title: Zonula occludens-1/NF-κB/CXCL8: a new regulatory axis for tumor angiogenesis.
abstract: Zonula occludens-1 (ZO-1) is a submembrane scaffolding protein that may display proinvasive functions when it relocates from tight junctions into the cytonuclear compartment. This article examines the functional involvement of ZO-1 in CXCL8/IL-8 chemokine expression in lung and breast tumor cells. ZO-1 small interfering RNA and cDNA transfection experiments emphasized regulation of CXCL8/IL-8 expressionviaa cytonuclear pool of ZO-1. Luciferase reporter assays highlighted a 173-bp region ofCXCL8/IL-8promoter that responded to ZO-1. Moreover, by using mutated promoter constructs, we identified a NF-κB site as critical in this activation. Furthermore, NF-κB pathway signaling analysis revealed both IκBα and p65 phosphorylation in ZO-1-overexpressing cells, and subsequent p65 silencing validated its requirement for CXCL8/IL-8 induction. Investigation of the functional implication of this regulatory axis next showed the proangiogenic activity of ZO-1 in bothex vivo andin vivoangiogenesis assays. Finally, we found that non-small-cell lung carcinoma that presented a cytonuclear ZO-1 pattern was significantly more angiogenic that that without detectable cytonuclear ZO-1 expression. Taken together, our results demonstrate that ZO-1 regulates CXCL8/IL-8 expressionviathe NF-κB signaling pathway and its p65 subunit, which subsequently modulates the transcription of IL-8. We also provide evidence of a newly identified regulatory pathway that could promote angiogenesis. Thus, our results support the concept that the ZO-1 shuttle from the cell junction to the cytonuclear compartment may affect both the intrinsic invasive properties of tumor cells and the establishment of the protumoral microenvironment.-Lesage, J., Suarez-Carmona, M., Neyrinck-Leglantier, D., Grelet, S., Blacher, S., Hunziker, W., Birembaut, P., Noël, A., Nawrocki-Raby, B., Gilles, C., Polette, M. Zonula occludens-1/NF-κB/CXCL8: a new regulatory axis for tumor angiogenesis.
authors.affiliation: INSERM, Unité Mixte de Recherche-S 903, Structure Fédérative de Recherche Champagne-Ardennes Picardie-Santé (SFR CAP), University of Reims Champagne-Ardenne, Reims, France.
authors.forename: Julien
authors.initials: J
authors.lastname: Lesage
authors.affiliation: Laboratory of Tumor and Development Biology, Grappe Interdisciplinaire de Génoprotéomique Appliquée (GIGA)-Cancer, University of Liège, Liège, Belgium.
authors.forename: Meggy
authors.initials: M
authors.lastname: Suarez-Carmona
authors.affiliation: INSERM, Unité Mixte de Recherche-S 903, Structure Fédérative de Recherche Champagne-Ardennes Picardie-Santé (SFR CAP), University of Reims Champagne-Ardenne, Reims, France.
authors.forename: Deborah
authors.initials: D
authors.lastname: Neyrinck-Leglantier
authors.affiliation: Department of Biochemistry and Molecular Biology, Medical University of South Carolina, Charleston, South Carolina, USA.
authors.forename: Simon
authors.initials: S
authors.lastname: Grelet
authors.affiliation: Laboratory of Tumor and Development Biology, Grappe Interdisciplinaire de Génoprotéomique Appliquée (GIGA)-Cancer, University of Liège, Liège, Belgium.
authors.forename: Silvia
authors.initials: S
authors.lastname: Blacher
authors.affiliation: Epithelial Cell Biology Laboratory, Institute of Molecular and Cell Biology, Singapore, Singapore.
authors.forename: Walter
authors.initials: W
authors.lastname: Hunziker
authors.affiliation: INSERM, Unité Mixte de Recherche-S 903, Structure Fédérative de Recherche Champagne-Ardennes Picardie-Santé (SFR CAP), University of Reims Champagne-Ardenne, Reims, France.|Laboratory of Biopathology, Centres Hospitaliers Universitaires, Reims, France.
authors.forename: Philippe
authors.initials: P
authors.lastname: Birembaut
authors.affiliation: Laboratory of Tumor and Development Biology, Grappe Interdisciplinaire de Génoprotéomique Appliquée (GIGA)-Cancer, University of Liège, Liège, Belgium.
authors.forename: Agnes
authors.initials: A
authors.lastname: Noël
authors.affiliation: INSERM, Unité Mixte de Recherche-S 903, Structure Fédérative de Recherche Champagne-Ardennes Picardie-Santé (SFR CAP), University of Reims Champagne-Ardenne, Reims, France.
authors.forename: Béatrice
authors.initials: B
authors.lastname: Nawrocki-Raby
authors.affiliation: Laboratory of Tumor and Development Biology, Grappe Interdisciplinaire de Génoprotéomique Appliquée (GIGA)-Cancer, University of Liège, Liège, Belgium.
authors.forename: Christine
authors.initials: C
authors.lastname: Gilles
authors.affiliation: INSERM, Unité Mixte de Recherche-S 903, Structure Fédérative de Recherche Champagne-Ardennes Picardie-Santé (SFR CAP), University of Reims Champagne-Ardenne, Reims, France; myriam.polette@univ-reims.fr.|Laboratory of Biopathology, Centres Hospitaliers Universitaires, Reims, France.
authors.forename: Myriam
authors.initials: M
authors.lastname: Polette
mesh_terms: D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D016209:Interleukin-8 / Q000235:genetics / Q000378:metabolism*; D061986:MCF-7 Cells; D016328:NF-kappa B / Q000378:metabolism*; D009389:Neovascularization, Pathologic / Q000235:genetics* / Q000378:metabolism; D011401:Promoter Regions, Genetic; D062826:Zonula Occludens-1 Protein / Q000378:metabolism*
chemical_list: D016209:Interleukin-8; D016328:NF-kappa B; C569042:TJP1 protein, human; D062826:Zonula Occludens-1 Protein
keywords: EMT; IL-8; ZO-1; tumor progression