Oncogenicity of Murine Mammary Tumor Virus Produced in Tissue Culture: Brief Communication2

Abstract
Murine mammary tumor virus (MuMTV), produced from a glucocorticoid-stimulated C3H mouse mammary adenocarcinoma cell line, was free of murine leukemia virus and oncogenic for weanling BALB/c mice. Adenocarcinomas were induced by MuMTV as early as 136 days post inoculation and with as low as 5×103 virus particles/mouse. Tumor incidence did not correlate directly with virus dose; rather, it was low at higher MuMTV concentrations (1.2×108 particles/mouse), reached an optimum at 1.3×105 particles/mouse, and decreased with virus dilution.