Over-expression of the Endocan gene in endothelial cells from hepatocellular carcinoma is associated with angiogenesis and tumour invasion

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.

Role of Novel Inflammatory Factors in Central Retinal Vein Occlusion with Macular Edema

Background and Objectives: To investigate associations among the aqueous humor levels of novel inflammatory factors, including FMS-related tyrosine kinase 3 ligand (Flt-3L), fractalkine, CXC chemokine ligand 16 (CXCL-16), and endocan-1; the severity of macular edema in central retinal vein occlusion (CRVO); and the prognosis of CRVO with macular edema after antivascular endothelial growth factor (VEGF) therapy. Materials and Methods: Aqueous humor was obtained during anti-VEGF treatment with intravitreal ranibizumab injection (IRI) in patients with CRVO and macular edema (n = 19) and during cataract surgery in patients with cataracts (controls, n = 20), and the levels of VEGF and novel inflammatory factors were measured. Macular edema was evaluated by central macular thickness (CMT) and neurosensory retinal thickness (TNeuro), and improvement was evaluated by calculating the percentage change in CMT and TNeuro from before to 1 month after IRI. Results: The levels of VEGF and the novel inflammatory factors were significantly higher in the CRVO group, and the levels of Flt-3L, CXCL-16, and endocan-1 were significantly correlated with each other and with the aqueous flare value. Baseline levels of Flt-3L, CXCL-16, and endocan-1 had a significantly negative correlation with the change in CMT, and the baseline level of CXCL-16 was significantly negatively correlated with the change in TNeuro. Conclusions: Relations among novel inflammatory factors should be further investigated. These findings may help improve understanding of macular edema in CRVO patients and aid the development of new treatments targeting novel inflammatory factors.

Prognostic Biomarkers in Pituitary Tumours: A Systematic Review

Pituitary tumours (PTs) are the second most common intracranial tumour. Although the majority show benign behaviour, they may exert aggressive behaviour and can be resistant to treatment. The aim of this review is to report the recently identified biomarkers that might have possible prognostic value. Studies evaluating potentially prognostic biomarkers or a therapeutic target in invasive/recurrent PTs compared with either non-invasive or non-recurrent PTs or normal pituitaries are included in this review. In the 28 included studies, more than 911 PTs were evaluated. A systematic search identified the expression of a number of biomarkers that may be positively correlated with disease recurrence or invasion in PT, grouped according to role: (1) insensitivity to anti-growth signals: minichromosome maintenance protein 7; (2) evasion of the immune system: cyclooxygenase 2, arginase 1, programmed cell death protein 1 (PD-1)/programmed death ligand 2, cluster of differentiation (CD) 80/CD86; (3) sustained angiogenesis: endothelial cell-specific molecule, fibroblast growth factor receptor, matrix metalloproteinase 9, pituitary tumour transforming gene; (4) self-sufficiency in growth signals: epidermal growth factor receptor; and (5) tissue invasion: matrix metalloproteinase 9, fascin protein. Biomarkers with a negative correlation with disease recurrence or invasion include: (1) insensitivity to anti-growth signals: transforming growth factor β1, Smad proteins; (2) sustained angiogenesis: tissue inhibitor of metalloproteinase 1; (3) tissue invasion: Wnt inhibitory factor 1; and (4) miscellaneous: co-expression of glial fibrillary acidic protein and cytokeratin, and oestrogen receptors α36 and α66. PD-1/programmed cell death ligand 1 showed no clear association with invasion or recurrence, while cyclin A, cytotoxic T lymphocyte-associated protein 4, S100 protein, ephrin receptor, galectin-3 , neural cell adhesion molecule, protein tyrosine phosphatase 4A3 and steroidogenic factor 1 had no association with invasion or recurrence of PT. With the aim to develop a more personalized approach to the treatment of PT, and because of the limited number of molecular targets currently studied in the context of recurrent PT and invasion, a better understanding of the most relevant of these biomarkers by well-d esigned interventional studies will lead to a better understanding of the molecular profile of PT. This should also meet the increased need of treatable molecular targets.

EpCAM, Ki67, and ESM1 Predict Hepatocellular Carcinoma Recurrence After Liver Transplantation

Liver transplantation (LT) is a good therapeutic decision, cures hepatocellular carcinoma (HCC) and promotes survival of cases with unrespectable HCC based on the Milan criteria. HCC still recur after LT. Identifying high risk tissue markers that predict recurrence becomes important for LT decision-making. Little is known regarding use of tissue expression of epithelial cell adhesion molecule (EpCAM) to predict HCC recurrence. This study investigates the role of EpCAM, Ki67, and endothelial-cell-specific molecule-1 (ESM1) as immunohistochemical markers to predict HCC recurrence after LT. It included 52 explanted HCC tissues from Egyptian patients who had undergone LT for HCC according to Milan criteria. Immunohistochemical staining was done on paraffin-embedded formalin-fixed tissue sections. HCC recurrence occurred in 13.5% cases. Positive EpCAM expression in HCC, was significantly associated with HCC recurrence, ( P =0.011), achieving 71.43% sensitivity, 84.44% specificity and 78.8% accuracy in predicting recurrence. High Ki67 percentage was significantly associated with HCC recurrence, ( P =0.005), achieving 57.14% sensitivity, 86.67% specificity and 82.69% accuracy in predicting HCC recurrence. ESM1 showed significant association with HCC recurrence ( P =0.041), with 71.43% sensitivity, 71.11% specificity and 71.15% accuracy in predicting HCC recurrence. EpCAM score and Ki67 percentage showed positive correlation. In conclusion, it is suggested that large tumor size (≥3 cm), advanced pathologic staging and Ki67 could be stratified as high risk predictors of HCC recurrence after LT. Although higher classes of Child-Turcotte-Pugh classification, high serum alpha-fetoprotein, microvascular invasion, positive EpCAM and ESM1 are stratified as lower risk predictors of HCC recurrence after LT.

Prognostic role of the endothelial cell-specific molecule-1 histopathologic expression in renal cell cancer

INTRODUCTION

To measure the level of endothelial cell-specific molecule-1 (ESM-1) expression among the Renal Cell Cancer (RCC) variants using by immunohistochemical method and determine the relationship between ESM-1 expression and RCC prognosis.

MATERIALS AND METHODS

ESM-1 immunoreactivity scores (IR) were measured in appropriate renal tumoral tissue blocks of 153 consecutive RCC patients in this retrospective analysis of prospectively collected data. Mean ESM-1 IR scores were calculated in patients who were pathologically diagnosed with clear cell RCC (ccRCC), papillary RCC (pRCC), and chromophobe RCC (chRCC). Progression-free survival and overall survival were evaluated using the log-rank test according to ESM-1 IR scores. Survival rates were calculated using Kaplan-Meier survival analysis.

RESULTS

In the ccRCC group, the mean ESM-1 IR scores of those with local invasion were significantly higher than those without local invasion (P = 0.014). The mean ESM-1 IR score of patients with metastatic ccRCC was significantly higher than those with non-metastatic ccRCC (P < 0.001). Considering all patients regardless of RCC subtype pathologies, the mean ESM-1 IR score in clinical stage 1 tumor was 3.82 ± 1.98, 4.87 ± 1.74 in clinical stage 2, 5.88 ± 2 in clinical stage 3, and 6.60 ± 2.23 in clinical stage 4. The mean ESM-1 IR score of patients with metastatic ccRCC was significantly higher than those with non-metastatic ccRCC (P < 0.001). The mean follow-up period for all patients in this study was 71 months (range 1-120 months). It has been shown that the higher the ESM-1 IR score, the lower the 10-year overall survival and disease-free survival rates (P = 0.026, P = 0.005).

CONCLUSION

Immunohistochemical expression of ESM-1 may be a promising prognostic biomarker in RCC. Currently, some prognostic scoring systems are available for patients with localized and metastasized RCC. Incorporating ESM-1 expression in RCC into these existing prognostic scoring systems could improve these models and enhance the quality of individual oncologic management in RCC patients.

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.

P2Y2R-Mediated PAK1 Activation Is Involved in ESM-1 Overexpression in RT-R-MDA-MB-231 through FoxO1 Regulation

ESM-1, overexpressed in several cancer types, is a potential cancer diagnostic and prognostic indicator. In our previous study, we determined that RT-R-TNBC cells were more aggressive than TNBC cells, and this difference was associated with ESM-1 overexpression. However, the mechanism explaining upregulated ESM-1 expression in RT-R-TNBC cells compared to TNBC cells was unclear. Therefore, we aimed to identify the mechanism by which ESM-1 is overexpressed in RT-R-MDA-MB-231 cells. RT-R-MDA-MB-231 cells were treated with various ESM-1 transcription factor inhibitors, and only the FoxO1 inhibitor downregulated ESM-1 expression. FoxO1 nuclear localization was modulated by JNK and p38 MAPKs, which were differentially regulated by PKC, PDK1 and PAK1. PAK1 profoundly modulated JNK and p38 MAPKs, whereas PKC and PDK1 affected only p38 MAPK. P2Y2R activated by ATP, which is highly released from RT-R-BC cells, was involved in PAK1 activation, subsequent JNK and p38 MAPK activation, FoxO1 induction, and ESM-1 expression in RT-R-MDA-MB-231 cells. These findings suggest for the first time that ESM-1 was overexpressed in RT-R-MDA-MB-231 cells and regulated through the P2Y2R-PAK1-FoxO1 signaling pathway.

The Role of MiR-181 Family Members in Endothelial Cell Dysfunction and Tumor Angiogenesis

Endothelial dysfunction plays a critical role in many human angiogenesis-related diseases, including cancer and retinopathies. Small non-coding microRNAs (miRNAs) repress gene expression at the post-transcriptional level. They are critical for endothelial cell gene expression and function and are involved in many pathophysiological processes. The miR-181 family is one of the essential angiogenic regulators. This review summarizes the current state of knowledge of the role of miR-181 family members in endothelial cell dysfunction, with emphasis on their pathophysiological roles in aberrant angiogenesis. The actions of miR-181 members are summarized concerning their targets and associated major angiogenic signaling pathways in a cancer-specific context. Elucidating the underlying functional mechanisms of miR-181 family members that are dysregulated in endothelial cells or cancer cells is invaluable for developing miRNA-based therapeutics for angiogenesis-related diseases such as retinopathies, angiogenic tumors, and cancer. Finally, potential clinical applications of miR-181 family members in anti-angiogenic tumor therapy are discussed.

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.

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.

Circulating microRNA 9-3p and serum endocan as potential biomarkers for hepatitis C virus-related hepatocellular carcinoma

BACKGROUND

The high mortality rate of hepatocellular carcinoma (HCC) in Egypt is due mainly to the increasing prevalence of hepatitis C virus infection (HCV) and late diagnosis of the carcinoma. MicroRNAs (miRNA), which regulate tumor proliferation and metastasis in HCC, may serve as a useful diagnostic approach for the early detection of HCC, thus decreasing its mortality. Meanwhile, endocan is a protein with angiogenic and inflammatory properties that are associated with tumor progression and poor outcomes.

AIM

To analyze the levels of miRNA 9-3p and endocan in HCV-infected HCC patients and correlate them with clinicopathological parameters.

METHODS

We compared levels of endocan and circulating miRNA 9-3p from 35 HCV-related HCC patients to 33 patients with HCV-induced chronic liver disease and 32 age and gender matched healthy controls recruited from inpatient and outpatient clinics of the National Liver Institute, Menoufia University, Egypt in the period from January to March 2021 in a case-control study. Serum samples from all groups were analyzed for HCV. Endocan was measured by enzyme-linked immunosorbent assays, and the expression levels of circulating miRNA 9-3p were measured by real-time quantitative reverse transcriptase PCR.

RESULTS

The levels of circulating miRNA 9-3p were significantly lower in the HCC group compared to the chronic liver disease (P < 0.001) and control (P < 0.001) groups, while levels in the chronic liver disease were significantly lower than those in the control group (P < 0.001). The levels of serum endocan were significantly higher in the HCC group compared to the chronic liver disease (P < 0.001) and control (P < 0.001) groups. Moreover miRNA 9-3p and endocan performed better than α-fetoprotein in discriminating HCC patients from cirrhosis and healthy patients. The levels of miRNA 9-3p were significantly inversely correlated to vascular invasion (P = 0.002), stage of advancement of Barcelona Clinical Liver Cancer (P < 0.001) and the metastatic site (P < 0.001) of the HCC group.

CONCLUSION

Circulating miRNA 9-3p and endocan can be used as novel biomarkers for the early diagnosis of HCV-related HCC.

Early Imaging and Molecular Changes with Neoadjuvant Bevacizumab in Stage II/III Breast Cancer

This prospective, phase II study evaluated novel biomarkers as predictors of response to bevacizumab in patients with breast cancer (BC), using serial imaging methods and gene expression analysis. Patients with primary stage II/III BC received bevacizumab 15 mg/kg (cycle 1; C1), then four cycles of neoadjuvant docetaxel doxorubicin, and bevacizumab every 3 weeks (C2-C5). Tumour proliferation and hypoxic status were evaluated using 18F-fluoro-3'-deoxy-3'-L-fluorothymidine (FLT)- and 18F-fluoromisonidazole (FMISO)-positron emission tomography (PET) at baseline, and during C1 and C5. Pre- and post-bevacizumab vascular changes were evaluated using dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI). Molecular biomarkers were assessed using microarray analysis. A total of 70 patients were assessed for treatment efficacy. Significant decreases from baseline in tumour proliferation (FLT-PET), vascularity, and perfusion (DCE-MRI) were observed during C1 (p ≤ 0.001), independent of tumour subtype. Bevacizumab treatment did not affect hypoxic tumour status (FMISO-PET). Significant changes in the expression of 28 genes were observed after C1. Changes in vascular endothelial growth factor receptor (VEGFR)-2p levels were observed in 65 patients, with a > 20% decrease in VEGFR-2p observed in 13/65. Serial imaging techniques and molecular gene profiling identified several potentially predictive biomarkers that may predict response to neoadjuvant bevacizumab therapy in BC patients.

Association of endocan expression with clinicopathological prognostic parameters in breast carcinoma

BACKGROUND

Breast cancer (BC) is a common malignancy in women. Some molecules, including endocan, are still under investigation as potential prognostic factors in BC.

OBJECTIVE

In the present study, we aimed to determine the relationship between endocan expression and clinicopathological prognostic parameters in BC.

METHODS

Two hundred and fifty-five patients diagnosed with BC were included in the present study. The immuno-reactivity scoring (IRS) system was used to reveal the tissue endocan expression levels.

RESULTS

We found that endocan expression is associated with tumor necrosis, tumor size, and the presence of lobular carcinoma in situ (LCIS) in BC. There was no relationship between endocan expression and survival as well as other clinicopathological prognostic parameters.

CONCLUSION

Endocan overexpression in BC is associated with some prognostic parameters, including tumor necrosis, tumor size, and the presence of LCIS. Further studies with larger series are needed to reveal the clinical and therapeutic implications of endocan in BC.

Serum Endocan Levels on Admission Are Associated With Worse Clinical Outcomes in COVID-19 Patients: A Pilot Study

Thrombotic and embolic complications in the cardiovascular system are evident and associated with worse prognosis in coronavirus disease 2019 (COVID-19) patients. Endothelial-specific molecule 1 (endocan) plays a role in vascular pathology. We hypothesized serum endocan levels on admission are associated with primary composite end point (mortality and intensive care unit hospitalization) in COVID-19 patients. Patients (n = 80) with laboratory, clinical, and radiological confirmed COVID-19 were included in this cross-sectional study. Ten milliliter of peripheral venous blood were drawn within 24 hours of admission to estimate serum endocan levels. Data were analyzed using SPSS version 26.0 (IBM). Patients with the primary composite end point had significantly higher serum endocan levels than patients without (852.2 ± 522.7 vs 550.2 ± 440.8 ng/L, respectively; P < .01). In the logistic regression analysis, only increased serum endocan levels and increase in age were independent predictors of the primary composite end point (P < .05). In the receiver operating characteristics curve analysis, we found that a serum endocan level of 276.4 ng/L had a 97% sensitivity and 85% specificity for prediction of the primary composite end point. Baseline serum endocan levels may prove useful as a prognostic factor in patients hospitalized for COVID-19.

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.

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.

Overexpression of miR-181a-5p inhibits retinal neovascularization through endocan and the ERK1/2 signaling pathway

Retinal neovascularization (RNV) is a common pathological feature of angiogenesis‐related retinopathy. Endocan inhibition has previously been reported to suppress RNV in oxygen‐induced retinopathy (OIR); however, its molecular mechanisms remain to be elucidated. Here, we investigated the role and mechanism of endocan in OIR. We established an OIR mouse model and detected aberrant endocan overexpression in OIR mouse retinas. Endocan inhibition through small interfering RNA or a neutralizing antibody inhibited vascular endothelial growth factor‐induced cell survival, cell proliferation, and tube formation in human retinal endothelial cells in vitro and reduced the RNV area in vivo. Using RNA sequencing, a luciferase reporter assay, and bioinformatics analyses, we identified endocan as a microRNA‐181a‐5p target gene. The antiangiogenic effect of miR‐181a‐5p on RNV was verified by intravitreal injection, and we showed that this involved the extracellular signal‐regulated protein kinases 1 and 2 (ERK1/2) signaling pathway. Collectively, our data demonstrate that miR‐181a‐5p/endocan regulates retinal angiogenesis through the ERK1/2 signaling pathway and might represent an attractive therapeutic strategy for RNV.

Can IL-33 and Endocan be New Markers for Retinopathy of Prematurity?

BACKGROUND

Retinopathy of Prematurity (ROP) is a pathophysiologic condition of the retina due to abnormal proliferation of retinal vessels.

OBJECTIVE

The study aimed too ascertain the importance of vascular endothelial growth factor (VEGF), insulin-like growth factor-1 (IGF-1), interleukin-33 (IL-33) and endocan in the diagnosis and follow-up of ROP.

METHODS

This prospective cohort study was conducted in the neonatal intensive care unit (NICU) of Health Science University, Zekai Tahir Burak Maternity Teaching Hospital, Ankara, Turkey, between February 2017 and August 2018. Preterm infants (gestational age (GA) of ≤32 weeks and birth weight of ≤1500 gr), diagnosed ROP were included in the study. VEGF, IGF-1, IL-33 and endocan levels were evaluated in the cord blood and in the serum before and after treatment of infants in the ROP and control groups.

RESULTS

A final number of 146 infants were included in the study. During the study period, 73 infants were identified as the ROP group, and 73 infants were allocated as the control group. In the ROP group, the cord blood VEGF value was higher than the control group (p <0.05). However, IGF-1 levels in the cord blood were lower in the ROP group than control (P<0.05). IL-33 and endocan values in the cord blood were similar in both control and ROP groups (p>0.05). Although serum levels of IL-33, VEGF and endocan were higher before laser treatment, these biomarkers decreased significantly after laser treatment (p <0.05).

CONCLUSION

We determined that serum IL-33 and endocan levels might be suggested as sensitive novel markers for the prediction of severe ROP.

Endothelial cell-specific molecule-1 as an invasiveness marker for pituitary null cell adenoma

BACKGROUND

Endothelial cell-specific molecule-1 (ESM-1) is a biomarker associated with tumor progression in pituitary adenoma. We specifically focused on one type of pituitary adenoma, namely null cell adenoma (NCA) and evaluated the relationship between invasion and ESM-1 expression in both vascular endothelial and adenoma tissues.

METHODS

Tissue samples from 94 patients with pituitary NCA were obtained through microscopic transsphenoidal resection. Tumor size and invasion were determined through preoperative magnetic resonance imaging. Immunohistochemical staining was performed to detect ESM-1 expression. ESM-1 index of ≥3 was defined as high expression.

RESULTS

Signs of invasion were observed in 46 (47.9%) of the 94 patients. Significant differences were observed in the invasion state and maximum tumor diameter between high and low expression of ESM-1 in vascular endothelial tissues (both P < 0.05). Significant positive associations were noted between ESM-1 expression in vascular endothelial tissues and tumor invasion (P = 0.002) and tumor size (P = 0.020). However, only tumor size was associated with ESM-1 expression in adenoma tissues (P = 0.016).

CONCLUSION

In NCA, a significant positive association between tumor invasion and ESM-1 expression was observed only in vascular endothelial tissues, suggesting that tumor progression occurs mainly through ESM-1-associated mechanism.

ESM1 as a Marker of Macrotrabecular-Massive Hepatocellular Carcinoma

PURPOSE

Macrotrabecular-massive hepatocellular carcinoma (MTM-HCC) is a novel morphological subtype of HCC associated with early relapse after resection or percutaneous ablation, independently of classical clinical and radiological prognostic factors. The aim of the present study was to identify immunohistochemical markers of MTM-HCC, to ease its diagnosis and implementation into clinical practice.

EXPERIMENTAL DESIGN

To identify potential biomarkers of MTM-HCC, we first analyzed gene expression profiling data from The Cancer Genome Atlas study and further selected two candidate biomarkers. Performance of both biomarkers for diagnosis of MTM-HCC was further tested by immunohistochemistry in two independent series of 67 and 132 HCC biopsy samples.

RESULTS

Analysis of RNA sequencing data showed that MTM-HCC was characterized by a high expression of neoangiogenesis-related genes. Two candidate biomarkers, Endothelial-Specific Molecule 1 (ESM1) and Carbonic Anhydrase IX (CAIX), were selected. In the discovery series, sensitivity and specificity of ESM1 expression by stromal endothelial cells for the detection of MTM-HCC were 97% (28/29), and 92% (35/38), respectively. Sensitivity and specificity of CAIX were 48% (14/29) and 89% (34/38). In the validation set, sensitivity and specificity of ESM1 for the identification of MTM-HCC were 93% (14/15) and 91% (107/117), respectively. Interobserver agreement for ESM1 assessment was good in both series (Cohen Kappa 0.77 and 0.76).

CONCLUSIONS

Using a molecular-driven selection of biomarkers, we identified ESM1 as a reliable microenvironment immunohistochemical marker of MTM-HCC. The results represent a step toward the implementation of HCC morpho-molecular subtyping into clinical practice.

Identification of ESM1 overexpressed in head and neck squamous cell carcinoma

Background

Endocan, also known as endothelial cell specific molecule-1 (ESM1), is a 50 kDa soluble proteoglycan which is frequently overexpressed in many cancer types. Whether it is dysregulated in head and neck squamous cell carcinoma (HNSCC) has not been investigated.

Methods

We analyzed the expression of ESM1 using bioinformatics analysis based on data from The Cancer Genome Atlas (TCGA), and then validated that ESM1 was significantly overexpressed in human HNSCC at the protein level using immunohistochemistry. We also analyzed the genes co-expressed with ESM1 in HNSCC.

Results

The most correlated gene was angiopoietin-2 (ANGPT2), a molecule which regulates physiological and pathological angiogenesis. Several transcription factor binding motifs including SMAD3, SMAD4, SOX3, SOX4, HIF2A and AP-1 components were significantly enriched in the promoter regions of the genes co-expressed with ESM1. Further analysis based on ChIP-seq data from the ENCODE (Encyclopedia of DNA Elements) project revealed that AP-1 is an important regulator of ESM1 expression.

Conclusions

Our results revealed a dysregulation of ESM1 and a potential regulatory mechanism for the co-expression network in HNSCC.

Role of SCFAs in gut microbiome and glycolysis for colorectal cancer therapy

Increased risk of colorectal cancer (CRC) is associated with altered intestinal microbiota as well as short-chain fatty acids (SCFAs) reduction of output The energy source of colon cells relies mainly on three SCFAs, namely butyrate (BT), propionate, and acetate, while CRC transformed cells rely mainly on aerobic glycolysis to provide energy. This review summarizes recent research results for dysregulated glucose metabolism of SCFAs, which could be initiated by gut microbiome of CRC. Moreover, the relationship between SCFA transporters and glycolysis, which may correlate with the initiation and progression of CRC, are also discussed. Additionally, this review explores the linkage of BT to transport of SCFAs expressions between normal and cancerous colonocyte cell growth for tumorigenesis inhibition in CRC. Furthermore, the link between gut microbiota and SCFAs in the metabolism of CRC, in addition, the proteins and genes related to SCFAs-mediated signaling pathways, coupled with their correlation with the initiation and progression of CRC are also discussed. Therefore, targeting the SCFA transporters to regulate lactate generation and export of BT, as well as applying SCFAs or gut microbiota and natural compounds for chemoprevention may be clinically useful for CRCs treatment. Future research should focus on the combination these therapeutic agents with metabolic inhibitors to effectively target the tumor SCFAs and regulate the bacterial ecology for activation of potent anticancer effect, which may provide more effective application prospect for CRC therapy.

Effects of the intestinal microbial metabolite butyrate on the development of colorectal cancer

Colorectal cancer (CRC) is one of the major health threats in developed countries. Changes in dietary components, such as more protein and lipid intake, can increase the risk of CRC. Diet affects CRC in many ways. They regulate the composition and function of gut microbiota, which have an amazing metabolic capacity and can produce short chain fatty acids (SCFAs), such as propionate, acetate, and butyrate. Butyrate is a principal energy source for colonic epithelial cells and plays an important role in maintaining the stability of gut microbiota and the integrity of intestinal epithelium. However, there are few studies reviewing the anti-CRC potentials of butyrate. This review summarizes the recent research progresses in the effect of gut microbiota imbalance and the decrease in intestinal microbial metabolite butyrate caused by unbalanced diet on CRC development, and discusses the mechanisms of butyrate-induced anti-CRC activities, which may guide people to prevent CRC by improving diet structures.

Endocan Overexpression in Pterygium

PURPOSE

The aim of this study was to evaluate the possible role of endocan in the pathogenesis of pterygium.

METHODS

The study was conducted on 33 patients with primary pterygium and 20 control subjects with normal bulbar conjunctiva. Patients with pterygium were graded into 3 groups as atrophic, fleshy, and intermediate, according to the Tan classification. Primary nasal pterygia and normal bulbar conjunctivas were surgically removed. Endocan expression was immunohistochemically investigated.

RESULTS

Endocan expression in epithelial and endothelial cells was statistically significantly higher in pterygium tissues than control tissues (P = 0.001). No significant correlation was observed between pterygium classification groups and endocan expression in both epithelial and endothelial cells (P > 0.05).

CONCLUSIONS

The results suggest that endocan may have a role in the pathogenesis of pterygium.

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.

Functional analysis of ESM1 by siRNA knockdown in primary and metastatic head and neck cancer cells

BACKGROUND

Genetic factors play a large role in cancer, and thus, there is a great desire to understand the effects of different genes in cancer and to also develop gene therapy for better treatments. Therefore, the development of alternative diagnosis and therapy modalities is of utmost importance. The aim of our study was to illuminate the role of ESM1 (endothelial cell-specific molecule-1, also known as Endocan) in proliferation and migration of head and neck cancer, thus helping to pave the way for new treatment modalities and predictive biomarkers.

METHODS

ESM1 expression was shown with immunofluorescence assay using confocal laser scanning microscope in primary and metastatic head and neck cancer cells. ESM1 expression was knocked down by RNA interference in head and neck cancer cells. Knockdown efficiency was evaluated by quantitative real-time RT-PCR and Western blot. Cell proliferation and migration assays were performed by xCELLigence real-time cell analysis system.

RESULTS

Immunofluorescence assay showed nuclear localization and high expression of ESM1 in primary and metastatic head and neck cancer cells. ESM1 mRNA and protein levels were significantly decreased in ESM1-knockdown cells compared to control. ESM1-knockdown cells showed reduced proliferation and migration activity when compared to control cells.

CONCLUSION

These findings suggest that ESM1 has roles on proliferation and migration of head and neck cancer cells.

Endocan silencing induces programmed cell death in hepatocarcinoma

Hepatocarcinoma is a type of high-grade malignant carcinoma identified worldwide. Its rapid development and late diagnosis prevents effective tumor resection in the majority of patients, and therefore recent studies have targeted metabolic signaling pathways and the tumor microenvironment for potential treatments. To investigate whether endocan may be a gene target for hepatocarcinoma treatment, the present study employed the following measures: MTT and Transwell assays, flow cytometry, western blotting and an mRFP-GFP-LC3 double fluorescence system. Following endocan gene silencing, cell proliferation was significantly inhibited and the number of invasive cells in the endocan siRNA-treated group was reduced compared with the control-siRNA treated-group. Furthermore, the apoptosis rate was 15% and autophagy was detected in the endocan short interfering (si)RNA-treated group compared with the control-siRNA treated-group. Using western blotting to detect NF-κB expression in the nucleus, the NF-κB expression was identified to be significantly reduced in the siRNA-treated group compared with the control groups. Endocan gene silencing inhibited hepatocarcinoma cell viability and invasion, whilst inducing apoptosis and autophagy. The results of the present study suggest that the effect of endocan gene silencing on cell survival was mediated via the NF-κB signaling pathway.

Significance of serum endothelial cell specific molecule-1 (Endocan) level in patients with erectile dysfunction: a pilot study

This study aimed to measure the serum endocan level of patients with erectile dysfunction (ED) and to investigate the possible association between the Endothelial-specific molecule-1 (Endocan) level and ED. Twenty healthy and sixty-four male patients included in the study were divided into four groups: severe ED (19 patients), moderate ED (24 patients), mild ED (21 patients) and control group (20 healthy men). The erectile function of all the patients was evaluated using the International Index of Erectile Function-5 (IIEF-5) questionnaire. The body mass index (BMI) of each participant was determined, together with levels of fasting blood glucose, total testosterone, low- and high-density lipoprotein cholesterol, triglyceride and endocan in serum samples. No significant difference was found between the three ED groups and the control group in terms of the mean age, BMI and the levels of cholesterol and fasting blood glucose (P>0.05). The mean serum endocan level was found to 1.076±0.5, 0.674±0.40 and 0.671±0.3 ng ml^-1 in the severe, moderate and mild ED groups, respectively. This indicated that the highest value was obtained from the severe ED group, and the difference between the severe ED group and the other groups was statistically significant. In the control group, the serum endocan level was 0.73±0.46 ng ml^-1, which was significantly higher compared to the moderate and mild ED groups (P<0.05). The significant difference between the control and ED groups in terms of the serum endocan level can assist in the evaluation of endothelial pathologies in the etiology ED.

Endocan: a novel biomarker associated with well-developed coronary collateral circulation in patients with stable angina and chronic total occlusion

Angiogenesis and arteriogenesis have a crucial role in the formation of coronary collateral vessels. It has been shown that endocan and vascular cell adhesion molecule-1 (VCAM-1) are potential angiogenetic factors. We investigated the relationship between serum endocan levels and grade of coronary collaterals, and also the correlation of endocan levels with serum VCAM-1 levels. Patients with stable angina and at least one total coronary occlusion at invasive coronary angiography were included in our study. Collateral degree was graded according to Rentrop and Cohen's classification. Patients who had grade 0 or 1 collateral vessels were included in the poorly-developed collateral group, and those with grade 2 or 3 coronary collateral vessels were included in the well-developed collateral group. Serum endocan and VCAM-1 levels were significantly higher in the well-developed collateral group (436.6 ± 213.3 ng/mL vs. 216.1 ± 78.5 ng/mL, p < .001; 11.02 ± 6.58 ng/mL vs. 6.78 ± 1.14 ng/mL, p < .001, respectively). In a logistic regression analysis, only serum endocan level remained as an independent predictor for good collateral development. In the ROC curve analysis, 282 ng/mL endocan level had an a 82 % sensitivity and 86 % specificity for prediction of the well-developed collateral group. Higher endocan level was related to better coronary collateral development. In the event that these results are confirmed in further studies, endocan may be considered as an anti-ischemic treatment strategy in order to improve collateral development.

Endocan and the respiratory system: a review

Endocan, formerly called endothelial cell-specific molecule 1, is an endothelial cell-associated proteoglycan that is preferentially expressed by renal and pulmonary endothelium. It is upregulated by proangiogenic molecules as well as by pro-inflammatory cytokines, and since it reflects endothelial activation and dysfunction, it is regarded as a novel tissue and blood-based relevant biomarker. As such, it is increasingly being researched and evaluated in a wide spectrum of healthy and disease pathophysiological processes. Here, we review the present scientific knowledge on endocan, with emphasis on the evidence that underlines its possible clinical value as a prognostic marker in several malignant, inflammatory and obstructive disorders of the respiratory system.

Inhibition of endocan attenuates monocrotaline-induced connective tissue disease related pulmonary arterial hypertension

Connective tissue disease related pulmonary arterial hypertension (CTD-PAH) is characterized by vascular remodeling, endothelial dysfunction and inflammation. Endocan is a novel endothelial dysfunction marker. The aim of the present study was to investigate the role of endocan in CTD-PAH. Monocrotaline (MCT)-induced PAH rats were used as the CTD-PAH model. Short hairpin RNA packed in a lentiviral vector used to inhibit endocan expression was intratracheally instilled in rats prior to the MCT injection. Endocan was found to be increased in the serum and lung of MCT-induced PAH rats. Short hairpin RNA mediated knockdown of endocan significantly decreased right ventricular systolic pressure, attenuated pulmonary remodeling and inflammatory responses in the lung. In the in vitro study, tumor necrosis factor-α (TNF-α) exposure caused increased endocan expression in the primary cultured rat pulmonary microvascular endothelial cells (RPMECs). Endocan knockdown inhibited the permeability increase and adhesion molecules secretion in RPMECs induced by TNF-α. In addition, TNF-α induced MAPK activation was blocked when endocan gene was knocked down. These data demonstrate that endocan may play an important role in the development of CTD-PAH. This study provides novel evidence to better understand the pathogenesis of CTD-PAH, which may be beneficial for the treatment of this disease.

Human cytomegalovirus infection contributes to glioma disease progression via upregulating endocan expression

The etiology of malignant glioma remains unclear. To examine the association between glioma and human cytomegalovirus (HCMV) infection and the possible mechanism through which HCMV contributes to malignant glioma, we investigated the expression of HCMV components and an angiogenesis marker, endocan, in 79 glioma specimens and 8 control brain samples. HCMV pp65 protein and DNA were detected in 65.8% (52 of 79) and 54.4% (43 of 79) of glioma specimens, respectively. The positive rate and expression levels of pp65 were significantly correlated with the glioma grades. The endocan expression was detected in 78.5% (62 of 79) of glioma specimens, and elevated endocan immunoreactivity was also significantly associated with high-grade glioma. The pp65 was predominantly detected and colocalized with endocan in the cytoplasm of tumor cells. Importantly, there was a significant positive correlation in detection rates between those 2 proteins. In control samples, neither HCMV pp65 nor endocan expression was detected. Moreover, the serum endocan levels in glioma patients were markedly higher than that in healthy subjects. In in vitro study, HCMV infection induced the expression of interleukin 6 and tumor necrosis factor-α in human glioblastoma U87 MG (U87) cells and human umbilical vein endothelial cells (HUVECs). Furthermore, elevated endocan levels were also observed in HCMV-infected U87 cells and HUVECs and antiviral treatment with ganciclovir reduced the endocan expression. These results suggest HCMV infection leads to glioma progression through an upregulation of endocan and the secretion of inflammatory cytokines. Thus, anti-HCMV treatment may represent a potentially novel therapeutic strategy for glioma.

Prognostic value of endocan expression in cancers: evidence from meta-analysis

Endocan is a 50 kDa dermatan sulfate proteoglycan. Numerous previous studies have indicated that endocan might be an attractive prognostic tumor biomarker. However, the results of different studies are inconsistent. We conducted a meta-analysis to explore the association between endocan expression and cancer prognosis. A systematic, comprehensive search of the PubMed, Embase, and China National Knowledge Infrastructure databases was performed. Expression of endocan and its association with overall survival were evaluated by pooled hazard ratios (HRs) and their 95% confidence intervals (CIs). In total, 15 eligible studies of 1,464 patients were finally included in this meta-analysis. A significant association was found between elevated endocan expression and poorer overall survival (pooled HR: 2.48, 95% CI: 2.12–2.90, P<0.001). In the cancer-type subgroup, significant associations were detected for gastrointestinal (HR: 2.27, 95% CI: 1.77–2.91, P<0.001) and hepatocellular (HR: 2.61, 95% CI: 1.96–3.48, P<0.001) carcinoma. Our results demonstrate that endocan could be useful to exploit as a novel prognostic biomarker for patients with cancer.

Endocan-expressing microvessel density as a prognostic factor for survival in human gastric cancer

AIM: To investigate the expression of endocan in tumour vessels and the relationships between endocan and the expression of vascular endothelial growth factor (VEGF) and prognosis in gastric cancer.

METHODS: This study included 142 patients with confirmed gastric cancer in a single cancer centre between 2008 and 2009. Clinicopathologic features were determined, and an immunohistochemical analysis of endocan-expressing microvessel density (MVD) (endocan-MVD), VEGF and vascular endothelial growth factor receptor 2 (VEGFR2) was performed. Potential relationships between endocan-MVD and clinicopathological variables were assessed using a Student’s t-test or an analysis of variance test. Spearman’s rank correlation was applied to evaluate the relationship between endocan-MVD and the expression of VEGF/VEGFR2. Long-term survival of these patients was analysed using univariate and multivariate analyses.

RESULTS: Positive staining of endocan was observed in most of the gastric cancer tissues (108/142) and in fewer of the normal gastric tissues. Endocan-MVD was not associated with gender or histological type (P > 0.05), while endocan-MVD was associated with tumour size, Borrmann type, tumour differentiation, tumour invasion, lymph node metastasis and TNM stage (P < 0.05). According to the Spearman’s rank correlation analysis, endocan-MVD had a positive correlation with VEGF (r = 0.167, P = 0.047) and VEGFR2 (r = 0.410, P = 0.000). The univariate analysis with a log-rank test indicated that the patients with a high level of endocan-MVD had a significantly poorer overall survival rate than those with a low level of endocan-MVD (17.9% vs 64.0%, P = 0.000). The multivariate analysis showed that a high level of endocan-MVD was a valuable prognostic factor.

CONCLUSION: Endocan-MVD significantly correlates with the expression of VEGF and VEGFR2 and is a valuable prognostic factor for survival in human gastric cancer.

A comparative analysis of ESM-1 and vascular endothelial cell marker (CD34/CD105) expression on pituitary adenoma invasion

OBJECTIVE

Pituitary adenomas are benign neoplasms that display invasive behavior-a characteristic traditionally associated with malignancy-through an ill-defined mechanism. The role of angiogenesis-related molecules in this pathological condition remains perplexing. Our purpose is to assess the impact of endocan (endothelial cell specific molecule-1, ESM-1), CD34 and CD105 on pituitary adenoma invasion.

METHODS

In this study, immunohistochemical analyses for endocan, CD34 and CD105 were performed on paraffin-embedded samples of 66 pituitary adenomas, five normal pituitaries, and five primary hepatic carcinomas. Knosp tumor grades based on magnetic resonance imaging coronal scanning were used to assess the invasiveness of each sample. The associations between endocan expression, CD34/CD105-positive microvessel densities (MVDs), and Knosp tumor invasion grades were evaluated.

RESULTS

These results showed that endocan protein expression in tumor cells (TCs) was higher than that in endothelial cells (ECs) and strongly correlated with Knosp grades (P < 0.001, Spearman's r = 0.616). Moreover, while endocan-positive TCs localized around the blood vessels in adenomas with higher Knosp grades, no significant association was found between CD34/CD105-MVDs and Knosp grades (CD34: P = 0.256, r = 0.142; CD105: P = 0.183, r = 0.166). Normal pituitary seemed to exhibit lower endocan expression and contained more CD34/CD105-MVDs than pituitary adenomas.

CONCLUSION

Endocan expresses in both TCs and ECs of pituitary adenoma. Endocan overexpression in TCs more accurately reflects invasiveness compared to that of CD34/CD105-MVDs and that angiogenesis may not be the primary driver of endocan-medicated pituitary adenoma invasion.

The Relationship between Serum Endocan Levels and Depression in Alzheimer's Disease

Objectives. Growing evidence suggests that angiogenic vascular factors may be involved in the pathogenic mechanism of Alzheimer's disease (AD), and recently endocan has been proposed as an angiogenic biomarker. The aim of this study was to measure serum endocan levels according to the presence of depression in AD and to investigate the association among the serum endocan levels, cognitive function, and depression in these patients. Methods. Serum endocan levels were measured in 26 AD patients with depression, 29 AD patients without depression, and 29 healthy controls using an enzyme-linked immunosorbent assay kit. The Mini-Mental State Examination-Korean version (MMSE-KC) and the Korean version of the Geriatric Depression Scale-Short Form (SGDS-K) were used to evaluate cognitive function and depressive symptoms, respectively. Results. Serum endocan levels were significantly lower in AD patients with depression than in AD patients without depression or healthy controls. Serum endocan levels were negatively correlated with SGDS-K scores but not with MMSE-KC scores in AD patients. Conclusions. This study suggests that serum endocan levels might be associated with depression in AD. Future studies are needed to investigate the pathophysiological mechanisms or the role of endocan in AD with depression.

Serum endothelial cell specific molecule-1 (endocan) levels in patients with obstructive sleep apnea

Objective: To investigate the level of endothelial cell specific molecule-1 (endocan) in obstructive sleep apnea (OSA). Methods: Study group included subjects with OSA. Control group included subjects who had no OSA on polysomnography and nonobese healthy subjects from population who had no OSA symptoms. Endocan levels of OSA and non-OSA subjects were compared. Results: Totally 106 individuals (63 OSA, 43 non-OSA) were included. Endocan levels were higher in OSA subjects than controls (1.25 ± 0.4 ng/ml vs 0.93 ± 0.3 ng/ml, p < 0.001). Endocan levels were correlated with BMI (r = 0.456, p < 0.001) and daytime PaO2 (r = -0.266, p < 0.042). In linear regression analysis there was no factor related to endocan level. Conclusion: Serum endocan is significantly higher in OSA. Further studies should be performed to better understand the relationship between endocan and OSA.

The non glycanated endocan polypeptide slows tumor growth by inducing stromal inflammatory reaction

Endocan expression is increasingly studied in various human cancers. Experimental evidence showed that human endocan, through its glycan chain, is implicated in various processes of tumor growth. We functionally characterize mouse endocan which is also a chondroitin sulfate proteoglycan but much less glycanated than human endocan. Distant domains from the O-glycanation site, located within exons 1 and 2 determine the glycanation pattern of endocan. In opposite to the human homologue, overexpression of mouse endocan in HT-29 cells delayed the tumor appearance and reduced the tumor growth rate. This tumor growth inhibition is supported by non glycanated form of mouse endocan. Non glycanated human endocan overexpressed in HT-29, A549 or K1000 cells also exhibited an anti-tumor effect. Moreover, systemic delivery of non glycanated human endocan also results in HT-29 tumor growth delay. In vitro, endocan polypeptide did not affect HT-29 cell proliferation, nor cell viability. In tumor tissue sections, a stromal inflammatory reaction was observed only in tumors overexpressing endocan polypeptide, and depletion of CD122+ cells was able to delete partially the anti-tumor effect of endocan polypeptide. These results reveal a novel pathway for endocan in the control of tumor growth, which involves inflammatory cells of the innate immunity.

Characteristics of serum endocan levels in infection

Objectives

Endocan is a newly recognized biomarker of sepsis. However, there have been no studies of the trends in endocan levels during infection and their associations with other clinical factors. The aim of this study was to assess the time course of endocan levels and the associations of endocan with clinical factors during infection by comparison with other biomarkers.

Methods

Serum samples and blood cultures were obtained from patients who were diagnosed with infection from June 2013 to March 2014. Serum endocan, C-reactive protein (CRP), and procalcitonin (PCT) levels during four periods during infection were measured (day 0, day 1-2, day 3-5, and day 6-10).

Results

A total of 78 patients were enrolled in this study. The median endocan level decreased by only 23% during infection, whereas both serum CRP and PCT levels decreased by more than 80%. Endocan levels were correlated to neither CRP levels nor PCT levels in each period. Endocan levels at day 0 in patients with bacteremia were higher than those without bacteremia (1.09 ng/mL vs 0.82 ng/mL, P=0.002), but neither CRP levels nor PCT levels at day 0 were different between the two groups. Areas under the receiver operator characteristic (ROC) curves of endocan, CRP, and PCT at day 0 were 0.662, 0.343, and 0.563, respectively. Positive blood cultures tended to be related to high endocan levels, but not significantly (odds ratio: 4.24, 95% CI: 0.99-10.34, P=0.05).

Conclusions

In bacteremic cases, serum endocan levels in bacteremia tended to be higher than in non-bacteremic cases. Although endocan level was not identified as a prognostic factor of bacteremia, further prospective study concerning the relationship between serum endocan level and bacteremia would be needed.

Endocan: A new marker for cancer and a target for cancer therapy

Endocan, previously known as endothelial cell-specific molecule-1 (ESM-1), was cloned from the human umbilical vein endothelial cell cDNA library. Endocan is a novel ESM, and a 50 kDa soluble proteoglycan. Endocan is secreted into the blood as the soluble proteoglycan, which is the form in the presence of chondroitin sulfate. In normal tissues, chondroitin sulfate/dermatan sulfate proteoglycan is expressed by endothelial cells (such as lung and kidney) and is overexpressed in several carcinoma endothelial cells. There are studies that identified high endocan expression in lung cancer, uterine cancer, kidney cancer, liver cancer, brain glioblastoma, breast cancer and other tumors. Tumor prognosis, metastasis and angiogenesis were shown to be associated with endocan expression. The majority of investigators believe that endocan regulates the tumor by tumor-associated inflammation, angiogenesis, lymphangiogenesis, the tumor cells themselves and other aspects. Endocan may be a new target for cancer therapy.

Evaluation of serum endothelial cell specific molecule-1 (endocan) levels as a biomarker in patients with pulmonary thromboembolism

The aim of this study was to investigate the relationship between pulmonary thromboembolism (PTE) and serum endocan levels. The study included 46 patients with a diagnosis of PTE and control group (25 healthy individuals). Serum endocan levels in all participants' blood samples were measured. The average age of the individuals was 61.76 ± 16.39 years. There was a significant difference in the serum endocan levels between the patients and those of the control group [321.93 ng/l (111.35-2511.33) and 192.77 ng/l (118.30-309.02), respectively; P < 0.030]. The serum endocan levels in the submassive [469.41 ng/l (258.13-800.54)] and the massive PTE groups [719.18 ng/l (319.84-2511.33)] were statistically higher than those in the control group [192.77 ng/l (118.30-309.02)] (P < 0.001 and P < 0.001, respectively). In addition, there was a statistically significant difference between the serum endocan levels of the nonmassive PTE group [188.57 ng/l (111.35-685.56)] and the submassive PTE group (P < 0.01). The serum endocan levels correlated with the international normalization ratio (INR), right ventricular dilatation (RVD) and SBP (r = 0.418, P = 0.004; r = 0.659, P < 0.001; r = -0.425, P = 0.003, respectively). In conclusion, serum endocan levels can be considered a practicable biomarker to determine the severity of PTEs and follow-up thrombolytic therapy.

Vascular changes in the developing rat retina in response to hypoxia

This study was carried out to investigate the roles of tight junction (TJ) proteins and other factors in the increased permeability of the blood retinal barrier (BRB) affecting the immature neonatal retina following a hypoxic insult. The expression of endothelial TJ proteins such as claudin-5, occludin and zonula occludens-1 (ZO-1) and endothelial cell specific molecule-1 (ESM-1), and associated structural changes in the blood vessels were analyzed in the retinas of 1-day-old Wistar rats subjected to hypoxia for 2 h and subsequently sacrificed at different time points ranging from 3 h to 14 d. The mRNA and protein expression of claudin-5, occludin & ZO-1 was found to be reduced in the hypoxic retina, although, at the ultrastructural level, the TJ between the endothelial cells and retinal pigment epithelial cells appeared to be intact. Following the hypoxic insult vascular endothelial cells frequently showed presence of cytoplasmic vacuoles, vacuolated mitochondria and multivesicular aggregations projecting into the lumen of the capillaries. The expression of ESM-1 in the immature retinas was found to be increased following hypoxic exposure. The structural and molecular changes in the hypoxic neonatal retinas were consistent with a hypoxia induced impairment of the BRB. Hypoxia reduced the expression of TJ proteins in the neonatal retina, but the role of increased ESM-1 expression in this process warrants further investigation.

Markers for sepsis diagnosis in the forensic setting: state of the art

Reliable diagnoses of sepsis remain challenging in forensic pathology routine despite improved methods of sample collection and extensive biochemical and immunohistochemical investigations. Macroscopic findings may be elusive and have an infectious or non-infectious origin. Blood culture results can be difficult to interpret due to postmortem contamination or bacterial translocation. Lastly, peripheral and cardiac blood may be unavailable during autopsy. Procalcitonin, C-reactive protein, and interleukin-6 can be measured in biological fluids collected during autopsy and may be used as in clinical practice for diagnostic purposes. However, concentrations of these parameters may be increased due to etiologies other than bacterial infections, indicating that a combination of biomarkers could more effectively discriminate non-infectious from infectious inflammations. In this article, we propose a review of the literature pertaining to the diagnostic performance of classical and novel biomarkers of inflammation and bacterial infection in the forensic setting.

Serum Endocan Level and the Severity of Coronary Artery Disease

Endothelial-specific molecule 1 (endocan) is expressed in endothelial cells. We investigated the relationship between acute coronary syndrome (ACS) and serum endocan levels. We included 30 individuals as a control group and 53 patients diagnosed with ACS. The severity of coronary artery disease was assessed by a modified Gensini stenosis and SYNTAX scoring system. There was a significant difference in serum endocan levels between the control group and the ACS group (0.75 ± 0.13 vs 0.86 ± 0.25 ng/mL, P = .014). There was also a significant difference in serum endocan levels between diabetic patients with ACS and nondiabetic patients with ACS (1.02 ± 0.33 vs 0.81 ± 0.21 ng/mL, P = .016). There was no significant correlation between serum endocan level, Gensini, and SYNTAX score ( r = .11, P = .53 and r = .16, P = .37). Endocan, a new biomarker of endothelial pathology, is significantly increased in patients with ACS.

Biological and clinical implications of endocan in gastric cancer

Endocan overexpression has been reported to be associated with poor prognosis in various cancer types such as breast cancer, kidney cancer, and lung cancer. However, the biological and prognostic significance of endocan in gastric cancer remains unknown. Here, we investigated the expression status of endocan in gastric cancer. Endocan expression status was determined in 255 gastric cancer specimens by immunohistochemical staining. The association of endocan protein with clinicopathological parameters and prognosis was subsequently determined. The oncogenic role of endocan in gastric cancer was examined using a small interfering RNA (siRNA) approach. Spearman regression correlation analysis showed that endocan expression was associated with the pathological tumor stage. In Cox regression analysis, endocan expression was found to be an independent prognostic factor for survival. Endocan promoted gastric cancer cell proliferation. Our findings indicate that endocan is a potential target for therapeutic intervention in gastric cancer.

Hepatic stellate cells and extracellular matrix in hepatocellular carcinoma: more complicated than ever

Hepatocellular carcinoma (HCC) is the fifth most common cancer worldwide and the third leading cause of cancer death. Recent epidemiological data indicate that the mortality rate of HCC will double over the next decades in the USA and Europe. Liver cancer progresses in a large percentage of cases during the clinical course of chronic fibro-inflammatory liver diseases leading to cirrhosis. Therefore, HCC development is regarded as the result of different environmental risk factors each involving different genetic, epigenetic- and chromosomal alterations and gene mutations. During tumour progression, the malignant hepatocytes and the activated hepatic stellate cells are accompanied by cancer-associated fibroblasts, myofibroblasts and immune cells generally called tumour stromal cells. This new and dynamic milieu further enhances the responsiveness of tumour cells towards soluble mediators secreted by tumour stromal cells, thus directly affecting the malignant hepatocytes. This results in altered molecular pathways with cell proliferation as the most important mechanism of liver cancer progression. Given this contextual complexity, it is of utmost importance to characterize the molecular pathogenesis of HCC, and to identify the dominant pathways/drivers and aberrant signalling pathways. This will allow an effective therapy for HCC that should combine strategies affecting both cancer and the tumour stromal cells. This review provides an overview of the recent challenges and issues regarding hepatic stellate cells, extracellular matrix dynamics, liver fibrosis/cirrhosis and therapy, tumour microenvironment and HCC.