Linked Life Data

7780970

Source:http://linkedlifedata.com/resource/pubmed/id/7780970

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
12
pubmed:dateCreated
1995-7-19
pubmed:abstractText
Sixty % of clones isolated from HeLa cells treated with toxic concentrations of a methylating carcinogen showed increased resistance to the cytotoxicity of N-methyl-N-nitrosourea. D37 values were 6- to 100-fold higher than in the parental cell population. The absence of detectable levels of the repair enzyme O6-methylguanine-DNA methyltransferase indicated that the resistant clones were able to tolerate the presence of O6-methylguanine in their DNA. Analysis of N-methyl-N-nitrosourea survival in the hybrids between tolerant clones and HeLa cells showed that tolerance can be either recessive or codominant. Fusion between tolerant clones indicated two complementation groups. We measured spontaneous mutation rates at microsatellites and at the hypoxanthine-guanine phosphoribosyl transferase (hprt) locus in several tolerant clones. All the clones of Complementation Group I showed unstable microsatellites and 4-8-fold increases in mutation rates at hprt. No significant alterations in spontaneous mutation rates were found in clones of Complementation Group II. The data indicate that tolerance to methylation damage can be conferred by alterations in at least two different gene products and that one of the two groups has the mutator phenotype typical of mismatch correction defective cells.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jun
pubmed:issn
0008-5472
pubmed:author
pubmed:issnType
Print
pubmed:day
15
pubmed:volume
55
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
2569-75
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1995
pubmed:articleTitle
A mutator phenotype characterizes one of two complementation groups in human cells tolerant to methylation damage.
pubmed:affiliation
Istituto Superiore di Sanita, Laboratory of Comparative Toxicology and Ecotoxicology, Rome, Italy.
pubmed:publicationType
Journal Article, Comparative Study, Research Support, Non-U.S. Gov't