Computational modeling of two-dimensional cell migration

Many types of cells on surfaces can navigate by protruding parts of their membranes in the form of lamellipodia or filopodia. Protrusions are driven mainly by the polymerization of actin filaments at the leading edge of the cell. After protrusion, actin filaments are anchored to the extracellular environment by forming focal adhesions. Myosin motors try to pull actin filaments toward the rear, resulting in the cell body advancing forward. In this study, we present a two-dimensional cell migration model that simulates cell protrusions and focal adhesions in a discrete manner. The protrusions are treated as an element that can grow and shrink simultaneously, mimicking actin polymerization and retrograde flow, respectively. By quantifying metrics including persistency and mean-squared displacement, we found that different choices of parameters, including the lifetime of protrusions and the extent of cell polarization, can vary a migration mode between ballistic and diffusive migration. We expect our model will provide a better understanding of cell migration driven by F-actin dynamics.