Aggressive Brain Tumors Can Originate From a Range of Nervous System Cells

Scientists have long believed that glioblastoma multiforme (GBM), the most aggressive type of primary brain tumor, begins in glial cells that make up supportive tissue in the brain or in neural stem cells. In a paper published October 18 in Science, however, researchers at the Salk Institute for Biological Studies have found that the tumors can originate from other types of differentiated cells in the nervous system, including cortical neurons.

GBM is one of the most devastating brain tumors that can affect humans. Despite progress in genetic analysis and classification, the prognosis of these tumors remains poor, with most patients dying within one to two years of diagnosis. The Salk researcher’s findings offer an explanation for the recurrence of GBM following treatment and suggest potential new targets to treat these deadly brain tumors.

"One of the reasons for the lack of clinical advances in GBMs has been the insufficient understanding of the underlying mechanisms by which these tumors originate and progress," says Inder Verma, a professor in Salk’s Laboratory of Genetics and the Irwin and Joan Jacobs Chair in Exemplary Life Science.

To better understand this process, Verma’s team harnessed the power of modified viruses, called lentiviruses, to disable powerful tumor suppressor genes that regulate the growth of cells and inhibit the development of tumors. With these tumor suppressors deactivated, cancerous cells are given free rein to grow out of control.