A novel strategy against bone invasion of oral cancer

Despite CD4+T cells have been demonstrated to play an important role for bone destruction in the microenvironment of inflammatory diseases, very little work has been done to demonstrate the contribution of these cell types to cancer bone invasion. In the present study, we investigated the mechanism of interaction between regulatory T cells (Tregs) and osteoclasts in a murine model of oral cancer to elucidate the role of Tregs in the bone invasion of oral cancer. Tregs were purified from the tumor of mouse oral cancer model and then cocultured with bone marrow cells. Secreted tartrate-resistant acid phosphatase (TRACP) 5b was determined as a marker of osteoclast number. Attenuation of osteoclast-derived TRACP5b was observed in the coculture of tumor derived Tregs and bone marrow cells, and this attenuation of TRACP5b was ameliorated by neutralization of cytotoxic T-lymphocyte-associated antigens-4 (CTLA-4).