HGF-Induced Cell Scatter - Cellular Potts Models: Multiscale Extensions and Biological Applications - page 28

FIGURE 2.10: Comparison of the time-evolution of the scattering index of
a round colony of 16 cells for experimental (dark line) and simulation (light
line). The parameters of the simulations are those of Figure 2.9. The error bars
show standard deviations over ten representative islands for the experiments
and over 10 simulations.

We initiate the simulation with a mass of 16 virtual cells, each of them
with an area of 160 m 2 (40 lattice sites), over an area of 700 m 700
m (350 350 sites), which is positioned inside a larger domain of 1000
m 1000 m (500 500 sites) to minimize the boundary eects. The HGF-
driven enhancement of cell motility is modeled by increasing the value of T,
e.g., taking it proportional to the concentration of the growth factor. Assum-
ing that the cells do not grow during the process, we set high surfac C . The
active cell cytoskeletal remodeling, which results in cell elongation, is instead
permitted by a low perimete C . The eective cell{cell adhesion is the same as
the cell{ECM adhesion, since experimental analysis suggests a reorganization
of intercellular bonds rather than a completely breakage of them as in the case
of ARO individuals. Finally, to model significant chemotaxis and persistent
component in cell movement, we set high chem

C = per C . In accordance with
culture measurements provided in [101], the HGF addition and uptake rates
are set equal (i.e., 510 4 s 1 ), while c " c . All the values of the parameters
used are summarized in Table C.2 in the Appendix C.
Figure 2.9 shows a typical simulation of a time-sequence evolution of a
colony of MLP-29 cells in the presence of HGF. After an initial stage in which
the surface of the colony roughens, with some cells radially protruding from
the surface, some branches develop still keeping contact with the neighboring
cell and the center of the island: this gives the colony the star-shaped con-
figuration experimentally found. As shown in the same image, as soon as the
HGF is no longer added (after 24 h 3000 MCS), the sprouts start a sort of