Comparison of Nude Mice with the Host Species for Evaluation of the Tumorigenicity of Guinea Pig and Hamster Cells Transformed in Vitro by Chemical Carcinogens Available to Purchase

Nude mice (nu/nu) were compared with the species of origin for determination of the tumorigenicity of cells from chemical carcinogen-transformed and noncarcinogenic chemically treated, nontransformed guinea pig and Syrian hamster cultures. The incidence and time of appearance of progressively growing tumors were similar in the host species and in nude mice after injection of 10⁷ transformed cells. Inoculation of 10⁸ nontransformed cells routinely was nontumorigenic in the host species and in nude mice. The nude mouse has potential as a sensitive and reliable alternative host to the species of origin to evaluate the tumorigenicity of xenogeneic mammalian cells from cell culture model systems of carcinogenesis.