Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P00750 (PLA)
 16,800 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Of 154 Chinese patients who underwent gynecological operations, 4 showed a positive fibrinogen leg scan for venous thrombosis, an overall incidence of 2.6%. In those who were on (OC) oral contraceptives and had major pelvic surgery for benign conditions, the incidence was 10.5%; in those who had Wertheim hysterectomy for carcinoma for cervix, it was 6.7%. This confirms the rarity of postoperative thromboembolism in the Chinese. Fragment E showed a biphasic rise after major operation due to tissue injury and venous thrombosis. In patients with malignancy, the postoperative fibrinolytic shutdown, represented by decreased plasminogen activator together with increased alpha 1 antitrypsin and C inhibitor levels, was more marked. In addition alpha 2 macroglobulin level was lower and fell significantly after operation. In patients on OCs, fragment E levels were higher after surgery and there was no decrease in plasminogen activator levels. Antithrombin 3 levels did not fall except in 3 of the 4 patients with venous thrombosis. A marked increase in fragment E level and a decrease in antithrombin 3 level might be useful diagnostic markers for postoperative venous thrombosis.
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PMID:Deep vein thrombosis and changes in coagulation and fibrinolysis after gynaecological operations in Chinese: the effect of oral contraceptives and malignant disease. 743 38

Matrix-degrading proteinases secreted by tumor cells play crucial roles in tumor cell invasion and metastasis. Serum-free conditioned media of 7 human gynecological carcinoma cell lines were examined for proteinases and their inhibitors by using gelatin zymography, reverse zymography and immunoblotting. All of three ovarian adenocarcinoma cell lines secreted urokinase-type plasminogen activator. Among them, a mucinous cystadenocarcinoma cell line also secreted tissue-type plasminogen activator, plasmin-like enzyme and trypsinogen. On the other hand, two ovarian undifferentiated carcinoma cell lines mainly secreted glatinase A or B. A choriocarcinoma cell line secreted multiple metalloproteinases in the highest amount, whereas an endometrial adenocarcinoma cell line (HEC-1) derived from an early clinical stage hardly secreted any gelatinolytic enzyme. The five high proteinases producers hardly secreted the corresponding inhibitors, such as tissue inhibitor of metalloproteinases (TIMP)-1, -2 or plasminogen activator inhibitor-1. In contrast to these highly malignant cell lines, a poor proteinase producer, HEC-1, secreted a large amount of TIMPs. Therefore, an enhanced proteolytic tendency appears to be associated with gynecological cancer cells established from highly malignant tumors.
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PMID:Characterization of matrix-degrading proteinases and their inhibitors secreted by human gynecological carcinoma cells. 762 22

We investigated immunohistochemically the localization of urokinase-type plasminogen activator (u-PA), tissue-type plasminogen activator (t-PA), plasminogen activator inhibitor-1 (PAI-1), plasmin inhibitor (PI), and transforming growth factor-beta (TGA-beta) in tissue sections to examine the relationships between their localization and local invasiveness, tumor size and cervical lymph node metastasis of head and neck squamous cell carcinomas (SCCs). In invasive carcinomas, u-PA, PAI-1 and PI were stained stronger in carcinoma cells than in surrounding connective tissues or normal epithelial cells. However, no relationship was found between cell invasiveness and the localization of t-PA and TGF-beta in invasive SCCs. The expression of these factors was not related to cervical lymph node metastasis or the size of head and neck SCCs. These results suggest a disorder of the fibrinolytic systems of carcinoma cells, and that u-PA play a part in the invasion of head and neck SCCs by degenerating connective tissue.
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PMID:[Immunohistological study of fibrinolytic factors of head and neck squamous cell carcinomas]. 770 77

The interaction of plasminogen activator-inhibitor (PAI-1) with a cell surface protease, guanidinobenzoatase (GB), has been studied in free solution and on the surface of colonic epithelial cells. It has been demonstrated that PAI-1 recognises and inhibits the iso enzymic form of GB associated with colonic carcinoma cells but fails to bind to the iso enzymic form of GB associated with normal donor colonic epithelial cells. This interaction is mediated by a lysyl binding site on the GB: complex formation prevents GB binding to fibrin fibrils which also involves lysyl binding sites.
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PMID:Selectivity of the plasminogen activator inhibitor (PAI-1) for the iso enzyme of guanidinobenzoatase on the surface of colonic carcinoma cells. 773 35

In this study we investigated the tumorigenicity, growth pattern and spontaneous metastatic ability of a series of nine human colorectal carcinoma cell lines after subcutaneous and intracaecal xenografting in nude mice. CaCo2 cells were found to be poorly tumorigenic to non-tumorigenic in either site; the other cell lines were tumorigenic in both sites. SW1116, SW480 and SW620 did not show local invasive in the NCI-H716 and LS174T cells were both invasive in the caecum, but only NCI-H716 was invasive in the subcutis. HT29 and 5583 (S and E) cells were invasive in the caecum and from that site metastatic to the lungs and/or the liver. HT29 and 5583S cells were both invasive in the subcutis, but 5583E cells were not. Of each category of in vivo behaviour in the caecum, one cell line was further investigated with regard to invasion in vitro (into embryonic chick heart fragments), E-cadherin expression in vivo and in vitro and in vitro production of u-PA and t-PA. These parameters were chosen in view of their purported role in extracellular matrix degradation and intercellular adhesion, which are all involved in the invasive and metastatic cascade. Invasion in vitro was not predictive for invasion or metastasis in vivo. In the cell line which showed invasion in embryonic chick heart tissue, heterogeneous E-cadherin expression was observed in vitro together with a relatively high production of u-PA. The non-invasive cell lines showed in vitro homogeneous expression of E-cadherin with a relatively low production of u-PA. In vivo expression of E-cadherin was either absent or heterogeneous. We conclude that: (1) colorectal carcinoma xenografts show site-specific modification of in vivo invasive and metastatic behaviour; (2) invasion in vitro does not correlate with invasion and metastasis in vivo; (3) in vitro non-invasion might be associated with homogeneous E-cadherin expression and low production of u-PA; (4) E-cadherin expression in vitro differs from E-cadherin expression in vivo. The results support the notion that the microenvironment in which cancer cells grow is one of the factors involved in the regulation of invasive and metastatic behaviour.
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PMID:In vivo and in vitro invasion in relation to phenotypic characteristics of human colorectal carcinoma cells. 784 Oct 40

The plasminogen activator (PA)/plasmin system is thought to be involved in processes such as tumor invasion and wound healing, during which epithelial and mesenchymal cells come close together. However, information on regulation of the PA/plasmin system during epithelial-mesenchymal interactions is scarce. Therefore, we examined the in vitro modulation of the production and activity of the components of the PA/plasmin system in squamous carcinoma cells (SCC-4) and normal human keratinocytes in relation to cell density and the presence or absence of fibroblasts (3T3 cells). There was an inverse relation between cell density and mRNA expression for urokinase-type plasminogen activator (u-PA) and u-PA receptor in both SCC-4 cells and keratinocytes. In addition, such a relation was found for plasminogen activator inhibitor types 1 (PAI-1) and 2 (PAI-2) in SCC-4 monocultures, but not in keratinocyte monocultures. In contrast to monocultures, variation of cell density did not affect the mRNA expression of the components of the PA/plasmin system in cocultures of SCC-4 cells or keratinocytes with 3T3 cells. However, the relative expression of mRNAs in co-cultures was clearly different from that in monocultures, especially at low cell density. For most of the components of the PA/plasmin system, a decrease in mRNA expression and u-PA receptor protein was observed at most cell densities, whereas for PAI-1 only in keratinocytes a marked increase was documented. Zymography of supernatants revealed that the levels of both free u-PA and PA-PAI were increased in SCC-4/3T3 co-cultures, whereas in keratinocytes/3T3 co-cultures, only levels of the PA-PAI complex were increased, while the amount of free u-PA activity decreased. This occurred despite the increase u-PA immunoreactivity and was probably caused by the markedly elevated levels of immunoreactive PAI-1. The results of the present study reveal that the production and synthesis of various components of the PA/plasmin system in keratinocytes and SCC-4 cells depend on the density of epithelial cells and are modulated by fibroblasts, probably through a direct cell-cell or cell-matrix contact. Fibroblast-induced modulations are similar in keratinocytes and SCC-4 cells except for the regulation of PAI-1, which is markedly enhanced only in keratinocytes. This suggests that the modulation of PA activity in the direct microenvironment may be different under physiologic and pathologic conditions.
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PMID:Differential regulation of plasminogen activation in normal keratinocytes and SCC-4 cells by fibroblasts. 786 Oct 5

Human colorectal carcinogenesis has been shown previously to be associated with impressive changes in the tissue levels of plasminogen activators and their inhibitors, exemplified by an increase in the urokinase-type plasminogen activator (u-PA) and the inhibitors PAI-1 and PAI-2, and a decrease in tissue-type plasminogen activator (t-PA). In the present study we evaluated the prognostic significance of these parameters to the overall survival of patients with colorectal cancer, in conjunction with several major clinicopathological parameters like age, gender, differentiation grade, and Dukes' stage. Univariate analyses revealed that a low t-PA antigen level, low t-PA activity, and high u-PA/t-PA antigen ratio in normal mucosa and a high u-PA and PAI-2 antigen level in carcinomas are prognostic for a poor overall survival of patients with colorectal cancer. The prognostic value of t-PA antigen and activity in normal mucosa, the antigen ratio of u-PA in carcinoma (C) and t-PA in corresponding normal (N) mucosa [u-PA(C)/t-PA(N) antigen ratio], and PAI-2 antigen in carcinomas was found to be independent from clinicopathological parameters by multivariate analyses. These observations illustrate the clinical importance of the plasminogen activation cascade at the tissue level in colorectal cancer invasion, metastasis, and survival.
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PMID:Prognostic relevance of plasminogen activators and their inhibitors in colorectal cancer. 803 38

The biochemical events associated with tumor invasion involve localized degradation of the basement membrane by tumor-associated proteinases. In this study, we have characterized the proteinase secretion profiles of 5 ovarian epithelial carcinoma cell lines (DOV 13, OVCA 420, OVCA 429, OVCA 432, OVCA 433) as well as normal ovarian epithelial cells. Immunocapture assays demonstrated that all 5 carcinoma cell lines produce both secreted and surface-associated plasminogen activator. Urinary-type plasminogen activator (u-PA) production was one order of magnitude greater than production of tissue-type plasminogen activator (t-PA). Furthermore, t-PA secretion by normal ovarian epithelial cells was not detectable, whereas u-PA production was 17- to 38-fold lower than in ovarian carcinoma cells. Western-blotting analysis demonstrated that u-PA was secreted as the single chain form (scu-PA) when cells were cultured in serum-free medium. Incubation of plasminogen with ovarian carcinoma cell-conditioned medium resulted in direct activation of the zymogen to plasmin. Furthermore, following incubation of cells with plasminogen, plasmin was eluted from the cell surface, indicating that ovarian carcinoma cells contain binding sites for plasminogen/plasmin which are accessible to surface-associated plasminogen activators. In addition to plasminogen activators, metalloproteinases were also produced by DOV 13, OVCA 429 and OVCA 433 cells. DOV 13 cells produce a 68-kDa metalloproteinase similar to matrix metalloproteinase 2 (MMP-2) whereas a 92-kDa enzyme similar to MMP-9 is secreted by OVCA 429 and 433. Together, ovarian carcinoma-associated plasminogen activators and metalloproteinases catalyze the hydrolysis of the major basement membrane protein components, type-IV collagen, type-IV gelatin, laminin and fibronectin. The enhanced proteolytic capability of ovarian carcinoma cells relative to normal ovarian epithelium suggests a biochemical mechanism by which invasion and spread of ovarian epithelial carcinoma may be mediated.
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PMID:Secretion of extracellular matrix-degrading proteinases is increased in epithelial ovarian carcinoma. 811 91

Expression of plasminogen activators (PA), tissue type (t-PA) and urokinase type (u-PA), as well as PA inhibitors (PAI), type-1 (PAI-1) and type 2 (PAI-2), were investigated immunohistochemically in 97 human pancreatic carcinomas. u-PA expression predominated in pancreatic carcinomas, compared with t-PA [u-PA expression in 76 specimens (78.4%) and t-PA in eight specimens (8.2%)]. PAI-1 expression was detected in 80 carcinoma specimens (82.5%) and PAI-2 in 79 carcinoma specimens (81.4%). PAI-2 expression was significantly lower in carcinomas with peritoneal metastasis (p < 0.02). Strong PAI-2 expression was associated with significantly higher survival than negative or weak PAI-2 expression (p < 0.05). We conclude that immunohistochemical analysis of PAI-2 expression in pancreatic carcinomas may yield important prognostic information.
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PMID:Expression of plasminogen activators and their inhibitors in human pancreatic carcinoma: immunohistochemical study. 823 43

Tumor cell adherence (TCA) to sites of surgical injury is a requisite step in implantation-mediated tumor recurrence. This study examined the relationship between tumor-associated plasminogen activator (PA) and the ability of tumor cells to remain adherent to surgical injury sites. High (1E8) and low (3A9) PA producing clones from the murine transitional carcinoma cell line 4909 were selected using an in vitro 125I fibrinolysis assay. Net cellular PA activity of each clone was determined from cell lysates using a chromogenic substrate assay. In vitro TCA and fibrin substrate lysis as a function of time were simultaneously measured using a tetrazolium dye assay in combination with an 125I fibrinolysis assay. In vivo TCA to in situ cautery-injured rat bladders was measured 30 minutes (n = 12 animals/cell line) and 24 hours (n = 18 animals/cell line) following tumor exposure with a radiolabeled TCA assay. In vitro and in vivo competitive binding assays evaluated the relative adherence of mixtures of the 1E8 and 3A9 clones. Cellular PA activity was 0.022, 0.014 and 0.007 units per mg. protein for the 1E8, 4909 and 3A9 cell lines. In vitro TCA to fibrin in the presence of plasminogen was significantly different for each cell line and demonstrated an inverse relationship with both plasminogen-dependent fibrin lysis and cellular PA activity (p < 0.0001). The in vivo assay showed that the percentage of 1E8 cells remaining adherent 24 hours after tumor exposure was significantly less than that of the 3A9 cells (p = 0.01). Both in vitro and in vivo competitive binding assays demonstrated preferential adherence of the 3A9 cell line. Cellular PA production appears to be a tumor-intrinsic variable that modulates TCA to surgical injury sites.
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PMID:Plasminogen activators: regulators of tumor cell adherence to sites of lower urinary tract surgical trauma. 834 79


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