Transforming growth factor-β inhibits prostaglandin production in amnion and A431 cells

Abstract

We studied the effect of transforming growth factor-β (TGF-β) on prostaglandin E 2 (PGE 2) production and mitogenesis in human amnion cells and compared the response in amnion cells with that in A431 cells. Both amnion cells and A431 cells respond to epidermal growth factor (EGF) with increased production of PGE 2 whereas EGF promotes mitogenesis in amnion cells but not in A431 cells. In amnion cells, TGF-β was not mitogenic, and did not alter the mitogenic response of cells to EGF. Treatment of amnion cells with TGF-β did, however, cause a decrease in PGE 2 production relative to untreated cells, although EGF stimulated PGE 2 production was not attenuated. In A431 cells, TGF-β acted to decrease PGE 2 production relative to untreated cells and to attenuate the stimulation of PGE 2 production effected by EGF. The inhibitory action of TGF-β on PG production in amnion and A431 cells is contrary to the stimulation of PG production in mouse calvaria reported by others and is suggestive that the effect of TGF-β on prostaglandin production, like its effect on growth, varies between different cell types. Inhibition of PG production by treatment of amnion or A431 cells with mefenamic acid did not alter thymidine incorporation into DNA in response to EGF; similarly, the addition of PGE 2 or PGF 2α to culture media of amnion or A431 cells had no effect on mitogenesis (in the absence or presence of EGF). Based on these findings, we conclude that PG production and EGF action on proliferation (stimulation in amnion cells; inhibition in A431 cells) are dissociated.