Immune targets in cancer treatment

August 1, 2005

Theoretically, the use of these immune response modifiers could lead to cancer control and regression of tumors.

Vienna, Austria - With an increasing understanding of the role of immunological targets in cancer treatment, J.C. Becker, M.D., of the University of Wurzburg, Germany, is currently investigating the role of several T-cell antigens including IAP, survivin and BCL2 families and their roles in apoptosis.

Dr. Becker presented, "New molecules with immunological relevance," at the 10th World Congress on Cancers of the Skin, here.

"The molecules we are focusing on are largely molecules which are involved in the regulation of apoptosis and therefore are mandatory for the tumor cell to express, grow and to progress," Dr. Becker tells Dermatology Times. "Some of the molecules include the survivin or melanoma IAP family, which are the inhibitors of apoptosis and the BCL2 family (BCL2, BCLX and MCL1). Theoretically, targeting these proteins could lead to cancer control and regression of tumors, but clinically it is still too early to tell," Dr. Becker says.

Dr. Becker discussed that the vast majority of malignancies are characterized by defects in apoptosis signaling, which is mediated by the two groups of apoptosis regulators including survivin, melanoma IAP and BCL2 families.

Such apoptosis regulators are critical factors contributing to the pathogenesis of cancer and represent very attractive targets for the design of new therapies.

"With respect to the study, these molecules may serve as suitable targets for cancer immunotherapy, Dr. Becker says. "Currently, we are looking into the immune response against these proteins and their cell-mediated effects. We are conducting a clinical trial immunizing patients to mount an immune response against survivan. It is still too early to determine outcomes but early analysis demonstrates that late stage tumor patients are able to mount an immune response, which is very promising."

Early findings

These are very early findings, however, Dr. Becker says that the findings of this first exploratory trial using these antigens for immunotherapy may provide new approaches to treatment including simultaneous targeting of several proteins or combination use with conventional chemotherapy.

"Targeting these apoptosis regulators may be very promising. Actually, these therapies could lead to the direct destruction of the tumor cells, because the molecules are not really effective in their function but serve as a target for cytotoxic T cells," Dr. Becker says.

Currently, Dr. Becker is investigating these responses in melanoma, colon cancer, cervical cancer and pancreatic cancer.

"If this proves effective, we would have a new immunotherapy approach for the treatment of cancer, especially melanoma which, to date, is completely non-treatable in a metastatic state. It would probably, as with other therapies, be used in combination with conventional approaches. The advantage of these molecules, when used in combination with chemotherapy or radiation, is that they make the cells more prone to attack on the immune system," Dr. Becker says.

"Furthermore, the important point is that, for a lot of practicing dermatologists, melanoma, once it has metastasized, is a fatal disease, and it seems now with new treatment approaches, not only what I am working on, but also other immunological treatment options, are now opening doors which might change the nature of metastatic melanoma to be treated."

What role?

Dr. Becker's research is ongoing and it remains unclear the role these apoptosis regulators will have in the treatment of cancer, but early findings are promising and encouraging. Theoretically, the use of these immune response modifiers could lead to cancer control and regression of tumors.