Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.4.21.73 (urokinase-type plasminogen activator)
 10,685 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Malignant human melanoma cells produce many matrix-degrading enzymes, including plasminogen activators and matrix metalloproteinases. These enzymes have substrate specificity for different components of ECM and most of them have been demonstrated to contribute to melanoma cell-mediated dissolution of matrices and to melanoma cell invasion. The degradation of complex matrices in vitro requires the cooperation of proteases with specificity for glycoproteins and collagens. The contribution of proteases to spontaneous melanoma metastasis was studied by overexpressing specific protease inhibitors in human melanoma cells. Overexpression of PAI-2 inhibited the spread of distant metastasis indicating a role for uPA/plasmin in melanoma invasion. Overexpression of TIMP-2, in contrast, reduced the growth rate of subcutaneous tumors, but did not inhibit metastasis, indicating that MMP activities promote melanoma growth in the skin and may not be required for metastatic dissemination. Thus, uPA and MMP activities are involved in different processes, but they both contribute to melanoma malignancy.
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PMID:Different roles for plasminogen activators and metalloproteinases in melanoma metastasis. 881 95

Matrilysin (PUMP-1) is a member of the matrix metalloproteinase (MMP) family of extracellular matrix degrading enzymes that has been found to be overexpressed in human prostate cancer. The rat ventral prostate (RVP) following castration has been used as a model for both tissue involution and apoptosis. Northern analysis and in situ hybridization were used to determine the time course and localization of matrilysin during 8 days of RVP involution. Northern analysis revealed that the 1.2 kb matrilysin mRNA was undetectable in normal RVP. An increase in the steady-state levels of matrilysin mRNA was observed 5 days after castration, and the levels began to decline by 8 days after castration. The mRNAs for tissue inhibitor of metalloproteinase-1 and urokinase-type plasminogen activator also showed a time-dependent induction during the course of involution. Localization of matrilysin by in situ hybridization indicated that the mRNA was produced by epithelial cells of the involuting RVP. The matrilysin message was observed in a small number of glands within the whole RVP. Matrilysin protein was present in the RVP and peaked 3 days after castration. The combination of proteinase genes expressed in the RVP following castration indicate that the MMP and serine protease families of enzymes may interact during tissue remodeling of the RVP following castration.
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PMID:Matrilysin expression in the involuting rat ventral prostate. 882 84

The studies described here examine the involvement of the fibrinolytic cascade and its endogenous inhibitors in the regulation of activity of matrix metalloproteinases and cartilage degradation related to non-inflammatory joint disease, like osteoarthritis. An interleukin-1-induced model of degradation using [35S]-labeled bovine and human articular cartilage explants was utilized. One goal of these studies was to compare the responses of bovine and human articular cartilage. Degradation was not inhibited by alpha 1-PI, PAI-1, alpha 2-macroglobulin, alpha 2-antiplasmin or TIMP-2, when IL-1 alone was added. Addition of human plasminogen to bovine explants, at concentrations found in human synovial fluid, increased degradation by three to four-fold. Under these conditions, the degradation was inhibited effectively by all of the endogenous inhibitors tested, indicating the presence of a cascade where activated chondrocytes are a source of u-PA. Plasminogen activated by u-PA gives plasmin, which is known to further activate pro-stromelysin. Stromelysin is essential for activation of collegenase. Not only TIMP, but also inhibitors at earlier steps of activation like PAI-1, alpha 2-antiplasmin, alpha 1-PI and alpha 2-macroglobulin inhibited degradation, and could provide cartilage protection in vivo. An experiment with human articular cartilage explants showed that very little or no degradation occurred when human articular cartilage explants were stimulated with interleukin-1 alone. Addition of human plasminogen (at physiologically relevant concentrations) resulted in significant degradation, which was inhibited in the same manner as in bovine explants, by inhibitors of the fibrinolytic cascade and TIMP. TIMP is much more efficient in human explants, indicating the limited participation of human plasmin in the degradation of human cartilage. Although speculative, it is possible that in vivo, cartilage degradation could be promoted not only by TIMP/MMP imbalance, but also accelerated by decreased levels of certain serpins in synovial fluid (e.g. PAIs, alpha 2-antiplasmin and alpha 1-PI).
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PMID:Plasminogen modulation of IL-1-stimulated degradation in bovine and human articular cartilage explants. The role of the endogenous inhibitors: PAI-1, alpha 2-antiplasmin, alpha 1-PI, alpha 2-macroglobulin and TIMP. 889 58

The expression of extracellular-matrix (ECM)-degrading proteases has been shown to be necessary for invasion of tumor cells into surrounding tissue. For several tumor types, overexpression of these proteases is dependent upon interactions with adjacent fibroblast cell populations. We previously demonstrated activation of matrix metalloprotease (MMP) and urokinase-type plasminogen activator (uPa) expression in a coculture model consisting of squamous cell carcinoma cells (SCC) with dermal fibroblasts. In the present study we have examined whether melanocytes, which are known to interact closely with keratinocytes of the basal epidermal layer, might influence ECM-degrading protease expression in SCC cells as well. Upon coculture of the human SCC cell line II-4 with the nontumorigenic mouse melanocyte cell line Melan-a or treatment of II-4 cells with Melan-a conditioned media, induction of expression of the MMP matrilysin and uPa was observed. In contrast, no induction was observed for stromelysin-1 or 92-kDa type IV collagenase. Matrilysin/uPa-inducing activity was found to act at the level of gene transcription for both matrilysin and uPa and was ubiquitously expressed among six different human melanocytic cell strains/lines, ranging from primary normal melanocytes to cell lines established from metastatic melanoma lesions. These data demonstrate that melanocytic cells can exert a paracrine influence in SCC cells on the expression of specific proteases involved in ECM turnover and tumor invasiveness.
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PMID:Melanocyte mediated paracrine induction of extracellular matrix degrading proteases in squamous cell carcinoma cells. 905 12

We have previously shown that the extracellular-matrix-degrading enzymes, urokinase-type plasminogen activator (u-PA), stromelysin 1, stromelysin 3, and matrilysin, may play an important role in the transition from lung preneoplasia to invasive carcinoma. Using in situ hybridization and immunohistochemistry, we analyzed serial frozen sections for the expression of these enzymes in 89 lung carcinomas including 25 neuroendocrine (NE) carcinomas (10 small-cell lung carcinomas, 7 large-cell NE carcinomas, 1 atypical, and 7 typical carcinoids) and 64 non-small-cell, non-NE carcinomas (29 squamous and 7 basaloid carcinomas, 23 adenocarcinomas, and 5 large-cell carcinomas). Proteases, except matrilysin, were more often expressed in stromal than cancer cells. In non-small-cell, non-NE carcinomas, stromal co-expression of u-PA and stromelysin 3 was seen in 80 to 90% of the tumors and was highly correlated (P < 0.0001). Stromal u-PA and stromelysin 3 expression was linked to tumor size (P = 0.01 and 0.03, respectively) and lymph node involvement (P = 0.001 and 0.02, respectively). Epithelial expression of u-PA was correlated to tumor size (P = 0.04). Epithelial expression of stromelysin 3 predominated in squamous and basaloid carcinomas (P = 0.0005) and was inversely correlated to squamous differentiation (P = 0.018). Epithelial expression of matrilysin predominated in adenocarcinomas and large-cell carcinomas (P = 0.07). In NE carcinomas including small-cell lung carcinomas, stromal expression of u-PA was correlated to lymph node metastasis (P = 0.017). Epithelial expression of all enzymes were significantly less frequent in NE than in non-NE tumors. We conclude that 1) epithelial expression of matrix proteases in lung cancer is linked to cell phenotype (NE versus non-NE, squamous versus glandular) and 2) their stromal, rather than epithelial, expression influences local metastasis.
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PMID:Expression of urokinase-type plasminogen activator, stromelysin 1, stromelysin 3, and matrilysin genes in lung carcinomas. 913 88

The expression of MMP-2, MMP-9, TIMP-1, TIMP-2, and the urokinase receptor were examined in fetal and normal prostate tissues, benign prostatic hyperplasia and prostate cancer (n = 117). In situ hybridization with digoxigenin-labeled oligonucleotide probes demonstrated that TIMP-1 and TIMP-2 were expressed at elevated levels in the stroma of Gleason sum 5 tissues, whereas MMP-2 and MMP-9 were expressed at relatively low levels. In higher Gleason sum tissues (GS 8-10), TIMP-1 and TIMP-2 were not expressed, whereas MMP-2 and MMP-9 were intensely expressed. Furthermore, TIMP-1 and TIMP-2 expression was high in organ-confined specimens (OC, n = 43), somewhat lower in specimens with capsular penetration (CP, n = 29), and low or negative in samples with surgical margin/seminal vesicle (M/SV, n = 17) and lymph node (LN, n = 13) involvement. In contrast, MMP-2 and MMP-9 expression was low in the OC tissues; and noticeably higher in CP, M/SV, and LN specimens. Finally, correlation of TIMP and MMP expression with GS and pathological stage versus cure rate further revealed that a high percentage of organ-confined, GS 5 specimens expressing TIMP and little MMP were cured. In comparison, few of the GS 7-10 patients with capsular penetration and expressing MMP and little TIMP were cured. The data suggest that TIMP-1 (and TIMP-2) and MMP-2 (and MMP-9) are independent predictors of outcome.
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PMID:In situ hybridization studies of metalloproteinases 2 and 9 and TIMP-1 and TIMP-2 expression in human prostate cancer. 917 26

Urokinase-type plasminogen activator (uPA) is a key serine protease involved in invasion and metastasis. We had shown that overproduction of uPA in tumor cells is controlled by a phospholipase D-protein kinase C-dependent pathway. Now we studied whether other signaling pathways participate in the regulation of constitutive uPA and metalloproteinase (MMP) overproduction in tumor cells. Staurosporine, a protein kinase inhibitor, stimulated uPA and MMP-9 secretion as measured by radial caseinolysis, zymography and Western blotting. Genistein, a specific tyrosine kinase inhibitor, reduced the constitutive and staurosporine-induced uPA and MMP-9 secretion. Interestingly, the phosphatase inhibitor vanadate stimulated uPA secretion. Verapamil, a calcium channel blocker, inhibited both endogenous and PMA-stimulated secretion of uPA but was unable to inhibit staurosporine-induced secretion. The alcohol n-butanol, a phospholipase D and protein kinase C inhibitor, besides inhibiting constitutive uPA secretion, blocked staurosporine-induced secretion. Our results suggest that constitutive and staurosporine-induced uPA and MMP-9 secretion by LM3 murine mammary tumor cells is controlled by an endogenous tyrosine kinase pathway and probably involves protein phosphatases. In addition, the staurosporine-induced signal regulating urokinase secretion is independent of extracellular calcium but dependent on phospholipase D.
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PMID:Secretion of urokinase and metalloproteinase-9 induced by staurosporine is dependent on a tyrosine kinase pathway in mammary tumor cells. 957 73

Matrix metalloproteinase-3 (MMP-3, or stromelysin-1) specifically hydrolyzes the Glu143-Leu144 peptide bond in 45-kDa single-chain urokinase-type plasminogen activator (scu-PA) and in its two-chain (tcu-PA) derivative, yielding a 17-kDa NH2-terminal domain comprising the u-PA receptor (u-PAR) binding site and a 32-kDa COOH-terminal moiety containing the serine proteinase domain of u-PA. The conversion is completely abolished in the presence of the MMP inhibitors EDTA or 1,10-phenanthroline. Biospecific interaction analysis indicates that binding of MMP-3 occurs through the 32-kDa fragment. The 32-kDa fragment derived from scu-PA (scu-PA-32k) has a specific activity of </=500 IU/mg, but it can be activated with plasmin to a two-chain derivative (tcu-PA-32k) with a specific activity of 79 000 IU/mg. tcu-PA and tcu-PA-32k moieties derived from scu-PA-32k by plasmin or from tcu-PA by MMP-3 have comparable amidolytic activities toward the chromogenic substrate S-2444 (kcat/Km of 110 and 160 mM-1 s-1, respectively) and similar plasminogen activating activities in a coupled chromogenic substrate assay. Specific binding of the 17-kDa NH2-terminal domain to THP-1 monocytoid cells is completely abolished by competition with scu-PA but is not affected by scu-PA-32k (residual binding of 88 +/- 9% (mean +/- SEM; n = 3) with 25-fold molar excess). Thus, MMP-3 removes a functional NH2-terminal u-PAR-binding domain from u-PA without affecting its enzymatic properties.
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PMID:Proteolytic cleavage of urokinase-type plasminogen activator by stromelysin-1 (MMP-3). 958 35

We show that osteopontin (OPN), bone sialoprotein (BSP) and GRGDSP peptides, in solution, induce activation of metalloproteinase-2 (MMP-2) secreted by human GCT23 giant cell tumour cells. Activation of MMP-2 is RGD sequence dependent, possibly involves anti-alphaVbeta3 integrins, is preceded by a change from spread to rounded cell morphology and is mimicked by the actin depolymerising agent cytochalasin B. Cells that had spread on OPN, BSP and GRGDSP substrata failed to activate MMP-2, but subsequent addition of soluble GRGDSP induced rounding and MMP-2 activation. Activation induced by GRGDSP and cytochalasin B was cell mediated, inhibited by EDTA, tissue inhibitor of metalloproteinase-2 (TIMP-2) and carboxyl terminal MMP-2 consistent with a role for membrane type (MT)-MMP but did not involve urokinase, plasmin or thrombin activity. Activation induced by GRGDSP and cytochalasin B, but not cell rounding, was inhibited by herbimycin A, cycloheximide and actinomycin D, suggesting a role for tyrosine kinases, protein and RNA synthesis, but was not associated with changes in mRNA for MT-MMP-1, MMP-1, MMP-2, TIMP-1 or TIMP-2. GRGDSP and cytochalasin B enhanced levels of membrane-associated pro- and active form MMP-1 and MMP-2 but not MT-MMP-1, stimulated cell surface MMP-1 staining and induced that of MT-MMP-1, MMP-2 and TIMP-2. This was consistent with the possible relocation of constitutive MT-MMP-1 to the cell surface as a prerequisite for subsequent cell surface MMP-2/TIMP-2/MT-MMP-1 complex formation and to the potential induction of conditions favourable for reciprocal cell surface MMP-1/MMP-2 activation. Our data provide a novel insight into interactions between RGD containing bone matrices, GCT cells and MMPs of potential relevance to GCT pathology.
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PMID:Activation of MMP-2 by human GCT23 giant cell tumour cells induced by osteopontin, bone sialoprotein and GRGDSP peptides is RGD and cell shape change dependent. 963 98

The activation of zymogen and the amount of proteinase and its inhibition are important in determining the eventual activity of matrix-degrading enzymes involved in tumor aggressiveness. To evaluate a gene complement leading to matrix metalloproteinase 2 (MMP-2; Mr 72,000 gelatinase) activity, membrane type 1 MMP (MT1-MMP), urokinase-type plasminogen activator, MMP-2, and tissue inhibitor of metalloproteinase 2 transcriptional levels were measured in gastric carcinoma biopsies. Comparative tumor:normal tissue reverse transcription-PCR in a cohort of 25 patients revealed up to a 10-fold difference in the expression of MT1-MMP, a metalloproteinase that has been proposed as a membrane receptor activator of MMP-2; a 1-unit increment resulted in a 30% risk to survival. A 20% risk also resulted from a 1-unit increment in the MT1-MMP: MMP-2 ratio, which showed differences of up to 15-fold. Instead, the expression of urokinase-type plasminogen activator, which trips off a cascade ending in the activation of MMP-2, as well as the expression of MMP-2 itself and its inhibitor, tissue inhibitor of metalloproteinase 2, lacked correlation with patient follow-up. Zymography revealed MMP-2 activities that were often in conflict with the transcription results and also with follow-up. The results suggest the evaluation of MT1-MMP and/or MT1-MMP:MMP-2 transcription as a new preoperative molecular-level prognostic factor for gastric carcinoma.
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PMID:Augmented membrane type 1 matrix metalloproteinase (MT1-MMP):MMP-2 messenger RNA ratio in gastric carcinomas with poor prognosis. 974 37


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