The nematic feedback between cancer cells and the extracellular matrix*

The reciprocal mechanical interaction between cancer cells and their extracellular matrix (ECM) has been shown to paly important roles in tumor growth, survival and metastasis. Previous studies have primarily focused on the cell-induced stiffness change of the ECM, which is often characterized using bulk measurement. On the cellular scale, however, ECM produce anisotropic mechanical microenvironment to the cells. Cell generated forces align ECM fibers, and the aligned fiber direct cell polarization and migration through contact guidance. These interactions create a nematic feedback between cancer cells and their local ECM. In this talk I will first discuss quantitative measurements of cellular response to 3D contact guidance cues, which are inevitiblly noisy and spatially heterogeneous. I will then discuss how cell-induced ECM alignment can be controlled by tumor geometry, and regulate the long-term invasive potential of tumor cells. Together, these results highlight the rich biomechanical functions and powerful control mechanisms of the ematic feedback between cancer cells and extracellular matrix.