Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0027627 (metastases)
 103,950 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The increased expression of proteolytic systems is one of the characteristics of transformed and malignant cells and their evaluations in whole tumor homogenates were considered as possible diagnostic and/or prognostic factors. Abnormal intracellular distribution, increased activities and secretion of cysteine proteinases (CPs) cathepsin B (Cat B) and L (Cat L), were associated with tumor progression. In the present study of matched pairs of breast carcinoma and normal breast tissue, the activities of Cat B and Cat L in breast carcinoma homogenates were found to be 20 and 50 fold higher, respectively, than in normal tissues. In contrast, a decrease in total inhibitory activity of cysteine proteinase inhibitors (CPIs) was observed but an average ratio between tumor and normal tissues was only 0.75. One of the CPIs, stefin A, was also determined immunochemically. The activities of CPs and CPIs were compared to the increased levels of cathepsin D (Cat D) activities in individual patients, but no statistically significant correlations were found. We correlated CPs and CPIs with morphological and receptor data as well as the axillary lymph node metastases. There was no statistical correlation of CP and CPIs with the number of lymph node metastases. However, highly elevated levels of Cat B and Cat L and lowered CPI activities in tumor cytosols were often associated with poorly differentiated carcinomas and those with negative ER and PR values. We conclude that cysteine-dependent proteolysis may play an important role in breast tumors.
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PMID:Cystatins and cathepsins in breast carcinoma. 151 89

Evidence has accumulated that invasion and metastasis in solid tumors require the action of tumor-associated proteases, which promote the dissolution of the surrounding tumor matrix and the basement membranes. Receptor-bound urokinase-type plasminogen activator (uPA) appears to play a key role in these events. uPA converts plasminogen into plasmin and thus mediates pericellular proteolysis during cell migration and tissue remodeling under physiological and pathophysiological conditions. uPA is secreted as an enzymatically inactive proenzyme (pro-uPA) by tumor cells and stroma cells. uPA exerts its proteolytic function on normal cells and tumor cells as an ectoenzyme after having bound to a high-affinity cell surface receptor. After binding, pro-uPA is activated by serine proteases (e.g. plasmin, trypsin or plasma kallikrein) and by the cysteine proteases cathepsin B or L, resp. Receptor-bound enzymatically active uPA converts plasminogen to plasmin which is bound to a different low-affinity receptor on tumor cells. Plasmin then degrades components of the tumor stroma (e.g. fibrin, fibronectin, proteoglycans, laminin) and may activate procollagenase type IV which degrades collagen type IV, a major part of the basement membrane. Hence receptor-bound uPA will promote plasminogen activation and thus the dissolution of the tumor matrix and the basement membrane which is a prerequisite for invasion and metastasis. Tissues of primary cancer and/or metastases of the breast, ovary, prostate, cervix uteri, bladder, lung and of the gastrointestinal tract contain elevated levels of uPA compared to benign tissues. In breast cancer uPA and PAI-1 antigen in tumor tissue extracts are independent prognostic factors for relapse-free and overall survival.
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PMID:Tumor-associated urokinase-type plasminogen activator: biological and clinical significance. 151 91

The production of metastasis appears to involve a number of different proteases including the urokinase form of plasminogen activator, cathepsin B, cathepsin D and various metalloproteases. Early data implicating these proteases in metastasis were mostly indirect and based on correlation studies in animal models. More recent work, using specific protease inhibitors and antibodies against proteases to block experimental metastasis, have provided more direct evidence that proteases play a role in cancer spread. In addition, transfection of genes encoding certain proteases increases the metastatic phenotype of the recipient cells. In human tumours, a number of different proteases also correlate with metastatic potential. It is concluded that certain proteases may be new prognostic markers in cancer as well as new targets for anti-metastatic therapy.
Clin Exp Metastasis 1992 May
PMID:The role of proteolytic enzymes in cancer invasion and metastasis. 158 84

Several lysosomal proteinases including the cysteine proteinase cathepsin B have been implicated in malignant progression of tumors. Many investigators have demonstrated correlations between increased activity of cathepsin B and increased metastatic capability of animal tumors or malignancy of human tumors. Such increases in cathepsin B activity in malignant tumors may reflect alterations in synthesis, in activation and processing, and/or in intracellular trafficking and delivery as well as in the endogenous inhibitors of cathepsin B. Increases in mRNA transcripts for cathepsin B have been observed in both murine and human tumors and multiple transcripts for cathepsin B have been identified, but an association of multiple transcripts with malignancy has not been confirmed. Cathepsin B precursors found in human malignant ascites fluid do not possess mannose-rich carbohydrates suggesting that a defect in the post translational processing of carbohydrate moieties on tumor cathepsin B may be responsible for the release of cathepsin B observed in many tumor systems. However, the intracellular trafficking of cathepsin B responsible for its association with plasma membrane/endosomal systems and for its release will require further study as both latent, precursor forms of cathepsin B and native forms of cathepsin B are involved. We speculate that malignant tumor cells adherent to basement membrane are capable of forming a digestive microenvironment in which lysosomal proteinases such as cathepsin B function optimally, a microenvironment similar to that formed between adherent osteoclasts and bone. One of the endogenous cysteine proteinase inhibitors, stefin A, also is affected by malignancy. Reduced expression (mRNA and protein) of stefin A is found as well as a reduction in its inhibitory capacity against cysteine proteinases. The data to date at both the molecular and protein levels supporting a functional role(s) for cathepsin B and its endogenous inhibitors in cancer progression are only correlative. Experimental approaches utilizing well-defined model systems in conjunction with genetic manipulation of cathepsin B and its endogenous inhibitors are needed to provide convincing evidence that cathepsin B has an important role in cancer.
Cancer Metastasis Rev 1990 Dec
PMID:Cathepsin B and its endogenous inhibitors: the role in tumor malignancy. 209 84

Cancers and parasites have a number of properties in common, particularly those that relate to their respective capacities to evade host defence mechanisms. This review highlights the similarities between metastatic tumours and schistosomes in particular, and describes the role that proteases may have in the migration, growth, survival and transmission of the different stages of the schistosome life-cycle in the vertebrate host. An elastase-like serine protease of schistosome larvae has been particularly well characterized, and its substrate profile and other properties are indicative of a role in facilitating migration of the parasite through skin tissue early after infection. The primary structures of a cathepsin B-like enzyme, and a putative 'haemoglobinase' found in adult worms have also recently been derived, these enzymes being responsible for degradation of haemoglobin in erythrocytes upon which the adults feed. Adult schistosome worms reside and produce eggs intravascularly, and the processes that mediate the extravasation and subsequent migration of the egg through host tissue are dependent on both blood platelets and the immune response. Fibrino(geno)lytic enzymatic activity that is present in the egg could modulate the thrombogenic potential that eggs might have as a result of their capacity to cause platelet aggregation in vitro and in vivo. The roles of other proteases and peptidases that have been found in schistosome larvae, worms and eggs are less clear. Some of these enzymes may modulate immunological and haemostatic defence mechanisms and thus prolong survival of the parasite, and the consequences of the interactions between schistosomes and host protease inhibitors could also be immune modulatory.
Cancer Metastasis Rev 1990 Dec
PMID:Proteases in the schistosome life cycle: a paradigm for tumour metastasis. 209 86

Lysosomal cysteine proteinases, cathepsins B, H and L, and tumor cathepsin-B-like protease, are capable of digesting bovine lens capsule, a typical basement membrane, in vitro. Cathepsins L and H proved most active in the pH range 5.0-7.0, whereas cathepsin B and cathepsin B-like protease showed greatest activity at pH 3.0. The process was slow and involved binding of the proteases to the basement membrane. These proteases, of which some are produced by malignant cells, may contribute to tumor spread and progression to metastatic disease.
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PMID:[Digestion in vitro of basal membrane, bovine lens capsule, by human liver lysosome cathepsins B, H and L and ascitic fluid tumor cathepsin B from ovarian adenocarcinoma]. 229 Jun 99

Treatment of tumor cells that have little if any metastatic potential with certain drugs that have little or no mutagenic activity has been found to result in marked phenotypic alterations of the cells, including development of a metastatic potential. We found that polar compounds and butyric acid, which are known to alter the expressions of normally silent genes, enhanced the lung-colonizing ability of cloned low-metastatic Lewis lung carcinoma cells. This change was accompanied by increases in the activities of degradative enzymes such as glycosidases, cathepsin B, and plasminogen activator; adhesion of the cells to culture dishes, monolayers of endothelial cells, and a subendothelial matrix; and homotypic aggregation. The effects of these drugs in enhancing the lung-colonizing ability of the cells was found to be reversible, suggesting that it was due to epigenetic alterations. Other investigators have shown that treatment of nonmetastatic tumor cells with 5-azacytidine, which causes hypomethylation of DNA and activates normally silent genes, results in the emergence of a small number of clones with a heritable but unstable metastatic phenotype. These findings suggest that epigenetic mechanisms are involved in rapid cellular phenotypic diversification and tumor progression.
Cancer Metastasis Rev 1986
PMID:Modification of the metastatic potential of tumor cells by drugs. 243 28

Cathepsin B activity, including that of a plasma membrane-associated cathepsin B, has been linked to tumor malignancy. As cathepsin B at the tumor cell surface has been hypothesized to play a role in the focal degradation of basement membrane during the metastatic cascade, we have examined the ability of human tumor cathepsin B to degrade laminin, an adhesive glycoprotein found exclusively in the basement membrane. We report that at pH 6.5 and 7.0 tumor cathepsin B degraded by specific, limited proteolysis both subunits of native laminin. The disappearance of both subunits and the appearance of lower Mr protein bands could be observed by sodium dodecyl sulfate polyacrylamide gel electrophoresis. Accumulation of degradation products was also observed using gel filtration chromatography and a fluorescamine assay. The proteolysis of laminin by tumor cathepsin B could be inhibited by an active site titrant for cysteine proteinases or stefin B, an endogenous low-Mr cysteine proteinase inhibitor.
Clin Exp Metastasis
PMID:Degradation of laminin by human tumor cathepsin B. 278 14

Malignant cells have the ability to invade and metastasize in great part because they secrete proteolytic enzymes. In order to investigate if the abnormal proteinase/antiproteinase balance of cancer bearing patients changes when the malignant tumor is destroyed, we studied 50 patients with invasive carcinoma of the cervix and 33 healthy women as a control group. Patients with cancer were treated with radiation according to the protocols of our hospital. The following serum determinations were performed: plasminogen activators (PA), cathepsin B (CB), antiproteinase alpha-1-antitrypsin (A1AT), trypsin inhibitory capacity (TIC) and antiproteolitic activity ratio (AAR), all of them before and after treatment. Serum proteolytic activity was elevated manyfold in all patients with invasive tumor as well A1AT. The antiproteolytic activity however, was significantly reduced to about 50% of its normal value in the same group of patients. In patients with good response to radiotherapy (tumor necrosis) a great reduction of proteinase activity as well as a recovery to normal of the AAR was observed. Contrary, in those with a poor response after radiation, proteolytic activity remained elevated and AAR diminished. It is concluded that serum PA, CB, A1AT and AAR values can be precise indicators of the presence of malignancy. These tests might be also of help for improving follow-up studies and for better prognostic estimates.
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PMID:[Protease-antiprotease balance in patients with invasive carcinoma of the cervix and uterus before and after radiotherapy]. 278 98

The cysteine proteinase cathepsin B (EC 3.4.22.1) is believed to take part in biochemical processes underlying tumor metastasis. In the present study, the cellular localization, intracellular levels and extracellular release of cathepsin B activity were examined in vitro in cells of two rat sarcoma variants, LW13K2 and RPS, differing in their capacity to metastasize spontaneously to the lung of syngeneic LEW/CUB rats. The LW13K2 sarcoma metastasizes rarely, whereas the LW13K2-derived RPS variant produces a metastasis incidence of above 50%. Using fluorescent cytochemical staining, microgranular reaction centers of cathepsin B were observed in the cell cytoplasm, in some cellular processes, with apical localization in some of them, as well as at the extreme cell periphery in cells of both sarcoma variants. The appearance of this distribution of cathepsin B activity was delayed in the RPS variant. Biochemically, the intracellular level of cathepsin B activity was significantly higher in homogenates of LW13K2 cells than RPS cells. In contrast to the intracellular enzyme activity, RPS cells cultured in serum-free medium at pH 6.5 released a substantially higher amount of cathepsin B activity than LW13K2 cells into the extracellular environment; at pH 7.4 the initially higher release of cathepsin B activity from RPS cells later equalized with that from LW13K2 cells. Taken together, the results indicate that changes of pericellular pH can modulate the extracellular release of cathepsin B in both sarcoma cell variants and suggest that the rate of cathepsin B release under conditions of mildly acid pericellular pH could be related to the incidence of metastases observed in these rat sarcoma variants. Total intracellular cathepsin B activity did not exhibit positive correlation with the metastatic potential of the studied rat sarcoma variants.
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PMID:Cathepsin B in cells of two rat sarcomas with different rates of spontaneous metastasis. 281 49


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