Profiling of circulating microRNAs in patients with Barrett's esophagus and esophageal adenocarcinoma

Liquid biopsy to identify Barrett's oesophagus, dysplasia and oesophageal adenocarcinoma: the EMERALD multicentre study

BACKGROUND

There is no clinically relevant serological marker for the early detection of oesophageal adenocarcinoma (EAC) and its precursor lesion, Barrett's oesophagus (BE).

OBJECTIVE

To develop and test a blood-based assay for EAC and BE.

DESIGN

Oesophageal MicroRNAs of BaRRett, Adenocarcinoma and Dysplasia (EMERALD) was a large, international, multicentre biomarker cohort study involving 792 patient samples from 4 countries (NCT06381583) to develop and validate a circulating miRNA signature for the early detection of EAC and high-risk BE. Tissue-based miRNA sequencing and microarray datasets (n=134) were used to identify candidate miRNAs of diagnostic potential, followed by validation using 42 pairs of matched cancer and normal tissues. The usefulness of the candidate miRNAs was initially assessed using 108 sera (44 EAC, 34 EAC precursors and 30 non-disease controls). We finally trained a machine learning model (XGBoost+AdaBoost) on RT-qPCR results from circulating miRNAs from a training cohort (n=160) and independently tested it in an external cohort (n=295).

RESULTS

After a strict process of biomarker discovery and selection, we identified six miRNAs that were overexpressed in all sera of patients compared with non-disease controls from three independent cohorts of different nationalities (miR-106b, miR-146a, miR-15a, miR-18a, miR-21 and miR-93). We established a six-miRNA diagnostic signature using the training cohort (area under the receiver operating characteristic curve (AUROC): 97.6%) and tested it in an independent cohort (AUROC: 91.9%). This assay could also identify patients with BE among patients with gastro-oesophageal reflux disease (AUROC: 94.8%, sensitivity: 92.8%, specificity: 85.1%).

CONCLUSION

Using a comprehensive approach integrating unbiased genome-wide biomarker discovery and several independent experimental validations, we have developed and validated a novel blood test that might complement screening options for BE/EAC.

TRIAL REGISTRATION NUMBER

NCT06381583.

Cost-effective identification of Barrett's esophagus in the community: A first step towards screening

BACKGROUND AND AIM

The first step towards developing a screening strategy for Barrett's esophagus (BE) is the identification of individuals in the community. Currently available tools include endoscopy, less-invasive non-endoscopic devices, and non-invasive risk stratification models. We evaluated the cost of potential strategies for identification of BE as a first step towards screening.

METHODS

Two hypothetical cohorts of the general population aged ≥ 50 years with BE prevalence rates of 1.9% and 6.8% were modeled. Four potential screening tools were evaluated: (i) risk stratification based on non-weighted clinical factors according to US/European guidelines, (ii) weighted risk stratification using algorithmic models, (iii) less-invasive devices such as Cytosponge + trefoil factor 3 (TFF3), and (iv) endoscopy. Using a decision-analytic model, the cost per BE case identified and the cost-effectiveness were compared for six potential BE screening strategies based on combinations of the four screening tools; (i) + (iv), (ii) + (iv), (iii) + (iv), (i) + (iii) + (iv), (ii) + (iii) + (iv), and only (iv).

RESULTS

The cost per BE case identified was lowest for the weighted risk stratification followed by Cytosponge-TFF3 then endoscopy strategy at both 1.9% and 6.8% BE prevalences (US$9282 and US$3406, respectively) although it was sensitive to the cost of less-invasive devices. This strategy was also most cost-effective for a BE prevalence of 1.9%. At BE prevalence of 6.8%, the Cytosponge-TFF3 followed by endoscopy strategy was most cost-effective.

CONCLUSIONS

Incorporating weighted risk stratification and less-invasive devices such as Cytosponge-TFF3 into BE screening strategies has a potential to cost-effectively identify BE in the community although device cost and the community prevalence of BE will impact the optimal strategy.

Circulating miR-133a-3p and miR-451a as potential biomarkers for diagnosis of coronary artery disease

BACKGROUND

Coronary artery disease (CAD) remains the leading cause of mortality and morbidity around the world. Despite significant progress in the diagnosis and treatment of cardiovascular diseases, still there is a clinical need to identify novel biomarkers for early diagnosis and treatment of CAD. The aim of the study is to investigate circulating miRNAs in CAD patients to identify potential biomarkers for early detection and therapeutic management of CAD.

METHODS

We assessed the expression of different candidate miRNAs (miR-21-5p, miR-133a-3p, miR-221-3p, miR-451a and miR-584-5p) in plasma from 50 CAD patients and 50 controls by qRT-PCR analysis.

RESULTS

The expression levels of miR-133a-3p (fold change (FC): 28.05, p < 0.0001), miR-451a (FC: 27.47, p < 0.0001), miR-584-5p (FC: 7.89, p < 0.0001), miR-21-5p (FC: 5.35, p < 0.0001) and miR-221-3p (FC: 5.03, p < 0.0001) were significantly up-regulated in CAD patients compared to controls. Receiver operating characteristic curve analysis showed that miR-133a-3p and miR-451a were powerful biomarkers for detecting CAD.

CONCLUSIONS

Our results suggested that miR-21-5p, miR-133a-3p, miR-221-3p, miR-451a and miR-584-5p may serve as independent biomarkers for CAD. Further, the combination of miR-133a-3p and miR-451a could be used as a specific signature in CAD diagnosis.

Advances in Screening for Barrett Esophagus and Esophageal Adenocarcinoma

Esophageal adenocarcinoma (EAC), the primary form of esophageal cancer in the United States, is a lethal cancer with exponentially increasing incidence. Screening for Barrett esophagus (BE), the only known precursor to EAC, followed by endoscopic surveillance to detect dysplasia and early-stage EAC and subsequent endoscopic treatment (to prevent progression of dysplasia to EAC and to treat early-stage EAC effectively) is recommended by several society guidelines. Sedated endoscopy (the primary current tool for BE screening) is both invasive and expensive, limiting its widespread use. In this review, we aim to provide a comprehensive review of recent innovations in the nonendoscopic detection of BE and EAC. These include swallowable cell sampling devices combined with protein and epigenetic biomarkers (which are now guideline endorsed as alternatives to sedated endoscopy), tethered capsule endomicroscopy, emerging peripheral blood-sampled molecular biomarkers, and exhaled volatile organic compounds. We also summarize progress and challenges in assessing BE and EAC risk, which is an important complementary component of the process for the clinical implementation of these innovative nonendoscopic tools, and propose a new paradigm for the strategy to reduce EAC incidence and mortality.

Epigenetic Alterations from Barrett's Esophagus to Esophageal Adenocarcinoma

Barrett's esophagus (BE) is a disease entity that is a sequela of chronic gastroesophageal reflux disease that may result in esophageal adenocarcinoma (EAC) due to columnar epithelial dysplasia. The histological degree of dysplasia is the sole biomarker frequently utilized by clinicians. However, the cost of endoscopy and the fact that the degree of dysplasia does not progress in many patients with BE diminish the effectiveness of histological grading as a perfect biomarker. Multiple or more quantitative biomarkers are required by clinicians since early diagnosis is crucial in esophageal adenocancers, which have a high mortality rate. The presence of epigenetic factors in the early stages of this neoplastic transformation holds promise as a predictive biomarker. In this review, current studies on DNA methylations, histone modifications, and noncoding RNAs (miRNAs) that have been discovered during the progression from BE dysplasia to EAC were collated.

Kyoto international consensus report on anatomy, pathophysiology and clinical significance of the gastro-oesophageal junction

OBJECTIVE

An international meeting was organised to develop consensus on (1) the landmarks to define the gastro-oesophageal junction (GOJ), (2) the occurrence and pathophysiological significance of the cardiac gland, (3) the definition of the gastro-oesophageal junctional zone (GOJZ) and (4) the causes of inflammation, metaplasia and neoplasia occurring in the GOJZ.

DESIGN

Clinical questions relevant to the afore-mentioned major issues were drafted for which expert panels formulated relevant statements and textural explanations.A Delphi method using an anonymous system was employed to develop the consensus, the level of which was predefined as ≥80% of agreement. Two rounds of voting and amendments were completed before the meeting at which clinical questions and consensus were finalised.

RESULTS

Twenty eight clinical questions and statements were finalised after extensive amendments. Critical consensus was achieved: (1) definition for the GOJ, (2) definition of the GOJZ spanning 1 cm proximal and distal to the GOJ as defined by the end of palisade vessels was accepted based on the anatomical distribution of cardiac type gland, (3) chemical and bacterial (Helicobacter pylori) factors as the primary causes of inflammation, metaplasia and neoplasia occurring in the GOJZ, (4) a new definition of Barrett's oesophagus (BO).

CONCLUSIONS

This international consensus on the new definitions of BO, GOJ and the GOJZ will be instrumental in future studies aiming to resolve many issues on this important anatomic area and hopefully will lead to better classification and management of the diseases surrounding the GOJ.

Comprehensive RNA dataset of tissue and plasma from patients with esophageal cancer or precursor lesions

In the past decades, the incidence of esophageal adenocarcinoma has increased dramatically in Western populations. Better understanding of disease etiology along with the identification of novel prognostic and predictive biomarkers are urgently needed to improve the dismal survival probabilities. Here, we performed comprehensive RNA (coding and non-coding) profiling in various samples from 17 patients diagnosed with esophageal adenocarcinoma, high-grade dysplastic or non-dysplastic Barrett’s esophagus. Per patient, a blood plasma sample, and a healthy and disease esophageal tissue sample were included. In total, this comprehensive dataset consists of 102 sequenced libraries from 51 samples. Based on this data, 119 expression profiles are available for three biotypes, including miRNA (51), mRNA (51) and circRNA (17). This unique resource allows for discovery of novel biomarkers and disease mechanisms, comparison of tissue and liquid biopsy profiles, integration of coding and non-coding RNA patterns, and can serve as a validation dataset in other RNA landscaping studies. Moreover, structural RNA differences can be identified in this dataset, including protein coding mutations, fusion genes, and circular RNAs.

Computational pathology aids derivation of microRNA biomarker signals from Cytosponge samples

BACKGROUND

Non-endoscopic cell collection devices combined with biomarkers can detect Barrett's intestinal metaplasia and early oesophageal cancer. However, assays performed on multi-cellular samples lose information about the cell source of the biomarker signal. This cross-sectional study examines whether a bespoke artificial intelligence-based computational pathology tool could ascertain the cellular origin of microRNA biomarkers, to inform interpretation of the disease pathology, and confirm biomarker validity.

METHODS

The microRNA expression profiles of 110 targets were assessed with a custom multiplexed panel in a cohort of 117 individuals with reflux that took a Cytosponge test. A computational pathology tool quantified the amount of columnar epithelium present in pathology slides, and results were correlated with microRNA signals. An independent cohort of 139 Cytosponges, each from an individual patient, was used to validate the findings via qPCR.

FINDINGS

Seventeen microRNAs are upregulated in BE compared to healthy squamous epithelia, of which 13 remain upregulated in dysplasia. A pathway enrichment analysis confirmed association to neoplastic and cell cycle regulation processes. Ten microRNAs positively correlated with columnar epithelium content, with miRNA-192-5p and -194-5p accurately detecting the presence of gastric cells (AUC 0.97 and 0.95). In contrast, miR-196a-5p is confirmed as a specific BE marker.

INTERPRETATION

Computational pathology tools aid accurate cellular attribution of molecular signals. This innovative design with multiplex microRNA coupled with artificial intelligence has led to discovery of a quality control metric suitable for large scale application of the Cytosponge. Similar approaches could aid optimal interpretation of biomarkers for clinical use.

FUNDING

Funded by the NIHR Cambridge Biomedical Research Centre, the Medical Research Council, the Rosetrees and Stoneygate Trusts, and CRUK core grants.

Barrett's esophagus: The pathomorphological and molecular genetic keystones of neoplastic progression

Barrett's esophagus is a widespread chronically progressing disease of heterogeneous nature. A life threatening complication of this condition is neoplastic transformation, which is often overlooked due to lack of standardized approaches in diagnosis, preventative measures and treatment. In this essay, we aim to stratify existing data to show specific associations between neoplastic transformation and the underlying processes which predate cancerous transition. We discuss pathomorphological, genetic, epigenetic, molecular and immunohistochemical methods related to neoplasia detection on the basis of Barrett's esophagus. Our review sheds light on pathways of such neoplastic progression in the distal esophagus, providing valuable insight into progression assessment, preventative targets and treatment modalities. Our results suggest that molecular, genetic and epigenetic alterations in the esophagus arise earlier than cancerous transformation, meaning the discussed targets can help form preventative strategies in at-risk patient groups.

Barrett's Esophagus: Diagnosis, Management, and Key Updates

Barrett's esophagus (BE) is the precursor lesion for esophageal adenocarcinoma (EAC) development. Unfortunately, BE screening/surveillance has not provided the anticipated EAC reduction benefit. Noninvasive techniques are increasingly available or undergoing testing to screen for BE among those with/without known risk factors, and the use of artificial intelligence platforms to aid endoscopic screening and surveillance will likely become routine, minimizing missed cases or lesions. Management of high-grade dysplasia and intramucosal EAC is clear with endoscopic eradication therapy preferred to surgery. BE with low-grade dysplasia can be managed with removal of visible lesions combined with endoscopic eradication therapy or endoscopic surveillance at present.

Circulating MicroRNAs in Relation to Esophageal Adenocarcinoma Diagnosis and Survival

BACKGROUND AND AIMS

Tissue miRNA can discriminate between esophageal adenocarcinoma (EA) and normal epithelium. However, no studies have examined a comprehensive panel of circulating miRNAs in relation to EA diagnosis and survival.

METHODS

We used all 62 EA cases from the US Multi-Center case-control study with available serum matched 1:1 to controls. Cases were followed for vital status. MiRNAs (n = 2064) were assessed using the HTG EdgeSeq miRNA Whole Transcriptome Assay. Differential expression analysis of miRNAs in relation to case-control status was conducted. In cases, Cox regression models were fit to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) for all-cause mortality. P values were adjusted using the Benjamini-Hochberg (BH) procedure for false discovery rate control. Predictive performance was assessed using cross-validation.

RESULTS

Sixty-eight distinct miRNAs were significantly upregulated between cases and controls (e.g., miR-1255b-2-3p fold change = 1.74, BH-adjusted P = 0.01). Assessing the predictive performance of these significantly upregulated miRNAs yielded 60% sensitivity, 65% specificity, and 0.62 AUC. miR-4253 and miR-1238-5p were associated with risk of mortality after EA diagnosis (HR = 4.85, 95% CI: 2.30-10.23, BH-adjusted P = 0.04 and HR = 3.81, 95% CI: 2.02-7.19, BH-adjusted P = 0.04, respectively).

CONCLUSIONS

While they require replication, these findings suggest that circulating miRNAs may be associated with EA diagnosis and survival.

A Physically Active Status Affects the Circulating Profile of Cancer-Associated miRNAs

Circulating miRNAs are ideal diagnostics and prognostics biomarkers in cancer since altered levels of specific miRNAs have been associated to development/progression of several cancers. Physical activity is a recognized preventive strategy against several cancers, but it may also modify the baseline levels of cancer-associated miRNAs and, hence, may act as a confounding pre-analytical variable. This study aimed at understanding whether physical activity-dependent changes in cancer-associated circulating miRNAs profile could act as a confounding variable. A panel comprising 179 miRNAs was assayed in plasma from 20 highly trained and 10 sedentary men. RT-qPCR data were analyzed with the 2^−2ΔΔCT methods and normalized on hsa-miR-320d, as determined by bioinformatics analysis. miRNAs associated with the diagnosis of the most prevalent cancers were considered. Only those miRNAs, relevantly associated with cancers, found ≥2-fold up- or downregulated in highly trained subjects compared to sedentary were disclosed. The results reveal that chronic physical activity determined modifications altering the baseline level of several cancer-associated miRNAs and, hence, their diagnostic and prognostic potential. In conclusion, based on our results, a physically active status emerges as an important pre-analytical variable able to alter the basal level of circulating miRNAs, and these alterations might be considered as potentially misleading the analytical output.

Urinary microRNA biomarkers for detecting the presence of esophageal cancer

Esophageal cancer (EC) including esophageal squamous cell carcinoma (ESCC) and adenocarcinoma (EAC) generally exhibits poor prognosis; hence, a noninvasive biomarker enabling early detection is necessary. Age- and sex-matched 150 healthy controls (HCs) and 43 patients with ESCC were randomly divided into two groups: 9 individuals in the discovery cohort for microarray analysis and 184 individuals in the training/test cohort with cross-validation for qRT-PCR analysis. Using 152 urine samples (144 HCs and 8 EACs), we validated the urinary miRNA biomarkers for EAC diagnosis. Among eight miRNAs selected in the discovery cohort, urinary levels of five miRNAs (miR-1273f, miR-619-5p, miR-150-3p, miR-4327, and miR-3135b) were significantly higher in the ESCC group than in the HC group, in the training/test cohort. Consistently, these five urinary miRNAs were significantly different between HC and ESCC in both training and test sets. Especially, urinary miR-1273f and miR-619-5p showed excellent values of area under the curve (AUC) ≥ 0.80 for diagnosing stage I ESCC. Similarly, the EAC group had significantly higher urinary levels of these five miRNAs than the HC group, with AUC values of approximately 0.80. The present study established novel urinary miRNA biomarkers that can early detect ESCC and EAC.

miR-194-5p protects against myocardial ischemia/reperfusion injury via MAPK1/PTEN/AKT pathway

Background

MicroRNA (miRNA), which participates in various physiological and pathological processes, is a highly conserved small RNA sequence. This study aimed to investigate the role of miR-194-5p in hypoxia/reoxygenation (H/R)-induced cardiomyocyte apoptosis and myocardial ischemia/reperfusion (I/R) injury.

Methods

We set up an H/R H9c2 cell model in vitro and an I/R mouse model in vivo. Then, cell vitality, apoptosis, and histopathological evaluation were conducted. Reactive oxygen species (ROS) generation and the activity of superoxide dismutase (SOD) and malondialdehyde (MDA) were examined by 2’,7’-Dichlorodihydrofluorescein diacetate (H2DCFDA), and enzyme-linked immunosorbent assay (ELISA), respectively. The level of creatine kinase isoenzyme (CK-MB), cardiac troponin I (cTnI), myoglobin (Mb) is examined by ELISA. The expression of Caspase-3, cleaved-Caspase-3, Bax, Bcl-2, phosphatase and tensin homolog deleted on chromosome ten (PTEN), and protein kinase B (AKT) was analyzed by western blot.

Results

Data showed the expression of miR-194-5p was decreased in H/R-induced H9c2 cells and I/R-induced mouse. Conversely, overexpression of miR-194-5p could improve cardiomyocyte damage in ischemic models in vivo and in vitro. Furthermore, mitogen-activated protein kinase 1 (MAPK1) was found as a direct target of miR-194-5p, which negatively regulated the expression of MAPK1. The up-regulation of MAPK1 inhibited the myocardial protection previously observed by miR-194-5p.

Conclusions

Our study shows overexpression of miR-194-5p protects against H/R injury in vitro and cardiac I/R injury in vivo, which involves the inhibition of cardiac apoptosis and oxidative stress by targeting MAPK1 expression via PTEN/AKT pathway. These findings supply novel insights into potential therapeutic targets for cardiovascular diseases.

Screening for Barrett's Oesophagus: Are We Ready for it?

Purpose of review

The targeted approach adopted for Barrett’s oesophagus (BO) screening is sub-optimal considering the large proportion of BO cases that are currently missed. We reviewed the literature highlighting recent technological advancements in efforts to counteract this challenge. We also provided insights into strategies that can improve the outcomes from current BO screening practises.

Recent findings

The standard method for BO detection, endoscopy, is invasive and expensive and therefore inappropriate for mass screening. On the other hand, endoscopy is more cost-effective for screening a high-risk population. A consensus has however not been reached on who should be screened. Risk prediction algorithms have been tested as an enrichment pre-screening tool reporting modest AUC’s but require more prospective evaluation studies. Less invasive endoscopy methods like trans-nasal endoscopy, oesophageal capsule endsocopy and non-endoscopic cell collection devices like the Cytosponge coupled with biomarker analysis have shown promise in BO detection with randomised clinical trial evidence.

Summary

A three-tier precision cancer programme whereby risk prediction algorithms and non-endoscopic minimally invasive cell collection devices are used to triage test a wider pool of individuals may improve the detection rate of current screening practises with minimal cost implications.

Role of Extracellular Vesicles in the Diagnosis and Pathogenesis of Barrett's Esophagus: A Mini-Review

Esophageal adenocarcinoma (EAC) continues to be a significant public health problem with survival rates that have remained stagnant. Although the population at the highest risk for EAC, i.e., patients with Barrett's esophagus (BE) has been clearly defined, patients with EAC continue to do poorly due to advanced stage at diagnosis. The field of extracellular vesicles (EV) could have huge application for the management of patients with BE and EAC by allowing timely diagnosis, serial monitoring, and improved understanding of disease biology. EV are actively packaged and actively secreted vesicles and contain microRNAs, proteins, lipids, and DNA. The contents of EV have been shown to provide useful insights into cellular transformation and pro-oncogenic processes. Early work shows promise but suffers from a high degree of technical and biological variation. The current review not only summarizes the current knowledge about EV as diagnostic biomarkers and their role in disease progression of BE and EAC but also provides the reader practical guidance to devise future experiments to perform well-designed studies.

Emerging roles of MiR-133a in human cancers

MicroRNAs (miRNAs) can post-transcriptionally regulate the expression of cancer-relevant genes via binding to the 3'-untranslated region (3'-UTR) of the target mRNAs. MiR-133a, as a miRNA, participate in tumorigenesis, progression, autophagy and drug-resistance in various malignancies. Based on the recent insights, we discuss the functions of miR-133a in physiological and pathological processes and its potential effects on cancer diagnosis, prognosis and therapy.

Progress in Screening for Barrett's Esophagus: Beyond Standard Upper Endoscopy

The rapid increase in the incidence of esophageal adenocarcinoma in Western populations over the past 4 decades and its associated poor prognosis, unless detected early has generated great interest in screening for the precursor lesion Barrett's esophagus (BE). Recently, there have been significant developments in imaging-based modalities and esophageal cell-sampling devices coupled with biomarker assays. In this review, the authors discuss the rationale for screening for BE and the factors to consider for targeting the at-risk population. They also explore future avenues for research in this area.

Extracellular miRNAs for the Management of Barrett's Esophagus and Esophageal Adenocarcinoma: A Systematic Review

Esophageal adenocarcinoma (EAC), the major histologic type of esophageal cancer (EC) in Western countries, is a disease with a poor prognosis, primarily due to usual diagnosis at an advanced stage. The prevalence of EAC has increased in recent years, both in Western countries and in Asia. Barrett's esophagus (BE) is a precursor lesion of EAC. Therefore, early detection and proper management of BE and EAC is important to improve prognosis. Here, we systematically summarize current knowledge about the potential utility of extracellular microRNAs (miRNAs), which are thought to be non-invasive biomarkers for many diseases, for these purposes. A search of the PubMed and Embase databases identified 22 papers about extracellular miRNAs that have potential utility for management of EAC. Among them, 19 were EAC-related and ten were BE-related; some of these dealt with both conditions. The articles included studies reporting diagnosis, prognosis, and treatment responses. Multiple papers report dysregulation of miR-194-5p in BE and miR-21-5p, -25-3p, and -93-5p in EAC. Although it will take time to utilize these miRNAs in clinical practice, they are likely to be useful non-invasive markers in the future.

Differential MicroRNA Signatures in the Pathogenesis of Barrett's Esophagus

OBJECTIVES:

Barrett's esophagus (BE) is the precursor lesion and a major risk factor for esophageal adenocarcinoma (EAC). Although patients with BE undergo routine endoscopic surveillance, current screening methodologies have proven ineffective at identifying individuals at risk of EAC. Since microRNAs (miRNAs) have potential diagnostic and prognostic value as disease biomarkers, we sought to identify an miRNA signature of BE and EAC.

METHODS:

High-throughput sequencing of miRNAs was performed on serum and tissue biopsies from 31 patients identified either as normal, gastroesophageal reflux disease (GERD), BE, BE with low-grade dysplasia (LGD), or EAC. Logistic regression modeling of miRNA profiles with Lasso regularization was used to identify discriminating miRNA. Quantitative reverse transcription polymerase chain reaction was used to validate changes in miRNA expression using 46 formalin-fixed, paraffin-embedded specimens obtained from normal, GERD, BE, BE with LGD or HGD, and EAC subjects.

RESULTS:

A 3-class predictive model was able to classify tissue samples into normal, GERD/BE, or LGD/EAC classes with an accuracy of 80%. Sixteen miRNAs were identified that predicted 1 of the 3 classes. Our analysis confirmed previous reports indicating that miR-29c-3p and miR-193b-5p expressions are altered in BE and EAC and identified miR-4485-5p as a novel biomarker of esophageal dysplasia. Quantitative reverse transcription polymerase chain reaction validated 11 of 16 discriminating miRNAs.

DISCUSSION:

Our data provide an miRNA signature of normal, precancerous, and cancerous tissue that may stratify patients at risk of progressing to EAC. We found that serum miRNAs have a limited ability to distinguish between disease states, thus limiting their potential utility in early disease detection.

The Diagnostic and Prognostic Value of a Liquid Biopsy for Esophageal Cancer: A Systematic Review and Meta-Analysis

Esophageal cancer is among the most aggressive diseases, and circulating tumor cells (CTCs) have been recognized as novel biomarkers for various cancers over the past two decades, including esophageal cancer. CTCs might provide crucial clinical information for predicting cancer prognosis, monitoring therapeutic responses or recurrences, or elucidating the mechanism of metastasis. The isolation of CTCs is among the applications of a "liquid biopsy". There are various technologies for liquid biopsies, and they are classified into two main methods: cytometric or non-cytometric techniques. Here, we review a total of 57 eligible articles to summarize various technologies for the use of a liquid biopsy in esophageal cancer and perform a meta-analysis to assess the clinical utility of liquid biopsies as a prognostic and diagnostic biomarker technique. For prognostic evaluation, the pooled hazard ratio in the cytometric assay is relatively higher than that of the non-cytometric assay. On the other hand, a combination of multiple molecules, using a non-cytometric assay, might be a favorable biomarker technique for the early diagnosis of esophageal cancer. Although determining strong evidence for a biomarker by using a liquid biopsy is still challenging, our meta-analysis might be a milestone for the future development of liquid biopsies in use with esophageal cancer.

Towards screening Barrett's oesophagus: current guidelines, imaging modalities and future developments

Barrett's oesophagus is the only known precursor to oesophageal adenocarcinoma (OAC). Although guidelines on the screening and surveillance exist in Barrett's oesophagus, the current strategies are inadequate. Oesophagogastroduodenoscopy (OGD) is the gold standard method in screening for Barrett's oesophagus. This invasive method is expensive with associated risks negating its use as a current screening tool for Barrett's oesophagus. This review explores current definitions, epidemiology, biomarkers, surveillance, and screening in Barrett's oesophagus. Imaging modalities applicable to this condition are discussed, in addition to future developments. There is an urgent need for an alternative non-invasive method of screening and/or surveillance which could be highly beneficial towards reducing waiting times, alleviating patient fears and reducing future costs in current healthcare services. Vibrational spectroscopy has been shown to be promising in categorising Barrett's oesophagus through to high-grade dysplasia (HGD) and OAC. These techniques need further validation through multicentre trials.

Detection of circulating BMP5 as a risk factor for Barrett's esophagus

Barrett's esophagus (BE) predisposes for the malignant condition of esophageal adenocarcinoma (EAC). Since BE patients have few or no symptoms, most of these patients are not identified and not included in surveillance programs. These BE patients are at risk of developing advanced-stage EAC. At present, non-invasive tests to identify BE patients from the general population are lacking. We and others showed that Bone Morphogenetic Protein 4 (BMP4), and other BMPs are upregulated in BE. We aimed to determine if circulating BMPs can be identified and used as blood biomarkers to identify BE patients at high risk in the general population. In this study, we could detect the different BMPs in the blood of 112 BE patients and 134 age- and sex-matched controls. Concentration levels of BMP2, BMP4, and BMP5 were elevated in BE patients, with BMP2 and BMP5 significantly increased. BMP5 remained significant after multivariate analysis and was associated with an increased risk for BE with an OR of 1.49 (p value 0.01). Per log (pg/mL) of BMP5, the odds of having BE increased by 50%. Future optimization and validation studies might be needed to prove its utility as a non-invasive method for the detection of BE in high-risk populations and screening programs.

Role of non-coding RNAs in esophageal carcinoma

In recent years, the research on the role of non-coding RNAs (ncRNAs) in tumors has received more and more attention. Although research on the role of ncRNAs in the early diagnosis, disease monitoring, treatment guidance, and prognosis prediction of esophageal carcinoma has been gradually carried out, there are still many problems that need to be addressed. In the current paper, I review the progress in the research of ncRNAs in esophageal carcinoma, with an aim to help provide new strategies for the prevention and treatment of esophageal carcinoma.

Circulating exosomal miRNAs as potential biomarkers for Barrett's esophagus and esophageal adenocarcinoma

Exosomes, a class of extracellular vesicles, are small membrane-bound vesicles derived from almost all cell types that can play important roles in intercellular communication. Exosomes contain proteins, lipids, and nucleic acids that are obtained from the parental cells and participate in various pathophysiological processes, including cell growth, migration, inflammation, immune regulation, and tumor pathogenesis. Moreover, exosomes might be applied in clinical settings, such as diagnosis, treatment, and outcome prediction of diseases, including various cancers. The incidence rates of Barrett's esophagus (BE) and esophageal adenocarcinoma (EAC) have increased in recent decades, and studies have proposed specific factors that may contribute to the development and progression of these diseases. However, how exosomes play a role in this pathological process needs to be clarified. Studies have identified candidate microRNAs (miRNAs) that might be related to BE/EAC. Further studies are needed to ascertain whether circulating exosomal miRNAs are altered before or after disease onset, which could also help understand the pathophysiology of and find potential targets for prevention, diagnosis, and therapy in BE/EAC. This review summarizes recent findings on the features of circulating exosomal miRNAs in BE/EAC, which could be valuable for the early diagnosis, therapeutic approaches, and outcome prediction of BE/EAC.

miR-194-5p inhibits LPS-induced astrocytes activation by directly targeting neurexophilin 1

Astrocytes are vitally involved in the development of neurodegenerative diseases and brain cancers. In this work, we investigated the potential ameliorative role of microRNA-194-5p (miR-194-5p) against lipopolysaccharide (LPS)-induced astrocytes activation and the mechanism underneath. Astrocytes were transfected with miR-194-5p mimic or inhibitor and subsequently induced with LPS. Cell proliferation was measured using MTT assay while Transwell assay was used for assessing cell migration. The concentrations of cyclooxygenase 2 (COX2) and cytokines (tumor necrosis factor-α (TNF-α), transforming growth factor β (TGF-β), interleukin (IL)-1β and IL-6) were determined by enzyme-linked immunosorbent assay (ELISA). Gene expression was assessed by quantitative reverse transcription PCR (RT-qPCR) while western blotting was used for quantifying relative protein expression. We found that miR-194-5p, downregulated in LPS-induced astrocytes, significantly inhibited LPS-induced cell proliferation and migration. In addition, miR-194-5p inhibited the release of COX2 and pro-inflammatory cytokines (TNF-α, TGF-β, IL-1β and IL-6). Moreover, the silencing of neurexophilin 1 (NXPH1), an in silico and mechanistically confirmed direct target of miR-194-5p, reverted the anti-inflammatory, anti-proliferative and anti-migratory effects of miR-194-5p. We anticipated that miR-194-5 inhibits the proliferation, invasion, and inflammatory reaction in LPS-induced astrocytes by directly targeting NXPH1. These findings hinted that miR-194-5p/NXPH1 axis exerts vital functions in astrocytes activation and neuroinflammation-associated diseases. This finding will open novel avenues for biomedical and neuroscience research.

Circulating microRNAs: Next-generation Cancer Detection

Early detection of cancer is crucial for its ultimate control and the prevention of malignant progression. In Japan, a nationwide project was conducted between 2014 and 2019 to develop novel cancer detection tools using serum microRNAs (miRNAs). Using the National Cancer Center Biobank, we collected more than 10,000 serum samples from patients with malignant diseases, including rare cancers such as ovarian cancer, gliomas, and sarcomas. Subsequently, comprehensive miRNA microarray analyses were performed for all samples. This serum miRNA database provides insights regarding miRNA biomarker candidates for each cancer type. Here, we summarize the major achievements of this national project. Notably, although circulating miRNAs packaged in extracellular vesicles are thought to be a cell-to-cell communication tool, the functional characteristics of the miRNAs listed in the project are still unknown. We hope that our findings will help elucidate the biological functions of circulating miRNAs.

Circulating microRNA expression profiling revealed miR-92a-3p as a novel biomarker of Barrett's carcinogenesis

The main intent of secondary prevention strategies for Barrett's esophagus (BE) patients relies in the prompt identification of patients with dysplasia (or intra-epithelial neoplasia; IEN) and early-stage adenocarcinoma (Barrett's adenocarcinoma; BAc). Despite the adequate characterization of the molecular landscape characterizing Barrett's carcinogenesis, no tissue and/or circulating biomarker has been approved for clinical use. A series of 25 serum samples (12 BE, 5 HG-IEN and 8 BAc) were analyzed for comprehensive miRNA profiling and ten miRNAs were found to be significantly dysregulated. In particular seven were upregulated (i.e. miR-92a-3p, miR-151a-5p, miR-362-3p, miR-345-3p, miR-619-3p, miR-1260b, and miR-1276) and three downregulated (i.e. miR-381-3p, miR-502-3p, and miR-3615) in HG-IEN/BAc samples in comparison to non-dysplastic BE. All the identified miRNAs showed significant ROC curves in discriminating among groups with AUC values range of 0.75-0.83. Validation of the results were performed by droplet digital PCR in two out of three tested miRNAs. To understand the cellular source of circulating miR-92a-3p, we analyzed its expression in endoscopy biopsy samples by both qRT-PCR and ISH analyses. As observed in serum samples, miR-92a-3p was over-expressed in HG-IEN/BAc samples in comparison to naïve esophageal squamous mucosa and BE and was mainly localized within the epithelial cells, supporting neoplastic cells as the main source of the circulating miRNA. Our data further demonstrated that circulating miRNAs are a promising mini-invasive diagnostic tool in the secondary follow-up and management of BE patients. Larger multi-Institutional studies should validate and investigate the most adequate miRNAs profile in discriminating BE patients in specific risk classes.

Novel Screening Alternatives for Barrett Esophagus

Barrett esophagus (BE) is the only known premalignant precursor to esophageal adenocarcinoma (EAC), a deadly malignancy that carries a dismal prognosis. Guidelines currently recommend screening for BE only in high-risk populations, such as patients with chronic gastroesophageal reflux disease (GERD) and 1 or more additional risk factors. A GERD-centered approach to BE screening likely leads to a large number of missed EAC cases, as the true population prevalence of BE is thought to be much higher than current estimates. Mass screening for BE has been proposed but is fraught with challenges. Esophagogastroduodenoscopy screening is the current gold standard for BE detection, but it is expensive and cumbersome and carries a small potential for unwanted harms. Transnasal endoscopy is simple, cost-effective, and well tolerated, but it has not found widespread acceptance among physicians and patients. Esophageal capsule endoscopy, despite being well tolerated and accepted, has not been shown to be cost-effective. Newer minimally invasive, nonendoscopic techniques for BE screening have shown promise in prospective clinical trials. Pragmatic head-to-head trials comparing these techniques will help determine the path forward and could herald a new future for population-based BE screening.

Recent advances in understanding and preventing oesophageal cancer

Oesophageal cancer is a common cancer that continues to have a poor survival. This is largely in part due to its late diagnosis and early metastatic spread. Currently, screening is limited to patients with multiple risk factors via a relatively invasive technique. However, there is a large proportion of patients diagnosed with oesophageal cancer who have not been screened. This has warranted the development of new screening techniques that could be implemented more widely and lead to earlier identification and subsequently improvements in survival rates. This article also explores progress in the surveillance of Barrett’s oesophagus, a pre-malignant condition for the development of oesophageal adenocarcinoma. In recent years, advances in early endoscopic intervention have meant that more patients are considered at an earlier stage for potentially curative treatment.

Novel Screening Tests for Barrett's Esophagus

PURPOSE OF REVIEW

There has been an exponential increase in the incidence of esophageal adenocarcinoma (EAC) over the last half century. Barrett's esophagus (BE) is the only known precursor lesion of EAC. Screening for BE in high-risk populations has been advocated with the aim of identifying BE, followed by endoscopic surveillance to detect dysplasia and early stage cancer, with the intent that treatment can improve outcomes. We aimed to review BE screening methodologies currently recommended and in development.

RECENT FINDINGS

Unsedated transnasal endoscopy allows for visualization of the distal esophagus, with potential for biopsy acquisition, and can be done in the office setting. Non-endoscopic screening methods being developed couple the use of swallowable esophageal cell sampling devices with BE specific biomarkers, as well as trefoil factor 3, methylated DNA markers, and microRNAs. This approach has promising accuracy. Circulating and exhaled volatile organic compounds and the foregut microbiome are also being explored as means of detecting EAC and BE in a non-invasive manner. Non-invasive diagnostic techniques have shown promise in the detection of BE and may be effective methods of screening high-risk patients.

Ensemble of decision tree reveals potential miRNA-disease associations

In recent years, increasing associations between microRNAs (miRNAs) and human diseases have been identified. Based on accumulating biological data, many computational models for potential miRNA-disease associations inference have been developed, which saves time and expenditure on experimental studies, making great contributions to researching molecular mechanism of human diseases and developing new drugs for disease treatment. In this paper, we proposed a novel computational method named Ensemble of Decision Tree based MiRNA-Disease Association prediction (EDTMDA), which innovatively built a computational framework integrating ensemble learning and dimensionality reduction. For each miRNA-disease pair, the feature vector was extracted by calculating the statistical measures, graph theoretical measures, and matrix factorization results for the miRNA and disease, respectively. Then multiple base learnings were built to yield many decision trees (DTs) based on random selection of negative samples and miRNA/disease features. Particularly, Principal Components Analysis was applied to each base learning to reduce feature dimensionality and hence remove the noise or redundancy. Average strategy was adopted for these DTs to get final association scores between miRNAs and diseases. In model performance evaluation, EDTMDA showed AUC of 0.9309 in global leave-one-out cross validation (LOOCV) and AUC of 0.8524 in local LOOCV. Additionally, AUC of 0.9192+/-0.0009 in 5-fold cross validation proved the model's reliability and stability. Furthermore, three types of case studies for four human diseases were implemented. As a result, 94% (Esophageal Neoplasms), 86% (Kidney Neoplasms), 96% (Breast Neoplasms) and 88% (Carcinoma Hepatocellular) of top 50 predicted miRNAs were confirmed by experimental evidences in literature.

Barrett's esophagus: novel strategies for screening and surveillance

Barrett’s esophagus is the precursor lesion for esophageal adenocarcinoma. Screening and surveillance of Barrett’s esophagus are undertaken with the goal of earlier detection and lowering the mortality from esophageal adenocarcinoma. The widely used technique is standard esophagogastroduodenoscopy with biopsies per the Seattle protocol for screening and surveillance of Barrett’s esophagus. Surveillance intervals vary depending on the degree of dysplasia with endoscopic eradication therapy confined to patients with Barrett’s esophagus and confirmed dysplasia. In this review, we present various novel techniques for screening of Barrett’s esophagus such as unsedated transnasal endoscopy, cytosponge with trefoil factor-3, balloon cytology, esophageal capsule endoscopy, liquid biopsy, electronic nose, and oral microbiome. In addition, advanced imaging techniques such as narrow band imaging, dye-based chromoendoscopy, confocal laser endomicroscopy, volumetric laser endomicroscopy, and wide-area transepithelial sampling with computer-assisted three-dimensional analysis developed for better detection of dysplasia are also reviewed.

Barrett's Esophagus and Esophageal Carcinoma: Can Biomarkers Guide Clinical Practice?

PURPOSE OF REVIEW

Despite gastrointestinal societal recommendations for endoscopic screening and surveillance of Barrett's esophagus, the rates of esophageal adenocarcinoma continue to rise. Furthermore, this current practice is costly to patients and the medical system without clear evidence of reduction in cancer mortality. The use of biomarkers to guide screening, surveillance, and treatment strategies might alleviate some of these issues.

RECENT FINDINGS

Incredible advances in biomarker identification, biomarker assays, and minimally-invasive modalities to acquire biomarkers have shown promising results. We will highlight recently published, key studies demonstrating where we are with using biomarkers for screening and surveillance in clinical practice, and what is on the horizon regarding novel non-invasive and minimally invasive methods to acquire biomarkers. Proof-of principle studies using in silico models demonstrate that biomarker-guided screening, surveillance, and therapeutic intervention strategies can be cost-effective and can reduce cancer deaths in patients with Barrett's esophagus.

Biomarker identification and trans-regulatory network analyses in esophageal adenocarcinoma and Barrett's esophagus

BACKGROUND

Esophageal adenocarcinoma (EAC) is an aggressive disease with high mortality and an overall 5-year survival rate of less than 20%. Barrett's esophagus (BE) is the only known precursor of EAC, and patients with BE have a persistent and excessive risk of EAC over time. Individuals with BE are up to 30-125 times more likely to develop EAC than the general population. Thus, early detection of EAC and BE could significantly improve the 5-year survival rate of EAC. Due to the limitations of endoscopic surveillance and the lack of clinical risk stratification strategies, molecular biomarkers should be considered and thoroughly investigated.

AIM

To explore the transcriptome changes in the progression from normal esophagus (NE) to BE and EAC.

METHODS

Two datasets from the Gene Expression Omnibus (GEO) in NCBI Database (https://www.ncbi.nlm.nih.gov/geo/) were retrieved and used as a training and a test dataset separately, since NE, BE, and EAC samples were included and the sample sizes were adequate. This study identified differentially expressed genes (DEGs) using the R/Bioconductor project and constructed trans-regulatory networks based on the Transcriptional Regulatory Element Database and Cytoscape software. Enrichment of Kyoto Encyclopedia of Genes and Genomes (KEGG) and Gene Ontology (GO) terms was identified using the Database for Annotation, Visualization, and Integrated Discovery (DAVID) Bioinformatics Resources. The diagnostic potential of certain DEGs was assessed in both datasets.

RESULTS

In the GSE1420 dataset, the number of up-regulated DEGs was larger than that of down-regulated DEGs when comparing EAC vs NE and BE vs NE. Among these DEGs, five differentially expressed transcription factors (DETFs) displayed the same trend in expression across all the comparison groups. Of these five DETFs, E2F3, FOXA2, and HOXB7 were up-regulated, while PAX9 and TFAP2C were down-regulated. Additionally, the majority of the DEGs in trans-regulatory networks were up-regulated. The intersection of these potential DEGs displayed the same direction of changes in expression when comparing the DEGs in the GSE26886 dataset to the DEGs in trans-regulatory networks above. The receiver operating characteristic curve analysis was performed for both datasets and found that TIMP1 and COL1A1 could discriminate EAC from NE tissue, while REG1A, MMP1, and CA2 could distinguish BE from NE tissue. DAVID annotation indicated that COL1A1 and MMP1 could be potent biomarkers for EAC and BE, respectively, since they participate in the majority of the enriched KEGG and GO terms that are important for inflammation and cancer.

CONCLUSION

After the construction and analyses of the trans-regulatory networks in EAC and BE, the results indicate that COL1A1 and MMP1 could be potential biomarkers for EAC and BE, respectively.

Circulating miRNAs in patients with Barrett's esophagus, high-grade dysplasia and esophageal adenocarcinoma

Background

Diagnostic screening of premalignant esophageal lesions is hampered by the absence of biomarkers indicative of metaplastic and/or malignant transformation. The aim of this exploratory study was to investigate the potential use of miRNAs as biomarkers capable of identifying patients with (pre)malignant lesions: Barrett's esophagus (BE) metaplasia, high-grade dysplasia (HGD) or esophageal adenocarcinoma (EAC).

Methods

A total of 69 patients were included in the study. Six serum samples from each of four study groups, i.e., patients with normal squamous epithelium (SE), BE, HGD and EAC, were profiled using the Nanostring miRNA analysis platform. Differential miRNA expression patterns then were validated in 69 patient samples using qRT-PCR.

Results

miRNA expression profiling revealed seven miRNAs with a 2-fold change in expression level. Validation by qRT-PCR confirmed that serum miR-320e levels were significantly decreased in the BE group compared to the SE (P≤0.001, AUC 0.790) and HGD groups (P≤0.005, AUC 0.786). Serum miR-199a-3p levels were significantly decreased in the BE group compared to the SE group (P≤0.001), area under the curve (AUC) of 0.813.

Conclusions

The results of this study suggest that decreased serum miRNA levels of miR-199a-3p and miR-320e could help to identify patients with BE and HGD.

Screening for Barrett's Esophagus: Are New High-Volume Methods Feasible?

New improved methods are required for the early detection of esophageal adenocarcinoma in order to reduce mortality from this aggressive cancer. In this review we discuss different screening methods which are currently under evaluation ranging from image-based methods to cell collection devices coupled with biomarkers. As Barrett's esophagus is a low prevalence disease, potential screening tests must be applied to an enriched population to reduce the false-positive rate and improve the cost-effectiveness of the program.

Identification of prognostic risk factors for esophageal adenocarcinoma using bioinformatics analysis

Purpose

Esophageal adenocarcinoma (EAC) is the most common type of esophageal cancer in Western countries. It is usually detected at an advanced stage and has a poor prognosis. The aim of this study was to identify key genes and miRNAs in EAC.

Methods

The mRNA microarray data sets GSE1420, GSE26886, and GSE92396 and miRNA data set GSE16456 were downloaded from the Gene Expression Omnibus database. Differentially expressed genes (DEGs) and differentially expressed miRNAs (DEMs) were obtained using R software. Functional enrichment analysis was performed using the DAVID database. A protein-protein interaction (PPI) network and functional modules were established using the STRING database and visualized by Cytoscape. The targets of the DEMs were predicted using the miRecords database, and overlapping genes between DEGs and targets were identified. The prognosis-related overlapping genes were identified using Kaplan-Meier analysis and Cox proportional hazard analysis based on The Cancer Genome Atlas (TCGA) database. The differential expression of these prognosis-related genes was validated using the expression matrix in the TCGA database.

Results

Seven hundred and fifteen DEGs were obtained, consisting of 313 upregulated and 402 downregulated genes. The PPI network consisted of 281 nodes; 683 edges were constructed and 3 functional modules were established. Forty-four overlapping genes and 56 miRNA- mRNA pairs were identified. Five genes, FAM46A, RAB15, SLC20A1, IL1A, and ACSL1, were associated with overall survival or relapse-free survival. FAM46A and IL1A were found to be independent prognostic indicators for overall survival, and FAM46A, RAB15, and SLC20A1 were considered independent prognostic indicators for relapse-free survival. Among them, the overexpression of RAB15 and SLC20A1 and lower expression of ACSL1 were also identified in EAC tissues based on the expression matrix in the TCGA database.

Conclusion

These prognosis-related genes and differentially expressed miRNA have provided potential biomarkers for EAC diagnosis and treatment.

Analysis of tissue and circulating microRNA expression during metaplastic transformation of the esophagus

Genetic changes involved in the metaplastic progression from squamous esophageal mucosa toward Barrett's metaplasia and adenocarcinoma are almost unknown. Several evidences suggest that some miRNAs are differentially expressed in Barrett's esophagus (BE) and esophageal adenocarcinoma. Among these, miR-143, miR-145, miR-194, miR-203, miR-205, miR-215 appear to have a key role in metaplasia and neoplastic progression. The aim of this study was to analyze deregulated miRNAs in serum and esophageal mucosal tissue biopsies to identify new biomarkers that could be associated with different stages of esophageal disease. Esophageal mucosal tissue biopsies and blood samples were collected and analyzed for BE diagnosis. Quantitative Real-time PCR was used to compare miRNA expression levels in serum and 60 disease/normal-paired tissues from 30 patients diagnosed with esophagitis, columnar-lined oesophagus (CLO) or BE. MiRNA expression analysis showed that miR-143, miR-145, miR-194 and miR-215 levels were significantly higher, while miR-203 and miR-205 were lower in BE tissues compared with their corresponding normal tissues. Esophageal mucosa analysis of patients with CLO and esophagitis showed that these miRNAs were similarly deregulated but to a lesser extent keeping the same trend and CLO appeared as intermediate step between esophagitis and BE. Analysis on circulating miRNA levels confirmed that miR-194 and miR-215 were significantly upregulated in both BE and CLO compared to esophagitis, while miR-143 was significantly upregulated only in the Barrett group. These findings suggest that miRNAs may be involved in neoplastic/metaplastic progression and miRNA analysis might be useful for progression risk prediction as well as for monitoring of BE/CLO patients.

Identification of key pathways and genes in Barrett's esophagus using integrated bioinformatics methods

Barrett's esophagus (BE) is a premalignant lesion of esophageal adenocarcinoma. The aim of the present study was to investigate the possible mechanisms and biomarkers of BE. To identify the differentially expressed microRNAs (DEmiRNAs) and genes (DEGs) in BE, the miRNA expression profile GSE20099 and the gene expression profiles GSE26886, GSE13083 and GSE34619 were obtained from the Gene Expression Omnibus (GEO) database. DEGs and DEmiRNAs were screened for using the GEO2R tool. Using DAVID, functional and pathway enrichment analysis was performed to explore the biological function of identified DEGs. The protein‑protein interaction (PPI) network was detected using STRING and constructed by Cytoscape software. Furthermore, targets of identified DEmiRNAs were predicted by the miRecords database, then integrated with the identified DEGs to obtain key genes involved in BE. In total, 311 DEGs were identified. These genes were significantly enriched in the pancreatic secretion, metabolic pathways and cytochrome P450 drug metabolism pathways. In the PPI network, 16 hub genes, including keratin 16, cystic fibrosis transmembrane conductance regulator, involucrin, protein kinase C α and cadherin 17 were identified. Following integration of the predicted target genes of DEmiRNAs with DEGs, three key BE genes were identified: PRKCA, CDH17 and epiregulin. In conclusion, a comprehensive bioinformatics analysis of identified DEGs and DEmiRNAs was performed to elucidate potential pathways and biomarkers involved in the development of BE.

Recent Advances in Screening for Barrett's Esophagus

OPINION STATEMENT

PURPOSE OF REVIEW: There is a pressing need for effective strategies to halt the increase in both the incidence and mortality of esophageal adenocarcinoma (EAC). Screening for Barrett's esophagus, which is the only known precursor of EAC, remains a ripe area for research, particularly with regard to identifying the target population, screening tools, and management of screen-detected populations. This review aims to explore in depth the rationale for screening for Barrett's esophagus, recent biotechnological advances which may have the potential of making screening feasible, and also highlight the challenges which will have to be overcome in order make screening for BE a realistic prospect.

RECENT FINDINGS

Imaging techniques such as portable transnasal endoscopy have the advantage of providing an immediate diagnosis of Barrett's esophagus as well as other significant pathologies such as reflux esophagitis and cancer; however, larger studies in non-enriched community screening populations are required to evaluate their feasibility. The capsule sponge is a cell-sampling device coupled with a biomarker, which has been most extensively evaluated with very promising results as regards feasibility, acceptability, accuracy, and cost-effectiveness. Its effectiveness in increasing the detection of Barrett's esophagus in primary care is currently being evaluated. Several Barrett's esophagus risk prediction scores have been developed with variable degrees of accuracy. Several minimally and non-invasive screening techniques have been studied including imaging and cell-sampling devices. Barrett's risk assessment models need to be further validated in independent, relevant screening populations with clear cut-offs for recommending screening to be defined.

microRNA involvement in the onset and progression of Barrett's esophagus: a systematic review

Esophageal adenocarcinoma (EAC) is a highly aggressive malignancy that develops from Barrett's esophagus (BE), an intestinal metaplasia of the distal esophagus. microRNAs (miRNAs), short non-coding regulatory RNAs, are frequently dysregulated in BE and are thought to play key roles in the onset of BE and its progression to EAC. miRNAs thus have potential diagnostic and prognostic value and are increasingly being used as cancer biomarkers. This review summarizes the current literature related to miRNAs that are dysregulated in BE within the context of Hedgehog, Notch, MAPK, NF kappa-B, Wnt and epithelial-mesenchymal transition (EMT) signaling which are thought to drive BE onset and progression. This comprehensive analysis of miRNAs and their associated signaling in the regulation of BE provides an overview of vital discoveries in this field and highlights gaps in our understanding of BE pathophysiology that warrant further investigation.

Barrett's esophagus transits to a cancer condition via potential biomarkers

AIM

In this study, the transcriptome profile of Barrett's esophagus (BE) was examined for identification potential related biomarkers in view of interacting charactering.

BACKGROUND

Since BE is known as a precursor of esophageal cancer, the molecular studies of this condition could be essential.

METHODS

Gene expression data of BE in comparison with normal cases, GSE34619 was retrieved from Gene Expression Omnibus. Differentially expressed genes (DEGs) were determined applying GEO2R online software. The DEGs then were analyzed in terms of centrality properties via constructing an interaction network.

RESULTS

The data indicate that there are two sets of hub-bottlenecks panels with distinguishable values in BE. The first group shows that BE is very susceptible to develop cancer, and the second one implied on central characteristic of some DEGs as previously were also reported for BE pathogenicity. In addition, these genes are also implicated in cancer shift from certain conditions.

CONCLUSION

On the whole, taking together these findings explain and support the cancerous origin of BE and introduced a panel of nominated biomarkers that could be more specific for BE rather than other types of esophageal problems. However, a complementary study to support this claim is suggested.

Bioinformatic analyses of microRNA-targeted genes and microarray-identified genes correlated with Barrett's esophagus

Barrett's esophagus (BE) is defined as a metaplasia condition in the distal esophagus, in which the native squamous epithelium lining is replaced by a columnar epithelium with or without intestinal metaplasia. It is commonly accepted that BE is a precancerous lesion for esophageal adenocarcinoma. The aim of this study was to investigate the aberrant microRNAs (miRNAs) and differentially expressed genes (DEGs) associated with BE based on online microarray datasets. One miRNA and five gene expression profiling datasets were retrieved from the Gene Expression Omnibus Database. Aberrant microRNAs and DEGs were obtained using R/Bioconductor statistical analysis language and software. 23 dysregulated miRNAs and 632 DEGs demonstrating consistent expression tendencies in the five gene microarrays were identified in BE. Moreover, 1962 target genes of aberrant miRNAs were predicted using three bioinformatic tools, namely TargetScan, RNA22-HSA and miRDB. Ultimately, 93 target DEGs were obtained, after which functional annotation was performed on DAVID Bioinformatics Resources. Among Gene Ontology (GO) biological processes, digestive tract development and epithelial cell differentiation have demonstrated significant associations with BE pathogenesis. In addition, analysis of the KEGG pathways has revealed associations with cancer. To enable further study, one miRNA-target DEGs regulatory network was constructed using Cytoscape. 6 target DEGs demonstrated higher-degree distributions in the network, and ROC analysis indicated that FNDC3B may be the best potential biomarker for BE diagnosis. The data presented herein may provide new perspectives for exploring BE pathogenesis and may offer hits with regard to potential biomarkers in BE diagnosis, prediction and therapeutic evaluation.

Circulating microRNAs as potential biomarkers to detect transformation of Barrett's oesophagus to oesophageal adenocarcinoma

Objective

Circulating microRNAs (miRNAs) are promising biomarkers for the early detection of cancers. This study aimed to address potential circulating miRNAs to monitor the progression from Barrett’s oesophagus (BO) to oesophageal adenocarcinoma (OAC).

Design

We comprehensively analysed tissue and serum miRNA expression profiles of BO mice model (L2-interleukin-1β (IL-1β) mice) using microarray analysis. To validate the data from mice, a published dataset of human plasma miRNAs, consisting of eight patients with OAC, eight with BO and six healthy controls, was used (GSE51410).

Results

We identified 20 upregulated miRNAs and 44 downregulated miRNAs both in tissues and in sera of 46-week-old mice compared with 28-week-old mice. Two of the 20 miRNAs (miR-128-3 p and miR-328-3 p) were upregulated, and five of the 44 miRNAs (miR-143-3 p, miR-144-3 p, miR-15a-5p, miR-1-3 p and miR-133b) were downregulated in plasma of patients with OAC compared with plasma of patients with BO. Receiver operating characteristic curve analysis revealed that a prediction index calculated by the above-mentioned seven miRNAs could discriminate between patients with OAC and those without OAC with the area under the curve of 0.91, sensitivity of 1 and specificity of 0.75.

Conclusions

Levels of the seven circulating miRNAs may represent the tissue miRNA levels and could be promising non-invasive biomarkers to evaluate the carcinogenic process of BO.

Expression signatures and roles of MicroRNAs in human oesophageal adenocarcinomas

The most common forms of oesophageal cancers are adenocarcinomas and squamous cell carcinoma (SCC). Although the incidence of SCC in the United States tends to be declining, the adenocarcinoma incidence caused by Barrett's oesophagus has been increasing. Oesophageal cancer is regarded as one of the most fatal malignancies with a short prognosis. Systemic manifestations of patients with PCNSL keep backward in spite of recent development of chemoradiotherapy. MicroRNAs are small non‐coding RNAs that can post‐transcriptionally down‐regulate the expression of genes by targeting mRNAs, causing their translational repression as well as degradation. MicroRNAs exert critical functions in many malignancy‐related biological processes, including cell apoptosis, metabolism, proliferation and differentiation. Many deregulated miRNAs have been identified in oesophageal adenocarcinomas, but their biological importance has not yet been fully elucidated. In this study, we review present evidence regarding the potential applications of oesophageal adenocarcinomas associated microRNAs for prognosis and diagnosis of this lethal disease.

Long Noncoding RNAs in the Pathogenesis of Barrett's Esophagus and Esophageal Carcinoma

For many years, only a small fraction of the human genome was believed to regulate cell function and development. This protein-coding portion composed only 1% to 2% of 3 billion human DNA base pairs-the remaining sequence was classified as junk DNA. Subsequent research has revealed that most of the genome is transcribed into a broad array of noncoding RNAs, ranging in size from microRNA (20-23 nucleotides) to long noncoding RNA (lncRNA, more than 200 nucleotides). These noncoding RNA classes have been shown to use diverse molecular mechanisms to control gene expression and organ system development. As anticipated, alterations in this large control system can contribute to disease pathogenesis and carcinogenesis. We review the involvement of noncoding RNAs, lncRNAs in particular, in development of Barrett's esophagus and esophageal carcinoma.