Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:1.5.1.3 (dihydrofolate reductase)
 5,819 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We compared the production of recombinant human granulocyte colony-stimulating factor (rhG-CSF) by Chinese hamster ovary (CHO) cells in a transient expression system, using different analogous vectors carrying a human G-CSF-encoding cDNA under the transcriptional control of the murine cytomegalovirus (CMV) major immediate early promoter. Comparison of two transcription units carrying a human (h)G-CSF cDNA deleted of 3'-untranslated (UTR) sequences containing AT-rich elements (ARE) and using 3'-UTR sequences for processing of transcripts from the SV40 early region or from the rabbit beta 1-globin gene showed that use of the sequences from the rabbit beta 1-globin gene resulted in 7- to 12-fold higher levels of rhG-CSF production. Deletion of ARE of hG-CSF cDNA resulted in increased rhG-CSF synthesis when transcription units using 3'-UTR sequences from the rabbit beta 1-globin gene were compared. By contrast, deletion of ARE did not appear to affect rhG-CSF production when 3'-UTR sequences from the SV40 early region were used. The most efficient G-CSF transcription unit, fused to a dihydrofolate reductase (DHFR) marker gene and transfected into a CHO cell line, yielded initial transfectant CHO cell lines secreting up to 21 micrograms rhG-CSF/1 x 10(6) cells in 24 h. After two rounds of DHFR gene amplification, a cell line was isolated that contains approx 12 copies of the vector and produces rhG-CSF at a rate of 90 micrograms/1 x 10(6) cells in 24 h.
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PMID:High-level expression of a cDNA for human granulocyte colony-stimulating factor in Chinese hamster ovary cells. Effect of 3'-noncoding sequences. 921 37

Mucopolysaccharidosis type I (MPS I) results from a deficiency of alpha-L-iduronidase enzyme (IDUA), an enzyme responsible for the catabolism of glycosaminoglycans. Genetically modified progenitor cells may permit a therapeutic effect similar to that obtained from allogeneic BMT without the associated risks. To that end, CD34+ peripheral blood hematopoietic progenitor cells from patients with MPS I were mobilized using G-CSF, collected by apheresis, and enriched using avidin-biotin separation techniques. These cells were cultured in a hollow fiber bioreactor and transduced with a retroviral vector (LP1CD) containing the cDNA for human IDUA and a murine dihydrofolate reductase (DHFR) enzyme. Approximately 4%-16% of the colonies expressed methotrexate drug resistance. Expression of the IDUA enzyme in the progenitor cells was initially high and declined after approximately 10 days of culture. These results indicate that PBPC from patients with MPS I can be mobilized, isolated, enriched, and transduced with a therapeutic gene.
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PMID:Mobilization and transduction of peripheral blood progenitor cells in patients with mucopolysaccharidosis I. 991 44

Umbilical cord blood has been intensively studied as a source of hematopoietic stem cells for transplantation as well as the target for gene therapy. In this study we used a single step density separation to obtain a light density mononuclear cells. The isolated cell population was significantly enriched with progenitor cells. The population also contained sufficient number of primitive hematopoietic stem cells, allowing expansion of cells in serial culture with the addition of IL-6, G-CSF, Epo and kit-ligand and long-term hematopoiesis on preliminary formed stromal layer. Addition of cytokines resulted in a significant increase of cell proliferative activity that is a susceptible target for retrovirally mediated gene transfer. Retroviral transduction with a mutated human dihydrofolate reductase gene assured a significant increase in metatrixate resistance of CFU-GM and selective growth advantage for the transduced cell population. Our data indicate that enriched mononuclear cell population from cord blood can reach high level of metatrixate resistance and is capable of generating a high amount of both drug-resistant progenitors and mature cells.
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PMID:Low Density Mononuclear Cells from Umbilical Cord Blood as a Target for Retrovirally Mediated Gene Transfer. 1268 40