The mechanism by which a drug kills cancer cells may be crucial to its effectiveness, according to new research from Rockefeller University, in New York City (Spisek R et al. Blood. doi:10.1182/blood-2006-10-054221 [published online February 13, 2007]). While most anticancer chemotherapies are immunosuppressive, bortezomib—a proteasome inhibitor— promotes an immune response.
Proteasomes regulate protein expression and function, and inhibiting them causes cell growth abnormalities and programmed cell death, particularly in cancer cells. As a cancer cell dies, heat shock proteins appear on its surface. This encourages the uptake of malignant cells by dendritic cells. The dendritic cells then alert memory and killer T cells to recognize the cancer cells as foreign, a process that could potentially lead to enhanced antitumor immunity.
Hampton T. Bortezomib’s Action. JAMA. 2007;297(13):1423. doi:10.1001/jama.297.13.1423-a