Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.4.21.73 (urokinase-type plasminogen activator)
 10,685 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

In LLC-PK1 cells urokinase-type plasminogen activator (uPA) mRNA has a short half-life. It is stabilized by inhibition of protein synthesis and by downregulation of protein kinase C (PKC). In the present study on uPA mRNA metabolism, we focused our attention on the 3' untranslated region (3'UTR) of the uPA mRNA, as this region is long and highly conserved among several mammalian species, including mice and humans. To investigate the possible role of the 3'UTR of uPA mRNA in mRNA metabolism, we inserted this region into the 3'UTR of the rabbit beta-globin gene that is linked to the cytomegalovirus promoter and stably transfected it into LLC-PK1 cells. While the parental globin mRNA was stable, the chimeric mRNA was degraded as rapidly as endogenous uPA mRNA, suggesting that the 3'UTR of uPA mRNA contains most of the information required for its rapid turnover. Further analysis showed that there are at least three independent determinants of instability in the 3'UTR; one is an AU-rich sequence located immediately 3' of the poly(A) addition signal, and one is a sequence containing a stem structure. One determinant seems to require ongoing RNA synthesis for its activity. All chimeric unstable globin mRNAs became stable in the presence of cycloheximide, a protein synthesis inhibitor, suggesting that the stabilization of mRNA by protein synthesis inhibition is not through a specific sequence in the mRNA. In PKC-downregulated cells, globin mRNAs with the complete 3'UTR or the AU-rich sequence were stabilized, suggesting that PKC downregulation stabilizes uPA mRNA through the AU-rich sequence. Here we discuss the significance of multiple, independently acting instability determinants in the regulation of uPA mRNA metabolism.
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PMID:Multiple instability-regulating sites in the 3' untranslated region of the urokinase-type plasminogen activator mRNA. 800 88

In LLC-PK1 cells, urokinase-type plasminogen activator (uPA) mRNA has a short half-life of 70 min. We have previously demonstrated that most of the regulatory regions responsible for the rapid turnover of uPA mRNA in LLC-PK1 cells reside in its 3' untranslated region (3' UTR), where there are at least three regulatory sites, one of which is A+U-rich. This A+U-rich sequence mediates uPA mRNA stabilization induced by protein kinase C (PKC) down-regulation. In this work, we found that uPA mRNA is rather stable in MDA-MB-231 cells with a half-life of 17 h. We compared the stability of hybrid globin mRNA containing different parts of uPA mRNA in its 3' UTR and found that the A+U-rich sequence of uPA mRNA renders otherwise stable globin mRNA unstable in LLC-PK1 cells but not in MDA-MB-231 cells. We identified a cytoplasmic protein of 40 kDa (p40) which specifically interacts with the A+U-rich sequence. Levels of p40 activity as detected by ultraviolet cross-linking were higher in MDA-MB-231 and PKC-down-regulated LLC-PK1 cells than in untreated LLC-PK1 cells. Prior treatment of the cytoplasm with a specific antibody against heterogeneous nuclear ribonucleoprotein C (hnRNP C) significantly reduced p40 activity. These results suggest a correlation between the A+U-rich sequence-dependent uPA mRNA stabilization in vivo and the binding of hnRNP C to the A+U-rich sequence in vitro.
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PMID:Enhanced stability of urokinase-type plasminogen activator mRNA in metastatic breast cancer MDA-MB-231 cells and LLC-PK1 cells down-regulated for protein kinase C--correlation with cytoplasmic heterogeneous nuclear ribonucleoprotein C. 924 23

Transgenic mice were previously described, carrying the cDNA of the human or murine protease urokinase-type plasminogen activator (uPA) while linked to the cell-specific promoter of the alphaA-crystallin gene. Surprisingly, these mice produced transgenic uPA in an ectopic manner specifically in the brain. Here we tested the possibility that this ectopic expression could have been contributed primarily by the uPA transgenic moiety. Several experimental approaches have been used. (a) Constructs consisting of uPA cDNA linked to the cell-specific promoters of the alphaA-crystallin or insulin genes yielded active uPA after transfection into cells where these promoters are thought to be inactive. (b) When reporter genes were inserted into these constructs between the promoter and the cDNA, the cDNA enhanced the chimeric reporter expression 5-50-fold. This effect was obtained upon stable or transient construct transfection into four different cell types. (c) Reporter enhancement also took place in the presence of the homologous uPA gene promoter. (d) Mapping of the cDNA through deletion-substitution analysis has detected fragments mediating positive or negative effects on reporter expression, all fragments residing in the 3'-untranslated region (3'UTR) of the uPA gene that was included in the cDNA. Some fragments exhibited cell-specific effects. One fragment (2002/2187) behaved like a classical transcriptional enhancer, enhancing reporter expression from different positions and orientations. (e) Transgenic mice have now been generated that carry a transgene consisting of the alphaA-crystallin promoter, the luciferase reporter gene and mouse uPA cDNA. Among four transgenic lines producing luciferase activity in the eye lens, three lines exhibited ectopic luciferase activity exclusively in the brain, where luciferase mRNA was localized through in situ hybridization. From these results we conclude that the 3'UTR of the uPA gene contains sequences capable of exerting variable effects on gene expression, including transcriptional enhancement. In addition, uPA cDNA correlates with transgenic brain expression. Therefore, we suggest that the 3'UTR of the uPA gene is involved in brain expression of the transgenes containing uPA cDNA as well as of the normal uPA gene.
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PMID:The 3'-untranslated region of the urokinase gene enhances the expression of chimeric genes in cultured cells and correlates with specific brain expression in transgenic mice. 949 43

2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD), a highly toxic compound that has recently attracted much attention as an environmental contaminant, elicits a variety of toxic responses. Most, if not all, of the toxic effects of TCDD are thought to result from alteration of gene expression. TCDD acts through both transcriptional and posttranscriptional mechanisms to alter gene expression of many genes. Transforming growth factor (TGF)-alpha and urokinase-type plasminogen activator (uPA) are examples of the genes up-regulated posttranscriptionally by TCDD by mRNA stabilization. While effects of TCDD on transcription have been extensively studied, the molecular mechanisms underlying the TCDD-induced changes in mRNA stability are poorly understood. In this study, we investigated the trans-acting factors involved in TCDD-dependent mRNA stabilization. UV-crosslinking study showed that a liver cytoplasmic protein of 50 kDa (p50) selectively recognized the 3' UTR of the uPA mRNA in a TCDD-dependent manner. We also showed that the activation of p50 by TCDD is mediated through a protein phosphorylation cascade but not via de novo protein synthesis. This is the first study to show the presence of the TCDD-dependent RNA binding activity which may be involved in TCDD-dependent stabilization of mRNA.
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PMID:2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) induces binding of a 50 kDa protein on the 3' untranslated region of urokinase-type plasminogen activator mRNA. 1083 33

Urokinase is thought to be involved in the formation of oral cancer, although there is a lack of genetic evidence. Our aim was to study single nucleotide polymorphisms in order to investigate the possibility. A total of 130 oral cancer patients and 105 controls were studied. Polymerase chain reaction (PCR) based restriction analysis was used to identify the C/T polymorphism of the urokinase gene, which is located on the 3'-untranslated region (3'-UTR) of chromosome 10. There was a significant difference in the distribution of the urokinase gene 3'-UTR C/T polymorphism frequency between cancer patients and the normal control group (P < 0.05). The "T" allele was prominent in the cancer group. The odds ratio for the risk of the "T" allele in cancer patients was 2.71 (95% CI = 1.325 approximately 5.562). The cancer patients were further categorized according to gender and whether or not they were habitual smokers or betel nut chewers. These clinical parameters were then compared with tumor cell differentiation and tumor progression. No significant differences were found. Therefore, the urokinase gene 3'-UTR "T" allele is associated with oral cancer and may play a role in oral cancer formation. However, we did not find the relationship between tumor progression and this polymorphism.
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PMID:Urokinase gene 3'-UTR T/C polymorphism is associated with oral cancer. 1535 78

Pathological findings pertaining to bronchopulmonary dysplasia (BPD) are consistent with a process of prolonged lung inflammation and impaired healing. The balance of the competing activities of coagulation and fibrinolysis may contribute to the premature lung's response to acute injury. We investigated the association of the urokinase gene polymorphism with BPD in ventilated preterm infants whose gestational age was below 30 weeks. BPD is defined as infants remaining dependent upon active respiratory support and/or oxygen supplementation and featuring characteristic radiographic changes in the lung fields on the 28th postnatal day (BPD-28d) and at a corrected age of 36 weeks of gestation (BPD-36w). Two hundred and four ventilated preterm infants were enrolled in the study. The typing of each specific genotype polymorphism was performed by polymerase chain reaction (PCR) and restriction analysis. Perinatal risk factors for BPD, genotype distribution, and allelic frequencies were compared between infants suffering from BPD (28-d), BPD (36-w) and their respective ventilated preterm infants who did not develop BPD infants. The genotype proportions of the urokinase 3'-UTR polymorphism for BPD (28-d), BPD (36-w) and their respective ventilated preterm infants who did not develop BPD did not differ significantly. There was no difference in allelic frequency for the urokinase 3'-UTR polymorphism between BPD (28-d), BPD (36-w) and their respective ventilated preterm infants who did not develop BPD infants. We concluded that urokinase gene 3'-UTR C/T polymorphism is not a suitable marker for predicting susceptibility and severity to BPD for preterm infants of Taiwanese.
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PMID:No association of urokinase gene 3'-UTR polymorphism with bronchopulmonary dysplasia for ventilated preterm infants. 1586 45

Increased urokinase receptor (uPAR) expression as well as stabilisation of uPAR mRNA contribute to the pathogenesis of lung inflammation and neoplasia. Post-transcriptional regulation of uPAR mRNA involves interaction of both coding and 3'-UTR sequences with regulatory uPAR mRNA binding proteins (Bps). In order to identify novel regulatory interactions, we performed gel mobility shift and UV cross-linking assays and found two distinct uPAR mRNA-protein complexes. We identified a rapidly migrating 40 kDa uPAR mRNABp that selectively bound a 110 nucleotide (nt) fragment of the uPAR mRNA 3'UTR. Chimeric beta-globin/uPAR mRNA containing the 110 nt 40 kDa protein binding fragment destabilised stable beta-globin mRNA with a rate of decay identical to that of chimeric beta-globin/uPAR containing the full uPAR 3'UTR. The 40 kDa uPAR 3'UTR Bp was purified using poly (U) sepharose and identified as heterogeneous nuclear ribonucleoprotein C (hnRNPC). Finally, we confirmed its interaction with the uPAR mRNA 3' UTR by gel mobility supershift assay using an anti-hnRNPC antibody. Direct in vivo interaction of hnRNPC with the uPAR mRNA 3'UTR was demonstrated by immunoprecipitation and combined RT PCR-Southern blotting assay. Co-transfection of hnRNPC cDNA in Beas2B cells reversed destabilisation of chimeric beta-globin/uPAR 3'UTR mRNA and its over-expression also induced uPAR protein and mRNA expression through stabilisation of uPAR mRNA. These observations indicate a novel mechanism of uPAR gene regulation in lung epithelial cells in which cis elements within a 110 nt uPAR mRNA 3'UTR sequence interact with hnRNPC to regulate uPAR mRNA stability.
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PMID:Regulation of urokinase receptor mRNA stability by hnRNP C in lung epithelial cells. 1601 Sep 78

Urokinase gene is believed to play a key role in tissue degradation and cell migration under various normal and pathological conditions, including cancer invasion and metastasis. It may be responsible in the development of prostate cancer (CaP), although there is lack of genetic evidence. Our aim was to study single nucleotide polymorphism (C/T) in 3'-untranslated region to investigate the possibility. DNA was extracted from blood samples of 103 CaP patients and 107 normal controls. Polymerase chain reaction (PCR) based restriction analysis was used to identify the C/T polymorphism of the urokinase gene. Significant difference in the frequency distribution of CT and TT genotypes in CaP patients as compared to normal was observed (p=0.04). Two folds risk for prostate cancer with T alleles in north Indian population was apparent. We also observed significant association for TT genotypes with higher Gleason score of tumors in CaP patients (p<0.05). A positive association was also evident in tobacco users having T alleles with risk of CaP. Our findings demonstrated a positive association of T allele of 3'UTR of urokinase gene with the risk of prostate cancer. We therefore hypothesize that C/T polymorphism may influence the etiology of CaP and is likely to become another new marker.
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PMID:Is urokinase gene 3'-UTR polymorphism associated with prostate cancer? 1719 53

We found that p53-deficient (p53(-/-)) lung carcinoma (H1299) cells express robust levels of cell surface uPAR and uPAR mRNA. Expression of p53 protein in p53(-/-) cells suppressed basal and urokinase (uPA)-induced cell surface uPAR protein and increased uPAR mRNA degradation. Inhibition of p53 by RNA silencing in Beas2B human airway epithelial cells conversely increased basal as well as uPA-mediated uPAR expression and stabilized uPAR mRNA. Purified p53 protein specifically binds to the uPAR mRNA 3' untranslated region (3'UTR), and endogenous uPAR mRNA associates with p53. The p53 binding region involves a 37-nucleotide uPAR 3'UTR sequence, and insertion of the p53 binding sequence into beta-globin mRNA destabilized beta-globin mRNA. Inhibition of p53 expression in these cells reverses decay of chimeric beta-globin-uPAR mRNA. These observations demonstrate a novel regulatory role for p53 as a uPAR mRNA binding protein that down-regulates uPAR expression, destabilizes uPAR mRNA, and thereby contributes to the viability of human airway epithelial or lung carcinoma cells.
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PMID:Regulation of urokinase receptor expression by p53: novel role in stabilization of uPAR mRNA. 1754 71

Interaction of urokinase-type plasminogen activator (uPA) with its receptor, uPAR, is a key regulatory step in uPA-mediated cell proliferation and migration. Our previous studies demonstrated that posttranscriptional stabilization of uPAR mRNA by uPA contributes to the induction of cell surface uPAR expression, and heterogeneous nuclear ribonuclear protein C1 (hnRNPC) binds to a 110 nt sequence of uPAR mRNA 3'-UTR, thereby preventing its degradation. These observations indicate that hnRNPC could be involved in the induction of uPAR expression by uPA. In the present study, we investigated this possibility and confirmed that uPA increased the binding of hnRNPC to the 3'-UTR of uPAR mRNA. Furthermore, uPA induced tyrosine phosphorylation of hnRNPC and uPAR expression through mRNA stabilization. Inhibition of hnRNPC tyrosine phosphorylation abolished its interaction with uPAR mRNA and suppressed mRNA stabilization and cell surface uPAR expression. Deletion experiments revealed that hnRNPC binds to uPAR mRNA through its RNA binding domain (RBD). Site-directed mutagenesis studies further indicated that phosphorylation of tyrosine residue 57 (Y57) present in RBD of hnRNPC by uPA is essential for uPAR 3'-UTR mRNA binding and uPAR expression. Increased hnRNPC interaction with the uPAR mRNA 3'-UTR through phosphorylation of Y57 represents a novel mechanism by which uPA regulates posttranscriptional uPAR mRNA turnover and cell surface uPAR expression.
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PMID:Posttranscriptional regulation of urokinase receptor expression by heterogeneous nuclear ribonuclear protein C. 1849 99


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