Attempted Induction of Tumor Antigens in Carcinogen-Treated Cells

Summary An attempt was made to confirm the hypothesis that tumorspecific transplantation antigens (TSTA) might be induced by chemical carcinogens in cells that otherwise remain normal. In 3 experiments, using 2 carcinogens and 2 strains of mice, we observed that syngeneic skin grafts from donor mice treated with either of these carcinogens exhibited excessive amounts of graft contraction or rejection. Immunodepression by any of 3 methods did not reduce the amount of graft rejection to a point where immunologic surveillance of nontumorous cells could be postulated as the responsible mechanism. The cytotoxicity of the carcinogens was the primary cause of the excessive rejection. In only 1 experiment did the data suggest a small immunologic component. Thus these experiments did not substantiate the hypothesis that TSTA could be induced by chemical oncogens in cells that otherwise remain normal.