THE P53-DEFICIENT MOUSE - A MODEL FOR BASIC AND APPLIED CANCER STUDIES

Inactivation of the p53 gene in the germline of mice by gene targeting has provided researchers with a model similar in many respects to the analogous human inherited cancer predispositian Li-Fraumeni syndrome. The viability of p53 null mice has allowed unexpected opportunities t o study the rob of p53 in many different in-vivo and in-vitro contexts . Null (p53-/-) mice have an average time to tumor development of 4.5 months, while half of the heterozygous (p53+/-) mice develop tumors by 18 months. The p53-deficient mice have been particularly valuable in examining the effects of p53 loss on tumor progression. In addition, t he mice hold significant promise as tools to assess carcinogens, terat ogens, chemopreventative agents, and cancer therapeutic regimens.