Biological and clinical implications of endocan in gastric cancer

Blood endocan as a biomarker for breast cancer recurrence

BACKGROUND

Endocan was reported to affect breast cancer patients negatively and was able to be detected from patients' blood.

OBJECTIVE

This study aimed to investigate if the measurement of blood endocan in breast cancer patients with high ESM1 expression could be an effective tool to detect postoperative recurrence compared with existing tumor markers.

METHODS

Blood was collected before and after the tumor resection from the mouse models of breast cancer, and endocan levels were measured while visualizing metastatic recurrence with noninvasive luminescence imaging. In clinical settings, blood was withdrawn from 16 breast cancer patients before and after the tumor resection, and the effect of lumpectomy on blood endocan level was evaluated. Additionally, the blood endocan from 20 patients diagnosed with postoperative recurrence was measured, and their positivity rate for endocan was compared with that for serum carcinoembryonic antigen (CEA) or cancer antigen 15-3 (CA15-3).

RESULTS

Our preclinical and clinical experiments revealed that blood endocan levels reflected tumor burden. Furthermore, over 60% of patients suffering from postoperative recurrence who tested negative for CEA or CA15-3 were positive for endocan.

CONCLUSIONS

Our results support the clinical significance of endocan in breast cancer patients for detecting breast cancer recurrence.

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.

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.

Screening lncRNAs with diagnostic and prognostic value for human stomach adenocarcinoma based on machine learning and mRNA-lncRNA co-expression network analysis

BACKGROUND

Stomach adenocarcinoma (STAD), is one of the most lethal malignancies around the world. The aim of this study was to find the long noncoding RNAs (lncRNAs) acting as diagnostic and prognostic biomarker of STAD.

METHODS

Base on TCGA dataset, the differentially expressed mRNAs (DEmRNAs) and lncRNAs (DElncRNAs) were identified between STAD and normal tissue. The machine learning and survival analysis were performed to evaluate the potential diagnostic and prognostic value of lncRNAs for STAD. We also build the co-expression network and functional annotation. The expression of selected candidate mRNAs and lncRNAs were validated by Quantitative real-time polymerase chain reaction (qRT-PCR) and GSE27342 dataset. GSE27342 dataset were also to perform gene set enrichment analysis.

RESULTS

A total of 814 DEmRNAs and 106 DElncRNAs between STAD and normal tissue were obtained. FOXD2-AS1, LINC01235, and RP11-598F7.5 were defined as optimal diagnostic lncRNA biomarkers for STAD. The area under curve (AUC) of the decision tree model, random forests model, and support vector machine (SVM) model were 0.797, 0.981, and 0.983, and the specificity and sensitivity of the three model were 75.0% and 97.1%, 96.9% and 96%, and 96.9% and 97.1%, respectively. Among them, LINC01235 was not only an optimal diagnostic lncRNA biomarkers, but also related to survival time. The expression of three DEmRNAs (ESM1, WNT2, and COL10A1) and three optimal diagnostic lncRNAs biomarkers (FOXD2-AS1, RP11-598F7.5, and LINC01235) in qRT-PCR validation was were consistent with our integrated analysis. Except for FOXD2-AS1, ESM1, WNT2, COL10A1, and LINC01235 were upregulated in STAD, which was consistent with our integration results. Gene set enrichment analysis results indicated that DNA replication, Cell cycle, ECM-receptor interaction, and P53 signaling pathway were four significantly enriched pathways in STAD.

CONCLUSION

Our study identified three DElncRNAs as potential diagnostic biomarkers of STAD. Among them, LINC01235 also was a prognostic lncRNA biomarkers.

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.

Downregulation of ENDOCAN in myeloid leukemia cells inhibits proliferation and promotes apoptosis by suppressing nuclear factor‑κB activity

Previous studies have demonstrated that ENDOCAN is elevated in leukemia, and it has been reported to be associated with poor prognosis. However, the functional role of ENDOCAN in the development of leukemia remains to be fully elucidated. In the present study, the expression levels of ENDOCAN were detected in THP‑1, U937, HL‑60 and K562 cells, and it was found that ENDOCAN was increased in U937 and K562 cells, compared with the other two cell lines. Subsequently, ENDOCAN was knocked down in U937 and K562 cells via lentiviral infection. It was found that cell proliferation and the expression of proliferating cell nuclear antigen were inhibited in myeloid leukemia cells following the silencing of ENDOCAN. ENDOCAN knockdown induced G0/G1‑phase cell cycle arrest in myeloid leukemia cells with a decreased expression of cyclin D1. Furthermore, cell apoptosis was increased in response to ENDOCAN silencing, which was accompanied by the downregulation of B‑cell lymphoma (BCL2) and the upregulation of BCL2‑associated X protein, cleaved caspases 3 and 9, and cleaved poly (ADP‑ribose) polymerase. Furthermore, it was demonstrated that the knockdown of ENDOCAN inhibited nuclear factor‑κB (NF‑κB) activity, as evidenced by the increased expression of NF‑κB inhibitor α (IκBα), decreased expression of phosphorylated (p‑)IκBα, p‑P65 and nuclear P65, and reduced NF‑κB DNA‑binding activity. In combination, the present findings suggested that ENDOCAN may serve as a potential therapeutic target in the treatment of leukemia.

A novel role of endocan in alleviating LPS-induced acute lung injury

AIMS

Endotoxin induced acute lung injury (ALI) is a critical complication of some clinical illnesses. Endothelial cell dysfunction and excessive pro-inflammation cytokine release are pivotal to the injury of alveolar-capillary membrane which is the typical characteristic of endotoxic lung injury. As a potential marker of endothelial cells, endocan plays an important role in many endothelial-dependent pathophysiological diseases. We speculated that endocan have anti-inflammatory property in ALI. Here, we investigated the role of endocan in LPS-induced ALI.

MATERIALS AND METHODS

Mice were randomly divided into 4 groups. LPS were used to construct ALI mice model by aerosolization for 20 min. Endocan was intraperitoneal injected at 30 min before LPS exposure. Levels of TNF-α, IFN-γ, IL-1β, IL-6 and MPO activities were detected by indicated ELISA. Cell apoptotic rate was determined by Annexin V/PI kit, ROS level and MPTP were detected by DCFH-DA and JC-1 kit, respectively. Seahorse XF96 was applied to evaluate the alteration of OCR and ECAR. Western blot and qRT-PCR were used to detect indicated molecules.

KEY FINDINGS

Endocan effectively decreased TNF-α, IFN-γ, IL-1β, and IL-6 levels as well as relieved pulmonary epithelium cell apoptosis caused by LPS exposure. Endocan significantly reversed LPS induced UPR^mt and promoted cell metabolism reprogramming which were crucial for the protective characteristic of endocan in ALI mice model.

SIGNIFICANCE

The above findings suggested endocan could significantly suppress inflammatory response in ALI model through attenuating UPR^mt associated apoptosis and switch cellular bioenergetics, indicating endocan could be considered as a promising compound against LPS induced ALI.

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 expression is correlated with poor progression-free survival in patients with pancreatic neuroendocrine tumors

Endocan expression has been reported to be associated with aggressive tumor progression and poor outcomes in various cancers, such as breast cancer, renal cell cancer, lung cancer, gastric cancer, and pituitary adenomas. However, the prognostic significance of endocan in neuroendocrine tumors remains unknown. Thus, the aim of this study was to determine the correlation between endocan expression in pancreatic neuroendocrine tumor (PNET) tissues and progression-free survival. This study included 73 patients with confirmed PNETs who were treated in a single tertiary center in north Taiwan between 1992 and 2015. Immunohistochemical endocan expression and microvessel density (MVD) were examined, and the relationships between these parameters and other clinicopathological characteristics were analyzed. The abovementioned patients were divided into groups according to their endocan expression levels (≥1% or <1%) and median MVDs. Negative endocan expression (P = .002) and a high MVD (P < .001) were significant and favorable prognostic factors for progression-free survival. However, positive endocan expression was significantly associated with a low MVD (P = .037) and tumor mitosis (Ki-67 index) (P = .028). Multivariate Cox regression analysis showed that positive endocan expression (hazard ratio: 4.778, P = .018) and lymph node involvement (hazard ratio: 5.121, P = .005) were independent prognostic factors for tumor recurrence.In conclusion, endocan expression was correlated with poor clinical outcomes in PNETs. Our data indicated that endocan expression may be a reliable marker for predicting tumor recurrence in patients with PNETs.

Endocan as a prognostic biomarker of triple-negative breast cancer

PURPOSE

Triple-negative breast cancer (TNBC) has aggressive characteristics and fewer treatment options than other subtypes. The purpose of this study was to explore prognostic biomarkers for TNBC that can be easily detected from the blood samples.

METHODS

MDA-MB-231 and MDA-MB-231BR, a brain metastatic variant of the human TNBC cell line MDA-MB-231, were used as less and more aggressive models of TNBC, respectively. The extent to which the candidate gene/protein identified by RNA sequencing correlated well with aggressiveness of TNBC and how much protein was detected from the blood of tumor-bearing mice were evaluated.

RESULTS

Both the in vitro proliferation and in vivo tumor growth of MDA-MB-231BR were more rapid than those of MDA-MB-231. RNA sequencing identified ESM1 as a gene that was expressed significantly more in MDA-MB-231BR than in MDA-MB-231, and qRT-PCR confirmed a significantly higher expression of ESM1 in MDA-MB-231BR xenograft in vivo. Furthermore, Kaplan-Meier analysis of relapse-free survival demonstrated that TNBC patients with high ESM1 expression had clearly worse relapse-free survival than those with low ESM1 expression, which was consistent with our preclinical findings. Endocan, a protein of ESM1 gene product, was successfully detected in both conditioned medium from MDA-MB-231BR and plasma samples from mice bearing MDA-MB-231BR xenograft, which showed a significantly distinct pattern from less aggressive MDA-MB-231. Moreover, bisulfite sequence analysis revealed that overexpression of ESM1 in MDA-MB-231BR might be attributed to DNA demethylation in an upstream region of the ESM1 gene.

CONCLUSION

This study indicates that endocan could be used as a blood-based prognostic biomarker in TNBC 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.

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.