Linked Life Data

7200803

Source:http://linkedlifedata.com/resource/pubmed/id/7200803

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
1982-8-26
pubmed:abstractText
In mammalian cells, inhibitors of DNA replication have been shown to induce chromosomal aberrations, cell death and changes in gene control. Inhibition of DNA synthesis has been reported to induce hypermethylation of mammalian DNA (enzymatic postsynthetic formation of 5-methylcytosine). These 5-methylcytosines in mammalian DNA have variously been suggested to be important in gene control, DNA repair, and control of DNA replication. In establishing the normal characteristics of enzymatic DNA methylation, we have demonstrated that, in asynchronously growing cells of both human and hamster origin, some cytosine methylation is delayed for several hours after strand synthesis and that this delayed methylation is completed before the DNA strand acts as a template for DNA replication in the next S-phase. Further, in testing whether the deleterious effects on mammalian cells of DNA synthesis inhibitors might be mediated via changes in enzymatic DNA methylation, we have found, contrary to some previous findings, no evidence for any change in the level of DNA methylation in DNA strands synthesized during 6 h of treatment of cells of human origin with high concentrations of four different inhibitors of DNA replication or during the 4 h following the 6 h treatment. Almost totally blocking DNA replication had no effect on the small amount of delayed methylation of DNA strands not involved in semi-conservative replication during the time of the experiment. This lack of effect on DNA methylation was obtained when the labelling medium contained normal, undialysed serum. In contrast, if dialysed serum was used in the labelling medium in order to maximize L-[Me-3H]methionine utilization, highly variable, totally irreproducible patterns of apparent DNA hypermethylation were obtained.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jan
pubmed:issn
0006-3002
pubmed:author
pubmed:issnType
Print
pubmed:day
26
pubmed:volume
696
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
15-22
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1982
pubmed:articleTitle
Characteristics of enzymatic DNA methylation in cultured cells of human and hamster origin, and the effect of DNA replication inhibition.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't