Cellular competition: forces shape our tissues 🛠️

Cellular competition is an essential surveillance mechanism that eliminates unwanted cells, playing a key role in development, infection response, and tumor formation. While the role of biochemical mechanisms in this process has been well studied, the impact of mechanical forces remains poorly understood, mainly due to challenges in measuring them accurately.

In a paper published in Nature Materials, scientists have uncovered a new form of cellular competition regulated by differences in cells' ability to transmit mechanical forces.

Cellular competition: a key mechanism for tissue balance?

Competition between cells plays a crucial role in maintaining tissue health, fighting infections, and preventing tumor development. Despite its importance, the fundamental mechanisms governing this phenomenon remain poorly understood.


When cells are considered "losers," they can be eliminated by biochemical signals that trigger their death. However, several studies have shown that cellular competition can also be influenced by mechanical forces. According to current consensus, "winner" cells exert pressure on "loser" cells, promoting their death and removal.

In a paper published in the journal Nature Materials, scientists demonstrated that mechanical tensions indeed play a fundamental role in cellular competition processes, but contrary to established models, winner cells could be under compression while eliminated cells were under tension.

The researchers sought to identify general mechanisms that could explain mechanical competition. They hypothesized that altering force transmission between cells by adjusting intercellular adhesion could trigger competition and strongly influence its outcome.

Mechanical forces: an unexpected role in cellular competition

By directly measuring forces within ex vivo tissues and different cell lines, scientists discovered that cells with stronger intercellular adhesion—and thus better force transmission—consistently prevailed. This mechanism works independently of the compression of loser cells, differences in growth rates, or cell density.

By mixing cell types where one had altered adherens junctions, they measured increased fluctuations in mechanical stress at the interfaces between the two tissues. If these local stress variations are not effectively dissipated by cells at the boundary, they generate significant out-of-plane tensions, leading to cell elimination.

When cells with different force transmission abilities compete, intercellular adhesion becomes a winning strategy: it allows dominant cells to better absorb stress fluctuations. Thus, these findings reveal a novel mechanism based on active resistance to elimination through strengthening intercellular adhesion.

This cell elimination mechanism could have major implications, particularly in maintaining tissue boundaries and understanding pathologies related to cellular invasion, such as cancer.