Transforming growth factor (TGF) β is known to have properties of both
a tumor suppressor and a tumor promoter. While it inhibits cell proliferation,
it also increases cell motility and decreases cell--cell adhesion. Coupling
mathematical modeling and experiments, we investigate the growth and motility
of oncogene--expressing human mammary epithelial cells under exposure to
TGF--β. We use a version of the well--known Fisher--Kolmogorov equation,
and prescribe a procedure for its parametrization. We quantify the simultaneous
effects of TGF--β to increase the tendency of individual cells and cell
clusters to move randomly and to decrease overall population growth. We
demonstrate that in experiments with TGF--β treated cells \textit{in
vitro}, TGF--β increases cell motility by a factor of 2 and decreases
cell proliferation by a factor of 1/2 in comparison with untreated cells.Comment: 15 pages, 4 figures; to appear in Computational and Mathematical
Methods in Medicin