Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: DrugBank:EXPT01586 (G418)
 2,237 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

To study and evaluate the potential of the haematopoietic system as a target for gene therapy in haemophilia A, we have infected murine bone-marrow cells with a recombinant retrovirus encoding blood-coagulation factor VIII and the bacterial enzyme neomycin-phosphotransferase. After transplantation of the infected bone marrow into lethally irradiated mice, the presence of intact vector could be demonstrated in DNA isolated from individual haematopoietic progenitor-cell-derived spleen colonies. About 8% of the spleen colonies were shown to contain the intact vector. Selection for resistance to the neomycin analogue G418 prior to transplantation specifically killed the uninfected bone-marrow cells and, as a result, over 90% of the spleen colonies contained the factor VIII vector. However, expression of factor VIII in vivo, either at the RNA or at the protein level could not be demonstrated. From these data we conclude that: 1) retroviral vectors can be used to transfer factor-VIII cDNA into haematopoietic progenitor cells; 2) the vector sequences are expressed immediately after integration; and 3) transcription of the vector is repressed in the progenitor-cell-derived cells.
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PMID:Toward gene therapy in haemophilia A: retrovirus-mediated transfer of a factor VIII gene into murine haematopoietic progenitor cells. 164 25

A yeast artificial chromosome (YAC) library in Saccharomyces cerevisiae consisting of 30,000 clones with an average insert size of 0.1 megabase pair of human DNA has been generated from primary fibroblast DNA. A YAC vector was modified to enable the recovery of both ends of a human DNA insert in plasmids in Escherichia coli and to confer G418 resistance to mammalian cells. A rapid method for yeast colony hybridization was used that exploits the ability of yeast spheroplasts to regenerate in a thin layer of calcium alginate. This method permits direct replica plating and processing of colonies from the primary transformation plate to nitrocellulose filters. Yeast colony hybridization conditions have been established to identify, within a YAC library of human genomic DNA, artificial chromosomes with homology to human DNA probes of unique single-copy sequence. An artificial chromosome with a 0.1-megabase-pair insert from the human Xq28 region has been identified by hybridization to a DNA probe that detects a unique sequence near the 3' end of the factor VIII gene.
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PMID:Rapid screening of a human genomic library in yeast artificial chromosomes for single-copy sequences. 266 48

Autologous seeding of vascular grafts has been in use since 1972; however, the fate of seeded cells has never been determined. While short-term retention has been determined by radioactively labeling cells, long-term studies of seeded cells have not been possible due to the lack of an appropriate marker system. We have developed a long-term marker system for endothelial cells by transfecting the cells with bacterial genes that can be detected by fluorescentally-labeled antibodies to these markers. Two bacterial genes, neo and cat both carried by a pSV2 plasmid construct were used to co-transfect cells. Transfects were selected by growth in the presence of G418. Transfected clones were expanded into monolayers that stained positive for cat by fluorescence, and retained the normal cobblestone morphology and factor VIII staining of endothelial cells. By stably transfecting cells with bacterial genes these cells can now be used to seed vascular grafts and follow the long-term fate of seeded cells.
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PMID:Transfection with bacterial genes as a marker for cells seeded on vascular flow surfaces. 266 14

Endothelial cells (ECs) play multiple physiological functions and are central to many pathological processes. Various biological studies as well as cell and gene therapy applications would benefit substantially from a procedure that would result in the expansion in culture of large numbers of highly differentiated human ECs. Here, we report the amplification in vitro of human EC populations, which occurred during the first phase of reversible immortalization resulting from the retroviral transfer of an oncogene that was subsequently excised by Cre-loxP-mediated site-specific recombination. Human umbilical vein endothelial cells (HUVECs) and human liver sinusoidal endothelial cells (HLSECs) were transduced with a retroviral vector that expresses the simian virus 40 large T (SV40T) gene flanked by positive and negative selectable markers and a pair of loxP recombination targets. Transduced HUVECs and HLSECs yielded clones with greatly extended life spans, referred to as HNNT-1 and HNNT-2 cells, respectively. HNNT-1 and HNNT-2 cells showed morphological characteristics of ECs and were maintained in culture up to population doubling level (PDL) 80 for HNNT-1 and PDL 65 for HNNT-2 cells. HNNT-1 and HNNT-2 cells were not tumorigenic when transplanted into severe combined immunodeficiency mice and were sensitive to ganciclovir as well as G418. Both cell clones expressed EC markers, which include factor VIII, VEGF receptors (Flt-1 and KDR/Flk-1), and CD34, and endocytosed acetylated low-density lipoproteins. Formation of capillary-like structures in a Matrigel assay was observed with HNNT-1 and HNNT-2 cells until at least PDL 50. Complete elimination of the transferred SV40T gene was achieved in virtually 100% of HNNT-1 and HNNT-2 cells after infection with a recombinant adenovirus expressing the Cre recombinase fused to a nuclear localization signal and subsequent selection with G418. Reverted cells maintained their differentiated EC phenotype. This study extends the utility of the reversible immortalization procedure and provides a means to expand primary human ECs of various sources for basic studies and possible cell and gene therapies.
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PMID:Controlled expansion of human endothelial cell populations by Cre-loxP-based reversible immortalization. 1181 87

To investigate the non-viral vector mediating human coagulation factor VIII gene expression in mouse 32D cell line, a recombinant plasmid vector, pRC/RSV-hFVIIIBDcDNA, was constructed by cloning B-domain-deleted (Delta760aa-1639aa) human factor VIII cDNA (hFVIIIBDcDNA) into plasmid vector, pRC/RSV. The plasmid RC/RSV-hFVIIIBDcDNA was then transfected by means of SuperFect Transfection Reagent into mouse 32D cell line. After screening with G418, the procoagulant activity (hFVIII:C) and antigen (hFVIII:Ag) of human factor VIII in the culture medium were detected using one-stage method and ELISA, respectively. Furthermore, RT-PCR was performed to observe the transcription of hFVIIIBDcDNA. The results showed that human coagulation factor VIII protein existed in culture medium with hFVIII:C up to 2.01 U/(10(6) cell x 24 hours) and hFVIII:Ag to 450.08 ng/(10(6) cell x 24 hours). RT-PCR displayed mRNA of hFVIIIBDcDNA in 32D cells. It is concluded that the recombinant plasmid RC/RSV-hFVIIIBDcDNA can successfully express human FVIII in mouse 32D cell line, and hFVIII expressed in vitro presents the similar coagulant activity to the native hFVIII existing in normal human plasma.
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PMID:[Non-viral vector mediating human coagulation factor VIII gene expression in mouse 32D cell line]. 1563 47