Evidence for Virus-related and Unrelated Antigens on Murine Lymphomas Induced by Chemical Carcineogens

SUMMARY-Ether-treated extracts of 7 CS7Bl lymphosarcomas induced by 3 different chemical car-cinogens, urethan (Ur), N-nitrosomethylurea (NMU) or 7,12-dimethylbenz[alanthracene (DMBA), were tested by immunodiffusion For the presence of group-specific antigens and all were Found positive. Direct cytotoxic tests and absorption tests with a murine anti-G serum and a rat antiradiation leukemia virus (RadlY) serum, using 9 other Ur, NMU, Or DMBA-induced CS7Bl lymphomas, demonstrated the presence of common ceil-surFace, virus-related antigens on the virus-induced E if G2 leukemia, the Radl Y lymphoma, and the chemically induced lymphomas. An antiserum raised in CS7Bl against Ur-induced C3HF or BAlB/c lymphomas exhibited a complement-dependent cytotoxic activity against 21 of 22 CS7Bl lymphomas induced by the 3 different carcinogens, against the El4 leukemia but not against the virus-induced E if G2 leukemia. The EifG2 leukemia also failed to absorb completely the specific cytotoxicity of the antichemi. cally induced lymphomas antiserum. CS7Bl multiparous or anJiembryo sera exerted a complement-dependent cytotoxicity on the chemically induced lymphomas but not on the E if G2 leukemia. Thus carcinogen-induced lymphosarcomas, in addition to Gross virus-related antigens, possess tumor-specific, cell-surface, cross-reacting antigens not related to the virus, which may represent modified expressions of cellular genetic inFormation and/or a retrogenetic expression.-J Natl Cancer Inst 50: 173-180,1973