Figure 3. Construction of the finite element model.

(A) Biochemical networks regulate the construction of signaling and structural proteins and lead to assembly and regulation of mechanical components. These mechanical components (especially actomyosin and adhesion systems) generate net interfacial tensions γ along the cell edges [41], [42] (B). Cancer cells (type “C”) generate invadopodia which push their way between the normal cells (labelled as type “N”). They then contract with a force assumed to be q times the tension γ_NN that acts along the boundaries of the surrounding cells. In the finite element model, the edge forces are generated using rods that lie along each edge and that have zero stiffness but carry a constant tension γ that is specific to the cell types that form the boundary. The viscosity µ of the contents of the cells is modeled using a series of orthogonal dashpots [46], only one set of which is illustrated in the figure.