Endothelial Cell-specific Molecule Research Articles

HULC long noncoding RNA silencing suppresses angiogenesis by regulating ESM-1 via the PI3K/Akt/mTOR signaling pathway in human gliomas.

Tumor angiogenesis plays a critical role in the tumor progression. Highly upregulated in liver cancer (HULC) is a long noncoding RNA (lncRNA) that acts as an oncogene in gliomas. We found that HULC, vascular endothelial growth factor (VEGF), and ESM-1 (endothelial cell specific molecule 1) expression and microvessel density were positively correlated with grade dependency in glioma patient tissues, and that HULC silencing suppressed angiogenesis by inhibiting glioma cells proliferation and invasion. This process induced anoikis and blocked the cell cycle at G1/S phase via the PI3K/Akt/mTOR signaling pathway, thus regulating the tumor-related genes involved in the above biological behavior in human glioma U87MG and U251 cells. However, these effects were reversed by ESM-1 overexpression, suggesting a mediating role of ESM-1 in the pro-angiogenesis effect of HULC. Our results define the mechanism of the pro-angiogenesis activity of HULC, which shows potential for application as a therapeutic target in glioma.

Endothelial cell-specific molecule–1/endocan: Diagnostic and prognostic value in patients suffering from severe sepsis and septic shock

PurposeThis study aims to assess the diagnostic and prognostic value of endocan in patients with severe sepsis or septic shock on a medical intensive care unit (ICU). Methods150 patients suspected for at least severe sepsis were enrolled on a medical ICU. On days 1, 3, and 8, plasma levels of endocan, procalcitonin (PCT), and interleukin (IL)-6 were measured. Follow-up on all-cause mortality was performed after 30 days and 6 months. ResultsEndocan correlated with Acute Physiology and Chronic Health Evaluation II (APACHE II), Sequential Organ Failure Assessment (SOFA), and Simplified Acute Physiology Score II (SAPS II) (P < .006). Endocan was higher in patients with at least severe sepsis compared with systemic inflammatory response syndrome (SIRS) or sepsis patients (P = .0006) on days 1, 3, and 8. With a minimum sensitivity of 70%, uniform cutoff levels were set for ≥ sepsis at 1.8 ng/mL, for ≥ severe sepsis at 2.6 ng/mL, for ≥ septic shock at 2.9 ng/mL. On day 1, endocan levels of the fourth quartile were significantly associated with 30-days and 6-months mortality compared to lower levels. After adjustment in Cox regressions, endocan still revealed prognostic value. ConclusionsEndocan showed diagnostic capacity to diagnose patients with severe sepsis and septic shock and revealed prognostic information for 30-days and 6-months all-cause mortality.

Adrenomedullin blockade induces regression of tumor neovessels through interference with vascular endothelial-cadherin signalling.

The cellular and molecular mechanisms by which adrenomedullin (AM) blockade suppresses tumor neovessels are not well defined. Herein, we show that AM blockade using anti-AM and anti-AM receptors antibodies targets vascular endothelial cells (ECs) and vascular smooth muscle cells (VSMCs), and induces regression of unstable nascent tumor neovessels. The underlying mechanism involved, and shown in vitro and in vivo in mice, is the disruption of the molecular engagement of the endothelial cell-specific junctional molecules vascular endothelial-cadherin (VE-cadherin)/β-catenin complex. AM blockade increases endothelial cell permeability by inhibiting cell-cell contacts predominantly through disruption of VE-cadherin/β-catenin/Akt signalling pathway, thereby leading to vascular collapse and regression of tumor neovessels. At a molecular level, we show that AM blockade induces tyrosine phosphorylation of VE-cadherin at a critical tyrosine, Tyr731, which is sufficient to prevent the binding of β-catenin to the cytoplasmic tail of VE-cadherin leading to the inhibition of cell barrier function. Furthermore, we demonstrate activation of Src kinase by phosphorylation on Tyr416, supporting a role of Src to phosphorylate Tyr731-VE-cadherin. In this model, Src inhibition impairs αAM and αAMR-induced Tyr731-VE-cadherin phosphorylation in a dose-dependent manner, indicating that Tyr731-VE-cadherin phosphorylation state is dependent on Src activation. We found that AM blockade induces β-catenin phosphorylation on Ser33/Ser37/Thr41 sites in both ECs and VSMCs both in vitro and in vivo in mice. These data suggest that AM blockade selectively induces regression of unstable tumor neovessels, through disruption of VE-cadherin signalling. Targeting AM system may present a novel therapeutic target to selectively disrupt assembly and induce regression of nascent tumor neovessels, without affecting normal stabilized vasculature.

Abstract 73: Dysregulation of Robo-4 causes Pathological Cerebrovascular Angiogenesis in Diabetes

Diabetes increases the risk and exacerbates the progress of cerebral complications including stroke and cognitive impairment. Diabetic Goto-Kakizaki (GK) rats suffer loss of vascular integrity and dysfunctional cerebral-neovascularization, despite augmented vascular endothelial growth factor (VEGF). Roundabout-4 (Robo-4) is an endothelial cell (EC) specific member axon guidance molecule that regulates EC stability via inhibiting VEGF signaling but its role in cerebrovascular maturation in diabetes remained unknown. We hypothesized that increased VEGF activation in diabetes reduces Robo-4 and uncouples its protective signaling by promoting its binding to activated β-3 integrin. Methods: Immunohistochemistry and immunoblotting are used to assess Robo-4 expression, pericyte/EC ratio and robo-4/β-3 integrin interaction in the brain and isolated microvascular endothelial cells (BMVEC). Transfection was used to overexpress Robo-4 in BMVEC in vitro and EC migration and trans-well permeability assays were used to examine EC function. Stereotaxic injection of adenoviral construct was used for local in vivo overexpression of robo-4 and its impact on neovascularization indices (Vascular Volume (VV), Surface area (SA), Tortuosity index (TI) and Vascular density (VD) was measured using 3D confocal microscopy. Results: Robo-4 expression was reduced in GK brains as well as in isolated BMVEC (35%* and 39%* vs control Wistar). In vitro, over expression of Robo-4 inhibited VEGF-induced permeability (80%*) and cell migration (70%*) in BMVEC vs control. In vivo over expression of Robo-4 improved vascular integrity and maturation as indicated by reduction of all pathological neovascularization indices (VV:70%*, SA:50%*, TI:20%*, VD:50%* vs control) and increased pericyte/EC ratio (40%* vs control). GK rats showed increase interaction between VEGF-activated β-3 integrin and Robo-4. Overexpression of Robo-4 decreased this interaction (40%* vs control). (*P&lt;0.05). Conclusion: Restoration of Robo-4 expression decreased pathological neovascularization and improved vessel integrity and maturation. Our results suggest that Robo-4 is a promising therapeutic target in treatment of diabetic pathological brain neovascularization.

Endocan: a new molecule playing a role in the development of hypertension and chronic kidney disease?

Recently, endocan-formerly known as endothelial cell-specific molecule 1 (ESM-1)--was found to be associated with entities such as cancer, hypertension, renal transplant rejection, and chronic renal failure. Endothelial cells of many organs secrete endocan, but the exact functions of this relatively new molecule have not been elucidated completely. Emerging evidence suggests, however, that endocan plays an important role in inflammation, upregulation of cell adhesion molecules, lymphocyte functions, and endothelial cytoskeleton rearrangement. As suggested above, endocan has a prognostic impact in hypertension, transplant rejection, and chronic renal failure. In the current review, the evidence regarding endocan, hypertension, and chronic renal failure are summarized.

Esm1 modulates endothelial tip cell behavior and vascular permeability by enhancing VEGF bioavailability.

Endothelial cell-specific molecule 1 (Esm1) is a secreted protein thought to play a role in angiogenesis and inflammation. However, there is currently no direct in vivo evidence supporting a function of Esm1 in either of these processes. To determine the role of Esm1 in vivo and the underlying molecular mechanisms. We generated and analyzed Esm1 knockout (Esm1(KO)) mice to study its role in angiogenesis and inflammation. Esm1 expression is induced by the vascular endothelial growth factor A (VEGF-A) in endothelial tip cells of the mouse retina. Esm1(KO) mice showed delayed vascular outgrowth and reduced filopodia extension, which are both VEGF-A-dependent processes. Impairment of Esm1 function led to a decrease in phosphorylated Erk1/2 (extracellular-signal regulated kinases 1/2) in sprouting vessels. We also found that Esm1(KO) mice displayed a 40% decrease in leukocyte transmigration. Moreover, VEGF-induced vascular permeability was decreased by 30% in Esm1(KO) mice and specifically on stimulation with VEGF-A165 but not VEGF-A121. Accordingly, cerebral edema attributable to ischemic stroke-induced vascular permeability was reduced by 50% in the absence of Esm1. Mechanistically, we show that Esm1 binds directly to fibronectin and thereby displaces fibronectin-bound VEGF-A165 leading to increased bioavailability of VEGF-A165 and subsequently enhanced levels of VEGF-A signaling. Esm1 is simultaneously a target and modulator of VEGF signaling in endothelial cells, playing a role in angiogenesis, inflammation, and vascular permeability, which might be of potential interest for therapeutic applications.

Mechanisms of endothelial cell migration.

Cell migration plays a central role in a variety of physiological and pathological processes during our whole life. Cellular movement is a complex, tightly regulated multistep process. Although the principle mechanisms of migration follow a defined general motility cycle, the cell type and the context of moving influences the detailed mode of migration. Endothelial cells migrate during vasculogenesis and angiogenesis but also in a damaged vessel to restore vessel integrity. Depending on the situation they migrate individually, in chains or sheets and complex signaling, intercellular signals as well as environmental cues modulate the process. Here, the different modes of cell migration, the peculiarities of endothelial cell migration and specific guidance molecules controlling this process will be reviewed.

FRI0361 The Effects of Adiponectin on the Expression of Endocan in Fibroblast-Like Synoviocytes

BackgroundEndocan, previously called endothelial cell-specific molecule (ESM-1), has been studied as a pro-angiogenic factor in tumor tissues. Endocan binds CD11a/CD18 integrin (also called LFA-1 for Leukocyte Function-associated Antigen-1) on human...

Increased serum levels of soluble vascular endothelial-cadherin in patients with systemic vasculitis

Henoch-Schönlein purpura (HSP) is a commonest systemic vasculitis (SV) in childhood characterized by an inflammatory reaction directed at vessels. Endothelial damage and perivascular leukocyte infiltrates are vital in the development of HSP. Vascular endothelial (VE)-cadherin is an endothelial cell-specific adhesion molecule, which plays critical roles in angiogenesis and endothelial integrity. Herein, we investigated the serum levels of soluble VE-cadherin (sVE-cadherin) in patients with HSP and other forms of SV. The serum levels of sVE-cadherin in 30 patients with HSP, together with patients with urticarial vasculitis, allergic vasculitis, Behcet disease, psoriasis vulgaris (PV) and atopic dermatitis (AD) and 26 health controls were measured by enzyme-linked immunosorbent assay. Serum levels of sVE-cadherin were significantly increased in patients with HSP in acute stage and patients with other forms of SV but not in patients with PV or AD. Moreover, Serum sVE-cadherin levels in HSP patients were correlated with the severity of this disease and serum concentrations of IgA anticardiolipin antibodies and vascular endothelial growth factor. Taken together, we show firstly that serum sVE-cadherin is abnormally increased in HSP patients. Increased serum levels of sVE-cadherin might be a novel biomarker for evaluating the severity of HSP and useful for identifying the presence of SV in inflammatory skin conditions.

Genome-Wide Analysis of Long Noncoding RNA (lncRNA) Expression in Hepatoblastoma Tissues

Long noncoding RNAs (lncRNAs) have crucial roles in cancer biology. We performed a genome-wide analysis of lncRNA expression in hepatoblastoma tissues to identify novel targets for further study of hepatoblastoma. Hepatoblastoma and normal liver tissue samples were obtained from hepatoblastoma patients. The genome-wide analysis of lncRNA expression in these tissues was performed using a 4×180 K lncRNA microarray and Sureprint G3 Human lncRNA Chips. Quantitative RT-PCR (qRT-PCR) was performed to confirm these results. The differential expressions of lncRNAs and mRNAs were identified through fold-change filtering. Gene Ontology (GO) and pathway analyses were performed using the standard enrichment computation method. Associations between lncRNAs and adjacent protein-coding genes were determined through complex transcriptional loci analysis. We found that 2736 lncRNAs were differentially expressed in hepatoblastoma tissues. Among these, 1757 lncRNAs were upregulated more than two-fold relative to normal tissues and 979 lncRNAs were downregulated. Moreover, in hepatoblastoma there were 420 matched lncRNA-mRNA pairs for 120 differentially expressed lncRNAs, and 167 differentially expressed mRNAs. The co-expression network analysis predicted 252 network nodes and 420 connections between 120 lncRNAs and 132 coding genes. Within this co-expression network, 369 pairs were positive, and 51 pairs were negative. Lastly, qRT-PCR data verified six upregulated and downregulated lncRNAs in hepatoblastoma, plus endothelial cell-specific molecule 1 (ESM1) mRNA. Our results demonstrated that expression of these aberrant lncRNAs could respond to hepatoblastoma development. Further study of these lncRNAs could provide useful insight into hepatoblastoma biology.

Endocan—A Novel Inflammatory Indicator in Newly Diagnosed Patients With Hypertension

Endothelial dysfunction is regarded as the initial lesion in the development of atherosclerosis. Endocan, previously called endothelial cell-specific molecule 1 (ESM-1), is a new candidate immunoinflammatory marker that may be associated with cardiometabolic risk factors. Therefore, we assessed serum levels of endocan in newly diagnosed patients with untreated essential hypertension (HT). A total of 18 patients with HT and 23 normotensive control participants were included in the study. Serum endocan levels, carotid intima-media thickness (cIMT), and high-sensitivity C-reactive protein (hsCRP) were measured. Serum endocan levels were significantly higher in the HT group (P < .001). In patients with HT, serum endocan levels correlated positively with cIMT and hsCRP (r = .551, P < .001 and r = .644, P < .001, respectively). Our findings suggest that circulating endocan levels represent a new marker in patients with essential HT. Endocan may be a surrogate endothelial dysfunction marker and may have a functional role in endothelium-dependent pathological disorders.

Detection of serum endothelial cell specific molecule 1 in gastric cancer patients and its clinical significance

To investigate the expression of serum endothelial cell specific molecule 1 (ESM-1) in gastric cancer and to evaluate the effect of serum ESM-1 as a potential serum biomarker. Serum ESM-1 was detected by enzyme-linked immunosorbent assay (ELISA) and CEA, CA19.9, CA72.4 were detected by electrochemiluminescence immunoassay (ECLIA) in 102 patients with gastric cancer preoperatively. At the same time, serum ESM-1, CEA, CA19-9, CA72-4 in 41 healthy adults volunteers were detected with the same method. In addition, the follow-up data of all the patients were collected. Compared to healthy volunteers, the serum ESM-1 level in gastric cancer patients increased (P<0.01). The sensitivity and specificity of serum ESM-1 were 73.9% and 51.2% respectively. In contrast, the sensitivities of CEA, CA19-9 and CA72-4 were only 16.1%, 18.3% and 23.2% respectively. High level of serum ESM-1 indicated poor outcomes (P<0.05). Serum ESM-1 increases in the peripheral blood of the gastric cancer patients. It may be a potential serum marker to help diagnosis and prediction of prognosis of gastric cancer patients.

Endocan in Hypertension and Cardiovascular Disease

In their pilot study, Balta et al reported that circulating endocan (endothelial cell specific molecule 1 [ESM-1]) levels may represent a new marker of essential hypertension. They found that in 18 patients with newly diagnosed hypertension, serum endocan levels correlated significantly with carotid intimamedia thickness (cIMT) and high-sensitivity C-reactive protein (hsCRP) compared with 23 normotensive controls. Therefore, Balta et al suggested that circulating endocan levels may represent a new marker for essential hypertension. Endocan is a protein encoded by the ESM-1 gene in humans. Due to possible confusion, it must be clarified that endocan is not related to endocannabinoids that are endogenous mediators that elicit multiple biological effects similar to those of marijuana. The focus of this editorial is specifically on endocan and its CV relationships. Endocan is a recombinant proteoglycan that can be produced from engineered HEK293 cells with efficient longterm production. This availability opens new opportunities to study the structure and functions of endocan. Abid et al tested the hypothesis that endocan, as a novel soluble dermatan sulfate proteoglycan, is differentially expressed in the intact endothelium and that site-specific expression is mediated by signals in the local microenvironment. Using a combination of analytical techniques, they reported that endocan is preferentially expressed in the endothelial lining of tumor xenografts, including human nonsmall cell lung cancer, rat glioma, and human renal cell carcinoma. They found that in vitro expression of endocan in human umbilical vein endothelial cells (HUVECs) was upregulated by a tumor cell-conditioned medium and that this was inhibited by the addition of neutralizing antibody to vascular endothelial growth factor (VEGF). The authors also found that treatment of HUVEC with VEGF resulted in a doseand time-dependent increase in messenger RNA (mRNA) in endocan. It therefore appeared to them that endocan is preferentially expressed in tumor endothelium in vivo with its expression regulated by tumor-derived factors. Akkok et al reported that peripheral blood stem cell (PBSC) collection in patients with multiple myeloma using PBSC apheresis decreased the angioregulatory cytokines, angiopoietin 22 and VEGF, which had been found to be increased in the patients with myeloma, while at the same time, PBSC apheresis resulted in an increase in endocan levels as a microvascular endothelial marker. Rennel et al appeared to show that among angiogenic growth factors, VEGF-A is a specific inducer of endocan transcription. This translates into increased protein levels in VEGF-A-treated endothelial cells. Rennel et al suggested that increased endocan protein expression in human renal cancer supports its role in tumor growth. Similar supportive data are available for colorectal cancer. When colorectal cancer is present, the expression of endocan is downregulated. However, endocan is positively correlated with tissue differentiation in colorectal cancer, which suggests that endocan is associated with the development and differentiation of colorectal cancer. Zhang et al studied endocan as a novel human endothelial cell-specific molecule whose expression is regulated by cytokines and VEGF. They found that endocan was expressed in actively proliferative or neogenic tissues and cells such as the germinal centers of lymph nodes, bronchial epithelium, neovasculature, endothelium, and glandular tissues. Endocan was not present in silent or resting tissues of cells such as the endothelium of the spleen and large arteries. Zhang et al considered that endocan may function as a marker for angiogenesis or oncogenesis and that the gene for endocan might be a candidate gene for the development of inflammatory tissue, metastases, neoplasia, and the development of tumors such that the expression level of endocan may be of value in early diagnosis and prognosis of some tumors. In line with this, Roudnicky et al found that both endocan and VEGF-A levels were more elevated in the plasma of patients with invasive bladder cancer than in healthy individuals. They therefore postulated that endocan might function as a useful biomarker for monitoring disease progression and the efficacy of therapies to target VEGF-A in patients with bladder cancer. Endocan has also been found to be overexpressed in renal clear cell carcinomas and as a result it may be a target marker for follow-up of these cancers and a potential way to evaluate their response to antiangiogenic therapies. Serum endocan has

Serum endocan levels as a marker of disease activity in patients with Behçet disease

Endocan is a novel human endothelial cell-specific molecule. The central role of leukocytes and endothelial dysfunction in the development of Behçet disease (BD) led us to hypothesize that endocan might be a marker of this disease. We investigated the relationship between serum levels of endocan and disease activity in patients with BD. In all, 33 patients (16 active, 17 inactive) with BD and 35 healthy persons were included in the study. Endocan and C-reactive protein were measured in all subjects. Patients with BD had significantly higher serum endocan levels. Mean serum levels of endocan were 1.29 ± 0.60 ng/mL (range: 0.58-2.99) in patients with BD and 0.75 ± 0.16 ng/mL (range: 0.48-1.21) in control subjects (P < .001). In patients with BD, serum endocan levels correlated moderately but significantly with C-reactive protein, erythrocyte sedimentation rate, and disease activity. Receiver operating characteristic curve analysis suggested that the optimum endocan level cut-off point for patients with BD was 0.87 ng/mL, with a sensitivity and specificity of 75.8% and 80%, respectively (area under curve 0.835, 95% confidence interval 0.738-0.932). The main limitation of our study is the relatively small sample size. Circulating endocan may be a marker of BD activity.

Plasma endothelial cell-specific molecule-1 (ESM-1) in management of community-acquired pneumonia

Endothelial cell-specific molecule (ESM)-1 is a soluble proteoglycan expressed by the vascular endothelium and which also circulates in the bloodstream. Inflammatory cytokines and proangiogenic growth factors increase its expression, and increased serum levels are found in immunocompetent patients with sepsis. The aim of this study was to investigate differential changes in plasma levels of ESM-1 before and after antibiotic treatment in hospitalized adult patients with community-acquired pneumonia (CAP). Plasma ESM-1 levels were measured in 82 adult patients with CAP and 82 healthy controls using a commercial enzyme-linked immunosorbent assay (ELISA). Upon initial hospitalization, Acute Physiology and Chronic Health Evaluation II (APACHE II), CURB-65, and Pneumonia Severity Index (PSI) scores were determined to assess CAP severity in these patients. Results showed a decline in the number of white blood cells (WBCs) and neutrophils, and decreases in the concentrations of C-reactive protein (CRP) and ESM-1 after antibiotic treatment. The plasma concentration of ESM-1, but not CRP or the WBC count, was correlated with the severity of CAP based on the PSI (r=0.554, p<0.001), CURB-65 (r=0.510, p<0.001), and APACHE II scores (r=0.447, p<0.001). Plasma levels of ESM-1 may be able to play a role in the diagnosis and clinical assessment of the severity of CAP, which could potentially guide the development of treatment strategies.

ESM-1 expression in stromal cells is predictive of recurrence after radiofrequency ablation in early hepatocellular carcinoma

The prognosis of hepatocellular carcinoma (HCC) treated by radiofrequency ablation (RFA) is mainly linked to tumor recurrence. So far, no tissue biomarker of recurrence has been validated in biopsy samples. We aimed at investigating the prognostic value of tissue biomarkers in HCC biopsy samples of patients treated with RFA. All consecutive naive patients from 3 university hospitals, with compensated cirrhosis, early-stage (BCLC 0/A) uninodular HCC treated with RFA, and available tumor biopsy, were included. Edmondson's grade, and the expression of cytokeratin 19, glutamine synthase, beta-catenin, epithelial cell adhesion molecule (EpCAM), and endothelial cell-specific molecule 1 (ESM-1) were assessed. Main clinical end points were overall and early recurrence. Statistical analyses were performed using Kaplan Meier, Log-rank test, and Cox models. 150 patients were included. Recurrence, death or liver transplantation occurred in 85, 51, and 12 patients, respectively. Median follow-up was 27months. ESM-1 expression by HCC stromal endothelial cells was observed in 58 patients (40%) and was associated with higher serum AFP levels, larger tumor, and more frequent expression of EpCAM and surrogate markers of activation of the Wnt-ß-catenin pathway. The 2 independent predictive factors of overall recurrence were serum AFP (HR 1.11 [1.002; 1.22], p=0.045) and ESM-1 expression (HR 1.56 [1.004; 2.43], p=0.048). ESM-1 expression was also an independent predictive factor of early recurrence (HR 1.81 [1.02; 3.21], p=0.042). ESM-1 expression by stromal endothelial cells, in tumor biopsy samples, has an independent predictive value of early recurrence after RFA.

Preparation of Anti-hECSM2 Mouse Monoclonal Antibodies and Their Application in the Analysis of hECSM2 Expression

Human endothelial cell-specific molecule 2 (hECSM2) is a novel, recently identified gene, the biological functions of which are still unclear. The aim of this study was to prepare anti-hECSM2 mouse monoclonal antibodies and investigate the endogenous expression of hECSM2 in cell lines and human tissues. Mouse monoclonal antibodies (MAbs) specifically against hECSM2 were prepared using the hybridoma method. Western blot and flow cytometry were used to detect the specificity of the antibodies. Immunofluorescence and immunohistochemistry were used to investigate the endogenous expression of hECSM2 in different kinds of cell lines and human tissues, respectively. Two anti-hECSM2 MAbs secreting hybridomas were selected. Experiments showed that these two antibodies were highly specific to hECSM2 and endogenous hECSM2 was located on the endothelial cell membrane. Our anti-hECSM2 mouse antibodies can be used for Western blot, flow cytometry, and immunohistochemistry study, and can be a valuable tool for investigating the function and distribution of hECSM2.

Endocan Is Upregulated on Tumor Vessels in Invasive Bladder Cancer Where It Mediates VEGF-A–Induced Angiogenesis

Tumor-associated blood vessels differ from normal vessels and proteins present only on tumor vessels may serve as biomarkers or targets for antiangiogenic therapy in cancer. Comparing the transcriptional profiles of blood vascular endothelium from human invasive bladder cancer with normal bladder tissue, we found that the endothelial cell-specific molecule endocan (ESM1) was highly elevated on tumor vessels. Endocan was associated with filopodia of angiogenic endothelial tip cells in invasive bladder cancer. Notably, endocan expression on tumor vessels correlated strongly with staging and invasiveness, predicting a shorter recurrence-free survival time in noninvasive bladder cancers. Both endocan and VEGF-A levels were higher in plasma of patients with invasive bladder cancer than healthy individuals. Mechanistic investigations in cultured blood vascular endothelial cells or transgenic mice revealed that endocan expression was stimulated by VEGF-A through the phosphorylation and activation of VEGFR-2, which was required to promote cell migration and tube formation by VEGF-A. Taken together, our findings suggest that disrupting endocan interaction with VEGFR-2 or VEGF-A could offer a novel rational strategy to inhibit tumor angiogenesis. Furthermore, they suggest that endocan might serve as a useful biomarker to monitor disease progression and the efficacy of VEGF-A-targeting therapies in patients with bladder cancer.

Identification of novel splice variants and exons of human endothelial cell-specific chemotaxic regulator (ECSCR) by bioinformatics analysis

Recent discovery of biological function of endothelial cell-specific chemotaxic regulator (ECSCR), previously known as endothelial cell-specific molecule 2 (ECSM2), in modulating endothelial cell migration, apoptosis, and angiogenesis, has made it an attractive molecule in vascular research. Thus, identification of splice variants of ECSCR could provide new strategies for better understanding its roles in health and disease. In this study, we performed a series of blast searches on the human EST database with known ECSCR cDNA sequence (Variant 1), and identified additional three splice variants (Variants 2–4). When examining the ECSCR gene in the human genome assemblies, we found a large unknown region between Exons 9 and 11. By PCR amplification and sequencing, we partially mapped Exon 10 within this previously unknown region of the ECSCR gene. Taken together, in addition to previously reported human ECSCR, we identified three novel full-length splice variants potentially encoding different protein isoforms. We further defined a total of twelve exons and nearly all exon–intron boundaries of the gene, of which only eight are annotated in current public databases. Our work provides new information on gene structure and alternative splicing of the human ECSCR, which may imply its functional complexity. This undoubtedly opens new opportunities for future investigation of the biological and pathological significance of these ECSCR splice variants.

Endothelial cell specific molecule 1 is today a relevant marker of respiratory failure in sepsis and polytrauma patients

Endothelial cell specific molecule 1 is today a relevant marker of respiratory failure in sepsis and polytrauma patients