Brain tumors may soon be treated by interrupting the process by which stem cells grow, a new study finds. Treatment usually consists of surgically removing the tumor, as well as some of the healthy material around it. However, this procedure can often result in the loss of brain functions, making surgery even more dangerous than usual.
Brain tumor stem cells are essential to the reproduction of cancer, and interrupting the development of these cells results in reductions in the spread of cancerous cells.
"These tumor stem cells are really the kingpins of cancers - the cells that direct and drive much of the harm done by tumors," Albert H. Kim, assistant professor of neurological surgery at the Washington University School of Medicine in St. Louis, said.
Glioblastoma is one form of brain cancer with the worst prognosis for patients. Just 30 percent of people with the disease live longer than two years after their initial diagnosis. The average life expectancy for patients is just 15 months after the disease is first detected by doctors. The disease strikes roughly 18,000 Americans each year.
Stem cells within glioblastomas and other cancers are highly resistant to all forms of treatment, including surgery, radiation, and chemotherapy. Once these cells avert the threat of a given treatment, they quickly encourage the growth of new cancer cells. This behavior makes such diseases notoriously difficult to treat. However, researchers found that these abilities must be continually maintained. Blocking this regular process appears to prevent the stem cells from directing the growth of cancerous cells.
A protein called Sox2 was found to be active in stems cells in brain cancer, as well as elsewhere throughout the body. Researchers discovered that production of this material could be adjusted by the introduction of a second protein, CDC20. The growth rate of cancers lacking CDC20 was reduced by as much as 90 percent. The study also found that patients with the shortest survival times following diagnosis also had the highest levels of CDC20.
"This discovery may help us attack the root of some of the deadliest brain tumors. A successful brain cancer treatment will very likely require blocking the tumor stem cells' ability to survive and replenish themselves," Kim said.
Future research is aimed at developing means of blocking CDC20 in brain tumors. One possibility is blocking the production of certain proteins by utilizing a technique known as RNA interference.
Discovery of the effect of CDC20 in the Sox2 protein, and what that could mean for the treatment of brain cancer in patients, was published in the journal Cell Reports.