[Wnt signalling pathway regulates the growth and several phenotypes of Rat-1 cells.]

The Wnt signaling pathway is thought to be functionally conserved in vertebrates and invertebrates and plays an important role during the embryonic and postembryonic development. Recent studies indicated that this pathway may be also involved in the controlled proliferation and migration of some kinds of fibroblasts during the wound healing process. To verify this assumption in vitro, we chose Rat-1, a kind of rat fibroblasts to investigate the regulation of Wnt signaling pathway to the growth and changes of several phenotypes of this kind of cells. Full length Wnt-3a cDNA was inserted in pcDNA 3.1 vector to construct the Wnt-3a mammalian expression vector, which was stably transfected into Rat-1 cells, and then to establish a cell model in which Wnt signaling pathway was constantly activated. When Wnt signaling pathway was activated constantly, Rat-1 cells exhibited morphological changes: grew more densely as a monolayer, adopted an elongated and refractile appearance, forming cord-like bundles lined up in a uniform direction. The results of MTT assay and FCM analysis indicated that more Rat-1/Wnt-3a cells entered into G(2) phase and the proliferation rate of the Rat-1/ Wnt-3a cells increased significantly compared to the non-transfected cells. Though the migration of Rat-1/Wnt-3a cells increased slightly by the method of Transwell migration assay, there was no statistic significance compared to the non-transfected cells. The result of in vitro scrape wound healing assay showed that for Rat-1/Wnt-3a cells the time course of wound healing decreased significantly. It is therefore concluded that the activation of Wnt signaling pathway can regulate some of the phenotypes of Rat-1 cells, facilitate cell proliferation and promote the scrape wound healing in vitro.