Linked Life Data

7099148

Source:http://linkedlifedata.com/resource/pubmed/id/7099148

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
1982-9-24
pubmed:abstractText
A cloned subline of human cell variants derived from KB cells (KB/6b), 6500-fold resistant to methotrexate (MTX), exhibited a stable 40-fold elevation of the enzyme dihydrofolate reductase (EC 1.5.1.3., DHFR) in the absence of the drug. No differences were detected between the enzyme isolated from resistant and parental KB cells. After the culture medium was supplemented with MTX, the resistant cells were shown to have an additional 5-fold increase in DHFR levels. This increment was dependent upon the concentration of exogenous MTX and was freely reversible. This behavior differs from that of other DHFR-overproducing mammalian cell lines previously reported. The half-life of DHFR in these cells in the presence or absence of MTX was the same, thus eliminating stabilization of the enzyme by MTX as being responsible for the modulation or "induction" phenomenon. Furthermore, the effect was blocked by cycloheximide and was not affected by actinomycin D. These results suggest that modulation of DHFR specific activity by MTX occurs at either the translational level or by as yet undefined post-transcriptional mechanism(s).
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Mar
pubmed:issn
0026-895X
pubmed:author
pubmed:issnType
Print
pubmed:volume
21
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
478-82
pubmed:dateRevised
2009-11-19
pubmed:meshHeading
pubmed:year
1982
pubmed:articleTitle
Effect of methotrexate on dihydrofolate reductase activity in methotrexate-resistant human KB cells.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.