Author: Sullivan Brandy
Date: October 2008
While the words of Lord Polonius in William Shakespeare's Hamlet may be more well-known amongst literary scholars, they also resonate amongst researchers due to a recent scientific advance in the combat against cancer. Scientists and clinicians at Children's National Medical Center and investigators at the University of Iowa have developed an approach in the combat against cancer that echoes this "self-principle" of looking within oneself that Lord Polonius advocates. By looking inward and utilizing the body's own immune system, these scientists and clinicians developed a new anti-tumor vaccine.
This novel anti-tumor vaccine, specific for neuroblastoma and melanoma cancers, allows for a more tumor-specific form of treatment. The vaccine induces an immune response though targeting proteins specific to tumors using immune stimulatory antigen loaded particles (ISAPs), which were developed by the Chief of Children's National General and Thoracic Surgery Dr. Anthony Sandler. This particular study was conducted in vivo using a mouse model. Specialized immune cells detect and engulf ISAPs, after their initial introduction into the body, and mark them as immune-stimulating "foreign bodies." Results showed that ISAPs are effective in hindering tumor growth in mice by activating immune cells, which in turn stimulate the immune system to react to the tumor. According to Sandler, the "creation of ISAPs allows us to target our treatments to the specific tumor of interest, a capability that will more effectively combat a wide range of these tumors in a personalized fashion."
Unfortunately, despite the encouraging results, the scientists found that the intensity to which the ISAPs reduced tumor growth was diminished by regulatory T-cells whose numbers increased when ISAPs were introduced into the body. Regulatory T-cells diminish the effect of ISAPs on tumor growth by suppressing the development of specific immune cells that detect and engulf ISAPs in the body. The researchers therefore employed the use of a regulatory T-cell suppressor, cyclosphosphamide or anti-CD25 antibody to rescue ISAPs' effects on tumor growth.
Overall, this new anti-tumor vaccine has the potential to offer patients a more targeted option for treatment through ISAPs. As Sandler suggests, "for tumors like neuroblastoma, [using] standard therapies like chemotherapy and/or surgical resection and subsequent treatment with this vaccine could quite possibly cure the patient of the disease in the not too distant future." Sandler's suggestion offers an optimistic outlook for patients diagnosed with neuroblastoma and melanoma cancers. Through combining the use of the body's own immunity and the scientific community's knowledge on tumors, a potential cure for cancer has been developed. Perhaps Lord Polonius was right after all in encouraging us to look inwards at our own capabilities to find the answers that we are looking for.
Written by: Brandy Sullivan
Edited by: Hoi See Tsao
Published by: Hoi See Tsao