Linked Life Data

8127941

Source:http://linkedlifedata.com/resource/pubmed/id/8127941

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
1994-4-14
pubmed:abstractText
Skin tumor promotion by phorbol ester is believed to be mediated by the phospholipid-dependent ser/thr kinase, protein kinase C (PKC). Long-wave ultraviolet radiation (320-400 nm, UVA), which has also been shown to promote skin tumors, induces elevated levels of PKC in murine fibroblasts, suggesting that UVA may promote the development of basal and squamous cell skin cancers by a mechanism involving PKC. To examine UVA effects on PKC in a model relevant to skin, we maintained normal human epidermal keratinocytes (NHEK) in serum-free medium and exposed the cultured cells to various doses of UVA or to the phorbol ester, 12-O-tetradecanoylphorbol-13-acetate (TPA). Fifty minutes after exposure to UVA (5-20 J/cm2), PKC activity was elevated up to three-fold in NHEK cytosolic fractions, and membrane-associated PKC activity was elevated up to two-fold by UVA. The TPA treatment induced a 10-fold increase in membrane-associate PKC activity only. Immunoblot analysis suggested that a UVA-induced increase in PKC protein occurred. Both UVA and TPA reduced the cell number by 50-75% in the first 24-48 h; however, irradiated cultures began to recover at 72 h post-UVA due to an increased proliferative rate beginning after 48 h. Treatment with TPA induced a high level of differentiation as measured by cornified envelope formation. Ultraviolet A irradiation exposure was not followed by increased differentiation. These findings suggest that acute UVA exposure elevates PKC activity in human keratinocytes and may act through PKC to promote actinic skin cancer. The molecular mechanism is like to differ from that of the phorbol esters, however.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jan
pubmed:issn
0031-8655
pubmed:author
pubmed:issnType
Print
pubmed:volume
59
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
53-7
pubmed:dateRevised
2007-11-15
pubmed:meshHeading
pubmed:year
1994
pubmed:articleTitle
Long-wave ultraviolet radiation induces protein kinase C in normal human keratinocytes.
pubmed:affiliation
Department of Dermatology, Columbia University, New York, NY 10032.
pubmed:publicationType
Journal Article, Comparative Study