Linked Life Data

19336724

Source:http://linkedlifedata.com/resource/pubmed/id/19336724

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
4
pubmed:dateCreated
2009-4-7
pubmed:abstractText
Prior research shows that topical application of free, nonfatty acid-conjugated vitamin E (DL-alpha-tocopherol) prevents skin cancer in mice, as well as immunosuppression induced by UVB radiation. This study investigated the chemopreventive potential of DL-alpha-tocopherol in humans through monitoring surrogate end point biomarkers in sun-damaged skin. Contralateral arms of healthy human volunteers with actinic keratoses (AK) were randomly assigned to receive either 12.5% DL-alpha-tocopherol or placebo in a crème base for 6 months. Changes in number of AKs, levels of p53 protein expression, proliferating cell nuclear antigen, and polyamines were assessed along with skin and systemic vitamin E levels. Following treatment, plasma concentration levels of DL-alpha-tocopherol were unchanged, but skin levels were highly elevated (P < 0.001). Levels of p53 and proliferating cell nuclear antigen did not change significantly, whereas number of AKs declined insignificantly in both placebo and treatment arms. Regression models showed significant decreases in putrescine, spermidine, spermine, and total polyamine concentrations following treatment. Topically applied DL-alpha-tocopherol was substantially absorbed in skin, but the 6-month application did not significantly reduce numbers of preexisting AKs on moderately to severely sun-damaged forearms. Increases in polyamine synthesis are expected during tumor initiation and promotion; conversely, the significant reductions in polyamine levels resulting from the topical DL-alpha-tocopherol application are consistent with reductions in tumorigenesis potential. Topical tocopherol did not normalize established sun-induced lesions, but DL-alpha-tocopherol-induced reductions in polyamine metabolism are consistent with the inhibition of skin squamous cell carcinogenesis as seen in previous human trials and animal models.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Apr
pubmed:issn
1940-6215
pubmed:author
pubmed:issnType
Electronic
pubmed:volume
2
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
394-400
pubmed:dateRevised
2010-9-16
pubmed:meshHeading
pubmed:year
2009
pubmed:articleTitle
Chemoprevention of human actinic keratoses by topical DL-alpha-tocopherol.
pubmed:affiliation
Arizona Cancer Center, University of Arizona, Tucson, AZ 85724-5024, USA. jfoote@email.arizona.edu
pubmed:publicationType
Journal Article, Randomized Controlled Trial, Research Support, N.I.H., Extramural