How Head Injury May Contribute To Brain Tumour: Study Explains Molecular Mechanism

The study suggests that genetic mutations and brain tissue inflammation act together to change the behaviour of cells, which become more likely to turn cancerous.

Scientists have long suspected that head injuries are possibly associated with increased rates of brain tumours, but there was no conclusive evidence to establish this. Now, a new study has provided an understanding at the molecular level for a particular type of tumour, called a glioma, and how head injury may contribute to the development.

The study, conducted by researchers from the University College of London (UCL) Cancer Institute, has been published in the journal Current Biology. It suggests that genetic mutations and brain tissue inflammation act together to change the behaviour of cells, which become more likely to turn cancerous.

While the study was carried out in mice, the researchers have stressed the importance of examining whether the findings may be relevant to human gliomas, too.

Gliomas are relatively rare but they can be often aggressive. They often arise in neural stem cells. The study investigated whether a more mature type of brain cells, called astrocytes, can also give rise to brain tumours.

The young adult mice selected for the study had brain injury. To examine the behaviour of astrocytes, the researchers injected the mice with a substance that would permanently label the astrocytes in red. They also inactivated a gene called p53, which plays a role in suppressing many different cancers.

In a control group, the mice were treated the same way, but the p53 gene was left intact in them.

In yet another group of mice, p53 was inactivated, but in the absence of injury.

The scientists observed changes in the astrocytes of mice that had injury and were without p53. “So we let the mice age, then looked at the cells again and saw that they had completely reverted to a stem-like state with markers of early glioma cells that could divide,” a press release from UCL quoted lead researcher Simona Parrinello as saying.

This suggested that mutations in certain genes were acting in concert with brain inflammation. As the inflammation increased during the process of ageing, the astrocytes would become more likely to initiate cancer.