Cancer can be wily, and those who treat the disease have amassed a wide array of weapons with which to fight it and kill tumors. Radiation therapy and various forms of chemotherapy were all thought to be separate but equal treatments. Now, however, new research is beginning to show that it's not just killing the cancer cells that matter. How they're killed may turn out to be just as important and could play a role in marshalling the body's immune response.
New research by Rockefeller University associate professor Madhav Dhodapkar, head of the Laboratory of Tumor Immunology and Immunotherapy, shows that one form of chemotherapy a drug called bortezomib kills tumor cells in such a way that it may allow the immune system to recognize them. In a first edition paper published online this week by the journal Blood, Dhodapkar, postdoctoral fellow Radek Spisek, and their colleagues show that unlike radiation or other chemical therapies, bortezomib can kill multiple myeloma cells in culture in such a way that it elicits a response by memory and killer T cells. The results suggest the drug has the potential to enhance patients' immunity to tumors, helping their bodies fight the disease more effectively.
Multiple myeloma is a cancer of immune cells in the bone marrow. Dhodapkar's experiments show that when treated with bortezomib in tissue culture, multiple myeloma cells die in such a way that a heat shock protein, called hsp90, migrate to their surface. When another group of immune cells, called dendritic cells, encounter hsp90 on the dying tumor cells, the protein acts as a signal for their activation. The dendritic cells then ingest them for presentation to memory and killer T cells, a progression that in humans could potentially lead to enhanced immunity. "If you could directly target the drug to these cells," Dhodapkar says, "it may be sufficient enough to create a vaccine. The exposure of heat shock proteins on dying cells represents an imm
Contact: Kristine Kelly