Left: Images of the cell cytoskeleton while applying forces to substrates of different rigidities.
“Most solid tumours are stiffer than normal tissue; for example, breast cancer is usually screened by detecting hard lumps in the breast,” explains junior group leader at IBEC and assistant professor at the University of Barcelona Pere Roca-Cusachs, who led the research. “What’s more, increasing or decreasing tissue stiffness can enhance or impair tumour progression respectively.”
“Just as you would need to sit on or press a mattress to know how soft it is, cells must apply forces to their surroundings to detect stiffness,” says Alberto Elosegui-Artola, first author on the paper. “They do this through different molecules including integrins, which directly bind cells to their surrounding extracellular matrix, and talin, which connects integrins to the cytoskeleton, or body, of the cell.”
Right: Scheme showing how talin and integrins connect the cell cytoskeleton to the surrounding tissue. Depending on whether the tissue is soft or stiff, applied forces will lead first to integrin unbinding or talin unfolding and subsequent vinculin binding.