Linked Life Data

11888904

Source:http://linkedlifedata.com/resource/pubmed/id/11888904

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
5
pubmed:dateCreated
2002-3-12
pubmed:abstractText
Breast cancer is one of the major causes of mortality among women in the United States. Although the causes of breast cancer remain unclear, it has been speculated that DNA base damage may lead to mutations that subsequently can be carcinogenic. Recently, defective oxidative DNA damage repair has been implicated in breast tumorigenesis. The major oxidative DNA lesion, 8-hydroxyguanine (8-oxoG), is increased in breast cancer, suggesting that this lesion may play a crucial role in the etiology of breast cancer. However, it is not known whether the repair of 8-oxoG or other oxidative base lesions is altered during breast carcinogenesis. We examined the ability of nuclear and mitochondrial extracts of two human breast cancer cell lines, MCF-7 and MDA-MB-468, to repair 8-oxoG lesion. We report that mitochondrial extracts from the two breast cancer cell lines are defective in the base excision repair of 8-oxoG relative to two noncancer cell lines. We also show that the incision activity of 8-oxoG was significantly lower in mitochondrial than in nuclear extracts in the breast cancer cell lines. The defective mitochondrial repair activity was not attributable to lower levels of human 8-hydroxyguanine DNA glycosylase, the base excision repair enzyme known to incise 8-oxoG in DNA. The repair of thymine glycol, another major oxidative DNA base lesion that blocks transcription and causes cell death, was similar in cancer and noncancer cells. Furthermore, nuclear extracts incised thymine glycol with a much higher efficiency than 8-oxoG. These data provide evidence for defective repair of 8-oxoG in mitochondria of MCF-7 and MDA-MB-468 breast cancer cell lines. These results may implicate 8-oxoG repair mechanisms in mitochondria of certain breast cancers.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Mar
pubmed:issn
0008-5472
pubmed:author
pubmed:issnType
Print
pubmed:day
1
pubmed:volume
62
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1349-55
pubmed:dateRevised
2004-11-17
pubmed:meshHeading
pubmed:year
2002
pubmed:articleTitle
Defective repair of 8-hydroxyguanine in mitochondria of MCF-7 and MDA-MB-468 human breast cancer cell lines.
pubmed:affiliation
Laboratory of Cellular and Molecular Biology, National Institute on Aging National Institutes of Health, National Institutes of Health, Baltimore, Maryland 21224, USA.
pubmed:publicationType
Journal Article