Friday, July 23, 2010
CANCER STEM CELLS ???
Brain tumor researchers have found that brain tumors arise from cancer stem cells living within tiny protective areas formed by blood vessels in the brain. Killing those cells is a promising strategy to eliminate tumors and prevents them from re-growing. The researchers have found that drugs that block new blood vessel formation can destroy the protected areas and stop cancer from developing.
For years, researchers thought all cells inside a tumor were the same. But recently, they've discovered something different -- a small group of cancer stem cells.
"They give rise to all the cells that make up the cancer," Dr. Gilbertson explains.
Dr. Gilbertson's research shows those cancer stem cells live close to blood vessels, which fuel them. In lab experiments, he's proven drugs that target the blood vessels also destroy the cancer stem cells and can ultimately wipe out the tumor.
"So, if you can target those cells, you can have a devastating effect on the disease," Dr. Gilbertson says. Drugs like Avastin and Tarceva are now being tested in humans to see if they can target the cancer stem cells. "It's this tangible way of actually getting at the heart of the disease," Dr. Gilbertson says.
The new findings from St. Jude indicates that it is possible to kill the cancer by disrupting the shielded compartments in the small capillaries of the brain where CSCs reside. Anti-angiogenic drugs, such as Avastin, block the formation of new blood vessels. In tests with mice, those same drugs cause a significant drop in cancer stem cells and slow tumor growth. Human clinical trials are currently in progress at St. Jude to determine the effectiveness of Avastin and another anti-angiogenic drug in eliminating tumors and preventing their recurrence in children with brain cancers.