IRF-1 expression in normal human epidermal keratinocytes.
Interferon gamma (IFN-gamma) is a potent inducer of cell growth arrest in human epidermal keratinocytes. Interferon regulatory factor-1 (IRF-1), an interferon-inducible gene, is a mediator of interferon action. It has also been suggested that IRF-1 may have a functional role as a tumor suppressor gene and may be associated with the antiproliferative effect of IFN-gamma. We examined the expression of IRF-1 mRNA in normal human epidermal keratinocytes (NHEK). Northern blot analysis demonstrated an increased expression of IRF-1 mRNA by IFN-gamma in NHEKs. This increased expression of IRF-1 mRNA by IFN-gamma was not blocked by treatment with cycloheximide, but was abolished by treatment with actinomycin D. In addition, neither pretreatment with TPA, a protein kinase C (PKC) activator, nor treatment with H7, a PKC inhibitor, affected the induction of IRF-1 mRNA by IFN-gamma. These results indicate that IFN-gamma-induced IRF-1 mRNA in NHEKs is transcriptional and PKC-independent.
Nakanishi
G
G
Department of Dermatology, Okayama University Medical School, Japan.
Fujimoto
W
W
Arata
J
J
D019307:1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine / Q000494:pharmacology; D000328:Adult; D002118:Calcium / Q000502:physiology; D002478:Cells, Cultured; D004268:DNA-Binding Proteins / Q000235:genetics*; D003609:Dactinomycin / Q000494:pharmacology; D005786:Gene Expression Regulation / Q000187:drug effects; D006801:Humans; D050856:Interferon Regulatory Factor-1; D007371:Interferon-gamma / Q000494:pharmacology; D015603:Keratinocytes / Q000378:metabolism*; D010750:Phosphoproteins / Q000235:genetics*; D012333:RNA, Messenger / Q000032:analysis; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology
D004268:DNA-Binding Proteins; C494257:IRF1 protein, human; D050856:Interferon Regulatory Factor-1; D010750:Phosphoproteins; D012333:RNA, Messenger; D003609:Dactinomycin; D007371:Interferon-gamma; D019307:1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine; D013755:Tetradecanoylphorbol Acetate; D002118:Calcium