靶向转酮醇酶样基因1 siRNA表达载体的构建及鉴定

目的构建针对转酮醇酶样基因1(TKTL1)特异性小干扰RNA(siRNA)真核表达载体并检测其沉默效应。方法采用人U6 SnRNA启动子,分别把被9 bp序列间隔的19 bp长短的TKTL1靶序列的反向重复序列,置于pEGFP-C1-U6质粒载体中,构建成TKTL1短发夹环RNA,产生重组质粒pEGFP-C1-U6/TKTL1,分别用PstⅠ和SalⅠ酶切鉴定及测序分析,并将重组质粒转染人结肠癌细胞株LoVo,通过RT-PCR检测TKTL1基因表达水平的变化。结果酶切鉴定与DNA测序分析证明,TKTL1基因的siRNA表达载体构建正确,RT-PCR结果表明转染重组质粒的LoVo细胞TKTL1基因的表达水平明显降低。结论成功构建了针对TKTL1基因的siRNA表达载体,转染LoVo细胞后可显著抑制TKTL1基因表达。     

人CD13基因克隆及其基因转染细胞株的构建

目的 克隆人CD13全长cDNA,构建稳定表达人CD13 分子的基因转染细胞株.方法 提取人外周血单个核细胞总RNA,通过RT-PCR 克隆人CD13基因,将人CD13基因重组入逆转录病毒表达载体pEGZ-Term.将重组逆转录病毒载体pEGZ-Term/CD13 和辅助病毒载体用脂质体法共转染包装细胞293T,收集含有完整重组逆转录病毒颗粒的293T细胞培养上清感染L929细胞,筛选获得Zeocin抗性的基因转染细胞.结果 成功克隆人CD13基因和构建逆转录病毒载体pEGZ-Term/ CD13,并成功获得稳定表达人CD13的基因转染细胞株L929/CD13.结论 成功克隆了人CD13基因及其逆转录表达载体,成功制备了稳定表达人CD13的基因转染细胞株,为研究CD13生物学功能奠定了基础.     

特异性针对大鼠甲状旁腺激素受体1基因siRNA表达载体构建及鉴定

目的:构建并筛选携带针对大鼠甲状旁腺激素受体1基因的pSUPERretro-GFP/Neo干扰逆转录病毒载体及鉴定。方法:根据Genbank筛选甲状旁腺激素受体1基因3个阳性克隆及1个阴性克隆序列,定向克隆入逆转录病毒载体pSUPERretro-GFP/Neo,并用RT-PCR和测序鉴定,将其转染至胰岛素-1细胞中,Westernblot观察甲状旁腺激素受体1基因表达,鉴定其转染效率。结果:菌落RT-PCR及基因测序鉴定结果表明序列正确,并能成功转染到胰岛素-1细胞株中,Western blot筛选最佳抑制基因。结论:成功构建并筛选出特异性沉默大鼠甲状旁腺激素受体1基因的pSUPERretro-GFP/Neo干扰逆转录病毒载体,为深入探讨大鼠甲状旁腺激素受体1基因的抗凋亡作用奠定了试验基础。     

14-3-3σ逆转录病毒载体的构建及稳定转染HaCat细胞系的建立

目的:构建14-3-3σ逆转录病毒载体,并建立高表达14-3-3σ的HaCat细胞系.方法:以人基因组为模板,通过PCR扩增出14-3-3σ基因的编码序列,定向插入到pLEGFP-N1质粒中,并在STBL3内进行扩增,刷选阳性克隆,酶切和测序验证后,转染293vr细胞进行病毒包装、扩增、纯化、获取逆转录病毒栽体.将逆转录病毒载体感染HaCat细胞后Western、实时荧光定量PCR法检测14-3-3σ的表达情况.结果:连接重组后经酶切和测序筛选出pLEGFP-N1-14-3-3σ;稳定转染的HaCat细胞系在倒置荧光显微镜下呈绿色荧光.Western和实时荧光定量PCR法表明14-3-3σ表达明显增强.结论:成功构建了14-3-3σ逆转录病毒载体,并构建了英稳定转染的HaCat细胞系.     

pSiRNA-Shh逆转录病毒载体的构建及对恶性脑胶质瘤细胞作用的离体实验研究

目的建立逆转录病毒介导的人Shh基因RNA干扰体外表达体系并观察对恶性脑胶质瘤细胞的作用。方法将人Shh基因RNA干扰双链转录DNA片段重组到逆转录病毒质粒Psilencer 5.1-H1 Retro中,构建成携带人Shh基因RNA干扰逆转录病毒载体pSiRNA-Shh,经PT67细胞包装后,产生的重组逆转录病毒感染恶性脑胶质瘤细胞株U251和CHG-5细胞,用WST-8、RT-PCR和Western Blotting分别检测对转染细胞活性、人Shh mRNA和蛋白表达的影响。结果重组pSiRNA-Shh质粒经测序鉴定正确。重组逆转录病毒滴度可达210×104CFU/ml,感染U251和CHG-5恶性脑胶质瘤细胞株后3 d能明显抑制细胞生长,RT-PCR和Western Blotting检测人Shh mRNA和蛋白表达水平明显低于阴性对照组和未干扰组。结论携带人Shh基因RNA干扰双链转录DNA片段的逆转录病毒体现出明显的抑制恶性脑胶质瘤细胞生长作用,为下一步开展基因治疗恶性脑胶质瘤奠定了基础。     

MYCT-1基因真核表达载体的构建及鉴定

目的构建MYCT-1(myc target)基因真核表达载体,观察其转染胃粘膜GES-1细胞系后的表达。方法用RT-PCR法合成MYCT-1 cDNA,克隆至表达载体pcDNA3.1上,测序验证无突变发生。将表达载体转染GES-1细胞,用RT-PCR和Western blot检测MYCT-1基因的表达。结果限制性内切酶酶切和DNA测序证实成功克隆了MYCT-1 cD-NA全长并正确插入了表达载体,在GES-1细胞中检测到MYCT-1 mRNA和蛋白。结论成功构建了MYCT-1真核表达载体,可在GES-1细胞中稳定表达。     

人FOXC2真核表达载体的构建及稳定转染C-33A细胞系的建立

目的构建人FOXC2真核表达载体,并转染人宫颈癌C-33A细胞,建立稳定转染的细胞系。方法应用PCR方法从人FOXC2克隆中扩增其cDNA编码区序列,并将其构建于pcDNA3.1（-）真核表达载体。经PCR和测序鉴定后,利用脂质体进行宫颈癌C-33A细胞的转染,应用G418筛选出稳定表达FOXC2的细胞系,通过RT-PCR及Westernblot法检测FOXC2的表达情况。结果成功构建pcDNA3.1（-）/FOXC2真核表达载体,建立稳定转染FOXC2的C-33A细胞系,并鉴定了FOXC2目的基因在C-33A细胞中的过表达。结论FOXC2真核表达载体的成功构建为进一步研究FOXC2基因在宫颈癌中的功能奠定了良好的实验基础。     

LIF真核表达载体的构建及其在MSCs中的稳定表达

目的在人骨髓间充质干细胞内大量稳定的表达人白血病抑制因子（human Leukemia Inhibitory Factor,hLIF）。方法应用RT-PCR方法从人蜕膜组织中扩增出白血病抑制因子,并将其构建于pcDNA3．1真核表达载体上。利用脂质体进行基因骨髓间充质干细胞的转染。利用G418进行基因的稳定表达筛选。通过RT-PCR和Westernblot方法进行基因表达的检测。结果成功扩增出人白血病抑制因子基因,成功构建hLIF-pcDNA3．1真核表达载体。转染LIF-pcDNA3．1的骨髓间充质干细胞经G418筛选,存活十代以上。经RT-PCR及Westernblot方法检测发现转染LIF-pcDNA3．1的骨髓间充质干细胞表达白血病抑制因子明显高于未转染的骨髓间充质干细胞。结论成功构建LIF-pcDNA3．1的真核表达载体并使其在骨髓间充质干细胞得到稳定表达。     

miRNA-19a对结肠癌LoVo细胞生物学特性影响的机制研究

目的探讨微小RNA(miRNA)-19a对结肠癌LoVo细胞生物学特性影响的可能机制。方法采用脂质体介导的转染方法将miRNA-19a模拟物转染到人结肠癌细胞系LoVo细胞;检测转染后miRNA-19a基因的表达;利用CCK8试剂盒检测细胞的增殖能力,TUNEL法检测细胞凋亡影响,细胞侵袭小室法检测细胞的体外侵袭力,RT-PCR和Western blot检测Hsp90/Akt信号通路的变化。结果转染miRNA-19a的结肠癌LoVo细胞,miRNA-19a表达上调,细胞体外增殖能力增强,细胞凋亡减少,细胞的侵袭力增强;细胞Hsp90和Akt的基因和蛋白表达升高。结论 miRNA-19a可通过上调Hsp90/Akt信号通路表达,促进LoVo细胞增殖,减少细胞凋亡,增强LoVo细胞的侵袭能力。     

大鼠组织因子基因克隆及其在C6细胞系中的表达

目的:克隆大鼠组织因子(tissue factor,TF)基因,构建真核表达载体pEGFP-N1-TF,转染C6大鼠神经胶质瘤细胞并检测转染细胞内TF表达水平.方法:采用RT-PCR法从Wistar大鼠肺组织中扩增TF基因,克隆到真核表达载体pEGFP-N1上.通过测序鉴定重组质粒中插入TF的完整性和可靠性.应用脂质体法将鉴定正确的重组质粒转入C6细胞中,荧光显微镜下观察EGFP报告基因的表达强度和转染效率,并对转染细胞的TF-eGFP融合蛋白进行Western blot检测.结果:成功构建pEGFP-N1-TF真核表达载体,转染C6细胞24 h后,在荧光显微镜下可以观测到荧光,并通过Western blot技术检测到TF-eGFP融合蛋白的表达.结论:重组真核表达载体pEGFP-N1-TF构建成功,转染C6细胞后获得了良好的瞬时表达.     

重组逆转录病毒pLNCX2-TH的构建及鉴定

目的：构建并鉴定重组逆转录病毒载体pLNCX2-TH,建立稳定的PT67产病毒细胞系,并观察其对NIH3T3细胞的感染效率,为基因调控干细胞分化治疗帕金森病奠定基础。方法：采用基因工程技术,将酪氨酸羟化酶（TH）基因片段克隆至逆转录病毒载体pLNCX2-MCS上,鉴定后用脂质体法转染PT67细胞进行病毒包装、扩增,最后通过感染NIH3T3细胞,测定病毒滴度。结果：酶切、测序结果与TH基因重组逆转录病毒载体的预期结果一致,病毒滴度达1.6×106pfu/mL,对NIH3T3细胞有较高的感染效率。结论：应用基因工程技术可成功构建重组逆转录病毒pLNCX2-TH,建立PT67产病毒细胞系,为帕金森病的基因治疗创造了条件。     

携带绿色荧光蛋白基因的逆转录病毒载体的构建及其介导的T细胞基因转移研究

为了构建含绿色荧光蛋白（green fluorescent protein，GFP）基因的逆转录病毒载体和研究逆转录病毒对T细胞的感染能力，利用亚克隆技术将磷酸甘油酸激酶启动子（phosphoglycerate kinase promoter，PGK）基因和GFP全长cDNA插入逆转录病毒载体pLXSN，采用磷酸钙沉淀法将重组载体转染PA317包装细胞，G418筛选出抗性克隆，收集滴度最高的病毒上清感染NIH3T3和T细胞，在倒置荧光显微镜下观察GFP表达情况。结果表明；重组逆转录病毒载体转染PA317包装细胞后，可在荧光显微镜下观察到GFP的表达。G418筛选后，含GFP的逆转录病毒可感染原代培养的T细胞。结论：逆转录病毒载体能够快速、稳定地将外源基因转移至T细胞，可作为介导T细胞基因转移的重要工具。     

人OVCA1基因的克隆及其对卵巢癌细胞生长的抑制作用

目的克隆人的OVCA1基因并探讨其对卵巢癌细胞生长的影响。方法从健康人卵巢组织中提取总RNA,采用逆转录酶-聚合酶链反应(RT-PCR)方法扩增OVCA1基因并克隆。脂质体法将含有OVCA1质粒和空载体分别转染入A2780细胞,G418筛选稳定转染细胞。MTT法检测OVCA1对A2780细胞生长的影响。结果测序证实获得了OVCA1基因;过表达OVCA1的细胞与对照组相比,生长速度明显减慢(P<0.05)。结论得到了OVCA1基因克隆;OVCA1在体外明显抑制卵巢癌细胞系A2780的生长。     

Quantification and characterization of autotransduction in retroviral vector producer cells

Gene therapy has evolved into a tempting strategy for the management of cancer and other life-threatening diseases. Various approaches employ retroviral vectors to deliver the therapeutic gene. The profound knowledge about retrovirus biology allows the generation of increasingly advanced vector systems as well as an accurate assessment and management of potential safety risks. This study focuses on the genetic stability of retrovirus producer cells as a basic safety requirement and its compromise by autotransduction. It has been shown previously that protection of retroviral packaging systems by superinfection interference is not guaranteed. The current study provides insight into the extent of autotransduction and the time point at which it occurs, and examines strategies to antagonize it. Therefore, a reconstituting vector system was used that obviates transgene expression in virus producer cells by physically separating transgene and promoter. Just on infection two functional expression cassettes are reconstituted, causing highly efficient transgene expression in transduced cells. Equipped with an enhanced green fluorescent protein-encoding gene, this vector allowed accurate quantification of autotransduced cells, which were then isolated by fluorescence-activated cell sorting and further characterized. Sequencing of recloned integrated vector copies demonstrated that high transgene expression levels were strictly associated with the presence of reverse-transcribed vector copies. Envelope protein expression levels, however, were found to be equal in autotransduced and noninfected virus producer cells. Finally, the occurrence of autotransduction could be assigned to an early time point after transfection and was successfully blocked by azidothymidine treatment, yielding a stable and homogeneous population of noninfected retrovirus producer cells.     

Production of minigene-containing retroviral vectors using an alphavirus/retrovirus hybrid vector system.

In an attempt to increase the synthesis of human clotting factors VIII and IX in transduced cells, optimized expression cassettes containing genomic genelike elements (minigenes) were assembled. Plasmid DNA containing factor VIII or factor IX minigenes and driven by three human cellular promoters (albumin, factor IX, PGK) or the strong viral promoter RSV-LTR were electroporated into TE671 and HepG2 cell lines, and clotting factor levels were determined by ELISA. In comparison with a parallel transfection of MLV-LTR-promoted retroviral vector plasmid DNAs, the PGK- and RSV-LTR-promoted minigene constructs produced equal or greater amounts of clotting factor proteins. A factor IX minigene cassette was cloned into the retrovirus-based gene transfer vector LN (in both forward and reverse orientations) and the minigene vector was introduced into the Phoenix retroviral packaging cell line. Analysis of neo(r) cells demonstrated that insertion of a factor IX minigene into the retroviral vector LN resulted in rearrangement of the factor IX sequence and loss of factor IX expression in the Phoenix packaging cell line. The same factor IX minigene was then inserted into an alphavirus/retrovirus hybrid vector that facilitates the synthesis of retroviral vector RNA in the cytoplasm of cells. Alphavirus/retrovirus virions were produced and used to transduce the Phoenix retroviral vector packaging cell line. The cytoplasmically produced factor IX minigene-containing retroviral vectors were collected and used to transduce TE671 cells. Analysis of transduced cells demonstrated stable transfer of the minigene and expression of factor IX.     

葡萄糖调节蛋白78真核表达载体及稳定转染人视网膜色素上皮细胞株的构建

背景：葡萄糖调节蛋白78是存在于内质网上最多的分子伴侣蛋白,具有保护细胞对抗细胞调亡的作用。目的：构建携带并正确表达外源性人葡萄糖调节蛋白78基因的重组真核表达载体,建立葡萄糖调节蛋白78基因稳定转染的人视网膜色素上皮细胞系。方法：扩增人葡萄糖调节蛋白78全长编码序列,将该目的基因与真核表达载体PEGFP-N1进行定向连接,其产物转化细菌感受态细胞,以PCR方法鉴定阳性克隆,并进行测序和分析比对,获得融合蛋白表达质粒载体pEGFP-grp78。通过阳离子脂质体介导将重组质粒pEGFP-grp78转染入体外培养的人视网膜色素上皮细胞,经G418筛选,建立稳定表达细胞系。结果与结论：体外培养的人视网膜色素上皮细胞株作为真核细胞表达系统,经荧光显微镜和RT-PCR方法检测,G418筛选的稳定转染细胞系中GFP大量表达,葡萄糖调节蛋白78mRNA的表达量是正常视网膜色素上皮细胞的4倍左右,表示脂质体介导的pEGFP-grp78质粒成功转染视网膜色素上皮细胞,并高效稳定表达葡萄糖调节蛋白78。     

Fas靶向RNA干扰逆转录病毒载体的构建及生物活性鉴定

本研究构建Fas靶向RNA干扰逆转录病毒载体,为探讨抑制Fas表达在再生障碍性贫血等疾病治疗中的意义、以及为促进RNA干扰技术的广泛开展奠定基础.用PCR方法获得小鼠U6＋27启动子盒及产生siRNA的相应DNA模板,然后连同增强绿色荧光蛋白（EGFP）基因克隆入商业化逆转录病毒载体pLXSN,以获得逆转录病毒载体穿梭质粒pLXSN/EGFP-siFas.包装、滴定重组逆转录病毒载体,并感染P815细胞,检测绿色荧光蛋白表达情况及对细胞Fas表达的抑制情况.结果表明：构建的逆转录病毒载体pLXSN/EGFP-siFas能够有效被包装并感染靶细胞,在靶细胞内可同时表达siRNA、绿色荧光蛋白以及新霉素抗性.结论：成功构建了抑制小鼠Fas表达的RNA干扰逆转录病毒载体.