Antigen(s) on human transitional cell carcinoma detected by a xenogeneic antiserum

In studies concerning human bladder cancer, antisera were raised in rabbits against human tumours, normal tissue, and cell lines derived from human tumours and were analysed by absorption and complement dependent microcytotoxicity tests. No significant selective cytotoxicity was discernible with any unabsorbed antisera. After absorption of A53, (an antiserum against the transitional cell carcinoma derived cell line T24) with peripheral blood cells and normal adult tissues, it was cytotoxic to two bladder cancer cell lines (T24 and J82) but not to four other cell lines. This activity was removed by absorption with each of two specimens of transitional cell carcinoma but not by normal bladder and by absorption with T24 or J82 but not with four other non-bladder cell lines. This functional specificity for transitional cell carcinomas could be due to a tumour associated antigen, a significant quantitative difference between tumour and normal cells, or an embryonic specificity re-expressed on the tumor. Further experiments are necessary to investigate these alternatives.