Construction and Preliminary Identification of Eukaryotic Expression Vector of Cryptosporidium parvum miR-2980

[Objective] This study aimed to construct and preliminarily identify the eu- karyotic expression vector of Cryptosporidium parvum miR-2980. [Method] The cp-miR- 2980 precursor was amplified from C. parvum genomic DNA and cloned into pMD18- T vector. The amplified precursor was then subcloned into pVAX I vector and identi- fied with restriction endonuclease digestion and sequencing. The recombinant plasmid pVAX-miR2980 was transfected into HCT-8 cells. Total RNA was extracted and the expression of cp-miR-2980 was evaluated by RT-PCR detection. [Result] The results showed that the recombinant eukaryotic expression vector pVAX-miR2980 was suc- cessfully constructed, which can express cp-miR-2980 in HCT-8 cell. [Conclusion] This study laid the foundation for further exploring the biological function of cp-miR-2980.

Construction of Eukaryotic Expression Vector for Pig Ghrelin Gene

[Objective] This study aimed to investigate the functions of transgenic growth related gene in pig growth. [Method] A pair of primers containing Nhe I and Hind Ⅲ restriction sites were designed by referring to the pig Ghrelin mRNA sequence published in Genbank. Total RNA was extracted from the small intestine tissue of 13/17 Robertson translocation heterozygous pig, and then was purified and used as the template in later RT-PCR reaction to amplify the full-length pig Ghrelin gene. The correct pig Ghrelin gene fragment was cloned into the pMD19-T simple vector for sequencing analysis. The obtained full-length cDNA of pig Ghrelin gene fragment was digested with both Nhe I and Hind Ⅲ, and then was linked into the eukaryotic expression vector pEGFP-N1 to obtain the recombinant plasmid pEGFPGhrelin. The recombinant plasmid was transected into the fibroblast cells to detect the fluorescence labeled gene expression. [Result] The nucleotide sequence extracted from 13/17 Robertson translocation heterozygous pig was the same as expected; and the eukaryotic expression vector pEGFP-Ghrelin was successfully constructed. [Conclusion] The eukaryotic expression vector constructed in this study can be further used in research on transgenic pigs, but also lays foundation for research on the regulatory mechanism of Ghrelin gene.

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.

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 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 Sbf I, Eco91 1 and 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-＊558Wand 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

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 （hPinl） genes. Methods： Total RNA was extracted from MG-63 cells, then the hPinl cDNA was amplified by RT-PCR. The same time the sense and antisense hPinl 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 BamHⅠ 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 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.

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

Effect of NHE1 antisense gene transfection on the biological behavior of SGC-7901 human gastric carcinoma cells

AIM: To study the effect of type 1 Na+/H+ exchanger (NHE1 ) antisense human gene transfection on the biological behavior of gastric carcinoma cell line SGC-7901. METHODS: Antisense NHE1 eukaryotic expression on vector pcDNA3.1 was constructed by recombinant DNA technique and transfected into gastric carcinoma cell line SGC-7901 with DOTAP liposome transfection method. Morphological changes of cells were observed with optic and electron microscopes. Changes in cell proliferative capacity, apoptosis, intracellular pH (pHi), cell cycle, clone formation in two-layer soft agar, and tumorigenicity in nude mice were examined. RESULTS: Antisense eukaryotic expressing vectors were successfully constructed and transfected into SGC-7901. The transfectant obtained named 7901 -antisense (7901-AS) stablely produced antisense NHE1. There was a significant difference between the pHi of 7901-AS cells (6.77 ± 0.05) and that of 7901-zeo cells and SGC-7901 cells (7.24 ± 0.03 and 7.26 ± 0.03, P < 0.01). Compared with SGC-7901 and 7901-zeo cells, 7901-AS cells mostly showed cell proliferation inhibition, G1/G0 phase arrest, increased cell apoptotic rate, recovery of contact inhibition, and density contact. The tumorigenicity in nude mice and cloning efficiency in the two-layer soft agar were clearly inhibited. CONCLUSION: NHE1 antisense gene significantly restrains the malignant behavior of human gastric carcinoma cells, suppresses cell growth and induces cell apoptosis, and partially reverses the malignant phenotypes of SGC-7901 . These results suggest a potential role for human tumor gene therapy.

Construction of eukaryotic expression plasmid pEGFP-N1-WWOX and its transient expression in SMMC-7721 cells

Objective： To construct eukaryotic expression plasmid pEGFP-NI-WWOX and transiently express it in SMMC-7721 cells. Methods： Total mRNA was extracted from normal human liver tissue. RT-PCR was used to amplify the aimed segments WWOX cDNA which was then digested with Hindlll and BamHI and inserted into a eukaryotic expression plasmid pEGFP-N 1 to construct pEGFP-N 1-WMVOX. The constructed plasmid was transfected into SMMC-7721 cells by lipofectamine 2000 - mediated transfer method. The expression of WWOX in transfected SMMC-7721 cells was detected 24, 36 and 48 h post-transfection with fluorescence microscope and the expression level of WWOX mRNA in transfected SMMC-7721 cells was assay by using RT-PCR. The change of MMWOX expression and cell proliferation rates were detected by immunocyto- chemistry and MTT methods respectively. Results： The results showed pEGFP-N1-WWOX was successfully constructed and expressed transiently in SMMC-7721 cells. At 48th hour post-transfection, the number of positive cells was increased significantly and much brighter green fluorescence could be detected, while no green fluorescence was detected in the control group. In SMMC-7721 cells transfected with pEGFP-NI-WWOX a high level of porcine WWOX was detected. WWOX ex- pressed by transfected cells could significantly inhibit the proliferation of SMMC-7721 cells. Conclusion： pEGFP-N1-WWOX was expressed successfully in SMMC-7721 cells, which suggested that might be used as a new therapeutic method for liver cancer.

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.

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.

Establishment of a Functional Cell Line Expressing both Subunits of H1a and H2c of Human Hepatocyte Surface Molecule ASGPR

To better understand the effect of a new split variant of human asialoglycoprotein receptor (ASGPR H1b) on ASGPR ligands’ binding ability, we established a functional cell line which expresses ASGPR.The full lengths of ASGPRH1a and H2c fragments from human liver were amplified by reverse transcript PCR (RT-PCR) and inserted into eukaryotic expression vector pIRES2EFP, pCDNA3.1 (Zeo+) respectively.The recombinants were cotransfected into HeLa cells.After selection by using Neocin and Zeocin, a stably transfected cell line was established, which was designated 4-1-6.The transcription and expression of ASGPRH1a and H2c in 4-1-6 were confirmed by RT-PCR, Western blotting and immunofluorescence.The endocytosis function of the artificial "ASGPR" on the surface of 4-1-6 was tested by FACS.It was found that the cell line 4-1-6 could bind ASGPR natural ligand molecular asialo-orosomucoid (ASOR).After the eukaryotic plasmid H1b/pCDNA3.1 (neo) was transfected into cell line 4-1-6, H1b did not down-regulate the ligand binding ability of ASGPR.The eukaryotic expression plasmid H1b/pcDNA3.1 (neo) and H2c/pcDNA3.1 (neo) were co-transfected transiently into Hela cell.Neither single H1b nor H1b and H2c could bind ASOR.In conclusion, a functional cell line of human asialoglycoprotein receptor (ASGPR) which expresses both H1a and H2c stably was established.The new split variant H1b has no effect on ASGPR binding to ASOR.ASGPRH1b alone can’t bind to ASOR, it yet can’t form functional complex with ASGPRH2c.

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.

Construction of the pIRES2-ZsGreen1 eukaryotic expression vector of factor Ⅸ gene and expression in HEK-293 cells

Objective To construct p IRES2-ZsG reen1/FⅨexpression vector,using the pcDNA/FⅨplasmid containing FⅨcDNA as template,and expressing in HEK-293cells.Methods The total ORF of FⅨgene was amlified from pcDNA/FⅨplasmid,then the amplified fragment was clonded into the p IRES2-ZsG reen1 vector using