title: Sodium o-phenylphenate (OPP-Na) promotes skin carcinogenesis in CD-1 female mice initiated with 7,12-dimethylbenz[a]anthracene.
abstract: Sodium o-phenylphenate (OPP-Na) was applied at a dose level of 5.0 mg/animal dermally to the fur-clipped dorsal area of female CD-1 mice twice weekly for 47 weeks after applications of 10 micrograms of 7,12-dimethylbenz[a]anthracene (DMBA) as an initiator twice weekly for 5 weeks. A total of 25 skin tumors (21 papillomas and four carcinomas) developed in 15 out of 20 mice (75%). The incidence and yield of skin tumors in this DMBA/OPP-Na group were significantly higher than in the DMBA/acetone-treated group where only six tumors (five papillomas and one carcinoma) were observed in five out of 20 mice (25%). Only one papilloma developed in OPP-Na/12-o-tetradecanoylphorbol 13-acetate (TPA) treated animals (initiation testing group), and no tumors were observed in mice receiving OPP-Na/acetone. OPP-Na elevated 5-bromodeoxyuridine(BrdU) incorporation in basal cells of mouse epidermis dose-relatedly and the thickness of the skin in the treated group was also increased to approximately 2- or 3-fold that of controls. In addition, high dose application (20 mg/mouse) caused ulceration. O-Phenylphenol (OPP) administration was associated with extensive corrosive effects. The data suggest that OPP-Na is an ulcerogenic agent which induces epidermal proliferation and which can act as a promoter, but not as an initiator or a complete carcinogen, in two-stage mouse skin carcinogenesis.
authors.affiliation: Department of Pathology, National Institute of Hygienic Sciences, Tokyo, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Takahashi
authors.forename: H
authors.initials: H
authors.lastname: Sato
authors.forename: K
authors.initials: K
authors.lastname: Toyoda
authors.forename: F
authors.initials: F
authors.lastname: Furukawa
authors.forename: K
authors.initials: K
authors.lastname: Imaida
authors.forename: R
authors.initials: R
authors.lastname: Hasegawa
authors.forename: Y
authors.initials: Y
authors.lastname: Hayashi
mesh_terms: D015127:9,10-Dimethyl-1,2-benzanthracene; D000818:Animals; D001713:Biphenyl Compounds; D002277:Carcinoma / Q000139:chemically induced / Q000473:pathology; D004357:Drug Synergism; D005260:Female; D051379:Mice; D008815:Mice, Inbred Strains; D010212:Papilloma / Q000139:chemically induced / Q000473:pathology; D012878:Skin Neoplasms / Q000139:chemically induced* / Q000473:pathology; D013755:Tetradecanoylphorbol Acetate
chemical_list: D001713:Biphenyl Compounds; D015127:9,10-Dimethyl-1,2-benzanthracene; C019046:4-phenylphenol; D013755:Tetradecanoylphorbol Acetate