Identification of loci of functional relevance to Barrett's esophagus and esophageal adenocarcinoma: Cross-referencing of expression quantitative trait loci data from disease-relevant tissues with genetic association data

Effect of Aspirin on Biomarkers of Barrett's Esophagus After Successful Eradication with Radiofrequency Ablation

OBJECTIVES/METHODS

Placebo-controlled phase II study evaluated aspirin's effect on CDX2 mRNA and prostanoid production in native and neosquamous epithelium after successful radiofrequency ablation (RFA) in Barrett's esophagus.

RESULTS

At 12 months TXB2, PGF2α, PGD2, PGE2, PGE1, and α13PGE2 increased in native squamous but not neosquamous epithelium in individuals randomized to placebo. Aspirin use significantly reduced CDX2 mRNA in native squamous epithelium, and was associated with decreases in PGE1, PGE2 and 13PGE2 in neosquamous epithelium.

CONCLUSIONS

After RFA, native squamous and neosquamous epithelium exhibit different molecular markers and responses to aspirin suggesting that different sources of squamous progenitors contribute to esophageal re-epithelization.

A bidirectional Mendelian randomization study integrating genome-wide association studies, expression quantitative trait locus, and methylation quantitative trait locus data revealed causal relationship between heavy cigarette dependence and Barrett's esophagus

Background

The association between smoking dependence and the risk of developing Barrett's esophagus remains unclear. This study aimed to investigate whether a causal relationship exists between smoking dependence and Barrett's esophagus, using Mendelian randomization analysis.

Methods

Two-sample Mendelian randomization analysis was conducted to evaluate the impact of smoking and Barrett's esophagus. Additionally, we applied summary data-based Mendelian randomization techniques to combine information from genome-wide association studies (GWAS) with expression quantitative trait locus and methylation quantitative trait locus.

Results

Multivariable Mendelian randomization showed an association between smoking per day (odds ratio = 1.2, 95% confidence interval: 1.038-1.38, p = 0.014) or current smoking (odds ratio = 2.41, 95% confidence interval: 1.06-5.5, p = 0.037) and Barrett's esophagus. Inverse variance-weighted methods of bidirectional Mendelian randomization also revealed that smoking per day was significantly associated with elevated risks of Barrett's esophagus (odds ratio = 1.34, 95% confidence interval: 1.092-1.649, p = 0.005), while Barrett's esophagus was also a susceptibility factor for smoking per day (odds ratio = 1.05, 95% confidence interval: 1.017-1.087, p = 0.003). By incorporating consistent summary data-based Mendelian randomization associations between DNA methylation and smoke/Barrett's esophagus, gene expression and smoke/Barrett's esophagus, and DNA methylation and gene expression, we identified that the genetic variant-cg00935895-RBM43 (ENSG00000184898)-smoke/Barrett's esophagus axis exerted an effect on smoke/Barrett's esophagus by altering the DNA methylation level, which regulated the expression level of RBM43.

Conclusions

Our study provides evidence of a bidirectional causal association between smoking and Barrett's esophagus from a genetic perspective, which sheds new light on the potential role of RBM43 as a mediator in facilitating the impact of smoking and Barrett's esophagus.

Decoding common genetic alterations between Barrett's esophagus and esophageal adenocarcinoma: A bioinformatics analysis

Background

Esophageal adenocarcinoma (EAC) is a common cancer with a poor prognosis in advanced stages. Therefore, early EAC diagnosis and treatment have gained attention in recent decades. It has been found that various pathological changes, particularly Barrett's Esophagus (BE), can occur in the esophageal tissue before the development of EAC. In this study, we aimed to identify the molecular contributor in BE to EAC progression by detecting the essential regulatory genes that are differentially expressed in both BE and EAC.

Materials and methods

We conducted a comprehensive bioinformatics analysis to detect BE and EAC-associated genes. The common differentially expressed genes (DEGs) and common single nucleotide polymorphisms (SNPs) were detected using the GEO and DisGeNET databases, respectively. Then, hub genes and the top modules within the protein-protein interaction network were identified. Moreover, the co-expression network of the top module by the HIPPIE database was constructed. Additionally, the gene regulatory network was constructed based on miRNAs and circRNAs. Lastly, we inspected the DGIdb database for possible interacted drugs.

Results

Our microarray dataset analysis identified 92 common DEGs between BE and EAC with significant enrichment in skin and epidermis development genes. The study also identified 22 common SNPs between BE and EAC. The top module of PPI network analysis included SCEL, KRT6A, SPRR1A, SPRR1B, SPRR3, PPL, SPRR2B, EVPL, and CSTA. We constructed a ceRNA network involving three specific mRNAs, 23 miRNAs, and 101 selected circRNAs. According to the results from the DGIdb database, TD101 was found to interact with the KRT6A gene.

Conclusion

The present study provides novel potential candidate genes that may be involved in the molecular association between Esophageal adenocarcinoma and Barrett's Esophagus, resulting in developing the diagnostic tools and therapeutic targets to prevent progression of BE to EAC.

Intestinal-Type Adenocarcinoma in Head and Neck: Dissecting Oncogenic Gene Alterations Through Whole Transcriptome and Exome Analysis

Adenocarcinomas of the nasal/paranasal sinuses are uncommon, but intestinal-type adenocarcinomas (ITACs) are important. Due to the rarity of these tumors, their molecular profile is not well known. To further investigate the molecular profile and find potential oncogenic drivers, we compared the whole transcriptome and exome of ITACs at different anatomic locations in the head and neck. Twenty-one head and neck adenocarcinomas were used in this study, divided into 10 sinonasal adenocarcinomas (SNT) and 11 extrasinonasal (T) head and neck adenocarcinomas according to anatomic location and histology. Tumor samples along with normal mucosa were microdissected from formalin-fixed, paraffin-embedded samples, and RNA and DNA were subjected to whole-transcriptome and -exome shotgun sequencing. Analysis of ITACs at sinonasal locations showed 410 subtype-specific differentially expressed (DE) genes and noncoding transcripts compared with the group of other anatomic locations, with 2909 subtype-specific DE genes. The groups shared 872 genes, with 17 highly different or opposing DE genes. Whole-exome mutation analysis revealed the gene MLL3 (KMT2C) to be exhibiting the most frequent loss-of-function mutations in all adenocarcinomas investigated. The results suggest that the head and neck ITACs investigated were mainly caused by loss-of-function mutations in MLL3 that disabled chromatin methylation and remodeling of all MLL3-targeted enhancers in the tumors. This changed the activity of multiple genes/gene clusters, supporting oncogenicity mostly via pathways of signaling, dedifferentiation, proliferation, migration, and immune and inflammatory deregulation, indicating a truly epigenetic event as the root cause for the heterogenous diversity of these enteric types of cancer. The data of this study form the basis for understanding cell fate determination and cellular homeostasis in the normal respiratory mucosa at different anatomic sites and show the contribution of different mucosal components to the etiology/molecular pathology of ITAC.

Cranberry Proanthocyanidins Mitigate Reflux-Induced Transporter Dysregulation in an Esophageal Adenocarcinoma Model

We recently reported that cranberry proanthocyanidins (C-PACs) inhibit esophageal adenocarcinoma (EAC) by 83% through reversing reflux-induced bacterial, inflammatory and immune-implicated proteins and genes as well as reducing esophageal bile acids, which drive EAC progression. This study investigated whether C-PACs' mitigation of bile reflux-induced transporter dysregulation mechanistically contributes to EAC prevention. RNA was isolated from water-, C-PAC- and reflux-exposed rat esophagi with and without C-PAC treatment. Differential gene expression was determined by means of RNA sequencing and RT-PCR, followed by protein assessments. The literature, coupled with the publicly available Gene Expression Omnibus dataset GSE26886, was used to assess transporter expression levels in normal and EAC patient biopsies for translational relevance. Significant changes in ATP-binding cassette (ABC) transporters implicated in therapeutic resistance in humans (i.e., Abcb1, Abcb4, Abcc1, Abcc3, Abcc4, Abcc6 and Abcc10) and the transport of drugs, xenobiotics, lipids, and bile were altered in the reflux model with C-PACs' mitigating changes. Additionally, C-PACs restored reflux-induced changes in solute carrier (SLC), aquaporin, proton and cation transporters (i.e., Slc2a1, Slc7a11, Slc9a1, Slco2a1 and Atp6v0c). This research supports the suggestion that transporters merit investigation not only for their roles in metabolism and therapeutic resistance, but as targets for cancer prevention and targeting preventive agents in combination with chemotherapeutics.

Mechanisms and pathophysiology of Barrett oesophagus

Barrett oesophagus, in which a metaplastic columnar mucosa that can predispose individuals to cancer development lines a portion of the distal oesophagus, is the only known precursor of oesophageal adenocarcinoma, the incidence of which has increased profoundly over the past several decades. Most evidence suggests that Barrett oesophagus develops from progenitor cells at the oesophagogastric junction that proliferate and undergo epithelial-mesenchymal transition as part of a wound-healing process that replaces oesophageal squamous epithelium damaged by gastroesophageal reflux disease (GERD). GERD also seems to induce reprogramming of key transcription factors in the progenitor cells, resulting in the development of the specialized intestinal metaplasia that is characteristic of Barrett oesophagus, probably through an intermediate step of metaplasia to cardiac mucosa. Genome-wide association studies suggest that patients with GERD who develop Barrett oesophagus might have an inherited predisposition to oesophageal metaplasia and that there is a shared genetic susceptibility to Barrett oesophagus and to several of its risk factors (such as GERD, obesity and cigarette smoking). In this Review, we discuss the mechanisms, pathophysiology, genetic predisposition and cells of origin of Barrett oesophagus, and opine on the clinical implications and future research directions.

Anatomical implication of less occurrence of inferior oblique muscle entrapment in orbital floor trapdoor fracture

PURPOSE

To examine the anatomy of the inferior oblique (IO) muscle and its surrounding structures to clarify why IO muscle entrapment develops less in orbital floor trapdoor fractures.

METHODS

Computed tomographic (CT) images on the unaffected sides were obtained from 64 patients with unilateral orbital fractures. On coronal planes, presence or absence of an infraorbital groove below the IO muscle was confirmed. At the level of the medial margin of the infraorbital groove/canal, the distance from the orbital floor to the IO muscle (IO-floor distance), the thickness of the orbital floor, and the shortest distance from the inferior rectus (IR) muscle to the orbital floor (shortest IR-floor distance) were measured. On quasi-sagittal planes, the distances from the inferior orbital rim to the inferior margin of the IO muscle (IO-rim distance) and the most anterior point of the infraorbital groove (groove-rim distance) were measured.

RESULTS

The infraorbital groove was found below the IO muscle in eight patients (12.5%), and the IO-rim and IO-floor distances were significantly longer than the groove-rim and shortest IR-floor distances, respectively (p < 0.001). The orbital floor below the IO muscle was significantly thicker than that below the IR muscle (p < 0.001).

CONCLUSION

Although the medial margin of the infraorbital groove is the most common fracture site, the IO muscle was not located above the groove in most cases. A longer IO-floor distance and thicker orbital floor below the IO muscle may also contribute to less occurrence of IO muscle entrapment in orbital floor trapdoor fractures.

Sex-Specific Genetic Associations for Barrett's Esophagus and Esophageal Adenocarcinoma

BACKGROUND & AIMS

Esophageal adenocarcinoma (EA) and its premalignant lesion, Barrett's esophagus (BE), are characterized by a strong and yet unexplained male predominance (with a male-to-female ratio in EA incidence of up to 6:1). Genome-wide association studies (GWAS) have identified more than 20 susceptibility loci for these conditions. However, potential sex differences in genetic associations with BE/EA remain largely unexplored.

METHODS

Given strong genetic overlap, BE and EA cases were combined into a single case group for analysis. These were compared with population-based controls. We performed sex-specific GWAS of BE/EA in 3 separate studies and then used fixed-effects meta-analysis to provide summary estimates for >9 million variants for male and female individuals. A series of downstream analyses were conducted separately in male and female individuals to identify genes associated with BE/EA and the genetic correlations between BE/EA and other traits.

RESULTS

We included 6758 male BE/EA cases, 7489 male controls, 1670 female BE/EA cases, and 6174 female controls. After Bonferroni correction, our meta-analysis of sex-specific GWAS identified 1 variant at chromosome 6q11.1 (rs112894788, KHDRBS2-MTRNR2L9, PBONF = .039) that was statistically significantly associated with BE/EA risk in male individuals only, and 1 variant at chromosome 8p23.1 (rs13259457, PRSS55-RP1L1, PBONF = 0.057) associated, at borderline significance, with BE/EA risk in female individuals only. We also observed strong genetic correlations of BE/EA with gastroesophageal reflux disease in male individuals and obesity in female individuals.

CONCLUSIONS

The identified novel sex-specific variants associated with BE/EA could improve the understanding of the genetic architecture of the disease and the reasons for the male predominance.