Establishment of Flp-In CHO recombinant cell lines stably expressing CYP2A13 and CYP2A13/POR / 中国药理学通报

Aim To construct Flp-In CHO cell line(CYP2A13-CHO)stably expressing cytochrome P450 family 2 subfamily A member 13(CYP2A13)and Flp-In CHO cell line(CYP2A13-POR-CHO)stably co-expressing CYP2A13 and cytochrome P450 oxidoreductase(POR), from which a cell line with better metabolic activity is selected.Method In our previous study, we had constructed a Flp-In CHO cell line(POR-Flp-In CHO)stably expressing POR using lentiviral vector.The recombinant plasmids of pcDNA5/FRT-CYP2A13 were constructed and transfected into Flp-In CHO cells and POR-Flp-In CHO cells through LipofectamineTM 2000.The expression and activity of CYP2A13 were detected by real-time quantitative PCR(qRT-PCR), Western blot and Aflatoxin B1(AFB1)/4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone(NNK)cytotoxicity assay and the metabolic activity was compared between CYP2A13-CHO and CYP2A13-POR-CHO.Results Compared with non-transfected cells, the mRNA and protein expression of CYP2A13 in CYP2A13-CHO and CYP2A13-POR-CHO cells both increased significantly.Besides, compared with CYP2A13-POR-CHO, CYP2A13-CHO cells were more sensitive to AFB1 and NNK.Conclusions The Flp-In CHO cell line stably expressing CYP2A13 and with better metabolic activity has been established successfully, which provides a tool for screening of pre-carcinogens that can be metabolically activated by CYP2A13.

Site-specific integration and stable expression of exogenous protein at a novel site on CHO cell chromosome / 中国药科大学学报

@#Finding stable expression sites on the chromosomes of Chinese hamster ovary (CHO) cells is an effective method to solve the problem of unstable expression of CHO cells in long-term culture. Our group used lentiviral transfection to integrate the tracer gene (Zsgreen1) into the chromosome of CHO cells and found multiple potential stable expression sites. This study verified the ability of one of the sites located in the 148052-148157 bp region on chromosome NW_003614241.1 to stably express exogenous proteins.The expression of Zsgreen1 gene was first observed, and CRISPR/Cas9 technology was then used to integrate the enhanced green fluorescent protein (EGFP) gene into this site. Three strains of EGFP gene integrated cells were obtained. After 60 generations of suspension culture, the fluorescence intensity of the cells had no significant changes, which proved that this site can stably express the EGFP gene. The same method was used to construct recombinant CHO cell lines expressing the human serum albumin (HSA) gene, and was verified by Western blot that this site could express and secrete HSA. It shows that the above-mentioned sites can be integrated and can stably express exogenous proteins.

Targeting peptide-decorated biomimetic lipoproteins improve deep penetration and cancer cells accessibility in solid tumor

The limited penetration of nanoparticles and their poor accessibility to cancer cell fractions in tumor remain essential challenges for effective anticancer therapy. Herein, we designed a targeting peptide-decorated biomimetic lipoprotein (termed as BL-RD) to enable their deep penetration and efficient accessibility to cancer cell fractions in a tumor, thereby improving the combinational chemo-photodynamic therapy of triple negative breast cancer. BL-RD was composed of phospholipids, apolipoprotein A1 mimetic peptide (PK22), targeting peptide-conjugated cytotoxic mertansine (RM) and photodynamic agents of DiIC18(5) (DiD). The counterpart biomimetic lipoprotein system without RM (termed as BL-D) was fabricated as control. Both BL-D and BL-RD were nanometer-sized particles with a mean diameter of less than 30 nm and could be efficiently internalized by cancer cells. After intravenous injection, they can be specifically accumulated at tumor sites. When comparing to the counterpart BL-D, BL-RD displayed superior capability to permeate across the tumor mass, extravasate from tumor vasculature to distant regions and efficiently access the cancer cell fractions in a solid tumor, thus producing noticeable depression of the tumor growth. Taken together, BL-RD can be a promising delivery nanoplatform with prominent tumor-penetrating and cancer cells-accessing capability for effective tumor therapy.

Construction of human telomerase reverse transcriptase periodontal ligament cell line mediated by adenovirus / 华西口腔医学杂志

OBJECTIVE@#This study aims to establish an effective and stable periodontal ligament cell line stably expressing human telomerase reverse transcriptase (hTERT) gene by using the adenovirus method.@*METHODS@#Polymerase chain reaction (PCR) was used to amplify the full length of hTERT gene to construct recombinant adenovirus plasmid pAd-pshuttle-cmv-hTERT. Packaged adenovirus particles were used for infection of human periodontal ligament cells. The expression levels of hTERT and osteogenic genes, such as alkaline phosphatase, Runt-related transcription factor 2, bone sialoprotein, osteocalcin, osteopontin, and collagen Ⅰ mRNA, were detected by quantitative real-time PCR (qRT-PCR). The ability of osteogenic differentiation was observed by alizarin red staining, and the cell proliferation was determined by CCK-8.@*RESULTS@#Adenovirus particles containing the hTERT gene were successfully constructed and infected with periodontal ligament cells. The infected cells were similar to normal periodontal ligament cells. The qRT-PCR results showed that hTERT and osteogenesis-associated genes were highly expressed in the periodontal ligament cell lines constructed by adenoviruses. Alizarin red staining showed that the periodontal ligament cell line had strong osteogenic differentiation capability. CCK-8 showed that the periodontal ligament cell line had strong proliferation capability.@*CONCLUSIONS@#The human periodontal ligament cell line with high efficiency and stable expression of hTERT was established by the adenovirus method, thereby providing an ideal cell line for studying the mechanism of periodontal regeneration.

Establishment of A549 cell line with stable expression of HIF1α mediated by lentiviral vector / 重庆医学

Objective To establish the A549 cell line with stable expression of HIF1α by using lentiviral vector system.Methods Primers were designed and synthesized with human HIF1α gene coding sequence by the National Center of Biotechnogical Information(NCBI) as the template.HIF1α was amplified by PCR.The HIF1α fragment recycled by enzyme digestion was recombined with prepared lentiviral vector HBLV-RFP-Puro.The recombinant plasmid was identified by PCR and gene sequencing.The recombinant plasmid and the auxiliary plasmid were co-transfect into 293T cell.After filtration and concentration of packaged virus,the viral titer was detected by using the dilution counting method.The prepared lentivirus was infected A549 cells.The drug screening was adopted to stabilize the transfected cell line.The transfection effect was detected and observed by fluorescence microscope and Western blotting.Results The HIF1α fragment amplified by PCR was successfully verified and the recombinant plasmid was successfully constructed by PCR and gene sequencing identification.High-titer LV-HIF1α was obtained by successful package.After LV-HIF1α infecting A549 cells,the cells showed the red fluorescence by fluorescence microscope.The expression level of HIF1α in the LV-HIF1α group was significant higher than that in the control group by Western blot.Conclusion The 549 cell line with HIF1α stable expression mediated by lentivirus is constructed successfully.

Lentiviral vector mediated up?regulation of miR?126 promotes migration and invasion on AGS cells / 实用医学杂志

Objective To establish an AGS cell line that stably expressing miR?126 and to study the effect of miR?126 on the proliferation and metastatic abilities of the AGS cell line in vitro. Methods AGS cells were infected by lentivirus with Lv?has?mir?126. After confirmation by RT?PCR ,CCK?8 and clone formation assays were used to evaluate the effect of miR?126 on AGS cell growth. Transwell migration and invasion assays were used to evaluate the effect of miR?126 on metastasis of AGS cells. Results We verified correct construction of recombinant AGS cells. RT?PCR confirmed mRNA levels of miR?126 existed significantly differences among the recombinant cell lines (P< 0.05). Proliferation assays and clone formation assays did not show a remarkable growth suppression in AGS?mir?126 cell line. However,transwell assay showed a notable acceleration in AGS?mir?126(P< 0.05). Conclusions We successfully constructed recombinant AGS cell line with stably high miR?126 expression level. MiR?126 could facilitate the metastasis of AGS cell in vitro.

Construction of human mucosa oral epithelial cell lines overexpressing telomerase reverse transcriptase gene mediated by lentivirus / 华西口腔医学杂志

<p><b>OBJECTIVE</b>To construct a cell line of oral mucosa epithelial cells that stably express human telomerase reverse transcriptase (hTERT) by lentiviral vectors, approaches for the establishment of stable and efficient immortalized oral mucosa epithelial cell lines were explored.</p><p><b>METHODS</b>Whole RNA was extracted from 293T cells. The hTERT gene was amplified by polymerase chain reaction (PCR) and cloned into the lentiviral vector as pLVX-puro-hTERT. The lentivirus particles were successfully packaged and used to infect primary oral epithelial cells. The positive cell clones were selected by puromycin. Finally, the expression of hTERT was examined by real-time fluorescent quantitative PCR (qRT-PCR) and Western blot analysis.</p><p><b>RESULTS</b>The sequencing results confirmed the construction of the recombinant lentivirus pLVX-puro-hTERT. The morphology of infected cells was similar to that of normal oral mucosal epithelial cells, with a cobble stone-like appearance. The qRT-PCR and Western blot results showed that hTERT was overexpressed in infected cells compared with the normal group (P<0.05).</p><p><b>CONCLUSIONS</b>The oral epithelial cell line with stable expression of hTERT was successfully established by the lentivirus, which provides an experimental basis for the establishment of a highly efficient and stable oral epithelial immortalized cell line.</p>

Stable expression and function of rat mu-opioid receptor in PC12 cells by lentivirus vector / 国际药学研究杂志

Objective To stably express rat mu-opioid receptor (rMOR) in PC12 cells with characteristics of neurons. Methods After the lentiviral vector pBPLV-rMOR-eGFP was constructed, the lentivirus was packaged and used to infect the PC12 cells. PC12 cells stably expressing rMOR was screened by the flow cytometry and the limiting dilution assay. The affinity and quantity of rMOR protein expressed in the PC12 were verified by radio-ligand binding assay. The function of rMOR was analyzed by cAMP overshooting. Results The eGFP protein in PC12-rMOR cells infected by the lentivirus could be clearly shown by the fluorescence microscope. Cell lines grew normally after every clone was enlargedly cultured. The affinity (Kd) and quantity (Bmax) values of rMOR were (0.51 ± 0.07) nmol/L and (1.58 ± 0.15)pmol/mg protein respectively in 3H-diprenorphine binding assay. The cAMP content increased (255 ±25.2) % after naloxone precipitated in chronic morphine-treated cells. Exogenous agmatine could dose-dependently inhibit the overshooting of cAMP by naloxone precipitated. Conclusion We have successfully established the PC12 cell model co-expressing stably rMOR and I1 style imidazoline receptor(I1R) without α2 adrenergic receptor, expressing properties of neurons, which is a good cell model in vitro for investigating the neural molecular mechanism of opioid addition and regulating the opioid receptor function by the system of agmatine and I 1 Rin the future.

Construction and identification of ERβ419 gene silencing recombined vectors of beagle ERβisoforms / 中国比较医学杂志

Objective To construct and identify retroviral-mediated short hairpin RNA ( shRNA ) expression vectors of ERβ419, and explore ERβ419 unknown biological function in beagles in future.Methods To screen out the most effective gene silencing sequence of beagle ERβ419 mRNA using qRT-PCR and Western Blot assays, imitate beagle estrogen target cells.Results qRT-PCR results showed, ERβ419-shRNA1 ( P <0.01 ) and ERβ419-shRNA3 ( P <0.01)differed significantly, Western Blot result as same as qRT-PCR,ERβ419-shRNA3 is the best choice.Conclusion Beagles ERβ419-shRNA3 retrain most effectively target gene repression. It is applied to explore ERβ419 unknown biological function in beagles reproductive system, and to prevent and treat beagles reproductive function diseases.

Stable expression and potential use of West Nile virus envelope glycoproteins preM/E as antigen in diagnostic tests

West Nile virus (WNV) envelope glycoproteins preM/E were stably expressed in baby hamster kidney cells and tested as antigen in a fluorescent antibody assay for WNV antibodies. Sera from horses, mice and chicken immunized with an inactivated WNV vaccine and, less consistently, sera from horses acutely infected with WNV, reacted specifically with viral antigens present in preM/E-expressing cells.

EXPRESIÓN GUS EN EXPLANTES DE Solanum phureja (Juz. et. Buk) Var. Criolla Colombia , TRANSFORMADOS CON Agrobacterium tumefaciens / Gus Expression in Solanum phureja Explants (Juz. et. Buk) Cultivar Criolla Colombia , Transformed with Agrobacterium tumefaciens

La expresión transitoria y estable del gen gusA-intron en explantes internodales de papa criolla variedad Criolla Colombia cocultivados con Agrobacterium tumefaciens es reportada. Con el fin de determinar la susceptibilidad de esta variedad a la transformación mediada por A. tumefaciens, explantes internodales de Solanum phureja fueron infectados con la cepa LBA4404 de A. tumefaciens que contiene el plásmido pCAMBIA2301. Este plásmido contiene el gen ntpII que confiere resistencia a kanamicina y el gen reportero gusA-intron. La selección de los explantes potencialmente transgénicos fue realizada en medios con kanamicina. La eficiencia de transformación estable y transitoria fue calculada con base en la actividad GUS (ß-glucuronidasa), detectada por el ensayo histoquímico X-gluc. La expresión transitoria y estable del gen gusA-intron fue observada en células del explante más bien que en tejidos completos. Estos resultados demuestran que la papa criolla (S. phureja Juz. et. Buk) variedad Criolla Colombia es susceptible a la infección por A. tumefaciens.

The stable and transient expression of the gusA-intron reporter gene in internodal explants of "Papa Criolla" cultivar Criolla Colombia co-cultivated with Agrobacterium tumefaciens is reported. In order to determine the susceptibility of this cultivar to the A. tumefaciens-mediated transformation, internodal explants of Solanum phureja were infected by A. tumefaciens containing the vector pCAMBIA2301. This vector contains the kanamycin resistance gene ntpII and the reporter gene gusA-intron. The selection of potential transgenic explants was performed on kanamycin-containing media. The stable and transient transformation efficiency was calculated on the basis of the GUS (ß-glucuronidase) activity, detected by the histochemical X-Gluc essay. Transient and stable expression of the gusA-intron gene is observed in explants cells rather than in whole tissues. Nonetheless, these results demonstrated that "Papa Criolla" (Solanum phureja Juz. et. Buk) Cultivar Criolla Colombia is susceptible to the Agrobacterium tumefaciens infection.

Stable Expression of Hantavirus H8205 Strain G1/IL-2 Gene and Immune Protection of the Fusion Gene / 华中科技大学学报（医学）（英德文版）

To explore the feasibility of stable expression of Hantavirus H8205 strain G1 segment and human IL-2 fusion gene in Vero cells, and to examine the immune protection effects on mice vaccinated with this recombinant eukaryotic expression vector containing Hantavirus G1 gene and IL-2 gene. With the help of lipofectamine, the Vero cells were transfected with pcDNA3.1/HisB-IL-2-G1 and the positive cells were selected by G418. IFAT and SDS-PAGE electrophoresis were used to determine the stable transfection and expression of recombinant protein.Each mouse was inoculated with plasmids intramuscularly (i.m.) three times, 2 boosts were given at 2-week intervals, serum anti-hantavirus antibodies were detected by ELISA and neutralizing antibodies (NAb) were detected by Plaque Reduction Neutralization Test. The fusion protein expressed in Vero cells was 78 kD, corresponding to the estimated molecular size. The neutralizing antibody titers of mice with pcDNA3.1/HisB-IL-2-G1 were 1:20-1:80. IL-2/G1 fusion gene could be transferred in Vero cells and stably express the fusion protein. Specific humeral immune responses in mice can be induced with the recombinant eukaryotic expression vector containing the fusion gene, which lays the foundation for further development of therapeutic HTNV vaccine.

CXCR4 gene expression promotes K562 cells chemotaxis / 基础医学与临床

Objective To construct the tranfected cell expressing the human CXCR4 gene and to identify the effect on its immigration. Methods Total RNA was isolated from peripheral blood monouclear cell (PBMC),the full-length CXCR4 gene was amplified by RT-PCR and was inserted into plasmids PBudCE4.1 which have two promtors, after the identification by digestion and sequencing,the recombinant was transfected into K562 cell by lipofectamineTM2000. After screening culture by zeocin, stable transfected K562 cell line was established, and transcription and exression of CXCR4 were checked by flow cytometry; the chemotactic activity of K562 cell transfected and untrandfected CXCR4 was analyzed by Transell plate. Results The eukaryotic expression plasmid PBudCE4.1/ CXCR4 was constructed successfully. The stable trasfected K562/CXCR4 cell lines which highly express CXCR4 was established,the chemotactic activity of K562/CXCR4 was increased significiantly than K562. ConclusionCXCR4 transfected K562 cell line was successfully established, and it can make the basis for the further research on mechanism of extramedullary infiltration in leukemia.

Comparison of Stable Expressions of Foreign Genes Driven by Different Promoters in Transgenic Dunaliella salina / 中国生物工程杂志

The purpose was to compare the difference between transgene expressions driven by homologous duplicated carbonic anhydrase (DCA) promoter and foreign CaMV35S promoter in the unicellular green alga, Dunaliella salina(D.salina).The CaMV35S promoter-bar construct and DCA promoter-bar construct into D.salina by a Backon 2000 electroporation system were introduced. After the repeated selections with the phosphinothricin (PPT) of 3mg/L, 3 PPT-resistant phenotype transformants were isolated from the CaMV-bar and DCA-bar pools of transformants of D. salina, respectively. The results of PCR and sequencing showed that bar genes were stably integrated into the genome of D.salina, and Southern bolts showed the number of transgene copy had no significant difference between both promoters. Semi-quantitive RT-PCR indicated that the mRNA levels of bar gene were higher in DCA-bar transformants than the CaMV-bar transformants, and could be increased under the induction of high salt in DCA-bar transformants but not in the CaMV-bar transformants. Analysis of growth rate of transformants showed DCA-bar transformants achieved the log stage faster than the CaMV-bar transformants. It is concluded that the homologous promoters have more advantages than the foreign promoters in the transgenic D.salina.

Establishment of Hepatocellular Carcinoma Cell Lines with Stable Decreased Expressing IGF1R Gene with siRNA / 中国普外基础与临床杂志

Objective To establish hepatocellular carcinoma(HCC) cell lines which olig-expressed IGF1R gene stably.Methods An eukaryotic expressing vector pSUPER-IGF1R-siRNA that could block IGF1R expressing was transferred into hepatocellular carcinoma cell lines SMMC7721 and Hep3B with Lipofectamine 2000 reagents.After transferred,cells were selected with G418 to obtain positive clones.The expressions of IGF1R,cyclin D1 and cyclin B1 were detected by RT-PCR and Western-blot.Cell growth curve were painted.Results Two cell lines clones were screened olig-expressing IGF1R gene stably.The experimental cell lines grew more slowly than control cell lines and the expression of cyclin D1 decreased(P

Expression and Intracellular Localization of Hepatitis C Viral Core Protein in Human Hepatoma Cell Line Transfected with Viral cDNA / 대한암학회지

PURPOSE: Establishment of the human liver cell lines which permanently express the HCV proteins is important for the large scale production of viral antigen and analysis of the mechanism of hepatocellular carcinogenesis by HCV. Here, we attempted to establish the human hepatoblastoma cell lines which stably express the HCV core protein and examined the intracellular localization of the core protein. MATERIALS AND METHODS: The cDNA of HCV core protein and neomycin resistance gene were expressed in HepG2 cells by the SRalpha promoter and human EF-1alpha gene promoter, respectively. The core protein was detected by immunofluorescence assay and western blotting. RESULTS: We obtained several HepG2 cell clones which express HCV core protein stably. In transient expression assay, the core protein was localized in the cytoplasm in about 90%, and localized in the nucleus in about 10% of the core-expressing HepG2 cells. But, in the stably expressing HepG2 cell clones, the core protein was localized only in the cytoplasm. No HepG2 cell containing core protein in the nucleus was found in all of the cells which stably express the core protein. CONCLUSION: The EF-1alpha gene promoter is highly efficient in the colony formation by neomycin resistance gene and is very useful for the isolation of human liver cell clones which express foreign genes stably. HCV core protein is localized in both nuclear and cytoplasm of human liver cell in short term but the cells containing the core protein in nucleus seem to disappear in long term culture.