Osteosarcoma is a highly malignant and metastatic cancer involving the bones of large breed dogs. Novel therapeutic approaches are needed to prevent metastasis following surgery and chemotherapy. This study is directed at understanding the role of growth factors and their receptors on tumor growth, metastasis, and chemotherapy resistance. Following completion of this study, the investigators should be in a position to begin to design therapeutic strategies. The treatment of canine bone cancer requires chemotherapy as well as surgical removal of cancerous tissue.
Many dogs develop a resistance to the chemotherapy.
This study will evaluate a new method to determine drug resistance. By doing so, investigators feel the measurements can be used as prognostic indicators and predictors of cases that might need altered therapeutic protocols. Tumors stimulate the growth of new blood vessels in order to grow. Endostatin, an inhibitor of new blood vessel growth, can induce impressive tumor suppression in mice. To use endostatin in dogs, a new form of intravenous gene therapy will be used to deliver the canine endostatin gene directly to the tumor blood vessels.