Growth and instabilities of healthy and cancerous tissues
Jean-François Joanny, Institut Curie, Paris
During development or during tumor growth, cells organize collectively by cell division and apoptosis in a tissue. The aim of our work is to build up theoretical tools based on non-equilibrium statistical mechanics and continuum mechanics to describe the mechanical properties of tissues and to apply them to various biologically relevant situations. We first show that because of the coupling between cell division and the local stress, a tissue can be considered as a visco-elastic liquid at time scales larger than the cell division time. We then show recent model experiments on cell aggregates showing the effect of mechanical stress on tissue growth. Finally, we use the hydrodynamic description to discuss the steady state structure of villis which are the protrusions of the surface of the intestine. We describe the formation of villis as a buckling instability of a polar cell monolayer. Similar instabilities occur as well for tube-like cellular structures such as arteries.