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Introduction: JUP, a homologue of β-catenin, is a cell-cell junction protein involved in adhesion junction and desmosome composition. JUP may have a controversial role in different malignancies dependence of its competence with or collaboration with β-catenin as a transcription factor. Objective: In this study, we focused on the role of JUP in tumor progress and metastasis of GC. We investigated whether that the function of JUP is related to its cellular location in GC development process from epithelium-like, low malignant GC to advanced EMT-phenotypic GC. Conclusion: Gradual loss of membrane and/or cytoplasm JUP was closely correlated with GC malignancy and poor prognostics. Knockdown of JUP in epithelium-like GC cells causes EMT and promotes GC cell migration and invasion. Ectopic expression of wild JUP in malignant GC cells led to an attenuated malignant phenotype such as reduced cell invasive potential. In mechanism, loss of membrane and/or cytoplasm JUP abolished the restrain of JUP to EGFR at cell membrane and resulted in increased p-AKT levels and AKT/GSK3β/β-catenin signaling activity. In addition, nuclear JUP interacts with nuclear β-catenin and TCF4 and played a synergistic role with β-catenin in promoting TCF4 transcription and its downstream target MMP7 expression to fuel GC cell invasion.

β-catenin-mediated signaling has been extensively studied in regard to its role in the regulation of human embryonic stem cells (hESCs). However, the results are controversial and the mechanism by which β-catenin regulates the hESC fate remains unclear. Here, we report that β-catenin and γ-catenin are functionally redundant in mediating hESC adhesion and are required for embryoid body formation, but both genes are dispensable for hESC maintenance, as the undifferentiated state of β-catenin and γ-catenin double deficient hESCs can be maintained. Overexpression of β-catenin induces rapid hESC differentiation. Functional assays revealed that TCF1 plays a crucial role in hESC differentiation mediated by β-catenin. Forced expression of TCF1, but not other LEF1/TCF family members, resulted in hESC differentiation towards the definitive endoderm. Conversely, knockdown of TCF1 or inhibition of the interaction between TCF1 and β-catenin delayed hESC exit from pluripotency. Furthermore, we demonstrated that GATA6 plays a predominant role in TCF1-mediated hESC differentiation. Knockdown of GATA6 completely eliminated the effect of TCF1, while forced expression of GATA6 induced hESC differentiation. Our data thus reveal more detailed mechanisms for β-catenin in regulating hESC fate decisions and will expand our understanding of the self-renewal and differentiation circuitry in hESCs., (Copyright © 2017. Published by Elsevier Inc.)