Construction of PR domain eukaryotic expression vector and its inhibitory effect on esophageal cancer cells

Objective：PR domain is responsible for the tumor suppressing activity of RIZ1.The study aimed to construct human PR domain eukaryotic expression vectors,transfect human esophageal cancer cells （TE13）,and evaluate the anticancer activity of PR domain on human esophageal cancer TE13 cells.Methods：First,mRNA was extracted from human esophageal cancer tissue by RT-PCR,then reversetranscribed to cDNA.After amplifying from the DNA template,PR domain was linked to T vector.Second,after extraction,PR domain was cut using enzyme and linked to pcDNA3.1（＋）.Then,the plasmid was transfered to Trans1-T1 phage resistant competent cells,following by extracting the ultrapure plasmid,and transfecting into TE13 cells.In the end,the protein expression of pcDNA3.1（＋）/PR domain in TE13 was detected by Western blot,and the apoptosis of TE 13 by technique of flow cytometry.Results：More than 5,000 bp purposed band of pcDNA3.1（＋）/PR domain plasmid was found by agarose gel electrophoresis.After transfection,the PR domain （molecular weight of about 28 Da） was found only in 3,4 and 5 groups by Western blot.Flow cytometry assay showed apoptosis in experimental group was significantly more than that in the control group （P＜0.05）.Conclusions：The PR domain eukaryotic expression vector was constructed successfully.The protein of the PR domain could be expressed in esophageal cancer TE13 cells firmly after transfection,and a single PR domain could promote apoptosis of TE13 cells.

Gene Cloning of Murine α-Fetoprotein Gene and Construction of Its Eukaryotic Expression Vector and Expression in CHO Cells

To clone the murine α fetoprotein (AFP) gene, construct the eukaryotic expression vector of AFP and express in CHO cells, total RNA were extracted from Hepa 1 6 cells, and then the murine α fetoprotein gene was amplified by RT PCR and cloned into the eukaryotic expression vector pcDNA3.1. The recombinant of vector was identified by restriction enzyme analysis and sequencing. After transient transfection of CHO cells with the vector, Western blotting was used to detect the expression of AFP. It is concluded that the 1.8kb murine α fetoprotein gene was successfully cloned and its eukaryotic expression vector was successfully constructed.

Cloning and construction of sense and antisense eukaryotic expression vector of human Pin1

Objective: To clone and construct eukaryotic expressing vectors of sense and antisense human Pin1 (hPin1) genes. Methods: Total RNA was extracted from MG-63 cells, then the hPin1 cDNA was amplified by RT-PCR. The same time the sense and antisense hPin1 genes were formed by binding BamH I and Hind III in cis and trans-directions. At the end they were cloned into the eukaryotic expressing vector pIRES2-EGFP in cis and trans directions using DNA recombinant technology. The recombinant vectors were further identified by digestion of BamH I and Hind III. Results: The results of sequencing showed that the orientation of the ligations and the reading frame were correct. After digested by BamH I and Hind III, two fragments exhibiting 5.3 kb and 0.99 kb were formed in sense and antisense eukaryotic expressing vectors. Electrophoretic results were completely coincident with theoretical calculation. Conclusion: Human Pin1 sense and antisense genes were successfully cloned and eukaryotic expressing vectors were successfully constructed.

Construction of bicistronic green fluorescent protein labeled pSELECT GFPzeo human bone morphogenetic protein 2 eukaryotic expression vector

Objective To construct green fluorescent protein (GFP)-labeled pSELECT-GFP zeohBMP2 eukaryotic expression vector.Methods The encoding fragment of hBMP2 gene was obtained from a recombinant plasmid pcDNA3.1/CT-hBMP2 by using polymerase

Construction of Eukaryotic Expression Plasmid of bFGF Gene in Rats and Its Expression in Tenocytes

The bFGF plays an important role in embryonic development of tendons and ligaments and in the healing of injuried tendons and ligaments. The eukaryotic expression plasmid of rat basic fibroblast growth factor （bFGF） gene was constructed in order to further investigate the bFGF function in molecular regulatory mechanism in the repair of tendons and ligaments and to provide the foundation for the clinical application. The cDNA fragments of bFGF were cloned from the skin of rats by RT-PCR, and recombinated to the pMD18-T vector. The cDNA encoding bFGF was cloned from the pMD18-T vector by RT-PCR, digested with restriction enzyme EcoR Ⅰ, Pst Ⅰ and bound to eukaryotic expression plasmid plRES2-EGFP to construct eukaryotic expression plasmid plRES2-EGFP-bFGF. The plRES2-EGFP-bFGF was transfected into the tenocytes by lipid-mediated ransfection technique. MTT test was used to detect the biological activity of bFGF in supernatants after the transfection. The expression of type Ⅰ and Ⅲ collagen genes was detected by using RT-PCR. It was verified that the plRES2-EGFP-bFGF was successfully constructed, and its transfection into tenocytes could significantly enhance the biological activity of bFGF, and increase the expression of type Ⅰ and Ⅲ collagen mRNA, suggesting that plRES2-EGFP-mediated bFGF gene therapy was beneficial to the repair of tendons and ligaments.

Overexpression of the mTERT gene by adenoviral vectors promotes the proliferation of neuronal stem cells in vitro and stimulates neurogenesis in the hippocampus of mice

We sought to construct the adenoviral vector carrying the gene encoding mouse telomerase reverse transcriptase（mTERT）,as well as detect its expression and effect on the proliferation of neuronal stem cells.mTERT was am-plified by RT-PCR and then the eukaryotic expression vector of pDC-EGFP-TERT was constructed.After DNA sequence analysis,we detected that there were 293 cells transfected with pDC-EGFP-TERT and helper adenovirus plasmid pBHG lox ΔE1,and three Cre using Lipofectamine 2000 mediation,named Ad-mTERT-GFP,to pack-age adenoviral particles.The Ad-mTERT-GFP was used to infect neuronal stem cells and then the expression and activity of mTERT were detected.In addition,Bromodeoxyuridine labeling test identified the impact of mTERT overexpression on proliferation of neuronal stem cells.The recombinant adenoviral vector confirmed that mTERT was successfully constructed.Overexpression of mTERT stimulated the proliferation of neuronal stem cells both in vitro and in vivo.mTERT overexpression via adenoviral vector carrying mTERT cDNA upregulated the ability of proliferation in neuronal stem cells.

Construction of Smac gene-carrying and human uroplakin Ib promoter-Regulated Genetic Vector and its Expression

Objective： To construct an eukaryotic expression vector that contains Smac gene, which is regulated by human Uroplakin Ib （UpIb） promoter. Methods： For the directionality of Smac expression in the transitional cell carcinoma of bladder, internal CMV and T7 promoter sequences in eukaryotic expression vector pcDNA3.1-Smac were replaced with UpIb promoter to construct a new plasmid. The plasmid DNA was identified by gel electrophoresis after being double digested at respective sites, and then the sequence was analyzed. The expression of Smac mRNA and protein in BIU87 cell line were detected after the transfection by using the newly constructed vector. Results： The Smac gene-carrying and UpIb promoter-regulated eukaryotic expression vector pcDNA3-UpIb-promoter-Smac was successfully constructed. The expression of Smac mRNA was approximately increased by 2.1 times and the expression of Smac protein was increased in about 71% BIU87 cells. Conclusion： The new vector can be effectively expressed in bladder cancer cells and be of great significance for bladder cancer-targeted gene therapy.

A Plasmid vector encoding functional human keratinocyte growth factor gene in vitro—Functional human KGF gene expression in vitro

In this study, we cloned human KGF (hKGF) genes using RT-PCR techniques and developed a eukaryotic expression plasmid vector capable of directing the expression of functional hKGF. Monolayer culture of human embryo lung fibro-blast (HLF) was used for isolation of total RNA. Then the total RNA was purified and reverse- transcribed into cDNA using an oligo (dT) primer. A full PCR fragment for hKGF was generated and cloned. Restriction digestion and nucleo-tide sequence analysis validated the complete hKGF transcription. The hKGF cDNA fragment was inserted into pEGFP-C2 vector by means of recombinant DNA technology and verified by restriction analysis and sequencing. We have constructed pEGFP-C2-hKGF encoding the green fluorescent protein (GFP). Furthermore, hKGF had the effect on AEC II proliferation. These results suggest that the potential appli-cation of a hKGF plasmid of gene expression should be useful for sustained AEC proliferation, and its in vivo efficacy needs to be validated. Keywords:

Construction of a HERG mutant L539fs/47-*558W pEGFP vector and the expression of the fusion protein in HEK293 cells

Objective:To construct a human ether-a-go-go-related gene(HERG)nonsense mutant L539fs/47-*558W into the autonomously fluorescent,eukaryotic expression vector pEGFP-C2,and to verify expression of the reconstruct in human embryonic kidney-293(HEK293)cells.Methods:The mutational fragment was subcloned into pEGFP-C2-HERG by double digestion of SbfⅠ,Eco91Ⅰand rejoining of T4 ligase.After verification,the recombinant pEGFP-C2-L539fs/47-*558W and pEGFP-C2-HERG were respectively transfected into HEK293 cells for 48 h by the Lipofect method to observe the expression location of the fusion protein by laser confocal imaging scanning in vivo.pcDNA3-L539fs/47-*558W and pcDNA3-HERG were transfected to observe the expression location of the HERG protein by immunofluoresceoce.The mutant protein size was determined by Western blotting.Results:The about 1 kb-sized mutation region cDNA fragment from pcDNA3-L539fs/47-*558W and the about 7.2 kb-sized target vector fragment from pcDNA3-HERG were ligated after purification and gel recovery.pEGFP-C2-L539fs/47*-558W,approximately 8.2 kb,was demonstrated successfully been constructed under agarose gel electrophoresis and further sequencing.Laser confocal imaging showed that pEGFP-C2-HERG was mainly expressed in the membrane,whereas truncated mutant-type HERG in the pEGFP-C2 vector was partially located in the cytoplasm,the others were transported to the cell membrane in living HEK293 cells.The same as the immunofluoresceoce results after transfection of pcDNA3-HERG and pcDNA3-L539fs/47-558W.Wild-type HERG-GFP fusion protein expressed 160 and 180 kDa bands.The mutant and mutant-GFP fusion proteins were 70 and 100 kDa,respectively.Conclusion:pEGFP-C2-L539fs/47-*558W was successfully constructed by double digestion method GFP had no effect on its protein expression and trafficking in HEK293 cells,which laid a foundation for the further study on L539fs/47-*558W.

Construction of recombinant plasmid pEGFP-C2-L539fs/47 and its expression in HEK293 cells

Objective:To reconstruct pEGFP-C2-L539fs/47,a HERG nonsense mutant in eukaryotic expression plasmid,and observe the fusion protein expressed in HEK293 cells(human embryo kidney cells).Methods:After double digestion of pcDNA3-L539fs/47 and pEGFP-C2-HERG with sbf I and Eco91 I,the small product fragment,from pcDNA3-L539fs/47,was subcloned into the big fragment of pEGFP-C2-HERG under T4 ligase.pEGFP-C2-L539fs/47 was identified by agarose gel electrophoresis and sequencing.pcDNA3-L539fs/47 and pEGFP-C2-L539fs/47 were transiently transfected into HEK293 cells by Lipofect,respectively.The expression of fusion protein in HEK293 cells was detected through immunofluorescence,laser confocal imaging scanning in vivo,Western blot and PCR.Results:Mutation region cDNA fragment(about 1 kb) and target vector fragment(about 7.2 kb) were ligated after purification and gel recovery.Agarose gel electrophoresis and sequencing successfully demonstrated eukaryotic expression plasmid pEGFP-C2-L539fs/47,constructed approximately 8.2 kb,sequencing consistent with template gene.The transfection efficiency of recombinant plasmid by fluorescence microscopy was more than60%.Western blot analysis detected pcDNA3-L539fs/47 expression of the protein size 60 KD,the expression of pEGFP-C2 fusion protein size of approximately 90 KD.The L539fs/47 gene expression in HEK293 cells was significant by PCR analysis.Confocal laser imaging showed that pEGFP-C2-L539fs/47 protein was successfully expressed in cytoplasm and cytomembrane of HEK293 cells.Conclusion:pEGFP-C2-L539fs/47 containing the HERG gene mutant was successfully constructed by double digestion method and expressed fusion protein in HEK293 cells,which laid a foundation for the further study on L539fs/47.

Stable Expression of Antibacterial Peptide CecropinB in Dairy Goat Mammary Gland Epithelial Cells

The paper aimed at constructing the eukaryotic expression vector of CecropinB and transfecting it into the goat mammary epithelial cell line. The recombinant plasmid inserted with CecropinB was transfected into the goat mammary epithelial cell by liposome Tfx^M-20. By screening with G418, the stable transfected goat mammary epithelial cell line was established and the transcription and expression of CecropinB were identified by RT-PCR and agarose diffusion experiment, respectively. Results showed that eukaryotic expression vector pECFP-B was constructed successfully. Stable transfected goat mammary epithelial cell line was established and the CecropinB protein was expressed successfully. It provides the solid foundation for further experimental studies on the function of CecropinB.

Construction and Identification of a Human Liver Specific MicroRNA Eukaryotic Expression Vector

MiR-122 is one of the non-coding RNAs which showed its effects on the lipo-metablism, virus infection and HCC forming through regulation of liver gene expression. Its eukaryotic expression vector was constructed by using pSuper which was widely applied in the siRNA expression. The precursor of human miR-122 gene was amplified by polymerase chain reaction （PCR） from the human genomic DNA. The positive clones were screened by PCR and restriction enzyme digestion. The new expression vector of miR-122 was named pHsa-m122. PHsa-m122 and its controls were transfected to HepG2 cells. The miR-122 expression activity was evaluated by GFP122i sensor reporter plasmid through fluorescence detection and Western blot. It was shown that the fluorescence intensity of GFP122si and pHsa-m122 co-transfection group was weaker than that of the controls, so the functional activity of expressed miR-122 was detected. When HepG2 cells were co-transfected with HBV1.3 and pHsa-m122 plasmids, the results showed miR-122 may down-regulate the gene expression of HBV. The human liver specific microRNA eukaryotic expression vector of miR-122 was constructed successfully, which may facilitate further study of its function in the development of liver virus infection diseases and HCC. Cellular ＆ Molecular Immunology.

猪催乳素的真核表达与生物活性验证

【目的】催乳素(Prolactin,PRL)具有广泛的生理调节作用,但其多效性机制仍不清楚。为了更好地研究猪PRL的多效性,本研究制备猪源PRL真核重组蛋白并验证其生物活性。【方法】利用分子克隆技术将猪PRL基因克隆到慢病毒表达载体pCDH-CMV-MCS-EF1-GFP+Puro中,经慢病毒包装获得携带猪PRL基因的PRL-慢病毒;用浓缩的PRL-慢病毒感染CHO-K1细胞,经嘌呤霉素筛选后,获得能够分泌PRL重组蛋白的阳性细胞系CHO-K1-PRL;利用镍柱亲和层析法对重组蛋白进行纯化并进行LC-MS/MS质谱鉴定,利用HC11细胞体外培养体系验证PRL重组蛋白的生物活性。【结果】成功构建了携带猪PRL基因的pCDH-CMV-6His-PRL-6HisEF1-GFP+Puro慢病毒表达载体;包装及浓缩后的PRL-慢病毒滴度为9.9×10^(8) TU/mL,其感染的CHO-K1细胞经嘌呤霉素筛选后得到阳性细胞系CHO-K1-PRL;从CHO-K1-PRL细胞培养液中成功纯化出重组蛋白,质量浓度为50μg/mL,LC-MS/MS质谱分析的覆盖率达94%,鉴定为猪PRL重组蛋白;重组PRL具有促进HC11细胞增殖及酪蛋白表达的生物活性。【结论】构建的细胞系CHO-K1-PRL可稳定表达具有生物活性的猪重组PRL,为猪PRL功能的研究和生产应用奠定了基础。

持续高糖状态对Kv11.1离子通道蛋白表达的影响

目的:探讨持续高浓度葡萄糖干预对Kv11.1离子通道蛋白表达的影响。方法:①采用双酶切法和基因重建技术将HERG基因插入到表达绿色荧光蛋白的真核表达载体pEGFP-N1中,构建Kv11.1离子通道蛋白的表达载体pEGFP-N1-HERG并测序验证。②pEGFP-N1-HERG表达载体鉴定成功后经脂质体转染HEK293T细胞,并通过不同糖浓度(5、17.5、30mmol/L)干预细胞48h后流式细胞仪检测细胞HERG离子通道蛋白绿色荧光平均表达量。结果:流式细胞仪检测pEGFP-N1-HERG融合蛋白平均荧光强度于不同浓度葡萄糖持续干预后分别为218.87(5mmol/L)、174.83(17.5mmol/L)、142.90(30mmol/L),三组间比较差异有统计学意义(均P<0.05)。结论:持续高糖状态抑制Kv11.1离子通道蛋白的表达,为糖尿病患者长期高糖状态时QT间期延长提供理论依据并奠定实验基础。

多星韭AwCHI 1的克隆与分析及真核表达载体的构建

查尔酮异构酶(Chalcone isomerase,CHI)是类黄酮物质合成途径中的关键酶,能催化柚皮素查尔酮生成柚皮素,进而转化生成各种类型的黄酮类化合物。根据多星韭(Allium wullichii)转录组测序结果,运用PCR技术克隆获取多星韭查尔酮异构酶的编码基因(AwCHI 1),对基因序列进行分析,同时与真核表达载体pBI121进行连接,将其转入农杆菌GV3101感受态细胞中,完成农杆菌的转化。研究结果不仅为该基因的功能解析研究奠定了基础,也为多星韭类黄酮代谢途径的研究提供了重要基因资源。

绵羊GSTA2基因克隆、生物信息学分析及真核表达载体构建

为阐明绵羊谷胱甘肽S转移酶α2(Glutathione S-transferase alpha 2,GSTA2)基因功能,利用牛GSTA2基因序列设计引物,提取绵羊皮肤组织总RNA,应用RT-PCR、基因克隆、生物信息学对GSTA2基因进行研究,构建真核表达载体,转染绵羊皮肤成纤维细胞,应用qPCR技术检测GSTA2基因的表达。结果表明,克隆到绵羊GSTA2基因672 bp编码区序列(GenBank登录号:OR440604.1),编码223个氨基酸,分子量为25.39 ku。氨基酸比对和系统进化树分析表明,绵羊与牛的GSTA2相似度最高,达87.39%。GSTA2的二级结构以α-螺旋和无规则卷曲为主。构建的真核表达载体pcDNA3.1-GSTA2转染绵羊皮肤成纤维细胞后,GSTA2基因表达量极显著上调(P <0.001)。说明成功克隆了绵羊新基因GSTA2的CDS序列,并成功构建了其真核表达载体。

努比亚山羊Rheb基因克隆、生物信息学分析及真核表达载体构建

【目的】研究旨在对努比亚山羊大脑富集Ras同源物(Ras homolog enriched in brain,Rheb)基因进行克隆和分析,并构建其真核表达载体,为进一步揭示Rheb对努比亚山羊骨骼肌调控的分子机理奠定基础。【方法】试验采用RT-PCR方法从努比亚山羊背最长肌组织中扩增Rheb基因,经琼脂糖凝胶电泳及测序验证正确后进行生物信息学分析,同时构建该基因真核表达载体,转染细胞后进行实时荧光定量PCR检测来验证所构建载体的正确性。【结果】努比亚山羊Rheb基因编码区序列长度为555 bp,编码184个氨基酸,Rheb蛋白分子式为C 910 H 1456 N 236 O 279 S 6,分子质量为20359.34 u,原子总数为2887,理论等电点为5.93。Rheb蛋白属于稳定的亲水性蛋白,不包含跨膜结构域。蛋白二级结构预测结果显示,努比亚山羊Rheb蛋白中α-螺旋、β-转角、延伸链和无规则卷曲分别占40.76%、7.07%、22.83%和29.35%。构建的真核表达载体pcDNA3.1-Rheb转染山羊骨骼肌细胞后,与空载体组相比,Rheb基因表达量极显著升高(P<0.01)。【结论】本试验成功克隆努比亚山羊Rheb基因编码区序列,并构建pcDNA3.1-Rheb真核表达载体,这为深入理解Rheb基因在努比亚山羊肌肉中的作用提供了理论支持。