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

Retroviral vectors carrying the neomycin phosphotransferase (neo) gene have been shown to confer G418 resistance to canine keratinocytes at relatively high frequency. To investigate the usefulness of keratinocytes as potential target cells for gene therapy, we used a retroviral vector (LASN) that contains both human adenosine deaminase (hADA) and neo genes. We show here that LASN-transduced canine keratinocytes expressed high levels of hADA, a human protein of therapeutic relevance. Selection of LASN-transduced keratinocytes in medium containing G418 resulted in a population of cells that expressed even higher levels of hADA, about 80-fold higher than the endogenous canine ADA level. However, the G418-selected cells had a reduced proliferative potential and altered morphology indicative of terminal differentiation. To test whether L-histidinol is more beneficial for selection of keratinocytes than G418, we constructed two retroviral vectors that contain both the neo and the histidinol dehydrogenase (hisD) genes. Cocultivation of primary keratinocytes with lethally irradiated PA317 retrovirus packaging cells that produce these vectors gave rise to 12-53% drug-resistant colonies in either G418 or L-histidinol. In contrast to G418, selection of transduced keratinocytes in L-histidinol had no apparent effect on the proliferative potential or morphology of drug-resistant cells containing the vectors. Given the utility of this selection system, two hisD-based generic constructs containing cloning sites for cDNA expression from either the retroviral promoter or from an internal human cytomegalovirus immediate early promoter were constructed. Our results suggest that hisD will be a useful selectable marker for use in studies of keratinocyte differentiation and for transfer of genes into keratinocytes for the purposes of gene therapy.
 ...
PMID:L-histidinol provides effective selection of retrovirus-vector-transduced keratinocytes without impairing their proliferative potential. 165 May 86

Gene targeting in mouse embryonic stem cells generates mutations by replacing an endogenous chromosomal region with a copy disrupted by a selectable genetic marker. The most commonly used selectable marker is the bacterial neo(r) gene, which confers resistance in mammalian cells to the antibiotic G418. Use of an alternative selectable marker, the Salmonella typhimurium gene hisD, should provide expanded applications for gene targeting. The hisD gene encodes the protein histidinol dehydrogenase, which catalyzes the conversion of histidinol to the amino acid histidine. Histidinol is toxic to mammalian cells, while histidine is an essential mammalian amino acid. Consequently, growth selection in cultures with media containing histidinol in place of histidine occurs by both histidine starvation and histidinol poisoning. The hisD selection is being tested for potential use in gene targeting experiments with mouse embryonic stem (ES) cells. Currently, most successful gene targeting experiments use primary embryonic fibroblast feeder layers, which assist in the maintenance of the pluripotential state of the embryonic stem cells. To support ES cell stability under histidinol selection, mice transgenic for the S. typhimurium hisD gene have been produced and used to generate embryonic fibroblast feeder cells. The transgenic embryonic fibroblasts survive under a wide range of histidinol-containing growth conditions and support growth of ES cell cultures.
 ...
PMID:Transgenic mice for the establishment of histidinol-resistant embryonic fibroblast feeder layers. 900 57