Linked Life Data

3927158

Source:http://linkedlifedata.com/resource/pubmed/id/3927158

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
1985-9-4
pubmed:abstractText
We have studied the effects of 5-bromodeoxyuridine (BrdUrd) at two genetic loci in diploid human lymphoblast cells. In thymidine kinase heterozygotes (tk +/-), a 2-h dose of BrdUrd induced a transient, non-heritable resistance to the thymidine analogue, trifluorothymidine (F3TdR). We have called this phenomenon pseudomutation and have shown that affected cells acquire the ability to survive in the presence of F3TdR and then, after degradation of F3TdR in the medium, return to an apparently normal wild-type state. Our data suggest that BrdUrd incorporation into DNA as a thymidine analogue is responsible for the effect, which we interpret as a temporary loss of thymidine kinase activity. This effect is not seen in tk +/+ homozygotes. In contrast, at the hypoxanthine-guanine phosphoribosyl transferase locus in tk +/- heterozygotes, BrdUrd did not induce a permanent, heritable resistance to 6-thioguanine (gene locus mutation). We detected such mutations only in the tk +/+ homozygote and only at external BrdUrd concentrations considerably higher than those which saturate the uptake of BrdUrd into DNA as a thymidine analogue. We postulate that the reduced TK enzyme levels (30%) in the heterozygote prevent the build-up of a sufficiently high intracellular BrdUrd triphosphate pool to promote the misincorporations as deoxycytidine triphosphate which may be responsible for gene locus mutation.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Aug
pubmed:issn
0027-5107
pubmed:author
pubmed:issnType
Print
pubmed:volume
151
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
95-108
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1985
pubmed:articleTitle
Mutational and pseudomutational effects of 5-bromodeoxyuridine in human lymphoblasts.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, Non-P.H.S.