Influence of Preinfection of C57BL/6 Mice with Graffi Leukemia Virus on 3-Methylcholanthrene-Induced Subcutaneous Sarcoma

When C57BL/6 mice were given both Graffi leukemia virus and 3-methyl-cholanthrene the development of either leukemia and/or sarcoma was dependent on the dose of each carcinogen given. A high dose of virus reduced sarcoma induction because the survival time of the mice was less than the average latency period required for sarcoma induction due to the high incidence of leukemia. A high dose of 3-methylcholanthrene (300 μg) increased the incidence of leukemia induction by a low dose of virus without affecting the incidence of sarcoma. This occurred since the latency period for sarcoma and leukemia coincided and 25% of the mice developed both leukemia and sarcoma. The combination of a low dose of virus and a low dose of 3-methylcholanthrene did not alter the incidence of leukemia or sarcoma; however, with this combination of virus and chemical carcinogens, the average latency period for the development of leukemia was delayed and the average latency period for sarcoma induction was accelerated. Graffi virus failed to increase the incidence of MCA induced sarcoma under the conditions studied.