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The Metzincins are a superfamily of zinc-dependent endopeptidases associated with the regulation of the extracellular matrix (ECM). Their members include A Disintegrin and Metalloproteinase with Thrombospondin Motifs (ADAMTSs), A Disintegrin and Metalloproteinases (ADAMs), and the matrix metalloproteinases (MMPs). Metzincins exhibit diverse functions associated with both physiological and pathological states that include the proteolytic degradation of the ECM, regulation of various growth factors, cell surface receptors, and chemokines, and mediation of biological functions such as extravasation, survival, and proliferation. In pathological conditions such as cancer associated with chronic inflammation and multiple sclerosis associated with neurodegeneration, dysregulation of Metzincin activities are a hallmark of disease progression and severity. Hence, Metzincins are therapeutic targets for various disease states and research into optimal Metzincin inhibitor design is an ongoing exploit. / Includes bibliography. / Dissertation (Ph.D.)--Florida Atlantic University, 2020. / FAU Electronic Theses and Dissertations Collection

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CoordenaÃÃo de AperfeiÃoamento de Pessoal de NÃvel Superior / O cÃncer colorretal(CCR) à altamente prevalente nos paÃses mais ricos e industrializados. As metaloproteinases de matriz (MMPs) sÃo importantes enzimas que facilitam a invasÃo e disseminaÃÃo do tumor em vÃrios tipos de cÃncer, inclusive o colorretal. Os inibidores teciduais de metaloproteinases (TIMPs) sÃo os principais inativadores fisiolÃgicos destas enzimas. Este estudo avaliou a expressÃo de metaloproteinase-2 (MMP-2), metaloproteinase-14 (MMP-14) e inibidor tecidual de metaloproteinases-2 (TIMP-2) no cÃncer colorretal. O imunomarcador CD68 foi utilizado para caracterizar a natureza das cÃlulas mononucleadas do estroma. Amostras teciduais de 50 casos de colectomias, devido ao cÃncer colorretal no perÃodo de 2004 a 2010, obtidas dos arquivos do Departamento de Patologia e Medicina Legal (DPML), Faculdade de Medicina da Universidade Federal do Cearà (UFC), foram analisadas. Realizou-se tissue microarrays e a seguir imuno-histoquÃmica para avaliar a expressÃo de MMP-2, MMP-14 e TIMP-2 de acordo com os seguintes escores baseados em outros relatos: 0= sem imunomarcaÃÃo ou raras cÃlulas marcadas (<5%); 1 = discreta marcaÃÃo na maioria (> 50%) das cÃlulas tumorais ou cÃlulas mononucleares do estroma, ou moderada marcaÃÃo em uma minoria de cÃlulas (<50 %); 2 =marcaÃÃo moderada na maioria (> 50%) de cÃlulas tumorais ou cÃlulas mononucleares ou intensa marcaÃÃo em minoria de cÃlulas (<50%); 3 = marcaÃÃo intensa na maioria (> 50%) de cÃlulas tumorais ou cÃlulas mononucleares. Observou-se relaÃÃo entre a expressÃo aumentada de MMP-14 em mononucleares de tumor primÃrio e casos sem metÃstases linfonodais (MMP-14, escores 2 e 3/N0 : 23/24 = 95%; N1-N3: 14/20 = 70%, p = 0,0353). No entanto, nenhuma relaÃÃo significativa foi encontrada entre a expressÃo de MMP-14, MMP-2 e TIMP-2 nos tumores primÃrios em cÃlulas cancerosas ou mononucleares e outros parÃmetros clÃnico-patolÃgicos. A imunoexpressÃo de MMP-2 foi negativa nas cÃlulas neoplÃsicas, em tumores primÃrios (47/47=100%) e metastÃticos (12/12 = 100%). A imunorreatividade de MMP-14 em cÃlulas neoplÃsicas foi frequentemente positiva em tumores primÃrios (50/50 = 100%) e metastÃticos (7/8= 88%). Em mononucleares, a maioria dos quais macrÃfagos (corados pelo CD68), a expressÃo positiva de MMP-14 tambÃm predominou marcadamente, tanto em tumores primÃrios (46/47 = 98%) como em carcinomas metastÃticos (9/10 = 90%). A expressÃo de TIMP-2 em cÃlulas neoplÃsicas, discreta, ocorreu em 70% de tumores primÃrios (35/50 casos) e 100% dos metastÃticos (8/8). A imunocoloraÃÃo para TIMP-2 em macrÃfagos associados ao tumor (TAMs) foi ainda mais elevada do que nas cÃlulas neoplÃsicas. Em conclusÃo, a MMP-14 e TIMP-2 sÃo frequentemente expressas em carcinomas colo-retais em ambas localizaÃÃes anatÃmicas, principalmente nas metÃstases para linfonodos , sugerindo que estas proteases desempenham papel importante na invasÃo local e na progressÃo tumoral neste tipo de cÃncer. A predominÃncia destes marcadores nas cÃlulas mononucleares (sobretudo macrÃfagos) , claramente evidentes na positividade para a MMP-2, enfatiza a importÃncia do microambiente tumoral no desenvolvimento de neoplasias. / The colorectal cancer (RCC) is highly prevalent in richer and industrialized countries. The matrix metalloproteinases (MMPs) are regarded as important for facilitating tumor invasion and spread in various cancers, including colorectal. Tissue inhibitors of metalloproteinases (TIMPs) are the major physiological inhibitors of MMPs. The expression of metalloproteinase-2 (MMP-2), metalloproteinase 14 (MMP-14) and tissue inhibitor of metalloproteinases-2 ( TIMP-2) in colorectal cancer was assessed. CD68 immunostaininig was utilized to the characterization of mononuclear cells nature. Paraffin-embedded tissues from patients undergoing colectomy for colorectal cancer in the period 2004 to 2010, were selected from the files of the Department of Pathology and Forensic Medicine (DPML), Medical School , Federal University of Cearà (UFC). Tissue microarrays were performed and slides were obtained for immunohistochemical detection of the expression of MMP-2, MMP-14 and TIMP-2 and the tissue samples analyzed. The following scores were applied: 0 = no immunostaining or rare labeled cells (<5%), 1 = slight marking the majority (> 50%) of tumor cells or stromal mononuclear cells, or moderate marking in a minority of cells (<50%) 2 = moderate labeling in the majority (> 50%) of tumor or mononuclear cells or intense marking in the minority of cells (<50%) and 3 = intense labeling in the majority (> 50%) of tumor cells or mononuclear cells. In this study, the relationship between increased expression of MMP-14 in mononuclear primary tumor cells and cases without lymph node metastases (MMP-14, 2 and 3/N0 scores: 23/26 = 88%; N1-N3: 14/21 = 67%, p = 0.0353) was stablished . However, no significant relationship was found between the immunohistochemical expression of MMP-14, MMP-2 and TIMP-2 in primary tumors in cancer cells and mononuclear cells and other clinico-pathological parameters. The expression of MMP-2 were negative in the neoplastic cells both in primary tumors (47/47 = 100%) and in metastatic ones (12/12 = 100%). The immunoreactivity of MMP-14 in neoplastic cells in primary tumors was positive (50/50 = 100%) and in all cases except one of metastatic carcinoma (7/8 = 88%). In mononuclear cells, most of them characterized as macrophages (CD68 stained), MMP-14 positive expression also predominated markedly, both in primary tumors (46/47 = 98%) and in metastatic carcinomas (9/10 = 90%). TIMP-2 expression in neoplastic cells of primary tumors occurred in 35/50 cases (70%) and lymph nodes showed positive immunostaining in all cases (8/8 = 100%). In both sites there were no cases with high expression. The TIMP-2 immunoreactivity in tumour associated macrophages (TAMs) was even higher than in the neoplastic cells. In conclusion, MMP-14 and TIMP-2 are frequently expressed in colorectal carcinomas in both anatomical sites , mainly in lymph node metastasis, suggesting that these proteases play an important role in local invasion and tumor progression of these cancers. The predominance of these biomarkers in mononuclear cells, clearly evident in the positivity for MMP-2, emphasizes the importance of tumor microenvironment in the development of neoplasms.

The Matrix Metalloproteinase (MMP) family are conventionally considered as key enzymes contributing to cancer-cell invasion through remodelling of the extracellular matrix (ECM). In contrast, MMP-8 has been shown to exert an anti-cancer role. In normal breast, MMP-8 expression is restricted to tumour suppressor myoepithelial cells (MECs), which form the interface between glandular epithelium and the ECM. In ductal carcinoma in situ (DCIS), MECs are altered; a consistent change is up-regulation of αvβ6-integrin, which is associated with loss of suppressor activity. Preliminary observations indicated that there is also loss of MMP-8 expression in DCIS-MEC. The aim of this study is to investigate the impact of loss of MEC derived MMP-8 on MEC function and how this might modulate tumour progression. To generate a model of DCIS MEC, an αvβ6 over-expressing cell line (Myo-β6) was generated from normal MECs (Myo-Puro). These cells were found to lose MMP-8 expression. To dissect gain-of-function effect, MMP-8 was re-introduced into Myo-β6 (MMP-8 WT). A proteolytic inactive form of MMP-8 was used to dissect the dependence of function on proteolysis. In-vitro analysis demonstrated that MMP-8 WT but not inactive MMP-8 significantly up-regulates MEC adhesion (p=0.0001) and spread (p=0.0003) on ECM, but reduces migration towards ECM proteins including Collagen-I (p=0.006) and fibronectin (p=0.01). Furthermore MMP-8 WT results in reduced numbers of filopodia/retraction fibres (p=0.01) and reduced protrusion length (p=0.0001) on MEC cell surface. MMP-8 promotes the localisation of α6β4-integrin to hemidesmosomal adhesive structures (p=0.003), and inhibits MEC gelatinase (p=0.002) and TGF-β activity. Conversely, knock-down of endogenous MMP-8 in Myo-Puro MECs promotes migration and filopodia/retraction fibre formation (p=0.05), increases gelatinase activity (p=0.007) and TGF-β signalling. To analyse the paracrine effect of MEC-derived MMP-8 on breast cancer cell invasion, MDA MB 231 or SUM159 cells were co-cultured with modified Myo-β6 cells in Boyden chamber invasion assays. A significant reduction in breast cancer cell invasion was observed only in the presence of MMP-8 WT (p=0.004) but not with inactive MMP-8. In contrast, MMP-8 knock-down in Myo-Puro MECs significantly enhanced breast cancer cell invasion (p=0.001). In order to recapitulate the DCIS stromal micro-ecology, 3D-organotypic cultures were constructed. In these systems there was a significant reduction in invasion only in the presence of MMP-8 WT MECs (p<0.001). Conversely, in the absence of Myo-Puro-derived MMP-8 breast cancer cell invasion was significantly up-regulated (p=0.007). These results suggest that MMP-8 does contribute to MEC tumour suppressor function via mechanisms dependent upon its proteolytic activity. These data support the hypothesis that loss of MMP-8 may contribute to the progression of DCIS to invasive disease.

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