Researchers Identify Target For Therapeutic Drugs To Fight Most Common Adult Brain Cancer

A research team at UT Southwestern Medical Center has discovered a cell-signaling mechanism instrumental in the most common brain cancer in adults. The study, published in today's issue of the journal Cancer Research, opens an avenue to develop therapeutic drugs to target the epidermal growth factor receptor genes that play a major role in the development of deadly brain tumors, researchers said. The median survival of patients with glioblastoma multiforme (GBM), a cancer of the supportive tissue of the brain, currently is about one year after diagnosis with the best treatments available, said Dr. Amyn Habib, assistant professor of neurology at UT Southwestern and the study's senior author. GBM, which accounts for 60 percent of brain tumors in adults older than 50 years, can infiltrate the brain extensively and sometimes becomes enormous before turning symptomatic. Researchers have known for years that tumor cells proliferate out of control by a mechanism characterized by an abnormally high number of copies of the epidermal growth factor receptor gene (EGFR). This overexpression of EGFR, Dr. Habib said, is a striking feature of glioblastoma multiforme, present in 40 percent to 50 percent of tumors and results in an uncontrolled multiplication of both normal EGFR and a mutant form called EGFRvIII. While studying human brain tumor tissue and human brain tumor cells from cell lines grown in the laboratory, Dr. Habib and his colleagues discovered that EGFRvIII generates a unique pattern of signaling (distinct from normal EGFR) that causes brain cancer cells in GBM to grow and multiply unchecked.