A receptor known to be active in bone metastases, but previously unexplored in primary bone tumors, is a potential therapeutic target in osteosarcoma, investigators from The University of Texas M. D. Anderson Cancer Center report in the March 1 issue of
Cancer Research.
The researchers found that the protein - interleukin-11 receptor alpha (IL-11Ra) - is highly expressed in primary osteosarcoma and in lung metastases from these tumors. Their research suggests the possibility of delivering therapeutic agents directly to osteosarcoma cells by targeting the receptor with circulating particles that display a peptide mimic of the natural ligand that binds IL-11Ra.
Osteosarcoma is the most common primary malignant tumor of bone. "Existing treatment has not changed the prognosis for osteosarcoma for the last 20 to 30 years," said lead investigator Valerae O. Lewis, M.D., associate professor and chief of Orthopedic Oncology at M. D. Anderson. "About 30 percent of patients still relapse and die of their disease. New therapeutic strategies and agents are needed."
The effectiveness of the current chemotherapy regimens for osteosarcoma is limited by toxic side effects, including damage to the heart and nerves, kidney failure and hearing loss, Lewis noted. Identification of a target specific for osteosarcoma cells opens the door for the development of therapies that can shut down the tumor cells without inflicting the collateral damage caused by conventional osteosarcoma treatments.
IL-11Ra is a target in bone metastasis; far less is known about its attributes, if any, in primary tumors of bone. To address IL-11R? as a potential molecular target in osteosarcoma, the authors confirmed the protein expression and localization of IL-11Ra in several mouse and human osteosarcoma cell lines.