Gliomas are tumours of the non-neuronal support cells of the central nervous system (CNS), known as glial cells. Glial cells are made up of a variety of cell types, such as astrocytes, oligodendrocytes and ependymal cells, which have many essential roles in maintenance and function of the CNS.
Matured glial cells are less likely to give rise to tumours because under normal conditions they do not divide and, as such, do not cause a build-up of cells (tumour). However, recent findings have demonstrated that a brain injury can cause astrocytes to behave like stem cells – the body’s raw materials – again, giving rise to dividing abilities.
Professor Parrinello and her research team used mice to model a scenario where they had a gene mutation known to increase brain tumour risk (simulating mutations that could accumulate through aging) as well as an early-life brain injury. They found the two worked together to further increase the brain tumour risk later in life.
Prof Parrinello said: “We know that normal tissues carry many mutations which seem to just sit there and not have any major effects. Our findings suggest that if on top of those mutations, an injury occurs, it creates a synergistic effect.”
As part of their research, published in Current Biology, the scientists looked at the medical records of more than 20,000 people diagnosed with head injuries, comparing the rate of brain cancer with a control group (no identified head injuries). They found patients who experience head injury were up to four times more likely to develop a brain cancer later in life. However, it is important to note that even after an injury, the risk of developing a brain cancer remains modest.