Multistep renal carcinogenesis in the Eker (Tsc 2 gene mutant) rat model.

Cancer is a heritable disorder of somatic cells. Environment and heredity both contribute to the origin of human cancer. The Eker (Tsc 2 gene mutant) rat model of hereditary renal carcinoma (RC) is an example of a Mendelian dominantly inherited predisposition to a specific cancer in an experimental animal. To the best of our knowledge, this was the first isolation of a Mendelian dominantly predisposing cancer gene in a naturally occurring animal model. Carcinogenesis looks like an opened Japanese fan, because initiated cells growing in several directions will develop into tumors having many gene abnormalities, and this is suggested by the edge of the fan. To search for such genetic alterations, we identified genes (Niban and Erc) that were expressed more abundantly in renal tumors than in the normal kidney.I will review this unique model for the study of multistep renal carcinogenesis and discuss cancer prevention and delay of carcinogenesis.