Previous studies have assumed that amelogenin is responsible for the therapeutic effect of the enamel matrix derivative (EMD) in periodontal tissue healing and regeneration. However, it is difficult to confirm this hypothesis because both the EMD and the amelogenins are complex mixtures of multiple proteins. Further adding to the difficulties is the fact that periodontal tissue regeneration involves various types of cells and a sequence of associated cellular events including the attachment, migration and proliferation of various cells. In this study, we investigated the potential effect of a 25-kDa recombinant porcine amelogenin (rPAm) on primarily cultured periodontal ligament fibroblasts (Pan, gingival fibroblasts (GF) and gingival epithelial cells (GEC) The cells were treated with 25-kDa recombinant porcine amelogenin at a concentration of 10 mu g/mL. We found that rPAm significantly promoted the proliferation and migration of PIXY, but not their adhesion Similarly, the proliferation and adhesion of GF were significantly enhanced by treatment with rPAm, while migration was greatly inhibited Interestingly, this recombinant protein inhibited the growth rate, cell adhesion and migration of GEC These data suggest that rPAm may play an essential role in periodontal regeneration through the activation of periodontal fibroblasts and inhibition of the cellular behaviors of gingival epithelial cells (C) 2010 Elsevier Inc All rights reserved