title: p-Nonylphenol acts as a promoter in the BALB/3T3 cell transformation.
abstract: p-Nonylphenol (NP) has attracted attention as an estrogenic contaminant, and the environmental pollution by NP has been found to be extensive. NP is classified as a phenolic antioxidant based on the chemical activity and structure. Some phenolic antioxidants are known to induce and/or enhance carcinogenesis. We examined the effects of NP on the two-stage transformation of BALB/3T3 cells, a model of two-stage carcinogenesis. The treatment by NP in the promotion phase markedly enhanced the transformation of the cells pre-treated with a subthreshold dose of a carcinogen, 3-methylcholanthrene (MCA), but not that of non-pretreated cells. The promoting activity of NP was approximately one hundredth of that of 12-O-tetradecanoylphorbol-13-acetate (TPA), a potent tumor promoter, in the cell transformation. The treatment by NP in the initiation phase did not induce cell transformation with and without post-treatment by TPA. These results indicate that NP acts as a pure promoter of cell transformation implying that it may cause the enhancement of carcinogenesis in vivo. The enhancement by NP of MCA-initiated transformation was suggested not to be mediated by estrogen receptors in BALB/3T3 cells because 17 beta-estradiol did not promote cell transformation in our experiments, and it has been reported that BALB/3T3 cells do not express estrogen receptors at a detectable level.
authors.affiliation: Division of Microbiology, National Institute of Health Sciences, 1-18-1 Kamiyoga, Setagaya-ku, Tokyo 158-8501, Japan. asakai@nihs.go.jp
authors.forename: A
authors.initials: A
authors.lastname: Sakai
mesh_terms: D016475:3T3 Cells; D000818:Animals; D002273:Carcinogens / Q000633:toxicity*; D002471:Cell Transformation, Neoplastic / Q000187:drug effects*; D003043:Cocarcinogenesis; D004785:Environmental Pollutants / Q000633:toxicity; D004958:Estradiol / Q000633:toxicity; D008748:Methylcholanthrene / Q000633:toxicity; D051379:Mice; D010636:Phenols / Q000633:toxicity*; D011960:Receptors, Estrogen / Q000187:drug effects; D013755:Tetradecanoylphorbol Acetate / Q000633:toxicity
chemical_list: D002273:Carcinogens; D004785:Environmental Pollutants; D010636:Phenols; D011960:Receptors, Estrogen; D004958:Estradiol; D008748:Methylcholanthrene; C041594:4-nonylphenol; D013755:Tetradecanoylphorbol Acetate