Epidermal growth factor-induced mitogen signals in cultured intestinal epithelial cells

Epidermal growth factor (EGF) stimulated proliferation of an intestinal cell line (IEC-6 cells), derived from rat jejunal crypts. EGF-induced tyrosine phosphorylation was analyzed by immunoblotting with a monoclonal antibody specific for phosphotyrosine. EGF initiated rapid tyrosine phosphorylation of proteins with molecular masses of 185, 170, 55, and 42 kilodalton (kDa). In addition, EGF caused the rapid elevation of intracellular free Ca2+ concentration. Thus, EGF-stimulated proliferation and its mitogen signals were clearly observed in IEC-6 cells, suggesting that EGF may play an important role in the maintenance and repair of the intestinal mucosa in vivo.