Oncogenicity of a nude mouse cell line transformed by a human papovavirus.

Primary cultures of NIH nude mouse (nu/nu) kidney cells were transformed with a human papovavirus (MMV). The transformed cell line expressed T-antigen, and MMV DNA was found to be associated with the cell DNA. When NIH nu/nu mice were inoculated with the transformed cells, they developed tumors at the injection site but failed to generate detectable levels of T-antibody. A control group of nu/+ littermates rejected the tumor inoculum but mounted an antibody response to T-antigen. It was proposed that nude mouse cells may be a suitable system to test oncogenicity of in vitro transformed cells.