THE INFLUENCE OF HUMAN SINGLE CHAIN INTELEUKIN-12 GENE TRANSDUCTION ON THE BIOIOGICAI BEHAVIOR OF HEPATOMA 7721 CELLS

Objective. To investigate the anti-tumor effects of human single chain interleukin-12 (hscIL-12).``Method. pcDNA/ hscIL-12 recombinant was transfected into human hepatic carcinoma cells (7721 cells)by lipofectin method. The 7721/hscIL-12 cells which secrete hscIL-12 stably, were obtained via G418 selection, and in vitro the influence of hscIL-12 gene transduction on the growth of tumor cells was evaluated by cell cycle analysis. In vivo, genetically engineered 7721 cells (7721/hscIL-12, 7721/pcDNA) and parental cells were implanted into BALB/c nude mice, respectively. 7721/pcDNA and 7721/hscIL-1 2 groups were divided into two sub-groups on day 8: one was administered with hPBL twice, 6 days at interval; the other was given equal volume of PBS. Mice were sacrificed on day 26, and spleens and tumors were taken out for histologic assay.``Results. hscIL-12 produced stably by 7721/hscIL-12 cells had bioactivity, and it was proved by Western blot, immunocytochemistry, and in situ hybridization. In vitro, compared with 7721 and 7721/pcDNA, the 7721/hscIL-12 grew much more slowly. FACS assay showed apparent Gl arrest of 7721/hscIL-12 cells. In animal experiment, on day 8 after inoculation, the tumors of 7721 and 7721/pcDNA group were up to 5 ～ 7mm,while those of 7721/hscIL-12 group were 2 ～4mm. When treated with hPBL, the tumor of 7721/hscIL-12 group disappeared completely. Histologically, the tumors from 7721/hsclL-12 without hPBL treatment had numerous lymphocyte infiltration, the tumor cells displayed depression looking, atrophy, focal necrosis and apoptosis, whereas the tumors of 7721 and 7721/pcDNA groups grew thrivingly.``Conclusion. hscIL-12 transduced 7721 cells could induced significant antitumor immune response which resulted in tumor regression totally when the hPBL was inoculated, and also hscIL-12 has certain effects on mice immune svstem. These findings suggest that hscIL-12 and hscIL-12 gene therapy might have promising prospects in clinical application.     

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     

乙型肝炎病毒X蛋白羧基端氨基酸缺失对肝癌细胞生物学行为的影响

目的探讨乙肝病毒X蛋白(HBx)羧基端缺失了40个氨基酸的突变体(HBx3′-40)和野生型HBx对Huh7和SMMC-7721肝癌细胞的生物学行为的影响。方法脂质体和磷酸钙法介导pcDNA3HBx3′-40和pcDNA3HBx重组体转染HBV(-)的人肝癌细胞Huh7和SMMC-7721。Neo基因PCR及Western印迹方法检测质粒DNA片断插入和HBx蛋白质的表达。借助生长曲线、平板克隆形成、细胞周期、凋亡和裸鼠成瘤实验以及氯霉素乙酰转移酶(CAT)-ELISA法对转染细胞的生物学活性进行检测。结果pcDNA3HBx3′-40组细胞生长速度明显快于pcDNA3HBx和pcDNA3组;pcDNA3HBx3′-40组克隆形成率明显高于pcDNA3HBx和pcDNA3组(P<0·05);流式细胞仪检测结果显示pcDNA3HBx3′-40表达能加速Huh7细胞由G0/G1期→S期的进程;但细胞凋亡检测显示无血清诱导的SMMC-7721细胞HBx3′-40组能部分取消HBx的促凋亡效应,并且该组几乎丧失了HBx的反式激活作用;裸鼠成瘤实验显示,pcDNA3HBx3′-40组成瘤体积明显大于pcDNA3HBx组和pcDNA3组,瘤体重量间差异具有统计学意义(P<0·05)。表明HBx3′-40对肝癌细胞的生长具有明显促增殖作用。结论HBx碳端缺失了40个氨基酸的突变体转染细胞对比野生型HBx显示促增殖能力明显增强,推测HBx通过缺失突变修饰其生物学功能,取消了野生型HBx的反式激活功能和抗增殖效应。另一方面,HBx114~154个氨基酸位点的缺失可能导致p53无法发挥其抑癌作用。     

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。     

肿瘤相关线粒体蛋白12对移植瘤细胞增殖的影响

目的探讨肿瘤相关线粒体蛋白12(TAMP12)对小鼠移植瘤细胞增殖的影响。方法采用脂质体法将TAMP12基因及空载体转染肝癌细胞系SMMC-7721,经G418筛选获得稳定高表达TAMP12细胞株(SMMC-7721-TAMP12)及对照细胞(SMMC-7721-pcDNA3.1),实时定量PCR和蛋白印迹检测TAMP12在这两组细胞中的表达。将SMMC-7721-TAMP12和对照SMMC-7721、SMMC-7721-pcDNA3.1三组细胞分别接种于BALB/cnu/nu小鼠的前肢腋下,连续观察荷瘤小鼠中肿瘤的生长状况。接种4周后处死小鼠,取瘤块分别测量瘤体质量和体积,应用实时定量PCR和免疫组化方法检测三组移植瘤中TAMP12的表达;透射电镜观察移植瘤细胞中亚细胞器形态;并应用基因芯片技术检测三组移植瘤肿瘤细胞中的基因差异表达。结果将经实时定量PCR和蛋白印迹检测显示高表达TAMP12的SMMC-7721和对照细胞分别接种裸鼠后,三组荷瘤小鼠中肿瘤的生长曲线呈现明显差异,转染TAMP12的荷瘤小鼠中肿瘤生长速度明显快于对照组荷瘤小鼠。肉眼观察可见实验组肿瘤组织中血管较对照组丰富;电镜观察发现实验组的细胞分裂增殖明显。基因芯片显示,该基因的高表达可促进多个与细胞增殖相关的基因表达上调。结论TAMP12基因具有促进细胞增殖的作用,其机制可能与调节细胞增殖的胰岛素样受体介导的信号转导通路有关。     

Expression of TN4 gene and its role in human hepatocarcinogenesis from Qidong, a liver cancer risk area

Background We investigated the expression and role of TN4 in the oncogenesis of human hepatocellular carcinoma (HCC) from Qidong which is a HCC risk area.Methods The expression of TN4 in HCC was observed using immunohistochemical staining (IHC). TN4 levels were manipulated in human liver cancer cell SMMC7721, using pcDNA3.1 eukaryotic expression constructs designed to express the complete TN4 cDNA. The biological changes of the cells were observed before and after transfection of TN4 and the change of gene expression was analysed by atlas cDNA expression array. Results Among 100 pairs of samples of HCC, TN4 down-regulation expression and up-regulation expression positive rate were 81% (81/100), 19% (19/100), respectively (P&lt;0.01). TN4 protein was mainly localized in cytoplasm and membrane. The positive rate of TN4 were 10% (3/30), 100% (70/70) in lymph node metastasis and no lymph node metastasis, respectively (P&lt;0.01).　The growth rates of the derivative SMMC7721-TN4 cell lines were decreased in comparasion with that of normal SMMC7721 cells and pcDNA- SMMC7721. Some gene expression was changed before and after transfection of TN4. At 30 days of post-implantation of SMMC7721-TN4, SMMC7721-pcDNA3, SMMC7721 group produced tumors of (301.9±143.4) mm3, (2418.7±362.8) mm3, (2317.4±587.8) mm3, respectively, (P&lt;0.01). Tumor inhibiting rate was 82.4% in TN4 transfection group. Sections of tumors were observed for their degree of tissue necrosis and there was higher degree of necrosis in tumors of the TN4-SMMC7721 cell group than those of the SMMC7721, SMMC7721-pcDNA groups.Conclusions TN4 may play an important role in the oncogenesis of human HCC, especially in Qidong, the HCC risk area and TN4 could be a candidate tumor suppressor gene for HCC.     

NNMT真核表达载体的构建并转染SMMC7721肝癌细胞株

目的构建pcDNA3.1(-)/NNMT(尼克酰胺-N-甲基化酶)真核表达载体并将其稳定转染到肝癌细胞系SMMC7721中。方法采用PCR法从PGEX4T-1/NNMT重组质粒中克隆得到NNMTcDNA全长序列,并将扩增的cDNA片段与pMD19-T载体连接后亚克隆到真核表达载体pcDNA3.1(-)中。重组子经酶切分析及测序鉴定后,用脂质体转染技术将其导入到人肝癌细胞系SMMC7721,经G418筛选并建立稳定的转染细胞株,应用RT-PCR检测转染前后该细胞株NNMT基因的mRNA表达水平。结果真核表达载体构建成功,经RT-PCR检测,重组质粒转染株的NNMT基因mRNA表达水平高于对照组,证实NNMT基因已经稳定转染到SMMC7721细胞中并得到表达。结论成功建立了人基因NNMT的稳定转染细胞株,为进一步研究NNMT的功能奠定了基础。     

CAAP1对人肝癌细胞SMMC-7721增殖、迁移和侵袭的影响

目的 探讨Caspase活性和凋亡抑制因子1(CAAP1)对人肝癌细胞SMMC-7721增殖、迁移和侵袭的影响.方法 构建CAAP1的过表达载体pcDNA3/CAAP1和敲降载体pSilencer 2.1-U6 neo/shR-CAAP1(shR-CAAP1),并进行鉴定.SMMC-7721分为4组:pcDNA3/CA...     

pcDNA3-MAGE-1真核表达载体的构建及其在Hepal-6细胞中的稳定表达

目的:构建真核表达载体,并在小鼠肝癌Hepal-6细胞中稳定表达,观察转染细胞的增殖能力和致瘤能力.方法:用PCR方法扩增SMMC-7721人肝癌细胞株MAGE-1全长序列,连接到真核表达载体pcDNA3中,构建真核表达pcDNA3-MAGE-1,脂质体法转染小鼠Hepal-6细胞.G418筛选阳性克隆(Hepal-6-MAGE-1),用RT-PCR和Western blotting检测阳性克隆中mRNA和蛋白质的表达;MTT法检测Hepal-6细胞和Hepal-6-MAGE-1细胞生长和增殖的变化;分别以Hepal-6细胞和Hepal-6-MAGE-1细胞接种于CA7BL/6j小鼠右侧背部皮下,观察Hepal-6-MAGE-1细胞的致瘤能力.结果:构建MAGE-1的真核表达载体转染Hepal-6细胞,PT-PCR与Western bohting检测分别在Hepal-6-MAGE-1细胞中检测到人MAGE-1基因的mNRA和蛋白质的表达,两组细胞增殖无统计学差异;两组各10只小鼠均皮下成瘤,且肿瘤大小没有明显差异.结论:成功构建了真核表达载体pcDNA3-MAGE-1,获得了稳定表达人MAGE-1基因的小鼠肝癌Hepal-6细胞株,并具有很好的增殖和致瘤能力.     

RASSF1A基因转染对人肺腺癌细胞株A549增殖的抑制作用

目的：观察外源性RASSF1A基因对人肺腺癌细胞A549增殖及NF- κB亚单位P65表达的影响。方法：利用脂质体转染技术将真核表达重组体pcDNA3.0-RASSF1A质粒和空载体pcDNA3.0质粒分别导入A549细胞，经G418筛选后获得稳定转染细胞克隆，Western blotting检测RASSF1A基因表达。采用MTT(四甲基偶氮唑盐)法、流式细胞仪分析转染细胞的生物学行为。 RT-PCR和Western blotting检测基因转染对P65表达的影响。结果：经脂质体转染和筛选，建立了稳定表达RASSF1A基因的A549细胞系。与未转染组和转染空白载体组比较，转染RASSF1A基因的细胞生长速度明显减慢（P<0.05），细胞周期中G1/G0期比例明显增加（P<0.05），而S期比例减少；转染组细胞核内P65蛋白表达明显降低（P<0.05），而全细胞P65蛋白及mRNA表达未见明显变化。结论：RASSF1A基因可能通过抑制P65活性而抑制人肺腺癌细胞A549的生长。     

脂质体介导p53基因对肝癌细胞生长的抑制作用

观察外源野生型p5 3基因在肝癌基因治疗方面的可行性。方法 :将载有人野生型 p5 3-cDNA的真核表达质粒pcDNA3 - p5 3,用阳离子脂质体介导转染人肝癌细胞系HepG3B细胞 ,用流式细胞仪检测pcDNA3-p5 3对HepG3B细胞生长的影响。结果 :通过观察细胞生长曲线与流式细胞仪检测细胞周期和细胞的凋亡指数发现 ,HepG3B细胞生长受到明显的抑制。结论 :脂质体介导的p5 3基因可在HepG3B细胞中表达 ,且明显抑制该细胞的生长。     

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。。     

微囊化转mIL-12基因CHO细胞皮下移植及联合5-FU对荷瘤小鼠的治疗作用

目的：观察微囊化CHO/pcDNA3.1/mIL-12细胞皮下移植及联合5-FU对荷瘤小鼠的治疗作用。方法：将微囊化的CHO/pcDNA3.1/mIL-12细胞移植到荷瘤小鼠的皮下,观察肿瘤的生长速度、荷瘤小鼠的生存期,20d后,检测小鼠血清Th1和Th2类细胞因子IFN-γ、IL-2、IL-12和IL-4、IL-10的水平及NK细胞和CTL细胞的活性。结果：经微囊化CHO/pcDNA3.1/mIL-12细胞皮下移植干预治疗后,小鼠血清Th1细胞因子水平明显升高,NK细胞和CTL细胞的活性明显增强,而Th2类细胞因子则明显降低;小鼠肿瘤的生长速度明显减慢,生存期明显延长;同时可部分改善化疗引起的免疫抑制作用。结论：微囊化的CHO/pcDNA3.1/mIL-12细胞皮下移植可以明显改善荷瘤小鼠的细胞免疫功能,部分减轻化疗引起的免疫抑制作用 ,对减慢肿瘤的生长速度和延长荷瘤小鼠的生存期均有明显的效果。     

Iodine-125 interstitial brachytherapy for experimental liver cancer

Objective：To study the effect of iodine-125 interstitial brachytherapy on liver cancer. Methods： Animal model of human liver cancer was established by injecting SMMC-7721 cells cultivated in vitro subcutaneously into the flank of BALB/c nude mice. Nude mice with tumor of 5 mm in diameter were randomly divided into 2 groups （n = 10）. One iodine-125 seed of apparent activity 0.8 mCi was implanted into the center of tumor in treatment group, whereas an inactive seed was implanted in control group. The other 20 nude mice with tumor reaching 10 mm in diameter were also treated as above. The size of tumor was determined weekly after implantation, and pathological examination and blood routine were taken on the 28th day. Results： Tumor growth was obviously inhibited in treatment group of tumor of 5 mm in diameter, and there was statistically significant difference in tumor volume between treatment and control groups （P〈0.01）. Around iodine-125 seed, apparent necrosis of tumor was shown in treatment group, accompanied by karyopyknosis and reduced plasma in residual tumor cells microscopically. Tumor growth was not inhibited in either treatment or control group of tumor of 10 mm in diameter. There was no obvious adverse effect except for decreased white blood cells in treatment groups. Conclusion： There is certain effect of iodine-125 interstitial braehytherapy on liver cancer, which is associated with the size of tumor.     

NF-κB与TNF的体内抗前列腺癌作用

探讨NF-κBI(NF-κB抑制剂)与融合基因PSP94-TNFαD11a联合注射抗前列腺癌的 作用。方法制作PC-3细胞裸鼠动物模型。肌注PSP94与TNFαD11a融合基因的pcDNA-PSP94-TNFαD11a真核表达质粒DNA,并联合肌注NF-κBI,同时设pcDNA-PSP94、pcDNA-PSP94联用NF-κBI、pcDNA-PSP94-TNFαD11a、NF-κBI、空载体、生理盐水和环磷酰胺对照组。注射后第10天处死动物,称瘤重、计算押瘤率。结果pcDNA-PSP94-TNFαD11a联合NF-κBI用药组抑瘤率(36％)高于pcDNA-PSP94-TNFαD11a组(20％),前者瘤重〔(1.87±0.934)g〕明显低于后者〔(2.32±1.373)g〕。差异具有显著性(P<0.05)。结论NF-κBI可提高TNF的抗前列腺癌作用。     

人血管内皮生长因子基因的克隆及真核表达质粒的构建

目的：克隆人血管内皮生长因子基因VEGF165片段。构建pcDNA3／VEGF165真核表达质粒。方法：采用逆转录聚合酶链式反应(RT-PCR)技术,从人肝癌细胞株SMMC-7721中扩增出血管内皮生长因子VEGF165基因片段,通过DNA重组技术将该基因片段重组于pcDNA3真核表达载体上,构建成pcDNA3／VEGF165重组质粒,分别用PCR扩增、酶切电泳分析及DNA测序的方法对重组DNA进行鉴定。结果：经PCR扩增、酶切电泳分析和DNA测序证实,本实验构建的重组质粒目的基因片段为人VEGF165cDNA。结论：本实验成功地克隆了VEGF165基因并构建了其真核表达质粒。为进一步研究用VEGF基因转染的方法来恢复或增强放疗后组织的血管生成能力奠定了基础。     

趋化因子IP10抑制乳腺癌细胞4T1播散转移的研究

目的观察增强IP10在肿瘤局部的表达对乳腺癌细胞4T1远端播散转移的作用。方法用电转染的方法建立稳定表达IP10的4T1细胞株IP10-4T1。将BALB/c小鼠分为IP10-4T1细胞组、4T1细胞组和转染pcDNA3的4T1细胞组(pcDNA3-4T1)。利用实验性肺转移模型和体外杀伤实验研究接种IP10-4T1对4T1细胞播散转移的影响。结果IP10-4T1细胞中IP10mRNA转录水平相对含量为0.92±0.12与未转染的4T1细胞(0.35±0.12)和pcDNA3-4T1细胞(0.29±0.08)比较差异有统计学意义(P<0.01)。IP10-4T1组对淋巴细胞的趋化指数为2.77±0.29,经CXCR3抗体处理后下降为1.71±0.20(P<0.05)。实验性肺转移结果显示,IP10-4T1组小鼠肺重为0.27g±0.02g,与4T1细胞组(0.48g±0.08g)和pcDNA3-4T1组(0.43g±0.16g)比较明显减轻(P=0.021);其肺表面形成的转移结节数较对照组少;IP10-4T1组肺组织中形成的4T1细胞克隆数为2.6±1.7,明显低于4T1组(34.0±6.3)和pcDNA3-4T1组(33.0±2.3,P<0.05);2/6的IP10-4T1组小鼠肺组织内可见转移灶,而对照组全部形成肺转移灶。接种IP10-4T1细胞组小鼠的淋巴细胞杀伤率在各个效/靶比均高于对照组(P<0.05)。结论增加肿瘤局部IP10的表达,能增强机体细胞免疫应答水平,通过肿瘤特异性的杀伤作用,抑制肿瘤细胞在体内播散转移。     

肿瘤相关抗原与白细胞介素2并用的抗瘤作用

本文以艾氏腹水瘤接种于 C57BL/6小鼠皮下为转移瘤模型。接种前先用肿瘤相关抗原(TAA)免疫,可明显增强白细胞介素2(IL-2)的抑瘤效果。三批每组45只小鼠的实验结果表明,对照组肿瘤逃逸率6.7%,IL-2治疗组17.8%,TAA 免疫和 IL-2并用组为37.8%。每只小鼠皮下接种瘤细胞2×10~6,一周后对照组有40%、IL-2组有30%、TAA IL-2组有20%的小鼠长出了肿瘤。停止治疗三周后 IL-2组和 TAA IL-2组肿瘤体积分别相当于对照组的0.56±0.10和0.34±0.23;停止治疗40天后,三组肿瘤平均重量分别为1.12g、0.64g和0.15g。IL-2组与对照组相比 p<0.001;TAA IL-2组与 IL-2组之间 p<0.001。过继注射 TAA 免疫小鼠的淋巴细胞,在推迟肿瘤出现、阻止肿瘤的初期生长和延长小鼠存活方面有明显而短暂的作用,但作用消失后有的肿瘤发展更快。     

信号肽重组mBD2在宫颈癌细胞中的稳定表达及活性测定

目的 探讨鼠重组beta防御素2(rmBD2)对SiHa细胞增殖的影响.方法 采用脂质体转染法将真核表达质粒pcDNA3.1( )/rmBD2转染SiHa细胞系,G418筛选出稳定表达细胞克隆.分别采用间接免疫荧光染色、RT-PCR方法检测稳定转染细胞中rmBD2蛋白和rmBD2 mRNA表达,并采用MTT法对稳定转染细胞株进行细胞增殖能力的测定.结果 采用100 μg/mL的G418浓度筛选质粒转染的SiHa细胞20 d,得到了rmBD2稳定表达细胞株SiHa/rmBD2及转染pcDNA3.1( )空质粒的对照细胞SiHa/K.免疫荧光染色显示SiHa/rmBD2细胞质中均有目的 蛋白的表达,转染效率为100%.提取稳定转染4、6、8、10 周SiHa/rmBD2细胞总RNA,RT-PCR反应扩增得到220 bp左右的目的 片段,而SiHa/K及SiHa细胞未见目的 蛋白表达.细胞生长曲线显示SiHa/rmBD2细胞的生长速度低于SiHa/K及SiHa细胞(P＜0.05).结论 本研究成功筛选了稳定表达rmBD2的细胞株SiHa/rmBD2,并采用间接免疫荧光染色、RT-PCR证实了rmBD2蛋白和rmBD2 mRNA的稳定表达,细胞增殖实验表明rmBD2可以明显抑制肿瘤细胞的增殖,为进一步研究rmBD2的抗肿瘤作用奠定了细胞学基础.     

SiRNA稳定抑制肝癌细胞hTERT基因的表达

目的：利用RNA干扰稳定筛选-抑制技术,抑制人端粒酶逆转录酶（hTERT）基因表达,探讨靶向hTERT基因RNAi与抑制肝癌细胞增殖的时-效关系．方法：设计靶向hTERT基因的小干扰RNA,构建重组表达质粒pGenesil—shRNA—hTERT并导入肝癌SMMC-7721细胞株,经G418筛选,建立稳定表达siRNA—hTERT的细胞株．采用real—time RT—PCR、MTF和PCR—TRAP法同时检测pGenesil—shRNA-hTERT稳定抑制组和未处理SMMC-7721细胞组hTERT基因表达、端粒酶活性及细胞增殖变化．结果：在稳定表达pGenesil—shRNA—hTERT的SMMC-7721细胞株中,RNAi效力持续、稳定存在,hTERTmRNA表达、端粒酶活性明显降低,瘤细胞增殖被抑制．结论：RNA干扰能持续、稳定地抑制靶基因hTERT mRNA表达及肿瘤细胞增殖,是有潜力的基因治疗肿瘤新方法．