Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0677930 (primary tumor)
 20,210 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Murine melanoma B16-F1 cells of low metastatic potential were transfected with the human gene for the prepro form of urokinase in an SV40 expression vector (plasmid pSV2-uPA), and cells expressing high amounts of the human urokinase gene product were selected for by an enzyme-linked immunosorbent assay specific for human high molecular weight urokinase. Southern analysis showed one of the cell lines (clone 7) had incorporated 150 copies of the pSV2-uPA plasmid into its genomic DNA. The human urokinase synthesized by the pSV2-uPA-transfected murine B16 cells was found to be glycosylated and did not bind to the murine cell surface urokinase receptor sites. In an in vivo assay that measures metastasis from a primary tumor (spontaneous metastatic assay), clone 7 cells showed an increased ability to metastasize (12 of 12 mice showed metastatic tumors), while control cells showed a lower ability to metastasize (only 2 of 11 mice showed metastatic tumors). In a second in vivo assay, which measures only the steps of the metastatic migration process during which tumor cells extravasate from the blood and then grow into pulmonary tumors (lung colonization assay), a significant multifold increase in the ability to form lung tumors was shown by the high human urokinase-secreting B16-F1 cells. In B16-F10 cells incorporating an antisense sequence to preprourokinase (plasmid pSV1-ASuPA-265) and secreting significantly decreased amounts of murine urokinase, a corresponding significant decrease in lung colonization was observed. These results provide direct experimental support for a role of secreted (non-surface-bound) urokinase in the colonization steps of the metastatic process. Furthermore, the data indicate that the higher lung colonization ability of the B16-F10 line than of the B16-F1 line is primarily based on the quantitative differences in their abilities to produce urokinase.
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PMID:Relationship between secreted urokinase plasminogen activator activity and metastatic potential in murine B16 cells transfected with human urokinase sense and antisense genes. 170 50

This prospectively randomized clinical trial was carried out in four Dutch hospitals to reduce the development of metachronous liver metastases and to get a better survival in patients with colorectal malignancies after surgically radical en bloc resection of the primary tumor and the regional lymph nodes. Three hundred seventeen patients were randomized to participate in three trial arms. One group of patients was treated by surgery alone (control group); in the other patients a catheter was placed in the dilated umbilical vein and advanced until the tip was lying in the left branch of the portal vein. Fifty percent of these patients got immediate postoperative portal infusion with 1 g 5-fluorouracil (5-FU) and 5000 U heparin daily for 7 days; the others received portal vein infusion with urokinase 10.000 U/hour for 24 hours only. Three hundred four patients were eligible. Overall hospital mortality was 3.6% (11 patients) and was not influenced by adjuvant treatment. After a median follow-up of 44 months 66 patients have died with relapse and 21 as a result of other causes. The chance of developing liver metastases and other distant metastases after portal infusion with 5-FU/heparin was one third of the chance in the control group (P less than 0.001). Only an insignificant reduction of the average death rate in the 5-FU/heparin group was found. In the urokinase group no significant effect in reducing metastases or in survival was noted. Before recommending cytotoxic portal infusion as an adjuvant treatment in patients with colorectal cancer, detailed analysis of other ongoing portal infusion studies has to be awaited and careful calculations have to be made regarding how many patients really can be saved by this treatment.
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PMID:Adjuvant portal liver infusion in colorectal cancer with 5-fluorouracil/heparin versus urokinase versus control. Results of a prospective randomized clinical trial (colorectal adenocarcinoma trial I). 240 56

Metastatic spread of malignant tumor appears to correlate with activation of the fibrolytic system. The role of fibrinolysis in growth and metastasis was examined in Lewis lung carcinoma of mice. The inhibition of fibrinolysis or proteases decreased the primary tumor growth and pulmonary metastasis, whereas the activation of fibrinolysis or proteases increased the number of metastatic foci in the lung. Electronmicroscopically, thrombus formation in the primary site prevented tumor invasion and metastasis formation. Plasminogen activator (PA) content of excised tumors was determined by SDS-PAGE, and major PA was found to be urokinase (UK) type. Immunohistochemical study with specific antisera was done. When tumor cells possessed a high level of UK, laminin and type IV collagen, components of the basement membrane, disappeared from tumor tissues. These findings suggest that PA through protease cascade plays a role in tumor invasion and metastasis. Clinically, patients with advanced cancer are usually in a hypercoagulable state with elevated fibrinogen, and fibrin deposition around tumor mass is a serious problem in cancer chemotherapy. UK infusion prior to 5-fluorouracil increased tissue concentration of antitumor agent. However, development of consumption coagulopathy characterized by progression from hypercoagulable state to disseminated intravascular coagulation has also been found in several cases.
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PMID:[Tumor metastasis and the fibrinolytic system]. 273 23

The prerequisite for a curative resection of metastases is their restriction to the key organs, the liver and lungs, in the sense of a limited dissemination. For long-term prognosis, the type of primary tumor as well as the radical resection of lung and liver metastases is essential. To improve the process of surgical indication and therapy of tumors, clear definitions for the terms "tumor recurrence" and "metastases" have been agreed upon. Research and clinical investigation have led to a better understanding of tumor-regulating factors, some of which are briefly described: Metastasis promoting factors include the lack of E-cadherin, which leads to a local penetration of basal membranes by tumor cells; CD44 seems to play an important role in cell-cell and cell-matrix interactions, apparently increasing the metastatic potential of tumors and reducing the long-term survival of patients. High levels of urokinase in primary tumors are also associated with a poorer prognosis, as well as plasminogen inactivator inhibitor PAI II, which plays a crucial role in tumor growth. Positive findings in bone marrow aspirates of patients with different malignancies, stained for cytokeratin 18, either are associated with higher recurrence rates in colon and breast cancer or can be correlated to the prognosis of patients with gastric cancer. Technical aspects of surgery for hepatic, pulmonary and skeletal metastases are presented and discussed with respect to curative and palliative indications.
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PMID:Surgical treatment of tumor metastases: general considerations and results. 753 64

Dissemination of tumor cells includes several steps, such as: (a) detachment of tumor cells from the primary tumor, (b) traversement of the basement membrane, and (c) migration into the extracellular matrix. In these processes, at least two important categories of proteins are involved: proteases and adhesion molecules. In this contribution we describe the expression and function of components of the plasminogen activator (PA) system (proteases) and of integrins (cell-matrix adhesion molecules) in a panel of four human melanoma cell lines with different invasive and metastatic capacity. Regarding the components of the PA system, we found differences in expression of urokinase-type PA (uPA) and type 1 and 2 PA inhibitors (PAI-1 and -2) between metastasizing and nonmetastasizing cell lines. Both components were exclusively expressed in the highly invasive and metastatic cell lines. Interestingly, studies on the expression of PA components in fresh human melanocytic lesions, showed expression of these components exclusively in advanced primary melanomas and melanoma metastases. Regarding integrin expression we found elevated levels of VLA-2 and VLA-6 in the highly invasive and metastatic cell lines compared with normal cultured melanocytes and nonmetastatic melanoma cell lines. In addition, increased adhesion of the highly metastatic cell lines to laminin (LM) and collagen (COLL) was observed. Furthermore, reduced adhesion of normal melanocytes and nonmetastatic melanoma cells to LM and CO was mainly due to the fact that the integrins involved in adhesion to these matrix components were present in an inactive state. Finally, differences were observed in expression of integrins involved in adhesion to fibronectin.
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PMID:Properties of metastasizing and nonmetastasizing human melanoma cells. 759 84

Degradation of the extracellular matrix plays a crucial role in cancer invasion. This degradation is accomplished by the concerted action of several enzyme systems, including generation of the serine protease plasmin by the urokinase pathway of plasminogen activation, different types of collagenases and other metalloproteinases, and other extracellular enzymes. The degradative enzymes are involved also in tissue remodelling under non-malignant conditions, and the main difference appears to be that mechanisms which regulates these processes under normal conditions are defective in cancer. Specific inhibitors have been identified for most of the proteolytic enzymes, e.g. plasminogen activator inhibitors (PAI's) and tissue inhibitors of metalloproteinases (TIMP's). It has been contemplated that these inhibitors counteracted the proteolytic activity of the enzymes, thereby inhibiting extracellular tissue degradation which in turn should prevent tumor cell invasion. This review focuses on plasminogen inhibitor type 1 (PAI-1). It is described that PAI-1 is not produced by the epithelial cancer cell but by the stromal cells in the tumors, suggesting a concerted action between stroma and tumor cells in the processes controlling proteolysis in cancer. The specific localization of PAI-1 to the tumor stroma and in many cases to areas surrounding the tumor vessels has lead us to suggest that PAI-1 serves to protect the tumor stroma from the ongoing uPA-mediated proteolysis. This hypothesis is supported by recent clinical data showing increased levels of PAI-1 in metastases as compared to the primary tumor as well as data demonstrating that high levels of PAI-1 in tumor extracts from breast, lung, gastric and ovarian cancer is associated with a shorter overall survival.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Plasminogen activator inhibitor type 1 in cancer: therapeutic and prognostic implications. 766 68

Proteolytic enzymes are required to mediate tumor cell invasion of adjacent tissues and spread of primary tumors to distant sites. Our objective was to examine the activities and molecular forms of plasminogen activator (PA) and matrix metalloproteases (MP) in primary and secondary growths of SC tumors of three human prostatic cell lines (Du-145, PC-3, and 1-LN-PC-3-1A [1-LN], a subline of PC-3) grown in nude mice. The plasminogen activator activities were 1.7 +/- 1.3 (+/- SD), 6.2 +/- 2.8, and 11.5 +/- 4.2 for Du-145, PC-3, and 1-LN in primary SC tumors, respectively. Urokinase was the predominant molecular form of PA found in each tumor as determined from its molecular size (predominantly 54 kDa with a minor activity of 33 kDa) and sensitivity to amiloride. Prominent MP activities of approximately 68, 76, and 96 kDa as well as lesser activities of about 56, 59, 63, 84, 165, and 180 kDa were found in 1-LN tumors, whereas only less active MP of 59, 68, and 96 kDa were detected in the parental PC-3 cells. Du-145 tumors expressed MP activities of 59 and 96 kDa. Treatment of 1-LN tumor extracts with p-aminophenylmercuric acetate (APMA) significantly reduced the MP activities of 76 and 165 kDa while increasing activities of 56, 59, 65, 68, and 84 kDa. The 76 and 165 kDa MP activities thus appear to be prominent proenzyme forms of MP expressed in the 1-LN tumor. Secondary growths of tumor were subsequently found near the site of initial injection of PC-3 and 1-LN cells following removal of the primary tumor. There was a 42% increase in PA activity in the PC-3 secondary tumors, but only an 8% increase in 1-LN secondary tumors. However, there was no difference in the activities or number of molecular forms of MP in extracts of PC-3 or 1-LN primary or secondary tumors. The substantial expression of MP activities in the more aggressive 1-LN subline of the human prostatic PC-3 cell line indicates that induction of certain MP may be an important regulatory event in prostate tumor progression.
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PMID:Plasminogen activator and metalloprotease activities of Du-145, PC-3, and 1-LN-PC-3-1A human prostate tumors grown in nude mice: correlation with tumor invasive behavior. 795 14

Four synthetic peptides (residues 20-30 and 17-34) within the growth factor-like domain (GFD) of murine and human urokinase-type plasminogen activator (uPA) were examined to determine whether they inhibit production of experimental and spontaneous lung metastasis by murine Lewis lung carcinoma (3LL) cells. In an in vivo experimental metastasis assay, which determines mainly the later steps of the metastatic migration process (extravasation from the bloodstream and then growth into pulmonary tumor), none of the peptides introduced by i.v. single co-injection into syngeneic C57B1/6 mice inhibited pulmonary metastasis, when 3LL cells were pre-incubated with the peptides followed by i.v. co-injection of the peptide and cells. In addition, none of the peptides, when injected i.p. daily for 7 days after i.v. tumor cell inoculation, reduced the number of lung tumor colonies. In a second in vivo assay that measures metastasis from a primary tumor (spontaneous metastasis model), multiple i.p. injections of the mouse peptide 17-34 for 7 days after s.c. tumor cell inoculation significantly inhibited metastatic lung tumor colonization in a dose-dependent manner, whereas human peptide 17-34 had no effect. Mouse and human peptide 20-30 had no effect either. The inhibition of lung metastasis was not due to direct antitumor effects of mouse peptide 17-34. Our results indicate that occupation of uPA receptors on 3LL cells by the enzymatically inactive mouse peptide 17-34 or prevention of rebinding of uPA synthesized by tumor cells to their receptor specifically reduced tumor cell invasion and formation of metastasis and that uPA may regulate more efficiently the mechanism involved in the entry of tumor cells into vascular circulation than extravasation during the metastatic process.
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PMID:Inhibition of metastasis of Lewis lung carcinoma by a synthetic peptide within growth factor-like domain of urokinase in the experimental and spontaneous metastasis model. 819 82

The relationship between the urokinase-type plasminogen activator (u-PA) content in extracts of cancer tissues and the histological grade or the extent of the primary tumor as prognostic factors in bladder cancer were examined in 55 cases of bladder cancer. The patients were divided into 2 groups, high u-PA (8 ng/ml of protein and more) and low u-PA (less than 8 ng/mg of protein) groups. The incidence of vascular invasion was 37% in the high u-PA group, and 7.1% in the low u-PA group (p < 0.05). The incidence of high u-PA group increased with the grade of cancer and the extent of the primary tumor. The 3-year survival rates were 87.3% in low u-PA group and 42.6% in high group (p < 0.005). The survival rates of the patients in the high u-PA group were lower than in the low group, by grade or stage. In a multivariate analysis, the prognostic value of u-PA antigen content was the same as that of tumor grade and stage. Therefore, the content of u-PA may be a useful prognostic marker for bladder cancer in addition to tumor grade and stage although the prognosis of the patients with bladder cancer is considered to be determined by many factors.
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PMID:[Urokinase-type plasminogen activator antigen as a prognostic factor in bladder cancer]. 841 19

At present the most used method to quantify tumor angiogenesis in human solid tumors is the count of intratumoral microvessels in the primary lesion. This method requires the use of specific markers to vascular endothelium and of immunohistochemical procedures to visualize microvessels. Several studies have found that intratumoral microvessel density (IMD) determined in the primary tumor is significantly associated with metastasis and prognosis in some solid neoplasia, particularly in operable breast carcinoma. The subjective evaluation of IMD made by two observers at the microscope is rapid and of low cost, but presents some difficulties, mainly the identification of the most vascularized area ("hot-spot") within each tumor. This method can be improved upon to attain a better reproducibility among different pathologists. For example, the use of a multiparametric computerized image analysis system (CIAS) seems to be a promising tool to improve accuracy, feasibility and reproducibility of microvessel counts, although there are still some open technical problems to completely automate its use. Angiogenic activity is the result of a balance between angiogenic stimuli and angio-inhibition. Therefore the determination of angiogenic peptides and/or natural angiogenesis inhibitors in the tumor tissue, serum, or urine of cancer patients seems to be a promising alternative to microvessel counting. At present it is possible to determine the expression of basic fibroblast growth factor (bFGF), vascular endothelial growth factor, and transforming growth factor beta using immunohistochemical methods. Serum and urine levels of bFGF can be assessed using an immunoenzymatic assay. Methods used to assess the expression and levels of urokinase-type plasminogen activator (uPA) or plasminogen activator inhibitor-1 (PAI-1) have also been developed, and correlate with angiogenic activity and prognosis of patients with breast cancer. Finally, some investigational methods to assess angiogenesis in vivo are presented and discussed. Angiogenesis is a very complex phenomenon. Thus it seems reasonable to hypothesize that its assessment by using concurrently several of the available methods may provide more valid, accurate, and comprehensive information on the angiogenic activity of each single tumor. For a reliable and reproducible assessment of angiogenesis for all of the assays, validation procedures and quality control protocols are mandatory.
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PMID:Novel methods for the determination of the angiogenic activity of human tumors. 853 66


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