Epigenetic inactivation of secreted frizzled-related protein 2 in esophageal squamous cell carcinoma

PYGO2 increases proliferation and migration capacities through critical signaling pathways in esophageal squamous cell carcinoma

Esophageal cancer, an increasingly prevalent malignancy, is a major concern for global health. The development of esophageal squamous cell carcinoma (ESCC) involves various genetic abnormalities that affect key cell signaling pathways, including Wnt, Hh, Apoptosis, MAPK, EGFR, AKT, Notch, and EMT. Additionally, this malignancy involves some changes in the expression of long noncoding RNAs (LncRNAs). The present study examines the relationship between PYGO2 gene expression and the activity of cell signaling pathways in KYSE-30 and YM-1ESCC cell lines. To this end, several cellular and molecular tests were performed, including cell migration, cell cycle, and apoptosis. Also, expression levels of CD133 and CD44 markers, real-time PCR, and western blot were analyzed after inducing PYGO2 protein expression in the cells. Overexpression of the PYGO2 protein resulted in the upregulation of Wnt pathway-related genes, leading to enhanced cell migration and proliferation and reduced apoptosis in both cell lines. Furthermore, PYGO2 gene expression induction analysis showed the correlation of several involved genes in Wnt, Hh, Apoptosis, MAPK, EGFR, AKT, and EMT pathways with various LncRNAs.

Prediction of recurrence free survival for esophageal cancer patients using a protein signature based risk model

BACKGROUND

Biomarkers to predict the risk of disease recurrence in Esophageal squamous cell carcinoma (ESCC) patients are urgently needed to improve treatment. We developed proteins expression-based risk model to predict recurrence free survival for ESCC patients.

METHODS

Alterations in Wnt pathway components expression and subcellular localization were analyzed by immunohistochemistry in 80 ESCCs, 61 esophageal dysplastic and 47 normal tissues; correlated with clinicopathological parameters and clinical outcome over 86 months by survival analysis. Significant prognostic factors were identified by multivariable Cox regression analysis.

RESULTS

Biomarker signature score based on cytoplasmic β-catenin, nuclear c-Myc, nuclear DVL and membrane α-catenin was associated with recurrence free survival [Hazard ratio = 1.11 (95% CI = 1.05, 1.17), p < 0.001, C-index = 0.68] and added significant prognostic value over clinical parameters (p < 0.001). The inclusion of Slug further improved prognostic utility (p < 0.001, C-index = 0.71). Biomarker Signature Scoreslug improved risk classification abilities for clinical outcomes at 3 years, accurately predicting recurrence in 79% patients in 1 year and 97% in 3 years in high risk group; 73% patients within low risk group did not have recurrence in 1 year, with AUC of 0.76.

CONCLUSIONS

Our comprehensive risk model predictive for recurrence allowed us to determine the robustness of our biomarker panel in stratification of ESCC patients at high or low risk of disease recurrence; high risk patients are stratified for more rigorous personalized treatment while the low risk patients may be spared from harmful side effects of toxic therapy.

Targeting the LSD1-G9a-ER Stress Pathway as a Novel Therapeutic Strategy for Esophageal Squamous Cell Carcinoma

Despite recent advances in the management and treatment of esophageal squamous cell carcinoma (ESCC), the prognosis remains extremely poor, and current nonsurgical treatment options are limited. To identify new therapeutic targets, we screened a curated library of epigenetic compounds using a panel of cancer cell lines and found that coinhibiting the histone demethylase LSD1 and the histone methyltransferase G9a potently suppresses cell growth; similar results were obtained by knocking down both LSD1 and G9a expression. Importantly, we also found that inhibiting LSD1 and G9a significantly decreased tumor growth in a xenograft mouse model with ESCC cell lines. To examine the clinical relevance of these findings, we performed immunohistochemical analyses of microarray profiling data obtained from human esophageal squamous cancer tissues and found that both LSD1 and G9a are upregulated in cancer tissues compared to healthy tissues, and this increased expression was significantly correlated with poor prognosis. Mechanistically, we discovered that inhibiting LSD1 and G9a induces cell death via S-phase arrest and apoptosis, and cotargeting ER stress pathways increased this effect both in vitro and in vivo. Taken together, these findings provide compelling evidence that targeting LSD1, G9a, and ER stress-related pathways may serve as a viable therapeutic strategy for ESCC.

Use of DNA methylation profiling in translational oncology

DNA methylation is a highly regulated process that has a critical role in human development and homeostatic control of the cell. The number of genes affected by anomalous DNA methylation in cancer-associated pathways is swiftly accelerating and with the advancement of molecular technologies, new layers of complexity are opening up and refining our strategies to combat cancer. DNA methylation profiling is an essential facet to understanding malignant transformation and is becoming an increasingly important tool for cancer diagnosis, prognosis and therapy monitoring. In this review, the role of DNA methylation in normal cellular function is discussed, as well as how epigenetic aberrations override normal cellular cues that lead to tumor initiation and propagation. The review also focuses on the latest advancements in DNA methylation profiling as a biomarker for early cancer detection, predicting patient clinical outcomes and responses to treatment and provides new insights into epigenetic-based therapy in clinical oncology.

Association between SFRP promoter hypermethylation and different types of cancer: A systematic review and meta-analysis

Abnormal methylation of secreted frizzled-related proteins (SFRPs) has been observed in various human cancer types. The loss of SFRP gene expression induces the activation of the Wnt pathway and is a vital mechanism for tumorigenesis and development. The aim of the present systematic review was to assess the association between SFRP methylation and cancer risk. A meta-analysis was systematically conducted to assess the clinicopathological significance of SFRP methylation in cancer risk. The Cochrane Library, PubMed and Web of Science databases were comprehensively searched, and 83 publications with a total of 21,612 samples were selected for the meta-analysis. The pooled odds ratios (ORs) and corresponding 95% confidence intervals (CIs) were calculated to evaluate the degree of associations between SFRP promoter methylation and cancer risk. Subgroup analysis, meta regression and sensitivity analysis were used to identify the potential sources of heterogeneity. SFRP1, SFRP2, SFRP4 and SFRP5 hypermethylation was significantly associated with cancer risk, with ORs of 8.48 (95% CI, 6.26-11.49), 8.21 (95% CI, 6.20-10.88), 11.41 (95% CI, 6.42-20.30) and 6.34 (95% CI, 3.86-10.42), respectively. SFRP2 methylation was significantly associated with differentiation in colorectal cancer (OR, 2.16; 95% CI, 1.02-4.56). The results of the present study demonstrated that SFRP methylation may contribute to carcinogenesis, especially in certain cancer types, including hepatocellular carcinoma and colorectal cancer.

The Silencing of SFRP2 Expression in ESCC Is Due to Methylation of the Gene Promoter

OBJECTIVE

Our aim of the study was to investigate the expression level and methylation status of the secreted frizzled-related protein 2 in esophageal squamous cell carcinoma and to evaluate the clinical utility of the marker.

MATERIAL AND METHODS

We first used Immunohistochemistry (ICH) to explore the expression level of secreted frizzled-related protein 2 protein in esophageal squamous cell carcinoma tissues and adjacent normal tissues and then used methylation-specific polymerase chain reaction and bisulfite sequencing polymerase chain reaction to detect methylation status of secreted frizzled-related protein 2.

RESULTS

Secreted frizzled-related protein 2 expression was notably reduced in patients with esophageal squamous cell carcinoma, whereas methylation of secreted frizzled-related protein 2 was increased in the majority of esophageal squamous cell carcinoma specimens.

CONCLUSION

Sum up, we have demonstrated the abnormal DNA hypermethylation, causing reduced or absent gene expression. Methylation testing of secreted frizzled-related protein 2 using epigenetic marker may be a significative screening method for patients with esophageal squamous cell carcinoma.

Epigenetic inactivation of tumour suppressor coding and non-coding genes in human cancer: an update

Cancer cells undergo many different alterations during their transformation, including genetic and epigenetic events. The controlled division of healthy cells can be impaired through the downregulation of tumour suppressor genes. Here, we provide an update of the mechanisms in which epigenetically altered coding and non-coding tumour suppressor genes are implicated. We will highlight the importance of epigenetics in the different molecular pathways that lead to enhanced and unlimited capacity of division, genomic instability, metabolic shift, acquisition of mesenchymal features that lead to metastasis, and tumour plasticity. We will briefly describe these pathways, focusing especially on genes whose epigenetic inactivation through DNA methylation has been recently described, as well as on those that are well established as being epigenetically silenced in cancer. A brief perspective of current clinical therapeutic approaches that can revert epigenetic inactivation of non-coding tumour suppressor genes will also be given.

Downregulation of RIKP by miR-200a promotes the invasive ability of esophageal cancer cells by upregulating the expression of LIN28 and MMP-14

Esophageal cancer (EC) is one of common digestive tract malignant tumors which morbidity and mortality were increased year by year. This study was aimed to investigate the role of microRNA (miR)-200a in EC. Human esophageal squamous cell carcinoma (ESCC) cells TE3 was transfected with miR-200a mimic or scramble control. Cell viability and invasion were assessed by MTT and Transwell assay, respectively. Binding effect of miR-200a on 3'UTR of RKIP was verified by luciferase activity assay. RKIP expression in miR-200a mimic transfected cells was measured. RKIP was overexpressed in miR-200a transfected cells and cell viability and invasion were measured. The expressions of Raf1, ERK, MMP-14, LIN28 and GRK-2 were also measured by qRT-PCR and Western blot analysis, respectively. Results showed that miR-200a mimic transfection increased cell viability and invasion of TE3 cells in vitro. miR-200a binding with 3'UTR of RKIP negatively regulated RKIP expression. RKIP overexpression inhibited effects of miR-200a on cell viability and invasion, as well as the increased phosphorylation levels of Raf1 and ERK. miR-200a increased expressions of MMP-14, LIN28 and GRK-2 in TE3 cells, and the up-regulations were inhibited by RKIP overexpression. In conclusion, the up-regulation of miR-200a in TE3 cells promoted cell viability and invasion via negatively regulating RKIP expression. RKIP was a direct target of miR-200a. miR-200a might be involved in activation of MAPK/ERK signaling pathway and expression of MMP-14, LIN28 and GRK-2 which were important factors of intracellular information transduction. Our findings demonstrated that miR-200a regulated ESCC cells via regulating RKIP expression.

Clinicopathological significance of c-MYC in esophageal squamous cell carcinoma

Esophageal squamous cell carcinoma is one of the most common malignant tumors. The oncogene c-MYC is thought to be important in the initiation, promotion, and therapy resistance of cancer. In this study, we aim to investigate the clinicopathologic roles of c-MYC in esophageal squamous cell carcinoma tissue. This study is aimed at discovering and analyzing c-MYC expression in a series of human esophageal tissues. A total of 95 esophageal squamous cell carcinoma samples were analyzed by the western blotting and immunohistochemistry techniques. Then, correlation of c-MYC expression with clinicopathological features of esophageal squamous cell carcinoma patients was statistically analyzed. In most esophageal squamous cell carcinoma cases, the c-MYC expression was positive in tumor tissues. The positive rate of c-MYC expression in tumor tissues was 61.05%, obviously higher than the adjacent normal tissues (8.42%, 8/92) and atypical hyperplasia tissues (19.75%, 16/95). There was a statistical difference among adjacent normal tissues, atypical hyperplasia tissues, and tumor tissues. Overexpression of the c-MYC was detected in 61.05% (58/95) esophageal squamous cell carcinomas, which was significantly correlated with the degree of differentiation (p = 0.004). The positive rate of c-MYC expression was 40.0% in well-differentiated esophageal tissues, with a significantly statistical difference (p = 0.004). The positive rate of c-MYC was 41.5% in T1 + T2 esophageal tissues and 74.1% in T3 + T4 esophageal tissues, with a significantly statistical difference (p = 0.001). The positive rate of c-MYC was 45.0% in I + II esophageal tissues and 72.2% in III + IV esophageal tissues, with a significantly statistical difference (p = 0.011). The c-MYC expression strongly correlated with clinical staging (p = 0.011), differentiation degree (p = 0.004), lymph node metastasis (p = 0.003), and invasion depth (p = 0.001) of patients with esophageal squamous cell carcinoma. The c-MYC was differentially expressed in a series of human esophageal tissues, and the aberrant c-MYC expression could be a potential factor in carcinogenesis and progression of esophageal squamous cell carcinoma. There was a statistical signification for c-MYC in esophageal squamous cell carcinoma patients to analyze clinicopathological features. It possibly becomes a new diagnostic indicator of esophageal squamous cell carcinoma.

Clinicopathological significance of wnt/β-catenin signaling pathway in esophageal squamous cell carcinoma

BACKGROUND/AIM

Esophageal squamous cell carcinoma (ESCC) is one of the most common malignant tumors. It has been reported that Wnt signaling pathway plays an important role in Esophageal Cancer progression, metastasis and invasion. However the clinicopathological significance of Wnt2, GSK3β, and β-catenin in ESCC has been little reported. In the present study, the aim of this study was to investigate the clinicopathologic and prognosis roles of Wnt2, GSK3β, and β-catenin in ESCC tissue.

METHODS

265 ESCC samples were analyzed by immunohistochemistry using Wnt2, GSK3β, and β-catenin antibodies. Then, correlation of Wnt2, GSK3β, and β-catenin expression with clinicopathological features and prognosis of ESCC patients was statistically analyzed.

RESULTS

Cytoplasmic Wnt2 overexpression was detected in 55.5% (147 of 265) ESCCs, which was significantly correlated with the degree of differentiation (P=0.031). Cytoplasmic GSK3β overexpression was detected in 7.2% (19 of 265) ESCCs, and aberrant β-catenin expression was identified in 54.3% (144 of 265) of ESCCs. The positive rate of Wnt2 significantly increased with the malignant degree of Kazak ESCC patients. The aberrant β-catenin expression in GSK3β-negative ESCC was significantly associated with the ethnic, tumor size, tumor location, degree of differentiation, AJCC stage, lymph node status. Furthermore, the expression of β-catenin implicated the ethnic difference (P=0.019). In Kaplan-Meier curve analysis, no significant correlation was observed between the expression of Wnt2, GSK3β, β-catenin and the poor prognosis of ESCCs.

CONCLUSION

The aberrant β-catenin expression could be an adverse underlying factor in carcinogenesis and progression of ESCC. There was a different statistical signification for β-catenin in Kazakhs to compare with Hans.

HOTAIR, a prognostic factor in esophageal squamous cell carcinoma, inhibits WIF-1 expression and activates Wnt pathway

Long non-coding RNAs (LncRNAs) have been recently found to be pervasively transcribed in the genome and critical regulators of the epigenome. HOTAIR, as a well-known LncRNA, has been found to play important roles in several tumors. Herein, the clinical application value and biological functions of HOTAIR were focused and explored in esophageal squamous cell carcinoma (ESCC). It was found that there was a great upregulation of HOTAIR in ESCC compared to their adjacent normal esophageal tissues. Meanwhile, patients with high HOTAIR expression have a significantly poorer prognosis than those with low expression. Moreover, HOTAIR was further validated to promote migration and invasion of ESCC cells in vitro. Then some specific molecules with great significance were investigated after HOTAIR overexpression using microarray and quantitative real time-polymerase chain reaction (qPCR). WIF-1 playing an important role in Wnt/β-catenin signaling pathway was selected and further tested by immunehistochemistry. Generally, inverse correlation between HOTAIR and WIF-1 expression was demonstrated both in ESCC cells and tissues. Mechanistically, HOTAIR directly decreased WIF-1 expression by promoting its histone H3K27 methylation in the promoter region and then activated the Wnt/β-catenin signaling pathway. This newly identified HOTAIR/WIF-1 axis clarified the molecular mechanism of ESCC cell metastasis and represented a novel therapeutic target in patients with ESCC.

Molecular alterations and clinical relevance in esophageal squamous cell carcinoma

Esophageal squamous cell carcinoma (ESCC) is one of the most common types of gastrointestinal cancers, and the fourth leading cause of cancer-related deaths in China. Early detection and intervention in time may dramatically increase the survival of the patients by initiating treatment regimens during earlier stages of ESCC or even during precancerous stages. Molecular classification will be useful for subtyping esophageal tumors or precancerous lesions to improve current therapeutics or early intervention of the disease. In this review, we summarize the findings in investigating the molecular alterations and clinical relevance of ESCC.

Progress in understanding the relationship between SFRP gene methylation and gastrointestinal tumors

Promoter DNA hypermethylation is the most common epigenetic modification in the human genome and is closely related with tumor progression and prognosis. Secreted frizzled-related proteins (SFRPs) act as antagonists of the Wnt signaling pathway, and their expression is frequently silenced as a result of promoter hypermethylation in a variety of tumors, which weakens the inhibition of the Wnt signaling pathway, leads to aberrant activation of this signaling pathway, and thereby promotes tumorigenesis and development. In this paper, we review the recent advances in understanding the relationship between SFRP gene methylation and gastrointestinal tumors.