Molecular biology of esophageal squamous cell carcinoma

Cohort size required for prognostic genes analysis of stage II/III esophageal squamous cell carcinoma

Background: Few overlaps between prognostic biomarkers are observed among different independently performed genomic studies of esophageal squamous cell carcinoma (ESCC). One of the reasons for this is the insufficient cohort size. How many cases are needed to prognostic genes analysis in ESCC? Methods: Here, based on 387 stage II/III ESCC cases analyzed by whole-genome sequencing from one single center, effects of cohort size on prognostic genes analysis were investigated. Prognostic genes analysis was performed in 100 replicates at each cohort size level using a random resampling method. Results: The number of prognostic genes followed a power-law increase with cohort size in ESCC patients with stage II and stage III, with exponents of 2.27 and 2.25, respectively. Power-law curves with increasing events number were also observed in stage II and III ESCC, respectively, and they almost overlapped. The probability of obtaining statistically significant prognostic genes shows a logistic cumulative distribution function with respect to cohort size. To achieve a 100% probability of obtaining statistically significant prognostic genes, the minimum cohort sizes required in stage II and III ESCC were approximately 95 and 60, respectively, corresponding to a number of outcome events of 33 and 36, respectively. Conclusion: In summary, the number of prognostic genes follows a power-law growth with the cohort size or events number in ESCC. The minimum events number required to achieve a 100% probability of obtaining a statistically significant prognostic gene is approximately 35.

Comparative genomic analysis of esophageal squamous cell carcinoma among different geographic regions

Introduction

Esophageal squamous cell carcinoma (ESCC) shows remarkable variation in incidence, survival, and risk factors. Although the genomic characteristics of ESCC have been extensively characterized, the genomic differences between different geographic regions remain unclear.

Methods

In this study, we sequenced 111 patients with ESCC from northern (NC) and southern (SC) China, combined their data with those of 1081 cases from previous reports, and performed a comparative analysis among different regions. In total, 644 ESCC cases were collected from six geographic regions (NC, SC, Xinjiang, China [XJC], Japan [JP], Vietnam [VN], and Europe & America [EA]) as the discovery cohort. Validation cohort 1 included 437 patients with ESCC from the NC region. Validation cohort 2 included 54 and 57 patients from the NC and SC regions, respectively.

Results

Patients with ESCC in different regions had different genomic characteristics, including DNA signatures, tumor mutation burdens, significantly mutated genes (SMGs), altered signaling pathways, and genes associated with clinical features. Based on both the DNA mutation signature and the mutation profile of the most common genes, the NC and SC groups were clustered close together, followed by the JP, XJC, EA, and VN groups. Compared to patients with ESCC from SC, SMGs, including KMT2D, FAT1, and NOTCH1 were more frequently identified in patients with ESCC from NC. Furthermore, some genes (TDG and DNAH8) correlated with overall survival in completely opposite ways in patients with ESCC from different geographical regions.

Conclusions

Our study provides insights into genomic differences in ESCC among different regions. These differences may be related to differences in environmental carcinogens, incidence, and survival.

FANCD2 limits acetaldehyde-induced genomic instability during DNA replication in esophageal keratinocytes

Individuals with Fanconi anemia (FA), a rare genetic bone marrow failure syndrome, have an increased risk of young-onset head and neck squamous cell carcinomas (SCCs) and esophageal SCC. The FA DNA repair pathway is activated upon DNA damage induced by acetaldehyde, a chief alcohol metabolite and one of the major carcinogens in humans. However, the molecular basis of acetaldehyde-induced genomic instability in SCCs of the head and neck and of the esophagus in FA remains elusive. Here, we report the effects of acetaldehyde on replication stress response in esophageal epithelial cells (keratinocytes). Acetaldehyde-exposed esophageal keratinocytes displayed accumulation of DNA damage foci consisting of 53BP1 and BRCA1. At physiologically relevant concentrations, acetaldehyde activated the ATR-Chk1 pathway, leading to S- and G2/M-phase delay with accumulation of the FA complementation group D2 protein (FANCD2) at the sites of DNA synthesis, suggesting that acetaldehyde impedes replication fork progression. Consistently, depletion of the replication fork protection protein Timeless led to elevated DNA damage upon acetaldehyde exposure. Furthermore, FANCD2 depletion exacerbated replication abnormalities, elevated DNA damage, and led to apoptotic cell death, indicating that FANCD2 prevents acetaldehyde-induced genomic instability in esophageal keratinocytes. These observations contribute to our understanding of the mechanisms that drive genomic instability in FA patients and alcohol-related carcinogenesis, thereby providing a translational implication in the development of more effective therapies for SCCs.

Systematic Review and Meta-analysis of the Most Common Genetic Mutations in Esophageal Squamous Cell Carcinoma

PURPOSE

Esophageal cancer is the second most common cancer among men and women. There is a need to systematically assess the current evidence to map out the contribution of genetic factors in the development of esophageal squamous cell carcinoma (ESCC).

METHODS

A literature search was carried out on published and unpublished studies up to August 2021 in Medline (PubMed), Embase (Ovid), Scopus, Proquest, Web of Science, and Google scholar. Studies that have reported the frequency of genetic mutations in ESCC were included in this study.

RESULTS

A total of 1238 titles were retrieved through searches, and finally, 56 articles, including 8114 samples, met our predefined inclusion criteria. Of the included studies, 31 were conducted in China, 12 in Japan, and the remaining were conducted in various nations, including Brazil, Korea, and Iran. Most of our included studies evaluated the TP53 (n = 37 studies) and PIK3CA (n = 30 studies) gene mutations. TP53 (68.6%; 95% CI: 61.6-74.9), CCND1 (39.3%; 95% CI: 26.2-54.1), MDM2 (24.9%; 95% CI: 9.5-51.0), NOTCH1/2/3 (17.9%; 95% CI: 15.0-21.2), KMT2D (17.4%; 95% CI: 12.4-23.8), CDKN2A (15.0%; 95% CI: 8.1-26.1), PIK3CA (13.8%; 95% CI: 10.3-18.1), FAT1 (13.3%; 95% CI: 11.7-15.0), and EGFR (9.9%; 95% CI: 5.6-17.0) were the most common involved genetic factors in developing ESCC.

CONCLUSION

This systematic review and meta-analysis revealed that more than 10% of ESCC patients had changes in TP53, CCND1, MDM2, NOTCH1/2/3, KMT2D, CDKN2A, PIK3CA, and FAT1 genes, which can highlight their role in developing ESCC. TP53, CCND1, and MDM2 are the most prevalent, demonstrating 68.6%, 39.3%, and 24.9% of the mutations in ESCC patients.

A multi-omics study delineates new molecular features and therapeutic targets for esophageal squamous cell carcinoma

Esophageal squamous cell carcinoma (ESCC) is a major histological subtype of esophageal cancer with inferior prognosis. Here, we conducted comprehensive transcriptomic, proteomic, phosphoproteomic, and metabolomic characterization of human, treatment-naive ESCC and paired normal adjacent tissues (cohort 1, n = 24) in an effort to identify new molecular vulnerabilities for ESCC and potential therapeutic targets. Integrative analysis revealed a small group of genes that were related to the active posttranscriptional and posttranslational regulation of ESCC. By using proteomic, phosphoproteomic, and metabolomic data, networks of ESCC-related signaling and metabolic pathways that were closely linked to cancer etiology were unraveled. Notably, integrative analysis of proteomic and phosphoproteomic data pinpointed that certain pathways involved in RNA transcription, processing, and metabolism were stimulated in ESCC. Importantly, proteins with close linkage to ESCC prognosis were identified. By enrolling an ESCC patient cohort 2 (n = 41), three top-ranked prognostic proteins X-prolyl aminopeptidase 3 (XPNPEP3), bromodomain PHD finger transcription factor (BPTF), and fibrillarin (FBL) were verified to have increased expression in ESCC. Among these prognostic proteins, only FBL, a well-known nucleolar methyltransferase, was essential for ESCC cell growth in vitro and in vivo. Furthermore, a validation study using an ESCC patient cohort 3 (n = 100) demonstrated that high FBL expression predicted unfavorable patient survival. Finally, common cancer/testis antigens and established cancer drivers and kinases, all of which could direct therapeutic decisions, were characterized. Collectively, our multi-omics analyses delineated new molecular features associated with ESCC pathobiology involving epigenetic, posttranscriptional, posttranslational, and metabolic characteristics, and unveiled new molecular vulnerabilities with therapeutic potential for ESCC.

In Vitro Assays of Biological Aggressiveness of Esophageal Squamous Cell Carcinoma

Researchers are developing new techniques and technologies to determine the characteristic features for cancer progression, thereby identifying potential targets and therapeutics to interfere these hallmark processes of cancer pathogenesis. The transformative researches using these in vitro methods have enable researchers to design precision treatments of patients with esophageal squamous cell carcinoma (ESCC). These in vitro methods mainly include analysis of cell proliferation, cytotoxicity, colony formation, invasion, and migration in ESCC cells for analyzing manipulations affecting the biological behavior of ESCC. Because of these studies, important information on molecular mechanisms of different genes and proteins as well as result of therapeutic interventions are confirmed in ESCC.

Molecular Deregulation of EPAS1 in the Pathogenesis of Esophageal Squamous Cell Carcinoma

Endothelial PAS domain-containing protein 1 (EPAS1) is an angiogenic factor and its implications have been reported in many cancers but not in esophageal squamous cell carcinoma (ESCC). Herein, we aim to examine the genetic and molecular alterations, clinical implications, and functional roles of EPAS1 in ESCC. High-resolution melt-curve analysis and Sanger sequencing were used to detect mutations in EPAS1 sequence. EPAS1 DNA number changes and mRNA expressions were analyzed by polymerase chain reaction. in vitro functional assays were used to study the impact of EPAS1 on cellular behaviors. Overall, 7.5% (n = 6/80) of patients with ESCC had mutations in EPAS1, and eight novel variants (c.1084C>T, c.1099C>A, c.1145_1145delT, c.1093C>G, c.1121T>G, c.1137_1137delG, c.1135_1136insT, and c.1091_1092insT) were detected. Among these mutations, four were frameshift (V382Gfs^*12, A381Lfs^*13, K379Ifs^*6, and K364Nfs^*12) mutations and showed the potential of non–sense-mediated mRNA decay (NMD) in computational analysis. The majority of patients showed molecular deregulation of EPAS1 [45% (n = 36/80) DNA amplification, 42.5% (n = 34/80) DNA deletion, as well as 53.7% (n = 43/80) high mRNA expression, 20% (n = 16/80) low mRNA expression]. These alterations of EPAS1 were associated with tumor location and T stages. Patients with stage III ESCC having EPAS1 DNA amplification had poorer survival rates in comparison to EPAS1 DNA deletion (p = 0.04). In addition, suppression of EPAS1 in ESCC cells showed reduced proliferation, wound healing, migration, and invasion in comparison to that of control cells. Thus, the molecular and functional studies implied that EPAS1 plays crucial roles in the pathogenesis of ESCC and has the potential to be used as a prognostic marker and as a therapeutic target.

Influence of microbiota on immunity and immunotherapy for gastric and esophageal cancers

Gastric and esophageal cancers are multifactorial and multistage-involved malignancy. While the impact of gut microbiota on overall human health and diseases has been well documented, the influence of gastric and esophageal microbiota on gastric and esophageal cancers remains unclear. This review will discuss the reported alteration in the composition of gastric and esophageal microbiota in normal and disease conditions, and the potential role of dysbiosis in carcinogenesis and tumorigenesis. This review will also discuss how dysbiosis stimulates local and systemic immunity, which may impact on the immunotherapy for cancer.

Biological and clinical relevance of metastasis-associated long noncoding RNAs in esophageal squamous cell carcinoma: A systematic review

Esophageal squamous cell carcinoma (ESCC) is a foremost cancer-related death worldwide owing to rapid metastasis and poor prognosis. Metastasis, as the most important reason for death, is biologically a multifaceted process involving a range of cell signaling pathways. Long noncoding RNAs (lncRNAs), as transcriptional regulators, can regulate numerous genomic processes and cellular processes such as cell proliferation, migration, and invasion. LncRNAs have also been shown to involve in/regulate the cancer metastasis-related signaling pathways. Hence, they have increasingly been brought to international attention in molecular oncology research. A number of researchers have attempted to reveal the biological and clinical relevance of lncRNAs in ESCC tumourigenesis and metastasis. The aberrant expression of these molecules in ESCC has regularly been reported to involve in various cellular processes and clinical features, including diagnosis, prognosis, and therapeutic responses. Here, we especially consider the pathways in which lncRNAs act as metastasis-mediated effectors, mainly by interacting with epithelial-mesenchymal transition-associated factors. We review the biological roles of lncRNAs through involving in ESCC metastasis as well as the clinical significance of the metastasis-related lncRNAs in cancer diagnosis and prognosis.

Introduction: Esophageal Squamous Cell Carcinoma-Current Status and Future Advances

Esophageal squamous cell carcinoma is the most common histological subtype of esophageal cancer. The carcinoma is more common in high-incidence areas such as in Central and Southeast Asia, Eastern and Southern Africa, South America, etc. Common risk factors associated with the cancer are tobacco smoking and excessive alcohol consumption. Dietary factors, genetic factors, microorganisms, and some other environmental factors may contribute to the etiopathogenesis of the disease. Despite the global incidence of esophageal squamous cell carcinoma decreases slightly in the recent years, esophageal squamous cell carcinoma is still a major cause of cancer-related morbidity and mortality worldwide. Further improvement of the outcomes of the patients with the disease could be achieved by early diagnosis, collaborative efforts of multidisciplinary clinical and research teams, use of standardized protocol for pathological reporting and staging of the disease, proper use of cancer tissue, as well as improvement in clinical, pathological, therapeutic, and research approaches to the cancer.

FAM134B promotes esophageal squamous cell carcinoma in vitro and its correlations with clinicopathologic features

Family with sequence similarity 134, member B (FAM134B) is an autophagy regulator of endoplasmic reticulum first discovered to be involved in the pathogenesis of esophageal squamous cell carcinoma (ESCC). The present study examined the functional behavior of FAM134B in cancer cells and the association of FAM134B expression with clinicopathologic factors in patients with ESCC. Expression at both the mRNA and protein levels was investigated using real-time polymerase chain reaction and immunohistochemistry. The results were correlated with the clinical and pathological features of the patients. In addition, in vitro functional assays were used to investigate the roles of FAM134B in ESCC cells in response to gene silencing with shRNA lentiviral particles. Overexpression of FAM134B mRNA and protein was present in 31.2% (n = 29/93) and 36.6% (n = 41/112), respectively, in tumors, whereas downregulation occurred in 39.8% (n = 37/93) and 63.4% (n = 71/112), respectively. Expression of FAM134B protein in ESCC correlated with histologic grade (P = .002) and pathologic stage (P = .012). In vitro suppression of FAM134B in ESCC induced significant reductions of cell proliferation and colony formation (P < .05). In addition, suppression of FAM134B caused reduction of wound healing, migration, and invasion capacities of ESCC. To conclude, FAM134B could play crucial roles in the initiation and progression of ESCC, and FAM134B protein expression has potential predictive value. Therefore, development of strategies targeting FAM134B could have therapeutic value in the management of patients with ESCC.

LncRNA DUXAP10 modulates cell proliferation in esophageal squamous cell carcinoma through epigenetically silencing p21

Esophageal Squamous Cell Carcinoma (ESCC) belongs to malignant tumor of human digestive system. It has greatly threatened human health both mentally and physically. Long non-coding RNAs have been discovered to be special molecular regulators in various cancers, including ESCC. LncRNA DUXAP10 is a newfound RNA, which is able to improve the progression of cancers ^1-3 . In this study, DUXAP10 was certified to be upregulated in ESCC tissues and cells. Besides, it was positively correlated with short survival time. Moreover, down-expression of DUXAP10 contributed to decreased cell proliferation and metastasis. Silenced DUXAP10 led to increased apoptosis rate and stagnation of cell cycle. Results of mechanism experiments suggested that DUXAP10 motivated ESCC progression through recruiting enhancer of zeste homolog 2 (EZH2) to the promoter of p21. Our findings suggested that the pseudogene-derived from lncRNA DUXAP10 drove the biological progression of ESCC. DUXAP10 was likely to be a potential therapeutic target for ESCC.

Evaluating the Correlation Between the Survival Rate of Patients with Esophageal Squamous Cell Carcinoma and Expression of p53 and Cyclin D1 Biomarkers Along with Other Prognostic Factors

OBJECTIVE

In the present study, we aimed to evaluate the relationship between the survival rate of patients with esophageal squamous cell carcinoma (SCC) and expression of two biomarkers along with age, gender, tumor margin, depth of invasion, site of tumor, tumor diameter, tumor grade, number of involved nodes, and vascular invasion.

MATERIALS AND METHODS

In this retrospective survey, medical records of patients referred to the Shohada-e Tajrish hospital during 2001 to 2005 were reviewed and subjects with definite diagnosis of SCC were included. Required data were extracted from the patients' records, and their prepared paraffin-embedded tissue blocks were collected under supervision of two pathologists. Immunohistochemistry (IHC) analysis was performed at the Firoozgar hospital in Tehran, Iran.

RESULTS

The studied population included 20 men (74%) and 7 women (26%). The mean age at diagnosis was 58 ± 22. Results showed significantly higher survival rates in women compared to men (85.7 vs. 40%) (p = 0.001) and in patients with well-differentiated tumors compared to poor-differentiated cases (20 vs. 5%) (p = 0.004). No significant relationship was found between p53 expression and prognostic factors like age, gender, the site, grade, and size of the tumor, depth of invasion, involvement of lymph nodes, and vascular invasion.

CONCLUSION

Positivity of p53 and cyclin D1 was not found to be predictive of survival in patients with esophageal SCC which might be due to the small sample size of the present survey. Further investigations with larger sample populations and longer follow-ups are required to evaluate this correlation.

The novel 19q13 KRAB zinc-finger tumour suppressor ZNF382 is frequently methylated in oesophageal squamous cell carcinoma and antagonises Wnt/β-catenin signalling

Zinc finger proteins (ZFPs) are the largest transcription factor family in mammals. About one-third of ZFPs are Krüppel-associated box domain (KRAB)-ZFPs and involved in the regulation of cell differentiation/proliferation/apoptosis and neoplastic transformation. We recently identified ZNF382 as a novel KRAB-ZFP epigenetically inactivated in multiple cancers due to frequent promoter CpG methylation. However, its epigenetic alterations, biological functions/mechanism and clinical significance in oesophageal squamous cell carcinoma (ESCC) are still unknown. Here, we demonstrate that ZNF382 expression was suppressed in ESCC due to aberrant promoter methylation, but highly expressed in normal oesophagus tissues. ZNF382 promoter methylation is correlated with ESCC differentiation levels. Restoration of ZNF382 expression in silenced ESCC cells suppressed tumour cell proliferation and metastasis through inducing cell apoptosis. Importantly, ZNF382 suppressed Wnt/β-catenin signalling and downstream target gene expression, likely through binding directly to FZD1 and DVL2 promoters. In summary, our findings demonstrate that ZNF382 functions as a bona fide tumour suppressor inhibiting ESCC pathogenesis through inhibiting the Wnt/β-catenin signalling pathway.

HPV, KRAS mutations, alcohol consumption and tobacco smoking effects on esophageal squamous-cell carcinoma carcinogenesis

Esophageal squamous-cell carcinoma (ESCC) is an invasive neoplastic disease generally associated with poor survival rates. The incidence of ESCC is characterized by marked geographic variation, with highest rates noted in developing Southeastern African, Central and Eastern Asian countries. In the developed Western European and North American regions where there is a low disease incidence, heavy alcohol and cigarette consumption constitute major risk factors. The toxic effects of both these risk factors cause chronic irritation and inflammation of the esophageal mucosa, while at the cellular level they further confer mutagenic effects by the activation of oncogenes (e.g., RAS mutations), inhibition of tumor-suppressor genes, and profound DNA damage. Viral infections, particularly with human papillomavirus, may activate specific antiapoptotic, proliferative and malignant cellular responses that may be intensified in combination with the effects of alcohol and tobacco. In countries with a high ESCC incidence, low socioeconomic status and an inadequate diet of poorly preserved food are combined with basic nutritional deficiencies and inadequate medical treatment. These conditions are favorable to the above-mentioned risk factors implicated in ESCC development, which may be present and/or habitually used in certain populations. New perspectives in epidemiological studies of ESCC development and its risk factors allow genome-wide research involving specific environments and habits. Such research should consist of adequately large and representative samples, should use newly designed informative genetic markers, and apply genomic variation analysis of the functional transcripts involved in malignant cell cycle regulation and neoplastic transformation in the multi-step process of ESCC carcinogenesis.

Evaluation of the Prevalence of Human Papillomavirus and Epstein-Barr Virus in Esophageal Squamous Cell Carcinomas

The aim of this study was to determine the possible involvement of human papillomavirus and Epstein-Barr virus in esophageal squamous cell cancer (ESCC) carcinogenesis in the Greek population. DNA was extracted from 30 ESCC and 27 normal esophageal specimens and screened for HPV type-specific or EBV infection by PCR-based assay. Seventeen out of 30 ESCC specimens (56%) were found positive for HPV DNA, of which 15 (88%) were typed as HPV-18 infected, one (5.9%) as HPV-16 infected, and one (5.9%) as infected by an HPV type different from the studied HPV-6, 11, 16, 18 and 33 subtypes. Six of the 27 normal esophageal specimens (22.2%) were positive for HPV infection, five typed as HPV-18 (83.3%) and one as HPV-16 (16.7%). All samples were negative for EBV genome detection as assessed by the PCR assay. No statistically significant correlation was found between the HPV status of the tumor samples and clinical parameters including sex, age of the patients, tobacco or alcohol use, differentiation grade of the lesions and stage of the disease. In conclusion, our findings indicate a statistically significant (p<0.001) overall association between ESCC and HPV infection, mostly related to the HPV-18 subtype, in the Greek population.

Linc-ROR promotes esophageal squamous cell carcinoma progression through the derepression of SOX9

BACKGROUND

Novel therapies tailored to the molecular composition of esophageal squamous cell carcinoma (ESCC) are needed to improve patient survival. We investigated the regulatory network of long intergenic non-protein coding RNA, regulator of reprogramming (linc-ROR) and sex-determining region Y-box 9 (SOX9), and their therapeutic relevance in ESCC.

METHODS

Linc-ROR and SOX9 expression were examined in ESCC specimens, cell lines, and cultured tumorspheres. We investigated the effects of linc-ROR on SOX9 expression and malignant phenotypes by CCK8, colony formation, Transwell, and sphere-forming assay. The linc-ROR/SOX9 interaction mediated by multiple microRNAs (miRNAs) was confirmed by bioinformatic analysis, luciferase assay, and RNA-binding protein immunoprecipitation, transient overexpression or antagonizing endogenous candidate miRNAs. The effect of linc-ROR depletion on tumor growth was assessed by xenograft assay.

RESULTS

A positive correlation between linc-ROR and SOX9 expression was found in clinical ESCC specimens (r = 0.562, P = 0.036), cell lines, and tumorspheres. Silencing of linc-ROR significantly inhibited cell proliferation, motility, chemoresistance, and self-renewal capacity. Mechanistically, linc-ROR modulating the derepression of SOX9 by directly sponging multiple miRNAs including miR-15b, miR-33a, miR-129, miR-145, and miR-206. Antagonizing these miRNAs counteracted with linc-ROR silencing, whereas the repression of SOX9 abrogated malignant phenotypes induced by the cocktail of miRNA inhibitors. Moreover, linc-ROR disruption was sufficient to attenuate tumor growth and cancer stem cell marker expression in vivo.

CONCLUSIONS

Our results demonstrate that the linc-ROR-miRNA-SOX9 regulatory network may represent a novel therapeutic target for ESCC.

HOTAIR regulates HK2 expression by binding endogenous miR-125 and miR-143 in oesophageal squamous cell carcinoma progression

Esophageal Squamous Cell Carcinoma (ESCC) is one of the most common malignant cancers worldwide with a high death rate worldwide. Long non-coding RNA (LncRNA) has been recently demonstrated to play a critical role in ESCC. LncRNA HOTAIR played important regulatory roles in ESCC. We highlight the molecular mechanisms by which HOTAIR could influence the expression of Hexokinase 2 (HK2) in ESCC through binding miR-125 and miR-143 directly. Taken together, this study identified a functional lncRNA HOTAIR involved with regulation of glycolysis via miRNA-125/miRNA-143-HK2 in ESCC cells. The “competitive endogenous RNA” (ceRNA) model of HOTAIR/miR-125 and miR143/HK2 interaction might serve as important targets for ESCC diagnosis and therapy.

Prevalence of Squamous Cell Carcinoma of the Esophagus in a Single Tertiary Center of South Africa: A Cross Sectional Analytic Study

The incidence of esophageal cancer varies widely in the world. In the Middle East, Africa, and Asia and parts of Europe, squamous cell carcinoma of the esophagus dominates the esophageal cancer landscape. Worldwide the rates are highest in Northern China, South Africa, Turkey and Iran. In the United States, the black population has a five-fold higher incidence of esophageal squamous cell carcinoma than the white population. To determine the prevalence of squamous cell carcinoma of the esophagus in a single tertiary center in South Africa. Patients referred to Gastroenterology Division of Steve Biko Academic Hospital for upper gastrointestinal endoscopy were recruited. Those with a known diagnoses of squamous cell carcinoma of the esophagus were recorded and those with suspicious lesions had biopsies done. These were then evaluated by an experienced histopathologist. 6118 patients were recruited. Squamous cell carcinoma was found in 59 patients giving us a prevalence of 0.96% 95%CI. The cancer was found mainly in back elderly males. The prevalence of squamous cell carcinoma of the esophagus in this single center study is 0.96%, 95% confidence interval and is a disease of black elderly males as seen elsewhere. Bigger multicenter studies are needed to further clarify this findings.

Clinical value of ctDNA in upper-GI cancers: A systematic review and meta-analysis

BACKGROUND

The recent expanding technical possibilities to detect tumor derived mutations in blood, so-called circulating tumor DNA (ctDNA), has rapidly increased the interest in liquid biopsies. This review and meta-analysis explores the clinical value of ctDNA in malignancies of the upper gastro-intestinal tract.

METHODS

PubMed, Cochrane and Embase databases were searched to identify studies reporting the diagnostic, prognostic or predictive value of ctDNA in patients with esophageal, gastric and pancreatic cancer, until January 2017. The diagnostic accuracy and, using random-effect pair-wise meta-analyses, the prognostic value of ctDNA was assessed.

RESULTS

A total of 34 studies met the inclusion criteria. For esophageal and gastric cancer, amplification of oncogenes in blood, such as HER2 and MYC, can be relevant for diagnostic purposes, and to predict treatment response in certain patient subpopulations. Given the limited number of studies assessing the role of ctDNA in esophageal and gastric cancer, the meta-analysis estimated the diagnostic accuracy and predictive value of ctDNA in pancreatic cancer only (n=10). The pooled sensitivity and specificity of ctDNA as a diagnostic tool in pancreatic cancer were 28% and 95%, respectively. Patients with pancreatic cancer and detectable ctDNA demonstrated a worse overall survival compared to patients with undetectable ctDNA (HR 1.92, 95% confidence interval (CI) 1.15-3.22, p=0.01).

CONCLUSION

The presence of ctDNA is significantly associated with a poor prognosis in patients with pancreatic cancer. The use of ctDNA in clinical practice is promising, although standardization of sequencing techniques and further development of high-sensitive detection methods is needed.

Trends in esophageal and esophagogastric junction cancer research from 2007 to 2016: A bibliometric analysis

BACKGROUND

This study aimed to analyze the scientific outputs of esophageal and esophagogastric junction (EGJ) cancer and construct a model to quantitatively and qualitatively evaluate pertinent publications from the past decade.

METHODS

Publications from 2007 to 2016 were retrieved from the Web of Science Core Collection database. Microsoft Excel 2016 (Redmond, WA) and the CiteSpace (Drexel University, Philadelphia, PA) software were used to analyze publication outcomes, journals, countries, institutions, authors, research areas, and research frontiers.

RESULTS

A total of 12,978 publications on esophageal and EGJ cancer were identified published until March 23, 2017. The Journal of Clinical Oncology had the largest number of publications, the USA was the leading country, and the University of Texas MD Anderson Cancer Center was the leading institution. Ajani JA published the most papers, and Jemal A had the highest co-citation counts. Esophageal squamous cell carcinoma ranked the first in research hotspots, and preoperative chemotherapy/chemoradiotherapy ranked the first in research frontiers.

CONCLUSION

The annual number of publications steadily increased in the past decade. A considerable number of papers were published in journals with high impact factor. Many Chinese institutions engaged in esophageal and EGJ cancer research but significant collaborations among them were not noted. Jemal A, Van Hagen P, Cunningham D, and Enzinger PC were identified as good candidates for research collaboration. Neoadjuvant therapy and genome-wide association study in esophageal and EGJ cancer research should be closely observed.

Molecular profiles in foregut oncology

Oncology is and will continue to evolve resulting from a better understanding of the biology and intrinsic genetic profile of each cancer. Tumor biomarkers and targeted therapies are the new face of precision medicine, so it is essential for all physicians caring for cancer patients to understand and assist patients in understanding the role and importance of such markers and strategies to target them. This review was initiated in an attempt to identify, characterize, and discuss literature supporting clinically relevant molecular markers and interventions. The efficacy of targeting specific markers will be examined with data from clinical trials focusing on treatments for esophageal, gastric, liver, gallbladder, biliary tract, and pancreatic cancers.

HDAC2 regulates cell proliferation, cell cycle progression and cell apoptosis in esophageal squamous cell carcinoma EC9706 cells

Increasing evidence has demonstrated that histone deacetylase 2 (HDAC2) participates in the regulation of a variety of biological processes in numerous tumors. However, the potential role of HDAC2 in the development and progression of esophageal squamous cell carcinoma (ESCC) remains elusive. Immunohistochemistry was utilized to detect the expression of HDAC2, Cell Counting Kit-8 was used to determine the cell proliferation, and flow cytometry was employed to investigate cell cycle and cell apoptosis. Finally, western blotting was employed to detect the protein expression of cyclin D1, p21, B cell lymphoma-2 (Bcl-2) and Bcl-2-associated X protein (Bax). The present study found that expression of HDAC2 protein in ESCC tissues was significantly increased compared with atypical hyperplasia tissues and normal esophageal mucosa (P<0.001). The expression of HDAC2 was not associated with the age or gender of patients (P>0.05), but was closely associated with the histological grade, invasion depth, tumor-node-metastasis stage and lymph node metastasis, respectively (all P<0.001). HDAC2 small interfering RNA effectively downregulated the expression of HDAC2 protein in ESCC EC9706 cells. Downregulation of HDAC2 expression evidently inhibited cell proliferation, arrested cell cycle at the G0/G1 phase and induced cell apoptosis in ESCC EC9706 cells, coupled with increased expression of p21 and Bax proteins and decreased expression of cyclin D1 and Bcl-2 proteins. Overall, the present findings suggest that HDAC2 may play an important role in the development and progression of ESCC and be considered as a novel molecular target for the treatment of ESCC.

Esophageal Cancer in Golestan Province, Iran: A Review of Genetic Susceptibility and Environmental Risk Factors

Esophageal squamous cell carcinoma (ESCC) is an aggressive tumor that is typically diagnosed only when the tumor has gained remarkable size, extended to peripheral tissues, and led to dysphagia. Five-year survival of advanced cancer is still very poor (19%), even with improved surgical techniques and adjuvant chemoradiation therapy. Therefore, early detection and prevention are the most important strategies to reduce the burden of ESCC. Our review will focus on the studies conducted in Golestan province, an area with a high prevalence of ESCC in northern Iran. We review three aspects of the research literature on ESCC: epidemiological features, environmental factors (including substance abuse, environmental contaminants, dietary factors, and human papillomavirus [HPV]), and molecular factors (including oncogenes, tumor suppressor genes, cell cycle regulatory proteins, and other relevant biomarkers). Epidemiological and experimental data suggest that some chemicals and lifestyle factors, including polycyclic aromatic hydrocarbons (PAHs), cigarette smoking, opium use, and hot tea drinking are associated with the development of ESCC in Golestan. HPV infects the esophageal epithelium, but so far, no firm evidence of its involvement in esophageal carcinogenesis has been provided. Some of these factors, notably hot tea drinking, may render the esophageal mucosa more susceptible to injury by other carcinogens. There are few studies at molecular level on ESCC in Golestan. Increasing awareness about the known risk factors of ESCC could potentially reduce the burden of ESCC in the region. Further studies on risk factors, identifying high risk populations, and early detection are needed.

Expression of MMP9, SERPINE1 and miR-134 as prognostic factors in esophageal cancer

Esophageal cancer (EC) is a malignant tumor with a typically poor prognosis for patients. It is well known that certain microRNA (miRNA/miR) genes can regulate other genes responsible for carcinogenesis. In the present study, a group of these genes (miR-21, miR-134, miR-205 and miR-495) and genes connected with cancer-related pathways (MET, MMP9, PDGFA and SERPINE1) were chosen for analysis in order to find a potential correlation between their expression and the clinicopathological factors of EC. Esophageal tumors and adjacent non-cancerous tissue specimens were collected from a total of 63 patients and embedded in paraffin. Commercial arrays were used on KYSE-30, KYSE-150 and KYSE-270 EC cell lines in order to find genes of different expression profiles compared with those acquired from the control Het-1A cell line. Quantitative polymerase chain reaction was used on formalin-fixed, paraffin-embedded samples in order to analyze the expression of the genes chosen in the earlier step. The results were analyzed by the Kruskal-Wallis and Mann-Whitney U tests, Spearman's rank correlation coefficient, Kaplan-Meier methods and the long-rank test. Only miR-495 was not expressed in the analyzed samples. The expression of MMP9 and SERPINE1 was significantly coefficient with age range (P=0.011 and P=0.044, respectively) according to the Kruskal-Wallis test. The Spearman's rank-order correlation measurement showed that there was a coefficient correlation between age and miR-134 expression. The same measurement demonstrated a correlation between age range and MMP9 expression. The expression of miR-134 and MMP9 were also found to be correlated. In all cases, a value of P<0.049 was recorded. Overall, the present study demonstrated that MMP9, SERPINE1 and miR-134 were the most prognostic genes in Caucasian patients with EC.

Identification of Novel FAM134B (JK1) Mutations in Oesophageal Squamous Cell Carcinoma

Mutation of FAM134B (Family with Sequence Similarity 134, Member B) leading to loss of function of its encoded Golgi protein and has been reported induce apoptosis in neurological disorders. FAM134B mutation is still unexplored in cancer. Herein, we studied the DNA copy number variation and novel mutation sites of FAM134B in a large cohort of freshly collected oesophageal squamous cell carcinoma (ESCC) tissue samples. In ESCC tissues, 37% (38/102) showed increased FAM134B DNA copies whereas 35% (36/102) showed loss of FAM134B copies relative to matched non-cancer tissues. Novel mutations were detected in exons 4, 5, 7, 9 as well as introns 2, 4-8 of FAM134B via HRM (High-Resolution Melt) and Sanger sequencing analysis. Overall, thirty-seven FAM134B mutations were noted in which most (31/37) mutations were homozygous. FAM134B mutations were detected in all the cases with metastatic ESCC in the lymph node tested and in 14% (8/57) of the primary ESCC. Genetic alteration of FAM134B is a frequent event in the progression of ESCCs. These findings imply that mutation might be the major driving source of FAM134B genetic modulation in ESCCs.

Association between Ras association domain family 1A promoter methylation and esophageal squamous cell carcinoma: a meta-analysis

RASSF1A has been reported to be a candidate tumor suppressor in esophageal squamous cell carcinoma (ESCC). However, the association between RASSF1A promoter methylation and ESCC remains unclear. Eligible studies were identified through searching PubMed, Medline, Web of Science, and the China National Knowledge Infrastucture database. Studies were pooled and odds ratios (ORs) with corresponding confidence intervals (CIs) were calculated. Funnel plots were also performed to evaluate publication bias. Twelve studies involving 859 cases and 675 controls were included in this meta-analysis. A significant association was observed between RASSF1A methylation and ESCC overall (OR = 11.7, 95% CI: 6.59-20.9, z=8.36, P<0.00001). Subgroup analysis showed that the OR for heterogeneous tissues was 5.35 (95% CI = 2.95-9.71) while for autologous tissues it was 16.0 (8.31-30.96). For patient sample size, the OR for the <50 subgroup was 9.92 (95% CI = 2.88-34.2) and for the 50 case group was 13.1 (95% CI = 6.59-25.91). The OR for a relationship between RASSF1A methylation and TNM stages was 0.27 (95% CI=0.10-0.77), whereas there were no significant differences in RASSF1A methylation in relation to gender and differentiation among ESCC cases. This meta-analysis suggests a significant association between RASSF1A methylation and ESCC.

Chinese herbal medicine for oesophageal cancer

BACKGROUND

Oesophageal cancer is the seventh leading cause of cancer death worldwide. Traditional Chinese herbal medicine is sometimes used as an adjunct to radiotherapy or chemotherapy for this type of cancer. This review was first published in 2007 and updated in 2009; this 2016 update is the latest version of the review.

OBJECTIVES

To assess the efficacy and possible adverse effects of the addition of Chinese herbal medicine to treatment with radiotherapy or chemotherapy for oesophageal cancer.

SEARCH METHODS

We searched the Cochrane Upper Gastrointestinal and Pancreatic Diseases Group Trials Register, the Cochrane Library, MEDLINE, EMBASE, Allied and Complementary Medicine Database (AMED), China National Knowledge Infrastructure (CNKI), VIP database, Wanfang database and the Chinese Cochrane Centre Controlled Trials Register up to 1 October, 2015. We also searched databases of ongoing trials, the Internet and reference lists.

SELECTION CRITERIA

Randomised controlled trials (RCTs) comparing the use of radiotherapy or chemotherapy with and without the addition of Chinese herbal medicine.

DATA COLLECTION AND ANALYSIS

At least two review authors independently extracted data and assessed trial quality.

MAIN RESULTS

We tried to contact the 142 study authors by telephone, and finally included nine studies with 490 participants. All included studies were conducted in China, and allocated advanced oesophageal cancer patients to radiotherapy or chemotherapy groups, with and without additional Chinese herbal medicine. Quality of life, short-term therapeutic effects, TCM symptoms and adverse events caused by radiotherapy or chemotherapy were reported in these studies. Overall, we considered the trials to be at unclear or high risk of bias.The quality of life measure was conducted before and after the intervention; our analysis showed a beneficial effect, both in number of participants experiencing an improvement (risk ratio (RR) 2.20, 95% confidence interval (CI) 1.42 to 3.39; 5 RCTs, 233 participants, change of performance status score ≥ 10) and number of participants experiencing a deterioration (RR 0.41, 95% CI 0.27 to 0.62; 6 RCTs, 287 participants, change of performance status score ≤ 10). We judged this to have low quality evidence, downgrading quality of evidence for risk of bias and imprecision, and upgrading quality of evidence for the large effect.For short-term therapeutic effects, the results suggest that traditional Chinese medicine (TCM) has a positive impact on improvement (complete response + partial response) (RR 1.17, 95% CI 1.02 to 1.35; 8 RCTs, 450 participants), moderate quality evidence and downgrading for risk of bias. There was no significant difference for progressive disease (RR 0.73, 95% CI 0.52 to 1.01; 8 RCTs, 450 participants), low quality evidence and downgrading for risk of bias and imprecision. Three studies assessed this outcome after four weeks or three months' follow-up, the remaining studies gave no detailed information for this outcome. TCM symptoms, which was similar to short-term therapeutic effects evaluated with TCM clinical criteria, was diagnosed in two studies of 88 people at the end of the intervention. The results suggest that TCM has a positive impact on both total effectiveness (RR 1.84, 95% CI 1.20 to 2.81) and ineffectiveness (RR 0.22, 95% CI 0.05 to 0.93); we judged the studies to have very low quality evidence, downgrading for risk of bias and imprecision.Nine studies reported a series of adverse events caused by radiotherapy or chemotherapy at the end of the intervention, including mucositis, radiation oesophagitis, arrest of bone marrow, gastrointestinal reactions, renal and hepatic impairment, white blood cell descent, neurotoxicity, cardiac toxicity and anaemia. For those containing multiple studies, we conducted a pooled analysis. As a result, TCM showed a significant effect on radiation oesophagitis (RR 0.66, 95% CI 0.47 to 0.94; 2 RCTs, 90 participants), gastrointestinal reactions (RR 0.54, 95% CI 0.36 to 0.81; 4 RCTs, 268 participants) and white blood cell descent (RR 0.60, 95% CI 0.44 to 0.83; 4 RCTs, 224 participants). The quality of evidence was low or very low, downgrading for risk of bias and imprecision.

AUTHORS' CONCLUSIONS

We currently find no evidence to determine whether TCM is an effective treatment for oesophageal cancer. The effect of TCM on short-term therapeutic effects is uncertain. TCM probably has positive effects on quality of life and on some adverse events caused by radiotherapy or chemotherapy in advanced oesophageal cancer patients undergoing radiotherapy or chemotherapy. The results of the review need to be interpreted cautiously owing to overall low quality evidence. Future trials should be large and correctly designed to detect important clinical effects and minimise risk of bias.

Cancer stem cells in oesophageal squamous cell carcinoma: Identification, prognostic and treatment perspectives

Cancer stem cells (CSCs) are a vital subpopulation of cells to target for the treatment of cancers. In oesophageal squamous cell carcinoma (ESCC), there are several markers such as CD44, ALDH, Pygo2, MAML1, Twist1, Musashi1, Side population (SP), CD271 and CD90 that have been proposed to identify the cancer stem cells in individual cancer masses. It has also been demonstrated that stem cell markers like ALDH1, HIWI, Oct3/4, ABCG2, SOX2, SALL4, BMI-1, NANOG, CD133 and podoplanin are associated with patient's prognosis, pathological stages, cancer recurrence and therapy resistance. Finding new cancer stem cell targets or designing drugs to manipulate the known molecular targets in CSCs could be useful for improvements in clinical outcomes of the disease. To conclude, data suggest that CSCs in oesophageal squamous cell carcinoma are related to resistance to therapy and poor prognosis of patients with ESCC. Therefore, innovative insights into CSC biology and CSC-targeted therapies will help to achieve more effective management of patients with oesophageal squamous cell carcinoma.

Current perspectives of mi-RNA in oesophageal adenocarcinoma: Roles in predicting carcinogenesis, progression and values in clinical management

Aberrant expressions of micro-ribonucleic acids (miRs) are closely associated with the pathogenesis in many human cancers. In oesophageal adenocarcinomas, altered expressions of different sets of miRs are noted to be associated with the development of adenocarcinoma from Barrett's oesophagus. In different studies, miRs such as miR-192, miR-196 and miR-21 were frequently noted to up-regulated whereas miR-203, miR-205 and miR-let-7 were commonly down-regulated during the development of Barrett's oesophagus to oesophageal adenocarcinoma. In addition, changes in the expression of miRs are associated with the predication of metastasis, prognosis and response to chemo-radiation in the patients with oesophageal adenocarcinoma. Experimental studies in manipulating the miRs in cancer cell lines could provide hints for therapeutics for the cancer. However, the number of studies reported on these aspects of oesophageal adenocarcinoma was limited and the miRs noted needed to be confirmed by additional studies. Overall, the mechanisms of involvements of miRs in pathogenesis and progression of oesophageal adenocarcinoma are complex. Although miRs have the potential to act as prognostic and clinical biomarkers for cancer therapy in oesophageal adenocarcinoma, more works in larger populations and clinical trials are needed to validate these clinical implications.

Inhibition of heat shock protein 90 suppresses squamous carcinogenic progression in a mouse model of esophageal cancer

PURPOSE

Heat shock protein 90 (Hsp90), a potential therapeutic target, has been widely recognized in vitro and in vivo in immunodeficient mice. Here, we aimed to evaluate the role of Hsp90 in an immunocompetent mouse model of esophageal squamous cell cancer (ESCC).

METHODS

The carcinogen 4-nitroquinoline 1-oxide (4NQO) was used to induce ESCC in C57BL/6 mice. Cancer progression was analyzed through observation of appearance, hematoxylin-eosin staining, immunohistochemical detection, and terminal dUTP nick-end labeling analysis.

RESULTS

4NQO led to the progressive appearance of preneoplastic and tumoral lesions in the esophagus, with 100 % incidence of ESCC in situ occurring only after 16 weeks of carcinogen exposure. Most of these lesions evolved spontaneously into highly invasive ESCC even after 4NQO withdrawal (weeks 16-22). Interestingly, there was marked upregulation of Hsp90 and its client proteins in tumoral lesions at 22 weeks. Hsp90 inhibition by intraperitoneal injection of SNX-2112 over the following 2 weeks downregulated AKT and cyclin D1 expression, leading to significant reduction in tumor incidence and prevention of ESCC progression. Moreover, SNX-2112 treatment decreased proliferating cell nuclear antigen expression and increased the number of apoptotic cells in ESCC tissues.

CONCLUSIONS

Our in vivo findings support the contribution of Hsp90 to ESCC progression, which was achieved by stimulating apoptosis and inhibition of cell proliferation, and provide a strong rationale for further evaluation of Hsp90 inhibitors for treating ESCC.

Esophageal squamous cell carcinoma (ESCC): advance in genomics and molecular genetics

Esophageal cancer is aggressive and has poor prognosis. Esophageal squamous cell carcinoma (ESCC) is histologically the most prevalent type of esophageal cancer and ranked as the sixth leading cause of cancer death worldwide. In recent years, cancer has been widely regarded as genetic disease, as well as epigenetic abnormalities including DNA methylation, histone deacetylation, chromatin remodeling, gene imprinting and noncoding RNA regulation. In this review, we will provide a general overview of genes, proteins and microRNAs that are involved in the development of ESCC, which aims to enhance our understanding of molecular mechanisms implicated in ESCC development and progression.

Ranking candidate genes of esophageal squamous cell carcinomas based on differentially expressed genes and the topological properties of the co-expression network

Background

The aim of this study was to identify the candidate genes of esophageal squamous cell carcinoma (ESCC).

Methods

Gene expression profiling of 17 ESCC samples and 17 adjacent normal samples, GSE20347, was downloaded from Gene Expression Omnibus database. The raw data were preprocessed, and the differentially expressed genes (DEGs) between ESCC and normal samples were identified by using SAM software (false discovery rate <0.001). Then, the co-expression network of DEGs was constructed based on Pearson’s correlation test (r-value ≥0.8). Furthermore, the topological properties of the co-expression network were analyzed through NetworkAnalyzer (default settings) of Cytoscape. The expression fold changes of DEGs and topological properties were utilized to identify the candidate genes of ESCC (Cri_n score >4), which were further analyzed based on DAVID functional enrichment analysis (P-value <0.05).

Results

A total of 1,063 DEGs were identified, including 490 up-regulated and 573 down-regulated DEGs. Then, the co-expression network of DEGs was constructed, containing 999 nodes and 46,323 edges. Based on the expression fold changes of DEGs and the topological properties of the co-expression network, DEGs were ranked, and the top 24 genes were candidate genes of ESCC, such as CRISP3, EREG, CXCR2, and CRNN. Furthermore, the 24 genes were significantly enriched in bio-functions regarding cell differentiation, glucan biosynthetic process and immune response.

Conclusion

The present study suggested that CRISP3, EREG, CXCR2, and CRNN might be causative genes of ESCC, and play vital roles in the development of ESCC. However, further experimental studies are needed to confirm our results.

Electronic supplementary material

The online version of this article (doi:10.1186/s40001-014-0052-x) contains supplementary material, which is available to authorized users.

miR326 maturation is crucial for VEGF-C-driven cortactin expression and esophageal cancer progression

Esophageal cancer is an aggressive human malignancy with increasing incidence in the developed world. VEGF-C makes crucial contributions to esophageal cancer progression that are not well understood. Here, we report the discovery of regulatory relationship in esophageal cancers between the expression of VEGF-C and cortactin (CTTN), a regulator of the cortical actin cytoskeleton. Upregulation of CTTN expression by VEGF-C enhanced the invasive properties of esophageal squamous cell carcinoma in vitro and tumor metastasis in vivo. Mechanistic investigations showed that VEGF-C increased CTTN expression by downregulating Dicer-mediated maturation of miR326, thereby relieving the suppressive effect of miR326 on CTTN expression. Clinically, expression of Dicer and miR326 correlated with poor prognosis in patients with esophageal cancer. Our findings offer insights into how VEGF-C enhances the robust invasive and metastatic properties of esophageal cancer, which has potential implications for the development of new biomarkers or therapies in this setting.

Inhibition of human esophageal squamous cell carcinomas by targeted silencing of tumor enhancer genes: an overview

Esophageal cancer has been reported as the ninth most common malignancy and ranks as the sixth most frequent cause of death worldwide. Esophageal cancer treatment involves surgery, chemotherapy, radiation therapy, or combination therapy. Novel strategies are needed to boost the oncologic outcome. Recent advances in the molecular biology of esophageal cancer have documented the role of genetic alterations in tumorigenesis. Oncogenes serve a pivotal function in tumorigenesis. Targeted therapies are directed at the unique molecular signature of cancer cells for enhanced efficacy with low toxicity. RNA interference (RNAi) technology is a powerful tool for silencing endogenous or exogenous genes in mammalian cells. Related results have shown that targeting oncogenes with siRNAs, specifically the mRNA, effectively reduces tumor cell proliferation and induces apoptotic cell death. This article will briefly review studies on silencing tumor enhancer genes related to the induction of esophageal cancer.

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.

DNA methylation and cancer development: molecular mechanism

DNA methylation is a significant regulator of gene expression, and its role in carcinogenesis recently has been a subject of remarkable interest. The aim of this review is to analyze the mechanism and cell regulatory effects of both hypo- and hyper-DNA methylation on cancer. In this review, we report new developments and their implications regarding the effects of DNA methylation on cancer development. Indeed, alteration of the pattern of DNA methylation has been a constant finding in cancer cells of the same type and differences in the pattern of DNA methylation not only occur in a variety of tumor types, but also in developmental processes Furthermore, the pattern of histone modification appears to be a predicator of the risk of recurrence of human cancers. It is well known that hypermethylation represses transcription of the promoter sections of tumor-suppressor genes leading to gene silencing. However, hypomethylation also has been identified as a cause of oncogenesis. Furthermore, experiments concerning the mechanism of methylation and its control have led to the discovery of many regulatory enzymes and proteins. This review reports on methods developed for the detection of 5-hydroxymethylcytosine methylation at the 5-methylcytosine of protein domains in the CpG context compared to non-methylated DNA, histone modification, and microRNA change.

Clinical impact of predicting CCND1 amplification using plasma DNA in superficial esophageal squamous cell carcinoma

BACKGROUND

This study was designed to evaluate the clinical benefit of predicting the cyclin D1 (CCND1) status using cell-free plasma DNA in superficial esophageal squamous cell carcinoma (ESCC) patients.

METHODS

The ratio of the CCND1 (11q13) dosage to the DRD2 (11q22-23) dosage (C/D ratio) as the CCND1 copy number was evaluated. This study was divided into three steps: (1) demonstration of the feasibility, (2) evaluation of whether the plasma C/D ratio assay could monitor tumor dynamics, and (3) a validation study in 63 consecutive superficial ESCC (pTis-T1) patients and 40 healthy volunteers.

RESULTS

(1) The plasma C/D ratio was significantly higher (p = 0.0369) in superficial ESCC patients than in the controls in a preliminary test. (2) The high plasma C/D ratio appeared to reflect the tumor levels of the CCND1 status and was reduced in postoperative plasma samples (p = 0.1154) and samples following endoscopic resection (p = 0.0845). (3) Validation analysis revealed that the plasma C/D ratio was significantly higher in superficial ESCC patients than in controls (p < 0.0001). The frequency of recurrence was significantly higher (p = 0.0198), and recurrence-free survival was significantly shorter (p = 0.0075) in patients with a high plasma C/D ratio. Moreover, a high C/D ratio was shown to be an independent risk factor for recurrence on multivariate analysis [p = 0.0334; odds ratio 10.58 (range 1.203-93.23)].

CONCLUSION

The prediction of CCND1 amplification by plasma DNA may be a new complementary clinical biomarker for recurrence in patients with superficial ESCC.

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.

Oncogene GAEC1 regulates CAPN10 expression which predicts survival in esophageal squamous cell carcinoma

AIM: To identify the downstream regulated genes of GAEC1 oncogene in esophageal squamous cell carcinoma and their clinicopathological significance.

METHODS: The anti-proliferative effect of knocking down the expression of GAEC1 oncogene was studied by using the RNA interference (RNAi) approach through transfecting the GAEC1-overexpressed esophageal carcinoma cell line KYSE150 with the pSilencer vector cloned with a GAEC1-targeted sequence, followed by MTS cell proliferation assay and cell cycle analysis using flow cytometry. RNA was then extracted from the parental, pSilencer-GAEC1-targeted sequence transfected and pSilencer negative control vector transfected KYSE150 cells for further analysis of different patterns in gene expression. Genes differentially expressed with suppressed GAEC1 expression were then determined using Human Genome U133 Plus 2.0 cDNA microarray analysis by comparing with the parental cells and normalized with the pSilencer negative control vector transfected cells. The most prominently regulated genes were then studied by immunohistochemical staining using tissue microarrays to determine their clinicopathological correlations in esophageal squamous cell carcinoma by statistical analyses.

RESULTS: The RNAi approach of knocking down gene expression showed the effective suppression of GAEC1 expression in esophageal squamous cell carcinoma cell line KYSE150 that resulted in the inhibition of cell proliferation and increase of apoptotic population. cDNA microarray analysis for identifying differentially expressed genes detected the greatest levels of downregulation of calpain 10 (CAPN10) and upregulation of trinucleotide repeat containing 6C (TNRC6C) transcripts when GAEC1 expression was suppressed. At the tissue level, the high level expression of calpain 10 protein was significantly associated with longer patient survival (month) of esophageal squamous cell carcinoma compared to the patients with low level of calpain 10 expression (37.73 ± 16.33 vs 12.62 ± 12.44, P = 0.032). No significant correction was observed among the TNRC6C protein expression level and the clinocopathologcial features of esophageal squamous cell carcinoma.

CONCLUSION: GAEC1 regulates the expression of CAPN10 and TNRC6C downstream. Calpain 10 expression is a potential prognostic marker in patients with esophageal squamous cell carcinoma.

Elevated serum levels of human relaxin-2 in patients with esophageal squamous cell carcinoma

AIM: To assess the prognostic value of serum human relaxin 2 (H2 RLN) level in patients with esophageal squamous cell carcinoma (ESCC).

METHODS: From October 1998 to September 2009, 146 patients with histopathologically confirmed ESCC were enrolled in this study. One hundred patients underwent en bloc esophagectomy, and 46 patients with unresectable tumors underwent palliative surgery. Five of the 146 patients died of surgical complications. Serum levels of H2 RLN were measured by enzyme linked immunosorbent assay. The relationship between serum H2 RLN level and each of the clinicopathological parameters was analyzed using the χ² test. Patients were classified into two groups according to their H2 RLN level (< 0.462 ng/mL vs≥ 0.462 ng/mL). When any analysis cell had fewer than five cases, the Fisher’s exact test was used. The statistical difference between groups A and B in each clinicopathological category was determined by the Student’s t test (two-tailed) or analysis of variance. Survival curves were plotted using the Kaplan-Meier method. The statistical difference in survival between the different groups was compared using the log-rank test. Survival correlation with the prognostic factors was further investigated by multivariate analysis using the Cox proportional hazards model with backward stepwise likelihood ratio.

RESULTS: ESCC patients tended to have significantly higher serum H2 RLN concentrations (0.48 ± 0.17 ng/mL, n = 141) compared with the healthy control group (0.342 ± 0.12 ng/mL, n = 112). There was a significant difference between patients with lymph node involvement (0.74 ± 0.15 ng/mL, n = 90), distant metastasis (0.90 ± 0.19 ng/mL, n = 32) and those without lymph node involvement (0.45 ± 0.12 ng/mL, n = 51), and distant metastasis (0.43 ± 0.14 ng/mL, n = 109), respectively (P < 0.01). Patients with high H2 RLN levels (≥ 0.462 ng/mL) had a poorer prognosis than patients with low serum H2 RLN levels (< 0.462 ng/mL; P = 0.0056). The H2 RLN level was also correlated with survival and tumor-node-metastasis staging, but not with age, tumor size, gender, lymphovascular invasion or the histological grade of tumors. Cox regression analysis showed that H2 RLN was an independent variable.

CONCLUSION: Serum concentrations of H2 RLN are frequently elevated in ESCC patients and are correlated with disease metastasis and survival. Serum concentrations of H2 RLN may be an important prognostic marker in ESCC patients.

The role of inflammation in HPV infection of the Oesophagus

BACKGROUND

Several human cancers are known to be associated with inflammation and/or viral infections. However, the influence of tumour-related inflammation on viral uptake is largely unknown. In this study we used oesophageal squamous cell carcinoma (OSCC) as a model system since this type of cancer is associated with chronic irritation, inflammation and viral infections. Although still debated, the most important viral infection seems to be with Human Papillomavirus (HPV). The present study focused on a possible correlation between inflammation, OSCC development and the influence of HPV infection.

METHODS

A total of 114 OSCC biopsies and corresponding normal tissue were collected at Groote Schuur Hospital and Tygerberg Hospital, Cape Town (South Africa), that were subjected to RNA and DNA isolation. RNA samples were analysed by quantitative Light Cycler RT-PCR for the expression of selected genes involved in inflammation and infection, while conventional PCR was performed on the DNA samples to assess the presence of integrated viral DNA. Further, an in vitro infection assay using HPV pseudovirions was established to study the influence of inflammation on viral infectivity using selected cell lines.

RESULTS

HPV DNA was found in about 9% of OSCC patients, comprising predominantly the oncogenic type HPV18. The inflammatory markers IL6 and IL8 as well as the potential HPV receptor ITGA6 were significantly elevated while IL12A was downregulated in the tumour tissues. However, none of these genes were expressed in a virus-dependent manner. When inflammation was mimicked with various inflammatory stimulants such as benzo-α-pyrene, lipopolysaccharide and peptidoglycan in oesophageal epithelial cell lines in vitro, HPV18 pseudovirion uptake was enhanced only in the benzo-α-pyrene treated cells. Interestingly, HPV pseudovirion infectivity was independent of the presence of the ITGA6 receptor on the surface of the tested cells.

CONCLUSION

This study showed that although the carcinogen benzo-α-pyrene facilitated HPV pseudovirion uptake into cells in culture, HPV infectivity was independent of inflammation and seems to play only a minor role in oesophageal cancer.

Oncogenic but non-essential role of N-myc downstream regulated gene 1 in the progression of esophageal squamous cell carcinoma

N-myc downstream regulated gene 1 (NDRG1/Cap43/Drg-1) has previously been shown to be dysregulated in esophageal squamous cell carcinoma (ESCC). In this study, we investigated the role of NDRG1 in the neoplastic progression of ESCC using ectopic gain-of-function and loss-of-function approaches. Stable transfectants of the KYSE30 ESCC cell line with altered NDRG1 levels were generated by lentiviral transduction. Although no measurable effects on in vitro cell proliferation were observed with altered NDRG1 expression, the ectopic overexpression of NDRG1 was positively linked to recognized markers of metastasis, angiogenesis and apoptotic evasion. Accordingly, in the nude mouse xenograft model system, NDRG1 overexpression promoted the in vivo growth of KYSE30 derived xenografts, which could be attributed to the reduced apoptotic and enhanced angiogenic activities associated with this gene. These processes were mediated in part by increased NFκB activity in NDRG1 overexpressing cells. Nevertheless, no significant phenotypic changes were observed in response to NDRG1 knock-down, suggesting that this gene might not be essential for the neoplastic progression of ESCC. Taken together, our results suggest that NDRG1 may play positive but dispensable roles in the progression of esophageal squamous cell carcinoma.