Detection of private and common tumor-associated antigens in murine sarcomas induced by different chemical carcinogens.

Two fibrosarcomas of similar histological type, induced in C3Hf mice by either methylcholanthrene or 3,4-benz(a)pyrene, were shown to have individually unique tumor-rejection antigens in classical transplantation-type experiments. By contrast, sera of autochthonous mice, which resisted only transplants of the immunizing sarcoma, were found to contain complement-dependent cytotoxic antibodies, specific for both sarcomas, in vitro. The existence of individually unique as well as common tumor-associated antigens in chemically-induced murine sarcomas is suggested. The private "tumor transplantation-type" antigens elicited tumor rejection responses in vivo. The common tumor-associated antigens, although immunogenic in autochthonous hosts, inducing the production of tumor-specific antibodies, failed to induce transplantation cross-resistance in vivo. This study supports the contention that, in carcinogen-induced murine tumors, and perhaps in human neoplasms as well the evaluation of humoral (and cell-mediated) immune responses in vitro may not reflect tumor rejection-type immune responses in vivo.