Linked Life Data

9277151

Source:http://linkedlifedata.com/resource/pubmed/id/9277151

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
1998-1-8
pubmed:abstractText
Photochemotherapy employing 8-methoxypsoralen and long-wavelength ultraviolet radiation (UVA, 320-400 nm) is widely used in the treatment of psoriasis. The photoactivation of psoralens in skin cells leads to formation of DNA photoadducts which may be responsible, at least in part, for the efficacy of these photochemotherapies. However, mutations arising from these adducts may also lead to the well-characterized increased incidence of squamous cell carcinoma. Mutations in the p53 tumor suppressor gene have been detected in many human cancers. To determine whether p53 mutations occur in squamous cell carcinomas in PUVA patients, PCR was used to amplify the exons (5-9) in which other studies have found a high frequency of point mutations. Gel electrophoresis was used to detect single-strand conformational polymorphisms. Aberrantly migrating bands were excised, reamplified and sequenced. Thirty-four specimens from 10 patients were examined. Specimens from one patient who had received no phototherapy as well as from normal controls were also analyzed. Five of the 10 patients showed at least one p53 mutation. In contrast to previously reported psoralen-induced p53 mutations in mice, the expected psoralen type mutations at alternating AT sites were not detected. All but two of the altered sequences occurred at dipyrimidine sites which is typical of solar type mutations. Two C-->T mutations and two dipyrimidine mutations (CC-->TT) were found. Other mutations included: C-->G, G-->T, C-->A and an 18 bp deletion. A review of therapeutic history of these patients showed that some had also received UVB phototherapy. Furthermore, because sunlight is thought to be beneficial for psoriasis, nontherapeutic, casual UVB exposure cannot be excluded. Our observations suggest that the SCC may have arisen from the solar mutations and that PUVA may enhance tumor progression or immune suppression.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Aug
pubmed:issn
0031-8655
pubmed:author
pubmed:issnType
Print
pubmed:volume
66
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
294-9
pubmed:dateRevised
2005-11-17
pubmed:meshHeading
pubmed:year
1997
pubmed:articleTitle
An unexpected spectrum of p53 mutations from squamous cell carcinomas in psoriasis patients treated with PUVA.
pubmed:affiliation
Department of Dermatology and Cutaneous Biology, Thomas Jefferson University, Philadelphia, PA 19107-5541, USA.
pubmed:publicationType
Journal Article