Cell-matrix and cell-cell mechanical interactions

Cell adhesion to the extracellular matrix (ECM) is a vital process of normal tissue cells such as fibroblasts, endothelial cells, and stem cells. Normal cells that fail to anchor to a solid environment and spread would not grow and divide and eventually enter apoptosis (programmed cell death) (Folkman and Greenspan, 1975; Discher et al., 2005). Furthermore, loss of anchorage dependence and the ability of cells to proliferate and survive in very soft environments (e.g., agar gel) or suspension is one of the long recognized signatures of cancerous transformation (Stoker et al., 1968; Wittelsberger et al., 1981; Vasiliev, 1984). The mechanisms governing cell behavior following its engagement with the ECM have been the focus of extensive research in recent years. Many intriguing new effects of the surrounding mechanics on cell behavior and fate have been discovered, and much has been learned about the mechanical and biochemical mechanisms involved, both on the cellular and molecular levels.