Linked Life Data

9042416

Source:http://linkedlifedata.com/resource/pubmed/id/9042416

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
1997-3-14
pubmed:abstractText
Insertion of a normal chromosome 11 into tumour cell lines can protect against a sensitivity to irradiation and oxidative stress. A possible mechanism underlying this effect is that there is a correction of a defect in the rejoining of double-strand breaks (dsb) by the chromosome insertion. In order to explore this hypothesis, three cell lines were evaluated for their ability to rejoin dsb: (1) a bladder carcinoma cell line ('parent') previously shown to be sensitive to irradiation and radical generating species; (2) a derivative of this cell line into which a normal chromosome 11 had been inserted by microcell fusion ('hybrid') showing corrected radiosensitivity; and (3) a 'revertant' cell line that had spontaneously lost the insert and reverted to the radiosensitive phenotype. Nuclear extracts from the 3 lines were isolated and evaluated for their capacity to rejoin plasmid (pUC18) DNA broken at defined restriction sites (SalI, EcoRI, KpnI, SmaI) in the lacZ gene. The extent of rejoining was determined by gel electrophoresis and the fidelity of rejoining determined by expression of the lacZ gene in E. coli DH5 alpha bacteria. Results suggest there is no difference between the 'parent', 'hybrid' and 'revertant' nuclear extracts in the fidelity and the total extent of rejoining, regardless of the type of break. However, there is an alteration in the distribution of rejoined products. Nuclear extracts from 'hybrid' cells tend to rejoin linear DNA into circular monomers with a greater efficiency than extracts from both 'parent' and 'revertant' cells. This alteration in distribution is observed when 3'- or 5'-protruding ends are rejoined but not in the rejoining of blunt ends. The results suggest that loci on chromosome 11 are involved in the rejoining of dsb, affecting the relative amount of the different rejoined products. Whether this alteration plays a role in the 'parent' cell's radiosensitivity is yet to be determined.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jan
pubmed:issn
0027-5107
pubmed:author
pubmed:issnType
Print
pubmed:day
31
pubmed:volume
383
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
21-30
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1997
pubmed:articleTitle
Rejoining of DNA double-strand breaks after the introduction of chromosome 11 into a radiosensitive bladder carcinoma cell line.
pubmed:affiliation
Division of Epidemiology and Cancer Prevention, British Columbia Cancer Agency, Vancouver, Canada.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't