Identification of endothelial cell-specific molecule-1 as a potential serum marker for colorectal cancer

Exploration and validation of a combined immune and metabolism gene signature for prognosis prediction of colorectal cancer

BACKGROUND

Colorectal cancer (CRC) is still one of the most frequently diagnosed malignancy around the world. The complex etiology and high heterogeneity of CRC necessitates the identification of new reliable signature to identify different tumor prognosis, which may help more precise understanding of the molecular properties of CRC and identify the appropriate treatment for CRC patients. In this study, we aimed to identify a combined immune and metabolism gene signature for prognosis prediction of CRC from large volume of CRC transcriptional data.

METHODS

Gene expression profiling and clinical data of HCC samples was retrieved from the from public datasets. IRGs and MRGs were identified from differential expression analysis. Univariate and multivariate Cox regression analysis were applied to establish the prognostic metabolism-immune status-related signature. Kaplan-Meier survival and receiver operating characteristic (ROC) curves were generated for diagnostic efficacy estimation. Real-time polymerase chain reaction (RT-PCR), Western blot and immunohistochemistry (IHC) was conducted to verified the expression of key genes in CRC cells and tissues.

RESULTS

A gene signature comprising four genes (including two IRGs and two MRGs) were identified and verified, with superior predictive performance in discriminating the overall survival (OS) of high-risk and low-risk compared to existing signatures. A prognostic nomogram based on the four-gene signature exhibited a best predictive performance, which enabled the prognosis prediction of CRC patients. The hub gene ESM1 related to CRC were selected via the machine learning and prognostic analysis. RT-PCR, Western blot and IHC indicated that ESM1 was high expressed in tumor than normal with superior predictive performance of CRC survival.

CONCLUSIONS

A novel combined MRGs and IRGs-related prognostic signature that could stratify CRC patients into low-and high- risk groups of unfavorable outcomes for survival, was identified and verified. This might help, to some extent, to individualized treatment and prognosis assessment of CRC patients. Similarly, the mining of key genes provides a new perspective to explore the molecular mechanisms and targeted therapies of CRC.

EMS1/DLL4-Notch Signaling Axis Augments Cell Cycle-Mediated Tumorigenesis and Progress in Human Adrenocortical Carcinoma

Adrenocortical carcinoma (ACC) is a rare malignant neoplasm that is prone to local invasion and metastasis. Meanwhile, overexpressed endothelial cell-specific molecule 1 (ESM1) is closely related to tumorigenesis of multitudinous tumors. However, the prognosis value and biological function of ESM1 in ACC remains undefined. In the current essay, the assessment in human ACC samples and multiple public cancer databases suggested that ESM1 was significantly overexpressed in ACC patients. The abnormal expression of ESM1 was evidently correlated with dismal overall survival (OS) in ACC patients. Then, the gene-set enrichment analysis (GSEA) was applied to unravel that ESM1 was mostly involved in cell cycle and Notch4 signaling pathway. Furthermore, in vitro experiment, RNA interference of ESM1 was carried out to state that ESM1 augments CDK1 and p21-mediated G2/M-phase transition of mitosis, cell proliferation via DLL4-Notch signaling pathway in human ACC cell line, SW13 cells. Additionally, two possible or available therapeutic strategies, including immunotherapy and chemotherapy, have been further explored. Immune infiltration analysis highlighted that no significant difference was found in ACC patients between EMS1^high and EMS1^low group for immune checkpoint-related genes. In addition, the overexpression of ESM1 might trigger the accumulation of tumor mutation burden (TMB) during the cell cycle of DNA replication in ACC. The gene-drug interaction network then indicated that ESM1 inhibitors, such as cisplatin, might serve as potential drugs for the therapy of ACC. Collectively, the results asserted that ESM1 and related regulators might act as underlying prognostic biomarkers or novel therapeutic targets for ACC.

Targeting Endothelial Cell-Specific Molecule 1 Protein in Cancer: A Promising Therapeutic Approach

Despite the dramatic advances in cancer research in the past few years, effective therapeutic strategies are urgently needed. Endothelial cell-specific molecule 1 (ESM-1), a soluble dermatan sulfate proteoglycan, also known as endocan, serves as a diagnostic and prognostic indicator due to its aberrant expression under pathological conditions, including cancer, sepsis, kidney diseases, and cardiovascular disease. Significantly, ESM-1 can promote cancer progression and metastasis through the regulation of tumor cell proliferation, migration, invasion, and drug resistant. In addition, ESM-1 is involved in the tumor microenvironment, containing inflammation, angiogenesis, and lymph angiogenesis. This article reviews the molecular and biological characteristics of ESM-1 in cancer, the underlying mechanisms, the currently clinical and pre-clinical applications, and potential therapeutic strategies. Herein, we propose that ESM-1 is a new therapeutic target for cancer therapy.

Prognostic Model of Colorectal Cancer Constructed by Eight Immune-Related Genes

Background

Colorectal cancer (CRC) is a common malignant tumor of the digestive tract with a high mortality rate. Growing evidence demonstrates that immune-related genes play a prominent role in the occurrence and development of CRC. The aim of this study was to investigate the prognostic value of immune-related genes in CRC.

Methods

Gene expression profiles and clinical data of 568 CRC and 44 non-tumorous tissues were obtained from The Cancer Genome Atlas (TCGA) database. First, we performed a differentially expressed gene (DEG) analysis and univariate Cox regression analysis to determine the DEGs associated with overall survival. Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses were subsequently performed for prognostic immune-related genes. Then, a multivariate Cox regression analysis was performed to establish the immune prognostic model and identify the independent prognostic factors of CRC. Next, in vitro experiments were done to further validate the model. Finally, we analyzed the correlation among immune-related genes, clinical traits, and immune cell infiltration.

Results

In total, 3,702 DEGs were obtained, and 338 prognostic immune-related genes were identified. Among them, 45 genes were significantly correlated with the prognosis of CRC patients. A TF-mediated network was set up to explore its internal mechanism. GO and KEGG analyses further illustrated that these genes were enriched in immune-and inflammatory-related pathways. Then, a prognostic prediction model composed of eight immune-related genes (SLC10A2, UTS2, FGF2, UCN, IL1RL2, ESM1, ADIPOQ, and VIP) was constructed. The AUC of the ROC curve for 1, 3, 5, and 10 years overall survival (OS) was 0.751, 0.707, 0.680, and 0.729, respectively. The survival analysis suggested that the OS of the high-risk group was significantly poorer than that of the low-risk group. Meanwhile, in vitro assays revealed that ESM1 and SLC10A2 exert opposing roles in colon cancer cell proliferation, validating the accuracy of the model. The correlation analysis indicated that immune cell infiltration was positively related to the model.

Conclusion

This study screened prognosis-related immune genes and developed a prognostic prediction model of CRC. These findings may help provide potential novel prognostic biomarkers and therapeutic targets for CRC. At the same time, the understanding of the CRC immune microenvironment status was deepened.

ESM-1 Overexpression is Involved in Increased Tumorigenesis of Radiotherapy-Resistant Breast Cancer Cells

The key barrier to the effectiveness of radiotherapy remains the radioresistance of breast cancer cells, resulting in increased tumor recurrence and metastasis. Thus, in this study, we aimed to clarify the difference between radiotherapy-resistant (RT-R) breast cancer (BC) and BC, and accordingly, analyzed gene expression levels between radiotherapy-resistant (RT-R) MDA-MB-231 cells and MDA-MB-231 cells. Gene expression array showed that ESM-1 was the most upregulated in RT-R-MDA-MB-231 cells compared to MDA-MB-231 cells. Then, we aimed to investigate the role of ESM-1 in the increased tumorigenesis of RT-R-BC cells. RT-R-MDA-MB-231, which showed an increased expression level of ESM1, exhibited significantly enhanced proliferation, colony forming ability, migration, and invasion compared to MDA-MB-231 cells, and ESM-1 knockdown effectively reversed these effects. In addition, compared to MDA-MB-231 cells, RT-R-MDA-MB-231 cells displayed improved adhesion to endothelial cells (ECs) due to the induction of adhesion molecules and increased MMP-9 activity and VEGF-A production, which were decreased by ESM-1 knockdown. Moreover, the expression of HIF-1α and activation of NF-κB and STAT-3 were increased in RT-R-MDA-MB-231 cells compared to MDA-MB-231 cells, and these effects were abolished by the knockdown of ESM-1. Finally, we confirmed the role of ESM-1 in tumorigenesis in an in vivo mouse model. Tumor volume, lung metastasis, and tumorigenic molecules (VEGF-A, HIF-1α, MMP-9, ICAM-1, VCAM-1, and phospho-NF-κB and phospho-STAT-3) were significantly induced in mice injected with ESM-1-overexpressing 4T1 cells and greatly enhanced in those injected with ESM-1-overexpressing RT-R-4T1 cells. Taken together, these results suggest for the first time that ESM-1 plays a critical role in tumorigenesis of breast cancer cells, especially RT-R-breast cancer cells, through the induction of cell proliferation and invasion.

A Prognostic Model Based on the Immune-related Genes in Colon Adenocarcinoma

Background: Immune-related genes (IRGs) are critically involved in the tumor microenvironment (TME) of colon adenocarcinoma (COAD). Here, the study was mainly designed to establish a prognostic model of IRGs to predict the survival of COAD patients. Methods: The Cancer Genome Atlas (TCGA), Immunology Database and Analysis Portal (ImmPort) database, and Cistrome database were utilized for extracting data regarding the expression of immune gene- and tumor-related transcription factors (TFs), aimed at the identification of differentially expressed genes (DEGs), differentially expressed IRGs (DEIRGs), and differentially expressed TFs (DETFs). Univariate Cox regression analysis was subsequently performed for the acquisition of prognosis-related IRGs, followed by establishment of TF regulatory network for uncovering the possible molecular regulatory association in COAD. Subsequently, multivariate Cox regression analysis was conducted to further determine the role of prognosis-related IRGs for prognostic prediction in COAD. Finally, the feasibility of a prognostic model with immunocytes was explored by immunocyte infiltration analysis. Results: A total of 2450 DEGs, 8 DETFs, and 79 DEIRGs were extracted from the corresponding databases. Univariate Cox regression analysis revealed 11 prognosis-related IRGs, followed by establishment of a regulatory network on prognosis-related IRGs at transcriptional levels. Functionally, IRG GLP2R was negatively modulated by TF MYH11, whereas IRG TDGF1 was positively modulated by TF TFAP2A. Multivariate Cox regression analysis was subsequently performed to establish a prognostic model on the basis of seven prognosis-related IRGs (GLP2R, ESM1, TDGF1, SLC10A2, INHBA, STC2, and CXCL1). Moreover, correlation analysis of immunocyte infiltration also revealed that the seven-IRG prognostic model was positively associated with five types of immunocytes (dendritic cell, macrophage, CD4 T cell, CD8 T cell, and neutrophil), which may directly reflect tumor immune state in COAD. Conclusions: Our present findings indicate that the prognostic model based on prognosis-related IRGs plays a crucial role in the clinical supervision and prognostic prediction of COAD patients at both molecular and cellular levels.

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.

Integrated genomic and methylation profile analysis to identify candidate tumor marker genes in patients with colorectal cancer

Aberrant genomic expression and methylation serve important roles in cancer development. Integrated analysis of genetic and methylation profiles may identify potential tumor marker genes for colorectal cancer (CRC) prediction. In the current study, DNA methylation and mRNA expression profiles associated with CRC were downloaded from The Cancer Genome Atlas database. Differentially expressed mRNAs and methylated genes between tumor samples and adjacent healthy tissues were identified. Candidate tumor marker genes and prognostic clinical factors were screened according to univariable and multivariable Cox regression analysis. A total of 218 DEGs with aberrant methylation levels were screened from tumor samples. A risk prediction model was constructed based on identified genes and clinical factors. Randomization tests were used to evaluate the performance of the prediction model, including area under the curve (AUC) calculation and cross-validation. Cox regression analysis revealed that eight genes and six prognostic clinical factors were significantly associated with survival outcomes. Functional and pathway enrichment analysis revealed that the eight genes were mainly involved in ‘cell adhesion’, ‘fatty acid metabolism’ and ‘cytokine receptor interaction’ pathways. After combining six clinical factors with eight genes, the accuracy of risk prediction model has been increased intensively. The P-values representing the association between risk grouping and prognosis decreased from 0.009 to 0.001 and the AUC increased from 0.992 to 0.999, indicating that the comprehensive risk prediction model exhibited a good performance for disease prognosis prediction. The current study integrated genomic and methylation profiles and identified eight tumor marker genes in CRC. These candidate genes may improve the prediction accuracy of CRC prognosis.

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.

Endocan expression in placenta of women with hypertension

AIM

The aim of our study was to determine the endocan-1 expression in placenta of hypertensive women, and its association with maternal and fetal outcomes.

METHODS

This was a cross-sectional study consisted of 21 pregnant women with hypertension and 23 without hypertension. The gestational age ranged from 28 to 39 weeks (hypertensive) and 32 to 40 weeks (normotensive). The paraffin embedded formalin fixed placenta tissue blocks were retrieved from the pathology archives. Endocan immunohistochemistry was performed on tissue sections of full thickness and maternal surface of the placenta. The endocan expression was determined in fetal endothelial cells, maternal endothelial cells, cytotrophoblasts, syncytiotrophoblasts and decidual cells. The differences in endocan expression in placenta between hypertensive and normotensive subjects were evaluated by Pearson chi-square test and t-test were used in the statistical analysis.

RESULTS

The endocan expression was significantly higher in fetal endothelial cells (P < 0.001), maternal endothelial cells (P = 0.003) and decidual cells (P < 0.001) in the placenta of women with hypertension. When comparing positive and negative endocan expression in maternal outcomes, endocan was associated with the development of pre-eclampsia (P = 0.03). Also, a positive endocan expression was associated with low birthweight (P = 0.001) and prematurity (P = 0.005) in the fetal outcomes.

CONCLUSION

This study showed endocan is highly expressed in fetal endothelial cells, maternal endothelial cells and decidual cells in placenta of hypertensive women. In addition, its expression was associated with poorer maternal and fetal outcomes. These findings suggest endocan may play an important role in the progression of hypertension in pregnancy.

Diagnostic and prognostic values of endothelial-cell-specific molecule-1 with malignant pleural effusions in patients with non-small cell lung cancer

Over-expressed endothelial-cell-specific molecule-1 (ESM-1) in tumor vascular endothelium contributes to tumor angiogenesis, metastasis, and poor prognosis. However, the content of ESM-1 in pleural effusion is unclear. A retrospective study was carried out to investigate the diagnostic and prognostic values of ESM-1 with malignant pleural effusions in patients with non-small cell lung cancer (NSCLC). ESM-1 levels in malignant pleural effusion (MPE) from 70 patients with NSCLC and 50 cases of benign pleural effusion (BPE) were measured using enzyme-linked immunosorbent assay. Receiver operating characteristic (ROC) curve was calculated to assess the diagnostic value of ESM-1. Survival curves were performed by Kaplan-Meier method and survival characteristics were compared by log-rank test. Univariable and multivariate Cox proportional hazards model were carried out to analysis the significance of different prognostic factors for overall survival (OS). ESM-1 levels were significantly higher in MPE than those in BPE (p < 0.001). By ROC curve analysis, with a cutoff level of 19.58 ng/ml, the accuracy, sensitivity, and specificity for ESM-1 diagnosis MPE were 82.5%, 81.4%, and 84.0%, respectively. Moreover, NSCLC patients with pleural fluid ESM-1 levels below 19.58 ng/ml had significant longer OS than those patients with higher levels (22.09 months vs. 11.49 months, p = 0.003). Multivariate survival analysis showed that high MPE ESM-1 level was an independent prognostic factor (HR, 1.007; p = 0.039) for the OS of NSCLC patients. This study showed that ESM-1 level in pleural effusion could be a potential diagnostic and prognostic marker in NSCLC patients with MPE.

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.

Cell Line Secretome and Tumor Tissue Proteome Markers for Early Detection of Colorectal Cancer: A Systematic Review

Objective: In order to find low abundant proteins secretome and tumor tissue proteome data have been explored in the last few years for the diagnosis of colorectal cancer (CRC). In this review we aim to summarize the results of studies evaluating markers derived from the secretome and tumor proteome for blood based detection of colorectal cancer. Methods: Observing the preferred reporting items for systematic reviews and meta-analysis (PRISMA) guidelines PubMed and Web of Science databases were searched systematically for relevant studies published up to 18 July 2017. After screening for predefined eligibility criteria a total of 47 studies were identified. Information on diagnostic performance indicators, methodological procedures and validation was extracted. Functions of proteins were identified from the UniProt database and the the Quality Assessment of Diagnostic Accuracy Studies-2 (QUADAS-2) tool was used to assess study quality. Results: Forty seven studies meeting inclusion criteria were identified. Overall, 83 different proteins were identified, with carcinoembryonic Antigen (CEA) being by far the most commonly reported (reported in 24 studies). Evaluation of the markers or marker combinations in blood samples from CRC cases and controls yielded apparently very promising diagnostic performances, with area under the curve >0.9 in several cases, but lack of internal or external validation, overoptimism due to overfitting and spectrum bias due to evaluation in clinical setting rather than screening settings are major concerns. Conclusions: Secretome and tumor proteome-based biomarkers when validated in blood yield promising candidates. However, for discovered protein markers to be clinically applicable as screening tool they have to be specific for early stages and need to be validated externally in larger studies with participants recruited in true screening setting.

The Metabolic Syndrome, Inflammation, and Colorectal Cancer Risk: An Evaluation of Large Panels of Plasma Protein Markers Using Repeated, Prediagnostic Samples

Metabolic syndrome (MetS), a set of metabolic risk factors including obesity, dysglycemia, and dyslipidemia, is associated with increased colorectal cancer (CRC) risk. A putative biological mechanism is chronic, low-grade inflammation, both a feature of MetS and a CRC risk factor. However, excess body fat also induces a proinflammatory state and increases CRC risk. In order to explore the relationship between MetS, body size, inflammation, and CRC, we studied large panels of inflammatory and cancer biomarkers. We included 138 participants from the Västerbotten Intervention Programme with repeated sampling occasions, 10 years apart. Plasma samples were analyzed for 178 protein markers by proximity extension assay. To identify associations between plasma protein levels and MetS components, linear mixed models were fitted for each protein. Twelve proteins were associated with at least one MetS component, six of which were associated with MetS score. MetS alone was not related to any protein. Instead, BMI displayed by far the strongest associations with the biomarkers. One of the 12 MetS score-related proteins (FGF-21), also associated with BMI, was associated with an increased CRC risk (OR 1.71, 95% CI 1.19–2.47). We conclude that overweight and obesity, acting through both inflammation and other mechanisms, likely explain the MetS-CRC connection.

Plasma Levels of Endothelial Cell-Specific Molecule-1 as a Potential Biomarker of Oral Cancer Progression

In Taiwan, oral cancer is the fourth most common cancer and the most common malignancy with a poor prognosis. Endothelial cell-specific molecule-1 (ESM-1) is secreted by vascular endothelial cells in the liver, lungs, kidneys, and gastrointestinal tract. ESM-1 expression is associated with tumor prognosis, metastasis, and angiogenesis in many cancers. However, few studies have examined the association of plasma ESM-1 levels with oral squamous cell carcinoma (OSCC) progression. We measured the plasma ESM-1 levels of 438 male OSCC patients through a commercial enzyme-linked immunosorbent assay. The Cancer Genome Atlas (TCGA) dataset was also used to analyze the ESM-1 levels in 328 OSCC patients and 33 normal tissues. Our results revealed that the plasma levels of ESM-1 in OSCC patients were significantly associated with the tumor (T) status but not with the lymph node status, metastasis, and cell differentiation. TCGA bioinformatics database analysis revealed that ESM-1 expression was significantly higher in OSCC patients than in normal individuals (p < 0.05). In addition, the examination revealed similar results for the ESM-1 expression levels and pathological stage in OSCC. In conclusion, plasma ESM-1 is a novel biomarker for predicting the T status in OSCC patients.

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.

Expressions of Endocan in Patients with Meningiomas and Gliomas

Objective. 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 tissue levels of endocan in common brain tumors, namely, meningiomas, low-grade gliomas (LGGs), and high-grade gliomas (HGGs). Patients and Methods. Endocan was assayed by commercially available enzyme linked immunosorbent assay (ELISA) kits in a total of 50 brain tumors (20 meningiomas, 19 LGGs, and 20 HGGs) and 15 controls. The results were compared to control brain tissues. Results. Each tumor group showed significant higher levels of endocan compared to controls (p < 0.05). In addition, endocan levels showed steady increase from the least (meningiomas) to the most (HGGs) malignant tumors and positive correlation was noted between the degree of malignancy and endocan level (p = 0.0001). Conclusion. Endocan, a vital molecule for angiogenesis, is expressed in common brain tumors and results suggest that endocan could be a marker for malignancy.

Collagen triple helix repeat containing 1 (CTHRC1) acts via ERK-dependent induction of MMP9 to promote invasion of colorectal cancer cells

Collagen triple helix repeat-containing 1 (CTHRC1) is known to be aberrantly upregulated in most human solid tumors, although the functional roles of CTHRC1 in colorectal cancer remain unclear. In this study, we investigated the occurrence of CTHRC1 upregulation and its role in vivo and in vitro. The expression profile and clinical importance of CTHRC1 were examined by reverse transcription-polymerase chain reaction and immunohistochemical analyses in normal and tumor patient samples. CTHRC1 was detectable in normal tissues, but also was highly expressed in tumor specimens. CTHRC1 upregulation was significantly associated with demethylation of the CTHRC1 promoter in colon cancer cell lines and tumor tissues. Clinicopathologic analyses showed that nodal status and expression of CTHRC1 (95% CI 0.999-3.984, p=0.05) were significant prognostic factors for disease-free survival. Promoter CpG methylation and hypermethylation status were measured by bisulfite sequencing and pyrosequencing analysis. Furthermore, we showed that overexpression of CTHRC1 in the SW480 and HT-29 cell lines increased invasiveness, an effect mediated by extracellular signal-regulated kinase (ERK)-dependent upregulation of matrix metalloproteinase 9 (MMP9). Consistent with this, we found that knockdown of CTHRC1 attenuated ERK activation and cancer cell invasivity. These results demonstrate that CTHRC1 expression is elevated in human colon cancer cell lines and clinical specimens, and promotes cancer cell invasivity through ERK-dependent induction of MMP9 expression. Our results further suggest that high levels of CTHRC1 expression are associated with poor clinical outcomes.

The EF-hand calcium-binding protein tescalcin is a potential oncotarget in colorectal cancer

Tescalcin (TESC) is an EF-hand calcium binding protein that is differentially expressed in several tissues, however it is not reported that the expression and functional roles of TESC in colorectal cancer. Levels of messenger RNA (mRNA) and protein expression of TESC in colorectal cancer tissues were assessed using RT-PCR, real time PCR, immunohistochemistry, and clinicopathologic analyses. Quantitative analysis of TESC levels in serum specimens was performed using sandwich ELISA. Colorectal cancer cells transfected with TESC small interfering RNA and short hairpin RNA were examined in cell proliferation assays, phospho-MAPK array, and mouse xenograft models. Here we demonstrated that TESC is overexpressed in colorectal cancer (CRC), but was not expressed in normal mucosa and premalignant dysplastic lesions. Furthermore, serum TESC levels were elevated in patients with CRC. Knockdown of TESC inhibited the Akt-dependent NF-κB pathway and decreased cell survival in vitro. Depletion of TESC reduced tumor growth in a CRC xenograft model. Thus, TESC is a potential diagnostic marker and oncotarget in colorectal cancer.

Serum endocan as a survival predictor for patients with liver cirrhosis

BACKGROUND

The relationship between endocan expression and outcome in patients with chronic liver disease is not fully understood.

OBJECTIVE

To examine whether serum endocan level is predictive of outcome in patients with liver cirrhosis.

METHODS

A total of 68 patients with liver cirrhosis were enrolled. Outcome predictors were analyzed using the Cox proportional hazards model. The overall survival rates were calculated using the Kaplan-Meier method, and differences were evaluated using the log-rank test.

RESULTS

During the median follow-up period (7.1 years), nine patients had hepatocellular carcinoma (HCC) and 10 patients died. Of the deceased patients, nine died due to hepatic decompensation or associated conditions. No significant factors were found to be predictive of the occurrence of HCC. In contrast, an elevated serum endocan level (≥2.0 ng⁄mL; HR 2.34 [95% CI 1.05 to 7.03]; P=0.037) and high Child-Pugh grade B⁄C (HR 2.65 [95% CI 1.30 to 6.89; P=0.006) were predictive of poor survival. Kaplan-Meier analysis revealed that the respective cumulative survival rates at five and 10 years were 97.1% and 87.4% in patients with serum endocan levels <2.0 ng⁄mL and 85.8% and 64.4% in patients with levels ≥2.0 ng⁄mL (P=0.009), respectively. Moreover, the cumulative survival rates were significantly different among the patient groups divided according to serum endocan level and Child-Pugh grade (P=0.002).

CONCLUSION

These findings suggest that serum endocan level may be a survival predictor for patients with liver cirrhosis.

Endothelial cell-specific molecule-1: a potential serum marker for gastric cancer

No ideal serum markers for gastric cancer (GC) screening have been identified. The aim of this study was to determine the usefulness of endothelial cell-specific molecule-1 (ESM-1) as a serum marker for GC. The ESM-1 levels in serum specimens from 114 patients with GC and 55 health subjects were measured using a sandwich ELISA kit. Receiver operating characteristic (ROC) curve was calculated to assess the diagnostic value of ESM-1. Survival curves by the Kaplan-Meier method were plotted to display overall survival distributions. Univariable and multivariable Cox regression analyses were performed to assess independent prognostic factors for overall survival in GC. We showed that the ESM-1 levels in the serum of patients with GC (83.7 ± 16.2 pg/mL) were significantly elevated compared to health subjects (44.7 ± 16.4 pg/mL). The accuracy, sensitivity, and specificity of ESM-1 for GC were 0.946, 98, and 80 %, respectively, by ROC curve analysis. The positive and negative predictive values were 91 and 93.6 %, respectively. The likelihood ratios of a positive or negative test result were 20.9 and 0.14, respectively. When analyzed with a Cox regression model, a higher serum ESM-1 level (≥84.2 pg/mL) was correlated with poor prognosis. This study suggests that serum ESM-1 level is increased in patients with GC and that ESM-1 can be used as a potential serum marker for early detection and prognosis evaluation of GC.

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.

Serum endocan as a novel prognostic biomarker in patients with hepatocellular carcinoma

Endocan is a vascular endothelium-derived factor regulated by angiogenic factors. The aim of this study was to determine whether serum endocan levels are prognostic for survival in patients with hepatocellular carcinoma (HCC). Serum endocan levels were measured in 64 HCC patients who were naïve to treatment, eight apparently healthy subjects, and 68 patients with liver cirrhosis; the latter two groups served as controls. Prognostic factors for the survival of HCC patients were examined using a Cox proportional hazards model. The median serum endocan levels were 1.145 ng/mL (range, 0.93-1.68 ng/mL) in healthy subjects, 1.93 ng/mL (range, 0.45-8.47 ng/mL) in liver cirrhosis patients, and 3.73 ng/mL (range, 0.74-10.95 ng/mL) in HCC patients (P = 0.0001). In HCC patients, elevated serum endocan levels were significantly associated with poor hepatic function (P = 0.015), a greater number of tumors (P = 0.034), and vascular invasion (P = 0.043). The median follow-up period was 23.0 months, and 33 HCC patients died during follow up. Multivariate analysis showed that serum endocan levels ≥ 2.20 ng/mL (hazard ratio 2.36, 95% confidence interval 1.22-5.36, P = 0.008) as well as elevated serum α-fetoprotein and des-γ-carboxy prothrombin levels were independent prognostic biomarkers for poor survival. The combination of serum endocan and these two additional markers was significantly predictive of worse survival (P < 0.0001). Thus, serum endocan may be a prognostic biomarker for survival in HCC patients, and the combination of serum endocan, α-fetoprotein, and des-γ-carboxy prothrombin levels can result in better prognostic stratification of these patients.

Genome-wide analysis of long noncoding RNA (lncRNA) expression in hepatoblastoma tissues

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

Detection and mechanism of action of ESM-1 in rat kidney transplantation under various immune states

OBJECTIVE

To investigate whether ESM-1 expression change reflects the impairment of endothelial cells and rejection after kidney transplantation, ESM-1 expression was detected under various immune states in this study.

METHODS

Kidney transplantations were performed from BN to LEW rats. Syngenic LEW-LEW grafts were used as controls. The LEW recipient rats were divided into acute rejection (AR) group, ciclosporin A (CsA) group and control group. In each group, 10 rats were sacrificed at 1, 5, and 7d after operation, respectively, and blood and kidney samples were collected. In the rat model of kidney transplantation, ESM-1 mRNA and ESM-1 protein expression were detected in various immune states to verify if ESM-1 can reflect endothelial cell impairment sensitively.

RESULTS

ESM-1 mRNA (1d vs. 3d, P<0.01;3d vs. 7d, P=0.018) and ESM-1 protein expression was upregulated significantly in the AR group (P<0.01, 5 and 7d), when compared to CsA group and control group. In CsA group, the cell apoptosis rate decreased when compared to AR group (P<0.01). Pathological impairment was more serious in AR group than in CsA group (P<0.01).

CONCLUSIONS

Peripheral blood ESM-1 mRNA and ESM-1 protein expression in kidney grafts can reflect the severity of endothelial cell impairment. Thus, ESM-1 may be used as a new indicator for AR prediction and diagnosis. Nevertheless, further investigation is required to test if it meets the criteria for clinical utility.

Endocan in cancers: a lesson from a circulating dermatan sulfate proteoglycan

As most proteoglycans exert their biological activities in the pericellular region, circulating Endocan has appeared since its discovery as an atypical dermatan sulfate proteoglycan, with distinctive structural and functional properties. Endocan is naturally expressed by endothelial cells, highly regulated in presence of proinflammatory and proangiogenic molecules, binds to matrix proteins, growth factors, integrin, and cells, and may be then considered as an accurate marker of endothelial activation. Consequently, Endocan expression has been associated with a growing number of pathological conditions where endothelium gets challenged and notably in highly vascularized cancers. In this context, Endocan has indeed been rapidly emerging as a promising tissue- and blood-based marker of the vascular growth and neoangiogenesis during cancer progression. Furthermore, very recent studies have reported an expression of Endocan by the tumor cells themselves. This highlights Endocan as a multifaceted molecule with a great interest for researchers and clinicians to better understand tumor development, from the bench to the clinics. With promising perspectives of clinical applications, Endocan thus appears as an exciting model for on going and future developments of proteoglycan-based approaches in cancer diagnostics and/or therapy.

Expression of endothelial cell-specific molecule-1 regulated by hypoxia inducible factor-1α in human colon carcinoma: impact of ESM-1 on prognosis and its correlation with clinicopathological features

Based on a previous finding that endothelial cell-specific molecule-1 (ESM-1) is a potential serum marker for colorectal cancer (CRC), the aim of this study was to clarify the clinicopathological significance of ESM-1 expression in CRC, and to explore the correlation between ESM-1 and HIF-1α in the tumorigenesis of CRC related to hypoxic conditions. ESM-1 mRNA expression was examined in CRC and corresponding normal mucosal tissues by reverse transcriptase-polymerase chain reaction (RT-PCR) and real-time RT-PCR. This experiment confirmed that ESM-1 levels were high in CRC. We screened the tissue samples of 143 CRC patients. By immunohistochemistry, we determined that the ESM-1 immunoreactivity was significantly correlated with the tumor size, depth of invasion, nodal status, distant metastasis and Dukes' stage, and was an independent prognostic factor for disease recurrence and worse survival outcome (P=0.001). The modulation of ESM-1 under hypoxia was investigated, and it was confirmed that ESM-1 expression was induced by HIF1-α and significantly attenuated by small interfering RNA (siRNA) targeting HIF-1α in CRC cells. These results showed that ESM-1 is significantly overexpressed, which is regulated by HIF-1α in CRC patients, and can be used as a potential biomarker and a therapeutic target for CRC.