References of "Gilles, Christine"
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See detailFhit regulates EMT targets through an EGFR/Src/ERK/Slug signaling axis in human bronchial cells.
Joannes, Audrey; Grelet, Simon; Duca, Laurent et al

in Molecular Cancer Research (2014), 12(5), 775-83

In many cancers, including lung carcinomas, Fragile histidine triad (Fhit) is frequently decreased or lost. Fhit status has recently been shown to be associated with elevated in vitro and in vivo ... [more ▼]

In many cancers, including lung carcinomas, Fragile histidine triad (Fhit) is frequently decreased or lost. Fhit status has recently been shown to be associated with elevated in vitro and in vivo invasiveness in lung cancer. Tumor cell invasion is facilitated by epithelial-mesenchymal transition (EMT), a process by which tumor cells lose their epithelial features to acquire a mesenchymal cell-like phenotype. In this study, the mechanism underlying Fhit-regulated EMT was deciphered. Using Slug knockdown, pharmacologic inhibitors PD98059, PP1, and gefitinib as well as an anti-EGFR antibody, it was demonstrated that Fhit silencing in bronchial cells induced overexpression of two primary EMT-associated targets, MMP-9 and vimentin, to regulate cell invasion dependent on an EGFR/Src/ERK/Slug signaling pathway. Moreover, ectopic expression of Fhit in Fhit-deficient lung cancer cells downregulated this pathway. Finally, an inverse correlation was observed between Fhit and phospho-EGFR levels in a cohort of human squamous cell lung carcinoma specimens. These results demonstrate a Fhit-dependent mechanism in the control of EMT-regulated EGFR signaling. IMPLICATIONS: This study adds new insight into the regulatory mechanism of EMT, a process known to increase resistance to conventional and targeted therapies in lung cancer. [less ▲]

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See detailDUSP3/VHR is a pro-angiogenic atypical dual-specificity phosphatase
Amand, Mathieu ULg; Erpicum, Charlotte ULg; BAJOU, Khalid ULg et al

in Molecular Cancer (2014)

Background DUSP3 phosphatase, also known as Vaccinia-H1 Related (VHR) phosphatase, encoded by DUSP3/Dusp3 gene, is a relatively small member of the dual-specificity protein phosphatases. In vitro studies ... [more ▼]

Background DUSP3 phosphatase, also known as Vaccinia-H1 Related (VHR) phosphatase, encoded by DUSP3/Dusp3 gene, is a relatively small member of the dual-specificity protein phosphatases. In vitro studies showed that DUSP3 is a negative regulator of ERK and JNK pathways in several cell lines. On the other hand, DUSP3 is implicated in human cancer. It has been alternatively described as having tumor suppressive and oncogenic properties. Thus, the available data suggest that DUSP3 plays complex and contradictory roles in tumorigenesis that could be cell type-dependent. Since most of these studies were performed using recombinant proteins or in cell-transfection based assays, the physiological function of DUSP3 has remained elusive. Results Using immunohistochemistry on human cervical sections, we observed a strong expression of DUSP3 in endothelial cells (EC) suggesting a contribution for this phosphatase to EC functions. DUSP3 downregulation, using RNA interference, in human EC reduced significantly in vitro tube formation on Matrigel and spheroid angiogenic sprouting. However, this defect was not associated with an altered phosphorylation of the documented in vitro DUSP3 substrates, ERK1/2, JNK1/2 and EGFR but was associated with an increased PKC phosphorylation. To investigate the physiological function of DUSP3, we generated Dusp3-deficient mice by homologous recombination. The obtained DUSP3-/- mice were healthy, fertile, with no spontaneous phenotype and no vascular defect. However, DUSP3 deficiency prevented neo-vascularization of transplanted b-FGF containing Matrigel and LLC xenograft tumors as evidenced by hemoglobin (Hb) and FITC-dextran quantifications. Furthermore, we found that DUSP3 is required for b-FGF-induced microvessel outgrowth in the aortic ring assay. Conclusions All together, our data identify DUSP3 as a new important player in angiogenesis. [less ▲]

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See detailInterplay between KLF4 and ZEB2/SIP1 in the regulation of E-cadherin expression.
Koopmansch, Benjamin ULg; Berx, Geert; Foidart, Jean-Michel ULg et al

in Biochemical and Biophysical Research Communications (2013), 431(4), 652

E-cadherin expression is repressed by ZEB2/SIP1 while it is induced by KLF4. Independent data from the literature indicate that these two transcription factors could bind close to each other in the ... [more ▼]

E-cadherin expression is repressed by ZEB2/SIP1 while it is induced by KLF4. Independent data from the literature indicate that these two transcription factors could bind close to each other in the proximal region of the E-cadherin gene promoter. We have here explored a potential competition between ZEB2 and KLF4 for the binding to the E-cadherin promoter. We show an inverse correlation between ZEB2 expression levels and KLF4 recruitment on the E-cadherin promoter in three breast cancer cell lines and in A431/HA.ZEB2 cells in which ZEB2 expression is induced by doxycycline (DOX). We identified a region of the E-cadherin promoter bound by KLF4 which is necessary for the activation of the E-cadherin promoter activity after KLF4 overexpression. This region is localized between positions -28 and -10 and thus overlaps with one of the ZEB2 binding sites. Deleting the bipartite ZEB2 binding site results in increased KLF4 induced E-cadherin promoter activity. Taken together, our results suggest that E-cadherin expression in cancer cells is controlled by a balance between ZEB2 and KLF4 expression levels. [less ▲]

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See detailRegulation of membrane-type 1 matrix metalloproteinase expression by zonula occludens-2 in human lung cancer cells.
Luczka, E.; Syne, Laïdya ULg; Nawrocki-Raby, B. et al

in Clinical & Experimental Metastasis (2013)

During tumor invasion, tumor epithelial cells acquire migratory and invasive properties involving important phenotypic alterations. Among these changes, one can observe reorganization or a loss of cell ... [more ▼]

During tumor invasion, tumor epithelial cells acquire migratory and invasive properties involving important phenotypic alterations. Among these changes, one can observe reorganization or a loss of cell-cell adhesion complexes such as tight junctions (TJs). TJs are composed of transmembrane proteins (occludin, claudins) linked to the actin cytoskeleton through cytoplasmic adaptor molecules including those of the zonula occludens family (ZO-1, -2, -3). We here evaluated the potential role of ZO-2 in the acquisition of invasive properties by tumor cells. In vivo, we showed a decrease of ZO-2 expression in bronchopulmonary cancers, with a preferential localization in the cytoplasm. In addition, in vitro, the localization of ZO-2 varied according to invasive properties of tumor cells, with a cytoplasmic localization correlating with invasion. In addition, we demonstrated that ZO-2 inhibition increases invasive and migrative capacities of invasive tumor cells. This was associated with an increase of MT1-MMP. These results suggest that ZO-2, besides its structural role in tight junction assembly, can act also as a repressor of tumor progression through its ability to reduce the expression of tumor-promoting genes in invasive tumor cells. [less ▲]

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See detailVimentin expression predicts the occurrence of metastases in non small cell lung carcinomas.
Dauphin, Maryline; Barbe, Coralie; Lemaire, Sarah et al

in Lung Cancer (2013), 81(1), 117-22

Epithelial-to-mesenchymal transition (EMT) is believed to contribute to tumour invasion. Vimentin expression by carcinoma cells is a largely recognized marker of EMT. This study aimed at examining ... [more ▼]

Epithelial-to-mesenchymal transition (EMT) is believed to contribute to tumour invasion. Vimentin expression by carcinoma cells is a largely recognized marker of EMT. This study aimed at examining vimentin expression in non small cell lung carcinomas (NSCLC) by immunohistochemistry to evaluate potential correlations between vimentin expression and the differentiation status, the TNM stage and the outcome of the patients. 295 NSCLC including 164 squamous cell carcinomas (SCC), 108 adenocarcinomas (AC) and 23 other NSCLC carcinomas have been examined by immunohistochemistry. Vimentin was indeed detected in 145 cases (49.2%). It was principally present in isolated tumour cells and invasive clusters, particularly in cells at the tumour/stroma interface. Vimentin expression was significantly more expressed in large cell neuroendocrine, adeno-squamous and sarcomatoid carcinomas than in SCC and AC and was significantly associated with the differentiation status of carcinomas. The follow-up of 193 patients further demonstrated that an extensive expression of vimentin (>50% of tumour cells) was associated with the occurrence of metastases. In conclusion, our data demonstrate that vimentin expression is a frequent event in NSCLC and that its expression can be associated with a lack of differentiation and the occurrence of metastases. [less ▲]

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See detailMyoferlin is a key regulator of EGFR activity in breast cancer.
Turtoi, Andrei ULg; Blomme, Arnaud ULg; Bellahcene, Akeila ULg et al

in Cancer Research (2013)

Myoferlin is a member of the ferlin family of proteins that participate in plasma membrane fusion, repair and endocytosis. While some reports have implicated myoferlin in cancer, the extent of its ... [more ▼]

Myoferlin is a member of the ferlin family of proteins that participate in plasma membrane fusion, repair and endocytosis. While some reports have implicated myoferlin in cancer, the extent of its expression in and contributions to cancer are not well established. In this study, we show that myoferlin is overexpressed in human breast cancers and that it is has a critical role in controlling degradation of the EGFR after its activation and internalization in breast cancer cells. Myoferlin depletion blocked EGF-induced cell migration and epithelial-to-mesenchymal transition. Both effects were induced as a result of impaired degradation of phosphorylated EGFR via dysfunctional plasma membrane caveolae and alteration of caveolin homooligomerization. In parallel, myoferlin depletion reduced tumor development in a chicken chorioallantoic membrane xenograft model of human breast cancer. Considering the therapeutic significance of EGFR targeting, our findings identify myoferlin as an novel candidate function to target for future drug development. [less ▲]

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See detailA dynamic in vivo model of epithelial-to-mesenchymal transitions in circulating tumor cells and metastases of breast cancer.
Bonnomet, Arnaud; Syne, Laïdya ULg; Brysse, Anne ULg et al

in Oncogene (2012), 31(33), 3741-53

Epithelial-to-mesenchymal transition (EMT) processes endow epithelial cells with enhanced migratory/invasive properties and are therefore likely to contribute to tumor invasion and metastatic spread ... [more ▼]

Epithelial-to-mesenchymal transition (EMT) processes endow epithelial cells with enhanced migratory/invasive properties and are therefore likely to contribute to tumor invasion and metastatic spread. Because of the difficulty in following EMT processes in human tumors, we have developed and characterized an animal model with transplantable human breast tumor cells (MDA-MB-468) uniquely showing spontaneous EMT events to occur. Using vimentin as a marker of EMT, heterogeneity was revealed in the primary MDA-MB-468 xenografts with vimentin-negative and vimentin-positive areas, as also observed on clinical human invasive breast tumor specimens. Reverse transcriptase-PCR after microdissection of these populations from the xenografts revealed EMT traits in the vimentin-positive zones characterized by enhanced 'mesenchymal gene' expression (Snail, Slug and fibroblast-specific protein-1) and diminished expression of epithelial molecules (E-cadherin, ZO-3 and JAM-A). Circulating tumor cells (CTCs) were detected in the blood as soon as 8 days after s.c. injection, and lung metastases developed in all animals injected as examined by in vivo imaging analyses and histology. High levels of vimentin RNA were detected in CTCs by reverse transcriptase-quantitative PCR as well as, to a lesser extent, Snail and Slug RNA. Von Willebrand Factor/vimentin double immunostainings further showed that tumor cells in vascular tumoral emboli all expressed vimentin. Tumoral emboli in the lungs also expressed vimentin whereas macrometastases displayed heterogenous vimentin expression, as seen in the primary xenografts. In conclusion, our data uniquely demonstrate in an in vivo context that EMT occurs in the primary tumors, and associates with an enhanced ability to intravasate and generate CTCs. They further suggest that mesenchymal-to-epithelial phenomena occur in secondary organs, facilitating the metastatic growth [less ▲]

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See detailRegulation of CXCL8/IL-8 expression by Zonula Occludens-1 in human breast cancer cells.
Brysse, Anne ULg; Mestdagt, Mélanie ULg; Polette, Myriam et al

in Molecular Cancer Research (2012), 10(1), 121-32

Accumulating data now suggest that ZO-1, once delocalized from tight junctions, could be implicated in the regulation of tumor promoting genes. Because of their major implication in different steps of ... [more ▼]

Accumulating data now suggest that ZO-1, once delocalized from tight junctions, could be implicated in the regulation of tumor promoting genes. Because of their major implication in different steps of tumor progression, we investigated here the influence of ZO-1 on chemokines expression in breast cancer cells. Using GeneArray analysis to compare chemokine mRNA expression in breast tumor cells transfected with a siRNA against ZO-1, we identified CXCL-8/IL-8 as a major potential target of ZO-1 signaling, being strongly downregulated following ZO-1 siRNA transfection. Examining further the relationship between ZO-1 and IL-8, we first demonstrated that CXCL8/IL-8 expression correlates with a relocalization of ZO-1 in several breast cancer cell lines. Moreover, CXCL8/IL-8 is downregulated in invasive BT549 cells transfected with 3 different ZO-1 siRNA and overexpressed in non-invasive BT20 and SKBR3 cells transfected with vectors expressing ZO-1. We also provide evidence for an activation of the CXCL8/IL-8 promoter by ZO-1. Finally, we demonstrate that the regulation of CXCL8/IL-8 by ZO-1 is independent of the beta-catenin pathway. Our results thus clearly demonstrate an implication of ZO-1 in CXCL8/IL-8 regulation. Because of the major implications of CXCL8/IL-8 in tumor invasion, such a regulation could play an important role in breast cancer progression. [less ▲]

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See detailInvasion and metastatic dissemination in breast cancer: mechanisms
Noël, Agnès ULg; Gilles, Christine ULg; Foidart, Jean-Michel ULg

in Revue Médicale de Liège (2011), 66(5-6), 274-278

Metastases formation is a complex process involving genetic and epigenetic modifications leading to several molecular pathway dysfunctions and alterations in the production and fonction of a panel of ... [more ▼]

Metastases formation is a complex process involving genetic and epigenetic modifications leading to several molecular pathway dysfunctions and alterations in the production and fonction of a panel of molecular mediators. Recent studies have shed light on the importance of multiple interactions occuring between tumor cells and host cells involved in the elaboration of a microenvironment permissive for tumor cell survival and growth. These tumor-host interactions are decisive, not only in the primary tumor, but also in secondary sites colonized by tumor cells. Cancer appears more and more as a sytemic disease in which tumor cell is one of the pawn in the game. System of defense are rapidly overwhelmed and tumor cells hijack host cells to promote their dissemination that likely occurs at earlier stages than initially anticipated. In the present review, we describe the novel concepts of metastases formation based on recent transcriptomic analyses and new insights acquired on the tumor microenvironment in the primary tumor and in secondary foci. [less ▲]

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See detailA propos d'un cas de rechute tardive de cancer du sein après traitement adjuvant
LOUSBERG, Laurence; SOMJA, Joan ULg; COLLIGNON, Joëlle ULg et al

in Revue Médicale de Liège (2011), 66(5-6), 306-310

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See detailCellules Tumorales Circulantes : détection, caractérisation et intérêts cliniques
Gilles, Christine ULg; COLLIGNON, Joëlle ULg; Noël, Agnès ULg et al

in Revue Médicale de Liège (2011), 66(5-6), 279-84

The metastatic process generates circulating tumor cells (CTCs) and disseminated tumor cells (DTCs) in bone marrow and other organs which can remain as occult metastases. Various methods and systems have ... [more ▼]

The metastatic process generates circulating tumor cells (CTCs) and disseminated tumor cells (DTCs) in bone marrow and other organs which can remain as occult metastases. Various methods and systems have been developed to allow the isolation and identification of those cells but major technical limitations still exist. Research on CTCs is a nevertheless tremendously growing field of cancer research because of their potential clinical applications. CTCs indeed convey predictive information for the development of metastasis and recurrence, and prognostic information regarding patient survival. CTCs enumeration could also be used to monitor the effectiveness of adjuvant treatments. Moreover, enhancing our basic understanding of the metastatic process, CTCs, and DTCs in particular, are thought to contain subpopulations of cells with stem cells properties that would be responsible for relapses. [less ▲]

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See detailThe Pbx Interaction Motif of Hoxa1 Is Essential for Its Oncogenic Activity
Delval, Stéphanie; Taminiau, Arnaud; Lamy, Juliette et al

in PLoS ONE (2011), 6(9), 2547

Hoxa1 belongs to the Hox family of homeodomain transcription factors involved in patterning embryonic territories and governing organogenetic processes. In addition to its developmental functions, Hoxa1 ... [more ▼]

Hoxa1 belongs to the Hox family of homeodomain transcription factors involved in patterning embryonic territories and governing organogenetic processes. In addition to its developmental functions, Hoxa1 has been shown to be an oncogene and to be overexpressed in the mammary gland in response to a deregulation of the autocrine growth hormone. It has therefore been suggested that Hoxa1 plays a pivotal role in the process linking autocrine growth hormone misregulation and mammary carcinogenesis. Like most Hox proteins, Hoxa1 can interact with Pbx proteins. This interaction relies on a Hox hexapeptidic sequence centred on conserved Tryptophan and Methionine residues. To address the importance of the Hox-Pbx interaction for the oncogenic activity of Hoxa1, we characterized here the properties of a Hoxa1 variant with substituted residues in the hexapeptide and demonstrate that the Hoxa1 mutant lost its ability to stimulate cell proliferation, anchorage-independent cell growth, and loss of contact inhibition. Therefore, the hexapeptide motif of Hoxa1 is required to confer its oncogenic activity, supporting the view that this activity relies on the ability of Hoxa1 to interact with Pbx. [less ▲]

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See detailFhit regulates invasion of lung tumor cells
Joannes, A.; Bonnomet, A.; Bindels, S. et al

in Oncogene (2010), 29(8), 1203-13

In many types of cancers, the fragile histidine triad (Fhit) gene is frequently targeted by genomic alterations leading to a decrease or loss of gene and protein expression. Fhit has been described as a ... [more ▼]

In many types of cancers, the fragile histidine triad (Fhit) gene is frequently targeted by genomic alterations leading to a decrease or loss of gene and protein expression. Fhit has been described as a tumor suppressor gene because of its ability to induce apoptosis and to inhibit proliferation of tumor cells. Moreover, several studies have shown a correlation between the lack of Fhit expression and tumor aggressiveness, thus suggesting that Fhit could be involved in tumor progression. In this study, we explored the potential role of Fhit during tumor cell invasion. We first showed that a low Fhit expression is associated with in vivo and in vitro invasiveness of tumor cells. Then, we showed that Fhit overexpression in Fhit-negative highly invasive NCI-H1299 cells by transfection of Fhit cDNA and Fhit inhibition in Fhit-positive poorly invasive HBE4-E6/E7 cells by transfection of Fhit small interfering RNA induce, respectively, a decrease and an increase in migratory/invasive capacities. These changes in cell behavior were associated with a reorganization of tight and adherens junction molecules and a regulation of matrix metalloproteinase and vimentin expression. These results show that Fhit controls the invasive phenotype of lung tumor cells by regulating the expression of genes associated with epithelial–mesenchymal transition. [less ▲]

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See detailEpithelial-to-mesenchymal transitions and circulating tumor cells.
Bonnomet, A.; Brysse, Anne ULg; Tachsidis, A. et al

in Journal of Mammary Gland Biology & Neoplasia (2010), 15(2), 261-73

Epithelial-to-mesenchymal transition (EMT) phenomena endow epithelial cells with enhanced migratory and invasive potential, and as such, have been implicated in many physiological and pathological ... [more ▼]

Epithelial-to-mesenchymal transition (EMT) phenomena endow epithelial cells with enhanced migratory and invasive potential, and as such, have been implicated in many physiological and pathological processes requiring cell migration/invasion. Although their involvement in the metastatic cascade is still a subject of debate, data are accumulating to demonstrate the existence of EMT phenotypes in primary human tumors, describe enhanced metastatic potential of EMT derivatives in animal models, and report EMT attributes in circulating tumor cells (CTCs). The relationships between EMT and CTCs remain largely unexplored, and we review here in vitro and in vivo data supporting a putative role of EMT processes in CTC generation and survival. [less ▲]

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See detailMMP-19 Deficiency Promotes Tenascin-C Accumulation and Allergen-induced Airway Inflammation.
Guéders, Maud ULg; Hirst, S.; Quesada Calvo, Florence ULg et al

in American Journal of Respiratory Cell and Molecular Biology (2010), 43(3), 286-95

Matrix metalloproteinases (MMPs) recently appeared as key regulators of inflammation, allowing recruitment and clearance of inflammatory cells and modifying the biological activity of many peptidic ... [more ▼]

Matrix metalloproteinases (MMPs) recently appeared as key regulators of inflammation, allowing recruitment and clearance of inflammatory cells and modifying the biological activity of many peptidic mediators by cleavage. MMP-19 is a newly described MMP and preferentially cleaves matrix proteins such as collagens and tenascin-C. The role of MMP-19 in asthma has not been described to date. The purpose of the present study was to assess MMP-19 expression in a murine asthma model and to address biological effects of MMP-19 deficiency in mice. Allergenexposed wild-type (WT) mice displayed an increased expression of MMP-19 mRNA and an increased number of MMP-19-positive cells in the lungs detected by immunohistochemistry. After allergen challenge of MMP-19 knockout (MMP-19-/-) mice, an exacerbated eosinophilic inflammation was detected in bronchoalveolar lavage fluid and bronchial tissue along with an increased airway responsiveness to methacholine. A shift towards increased Th2-driven inflammation in MMP-19-/- mice was demonstrated by 1) increased numbers of cells expressing the IL-33 receptor T1/ST2 in lung parenchyma, 2) increased IgG1 levels in serum and 3) higher levels of IL-13 and CCL11 in lung extracts. Tenascin-C was found accumulated in peribronchial areas of MMP-19-/- after allergen challenges as assessed by Western blot and immunohistochemistry analysis. We conclude that MMP-19 is a new mediator in asthma, preventing tenascin-C accumulation and directly or indirectly controlling Th2-driven airway eosinophilia and airway hyperreactivity. Our data suggest that MMP-19 might act on Th2 inflammation homeostasis through preventing tenascin protein accumulation. [less ▲]

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See detailTransforming growth factor-beta1-mediated Slug and Snail transcription factor up-regulation reduces the density of Langerhans cells in epithelial metaplasia by affecting E-cadherin expression
Herfs, Michael ULg; Hubert, Pascale ULg; Kholod, Natalia et al

in American Journal of Pathology (2008), 172(5), 1391-402

Epithelial metaplasia (EpM) is an acquired tissue abnormality resulting from the transformation of epithelium into another tissue with a different structure and function. This adaptative process is ... [more ▼]

Epithelial metaplasia (EpM) is an acquired tissue abnormality resulting from the transformation of epithelium into another tissue with a different structure and function. This adaptative process is associated with an increased frequency of (pre)cancerous lesions. We propose that EpM is involved in cancer development by altering the expression of adhesion molecules important for cell-mediated antitumor immunity. Langerhans cells (LCs) are intraepithelial dendritic cells that initiate immune responses against viral or tumor antigens on both skin and mucosal surfaces. In the present study, we showed by immunohistology that the density of CD1a LCs is reduced in EpM of the uterine cervix compared with native squamous epithelium and that the low number of LCs observed in EpM correlates with the down-regulation of cell-surface E-cadherin. We also demonstrated that transforming growth factor- 1 is not only overexpressed in metaplastic tissues but also reduces E-cadherin expression in keratinocytes in vitro by inducing the promoter activity of Slug and Snail transcription factors. Finally, we showed that in vitro-generated LCs adhere poorly to keratinocytes transfected with either Slug or Snail DNA. These data suggest that transforming growth factor- 1 indirectly reduces antigenpresenting cell density in EpM by affecting E-cadherin expression, which might explain the increased susceptibility of abnormal tissue differentiation to the development of cancer by the establishment of local immunodeficiency responsible for EpM tumorigenesis. [less ▲]

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See detailthe metalloproteinase ADAM-12 regulates bronchial epithelial cell proliferation and apoptosis.
Rocks, Natacha ULg; Estrella, C.; Paulissen, Geneviève ULg et al

in Cell Proliferation (2008), 41(6), 988-1001

Objectives: The ADAMs (a disintegrin and metalloproteinase) enzymes compose a family of membrane-bound proteins characterized by their multi-domain structure and ADAM-12 expression is elevated in human ... [more ▼]

Objectives: The ADAMs (a disintegrin and metalloproteinase) enzymes compose a family of membrane-bound proteins characterized by their multi-domain structure and ADAM-12 expression is elevated in human non-small cell lung cancers. The aim of this study was to investigate the roles played by ADAM-12 in critical steps of bronchial cell transformation during carcinogenesis. Materials and methods: To assess the role of ADAM-12 in tumorigenicity, BEAS-2B cells were transfected with a plasmid encoding human full-length ADAM-12 cDNA, and then the effects of ADAM-12 overexpression on cell behaviour were explored. Treatment of clones with heparin-binding epidermal growth factor (EGF)-like growth factor (HB-EGF) neutralizing antibodies as well as an EGFR inhibitor allowed the dissection of mechanisms regulating cell proliferation and apoptosis. Results: Overexpression of ADAM-12 in BEAS-2B cells promoted cell proliferation. ADAM-12 overexpressing clones produced higher quantities of HB-EGF in their culture medium which may rely on membrane-bound HB-EGF shedding by ADAM-12. Targeting HB-EGF activity with a neutralizing antibody abrogated enhanced cell proliferation in the ADAM-12 overexpressing clones. In sharp contrast, targeting of amphiregulin, EGF or transforming growth factor-α failed to influence cell proliferation; moreover, ADAM-12 transfectants were resistant to etoposide-induced apoptosis and the use of a neutralizing antibody against HB-EGF activity restored rates of apoptosis to be similar to controls. Conclusions: ADAM-12 contributes to enhancing HB-EGF shedding from plasma membranes leading to increased cell proliferation and reduced apoptosis in this bronchial epithelial cell line. [less ▲]

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See detailThe E-cadherin-repressed hNanos1 gene induces tumor cell invasion by upregulating MT1-MMP expression
Bonnomet, A.; Polette, M.; Strumane, K. et al

in Oncogene (2008), 27(26), 3692-9

In this study, we examined the role of the E-cadherin-repressed gene human Nanos1 (hNanos1) in tumor invasion process. First, our in vivo study revealed that hNanos1 mRNAs were overexpressed in invasive ... [more ▼]

In this study, we examined the role of the E-cadherin-repressed gene human Nanos1 (hNanos1) in tumor invasion process. First, our in vivo study revealed that hNanos1 mRNAs were overexpressed in invasive lung carcinomas. Moreover, hNanos1 was co-localized with MT1-MMP (membrane type 1-matrix metalloproteinase) in E-cadherin-negative invasive lung tumor clusters. Using an inducible Tet-on system, we showed that induction of hNanos1 expression in DLD1 cells increased their migratory and invasive abilities in a three-dimensional migration and in a modified Boyden chamber assay. Accordingly, we demonstrated that hNanos1 upregulated MT1-MMP expression at the mRNA and protein levels. Inversely, using an RNA interference strategy to inhibit hNanos1 expression in invasive Hs578T, BT549 and BZR cancer cells, we observed a downregulation of MT1-MMP mRNA and protein and concomitantly a decrease of the invasive capacities of tumor cells in a modified Boyden chamber assay. Taken together, our results demonstrate that hNanos1, by regulating MT1-MMP expression, plays an important role in the acquisition of invasive properties by epithelial tumor cells. [less ▲]

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See detailGSK-3-specific inhibitor-supplemented hESC medium prevents the epithelial-mesenchymal transition process and the up-regulation of matrix metalloproteinases in hESCs cultured in feeder-free conditions
Ullmann, U.; Gilles, Christine ULg; De Rycke, M. et al

in Molecular Human Reproduction (2008), 14(3), 169-79

Feeder-free culture induces spontaneous differentiation of human embryonic stem cells (hESCs), identified as an epithelial to mesenchymal transition (EMT). The maintenance of pluripotency of hESCs in ... [more ▼]

Feeder-free culture induces spontaneous differentiation of human embryonic stem cells (hESCs), identified as an epithelial to mesenchymal transition (EMT). The maintenance of pluripotency of hESCs in feeder-free cultures through the activation of the WNT pathway using a glycogen synthase kinase (GSK)-3-specific inhibitor (BIO) was reported. The aim of this study was to determine the effect of BIO on the EMT process. In contrast with those grown in feeder-free conditions with control medium, hESC colonies cultured with BIO-supplemented hESC medium did not show any fibroblast-like cells at the periphery. Transmission electron microscopy, relative quantitative real-time RT–PCR and immunostaining analyses showed the presence of epithelial features and a diminution of mesenchymal features in the BIO-treated hESCs such as a strong E-cadherin expression, the down-regulation of Vimentin, Snail and Slug expressions and a cytoplasmic β-catenin expression. An up-regulation of matrix metalloproteinases (MMP) MMP-2, MMP-9, MT-1MMP (membrane-type 1 MMP) and EMMPRIN (extracellular MMP inducer) expression was also found associated with the EMT occurring in feeder-free hESCs cultures using mouse embryonic fibroblasts conditioned medium (MEF CM). The presence of BIO clearly down-regulated the expression of these MMPs. This study showed that BIO, a GSK-3-specific inhibitor, prevents the EMT process which is associated with the feeder-free hESC culture. Nevertheless, BIO was not sufficient to expand hESCs in a long-term culture system. [less ▲]

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