E. Bade and B. Nitzgen, Fakultät für Biologie, Universitdt Konstanz, D-7750 Konstanz, West Germany
A precise regulation of liver-cell growth and migration is essential for normal development and regeneration. In vivo control is exerted through humoral (hormonal and non-hormonal) and local (cell-cell and cell-matrix) interactions.
To study some of these control mechanisms, we used a rat-liver epithelial cell line that, at saturation, forms a cobblestone-type lawn (‘density inhibition’). The cells can be maintained in serum-free medium. They synthesize and secrete the ECM glycoproteins fibronectin and laminin and organize these proteins into typical extracellular networks. The cells possess receptors for EGF (105/cell) and respond to this factor and to insulin with growth and changes in morphology and behaviour. At optimum concentrations of insulin (2 µg/ml) plus EGF (10 ng/ml) the cells are also stimulated to migrate. Migrating cells deposit fibronectin and laminin onto the substratum, forming well-defined ECM migration...
