Expression and localization of membrane-type-1 matrix metalloproteinase, CD 44, and laminin-5gamma2 chain during colorectal carcinoma tumor progression

Laminin 332 in cancer: When the extracellular matrix turns signals from cell anchorage to cell movement

Laminin 332 is crucial in the biology of epithelia. This large extracellular matrix protein consists of the heterotrimeric assembly of three subunits - α3, β3, and γ2 - and its multifunctionality relies on a number of extracellular proteolytic processing events. Laminin 332 is central to normal epithelium homeostasis by sustaining cell adhesion, polarity, proliferation, and differentiation. It also supports a major function in epithelial tissue formation, repair, and regeneration by buttressing cell migration and survival and basement membrane assembly. Interest in this protein increased after the discovery that its expression is perturbed in tumor cells, cancer-associated fibroblasts, and the tumor microenvironment. This review summarizes current knowledge regarding the established involvement of the laminin 332 γ2 chain in tumor invasiveness and discusses the role of its α3 and β3 subunits.

Basal localization of MT1-MMP is essential for epithelial cell morphogenesis in 3D collagen matrix

The membrane-anchored collagenase membrane type 1 matrix metalloprotease (MT1-MMP) has been shown to play an essential role during epithelial tubulogenesis in 3D collagen matrices; however, its regulation during tubulogenesis is not understood. Here, we report that degradation of collagen in polarized epithelial cells is post-translationally regulated by changing the localization of MT1-MMP from the apical to the basal surface. MT1-MMP predominantly localizes at the apical surface in inert polarized epithelial cells, whereas treatment with HGF induced basal localization of MT1-MMP followed by collagen degradation. The basal localization of MT1-MMP requires the ectodomains of the enzyme because deletion of the MT-loop region or the hemopexin domain inhibited basal localization of the enzyme. TGFβ is a well-known inhibitor of tubulogenesis and our data indicate that its mechanism of inhibition is, at least in part, due to inhibition of MT1-MMP localization to the basal surface. Interestingly, however, the effect of TGFβ was found to be bi-phasic: at high doses it effectively inhibited basal localization of MT1-MMP, whereas at lower doses tubulogenesis and basal localization of MT1-MMP was promoted. Taken together, these data indicate that basal localization of MT1-MMP is a key factor promoting the degradation of extracellular matrix by polarized epithelial cells, and that this is an essential part of epithelial morphogenesis in 3D collagen.

Three-dimensional culture of sebaceous gland cells revealing the role of prostaglandin E2-induced activation of canonical Wnt signaling

BACKGROUND

Prostaglandin E2 (PGE2) is a proinflammatory mediator and activates the canonical Wnt-β-catenin signaling pathway in hematopoietic stem cells. The SZ95 cell line was established from human sebaceous gland cells and is studied as a model system for these cells. Given that 2D culture of SZ95 cells does not recapitulate the organization of sebaceous glands in situ, we developed a 3D culture system for these cells and examined the effects of PGE2 on cell morphology and function.

RESULTS

SZ95 cells maintained in 3D culture formed organoids that mimicked the organization of sebaceous glands in situ, including the establishment of a basement membrane. Organoids exposed to PGE2 were larger and adopted a more complex organization compared with control organoids. PGE2 activated the canonical Wnt signaling pathway as well as increased cell viability and proliferation, mitochondrial metabolism, and lipid synthesis in the organoids.

CONCLUSIONS

Culture of SZ95 cells in 3D culture system recapitulates the structure and susceptibility to PGE2 of sebaceous glands in situ and should prove useful for studies of the response of these glands to inflammation and other environmental stressors. Our results also implicate PGE2-induced activation of canonical Wnt signaling pathway in regulation of the morphology,proliferation, and function of "semi-vivo" sebaceous glands.

Tumor suppressive microRNA-218 inhibits cancer cell migration and invasion through targeting laminin-332 in head and neck squamous cell carcinoma

Recent our microRNA (miRNA) expression signature revealed that expression of microRNA-218 (miR-218) was reduced in cancer tissues, suggesting a candidate of tumor suppressor in head and neck squamous cell carcinoma (HNSCC). The aim of this study was to investigate the functional significance of miR-218 and its mediated moleculer pathways in HNSCC. Restoration of miR-218 in cancer cells led to significant inhibition of cell migration and invasion activities in HNSCC cell lines (FaDu and SAS). Genome-wide gene expression analysis of miR-218 transfectants and in silico database analysis showed that focal adhesion pathway was a promising candidate of miR-218 target pathways. The laminins are an important and biologically active part of the basal lamina, the function of that are various such as influencing cell differentiation, migration and adhesion as well as proliferation and cell survival. Interestingly, all components of laminin-332 (LAMA3, LAMB3 and LAMC2) are listed on the candidate genes in focal adhesion pathway. Furthermore, we focused on LAMB3 which has a miR-218 target site and gene expression studies and luciferase reporter assays showed that LAMB3 was directly regulated by miR-218. Silencing study of LAMB3 demonstrated significant inhibition of cell migration and invasion. In clinical specimens with HNSCC, the expression levels of laminin-332 were significantly upregulated in cancer tissues compared to adjacent non-cancerous tissues. Our analysis data showed that tumor suppressive miR-218 contributes to cancer cell migration and invasion through regulating focal adhesion pathway, especially laminin-332. Tumor suppressive miRNA-mediated novel cancer pathways provide new insights into the potential mechanisms of HNSCC oncogenesis.

The liberation of CD44 intracellular domain modulates adenoviral vector transgene expression

The success of gene therapy in the ocular environment is partly due to the presence of hyaluronan in vitreous. Here we explore the mechanism of hyaluronan-mediated enhancement of adenoviral vector transgene expression. Introduction of hyaluronan receptor CD44 into CD44-negative cells followed by transduction in the presence of vitreous with an adenoviral vector containing an IL-12-coding transgene increases IL-12 secretion. We demonstrate that sequential CD44 proteolysis is responsible for hyaluronan-mediated enhancement. Metalloproteinase or γ-secretase inhibitors decrease adenoviral-mediated transgene expression. Deletion of these proteolytic sites in CD44 also inhibits transgene expression. Expression of CD44 with a mutation to prevent phosphorylation of serine 325 inhibits the response to vitreous. Expression of the CD44 intracellular domain enhances transgene expression in the absence of vitreous. CD44-mediated enhancement of gene expression was observed with vectors using different promoters and appears because of an increase in mRNA production, not because of an increase in vector transduction as determined by quantitative RT-PCR and quantitative PCR, respectively. These data fit a model where the interaction of hyaluronan in vitreous and CD44 modulates transgene expression by initiating CD44 proteolysis and release of the cytoplasmic domain, resulting in increased transgene transcription.

The Wnt/planar cell polarity protein-tyrosine kinase-7 (PTK7) is a highly efficient proteolytic target of membrane type-1 matrix metalloproteinase: implications in cancer and embryogenesis

PTK7 is an essential component of the Wnt/planar cell polarity (PCP) pathway. We provide evidence that the Wnt/PCP pathway converges with pericellular proteolysis in both normal development and cancer. Here, we demonstrate that membrane type-1 matrix metalloproteinase (MT1-MMP), a key proinvasive proteinase, functions as a principal sheddase of PTK7. MT1-MMP directly cleaves the exposed PKP(621)↓LI sequence of the seventh Ig-like domain of the full-length membrane PTK7 and generates, as a result, an N-terminal, soluble PTK7 fragment (sPTK7). The enforced expression of membrane PTK7 in cancer cells leads to the actin cytoskeleton reorganization and the inhibition of cell invasion. MT1-MMP silencing and the analysis of the uncleavable L622D PTK7 mutant confirm the significance of MT1-MMP proteolysis of PTK7 in cell functions. Our data also demonstrate that a fine balance between the metalloproteinase activity and PTK7 levels is required for normal development of zebrafish (Danio rerio). Aberration of this balance by the proteinase inhibition or PTK7 silencing results in the PCP-dependent convergent extension defects in the zebrafish. Overall, our data suggest that the MT1-MMP-PTK7 axis plays an important role in both cancer cell invasion and normal embryogenesis in vertebrates. Further insight into these novel mechanisms may promote understanding of directional cell motility and lead to the identification of therapeutics to treat PCP-related developmental disorders and malignancy.

Navigating ECM barriers at the invasive front: the cancer cell-stroma interface

A seminal event in cancer progression is the ability of the neoplastic cell to mobilize the necessary machinery to breach surrounding extracellular matrix barriers while orchestrating a host stromal response that ultimately supports tissue-invasive and metastatic processes. With over 500 proteolytic enzymes identified in the human genome, interconnecting webs of protease-dependent and protease-independent processes have been postulated to drive the cancer cell invasion program via schemes of daunting complexity. Increasingly, however, a body of evidence has begun to emerge that supports a unifying model wherein a small group of membrane-tethered enzymes, termed the membrane-type matrix metalloproteinases (MT-MMPs), plays a dominant role in regulating cancer cell, as well as stromal cell, traffic through the extracellular matrix barriers assembled by host tissues in vivo. Understanding the mechanisms that underlie the regulation and function of these metalloenzymes as host cell populations traverse the dynamic extracellular matrix assembled during neoplastic states should provide new and testable theories regarding cancer invasion and metastasis.

Proteolytic and non-proteolytic roles of membrane type-1 matrix metalloproteinase in malignancy

This manuscript provides an overview of the dynamic interactions which play an important role in regulating cancer cell functions. We describe and discuss, primarily, those interactions which involve membrane type-1 matrix metalloproteinase (MT1-MMP), its physiological inhibitor tissue inhibitor of metalloproteinases-2 (TIMP-2), furin-like proprotein convertases and the low density lipoprotein-related protein 1 (LRP1) signaling scavenger receptor. The interaction among these cellular proteins controls the efficiency of the activation of MT1-MMP and the unorthodox intracellular signaling which is generated by the catalytically inert complex of MT1-MMP with TIMP-2 and which plays a potentially important role in the migration of cancer cells. Our in-depth understanding of these cellular mechanisms may provide the key to solving the puzzling TIMP-2 paradox. This unsolved paradox arises from the fact that TIMP-2 is a powerful inhibitor of MMPs including MT1-MMP, but at the same time high levels of TIMP-2 positively correlate with an unfavorable prognosis in cancer patients. Solving the TIMP-2 paradox may lead to solving a similar PAI-1 paradox and produce a clearer understanding of the biochemical mechanisms which control the functionality of the urokinase-type plasminogen activator*urokinase receptor*plasminogen activator inhibitor type-1 (uPAR*uPA*PAI-1) system in cancer.

Matrix metalloproteinases, T cell homing and beta-cell mass in type 1 diabetes

The pathogenesis of type 1 diabetes begins with the activation of autoimmune T killer cells and is followed by their homing into the pancreatic islets. After penetrating the pancreatic islets, T cells directly contact and destroy insulin-producing beta cells. This review provides an overview of the dynamic interactions which link T cell membrane type-1 matrix metalloproteinase (MT1-MMP) and the signaling adhesion CD44 receptor with T cell transendothelial migration and the subsequent homing of the transmigrated cells to the pancreatic islets. MT1-MMP regulates the functionality of CD44 in diabetogenic T cells. By regulating the functionality of T cell CD44, MT1-MMP mediates the transition of T cell adhesion to endothelial cells to the transendothelial migration of T cells, thus, controlling the rate at which T cells home into the pancreatic islets. As a result, the T cell MT1-MMP-CD44 axis controls the severity of the disease. Inhibition of MT1-MMP proteolysis of CD44 using highly specific and potent synthetic inhibitors, which have been clinically tested in cancer patients, reduces the rate of transendothelial migration and the homing of T cells. Result is a decrease in the net diabetogenic efficiency of T cells and a restoration of beta cell mass and insulin production in NOD mice. The latter is a reliable and widely used model of type I diabetes in humans. Overall, existing experimental evidence suggests that there is a sound mechanistic rationale for clinical trials of the inhibitors of T cell MT1-MMP in human type 1 diabetes patients.

Metaloproteinases 1 e 7 e câncer colorretal

A metaloproteinase-1 (MMP-1) e a metaloproteinase-7 (MMP-7) são proteinases da matriz extracelular (MEC), zinco-dependentes, envolvidas no processo inicial da carcinogênese por permitirem a invasão tumoral na célula e promover o processo de metastatização. O polimorfismo dessas proteinases tem sido estudado recentemente com o objetivo de validar susa expressão e/ou atividade como marcador prognóstico. Evidências cumulativas revelam importante papel das MMP's 1 e 7 em diferentes fases da carcinogênese. A MMP-1 tem ação direta sobre a principal proteína da MEC, que é o colágeno do tecido intersticial conectivo. Sua expressão aumentada neste tecido pode indicar alto potencial de disseminação tumoral em diferentes tipos de câncer, incluindo o colorretal. A associação deste aumento da expressão também parece ser verdadeira para a MMP-7.

Cyclooxygenase-2 expression correlates with membrane-type-1 matrix metalloproteinase expression in colorectal cancer tissue

PURPOSE

Elevated expression of cyclooxygenase-2 has been found in colorectal cancer. One of the mechanisms through which cyclooxygenase-2 affects tumorigenesis is through its overexpression, which leads to increased invasiveness of cancer cells. A crucial step in this pathway is thought to be the induction of membrane-type-1 matrix metalloproteinase, which activates matrix metalloproteinase-2. However, to date there have been few clinicopathologic studies concerning cyclooxygenase-2-mediated invasiveness in human colorectal cancer tissues.

METHODS

We performed immunohistochemical analysis of the respective antigens on colorectal cancer specimens obtained by surgical resections from 96 patients with colorectal cancer.

RESULTS

Cyclooxygenase-2 and membrane-type-1 matrix metalloproteinase expression was positive exclusively in cancer cells in 88 cases (92 percent) and 23 cases (24 percent), respectively. All 23 cases expressing membrane-type-1 matrix metalloproteinase also expressed cyclooxygenase-2. Matrix metalloproteinase-2 expression was positive in cancer cells in 20 cases (21 percent) and stromal cells in 52 cases (54 percent). Expression of matrix metalloproteinase-2 in cancer cells correlated with lymphatic invasion and local recurrence. Statistically, a significant correlation was found between cyclooxygenase-2 and membrane-type-1 matrix metalloproteinase expression, and membrane-type-1 matrix metalloproteinase and matrix metalloproteinase-2 expression in cancer cells. There was no association between cyclooxygenase-2 expression and matrix metalloproteinase-2 expression. However, immunostaining of serial sections revealed that in the majority of cases examined, nearly 100 percent of cancer cells expressing matrix metalloproteinase-2 also coexpressed cyclooxygenase-2.

CONCLUSIONS

This study indicates strong association between both cyclooxygenase-2 and membrane-type-1 matrix metalloproteinase expression, and membrane-type-1 matrix metalloproteinase and matrix metalloproteinase-2 in colorectal cancer. These results support our thesis of a direct correlation between cyclooxygenase-2 and membrane-type-1 matrix metalloproteinase expression--with consequent association between cyclooxygenase-2 and matrix metalloproteinase-2 activation, and tumor invasiveness andrecurrence in certain cases of colorectal cancer.

Myofibroblastic stromal reaction and expression of tenascin-C and laminin in prostate adenocarcinoma

The aim of this study was to analyse relationship between changes of the stroma and expression of tenascin-C (TN-C) and laminin in prostate carcinoma. Tenascin-C immunostaining was increased, and laminin decreased in carcinomas compared with peritumoral tissue and benign prostate hyperplasia (P<0.05). Statistical analysis confirmed connection between stromal changes and TN-C expression in prostate carcinoma (P<0.05). Gleason pattern 3 carcinomas showed more pronounced stromal reaction and TN-C expression compared with Gleason pattern 4 carcinomas (P<0.05). The main cells in prostate cancer stroma are myofibroblasts that are also responsible for tenascin production. Degradation of laminin was not connected with myofibroblastic stromal changes.