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See detailEGFR activation and signaling in cancer cells are enhanced by the membrane-bound metalloprotease MT4-MMP.
Paye, Alexandra ULg; Truong, Alice ULg; Yip, Cassandre ULg et al

in Cancer research (2014)

MT4-MMP (MMP-17) is a GPI-anchored matrix metalloprotease expressed on the surface of cancer cells which promotes tumor growth and metastasis. In this report, we identify MT4-MMP as an important driver of ... [more ▼]

MT4-MMP (MMP-17) is a GPI-anchored matrix metalloprotease expressed on the surface of cancer cells which promotes tumor growth and metastasis. In this report, we identify MT4-MMP as an important driver of cancer cell proliferation through CDK4 activation and retinoblastoma protein (Rb) inactivation. We also determine a functional link between MT4-MMP and the growth factor receptor EGFR. Mechanistic experiments revealed direct association of MT4-MMP and its positive effects on EGFR phosphorylation in response to TGF- and EGF in cancer cells. Notably, the effects of MT4-MMP on proliferation and EGFR activation did not rely on metalloprotease activity. Clinically, MT4-MMP and EGFR expression were correlated in human triple negative breast cancer specimens. Altogether our results identify MT4-MMP as a positive modifier of EGFR outside-in signaling that acts to cooperatively drive cancer cell proliferation. [less ▲]

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See detailAn Easy, Convenient Cell and Tissue Extraction Protocol for Nuclear Magnetic Resonance Metabolomics.
Matheus, Nicolas ULg; Hansen, Sylvain ULg; Rozet, Eric ULg et al

in Phytochemical analysis : PCA (2014)

INTRODUCTION: As a complement to the classic metabolomics biofluid studies, the visualisation of the metabolites contained in cells or tissues could be a very powerful tool to understand how the local ... [more ▼]

INTRODUCTION: As a complement to the classic metabolomics biofluid studies, the visualisation of the metabolites contained in cells or tissues could be a very powerful tool to understand how the local metabolism and biochemical pathways could be affected by external or internal stimuli or pathologies. Therefore, extraction and/or lysis is necessary to obtain samples adapted for use with the current analytical tools (liquid NMR and MS). These extraction or lysis work-ups are often the most labour-intensive and rate-limiting steps in metabolomics, as they require accuracy and repeatability as well as robustness. Many of the procedures described in the literature appear to be very time-consuming and not easily amenable to automation. OBJECTIVE: To find a fast, simplified procedure that allows release of the metabolites from cells and tissues in a way that is compatible with NMR analysis. METHODS: We assessed the use of sonication to disrupt cell membranes or tissue structures. Both a vibrating probe and an automated bath sonicator were explored. RESULTS: The application of sonication as the disruption procedure led to reproducible NMR spectral data compatible with metabolomics studies. This method requires only a small biological tissue or cell sample, and a rapid, reduced work-up was applied before analysis. The spectral patterns obtained are comparable with previous, well-described extraction protocols. CONCLUSION: The rapidity and the simplicity of this approach could represent a suitable alternative to the other protocols. Additionally, this approach could be favourable for high- throughput applications in intracellular and intratissular metabolite measurements. Copyright (c) 2014 John Wiley & Sons, Ltd. [less ▲]

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See detailMolecular mechanisms of type I collagen-induced apoptosis in breast carcinoma cells
Maquoi, Erik ULg; Assent, Delphine ULg; Foidart, Jean-Michel ULg et al

Poster (2013, September 27)

Objective: As invading breast carcinoma cells breach the underlying basement membrane, they become confronted with a dense three-dimensional reactive stroma dominated by type I collagen. To develop ... [more ▼]

Objective: As invading breast carcinoma cells breach the underlying basement membrane, they become confronted with a dense three-dimensional reactive stroma dominated by type I collagen. To develop metastatic capabilities, invading tumour cells must acquire the capacity to negotiate this hostile microenvironment. By enmeshing cells in a dense fibrillar network, type I collagen acts as a physical barrier for cell migration as well as an endogenous antigrowth signal, partly by inducing apoptosis in epithelial cells. Aberrant cell survival resulting from an acquired resistance toward apoptosis represents a prominent hallmark of cancers. However, the molecular mechanisms implicated in collagen-induced apoptosis remain poorly defined. Here, we investigate the molecular mechanisms by which type I collagen induces apoptosis in breast carcinoma cells and identify MMP-14, a membrane-anchored matrix metalloproteinase, as a key anti-apoptotic factor. Methods: To investigate the induction of apoptosis by collagen, human breast adenocarcinoma MCF-7 cells overexpressing or not MMP-14 were plated on plastic plates or embedded within three dimensional type I collagen gels (Col3D). Cell death was evaluated by measuring cytoplasmic histone-associated DNA fragments (Cell Death Detection ELISA). The percentage of cells with an apoptotic nuclear morphology was also determined. The interactions between cancer cells and Col3D were analyzed by confocal microscopy and the impact of Col3D on the transcriptome of cancer cells was investigated using Illumina HT-12 BeadArrays. Results: When cultured within Col3D gels, MCF-7 cells displayed a round morphology and a cell death characterized by a Z-VAD-FMK-dependent chromatin condensation, nuclear segmentation and oligonucleosomal DNA fragmentation was induced. Transfection of MCF-7 cells with MMP-14 cDNA promoted the interactions between cells and collagen and prevented apoptosis. A transcriptomic analysis revealed that culturing MCF-7 cells within Col3D altered the expression of about 700 genes, irrespective of MMP-14 expression. Col3D modulated the expression of several apoptosis-related genes. Interestingly, MMP-14 activity was sufficient to prevent the Col3D-dependent induction of Bcl2-Interacting Killer (BIK), a pro-apoptotic member of the Bcl-2 family. Conclusions: Our results shed light on the molecular mechanisms by which a collagen-rich microenvironment triggers apoptosis in invading breast cancer cells. Furthermore, we demonstrate that MMP-14 promotes tumour progression by circumventing apoptosis. [less ▲]

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See detailMT1-MMP protects breast carcinoma cells against type I collagen-induced apoptosis
Maquoi, Erik ULg; Assent, Delphine; Detilleux, Julien et al

in Oncogene (2012), 31(4), 480-93

As invading breast carcinoma cells breach their underlying basement membrane, they become confronted with a dense three-dimensional reactive stroma dominated by type I collagen. To develop metastatic ... [more ▼]

As invading breast carcinoma cells breach their underlying basement membrane, they become confronted with a dense three-dimensional reactive stroma dominated by type I collagen. To develop metastatic capabilities, invading tumor cells must acquire the capacity to negotiate this novel microenvironment. Collagen influences the fate of epithelial cells by inducing apoptosis. However, the mechanisms used by invading tumor cells to evade collagen-induced apoptosis remain to be defined. We demonstrate that membrane type-1 matrix metalloproteinase (MT1-MMP/MMP-14) confers breast cancer cells with the ability to escape apoptosis when embedded in a collagen gel and after orthotopic implantation in vivo. In the absence of MMP-14-dependent proteolysis, type I collagen triggers apoptosis by inducing the expression of the pro-apoptotic Bcl-2-interacting killer in luminal-like breast cancer cells. These findings reveal a new mechanism whereby MMP-14 activity promotes tumor progression by circumventing apoptosis. [less ▲]

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See detailNew and Paradoxical Roles of Matrix Metalloproteinases in the Tumor Microenvironment.
Noël, Agnès ULg; Gutierrez-Fernandez, A; Sounni, Nor Eddine ULg et al

in Frontiers in Pharmacology of Anti-Cancer Drugs (2012), 3(140), 1

Processes such as cell proliferation, angiogenesis, apoptosis, or invasion are strongly influenced by the surrounding microenvironment of the tumor. Therefore, the ability to change these surroundings ... [more ▼]

Processes such as cell proliferation, angiogenesis, apoptosis, or invasion are strongly influenced by the surrounding microenvironment of the tumor. Therefore, the ability to change these surroundings represents an important property through which tumor cells are able to acquire specific functions necessary for tumor growth and dissemination. Matrix metalloproteinases (MMPs) constitute key players in this process, allowing tumor cells to modify the extracellular matrix (ECM) and release cytokines, growth factors, and other cell-surface molecules, ultimately facilitating protease-dependent tumor progression. Remodeling of the ECM by collagenolytic enzymes such as MMP1, MMP8, MMP13, or the membrane-bound MT1-MMP as well as by other membrane-anchored proteases is required for invasion and recruitment of novel blood vessels. However, the multiple roles of the MMPs do not all fit into a simple pattern. Despite the pro-tumorigenic function of certain metalloproteinases, recent studies have shown that other members of these families, such as MMP8 or MMP11, have a protective role against tumor growth and metastasis in animal models. These studies have been further expanded by large-scale genomic analysis, revealing that the genes encoding metalloproteinases, such as MMP8, MMP27, ADAM7, and ADAM29, are recurrently mutated in specific tumors, while several ADAMTSs are epigenetically silenced in different cancers. The importance of these proteases in modifying the tumor microenvironment highlights the need for a deeper understanding of how stroma cells and the ECM can modulate tumor progression. [less ▲]

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See detailSoluble forms of VEGF receptor-1 and -2 promote vascular maturation via mural cell recruitment.
LORQUET, Sophie ULg; Berndt, Sarah; Blacher, Silvia ULg et al

in FASEB Journal (2010), 24(10), 3782-95

Two soluble forms of vascular endothelial growth factor (VEGF) receptors, sVEGFR-1 and sVEGFR-2, are physiologically released and overproduced in some pathologies. They are known to act as anti-VEGF ... [more ▼]

Two soluble forms of vascular endothelial growth factor (VEGF) receptors, sVEGFR-1 and sVEGFR-2, are physiologically released and overproduced in some pathologies. They are known to act as anti-VEGF agents. Here, we report that these soluble receptors contribute to vessel maturation by mediating a dialogue between endothelial cells (EC) and mural cells that leads to blood vessel stabilization. Through a multidisciplinary approach, we provide evidences that these soluble VEGF receptors promote mural cell migration through a paracrine mechanism involving interplay in EC between VEGF/VEGFR-2 and sphingosine-1- phosphate type-1 (S1P)/S1P1 pathways that leads to endothelial nitric oxyde synthase (eNOS) activation. This new paradigm is supported by the finding that sVEGFR-1 and -2: 1) induce an eNOS-dependent outgrowth of a mural cell network in an ex vivo model of angiogenesis, 2) increase the mural cell coverage of neovessels in vitro and in vivo, 3) promote mural cell migration towards EC, 4) stimulate endothelial S1P1 overproduction and eNOS activation that promote the migration and the recruitment of neighboring mural cells. These findings provide new insights into mechanisms regulating physiological and pathological angiogenesis and vessel stabilization. [less ▲]

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See detailMembrane type 1 matrix metalloproteinase detection in tumors, using the iodinated endogenous [123I]-tissue inhibitor 2 of metalloproteinases as imaging agent.
Van Steenkiste, Magali; Oltenfreiter, Ruth; Frankenne, Francis et al

in Cancer Biotherapy & Radiopharmaceuticals (2010), 25(5), 511-20

Matrix metalloproteinases (MMPs) are principal participants in tumor development. In addition to serve as a useful biochemical marker, MMP expression may also provide a target for the diagnostic in vivo ... [more ▼]

Matrix metalloproteinases (MMPs) are principal participants in tumor development. In addition to serve as a useful biochemical marker, MMP expression may also provide a target for the diagnostic in vivo imaging of tumors, using a radiolabeled inhibitor. This study investigates the use of membrane type 1 (MT1)-MMP as target for in vivo tumor diagnosis. Specific binding of the endogenous tissue inhibitor of metalloproteinase-2 (TIMP-2) to MT1-MMP has been previously described. In this study, biodistribution and imaging experiments were performed on MT1-MMP-overexpressing (S.1.5) and control (C.IV.3) tumor-inoculated mice using [(123)I]-recombinant human TIMP-2 (rhTIMP-2) as radioligand and [(123)I]-rhTIMP-1 as control. The expression profile was controlled in vitro and on tumor extracts. rhTIMP-2 as well as rhTIMP-1 were labeled using the Iodogen method and characterized. Biodistribution of [(123)I]-rhTIMP-2 showed a tumor uptake of 2.87% +/- 1.58% ID/g at 3 hours postinjection in S.1.5. Tumor values of [(123)I]-rhTIMP-1 and [(123)I]-rhTIMP-2 evaluated in S.1.5 and C.IV.3, respectively, were significantly lower. Planar imaging revealed significant uptake of [(123)I]-rhTIMP-2 in S.1.5 compared with contralateral background areas. This could not be observed in C.IV.3 and with [(123)I]-rhTIMP-1 in S.1.5. All tumors were well established (200-800 mg). These results suggest that rhTIMP-2 holds potential for development of radiotracers for in vivo imaging in overexpressing MT1-MMP but not in similar tumors that do not express this protease. [less ▲]

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See detailMatrix metalloproteinases at cancer tumor-host interface
Noël, Agnès ULg; Jost, M.; Maquoi, Erik ULg

in Seminars in Cell & Developmental Biology (2008), 19

The increasing diversity in both substrates and functions of matrix metalloproteinases (MMPs) makes these enzymes central regulators in the complex tumor ecosystem composed of cancer cells and their ... [more ▼]

The increasing diversity in both substrates and functions of matrix metalloproteinases (MMPs) makes these enzymes central regulators in the complex tumor ecosystem composed of cancer cells and their microenvironment. In the majority of cancers, membrane-associated and extracellular proteases are mainly produced by host cells including inflammatory cells, endothelial cells, pericytes and fibroblasts. Recent data based on in vitro and in vivo studies have demonstrated the relevance of these enzymes in multiple processes controlling cancer growth, angiogenesis and metastatic dissemination. This review will present the emerging MMP-related features of cancer cells and host cells. [less ▲]

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See detailWhat are subcutaneous adipocytes really good for...?
Klein, j; Permana, P. A.; Owecki, M. et al

in Experimental Dermatology (2007), 16(1), 45-70

Our acute awareness of the cosmetic, psychosocial and sexual importance of subcutaneous adipose tissue contrasts dramatically with how poorly we have understood the biology of this massive, enigmatic ... [more ▼]

Our acute awareness of the cosmetic, psychosocial and sexual importance of subcutaneous adipose tissue contrasts dramatically with how poorly we have understood the biology of this massive, enigmatic, often ignored and much-abused skin compartment. Therefore, it is timely to recall the exciting, steadily growing, yet underappreciated body of evidence that subcutaneous adipocytes are so much more than just 'fat guys', hanging around passively to conspire, at most, against your desperate attempts to maintain ideal weight. Although the subcutis, quantitatively, tends to represent the dominant architectural component of human skin, conventional wisdom confines its biological key functions to those of energy storage, physical buffer, thermoregulation and thermoinsulation. However, already the distribution of human superficial adipose tissue, by itself, questions how justified the popular belief is that 'skin fat' (which actually may be more diverse than often assumed) serves primarily thermoinsulatory purposes. And although the metabolic complications of obesity are well appreciated, our understanding of how exactly subcutaneous adipocytes contribute to extracutaneous disease - and even influence important immune and brain functions! - is far from complete. The increasing insights recently won into subcutaneous adipose tissue as a cytokine depot that regulates innate immunity and cell growth exemplarily serve to illustrate the vast open research expanses that remain to be fully explored in the subcutis. The following public debate carries you from the evolutionary origins and the key functional purposes of adipose tissue, via adipose-derived stem cells and adipokines straight to the neuroendocrine, immunomodulatory and central nervous effects of signals that originate in the subcutis - perhaps, the most underestimated tissue of the human body. The editors are confident that, at the end, you shall agree: No basic scientist and no doctor with a serious interest in skin, and hardly anyone else in the life sciences, can afford to ignore the subcutaneous adipocyte - beyond its ample impact on beauty, benessence and body mass. [less ▲]

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See detailMembrane-type 4 matrix metalloproteinase promotes breast cancer growth and metastases
Chabottaux, Vincent; Sounni, Nor Eddine ULg; Pennington, C. J. et al

in Cancer Research (2006), 66(10), 5165-5172

Membrane-type matrix metalloproteinases (MT-MMP) constitute a subfamily of six distinct membrane-associated MMPs. Although the contribution of MT1-MMP during different steps of cancer progression has been ... [more ▼]

Membrane-type matrix metalloproteinases (MT-MMP) constitute a subfamily of six distinct membrane-associated MMPs. Although the contribution of MT1-MMP during different steps of cancer progression has been well documented, the significance of other MT-MMPs is rather unknown. We have investigated the involvement of MT4-MMP, a glycosylphosphatidylinositol-anchored protease, in breast cancer progression. Interestingly, immunohistochemical analysis shows that MT4-MMP production at protein level is strongly increased in epithelial cancer cells of human breast carcinomas compared with normal epithelial cells. Positive staining for MT4-MMP is also detected in lymph node metastases. In contrast, quantitative reverse transcription-PCR analysis reveals similar MT4-MMP mRNA levels in human breast adenocarcinomas and normal breast tissues. Stable transfection of MT4-MMP cDNA in human breast adenocarcinoma MDA-MB-231 cells does not affect in vitro cell proliferation or invasion but strongly promotes primary tumor growth and associated metastases in RAG-1 immunodeficient mice. We provide for the first time evidence that MT4-MMP overproduction accelerates in vivo tumor growth, induces enlargement of i.t. blood vessels, and is associated with increased lung metastases. These results identify MT4-MMP as a new putative target to design anticancer strategies. [less ▲]

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See detailModulation of angiogenesis during adipose tissue development in murine models of obesity.
Vörös, Gabor; Maquoi, Erik ULg; Demeulemeester, Diego et al

in Endocrinology (2005), 146(10), 4545-4554

Development of vasculature and mRNA expression of 17 pro- or antiangiogenic factors were studied during adipose tissue development in nutritionally induced or genetically determined murine obesity models ... [more ▼]

Development of vasculature and mRNA expression of 17 pro- or antiangiogenic factors were studied during adipose tissue development in nutritionally induced or genetically determined murine obesity models. Subcutaneous (SC) and gonadal (GON) fat pads were harvested from male C57Bl/6 mice kept on standard chow [standard fat diet (SFD)] or on high-fat diet for 0-15 wk and from male ob/ob mice kept on SFD. Ob/ob mice and C57Bl/6 mice on high-fat diet had significantly larger SC and GON fat pads, accompanied by significantly higher blood content, increased total blood vessel volume, and higher number of proliferating cells. mRNA and protein levels of angiopoietin (Ang)-1 were down-regulated, whereas those of thrombospondin-1 were up-regulated in developing adipose tissue in both obesity models. Ang-1 mRNA levels correlated negatively with adipose tissue weight in the early phase of nutritionally induced obesity as well as in genetically determined obesity. Placental growth factor and Ang-2 expression were increased in SC adipose tissue of ob/ob mice, and thrombospondin-2 was increased in both their SC and GON fat pads. mRNA levels of vascular endothelial growth factor (VEGF)-A isoforms VEGF-B, VEGF-C, VEGF receptor-1, -2, and -3, and neuropilin-1 were not markedly modulated by obesity. This modulation of angiogenic factors during development of adipose tissue supports their important functional role in obesity. [less ▲]

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See detailRole of Gas-6 in adipogenesis and nutritionally induced adipose tissue development in mice.
Maquoi, Erik ULg; Vörös, Gabor; Carmeliet, Peter et al

in Arteriosclerosis, Thrombosis, and Vascular Biology (2005), 25(5), 1002-1007

OBJECTIVE: A potential role of growth arrest-specific gene 6 (Gas-6) in energy storage in adipose tissue was investigated in murine models of obesity. Gas-6 is a ligand for the Axl, C-Mer, and Sky family ... [more ▼]

OBJECTIVE: A potential role of growth arrest-specific gene 6 (Gas-6) in energy storage in adipose tissue was investigated in murine models of obesity. Gas-6 is a ligand for the Axl, C-Mer, and Sky family of tyrosine kinase receptors. METHODS AND RESULTS: Whereas Gas-6, C-Mer, and Sky were expressed in mature murine adipocytes, the expression of Axl was restricted to the stromal-vascular fraction, which includes pre-adipocytes. During the in vitro conversion of adipogenic 3T3-F442A cells into mature adipocytes, the expression of Gas-6 increased in undifferentiated confluent pre-adipocytes during a transient phase of growth arrest. On treatment of these cells with an adipogenic medium, Gas-6 expression decreased sharply, coinciding with expression of early adipocytes markers. This modulation was not observed in the nonadipogenic 3T3-C2 cells. The Gas-6 mRNA level was transiently downregulated during nutritionally induced expansion of adipose tissues in vivo. When kept on a standard diet, no significant difference in either total body weight or weight of gonadal or subcutaneous fat pads was observed between Gas-6 deficient and wild-type mice. On exposure to a high-fat diet, however, Gas-6-deficient mice had significantly less fat mass than their wild-type counterparts. CONCLUSIONS: Gas-6 enhances the accumulation of adipose tissue in diet-induced obese mice. [less ▲]

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See detailAnti-invasive, antitumoral, and antiangiogenic efficacy of a pyrimidine-2,4,6-trione derivative, an orally active and selective matrix metalloproteinases inhibitor
Maquoi, Erik ULg; Sounni, Nor Eddine ULg; Devy, L. et al

in Clinical Cancer Research : An Official Journal of the American Association for Cancer Research (2004), 10(12, Pt 1), 4038-4047

Purpose: The implication of matrix metalloproteinases (MMPs) in the major stages of cancer progression has fueled interest in the design of synthetic MMP inhibitors (MMPIs) as a novel anticancer therapy ... [more ▼]

Purpose: The implication of matrix metalloproteinases (MMPs) in the major stages of cancer progression has fueled interest in the design of synthetic MMP inhibitors (MMPIs) as a novel anticancer therapy. Thus far, drugs used in clinical trials are broad-spectrum MMPIs the therapeutic index of which proved disappointingly low. The development of selective MMPIs for tumor progression-associated MMPs is, thus, likely to offer improved therapeutic possibilities. Experimental Design: The anti-invasive capacity of a series of pyrimidine-trione derivatives was tested in vitro in a chemoinvasion assay, and the most potent compound was further evaluated in vivo in different human tumor xenograft models. The activity of this novel selective MMPI was compared with BB-94, a broad-spectrum inhibitor. Results: Ro-28-2653, an inhibitor with high selectivity for MMP-2, MMP-9, and membrane type 1 (MT1)-MMP, showed the highest anti-invasive activity in vitro. In vivo, Ro-28-2653 reduced the growth of tumors induced by the inoculation of different cell lines producing MMPs and inhibited the tumor-promoting effect of fibroblasts on breast adenocarcinoma cells. Furthermore, Ro-28-2653 reduced tumor vascularization and blocked angiogenesis in a rat aortic ring assay. In contrast, BB-94 up-regulated MMP-9 expression in tumor cells and promoted angiogenesis in the aortic ring assay. Conclusion: Ro-28-2653, a selective and orally bioavailable MMPI with inhibitory activity against MMPs expressed by tumor and/or stromal cells, is a potent antitumor and antiangiogenic agent. In contrast to broad-spectrum inhibitors, the administration of Ro-28-2653 was not associated with the occurrence of adverse side effects that might hamper the therapeutic potential of these drugs. [less ▲]

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See detailMembrane associated proteases and their inhibitors in tumour angiogenesis
Noël, Agnès ULg; Maillard, Catherine ULg; Rocks, Natacha ULg et al

in Journal of Clinical Pathology (2004), 57(6), 577-584

Cell surface proteolysis is an important mechanism for generating biologically active proteins that mediate a range of cellular functions and contribute to biological processes such as angiogenesis ... [more ▼]

Cell surface proteolysis is an important mechanism for generating biologically active proteins that mediate a range of cellular functions and contribute to biological processes such as angiogenesis. Although most studies have focused on the plasminogen system and matrix metalloproteinases ( MMPs), recently there has been an increase in the identification of membrane associated proteases, including serine proteases, ADAMs, and membrane-type MMPs (MT-MMPs). Normally, protease activity is tightly controlled by tissue inhibitors of MMPs (TIMPs) and plasminogen activator inhibitors (PAIs). The balance between active proteases and inhibitors is thought to determine the occurrence of proteolysis in vivo. High concentrations of proteolytic system components correlate with poor prognosis in many cancers. Paradoxically, high (not low) PAI-1 or TIMP concentrations predict poor survival in patients with various cancers. Recent observations indicate a much more complex role for protease inhibitors in tumour progression and angiogenesis than initially expected. As knowledge in the field of protease biology has improved, the unforeseen complexities of cell associated enzymes and their interaction with physiological inhibitors have emerged, often revealing unexpected mechanisms of action. [less ▲]

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See detailUp-regulation of vascular endothelial growth factor-A by active membrane-type 1 matrix metalloproteinase through activation of Src-tyrosine kinases
Sounni, Nor Eddine ULg; Roghi, C.; Chabottaux, Vincent et al

in Journal of Biological Chemistry (2004), 279(14), 13564-13574

Membrane-type 1 matrix metalloproteinase (MT1-MMP) and vascular endothelial growth factor ( VEGF) are two key molecules involved in pericellular proteolysis and cell proliferation during tumor growth and ... [more ▼]

Membrane-type 1 matrix metalloproteinase (MT1-MMP) and vascular endothelial growth factor ( VEGF) are two key molecules involved in pericellular proteolysis and cell proliferation during tumor growth and angiogenesis. Our previous data showed that MT1-MMP overexpression in human breast carcinoma MCF7 cells induced an up-regulation of VEGF expression. This effect was associated in vivo with accelerated tumor growth and angiogenesis. We now provide evidence that MT1-MMP overexpression specifically affected VEGF-A production and failed to influence that of other VEGF family members ( VEGF, B, C, D, or PlGF) or their receptors. The up-regulation of VEGF-A by MT1-MMP was related to an increased transcriptional activation rather than to a modification of mRNA stability. It was blocked by synthetic MMP inhibitors, TIMP2, but not TIMP-1 and abolished by a partial deletion of the catalytic domain or the cytoplasmic tail of MT1-MMP. Analysis of the signal transduction mechanisms demonstrated that MT1-MMP acts through a signaling pathway involving Src tyrosine kinases. Thus, our results provide new insight into the mechanisms of action of MT1-MMP during angiogenesis and suggest that the full enzymatic activity of MT1-MMP is required for a specific up-regulation of VEGF-A through an activation of Src tyrosine kinase pathways. [less ▲]

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See detailInfluence of membrane-bound tumor necrosis factor (TNF)-alpha on obesity and glucose metabolism
Vörös, Gabor; Maquoi, Erik ULg; Collen, Désiré et al

in Journal of Thrombosis and Haemostasis [=JTH] (2004), 2(3), 507-513

OBJECTIVES: To investigate the influence of transmembrane tumor necrosis factor (TNF)-alpha on adipose tissue development and insulin-mediated glucose metabolism. METHODS AND RESULTS: TNF-alpha and ... [more ▼]

OBJECTIVES: To investigate the influence of transmembrane tumor necrosis factor (TNF)-alpha on adipose tissue development and insulin-mediated glucose metabolism. METHODS AND RESULTS: TNF-alpha and lymphotoxin-alpha-deficient mice expressing non-cleavable transmembrane TNF-alpha (Tg-tmTNF-alpha) and TNF-alpha/lymphotoxin-alpha double knockout (control) mice were kept on high-fat diet for 15 weeks. The food intake and feeding efficiency of Tg-tmTNF-alpha mice were significantly higher compared with control mice. At the end of the study, Tg-tmTNF-alpha mice had a significantly higher total body weight, as well as subcutaneous and gonadal adipose tissue mass. Histological analysis revealed that the expression of Tg-tmTNF-alpha resulted in a significantly increased adipocyte area and blood vessel density. Plasma leptin levels correlated positively with adipose tissue mass. The plasma levels of total cholesterol and HDL-cholesterol were significantly increased and LDL-cholesterol levels significantly decreased in Tg-tmTNF-alpha mice. Fasting blood glucose and plasma insulin levels were not different between the two genotypes and intraperitoneal glucose and insulin tolerance tests did not show significant differences. CONCLUSIONS: Transmembrane TNF-alpha enhances adipose tissue formation without altering insulin-mediated glucose metabolism in mice with nutritionally induced obesity. [less ▲]

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See detailRegulation of membrane-type 1 matrix metalloproteinase activity by vacuolar H+-ATPases
Maquoi, Erik ULg; Peyrollier, K.; Noël, Agnès ULg et al

in Biochemical Journal (2003), 373(Pt 1), 19-24

Membrane-type I matrix metalloprotemase (MT1-MMP) is a key enzyme in normal development and malignant processes. The regulation of MT1-MMP activity on the cell surface is a complex process involving ... [more ▼]

Membrane-type I matrix metalloprotemase (MT1-MMP) is a key enzyme in normal development and malignant processes. The regulation of MT1-MMP activity on the cell surface is a complex process involving autocatalytic processing, tissue inhibitor of MMPs (TIMP) binding and constitutive internalization. However, the fate of internalized MT1-MMP is not known. Acidification of intracellular vacuolar compartments is essential for membrane trafficking, protein sorting and degradation. This acidification is controlled by vacuolar H+-ATPases, which can be selectively inhibited by bafilomycin-A(1). Here, we treated human tumour cell lines expressing MT1-MMP with bafilomycin-A(1), and analysed its effects on MT1-MMP activity, internalization and processing. We show that the activity of MT1-MMP on the cell surface is constitutively down-regulated through a vacuolar HI-ATPase-dependent degradation process. Blockade of this degradation caused the accumulation of TIMP-free active MT1-MMP molecules on the cell surface, although internalization was not affected. As a consequence of this impaired degradation, pro-MMP-2 activation was strongly enhanced. This study demonstrates that the catalytic activity of MT1-MMP on the cell surface is regulated through a vacuolar H+-ATPase-dependent degradation process. [less ▲]

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See detailEnhanced nutritionally induced adipose tissue development in mice with stromelysin-1 gene inactivation.
Maquoi, Erik ULg; Demeulemeester, Diego; Vörös, Gabor et al

in Thrombosis and Haemostasis (2003), 89(4), 696-704

To investigate a potential role of stromelysin-1 (MMP-3) in development of adipose tissue, 5 week old male MMP-3 deficient mice (MMP-3(-/-)) and wild-type (MMP-3(+/+)) controls were kept on a high fat ... [more ▼]

To investigate a potential role of stromelysin-1 (MMP-3) in development of adipose tissue, 5 week old male MMP-3 deficient mice (MMP-3(-/-)) and wild-type (MMP-3(+/+)) controls were kept on a high fat diet (HFD) for 15 weeks. MMP-3(-/-) mice were hyperphagic and gained more weight than the MMP-3(+/+) mice. At the time of sacrifice, the body weight of the MMP-3(-/-) mice was significantly higher than that of the MMP-3(+/+) mice, as was the weight of the isolated subcutaneous (SC) and gonadal (GON) fat deposits. Significant adipocyte hypertrophy was observed in the GON but not in the SC adipose tissue of MMP-3(-/-) mice. Fasting plasma glucose and cholesterol levels were comparable in both genotypes, whereas triglyceride levels were significantly lower in MMP-3(-/-) mice. Staining with an endothelial cell specific lectin revealed a significantly higher blood vessel density and larger total stained area in the GON adipose tissues of MMP-3(-/-) mice. Thus, in a murine model of nutritionally induced obesity, MMP-3 impairs adipose tissue development, possibly by affecting food intake and/or adipose tissue-related angiogenesis. [less ▲]

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See detailDeficiency of tissue inhibitor of matrix metalloproteinase-1 (TIMP-1) impairs nutritionally induced obesity in mice.
Lijnen, Roger; Demeulemeester, Diego; Van Hoef, B. et al

in Thrombosis and Haemostasis (2003), 89(2), 249-255

Tissue inhibitor of matrix metalloproteinase-1 deficient (TIMP-1(-/-)) mice and wild-type (TIMP-1(+/+)) controls were kept on a standard (SFD) or a high fat diet (HFD) for 15 weeks. At the time of ... [more ▼]

Tissue inhibitor of matrix metalloproteinase-1 deficient (TIMP-1(-/-)) mice and wild-type (TIMP-1(+/+)) controls were kept on a standard (SFD) or a high fat diet (HFD) for 15 weeks. At the time of sacrifice, TIMP-1(-/-) mice on HFD had a significantly lower body weight (29 +/- 1.5 versus 41 +/- 1.8 g, p <0.005), and significantly less subcutaneous (0.81 +/- 0.19 versus 1.78 +/- 0.21 g, p <0.05) and gonadal (0.87 +/- 0.17 versus 1.85 +/- 0.18 g, p <0.005) fat mass. These differences were much less pronounced for mice on SFD. On HFD but not on SFD, adipocyte diameters were significantly lower in the adipose tissue of TIMP-1(-/-) mice. Plasma leptin levels in TIMP-1(-/-) mice on HFD were significantly lower as compared to TIMP-1(+/-) mice, and strongly correlated with adipose tissue mass for both genotypes. Staining with an endothelial cell specific lectin revealed a significantly higher blood vessel density, larger stained area and vessel size in adipose tissue of TIMP-1(-/-) mice on HFD. This difference disappeared after normalization to the adipocyte number, suggesting that it does not represent a true enhancement of angiogenesis. Thus, in a murine model of nutritionally induced obesity, TIMP-1 promotes adipose tissue development. [less ▲]

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See detailDifferential expression of plasminogen activator inhibitor-1, tumor necrosis factor-alpha, TNF-alpha converting enzyme and ADAMTS family members in murine fat territories
Vörös, Gabor; Maquoi, Erik ULg; Collen, Désiré et al

in Biochimica et Biophysica Acta-Gene Structure and Expression (2003), 1625(1), 36-42

ur objective was to investigate expression of A disintegrin and metalloproteinase (ADAM) and ADAM proteins with a thrombospondin (TS) motif (ADAMTS) family members in adipose tissue of lean and obese mice ... [more ▼]

ur objective was to investigate expression of A disintegrin and metalloproteinase (ADAM) and ADAM proteins with a thrombospondin (TS) motif (ADAMTS) family members in adipose tissue of lean and obese mice. Five-week-old male mice were kept on standard chow (SFD) or on high fat diet (HFD) for 15 weeks, and subcutaneous (SC) and gonadal (GON) adipose tissue, as well as mature adipocytes and stromal–vascular (S–V) cells were harvested. mRNA levels of plasminogen activator inhibitor-1 (PAI-1), tumor necrosis factor-α (TNF-α), ADAM-17 (TACE or TNF-α converting enzyme), ADAMTS-1 and ADAMTS-8 were quantified in isolated adipose tissues and cell fractions, and during differentiation of murine preadipocytes. The HFD resulted in a significantly enhanced weight of isolated SC and GON fat pads, and in enhanced blood levels of glucose, cholesterol and PAI-1. ADAM-17, TNF-α, PAI-1, ADAMTS-1 and ADAMTS-8 mRNA were detected in both SC and GON adipose tissue of lean mice (SFD). In SC adipose tissue of obese mice (HFD), the expression of ADAM-17 and PAI-1 was enhanced and that of ADAMTS-1 reduced, whereas in GON adipose tissue expression of TNF-α was enhanced and that of ADAMTS-8 reduced. In lean and obese mice, expression of ADAM-17, ADAMTS-1 and ADAMTS-8 was higher in the S–V cell fraction than in mature adipocytes. During differentiation of murine 3T3-F442A preadipocytes, expression of ADAM-17 and ADAMTS-1 remained virtually unaltered, whereas that of ADAMTS-8 decreased as adipocytes matured. Several ADAM and ADAMTS family members are expressed in adipose tissue and during differentiation of preadipocytes. Modulation of their expression upon development of obesity is adipose tissue-dependent. [less ▲]

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