MEMPHIS, Jan. 18 (UPI) -- U.S. researchers suggested Wednesday they have found the place in the brain where tumors develop -- which may offer a roadmap to new therapies.
Richard Gilbertson, co-director of the Neurobiology and Brain Tumor Program at St. Jude Children's Research Hospital in Memphis, writing in the January issue of the journal Cancer Cell, said that the tumors arise from cancer stem cells that take refuge in a niche between microscopic blood vessels in the brain.
The researchers demonstrated that the cancer stem cells are located in vascular niches by identifying cells carrying a protein called nestin that marks stem cells in four types of brain cancer: medulloblastoma, ependymoma, oligodendroglioma and glioblastoma.
They found that tumors with the densest system of tiny blood vessels contained the greatest number of nestin-positive cells. These nestin-positive cells lie next to the blood vessels. "This is strong evidence that the cells making up the vascular niche send signals to cancer stem cells in the brain, causing them to grow and multiply," Gilbertson said.
"These niches might also protect cancer stem cells from chemotherapy drugs and irradiation therapy," he suggested. "So our findings could explain why aggressive tumors rapidly produce new blood vessels and why brain tumors reappear following treatment."
He said that if scientists can find ways of invading the niches and disrupting the cancer stem cells they may be able to develop pharmaceuticals that can attack hard-to-defeat brain cancers.
