Tumourigenicity testing in immunosuppressed mice: advantages and disadvantages

Optimal conditions for the detection of malignant cells substrates were investigated. Three approaches were used: (1) neonatally thymectomized, antithymocyte serum (ATS) treated mice, (2) thymectomized, lethally irriadiated, bone marrow reconstituted (T-B+mice, and (3) congenitally athymic nu/nu (nude) mice. All three systems successfully distinguished between normal and malignant cell lines. However, differences were observed between different colonies of nude mice as to their capacity to support progressive growth of certain tumours. Advantages and disadvantages of the immunosuppressed mouse model system will be discussed. They will include: (a) detection of malignant cells in mixed populations, (b) need for different routes of inoculation for different cell types, (c) comparison with other malignancy testing systems, (d) long term versus short term immunosuppression.