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Monocyte membrane type 1-matrix metalloproteinase. Prostaglandin-dependent regulation and role in metalloproteinase-2 activation.

Membrane type 1-matrix metalloproteinase (MT1-MMP)-mediated activation of MMP-2 is thought to be important in the proteolysis of extracellular matrix in pathological events in which monocytes/macrophages are found. Here we report on the induction and regulation of human monocyte MT1-MMP and its role in MMP-2 activation. Activation of monocytes by lipopolysaccharide resulted in the induction of MT1-MMP mRNA and protein that was suppressed by inhibitors of prostaglandin synthesis (indomethacin), adenylyl cyclase (SQ 22536), and protein kinase A (Rp-cAMPs). Suppression of MT1-MMP by indomethacin and SQ 22536 was reversed by prostaglandin E(2) and dibutyryl cyclic AMP, respectively, demonstrating that induction of monocyte MT1-MMP is regulated through a prostaglandin-cAMP pathway. Functional analysis revealed that pro-MMP-2 in the supernatants from human bone marrow stromal fibroblasts, normal male-derived fibroblasts and melanoma cells (A2058) was converted to active MMP-2 when cultured with activated but not control monocytes. Antibodies against MT1-MMP blocked the activation of MMP-2. Tissue inhibitor of metalloproteinase-2 regulation of MMP-2 activation was shown through the addition of varying amounts of recombinant tissue inhibitor of metalloproteinase-2 with pro-MMP-2 to MT1-MMP-expressing monocytes. These findings demonstrate that activated monocytes express functionally active MT1-MMP that may play a significant role in the activation of MMP-2 produced by other cells and as such influence developmental and pathological conditions.

Adenine↗

Transformation of epithelial Madin-Darby canine kidney cells with p60(v-src) induces expression of membrane-type 1 matrix metalloproteinase and invasiveness.

Membrane-type 1 matrix metalloproteinase (MT1-MMP) is expressed both in carcinoma cells and in surrounding stromal fibroblasts. MT1-MMP localizes to the surface of tumor cells and is thought to play an important role in tumor invasion. To analyze the mechanism of MT1-MMP gene expression in epithelial tumor cells, the dog kidney epithelial cell line Madin-Darby canine kidney (MDCK) was transformed by oncogenes, including v-src, and expression of MT1-MMP was examined. Transformation of MDCK cells with v-src resulted in loss of cell-to-cell contacts and morphological change. Expression of MT1-MMP in v-src-transformed cells was identified by Northern and Western blotting. Gelatin zymography analysis showed that progelatinase A in the culture medium was processed from latent to activated form by MDCK cells transformed with v-src. The MDCK cells transformed by v-src were tumorigenic in the subcutis (ectopic) and kidney (orthotopic) of nude mice and spontaneously metastasized to the lung after orthotopic implantation. These results suggest that MT1-MMP induced by v-src transformation may promote invasiveness of transformed cells.

Animals↗

Elevated matrix metalloproteinase-9 in patients with systemic sclerosis.

Matrix metalloproteinase-9 (MMP-9) has been implicated in the pathogenesis of cancer, autoimmune disease, and various pathologic conditions characterized by excessive fibrosis. In this study, we investigated the expression of MMP-9 and its clinical significance in systemic sclerosis (SSc). The patients (n = 42) with SSc had higher concentrations of MMP-9 and of tissue inhibitor of metalloproteinase-1 (TIMP-1) and a higher ratio of MMP-9 to TIMP-1 in sera than healthy controls (n = 32). Serum MMP-9 concentrations were significantly higher in the diffuse type (n = 23) than the limited type of SSc (n = 19). Serum concentrations of MMP-9 correlated well with the degree of skin involvement, as determined by the Rodnan score and with serum concentrations of transforming growth factor beta. Moreover, dermal fibroblasts from patients with SSc produced more MMP-9 than those from healthy controls when they were stimulated with IL-1beta, tumor necrosis factor alpha, or transforming growth factor beta. Such an increase in MMP-9 production was partially blocked by treatment with cyclosporin A. In summary, the serum MMP-9 concentrations were elevated in SSc patients and correlated well with skin scores. The increased MMP-9 concentrations may be attributable to overproduction by dermal fibroblasts in SSc. These findings suggest that the enhanced production of MMP-9 may contribute to fibrogenic remodeling during the progression of skin sclerosis in SSc.

Adult↗

Urinary matrix metalloproteinases and their endogenous inhibitors predict hepatic regeneration after murine partial hepatectomy.

BACKGROUND: Matrix metalloproteinases (MMPs) play a key role in extracellular matrix remodeling events associated with hepatic regeneration after partial hepatectomy. We therefore hypothesized that urinary MMPs and their endogenous tissue inhibitors of matrix metalloproteinases (TIMPs) might also provide important information regarding initiation and progression of liver regeneration. METHODS: Groups of 20 mice underwent sham operations, two-thirds hepatectomy, or treatment with the angiogenesis inhibitor, AGM-1470,O-chloroacetyl-carbamoyl-fumagillol (TNP-470), after two-thirds hepatectomy to prevent hepatic regeneration. Urine was collected preoperatively and for 24 days after surgery and tested for MMP-2, MMP-9, TIMP-1, and TIMP-2 using substrate gel electrophoresis (zymography) and Western blot analysis. RESULTS: During hepatic regeneration, MMP-9 was detected in the urine at significantly lower levels on postoperative day 8 when the liver returned to its preoperative mass. In contrast, urine from mice whose livers were inhibited from regenerating (TNP-treated groups) contained increased levels of the gelatinases MMP-2 and MMP-9. The MMP inhibitors, TIMP-1 and TIMP-2, were significantly reduced in the urine of mice with normally regenerating livers but were increased in the urine of mice treated with TNP-470 on day 8. CONCLUSIONS: We demonstrate that (1) urinary MMPs and their cognate inhibitors, the TIMPs, can be detected in the urine of mice undergoing partial hepatectomy, (2) the presence of these remodeling proteins in the urine may predict the progressive return of the partially resected liver to its preoperative mass, and (3) analysis of urinary MMPs and TIMPs may someday provide a noninvasive means of monitoring the status of patients undergoing hepatic resection and transplantation.

Angiogenesis Inhibitors↗

C5a mediates secretion and activation of matrix metalloproteinase 9 from human eosinophils and neutrophils.

Matrix metalloproteinase 9 (MMP-9) is a crucial proteinase, utilized by both eosinophils and neutrophils, that mediates transmigration through extracellular basement membranes. We have found that neutralization of MMP-9 by a monoclonal antibody or a chemical inhibitor blocked C5a dependent chemotaxis of these granulocytes in vitro. The levels of MMP-9 secreted by the action of C5a from eosinophils were about 50-fold lower than those from neutrophils, consistent with results from confocal microscopy, where the density of MMP-9 containing granules was fewer within eosinophils than in neutrophils. Zymography indicated gelatin degrading activity of the molecular size of pro MMP-9 in supernatants from eosinophils and neutrophils stimulated by C5a, with no evidence of proteolytic activation. Instead MMP-9 activation appeared oxidative, since inhibition of NADPH oxidase and nitric oxide synthase by DPI or L-NIL abrogated C5a-mediated chemotaxis through basement membranes. In keeping with this mode of activation, C5a, known as an agent of superoxide generation, was also found to induce secretion of nitric oxide from human eosinophils and rat granulocytes and monocytes. In conclusion C5a is an important mediator that brings about secretion and oxidative activation of MMP-9, a requisite protease for transmigration, from both eosinophils and neutrophils.

Animals↗

Estradiol and tamoxifen regulate endostatin generation via matrix metalloproteinase activity in breast cancer in vivo.

Matrix metalloproteinases (MMP) are important regulators of tumor progression and angiogenesis. MMPs generate both proangiogenic and antiangiogenic fragments, such as vascular endothelial growth factor and endostatin. The in vivo activation of MMPs and endostatin generation occur mainly in the extracellular environment by interactions of different cell types. Therefore, these processes are necessary to study in the extracellular space in vivo. Sex steroids play a dominant role in breast carcinogenesis, by largely unknown mechanisms. In the present study, we used in vivo microdialysis to directly quantify MMP-2 and MMP-9 activity and sample endostatin from both stroma (murine) and tumor (human) cells in vivo in solid MCF-7 tumors in nude mice. We found that tamoxifen in combination with estradiol increased tumor MMP-2/MMP-9 in vivo activity, endostatin levels, and decreased tumor vascularization compared with estradiol treatment only. The stroma-derived endostatin was three to five times higher than cancer cell-generated endostatin. After inhibition of MMP-2/MMP-9, endostatin levels decreased, providing evidence that these proteases are highly involved in the generation of endostatin. Our results support the previously reported concept that MMPs may serve as negative regulators of angiogenesis. The regulation of endostatin generation by modulation of MMP-2/MMP-9 activities suggests a previously unrecognized mechanism of estradiol and tamoxifen, which may have implications for the pathogenesis of breast cancer.

Adenocarcinoma↗

Expression of matrix metalloproteinases and tissue inhibitors of metalloproteinases in HTLV-I-associated myelopathy.

Matrix metalloproteinases (MMPs) have been reported to be involved in inflammatory disorders of the central nervous system (CNS). However, little is known about the role of MMPs in the pathogenesis of HTLV-I-associated myelopathy (HAM)/Tropical spastic paraparesis (TSP). To address this issue, we examined the tissue expression and localization of MMPs and their inhibitors, tissue inhibitors of metalloproteinases (TIMPs) in the spinal cord lesions of HAM/TSP using immunohistochemistry. In addition, the blood and cerebrospinal fluid (CSF) levels of MMPs and TIMPs of the patients with HAM/TSP were determined using sandwich enzyme immunoassays (SIA) and gelatin zymography. Immunohistochemical studies revealed that collagen IV and decorin immunoreactivity on the basement membrane of CNS parenchymal vessels was partially disrupted where inflammatory mononuclear cells infiltrated in active-chronic lesions of HAM/TSP. In these lesions, MMP-2 (gelatinase A) was immunostained mainly on the surface of foamy macrophages and lymphocytes, whereas MMP-9 (gelatinase B) expression was positive in the intravascular and perivascular mononuclear cells but not on foamy macrophages. In contrast, inactive chronic lesions of the spinal cords of the HAM/TSP contained fewer MMP-2-positive or MMP-9-positive mononuclear cells than active-chronic lesions. Many parenchymal vessels had thickened vascular walls which showed increased immunoreactivity to decorin. SIA revealed that production levels of MMP-2 and MMP-9 in both blood and CSF were higher in the patients with HAM/TSP than those in non-inflammatory other neurological disease controls (ONDs). Using zymography, proMMP-9 was detected more frequently in the CSF of patients with HAM/TSP than those in ONDs. Taken together, our data indicate that MMP-2 and MMP-9 may play an important role in the blood-brain barrier breakdown and tissue remodeling in the CNS of HAM/TSP.

Aged↗

Delayed tooth eruption in membrane type-1 matrix metalloproteinase deficient mice.

Membrane-type 1 matrix metalloproteinase (MT1-MMP) is expressed highly in mineralizing tissues including bones and teeth. Mice deficient in MT1-MMP (-/-) display severe defects in skeletal development including dwarfism, osteopenia, and craniofacial abnormalities. Death occurs in these mice by about 3 weeks of age. Since MT1-MMP is expressed by the ameloblasts of the enamel organ and by the odontoblasts of the dental papilla, we asked if the developing teeth were adversely affected in the knockout animals. Molars from MT1-MMP -/- mice and controls were examined by histological, X-ray, and SEM analysis at 4, 18-20, and 25 days of postnatal development. At 4 days of development the molars from the -/- mice appeared histologically normal. At 18-20 days of development, the first molars of the -/- mice had apparently normal tooth crowns with normal dentin and enamel; however, the roots were truncated and the teeth had not yet erupted. In contrast to the -/- mice, the first molars of the 18-20-day control animals had erupted. SEM analysis of a -/- first molar and incisor revealed a normal enamel prism pattern. However, X-ray analysis demonstrated that tooth eruption was delayed by approximately 5 days and that the tooth roots were abnormally short in the knockout animals. Since MT1-MMP-deficient mice have been demonstrated to display a generalized increase in bone resorption, these data suggest that inefficient growth of bone surrounding the tooth root complex causes a delay in tooth eruption.

Animals↗

Limited processing of pro-matrix metalloprotease-2 (gelatinase A) overexpressed by transfection in PC-3 human prostate tumor cells: association with restricted cell surface localization of membrane-type matrix metalloproteinase-1.

The expression and activation of matrix metalloproteinases (MMPs) by tumor cells is correlated with progression to invasive and metastatic status. The purpose of this study was to examine the role of increased MMP-2 (gelatinase A) expression in prostate cancer progression utilizing human prostate PC-3 cancer cells that overexpress MMP-2 using gene transfection. PC-3 cells were transfected with pCR-3 vector only and pCR-3 MMP-2 plasmids employing the LipofectAMINE method, and stable transfectants were selected with G418. The expression of MMP-2, tissue inhibitor of metalloproteinase-2 (TIMP-2), and membrane-type MMP 1 (MT1-MMP) in PC-3 parental and transfected cells under serum-free conditions was determined by zymography, immunoblotting, immunofluorescent microscopy, Northern blotting, and/or reverse transcriptase-polymerase chain reaction (RT-PCR). MMP-2 transfected cells produced primarily the proenzyme form of MMP-2; the parental and vector control transfected PC-3 cells did not express any MMP-2 that was detectable by the methods we employed. Treatment of PC-3 MMP-2 transfected cells with Concanavalin A (Con A), in contrast to HT-1080 cells, processed only a small amount of the secreted 72-kd proenzyme to a 62-kd intermediate and a cell-associated 59-kd active form. The low level of secreted pro-MMP-2 processing induced by Con A was inhibited by serine protease inhibitors and was unaffected by cyclic adenosine monophosphate (cAMP). Immunoblotting showed that these cells produced abundant TIMP-2 and lower amounts of MT1-MMP in comparison with Con A-responding HT-1080 cells. HT-1080 cells respond to Con A by translocating MT1-MMP from intracellular localization sites to the plasma membrane, an effect not observed in PC-3 cells. The molecular basis for the low level of processing of pro-MMP-2 by PC-3 cells may be due to an overabundance of TIMP-2 and/or a low level of cell surface active MT1-MMP.

Blotting, Northern↗

Myelin formation during development of the CNS is delayed in matrix metalloproteinase-9 and -12 null mice.

The matrix metalloproteinases (MMPs) are implicated in several activities within the nervous system. Although many functions of abnormally elevated MMPs are undesirable, the discrete expression of particular MMP members can have beneficial roles. We previously found that MMP-9 expressed locally around a demyelinating lesion of the spinal cord of adult mice facilitated remyelination. In the current study, we have addressed whether and how MMPs might be required for myelin formation in normal ontogeny. Using a probe for multiple MMPs and the developing mouse optic nerve, we found two members, MMP-9 and -12, to be upregulated during the period of myelin formation. These MMPs partake in myelinogenesis because myelination in the corpus callosum of MMP-9 and/or MMP-12 null mice was deficient from postnatal days 7 to 14 compared with that of wild-type mice. The deficient myelination was correlated with fewer mature oligodendrocytes, but similar precursor cell numbers, in MMP null animals compared with wild type. Because an important growth factor for oligodendrocyte maturation is insulin-like growth factor-1 (IGF-1), we addressed whether this was involved in the deficient myelination in MMP null mice. Indeed, the addition of IGF-1 normalized the lack of maturation of oligodendrocytes that occurred in cultures from MMP-12 null mice. Furthermore, we determined that IGF binding protein 6 (IGFBP-6), which sequesters IGF-1, was a substrate for MMP processing. Finally, we found IGFBP-6 levels to remain high in MMP-deficient mice. These results reveal a novel function for MMP-9 and -12 in developmental myelination likely through regulating IGF-1 bioavailability.

Animals↗

Immunolocalization of matrix metalloproteinases in rabbit carotid arteries after balloon denudation.

Extracellular matrix-degrading enzymes may play a key role in vascular remodeling after arterial wall injury. We investigated the immunolocalization of matrix metalloproteinases (MMPs) in rabbit carotid arteries after balloon denudation. Positive immunostaining for MMP-1, -2, -3, and -9 appeared through the neointima 1 week after balloon denudation. The localization of immunopositive smooth muscle cells (SMCs) for MMP- 1, -3, and -9, particularly for MMP-9, was almost similar to that of replicative SMCs and became confined to the luminal surface layer of the neointima at later time periods. However, MMP-2-positive SMCs appeared also in the basal layer of the neointima at 2 weeks, increased at 4 weeks, and then totally occupied the neointima at 6 weeks. The MMP-2-positive SMCs in the basal layer of the neointima at 4 and 6 weeks were negative for proliferation-associated antigens and were surrounded by extracellular matrix proteins. Our results suggest that all MMPs act in coordination to promote replication and migration of SMCs in the earlier phases of neointimal formation and that MMP-2 independently contributes to the later stages by facilitating the migration but not replication of SMCs from the media to the intima.

Animals↗

Design and synthetic considerations of matrix metalloproteinase inhibitors.

Experimental evidence confirms that the matrix metalloproteinases (MMPs) play a fundamental role in a wide variety of pathologic conditions that involve connective tissue destruction including osteoarthritis and rheumatoid arthritis, tumor metastasis and angiogenesis, corneal ulceration, multiple sclerosis, periodontal disease, and atherosclerosis. Modulation of MMP regulation is possible at several biochemical sites, but direct inhibition of enzyme action provides a particularly attractive target for therapeutic intervention. Hypotheses concerning inhibition of specific MMP(s) with respect to disease target and/or side-effect profile have emerged. Examples are presented of recent advances in medicinal chemistry approaches to the design of matrix metalloproteinase inhibitors (MMPIs), approaches that address structural requirements and that influence potency, selectivity, and bioavailability. Two important approaches to the design, synthesis, and biological evaluation of MMPIs are highlighted: (1) the invention of alternatives to hydroxamic acid zinc chelators and (2) the construction of nonpeptide scaffolds. One current example in each of these two approaches from our own work is described.

Animals↗

Respective contribution of neutrophil elastase and matrix metalloproteinase 9 in the degradation of BP180 (type XVII collagen) in human bullous pemphigoid.

Bullous pemphigoid is a blistering disorder associated with autoantibodies directed against two components of hemidesmosomes, BP180 and BP230. Autoantibodies to the extracellular collagenous domain of BP180 are thought to play a key role in the pathogenesis of the disease. In a murine model of bullous pemphigoid, neutrophil elastase and 92 kDa gelatinase (matrix metalloproteinase 9) have been implicated in subepidermal blister formation via proteolytic degradation of BP180. In this study we sought to elucidate the contribution of these two enzymes to subepidermal blister formation by assessing the expression, localization, and activity of the two proteases in lesional skin, serum samples, and blister fluids obtained from 17 patients with bullous pemphigoid. The results indicate that (i) neutrophil elastase is found in skin biopsy specimens from bullous pemphigoid lesions and is recovered as active enzyme in blister fluids, and (ii) although proform of matrix metalloproteinase 9 is present in lesional skin, it is present only as proenzyme in blister fluids, which also contain high levels of tissue inhibitor of metalloproteinase-1. Next, the capacity of matrix metalloproteinase 9 and neutrophil elastase to degrade a recombinant protein corresponding to the extracellular collagenous domain of the BP180 was studied. Our data illustrate that (i) recombinant matrix metalloproteinase 9, neutrophil elastase, and blister fluid from bullous pemphigoid patients are all able to hydrolyze recombinant BP180; (ii) the pattern of recombinant BP180 proteolysis with blister fluid was similar to that obtained with neutrophil elastase; and (iii) recombinant BP180 degradation by blister fluid could be inhibited by chloromethylketone, a specific elastase inhibitor, but not by batimastat, a wide spectrum matrix metalloproteinase inhibitor. Our results confirm the importance of neutrophil elastase but not matrix metalloproteinase 9 in the direct cleavage of BP180 autoantigen and subepidermal blister formation in human bullous pemphigoid.

Aged↗

Paracrine regulation of matrix metalloproteinase expression in the normal human endometrium.

Endometrial expression of matrix metalloproteinase (MMP)-3, MMP-7 and MMP-11 occurs during menstrual breakdown and subsequent estrogen-mediated growth, but not during the secretory phase. These enzymes are suppressed by progesterone treatment. Paracrine factors, including transforming growth factor-beta (TGF-beta) and retinoic acid, are also critical for MMP regulation in the endometrium. In contrast, inflammatory cytokines such as interleukin-1alpha may block or interfere with steroid-mediated MMP regulation at ectopic sites of growth. Using in vitro models, our laboratory has investigated the complex interactions between progesterone and locally produced cytokines that may affect MMP expression during the development of endometriosis. Our results indicate that targeting the regulation of MMPs may represent an appropriate therapeutic strategy for the treatment of endometriosis. Copyrightz1999S. KargerAG,Basel

Adult↗

Assay of matrix metalloproteinases types 1, 2, 3 and 9 in breast cancer.

Matrix metalloproteinases (MMPs) are zinc dependent endopeptidases implicated in cancer invasion and metastasis. Gelatin zymography was performed on 84 human breast carcinomas and seven normal breast tissues. The precursor form of MMP-2 (72 kDa) was found in 11 (12%) samples, while its two activated forms, i.e. 62 kDa and 59 kDa, were found in three (6%) and 34 (40%) samples respectively. In contrast to MMP-2, most of the samples (52%) contained MMP-9 in its precursor form. Using ELISA, MMP-1 levels were found in 12% of the samples while MMP-3 levels were found in only 2% of the samples. Levels of MMP-2, -3 and -9 correlated inversely with numbers of nodal metastases. Neither MMP-2 nor -9 levels were significantly related to patient outcome. However, patients with high levels of a 50-kDa gelatinase band after zymography had a significantly better survival than patients with low levels. This species was never observed in normal breast tissue.

Breast↗

Matrix metalloproteinases 2 and 9 (gelatinases A and B) expression in malignant mesothelioma and benign pleura.

Matrix metalloproteinases (MMPs), in particular the gelatinases (MMP-2 and -9), play a significant role in tumour invasion and angiogenesis. The expression and activities of MMPs have not been characterised in malignant mesothelioma (MM) tumour samples. In a prospective study, gelatinase activity was evaluated in homogenised supernatants of snap frozen MM (n=35), inflamed pleura (IP, n=12) and uninflammed pleura (UP, n=14) tissue specimens by semiquantitative gelatin zymography. Matrix metalloproteinases were correlated with clinicopathological factors and with survival using Kaplan-Meier and Cox proportional hazard models. In MM, pro- and active MMP-2 levels were significantly greater than for MMP-9 (P=0.006, P<0.001). Active MMP-2 was significantly greater in MM than in UP (P=0.04). MMP-2 activity was equivalent between IP and MM, but both pro- and active MMP-9 activities were greater in IP (P=0.02, P=0.009). While there were trends towards poor survival with increasing total and pro-MMP-2 activity (P=0.08) in univariate analysis, they were both independent poor prognostic factors in multivariate analysis in conjunction with weight loss (pro-MMP-2 P=0.03, total MMP-2 P=0.04). Total and pro-MMP-2 also contributed to the Cancer and Leukemia Group B prognostic groups. MMP-9 activities were not prognostic. Matrix metalloproteinases, and in particular MMP-2, the most abundant gelatinase, may play an important role in MM tumour growth and metastasis. Agents that reduce MMP synthesis and/or activity may have a role to play in the management of MM.

Adult↗

Polymorphisms of the promoter regions of matrix metalloproteinases genes MMP-1 and MMP-9 in breast cancer.

PURPOSE: Matrix metalloproteinases play a crucial role in the cancer invasion and metastasis, angiogenesis and tumorigenicity. A single guanine insertion--the 1G/2G polymorphism in the promoter of the matrix metalloproteinase 1 (MMP-1) gene creates a binding site for the transcription factor AP-1 and thus may affect the transcription level of MMP-1. The C-->T substitution at the polymorphic site of the MMP-9 gene promoter results in a higher transcription activity of the T-allelic promoter trough the loss of binding site for a repressor protein. The aim of this work was to investigate the influence of 1G/2G and C-->T polymorphisms on the MMP-1 and MMP-9 level and therefore on the occurrence and progression of breast cancer. EXPERIMENTAL DESIGN: We investigated the distribution of genotypes and frequency of alleles of the 1G/2G and C-->T polymorphisms for 270 patients with breast cancer and 300 healthy women served as control. The genotypes were determined by RFLP-PCR. Additionally, we estimated the level of MMP-1 and MMP-9 antigens in tumor samples and normal breast tissue using ELISA. RESULTS: The levels of MMP-1 in tumor samples of node positive patients ware significantly higher than in samples of node negative patients (p<0.05). Increased level of MMP-9 correlates with Bloom-Richardson grading III (p<0.05), increased tumor size (p<0.05) and absence of estrogen and progesterone receptors (p<0.01). Additionally, both MMP-1 and MMP-9 levels were higher in tumor than in the normal breast tissue. We showed the higher risk of metastasis development in lymph node for the 2G/2G genotype (OR=2.14; CI 95% 1.24;3.69) and the 2G allele carriers (OR=1.68; CI 95% 1.19;2.39). We found correlation between the T allele (OR=2.61; CI 95% 1.33;4.87), 2G (OR=2.58; CI 95% 1.35;4.91) and malignance. CONCLUSION: The results suggest that MMP-1 is responsible for the local invasion and MMP-9 is associated with the malignance and the growth of the tumor. We suggest that the 2G allele of the 1G/2G MMP-1 gene polymorphism may be associated with the lymph node metastasis in patients with breast cancer and therefore it can be considered as a progression marker in this disease.

Adult↗

Expression of matrix metalloproteinases and inhibitor by human retinal pigment epithelium.

Extracellular matrix turnover is initiated, at least in part, by the regulated secretion of members of a family of matrix metalloproteinases. The authors show that interstitial collagenase, stromelysin, two gelatinases (the 72-kD and 92-kD type IV collagenases), and the tissue inhibitor of metalloproteinases (TIMP) are secreted into the culture medium of human retinal pigment epithelium (RPE). These enzymes and their inhibitor were identified by probing immunoblots of western transfers with specific polyclonal antibodies that were made against these proteins or against peptides containing unique sequences from these proteins. Stromelysin and the gelatinases are also active against substrates that are polymerized into polyacrylamide gel before electrophoresis and require metal ions (probably zinc and/or calcium) for activity. The phorbol mitogen, 12-tetradecanoylphorbol-13-acetate, differentially increases the levels of these metalloproteinases and TIMP found in retinal pigment epithelium culture medium with stromelysin and the 92-kD type IV collagenase responding most strongly and TIMP actually decreasing in certain cases. Additional changes in metalloproteinase profiles are observed after approximately 20 passage of several RPE lines in culture. Modulation of extracellular matrix turnover by changing RPE secretion of these matrix metalloproteinases and their TIMP, may play a central role in the normal function and in the pathology of the retina.

Blotting, Western↗