ZO-1 Intracellular Localization Organizes Immune Response in Non-Small Cell Lung Cancer.

Delocalization of zonula occludens-1 (ZO-1) from tight junctions plays a substantial role in epithelial cell plasticity observed during tumor progression. In vitro, we reported an impact of ZO-1 cyto-nuclear content in modulating the secretion of several pro-inflammatory chemokines. In vivo, we demonstrated that it promotes the recruitment of immune cells in mouse ear sponge assays. Examining lung cancers, we showed that a high density of CD8 cytotoxic T cells and Foxp3 immunosuppressive regulatory T cells in the tumor microenvironment correlated with a cyto-nuclear expression of ZO-1. Taken together, our results support that, by affecting tumor cell secretome, the cyto-nuclear ZO-1 pool may recruit immune cells, which could be permissive for tumor progression.

EMT and inflammation: inseparable actors of cancer progression.

Tumors can be depicted as wounds that never heal, and are infiltrated by a large array of inflammatory and immune cells. Tumor-associated chronic inflammation is a hallmark of cancer that fosters progression to a metastatic stage, as has been extensively reviewed lately. Indeed, inflammatory cells persisting in the tumor establish a cross-talk with tumor cells that may result in a phenotype switch into tumor-supporting cells. This has been particularly well described for macrophages and is referred to as tumor-associated 'M2' polarization. Epithelial-to-mesenchymal transition (EMT), the embryonic program that loosens cell-cell adherence complexes and endows cells with enhanced migratory and invasive properties, can be co-opted by cancer cells during metastatic progression. Cancer cells that have undergone EMT are more aggressive, displaying increased invasiveness, stem-like features, and resistance to apoptosis. EMT programs can also stimulate the production of proinflammatory factors by cancer cells. Conversely, inflammation is a potent inducer of EMT in tumors. Therefore, the two phenomena may sustain each other, in an alliance for metastasis. This is the focus of this review, where the interconnections between EMT programs and cellular and molecular actors of inflammation are described. We also recapitulate data linking the EMT/inflammation axis to metastasis.

Zonula occludens-1/NF-κB/CXCL8: a new regulatory axis for tumor angiogenesis.

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 expression via a cytonuclear pool of ZO-1. Luciferase reporter assays highlighted a 173-bp region of CXCL8/IL-8 promoter 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 both ex vivo and in vivo angiogenesis 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 expression via the 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.

Soluble factors regulated by epithelial-mesenchymal transition mediate tumour angiogenesis and myeloid cell recruitment.

Epithelial-mesenchymal transition (EMT) programmes provide cancer cells with invasive and survival capacities that might favour metastatic dissemination. Whilst signalling cascades triggering EMT have been extensively studied, the impact of EMT on the crosstalk between tumour cells and the tumour microenvironment remains elusive. We aimed to identify EMT-regulated soluble factors that facilitate the recruitment of host cells in the tumour. Our findings indicate that EMT phenotypes relate to the induction of a panel of secreted mediators, namely IL-8, IL-6, sICAM-1, PAI-1 and GM-CSF, and implicate the EMT-transcription factor Snail as a regulator of this process. We further show that EMT-derived soluble factors are pro-angiogenic in vivo (in the mouse ear sponge assay), ex vivo (in the rat aortic ring assay) and in vitro (in a chemotaxis assay). Additionally, conditioned medium from EMT-positive cells stimulates the recruitment of myeloid cells. In a bank of 40 triple-negative breast cancers, tumours presenting features of EMT were significantly more angiogenic and infiltrated by a higher quantity of myeloid cells compared to tumours with little or no EMT. Taken together, our results show that EMT programmes trigger the expression of soluble mediators in cancer cells that stimulate angiogenesis and recruit myeloid cells in vivo, which might in turn favour cancer spread.

Cystic fibrosis airway epithelium remodelling: involvement of inflammation.

Chronic inflammation is a hallmark of cystic fibrosis (CF) lung disease and airway epithelium damage and remodelling are important components of lung pathology progression in CF. Whether this remodelling is secondary to deleterious infectious and inflammatory mediators, or to alterations of CF human airway epithelial (HAE) cells, such as their hyper inflammatory phenotype or their basic cystic fibrosis transmembrane conductance regulator (CFTR) default, remains debated. In this study, we evaluated the involvement of alterations of CF HAE cells in airway epithelium remodelling. HAE cells from non-CF and CF patients were cultured in an air-liquid interface, with and without inflammatory stimulation, along the regeneration process, and the remodelling of the reconstituted epithelium was analysed. We confirmed that CF HAE cells showed a hyperinflammatory phenotype which was lost with time. In comparison to non-CF epithelium, CF epithelium regeneration in the absence of exogenous inflammation was higher and exhibited basal cell hyperplasia. This remodelling was mimicked by inflammatory stimulation of non-CF cells and was absent when CF HAE cells were no longer hyperinflamed. Moreover, the number of goblet cells was similar in non-CF and CF cultures and increased equally under inflammatory stimulation. Finally, whatever the inflammatory environment, CF cultures showed a delay in ciliated cell differentiation. In conclusion, alterations of CF HAE cells partly regulate airway epithelium remodelling following injury and regeneration. This remodelling, together with goblet cell hyperplasia induced by exogenous inflammation and alteration of ciliated cell differentiation, may worsen mucociliary clearance impairment, leading to injury.

Cation-anion interactions and polar structures in the solid state.

Complicated structures where oxygen and fluorine are found together in one framework, where deviations from Pauling's second crystal rule (PSCR) are expected, often result in structures with important physical properties. The [NbOF5]2- anion and therefore all the individual Nb-O and Nb-F bonds are ordered in noncentrosymmetric KNaNbOF5 and centrosymmetric CsNaNbOF5. The Na/K- and Na/Cs-O/F interactions in these phases, in particular the expected deviations from PSCR and the bond valence model, reveal the essential role of the small potassium cations in the acentric packing of the [NbOF5]2- anion. KNaNbOF5 crystallizes in the orthorhombic and polar space group Pna21 (No. 33) with lattice constants a = 11.8653(11) A, b = 5.8826(6) A, c = 8.1258(8) A, and Z = 4, while CsNaNbOF5 crystallizes in the orthorhombic space group Pbcn (No. 60) with lattice constants a = 8.3155(7), b = 13.3176(11), c = 11.1314(9), and Z = 8.

RbGa3(P3O10)2: a new gallium phosphate isotypic with RbAl3(P3O10)2.

Rubidium trigallium bis(triphosphate), RbGa3(P3O10)2 has been synthesized by solid-state reaction and studied by single-crystal X-ray diffraction at room temperature. This compound is the first anhydrous gallium phosphate containing both GaO4 tetrahedra (Ga1) and GaO6 octahedra (Ga2 and Ga3). The three independent Ga atoms are located on sites with imposed symmetry 2 (Wickoff positions 4a for Ga1 and 4b for Ga2 and Ga3). The GaO4 and GaO6 polyhedra are connected through the apices to triphosphate groups and form a three-dimensional host lattice. This framework presents intersecting tunnels running along the [001] and <110> directions, where the Rb2+ cations are located on sites with imposed symmetry 2 (Wickoff position 4a). The structure also exhibits remarkable features, such as infinite helical columns created by the junction of GaO4 and PO4 tetrahedra.