title: Altered expression of interleukin-1 receptor antagonist in different stages of mouse skin carcinogenesis.
abstract: Interleukin-1 receptor antagonist (IL-1Ra) is an endogenous inhibitor of interleukin-1. The expression of IL-1Ra and interleukin-1alpha (IL-1alpha) was measured in murine epidermis after treatment with tumor promoters and in tumor cell lines. A single treatment with three different tumor promoters (12-O-tetradecanoylphorbol-13-acetate (TPA), anthralin, and thapsigargin) induced IL-1Ra mRNA with different kinetics in mouse skin. The expression of IL-1Ra mRNA also was induced by TPA and IL-1alpha in a dose-related and time-dependent manner in cultured mouse keratinocytes. Expression of IL-1Ra mRNA peaked 6 h after treatment. Both IL-1Ra and IL-1alpha protein and IL-1Ra and IL-1alpha mRNA were measured in various keratinocyte tumor cell lines (C50, MT1/2, HEL30, JWF2, CH72, and BPCC2). The expression of IL-1alpha was increased in papilloma and squamous cell carcinoma cell lines. IL-1Ra protein also was increased in nontumorigenic and papilloma cell lines; however, the expression was dramatically reduced in some carcinoma cell lines. Finally, we detected IL-1alpha and IL-1Ra protein in mouse skin tumors by western blot analysis, and localization was assessed by immunohistochemical analysis. Positive staining for both IL-1alpha and IL-1Ra was observed in the cytoplasm and was most prominent in the suprabasal layer. Although IL-1Ra protein increased in papillomas and carcinomas, IL-1alpha protein was not significantly increased above basal level in most tumors.
mesh_terms: D015127:9,10-Dimethyl-1,2-benzanthracene; D000818:Animals; D000875:Anthralin; D015152:Blotting, Northern; D015153:Blotting, Western; D002273:Carcinogens; D002294:Carcinoma, Squamous Cell / Q000139:chemically induced / Q000235:genetics* / Q000378:metabolism; D016764:Cell Polarity; D003593:Cytoplasm / Q000737:chemistry; D018450:Disease Progression; D004817:Epidermis / Q000187:drug effects / Q000378:metabolism* / Q000473:pathology; D015972:Gene Expression Regulation, Neoplastic; D006965:Hyperplasia; D007249:Inflammation; D053590:Interleukin 1 Receptor Antagonist Protein; D007375:Interleukin-1 / Q000096:biosynthesis / Q000235:genetics; D015603:Keratinocytes / Q000187:drug effects / Q000378:metabolism; D051379:Mice; D018632:Mice, Inbred SENCAR; D009363:Neoplasm Proteins / Q000096:biosynthesis* / Q000235:genetics; D010212:Papilloma / Q000139:chemically induced / Q000235:genetics* / Q000378:metabolism; D011230:Precancerous Conditions / Q000139:chemically induced / Q000235:genetics* / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D012334:RNA, Neoplasm / Q000378:metabolism; D012795:Sialoglycoproteins / Q000096:biosynthesis* / Q000235:genetics; D012871:Skin Diseases / Q000139:chemically induced / Q000235:genetics* / Q000378:metabolism; D012878:Skin Neoplasms / Q000139:chemically induced / Q000235:genetics* / Q000378:metabolism; D013755:Tetradecanoylphorbol Acetate; D019284:Thapsigargin; D014407:Tumor Cells, Cultured