|Full text PDF:||http://vts.uni-ulm.de/docs/2013/8824/vts_8824_13180.pdf|
Background: Pancreatic stellate cells (PSCs) are the key fibrogenic cells responsible for the strong desmoplasia in pancreatic ductal adenocarcinoma. However, the factors mediating the effect of PSCs on pancreatic cancer cells have not been clearly identified. Methods: Effects of PSC supernatant (PSC-SN) and different adhesive molecules on trans-migration, adhesion and motility of PCCs (Panc1, UlaPaCa) were investigated by modified Boyden chamber assay, adhesion assay and single cell tracking assay, respectively. Organization of cytoskeleton and formation of focal adhesions were examined by fluorescence staining. Integrin expression and FAK phosphorylation were assessed by Western blot. Results: PSC-SN dose-dependently induced trans-migration of Panc1 and UlaPaCa cells, mainly by improving cell adhesion and random motility. PSC-SN-mediated cell adhesion was a prerequisite for the stimulation on PCC migration. The chemokines contained in PSC-SN, however, were not sufficient to promote the migration of PCCs. In contrast to poly-L-lysine, fibronectin and laminin, only collagen I showed comparable effect to PSC-SN on PCC behavior, including polarized morphology, facilitated adhesion, accelerated motility, and stimulated trans-migration. Both PSC-SN and collagen I induced haptokinesis of Panc1 and haptotaxis of UlaPaCa cells. Blocking antibodies against integrin alpha 2 beta 1 significantly attenuated PSC-SN- and collagen I-induced trans-migration as well as adhesion. In PCCs stimulated by PSC-SN or collagen I, polymerization of F-actin and formation of focal adhesions were obviously induced. In a time course Western blot, phosphorylation of FAK (Try397) was constantly enhanced by PSC-SN/collagen I. Inhibition of FAK function significantly diminished the effect of PSC-SN/collagen I on PCC hapto-migration. Conclusions: Collagen I is the major mediator for PSC-SN-induced haptokinesis of Panc1 and haptotaxis of UlaPaCa by activating FAK signaling via binding to integrin alpha 2 beta 1.