THE EFFECTS OF GROWTH-FACTORS ON HUMAN NORMAL PLACENTAL CYTOTROPHOBLAST CELL-PROLIFERATION

The effects of growth factors mere investigated on the proliferation o f a normal placental cytotrophoblast cell line (NPC). Epidermal growth factor (EGF), transforming growth factor alpha (TGF alpha) and insuli n-like growth factor-I (IGF-I) stimulated NPC cell proliferation, In c ontrast, TGF beta 1 was found to be a negative regulator, inhibiting E GF-induced cell proliferation. When EGF/TGF alpha receptor was analyse d by radio-ligand binding, two binding sites of different affinities m ere revealed in the proliferating NPC cells but only the low affinity binding site was detected in the non-proliferating cytotrophoblast cel ls in primary cultures. The results suggest that EGF stimulates cytotr ophoblast proliferation through high affinity binding sites.