EFFECTS OF 12-O-TETRADECANOYLPHORBOL-13-ACETATE ON CARCINOGENESIS IN THE HETEROTOPICALLY TRANSPLANTED RAT URINARY-BLADDER

  • 1 January 1984
    • journal article
    • research article
    • Vol. 75  (9) , 756-762
Abstract
12-O-Tetradecanoylphorbol-13-acetate (TPA) was tested for possible tumor-enhancing effects on urinary bladder carcinogenesis using the heterotopically transplanted bladder (HTB) model. Weekly administration of TPA at 1.0 .mu.g/wk to N-methyl-N-nitrosourea-initiated HTB did not increase tumor incidence, but instead, resulted in a significantly high incidence of nodulopapillary hyperplasia, an early neoplastic lesion, suggesting possible tumor enhancement by TPA. In addition, administration of a high dose of TPA with or without a carcinogen treatment led to the development of numerous finger-like epithelial projections on the luminal surface of the HTB. Evidence indicates that epithelial projections are formed as a result of proliferation of intermediate cells. Whether these structures evolve into true neoplastic lesions is at present unknown.