Morphological Study on the Mechanism of Tumor-selective Cytocidal Action of Tumor Necrosis Factor

Using light microscopy and electron microscopy, we observed the morphological changes inheuman hepatocellular carcinoma cell line (SMMC-7721) treated with tumor necrosis tumor necrosis factor (TNF)and the cytocidal effect of TNF on the heterotransplanted human hepatocellular carcinoma. It wasfound that the changes of the injury occurred earlier in the cell membranes than in the nuclei duringthe course of TNF killing of SMMC-7721 cells and there were similar lesions around the necroticarea in the heterotransplanted human hepatocellular carcinoma in the nude mice as compared withthose produced in SMMC-7721 cells. In addition, the determination of the DNA content in TNF-treated SMMC-7721 cells and controls revealed no significant difference between them. On the basisof these results and Darzynkiewicz's proposals, it is suggested that TNF exerts its tumor-selectivekilling effect by binding to a specific to a specific plasma membrane receptor to disturb synthesis or assembly ofcell membrane components, thus causing the plasma membrane injury and finally cell lysis.     

p27mt对裸鼠肝癌移植瘤组织VEGF表达的影响

目的:研究外源性突变型p27基因(p27mt)对裸鼠皮下肝癌移植瘤血管生长的影响。方法:用人原发性肝癌细胞株SMMC-7721构建人肝癌裸鼠皮下移植瘤模型,将腺病毒介导的突变型p27(Ad-p27mt组)注射瘤体2,1d后观察移植瘤的血管变化,免疫荧光法检测组织中血管内皮细胞生长因子(VEGF)的表达。结果:Ad-p27mt组移植瘤血管单支、纤细,VEGF表达低于对照组和Ad-Lac Z组(P<0.05)。结论:p27mt抑制裸鼠皮下移植瘤滋养血管生成可能通过降低血管中VEGF表达完成。     

重组腺病毒ADV-TK 基因的构建及其对肝癌细胞的杀伤作用

目的 探讨含胸苷激酶(TK)自杀基因的重组腺病毒(ADV-TK)对肝癌细胞的杀伤作用.方法 采用细胞内同源重组法构建出携带TK基因的ADV-TK,经PCR鉴定正确后进行扩增、纯化和滴度测定,将ADV-TK感染人肝癌细胞株SMMC-7721,MTT法检测受感染的SMMC-7721细胞被不同浓度GCV作用后的细胞存活率情况.结果 构建的重组腺病毒中带有TK基因,用相同滴度的重组腺病毒和不同浓度的GCV作用于肝癌细胞株SMMC-7721后.MTT法检测到细胞的存活率随着GCV浓度的增加而不断降低.结论 本实验构建的携带TK基因的复制缺陷型腺病毒对肝癌细胞具有明显的杀伤作用.     

重组腺病毒载体转染p16基因对肝癌细胞的生长抑制作用

目的：通过腺病毒转染p16基因观察对肝癌SMMC-7721细胞的杀伤作用。方法：克隆人p16基因全长cDNA序列，构建携带p16基因的增殖缺陷型重组腺病毒p16(AdV-p16)，以AdV-p16感染人肝癌SMMC-7721细胞，观察p16基因的表达及其对细胞的生长抑制或杀伤作用。结果：AdV．p16能介导外源基因p16在肝癌SMMC-7721细胞系中高效表达。在感染AdV-p16后随重复感染度(MOI)升高p16基因阳性表达率升高，四甲基偶氮唑蓝染色法(MTT)实验结果表明，SMMC-7721细胞的生长受抑制。结论：腺病毒能够介导p16基因在肝癌细胞中高效表达，促进细胞周期阻滞和诱导肿瘤细胞凋亡。     

靶向肝癌表达p16基因的腺病毒载体对裸鼠移植瘤的抗癌活性

目的:利用已构建好的在肝癌细胞中定向表达p16基因的腺病毒载体AdAFP-p16,研究腺病毒介导p16基因的表达对肝癌裸鼠移植瘤的抗癌活性.方法:培养肝癌细胞SMMC-7721,于裸鼠右侧腹部近腋下皮肤注射1×106细胞数细胞悬液,建立裸鼠肝癌移植瘤模型.成瘤后给于瘤体内AdAFP-p16病毒注射治疗,病毒总量1×109 pfu/只,观察AdAFP-p16对肝癌模型的抗肿瘤疗效以及p16基因表达引起的肝癌细胞病理变化.结果:AdAFP-p16能够介导p16基因在肝癌细胞中特异性表达,具有明显的肿瘤生长抑制作用,抑制率可达60.12%(P＜0.01),引起肝癌细胞的坏死.结论:AFP启动子控制的p16基因在肝癌细胞中定向表达,能够抑制肝癌模型的生长,对肝癌综合治疗具有重要意义.     

绿茶提取物EGCG对人肝癌裸鼠移植瘤凋亡和血管生成的影响

目的：用人肝癌SMMC-7721细胞建立裸鼠移植瘤模型,观察绿茶提取物EGCG单体对裸鼠移植瘤凋亡和血管生成的影响。方法：用人肝癌SMMC-7721细胞建立裸鼠移植瘤模型,待皮下移植瘤形成后,将裸鼠随机分为实验组和对照组,每天分别给予EGCG单体溶液50mg/kg.只灌胃和生理盐水灌胃,3周后瘤块离体称重,计算抑瘤率;透射电镜观察实验组与对照组肝癌移植瘤超微结构;用TUNEL法检测移植瘤中人肝癌SMMC-7721细胞凋亡的情况;用免疫组织化学法检测移植瘤中VEGF蛋白表达的变化,并通过CD34表达检测微血管密度（MVD）;用RT-PCR检测移植瘤中VEGF mRNA的表达。结果：实验组裸鼠经EGCG单体溶液灌胃后,皮下移植瘤体积、重量明显小于对照组,抑瘤率为30.13%±5.17%;透射电镜观察,实验组肝癌移植瘤组织见不同时期凋亡细胞,部分形成凋亡小体;TUNEL法检测实验组移植瘤中人肝癌SMMC-7721细胞凋亡明显多于对照组（P〈0.05）;实验组移植瘤中VEGF蛋白和mRNA表达均明显下调（P〈0.05）,实验组MVD较对照组明显下降（P〈0.05）。结论：绿茶提取物EGCG可能通过增加人肝癌SMMC-7721细胞凋亡,抑制新生血管生成达到抗癌作用     

稳定表达外源性p16基因肝癌SMMC-7721细胞株的建立及鉴定

目的构建稳定表达外源性p16基因的肝癌SMMC-7721细胞株。方法利用脂质体介导的基因转染方法,借助真核质粒表达载体pcDNA3．1( ),将外源性p16基因转染入此基因表达下调的人肝癌细胞株SMMC-7721细胞中,经G418筛选,建立稳定表达的细胞株,用逆转录聚合酶链反应(RT—PCR)及免疫组织化学法鉴定p16基因的表达,同时对细胞株分泌蛋白进行活性检测。结果转染p16基因的SMMC-7721细胞中可以检测到p16mRNA及蛋白的表达。结论建立稳定表达P16抑癌蛋白的SMMC-7721细胞株有助于研究p16抑癌基因在肝癌发生中的作用。     

单纯疱疹病毒Ⅱ型胸苷激酶基因旁观者效应的实验研究

目的 :研究单纯疱疹病毒Ⅱ型胸苷激酶基因 (HSV -Ⅱtk)对人原发性肝细胞癌SMMC - 772 1的旁观者效应 .方法 :HSV -Ⅱtk基因通过阳离子脂质体Lipofectin介导 ,体外转染人原发性肝细胞癌SMMC -772 1,孵育 18h .取出细胞及上清液 ,对倍稀释 ( 2× ,4× ,8× ,16× ,3 2× )后分别加入另一 2 4孔板 .结果 :正常SMMC - 772 1细胞的浓度升高 ,亲本细胞的存活率随之降低 ,两者呈明显的负向相关关系 ;细胞组的OD值明显低于上清液组及空白对照组 (P <0 0 1) ;细胞组可见凋亡峰出现 ,而上清液组则无凋亡峰出现 .结论 :HSV -Ⅱtk基因对人原发性肝细胞癌SMMC - 772 1细胞具有旁观者效应 ,其作用机制可能与细胞紧密连接及细胞凋亡有关     

PEG-PEI/Fe_3O_4纳米磁流体-TK对裸鼠移植性肝癌细胞靶向杀伤作用研究

目的研究PEG-PEI／Fe3O4纳米磁流体-TK对人肝癌细胞系SMMC-7721裸鼠移植瘤模型的靶向性治疗作用。方法建立人原发性肝癌稞鼠皮下移植瘤模型，将荷瘤裸鼠随机分成肿瘤对照组、纯自杀基因组、PEG-PEI／Fe3O4纳米磁流体-TK组3组。对照组不作任何处理，实验组于瘤体内分别直接注射纯自杀基因、PEG-PEI／Fe3O4纳米磁流体-TK，同时于裸鼠腹腔内注射GCV，观察不同时段皮下肿瘤的生长情况并做病理学检查，免疫组化法检测肿瘤微血管密度（MVD）以及血管内皮细胞生长因子（VEGF）的表达量，原位末端标记（TUNEL）法检测细胞原位凋亡。同时，用RT-PCR检测肿瘤鼠心，肝，肾的自杀基因表达情况。结果裸鼠皮下成瘤率100％；研究PEG-PEI／Fe3O4纳米磁流体-TK组的肿瘤体积、血清AFP含量、肿瘤MVD和VEGF表达强度均明显低于对照组、纯自杀基因组（P〈0．05），细胞凋亡指数都明显高于后两组（P〈0．05），可见较多的凋亡细胞。RT—PCR测示肿瘤鼠心，肝，肾未见自杀基因表达，而肿瘤细胞则出现自杀基因表达。结论PEG-PEI／Fe3O4纳米磁流体-TK可显著抑制肿瘤的生长，并对肿瘤治疗具有靶向性，是一种较为理想的肝脏肿瘤靶向给药系统，有望成为治疗原发性肝癌的新型生物制剂之一。     

人肝细胞癌转铁蛋白受体显像及靶向治疗研究

目的 探讨^131I-D2C5用于肿瘤受体成像和放射免疫治疗的价值。方法 人肝细胞癌SMMC-7721采用隧道包埋法植入Balb／c（-／-）裸鼠肝左叶,建立原位种植肿瘤模型。①12只荷瘤裸鼠随机分为两组,每组6只,分别经尾静脉注射^131I-D2C5、^131I-mIgG,放射剂量均为14．8MBq／只;SPECT采集^131I-D2C5和^131I-mIgG注射后6h、24h放射白显影图像;γ计数器检测体内放射性分布。②18只荷瘤裸鼠随机分为两组,每组9只,每周分别经腹腔注射^131I-D2C5 ,^131I-mIgG,连续6周;另外9只荷瘤裸鼠每周腹腔注射生理盐水200肛l作为对照组。8周后比较各组肿瘤体积,计算其生长抑制率,评估肿瘤坏死程度。结果 注射^131I-D2C5后6h时,裸鼠肝肿瘤部位显影,24h时肿瘤显影最清晰。注射^131I-mIgG后,肿瘤部位未见明显放射性浓聚。24h时^131I-D2C5组裸鼠体内肿瘤／血为6．6,肿瘤／肝为2．2,肿瘤／肌肉为20．8。静脉注射^131I-D2C5导向治疗较^131I-mIgG更显著抑制人肝细胞癌裸鼠模型中肿瘤的生长,促进肿瘤坏死。结论 ^131I-D2C5能与人肝细胞癌SMMC-7721高特异性、高亲和力地结合。在肝癌显像及生物靶向治疗中具有广泛的应用前景。     

酒精滥用对HIV脑炎动物模型的影响

目的研究氯化锂对人SMMC-7721肝癌细胞增殖和对荷肝癌小鼠肿瘤生长的抑制作用。方法采用噻唑蓝(MTT)法观察氯化锂(LiCl)对SMMC-7721细胞增殖的抑制作用;以流式细胞仪分析氯化锂处理SMMC-7721肝癌细胞后,细胞凋亡情况;同时利用小鼠H22肝癌细胞实体瘤模型,观察氯化锂对荷肝癌小鼠肿瘤生长的抑制作用;对肿瘤组织超微结构进行透射电镜观察。结果氯化锂对SMMC-7721细胞具有抑制作用并有浓度依赖性;且氯化锂可诱导SMMC-7721细胞发生凋亡;荷肝癌小鼠动物实验中氯化锂中浓度组和高浓度组抑瘤率分别达到50.0%和60.7%,提示氯化锂对小鼠的肿瘤生长具有一定的抑制作用;电镜下可见氯化锂处理组肿瘤组织的凋亡细胞和凋亡小体。结论氯化锂对SMMC-7721细胞的增殖和荷肝癌小鼠肿瘤的生长具有抑制作用,作用机制可能与其诱导肝癌细胞凋亡有关。     

Replication-incompetent Adenovirus Vector-mediated MDA-7/IL-24 Selectively Induces Growth Suppression and Apoptosis of Hepatoma Cell Line SMMC-7721

In order to investigate the effect of replication-incompetent adenovirus vector expressing MDA-7/IL-24 on tumor growth and apoptosis of human hepatocellular carcinoma （HCC） cell line SMMC-7721 and normal liver cell line L02, the recombinant replication-incompetent Ad.mda-7 virus vector was constructed and infected into the HCC cell line SMMC-7721 and normal liver cell line L02. RT-PCR was performed to examine the expression of MDA-7 mRNA. The concentrations of MDA-7/IL-4 in culture superuatants were determined by using ELISA. MTT and Hoechst staining assay were applied to observe the inhibitory and killing effects of MDA-7 on the HCC cells. By using flow cytometry, the apoptosis, cell cycle and proliferation of SMMC-7721 and L02 cells were measured. The results showed recombinant replication-incompetent virus expressing MDA-7/IL-24 was constructed successfully, and RT-PCR revealed that it could mediate the high expression of the exogenous gene MDA-7/IL-24 in SMMC-7721 and L02 cells. The expression of MDA-7/IL-24 proteins in the culture superuatant was detectable by ELISA. Ad.mda-7 infection induced apoptosis and growth suppression in SMMC-7721 cells and an increased percentage of HCC cells in the GyM phase of the cell cycle, but not in L02 cells. It was concluded that mda-7/IL-24 gene, mediated with replication-incompetent adenovirus vector, could selectively induce growth suppression and apoptosis in HCC cell line SMMC-7721 but without any toxic side-effect on normal liver line L02.     

全反式维甲酸增强超声微泡包裹的单纯疱疹病毒胸苷激酶自杀基因治疗荷肝癌裸鼠的效果

目的探讨全反式维甲酸(all-trans retinoic acid,ATRA)能否提高微泡包裹的单纯疱疹病毒胸苷激酶(herpes simplex virus thymidine kinase,HSV-TK)自杀基因对肝癌的体内治疗作用。方法用人肝癌SMMC-7721细胞建立皮下裸鼠移植瘤模型,先检测不同剂量ATRA的抗肿瘤效应;再用ATRA联合基因治疗,实验分4组:磷酸盐缓冲液组、ATRA组、HSV-TK组、联合治疗组,各组测量肿瘤体积,计算抑瘤率,Western blot检测输注的目的基因质粒的表达,HE染色行病理学观察,免疫组化法检测连接蛋白Cx32的表达。结果 ATRA在1 mg/kg下无抗肝癌作用,但≥4 mg/kg即具有明显抗肝癌效应;抑瘤率在磷酸盐缓冲液组、ATRA组、HSV-TK组、联合治疗组分别为0、(7.46±7.25)%、(37.65±3.87)%、(59.04±3.08)%,联合治疗组分别与磷酸盐缓冲液组、ATRA组、HSV-TK组比较,差异有统计学意义(P<0.05)。HE结果显示:采用ATRA联合基因治疗后,肿瘤坏死细胞明显较对照组多,免疫组化结果显示:ATRA处理过的组织中,Cx32蛋白表达增加,且以胞膜表达为主。结论 ATRA具有抗肝癌作用;ATRA能增强超声微泡包裹的HSV-TK自杀基因杀伤肝癌的效果,其可能机制与ATRA促进了Cx32蛋白的正常表达有关。     

单链抗体导向的慢病毒介导VP22-TK系统对MUC1+人卵巢癌裸鼠腹腔移植瘤的作用

目的探讨抗MUC1单链抗体(scFv)导向的慢病毒介导的单纯疱疹病毒结构蛋白VP22和胸苷激酶(TK)融合基因及丙氧鸟苷(GCV)自杀基因系统对MUC1+人卵巢上皮癌的特异靶向性生长抑制作用.方法将慢病毒包装质粒、包膜质粒、转移载体质粒采用磷酸钙沉淀法共转染包装细胞293T,收集病毒上清,并建立MUC1+人卵巢上皮癌(3AO)细胞株腹腔移植瘤模型.单药组分为scFv-VP22-TK+生理盐水(NS)组、VP22-TK+NS组、NS+NS组,分别用慢病毒scFv-VP22-TK、VP22-TK或NS 1 ml腹腔注射,继予NS腹腔注射;联合用药组分为scFv-VP22-TK+GCV组、VP22-TK+GCV组、NS+GCV组分别应用慢病毒scFv-VP22-TK、VP22-TK及NS腹腔注射,24 h后给予GCV腹腔注射治疗.每组裸小鼠均为5只.观察各组裸鼠的生存时间及慢病毒的毒性作用.结果平均生存时间scFv-VP22-TK+NS组、VP22-TK+NS组、NS+NS组、NS+GCV组、VP22-TK+GCV组、scFv-VP22-TK+GCV组分别为18.4 d±2.9 d、18.8 d±1.5 d,17.6 d±1.1 d,18.5 d±1.6 d,24 d±5 d和46 d±22 d, 6组比较,差异有显著意义(χ2=24.82,P=0.002);并且scFv-VP22-TK+GCV组较VP22-TK+GCV组裸鼠平均生存时间明显延长(χ2=7.43,P=0.006).结论抗MUC1 scFv靶向的慢病毒介导的VP22-TK/GCV系统对MUC1+人卵巢上皮癌具有高效靶向杀伤作用.     

Down-regulation of lung resistance related protein by RNA interference targeting survivin induces the reversal of chemoresistances in hepatocellular carcinoma

Background Both survivin and lung resistance related protein （LRP） are hepatocellular carcinoma （HCC）. But the relationship between survivin and LRP is investigate the effects of down-regulation of survivin on LRP expressions and the both in vitro and in vivo. related to the chemoresistances in ndefinite. The aim of this study was to reversal of chemoresistances in HCC Methods The expressions of survivin were detected by RT-PCR and Western blotting in HCC cell line SMMC-7721 and SMMC-7721/ADM. The sensitivities of these two cell lines to ADM were evaluated by MTT assays. SiRNA which targeted survivin was transfected into SMMC-7721/ADM cells, then the sensitivity of SMMC-7721/ADM cells to ADM and the expressions of survivin and LRP were detected respectively. SMMC-7721/ADM cells were transplanted subcutaneously into nude mice to establish xenograft tumors. Antitumor activities of RNA interference （RNAi） targeting survivin, various doses of ADM and combination therapies were observed respectively. Possible toxicities were evaluated. LRP expression changes were tested. Student＇s ttest was used for evaluating statistical significance. Results The expressions of survivin in SMMC-7721/ADM cell line showed significant elevation compared to those in SMMC-7721 cell line （P 〈0.05）. Positive siRNA down-regulated the expressions of survivin significantly （P 〈0.05）. SiRNA targeting survivin could sensitize SMMC-7721/ADM cells to ADM and down-regulate the expressions of LRP significantly （P 〈0.05）. Growths of the tumors were significantly inhibited in positive siRNA group as compared with those in the control group from the 8th day （P 〈0.05）. Combination therapies caused significant tumor inhibitions compared with tumors of nude mice in the other three groups respectively （P 〈0.05）. No toxicities were found in nude mice treated by siRNA and combination therapies. The expressions of LRP were markedly reduced in tumors treated with siRNA targeting survivin （P 〈0.05）. Conclusions Down regulation of survivin gene by RNAi can increase chemosensitivity of HCC both in vitro and in vivo. The reversal of drug resistance may be reduced through the inhibitions of LRP.     

Effects of HSP70 antisense oligonucleotide on the proliferation and apoptosis of human hepatocellular carcinoma cells

The study investigated the effects of heat shock protein 70(HSP70) antisense oligonucleotide(ASODN) on the proliferation and apoptosis of a human hepatocellular carcinoma cell line(SMMC-7721 cells) in vitro.HSP70 oligonucleotide was transfected into SMMC-7721 cells by the mediation of SofastTM transfection reagent.Inhibition rate of SMMC-7721 cells was determined by using MTT method.Apoptosis rate and cell cycle distribution were measured by flow cytometry.Immunocytochemistry staining was used to observe th...     

人肝癌原位移植瘤的活体动态观察

目的 建立GFP（绿色荧光蛋白）/Luciferase（荧光素酶,Luc）双标高效表达的人肝癌细胞系SMMC-7721-GFP/Luc,并建立该细胞的裸小鼠肝原位移植瘤动物模型,利用小动物活体成像系统观察裸小鼠肝原位移植瘤的生长及转移情况.方法 应用慢病毒转染的方法建立GFP/I.alC双标的SMMC-7721细胞系,接种于裸小鼠肝原位,采用活体成像技术监测该细胞在小鼠体内深部组织的表达情况.结果 成功建立了GFP/Luc双标表达率接近100%的SMMC-772l-GFP/Luc细胞系,进行裸小鼠肝原位移植后,应用活体成像系统可观察到裸小鼠肝原位早期的微小病灶和晚期移植瘤的生长情况.而且,随着肿瘤移植时间的延长,移植瘤体积的增大,活体成像检测到的发光面积逐渐增大,发光强度也逐渐增加.结论 活体荧光成像系统可直接观察肝原位移植瘤模型中肿瘤的生长及转移,有助于了解人肝癌的生物学行为及其特性,鉴于其敏感、直观,动态、可靠的优点,它将为肝癌的进一步研究提供极其有益的帮助.     

RMP基因在体内对肝癌细胞株SMMC-7721的生长抑制作用

目的探讨RMP基因在体内抑制肿瘤细胞生长的作用及其机制。方法通过体外构建真核表达载体pGPU6-Neo-RMP-484、pFLAG-CMV-4-RMP以及稳定表达细胞株shRNA-SMMC-7721、RMP-SMMC-7721,并测定RMPmRNA表达的变化,荷瘤裸鼠皮下注射各组肝癌细胞,观察移植瘤的大小及病理变化。结果成功构建了真核表达载体及稳定表达细胞系。实验组移植瘤体积、质量、病理及肿瘤相关蛋白的表达量均有明显变化。结论RMP基因在体内能有效地抑制肝癌细胞的生长,为RMP对肝癌的基因治疗/基因干预提供了有价值的靶点及体内分子机制的实验依据,为深入研究奠定了基础。。     

全反式维甲酸增强携单纯疱疹病毒胸苷酸激酶基因的超声微泡对SMMC-7721细胞的旁观者效应

目的观察经全反式维甲酸(all-trans retinoic acid,ATRA)诱导后,单纯疱疹病毒胸苷酸激酶/丙氧鸟苷系统(HSV-TK/GCV)对人肝癌细胞SMMC-7721旁观者效应的影响。方法免疫组化法观察经全反式维甲酸诱导前后SMMC-7721细胞连接蛋白Cx32的表达;将含有HSV-TK基因的质粒通过静电吸附在脂质微泡表面上,采用超声辐照转染并用倒置显微荧光镜及RT-PCR观察TK基因的转入及表达;MTT法观察经全反式维甲酸诱导后HSV-TK/GCV对肝癌细胞SMMC-7721的旁观者效应。结果经全反式维甲酸诱导后SMMC-7721细胞膜上Cx32表达明显增加,而胞质内仅少量表达;通过超声辐照后HSV-TK基因可顺利转入SMMC-7721细胞中并稳定表达;与对照组相比,经全反式维甲酸诱导组可明显提高HSV-TK/GCV对肝癌细胞SMMC-7721的旁观者效应(P<0.05)。结论全反式维甲酸可提高SMMC-7721细胞中连接蛋白Cx32的表达且能正确定位于细胞膜上,这可能与其能增强HSV-TK/GCV系统对肝癌细胞SMMC-7721的旁观者效应有关。