Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C1140680 (ovarian cancer)
 28,141 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We have identified a soluble form of the human urokinase plasminogen activator (uPA) receptor (uPAR) in the ascitic fluids from patients with ovarian cancer. After purification of uPAR from the ascitic fluids by ligand-affinity chromatography (pro-uPA Sepharose), the uPAR was initially identified by cross-linking to a radiolabeled amino-terminal fragment of human uPA. The uPAR purified from the ascitic fluid has no bound ligand (uPA), as similar amounts can be purified by ligand-affinity chromatography as by immuno-affinity chromatography. uPAR from ascitic fluids partitions in the water phase after a temperature-dependent phase separation of a detergent extract. It therefore lacks at least the lipid moiety of the glycophospholipid anchor present in cellular-bound uPARs. It is highly glycosylated and the deglycosylated form has the same electrophoretic mobility as previously characterized cellular uPAR from other sources. The immunoreactivity of the purified uPAR from the ascitic fluid is indistinguishable from that of characterized uPAR, demonstrated by Western blotting with three different anti-uPAR monoclonal antibodies. The uPAR was found in 11 of 11 ascitic fluids from patients with ovarian cancer and in elevated amounts in the plasma from 2 of 3 patients. The concentration of soluble uPAR in the ascitic fluid was estimated to range between 1 and 10 ng/ml. Human soluble uPAR, derived from the tumor cells, was also found in the ascitic fluid and serum from nude mice xenografted intraperitoneally with three different human ovarian carcinomas.
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PMID:A ligand-free, soluble urokinase receptor is present in the ascitic fluid from patients with ovarian cancer. 822 31

A recombinant soluble human urokinase receptor comprising amino acids 1-277 was cloned and transfected into CHO cells. The mutant protein (rec-uPAR277), purified from the CHO cell supernatant by affinity chromatography on immobilized urokinase (uPA), in a four-fold excess, completely abolished the binding of FITC-labeled pro-uPA to the human ovarian cancer cell line, OV-MZ-6. This invasive and tumorigenic cancer cell line expresses uPA, its inhibitor PAI-1, and the high-affinity receptor for uPA, uPAR. Rec-uPAR277 significantly reduced the proliferation of OV-MZ-6 cells in a concentration-dependent manner without altering the viability of the cells. Invasion of OV-MZ-6 cells tested in an in vitro Matrigel invasion assay was inhibited by rec-uPAR277 up to 75%. In conclusion, these results demonstrate that rec-uPAR277 can function as a scavenger for uPA in vitro by inhibiting proliferation and invasion of human cancer cells.
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PMID:Recombinant soluble urokinase receptor as a scavenger for urokinase-type plasminogen activator (uPA). Inhibition of proliferation and invasion of human ovarian cancer cells. 828 66

Evidence has accumulated that urokinase-type plasminogen activator (uPA), its inhibitor (PAI-1) and receptor (uPAR) are involved in tumor invasion and metastasis. We analyzed the DNA sequences encoding these factors to see if they are altered in the ovarian cancer cell lines OV-MZ-6, OV-MZ-19, and OVCAR-3. In the uPA-encoding cDNA derived from OV-MZ-6 cells (but not in the uPA-cDNA from OVCAR-3 and OV-MZ-19), a so-far unknown mutation was identified in codon 121, resulting in a proline to leucine exchange. This exchange creates an AluI restriction site making restriction fragment length polymorphism (RFLP) analyses possible. Previously published PAI-1 sequences pointed to a variation of amino acid 15 of the PAI-1 signal sequence representing either threonine or alanine, which was confirmed in the present study. The uPAR cDNAs of all three cell lines encoded the published wild-type sequence. In order to elucidate the possible role of the Pro121Leu exchange in uPA and the Ala/Thr variants in the signal sequence of PAI-1 in the development and/or progression of human ovarian cancer, we studied the presence of these mutants or variants in a series of 22 ovarian cancer tissues. In addition to the wild-type sequence, the Pro121Leu exchange in the uPA sequence was detected in 10 out of 22 tumor tissues; 11 tumors carried exclusively the Pro121 allele; in one case exclusively the Leu121 allele was detected. In 18/22 tumors, triplet 15 in the signal sequence of PAI-1 encoded alanine, four DNAs contained both the Ala and the Thr allele. Furthermore, we analyzed another known common single-base-pair insertion/deletion polymorphism (ins/del allele) found in the promoter region of the PAI-1 gene and thought to be of functional importance in regulating PAI-1 gene expression. The PAI-1 ins-allele was found in 3/22, the del-allele in 6/22 and both alleles in 13/22 ovarian cancer tissues. In genomic DNA isolated from peripheral blood of 23 healthy donors, we observed similar allele frequencies of the three polymorphisms as found in the 22 ovarian carcinomas. Taken together, these results suggest that the polymorphisms observed in the uPA and PAI-1 genes may not be linked to ovarian cancer.
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PMID:Mutational analysis of the genes encoding urokinase-type plasminogen activator (uPA) and its inhibitor PAI-1 in advanced ovarian cancer. 919 91

Ascites and serum of patients with ovarian carcinoma contain a soluble form of urokinase-type plasminogen activator receptor (uPAR). We now report that pro-uPA-Sepharose-purified uPAR from ascites of patients with ovarian carcinoma is the full-length molecule missing the glycosyl-phosphatidylinositol anchor, as determined by its amino acid composition. We next examined the significance of determining serum soluble uPAR (suPAR) levels in ovarian cancer patients using a specific ELISA and compared the results with serum concentrations of CA-125, an established diagnostic marker. Serum from pre- and postoperative ovarian cancer patients was assayed for suPAR and CA-125. The majority of the patients with ovarian cancer had enhanced preoperative serum levels of suPAR compared with healthy controls, but suPAR concentrations decreased after operation. Although uPAR was associated with most ovarian carcinomas, it appeared to be a less specific indicator for ovarian cancer than CA-125. On the other hand, suPAR was more specific for other types of solid tumors. Moreover, we have observed some cases of ovarian cancer that showed increase of suPAR but not of CA-125. The prognostic significance of serum suPAR assay for survival of ovarian carcinoma patients was evaluated using Cox's proportional hazards analysis. Our preliminary data show that high preoperative levels of suPAR were associated with worse survival of the patients, whereas CA-125 had no prognostic implications. This is the first report evaluating the assay of serum suPAR levels in ovarian cancer and analyzing its value as a tumor or prognostic marker.
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PMID:The level of urokinase-type plasminogen activator receptor is increased in serum of ovarian cancer patients. 958 23

The urokinase-type plasminogen activator receptor (u-PAR) has been implicated in tumor progression, and previous studies have shown that the expression of this gene is strongly up-regulated by PMA. Although the signaling mechanism by which PMA modulates u-PAR expression is not known, the effect of this phorbol ester on the expression of other genes has been ascribed to activation of the c-Raf-1-ERK signaling pathway. However, in the current study we examined an alternate possibility that the inductive effect of PMA on u-PAR expression also required a JNK1-dependent signaling cascade usually associated with stress-inducing stimuli. PMA treatment of the u-PAR-deficient OVCAR-3 ovarian cancer cells, which contain low JNK activities, resulted in a rapid (5 min) increase in JNK activity. Maximal JNK activity (12-fold induction) occurred after 30 min; this preceding the earliest detected rise in u-PAR protein (2 h). Dose-response studies with PMA also indicated that the increased JNK activity was tightly correlated with elevated u-PAR protein levels. The stimulation of u-PAR promoter activity by PMA required an intact upstream AP-1 motif (-184) and in PMA-treated cells this motif was bound with c-Jun as indicated from mobility shift assays. PMA up-regulated the c-Jun trans acting activity as indicated by the higher activity of a GAL4-regulated luciferase reporter in phorbol-ester-treated cells co-transfected with an expression vector encoding the c-Jun transactivation domain fused to the GAL4 DNA-binding domain. The ability of PMA to stimulate u-PAR promoter activity was effectively titrated out by the co-expression of either a kinase-defective JNK1 or a dominant negative MEKK1 the latter being an upstream activator of JNK1. Conversely, u-PAR promoter activity was stimulated by the co-expression of a constitutively active MEKK1 and this induction was antagonized by the inclusion of the kinase-defective JNK1 plasmid. We also determined the biological significance of the JNK1-dependent signaling cascade in regulating u-PAR promoter activity by c-Ha-ras since this oncogene is activated and/or overexpressed in a variety of tumors including ovarian cancer. Transfection of an activated c-Ha-ras into OVCAR-3 cells stimulated u-PAR promoter activity over 20-fold and this could be countered by the individual expression of dominant negative expression constructs to Rac-1, MEKK1 or JNK1. Taken together, these data suggest that the PMA- or c-Ha-Ras-dependent stimulation of u-PAR gene expression requires a JNK1-dependent signaling module and that, at least for PMA, the concurrent stimulation of a JNK1-independent signaling module is also required. Thus, caution should be exercised in invoking linear signaling modules to account for the regulation of inducible gene expression.
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PMID:Stimulation of urokinase-type plasminogen activator receptor expression by PMA requires JNK1-dependent and -independent signaling modules. 967 6

Ovarian cancer metastasis is associated with an increase in the urokinase-type plasminogen activator (uPA) and its receptor uPAR. We present evidence that binding of uPA to uPAR provokes a mitogenic response in the human ovarian cancer cell line OV-MZ-6 in which endogenous uPA production had been significantly reduced by stable uPA 'antisense' transfection. High molecular weight (HMW) uPA, independent of its enzymatic activity, produced an up to 95% increase in cell number concomitant with 2-fold elevated [3H]thymidine incorporation as did the catalytically inactive but uPAR binding amino-terminal fragment of uPA, ATF. uPA-induced cell proliferation was significantly decreased by blocking uPA/uPAR interaction by the monoclonal antibody IIIF10 and by soluble uPAR. The efficiency of the uPAR binding synthetic peptide cyclo19,31 uPA19-31 to enhance OV-MZ-6 cell growth proved this molecular domain to be the minimal structural determinant for uPA mitogenic activity. Dependence of uPA-provoked cell proliferation on uPAR was further demonstrated in Raji cells which do not express uPAR and were thus not induced by uPA. However, upon transfection with full-length uPAR, Raji cells acquired a significant growth response to HMW uPA and ATF.
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PMID:Urokinase induces proliferation of human ovarian cancer cells: characterization of structural elements required for growth factor function. 982 67

The glycosylphosphatidylinositol (GPI)-anchored, multifunctional receptor for the serine proteinase, urokinase plasminogen activator (uPAR, CD87), regulates plasminogen activation and cell migration, adhesion, and proliferation. uPAR occurs in functionally distinct, membrane-anchored and soluble isoforms (s-uPAR) in vitro and in vivo. Recent evidence indicates that s-uPAR present in the circulation of cancer patients correlates with tumor malignancy and represents a valuable prognostic marker in certain types of cancer. We have therefore analyzed the mechanism of uPAR shedding in vitro. We present evidence that uPAR is actively released from ovarian cancer cells since the rate of receptor shedding did not correlate with uPAR expression. While s-uPAR was derived from the cell surface, it lacked the hydrophobic portion of the GPI moiety indicating anchor cleavage. We show that uPAR release is catalyzed by cellular GPI-specific phospholipase D (GPI-PLD), an enzyme cleaving the GPI anchor of the receptor. Thus, recombinant GPI-PLD expression increased receptor release up to fourfold. Conversely, a 40% reduction in GPI-PLD activity by GPI-PLD antisense mRNA expression inhibited uPAR release by more than 60%. We found that GPI-PLD also regulated uPAR expression, possibly by releasing a GPI-anchored growth factor. Our data suggest that cellular GPI-PLD might be involved in the generation of circulating prognostic markers in cancer and possibly regulate the function of GPI-anchored proteins by generating functionally distinct, soluble counterparts.
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PMID:Cellular glycosylphosphatidylinositol-specific phospholipase D regulates urokinase receptor shedding and cell surface expression. 1039 92

Urokinase-type plasminogen activator (uPA), its receptor (uPAR) and inhibitor, plasminogen activator-type 1 (PAI-1) are proposed to be of prognostic significance in some cancers. To determine the prognostic value of the urokinase plasminogen activation system in ovarian cancer, levels of uPA, uPAR, and PAI-1 were measured in extracts of ovarian cancer tissue using ELISA tests. uPA and PAI-1 were determined in 70 tumor extracts and uPAR in 43 extracts. Levels were correlated with age, tumor histology, stage, grade, lymph node and metastatic status, residual disease, risk of recurrence, epidermal growth factor receptor (EGFR) expression, cathepsin D (Cath-D), and c-erbB-2 levels. uPA and uPAR did not exhibit correlation with any of these parameters. However, patients with high grade tumor, recurrence, and lower EGFR and Cath-D had significantly higher PAI-1 levels compared to those of others (P < 0.05). Kaplan-Meier plots of survival were compared. uPA and uPAR were not related to disease-free or overall survival. Although low PAI-1 appeared to predict a longer overall survival, the difference was not statistically significant. Multivariate analysis revealed that PAI-1 was a predictor for overall survival although it was not as strong as stage. These results suggest that elevated PAI-1 seems to be correlated with an unfavorable prognosis in ovarian cancer.
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PMID:Clinical relevance of urokinase-type plasminogen activator, its receptor and inhibitor type 1 in ovarian cancer. 1124 Jul 1

The urokinase type plasminogen activator (uPA), together with its receptor uPAR and the plasminogen activator inhibitor type-1 (PAI-1) plays a pivotal role during tumor invasion and metastasis. Integrins, via interaction with the extracellular matrix (ECM), control cell adhesion and motility. The two systems are functionally linked because uPAR and PAI-1 bind to the ECM component vitronectin (VN). Because integrin signaling alters gene expression patterns, we investigated whether the expression levels of uPA, uPAR, and PAI-1 are affected by ECM/integrin interactions. Expression of uPA, uPAR, and PAI-1 was significantly enhanced when human ovarian cancer cells (OV-MZ-6) were cultivated on fibronectin or collagen type IV. In contrast, VN induced down-regulation of uPA and uPAR while increasing PAI-1 by up to 4-fold. VN-dependent decrease of uPA protein was paralleled by a significant reduction of uPA promoter activity that was even more pronounced upon alpha(v)beta(3) overexpression and depended on the presence of intact Rel protein-binding sites. The activity of Rel transcription factors was also significantly reduced upon alpha(v)beta(3)-mediated cell adhesion to VN. The activity of the Rel-unresponsive PAI-1 promoter was up to 5-fold induced as a function of alpha(v)beta(3)/VN interaction. Thus, the balance between available concentrations of uPA, uPAR, PAI-1, and integrins in human ovarian cancer cells might provide a switch within the regulation of their invasive phenotype.
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PMID:Integrin alpha(v)beta(3)/vitronectin interaction affects expression of the urokinase system in human ovarian cancer cells. 1133 Dec 80

Focussing of the serine protease urokinase (uPA) to the tumor cell surface via interaction with its receptor (uPAR) is an important step in tumor invasion and metastasis. The human ovarian cancer cell line OV-MZ-6#8 was stably transfected with expression plasmids either encoding cell-associated uPAR (GPI-uPAR) or a soluble form of uPAR (suPAR) lacking its glycan lipid anchor. In vitro, high level synthesis of functionally active recombinant suPAR inhibited cell proliferation and led to reduced cell-associated fibrin matrix degradation, whereas fibrinolytic activity was increased in OV-MZ-6#8 cells overexpressing GPI-uPAR. Both OV-MZ-6#8-derived clones were inoculated into the peritoneum of nude mice and tested for tumor growth and spread. High level synthesis of recombinant suPAR (without altering the physiological expression levels of GPI-uPAR and uPA in these cells) resulted in a significant reduction of tumor burden (up to 86%) in the xenogeneic mouse model. In contrast, overexpression of GPI-uPAR in tumor cells did not affect tumor growth. Our results demonstrate that high levels of suPAR in the ovarian cancer cell vicinity can act as a potent scavenger for uPA, thereby significantly reducing tumor cell growth and cancer progression in vivo.
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PMID:High level synthesis of recombinant soluble urokinase receptor (CD87) by ovarian cancer cells reduces intraperitoneal tumor growth and spread in nude mice. 1151 32


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