Endocan in cancers: a lesson from a circulating dermatan sulfate proteoglycan. Int J Cell Biol. 2013;2013:705027. [PMID: 23606845 PMCID: PMC3625564 DOI: 10.1155/2013/705027]

Endothelial-secreted Endocan activates PDGFRA and regulates vascularity and spatial phenotype in glioblastoma

Extensive neovascularization is a hallmark of glioblastoma (GBM). In addition to supplying oxygen and nutrients, vascular endothelial cells provide trophic support to GBM cells via paracrine signaling. Here we report that Endocan (ESM1), an endothelial-secreted proteoglycan, confers enhanced proliferative, migratory, and angiogenic properties to GBM cells and regulates their spatial identity. Mechanistically, Endocan exerts at least part of its functions via direct binding and activation of the PDGFRA receptor. Subsequent downstream signaling enhances chromatin accessibility of the Myc promoter and upregulates Myc expression inducing stable phenotypic changes in GBM cells. Furthermore, Endocan confers radioprotection on GBM cells in vitro and in vivo. Inhibition of Endocan-PDGFRA signaling with ponatinib increases survival in the Esm1 wild-type but not in the Esm1 knock-out mouse GBM model. Our findings identify Endocan and its downstream signaling axis as a potential target to subdue GBM recurrence and highlight the importance of vascular-tumor interactions for GBM development.

Endocan, a novel glycoprotein with multiple biological activities, may play important roles in neurological diseases

Endothelial cell specific-1 (ESM-1), also known as endocan, is a soluble dermatan sulfate proteoglycan that is mainly secreted by endothelial cells. Endocan is associated with tumorigenesis and cancer progression and is also related to cardiovascular disorders, autoimmune diseases, and sepsis. The phenylalanine-rich region and linear polysaccharide of endocan are necessary for the protein to exert its biological functions. Elevated plasma endocan levels reflect endothelial activation and dysfunction. In addition, endocan participates in complex inflammatory responses and proliferative processes. Here, we reviewed current research on endocan, elaborated the protein's structure and biological functions, and speculated on its possible clinical value in nervous system diseases. We conclude that endocan may be a glycoprotein that plays an important role in neurological disorders.

Roles of endothelial cell specific molecule‑1 in tumor angiogenesis (Review)

Angiogenesis plays a crucial role in tumor growth and metastasis, and is heavily influenced by the tumor microenvironment (TME). Endothelial cell dysfunction is a key factor in tumor angiogenesis and is characterized by the aberrant expression of pro-angiogenic factors. Endothelial cell specific molecule-1 (ESM1), also known as endocan, is a marker of endothelial cell dysfunction. Although ESM1 is primarily expressed in normal endothelial cells, dysregulated ESM1 expression has been observed in human tumors and animal tumor models, and implicated in tumor growth, metastasis and angiogenesis. The precise role of ESM1 in tumor angiogenesis and its potential regulatory mechanisms are not yet conclusively defined. However, the aim of the present review was to explore the involvement of ESM1 in the process of tumor angiogenesis in the TME and the characteristics of neovascularization. In addition, the present review discusses the interaction between ESM1 and angiogenic factors, as well as the mechanisms through which ESM1 contributes to tumor angiogenesis. Furthermore, the reciprocal regulation between ESM1 and the TME is explored. Finally, the potential of targeting ESM1 as a therapeutic strategy for tumor angiogenesis is presented.

Expression of endocan and vascular endothelial growth factor and their correlation with histopathological prognostic parameters in pheochromocytoma

OBJECTIVE

Endocan and vascular endothelial growth factor (VEGF) are markers expressed in various cancer types that are highly vascular, and they have prognostic significance for these cancers. In this study, we aimed to show the expression of endocan and VEGF in pheochromocytoma tumor tissues and to evaluate their correlations with histopathological parameters.

MATERIAL AND METHODS

Thirty-eight patients who had been operated for pheochromocytoma were included in the study. As the control group, 28 subjects whose specimens contained normal adrenal medulla tissue were included. The formalin-fixed paraffin-embedded specimens of pheochromocytoma patients were evaluated for Pheochromocytoma of the Adrenal gland Scaled Score (PASS). Sections were then stained for immunohistochemical analysis. The degree of endocan and VEGF positivity was determined by the proportion of stained cells on a negative to strong scale.

RESULTS

Endocan (p < 0.001) and VEGF (p = 0.004) expressions were found to be significantly higher in the pheochromocytoma group than in the control group. In the pheochromocytoma group, total PASS score (r = 0.714; p < 0.001) and most of the PASS score components were positively correlated with the level of endocan expression. Median Ki-67 index (p = 0.010), total PASS score (p < 0.001), tumor cell spindling (p = 0.048), and nuclear pleomorphism (p = 0.030) were higher in pheochromocytoma with VEGF expression than in those without.

CONCLUSION

If our findings are supported by studies with a larger sample size, we think that endocan has the potential to be used both as a tumor marker and in predicting malignancy potential in patients with pheochromocytoma, and that the detection of VEGF expression in these tumors is also associated with an increase in malignancy potential.

Is maternal serum endocan level a novel marker in gestational diabetes mellitus?

AIM

To determine whether there was a significant difference between serum endocan levels of pregnant women with and without gestational diabetes mellitus (GDM).

METHODS

A total of 90 pregnant women, 45 with gestational diabetes and 45 healthy pregnant women, between 24 and 28 gestational weeks, were included in this prospective case-control study. The pregnant women were screened for gestational diabetes using a two-step protocol. Serum endocan levels were measured using a commercially available enzyme-linked immunosorbent assay (ELISA) kit. A p-value of <0.05 was considered statistically significant.

RESULTS

Serum endocan level was significantly higher in the GDM group than in healthy controls (168.46 ± 160.6 vs. 105.66 ± 26.52 pg/mL, respectively; p < 0.001). Serum endocan concentrations were positively correlated with the results of 50 g oral glucose challenge test (GCT) (p < 0.001). Receiver operating characteristic curve analysis showed that endocan with a cut-off point of 133.9 ng/dL indicated women with GDM with a sensitivity of 55.6% and specificity of 88.9% (area under the curve [AUC]: 0.737, 95% CI: 0.634-0.824). The overall differential performance of endocan according to the GDM groups was determined as 73.7% (p < 0.001). Maternal serum endocan level was positively correlated with fasting glucose, postprandial glucose, and glycated hemoglobin (HbA1c) (p < 0.001).

CONCLUSIONS

Elevated endocan levels in gestational diabetes were correlated with fasting glucose, postprandial glucose, HbA1c, and oral glucose tolerance test (OGTT) results. Despite the low sensitivity of 55.6% and the high specificity of 88.9%, we found a high differential performance rate indicating that serum endocan levels were important for the pathophysiology of GDM and should be investigated for the possibility of being a novel marker in larger populations.

Serum endocan as a predictive biomarker of cardiovascular risk in obese pediatric patients

BACKGROUND

Endocan is a soluble dermatan sulfate proteoglycan (50 kDa) secreted by endothelial cells and expressed by dermal, coronary, pulmonary and adipose tissue microvasculature. It plays an important role in the pathogenesis of vascular disorders, inflammatory state, endothelium dysfunction and neoangiogenesis. Aims of the study were to compare fasting serum endocan levels between children with obesity and healthy controls and to investigate the relationships between endocan, body mass index (BMI) and other indices of cardiometabolic risk.

METHODS

This single-center, observational, retrospective study included 19 pediatric patients with obesity aged 11.94 ± 0.52 years and 19 lean matched controls. Each patient underwent clinical and auxological examination and laboratory investigations including routine organs function tests and lipid profile. Homeostasis model assessment of insulin resistance (HOMA-IR) was calculated. Fasting endocan serum levels were measured using an enzyme-linked immunosorbent assay (ELISA).

RESULTS

Compared to healthy subjects, serum endocan levels were found to be significantly upraised in children with obesity. Endocan resulted significantly correlated with insulin levels (rho 0.47; p = 0.04); in addition, an association with HOMA-IR values with a trend toward the statistical significance (rho 0.43; p = 0.07) was found. No significant correlation with fasting blood glucose values and lipid serum levels was demonstrated. Although not statistically significant, a correlation between endocan and the presence and grading of liver steatosis on ultrasound (rho 0.51; p = 0.08 and rho 0.51; p = 0.08, respectively) was found.

CONCLUSIONS

These findings confirm the association between endothelial damage and insulin resistance in children with obesity. Endocan could be used as a biomarker of early endothelial dysfunction in children with obesity and could be a valid predictor of future cardiovascular risk in adulthood.

Can endocan serve as a molecular "hepatostat" in liver regeneration?

BACKGROUND

Intriguingly, liver regeneration after injury does not induce uncontrolled growth and the underlying mechanisms of such a "hepatostat" are still not clear. Endocan, a proteoglycan, was implicated in liver regeneration. It can support the function of hepatocyte growth factor/scatter factor in tissue repair after injury. Endostatin, a 20 kDa C-terminal fragment of collagen XVIII, may modulate the cessation of liver regeneration. eEF2K, a protein kinase that regulates protein synthesis, can regulate angiogenesis. Thus, we investigated the role of endocan, endostatin and eEF2K during normal liver regeneration.

METHODS

Serum samples and regenerating remnant liver tissues were obtained on various days after partial hepatectomy in rats. mRNA expression levels of Vegf and Pcna were analyzed in addition to immunohistochemical evaluations. Liver tissue protein levels of endostatin, endocan and p-eEF2K/eEF2K were determined with Western blot. Serum levels of endostatin and endocan were assessed with ELISA.

RESULTS

Pcna expression level in residual liver tissues peaked on day-1, while Vegf expression reached its highest level on days 1-3 after partial hepatectomy (70%). Endocan activity declined gradually on days 1-7. The decrease in liver endocan expression was accompanied by an increase in serum endocan levels. Partial hepatectomy induced a rapid increase in liver endostatin levels. Following its surge on day-1, endostatin expression gradually declined, which was accompanied by a peak in serum endostatin. Finally, partial hepatectomy was shown to regulate eEF2K; thus, increasing protein translation.

CONCLUSIONS

We revealed possible mechanistic insights into liver regeneration by examining the associations of Pcna, Vegf, endocan, endostatin, eEF2K with hepatic regeneration after partial hepatectomy. Indeed, endocan might serve as a useful biomarker to monitor clinical prognosis in a plethora of conditions such as recovery of donor's remaining liver after living-donor liver transplant. Whether endocan might represent a strategy to optimize liver regeneration when given therapeutically needs to be investigated in future studies.

Endothelial-Specific Molecule 1 Inhibition Lessens Productive Angiogenesis and Tumor Metastasis to Overcome Bevacizumab Resistance

The development of drug resistance in malignant tumors leads to disease progression, creating a bottleneck in treatment. Bevacizumab is widely used clinically, and acts by inhibiting angiogenesis to "starve" tumors. Continuous treatment can readily induce rebound proliferation of tumor blood vessels, leading to drug resistance. Previously, we found that the fragment crystallizable (Fc) region of bevacizumab cooperates with the Toll-like receptor-4 (TLR4) ligand to induce M2b polarization in macrophages and secrete tumor necrosis factor-α (TNFα), which promotes immunosuppression, tumor metastasis, and angiogenesis. However, the downstream mechanism underlying TNFα-mediated bevacizumab resistance requires further investigation. Our RNA-Seq analysis results revealed that the expression of endothelial cell specific molecule-1 (ESM1) increased significantly in drug-resistant tumors and promoted metastasis and angiogenesis in vitro and in vivo. Furthermore, TNFα induced the upregulation of ESM1, which promotes metastasis and angiogenesis and regulates matrix metalloprotease-9 (MMP9), vascular endothelial growth factor (VEGF), and delta-like ligand-4 molecules (DLL4). Accordingly, the curative effect of bevacizumab improved by neutralizing ESM1 with high-affinity anti-ESM1 monoclonal antibody 1-2B7 in bevacizumab-resistant mice. This study provides important insights regarding the molecular mechanism by which TNFα-induced ESM1 expression promotes angiogenesis, which is significant for elucidating the mechanism of bevacizumab drug resistance and possibly identifying appropriate biosimilar molecules.

Prognostic and Diagnostic Value of Endocan in Kidney Diseases

Endocan, previously called endothelial cell-specific molecule-1, is a soluble proteoglycan that is predominantly expressed in vascular endothelial cells of the lungs and kidneys. It is upregulated by proinflammatory cytokines and plays a critical role in inflammatory, proliferative, and neovascularization processes. The utility of endocan as a biomarker in a wide spectrum of diseases is being increasingly acknowledged. In this review, we summarize the current evidence concerning the role of endocan in kidney diseases, with emphasis on its prognostic and diagnostic value. It seems that the determination of plasma endocan levels may provide useful prognostic information in many types of renal failure such as chronic kidney disease, IgA nephropathy, and diabetic nephropathy. Endocan could additionally improve the early diagnostic evaluation of acute kidney disease, chronic renal allograft injury, and acute rejection after kidney transplantation, thus contributing to endothelial cell injury monitoring in a timely manner.

Endocan, a Soluble Marker of Endothelial Cell Activation Is a Molecular Marker of Disease Severity in Women with Preeclampsia

Endocan is a proteoglycan secreted by activated endothelium that regulates angiogenesis via interaction with hepatocyte growth factor (HGF). We hypothesized that women diagnosed with preeclampsia (PE) and/or fetal growth restriction (FGR) have elevated circulating endocan concentrations in direct relationship with severity of clinical manifestations. Serum concentration of endocan and HGF were analyzed in 224 women grouped as healthy pregnant controls (P-CRL, n = 77), PE with severe features (sPE, n = 83), chronic hypertension (crHTN: n = 36), idiopathic FGR (n = 18), and healthy non-pregnant controls (NP-CRL, n = 7). Endocan and HGF measured by immunoassay were analyzed along with markers of inflammation, angiogenesis, and protein misfolding (urine congophilia). Endocan expression in the placenta and/or myometrium was studied by immunohistochemistry and real-time PCR. Compared to gestational age-matched P-CRL, women with early-onset sPE had higher circulating endocan concentrations. Among women with PE and/or FGR, endocan concentration correlated with soluble endoglin and urine congophilia but not with HGF or markers of inflammation or angiogenesis. In the placenta, endocan was expressed in villous and extravillous trophoblasts and endothelium. Intense endocan immunostaining was observed in plaque-like aggregations of sPE placentas complicated with FGR. In addition, thickened blood vessels in the myometrium of sPE patients stained positive for endocan. Women with early-onset sPE have elevated serum endocan likely reflecting chronic endothelial activation. Enhanced expression and/or deposition of endocan at the sites of placental injury and in remodeled maternal blood vessels supports a role for endocan in either vascular rescue or as a contributor to FGR and perhaps long-term cardiovascular morbidity.

Endocan: A Key Player of Cardiovascular Disease

Endothelial dysfunction is considered to be an early change in atherosclerosis. Endocan, also known as endothelial cell specific molecule-1, is a soluble proteoglycan mainly secreted by endothelial cells. Inflammatory factors such as IL-1β and TNF-α can up regulate the expression of endocan and then affect the expression of cell adhesion molecules, such as ICAM-1 and VCAM-1, which play an important role in promoting leukocyte migration and inflammatory response. Elevated plasma levels of endocan may reflect endothelial activation and dysfunction, and is considered to be a potential immuno-inflammatory marker that may be related to cardiovascular disease. In the case of hypertension, diabetes, angina pectoris and acute myocardial infarction, the increase or decrease of serum endocan levels is of great significance. Here, we reviewed the current research on endocan, and emphasis its possible clinical value as a prognostic marker of cardiovascular disease. Endocan may be a useful biomarker for the prognosis of cardiovascular disease, but more research is needed on its mechanism of action.

Proteoglycan Endocan: A multifaceted therapeutic target in Cancer

Endocan is known to be a circulating dermatan sulfate proteoglycan that regulates endothelial cell function. Dysregulation of endocan expression is observed not only in the tumor vasculature but also in cancer cells. Accumulating evidence has revealed that disordered endocan facilitates cancer progression via enhancing cancer cell proliferation, cell mobility, and cancer stemness properties. Recently, various interacting proteins and diverse subcellular localizations of endocan were identified in cancer cells. Herein, we summarize the application of endocan in cancer diagnoses and prognoses using serum and tumor specimens. We further discuss that the aberrant molecular characteristics of endocan may be due to the mislocalization of endocan in cancer cells. Defining the specific cellular roles of endocan will provide a promising diagnostic factor and therapeutic target for cancer patients.

Chondroitin Sulfate/Dermatan Sulfate-Protein Interactions and Their Biological Functions in Human Diseases: Implications and Analytical Tools

Chondroitin sulfate (CS) and dermatan sulfate (DS) are linear anionic polysaccharides that are widely present on the cell surface and in the cell matrix and connective tissue. CS and DS chains are usually attached to core proteins and are present in the form of proteoglycans (PGs). They not only are important structural substances but also bind to a variety of cytokines, growth factors, cell surface receptors, adhesion molecules, enzymes and fibrillary glycoproteins to execute series of important biological functions. CS and DS exhibit variable sulfation patterns and different sequence arrangements, and their molecular weights also vary within a large range, increasing the structural complexity and diversity of CS/DS. The structure-function relationship of CS/DS PGs directly and indirectly involves them in a variety of physiological and pathological processes. Accumulating evidence suggests that CS/DS serves as an important cofactor for many cell behaviors. Understanding the molecular basis of these interactions helps to elucidate the occurrence and development of various diseases and the development of new therapeutic approaches. The present article reviews the physiological and pathological processes in which CS and DS participate through their interactions with different proteins. Moreover, classic and emerging glycosaminoglycan (GAG)-protein interaction analysis tools and their applications in CS/DS-protein characterization are also discussed.

The significance of endocan immunohistochemical expression in chronic plaque psoriasis

BACKGROUND

Psoriasis is a chronic inflammatory skin disease with immune-mediated mechanism. Endocan is a soluble dermatan sulfate proteoglycan expressed by endothelium of blood vessels.

AIMS

The present study aims to evaluate immunohistochemical localization of endocan in psoriatic skin in comparison with normal skin and to correlate its expression with the clinical and pathological data of psoriasis.

PATIENTS/METHODS

Skin biopsies from 36 psoriatic patients and 40 normal subjects were taken and processed for immunohistochemical staining of endocan.

RESULTS

Endocan was expressed in 63.9% and in 36.1% of epidermal keratinocytes and dermal endothelial and inflammatory cells of psoriatic skin, respectively, compared with its expression in 30% of epidermis of normal skin. Diffuse epidermal expression of endocan was in favor of cases with more angiogenesis and its intense expression was in favor of marked acanthosis and with cases affecting trunk as main presentation. Positive dermal endocan expression was significantly associated with marked parakeratosis and with more angiogenesis.

CONCLUSION

Endocan is over-expressed in psoriatic skin from epidermal keratinocytes and dermal endothelial and inflammatory cells. Endocan enhances angiogenesis and proliferation of psoriatic skin contributing to pathogenic mechanisms of psoriasis.

Endocan, a novel inflammatory marker, is upregulated in human chondrocytes stimulated with IL-1 beta

Endocan is a circulating proteoglycan, involved in immunity, inflammation, and endothelial function. It has been recently suggested as a biomarker of inflammation, increased angiogenesis, and cancer. In vitro studies have shown that endocan expression could be upregulated by inflammatory cytokines and proangiogenic molecules. High endocan levels were also shown in arthritic joint tissues and particularly in sites characterized by severe inflammation. This study was performed to evaluate endocan expression in chondrocytes stimulated with IL-ß. mRNA and related protein production were measured for endocan, TNF-α, and IL-6. NF-kB activity was also evaluated. IL-1ß treatment induced a significant upregulation of both endocan and the inflammatory parameters as well as NF-kB activity. The treatment of chondrocytes with the specific NF-kB inhibitor before IL-1ß stimulation was able to reduce endocan and the inflammatory markers over-expression. The results of our study indicated that endocan is also expressed in human chondrocytes; furthermore, consistent with previous results in other cell types and tissues, IL-1ß-induced inflammatory response involves the expression of endocan through NF-kB activation. In this context, endocan seems to be an important inflammatory marker associated with the activation of NF-kB pathway.

The vasodilatory mechanism of nitric oxide and hydrogen sulfide in the human mesenteric artery in patients with colorectal cancer

Recent studies have focused on the role of gasotransmitters in cancer progression and prevention. Therefore, the current study was designed to explore the vasodilator activity of NO and H₂S in the human mesenteric arteries of patients with colorectal cancer (CRC) via the activation of K⁺ channels. A total of two sets of experiments were established for the current investigation. Blood samples from patients with CRC were obtained to detect serum levels of endocan and malondialdehyde (MDA). The role of K⁺ channels in mediating the vasodilation of the human mesenteric artery in response to sodium nitroprusside (SNP) and sodium disulfide (Na₂S) was assessed. The level of serum endocan was indicated to be decreased in patients with CRC compared with healthy individuals, while the level of serum MDA remained unaltered between groups. The arterial rings pre-contracted with norepinephrine were first relaxed by the cumulative addition of increasing concentrations of either SNP (30 nM-30 µM) or (1-6 mM). Maximal relaxation rates were then calculated at 15 min intervals for 60 min. Pre-incubation of arterial rings for 20 min with individual K⁺ channel blockers was indicated to significantly reduce SNP- and Na₂S-induced relaxation at different time points. Pre-treatment of L-nitro-arginine methyl ester did not alter vasodilation that was induced by Na₂S. Furthermore, vasodilation of the CRC mesenteric artery was not altered by the synergistic application of SNP and Na₂S, while pre-incubation of arterial rings with D,L-propargylglycine significantly enhanced vasodilation induced by SNP. These results indicated that endothelial dysfunction and oxidative stress do not serve roles in the pathogenesis of CRC. The dilatory mechanisms of NO and H₂S in mesenteric arteries of patients with CRC were K⁺ channel- and time-dependent, and the activity of cystathionine γ-lyase enzyme inhibited the ability of exogenous NO in vasodilation processes.

Serum endocan levels in relation to traditional and non-traditional anthropometric indices in adult population

Background

Association between endocan and nontraditional anthropometric indices, as distinct cardiovascular disease risk factors, has not been examined in previous studies. Endocan is a novel inflammation biomarker with its higher levels involved in cardiometabolic diseases development. Taking into consideration that obesity is an independent risk factor for many cardiometabolic diseases, we aimed to explore the relationship between endocan levels and novel anthropometric indices [i.e., body adiposity index (BAI), cardiometabolic index (CMI), a body shape index, body roundness index, conicity index, lipid accumulation product index and visceral adiposity index] and traditional ones [i.e., waist circumference, hip circumference, body mass index, waist-to-height ratio and waist-to-hip ratio] in adult population.

Methods

A total of 177 participants were included. Anthropometric indices and biochemical parametres were measured.

Results

Univariate regression analysis demonstrated positive correlations of endocan and almost all anthropometric data. To explore independent associations of endocan and anthropometric parameters, the Model which fulfilled criteria for ordinal regression testing was created. Adjusted odds for BAI given in the Model (OR=1.120, 95% CI 1.036-1.212, P=0.004), demonstrated that a rise in BAI by 1 unit increased the probability of higher endocan concentration by 12%. As well, a rise in CMI for 1 unit, increased the probability for higher endocan levels for 2.6 times (OR=2.599, 95% CI 1.006-6.712, P=0.049). A total of 20.1% of variation in endocan levels could be explained by this Model.

Conclusions

Non-traditional obesity indices, BAI and CMI independently correlated with higher serum endocan levels in adult population.

Endocan: A novel biomarker for risk stratification, prognosis and therapeutic monitoring in human cardiovascular and renal diseases

The vascular endothelium is localized at the interface between the blood and surrounding tissues, playing a pivotal role in the maintenance of tissue-fluid homeostasis and in the regulation of host defense, inflammation, vascular tone and remodeling, angiogenesis and haemostasis. The dysfunctional endothelium was shown to be implicated in the pathophysiology of several endothelial-dependent disorders, such as arterial hypertension, coronary artery disease, heart failure and chronic kidney disease, in which it is an early predictor of cardiovascular events. Endocan is a soluble dermatan sulphate proteoglycan mainly secreted by the activated endothelium. It is upregulated by several proinflammatory cytokines and proangiogenic factors and may itself contribute to the inflammatory status. In addition of being a surrogate marker of inflammation and endothelial dysfunction, it seems to be involved in the regulation of several proliferative and neovascularization processes. Therefore, its utility as a biomarker in a wide spectrum of diseases has been increasingly explored. Here, we review the current evidence concerning the role of endocan in several human cardiovascular and renal diseases, where it seems to be a promising biomarker for risk stratification, prognosis and therapeutic monitoring.

Circulating Proteoglycan Endocan Mediates EGFR-Driven Progression of Non-Small Cell Lung Cancer

Although new generations of EGFR-tyrosine kinase inhibitors (EGFR-TKI) have been developed for the treatment of patients with non-small cell lung cancer (NSCLC) with EGFR-mutant tumors, TKI resistance often returns as a result of additional EGFR mutations. In addition to seeking for next-generation EGFR-TKI, developing novel EGFR-targeting strategies may hold the key to overcome the vicious cycle of TKI resistance. Endocan is known as a receptor tyrosine kinase ligand enhancer in tumorigenesis, but the impact of endocan on EGFR-driven NSCLC progression remains unknown. In this study, higher endocan levels were found in lung tumors compared with cancer-free tissues and correlated with poor prognosis in patients with NSCLC harboring mutant EGFR; circulating endocan levels were also significantly higher in patients with mutant EGFR. Endocan facilitated EGFR signaling via direct binding and enhancing of the EGF-EGFR interaction and supported the growth of tumors driven by mutated EGFR. Activated EGFR in turn upregulated expression of endocan via JAK/STAT3 and ERK/ELK cascades, thus forming a positive regulatory loop of endocan-EGFR signaling. On the basis of the binding region between endocan and EGFR, we designed therapeutic peptides and demonstrated promising therapeutic effects in xenografts harboring EGFR mutations including TKI-resistant T790M. Together, our findings highlight the novel interaction between endocan and EGFR and new opportunities to effectively target endocan-EGFR regulatory axis in patients with TKI-resistant NSCLC. SIGNIFICANCE: Endocan is a novel and critical regulator of EGF/EGFR signaling and serves as an alternative target of EGFR-TKI resistance in NSCLC.

Changes of Endocan and its effect on hepatic stem cells during the rapid proliferation process of residual liver after ALPPS procedure

To establish a stable animal model of associating liver partition and portal vein ligation for staged hepatectomy (ALPPS), as well as to explore whether Endocan and HGF/c-Met signalling pathway participate in the regeneration of residual liver through hepatic stem cells after ALPPS procedure. C57BL/6J male mice weighing 18-22 g were used in this study. The liver regeneration index was expressed as the ratio of Future Liver Remnant (FLR)/Body weight (BW) × 100%. Expression of hepatic stem cell marker CK19 was assessed by immunohistochemical method. Serum levels of vascular endothelial growth factor (VEGF) and Endocan were detected by ELISA. VEGF, Endocan and c-Met contents in residual liver were observed by Western blot analysis. The expression levels of Endocan and HGF/c-Met pathway-related genes were evaluated by qRT-PCR. Compared with the portal vein ligation (PVL) group and sham group, the ALPPS group had more CK19 positive cells and a higher liver regeneration index (P < .05). The serum levels of VEGF in the ALPPS group were increased significantly (P < .05) from the first day and decreased from the second day after surgery, and maintained consistently higher than that of the sham group (P < .05). Western blot showed that the expressions of VEGF and Endocan in ALPPS group were significantly higher than those in both sham and PVL groups at different time points. The Endocan plays a role in the rapid regeneration of residual liver after ALPPS, likely through the interaction with the HGF/c-Met pathway to affect the hepatic stem cell population. SIGNIFICANCE OF THE STUDY: Our animal study provides valuable insights on the effect of Endocan in the process of rapid regeneration of residual liver after ALPPS, which would lead to the possible expansion of clinical research on ALPPS surgery and further studies on its molecular underpinning during liver regeneration.

Impact of the ESM-1 Gene Expression on Outcomes in Stage II/III Gastric Cancer Patients Who Received Adjuvant S-1 Chemotherapy

BACKGROUND/AIM

Endothelial cell-specific molecule-1 (ESM-1) is a soluble proteoglycan which has important role in various biological events. We investigated the impact of the ESM-1 expression in cancer tissues on outcomes in stage II/III gastric cancer patients who received adjuvant S-1 chemotherapy.

PATIENTS AND METHODS

The ESM-1 mRNA expression in cancerous tissues and adjacent normal mucosa from 253 patients was measured. The associations between the ESM-1 gene expression and the survival and clinicopathological features were investigated.

RESULTS

A significant association was observed between high ESM-1 expression and undifferentiated adenocarcinoma. The overall survival curve was significantly lower in patients with high ESM-1 expression than in those with low expression (p=0.005). High ESM-1 expression was a significant independent prognosticator (HR=2.291, p=0.007).

CONCLUSION

ESM-1 gene expression in cancerous tissues is an important prognosticator in stage II/III gastric cancer patients who received adjuvant S-1 chemotherapy.

Prediction and identification of novel HLA-A*0201-restricted cytotoxic T lymphocyte epitopes from endocan

Background

Prediction and identification of cytotoxic T lymphocyte (CTL) epitopes from tumor associated antigens is a crucial step for the development of tumor immunotherapy strategy. Endocan has been identified as antigen overexpressed in various tumors.

Methods

In this experiment, we predicted and identified HLA-A2-restricted CTL epitopes from endocan by using the following procedures. Firstly, we predicted the epitopes from the amino acid sequence of endocan by computer-based methods; Secondly, we determined the affinity of the predicted peptide with HLA-A2.1 molecule by peptide-binding assay; Thirdly, we elicited the primary T cell response against the predicted peptides in vitro; Lastly, we tested the specific CTLs toward endocan and HLA-A2.1 positive target cells.

Results

These data demonstrated that peptides of endocan containing residues 4–12 and 9–17 could elicit specific CTLs producing interferon-γ and cytotoxicity.

Conclusions

Therefore, our findings suggested that the predicted peptides were novel HLA-A2.1-restricted CTL epitopes, and might provide promising target for tumor immunotherapy.

Relationship between Serum Endocan Levels and Childhood Community-Acquired Pneumonia

OBJECTIVES

Community-acquired pneumonia (CAP) is a potentially lethal lower respiratory tract infection for children. For this reason, early recognition and appropriate treatment is essential. In addition, we need to determine which patient will be hospitalized or not hospitalized. Here, we aimed to evaluate the plasma endocan level to determine whether it is effective in making the decision on hospitalization and the assessment of the response to treatment in patients with CAP.

MATERIALS AND METHODS

This prospective case-control study was conducted between November 2015 and May 2016 at Erciyes University School of Medicine. Fifty-three patients diagnosed as CAP with clinical and radiological findings were enrolled in the study. The patients were divided into various subgroups, such as inpatient, outpatient, complicated, non-complicated, dead patients, etc., and the levels of endocan were compared between the control group and those various groups.

RESULTS

A total of 53 children with a diagnosis of CAP and 55 healthy children were enrolled in the study. Patients were divided into two groups: hospitalized patients and outpatients. There was no statistically significant difference between these groups' serum endocan levels on the 1st day and serum endocan levels on the 4th day (p=0.783, p=0.419).

CONCLUSION

Serum endocan level had no significant value in predicting patients' hospitalization. On the other hand, high serum endocrine levels may be important in predicting the severity and prognosis of the disease.

ESM-1: A Novel Tumor Biomaker and its Research Advances

Background:

Cancer kills nearly 9,000,000 people worldwide, and its mortality was reported up to 28% in the past decade. Few available tumor markers have been known to help early stage diagnosis. In this study, Endocan was taken as a novel tumor marker, which has been found in many cancers related to cancer cell proliferation, neoangiogenesis, etc.

Methods:

Studies on Endocan and its correlation with cancer were reviewed, and key points of meaningful studies on the structure, pathways and targeted agents of Endocan were drawn.

Results:

Endocan leads to tumorigenesis and promotes tumor cells proliferation via HGF/SF signal transmission pathway, suppresses tumor cells apoptosis via NF-κB signaling pathway and promotes angiogenesis within tumors via VEGF and HIF pathway. Medicine suppressing the expression of Endocan could prevent tumorigenesis and even improve survival rate of mice with tumor significantly.

Conclusion:

Endocan is capable of promoting prognosis of cancer patients. Moreover, Endocan is supposed to a potential target of tumor-targeted therapy.

WITHDRAWN: ESM1-dependent mesenchymal transition enhances radioresistance of glioblastoma via transcriptional regulation of NFκB

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Expression of endocan and vascular endothelial growth factor in recurrent minor aphthous ulcers

Background

Recurrent aphthous ulcers (RAU) are common painful inflammatory lesions of the mucous lining of the mouth. Endocan, previously identified as endothelial cell specific molecule-1, is implicated as a vital player in the regulation of several inflammatory processes. A number of inflammatory cytokines and pro-angiogenic growth factors including VEGF upregulate endothelial cells synthesis and expression of endocan.

Material and Methods

Clinical scores of pain and ulcer size as well as level of endocan and VEGF were determined in swaps from aphthous ulcer and contra lateral normal mucosa in 30 patients (nine males and twenty one females) with age ranging from 18 to 45 years and mean age is 31.5 years.

Results

In the early days of ulcer development, ulcer showed statistically significantly higher mean endocan (8.2 ±5.3) and VEGF levels (1220.7 ±294.6) than control healthy mucosal site (1.1 ±0.5) and (518.6 ± 61.7) respectively. An increase in endocan is associated with an increase in pain score and vice versa. A statistically significant positive correlation were also found between endocan and VEGF levels.

Conclusions

Endocan and VEGF are strongly associated with the destructive phase of minor aphthous ulcers especially Endocan which was positively correlated with pain severity.

Key words:Endocan, ESM-1, VEGF, Recurrent Apthous Ulcer.

Adipocyte proteome and secretome influence inflammatory and hormone pathways in glioma

Gliomas represent the most common primary malignant brain tumors in adults, with an extremely poor prognosis. Among several risk factors, lifestyle was also recently identified as a major risk factor for the development of primary glioma. In the present study, we explore the relationship between obesity and glioma in a cellular model. Thus, we have study the influence of adipocytes secretome on glioma cell line GL261. Using the 3T3-L1 adipocyte cell line, and its conditioned medium (adipokines-enriched medium), we showed that adipocyte-released factors relate with glioma angiogenic, growth, hormones and metabolic behavior by MALDI-TOF-MS and proteomic array analysis. In a first view, STI1, hnRNPs and PGK1 are under expressed on CGl. Similarly, both carbonic anhydrase and aldose reductase are even suppressed in glioma cells that grown under adipokines-enriched environment. Contrariwise, RFC1, KIF5C, ANXA2, N-RAP and RACK1 are overexpressed in GL261 cell the in the presence of the adipokines-enriched medium. We further identified the factors that are released by adipocyte cells, and revealed that several pro-inflammatory and angiogenic factors, such as IL-6, IL-11, LIF, PAI-1, TNF-α, endocan, HGF, VEGF IGF-I, were secreted to the medium into a high extent, whereas TIMP-1 and SerpinE1 were under expressed on CGl. This study discloses an interesting in vitro model for the study of glioma biology under a "obesity" environment, that can be explored for the understanding of cancer cells biology, for the search of biomarkers, prognostic markers and therapeutic approaches.

Serum endocan concentration and its correlation with severity of hypertensive disorders in pregnancy

Introduction: Endocan plays a role in the development of vascular tissue in health and disease and is an indicator of endothelial cells activation and angiogenesis.Objective: The aim of this study was to investigate the relationship between endocan serum levels and various types of hypertensive disorders in pregnant women.Patients and methods: We created three study groups (preeclampsia [n = 60], chronic hypertension [n = 39], gestational hypertension [n = 58]) and the control group consisting of 59 healthy pregnant women. The endocan serum concentration was assessed using commercially available ELISA kit.Results: There were no statistically significant differences in endocan serum levels (pg/mL) in each study group compared to controls. The multiple regression did not reveal significant differences between endocan levels in each study group after adjustment for prepregnancy BMI. We did not find any significant correlations between the endocan serum level and patients' age, gestational age (GA) at sample collection, prepregnancy BMI, systolic blood pressure, diastolic blood pressure, and 24-hour urinary protein excretion in each analyzed group. Moreover, in the preeclamptic participants, we did not observe a significant relationship between the endocan concentration and the features indicating the severity of the disease other than elevated blood pressure. There were no differences in endocan serum level in preeclampsia subgroups: early-onset versus late-onset and mild versus severe preeclampsia.Conclusions: Endocan is not involved in the pathogenesis of hypertensive disorders in pregnant women and could not be regarded as a marker of endothelial dysfunction in these cases.

The association of elevated circulating endocan levels with lung function decline in COPD patients

Background

Endocan is thought to be a novel inflammatory marker that is associated with a variety of inflammatory diseases. However, its role in the pathogenesis of COPD remains unclear. This study aims to explore the potential role of endocan in COPD.

Methods

In total, 27 healthy volunteers, 55 COPD patients and 36 acute exacerbation of chronic obstructive pulmonary disease (AECOPD) patients were included in the study. Basic demographic characteristics, clinical features and blood samples were collected. Magnetic luminex screening assays were used to detect the concentration of endocan, Fas and Fas ligand (Fas-L) in plasma. Differences between groups were compared using an Independent sample t-test, Welch’s t-test, chi-squared test and Wilcoxon rank sum test. The correlations of plasma endocan with lung function parameters, Fas and Fas-L were analyzed by Pearson’s partial correlation test (adjusted for age, gender, body mass index and smoking history) and multiple linear regression.

Results

Plasma endocan levels in COPD patients were significantly higher than those in healthy volunteers (509.7±18.25 pg/mL vs 434.8±18.98 pg/mL (P=0.0124)), and AECOPD patients had the highest levels of endocan (524.7±27.18 pg/mL). Correlation analysis showed that circulating endocan had a negative correlation to FEV₁/FVC, FEV₁/predictive and FVC (adjusted r=−0.213, P=0.03; adjusted r=−0.209, P=0.034; and adjusted r=−0.300, P=0.002, respectively), and had a positive correlation to Fas (adjusted r=0.280, P=0.004).

Conclusion

Our study shows that elevated circulating endocan levels are associated with reduced lung ventilation function in COPD and AECOPD patients. In addition, endocan may influence apoptosis in COPD, suggesting that endocan may play a role in COPD pathogenesis.

Evaluation of Aqueous Endocan and Endostatin Levels in Patients With Pseudoexfoliation Syndrome

PURPOSE

The purpose of the present study was to evaluate the aqueous humor endocan and endostatin levels in patients with pseudoexfoliation (PEX) syndrome and to compare the results with healthy individuals.

MATERIALS AND METHODS

Twenty nine cataract patients with PEX syndrome (PEX group) and 32 cataract patients without PEX syndrome (control group) were enrolled in the study. Endocan and endostatin were measured in the aqueous humor of the PEX and control groups by enzyme-linked immunosorbent assay.

RESULTS

There was no difference between the PEX and control groups in terms of age (P=0.721) and sex (P=0.902). The aqueous levels of endocan in patients with PEX (26.39±5.80 pg/mL) was significantly higher than in the control group (11.42±2.44 pg/mL) (P=0.039). The aqueous levels of endostatin was 12.00±1.35 ng/mL in the PEX group and 14.22±3.31 ng/mL in the control group, however, the difference was not statistically significant (P=0.41).

CONCLUSIONS

The findings of the present study could suggest that the increased levels of aqueous endocan may be related to pathogenesis of PEX. However, levels of aqueous endostatin did not show any significant difference in PEX.

Serum endocan and circadian heart rate variability in non-dialysis stage 5 chronic kidney disease patients

BACKGROUND

Chronic kidney disease (CKD) is very common now and is associated with high overall and cardiovascular mortality. Numerous studies have reported that elevated heart rate (HR) is a risk factor for cardiovascular mortality. We investigated the link between serum endocan and circadian heart rate variability in non-dialysis stage 5 CKD patients.

METHODS

In a cross-sectional study, we enrolled 54 prevalent n non-dialysis stage 5 CKD patients (32 males, aged 48.2 ± 14.92 years). HR was measured with an automatic system. Serum endocan level was analyzed by ELISA.

RESULTS

Night/day HR ratio was independently predicted by serum endocan level (P < 0.01) and hypertension history (P < 0.05). Adjusted R² of the model was 0.222.

CONCLUSION

Increased serum endocan is significantly associated with circadian heart rate variability in non-dialysis stage 5 CKD patients. Further investigation is needed to explore the potential benefits of serum endocan lowering therapy in this patient group.

Maternal Serum Endocan Concentration in Pregnancies Complicated by Intrauterine Growth Restriction

OBJECTIVES

Endocan plays a role in the development of vascular tissue in health and disease and is an indicator of endothelial cells activation and angiogenesis. Therefore, this study aimed to investigate the relationship between maternal endocan serum level and intrauterine growth restriction (IUGR) as well as ultrasound Doppler flow measurements indicating placental insufficiency.

METHODS

This study included a group of women with IUGR (n = 37) and a group of healthy pregnant women (controls, n = 37). The endocan serum concentrations were assessed using commercially available enzyme-linked immunosorbent assay kit. Every woman underwent an ultrasound examination with Doppler flow measurements of the uterine arteries, umbilical vessels, and fetal middle cerebral artery. We used the cerebroplacental ratio (CPR) to determine placental insufficiency.

RESULTS

We found significant differences in median (interquartile) endocan serum level (pg/mL) between study and control groups (464 [374-532] vs 339 [189-496], respectively; P < .001). The endocan serum level correlated neither with umbilical cord blood gases nor with Apgar score. Ultrasound Doppler findings revealed significant differences in middle cerebral artery pulsatility index (PI), umbilical artery PI, CPR, as well as mean uterine arteries PI between IUGR group and controls. In the study group, we found significant correlations between the serum endocan and CPR ( R = 0.56, P < .001) as well as between serum endocan and mean uterine arteries PI ( R = 0.46, P = .006).

CONCLUSION

Endocan is likely involved in the pathogenesis of IUGR in pregnant women and possibly is a useful marker of endothelial dysfunction in these cases.

Diagnostic Significance of Measuring Vascular Endothelial Growth Factor for the Differentiation between Malignant and Tuberculous Pleural Effusion

Malignancy and tuberculosis are common causes of lymphocytic exudative pleural effusion. However, it is occasionally difficult to differentiate malignant pleural effusion from tuberculous pleural effusion. Vascular endothelial growth factor (VEGF) is a critical cytokine in the pathogenesis of malignant pleural effusion. Endocan is a dermatan sulfate proteoglycan that is secreted by endothelial cells. Importantly, endocan mediates the vascular growth-promoting action of VEGF. The aim of this study was to evaluate the diagnostic significance of VEGF and endocan in pleural effusion. We thus measured the levels of VEGF and endocan in the pleural effusion and serum samples of patients with lung cancer (n = 59) and those with tuberculosis (n = 32) by enzyme-linked immunosorbent assay. Lung cancer included 40 cases of adenocarcinoma, 13 of squamous cell carcinoma, and 6 of small cell carcinoma. Pleural effusion VEGF levels were significantly higher in the malignant group than in the tuberculosis group (2,091.47 ± 1,624.80 pg/mL vs. 1,291.05 ± 1,100.53 pg/mL, P < 0.05), whereas pleural effusion endocan levels were similar between the two groups (1.22 ± 0.74 ng/mL vs. 0.87 ± 0.53 ng/mL). The areas under the curve of VEGF and endocan were 0.73 and 0.52, respectively. Notably, the VEGF levels were similar in malignant pleural effusion, irrespective of the histological type of lung cancer. Moreover, no significant difference was found in the serum VEGF and endocan levels between patients with lung cancer and those with tuberculosis. In conclusion, high VEGF levels in pleural effusion are suggestive of malignant pleural effusion.

The effect of subcutaneous methotrexate on markers of metabolic syndrome in psoriatic patients - preliminary report

INTRODUCTION

Methotrexate (MTX) has anti-proliferative and anti-inflammatory effects in psoriasis. Moreover, low doses can reduce the risk of developing cardiovascular diseases. It turns out that psoriasis and atherosclerosis have a similar pathogenetic mechanism: the same pro-inflammatory cytokines, Th1 and Th17, are involved in both diseases.

AIM

To evaluate the effects of metabolic markers, protective cytokines (interleukin 10 (IL-10), transforming growth factor β (TGF-β)) and a marker of endothelial damage (endocan) in patients with plaque psoriasis.

MATERIAL AND METHODS

The study included 24 patients aged 27-69 years (9 female, 15 male) with plaque psoriasis. The metabolic syndrome according to the International Diabetes Federation (IDF) was evaluated. The laboratory tests were performed under fasting conditions: C-reactive protein (CRP), glucose, total cholesterol, triglycerides, high-density lipoprotein (HDL), uric acid, endocan, IL-10, and TGF-β. After 12 weeks of treatment with MTX injections 15 mg/week, every patient was assessed with the same laboratory tests.

RESULTS

After treatment we observed a statistically significant increase of endocan and IL-10, but no significant differences in the titer of TGF-β. C-reactive protein was reduced by approximately 54.7%. No improvement of lipid profile was observed, and even a significant increase in triglycerides was noted. Similarly, no significant difference was seen in the case of glucose and uric acid prior to and after treatment.

CONCLUSIONS

Methotrexate in low doses in short-term treatment decreases CRP (anti-inflammatory effect) and increases endocan and IL-10 (potential protective role). Methotrexate is characterized by good efficacy and tolerability in therapy of patients with psoriasis.

Clinical validation of serum endocan (ESM-1) as a potential biomarker in patients with renal cell carcinoma

To determine the suitability of serum endocan (ESM-1) levels for diagnosing and monitoring renal cell carcinoma (RCC), we measure serum ESM-1 levels in 56 RCC patients who had undergone radical or partial nephrectomies and 56 age- and sex-matched healthy kidney donors. Measurements were made before and 1 month and 3 months after surgery. The areas under the curve (AUCs) were determined from receiver operating characteristic (ROC) analyses. RCC patients had higher mean serum ESM-1 levels than control subjects (0.59 ± 0.07 vs. 0.52 ± 0.08 ng/mL, P < 0.001), with an AUC of 0.721 (95% CI: 0.628–0.817). In patients with tumors larger than 2 cm (n = 40) and those with clear-cell histology (n = 44), the AUCs for ESM-1 were 0.771 and 0.721, respectively. In control subjects, serum ESM-1 levels were higher in older (>50 years) individuals (P < 0.001). Among the study cohort, the AUCs for ESM-1 were 0.813 in individuals 50 years of age or younger (n = 55) and 0.637 in individuals older than 50 years (n = 57). In RCC patients, serum ESM-1 levels were reduced 1 month (P = 0.047) and 3 months (P = 0.009) after surgery. These results suggest serum ESM-1 can serve as a serologic biomarker for diagnosing and monitoring RCC, particularly in patients younger than 50 years.

Endocan Concentration in Patients With Primary Hypertension

Inflammation and endothelial dysfunction may play an important role in the multifactorial pathogenesis of hypertension. Endocan is also thought to play a role in cell adhesion and inflammatory disorders. The aim of the study was to compare endocan concentrations in patients with primary hypertension and healthy volunteers. There were 104 patients with hypertension (study group) and 21 healthy volunteers (control group). The correlation between endocan, catecholamines, and blood pressure control in patients with primary hypertension and the control group was analyzed. The median endocan concentration in the study group (2.03 ng/mL) was significantly higher than in the control group (1.09 ng/mL, P = .0001). Endocan concentration was correlated positively with renalase ( r = .2, P = .047) and norepinephrine ( r = .25, P = .02). Negative correlation was observed between endocan and body mass index ( r = −.25, P = .016) and leukocyte count ( r = −.36, P = .0004). The present study reports higher plasma endocan concentration in patients with treated, well-controlled primary hypertension compared with healthy volunteers. The higher endocan concentration in the study group may reflect endothelial dysfunction in this population.

Endocan: A Novel Marker of Endothelial Dysfunction in C1-Inhibitor-Deficient Hereditary Angioedema

BACKGROUND

Hereditary angioedema (HAE) related to C1-inhibitor deficiency is a rare autosomal dominant disorder. Vascular cell adhesion molecules (VCAM) are known as endothelial activation markers. Endocan (also called ESM-1) is proposed as an endothelial dysfunction indicator. We aimed to investigate endothelial activation in attack-free periods in HAE patients by measuring their levels of endocan and VCAM-1.

METHODS

Twenty-six HAE patients (22 female, mean age 40 ± 13 years) and 38 healthy control patients (13 female, mean age 36.9 ± 12 years) were included in the study. Peripheral blood samples were collected from HAE patients during symptom-free periods and control subjects. Endocan and VCAM-1 levels were measured using the enzyme-linked immunosorbent assay method.

RESULTS

The median serum levels of endocan (647 ± 101 ng/mL) and VCAM-1 (500 ± 79 ng/mL) in the HAE patients were significantly higher than in the control patients (391 ± 41 and 325 ± 4; p < 0.001 for both).

CONCLUSION

The increased endocan and VCAM-1 levels may reflect an endothelial activation even in attack-free periods in HAE patients.

Serum endocan levels in patients with cardiac syndrome X

BACKGROUND

Endocan is a recently introduced marker of endothelial dysfunction and is also associated with inflammation and atherosclerosis. To date, the relationship between cardiac syndrome X (CSX) and endocan has not been studied. The objective of this study was to compare the serum endocan levels of patients with CSX with those of control subjects.

PATIENTS AND METHODS

In this study, 50 patients were included in the CSX group and 28 patients in the control group. Patients with pathological conditions that could potentially influence endothelial functions were excluded. Endocan serum concentrations were measured using an enzyme-linked immunosorbent assay.

RESULTS

The mean endocan level of the CSX group was significantly higher than that of the control group (3051.3 ± 1900.5 ng/l vs. 2088.1 ± 522.2 ng/l; p = 0.002). There was no difference between the two groups in terms of age, gender, hypertension, diabetes mellitus, dyslipidemia, and smoking status. In receiver operating characteristic (ROC) curve analysis, endocan levels greater than 2072 ng/l had a 72% sensitivity and 54% specificity (p = 0.002) for accurately predicting a diagnosis of CSX.

CONCLUSION

The results of this study suggest that patients with CSX have higher endocan levels. Therefore, endocan may be valuable in helping uncover the underlying pathogenesis of CSX.

Serum endocan levels before and after surgery on low-grade gliomas

BACKGROUND

Endocan has been shown to be a marker for several cancers and may show degree of malignancy. The aim of this study is to assess serum levels of endocan before and after surgery on low-grade gliomas (LGGs).

METHODS

Endocan was assayed by commercially available enzyme-linked immunosorbent assay (ELISA) kits in a total of 19 patients and 12 controls. Serial serum samples were obtained before and after surgery (1^st day, 1^st week, and 1^st month of surgery). Control samples were collected from cord blood during cesarean section. The results were compared with control brain tissues.

RESULTS

Controls showed significantly lower serum endocan levels compared to before and after surgery (P < 0.05). There is a trend of increase in mean serum levels from before surgery and during the very early period after surgery (during first week); however, in the first month, mean serum levels became lower.

CONCLUSION

Endocan, a vital molecule for angiogenesis, is highly expressed before and after surgery in LGGs, but long-term data is needed. Furthermore, future studies should include high-grade gliomas to discuss whether endocan is associated with recurrence and response to treatment.

Epistatic interaction between the lipase-encoding genes Pnpla2 and Lipe causes liposarcoma in mice

Liposarcoma is an often fatal cancer of fat cells. Mechanisms of liposarcoma development are incompletely understood. The cleavage of fatty acids from acylglycerols (lipolysis) has been implicated in cancer. We generated mice with adipose tissue deficiency of two major enzymes of lipolysis, adipose triglyceride lipase (ATGL) and hormone-sensitive lipase (HSL), encoded respectively by Pnpla2 and Lipe. Adipocytes from double adipose knockout (DAKO) mice, deficient in both ATGL and HSL, showed near-complete deficiency of lipolysis. All DAKO mice developed liposarcoma between 11 and 14 months of age. No tumors occurred in single knockout or control mice. The transcriptome of DAKO adipose tissue showed marked differences from single knockout and normal controls as early as 3 months. Gpnmb and G0s2 were among the most highly dysregulated genes in premalignant and malignant DAKO adipose tissue, suggesting a potential utility as early markers of the disease. Similar changes of GPNMB and G0S2 expression were present in a human liposarcoma database. These results show that a previously-unknown, fully penetrant epistatic interaction between Pnpla2 and Lipe can cause liposarcoma in mice. DAKO mice provide a promising model for studying early premalignant changes that lead to late-onset malignant disease.

Liposarcoma is an often fatal adult-onset tumor of fat tissue. Lipolysis, the central pathway of fat tissue metabolism, has been implicated in cancer. We generated mice that were deficient in two key enzymes of lipolysis, adipose triglyceride lipase (ATGL) and hormone-sensitive lipase (HSL). Strikingly, all mice with combined ATGL and HSL deficiency developed liposarcoma by 11–14 months of age. No liposarcoma occurred in single knockout or normal controls. Transcriptome analysis revealed that a subset of genes is dysregulated by 3 months of age. Our study reveals a novel epistatic interaction in fat cells between these two lipase genes and that causes a unique form of liposarcoma in mice. The double knockout mice provide a novel tool to study the early stages of liposarcoma development, prognostic markers and preventive treatments.

Endocan Levels and Coronary Collateral Circulation in Stable Angina Pectoris: A Pilot Study

We investigated the relationship between endocan (a marker of systemic inflammation) and the development of coronary collateral circulation (CCC) as evaluated by coronary angiography in patients with chronic stable angina pectoris. A total of 90 patients (32 poor CCC and 58 good CCC) were included in this study. Endocan levels were determined using a commercially available sandwich enzyme-linked immunosorbent assay kit with high sensitivity and specificity for detection of human endocan. In multivariate logistic regression analysis, low endocan levels were independently associated with good CCC ( P < .001). Moreover, low high-sensitivity C-reactive protein levels were also independently associated with good CCC ( P = .020). We found an optimal cutoff point for endocan of 1.7 ng/mL; it predicted the presence of good CCC with a sensitivity of 72.4% and specificity of 65.6% ( P < .001). The results of the present study suggest that measurement of endocan level may help clinicians to predict the development of CCC in patients with stable coronary artery disease.