Cancer cells have evaded the immune system by using a "cloak of invisibility" made from ribosomes.

One of the primary functions of the immune system is to identify and eliminate potentially harmful cells. However, cancer cells go to great lengths to survive and evade immune surveillance. As a result, many patients with oncological conditions do not respond to immunotherapy or become resistant to it.

The authors of the study, published in the journal Cell, discovered that cancer cells circumvent the immune system by modifying their ribosomes. It is important to note that each cell in the human body contains millions of ribosomes, which synthesize protein molecules from amino acids. Previously, ribosomes were thought to be identical structures that produced proteins according to the instructions of the cell nucleus.

Now, scientists have identified a specific subtype of ribosomes featuring what is called a P-stalk (one of the movable elements of ribosomes). This component plays a crucial role in how cells respond to signals from the immune system, participating in the regulation of processes governed by cytokines—small protein molecules that help cells communicate and coordinate the body's defense responses.

Healthy cells utilize ribosomes with P-stalks, accumulating more antigens—proteins that signal threats—on their surface to become more noticeable to the immune system. In contrast, cancer cells reduce the number of such ribosomes. This impacts the synthesis of certain proteins and decreases the number of antigens on their surface.

“By altering their ribosomes, cancer cells create a sort of 'invisibility cloak' that allows them to hide from the immune system. The findings change the perception of ribosomes as passive and uniform machines,” noted co-author of the study Liam Faller (Liam Faller).

Since ribosomes are among the oldest and most crucial components of cells, the fact that they are more diverse and dynamic than previously thought is significant for biological research. For instance, understanding the precise mechanisms by which ribosomes are modified could enhance the effectiveness of immunotherapy (provided that medical professionals learn to block this ability).

The results of this study also offer a new perspective on the interaction between cancer cells and the immune system, paving the way for new strategies in the treatment of oncological diseases and other conditions related to immune dysfunction.