Linked Life Data

16111924

Source:http://linkedlifedata.com/resource/pubmed/id/16111924

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
2005-12-30
pubmed:abstractText
Using siRNA technology, we down-regulated in human B-lymphoblastoid TK6 cells the two major oxidative DNA glycosylases/AP lyases that repair free radical-induced base damages, hNTH1 and hOGG1. The down-regulation of hOGG1, the DNA glycosylase whose main substrate is the mutagenic but not cytotoxic 8-oxoguanine, resulted in reduced radiation cytotoxicity and decreased double strand break (DSB) formation post-irradiation. This supports the idea that the oxidative DNA glycosylases/AP lyases convert radiation-induced clustered DNA lesions into lethal DSBs and is in agreement with our previous finding that overexpression of hNTH1 and hOGG1 in TK6 cells increased radiation lethality, mutant frequency at the thymidine kinase locus and the enzymatic production of DSBs post-irradiation [N. Yang, H. Galick, S.S. Wallace, Attempted base excision repair of ionizing radiation damage in human lymphoblastoid cells produces lethal and mutagenic double strand breaks, DNA Repair (Amst) 3 (2004) 1323-1334]. Interestingly, cells deficient in hNTH1, the DNA glycosylase that repairs a major lethal single free radical damage, thymine glycol, were more radiosensitive but at the same time fewer DSBs were formed post-irradiation. These results indicate that hNTH1 plays two roles in the processing of radiation damages: repair of potentially lethal single lesions and generation of lethal DSBs at clustered damage sites. In contrast, in hydrogen peroxide-treated cells where the majority of free radical DNA damages are single lesions, the base excision repair pathway functioned to protect the cells. Here, overexpression of hNTH1 and hOGG1 resulted in reduced cell killing while suppression of glycosylase expression resulted in elevated cell death.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jan
pubmed:issn
1568-7864
pubmed:author
pubmed:issnType
Print
pubmed:day
5
pubmed:volume
5
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
43-51
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
2006
pubmed:articleTitle
Base excision repair by hNTH1 and hOGG1: a two edged sword in the processing of DNA damage in gamma-irradiated human cells.
pubmed:affiliation
Department of Microbiology and Molecular Genetics, The Markey Center for Molecular Genetics, The University of Vermont, 95 Carrigan Drive, Stafford Hall, Burlington, VT 05405-0068, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, Non-P.H.S., Research Support, N.I.H., Extramural