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See detailThe proteolytic activity of MT4-MMP is required for its proangiogenic and pro-metastatic promoting effects
Host, Lorin; Paye, Alexandra ULg; Detry, Benoît ULg et al

in International Journal of Cancer = Journal International du Cancer (2012), 131(7), 1537-1548

MT4-MMP expression in breast adenocarcinoma stimulates tumor growth and metastatic spreading to the lung. However whether these pro-tumorigenic and pro-metastatic effects of MT4-MMP are related to a ... [more ▼]

MT4-MMP expression in breast adenocarcinoma stimulates tumor growth and metastatic spreading to the lung. However whether these pro-tumorigenic and pro-metastatic effects of MT4-MMP are related to a proteolytic action is not known yet. Through site directed mutagenesis MT4-MMP has been inactivated in cancer cells through Glutamic acid 249 substitution by Alanine in the active site. Active MT4-MMP triggered an angiogenic switch at day 7 after tumor implantation and drastically accelerated subcutaneous tumor growth as well as lung colonization in RAG -/- mice. All these effects were abrogated upon MT4-MMP inactivation. In sharp contrast to most MMPs being primarily of stromal origin, we provide evidence that tumor-derived MT4-MMP, but not host-derived MT4-MMP contributes to angiogenesis. A genetic approach using MT4-MMP-deficient mice revealed that the status of MT4-MMP produced by host cells did not affect the angiogenic response. Despite of this tumor intrinsic feature, to exert its tumor promoting effect, MT4-MMP requires a permissive microenvironment. Indeed, tumor-derived MT4-MMP failed to circumvent the lack of an host angio-promoting factor such as lasminogen activator inhibitor (PAI-1). Overall, our study demonstrates the key contribution of MT4-MMP catalytic activity in the tumor compartment, at the interface with host cells. It identifies MT4-MMP as a key intrinsic tumor cell determinant that contributes to the elaboration of a permissive microenvironment for metastatic dissemination [less ▲]

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See detailInduction of membrane-type matrix metalloproteinase 1 (MT1-MMP) expression in human fibroblasts by breast adenocarcinoma cells.
Polette, M.; Gilles, Christine ULg; Marchand, V. et al

in Clinical & Experimental Metastasis (1997), 15(2), 157-63

Membrane-type matrix metalloproteinase 1 (MT1-MMP) has been recently described as an activator of proMMP-2 (MMP-2) which is involved in tumor invasion. We have shown by in situ hybridization that MT1-MMP ... [more ▼]

Membrane-type matrix metalloproteinase 1 (MT1-MMP) has been recently described as an activator of proMMP-2 (MMP-2) which is involved in tumor invasion. We have shown by in situ hybridization that MT1-MMP is produced by stromal cells in close contact to preinvasive and invasive tumor cells of breast carcinomas. Of particular interest was the observation that some fibroblasts express this enzyme in focal areas in preinvasive lesions, suggesting that particular tumor cells may stimulate fibroblasts to produce MT1-MMP. We have therefore compared the ability of two different breast cancer cell lines, one non-invasive (MCF7) and one invasive (MDA-MB-231) to stimulate MT1-MMP production in human fibroblasts with consequent proMMP-2-activation. The MDA-MB-231 conditioned medium induced MT1-MMP mRNAs in human fibroblasts and a parallel activation of proMMP-2 whereas MCF7 conditioned medium did not have any effect. These results suggest the existence of soluble factor(s) secreted by invasive or some preinvasive breast tumor cells which stimulate fibroblasts to produce and activate MMPs, and emphasize the cooperation between cancer and stromal cells in tumor invasion. [less ▲]

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See detailImplication of collagen type I-induced membrane-type 1-matrix metalloproteinase expression and matrix metalloproteinase-2 activation in the metastatic progression of breast carcinoma.
Gilles, Christine ULg; Polette, M.; Seiki, M. et al

in Laboratory Investigation : Journal of Technical Methods & Pathology (1997), 76(5), 651-60

We have previously demonstrated that fibroblasts and invasive human breast carcinoma (HBC) cells specifically activate matrix metalloproteinase-2 (MMP-2) when cultured on 3-dimensional gels of type I ... [more ▼]

We have previously demonstrated that fibroblasts and invasive human breast carcinoma (HBC) cells specifically activate matrix metalloproteinase-2 (MMP-2) when cultured on 3-dimensional gels of type I collagen but not a range of other substrates. We show here the constitutive expression of membrane-type 1 (MT1)-MMP in both fibroblasts, and invasive HBC cell lines, that have fibroblastic attributes presumably acquired through an epithelial-to-mesenchymal transition (EMT). Treatment with collagen type I increased the steady-state MT1-MMP mRNA levels in these cells but did not induce either MT1-MMP expression or MMP-2 activation in noninvasive breast carcinoma cell lines, which retain epithelial features. Basal MT3-MMP mRNA expression had a pattern similar to that of MT1-MMP but was not up-regulated by collagen. MT4-MMP mRNA was seen in both invasive and noninvasive HBC cell lines and was also not collagen-regulated, and MT2-MMP mRNA was not detected in any of the HBC cell lines tested. These data support a role for MT1-MMP in the collagen-induced MMP-2-activation seen in these cells. In situ hybridization analysis of archival breast cancer specimens revealed a close parallel in expression of both collagen type I and MT1-MMP mRNA in peritumoral fibroblasts, which was correlated with aggressiveness of the lesion. Relatively high levels of expression of both mRNA species were seen in fibroblasts close to invasive tumor nests and, although only focally, in certain areas close to preinvasive tumors. These foci may represent hot spots for local degradation and invasive progression. Collectively, these results implicate MT1-MMP in collagen-stimulated MMP-2 activation and suggest that this mechanism may be employed in vivo by both tumor-associated fibroblasts and EMT-derived carcinoma cells to facilitate increased invasion and/or metastasis. [less ▲]

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See detailMT-MMP Expression and localisation in human lung and breast cancers
Polette, M.; Nawrocki-Raby, B.; Gilles, Christine ULg et al

in Virchows Archiv : An International Journal of Pathology (1996), 428(1), 29-35

Thirteen primary pulmonary squamous cell carcinomas, 4 specimens of normal lung from around tumours, 4 benign proliferations of the mammary gland and 16 breast carcinomas were analysed by in situ ... [more ▼]

Thirteen primary pulmonary squamous cell carcinomas, 4 specimens of normal lung from around tumours, 4 benign proliferations of the mammary gland and 16 breast carcinomas were analysed by in situ hybridisation. Northern blot and immunohistochemistry for the expression of a recently described metalloproteinase (MMP), the MT-MMP (membrane-type matrix metalloproteinase). This MT-MMP can activate gelatinase A, involved in the degradation of basement membranes. In situ hybridisation revealed MT-MMP transcripts distributed in both tumour and stromal cells in squamous cell lung cancers, whereas these mRNAs were principally detected in stromal cells in close contact to tumour clusters in breast carcinomas and in lung adenocarcinomas. Northern blot analysis showed a parallel expression of MT-MMP and gelatinase A transcripts in both lung and breast cancers. Immunohistochemistry displayed a more extensive distribution of MT-MMP in pulmonary and mammary carcinomas with numerous labelled preinvasive and infiltrating cancer cells and stromal cells near the tumour cells. The large degree of expression of MT-MMP in these cancers indicates a potential role of this enzyme in tumour progression. The finding of MT-MMP transcripts in stromal cells in the vicinity of lung and breast tumour cells emphasises the cooperation between these cells and cancer cells for the expression of MT-MMP and in tumour invasion in vivo. [less ▲]

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See detailStimulation of the 92-Kd Type Iv Collagenase Promoter and Enzyme Expression in Human Melanoma Cells
Lauricella-Lefebvre, M. A.; Castronovo, Vincenzo ULg; Sato, H. et al

in Invasion & Metastasis (1993), 13(6), 289-300

The 92-kD type IV collagenase is a member of the metalloproteinase family which degrades type IV collagen, a major component of basement membrane and is involved in tumor invasion and metastasis. The ... [more ▼]

The 92-kD type IV collagenase is a member of the metalloproteinase family which degrades type IV collagen, a major component of basement membrane and is involved in tumor invasion and metastasis. The promoter and adjacent regulatory sequences of the 92-kD type IV collagenase have been identified previously and three cis-acting elements homologous to the binding sites for AP-1, NF-KB and SP-1 proteins contributed to induction of the promoter activity by 12-O-tetradecanoylphorbol 13-acetate (TPA) and tumor necrosis factor (TNF-alpha) in HT1080 cells. To date, no direct correlation between promoter activity and expression of the 92-kD type IV collagenase has been reported in normal or cancer cells. In this study, the effects of the transcriptional stimulation of the 92-kD type IV collagenase gene on the expression of the enzyme in human A2058 melanoma cells was analyzed by zymography experiments. Quantitative immunoblots using a monoclonal antibody that recognized specifically and exclusively the 92-kD type IV collagenase, confirmed that the 92-kD gelatinase was 92-kD type IV collagenase. Stimulation of the promoter activity resulted in increased gelatinase activity in the culture medium of A2058 cells. A direct correlation between TPA- and TNF-alpha-mediated promoter stimulation of the 92-kD type IV collagenase gene and its expression was also demonstrated in the human fibrosarcoma HT1080 cells. Interleukin-1 alpha failed to induce 92-kD gene promoter activity and type IV collagenase expression in melanoma and fibrosarcoma cell lines. Our data demonstrated that TPA- and TNF-alpha-induced 92-kD type IV collagenase promoter stimulation leads to a proportional increase of enzyme expression and secretion and thus could contribute to the activation of the invasive phenotype. [less ▲]

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