人Bax启动子荧光素酶报告基因的构建和鉴定

[目的]克隆人Bax基因的启动子,插入荧光素酶报告基因载体中,并在细胞内检测其活性。[方法]采用PCR技术从人HepG2细胞中扩增出Bax启动子,插入荧光素酶报告基因载体pGL3-basic中,经测序确定所扩增的DNA序列,并将其转染入H1299细胞中检测其活性。[结果]测序结果表明扩增的Bax启动子序列正确,双报告基因实验检测荧光素酶活力表明构建的报告基因具有启动子活性。[结论]克隆了Bax启动子,成功构建了人Bax启动子报告基因,为p53家族凋亡通路的功能研究提供了必要的实验材料。     

转录因子STAT5A启动子荧光素酶报告基因质粒的构建及鉴定

目的： 利用分子克隆的方法构建转录因子STAT5A启动子荧光素酶报告基因质粒并鉴定其效应。方法： 以乳腺癌MCF7细胞基因组DNA为模板,采用PCR方法扩增STAT5A基因的启动子序列,并将其克隆至荧光素酶报告基因质粒pGL3-Enhancer中,经过菌液扩增、酶切、测序等方法获得目的质粒,并通过双荧光报告基因实验进一步验证其功能。结果： 构建的STAT5A启动子荧光素酶报告基因质粒pGL3-STAT5A-pro-luc-E序列正确,且具有转录活性。在双荧光报告基因实验中发现重组载体pGL3-STAT5A-pro-luc-E荧光素酶的相对活性约为阴性对照pGL3-Enhancer的8倍（P<0.01）,而pGL3-STAT5A-pro-N-luc-E荧光素酶的相对活性约是阴性对照pGL3-Enhancer的6倍（P<0.01）。结论： 本项目成功构建了转录因子STAT5A启动子荧光素酶报告基因质粒,为进一步研究STAT信号转导及转录激活蛋白信号通路提供了重要的研究工具。     

人CYP19基因启动子荧光素酶报告基因载体的构建

[目的]克隆人CYP19基因启动子PⅠ.3（-345～-234bp）、PⅡ（-517～-278bp）和PⅠ.7（-299～＋81bp）片段,构建启动子荧光素酶报告基因载体。[方法]采用生物合成PⅠ.3（-345～-234bp）、PⅡ（-517～-278bp）和PⅠ.7（-299～＋81bp）区域基因片段,通过HindⅢ和KpnⅠ酶切连接到pGL3-Basic载体上。[结果]测序验证pGL3-Basic-PⅠ.3,pGL3-Basic-PⅡ和pGL3-Basic-PⅠ.7构建成功。[结论]pGL3-Basic-PⅠ.3,pGL3-Basic-PⅡ和pGL3-Basic-PⅠ.7荧光素酶报告基因载体的成功构建,为进一步研究CYP19基因组织特异性表达奠定基础。     

MDR1启动子/荧光素酶质粒的构建及其在朊蛋白高表达胃癌细胞中的活性检测

目的：构建含MDR1基因启动子的荧光素酶报告基因质粒,并检测其在朊蛋白高表达胃癌细胞系中的活性表达。方法：PCR克隆人MDR1基因启动子片段,通过亚克隆将启动子分别插入到pMD18-T载体和荧光素酶报告基因pGL3-Enhancer载体中,建立含MDR1启动子的荧光素酶报告基因质粒pGL-MDR1,并经测序及酶切确定扩增序列;脂质体基因转染法将pGL-MDR1转染入朊蛋白高表达胃癌细胞系SGC7901-PrP,并测定其荧光素酶活性。结果：PCR克隆出MDR1启动子经DNA测序证实序列正确,pGL-MDR1转染入朊蛋白高表达胃癌细胞系的荧光素酶活性,较转染入pcDNA3.1空载体细胞系相比升高3-5倍。结论：成功构建含MDR1启动子的荧光素酶报告基因质粒;上调朊蛋白表达可激活MDR1的转录活性。     

NGAL基因5''''侧翼区转录调控元件萤火虫荧光素酶报告基因表达载体的构建与鉴定

背景与目的:构建NGAL基因5'侧翼区转录调控元件萤火虫荧光素酶报告基因表达载体.材料与方法:以PCR法从SHEEC食管癌细胞基因组DNA中扩增NGAL基因5'侧翼转录调控区不同长度片段G0-G6(-1431～ 84).PCR产物经pGEM-Teasy转载,再定向亚克隆插入pGL3-Basic.重组子通过特异限制性内切酶切割,琼脂糖电泳予以鉴定.结果:成功构建NGAL基因5'侧翼区转录调控元件萤火虫荧光素酶报告基因表达载体7个,pGLB-GO～G6.结论:为借助于双荧光素酶报告基因检测系统研究确定NGAL基因5'侧翼转录调控区转录调控元件的分布特点以及转录调控元件与转录调控蛋白之间相互作用的性质提供了基本实验条件.     

MDR1启动子/荧光素酶质粒的构建及其在朊蛋白高表达胃癌细胞中的活性检测

目的:构建含MDR1基因启动子的荧光素酶报告基因质粒,并检测其在朊蛋白高表达胃癌细胞系中的活性表达。方法:PCR克隆人MDRl基因启动子片段,通过亚克隆将启动子分别插入到pMD18-T载体和荧光素酶报告基因pGL3-Enhancer载体中,建立含MDR1启动子的荧光素酶报告基因质粒pGL-MDR1,并经测序及酶切确定扩增序列;脂质体基因转染法将pGL-MDR1转染入朊蛋白高表达胃癌细胞系SGC7901-PrP,并测定其荧光素酶活性。结果:PCR克隆出MDR1启动子经DNA测序证实序列正确,pGL-MDR1转染入朊蛋白高表达胃癌细胞系的荧光素酶活性,较转染入pcDNA3.1空载体细胞系相比升高3~5倍。结论:成功构建含MDRl启动子的荧光素酶报告基因质粒;上调朊蛋白表达可激活MDR1的转录活性。     

腺病毒介导的双荧光素酶报告系统的构建及其应用

目的： 构建腺病毒介导的双荧光素酶报告系统,并利用其筛选一种广谱高活性启动子。方法：将待检测启动子控制的萤火虫荧光素酶（Fluc）基因表达框插入腺病毒E1区,CMV启动子控制的海肾荧光素酶（Rluc）基因表达框插入E3区作为内参,构建腺病毒介导的双荧光素酶报告系统。检测不同病毒感染量条件下测得的启动子活性数据差异、组内差异,难转染细胞内的转染情况,分析该系统的操作简便性、稳定可靠性。应用该系统检测常用启动子CAG、CASI及新启动子CCAU在一系列细胞内的活性,从中筛选出一种广谱高活性启动子。结果： 成功构建了腺病毒介导的双荧光素酶报告系统;不同MOI值下测得的各启动子相对活性值无显著差异（P>0.05）;在所实验的细胞内均能有效且准确地测定各启动子的活性,且复孔间方差小;CCAU在所实验的9株细胞中的表达活性显著（P<0.05）或极显著地（P<0.01）高于CASI以及CAG的表达活性。结论： 构建获得的腺病毒介导双荧光素酶报告系统操作简便、稳定可靠、通用性强,可作为启动子活性筛选的一种新方法;利用该系统筛选获得了一种新的广谱高活性启动子CCAU。     

基于双荧光素酶报告基因的DNA损伤与修复检测系统的建立与应用

目的： 建立一种能够同时对环境致癌物所致HepG2细胞DNA损伤和细胞对损伤DNA的修复能力进行快速检测的系统。方法：5 μmol/L氯化镉体外损伤质粒pTK-RL,质粒pgadd153-luc和体外受损的质粒pTK-RL共转染到HepG2细胞中,以16种已知致癌物或3种无遗传毒性的非致癌物刺激细胞,利用双荧光素酶检测方法同时检测DNA损伤和细胞的修复能力;双荧光素酶检测系统检测居民区、垃圾焚烧厂和农田3个不同污染区土壤中非挥发性有机提取物对DNA的损伤作用和细胞对该损伤的修复能力;彗星实验检测DNA的损伤。结果：双荧光素酶报告基因检测系统均可检出已知环境致癌物对DNA损伤与修复能力的影响,非致癌物均未检测到DNA损伤作用和对细胞DNA修复能力的影响;3个不同污染区土壤中非挥发性有机提取物均可诱导DNA损伤并抑制细胞对DNA损伤的修复能力,强度为居民区>垃圾焚烧厂>农田土壤。结论：在本研究条件下建立了可同时检测环境致癌物DNA损伤与细胞修复能力的双荧光素酶报告基因检测系统并可用于环境污染区检测。     

红色荧光蛋白和荧光素酶双报告基因转基因小鼠的建立

背景与目的:活体动物体内光学成像(optical in vivo imaging)主要采用生物发光与荧光两种技术。生物发光是用荧光素酶(luciferase,Luc)基因标记细胞或DNA,而荧光技术则采用荧光报告基团(GFP、RFP、Cyt及dyes等)进行标记,利用一套非常灵敏的光学检测仪器,能够直接监控活体生物体内的细胞活动和基因行为,生物发光成像具有高的灵敏度和特异性,同时生物发光信号可用于精确定量,而荧光成像具有方便、便宜、直观、标记靶点多样和易于被大多数研究人员接受的优点。本研究基于慢病毒介导的转基因方法制备红色荧光蛋白(red fluorescent protein,RFP)和Luc双报告基因转基因小鼠(即RL转基因小鼠),将这两种技术融为一体。方法:制备携带RFP和Luc基因(简写RL基因)的慢病毒,然后将携带RL基因的慢病毒注入小鼠单细胞受精卵卵周隙以感染受精卵,胚胎移植进假孕母鼠以获得仔鼠,应用小动物活体成像仪、体视荧光显微镜和PCR等在蛋白和DNA水平上筛选和鉴定,并获得RL转基因小鼠。结果:移植卵周隙注射有慢病毒的胚胎125枚给6只假孕母鼠,其中4只假孕母鼠怀孕,共生仔鼠20只;利用小动物活体成像仪检测RFP和Luc表达,在蛋白水平证实20只F0代中,3只高表达RFP和Luc;DNA水平检测证实,3只RFP和Luc阳性的小鼠基因组中确实整合有外源转基因RL,预示基因型鉴定结果很好验证了小动物活体成像仪筛选和鉴定结果。此外,RL转基因首建鼠基因组中整合的RL转基因可稳定遗传至下一代,并能正常表达。RL转基因小鼠主要脏器均可见红色荧光和Luc信号,但不同脏器间荧光和Luc强度有差异。结论:成功制备RL双报告基因转基因小鼠,为后续研究干细胞在肿瘤发生、发展和转移中的作用和造血重构等提供双报告基因标记的各种移植用供体细胞,并对此供体细胞及其在体内衍生的细胞进行灵敏的非损伤、实时可视化体内跟踪。     

Vegfr2-luc转基因子代小鼠的鉴定

背景与目的 Vegfr2-luc转基因小鼠体内血管内皮生长因子受体2(vascular endothelial growth factor recep- tor 2,VEGFR2)的表达可以驱动荧光素酶报告基因(luciferase,luc)的表达,是活体动物水平实时监测血管生成情况的有利工具。本研究旨在对子代Vegfr2-luc转基因小鼠进行鉴定,以确定能否用于血管生成研究。方法 PCR检测新生小鼠基因组内luc基因;利用活体成像技术观察新生Vegfr2-luc转基因小鼠生长发育过程中以及皮肤伤口修复过程中 luc基因表达水平的变化情况;荧光素酶报告基因检测试剂盒检测成年(8周龄)转基因小鼠各脏器荧光素酶的活性和Real-time PCR检测各器官VEGFR2 mRNA的表达水平。结果 PCR结果显示50%(56/112)的新生小鼠携带luc基因。活体成像结果显示随着Vegfr2-luc转基因小鼠发育成熟,luc表达量逐渐降低(P<0.001);在皮肤伤口修复过程中, 伤口处luc表达水平先增强后降低(P<0.001)。雌性成年转基因小鼠各脏器VEGFR2 mRNA的表达水平与荧光素酶活性呈正相关(r=0.948,P<0.001)。将睾丸组织除外,雄性成年转基因小鼠各脏器VEGFR2mRNA的表达水平与荧光素酶活性同样呈正相关(r=0.836,P<0.001)。结论 Vegfr2-luc转基因子代小鼠体内luc表达水平的变化可以反映VEGFR2 的表达情况。     

The modified firefly luciferase reporter gene (luc+) but not Renilla luciferase is induced by all-trans retinoic acid in MCF-7 breast cancer cells

Luciferase genes are widely used as reporters to analyze promoter and regulatory elements. We found that a luciferase reporter gene vector with a modified firefly luciferase gene (luc+), but not Renilla luciferase (Rluc), was induced by all-trans retinoic acid (tRA) in the MCF-7 breast cancer cell line. tRA (5 × 10^–6 M) increased luciferase activity of the pGL3 promoter vector (containing luc+) up to 3.8-fold in MCF-7 cells, but not in LNCaP prostate cancer cells or JEG-3 choriocarcinoma cells. Chimeric plasmids were constructed and showed that tRA-induction required the luc+ gene, but not any specific promoter or vector sequence. Time course and dose-response studies of tRA-induction indicated that longer treatment (>24 h) and higher tRA dose (>10^–6 M) were required for luc+ induction compared with those for a positive retinoic acid response element (maximum induction at 6 h and 10^–8 M tRA). Studies with the translation inhibitor, cycloheximide, indicated the half-life of the luc+ protein was increased from 9.7 ± 1.5 to 22.1 ± 3.1 h with tRA treatment. Other retinoids, TTNPB, a retinoic acid receptor /-specific ligand, and a retinoid X receptor ligand, did not significantly increase luc+ expression. Caution is needed in analysis of retinoid responsive gene regulation with the luciferase reporter system in MCF-7 cells, especially at high retinoid concentrations.     

Biodistribution of an adenoviral vector carrying the luciferase reporter gene following intravesical or intravenous administration to a mouse.

The biodistribution and resulting pattern of transgene expression were determined following intravesical administration of an adenoviral vector carrying the luciferase reporter gene (AdLuc). Female BALB/c mice were subjected to intravesical instillation of 1 x 10(9) or 5 x 10(9) plaque-forming units of AdLuc. After sacrifice, transgene expression was detected in tissues using luciferase assays; vector DNA was detected by vector-specific polymerase chain reaction. These experiments showed very little vector dissemination outside of the bladder by this route of administration. High-level expression of the vector transgene in the bladder was found to diminish by severalfold after 3 days. In a supporting study, vector dissemination and resulting transgene expression were determined following tail vein injection of 5 x 10(9) plaque-forming units of AdLuc. Vector was distributed to and expressed in every organ analyzed, with the highest concentration and level of expression observed in the liver.     

4ARE强化的双荧光蛋白报告基因载体的构建及鉴定

目的:构建4ARE强化的红、绿双荧光蛋白报告基因载体。方法:人工合成3对ARE序列,经退火和磷酸化后插入pARE-TK-GFP载体,构建成p4ARE-TK-GFP载体。以质粒pDsRed2-N1为模板,PCR扩增红色荧光蛋白及其启动子序列与pMD18-T载体连接,构建成pMD-DsRed载体。用Ade I酶和BspT I酶对载体pMD-DsRed和p4ARE-TK-GFP进行双酶切,连接产物转化大肠埃希菌DH5α 感受态细胞后,挑取阳性克隆子进行质粒抽提酶切及测序鉴定。结果:经酶切及DNA测序证实,目的片段ARE及DsRed的序列完全正确,重组双荧光蛋白报告基因载体成功转入DH5α。结论:成功构建4ARE强化的双荧光蛋白报告基因载体并在DH5α内表达,为进一步研究ARE的调控作用奠定了基础。     

报告基因荧光素酶在科研中的应用

目的:总结报告基因荧光素酶在医学研究中的新进展.方法:应用pubmed及CNKI期刊全文数据库,以报告基因和荧光素酶为关键词,检索1996-01-2007-12相关文献,共收集文献617篇.纳入标准:1)荧光素酶的生物学特性;2)荧光素酶作为报告基因的应用.根据纳入标准,精选55篇文献,并查看每篇文献后的引文,最后纳入19篇文献进行了综述.结果:荧光素酶是在氧气存在下使底物发光的一类酶,该酶类与底物的结合特异性很强,检出的灵敏度高,因没有激发光的非特异性干扰,信噪比较高,具有其他报告基因不可替代的优势,在基因工程研究中被广泛作为报告基因用于单个细胞、转基因生物、动物和人体基因表达的实时、低光成像,是一种非常实用的研究方法.结论:荧光素酶作为报告基因显示出良好的前景,已成为医学研究领域的重要工具,特别是对推动基因工程研究的发展具有重要作用.     

Imaging tri-fusion multimodality reporter gene expression in living subjects

Imaging reporter gene expression in living subjects with various imaging modalities is a rapidly accelerating area of research. Applications of these technologies to cancer research, gene therapy, and transgenic models are rapidly expanding. We report construction and testing of several triple fusion reporter genes compatible with bioluminescence, fluorescence and positron emission tomography (PET) imaging. A triple fusion reporter vector harboring a bioluminescence synthetic Renilla luciferase (hrl) reporter gene, a reporter gene encoding the monomeric red fluorescence protein (mrfp1), and a mutant herpes simplex virus type 1 sr39 thymidine kinase [HSV1-truncated sr39tk (ttk); a PET reporter gene] was found to preserve the most activity for each protein component and was therefore investigated in detail. After validating the activities of all three proteins encoded by the fusion gene in cell culture, we imaged living mice bearing 293T cells transiently expressing the hrl-mrfp-ttk vector by microPET and using a highly sensitive cooled charge-coupled device camera compatible with both bioluminescence and fluorescence imaging. A lentiviral vector carrying the triple fusion reporter gene was constructed and used to isolate stable expressers by fluorescence-activated cell sorting. These stable 293T cells were further used to show good correlation (R(2) approximately 0.74-0.85) of signal from each component by imaging tumor xenografts in living mice with all three modalities. Furthermore, metastases of a human melanoma cell line (A375M) stably expressing the triple fusion were imaged by microPET and optical technologies over a 40-50-day time period in living mice. Imaging of reporter gene expression from single cells to living animals with the help of a single tri-fusion reporter gene will have the potential to accelerate translational cancer research.     

High-throughput measurement of the Tp53 response to anticancer drugs and random compounds using a stably integrated Tp53-responsive luciferase reporter

Human Tp53 is normally a short-lived protein. Tp53 protein is stabilized and levels are increased in response to a variety of cellular stresses, including those induced by genotoxic anticancer drugs and environmental exposures. To engineer an efficient assay based on this property, we constructed and integrated a Tp53-specific reporter system into human cancer cells, termed p53R cells. We tested a range of conventional chemotherapeutic agents as well as over 16 000 diverse small compounds. Ionizing radiation and two-thirds of conventional chemotherapeutic agents, but only 0.2% of diverse compounds activated Tp53 activity by two-fold or greater, consistent with the presumptive genotoxic activation of Tp53 function. Cytotoxicity was independent of TP53 genetic status when paired, syngeneic wild-type TP53 and TP53-null cells in culture were treated with compounds that activated Tp53. From the unbiased survey of random compounds, Tp53 activation was strongly induced by an analog of AMSA, an investigational anti-cancer agent. Tp53 was also strongly induced by an N-oxide of quinoline and by dabequine, an experimental antimalarial evaluated in humans; dabequine was reported to be negative in other screens of mutagenicity and clastogenicity but carcinogenic in animal studies. Further exploration of antimalarial compounds identified the common medicinals chloroquine, quinacrine, and amodiaquine as Tp53-inducers. Flavonoids are known to have DNA topoisomerase activity, a Tp53-inducing activity that is confirmed in the assay. A reported clinical association of Tp53 immunopositive colorectal cancers with use of the antihypertensive agents was extended by the demonstration of hydralazine and nifedipine as Tp53-inducers. p53R cells represent an efficient Tp53 functional assay to identify chemicals and other agents with interesting biologic properties, including genotoxicity. This assay may have utility in the identification of novel chemotherapeutic agents, as an adjunct in the pharmaceutical optimization of lead compounds, in the exploration of environmental exposures, and in chemical probing of the Tp53 pathway.     

High-throughput measurement of the Tp53 response to anticancer drugs and random compounds using a stably integrated Tp53-responsive luciferase reporter

The p53R cell line characterized in the publication was derivedfrom