Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
12
pubmed:dateCreated
2008-11-10
pubmed:abstractText
To get a clue to understand how mutations in the XPD gene result in different skin cancer susceptibilities in patients with xeroderma pigmentosum (XP) or trichothiodystrophy (TTD), a thorough understanding of their nucleotide excision repair (NER) defects is essential. Here, we extensively characterize the possible causes of NER defects in XP-D and in TTD fibroblasts. The 3 XP-D cell strains examined were similarly deficient in repairing UV-induced cyclobutane pyrimidine dimers (CPDs) and (6-4) photoproducts (6-4PPs) from genomic DNA. The severity of NER defects correlated with their UV sensitivities. Possible alterations of TFIIH (which consists of 10 subunits including XPD) were then examined. All XP-D cell strains were normal in their concentrations of TFIIH, and displayed normal abilities to recruit TFIIH to sites of UV-induced DNA damage. However, replication protein A (RPA; single-stranded DNA binding protein) accumulation at DNA damage sites, which probably reflects the in vivo XPD helicase activity of TFIIH, is similarly impaired in all XP-D cell strains. Meanwhile, all 3 TTD cell strains had approximately 50% decreases in cellular TFIIH content. Importantly, 2 of the 3 TTD cell strains, which carry the major XPD mutations found in TTD patients, showed defective recruitment of TFIIH to DNA damage sites. Moreover, RPA accumulation at damage sites was impaired in all TTD cell strains to different degrees, which correlated with the severity of their NER defects. These results demonstrate that XP-D and TTD cells are both deficient in the repair of CPDs and 6-4PPs, but TTD cells have more multiple causes for their NER defects than do XP-D cells. Since TFIIH is a repair/transcription factor, TTD-specific alterations of TFIIH possibly result in transcriptional defects, which might be implication for the lack of increased incidence of skin cancers in TTD patients.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Dec
pubmed:issn
1568-7864
pubmed:author
pubmed:issnType
Print
pubmed:day
1
pubmed:volume
7
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1990-8
pubmed:dateRevised
2010-11-18
pubmed:meshHeading
pubmed:year
2008
pubmed:articleTitle
Comparative study of nucleotide excision repair defects between XPD-mutated fibroblasts derived from trichothiodystrophy and xeroderma pigmentosum patients.
pubmed:affiliation
Radioisotope Research Center, Nara Medical University School of Medicine, Kashihara, Nara 634-8521, Japan.
pubmed:publicationType
Journal Article, Comparative Study, Research Support, Non-U.S. Gov't