Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.4.21.7 (plasmin)
 9,023 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

In untreated patients with inoperable lung cancer, serum levels of alpha1-antitrypsin were found significantly increased in comparison to patients with non malignant diseases of the lung, alpha2-macroglobulin levels were unchanged in both groups of patients. There was also no difference in alpha2-macroglobulins in cancer patients reacting with DNCB and in non-reactors. Thus alpha2-macroglobulin levels do not seem to correlate with the immunestatus of cancer patients. Proteinase inhibitors are involved in a variety of biological processes including blood, clotting, digestion, and sperm capacitation. alpha1-antitrypsin, a alpha-globulin with a molecular weight of about 60,000 has been found to be decreased in patients' serum under several pathological conditions. A clear correlation exists between alpha1-antitrypsin deficiency and hereditary pulmonary emphysema (1, 2), respiratory distress syndrome (3), and juvenile cirrhoses of the liver (4). Elevated serum levels of alpha1-antitrypsin have also been found in some cancer cases. Thirty years ago a cancer test was developed on the basis of differences in the antiproteolytic activity in cancer patients' sera and in patients with other non-neoplastic diseases (5, 6). Several authors have tried to confirm these early data regarding specifity and sensitivity with respect to a screening test for cancer (7, 8). Methods of these authors were based mainly on enzyme substrate inhibition assays by addition of the patients' sera. Recently a commercially available test, based on immune-precipitation according to Mancini (9), has been developed (Behring-Werke, Partigen). By using this standardized method for determinating alpha1-antitrypsin, Harris et al. have recently demonstrated that patients with inoperable lung cancer have significantly elevated levels of this antiprotease in their sera (10), in comparison to patients with non malignant diseases of the lung. alpha2-macroglobulin is a serum protein with a molecular weight of 800,000 and with known antiprotease activity and can therefore bind trypsin, plasmin, elastase, and collagenase and it is known that alpha2-macroglobulin decreases with increasing of age. Changes of alpha-macroglobulin have also been observed in several pathological conditions (11). James et al. 4ave found decreases in serum of myeloma patients (12). An association between the development and function of lymphocytes and alpha2-macroglobulin has been suggested by several authors (13, 14). This alpha2-globulin has also been demonstrated on the surface of peripheral blood lymphocytes (15) and there is evidence that it is synthesized by lymphocytes (16). The purpose of the present study was to determine serum alpha1-antitrypsin levels in patients with inoperable lung cancer and to determine whether there is also an inverse correlation to alpha2-macroglobulin. It was further attempted to correlate alpha2-macroglobulin with general immunological parameters, as it is known that patients with lung cancer show a decreased general immune-reactivity (17).
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PMID:Serum levels of alpha1-antitrypsin and alpha2-macroglobulin in lung cancer. 6 86

Component levels of the fibrinolysin system in the plasma and ascitic fluid of Swiss mice bearing Ehrlich ascites tumor cells were determined during a 15-day tumor growth time phase. During tumor growth, the concentration of plasminogen in the ascitic fluid decreased inversely to the total packed cell volume. Free plasmin was not present in the ascitic fluid nor was there any measurable plasminogen activator activity. Both antiplasmin activity and fibrinogen levels present in the fluid decreased during tumor growth. The nuclear and mitochondrial-microsomal subcellular fractions of the tumor cell exhibited plasminogen activator activity. No significant changes in the above parameters occurred in the plasma during the tumor growth period we studied.
J Natl Cancer Inst 1975 Apr
PMID:Proteases during the growth of Ehrlich ascites tumor. I. The fibrinolysin system. 12 66

Upon the plasmin digestion of human fibrinogen, an early cleavage product, which has been designated as fragment A, was isolated, and to study the action of plasmin in the circulation, radioimmunoassay for fragment A was carried out. This assay used rabbit immune serum obtained by injection of fragment A mixed with complete Freund's adjuvant, and fragment A was labeled with 125I using the Chloramin-T method. In 20 normal healthy donors its serum level was 3.57 +/- 1.62 microgram/ml (mean +/- SD), and it was increased significantly in certain diseases, such as acute leukemias, cardiovascular disorders, malignancies, renal failure, systemic lupus erythematosus and sepsis.
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PMID:Radioimmunoassay of an early plasmin degradation product of human fibrinogen, "fragment A", and its clinical application. 14 16

Plasminogen activator of cell origin converts the plasma protein plasminogen to the proteolytic enzyme plasmin. Recently, high levels of activator have been observed to be particularly associated with tumours and transformed cells, and a functional relationship between plasminogen activation and malignancy has been proposed. In this paper we have attempted to induce transformation-like morphology and growth in a population of confluent quiescent cells in tissue culture, by inducing plasminogen activation. Untransformed 3T3 cells grown to confluence in plasminogen-free medium were subjected to plasminogen activation by the addition of urokinase and plasminogen or plasminogen-containing acid-treated serum, or plasmin. Under these conditions, the previously well ordered monolayers became disrupted, with multilayering, and discontinuities in the cell sheet, and the cells simultaneously grew to significantly higher densities. Removal of the plasmin-containing medium supplements effected some restoration of normal morphology. Thus, lhen plasmin was present 3T3 cells did not become transformed, but expresses transformation-like features. Well ordered monolayer morphology and quiescence in 3T3 cells at confluence are therefore dependent upon the absence of plasminogen activation.
Br J Cancer 1979 Jun
PMID:Plasminogen activation transforms the morphology of quiescent 3T3 cell monolayers and initiates growth. 15 38

Biolgic distribution of 99mTc-labeled fibrinolytic agent, urokinase, and 99mTc-labeled mannitol, which was obtained as a side-product in the preparation of 99mTc(Sn)-urokinase, have been studied in Ehrlich's tumor-bearing mice to get a promising indicator for the positive delineation of malignant tumor. The preparation of 99mTc-labeled radiopharmaceuticals, 99mTc-UK and 99mTc-Man, was made by the reduction with stannous chloride and labeling efficiency was examined by Sephadex G-25M gel chromatography and by silica gel plate thin layer chromatography. Labeling yield of 99mTc-UK by Sephadex G25M in 0.9% NaCl eluant was 13% and that of 99mTc-Man by TLC in 85% methanol solvent was over 95%. A higher uptake to the implanted solid tumor tissue in mice was found in 99mTc-Man than in 99mTc-UK, of which the excellent tumor accumulation was expected from the positive delineation of malignant tumor with 131I-fibrinogen, 131I-fibrinogen antibody and 125I-plasmin. The poor result in 99mTc-UK, however, may be attributed to the poor fibrinolytic activity of Ehrlich's tumor. In biologic distribution of 99mTc-UK was found high concentration for liver kidney and stomach. In the other hand, a higher tumor tissue uptake, a fast blood disappearance and a low concentration for different organs were found in biologic distribution of 99mTc-Man. Therefore, 99mTc-Man may be assumed as a more preferable 99mTc-labeled tumor localizing radiopharmaceuticals, to which it would be needed as absolute biologic characteristics that 99mTc-labeled compounds possess a high tumor uptake as well as a fast blood disappearance with a low uptake for different organs. However, the possible delineation with 99mTc-labeled fibrinolytic agents, including urokinase and streptokinase, may be promised for malignant tumors in human-subject, which generally have a higher activity in fibrinogenesis than in fibrinolysis.
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PMID:[Tumor affinity of 99mTc-labeled radiopharmaceuticals, 99mTc-Sn-urokinase and 99mTc-Sn-mannitol]. 57 26

In the last 11 years the authors have succeeded in isolating nearly 40 enzyme inhibitors of small molecular size from microbial origins. These inhibitors proved to be not only useful tools in analyses of homeostasis of living organisms but also promising agents for cancer chemotherapy. Leupeptin was originally isolated as an inhibitor against serine or thiol proteases such as trypsin, plasmin, papain and cathepsin B. And soon it was demonstrated that leupeptin suppressed chemical carcinogenesis in rats. Pepstatin has an extremely strong activity to inhibit pepsin and cathepsin D. It also inhibits ascites accumulation caused by neoplastic diseases. Bestatin is a specific inhibitor against aminopeptidase B and leucine aminopeptidase. The enzymes are located on the surface membrane in various kinds of cells including lymphocytes. Bestatin was shown to enhance not only blastogenesis of lymphocytes in vitro but also establishment of delayed-type hypersensitivity in vivo. Combined use of bestatin and other antitumor agents gave promising results in animal experiments. Studies on enzyme inhibitors have provided us a new approach to cancer chemotherapy.
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PMID:Enzyme inhibitors in relation to cancer therapy. 61 3

Thromboplastic and fibrinolytic activities of 14 lines of cultured human cancer cells were estimated by modified Astrup's methods. High tissue thromboplastic activity was found in one line of urinary-bladder cancer, 2 lines of gastric cancer and one line of lung cancer, but no activity was found in 6 lines of lung cancer. High fibrinolytic activity was noted in one line of gastric cancer and 2 lines of lung cancer, but no activity was seen in 6 lines of lung cancer and one line of gastric cancer. No plasmin activity was found. The tumour cell lines could be classified into 3 groups on the basis of the 2 activities. Cancer cell lines could also be classified into 2 groups: with high or low release of thromboplastin into culture media. Fibrinolytic activity was found in the culture media of all cell lines with high fibrinolytic activity. Fibrinolytic activity, but not thromboplastic activity, seemed to be influenced by the constituents of culture media. No definite correlation was found between the 2 activities and the histological types of the parent tumours of the cultured cells.
Br J Cancer 1979 Jan
PMID:Thromboplastic and fibrinolytic activities of cultured human cancer cell lines. 75 28

Anticoagulants (heparin, warfarin, fibrinolysin and others) reduced incidence of cancer metastases by inhibiting the formation of a fibrin matrix indispensable for peripheral fixation of circulating cancer cells. Apart from their specific anticoagulant activity most of these substances interfere directly with cell growth and metabolism, stimulating also immunologic anticancer mechanism. In clinical cases, favourable results have been obtained in various forms of metastasizing cancer, and especially in Hodgkin's disease and leukemias, by combining anticoagulant and cytostatic treatment. The results observed in other forms of cancer, though promising, are still controversial. The potential dangers and side effects of anticoagulant treatment in cancer are discussed.
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PMID:Anticoagulants and cancer. A review. 76 99

Cultured mouse blastocysts produce plasminogen activator, a protease that converts the zymogen plasminogen into the trypsin-like enzyme, plasmin. We have fractionated the blastocyst and cultured the constituent cell types. Trophoblast outgrowths free of inner cell mass derivatives secrete plasminogen activator during a time period that closely parallels the invasive phase of trophoblast cells in utero. Isolated inner cell masses also produce plasminogen activator; further fractionation of the inner cell mass as well as studies with primary cultures obtained from midgestation tissues demonstrate that enzyme formation is restricted entirely to parietal endoderm cells. Secretion of the enzyme may facilitate the migration of parietal endoderm cells along the trophoblast layer as the yolk sac cavity enlarges during gestation. F9 embryonal carcinoma cells do not secrete detectable amounts of plasminogen activator. However, when these cells are induced to differentiate, the resulting parietal endoderm-like cells are capable of producing the enzyme. These results are consistent with previous findings suggesting that plasminogen activator production may be a characteristic of invasive and/or migratory cells.
Cancer Res 1976 Nov
PMID:Differentiation of early mouse embryonic and teratocarcinoma cells in vitro: plasminogen activator production. 97 58

Electrophoresis in 3.5% polyacrylamide gel was used to determine the patterns of fibrinogen heterogeneity in healthy subjects, in postoperative patients and in patients with cancer or occlusive vascular disease. Two major and one minor fibrinogen fractions, differing in molecular weight, were identified, and their concentrations in blood determined. The high-molecular-weight (HWM) fraction was found in greatest concentration after operation, during the period of hyperfibrinogenemia, whereas no simultaneous increase of lower-molecular-weight (LMW and LMW') fractions occurred, suggesting that these were derivatives of HMW ("native") fibrinogen. No correlation between the concentrations of the LMW and LMW' fractions and fibrinolytic activity was found, suggesting that direct degradation of HMW fibrinogen by plasmin was unlikely. The high fibrinogen level in cancer patients was related to increased concentrations of HMW and LMW fractions, whereas in the vascular-disease patients it was due exclusively to increased concentrations of LMW and LMW' fibrinogen. Serial observations indicated little fluctuation in the concentration of these fractions, indicating a persistently accelerated rate of conversion of HMW to LMW and LMW' fibrinogen in occlusive vascular disease. Possible pathogenic implications are discussed.
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PMID:Fibrinogen heterogeneity in cancer, in occlusive vascular disease, and after surgical procedures. 99 69


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