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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
4
pubmed:dateCreated
2008-3-4
pubmed:abstractText
Immunosuppressive medication in renal transplant recipients (RTR) strongly increases the risk of cancers on sun-exposed skin. This increased risk was considered an inevitable collateral effect of immunosuppression, because UV-induced carcinomas in mice were found to be highly antigenic. Here, we posed the question whether immunosuppression also increases the frequency of p53-mutant foci ('p53 patches'), putative microscopic precursors of squamous cell carcinomas. As the majority of RTR was kept on azathioprine for most of the time, we investigated whether this drug could increase UV-induced p53 patches by immunosuppression. As azathioprine can impair UV-damaged DNA repair under certain conditions, we also investigated whether DNA repair was affected. Archive material of RTR and immunocompetent patients (ICP), as well as azathioprine-administered hairless mice were examined for p53 patches. DNA repair was investigated by ascertaining the effect of azathioprine on unscheduled DNA synthesis (UDS) in UV-irradiated human keratinocytes. P53 patches were more prevalent in RTR than in ICP in normal skin adjacent to carcinomas (P = 0.02), in spite of a lower mean age in the RTR (52 vs 63 years, P = 0.001), but we found no increase in UV-induced p53 patches in mice that were immunosuppressed by azathioprine. We found a significant reduction in DNA repair activity in keratinocytes treated with azathioprine (P = 0.011). UV-induced UDS in humans is dominated by repair of cyclobutane pyrimidine dimers, and these DNA lesions can lead to 'UV-signature' mutations in the P53 gene, giving rise to p53 patches.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Apr
pubmed:issn
1600-0625
pubmed:author
pubmed:issnType
Electronic
pubmed:volume
17
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
349-55
pubmed:dateRevised
2008-11-21
pubmed:meshHeading
pubmed-meshheading:17979968-Adult, pubmed-meshheading:17979968-Aged, pubmed-meshheading:17979968-Animals, pubmed-meshheading:17979968-Azathioprine, pubmed-meshheading:17979968-Carcinoma, Squamous Cell, pubmed-meshheading:17979968-Cell Transformation, Neoplastic, pubmed-meshheading:17979968-Clone Cells, pubmed-meshheading:17979968-DNA Repair, pubmed-meshheading:17979968-Epidermis, pubmed-meshheading:17979968-Female, pubmed-meshheading:17979968-Genes, p53, pubmed-meshheading:17979968-Humans, pubmed-meshheading:17979968-Immunocompetence, pubmed-meshheading:17979968-Immunocompromised Host, pubmed-meshheading:17979968-Immunosuppressive Agents, pubmed-meshheading:17979968-Keratinocytes, pubmed-meshheading:17979968-Kidney Transplantation, pubmed-meshheading:17979968-Male, pubmed-meshheading:17979968-Mice, pubmed-meshheading:17979968-Mice, Hairless, pubmed-meshheading:17979968-Middle Aged, pubmed-meshheading:17979968-Mutation, pubmed-meshheading:17979968-Skin Neoplasms, pubmed-meshheading:17979968-Ultraviolet Rays
pubmed:year
2008
pubmed:articleTitle
More epidermal p53 patches adjacent to skin carcinomas in renal transplant recipients than in immunocompetent patients: the role of azathioprine.
pubmed:affiliation
Department of Dermatology, Leiden University Medical Center, Leiden, The Netherlands. y.g.l.de_graaf@lumc.nl
pubmed:publicationType
Journal Article