Protein alterations in ESCC and clinical implications: a review

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.

MiRNA-145 and Its Direct Downstream Targets in Digestive System Cancers: A Promising Therapeutic Target

MicroRNAs (miRNAs) play a vital role in the onset and development of many diseases, including cancers. Emerging evidence shows that numerous miRNAs have the potential to be used as diagnostic biomarkers for cancers, and miRNA-based therapy may be a promising therapy for the treatment of malignant neoplasm. MicroRNA-145 (miR-145) has been considered to play certain roles in various cellular processes, such as proliferation, differentiation and apoptosis, via modulating the expression of direct target genes. Recent reports show that miR-145 participates in the progression of digestive system cancers, and plays crucial and novel roles in cancer treatment. In this review, we summarize the recent knowledge concerning the function of miR-145 and its direct targets in digestive system cancers. We discuss the potential role of miR-145 as a valuable biomarker for digestive system cancers and how miR-145 regulates these digestive system cancers via different targets to explore the potential strategy of targeting miR-145.

Identification of differentially expressed proteins in the locoregional recurrent esophageal squamous cell carcinoma by quantitative proteomics

Background

This study aimed to identify potential biomarkers associated with locoregional recurrence in patients with esophageal squamous cell carcinoma (ESCC) after radical resection.

Methods

We performed a quantitative proteomics analysis using isobaric tags for relative and absolute quantification (iTRAQ) with reversed-phase liquid chromatography-mass spectrometry (RPLC-MS) to identify differential expression proteins (DEPs) between a locoregional recurrence group and good prognosis group of ESCC after radical esophagectomy. The bioinformatics analysis was performed with ingenuity pathway analysis software (IPA) and Gene Ontology (GO) database using the software of MAS 3.0. Kaplan-Meier (KM) Plotter Online Tool (http://www.kmplot.com) was used to evaluate the relationship between the differential expression of proteins and survival in patients with ESCC.

Results

More than 400 proteins were quantitated of which 27 proteins had upregulated expression and 55 proteins had downregulated expression in the locoregional recurrence group compared to the good prognosis group. These 82 DEPs were associated with biological procession of cancer development including cellular movement, cellular assembly and organization, cellular function and maintenance, cellular growth and proliferation, cell death and survival, DNA replication recombination and repair, and so on. Of these DEPs, SPTAN1 and AGT proteins were identified to be associated with RFS in ESCC. SPTAN1 was positively associated with RFS and AGT was negatively associated with RFS. Expression of SPTAN1 tended to have favorable OS while expression of AGT tended to have poor OS.

Conclusions

Our results demonstrated that quantitative proteomics is an effective discovery tool to identify biomarkers for prognosis prediction in ESCC. However, it needs more studies with large populations of ESCC to validate these potential biomarkers.

miR-875-5p exerts tumor-promoting function via down-regulation of CAPZA1 in esophageal squamous cell carcinoma

Esophageal squamous cell carcinoma (ESCC) is one of the leading causes of cancer deaths worldwide. Currently, efficient genetic markers for diagnosis and treatment of ESCC are lacking. MicroRNAs (miRNAs) are global genetic regulators that control cancer gene expression by binding to the 3'untranslated regions (3'UTRs) of targeting mRNAs. In addition, miRNAs function as oncogenes or tumor suppressors in the progression of tumors. In the current study, we found that hsa-miR-875-5p (miR-875-5p) exhibited amplification in ESCC according to the TCGA database. Then, xCELLigence Real-Time Cell Analyzer (RTCA)-MP system and colony formation assays were employed to detect cell proliferationand colony formationability. The results showed that miR-875-5p promoted the proliferation ESCC cells. Subsequently, transwell results indicated that miR-875-5p promoted the invasion and migration of ESCC cells. Furthermore, we showed that miR-875-5p was able to bind to CAPZA13'UTR, which contains the single nucleotide polymorphism (SNP), rs373245753, as reported in our previous study involving WGS and WES on ESCC. Subsequently, mRNA affinity pull-down assays verifiedthat the SNP disrupts miR-875-5p binding to CAPZA1. The current study is the first demonstration that miR-875-5p may function as an oncogene via down-regulation of CAPZA1 expression in ESCC.

RYBP inhibits esophageal squamous cell carcinoma proliferation through downregulating CDC6 and CDC45 in G1-S phase transition process

AIMS

RING1 and YY1-binding protein (RYBP) is an epigenetic regulator and plays crucial roles in embryonic development. The anti-tumor effect of RYBP has been reported in several cancers recently, but the role of RYBP in esophageal squamous cell carcinoma (ESCC) has not been fully elucidated. The present study aimed to investigate the biological function and the underlying molecular mechanisms of RYBP in ESCC.

MATERIALS AND METHODS

We detected the expression of RYBP in ESCC tissue microarrays (TMA) by immunohistochemistry. Cell proliferation was assessed by CCK8 and colony formation assays. Cell cycle was analyzed by flow cytometry. Gene expression was determined by transcriptome arrays, quantitative real-time PCR (qRT-PCR) and Western blot. Four-week-old male nude mice were used to evaluate the effect of RYBP in ESCC growth.

KEY FINDINGS

We found that RYBP was downregulated in ESCC compared with adjacent normal tissues. A high level of RYBP expression predicted a better outcome of ESCC patients. Furthermore, overexpression of RYBP inhibited ESCC growth both in vitro and in vivo. Transcriptome arrays and functional studies showed that RYBP decreased the expression of genes related to cell cycles, especially CDC6 and CDC45, which were essential to initiate the DNA replication and G1-S transition.

SIGNIFICANCE

Taken together, our study suggests that RYBP suppresses ESCC proliferation by downregulating CDC6 and CDC45, thus inhibiting the G1-S transition.

Identification of key genes and pathways associated with esophageal squamous cell carcinoma development based on weighted gene correlation network analysis

Background: As one of the most aggressive malignancies, esophageal squamous cell carcinoma(ESCC) remains one of the leading causes of cancer related death worldwide. The majority of ESCCs are diagnosed at advanced stages with poor five-year survival rate, making it urgent to identify specific genes and pathways associated with its initiation and prognosis.

Materials and Methods: The differentially expressed genes in TCGA were analysed to construct a co-expression network by WGCNA. Gene ontology (GO) terms and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways analysis were performed for the selected genes. Module-clinical trait relationships were analyzed to explore the genes and pathways that associated with clinicopathological parameters of ESCC. Log-rank tests and COX regression were used to identify the prognosis-related genes.

Results: The brown module containing 716 genes which most significantly contributed to ESCC. GO analysis suggested enrichment of adaptive immune response, cyclin-dependent protein serine, regeneration and mRNA metabolic process. KEGG analysis indicated pathways including Cellular senescence, Ribosome biogenesis, Proteasome, Base excision repair and p53 signaling pathway. Clinical stage was associated with cyan module; clinical M was associated with grey60 module; clinical T was associated with darkturquoise module; while clinical N, histological type and cancer location were associated with turquoise module. Key genes of TCP1, COQ3, PTMA and MAPRE1 might be potential prognostic markers for ESCC.

Discussion: Differentially expressed genes and key modules contributing to initiation and progression in ESCC were identified by WGCNA. These findings provide novel insights into the mechanisms underlying the initiation, prognosis and treatment of ESCC.

Antiproliferative Effects of Free and Encapsulated Hypericum Perforatum L. Extract and Its Potential Interaction with Doxorubicin for Esophageal Squamous Cell Carcinoma

Objectives

Esophageal squamous cell carcinoma (ESCC) is considered as a deadly medical condition that affects a growing number of people worldwide. Targeted therapy of ESCC has been suggested recently and required extensive research. With cyclin D1 as a therapeutic target, the present study aimed at evaluating the anticancer effects of doxorubicin (Dox) or Hypericum perforatum L. (HP) extract encapsulated in poly(lactic-co-glycolic acid) (PLGA) nanoparticles on the ESCC cell line KYSE30.

Methods

Nanoparticles were prepared using double emulsion method. Cytotoxicity assay was carried out to measure the anti-proliferation activity of Dox-loaded (Dox NPs) and HP-loaded nanoparticles (HP NPs) against both cancer and normal cell lines. The mRNA gene expression of cyclin D1 was evaluated to validate the cytotoxicity studies at molecular level.

Results

Free drugs and nanoparticles significantly inhibited KYSE30 cells by 55–73% and slightly affected normal cells up to 29%. The IC₅₀ of Dox NPs and HP NPs was ~ 0.04–0.06 mg/mL and ~ 0.6–0.7 mg/mL, respectively. Significant decrease occurred in cyclin D1 expression by Dox NPs and HP NPs (P < 0.05). Exposure of KYSE-30 cells to combined treatments including both Dox and HP extract significantly increased the level of cyclin D1 expression as compared to those with individual treatments (P < 0.05).

Conclusion

Dox NPs and HP NPs can successfully and specifically target ESCC cells through downregulation of cyclin D1. The simultaneous use of Dox and HP extract should be avoided for the treatment of ESCC.

HCRP1 inhibits cell proliferation and invasion and promotes chemosensitivity in esophageal squamous cell carcinoma

Hepatocellular carcinoma related protein 1 (HCRP1), which is essential for internalization and degradation of ubiquitinated membrane receptors, was reported to play crucial roles in cancer pathogenesis and progression. However, the functional roles of HCRP1 in esophageal squamous cell carcinoma (ESCC) remain unknown. In this study, we investigated the effects of HCRP1 on ESCC cells and the underlying mechanism. Our results demonstrated that HCRP1 was lowly expressed in ESCC tissues and cell lines. Overexpression of HCRP1 significantly suppressed ESCC cell proliferation and invasion as well as the epithelial-mesenchymal transition (EMT) process. Furthermore, HCRP1 increased the sensitivity of ESCC cells towards cisplatin/fluorouracil. Mechanistically, HCRP1 inhibited the activity of Wnt/β-catenin signaling pathway in ESCC cells. In conclusion, these findings indicated that HCRP1 suppressed ESCC cell proliferation and invasion through regulation of the Wnt/β-catenin pathway. Therefore, HCRP1 may function as a tumor suppressor in ESCC progression.

Overexpression of PRR11 promotes tumorigenic capability and is associated with progression in esophageal squamous cell carcinoma

INTRODUCTION

Esophageal squamous cell carcinoma (ESCC) is one of the most common malignancies of gastrointestinal tract in the world, and the long-term prognosis for ESCC patients still remains dismal due to the lack of effective early diagnosis biomarkers.

MATERIALS AND METHODS

Western blot and immunochemistry were used to determine the expression of PRR11 in 201 clinicopathologically characterized ESCC specimens. The effects of PRR11 on stem cell-like traits and tumorigenicity were examined by tumor sphere formation assay and SP assays in vitro and by a tumorigenesis model in vivo. The mechanism by which PRR11 mediated Wnt/β-catenin signaling was explored using luciferase reporter, immuno-chemistry, and real time-PCR (RT-PCR) assays.

RESULTS

We found that PRR11 was markedly upregulated, at the level of both transcription and translation, in ESCC cell lines as compared with normal esophageal epithelial cells (NECCs). Immunohistochemical analysis showed that 69.2% paraffin-embedded archival ESCC specimens exhibited high levels of PRR11 expression, and multivariate analysis revealed that PRR11 upregulation might be an independent prognostic indicator for the survival of patients with ESCC. Furthermore, overexpression of PRR11 dramatically enhanced, whereas inhibition of PRR11 reduced the capability of cancer stem cell (CSC)-like phenotypes and tumorigenicity of ESCC cells both in vitro and in vivo. Mechanically, we demonstrated PRR11-enhanced tumorigenicity of ESCC cells via activating Wnt/β-catenin signaling, and PRR11 expression is found to be significantly correlated with β-catenin nuclear location in ESCC.

CONCLUSION

Our findings suggest that the PRR11 might represent a novel and valuable prognostic marker for ESCC progression and play a role during the development and progression of this malignancy.

MASAN: a novel staging system for prognosis of patients with oesophageal squamous cell carcinoma

BACKGROUND

Oesophageal squamous cell carcinoma (ESCC) is one of the most malignant cancers worldwide. Treatment of ESCC is in progress through accurate staging and risk assessment of patients. The emergence of potential molecular markers inspired us to construct novel staging systems with better accuracy by incorporating molecular markers.

METHODS

We measured H scores of 23 protein markers and analysed eight clinical factors of 77 ESCC patients in a training set, from which we identified an optimal MASAN (MYC, ANO1, SLC52A3, Age and N-stage) signature. We constructed MASAN models using Cox PH models, and created MASAN-staging systems based on k-means clustering and minimum-distance classifier. MASAN was validated in a test set (n = 77) and an independent validation set (n = 150).

RESULTS

MASAN possessed high predictive accuracies and stratified ESCC patients into three prognostic groups that were more accurate than the current pTNM-staging system for both overall survival and disease-free survival. To facilitate clinical utilisation, we also constructed MASAN-SI staging systems based on staining indices (SI) of protein markers, which possessed similar prognostic performance as MASAN.

CONCLUSION

MASAN provides a good alternative staging system for ESCC prognosis with a high precision using a simple model.

Are Serum Mac 2-Binding Protein Levels Elevated in Esophageal Cancer? A Control Study of Esophageal Squamous Cell Carcinoma Patients

Objective

Elevated serum Mac 2-binding protein (M2BP) levels have been observed in some cancers. As far as we know, its importance has not been investigated in esophageal squamous cell carcinoma (ESCC). The investigated problem of this study was to evaluate whether there was a difference between ESCC patients and the control group in terms of M2BP. Also, we evaluated the diagnostic performance of serum M2BP alone or in combination with the CEA for patients with ESCC.

Material and Methods

Blood serum samples were collected from 50 healthy donors and 150 patients with ESCC. M2BP levels of all 200 samples were quantified by ELISA (enzyme-linked immunosorbent assay). Patients who had been diagnosed with ESCC and did not have any other malignancies were enrolled to study.

Results

The two groups did not significantly differ in terms of age (p > 0.05). In the control group, the mean serum M2BP level was 14.97 ± 3.46 ng/mL. The mean serum M2BP level of the ESCC patients was 176.65 ± 22.14 ng/mL. The serum M2BP level was significantly higher in patients with ESCC than in the control group (p < 0.001). Gender was also comparable in both groups (p = 0.695).

Conclusions

Our analysis demonstrated that this marker may be associated with the mechanism of the disease. Despite that serum M2BP is not a specific marker for ESCC, it can be used as an adjuvant biomarker for the diagnosis of ESCC.

Construction of an oesophageal cancer-specific ceRNA network based on miRNA, lncRNA, and mRNA expression data

AIM

To explore the expression profiles of microRNAs (miRNAs), long non-coding RNAs (lncRNAs), and mRNAs in oesophageal squamous cell carcinoma (ESCC) in order to construct an oesophageal cancer-specific competing endogenous RNA (ceRNA) network.

METHODS

In this work, the expression data of miRNAs, lncRNAs, and mRNAs in ESCC were obtained. An oesophageal cancer-specific ceRNA network was then constructed and investigated.

RESULTS

CeRNAs have the ability to reduce the targeting activity of miRNAs, leading to the de-repression of specific mRNAs with common miRNA response elements. CeRNA interactions have a critical effect in gene regulation and cancer development.

CONCLUSION

This study suggests a novel perspective on potential oesophageal cancer mechanisms as well as novel pathways for modulating ceRNA networks for treating cancers.

A nomogram based on phosphorylated AKT1 for predicting locoregional recurrence in patients with oesophageal squamous cell carcinoma

Background: The AKT signalling pathway controls survival and growth in many malignant tumours. However, the prognostic value of phosphorylated AKT1 (p-AKT1) for locoregional-progression free survival (LPFS) in oesophageal squamous cell carcinoma (ESCC) has not been established. Our aim was to develop a nomogram to predict local recurrence using p-AKT1 and main clinical characteristics in patients with thoracic ESCC undergoing radical three-field lymph node dissection.

Methods: Immunohistochemistry was performed to examine p-AKT1 expression in 181 thoracic ESCC patients. The Kaplan-Meier method was used to calculate LPFS. Cox regression analysis was also performed to evaluate prognostic factors. A nomogram comprising biological and clinical factors was established to predict LPFS.

Results: The 5-year LPFS rate was 63.9%. Multivariate analysis revealed that expression of p-AKT1 (p<0.001), pathologic N category (p=0.004) and number of lymph nodes retrieved (p=0.001) were independent prognostic factors for LPFS. Increased expression of p-AKT1 was associated with decreased LPFS in patients with ESCC. In addition, a nomogram was established based on all significant independent factors for locoregional recurrence risk. Harrell's c-index for predicting LPFS was 0.78.

Conclusion: Activation of AKT1 was associated with poor locoregional control in ESCC patients. The nomogram, based on p-AKT1 expression and clinically significant parameters, could be used as an accurate stratification model for predicting locoregional recurrence in patients with ESCC after radical resection.

Overexpression of stathmin plays a pivotal role in the metastasis of esophageal squamous cell carcinoma

Purpose

Esophageal squamous cell carcinoma (ESCC) is a serious malignant tumor that affects human health. We analyzed the correlation between serum stathmin level and ESCC and elucidated the molecular mechanisms of stathmin's promotion of ESCC cell invasion and metastasis.

Methods

Stathmin level in ESCC and healthy control serum were detected by enzyme-linked immunosorbent assay (ELISA), and the clinical parameters were analyzed. We established ESCC cells with stathmin overexpression or knockdown and then evaluated the effects of stathmin on invasion and metastasis in ESCC. Differentially expressed genes were analyzed by Human Transcriptome Array and confirmed by RT-PCR. The expression levels of the integrin family, focal adhesion kinase (FAK) and extracellular signal-regulated kinase (ERK) were detected by immunoblotting.

Results

Serum levels of stathmin were significantly higher in ESCC than in control serum and associated with lymph node metastasis, tumor stage and size. Furthermore, we found that stathmin promoted migration and invasion of ESCC cells in vitro and in vivo. In addition, we confirmed that the activation of the integrinα5β1/FAK/ERK pathway is increased in stathmin-overexpression cells and accelerates cell motility by enhancing cell adhesion ability.

Conclusion

Stathmin may predict a potential metastasis biomarker for ESCC.

Comprehensive analysis of differential co-expression patterns reveal transcriptional dysregulation mechanism and identify novel prognostic lncRNAs in esophageal squamous cell carcinoma

Esophageal squamous cell carcinoma (ESCC) is one of the most common malignancies worldwide and occurs at a relatively high frequency in People's Republic of China. However, the molecular mechanism underlying ESCC is still unclear. In this study, the mRNA and long non-coding RNA (lncRNA) expression profiles of ESCC were downloaded from the Gene Expression Omnibus database, and then differential co-expression analysis was used to reveal the altered co-expression relationship of gene pairs in ESCC tumors. A total of 3,709 mRNAs and 923 lncRNAs were differentially co-expressed between normal and tumor tissues, and we found that most of the gene pairs lost associations in the tumor tissues. The differential regulatory networking approach deciphered that transcriptional dysregulation was ubiquitous in ESCC, and most of the differentially regulated links were modulated by 37 TFs. Our study also found that two novel lncRNAs (ADAMTS9-AS1 and AP000696.2) might be essential in the development of ectoderm and epithelial cells, which could significantly stratify ESCC patients into high-risk and low-risk groups, and were much better than traditional clinical tumor markers. Further inspection of two risk groups showed that the changes in TF-target regulation in the high-risk patients were significantly higher than those in the low-risk patients. In addition, four signal transduction-related DCmRNAs (ERBB3, ENSA, KCNK7, MFSD5), which were differentially co-expressed with the two lncRNAs, might also have the predictive capacity. Our findings will enhance the understanding of ESCC transcriptional dysregulation from a view of cross-link of lncRNA and mRNA, and the two-lncRNA combination may serve as a novel prognostic biomarker for clinical applications of ESCC.

Yield of p53 expression in esophageal squamous cell cancer and its relationship with survival

BACKGROUND/AIMS

Esophageal squamous cell carcinoma (ESCC) is the most aggressive type of cancer. Mutation of tumor suppressor gene p53 is observed in many gastrointestinal malignancies including ESCC. The immunohistochemical protein expression of mutant p53 has been proposed as a potential tool to evaluate the biological behavior of ESCC. Predictive value of p53 for survival is debatable, hence this study was formulated to know the survival of patients with p53 expression in ESCC.

PATIENTS AND METHODS

We prospectively included 91 consecutive patients of ESCC from August 2014 to August 2016. Biopsy specimens were treated immunohistochemically and expression of p53 gene was analyzed by Immunoreactive Score (IRS). These findings were then compared with clinicopathological parameters such as age, gender, histological grades, and TNM stages. All patients received treatment and were kept under regular follow-up.

RESULTS

M: F ratio was 2.03:1. p53 expression analyzed by IRS showed low expression (score ≤6) in 35 patients (38.46%) and high expression (>6) in 56 patients (61.54%). Level of p53 expression increased significantly with increasing histological grades of ESCC and TNM stage (P ≤ 0.001). Multivariate analysis shows p53 expression as independent predictor of survival. After 1 year of follow up, survival in the p53 high-expression group was 67.86% [standard error (SE) = 0.0473, confidence interval (CI) = 0.75-0.97) and in low p53 expression group was 91.43% (SE = 0.06, CI = 0.53-0.78) with statistically significant difference P = 0.0001 when analyzed with Kaplan-Meier method.

CONCLUSION

Expression of p53 correlates with the survival and is a simple, effective and reproducible modality to determine the prognosis and survival in ESCC.

Predicting malignant transformation of esophageal squamous cell lesions by combined biomarkers in an endoscopic screening program

AIM

To determine the association of p53, carcinoembryonic antigen (CEA) and CA19-9 protein expression with esophageal carcinogenesis.

METHODS

An iodine staining endoscopic screening program of esophageal lesions was carried out in the high-incidence area of Feicheng County, China. Seventy-seven patients with basal cell hyperplasia (BCH), 247 with low-grade dysplasia (LGD), 51 with high-grade dysplasia (HGD), 134 with invasive cancer, and 80 normal controls diagnosed by mucous membrane biopsy pathology were enrolled. Immunohistochemical detection of p53, CEA and CA19-9 proteins was performed. In the ROC curve analysis, the expression of a single biomarker and the expression of a combination of biomarkers were used to predict the risk of these four esophageal lesions.

RESULTS

The positive rates of p53 protein expression in invasive cancer, HGD, LGD, BCH and the normal control groups were 53.0%, 52.9%, 35.6%, 27.3% and 20.0%, respectively; the positive rates of CA19-9 protein expression were 44.0%, 33.3%, 16.5%, 9.2% and 6.2%, respectively; the positive rates of CEA protein expression were 74.6%, 60.8%, 23.3%, 23.7% and 16.2%, respectively. The positive rates of the combined expression of the three biomarkers were 84.3%, 76.5%, 47.6%, 42.9% and 27.5%, respectively. In the receiver operating characteristic curves of the combination of the three biomarkers, the specificity was 88.8% for the normal controls, and the sensitivity was 58.2% for invasive cancer, 25.5% for HGD, 11.2% for LGD, and 6.5% for BCH.

CONCLUSION

p53, CEA and CA19-9 protein expression was correlated with esophageal carcinogenesis, and testing for the combination of these biomarkers is useful for identifying high-risk patients with precancerous lesions.

PTK7 regulates radioresistance through nuclear factor-kappa B in esophageal squamous cell carcinoma

Tumor radioresistance is a major reason for decreased efficiency of cancer radiation therapy. Although a number of factors involved in radioresistance have been identified, the molecular mechanisms underlying radioresistance of esophageal squamous cell carcinoma (ESCC) have not been elucidated. In this study, we investigated the role of oncogenic protein tyrosine kinase 7 (PTK7) in the resistance of ESCC to radiation therapy. ESCC cell lines with high PTK7 expression were more refractive to radiation than those with low PTK7 levels. In radioresistant ESCC cells, PTK7 knockdown by specific siRNAs decreased the survival of irradiated cells and increased radiation-induced apoptosis, while in radiosensitive ESCC cells, PTK7 overexpression promoted cell survival and inhibited radiation-induced apoptosis. We hypothesized that PTK7 could regulate the activation of transcription factor NF-kB known for its role in cancer radioresistance. Our results indicated that the inhibition of PTK7 suppressed nuclear translocation of NF-kB subunit p65 induced by radiation, suggesting relevance of PTK7 expression with NF-kB activation in radioresistant ESCC. Furthermore, the levels of inhibitor of apoptosis proteins (IAPs), XIAP, and survivin, encoded by NF-kB-regulated genes, were induced in irradiated radioresistant cells but not in radiosensitive cells, while PTK7 knockdown downregulated IAP expression. Our findings revealed a novel mechanism underlying radioresistance in ESCC, which is associated with PTK7 and NF-kB-dependent apoptosis. These results suggest that the manipulation of PTK7 expression can be instrumental in enhancing ESCC response to radiotherapy. This study demonstrates that PTK7 plays a significant role in ESCC radioresistance via the NF-kB pathway.

KLF4 is downregulated but not mutated during human esophageal squamous cell carcinogenesis and has tumor stage-specific functions

The transcriptional regulator Krüppel-like factor 4 (KLF4) is decreased in human esophageal squamous cell cancer (ESCC), and Klf4 deletion in mice produces squamous cell dysplasia. Nonetheless the mechanisms of KLF4 downregulation in ESCC and the functions of KLF4 during ESCC development and progression are not well understood. Here, we sought to define the regulation of KLF4 and delineate the stage-specific effects of KLF4 in ESCC. We found that KLF4 expression was decreased in human ESCC and in 8 of 9 human ESCC cell lines. However, by genomic sequencing, we observed no KLF4 mutations or copy number changes in any of 52 human ESCC, suggesting other mechanisms for KLF4 silencing. In fact, KLF4 expression in human ESCC cell lines was increased by the DNA methylation inhibitor 5-azacytidine, suggesting an epigenetic mechanism for KLF4 silencing. Surprisingly, while KLF4 decreased in high-grade dysplasia and early stage tumors, KLF4 increased with advanced cancer stage, and KLF4 expression in ESCC was inversely correlated with survival. Interestingly, KLF4 promoted invasion of human ESCC cells, providing a functional link to the stage-specific expression of KLF4. Taken together, these findings suggest that KLF4 loss is necessary for esophageal tumorigenesis but that restored KLF4 expression in ESCC promotes tumor spread. Thus, the use of KLF4 as a diagnostic and therapeutic target in cancer requires careful consideration of context.

Initiation of esophageal squamous cell carcinoma (ESCC) in a murine 4-nitroquinoline-1-oxide and alcohol carcinogenesis model

Esophageal squamous cell carcinomas (ESCCs) are very common, aggressive tumors, and are often associated with alcohol and tobacco abuse. Because ESCCs exhibit high recurrence rates and are diagnosed at late stages, identification of prognostic and drug targets for prevention and treatment is critical. We used the 4-nitroquinoline-1-oxide (4-NQO) murine model of oral carcinogenesis and the Meadows-Cook model of alcohol abuse to assess changes in the expression of molecular markers during the initial stages of ESCC. Combining these two models, which mimic chronic alcohol and tobacco abuse in humans, we detected increased cellular proliferation (EGFR and Ki67 expression), increased canonical Wnt signaling and downstream elements (β-catenin, FoxM1, and S100a4 protein levels), changes in cellular adhesive properties (reduced E-cadherin in the basal layer of the esophageal epithelium), and increased levels of phosphorylated ERK1/2 and p38. Additionally, we found that treatment with ethanol alone increased the numbers of epithelial cells expressing solute carrier family 2 (facilitated glucose transporter, member 1) (SLC2A1) and carbonic anhydrase IX (CAIX), and increased the phosphorylation of p38. Thus, we identified both 4-NQO- and ethanol-specific targets in the initial stages of esophageal carcinogenesis, which should lead to the development of potential markers and therapeutic targets for human ESCC.

Expression of Cyclin D1 and P16 in Esophageal Squamous Cell Carcinoma

BACKGROUND Esophageal squamous cell carcinoma (ESCC) is one of the lethal cancers with a high incidence rate in Asia. Many genes including cyclin D1 and p16 play important role in its carcinogenesis. We aimed to analyze the expressions of cyclin D1 and p16 with the various clinicopathological characteristics of ESCC. METHODS We examined 30 biopsy samples of ESCC for cyclin D1 and p16 protein expressions using immunohistochemistry. Immunointensity was classified as no immunostaining (-), weakly immunostaining (+), weak immunostaining (++) and strongly positive immunostaining (+++). RESULTS Out of the 30 cases, positive expression of cyclin D1 was detected in 26 cases (86.7%). The percentage of tumors with invasion to the adventitia (88.2%), lymph node metastasis (87.5%), and tumors which were poorly differentiated (92.9%) were higher in cyclin D1 positive tumors than in the cyclin D1 negative tumors. However no significant association was found between cyclin D1 expression and the different clinicopathological parameters.There were 22 cases of ESCC (73.3 %) which showed negativity for p16. The percentage of tumors with invasion to the adventitia (82.4%) and poorly differentiated tumors (92.9%) were higher in the p16 negative tumors than in the p16 positive tumors. There was significant association between the histological grade and p16 expression (p=0.012). However, there were no significant association with regard to site, size and lymph node status of the tumors and p16 expression. CONCLUSION The study shows that alterations of cyclin D1 and p16 play an important role in ESCC. Loss of p16 expression was associated with poor differentiation.

Deregulation of SLIT2-mediated Cdc42 activity is associated with esophageal cancer metastasis and poor prognosis

INTRODUCTION

SLIT2, a secreted protein, has been found to inactivate Cdc42 GTPase to modulate neural cell migration. However, alteration of SLIT2-mediated Cdc42 in terms of migration regulation remains undefined in esophageal squamous cell carcinoma (ESCC).

METHODS

We report here in ESCC cell, animal, and clinical models that SLIT2 acts as a migration suppressor and serves as a prognostic biomarker.

RESULTS

The immunohistochemistry data indicated that 31.8% (49 of 154) of tumors from ESCC patients showed low expression of SLIT2 protein which correlated with poor overall survival and disease-free survival. DNA methylation analysis suggested that promoter hypermethylation is responsible for low expression of SLIT2 in ESCC. Knockdown of SLIT2 increased ESCC cell migration, while SLIT2 stable overexpression reduced cell migration. ESCC cells treated with conditioned media from cells overexpressing SLIT2 also suppressed cell migration. Importantly, silencing of SLIT2 decreased the complex formation, and thus induced Cdc42 activity and promoted membrane localization of focal adhesion kinase and Paxillin. Anti-metastatic effect of SLIT2 was confirmed in an experimental metastasis model of SLIT2 knockdown ESCC cells.

CONCLUSION

Our results provide novel evidence that low expression of SLIT2 correlates with poor prognosis and promotes metastasis in ESCC, which may be regulated by the Cdc42-mediated pathways.

ZNF282 (Zinc finger protein 282), a novel E2F1 co-activator, promotes esophageal squamous cell carcinoma

Zinc finger protein 282 (ZNF282) is a newly identified transcription factor and little is known about its expression and function. Originally, ZNF282 is known to bind U5RE (U5 repressive element) of HLTV-1 (human T cell leukemia virus type 1) with a repressive effect. Recently we reported that ZNF282 functions as an estrogen receptor co-activator and plays an essential role in breast tumorigenesis. Although these results suggest the possible role of ZNF282 in cancers, clinical significance and function of ZNF282 are completely unknown in most of cancers. Here we found that ZNF282 was frequently overexpressed in esophageal squamous cell carcinoma (ESCC) (n=165) compared with normal esophageal epithelium and its overexpression was correlated with adverse clinical outcome. Multivariate survival analysis indicated that ZNF282 expression was an independent prognostic predictor for poor survival in ESCC (HR: 2.56 (95% CI 1.54-4.26), p<0.001). In addition, depletion of ZNF282 inhibited the cell cycle progression, migration, and invasion of ESCC cells and reduced the tumorigenicity of ESCC xenograft in nude mouse. We further showed that ZNF282 is required for E2F1-mediated gene expression in ESCC cells. Thus, ZNF282 is E2F1 co-activator involved in ESCC and elevated expression of ZNF282 is an independent adverse prognostic factor in ESCC.

High Expression of GRP78 Promotes Invasion and Metastases in Patients with Esophageal Squamous Cell Carcinoma

BACKGROUND

Esophageal squamous cell carcinoma (ESCC) has a poor prognosis due to its high frequency of metastasis and invasion. Recent studies have suggested glucose-regulated protein 78KD (GRP78) may play important roles in progression and development of malignant tumors. However, the mechanisms of invasion and metastasis of ESCC in relation to GRP78 still remain obscure.

AIM

The aim of this study was to investigate the effect of GRP78 on invasion and metastasis of ESCC and to explore its potential mechanism.

METHODS

GRP78 expression levels in ESCC tissues were examined by immunohistochemistry. RT-PCR and western blot were used to test the relative expression of GRP78 in non-metastatic and high-metastatic ESCC cells. In vitro and in vivo studies were both performed to investigate the role of GRP78 in invasion and metastasis of ESCC cells. The expression of metastasis-related proteins was examined by western blot in GRP78-depleted cells.

RESULTS

The expression of GRP78 is correlated with invasion, metastasis and poor prognosis in ESCC patients. GRP78 expression was significantly higher in highly metastatic cells compared with ESCC non-metastatic cells. In addition, down-regulation of GRP78 significantly inhibited the metastatic potential of ESCC cells in both in vitro and in vivo studies. The expression of MMP-2 and MMP-9 were down-regulated in GRP78-depleted ESCC cells.

CONCLUSIONS

The present study demonstrated that GRP78 plays important roles in invasion and metastasis of ESCC, indicating that GRP78 might be used as a potential prognostic and therapeutic marker in patients with ESCC by modulating the expression of MMP-2 and MMP-9.

Decreased expression of ARID1A contributes to infiltrative growth of esophageal squamous cell carcinoma

The clinical outcome for esophageal squamous cell carcinoma (ESCC) patients is often poor because of the invasive nature of this tumor type. AT-rich interactive domain 1A (ARID1A) functions as a tumor suppressor, and its gene mutation has been reported in various human malignancies. ARID1A is a non-catalytic subunit of the SWItch/Sucrose Non Fermentable (SWI/SNF) chromatin-remodeling complex that regulates gene transcription. Decreased expression of ARID1A protein has been reported to decrease the expression of E-cadherin, an adhesion protein. However, the correlation between ARID1A and E-cadherin expression status in ESCC remains largely unknown. To address this issue, we examined the expression of ARID1A and E-cadherin in tumor specimens excised from 83 ESCC patients using immunohistochemical analysis. The intensity of the ARID1A immunoreactivity was significantly lower in tumors with a growth pattern characterized by ill-defined borders than that in tumors with an expansive growth pattern having a well-demarcated border or tumors with an intermediate growth pattern. Thus, decreased ARID1A immunoreactivity correlated with infiltrative growth of ESCC. In contrast, E-cadherin status did not correlate with the infiltrative growth pattern of ESCC. Moreover, ARID1A expression status did not significantly correlate with any of other clinicopathological factors, E-cadherin expression levels, or the clinical outcome of the patients. On the other hand, the patients with tumors expressing low levels of E-cadherin exhibited significantly lower survival rates than those with high expression. In conclusion, reduced ARID1A expression in tumor tissues contributes to infiltrative growth of ESCC, irrespective of E-cadherin expression levels.

c-Met in esophageal squamous cell carcinoma: an independent prognostic factor and potential therapeutic target

Background

c-Met is widely known as a poor prognostic factor in various human malignancies. Previous studies have suggested the involvement of c-Met and/or its ligand, hepatocyte growth factor (HGF), in esophageal squamous cell carcinoma (ESCC), but the correlation between c-Met status and clinical outcome remains unclear. Furthermore, the identification of a novel molecular therapeutic target might potentially help improve the clinical outcome of ESCC patients.

Methods

The expression of c-Met and HGF was immunohistochemically assessed in 104 surgically obtained tissue specimens. The correlation between c-Met/HGF expression and patients’ clinicopathological features, including survival, was evaluated. We also investigated changes in cell functions and protein expression of c-Met and its downstream signaling pathway components under treatments with HGF and/or c-Met inhibitor in ESCC cell lines.

Results

Elevated expression of c-Met was significantly correlated with tumor depth and pathological stage. Patients with high c-Met expression had significantly worse survival. In addition, multivariate analysis identified the high expression of c-Met as an independent prognostic factor. Treatment with c-Met inhibitor under HGF stimulation significantly inhibited the invasive capacity of an ESCC cell line with elevated c-Met mRNA expression. Moreover, c-Met and its downstream signaling inactivation was also detected after treatment with c-Met inhibitor.

Conclusions

The results of our study identified c-Met expression as an independent prognostic factor in ESCC patients and demonstrated that c-Met could be a potential molecular therapeutic target for the treatment of ESCC with elevated c-Met expression.

Electronic supplementary material

The online version of this article (doi:10.1186/s12885-015-1450-3) contains supplementary material, which is available to authorized users.

Surgical treatments for esophageal cancers

The following, from the 12th OESO World Conference: Cancers of the Esophagus, includes commentaries on the role of the nurse in preparation of esophageal resection (ER); the management of patients who develop high-grade dysplasia after having undergone Nissen fundoplication; the trajectory of care for the patient with esophageal cancer; the influence of the site of tumor in the choice of treatment; the best location for esophagogastrostomy; management of chylous leak after esophagectomy; the optimal approach to manage thoracic esophageal leak after esophagectomy; the choice for operational approach in surgery of cardioesophageal crossing; the advantages of robot esophagectomy; the place of open esophagectomy; the advantages of esophagectomy compared to definitive chemoradiotherapy; the pathologist report in the resected specimen; the best way to manage patients with unsuspected positive microscopic margin after ER; enhanced recovery after surgery for ER: expedited care protocols; and long-term quality of life in patients following esophagectomy.

A panel of overexpressed proteins for prognosis in esophageal squamous cell carcinoma

Esophageal squamous cell carcinoma (ESCC) is a common cancer with poor prognosis. In order to identify useful biomarkers for accurately classifying prognostic risks for ESCC patients, we examined the expression of six proteins by immunohistochemistry (IHC) in 590 paraffin-embedded ESCC samples. The candidate proteins include p53, EGFR, c-KIT, TIMP1 and PI3K-p110α reported to be altered in ESCC tissues as well as another important component of PI3K, PI3K-p85α. Of the six proteins tested, p53, EGFR, c-KIT, TIMP1 and PI3K-p85α were detected with high expression in 43.0%, 36.6%, 55.9%, 70.7% and 57.1% of tumors, respectively. Significant associations were found between high expression of PI3K-p85α, EGFR and p53 and poor prognosis (P = 0.00111; 0.00001; 0.00426). Applying these three proteins as an IHC panel could divide patients into different subgroups (P<0.000001). Multivariate cox regression analysis indicated that the three-protein panel was an independent prognostic factor with very high statistical significance (HR = 2.090, 95% CI: 1.621–2.696, P = 0.00000001). The data suggest that the three-protein panel of PI3K-p85α, EGFR and p53 is an important candidate biomarker for the prognosis of patients with ESCC.

Aurora-A enhances malignant development of esophageal squamous cell carcinoma (ESCC) by phosphorylating β-catenin

The Aurora-A gene encodes a serine/threonine protein kinase that is frequently overexpressed in several types of human tumors. The overexpression of Aurora-A has been observed to associate with the grades of differentiation, invasive capability and distant lymph node metastasis of esophageal squamous cell carcinoma (ESCC). However, the molecular mechanism by which Aurora-A promotes malignant development of ESCC is still largely unknown. In this study, we show that Aurora-A overexpression enhances tumor cell invasion and metastatic potential in vitro and in vivo. Furthermore, Aurora-A overexpression inhibits the degradation of β-catenin, promotes its dissociation from cell-cell contacts and increases its nuclear translocation. We also demonstrate for the first time that Aurora-A directly interacts with β-catenin and phosphorylates β-catenin at Ser552 and Ser675. Substitutions of serine residue with alanine at single or both positions substantially attenuate Aurora-A-mediated stabilization of β-catenin, abolish its cytosolic and nuclear localization as well as transcriptional activity. In addition, Aurora-A overexpression is significantly correlated with increased cytoplasmic β-catenin expression in ESCC tissues. In view of our results, we propose that Aurora-A-mediated phosphorylation of β-catenin is a novel mechanism of malignancy development of tumor.

TPX2 expression is associated with cell proliferation and patient outcome in esophageal squamous cell carcinoma

BACKGROUND

The molecular and genetic changes underlying esophageal squamous cell carcinoma (ESCC) tumor formation and rapid progression are poorly understood. Using high-throughput data analysis, we examined molecular changes involved in ESCC pathogenesis and investigated their clinical relevance.

METHODS

Five independent microarray datasets were examined for differentially expressed genes and pathways. For validation, mRNA expression in tumor and matched normal tissues from 16 ESCC cases was examined by cDNA microarray, and protein expression in 97 ESCC specimens was investigated using immunohistochemical stains. The association between clinicopathological parameters and the expression of Aurora kinase A (Aurora-A) and TPX2 was analyzed. The impact of TPX2 expression was also assessed in ESCC cancer cells.

RESULTS

AURKA and TPX2, members of the "Role of Ran in mitotic spindle regulation" pathway, were selected for further investigation. Verification by cDNA microarray showed that both genes were overexpressed in tumor tissues, and immunohistochemical staining showed Aurora-A and TPX2 expression in 88.4 and 90.6 % of ESCC specimens, respectively. High TPX2 expression was a significant prognosticator for overall and disease-free survival in univariate analysis and remained an independent prognostic factor in multivariate analysis (HR 1.802, p = 0.037). TPX2 knockdown clones showed inhibited cellular proliferation in growth curve studies and formed fewer colonies in the clonogenic assay.

CONCLUSIONS

Using bioinformatics resources, which were validated by microarray analysis and immunohistochemistry stains, and manipulation of TPX2 expression in ESCC cell lines, we demonstrated that TPX2 expression is associated with cell proliferation and poor prognosis among patients with resected ESCC.

Cytokines association with clinical and pathological changes in esophageal squamous cell carcinoma

Carcinogenic transformation of cells in esophageal squamous cell carcinoma (ESCC) is characterized on molecular level by, among other things, changes in protein expression. Among all proteins related to inflammation, cytokines may be implicated as possible biological markers of esophageal cancer. These biomarkers, near imaging techniques, may be helpful in diagnosis and monitoring therapy in ESCC patients. This review demonstrates findings of researches on dysregulation of cytokines in ESCC and their clinical and pathological implications. Articles on cytokines were selected according to the following criteria: (i) the study was performed at protein level, (ii) the differences in cytokines expression or concentration were detected in tissues or serum from ESCC patients, (iii) the alterations of cytokines levels were detected by: immunohistochemistry (IHC), western blot (WB) and enzyme-linked immunosorbent assay (ELISA). Members of VEGF family seem to play an essential role as potential markers in ESCC. The results of all cytokines researches are promising but further studies are necessary to establish the biological significance of these peptydes in ESCC, their potential usefulness for early diagnosis, pre- and postoperative prognosis and monitoring of the respond to chemo- and radiotherapy of cancer patients.

Clinical significance of serum Stathmin in esophageal squamous cell carcinoma

AIM: To detect serum Stathmin in patients with esophageal squamous cell carcinoma (ESCC) and evaluate its correlation with clinicopathological parameters in ESCC.

METHODS: Serum levels of Stathmin were measured by enzyme-linked immunosorbent assay (ELISA) in 74 patients with ESCC and 81 healthy individuals. Serum levels of Cyfra21-1 were measured by ELISA, and those of CEA, CA19-9 and CA72-4 were measured by chemiluminescence.

RESULTS: Serum levels of Stathmin in ESCC patients were significantly higher than those in healthy controls (P < 0.001). Serum levels of Stathmin were correlated with lymph node metastasis (P = 0.036), but not with age, gender, tumor differentiation, TNM stage or tumor size. According to the ROC curve, the sensitivity and specificity of serum Stathmin were significantly higher than those of Cyfra21-1 for diagnosis of esophageal squamous cell carcinoma. The sensitivity of serum Stathmin for diagnosis of ESCC was 94.6%.

CONCLUSION: Serum Stathmin levels increase in ESCC patients. Detection of serum Stathmin is helpful for diagnosis and prognostic evaluation of esophageal cancer. Stathmin may serve as a new potential serum tumor marker for clinical detection, therapy and prognostic evaluation of ESCC.

Immunohistochemical Analysis of P53 and PRB in Esophageal Squamous Cell Carcinoma

BACKGROUND

Esophageal squamous cell carcinoma (ESCC) is one of the fatal cancers with a high incidence rate in Asia. Many genes including p53 and pRb play an important role in its carcinogenesis. Expressions of p53 and pRb proteins have been associated with prognosis of ESCC.

OBJECTIVE

The study was undertaken to analyze the expressions of p53 and pRb with the various clinicopathological characteristics including stage and grade of ESCC.

MATERIALS AND METHODS

We examined 30 biopsy samples of ESCC for p53 and pRb protein expressions using immunohistochemistry. Immunointensity was classified as no immunostaining (-), weakly immunostaining (+), weak immunostaining (++) and strongly positive immunostaining (+++).

RESULTS

Significant association was seen between positive p53 expression and tumor size (p=0.042), invasion to adventitia (p=0.009) and lymph node metastasis (p=0.014), and negative pRb expression was associated with invasion to the adventitia (p=0.015) and lymph node metastasis (p=0.003) There was significant association of p53+/ pRb- (n=11) with tumor invasion to adventitia (p=0.001), lymph node metastasis (p=0.0007) and TNM staging (p=0.042).

CONCLUSION

The study shows that p53 and pRb proteins, individually as well as synergistically, may serve as putative prognostic markers in ESCC.

Targeted knockdown of IQGAP1 inhibits the progression of esophageal squamous cell carcinoma in vitro and in vivo

IQGAP1 is a scaffolding protein that can regulate several distinct signaling pathways. The accumulating evidence has demonstrated that IQGAP1 plays an important role in tumorigenesis and tumor progression. However, the function of IQGAP1 in esophageal squamous cell carcinoma (ESCC) has not been thoroughly investigated. In the present study, we showed that IQGAP1 was overexpressed in ESCC tumor tissues, and its overexpression was correlated with the invasion depth of ESCC. Importantly, by using RNA interference (RNAi) technology we successfully silenced IQGAP1 gene in two ESCC cell lines, EC9706 and KYSE150, and for the first time found that suppressing IQGAP1 expression not only obviously reduced the tumor cell growth, migration and invasion in vitro but also markedly inhibited the tumor growth, invasion, lymph node and lung metastasis in xenograft mice. Furthermore, Knockdown of IQGAP1 expression in ESCC cell lines led to a reversion of epithelial to mesenchymal transition (EMT) progress. These results suggest that IQGAP1 plays crucial roles in regulating ESCC occurrence and progression. IQGAP1 silencing may therefore develop into a promising novel anticancer therapy.

Genomic and molecular characterization of esophageal squamous cell carcinoma

Esophageal squamous cell carcinoma (ESCC) is prevalent worldwide and particularly common in certain regions of Asia. Here we report the whole-exome or targeted deep sequencing of 139 paired ESCC cases, and analysis of somatic copy number variations (SCNV) of over 180 ESCCs. We identified previously uncharacterized mutated genes such as FAT1, FAT2, ZNF750 and KMT2D, in addition to those already known (TP53, PIK3CA and NOTCH1). Further SCNV evaluation, immunohistochemistry and biological analysis suggested their functional relevance in ESCC. Notably, RTK-MAPK-PI3K pathways, cell cycle and epigenetic regulation are frequently dysregulated by multiple molecular mechanisms in this cancer. Our approaches also uncovered many druggable candidates, and XPO1 was further explored as a therapeutic target because it showed both gene mutation and protein overexpression. Our integrated study unmasks a number of novel genetic lesions in ESCC and provides an important molecular foundation for understanding esophageal tumors and developing therapeutic targets.

Overexpression of OLC1 promotes tumorigenesis of human esophageal squamous cell carcinoma

PURPOSE

OLC1 was recently identified to be a potential oncogene. However, the role of OLC1 in human esophageal cell carcinoma (ESCC) is unknown. The aim of this study was therefore to evaluate the expression of OLC1 in human ESCC from normal, premalignant, and malignant lesions, and to clarify the mechanisms by which OLC1 contributes to the progression of ESCC.

EXPERIMENTAL DESIGN

Two hundred and fourteen paired ESCC specimens, and an independent set from 28 ESCC patients, were used to analyze the correlation between OLC1 expression and the pathological characteristics of tumors using immunohistochemistry. Stable OLC1-overexpressing and OLC1-interfering esophageal cancer cells were established and a series of experimental methods were used to investigate the biological functions and mechanisms of action of OLC1.

RESULTS

We showed that OLC1 was overexpressed in 145 of 214 (67.8%) of human ESCC specimens, compared with in only 59 of 214 (27.57%) paired adjacent normal tissues (P<0.001). OLC1 overexpression occurred at a rate of 35% (10/28) at the stage of mild/moderate dysplasia, but was significantly upregulated to 66% (22/33) at the stages of severe dysplasia and in situ carcinoma, while 71% positive staining (22/28) was observed in invasive carcinoma tissues compared with normal tissues (P<0.05). We also provided evidence that OLC1 abnormalities significantly altered the cell proliferation and apoptosis induced by cytotoxic agents. OLC1 overexpression suppressed apoptosis, and was associated with attenuated caspase-3 activation and increased Bcl-2 stability.

CONCLUSION

Our study provides strong evidence suggesting OLC1 abnormalities may contribute to the development of human ESCC and have some important clinical significance.

EMP1, a member of a new family of antiproliferative genes in breast carcinoma

This study aimed to analyze the expression, clinical significance of epithelial membrane protein 1 (EMP1) in breast carcinoma and the biological effect in its cell line by EMP1 overexpression. Immunohistochemistry and western blot were used to analyze EMP1 protein expression in 67 cases of breast cancer and 35 cases of normal tissues to study the relationship between EMP1 expression and clinical factors. Quantitative real-time RT-PCR and western blot were used to detect the mRNA level and protein of EMP1. MTT assay, migration and invasion assays were also conducted as to the influence of the upregulated expression of EMP1 that might be found on MCF-7 cell biological effect. The relative amount of EMP1 protein in breast cancer tissue was found to be significantly lower than in normal tissues (P < 0.05). The level of EMP1 protein expression was correlated with T stages, lymph node metastasis, clinic stage, and histological grade (P < 0.05). Meanwhile, loss of EMP1 expression correlated significantly with poor overall survival time by Kaplan-Meier analysis (P < 0.05). The result shown that MCF-7 cell transfected EMP1 had a lower survival fraction, higher cell apoptosis, significant decrease in migration and invasion, higher caspase-9, and lower VEGFC protein expression compared with MCF-7 cell untransfected EMP1 (P < 0.05). EMP1 expression decreased in breast cancer and correlated significantly with lymph node metastasis, clinic stage, histological grade, and poor overall survival, T stages, suggesting that EMP1 may play important roles as a negative regulator to breast cancer MCF-7 cell by regulating the expression of caspase 9 and VEGFC protein.

Overexpression of WRAP53 is associated with development and progression of esophageal squamous cell carcinoma

BACKGROUND

Esophageal squamous cell carcinoma (ESCC) is a highly aggressive cancer whose underlying molecular mechanisms are poorly understood. The natural antisense transcript (NAT) WRAP53 regulates p53 expression and WRAP53 protein is a component of telomerase. NATs play key roles in carcinogenesis, and although WRAP53 is known to increase cancer cell survival, its role in ESCC clinicopathology is unknown. The aim of this study was to investigate WRAP53 expression in ESCC and to correlate it with clinicopathological characteristics.

METHODS

WRAP53 mRNA and protein expression was measured by quantitative PCR (qRT-PCR) and western blotting, respectively, in 4 ESSC cells lines and in 45 paired ESCC and non-neoplastic esophageal mucosa tissues. To correlate WRAP53 protein expression with clinicopathological characteristics, immunohistochemistry (IHC) was performed on 134 ESCC and 85 non-neoplastic esophageal mucosa tissues.

RESULTS

Expression of WRAP53 was detected in all ESCC cell lines and was upregulated in the ESCC tissues compared with the corresponding non-neoplastic tissues (P<0.01). More cells expressed WRAP53 protein in the ESCC tissues than in the non-neoplastic tissues (P<0.01). Overexpression of WRAP53 was significantly correlated with tumor infiltration depth (P = 0.000), clinical stage (P = 0.001), and lymph node metastasis (P = 0.025). Wrap53 expression was not correlated with age, gender, or tumor differentiation.

CONCLUSION

This report indicates increased expression of WRAP53 in ESCC and that WRAP53 overexpression is correlated with tumor progression. WRAP53 may play a significant role in ESCC; accordingly, WRAP53 could be a useful biomarker for ESCC.

Long non-coding RNA HOTAIR, a driver of malignancy, predicts negative prognosis and exhibits oncogenic activity in oesophageal squamous cell carcinoma

Background:

HOX transcript antisense RNA (HOTAIR), which is expressed from the homebox C gene (HOXC) locus, is capable of reprogramming chromatin organisation and promoting cancer cell metastasis and can simultaneously bind the polycomb repressive complex 2, which enhances H3K27 trimethylation, and the LSD1-CoREST-REST complex, which is critical for H3K4 demethylation. Clinically, the overexpression of HOTAIR is a powerful predictor of the tumour progression and overall survival in patients with diverse cancers. The relationship between HOTAIR and oesophageal squamous cell carcinoma (ESCC), however, remains unclear. We investigated the role of HOTAIR in the pathogenesis of ESCC.

Methods:

We used quantitative real-time PCR to determine the level of HOTAIR in ESCC cell lines and 100 ESCC samples from patients; 56 adjacent non-neoplastic tissues were used as controls. We measured the effect of HOTAIR knockdown and overexpression in ESCC cell lines using colony formation assays, anchorage-independent growth assays, the CCK-8 assay, transwell migration and invasion assays, and Annexin V-binding assays. We analysed the growth of ESCC xenograft tumours in nude mice. Changes in the gene expression and methylation levels in ESCC cell lines were analysed using gene expression microarrays and the Infinium HumanMethylation450K BeadChip assay, respectively.

Results:

The levels of HOTAIR were increased in ESCC cell lines and patient samples compared with the controls; the expression levels correlated with the disease stage and survival time. The knockdown of HOTAIR in the KYSE510 and KYSE180 ESCC cell lines using small hairpin RNAs (shRNAs) reduced the ability of the cells to form foci, migrate, and invade the extracellular matrix in culture, altered cell cycle progression, and increased the sensitivity of the cells to apoptosis. The HOTAIR knockdown reduced cancer cell metastasis in vivo, and the tumours formed by HOTAIR-silenced ESCC cells were smaller, both in size and weight, than the tumours and metastases formed by the shRNA vector control cells in a mouse xenograft model. The results of the gene microarray study showed that HOTAIR reprogrammed the gene expression profile of ESCC cells, and the gene ontology analysis revealed an enrichment in genes that are important for tumorigenesis, such as genes involved in cell migration and the regulation of the cell cycle. Comparing the gene expression profiles and DNA methylation analysis between the KYSE180 and KYSE180_HOTAIR cells revealed that only a small proportion of the methylation changes were correlated with gene expression changes.

Conclusion:

HOX transcript antisense RNA is upregulated in ESCC cell lines and patient samples, and promotes ESCC cell proliferation and tumour metastasis in mice. The knockdown of HOTAIR resulted in significant changes in gene expression, and data analysis suggested that HOTAIR-mediated gene regulation has a critical role in ESCC progression and is a novel epigenetic molecular target for treating ESCC patients.

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.

Expression of breast cancer anti-estrogen resistance 1 in relation to vascular endothelial growth factor, p53, and prognosis in esophageal squamous cell cancer

The purpose of this study was to clarify the role of breast cancer anti-estrogen resistance 1 (BCAR1) expression in relation to vascular endothelial growth factor (VEGF), p53, and proliferation in esophageal squamous cell cancer (ESCC). Expression of BCAR1, VEGF, p53, and the ki-67 proliferative index were examined by tissue microarray and immunohistochemistry in 106 specimens with ESCC and matched adjacent normal tissues. Among them, 40 cases were simultaneously examined by Western blot. Both Western blot and immunohistochemistry showed that BCAR1 expression was substantially higher in ESCC than in adjacent normal tissues (P < 0.001). BCAR1 expression was significantly connected with degree of tumor differentiation, with poorly differentiated tumors showing higher BCAR1 expression (P < 0.001). BCAR1 expression was significantly and positively correlated with VEGF and p53 expression levels (r= 0.541, P < 0.001; r= 0.374; P < 0.001) but not proliferative index (r= 0.44; P= 0.066). Additionally, a significant relationship was also observed between VEGF and p53 (r= 0.321; P= 0.001). Kaplan-Meier survival analysis revealed that patients with high BCAR1 expression had significantly shorter survival times than those with low BCAR1 expression levels (median survival 40 months vs. 27 months, P= 0.09). Multivariate analysis also revealed that levels of BCAR1 expression (hazard ratio 2.250, P= 0.015) was a significant and independent prognostic indicator. High expression of BCAR1 is associated with elevated VEGF and p53 expression levels, as well as poor prognosis in ESCC. Therefore, BCAR1 may be a potential candidate for predicting prognosis and a new therapy target for ESCC.

Elevated maspin expression is associated with better overall survival in esophageal squamous cell carcinoma (ESCC)

Tumor suppressor maspin is a differentially regulated gene in the progression of many types of cancer. While the biological function of maspin in blocking tumor invasion and metastasis is consistent with the loss of maspin expression at the late stage of tumor progression, the differential expression and the biological significance of maspin in early stage of tumor progression appear to be complex and remain to be elucidated. In the current study, we examined the expression of maspin in 84 esophageal squamous cell carcinoma (ESCC) cases (stages I–III) and 55 non-tumor adjacent esophageal tissue specimens by immunohistochemical (IHC) staining. The correlation of maspin with clinicopathological parameters was analyzed. Compared to normal esophageal squamous tissue where 80% (47/55) of the cases expressed maspin at a low to moderate level, all ESCC specimens (100% (84/84)) were positive for maspin expression at a moderate to high level. ESCC with low or moderate maspin expression had significantly shorter postoperative survival rates compared to those that had high maspin expression (p<0.001). Since the correlation of maspin with ESCC histology and the correlation of maspin with ESCC prognosis seem to be at odds, we further investigated the biological function of maspin in ESCC using the established ESCC cell lines. The expression of maspin in five human esophageal squamous cancer cell lines (T12, E450, KYSE150, EC109, and KYSE510) was examined by the Western blot. ESCC cell line KYSE510 that did not express maspin and was stably transfected by maspin cDNA or an empty vector. The resulting transfected cells were characterized in vitro. Maspin expression significantly inhibited cell proliferation, motility and matrigel invasion. Taken together, our data suggest that the transient up-regulation of maspin in the early development of ESCC may be a defense mechanism against further transition towards more malignant phenotypes, ultimately slowing down ESCC tumor progression.

Invasive and prognostic significance of pRB in esophageal squamous cell carcinoma: a meta-analysis

This paper investigates the association between protein retinoblastoma (pRB) loss and the T,N stage and prognosis in esophageal squamous cell carcinomas (ESCCs) using meta-analysis. We conducted a meta-analysis of 16 studies, comprising 1,117 patients to clarify this issue. All the studies searched by the electronic literature PubMed and http://www.KJEBM.com, which had been published during the period from January 1996 to January 2012 according to the inclusion criteria. Summary odds ratios (OR) were calculated using fixed or random-effects models. The summary odds ratios (ORs) for pRB inactive were 0.64 (95% confidence interval [CI]:0.45-0.91, P = 0.01) for T1/T2 versus T3/T4 tumors; summary OR = 0.69 (95% CI:0.51-0.94, P = 0.02) for N0 versus N1 tumors. The association between pRB loss and prognosis was examined in nine studies, and the summary hazard ratio was 1.39 (95% CI:1.11-1.74, P = 0.004). pRB inactive was significant associated with T3/T4 tumors and N1 stage as well as adverse prognosis for ESCCs. It appears warranted to prospectively validate that pRB loss may be used for subdividing the T,N stage evaluation of patients with ESCCs, and these patients may be the preponderant people for individualized treatment or target therapy.

Expression and phosphorylation of stathmin correlate with cell migration in esophageal squamous cell carcinoma

Microtubules play extensive roles in cellular processes, including cell motility. Stathmin is an important protein which destabilizes microtubules. The essential function of stathmin is closely associated with its phosphorylation status. Stathmin is overexpressed in many human cancers and has a significant relationship with clinical characteristics such as grade, tumor size and prognosis. We demonstrated that stathmin was overexpressed in ESCC tissues using both 2-DE and immunohistochemistry analysis. In addition, overexpression of stathmin was significantly correlated with histological grade in ESCC. However, no correlation was found with age, gender and lymph node metastasis. Knockdown of stathmin with siRNA impaired cell migration in KYSE30 and KYSE410 cells. When EC0156 cells were treated with paclitaxel, stathmin was stably phosphorylated and migration was impaired. These observations suggest that stathmin may have a more important function in ESCC development and migration. The present study provides further understanding of the importance of stathmin in ESCC therapy or diagnosis.

p14ARF repression induced by promoter methylation associated with metastasis in esophageal squamous cell carcinoma

The objective of this study is to evaluate the promoter methylation status of the p14ARF in esophageal squamous cell carcinoma (ESCC). Cell lines were treated with the demethylation agent 5-aza-2'-deoxycytidine, and p14ARF messenger RNA (mRNA) expression was detected by reverse transcription-polymerase chain reaction. We analyzed the methylation status of p14ARF promoter by methylation-specific polymerase chain reaction in 50 ESCC and their noncarcinoma tissues. Then demethylation caused by 5-aza-2'-deoxycytidine increased the p14ARF mRNA expression level in esophagus cancer cell lines. p14ARF methylation was found in 48% (24 of 50) of ESCC patients but only in 18% (9 of 50) corresponding noncarcinoma tissues (P = 0.001). There was a statistically significant correlation between the presence of methylation and tumor metastasis (P < 0.001). The p14ARF mRNA was lower in ESCC tissues than nontumor tissues (mean ± standard deviation, 0.47 ± 0.32 vs. 1.40 ± 0.58; P = 0.002). Meanwhile, a signification association was found between the methylation status of p14ARF promoter and p14ARF mRNA expression in tissues (P < 0.05). The aberrant promoter methylation of p14ARF is a common phenomenon in ESCC, which may be an important mechanism of downregulating p14ARF mRNA expression.