Although stem cells have impressive potential for treating disease, these multitalented precursors have a dark side: tumors use them to divide and spread. Interfering with this process may be a new way to treat the deadly brain cancer known as glioblastoma multiforme (GBM), according to a report in the December 7 issue of Nature.
Angelo Vescovi of the University of Milan and colleagues found that certain proteins called bone morphogenetic proteins dramatically hindered the growth of cultured GBM cells. When mice that had received transplants of human GBM cells were treated with the proteins, they developed much smaller tumors. The mice also survived longer: 80 percent were still alive after four months, all animals that did not receive the proteins had died by then.
These proteins help the healthy brain develop by triggering a specific relay of signals within each cell, thus guiding the cell’s development and determining its fate. The authors believe that by activating this pathway in brain tumors, the proteins divert the cells away from a cancerous path, thus reducing the pool of stem cells that are likely to become tumors.
“These results support a new approach to GBM treatment—inducing differentiation of the tumor-initiating cells, rather than killing them,” the authors wrote. The proteins or compounds like them could be used along with conventional therapy, helping patients survive a cancer that is currently fatal within two years for 75 percent of patients.