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  • MT1-MMP  (4)
  • matrix metalloproteinase  (2)
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  • 1
    ISSN: 1573-7276
    Schlagwort(e): EMT ; human breast cancer ; MMP-2 activation ; MT1-MMP ; invasion ; vimentin
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract We have previously reported that human breast carcinoma (HBC) cell lines expressing the mesenchymal intermediate filament protein vimentin (VIM+) are highly invasive in vitro, and highly metastatic in nude mice when compared to their VIM– counterparts. Since only VIM+ cell lines can be induced to activate matrix metalloproteinase-2 (MMP-2) upon stimulation with Concanavalin A (Con A), we have examined here membrane type 1 MMP (MT1-MMP), a cell surface activator of MMP-2. Northern analysis reveals baseline expression of MT1-MMP in five of the six VIM+ cell lines studied (MDA-MB-231, MDA-MB-435, BT-549, Hs578T, MCF-7ADR), each of which showed variable activation of exogenous MMP-2 after treatment with Con A. In contrast, the four VIM–, poorly invasive HBC cell lines studied (MCF-7, T47D, MDA-MB 468, ZR-75-1) lacked baseline MT1-MMP mRNA expression, and showed no induction of either MT1-MMP expression or MMP-2-activation with Con A. Such differential MT1-MMP expression was confirmed in vivo using in situ hybridization analysis of nude mouse tumor xenografts of representative cell lines. Western analysis of the MDA-MB-231 cells revealed baseline membrane expression of a 60 kDa species, which was strongly induced by Con A treatment along with a weaker band co-migrating with that from MT1-MMP-transfected COS-1 cells (63 kDa), presumably representing latent MT1-MMP. MT1-MMP immunofluorescence strongly decorated Con A-stimulated MDA-MB-231 cells in a manner consistent with membranous staining, but did not decorate the unstimulated MDA-MB-231 cells or MCF-7 cells under either condition. Collectively, the results suggest the constitutive production of active MT1-MMP which is unavailable for either MMP-2 activation or immuno-decoration until Con A treatment. Since VIM expression arises by virtue of the so-called epithelial to mesenchymal transition (EMT) in invasive embryonic epithelia, we propose that this represents a major metastasis mechanism in breast carcinomas. MT1-MMP on the surface of such ÔfibroblastoidÕ carcinoma cells may mediate a paracrine loop for the utilization of stromally produced MMP-2, and contribute to the poorer survival associated with VIM+ breast carcinomas.
    Materialart: Digitale Medien
    Standort Signatur Einschränkungen Verfügbarkeit
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  • 2
    ISSN: 1573-7276
    Schlagwort(e): matrix metalloproteinase ; MDCK cells ; metastasis ; MT1-MMP ; TIMP-1
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract This article discusses the transformation of epithelial Madin-Durby canine kidney (MDCK) cells with v-src induced expression of membrane-type 1-matrix metalloproteinase (MT1-MMP) and metastatic growth in nude mice (Kadono Y et al., Cancer Res 1998; 58: 2240–44). To analyze genes associated with invasive phenotype of v-src MDCK cells, mRNA differential display was performed between control and the transformed cells. A clone 12′, the expression of which was clearly up-regulated in the transformed cells, encoded a protein 81% homologous to human tissue inhibitor of matrix metalloproteinases-1 (TIMP-1). Northern hybridization showed that only MT1-MMP expression was enhanced and other matrix metalloproteinases (MMPs) were undetectable or rather repressed in the transformed cells. Proteolytic activity against type I gelatin was observed in v-src MDCK cells, which was inhibited only by TIMP-2 but not by TIMP-1. MDCK cells stably transfected with the MT1-MMP gene also degraded gelatin, which was selectively inhibited by TIMP-2. These results suggest that MT1-MMP, the expression of which is induced in v-src MDCK cells, degrades extracellullar matrix by itself rather than through the activation of progelatinase A, which in turn contributes to the metastasis of the transformed cells.
    Materialart: Digitale Medien
    Standort Signatur Einschränkungen Verfügbarkeit
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  • 3
    ISSN: 1573-7276
    Schlagwort(e): activation of proMMP-2 ; lymph node metastasis ; matrix metalloproteinase ; membrane-type matrix metalloproteinase ; oral squamous cell carcinoma ; tissue inhibitor of metalloproteinases
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract We measured the production levels of seven different matrix metalloproteinases (MMP-1, 2, 3, 7, 8, 9 and 13) and two tissue inhibitors of metalloproteinases (TIMP-1 and 2) in the homogenates of human oral squamous cell carcinomas and control normal squamous epithelia by the corresponding sandwich enzyme immunoassay systems. The levels of MMP-1, 2, 3, 8, 9, 13 and TIMP-1 were significantly higher in the carcinoma samples than in the control. Among them, only the production level of MMP-2 was significantly higher in the carcinomas with cervical lymph node metastasis than in those without metastasis (P 〈 0.05). Gelatin zymography demonstrated that activation ratio of the zymogen of MMP-2 (proMMP-2) is significantly higher in the carcinomas with lymph node metastasis than in those without metastasis (P 〈 0.05) or normal control (P 〈 0.01). Quantitative RT-PCR for membrane-types 1, 2 and 3 MMPs (MT1, 2 and 3-MMPs), which activate proMMP-2 in vitro, demonstrated that MT1-MMP is predominantly expressed in the carcinoma tissues, and the expression level is significantly higher in the carcinomas with lymph node metastasis than in those without metastasis (P 〈 0.05) or the control samples (P 〈 0.05). Although MT2-MMP and MT3-MMP were detected in approximately 30% of the carcinoma cases, their expression levels were extremely lower compared with that of MT1-MMP. There was a direct correlation between the MT1-MMP expression level and proMMP-2 activation ratio (r = 0.62, P 〈 0.01). In situ hybridization and immunohistochemistry indicated that carcinoma cells and stromal cells adjacent to carcinoma cell nests express MT1-MMP transcripts and protein. MMP-2 and TIMP-2 were also immunolocalized to the carcinoma cells in the carcinoma samples. By in situ zymography, gelatinolytic activity was demonstrated in the carcinoma cell nests and abolished by the treatment with an MMP inhibitor, BB94. These results suggest that among seven different MMPs, the production of proMMP-2 and its activation mediated by MT1-MMP play an important role in the cervical lymph node metastasis of the human oral squamous cell carcinomas.
    Materialart: Digitale Medien
    Standort Signatur Einschränkungen Verfügbarkeit
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  • 4
    ISSN: 1573-7276
    Schlagwort(e): invasion ; MT1-MMP ; promoter ; transformant ; v-src
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract Membrane-type 1 matrix metalloproteinase (MT1-MMP) expressed in tumor cells is believed to be important for the pericellular degradation of extracellular matrices during invasion and metastasis. To analyze the mechanism by which MT1-MMP becomes expressed in cancer cells, we assessed the MT1-MMP promoter region for the presence of cis-acting promoter elements that support transcription in transformed cells. Our tumor model consisted of Madin–Darby canine kidney (MDCK) cells transformed by v-src (src4 cells). MT1-MMP mRNA was only faintly detected in parental cells but was strongly expressed in the src4 cells. In parallel, src4 cells invaded into collagen gels, whereas MDCK cells did not. When MDCK and src4 cells were transiently transfected with a plasmid containing of −3000 to −99 nt from the upstream region of the MT1-MMP gene, the promoter activity was 2.6-fold higher in src4 cells than in MDCK cells. Furthermore, the region between −399 and −356 nt was found to contain the src4-specific enhancer element(s). Tandem Sp1 binding sites were also found to be essential in promoting transcription. An Egr-1 site that partially overlaps with the Sp1 sites was found to cooperate with the src4-specific enhancer and to also contribute weakly to the basal promoter activity. The presence of transcription factors that bind to the src4-specific enhancer site was detected by mobility-shift assays in src4 cell nuclear extracts but only weakly in MDCK extracts. Thus, we have identified a novel enhancer element that acts specifically in the transformed cells to enhance MT1-MMP expression.
    Materialart: Digitale Medien
    Standort Signatur Einschränkungen Verfügbarkeit
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  • 5
    ISSN: 1573-7276
    Schlagwort(e): MT1-MMP ; Mts1 ; MDCK ; tumor invasion ; tubulogenesis
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract Madin-Darby canine kidney (MDCK) epithelial cells form branching tubules in three-dimensional collagen gel in the presence of hepatocyte growth factor (HGF). Membrane type-1 matrix metalloproteinase (MT1-MMP), expression of which was induced by collagen-gel culture, was demonstrated to play an essential role in tubular formation (Y. Kadono et al. Biochem Biophys Res Commun 1998; 251: 681–7 [13]). Oncogenic transformation of MDCK cells by erbB2 and v-src induced expression of MT1-MMP, loss of cell-cell adhesion and scattered invasion into collagen gel. mRNA differential display and Northern hybridization identified metastasis-associated mts1 as one of the genes co-induced with MT1-MMP by oncogenic transformation or collagen-gel culture of MDCK cells. Expression of antisense RNA to mts1 in MDCK cells interfered with the extension of tubules into the collagen gel, however, it did not affect the morphological changes induced by HGF in culture on plastic dishes. ErbB2-transformant transfected with mts1 antisense construct, which showed unaltered morphology in culture on plastic dishes, did not scatter into collagen gel but formed aggregates. These results suggested that Mts1 contributes not only to tumor invasion but also to kidney tubulogenesis in cooperation with MT1-MMP. The coordinated action of MT1-MMP and Mts1, which is responsible for the highly invasive properties of mesenchymal cells, may be involved in epithelial tubulogenesis and invasion of malignant carcinoma cells.
    Materialart: Digitale Medien
    Standort Signatur Einschränkungen Verfügbarkeit
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