Mathematical model for simulation of morphological changes associated to crypt fission in the colon

Morphological changes due to colorectal cancer propagation by an abnormal crypt fission is an interesting application arising in medicine and biology, that we try to analyse by a differential equations model coupled with a discrete crypt fission model. A colonic crypt can slowly change its shape in three steps: growth, bifurcation and fission. Fission is a rare event in a normal tissue, however if transit cells are unable to differentiate, due to an activation of Wnt signaling, then it may become fast and uncontrolled and cause a formation of aberrant crypt foci (ACF), defined as clusters of aberrant crypts. The differential equation system is composed by a convective diffusive equation for transit cell density and an elliptic equation for cell pressure, both defined on a manifold. The discrete crypt fission model acts in a set of adjacent crypts in order to investigate the ACF dynamics, due to a differentiation block. By using a Galerkin finite element method we solve numerically the differential equation model and show some interesting results about an ACF formation caused by a deformation and fission of abnormal crypts.