Cells in different parts of the brain carry the same genes, but they also contain factors that modify the use of those genes, suppressing some genes and activating others to allow the cells to take on specialized characteristics as the brain matures. These changes in gene activity levels are called changes in gene expression.
The researchers found that tumors arising in different regions of the brain retain distinct patterns of gene expression. These patterns provided genetic fingerprints or bar codes for the location of PAs, as well as for another glial cell tumor called an ependymoma. In addition, scientists also detected these distinct patterns of expression in normal glia and stem cells from these brain locations, suggesting that genetic fingerprints can be used to identify the potential origins of brain tumors.
"There's been a movement in recent years to link normal brain development to pediatric neuro-oncology, and these findings affirm that as a necessary approach," Gutmann says. "We won't fully understand the causes of pediatric brain tumors until we consider them in the context of factors that shape the development and specialization of different brain regions."