

木犀草素对胶质瘤细胞的抗增殖作用及其机制研究

目的 研究木犀草素对人胶质瘤U251细胞增殖的抑制作用及其机制.方法 将体外培养的胶质瘤U251细胞分为对照组、木犀草素组(依木犀草素浓度不同分为3个亚组),CCK-8法测定细胞增殖率,流式细胞仪测定细胞凋亡率,Hoechst PI核染色法观察细胞核凋亡,Western blot法检测胶质瘤U251细胞内B淋巴细胞瘤-...     

microRNA-21在神经胶质瘤患者外周血清中的表达及意义

目的 探究神经胶质瘤患者外周血清中microRNA-21的表达水平,并运用生物信息学方法 预测其靶基因及功能.方法 选取神经胶质瘤患者53例作为试验组,另选取同期健康人群50例作为对照组.采用RT-PCR技术检测两组外周血清中microRNA-21的相对表达量,采用UCSC数据库分析microRNA-21在人类基因中的位置及保守性,采用Targetscan数据库和CoMeTa数据库联合预测microRNA-21的靶基因并进一步分析其靶基因的功能富集和信号通路富集情况.结果 试验组外周血清中microRNA-21的相对表达量(2.53±0.95)高于对照组(1.05±0.64),差异有统计学意义(P<0.05);microRNA-21定位于人染色体17q23.1上,具有高度保守性;生物信息学分析显示microRNA-21的潜在靶基因包括BCL2、SOCS3、MEF2C、PP3CA等146个;功能富集(GO)分析显示microRNA-21的靶基因主要富集于RNA合成代谢、细胞增殖凋亡、转录、磷代谢、细胞信号传导等过程中,而KEGG Pathway分析显示microRNA-21靶基因主要富集于丝裂原活化蛋白激酶(MAPK)信号通路、神经营养素信号通路、Janus激酶-信号转导与转录激活子(JAK-STAT)信号通路、细胞因子-细胞因子受体相互作用、趋化因子信号通路、Toll样受体信号通路、T细胞受体信号通路、细胞凋亡信号通路、转化生长因子(TGF)-β信号通路等通路中.结论 神经胶质瘤患者外周血microRNA-21高表达,并通过调控多条信号通路中多的种靶基因进而参与导致神经胶质瘤的发病.     

Platelet activation by mercuric compounds

We previously showed that at low concentrations (0.01-10 mu mol l) mercury (Hg) compounds (especially methylmercuric chloride) may act synergistically with physiological agonists to activate platelets and may also cause changes in blood coagulation in experimental animals. Result obtained in this study indicate that the activation of pig blood platelets by methylmercuric chloride (MMC) is not dependent on membrane receptors for fibrinogen and ADP. Furthermore, we have calculated that pig platelets take up approximately 13-fold more Hg than plasma proteins during incubation of platelet-rich plasma with MMC. These findings may explain the recently reported link between vascular events and Hg poisoning.     

Platelet activation by mercuric compounds

We previously showed that at low concentrations (0.01-10 micromol/l) mercury (Hg) compounds (especially methylmercuric chloride) may act synergistically with physiological agonists to activate platelets and may also cause changes in blood coagulation in experimental animals. Result obtained in this study indicate that the activation of pig blood platelets by methylmercuric chloride (MMC) is not dependent on membrane receptors for fibrinogen and ADP. Furthermore, we have calculated that pig platelets take up approximately 13-fold more Hg than plasma proteins during incubation of platelet-rich plasma with MMC. These findings may explain the recently reported link between vascular events and Hg poisoning.     

Anti-cancer effect of iNOS inhibitor and its correlation with angiogenesis in gastric cancer

AIM: To observe the anti-cancer effect of iNOS selective inhibitor (aminoguanidine, AG) and investigate the relationship between iNOS inhibitor and angiogenesis, infiltration or metastasis in MFC gastric cancer xenografts. METHODS: Fifty athymic mice xenograft models were established by inoculating gastric cancer cell MFC subcutaneously. Twenty-four hours later, 0.9% sodium chloride solution, mitomycin, low dosage AG, high dosage AG, mitomycin and AG were administered by intraperitoneal injection respectively. Thus these mice were divided into five groups of 10 each randomly: control group, MMC group, AGL group, AGH group, MMC+AGH group. Two weeks later the mice were killed, and the tumor weight, inhibitory rate were evaluated. Greiss assay was used to detect the nitric oxide levels in plasma. HE and immunohistochemistry staining were used to examine microvessel density (MVD) and the expression of iNOS, VEGF, and PCNA. Apoptosis was detected by using TUNEL assay. RESULTS: The inhibitory rates in MMC+AGH group and AGH group were 52.9% and 47.1% respectively, which is significant statistically compared with that of control group (0). In treatment groups, the cell proliferation index (PI) was lower and apoptosis index was higher than those of control group. Microvessel density, iNOS, and VEGF in MMC+ AGH group were 8.8±2.6, 2.4±1.1, and 2.1±1.4 respectively, which is significant statistically compared with those of control group (68.3±10.6, 11.3±1.3, and 10.3±1.6). The NO level in plasma of MMC+ AGH and AGH group were 12.7±2.1 and 12.9±2.0 μmol/L. Compared with that of control group (46.6±2.3 μmol/L), the difference is statistically significant. CONCLUSION: AG has anticancer effect on gastric cancer, and it has positive synergistic effect with chemotherapeutic drugs. It may play important inhibitory roles in angiogenesis of gastric cancer. The anticancer effect of iNOS inhibitors may include inducing cell apoptosis, suppressing cell proliferation and reducing angiogenesis.     

树突状细胞增强细胞因子诱导的杀伤细胞抗神经胶质瘤细胞作用及机制研究

目的探讨细胞因子诱导的杀伤细胞（CIK）与树突状细胞（DC）共培养后DC-CIK混合细胞抗神经胶质瘤细胞的免疫作用。方法分离健康人外周血单个核细胞,分别于体外诱导DC和CIK,然后共培养成DC-CIK细胞。实验分DC组、DC-CIK组、DC-T组和CIK组。Elisa试剂盒检测各组培养上清中IL-12和IFN．1的含量,流式细胞仪检测细胞表型,CCK一8法体外检测对神经胶质瘤细胞的杀伤活性。结果DC-CIK组培养上清中IL-12和IFN-1的含量分别为（110．24±2．22）mg／L和INF·Y／（913．46±20．64）mg／L,明显高于其它三组（P〈0．05）。DC—CIK组cDi细胞（61．34-1．31）％、CD3／CD56细胞（29．4±1．03）％也明显增加（P〈0．05）。对神经胶质瘤细胞的杀伤活性,DC—CIK组为（54．67±2．62）％,与DC组（19．44±1．07）％、DC—T组（21．27±1．85）％和CIK组（36．52±2．06）％比较,差异有统计学意义（P〈0．05）。结论DC—CIK细胞能诱导明显的神经胶质瘤细胞杀伤活性,为颅内肿瘤的免疫治疗提供了依据。     

钙盐浸润法制备腹主动脉瘤模型

目的探讨氯化钙浓度对兔腹主动脉瘤模型建立的影响,为腹主动脉瘤的实验研究提供基础。方法选取雄性新西兰大白兔30只,随机分成3组:0.5 mol/L氯化钙组、0.75 mol/L氯化钙组和对照组,分别用含0.5mol/L氯化钙、0.75 mol/L氯化钙和生理盐水的海绵包绕浸润腹主动脉,制备兔腹主动脉瘤模型。术后6周观察各组兔腹主动脉扩张率及动脉壁组织学变化。结果 0.5 mol/L氯化钙组、0.75 mol/L氯化钙组和对照组的腹主动脉扩张率分别为87.31%、124.12%和12.10%,各组间差异有显著性(P<0.01),0.75 mol/L氯化钙组比0.5 mol/L氯化钙组具有更明显的弹性纤维破坏降解、平滑肌细胞减少、腹主动脉扩张。结论 0.75 mol/L氯化钙浸润法是一种简单可行的兔腹主动脉瘤模型制备方法。     

Effects of motilin and ursodeoxycholic acid on gastrointestinal myoelectric activity of different origins in fasted rats

AIM: To investigate gastrointestinal migrating myoelectric complex (MMC) and the effects of porcine motilin and ursodeoxycholic acid (UDCA) on MMC of gastrointestinal tract of different origins in fasted rats. METHODS: Three bipolar silver electrodes were chronically implanted on the antrum, duodenum and jejunum. Seven days later 24 experimental rats were divided into 2 groups. One group was injected with porcine motilin via sublingual vein at a dose of 20 microg/kg, the other group was perfused into stomach with UDCA. The gastrointestinal myoelectric activity was recorded 1 h before and 2 h after the test substance infusions into the rats. RESULTS: In all fasted rats a typical pattern of MMC was observed. Among the totally 68 activity fronts recorded in fasted rats under control, 67% started in duodenum, and 33% in antrum. MMC cycle duration and duration of phase III of antral origin were longer than those of duodenal origin. Administration of 20 microg/kg porcine motilin induced a premature antral phase III of antral origin. But perfusion into stomach with UDCA resulted in shorter MMC cycle duration, longer duration of phase III of duodenal origin, which were followed with shorter cycle duration and duration of antral phase III. CONCLUSION: In fasted rats, MMC could originate from antrum and duodenum respectively. The characteristics of MMC of different origins may contribute to the large variations within subjects. The mechanisms of different origins of phase III may be different. Porcine motilin and UDCA could affect MMC of different origins of the gastrointestinal tract in fasted state, respectively.     

Mitomycin C-induced organ toxicity in Wistar rats: a study with special focus on the kidney

Summary Two studies were performed to investigate acute and chronic organ toxicity after Mitomycin C (MMC) administration in Wistar rats. Six rats received 2.5 mg/kg MMC i.p. once and were followed for 5 consecutive days. The alanine aminopeptidase (AAP)/creatinine ratio increased significantly, compared to a control group receiving saline. Four groups of rats were injected i.p. weekly for 5 weeks; 6 control rats with saline, 7 rats with 1.7 mg/kg of MMC, 7 rats with 10 mg/kg 5-fluorouracil (5-FU) and 7 rats with MMC as well as 5-FU. The latter two groups were included to study possible toxicity synergism between the two drugs. A significant decrease in AAP excretion in the MMC group, as well as a nonsignificant decrease in the MMC/5-FU group were the most remarkable observations. Light microscopy did not show renal changes, but did show alveolar septal congestion after repeated MMC injections. It is concluded that MMC causes tubular damage in Wistar rats, with acute leakage of enzyme from the cells, followed by enzyme depletion during chronic treatment. Also MMC induces pulmonary changes in Wistar rats. To what extent these changes represent early stages of toxicity remains to be elucidated.     

氯化甲基汞诱导NCI-H446细胞凋亡的体外实验研究

目的 探讨氯化甲基汞(MMC)诱导NCI-H446细胞凋亡发生的可能机制.方法 通过分子生物学方法,检测调控细胞凋亡的关键基因Bcl-2、Bax和caspase-3在mRNA水平的表达情况.结果 MMC组细胞Bcl-2 mRNA水平低于对照组,并存在着时间依赖性降低趋势,至24 h达到最低;Bax及caspase-3 mRNA水平高于对照组,并存在着时间依赖性增高趋势,至24 h达到最高.结论 MMC能够在体外诱导NCI-H446细胞发生凋亡.     

十二指肠球部溃疡患者胃肠运动功能障碍的动力学研究

目的　观察Du患者胃肠运动功能障碍。方法　通过胃肠测压方法对Du患者进行MMC测定。结果　 49例Du患者11/4 9(2 2 4% )出现MMC3期 ;对照组则高达 14 /2 0 (70 % )出现完整MMC3期。对照组MMC3期波幅明显高于Du组 (P <0 0 1)。结论　Du组患者确实存在MMC异常 ,在其发病机理中有一定作用。