O05 - Validating antibodies for cross-species applications in murine, human, and canine osteosarcoma

Abstract:

Background: Pet dogs develop osteosarcoma approximately 10 times as frequently as human patients, providing a crucial source of biospecimen and allowing researchers to fill critical knowledge gaps. However, comparative studies are constrained by the lack of appropriately validated antibodies across murine, canine, and human samples, which may limit the translational value of model species.

Objective: To curate a panel of antibodies that identify targets across murine, canine, and human tissues with a focus on the pulmonary metastatic osteosarcoma microenvironment.
Animals: Murine, canine, and human osteosarcoma and non-tumor control tissues (lung, brain, liver, and spleen) were collected and processed using a standard operating procedure.

Methods: Immunohistochemical labeling was performed for each antibody in all three species using the same concentration and antigen retrieval conditions. Results were examined by a board-certified pathologist to confirm appropriate immunolabeling. Antibodies were further validated using western blots.

Results: We identified a panel of antibodies that detect components of the microenvironment of metastatic osteosarcoma across murine, canine, and human lung tissues, including immune cells (CD3, CD20, CD204, FOXP3, IBA1), pneumocytes (TTF-1), endothelium (CD31), lymphatics (PROX1), and osteosarcoma cells (ALPL, RUNX2, SAT2B).
Conclusions and Clinical Importance: Murine models and tumor bearing pet dogs are critical components of comparative oncology that aid in the advancement of human osteosarcoma therapies. This project identified a panel of antibodies that can be applied to metastatic osteosarcoma within murine, canine, and human lung. Validating cross-species antibodies ensures that generated data achieves its full translational value while being efficient, cost effective, and precise.