Deadly Transformation

By transforming themselves into blood-vessel cells, brain-cancer cells have the ability to defy drugs that attempt to cut off blood in order to starve a brain tumor.

The blood vessel cells work around cancer treatments designed to cut off a tumor's blood supply, depriving the tumor of oxygen and nutrients. This maneuver makes treating certain brain cancers -- such as glioblastoma, the most common brain tumor -- nearly impossible to treat. About 13,000 people in the U.S. die each year from glioblastomas, which affect men more frequently than women.

Inder Verma, a genetics professor at the Salk Institute for Biological Studies, in La Jolla, Calif., and study leader, said disrupting tumor blood vessels is not enough, adding researchers must also prevent the conversion of tumor cells into blood vessel cells.

The finding may lead to new drug targets for glioblastoma and other brain cancer therapies.

Most patients with glioblastomas die in less than a year and essentially none has long-term survival, according to the National Academy of Sciences.