uPA Expression Research Articles

Infiltration of T cells promotes the metastasis of ovarian cancer cells via the modulation of metastasis-related genes and PD-L1 expression.

Due to its high ability to disseminate, ovarian cancer remains one of the largest threats to women's health, worldwide. Evidence showed that the immune cells infiltrating the tumor microenvironment are crucial in mediating metastasis. Therefore, it is necessary to understand which types of immune cells are involved in metastasis, and to determine the mechanisms by which they influence the process. By immunohistochemistry, we found that higher concentrations of intratumoral CD8+ T cells were found to be correlated with an advanced grade and stage of ovarian cancer. Additionally, the infiltration of stromal CD8+ T cells was also significantly higher in tissues with advanced stages and metastatic tumors. A positive correlation between the infiltration of FoxP3+ Treg cells and histological grade was also observed, regardless of location. PD-L1 expression in metastatic tumors was also higher than that in paired primary ovarian tumors. Transwell migration and invasion assays revealed the increased migration and invasion of ovarian cancer cell lines (A2780CP and ES2) and ascites-derived ovarian cancer cells following co-culturing with CD8+ T cells. Enhanced expression of MMP-9, uPA, VEGF, bFGF, IL-8, IL-10, and PD-L1 by cancer cells following co-culturing with CD8+ T cells were also detected by qPCR, ELISA or flow cytometry. In conclusion, our findings suggest that the infiltrated T cells could promote the development of ovarian cancer, and provide another mechanism of immune evasion mediated by T cells.

The expression of urokinase-type plasminogen activator system in upper tract urothelial carcinoma and its prognostic value after radical nephroureterectomy

BackgroundTo evaluate the expression pattern and prognostic role of the urokinase-type plasminogen activator (uPA) system in patients who underwent radical nephroureterectomy (RNU) for nonmetastatic upper tract urothelial carcinoma (UTUC). MethodsA total of 732 patients who were treated with RNU for clinically nonmetastatic UTUC comprised our analytical cohort. Immunohistochemical staining of uPA, uPA receptor (uPAR) and uPA inhibitor (PAI-1) was performed using Murine IgG1 monoclonal antibodies. Outcomes of interest were recurrence-free survival, cancer-specific survival, and overall survival. ResultsThe median age of the patients was 69.8 years and 56.6% of them were males. Overall, overexpression of uPA, uPAR, and PAI-1 was observed in 292 (39.9%), 346 (47.3%), and 345 (47.1%) patients, respectively. The uPA system components showed a statistically significant association with adverse clinicopathologic features such as lymphovascular invasion, multifocality, sessile tumors, and advanced pathologic stage (P < 0.01). On multivariable models, higher pathologic tumor stage, multifocality, and lymph node involvement were associated with RFS, OS, and CSS, but not the overexpression of uPA, uPAR, or PAR-1. In patients with organ-confined disease (≤pT2N0), however, uPA was significantly associated with RFS (hazard ratio [HR]: 2.04, 95% confidence interval [CI]: 1.21–3.43), OS (HR: 1.59, 95% CI:1.08–2.24) and CSS (HR: 2.55, 95% CI:1.44–4.52). uPA improved the predictive accuracy of a standard post-RNU model for all 3 endpoints, in organ-confined disease, by a prognostically significant margin. ConclusionsOverexpression of uPA system components was associated with adverse clinicopathologic characteristics and survival outcomes on the univariable, but not multivariable analyses. uPA expression was an independent predictor of survival outcomes in patients with organ-confined disease. While the clinical value of the uPA system remains limited in this cohort, further studies are needed to identify a marker or constellation of markers of high predictive value to help in counseling and treatment planning of UTUC patients.

Urokinase-Type Plasminogen Activator Protects Cerebral Cortical Neurons from Soluble Aβ-Induced Synaptic Damage.

Soluble amyloid β (Aβ)-induced synaptic dysfunction is an early event in the pathogenesis of Alzheimer's disease (AD) that precedes the deposition of insoluble Aβ and correlates with the development of cognitive deficits better than the number of plaques. The mammalian plasminogen activation (PA) system catalyzes the generation of plasmin via two activators: tissue-type (tPA) and urokinase-type (uPA). A dysfunctional tPA-plasmin system causes defective proteolytic degradation of Aβ plaques in advanced stages of AD. In contrast, it is unknown whether uPA and its receptor (uPAR) contribute to the pathogenesis of this disease. Neuronal cadherin (NCAD) plays a pivotal role in the formation of synapses and dendritic branches, and Aβ decreases its expression in cerebral cortical neurons. Here we show that neuronal uPA protects the synapse from the harmful effects of soluble Aβ. However, Aβ-induced inactivation of the eukaryotic initiation factor 2α halts the transcription of uPA mRNA, leaving unopposed the deleterious effects of Aβ on the synapse. In line with these observations, the synaptic abundance of uPA, but not uPAR, is decreased in the frontal cortex of AD patients and 5xFAD mice, and in cerebral cortical neurons incubated with soluble Aβ. We found that uPA treatment increases the synaptic expression of NCAD by a uPAR-mediated plasmin-independent mechanism, and that uPA-induced formation of NCAD dimers protects the synapse from the harmful effects of soluble Aβ oligomers. These data indicate that Aβ-induced decrease in the synaptic abundance of uPA contributes to the development of synaptic damage in the early stages of AD.SIGNIFICANCE STATEMENT Soluble amyloid β (Aβ)-induced synaptic dysfunction is an early event in the pathogenesis of cognitive deficits in Alzheimer's disease (AD). We found that neuronal urokinase-type (uPA) protects the synapse from the deleterious effects of soluble Aβ. However, Aβ-induced inactivation of the eukaryotic initiation factor 2α decreases the synaptic abundance of uPA, leaving unopposed the harmful effects of Aβ on the synapse. In line with these observations, the synaptic expression of uPA is decreased in the frontal cortex of AD brains and 5xFAD mice, and uPA treatment abrogates the deleterious effects of Aβ on the synapse. These results unveil a novel mechanism of Aβ-induced synaptic dysfunction in AD patients, and indicate that recombinant uPA is a potential therapeutic strategy to protect the synapse before the development of irreversible brain damage.

Inhibitory Effects of a Reengineered Anthrax Toxin on Canine Oral Mucosal Melanomas

Canine oral mucosal melanomas (OMM) are the most common oral malignancy in dogs and few treatments are available. Thus, new treatment modalities are needed for this disease. Bacillus anthracis (anthrax) toxin has been reengineered to target tumor cells that express urokinase plasminogen activator (uPA) and metalloproteinases (MMP-2), and has shown antineoplastic effects both, in vitro and in vivo. This study aimed to evaluate the effects of a reengineered anthrax toxin on canine OMM. Five dogs bearing OMM without lung metastasis were included in the clinical study. Tumor tissue was analyzed by immunohistochemistry for expression of uPA, uPA receptor, MMP-2, MT1-MMP and TIMP-2. Animals received either three or six intratumoral injections of the reengineered anthrax toxin prior to surgical tumor excision. OMM samples from the five dogs were positive for all antibodies. After intratumoral treatment, all dogs showed stable disease according to the canine Response Evaluation Criteria in Solid Tumors (cRECIST), and tumors had decreased bleeding. Histopathology has shown necrosis of tumor cells and blood vessel walls after treatment. No significant systemic side effects were noted. In conclusion, the reengineered anthrax toxin exerted inhibitory effects when administered intratumorally, and systemic administration of this toxin is a promising therapy for canine OMM.

The urokinase-type plasminogen activator and inhibitors in resectable lung adenocarcinoma

BackgroundThe urokinase-type plasminogen activator (uPA) system is closely related to the occurrence and progression of cancer in many aspects. Previous studies demonstrated that the conclusions about the prognosis value of uPA, plasminogen activator inhibitor 1 (PAI-1) and plasminogen activator inhibitor 2 (PAI-2) in lung cancer are controversial, so this study was performed for the exploration of the predictive effect of uPA, PAI-1 and PAI-2 on the overall survival (OS) of resectable pulmonary adenocarcinoma patients. MethodsUPA, PAI-1 and PAI-2 expression levels were assayed by immunohistochemical staining based on tissue microarray (TMA) that is composed of formalin-fixed paraffin-embedded specimens from 84 resectable lung adenocarcinoma patients from July 2004 to June 2009. The relationship of IHC, mRNA expression levels of three molecules were investigated respectively. The three molecules’ relationship with clinicopathologic parameters and OS was explored by Chi-square, Kaplan-Meier, and Cox regression analyses. The Cancer Genome Atlas (TCGA) database was used to analyze differential gene expressions of RNA-sequencing data of pulmonary adenocarcinoma and normal tissues, and Kaplan-Meier methods were adopted to confirm the prognostic value of uPA, PAI-1 and PAI-2 in resectable lung adenocarcinoma in TCGA database and the R package MethylMix was used to conduct an analysis integrating methylation data and gene expression of RNA-sequencing data based on TCGA. ResultsUPA, PAI-1 and PAI-2 had much higher IHC expression levels in tumor than those in the normal tissues (uPA, Z = -10.511; PAI-1, Z = -4.836; PAI-2, Z = -6.794; all P < 0.0001). High DNA methylation level of gene uPA resulted in the decrease of its expression. In addition, expression level of PAI-2 was positively associated with tumor size (χ2 = 8.372, P = 0.004). Multivariate analyses showed TNM stage III was an independent adverse prognostic factor (hazard ratio = 3.736, 95 % confidence interval = 1.097–12.72, P = 0.035). Kaplan-Meier method revealed that uPA, PAI-1 and PAI-2 expression levels were not related to the OS for 84 resectable lung adenocarcinoma patients. According to TCGA data, PAI-1 expression level was identified as a potential adverse predictor for prognosis of resectable lung adenocarcinoma (Gehan-Breslow-Wilcoxon test, P = 0.025). ConclusionsOur data show that, the expression levels of uPA, PAI-1 and PAI-2 are significantly up-regulated in resectable lung adenocarcinoma. Besides, this study highlights PAI-1 as a latent adverse prognostic factor in resectable adenocarcinoma of lung.

Downregulation of uPAR promotes urokinase translocation into the nucleus and epithelial to mesenchymal transition in neuroblastoma.

The urokinase system is involved in a variety of physiological processes, such as fibrinolysis, matrix remodeling, wound healing, and regeneration. Upon binding to its cognate receptor urokinase‐type plasminogen activator receptor (uPAR), urokinase‐type plasminogen activator (uPA) catalyzes the conversion of plasminogen to plasmin and the activation of matrix metalloproteases. Apart from this, uPA–uPAR interaction can lead to the activation of transcription factors, mitogen‐activated protein kinase signaling pathways and RTK cascades. Elevated expression of uPA and uPAR is markedly associated with cancer progression and metastasis and correlates with a poor prognosis in clinics. Targeting the urokinase system has proved to be effective in experimental models in vitro and in vivo, however, in clinics the inhibition of the uPA/uPAR system has fallen short of expectations, suggesting that the question of the functional relevance of uPA/uPAR system is far from being moot. Recently, using CRISPR/Cas9 technology, we have shown that uPAR knockout decreases the proliferation of neuroblastoma Neuro2a cells in vitro. In the present study we demonstrate that uPAR expression is essential for maintaining the epithelial phenotype in Neuro2a cells and that uPAR silencing promotes epithelial‐mesenchymal transition (EMT) and increased cell migration. Accordingly, uPAR knockout results in the downregulation of epithelial markers (E‐cadherin, occludin, and claudin‐5) and in the increase of mesenchymal markers (N‐cadherin, α‐smooth muscle actin, and interleukin‐6). In search of the molecular mechanism underlying these changes, we identified uPA as a key component. Two key insights emerged as a result of this work: in the absence of uPAR, uPA is translocated into the nucleus where it is presumably involved in the activation of transcription factors (nuclear factor κB and Snail) resulting in EMT. In uPAR‐expressing cells, uPAR functions as a uPA “trap” that binds uPA on the cell surface and promotes controlled uPA internalization and degradation in lysosomes.

Rhus verniciflua Stokes extract suppresses migration and invasion in human gastric adenocarcinoma AGS cells.

BACKGROUND/OBJECTIVESMany studies have suggested that Rhus verniciflua Stokes (RVS) and its extract are anticancer agents. However, RVS had limited use because it contains urushiol, an allergenic toxin. By improving an existing allergen-removal extraction method, we developed a new allergen-free Rhus verniciflua Stokes extract (RVSE) with higher flavonoid content. In this study, we examined whether RVSE inhibits the ability of AGS gastric cancer cells to migrate and invade.MATERIALS/METHODSThe flavonoids content of RVSE was analyzed by HPLC. The effects of RVSE on migration and invasion in AGS cells were analyzed by each assay kit. Matrix metalloproteinase (MMP)-9, plasminogen activator inhibitor-1 (PAI-1) and urokinase-type plasminogen activator (uPA) protein expression was analyzed by protein antibody array. The Phosphorylation of signal transducer and activator of transcription (STAT) 3 were assayed by Western blot analysis.RESULTSRVSE treatment with 0–100 μg/mL dose-dependently reduced the ability of AGS cells to migrate and invade. Notably, treatment with RVSE strongly inhibited the expression of MMP-9 and uPA and the phosphorylation of STAT3. In contrast, RVSE treatment dramatically increased the expression of PAI-1. These results indicate that the inhibition of MMP-9 and uPA expression and STAT3 phosphorylation and the stimulation of PAI-1 expression contributed to the decreased migration and invasion of AGS cells treated with RVSE.CONCLUSIONSThese results suggest that RVSE may be used as a natural herbal agent to reduce gastric cancer metastasis.

Urokinase-type plasminogen activator (uPA) regulates the expression and function of growth-associated protein 43 (GAP-43) in the synapse

Growth-associated protein 43 (GAP-43) plays a central role in the formation of presynaptic terminals, synaptic plasticity, and axonal growth and regeneration. During development, GAP-43 is found in axonal extensions of most neurons. In contrast, in the mature brain, its expression is restricted to a few presynaptic terminals and scattered axonal growth cones. Urokinase-type plasminogen activator (uPA) is a serine proteinase that, upon binding to its receptor (uPAR), catalyzes the conversion of plasminogen into plasmin and activates signaling pathways that promote cell migration, proliferation, and survival. In the developing brain, uPA induces neuritogenesis and neuronal migration. In contrast, the expression and function of uPA in the mature brain are poorly understood. However, recent evidence reveals that different forms of injury induce release of uPA and expression of uPAR in neurons and that uPA/uPAR binding triggers axonal growth and synapse formation. Here we show that binding of uPA to uPAR induces not only the mobilization of GAP-43 from the axonal shaft to the presynaptic terminal but also its activation in the axonal bouton by PKC-induced calcium-dependent phosphorylation at Ser-41 (pGAP-43). We found that this effect requires open presynaptic N-methyl-d-aspartate receptors but not plasmin generation. Furthermore, our work reveals that, following its activation by uPA/uPAR binding, pGAP-43 colocalizes with presynaptic vesicles and triggers their mobilization to the synaptic release site. Together, these data reveal a novel role of uPA as an activator of the synaptic vesicle cycle in cerebral cortical neurons via its ability to induce presynaptic recruitment and activation of GAP-43.

Elevated levels of serum urokinase plasminogen activator predict poor prognosis in hepatocellular carcinoma after resection

BackgroundUrokinase plasminogen activator (uPA) is an extracellular matrix-degrading protease that is involved in the invasiveness and progression of cancer. There is good evidence that uPA expression is a clinically relevant biomarker in some solid tumors, but its role in hepatocellulcar carcinoma (HCC) is uncertain. We evaluated the prognostic value of serum uPA before surgery in HCC patients receiving curative resection.MethodsSerum uPA levels were determined by enzyme-linked immunosorbent assay in 282 HCC patients who received complete liver resections at Kaohsiung Chang Gung Memorial Hospital. Overall survival (OS) curves were constructed using the Kaplan-Meier method and compared using the log-rank test. A Cox proportional -hazards regression model was used to identify independent prognostic factors. The median follow-up time was 52 months.ResultsPatients with higher pretreatment serum uPA (≥1 ng/ml) had significantly shorter OS (p = 0.002). Patients with liver cirrhosis, hypoalbuminemia, and thrombocytopenia were significantly more likely to present with elevated uPA levels. Multivariate Cox regression analyses indicated that high pretreatment serum uPA [hazard ratio (HR), 1.848, p = 0.006], vascular invasion (HR, 2.940, p < 0.001), and pathology stage III/IV (HR, 3.517, p < 0.001) were independent prognostic factors for OS. In further stratified analyses, the combination of serum uPA and AFP had more capacity to predict OS.ConclusionsWe conclude that uPA is a clinically relevant biomarker in HCC patients receiving curative resection, with higher expression of uPA being associated with higher mortality. This also highlights the potential utility of uPA as a therapeutic target for improved treatment strategies.

Urokinase Plasminogen Activator Overexpression Reverses Established Lung Fibrosis.

Impaired plasminogen activation (PA) is causally related to the development of lung fibrosis. Prior studies demonstrate that enhanced PA in the lung limits the severity of scarring following injury and in vitro studies indicate that PA promotes matrix degradation and fibroblast apoptosis. These findings led us to hypothesize that increased PA in an in vivo model would enhance the resolution of established lung fibrosis in conjunction with increased myofibroblast apoptosis. Transgenic C57BL/6 mice with doxycycline inducible lung-specific urokinase plasminogen activator (uPA) expression or littermate controls were treated (day 0) with bleomycin or saline. Doxycycline was initiated on days 1, 9, 14, or 21. Lung fibrosis, stiffness, apoptosis, epithelial barrier integrity, and inflammation were assessed. Protection from fibrosis with uPA upregulation from day 1 through day 28 was associated with reduced parenchymal stiffness as determined by atomic force microscopy. Initiation of uPA expression beginning in the late inflammatory or the early fibrotic phase reduced stiffness and fibrosis at day 28. Induction of uPA activity in mice with established fibrosis decreased lung collagen and lung stiffness while increasing myofibroblast apoptosis. Upregulation of uPA did not alter lung inflammation but was associated with improved epithelial cell homeostasis. Restoring intrapulmonary PA activity diminishes lung fibrogenesis and enhances the resolution of established lung fibrosis. This PA-mediated resolution is associated with increased myofibroblast apoptosis and improved epithelial cell homeostasis. These studies support the potential capacity of the lung to resolve existing scar in murine models.

Urokinase-type plasminogen activator is a modulator of synaptic plasticity in the central nervous system: implications for neurorepair in the ischemic brain.

The last two decades have witnessed a rapid decrease in mortality due to acute cerebral ischemia that paradoxically has led to a rapid increase in the number of patients that survive an acute ischemic stroke with various degrees of disability. Unfortunately, the lack of an effective therapeutic strategy to promote neurological recovery among stroke survivors has led to a rapidly growing population of disabled patients. Thus, understanding the mechanisms of neurorepair in the ischemic brain is a priority with wide scientific, social and economic implications. Cerebral ischemia has a harmful effect on synaptic structure associated with the development of functional impairment. In agreement with these observations, experimental evidence indicates that synaptic repair underlies the recovery of neurological function following an ischemic stroke. Furthermore, it has become evident that synaptic plasticity is crucial not only during development and learning, but also for synaptic repair after an ischemic insult. The plasminogen activating system is assembled by a cascade of enzymes and their inhibitors initially thought to be solely involved in the generation of plasmin. However, recent work has shown that in the brain this system has an important function regulating the development of synaptic plasticity via mechanisms that not always require plasmin generation. Urokinase-type plasminogen activator (uPA) is a serine proteinase and one of the plasminogen activators, that upon binding to its receptor (uPAR) not only catalyzes the conversion of plasminogen into plasmin on the cell surface, but also activates cell signaling pathways that promote cell migration, proliferation and survival. The role of uPA is the brain is not fully understood. However, it has been reported while uPA and uPAR are abundantly found in the developing central nervous system, in the mature brain their expression is restricted to a limited group of cells. Remarkably, following an ischemic injury to the mature brain the expression of uPA and uPAR increases to levels comparable to those observed during development. More specifically, neurons release uPA during the recovery phase from an ischemic injury, and astrocytes, axonal boutons and dendritic spines recruit uPAR to their plasma membrane. Here we will review recent evidence indicating that binding of uPA to uPAR promotes the repair of synapses damaged by an ischemic injury, with the resultant recovery of neurological function. Furthermore, we will discuss data indicating that treatment with recombinant uPA is a potential therapeutic strategy to promote neurological recovery among ischemic stroke survivors.

Fusion of macrophages promotes breast cancer cell proliferation, migration and invasion through activating epithelial-mesenchymal transition and Wnt/β-catenin signaling pathway

Cell fusion is a highly regulated process involved in cancer development, tissue regeneration and other physiological and pathological events. Many studies have shown that cancer cells can fuse with different types of cells such as mesenchymal stem cells (MSCs) and macrophages, which are behaved as two important fusogenic candidates in the tumor microenvironment. However, the underlying mechanisms of cell fusion between macrophages and malignant cells in cancer progression has not been fully clarified. The aim of the present study was to investigate the effects and mechanisms of cell fusion between macrophages and breast cancer cells on tumorigenesis and metastasis. Our results indicated that the hybrids exhibited enhanced proliferation, colony formation, migration and invasion capabilities, as well as suppressed apoptosis compared with parental breast cancer cells. Moreover, the hybrid cells displayed EMT with a significant downregulation of E-cadherin and upregulation of N-cadherin, Vimentin and Snail, as well as an obviously increased expression of MMP-2, MMP-9, uPA and S100A4. Mechanistically, we found that the TCF/LEF transcription factor activity of Wnt/β-catenin pathway and the expression of its downstream target genes including cyclin D1 and c-Myc were increased in the hybrid cells. Furthermore, our data confirmed that the promoting effects of fusion of macrophages on breast cancer cell proliferation, migration and invasion could be blocked by treatment with XAV-939, a Wnt/β-catenin signaling pathway inhibitor. In conclusion, our findings demonstrate that fusion of macrophages promotes proliferation, migration and invasion of breast cancer cells through activating EMT and Wnt/β-catenin signaling pathway. Our current study will further contribute to elucidate the mechanism of cell fusion in tumorigenesis and metastasis, and to develop a new therapeutic strategy for breast cancer treatment.

Relationships of protein biomarkers of the urokinase plasminogen activator system with expression of their cognate genes in primary breast carcinomas.

BackgrounduPA, its receptor uPAR, and inhibitors PAI‐1 and PAI‐2 play key roles in membrane remodeling/invasion and in predicting response to chemotherapy. We identified novel relationships of these biomarkers with ER/PR that indicate clinical utility for assessing breast carcinoma outcomes.MethodsRetrospective studies were performed with de‐identified results of (a) uPA, uPAR, and PAI‐1; (b) estrogen (ER) and progestin receptor (PR); and (c) clinical outcomes. Relative expression of 22 000 genes from microarray of RNA from LCM‐procured breast cancer cells was used with R Studio version 3.4.1.ResultsPrimary ER/PR status was related to uPA, uPAR, or PAI‐1 levels. ER− or PR− cancers expressed elevated uPA, uPAR, and PAI2 mRNA compared to ER+ or PR+ cells. Inverse relationships between ER/PR protein and expression of uPA, uPAR, and PAI‐2 were observed, whereas HER2 status was unrelated. qPCR analyses showed RERG and NQO‐1 expressions were elevated in uPA− lesions, while CD34 and EDG‐1 were elevated in uPAR− cancers. ERBB4 was overexpressed in PAI‐1+ carcinomas. Cox regression analyses revealed relationships of ER/PR status and uPA system members with regard to clinical outcomes of breast cancer.Conclusions uPA, uPAR, PAI1, or PAI2 expression was increased in either ER− or PR− cancers similar to that of protein content in ER−/PR− carcinomas, suggesting sex hormones regulate the uPA system in breast cancer. Results revealed protein content of uPA system members was related to ER/PR status of primary lesions. Use of LCM‐procured carcinoma cells uncovered relationships between expression of known cancer−associated genes and protein content of uPA system members. Collectively, results indicate evaluation of ER and PR protein of primary breast cancers combined with analyses of uPA, uPAR, and PAI‐1 protein content improves assessment of clinical outcomes.

TGF-β-mediated regulation of plasminogen activators is human telomerase reverse transcriptase dependent in cancer cells.

Telomerase is a specialized reverse transcriptase/terminal transferase enzyme that adds telomeric repeat sequences at the extreme end of a newly replicated chromosome. Apart from telomere lengthening, telomerase has many extracurricular activities. Telomerase is known to regulate the expression of many genes and helps in cancer progression and epithelial-to-mesenchymal transitions (EMTs). We have previously reported that human telomerase reverse transcriptase (hTERT) regulates the expression of plasminogen activator such as urokinase-type plasminogen activator (uPA) in cancer cells following a genome-wide transcriptomic study. Here, we present data substantiating these results in terms of real-time assays, western blots, and immunofluorescence. Another aim of this study is to find out the possible mechanism by which hTERT regulates the expression of plasminogen activators. We have used some molecular biology techniques such as quantitative real-time polymerase chain reaction, western blotting, and immunofluorescence and some assays such as wound healing assay and colony formation assay to solve this question. In this study, we show a positive association between hTERT and uPA. We also demonstrate that hTERT enhances uPA expression concomitant with EMT. Knocking down of hTERT reduces uPA expression as well as reverses EMT in cancer cells. We have also found that uPA is a transforming growth factor beta (TGF-β)-induced protein. Our observations establish that TGF-β-induced uPA expression is hTERT dependent.

Knockdown of Notch1 inhibits nasopharyngeal carcinoma cell growth and metastasis via downregulation of CCL2, CXCL16, and uPA.

Notch pathway is a highly conserved cell signaling system that plays very important roles in controlling multiple cell differentiation processes during embryonic and adult life. Multiple lines of evidence support the oncogenic role of Notch signaling in several human solid cancers; however, the pleiotropic effects and molecular mechanisms of Notch signaling inhibition on nasopharyngeal carcinoma (NPC) remain unclear. In this study, we evaluated Notch1 expression in NPC cell lines (CNE1, CNE2, SUNE1, HONE1, and HK1) by real-time quantitative PCR and Western blot analysis, and we found that CNE1 and CNE2 cells expressed a higher level of Notch1 compared with HONE1, SUNE1, and HK1 cells. Then Notch1 expression was specifically knocked down in CNE1 and CNE2 cells by Notch1 short hairpin RNA (shRNA). In Notch1 knockdown cells, cell proliferation, migration, and invasion were significantly inhibited. The epithelial-mesenchymal transition of tumor cells was reversed in Notch1-shRNA-transfected cells, accompanied by epithelioid-like morphology changes, increased protein levels of E-cadherin, and decreased expression of vimentin. In addition, knockdown of Notch1 markedly inhibited the expression of urokinase plasminogen activator (uPA) and its receptor uPAR, and chemokines C-C motif chemokine ligand 2 and C-X-C motif chemokine ligand 16, indicating that these factors are downstream targets of Notch1. Furthermore, deleting uPA expression had similar effects as Notch1. Finally, knockdown of Notch1 significantly diminished CNE1 cell growth in a murine model concomitant with inhibition of cell proliferation and induction of apoptosis. These results suggest that Notch1 may become a novel therapeutic target for the clinical treatment of NPC.

Inhibition by Epigallocatechin Gallate of IL-1-Induced Urokinase-Type Plasminogen Activator Expression and Collagen Degradation by Corneal Fibroblasts.

The proinflammatory cytokine interleukin (IL)-1 is implicated in corneal ulceration and promotes collagen degradation by corneal fibroblasts cultured in a three-dimensional (3D) collagen gel. Epigallocatechin-3-gallate (EGCG), the principal polyphenol in extracts of green tea, has various beneficial health effects, some of which appear to be mediated through direct or indirect inhibition of protease activity. We therefore examined the effect of EGCG on IL-1β-induced collagen degradation by corneal fibroblasts embedded in a collagen gel. Human corneal fibroblasts were cultured in a type I collagen gel. Collagen degradation was assessed by measurement of hydroxyproline in acid hydrolysates of culture supernatants. The expression of urokinase-type plasminogen activator (uPA) was examined by real-time and RT-PCR analysis and by fibrin zymography, and that of the collagenase matrix metalloproteinase 1 (MMP1) was detected by immunoblot analysis. EGCG inhibited IL-1β-induced, plasminogen-dependent collagen degradation by corneal fibroblasts in a concentration-dependent manner. It also attenuated the IL-1β-induced expression of uPA at both mRNA and protein levels. EGCG inhibited the IL-1β-induced conversion of exogenous plasminogen to plasmin as well as the plasminogen-dependent activation of pro-MMP1 in the 3D cultures without a substantial effect on pro-MMP1 abundance. EGCG inhibits IL-1β-induced collagen degradation by corneal fibroblasts, with this effect likely being mediated by suppression of the upregulation of uPA, the uPA-mediated conversion of plasminogen to plasmin, and the plasmin-mediated activation of pro-MMP1. EGCG thus warrants further investigation as a potential treatment for corneal ulcer.

MicroRNA-378-3p/5p suppresses the migration and invasiveness of oral squamous carcinoma cells by inhibiting KLK4 expression.

Distant metastasis frequently occurs in oral squamous cell carcinoma (OSCC) and contributes to the adverse prognosis for patients with OSCC. However, the potential mechanisms behind the metastasis have not yet been clarified. This study investigated the role of miR-378 in the migration and invasiveness of OSCC in vitro and in vivo. According to our results, the migration and invasiveness of OSCC cells were increased in cells overexpressing miR-378, and reduced in cells where miR-378-3p/5p was silenced. In addition, overexpression of miR-378 suppressed the expressions and activities of matrix metalloproteinase 9 (MMP-9) and MMP-2. Epithelial-mesenchymal transition (EMT) was restrained by overexpression of miR-378, as evidenced by an increase in E-cadherin expression and decrease in N-cadherin and uPA expression. However, knockdown of miR-378-3p/5p produced the opposite results. Moreover, kallikrein-related peptidase 4 (KLK4) was confirmed to be a target gene of miR-378. Overexpression of KLK4 reversed the induced decrease in migration and invasiveness of cells overexpressing miR-378 by upregulating the levels of MMP-9, MMP-2, and N-cadherin, and downregulating the level of E-cadhrin. Finally, the number of metastasis nodules in the lung tissues of nude mice was reduced by overexpression of miR-378, whereas the number of metastases increased with knockdown of miR-378. Taken together, our results suggest that the miR-378-KLK4 axis is involved in the mechanisms behind the migration and invasiveness of OSCC cells. Targeting the miR-378-KLK4 axis may be an effective measure for treating OSCC.

TLR5 activation induces expression of the pro-inflammatory mediator Urokinase Plasminogen Activator via NF-κB and MAPK signalling pathways in human dental pulp cells.

To explore the involvement of TLR5 in pulp inflammation and to examine the effects of TLR5 activation with its ligand, FlaB protein, on pro-inflammatory gene expression. TLR5 expression in dental pulp tissues and human dental pulp cells (hDPCs) were determined by immunohistochemistry, immunocytochemistry, Western blots and RT-PCR analyses. To examine the role of TLR5, hDPCs were treated with recombinant FlaB protein (500ngmL-1 ) to activate the receptor or with a small interfering RNA against TLR5 (si-TLR5) to downregulate the receptor. After exposure to FlaB, the expression of inflammation-related proteins was screened using a protein array kit. Western blots or qRT-PCR analyses were performed to identify changes in the expression of uPA (urokinase plasminogen activator), TIMPs (tissue inhibitor of metalloproteinases), and IL-6 and to determine their signalling pathways. Statistical analysis was performed using one-way analysis of variance (anova) with Tukey post hoc test; P<0.05 was considered statistically significant. TLR5 expression was identified in pulp tissues and hDPCs. Inthe protein array analysis, treatment with FlaB significantly increased uPA expression (P<0.01) andsignificantly decreased TIMP1/4 (P<0.05). FlaB treatment also significantlyincreased expression of the inflammatory marker IL-6 (P<0.01). FlaB treatment increased phosphorylation of the NF-κB p65 subunit, JNK, p38 and ERK. Chemical inhibitors of NF-κB (Bay11-7082), p38 (SB202190) or ERK (U0126) decreased the FlaB induction of uPA expression. Downregulation of TLR5 expression by siRNA decreased the FlaB induction of uPA protein and p65 phosphorylation. TLR5 activation with FlaB treatment induced the expression of uPA via the NF-κB and MAPK signalling pathways. Flagellin-bearing oral bacteria may cause pulp inflammation through TLR5. The findings provide new clues to control pulpal diseases by targeting TLR5 signalling pathways.

Stromal coexpression of uPA/PAI-1 protein predicts poor disease outcome in endocrine-treated postmenopausal patients with receptor-positive early breast cancer

To evaluate whether uPA/PAI-1 protein in hormone receptor-positive (HR+) breast tumor can predict prognosis in early breast cancer (BC). 606 women with HR+BC who had ≥5 years of endocrine therapy and in whom tumor tissue was available were included in this analysis. Stromal uPA/PAI-1 protein expression was evaluated by immunohistochemistry and correlated with distant recurrence-free survival (DRFS) and overall survival (OS). Stromal uPA was detected in 292/538 tumors (54.3%) while 269/505 samples (53.3%) exhibited stromal PAI-1. Co-expression of both proteins was found in 163/437 (37.3%) samples. Stromal uPA/PAI-1 co-expression was not associated with tumor size, age, nodal status, grading, or receptor status. Tumor stroma with both uPA and PAI-1 protein expression were more likely to have a shorter DRFS (HR: 1.87; 95%CI 1.18-2.96; p = 0.007) and OS (HR: 1.29; 95%CI 0.93-1.80; p = 0.129) than women without uPA/PAI-1 co-expression. After a median follow-up of 10 years, women with uPA/PAI-1-positive tumors experienced a significantly shorter DRFS (86.5% vs 72.4%; p < 0.001) and OS (70.4% vs 58.9%; p = 0.020) compared to women with uPA/PAI-1 negative tumors. Stromal co-expression of uPA and PAI-1 in breast cancer predicts poor DRFS and OS in postmenopausal women with HR+early-stage BC who receive endocrine therapy.

Expression of urokinase plasminogen activator (uPA) in the leukocytes and tissues of patients with benign and malignant breast lesions.

To show that the expression of urokinase plasminogen activator (uPA) in the leucocytes of patients with benign and malignant breast lesions correlates with its expression in the lesions, and to explore the role of uPA as a tumour marker in breast cancer. Using real time reverse transcriptase - polymerase chain reaction (RT-PCR), we examined the expression of uPA in leukocytes and tissues of three groups of women: a) with breast cancer (BC), b) with benign breast lesions and c) a control group of healthy women. An arbitrary value of 1 was assigned to the level of uPA expressed in the leucocytes of the healthy controls; all other measurements were expressed as a function of this value. The expression of uPA was significantly higher in BC samples compared to benign breast lesion (5.7 versus 3.8 times; p < 0.001). The leukocyte uPA of healthy volunteers was significantly lower than the leukocyte uPA from patients with breast lesions (p < 0.001). Leukocyte uPA level of patients with BC was higher compared to leukocyte uPA of women with benign lesions (p < 0.01). The expression of tissue uPA was the highest in triple-negative breast cancer. Methylation status was similar across tissue and leukocyte samples. Leukocyte uPA can be considered a surrogate of the tissue uPA expressed in BC samples. These results further support the use of leukocyte uPA as a biochemical marker of breast cancer.