Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.4.23.5 (cathepsin D)
 4,130 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Urokinase (u-PA) proteolytically cleaves both human plasma (pFn) and cellular (cFn) dimeric fibronectin (M(r) 440,000) into four major polypeptides of approximately M(r) 210,000, 200,000, 25,000, and 6,000. Amino acid sequence analysis of the polypeptide fragments indicated that the enzymatic cleavage of Fn occurs at two sites: 1) between an arginine/alanine peptide bond located C-terminal to residue 259; this cleavage liberates the N-terminal M(r) 25,000 fragment and the M(r) 210,000 and M(r) 200,000 polypeptides derived from the A and B chains of Fn, respectively; and 2) between an arginine/threonine peptide bond located C-terminal to residue 2,299, thereby yielding an M(r) 6,000 dimeric fragment containing the C-terminal interchain disulfide bonds. Predigestion of Fn with u-PA increased the molecule's vulnerability to further attack by the enzymes plasmin and cathepsin D. These data provide further biochemical evidence for the proteolytic cleavage of fibronectin by plasminogen activators and substantiate that u-PA digestion of Fn may be an initial event in the local degradation of the extracellular matrix by malignant cells, possessing elevated levels of these enzymes.
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PMID:Localization of the cleavage sites on fibronectin following digestion by urokinase. 146 74

Tumor cell invasion and metastasis is a multifactorial process, which at each step may require the action of proteolytic enzymes such as collagenases, cathepsins, plasmin, or plasminogen activators. An enzymatically inactive proenzyme form of the urokinase-type plasminogen activator (pro-uPA) is secreted by tumor cells which may be converted to an enzymatically active two-chain uPA-molecule (HMW-uPA) by plasmin-like enzymes. Action of proteases on pro-uPA may generate the enzymatically active or inactive high-molecular-weight form of uPA (HMW-uPA). Some proteases (plasmin, cathepsin B and L, kallikrein, trypsin or thermolysin) activate pro-uPA by cleaving the peptide bond Lys158 and IIe159. Other proteases (elastase, thrombin) cleave pro-uPA at different positions to yield enzymatically inactive HMW-uPA. HMW-uPA may be split into the enzymatically active LMW-uPA and the enzymatically inactive ATF (amino terminal fragment). ATF may be cleaved between peptide sequence 20 and 40 within the receptor binding domain of uPA (GFD). Such impaired ATF does not bind to uPA-receptors. Action of the bacterial endoproteinase Asp-N from Pseudomonas fragi mutant on pro-uPA or HMW-uPA, however, generates intact ATF which efficiently competes for binding of HMW-uPA or pro-uPA to receptors on tumor cells. High uPA-antigen content (pro-uPA, HMW-uPA, or LMW-uPA) in breast cancer tissue (not in plasma) indicates an elevated risk for the patient of recurrences and shorter overall survival. Thus pro-uPA/uPA-antigen content in breast cancer tissue serves as an independent prognostic parameter for the outcome of the disease. Cathepsin D is also an independent prognostic factor for recurrences and overall survival. High content of cathepsin D in breast cancer tumors is, however, not correlated with elevated levels of pro-uPA/uPA indicating that synthesis and release of cathepsin D and pro-uPA/uPA are independent events.
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PMID:Biological and clinical relevance of the urokinase-type plasminogen activator (uPA) in breast cancer. 180 51

The concentrations of cathepsin D (Cath D), urokinase (uPA) and two plasminogen activator inhibitors (PAI-1 and PAI-2) were analysed in the cytosols of 130 human mammary tumours (43 benign tumours and 87 primary and unilateral breast carcinomas). uPA, PAI-1 and PAI-2 levels were measured by antigenic immunoassays and Cath D by immunoradiometric assay. The median levels of the four parameters were significantly higher in the malignant tumours than in the benign ones. Cath D and uPA increases were 4-fold and 5-fold respectively. PAI-1 and PAI-2 increases were much more important, 74-fold and 29-fold respectively. In malignant tumours, median levels of Cath D and uPA did not vary according to classical prognostic factors (histologic grade, presence or absence of axillary lymph nodes, steroid receptors, UICC stage, tumour size, age, and menopausal status). However, PAI-1 decreased in ER+ and PR+ tumours and PAI-2 increased in menopausal women's tumours. When Cath D, uPA, PAI-1 and PAI-2 levels in malignant tumours were compared, positive correlations were found for all combinations. The implication of plasminogen activator inhibitors in the phenomenon was surprising and merits further investigation using tools other than global antigen measurements in tumours.
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PMID:Relationship between cathepsin D, urokinase, and plasminogen activator inhibitors in malignant vs benign breast tumours. 193 18

The capacity of solid tumours to invade the surrounding tissue and to metastasize, is correlated with the formation and degradation of structural elements in the vicinity of the tumour cells. Substances with both procoagulant activity and fibrinolytic activity are important factors in the formation or degradation of a "fibrin-fibronectin-gel matrix". This gel is subsequently transformed into the extracellular matrix, which, together with cells, will form the tumour stroma. When analyzing tumour stroma degradation products, it is obvious that the protease plasmin catalyses the disintegration of fibrin and fibronectin. Additional compounds of the tumour stroma and of the basal membrane are also, at least in part, broken down by plasmin or other proteases, such as collagenase IV and cathepsin D. The plasminogen activator urokinase (uPA) seems to play a central role as it was shown that elevated content of uPA is correlated with a high risk of early relapse and shorter overall survival, at least in breast cancer. It has been shown, that by means of quantifying uPA, patients with a relative high or low risk can even be selected within the classical risk groups, which so far are defined by the locoregional extension of the tumour and the hormone receptor status only. Evidently, as uPA content in human breast cancer tissue is an independent prognostic factor, one may speculate, that those experimental or in vitro data, which correlated increase in uPA-synthesis with malignancy, may be of direct relevance for human tumour biology. Moreover, due to these recent observations on the prognostic significance of tumour-associated proteases, new aspects for the selection of risk collectives within the node-negative breast cancer patients for adjuvant therapy have to be considered. It may well be possible, that one may affect tumour invasion and metastasis by inhibiting protease action of solid tumours by disturbing the binding of proteases to tumour cell surface receptors. As it is only a quantitative aspect, which separates benign physiological processes from tumour cell pathophysiology, experimental evidence suggests, that less drastic forms of palliative therapy can be proposed.
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PMID:[Clinical and prognostic significance of tumor-associated proteases in gynecologic oncology]. 204 Apr 18

Prognostic factors are highly needed to divide node negative breast cancer patients into groups of low versus high risk of recurrence and death. In order to invade and spread, cancer cells must degrade extracellular matrix proteins. Accordingly, tumor levels of molecules involved in this degradation might be associated with patient outcome. Previous work has demonstrated that high levels of the aspartyl protease cathepsin D in breast cancer are associated with a poor prognosis and similar findings have been reported for molecules involved in the urokinase pathway of plasminogen activation. Interactions between different protease systems have been described and data suggest that several proteolytic enzymes may be operable at the same time in a tumor. In the present study we measured cathepsin D (n=162), uPA (n=116), uPAR (n=109) and PAI-1 (n=135) in tumor cytosols obtained from a population of node negative breast cancer patients. A significant correlation was found between levels of uPA, uPAR, and PAI-1. Levels of cathepsin D were directly related to levels of uPA and uPAR. With a median observation time of 4.81 years, univariate survival analyses showed that high levels of uPA and cathepsin D significantly predicted a shorter disease free survival, while only high levels of cathepsin D were able to significantly predict a shorter overall survival. Tumor levels of uPAR and PAI-1 gave mixed results depending on the cut-off point chosen. Interestingly, multivariate analysis demonstrated that PAI-1 and cathepsin D were independent significant prognostic indicators for disease-free survival while only cathepsin D was helpful in overall survival. The five year relapse rate of patients with low PAI-1 and low cathepsin D was 13% while patients who had greater than the median value for both of these molecules had a 5 year relapse rate of 40%. These data would indicate that at least two different protease systems are active in spread of node negative breast cancer and that measurement of these molecules may aid in the decisions to be made when offering adjuvant treatment to these patients.
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PMID:Low cathepsin D and low plasminogen activator type 1 inhibitor in tumor cytosols defines a group of node negative breast cancer patients with low risk of recurrence. 949 71

Tumor biological factors uPA, PAI-1, cathepsin D, S-phase fraction (SPF), MIB1 (Ki-67), p53, and HER-2/neu were assessed in 100 node-negative breast cancer patients. Their prognostic impact on disease-free (DFS) as well as overall survival (OS) was compared to that of traditional factors tumor size, grading, and steroid hormone receptor status. Antigen levels of uPA, its inhibitor PAI-1, and cathepsin D were determined in tumor tissue extracts by immunoenzymatic methods. SPF was determined by flow cytofluorometry, MIB1, p53, and HER-2/neu by immunohistochemistry in adjacent routinely formalin-fixed paraffin sections. Median follow-up in all patients still alive at time of analysis was 76 months. Univariate analysis determined PAI-1 (p = 0.0001), uPA (p = 0.0437), MIB1 (p = 0.0214), and SPF (p = 0.0248) as statistically significant prognostic factors for DFS. In contrast, tumor size, steroid hormone receptor status, grading, p53, HER-2/neu, and cathepsin. D failed to be of prognostic value. In multivariate analysis, including the statistically significant prognostic factors PAI-1, uPA, MIB1, and SPF, only PAI-1 (p = 0.0003, relative risk: 4.7) proved to be of independent statistical significance for DFS. Regarding OS, PAI-1 was the only statistically significant prognostic factor in univariate (p = 0.0001) as well as multivariate analysis (p = 0.0000, relative risk: 7.1). Thus, factors describing the invasive and metastatic capacity of tumor cells (uPA, PAI-1) and factors related to their proliferative activity (SPF, MIB1) provide valuable prognostic information in node-negative breast cancer patients.
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PMID:Prognostic impact of tumor biological factors on survival in node-negative breast cancer. 970 82

This study was aimed at testing the hypothesis that the expression of proteases essentially produced by reactive stromal cells (stromelysin-3 [ST3], gelatinase A [GELA], and urokinase [uPA]) is predictive of prognosis in patients with breast cancer. This was a study of patients with node-positive and node-negative breast cancer diagnosed from 1980 to 1986 and with an average of 10 years follow-up. ST3 (665 cases), GELA, and uPA (575 cases each) expression was obtained by in situ hybridization on formalin-fixed, paraffin-embedded material using mRNA antisense probes. ST3 was expressed by 86.6% of the cases; GELA, 77.7%; and uPA, 64.7%. A significant correlation (P < .05) was found between high (more than 10%) ST3 expression and a younger age, lymph node involvement, poor nuclear grade, ductal histology, aneuploidy, and HSP-27 expression. High GELA expression was significantly associated with c-erbB2, ductal histology, and HSP-27 expression. High uPA expression correlated with poor nuclear grade, ductal histology, lack of estrogen and progesterone receptors, and p53 protein accumulation. High level of expression of all three proteases correlated significantly with each other and with cathepsin D expression by reactive stromal cells. By univariate analysis, both ST3 and uPA expression significantly predicted a shorter recurrence-free survival (ST3, P = .0199; uPA, P = .0269). By multivariate analyses, the prognostic significance was lost, most particularly at longer term. This study adds support to the concept that protease expression by reactive stromal cells is related to cancer cell characteristics but that their contribution to cancer progression is marginal.
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PMID:Prognostic significance of stromelysin 3, gelatinase A, and urokinase expression in breast cancer. 974 15

After long-term follow-up, the prognostic impact of the following proteolytic factors associated with tumor invasion and metastasis was evaluated in 276 primary breast cancer patients: uPA (urokinase-type plasminogen activator), PAI-1 (uPA inhibitor type 1), and cathepsins B, D and L. The median follow-up of patients still alive at the time of analysis was 109 months. To date 119 patients (43%) have relapsed and 117 (42%) have died. Antigen levels of uPA and PAI-1 were determined by ELISA in detergent extracts; cathepsin B, D, and L content was determined in cytosol fractions of the primary tumor: cathepsin D by ELSA and cathepsin B and L by ELISA. In multivariate analysis (Cox model) for disease-free survival (DFS), lymph node status (p < 0.001; RR = 3.8), cathepsin L (p < 0.001; RR = 2.6) and PAI-1 (p = 0.027; RR = 1.7) were significant factors in all patients. In addition to these factors, grading was significant for overall survival (OS). In another multivariate approach, CART (Classification And Regression Trees) analysis, lymph node status (p < 0.001) turned out to be the strongest discriminator for patients at high risk of relapse. In the node-negative patient subset, PAI-1 was the strongest risk group discriminator (p < 0.001): in this subset, patients with low levels of both PAI-1 and cathepsin D had a very low relapse rate of only 3.2% compared to 39% in the remaining node-negative patients. In node-positive patients cathepsin L gave the best risk group assessment (p = 0.001). In conclusion, tumor-associated PAI-1 and cathepsins D and L provide significant, statistically independent prognostic information for DFS and OS in primary breast cancer, even after a median follow-up period of almost 10 years.
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PMID:Long-term follow-up confirms prognostic impact of PAI-1 and cathepsin D and L in primary breast cancer. 1076 46

Cancer invasion and metastasis develop through a sequence of processes involving loss of cell-cell and cell-matrix adhesions, proteolysis and induction of angiogenesis. We reviewed the current literature on the molecules that have been shown to play a significant role in these three steps of metastatisation in bladder cancer (BC) cells and their host microenvironment. Particular emphasis was given to markers that are assessable through immunohistochemistry and for which an additional prognostic value over the TNM variables has been recognized, in order to identify a subset of tumour markers readily available for application in daily clinical practice. We conclude that markers such as E-cadherin, Sialosyl-LeX, laminin, collagen IV, TSP-1 and MVD are useful prognostic markers, alpha, beta, and gamma catenin, MMP-2 and -9, uPAR, PD-ECGF and Bfgf can be considered potentially useful, while research on CD44, MMP-1 and -3, uPA, cathepsin D and VEGF has proved inconclusive. Further research in this field should concentrate on the molecules listed in the first group.
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PMID:Metastasis markers in bladder cancer: a review of the literature and clinical considerations. 1530 99

Cancer development is essentially a tissue remodeling process in which normal tissue is substituted with cancer tissue. A crucial role in this process is attributed to proteolytic degradation of the extracellular matrix (ECM). Degradation of ECM is initiated by proteases, secreted by different cell types, participating in tumor cell invasion and increased expression or activity of every known class of proteases (metallo-, serine-, aspartyl-, and cysteine) has been linked to malignancy and invasion of tumor cells. Proteolytic enzymes can act directly by degrading ECM or indirectly by activating other proteases, which then degrade the ECM. They act in a determined order, resulting from the order of their activation. When proteases exert their action on other proteases, the end result is a cascade leading to proteolysis. Presumable order of events in this complicated cascade is that aspartyl protease (cathepsin D) activates cysteine proteases (e.g. cathepsin B) that can activate pro-uPA. Then active uPA can convert plasminogen into plasmin. Cathepsin B as well as plasmin are capable of degrading several components of tumor stroma and may activate zymogens of matrix metalloproteinases, the main family of ECM degrading proteases. The activities of these proteases are regulated by a complex array of activators, inhibitors and cellular receptors. In physiological conditions the balance exists between proteases and their inhibitors. Proteolytic-antiproteolytic balance may be of major significance in the cancer development. One of the reasons for such a situation is enhanced generation of free radicals observed in many pathological states. Free radicals react with main cellular components like proteins and lipids and in this way modify proteolytic-antiproteolytic balance and enable penetration damaging cellular membrane. All these lead to enhancement of proteolysis and destruction of ECM proteins and in consequence to invasion and metastasis.
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PMID:Proteolytic-antiproteolytic balance and its regulation in carcinogenesis. 1576 61


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