How your thoughts can fuel brain tumours: scientists reveal how cancer hijacks the process of thinking.

Published: 20:26, 24 April 2015.

Source: Ellie Zolfagharifard for mailonline.

Link: http://www.dailymail.co.uk/sciencetech/article-3054495/How-THOUGHTS-cause-deadly-brain-tumours-grow-Cancer-hijack-neurons-control-thinking-claims-study.html

Science field: Medical study investigation

Summary:

Study found tumours are fuelled by a process known as myelination. Process insulates nerve cells, allowing them to carry thoughts faster. Scientists say tumours grew faster when closer to these nerve cells. In theory, doctors could slow the growth of these tumours using sedatives.

Glossary:

-          Fuelled: something that maintains, encourages, or stimulates.

-          Insulate: to isolate or detach.

-          Myelin: a white tissue forming an insulating sheath (myelin sheath) around certain nerve fibres. Damage to the myelin sheath causes neurological disease, as in multiple sclerosis.

-          Hijack: to seize, divert, or appropriate (a vehicle or the goods it carries) while in transit.

-          Outer: being or located on the outside; external.

Review:

The basic act of thinking can increase the growth of deadly brain tumours, according to a new study. Scientists have found that high-grade gliomas, the most fatal type of brain tumour, increase in size by hijacking the process of creating thoughts. These tumours often spread to the cerebral cortex, which is the brain's folded outer layer that helps us perceive the world, form conscious thoughts and use language.

They hijack a process known as myelination, which creates a protective layer around nerve fibres, allowing them to carry thoughts more quickly.

By looking at mouse models, the researchers found that the brain tumours grew faster when they were closer to these highly active nerve cells. It is rare for an organ's main function to drive the growth of tumours within it. They don't think about bile production promoting liver cancer growth, or breathing promoting the growth of lung cancer. But they've shown that brain function is driving these brain cancers.

High-grade gliomas are the leading cause of brain-tumour death in children and adults. Survival rates have scarcely improved in the last 30 years.

Clinically, fighting high-grade gliomas is a lot like trying to fight a forest fire. The new findings indicate that this metaphorical forest fire has been difficult to extinguish because there is something akin to gasoline seeping up from the soil.

Scientists identified a specific protein, called neuroligin-3, which is largely responsible for the increase in tumour growth associated with thoughts in the cerebral cortex. In healthy tissue, neuroligin-3 helps to direct the formation and activity of synapses, playing an important role in the brain's ability to remodel itself. But the new study showed that a secreted form of neuroligin-3 promotes tumour growth. This group of tumours hijacks a basic mechanism of neuroplasticity. Into the cerebral cortex of mice with these light-sensitive proteins, scientists implanted cancer cells from a human. After the tumours became established, neurons near the tumours were activated with light. Scientists then compared tumour growth between these mice and a control group with implanted tumours but without the nerve activation.

Increased tumour size in the mice that received stimulation using light revealed that brain activity fed the brain tumours. In theory, doctors could slow the growth of these tumours using sedatives that reduce mental activity, but there are serious ethical implications involved in this treatment. I hope work will lead to the development of drugs that specifically block the tumour-stimulating activities of neuroligin-3.

Written by Rebeca Mees