Therapy Recognizes Receptor Mutation, Prevents New Melanoma Formation.(Brief Article)

2002 JAN 23 - (NewsRx.com & NewsRx.net) -- by Sonia Nichols, senior medical writer - Duke University researchers say they have created a tumor vaccine that targets mutated receptors on malignant tumors but also circumvents abnormal immune response.

An interdepartmental group at the university's medical center created the tumor vaccine using dendritic cells, which while effecting powerful response against targeted antigens can also work overtime, generating autoimmune response activity in some people. "Targeting the epidermal growth factor receptor variant III (EGFRvIII), which is a mutation specific to tumor tissue, could eliminate this risk," said Amy B. Heimberger, an investigator in the Division of Neurosurgery at Duke, and coauthors in the journal Neurosurgery.

According to the researchers, the tumor antigen is often seen in tumors that have either originated or spread to the brain, which led them to study the efficacy of the new vaccine on a murine model of intracerebral melanoma.

Describing the structural elements of the vaccine, Heimberger and team said dendritic cells were "mixed with a keyhole limpet hemocyanin conjugate of the tumor-specific peptide, PEP-3, which spans the EGFRvIII mutation." They also developed a control vaccine containing dendritic cells and the nonsequence-specific peptide PEP-1. Both of the vaccines were administered to mice subsequently challenged with intracerebral implantations of melanoma expressing genes for the mutant receptor.

The novel vaccine induced immune response against the tumor-specific antigen, and increased survival as well. "Among mice challenged ...