LOS ANGELES (Sept. 1, 2006) One therapy for treating brain tumors alerts the immune system to the presence of foreign material. A second therapy enhances the first and prolongs the immune system's response. Now, in an animal study conducted at Cedars-Sinai Medical Center's Maxine Dunitz Neurosurgical Institute, researchers have combined the two in a form that appears effective when injected directly into a malignant brain tumor.
The result, extended length of survival, even after "rechallenge," is detailed in the Sept. 1 issue of the journal Cancer Research.
Dendritic cell immunotherapy, pioneered at the Institute in the treatment of deadly, recurring brain tumors called gliomas, is one component of the experimental procedure. The treatment is usually performed after a patient's tumor has been surgically removed. Proteins from the tumor are collected, cultured and introduced in a Petri dish to dendritic cells taken from the patient's blood. The "new" dendritic cells are then injected into the patient's bloodstream. When they encounter lingering tumor cells, they initiate an immune response.
Dendritic cells are specialized "antigen-presenting cells" responsible for alerting the immune system to foreign matter and eliciting an attack. They normally exist in the body to clear debris, such as dead cells, detecting antigens in the process.
The new approach bypasses the tumor-cell extraction and culturing process of dendritic cell immunotherapy. Instead, dendritic cells derived from the patient's bone marrow are attached to a virus engineered to express interleukin-23 (IL-23), a recently discovered cytokine, a protein that regulates immune responses. The dendritic cells are then injected directly into an existing tumor.
IL-23 allows dendritic cells to recognize antigens, such as live glioma cells, that otherwise escape surveillance without immune therapy manipulation. It also has several other properties that significantly
Contact: Sandra Van
Cedars-Sinai Medical Center