title: Triethylenemelamine: an initiator of two-stage carcinogenesis in mouse skin which lacks the potential of a complete carcinogen.
abstract: The dorsal skin of female CD-1 mice was treated with triethylenemelamine (TEM) to determine whether this agent acted either as a complete carcinogen or as an initiator of carcinogenesis. A dose of 0.01-1.0 mumol of TEM applied once a week for 32 weeks to the skin of the backs of mice did not produce any detectable tumors. A dose of 2.5 mumol applied once a week over the same period produced only a single papilloma in a group of 20 mice. However, when mice were treated with a single dose of 1 mumol of TEM followed by promotion with 12-O-tetradecanoylphorbol-13-acetate (TPA) twice a week, 88% of the mice produced papillomas after 28 weeks. Using the same protocol, a single application of hexamethylmelamine (HMM), pentamethylmelamine (PMM), or melamine followed by promotion with TPA had no significant tumor initiating activity. These data suggest that TEM acts primarily as an initiator of two-stage carcinogenesis.
mesh_terms: D000818:Animals; D002273:Carcinogens / Q000633:toxicity*; D003043:Cocarcinogenesis; D005260:Female; D051379:Mice; D010212:Papilloma / Q000139:chemically induced*; D012878:Skin Neoplasms / Q000139:chemically induced*; D013755:Tetradecanoylphorbol Acetate / Q000633:toxicity; D013997:Time Factors; D014265:Triethylenemelamine / Q000633:toxicity*
chemical_list: D002273:Carcinogens; D014265:Triethylenemelamine; D013755:Tetradecanoylphorbol Acetate