A new study led by scientists at the University of Rochester has focused on a mechanism that can lead to cognitive impairment in brain cancer patients receiving brain radiation therapy,media New Atlas reported. Scientists hope the new understanding will lead to the development of novel ways to protect the brain from damage during life-saving cancer treatments.
In the United States, nearly 25,000 people are diagnosed with brain tumours each year, and many of them will receive radiation therapy, a vital part of the treatment process. Unfortunately, more than 80% of patients receive a treatment called whole-brain radiation therapy, which may continue to develop into signs of permanent cognitive impairment.
Previous studies have found that radiation transmitted to the brain during cancer treatment appears to activate brain immune cells called small glial cells. Overactive small glial cells can damage a healthy brain by damaging synapses that connect neurons.
The new study provides the most detailed analysis to date to understand how radiation activates the process by conducting several rodent studies to accurately see where small glial cells destroy synapses. The researchers observed that radiation-triggered small glial cells destroy immature dendritic nerve synapses that connect synapses and neurons.
Kerry O’Banion, senior author of the new study, explained: “The brain goes through a constant process of self-renewal, and cells in the immune system, like gardeners, carefully prune the synapses that connect neurons. When exposed to radiation, these cells become overactive and break the nodules on nerve cells, making them connected to ‘neighbors’. “
But perhaps most importantly, the new study describes a potential way to stop this radiation-induced brain injury. Studies have shown that a receptor called CR3 is critical to the process, and when the receptor is blocked, the radiation-triggered small glial cells do not seem to be able to disrupt these synaptic connections.
Interestingly, the study found that this enhanced small glial cell activity was more pronounced in male mice. This suggests that the brains of female mice may have greater resistance to radiation-induced damage to small glial cells. In rodent studies, a considerable number of previous studies have confirmed the role of many small glial cells that are gender-specific. Thus, although it is not clear how widespread these observations are in humans, the differences seen in females and males are not unexpected or unprecedented.
The new study paves the way for the development of new methods that could prevent brain damage in people undergoing cancer treatment. In addition to therapeutic agents that may block CR3 receptors during radiation therapy, a more common approach may be to simply weaken the patient’s immune response during a particular radiation period.
The new study was published in the journal Scientific Reports.