The effects of steroid sex hormones on the established cell lines derived from human urinary bladder cancer, T24, and from human transitional cell cancer of the urinary tract, 253J, were examined using the colony formation method. Of the seven kinds of steroid hormones tested, estradiol-17 beta was intensively cytotoxic for both cells. The cytotoxic effect was depended on the dose and time of treatment. The combined effect of Adriamycin and estradiol-17 beta on T24 cells could be recognized at low concentrations of Adriamycin (less than or equal to 10(-3) micrograms/ml) after exposure for 24 h.</p
