Growth of normal and neoplastic urothelium and response to epidermal growth factor in a defined serum-free medium.

We have developed a defined serum-free medium for the in vitro growth of normal and neoplastic urothelium. Growth of epithelial cells in this medium was stimulated while proliferation of fibroblasts was inhibited. The medium allowed for the isolation of a new line from a high grade human bladder carcinoma. Several strains of normal human urothelium that could be passaged several times in culture were also obtained. Although growth of normal and neoplastic urothelial cells in the defined medium was not stimulated by epidermal growth factor, the presence of 50 ng/ml epidermal growth factor induced morphological changes suggestive of terminal maturation of normal urothelium, implying that epidermal growth factor either acted as an epithelial maturation factor or induced the secretion of such a factor.