Prevention strategies for esophageal cancer: Perspectives of the East vs. West

Research Progress on the Predicting Factors and Coping Strategies for Postoperative Recurrence of Esophageal Cancer

Esophageal cancer is one of the malignant tumors with poor prognosis in China. Currently, the treatment of esophageal cancer is still based on surgery, especially in early and mid-stage patients, to achieve the goal of radical cure. However, esophageal cancer is a kind of tumor with a high risk of recurrence and metastasis, and locoregional recurrence and distant metastasis are the leading causes of death after surgery. Although multimodal comprehensive treatment has advanced in recent years, the prediction, prevention and treatment of postoperative recurrence and metastasis of esophageal cancer are still unsatisfactory. How to reduce recurrence and metastasis in patients after surgery remains an urgent problem to be solved. Given the clinical demand for early detection of postoperative recurrence of esophageal cancer, clinical and basic research aiming to meet this demand has been a hot topic, and progress has been observed in recent years. Therefore, this article reviews the research progress on the factors that influence and predict postoperative recurrence of esophageal cancer, hoping to provide new research directions and treatment strategies for clinical practice.

Comparison of tumor-associated and nontumor-associated esophageal mucosa microbiota in patients with esophageal squamous cell carcinoma

Esophageal microbiota plays important roles in esophageal squamous cell carcinoma (ESCC). The aims of this study were to clarify the changes in the bacterial community during ESCC development and identify latent pathogenic bacteria which may contribute to esophageal carcinogenesis and progression. Fresh tumor and nontumor esophageal mucosal samples were collected from 31 men with ESCC. High-throughput 16s rRNA sequencing was performed, and the operational taxonomic unit data and bacterial classification annotation were obtained and analyzed. The Ace, Chao, Shannon, Simpson indexes, and operational taxonomic unit numbers were higher in nontumor tissues than in tumor tissues, although without statistical significance. There were 4 phyla and 28 genera found to show significant differences between tumor and nontumor samples. The general probiotic Lactobacillus was 1.98-fold higher in nontumor tissues, while the general pathogenic genera Fusobacterium was 4.35-fold higher in tumor tissues. For tumor tissue samples, the genera Treponema and Brevibacillus were significantly higher in N1 and N2 stages, respectively, and Acinetobacter was significantly higher in T3 stage. For nontumor tissues, the genus Fusicatenibacter was significantly higher in T2 stage, and Corynebacterium, Aggregatibacter, Saccharimonadaceae-TM7x, and Cupriavidus were significantly higher in T4 stage. Additionally, bacteria related to nitrotoluene degradation were enriched in nontumor tissues, while bacteria related to base excision repair were enriched in tumor tissues. The relative abundance of several phyla and genera are different between tumor and nontumor tissue samples. The altered bacterial microbiota is correlated with different tumor stages and some microbes may take part in the carcinogenesis and development of ESCC.

Endoscopic Screening for Second Primary Tumors of the Esophagus Among Head and Neck Cancer Patients

Malignancies of the head and neck (HN) region and esophagus are among the most common cancers worldwide. Due to exposure to common carcinogens and the theory of field cancerization, HN cancer patients have a high risk of developing second primary tumors (SPTs). In our review of 28 studies with 51,454 HN cancer patients, the prevalence of SPTs was 12%. The HN area is the most common site of SPTs, followed by the lungs and esophagus, and 13% of HN cancer patients have been reported to have esophageal high-grade dysplasia or invasive carcinoma. The prognosis of HN cancer patients with concomitant esophageal SPTs is poor, and therefore identifying esophageal SPTs as early as possible is of paramount importance for risk stratification and to guide the treatment strategy. Image-enhanced endoscopy, especially using narrow-band imaging endoscopy and Lugol’s chromoendoscopy, has been shown to improve the diagnostic performance in detecting esophageal neoplasms at an early stage. Moreover, the early detection and minimally invasive endoscopic treatment of early esophageal neoplasm has been shown to improve the prognosis. Well-designed prospective studies are warranted to establish appropriate treatment and surveillance programs for HN cancer patients with esophageal SPTs.

Trends in Incidence and Mortality of Esophageal Cancer in Huai'an District, a High-Risk Area in Northern Jiangsu Province, China

PURPOSE

This study aimed to provide a clear comparable figure of the trends in incidence and mortality rates of esophageal cancer (EC) in Huai'an District, Huai'an City, Jiangsu Province, China, a high-risk area for EC.

METHODS

The data for age- and sex-specific incidence rates between 1998 and 2016, the mortality rates in 1990-2016 and the number of EC patients were obtained from Huai'an District Cancer Registry. Crude rates, Age-standardized rates (ASRs) by world standard population and truncated age-standardized rates of EC incidence and mortality were calculated. The joinpoint regression analysis was used to calculate the annual percent changes (APC), average annual percent changes (AAPC), and their 95% confidence intervals (CIs).

RESULTS

Overall, 20,892 new EC cases and 20,806 EC deaths were registered in Huai'an District. ASR of EC incidence from 1998 to 2016 and mortality from 1990 to 2016 were 73.32/100,000 and 60.03/100,000, respectively. The ASR illustrated that the incidence of EC had significant downward trends in total, male and female (AAPC = -4.65, -4.90, and -5.51, respectively, p <.01). The age-specific incidence and mortality rates of EC increased dramatically in people over the age of 40, and peaked in people between the ages 70-74. In the subdivisions of Huai'an District, geographical diversities in the crude incidence and mortality rates of EC were found.

CONCLUSION

In summary, the incidence and mortality rates of EC showed downward trends in Huai'an District. However, the burden of EC still remained serious in this high-risk area. Cost-effective methods of intervention and health education should be enhanced for improving EC prevention.

Long noncoding RNA DGCR5 involves in tumorigenesis of esophageal squamous cell carcinoma via SRSF1-mediated alternative splicing of Mcl-1

Long noncoding RNAs (lncRNAs) emerge as essential roles in the regulation of alternative splicing (AS) in various malignancies. Serine- and arginine-rich splicing factor 1 (SRSF1)-mediated AS events are the most important molecular hallmarks in cancer. Nevertheless, the biological mechanism underlying tumorigenesis of lncRNAs correlated with SRSF1 in esophageal squamous cell carcinoma (ESCC) remains elusive. In this study, we found that lncRNA DiGeorge syndrome critical region gene 5 (DGCR5) was upregulated in ESCC clinical samples, which associated with poor prognosis. Through RNA interference and overexpression approaches, we confirmed that DGCR5 contributed to promote ESCC cell proliferation, migration, and invasion while inhibited apoptosis in vitro. Mechanistically, DGCR5 could directly bind with SRSF1 to increase its stability and thus stimulate alternative splicing events. Furthermore, we clarified that SRSF1 regulated the aberrant splicing of myeloid cell leukemia-1 (Mcl-1) and initiated a significant Mcl-1L (antiapoptotic) isoform switch, which contributed to the expression of the full length of Mcl-1. Moreover, the cell-derived xenograft (CDX) model was validated that DGCR5 could facilitate the tumorigenesis of ESCC in vivo. Collectively, our findings identified that the key biological role of lncRNA DGCR5 in alternative splicing regulation and emphasized DGCR5 as a potential biomarker and therapeutic target for ESCC.

Prevention Strategies for Esophageal Cancer-An Expert Review

Simple Summary

In the last decades, there has been a rapid increase in the incidence and prevalence of esophageal cancer in many countries around the world. Although several important risk factors have been identified, strong evidence-based preventive strategies are still lacking, and the prognosis of patients diagnosed with esophageal cancer remains poor, with an average survival rate of 5 years for only 20%. This review is an attempt to summarize the epidemiology and risk factors of EC and to highlight the unresolved aspects of current prevention strategies in order to plan more fruitful future initiatives aimed at ameliorating the disappointing prognosis of this kind of digestive tumor.

Abstract

In the last 30 years, we have witnessed a rapid increase in the incidence and prevalence of esophageal cancer in many countries around the word. However, despite advancements in diagnostic technologies, the early detection of this cancer is rare, and its prognosis remains poor, with only about 20% of these patients surviving for 5 years. The two major forms are the esophageal squamous cell carcinoma (ESCC), which is particularly frequent in the so-called Asian belt, and the esophageal adenocarcinoma (EAC), which prevails in Western populations. This review provides a summary of the epidemiological features and risk factors associated with these tumors. Moreover, a major focus is posed on reporting and highlighting the various preventing strategies proposed by the most important international scientific societies, particularly in high-risk populations, with the final aim of detecting these lesions as early as possible and therefore favoring their definite cure. Indeed, we have conducted analysis with attention to the current primary, secondary and tertiary prevention guidelines in both ESCC and EAC, attempting to emphasize unresolved research and clinical problems related to these topics in order to improve our diagnostic strategies and management.

Radiation-resistance increased by overexpression of microRNA-21 and inhibition of its target PTEN in esophageal squamous cell carcinoma

Objective

Overexpression of microRNA-21 (miR-21) increases the radiation resistance of esophageal squamous cell carcinoma (ESCC). However, the molecular mechanism responsible for this action is still unclear. In the present study, we investigated the role of phosphatase and tensin homolog deleted on chromosome 10 (PTEN) in miR-21-enhanced radiation resistance in patients with ESCC.

Methods

We evaluated the association between miR-21 levels and radiation resistance in patients with ESCC. We also investigated the role of PTEN in the proliferation and apoptosis of ESCC cells transfected with miR-21 inhibitor during irradiation, using PTEN small interfering RNA (siRNA).

Results

MiR-21 levels were significantly higher in radiation-resistant patients. Downregulation of miR-21 during irradiation suppressed the radiation resistance of ESCC cells, demonstrated by decreased cell proliferation and increased cell apoptosis. PTEN siRNA attenuated miR-21-induced suppression of radiation resistance in ESCC cells.

Conclusions

These results suggest that miR-21 enhanced the radiation resistance of ESCC by inhibiting PTEN. MiR-21 and PTEN are potential therapeutic biotargets for ESCC.

Epidemiology of esophageal cancer: update in global trends, etiology and risk factors

Esophageal cancer is the eighth most common type of cancer worldwide and constitutes the sixth leading cause of cancer deaths. It is characterized by its high mortality rate, poor prognosis at time of diagnosis and variability based on geographic location. Present day, the prevalence of esophageal cancer is in transition. Although esophageal squamous cell carcinoma continues to be the most prevalent type worldwide, esophageal adenocarcinoma is quickly becoming the most prevalent type in developed countries. Risk factors for the development of esophageal squamous cell carcinoma include low socioeconomic status, consumption of tobacco, alcohol, hot beverages, and nitrosamines. Additionally, micronutrient deficiencies have also been linked to the development of esophageal squamous cell cancer. These include vitamin C, vitamin E, and folate. With respect to esophageal adenocarcinoma, risk factors include Barrett's esophagus, gastroesophageal reflux disease, obesity, and tobacco consumption. Screening for esophageal cancer will likely play an essential role in prevention, and consequently, mortality in the future. Present day, there are no established guidelines for esophageal squamous cell cancer screening. Guidelines for esophageal adenocarcinoma are more well established but lack concrete evidence in the form of randomized controlled trials. This review will discuss the epidemiology, risk factors, and current prevention strategies for esophageal cancer in depth. It is our aim to raise awareness on the aforementioned topics to increase public health efforts in eradicating this disease.

Trends in incidence and mortality of esophageal cancer in Inner Mongolia, 2010-2015

Background

Esophageal cancer is among the leading cancer types in Inner Mongolia. This study aimed to investigate the incidence and mortality rates of esophageal cancer in 2015 and the trends in these rates in the 2010–2015 period in this region.

Methods

National Colorectal Cancer Roundtable (NCCR) screening methods and criteria were used to extract data from 10 cancer registries stratified by area (urban/rural), sex, and age group. The Chinese standard population in 2000 and Segi's world population were used to calculate age‐standardized rates. The annual percentage change (APC) in these rates was calculated using the Joinpoint Regression Program.

Results

In 2015, Inner Mongolia had 4324 new cases (4027 male vs. 297 female patients) and 3559 deaths (3300 male vs. 259 female patients) from esophageal cancer. The crude incidence, age‐standardized incidence by Chinese population, age‐standardized incidence by world population, and cumulative incidence were 13.45/100 000, 9.92/100 000, 10.18/100 000, and 1.30%, respectively. The corresponding figures for mortality were 11.32/100 000, 8.35/100 000, 8.53/100 000, and 1.04%. The incidence and mortality increased with age between 40 and 80 years. The rates in rural dwellers, especially men, showed negative APC (−13.25% vs. −11.08%; P < 0.05).

Conclusions

The incidence and mortality rates of esophageal cancer in Inner Mongolia increased between 2010 and 2015. The rates were higher in men in rural areas, middle‐aged and elderly individuals. Prevention and control programs focused on these groups, in addition to early diagnosis and treatment of esophageal cancer, are needed to reduce these rates.

Key points

Significant findings of the study: In Inner Mongolia, incidence and mortality rates of esophageal cancer were higher in urban areas than in rural areas and in men than in women between 2010 and 2015, and in middle‐aged and elderly than in younger people.

What this study adds: Prevention and control programs, in addition to early diagnosis and treatment of esophageal cancer, should be tailored to specifically target men in rural areas and middle‐aged and elderly individuals in order to reduce the incidence and mortality rates of this pathology.

Linking Cancer Stem Cell Plasticity to Therapeutic Resistance-Mechanism and Novel Therapeutic Strategies in Esophageal Cancer

Esophageal cancer (EC) is an aggressive form of cancer, including squamous cell carcinoma (ESCC) and adenocarcinoma (EAC) as two predominant histological subtypes. Accumulating evidence supports the existence of cancer stem cells (CSCs) able to initiate and maintain EAC or ESCC. In this review, we aim to collect the current evidence on CSCs in esophageal cancer, including the biomarkers/characterization strategies of CSCs, heterogeneity of CSCs, and the key signaling pathways (Wnt/β-catenin, Notch, Hedgehog, YAP, JAK/STAT3) in modulating CSCs during esophageal cancer progression. Exploring the molecular mechanisms of therapy resistance in EC highlights DNA damage response (DDR), metabolic reprogramming, epithelial mesenchymal transition (EMT), and the role of the crosstalk of CSCs and their niche in the tumor progression. According to these molecular findings, potential therapeutic implications of targeting esophageal CSCs may provide novel strategies for the clinical management of esophageal cancer.

lncTUG1/miR-144-3p affect the radiosensitivity of esophageal squamous cell carcinoma by competitively regulating c-MET

Background

Long noncoding RNAs (lncRNAs) are involved in the progression of various cancers and affect the response to radiotherapy. This study focused on clarifying the underlying mechanism by which lncTUG1 affects the radiosensitivity of esophageal squamous cell carcinoma (ESCC).

Methods

lncTUG1, miR-144-3p and MET expression levels were detected in ESCC tissues and cells by qRT-PCR. Western blotting was used to examine the protein levels of MET, p-AKT and EGFR. The dual-luciferase reporter system and RNA immunoprecipitation (RIP) assays were used to confirm the interaction between lncTUG1 and miR-144-3p or miR-144-3p and MET. MTT, colony formation and flow cytometry assays were applied to examine the behavioral changes in EC9706 and KYSE30 cells.

Results

lncTUG1 was upregulated in ESCC cells and tissues, and lncTUG1 expression was associated with an advanced pathological stage. The bioinformatics analysis revealed that lncTUG1 could specifically bind to miR-144-3p, which was downregulated in ESCC. There was a negative correlation between lncTUG1 and miR-144-3p. LncTUG1 inhibition retarded proliferation and colony formation and induced apoptosis in ESCC cells. Moreover, lncTUG1 knockdown dramatically improved the effect of radiotherapy on ESCC development both in vivo and in vitro. Furthermore, MET was revealed as a downstream target of miR-144-3p and is downregulated by it. LncTUG1 promoted the progression of ESCC and elevated radiotherapy resistance in ESCC cells, accompanied by a high level of MET expression. Moreover, we found that knockdown of lncTUG1 enhanced the radiosensitivity of ESCC cells via the p-AKT signaling pathway.

Conclusion

Our results indicate that lncTUG1 enhances the radiotherapy resistance of ESCC by lowering the miR-144-3p level and modulating the MET/EGFR/AKT axis.

Increased CDKL3 expression predicts poor prognosis and enhances malignant phenotypes in esophageal squamous cell carcinoma

BACKGROUND

Cyclin-dependent kinase-like 3 (CDKL3) is a putative protein serine kinase and plays an important role in the regulation of cell growth and/or differentiation. However, studies on the function of CDKL3 in esophageal squamous cell carcinoma (ESCC) is limited. In our study, we explored the role and prognosis of CDKL3 in ESCC and underlying mechanism.

MATERIALS AND METHODS

The expression of CDKL3 was investigated by quantitative reverse transcription polymerase chain reaction and immunohistochemical staining. CDKL3 expression was downregulated by the RNAi-mediated knockdown. The functions of CDKL3 on cell growth were assessed by Celigo image cytometry, MTT assay, cell-cycle analysis, Annexin V assay, and caspase-3/7 activity analysis. The effect of CDKL3 on cellular invasive was investigated by the Transwell assay. Pathscan Stress Signaling Antibody Array was used to study the underlying mechanism. Additionally, the association between the survival and CDKL3 expression in ESCC were evaluated based on the TCGA data.

RESULTS

CDKL3 was highly expressed in ESCC tissues and cell lines. TE-1 cells transfected with CDKL3-shRNA-lentivirus significantly decreased CDKL3 expression and resulted in inhibiting cell proliferation, inducing the S-phase cell-cycle arrest, attenuating cellular invasive and increasing cell apoptosis. The expression of pERK1/2, p-Akt, p-Smad2, p-p38 mitogen-activated protein kinase, cleaved caspase-7, and phospho-Chk1 were significantly decreased by CDKL3 knockdown. In addition, high expression of CDKL3 was associated with shorter overall survival.

CONCLUSION

Our findings suggest that higher expression of CDKL3 is correlated with poor prognosis in patients with ESCC and play a vital role in the malignant phenotype of ESCC cell lines, which indicating that CDKL3 may be as a new therapeutic target in ESCC.

REV7 confers radioresistance of esophagus squamous cell carcinoma by recruiting PRDX2

Radiotherapy has been widely used for the clinical management of esophageal squamous cell carcinoma. However, radioresistance remains a serious concern that prevents the efficacy of esophageal squamous cell carcinoma (ESCC) radiotherapy. REV7, the structural subunit of eukaryotic DNA polymerase ζ, has multiple functions in bypassing DNA damage and modulating mitotic arrest in human cell lines. However, the expression and molecular function of REV7 in ESCC progression remains unclear. In this study, we first examined the expression of REV7 in clinical ESCC samples, and we found higher expression of REV7 in ESCC tissues compared to matched adjacent or normal tissues. Knockdown of REV7 resulted in decreased colony formation and increased apoptosis in irradiated Eca‐109 and TE‐1 cells coupled with decreased tumor weight in a xenograft nude mouse model postirradiation. Conversely, overexpression of REV7 resulted in radioresistance in vitro and in vivo. Moreover, silencing of REV7 induced increased reactive oxygen species levels postirradiation. Proteomic analysis of REV7‐interacting proteins revealed that REV7 interacted with peroxiredoxin 2 (PRDX2), a well‐known antioxidant protein. Existence of REV7‐PRDX2 complex and its augmentation postirradiation were further validated by immunoprecipitation and immunofluorescence assays. REV7 knockdown significantly disrupted the presence of nuclear PRDX2 postirradiation, which resulted in oxidative stress. REV7‐PRDX2 complex also assembled onto DNA double‐strand breaks, whereas REV7 knockdown evidently increased double‐strand breaks that were unmerged by PRDX2. Taken together, the present study sheds light on REV7‐modulated radiosensitivity through interacting with PRDX2, which provides a novel target for ESCC radiotherapy.

Synthesis and biological evaluation of novel 2-oxo-1,2-dihydroquinoline-4-carboxamide derivatives for the treatment of esophageal squamous cell carcinoma

No new and effective treatments have been approved for the treatment of esophageal squamous cell carcinoma (ESCC) in the past decade. Cisplatin and 5-fluoruracil are the most commonly used drugs for this disease. In order to develop a new class of drugs effective in our ESCC phenotypic screens, we began a systematic approach to generate novel compounds based on the 2-oxo-1,2-dihydroquinoline-4-carboxamide fragment. Herein, we report on the synthesis and initial assessment of 55 new analogues in two ESCC cell lines. Some of the active analogues with IC₅₀ values around 10 μM were tested in three additional cell lines. Our structure-activity relationships revealed remarkable alterations in the anti proliferative activities upon modest chemical modifications and autophagy modulation is a suggested mechanism of action.

Methylation decreases the Bin1 tumor suppressor in ESCC and restoration by decitabine inhibits the epithelial mesenchymal transition

Bridging integrator-1 (Bin1), as a tumor suppressor, is frequently attenuated or even abolished in multiple primary cancers. A reduced expression of Bin1 caused by DNA methylation, has been reported in breast and prostate cancers. However, the methylation status of Bin1 and potent biological functions in esophageal squamous cell carcinoma (ESCC) remain unclear. In a previous study, we showed that the Bin1 expression was low in ESCC tissues. Herein, we further characterized this mechanism, confirming that gene hypermethylation was significantly correlated with the aberrant attenuation of Bin1. In addition, the Bin1 hypermethylation was associated with the poorer clinical parameters and shorter survival times of ESCC patients. Methylation-specific reverse transcription-polymerase chain reaction (MS-RT-PCR) showed that Bin1 was hypermethylated in several ESCC cell lines, which might be the main cause of reduced Bin1 expression. In addition, treatment with the de-methylation agent Decitabine (DAC) could restore Bin1 expression and evidently restrained ESCC cell malignant behaviors, particularly the epithelial mesenchymal transition (EMT) via reactivating the PTEN/AKT signaling pathway to inhibit matrix metalloproteinase (MMP)-2 and MMP-9 expression in vitro and in vivo. In conclusion, these results demonstrated that Bin1 methylation could augment the malignant biological behaviors of ESCC and predict the poor prognosis for ESCC patients, thus indicating the potential clinical application value of DAC-based de-methylation therapy in ESCC.

Endoscopic diagnosis and treatment of early esophageal squamous neoplasia

Esophageal cancer is one of the leading causes of cancer-related death and is associated with high morbidity and mortality. It carries a poor prognosis as more than half of patients present with advanced and unresectable disease. One contributing factor is the increased risk of lymph node metastases at early stages of disease. As such, it is essential to detect squamous cell neoplasia (SCN) at an early stage. In order to risk stratify lesions, endoscopists must be able to perform image enhanced endoscopy including magnification and Lugol’s chromoendoscopy. The assessment of both the horizontal extent and depth of any lesion is also of utmost importance prior to treatment. Endoscopic mucosal resection and submucosal dissection remain the standard of care with literature supportive their respective use. Radiofrequency ablation and other endoscopic treatments are currently available although should not be considered first line at this time. Our objective is to review the current options for the endoscopic diagnosis and treatment of esophageal SCN.

Association between coffee or tea drinking and Barrett's esophagus or esophagitis: an Italian study

BACKGROUND/OBJECTIVES

Only a few papers have treated of the relationship between Barrett's esophagus (BE) or erosive esophagitis (E) and coffee or tea intake. We evaluated the role of these beverages in BE and E occurrence.

SUBJECTS/METHODS

Patients with BE (339), E (462) and controls (619) were recruited. Data on coffee and tea and other individual characteristics were collected using a structured questionnaire.

RESULTS

BE risk was higher in former coffee drinkers, irrespective of levels of exposure (cup per day; ⩽1: OR=3.76, 95% CI 1.33-10.6; >1: OR=3.79, 95% CI 1.31-11.0; test for linear trend (TLT) P=0.006) and was higher with duration (>30 years: OR=4.18, 95% CI 1.43-12.3; TLT P=0.004) and for late quitters, respectively (⩽3 years from cessation: OR=5.95, 95% CI 2.19-16.2; TLT P<0.001). The risk of BE was also higher in subjects who started drinking coffee later (age >18 years: OR=6.10, 95% CI 2.15-17.3). No association was found in current drinkers, but for an increased risk of E in light drinkers (<1 cup per day OR =1.85, 95% CI 1.00-3.43).A discernible risk reduction of E (about 20%, not significant) and BE (about 30%, P<0.05) was observed in tea drinkers.

CONCLUSIONS

Our data were suggestive of a reduced risk of BE and E with tea intake. An adverse effect of coffee was found among BE patients who had stopped drinking coffee. Coffee or tea intakes could be indicative of other lifestyle habits with protective or adverse impact on esophageal mucosa.

African-American esophageal squamous cell carcinoma expression profile reveals dysregulation of stress response and detox networks

BACKGROUND

Esophageal carcinoma is the third most common gastrointestinal malignancy worldwide and is largely unresponsive to therapy. African-Americans have an increased risk for esophageal squamous cell carcinoma (ESCC), the subtype that shows marked variation in geographic frequency. The molecular architecture of African-American ESCC is still poorly understood. It is unclear why African-American ESCC is more aggressive and the survival rate in these patients is worse than those of other ethnic groups.

METHODS

To begin to define genetic alterations that occur in African-American ESCC we conducted microarray expression profiling in pairs of esophageal squamous cell tumors and matched control tissues.

RESULTS

We found significant dysregulation of genes encoding drug-metabolizing enzymes and stress response components of the NRF2- mediated oxidative damage pathway, potentially representing key genes in African-American esophageal squamous carcinogenesis. Loss of activity of drug metabolizing enzymes would confer increased sensitivity of esophageal cells to xenobiotics, such as alcohol and tobacco smoke, and may account for the high incidence and aggressiveness of ESCC in this ethnic group. To determine whether certain genes are uniquely altered in African-American ESCC we performed a meta-analysis of ESCC expression profiles in our African-American samples and those of several Asian samples. Down-regulation of TP53 pathway components represented the most common feature in ESCC of all ethnic groups. Importantly, this analysis revealed a potential distinctive molecular underpinning of African-American ESCC, that is, a widespread and prominent involvement of the NRF2 pathway.

CONCLUSION

Taken together, these findings highlight the remarkable interplay of genetic and environmental factors in the pathogenesis of African-American ESCC.

Expression of VRK1 and the downstream gene BANF1 in esophageal cancer

Esophageal cancer is considered one of the most malignant tumors, being characterized by rapid progression and poor outcomes. China has the highest incidence of esophageal cancer in the world. Hence, it is necessary to clarify the mechanisms underlying esophageal cancer progression. In this study, we examined the expression of vaccinia-related kinase 1 (VRK1) and barrier to autointegration factor 1 (BANF1) in tumor tissues at the mRNA and protein levels via real-time PCR and immunohistochemical analyses. The mRNA and protein expression levels of VRK1 and BANF1 were higher in tumor tissues than in adjacent normal tissues. ROC curve analysis showed that VRK1 and BANF1 yielded AUCs of 0.790 and 0.735, respectively, for the detection of esophageal squamous cell carcinoma(ESCC) patients. In conclusion, our study indicates that VRK1 and BANF are promising novel therapeutic targets for esophageal cancer.