Cellular fibronectin is induced by epidermal growth factor, but not by dexamethasone or cyclic AMP in rat liver epithelial cells.

Epidermal growth factor (EGF) induces fibronectin (FN) and FN mRNA in rat liver epithelial cells, under conditions where the factor also induces the cells to migrate. Newly synthesized protein is secreted into the medium and deposited as substratum-bound extracellular matrix. The levels of mRNA and the amount of protein synthesized are not influenced by cyclic AMP or dexamethasone, factors that have been found to modulate FN expression in other cells. However, the cells are sensitive to the factors, suggesting a cell-specific regulation. The EGF-induced RNA contains the sequences EIIIA and EIIIB characteristic of cellular fibronectin.