A gene that helps control the growth of stem cells during brain development also plays a role in regulating the growth of malignant glioma, a deadly brain cancer, according to a new study. The gene, Olig2 (oligodendrocyte lineage transcription factor 2), produces a protein found only in the nervous system that controls the activity of other genes. Experiments in mice suggest that this protein could be a potential target of therapies that are specific to the nervous system.

Drs. Charles Stiles and David Rowitch of the Dana-Farber Cancer Institute led the study, which appeared in the February 15 Neuron. Using tumor tissue from patients with glioma, the researchers found that the Olig2 protein was expressed in two types of cells - cancer stem cells and progenitor cells - that contribute to the growth of glioma. Further experiments in mice indicated that the protein helps regulate a cellular process, or pathway, involved in tumor growth.

Together with previous research, the new findings suggest that Olig2 controls a critical pathway involved in the proliferation of normal and malignant stem cells in the central nervous system. The results also highlight the benefits of stem cell research in understanding human cancers, says lead author Dr. Keith Ligon of Dana-Farber.

The researchers describe Olig2 as a "gateway" gene for the development of brain tumors for several reasons. First, the Olig2 protein is crucial for the development of neural stem cells and their progeny specifically in the central nervous system. Second, the activity of Olig2 is deregulated in brain cancer. And finally, Olig2 activity is required for the formation of some tumors.

When the researchers blocked Olig2 activity in mice that develop brain cancer, 91 percent of the animals did not form tumors.