How does immune system know which cells can become cancerous? They tell about it themselves

Cancer occurs due to incorrect mutations of the cells. These mutations that could kickstart development of cancer happen all the time, but body’s immune system is usually able to remove cancer cells early. But how does the body know when the cell is about to become cancerous? Scientists from the University of Edinburgh found that regular cells can take on characteristics of immune cells, sending a warning signal.

Skin cancer cells. Human body is able to detect cells that are in danger of becoming cancerous pretty early, stopping cancer in its tracks. Image credit: Mateus Figueiredo via Wikimedia (CC BY 4.0)

Older cells have to be eliminated in order to preserve the vitality of the body as well as prevent age-related diseases. The process, known as senescence, is a natural body’s way of dealing with ageing cells. Now scientists think that senescence may also help the body detect cancer cells sooner, which helps avoiding development of tumours. In essence, senescence identifies damaged cells in danger of turning cancerous and prevents them from growing and dividing. This essentially stops cancer in its tracks even before it starts going.

This mechanism is triggered by the stressed cell itself. They take some characteristics of immune cells, which is a sign that they they are stressed or in danger. Senescence can also be triggered when genes, known as oncogenes, become active. Oncogenes have the potential to cause cancer. Up until now scientists didn’t quite understand the mechanism, how immune system understands that oncogenes are on. Now they found that key immune molecules inside cells, called TLR2 and TLR10, detect this change, initiating a cascade of chemical signals that cause inflammation. This signals the immune system that the cells are stressed and damaged and should be removed to avoid further diseases.

Scientists knew that TLR2 and TLR10 molecules are responsible for detecting bacterial and viral infections, but the fact that they are playing a role in regulation of ageing is completely new. Scientists say that senescence now is a hot research area, which has a huge potential to spawn new generation of anti-cancer drugs. New therapies would attack cancer in its early stages, preventing the growth of tumours and allowing for a quick and full recovery. Of course, those treatments are still years away, but first steps are already being taken.

Dr Juan-Carlos Acosta, one of the authors of the study, said: “The results of the study extend our knowledge of molecular mechanisms controlling senescence and may lead to new strategies for development of anti-cancer and anti-aging therapeutics”.

Your immune system is removing potentially cancerous cells every day. It is a never-ending task. Sometimes cells become cancerous anyway and tumours start forming. Understanding how this happens could lead to more effective treatments and prevention methods.

 

Source: University of Edinburgh