Figure 1

Schematic of the biomechanical forces in the tumor microenvironment. As tumor cells proliferate they sequentially create new solid material (i.e. cells and matrix components) which generate radial and circumferential solid stresses. In the tumor center, circumferential and radial stresses are compressive while in the periphery, radial stress is compressive and circumferential stress is tensile (direction indicated with arrows). Compressive stresses in the tumor interior squeeze tumor components, including lymphatic and blood vessels (note compressed lumen of blood vessel and high density of cells and extracellular matrix in dark green). After the tumor is cut and the stresses are released, the tumor interior decompresses (note extended lumen of blood vessel, relaxed cells and extracellular matrix in light green). Reproduced and modified with permission from Prof. Rakesh K. Jain [55].