RESUMO
Satisfactory experimental models for preclinical prediction in cancerology must answer the following criteria: reproducibility of the method used for inducing tumors; clinical, pathological and kinetic similarity with the corresponding human tumors. We have developed a model of osteosarcoma locally induced by insoluble radioactive cerium chloride (144Ce CI3) in Sprague Dawley rats. This method yields over 80% of bone tumors at the injection site, of which approximately half are histologically similar to human tumors. These tumors double their volume fairly slowly (in approximately 20 days); lung metastases occur both early and frequently (80% of animals). A transplantable tumor was developed from an induced osteosarcoma and adapted to the Curie strain. Transplantation in the bone, next to the bone, or under the skin is followed by widespread metastatic dissemination. The kinetics and histological features of the primary tumor are maintained. Tumor 85 strontium uptake is similar to that seen in human osteosarcomas. These new models of osteosarcomas are being used for evaluating new cancer chemotherapeutic agents and interferon, etc.
