UV-DNA damage in mouse and human cells induces the expression of tumor necrosis factor alpha.
Photochem Photobiol
; 67(5): 541-6, 1998 May.
Article
de En
| MEDLINE
| ID: mdl-9644008
ABSTRACT
Ultraviolet light induces the expression of tumor necrosis factor alpha (TNF alpha) in many mammalian cells. We have examined the signal for this induction in a human DNA repair-deficient cell line carrying a transgene composed of the murine TNF regulatory sequences fused to the chloramphenicol acetyltransferase (CAT) structural gene. When compared by fluence, UVC was a more efficient inducer of CAT than was UVB, but they were equivalent inducers when compared by the frequency of cyclobutyl pyrimidine dimers produced by each source. Further, treatment of UV-irradiated cells with the prokaryotic DNA repair enzyme T4 endonuclease V increased the level of repair of dimers and concomitantly reduced CAT gene expression. Membrane-bound TNF alpha expression was increased by UV and reduced by repair of dimers. Finally, in the TNFcat transgene system, DNA damage directly to the cell with the transgene was required as cocultivation of unirradiated TNFcat cells with UV-irradiated cells did not increase CAT activity. These results show that DNA damage is a signal for the induction of TNF alpha gene expression in mouse and human cells.
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Collection:
01-internacional
Base de données:
MEDLINE
Sujet principal:
Rayons ultraviolets
/
Altération de l'ADN
/
Régulation de l'expression des gènes
/
Facteur de nécrose tumorale alpha
Limites:
Animals
/
Humans
Langue:
En
Journal:
Photochem Photobiol
Année:
1998
Type de document:
Article
Pays d'affiliation:
États-Unis d'Amérique