Cancer cells 'talk' to their environment, and it talks back

Cancer cells 'talk' to their environment, and it talks back

Interactions between an animal cell and its environment, a fibrous network called the extracellular matrix, play a critical role in cell function, including growth and migration. But less understood is the mechanical force that governs those interactions.

Researchers have devised a method for measuring the force a cell -- in this case, a breast cancer cell -- exerts on its fibrous surroundings. Understanding those forces has implications in many disciplines, including immunology and cancer biology, and could help scientists better design biomaterial scaffolds for tissue engineering.

The group developed 3-D traction-force microscopy to measure the displacement of fluorescent marker beads distributed in a collagen matrix. The beads are displaced by the pulling of migrating breast cancer cells embedded in the matrix. An important part of the puzzle was to calculate the force exerted by the cells using the displacement of the beads.

The group's paper, "Fibrous nonlinear elasticity enables positive mechanical feedback between cells and extracellular matrices," published in Proceedings of the National Academy of Sciences.

When the cancerous cell migrates that serious problems can arise. That migration occurs through "cross-talk" between the cell and the matrix, the group found. As the cell pulls on the matrix, the fibrous matrix stiffens; in turn, the stiffening of the matrix causes the cell to pull harder, which stiffens the matrix even more.

This increased stiffening also increases cell force transmission distance, which can potentially promote metastasis of cancer cells.

"We've shown that the cells are able to align the fibers in their vicinity by exerting force," author said. "We've also shown that when the matrix is more fibrous - less like a continuous material and more like a mesh of fibers - they're able to align the fibers through the production of force. And once the fiber is aligned and taut, it's easier for cells to pull on them and migrate."