Abstract |
The effect of the tumor promoter 12-O-tetradecanoylphorbol-13-acetate (TPA) on the growth of epithelial cells from rat, hamster, and human respiratory tract has been measured by monitoring colony formation in culture. TPA and its active derivatives stimulated colony formation of rat tracheal epithelial cells in a concentration-dependent manner, while tracheal epithelial cells from the hamster and human bronchial epithelial cells were inhibited from forming colonies by these agents. These results show that normal cells from these species vary in biological response to tumor promoters, implying that selective induction of terminal differentiation in normal cells may not be a universal mechanism of action of tumor promoters. (Copyright (c) Cancer Research 47, 541-546, January 15, 1987.) |