Researchers at the University of Virginia School of Medicine have determined that a rare form of childhood brain cancer, previously thought to have a simple structure, actually grows in a very complex way.
Some medulloblastoma tumor cells, researchers discovered, actually turn into another type of cell. And if physicians can intervene, the possibility of stopping the disease increases.
“I would think this is going to happen in all kinds of cancer types,” said Hui Zong, of UVa’s Department of Microbiology, Immunology and Cancer Biology and the UVa Cancer Center, in a news release Wednesday. “Just like the formation of a new organ, cancer is formed by a collection of cell types that mutually support and reciprocally regulate each other. So network formation should be the norm rather than the exception.”
Medulloblastoma is rare, but it’s the most common type of cancerous brain tumor in children, according to the Mayo Clinic. It starts in the lower back part of the brain, the cerebellum, and begins to affect muscle coordination, balance and movement.
For years, researchers have believed that medulloblastoma is just one type of cells that proliferate out of control, Zong said — but the cancer’s rate of growth didn’t match the typical rate of tumor cells.
Using an innovative model of the disease, Zong and his team marked tumor cells so that they would appear green. That led to the first surprise: While all other cell types outside the tumor are colorless, a cell type called astrocyte appeared green, which never happens in normal brain regions.
“The fact that tumor-associated astrocytes share the same color with tumor cells suggests that they actually come from tumor cells,” he said. “So some tumor cells basically completely change their identity to make a separate cell type.”
Researchers found that the astrocytes hijack immune cells called microglia for the benefit of the tumor, fueling the growth of the tumor.
That complex process exposes medulloblastoma to many potential interventions to stop its progression, the researchers say.
Zong and his colleagues have described their findings in the scientific journal “Cell.” Their research was supported by grants from the Department of Defense and the National Institutes of Health.