Dual effect of transforming growth factor beta1 on cell adhesion and invasion in human placenta trophoblast cells

Transforming growth factor beta (TGFbeta) has been shown to be a multifunctional cytokine required for embryonic development and regulation of trophoblast cell behaviors. In the present study, a non-transformed cell-line representative of normal human trophoblast (NPC) was used to examine the effect of TGFbeta1 on trophoblast cell adhesion and invasion. In vitro assay showed that TGFbeta1 could significantly promote intercellular adhesion, while inhibiting cell invasion across the collagen I-coated filter. Reverse transcription (RT)-PCR and gelatin zymography demonstrated that TGFbeta1 evidently repressed the mRNA expression and proenzyme production of matrix metalloproteinase (MMP)-9, but exerted no effect on mRNA expression and secretion of MMP-2. On the other hand, both the mRNA and protein expression of epithelial-cadherin and beta-catenin were obviously upregulated by TGFbeta1 in dose-dependent fashion, as revealed by RT-PCR and western-blot analysis. What is more, one of the critical TGFbeta signaling molecules - Smad2 was notably phosphorylated in TGFbeta1-treated NPC cells. The data indicates that cell invasion and adhesion are coordinated processes in human trophoblasts and that there exists paracrine regulation on adhesion molecules and invasion-associated enzymes in human placenta.