Inhibitor of apoptosis proteins as a therapeutic target in breast cancer

Excerpt

Apoptosis is the process of programmed cell death by which damaged or unhealthy cells are normally destroyed. Cancer cells are able to avoid apoptosis and thereby survive inappropriately. Inhibitor of apoptosis proteins (IAPs) are a family of proteins that block apoptosis in normal cells, by binding to active caspases, the proteases that mediate cell death. There are eight human IAPs, including NAIP, XIAP, cIAP1, cIAP2, livin, survivin and apollon. An upregulation of IAPs could cause resistance to apoptosis. Targeting IAPs in cancer therapy may therefore improve the clinical effectiveness of apoptosis-inducing chemotherapeutics. A number of studies have shown that XIAP and survivin are up-regulated in cancer, and inhibiting these IAPs increased the apoptotic response induced by some chemotherapeutics. We aim, first, to examine the expression profile of all IAPs in breast cancer and, second, to determine whether inhibiting IAPs will enhance the apoptotic response to traditional chemotherapeutics and newly developed targeted therapies, such as Herceptin. …