Tracolimus, an immunosuppressant, prevents organ rejection by a transplant recipient's immune system by decreasing immune system activity. Tracolumus binds to and inactivates a protein called calcineurin in immune cells.
The team found that calcineurin not only stimulates the immune system, but also stimulates the growth of new blood vessels to tumors. By inactivating calcineurin, orally administered Tracolimus was found to reduce blood vessel growth to tumors by over 70% in a pre-clinical breast cancer model. If successfully replicated in human trials, Tracolimus could someday serve as a therapeutic strategy to inhibit tumor growth in breast cancer patients.