April 11, 2007 -- Developing brain tumors can coax assistance from nearby cells known as microglia, according to a new study from scientists at Washington University School of Medicine in St. Louis. The researchers have identified one protein made by microglia that helps accelerate tumor growth and are looking for others.
The results, published online this month in Human Molecular Genetics, come from a mouse model of neurofibromatosis 1 (NF1), a genetic condition that significantly increases childhood brain tumor risk. But senior author David Gutmann, M.D., Ph.D., the Donald O. Schnuck Family Professor of Neurology, says the findings also have implications for sporadic brain tumors, which affect many more people.
"Until now, we've never really had a good system for studying how microglia may contribute to general brain tumor formation," says Gutmann, who is director of the Neurofibromatosis Center and co-director of the neuro-oncology program at the Siteman Cancer Center at Washington University and Barnes-Jewish Hospital. "We're going to use this model to better understand how brain cells that become tumors interact with microglia, and to probe how we might block those interactions."
Gutmann hopes to create approaches for shutting down microglia, which exist both in a resting state and an activated state. Tumors likely need microglia to be activated before they can convince them to send out growth signals. The tumor then exploits these signals to enable its rapid growth. If scientists can block microglia activation, they place the tumor's potential partner in crime out of its reach.
"From a therapeutic standpoint, we're very focused in cancer therapy on poisoning the cancer cell," Gutmann says. "But why not also deprive the cancer cell of the growth signals it receives from the normal surrounding tissue? These cells may actually decide whether a tumor forms at all and whether it continues to grow."