Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
1992-2-12
pubmed:abstractText
Expression of the bacterial gene for cytosine deaminase (CD; EC 3.5.4.1) in mammalian cells was evaluated as a negative selection system or suicide vector for potential use in gene transfer studies and therapies. Mammalian cells, unlike certain bacteria and fungi, do not contain the enzyme CD and do not ordinarily metabolize cytosine to uracil. Nor do they metabolize the innocuous compound 5-fluorocytosine to the highly toxic compound 5-fluorouracil. The Escherichia coli CD gene underwent PCR oligonucleotide-directed mutagenesis to enhance its expression in a eukaryotic system and it was then cloned into an expression vector, pLXSN, that also contains a neomycin-resistance gene. Murine fibroblast lines were transfected with the plasmid and subjected to brief selection in the neomycin analogue G418. Lysates from these cell populations exhibited significant CD activity detected by conversion of radiolabeled cytosine to uracil. In clonogenic assays transfected cells expressing CD were selectively killed by incubation in 5-fluorocytosine, whereas control cell lines were not. Dose-response studies evaluating [3H]thymidine incorporation or cloning efficiency demonstrated profound inhibition at and above 65 micrograms of 5-fluorocytosine per ml. Mixed cellular assays showed that CD-positive cells could be eliminated without bystander killing of other cells. Retrovirus-mediated CD gene transfer into various tissues was also demonstrated. Thus CD, with its ability to produce the toxic antimetabolite 5-fluorouracil from 5-fluorocytosine, may be useful as a negative selection system for studies and treatments employing gene transfer techniques.
pubmed:commentsCorrections
http://linkedlifedata.com/resource/pubmed/commentcorrection/1729703-1098864, http://linkedlifedata.com/resource/pubmed/commentcorrection/1729703-2299679, http://linkedlifedata.com/resource/pubmed/commentcorrection/1729703-2539360, http://linkedlifedata.com/resource/pubmed/commentcorrection/1729703-2631796, http://linkedlifedata.com/resource/pubmed/commentcorrection/1729703-2645293, http://linkedlifedata.com/resource/pubmed/commentcorrection/1729703-2673119, http://linkedlifedata.com/resource/pubmed/commentcorrection/1729703-2675132, http://linkedlifedata.com/resource/pubmed/commentcorrection/1729703-2694931, http://linkedlifedata.com/resource/pubmed/commentcorrection/1729703-2786000, http://linkedlifedata.com/resource/pubmed/commentcorrection/1729703-2845412, http://linkedlifedata.com/resource/pubmed/commentcorrection/1729703-3002636, http://linkedlifedata.com/resource/pubmed/commentcorrection/1729703-3507689, http://linkedlifedata.com/resource/pubmed/commentcorrection/1729703-3785217, http://linkedlifedata.com/resource/pubmed/commentcorrection/1729703-5955812, http://linkedlifedata.com/resource/pubmed/commentcorrection/1729703-6271971, http://linkedlifedata.com/resource/pubmed/commentcorrection/1729703-773604
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jan
pubmed:issn
0027-8424
pubmed:author
pubmed:issnType
Print
pubmed:day
1
pubmed:volume
89
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
33-7
pubmed:dateRevised
2009-11-18
pubmed:meshHeading
pubmed:year
1992
pubmed:articleTitle
Transfer of the bacterial gene for cytosine deaminase to mammalian cells confers lethal sensitivity to 5-fluorocytosine: a negative selection system.
pubmed:affiliation
Cellular Immunology Section, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892.
pubmed:publicationType
Journal Article, In Vitro