The interaction with Sp1 and reduction in the activity of histone deacetylase 1 are critical for the constitutive gene expression of IL-1 alpha in human melanoma cells.

Abstract

A375-6 human melanoma cells are sensitive to the antiproliferative effect of IL-1. After a long period of culturing, we have obtained cells resistant to IL-1. The resistant clone A375-R8 constitutively produced IL-1 alpha. In this study, we identified a sequence, CGCC, located at -48 to -45 upstream of the transcription start site, to be essential for the constitutive IL-1 alpha gene activation. Specificity protein 1 (Sp1) and Sp3 bound to the nucleotide containing the sequence. Although the binding level to the nucleotide and expression level of Sp1 and Sp3 are comparable in A375-R8 and A375-6 cells, transactivation activity of Sp1 is higher in A375-R8 cells as compared with A375-6 cells. Sp3 could not transactivate the IL-1 alpha promoter. These results suggest that Sp1 but not Sp3 is important for IL-1 alpha gene activation. Trichostatin A (TSA), an inhibitor of histone deacetylase (HDAC), greatly augmented the IL-1 alpha promoter activity in A375-6 cells to the level comparable with that in A375-R8 cells. TSA also induced IL-1 alpha mRNA expression in A375-6 cells. Sp1 and Sp3 bound to HDAC1 in A375-R8 and A375-6 cells. The chromatin immunoprecipitation assay revealed the binding of Sp1 and HDAC1 to the promoter region of the IL-1 alpha gene. The activities of HDAC bound to Sp1 and Sp3, and that of HDAC1 was lower in A375-R8 cells as compared with A375-6 cells. These results indicate that the reduction in the activity and interaction of HDAC1 with Sp1 are critical for the constitutive IL-1 alpha gene expression.

• Authors: Kazuaki Enya, Hidetoshi Hayashi, Takemasa Takii, Nobumichi Ohoka, Shinya Kanata, Takashi Okamoto, Kikuo Onozaki
• Journal: Journal of leukocyte biology (J Leukoc Biol) Vol. 83 Issue 1 Pg. 190-9 (Jan 2008) ISSN: 0741-5400 [Print] United States
• PMID: 17906119 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Interleukin-1alpha
• Sp1 Transcription Factor
• Sp3 Transcription Factor
• DNA
• HDAC1 protein, human
• Histone Deacetylase 1
• Histone Deacetylases

Topics

• Cell Line, Tumor
• DNA (immunology)
• Enzyme Activation (immunology)
• Gene Expression Profiling
• Histone Deacetylase 1
• Histone Deacetylases (metabolism)
• Humans
• Interleukin-1alpha (biosynthesis, genetics)
• Melanoma (immunology)
• Reverse Transcriptase Polymerase Chain Reaction
• Sp1 Transcription Factor (biosynthesis, metabolism)
• Sp3 Transcription Factor (biosynthesis, metabolism)
• Tumor Cells, Cultured