A New Approach to Cancer Therapy

Implant Makes Cells Kill Cancer is a Technology Review article. The article is focused around an approach to cancer that holds much promise because, unlike chemotherapy and radiation treatments, it would avoid unpleasant side effects. The approach entails getting our immune systems to destroy cancerous growths. Cancer can be viewed as a failure of the immune system to neutralize alien and harmful cells. The immune system is a natural defense and, when effective, avoids the necessity of collateral damage to healthy tissue caused by chemical and radiation therapy. A polymer implant, developed by researchers at Harvard University, could get immunological cells to destroy cancer.

There is good news in that animal studies, utilizing the implant, have yielded very positive results. In addition the implant approach may be utilized to gear up the immune system to counter arthritis and diabetes. The polymer might also become useful in stimulating stem cells to repair damaged tissue.

A signal from the polymer activates dendritic cells through a display of cancer specific antigens which "train" dendritic cells. But the polymer also is covered with DNA fragments similar to DNA found in bacteria. The intent to signal cells of a bacterial infection is clear and the effect of this is to cause dendritic cells to become highly activated and capable of mounting a stronger response to a cancerous tumor.

The related research paper was published in Nature Materials (8, 151 - 158 (2009) doi:10.1038/nmat2357) and is titled Infection-mimicking materials to program dendritic cells in situ. It is authored by Omar A. Ali, Nathaniel Huebsch, Lan Cao, Glenn Dranoff and David J. Mooney. The following is the abstract from that paper:

Cancer vaccines typically depend on cumbersome and expensive manipulation of cells in the laboratory, and subsequent cell transplantation leads to poor lymph-node homing and limited efficacy. We propose that materials mimicking key aspects of bacterial infection may instead be used to directly control immune-cell trafficking and activation in the body. It is demonstrated that polymers can be designed to first release a cytokine to recruit and house host dendritic cells, and subsequently present cancer antigens and danger signals to activate the resident dendritic cells and markedly enhance their homing to lymph nodes. Specific and protective anti-tumour immunity was generated with these materials, as 90% survival was achieved in animals that otherwise die from cancer within 25 days. These materials show promise as cancer vaccines, and more broadly suggest that polymers may be designed to program and control the trafficking of a variety of cell types in the body.