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Background: CXCR4 and glycogen synthase kinase-3β (GSK3β) promote proliferation and invasion of pancreatic cancer. Inhibition of CXCR4 suppresses GSK3β expression. However, the molecular mechanism by which CXCR4 contributes to human pancreatic cancer metastasis is not completely understood. In this study, therefore, we analyzed the effect of CXCR4 on GSK3β expression and its molecular mechanism. Methods: PANC-1 and SW-1990 cells were used in this study. PANC-1 and SW-1990 cell lines which stably expressed upregulated or downregulated CXCR4 were used for further study. Western blotting was employed to detected the expression of CXCR4, GSK3β and MMP-2. Cell invasion assay was used to detect the effect of the Akt pathway on CXCR4-induced GSK3β expression. Results: Overexpression of CXCR4 promoted GSK3β expression and silencing of CXCR4 suppressed GSK3β expression. Overexpression of CXCR4 activated cyclin D1 and p-Akt expression, but inhibited p21 expression. Silencing of CXCR4 had the reverse effect. CXCR4 promoted GSK3β expression and PANC-1 invasion by Akt signaling. CXCR4 upregulated GSK3β expression, at least in part, at the level of transcription. Conclusions: CXCR4 promotes GSK3β expression via the Akt cell signaling pathway in pancreatic cancer cells. [ABSTRACT FROM AUTHOR]

S100A4 expression is associated with poor clinical outcomes of patients with pancreatic cancer. The effects of loss or gain of S100A4 were examined in pancreatic cancer cell lines. S100A4 downregulation remarkably reduces cell migration and invasion, inhibits proliferation, and induces apoptosis in pancreatic tumor cells. S100A4 downregulation results in significant cell growth inhibition and apoptosis in response to TGF-β1, supporting a non-canonical role of S100A4 in pancreatic cancer. The role of S100A4 in tumor progression was studied by using an orthotopic human pancreatic cancer xenograft mouse model. Tumor mass is remarkably decreased in animals injected with S100A4-deficient pancreatic tumor cells. P27Kip1 expression and cleaved caspase-3 are increased, while cyclin E expression is decreased, in S100A4-deficient pancreatic tumors in vivo. S100A4-deficient tumors have lower expression of vascular endothelial growth factor, suggesting reduced angiogenesis. Biochemical assays revealed that S100A4 activates Src and focal adhesion kinase (FAK) signaling events, and inhibition of both kinases is required to maximally block the tumorigenic potential of pancreatic cancer cells. These findings support that S100A4 plays an important role in pancreatic cancer progression in vivo and S100A4 promotes tumorigenic phenotypes of pancreatic cancer cells through the Src-FAK mediated dual signaling pathway. [ABSTRACT FROM AUTHOR]