Molecular landscape of esophageal cancer: implications for early detection and personalized therapy

Hypoxia‑regulated exosomal miR‑185 inhibits esophageal squamous cell carcinoma progression and predicts prognosis

Despite advances in treatment and diagnosis, the prognosis of patients with esophageal squamous cell carcinoma (ESCC) remains poor. MicroRNAs (miRNAs/miRs) are associated with prognosis in esophageal cancer, indicating that they may help guide treatment decisions. The aim of the present study was to explore exosomal miR-185 as a candidate prognostic biomarker and therapeutic target in ESCC, to investigate its biological function and clinical significance, and to ascertain the applicability of circulating exosomal miR-185 for the development of targeted drugs for ESCC treatment. A GeneChip miRNA array was used to compare exosomal miRNA expression in ESCC cell lines under hypoxia with those under normoxia. Exosomal miR-185 expression was then confirmed by reverse transcription-quantitative PCR. Patient background and prognosis were compared between high and low miR-185 expression groups. Functional analyses were performed to evaluate the antitumor effects of miR-185 in ESCC cells. Global Gene Set Enrichment Analysis of The Cancer Genome Atlas data was also performed, and differentially expressed exosomal miRNAs under hypoxia were identified compared to those under normoxia. Hypoxia markedly decreased the expression of exosomal miR-185 in KYSE-960 and T.Tn cell culture media. Overexpression of miR-185 suppressed the migration, invasion and colony-forming abilities of ESCC lines, and also suppressed cell cycle progression and promoted apoptosis after cisplatin treatment. Notably, high miR-185 expression was associated with signaling pathways related to cell death, DNA damage and p53. Furthermore, circulating exosomal miR-185 levels were associated with cN and cStage, and could predict progression-free survival and disease-specific survival of patients with ESCC after initial treatment. In conclusion, miR-185 holds potential as a prognostic biomarker and therapeutic target in ESCC.

Keratin 17 and Collagen type 1 genes: Esophageal cancer molecular marker discovery and evaluation

One hundred eighty pairs of tissues of esophageal squamous cell carcinoma (ESCC) were tested by the transcriptome sequencing in order to explore etiology factors. The chi-square test and correlation analysis demonstrated that the relative expression levels of keratin 17 (KRT17) and collagen type I α1 chain (COL1A1) were significantly higher in EC with diabetes. Expression of KRT17 was correlated with blood glucose (r = 0.204, p = 0.001) and tumor size (r = -0.177, p = 0.038) in patients. COL1A1 correlated with age (r = -0.170, p = 0.029) and blood glucose levels (r = 0.190, p = 0.015). Experimental results of qRT-PCR: KRT17 and COL1A1 genes were highly expressed in ESCC (p < 0.05). When the two genes were used as a combination test, the positive detection rate of EC was 90.6%, and the ROC curve had greater power. The KRT17 and COL1A1 genes had the potential to be biomarkers for the diagnosis of ESCC.

Latest insights into the global epidemiological features, screening, early diagnosis and prognosis prediction of esophageal squamous cell carcinoma

As a highly invasive carcinoma, esophageal cancer (EC) was the eighth most prevalent malignancy and the sixth leading cause of cancer-related death worldwide in 2020. Esophageal squamous cell carcinoma (ESCC) is the major histological subtype of EC, and its incidence and mortality rates are decreasing globally. Due to the lack of specific early symptoms, ESCC patients are usually diagnosed with advanced-stage disease with a poor prognosis, and the incidence and mortality rates are still high in many countries, especially in China. Therefore, enormous challenges still exist in the management of ESCC, and novel strategies are urgently needed to further decrease the incidence and mortality rates of ESCC. Although the key molecular mechanisms underlying ESCC pathogenesis have not been fully elucidated, certain promising biomarkers are being investigated to facilitate clinical decision-making. With the advent and advancement of high-throughput technologies, such as genomics, proteomics and metabolomics, valuable biomarkers with high sensitivity, specificity and stability could be identified for ESCC. Herein, we aimed to determine the epidemiological features of ESCC in different regions of the world, especially in China, and focused on novel molecular biomarkers associated with ESCC screening, early diagnosis and prognosis prediction.

IL-1β promotes esophageal squamous cell carcinoma growth and metastasis through FOXO3A by activating the PI3K/AKT pathway

Esophageal cancer is a common type of cancer that poses a significant threat to human health. While the pro-inflammatory cytokine IL-1β has been known to contribute to the development of various types of tumors, its role in regulating esophageal cancer progression has not been extensively studied. Our studies found that the expression of IL-1β and FOXO3A was increased in esophageal squamous cell carcinoma (ESCC). IL-1β not only increased the proliferation, migration, and invasion of two ESCC cell lines but also promoted tumor growth and metastasis in nude mice. We also observed that IL-1β and FOXO3A regulated the process of epithelial-mesenchymal transition (EMT) and autophagy. The PI3K/AKT pathway was found to be involved in the changes of FOXO3A with the expression level of IL-1β. The AKT agonist (SC79) reversed the reduction of FOXO3A expression caused by the knockdown of IL-1β, indicating that IL-1β plays a role through the PI3K/AKT/FOXO3A pathway. Furthermore, the knockdown of FOXO3A inhibited ESCC development and attenuated the pro-cancer effect of overexpressed IL-1β. Targeting IL-1β and FOXO3A may be potentially valuable for the diagnosis and treatment of ESCC.

DNA methylation markers in esophageal cancer

Background

Esophageal cancer (EC) is a prevalent malignancy characterized by a low 5-year survival rate, primarily attributed to delayed diagnosis and limited therapeutic options. Currently, early detection of EC heavily relies on endoscopy and pathological examination, which pose challenges due to their invasiveness and high costs, leading to low patient compliance. The detection of DNA methylation offers a non-endoscopic, cost-effective, and secure approach that holds promising prospects for early EC detection.

Methods

To identify improved methylation markers for early EC detection, we conducted a comprehensive review of relevant literature, summarized the performance of DNA methylation markers based on different input samples and analytical methods in EC early detection and screening.

Findings

This review reveals that blood cell free DNA methylation-based method is an effective non-invasive method for early detection of EC, although there is still a need to improve its sensitivity and specificity. Another highly sensitive and specific non-endoscopic approach for early detection of EC is the esophageal exfoliated cells based-DNA methylation analysis. However, while there are substantial studies in esophageal adenocarcinoma, further more validation is required in esophageal squamous cell carcinoma.

Conclusion

In conclusion, DNA methylation detection holds significant potential as an early detection and screening technology for EC.

Novel milestones for early esophageal carcinoma: From bench to bed

Esophageal cancer (EC) is the seventh most common cancer worldwide, and esophageal squamous cell carcinoma (ESCC) accounts for the majority of cases of EC. To effectively diagnose and treat ESCC and improve patient prognosis, timely diagnosis in the initial phase of the illness is necessary. This article offers a detailed summary of the latest advancements and emerging technologies in the timely identification of ECs. Molecular biology and epigenetics approaches involve the use of molecular mechanisms combined with fluorescence quantitative polymerase chain reaction (qPCR), high-throughput sequencing technology (next-generation sequencing), and digital PCR technology to study endogenous or exogenous biomolecular changes in the human body and provide a decision-making basis for the diagnosis, treatment, and prognosis of diseases. The investigation of the microbiome is a swiftly progressing area in human cancer research, and microorganisms with complex functions are potential components of the tumor microenvironment. The intratumoral microbiota was also found to be connected to tumor progression. The application of endoscopy as a crucial technique for the early identification of ESCC has been essential, and with ongoing advancements in technology, endoscopy has continuously improved. With the advancement of artificial intelligence (AI) technology, the utilization of AI in the detection of gastrointestinal tumors has become increasingly prevalent. The implementation of AI can effectively resolve the discrepancies among observers, improve the detection rate, assist in predicting the depth of invasion and differentiation status, guide the pericancerous margins, and aid in a more accurate diagnosis of ESCC.

Concordance of assessments of four PD-L1 immunohistochemical assays in esophageal squamous cell carcinoma (ESCC)

OBJECTIVE

Given real-world limitations in programmed death-ligand 1 (PD-L1) testing, concordance studies between PD-L1 assays are needed. We undertook comparisons of PD-L1 assays (DAKO22C3, Ventana SP263, Ventana SP142, E1L3N) among observers in esophageal squamous cell carcinoma (ESCC) to provide information on the analytical and clinical comparability of four PD-L1 IHC assays.

METHODS

Paraffin embedded samples of 50 cases of esophageal squamous cell carcinoma were obtained, satined with all four PD-L1 assays. PD-L1 was evaluated by 68 pathologists from 19 different hospitals. PD-L1 expression was assessed for combined positive score (CPS).

RESULTS

The expression sensitivity of SP263 was the highest in ESCC, followed by 22C3, E1L3N and SP142. Taking CPS 10 as the critical value, inter-observer concordance for CPS scores among 68 physicians was assessed for the 22C3, SP263, SP142, and E1L3N assays, yielding values of 0.777, 0.790, 0.758, and 0.782, respectively. In the comparison between assays, the overall CPS scores concordance rates between 22C3 and SP263, SP142, and E1L3N were 0.896, 0.833, and 0.853, respectively. 22C3 and SP263 have high concordance, with OPA of 0.896, while E1L3N and SP142 have the highest concordance, with OPA of 0.908.

CONCLUSION

In ESCC, the concordance of PD-L1 evaluation among observers is good, and the immune cell score is still an important factor affecting the concordance of interpretation among observers. Cases near the specific threshold are still the difficult problem of interpretation. SP263 had the highest CPS score of the four assays. SP263 cannot identify all 22C3 positive cases, but had good concordance with 22C3.E1L3N and SP142 showed high concordance.

Expression of PTP4A1 in circulating tumor cells and its efficacy evaluation in patients with early- and intermediate-stage esophageal cancer

The objective of this study is to investigate the expression of protein tyrosine phosphatase type I (PTP4A1) in circulating tumor cells (CTCs) in patients with early- and intermediate-stage esophageal cancer and its clinical value in evaluating patient prognosis. Tissue and peripheral blood samples were collected from patients with esophageal cancer, as well as their clinical data. Follow-up was performed on all patients. PTP4A1 expression in the CTCs of patients were analyzed by regression analysis, and its correlation with the clinical characteristics of esophageal cancer was discussed. The numbers of mixed tumor cells and T-CTCs were significantly correlated with lymph node metastasis. Advanced tumor-node metastasis (TNM) stage (odds ratio = 12.063) and lymph node metastasis (odds ratio = 13.541) were influencing factors of PTP4A1+MCTC expression disorders in patients with esophageal cancer. The receiver operating characteristic curve showed that TNM stage and lymph node metastasis had a high predictive efficiency for PTP4A1+MCTCs, with an area under the ROC curve of 0.725. PTP4A1+mixed tumor cells had strong predictive value for the efficacy of neoadjuvant therapy, with a sensitivity of 94.7% and a specificity of 63.6%. Advanced TNM stage and lymph node metastasis are influencing factors for increased CTCs and poor expression of PTP4A1 in patients with esophageal cancer.

PHGDH promotes esophageal squamous cell carcinoma progression via Wnt/β-catenin pathway

PURPOSE

Esophageal squamous carcinoma (ESCC) with a high incidence in China, lacks effective therapeutic targets. Phosphoglycerate dehydrogenase (PHGDH) is a key enzyme in serine biosynthesis. However, the biological role of PHGDH in ESCC has not been revealed.

METHODS

The expression of PHGDH in ESCC was investigated by UALCAN. The relationship between PHGDH expression and its prognostic value was analyzed by Kaplan-Meier and univariate Cox regression. Further, the potential functions of PHGDH involved in ESCC were explored through DAVID database and GSEA software. In addition, the expression of PHGDH was verified in ESCC. Then, the effects of PHGDH knockdown on ESCC were evaluated in vitro and in vivo by cell proliferation, clone formation, cell cycle, apoptosis, tube formation assays and ESCC cells derived xenograft model. In addition, western blotting and immunohistochemistry were used to detect the expression of Wnt/β-catenin pathway which was associated with PHGDH.

RESULTS

Bioinformatics analysis found that PHGDH was highly expressed in ESCC, and meaningfully, patients with high PHGDH expression had a poor prognosis. Moreover, the overexpression of PHGDH was verified in ESCC. Afterwards, PHGDH knockdown inhibited the cell proliferation, induced cell cycle arrest and apoptosis in ESCC cells, and inhibited the angiogenesis of HUVECs induced by ESCC conditioned medium, as well as inhibited the growth of xenograft tumor. Mechanistically, PHGDH knockdown inhibited Wnt/β-catenin signaling pathway in ESCC.

CONCLUSION

High expression of PHGDH predicts a poor prognosis for ESCC. PHGDH knockdown inhibits ESCC progression by suppressing Wnt/β-catenin signaling pathway, indicating that PHGDH might be a potential target for ESCC therapy.

Daurisoline suppresses esophageal squamous cell carcinoma growth in vitro and in vivo by targeting MEK1/2 kinase

Esophageal squamous cell carcinoma (ESCC) accounts for 90% of esophageal cancers and has a high mortality rate worldwide. The 5-year survival rate of ESCC patients in developing countries is <20%. Hence, there is an urgent need for developing new and effective treatments that are based on newly-discovered emerging molecules and pathways to prevent ESCC occurrence and recurrence. We investigated the effects of Daurisoline, a bis-benzylisoquinoline alkaloid extracted from the rhizome of menisperum dauricum, on ESCC cell proliferation and elucidated the molecular mechanisms underlying its functions. To explore the effects of Daurisoline on ESCC growth in vitro and in vivo, cell proliferation assays and anchorage-independent growth assays were performed and a patient-derived xenograft (PDX) model was established. Subsequently, phosphoproteomics, molecular docking analysis, pull down assays, mutation experiments and in vitro kinase assay were performed to explore the mechanism of Daurisoline's function on ESCC. Daurisoline inhibited ESCC proliferation in vitro and reduced ESCC PDX exnograft growth in vivo by reducing ERK1/2 phosphorylation. Furthermore, it directly bound to MEK1 (at Asn78 and Lys97) and MEK2 (at Asp194 and Asp212) kinases to inactivate the ERK1/2 signaling pathway. Our results suggest that Daurisoline is a dual inhibitor of MEK1 and MEK2 and suppresses ESCC growth both in vitro and in vivo by inactivating the ERK1/2 signaling pathway. This is first report on the use of MEK inhibitor for ESCC and highlights its potential applications for ESCC treatment and prevention.

Long intergenic non-protein coding RNA 00858 participates in the occurrence and development of esophageal squamous cell carcinoma through the activation of the FTO-m6A-MYC axis by recruiting ZNF184

OBJECTIVES

We aimed at probing impact of LINC00858 on esophageal squamous cell carcinoma (ESCC) progression via ZNF184-FTO-m⁶A-MYC axis.

METHODS

Expression of related genes (LINC00858, ZNF184, FTO, and MYC) was detected in ESCC tissues or cells and their relationships were assessed. After expression alterations in ESCC cells, cell proliferation, invasion, migration, and apoptosis were detected. Tumor formation in nude mice was conducted.

RESULTS

LINC00858, ZNF184, FTO, and MYC were overexpressed in ESCC tissues and cells. LINC00858 enhanced ZNF184 expression to upregulate FTO, which augmented MYC expression. LINC00858 knockdown diminished ESCC cell proliferative, migratory, and invasive properties while elevating apoptosis, which was negated by FTO overexpression. FTO knockdown exerted similar functions of LINC00858 knockdown on ESCC cell movements, which was annulled by MYC upregulation. Silencing LINC00858 repressed tumor growth and related gene expression in nude mice.

CONCLUSIONS

LINC00858 modulated MYC m⁶A modification via FTO by recruiting ZNF184, thus facilitating ESCC progression.

Mir-421 and mir-550a-1 are potential prognostic markers in esophageal adenocarcinoma

OBJECTIVE

To identify the prognostic indicators of esophageal adenocarcinoma (EAC) for future EAC diagnosis and treatment.

METHODS

The EAC dataset from The Cancer Genome Atlas was screened for differentially expressed microRNAs (miRNAs) and mRNAs associated with EAC. Weighted gene coexpression network analysis was performed to cluster miRNAs or mRNA with similar expression patterns to identify the miRNAs or mRNA that are highly associated with EAC. Prognostic miRNAs for overall survival (OS) were identified using Cox proportional-hazards regression analysis and least absolute shrinkage and selection operator based on survival duration and status. Two types of miRNAs were selected to develop a prognostic signature model for EAC using multiple Cox regression analysis. Furthermore, the signature was validated using internal validation sets 1 and 2. The receiver operating characteristic curve and concordance index were used to evaluate the accuracy of the signature and validation sets. The expression of miR-421, miR-550a-3p, and miR-550a-5p was assessed using quantitative polymerase chain reaction (qPCR). The proliferation, invasion, and migration of EAC cells were assessed using CCK8 and transwell assays. The OS of target mRNAs was assessed using Kaplan-Meier analysis. Functional enrichment analysis of the target mRNAs was performed using Metascape.

RESULTS

The prognostic signature and validation sets comprising mir-421 and mir-550a-1 had favorable predictive power in OS. Compared with the patients with EAC in the high-expression group, those assigned to the low-expression group displayed increased OS according to survival analysis. Differential and qPCR analysis showed that miR-421, miR-550a-3p, and miR-550a-5p were highly expressed in the EAC tissues and cell lines. Moreover, the downregulation of miR-421 and miR-550a-3p with inhibitor markedly suppressed the proliferation, invasion, and migration in OE33 cells compared with the negative control. A total of 20 target mRNAs of three miRNAs were predicted, among which seven target mRNAs-ASAP3, BCL2L2, LMF1, PPM1L, PTPN21, SLC18A2, and NR3C2-had prognostic value; PRKACB, PDCD4, RPS6KA5, and BCL2L2 were enriched in the miRNA cancer pathway.

CONCLUSION

Prognostic indicators of EAC may be useful in future EAC diagnosis and treatment.

Association between serum baseline C1q and IgG levels and the efficacy of combined immunotherapy in patients with esophageal squamous cell carcinoma: a retrospective study

BACKGROUND

To assess the clinical value of serum complement component 1q (C1q) and immunoglobulin G (IgG) levels in predicting the response to combined immunotherapy in patients with esophageal squamous cell carcinoma.

METHODS

We conducted a retrospective study of 44 patients with esophageal squamous cell carcinoma who received combined immunotherapy in our hospital. Serum IgG and C1q levels were collected before and three weeks after immunotherapy treatment, together with other data on clinical and demographic characteristics.

RESULTS

Twenty seven patients (61.4%) showed partial response (PR), 13 (29.5%) stable disease (SD), and 4 (9.1%) progressive disease (PD). None of the patients presented complete response (CR). The PR group displayed lower IgG and higher C1q levels both before and after immunotherapy than patients showing SD or PD. The IgG reduction (59.3%) and C1q increment (70.3%) in the PR group three weeks post-treatment were significantly larger than those in patients showing SD or PD. Moreover, the pretreatment C1q level and the post-treatment change of C1q levels were strongly associated with the immunotherapy response.

CONCLUSIONS

High pre- and post-treatment C1q levels and reduced post-treatment IgG levels correlate with efficacy of combined immunotherapy in patients with esophageal squamous cell carcinoma. Serum baseline C1q level may predict immunotherapy response in such patients.

LncRNA HOXA10-AS promotes the progression of esophageal carcinoma by regulating the expression of HOXA10

Esophageal cancer (EC) remains a primary cause of cancer-associated fatality worldwide and is characterized by poor prognosis. HOXA10-AS is reported to be relevant with the development of different human cancers. However, its role and regulatory mechanism in EC are still obscure. Our study targeted at investigating the functional and mechanical roles of HOXA10-AS in EC. We confirmed by RT-qPCR that HOXA10-AS presented a remarkably high expression in EC cells. Functional experiments demonstrated that knocking down HOXA10-AS weakened proliferation, invasion and migration in vitro and impeded tumorigenesis in vivo. Further, we found that HOXA10-AS positively regulated its neighbor gene HOXA10 and influenced EC cell biological activities depending on HOXA10. Mechanistically, we showed that HOXA10-AS combined with FMR1 to target and stabilize HOXA10 mRNA. Moreover, HOXA10 served as a transcriptional factor to stimulate the transcription of its target gene CHDH. Finally, rescue assays confirmed that HOXA10 influenced EC cell growth through modulating CHDH. In conclusion, our study first determines the function of HOXA10-AS in EC and demonstrates its mechanism relating to HOXA10/CHDH, suggesting HOXA10-AS as a potential novel target for EC treatment. [Figure: see text].

A New Model of Esophageal Cancers by Using a Detergent-Free Decellularized Matrix in a Perfusion Bioreactor

The lack of physiologically relevant human esophageal cancer models has as a result that many esophageal cancer studies are encountering major bottleneck challenges in achieving breakthrough progress. To address the issue, here we engineered a 3D esophageal tumor tissue model using a biomimetic decellularized esophageal matrix in a customized bioreactor. To obtain a biomimetic esophageal matrix, we developed a detergent-free, rapid decellularization method to decellularize porcine esophagus. We characterized the decellularized esophageal matrix (DEM) and utilized the DEM for the growth of esophageal cancer cell KYSE30 in well plates and the bioreactor. We then analyzed the expression of cancer-related markers of KYSE30 cells and compared them with formalin-fixed, paraffin-embedded (FFPE) esophageal squamous cell carcinoma (ESCC) tissue biospecimens. Our results show that the detergent-free decellularization method preserved the esophageal matrix components and effectively removed cell nucleus. KYSE30 cancer cells proliferated well on and inside the DEM. KYSE30 cells cultured on the DEM in the dynamic bioreactor show different cancer marker expressions than those in the static well plate, and also share some similarities to the FFPE-ESCC biospecimens. These findings built a foundation with potential for further study of esophageal cancer behavior in a biomimetic microenvironment using this new esophageal cancer model.

Factors Associated With Esophagus Cancers in Togo, Sub-Saharan Africa

Background

Esophagus cancer is cancer of poor prognosis, of often late diagnosis. The objective of this study was to describe the factors associated with esophagus cancers in the Togolese population.

Methods

It was a retrospective descriptive, cross-sectional study, on esophagus cancers histologically diagnosed at the Pathological Laboratory of Lomé over a period of 31 years (1990-2021).

Results

We have collected 144 cases of esophagus cancer. The average age of patients was 57 ± 12 years, and the sex ratio was 2.34. The most applicant service was the service of Hepato Gastroenterology of CHU Campus (30.6%). Alcohol (57.6%), tobacco (45.8%) were the most present risk factors. Biopsies were the most addressed (97.2%). The average duration of symptom evolution was 6.42 months and the main symptom at the time of diagnosis was dysphagia (36.8%). The location of cancer was the lower third for 71.5% of cases. At histology, epidermoid carcinoma was the dominant type (90.3%). Male sex was statistically associated with the occurrence of epidermoid carcinoma and female sex with the occurrence of adenocarcinoma (P < .001). Alcohol, smoking, and consumption of hot foods were statistically associated with the occurrence of epidermoid carcinoma in this study (P < .05).

Conclusion

Esophagus cancer remains a serious condition for late diagnosis. These are mainly epidermoid carcinomas and having alcohol and tobacco as risk factors. The awareness of the population on the main risk factors would reduce the incidence of oesophagus cancers within the Togolese population.

The Role of Alternative Splicing Factors hnRNP G and Fox-2 in the Progression and Prognosis of Esophageal Cancer

Aim. Alternative splicing (AS) has been widely demonstrated in the occurrence and progression of many cancers. Nevertheless, the involvement of cancer-associated splicing factors in the development of esophageal carcinoma (ESCA) remains to be explored. Method. RNA-Seq data and the corresponding clinical information of the ESCA cohort were downloaded from The Cancer Genome Atlas database. Bioinformatics methods were used to further analyzed the differently expressed AS (DEAS) events and their splicing network. Kaplan–Meier, Cox regression, and unsupervised cluster analyses were used to assess the association between AS events and clinical characteristics of ESCA patients. The splicing factors screened out were verified in vitro at the cellular level. Results. A total of 50,342 AS events were identified, of which 3,988 were DEAS events and 46 of these were associated with overall survival (OS) of ESCA patients, with a 5-year OS rate of 0.941. By constructing a network of AS events with survival-related splicing factors, the AS factors related to prognosis can be further identified. In vitro experiments and database analysis confirmed that the high expression of hnRNP G in ESCA is related to the high invasion ability of ESCA cells and the poor prognosis of ESCA patients. In contrast, the low expression of fox-2 in esophageal cancer is related to a better prognosis. Conclusion. ESCA-associated AS factors hnRNP G and Fox-2 are of great value in deciphering the underlying mechanisms of AS in ESCA and providing clues for therapeutic goals for further validation.

Bombyx mori Cecropin D could trigger cancer cell apoptosis by interacting with mitochondrial cardiolipin

Cecropin D is an antimicrobial peptide from Bombyx mori displaying anticancer and pro-apoptotic activities and, together with Cecropin XJ and Cecropin A, one of the very few peptides targeting esophageal cancer. Cecropin D displays poor similarity to other cecropins but a remarkable similarity in the structure and activity spectrum with Cecropin A and Cecropin XJ, offering the possibility to highlight key motifs at the base of the biological activity. In this work we show by NMR and MD simulations that Cecropin D is partially structured in solution and stabilizes its two-helix folding upon interaction with biomimetic membranes. Simulations show that Cecropin D strongly interacts with the surface of cancer cell biomimetic bilayers where it recognises the phosphatidylserine headgroup often exposed in the outer leaflet of cancerous cells by means of specific salt bridges. Cecropin D is also able to penetrate deeply in bilayers containing cardiolipin, a phospholipid found in mitochondria, causing significant destabilization in the lipid packing which might account for its pro-apoptotic activity. In bacterial membranes, phosphatidylglycerol and phosphatidylethanolamine act synergically by electrostatically attracting cecropin D and providing access to the membrane core, respectively.

Cisplatin-induced pyroptosis is mediated via the CAPN1/CAPN2-BAK/BAX-caspase-9-caspase-3-GSDME axis in esophageal cancer

Esophageal cancer is the seventh most common cancer globally. Chemotherapy resistance remains a significant challenge in the treatment of esophageal cancer patients. Cisplatin can damage tumor cells by inducing pyroptosis. However, the underlying molecular mechanisms remain unclear. In this work, we aim to investigate pyroptosis-dependent molecular mechanisms underlying cisplatin sensitivity and find potential biomarkers to predict response to cisplatin-based chemotherapy for esophageal cancer patients. Pyroptosis-associated proteins were screened via proteomics for esophageal cancer (n = 124) and bioinformatics analysis. We observed that high calpain-1 (CAPN1) and calpain-2 (CAPN2) expression were associated with favorable clinical outcomes and prolonged survival in esophageal cancer patients. We employed immunohistochemistry to evaluate the expression of CAPN1 and CAPN2 in pretreatment tumor biopsies from 108 patients with esophageal cancer who received concurrent chemoradiotherapy (CCRT). These results suggested that esophageal cancer patients with high expression of both CAPN1 and CAPN2 are likely to experience a complete response to CCRT and have significantly better survival. Western blotting, LDH release, calpain activity and cell viability assays indicated that cisplatin could activate calpain activity, while calpain inhibition or knockout suppressed cisplatin-induced pyroptosis. Mechanistically, we uncovered a novel mechanism whereby cisplatin induced pyroptosis via activation of a CAPN1/CAPN2-BAK/BAX-caspase-9-caspase-3-GSDME signaling axis in esophageal cancer cells. Collectively, this study is the first to explore the effects of calpain on cisplatin-induced pyroptosis in esophageal cancer cells. Further, our findings also imply that the combination of CAPN1 and CAPN2 could be considered as a promising biomarker of cisplatin sensitivity and prognosis in patients with esophageal cancer, providing a possibility to guide individualized treatment.

Prognostic score model based on six m6A-related autophagy genes for predicting survival in esophageal squamous cell carcinoma

BACKGROUND

Prognostic signatures based on autophagy genes have been proposed for esophageal squamous cell carcinoma (ESCC). Autophagy genes are closely associated with m6A genes. Our purpose is to identify m6A-related autophagy genes in ESCC and develop a survival prediction model.

METHODS

Differential expression analyses for m6A genes and autophagy genes were performed based on TCGA and HADd databases followed by constructing a co-expression network. Uni-variable Cox regression analysis was performed for m6A-related autophagy genes. Using the optimal combination of feature genes by LASSO Cox regression model, a prognostic score (PS) model was developed and subsequently validated in an independent dataset.

RESULTS

The differential expression of 13 m6A genes and 107 autophagy genes was observed between ESCC and normal samples. The co-expression network contained 13 m6A genes and 96 autophagy genes. Of the 12 m6A-related autophagy genes that were significantly related to survival, DAPK2, DIRAS3, EIF2AK3, ITPR1, MAP1LC3C, and TP53 were used to construct a PS model, which split the training set into two risk groups with significant different survival ratios (p = 0.015, 1-year, 3-year, and 5-year AUC = 0.873, 0.840, and 0.829). Consistent results of GSE53625 dataset confirmed predictive ability of the model (p = 0.024, 1-year, 3-year, and 5-year AUC = 0.793, 0.751, and 0.744). The six-gene PS score was an independent prognostic factor from clinical factors (HR, 2.362; 95% CI, 1.390-7.064; p-value = 0.012).

CONCLUSION

Our study recommends 6 m6A-related autophagy genes as promising prognostic biomarkers and develops a PS model to predict survival in ESCC.

LAMP2 as a Biomarker Related to Prognosis and Immune Infiltration in Esophageal Cancer and Other Cancers: A Comprehensive Pan-Cancer Analysis

Esophageal cancer (ESCA) is a common malignant tumor with poor prognosis. Accumulating evidence indicates an important role of lysosomal-associated membrane protein 2 (LAMP2) in the progression and development of various cancers. In this study, we obtained RNA-sequencing raw count data and the corresponding clinical information for ESCA samples from The Cancer Genome Atlas and Gene Expression Omnibus databases. We comprehensively investigated the expression and prognostic significance of LAMP2 and relationships between LAMP2 expression and prognosis, different clinicopathological parameters, and immune cell infiltration in ESCA. We also obtained the differentially expressed genes between the high LAMP2 expression and low LAMP2 expression groups in ESCA and performed a functional enrichment analysis of the 250 linked genes most positively related to LAMP2 expression. Moreover, we performed the pan-cancer analysis of LAMP2 to further analyze the role of LAMP2 in 25 commonly occurring types of human cancer. We also verified and compared the expression of LAMP2 in 40 samples of human ESCA tissue and adjacent tissues. The results indicated that LAMP2 expression was significantly upregulated in ESCA and various human cancers. In addition, LAMP2 expression was associated with certain clinicopathological parameters, prognosis, and immune infiltration in ESCA and the other types of cancer. Our study represents a comprehensive pan-cancer analysis of LAMP2 and supports the potential use of the modulation of LAMP2 in the management of ESCA and various cancers.

LINC00114 stimulates growth and glycolysis of esophageal cancer cells by recruiting EZH2 to enhance H3K27me3 of DLC1

Objective

LINC00114 could promote the development of colorectal cancer, but its mechanism has been rarely discussed in esophageal cancer (EC). Herein, we explored the molecular mechanism of LINC00114 via mediating enhancer of zeste homolog 2/deleted in liver cancer 1 (EZH2/DLC1) axis in EC.

Methods

LINC00114, EZH2 and DLC1 expression in EC tissues and cells were tested. LINC00114, EZH2 and DLC1 expression were altered in EC cells through transfection with different constructs, and cell proliferation, migration, invasion, apoptosis and glycolysis were subsequently observed. The interaction between LINC00114 and EZH2 and that between EZH2 and DLC1 were explored. Tumor formation was also conducted to confirm the in vitro results.

Results

The expression levels of LINC00114 and EZH2 were elevated while those of DLC1 were reduced in EC. Inhibiting LINC00114 or reducing EZH2 blocked cell proliferation, migration, invasion and glycolysis and induce cell apoptosis in EC. LINC00114 promoted H3K27 trimethylation of DLC1 by recruiting EZH2. Knockdown of DLC1 stimulated cell growth and glycolysis in EC and even mitigated the role of LINC00114 inhibition in EC. In vivo experiment further confirmed the anti-tumor effect of LINC00114 inhibition in EC.

Conclusion

The data indicate that LINC00114 promotes the development of EC by recruiting EZH2 to enhance H3K27me3 of DLC1.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13148-022-01258-y.

The Involvement of WDHD1 in the Occurrence of Esophageal Cancer as a Downstream Target of PI3K/AKT Pathway

Esophageal cancer is one of the most common malignant tumors in the world, which is characterized by high incidence, strong invasiveness, high mortality, and poor prognosis. At present, the therapies include surgery, endoscopic resection, radiotherapy and chemotherapy, targeted therapy, and immunotherapy. The five-year survival rate of esophageal cancer has not been significantly improved, although the medical level has been continuously improved and the management and application of different therapies have been improved day by day. At present, an abnormal gene expression is still regarded as an important factor in the occurrence and development of esophageal cancer. WD repeat and HMG-box DNA binding protein 1(WDHD1), as a key gene, plays an important role in the occurrence of esophageal cancer. It is known that the protein encoded by WDHD1 is the downstream target of the PI3K/AKT pathway. When PI3Ks is activated by extracellular signals, PI(4,5)P2 on the inner side of the plasma membrane will be converted into PI(3,4,5)P3. Then, PI(3,4,5)P3 can be converted into PI(3,4)P2,PI(4)P and PI(3)P by dephosphorylation of some regulatory factors. PI(3,4,5)P3 recruited AKT to the plasma membrane and combined with its pH domain, resulting in conformational change of AKT. Subsequently, AKT was completely activated by PDK1 and PDK2 and begins to move to the cytoplasm and nucleus. In this process, AKT continuously phosphorylates downstream substrates. WDHD1, as a downstream target of AKT, is also phosphorylated and induces DNA replication. Besides the abnormal regulation of cells by other downstream targets of AKT, it also becomes a potential pathway that may eventually lead to the occurrence of esophageal cancer.

Prognostic variables for conditional survival in patients with esophageal squamous cell carcinoma who underwent minimally invasive surgery

Background

Esophageal squamous cell carcinoma (ESCC) survival is mainly reported at the time of treatment. Conditional survival is another prognostic tool to evaluate ESCC patients who has survived more than one year since treatment.

Methods

We analyzed data from 705 ESCC patients who underwent minimally invasive surgery between 2013 and 2016. Using the Kaplan–Meier method, we computed a 5-year relative conditional survival. We also investigated the prognostic factors associated with survival using Cox proportional hazards models.

Results

Conditional survival improved over time for all cohorts of ESCC patients who survived a period after surgery. The greatest improve in conditional survival were observed in patients 2 years after surgery. In addition, the results of the Cox survival model from the time of surgery, T stage (p < 0.001), N stage (p < 0.001), and anastomotic leak (p = 0.022), were significantly associated with survival. However, the results of the Cox survival model from 2 years after surgery, N stage (p < 0.001), and anastomotic leak (p = 0.032) were significantly associated with survival.

Conclusion

For ESCC patients who survived a period after surgery, the largest increases in conditional survival were observed in patients 2 years after surgery. We suggest that patients with anastomotic leakage and higher T and N stages should be strictly screened according to various time, and that conditional survival should be used as a powerful prognostic tool for ESCC patients.

Down-regulation of kappa opioid receptor promotes ESCC proliferation, invasion and metastasis via the PDK1-AKT signaling pathway

BACKGROUND

As a class of the opioid receptors, the kappa opioid receptor (KOR) has been verified to be a potential biomarker and therapeutic target for human malignant tumors. However, a thorough understanding of whether KOR affects progression of esophageal squamous cell carcinoma (ESCC) is still lacking. This study focused on exploring the effect of knocking down KOR in ESCC and its underlying mechanism.

METHODS

Bioinformatics analysis was used to compare the different expression level of OPRK1 (KOR gene) in tumor and adjacent normal tissues, and predict the relationship between KOR expression and overall survival. RNA-sequence analysis was performed to detect the altered functions and mechanisms after down regulating KOR. The in vitro and in vivo assays were used to detect the effects of down-regulated KOR on cell proliferation, migration and invasion. Substrate gel zymography and 3D cell culture assays were used to find the effect of KOR knockdown on the degradation of extracellular matrix (ECM), and immunefluorescence was performed to detect the altered cytoskeleton. Western blotting and immunohistochemistry were used to explore the underlying mechanism pathway.

RESULTS

Bioinformatics analysis revealed that the expression of OPRK1 was lower in tumor tissue than that in adjacent normal tissues, and lowered expression of KOR was associated with poorer overall survival. The in vitro assays demonstrated that down-regulation of KOR enhanced ESCC proliferation, metastasis and invasion. Western blotting revealed that down-regulation of KOR could activate PDK1-AKT signaling pathway, which actively regulated the cancer progression. Down-regulation of KOR enhanced the formation of invadopodia, secretion of matrix metalloproteinase-2 (MMP2) and rearrangement of cytoskeleton, which were positively related with the invasion of ESCC. KOR knockdown enhanced the tumor invasion and elevated the AKT phosphorylation in nude mice. The AKT kinase inhibition could reverse the effect of down-regulation of KOR.

CONCLUSION

KOR might act as a tumor suppressor in ESCC and down-regulation of KOR could enhance the ESCC tumor phenotype. Video Abstract.

MicroRNAs and Corresponding Targets in Esophageal Cancer as Shown In Vitro and In Vivo in Preclinical Models

Squamous cell carcinoma of the esophagus is associated with a dismal prognosis. Therefore, identification of new targets and implementation of new treatment modalities are issues of paramount importance. Based on a survey of the literature, we identified microRNAs conferring antitumoral activity in preclinical in vivo experiments. In the category of miRs targeting secreted factors and transmembrane receptors, four miRs were up-regulated and 10 were down-regulated compared with five out of nine in the category transcription factors, and six miRs were down-regulated in the category enzymes, including metabolic enzymes. The down-regulated miRs have targets which can be inhibited by small molecules or antibody-related entities, or re-expressed by reconstitution therapy. Up-regulated miRs have targets which can be reconstituted with small molecules or inhibited with antagomirs.

Circ_0006948 Contributes to Cell Growth, Migration, Invasion and Epithelial-Mesenchymal Transition in Esophageal Carcinoma

BACKGROUND

Circular RNAs (circRNAs) can act as promoters or inhibitors in cancer progression. Has_circ_0006948 (circ_0006948) was reported to aggravate the malignant behaviors of esophageal carcinoma (EC).

AIMS

This study focused on investigating the molecular mechanism of circ_0006948 in EC progression.

METHODS

The quantitative real-time polymerase chain reaction was performed to detect the expression of circ_0006948, microRNA-4262 (miR-4262) and fibronectin type III domain containing 3B (FNDC3B). Cell growth analysis was conducted by Cell Counting Kit-8 and colony formation assays. Cell migration and invasion were assessed by transwell assay. Epithelial-mesenchymal transition (EMT)-associated proteins and FNDC3B protein expression were assayed using western blot. Dual-luciferase reporter and RNA pull-down assays were performed to validate the target combination. Xenograft tumor assay was used for investigating the role of circ_0006948 in vivo.

RESULTS

Circ_0006948 was upregulated in EC tissues and cells. Downregulating the expression of circ_0006948 or FNDC3B repressed cell growth, migration, invasion and EMT in EC cells. Target analysis indicated that miR-4262 was a target for circ_0006948 and FNDC3B was a downstream gene for miR-4262. Moreover, circ_0006948 could affect the expression of FNDC3B via sponging miR-4262. The effects of si-circ_0006948#1 on EC cells were partly restored by miR-4262 inhibition or FNDC3B overexpression. In addition, circ_0006948 also facilitated EC tumorigenesis in vivo by targeting the miR-4262/FNDC3B axis.

CONCLUSION

Taken together, circ_0006948 functioned as an oncogenic factor in EC by the miR-4262-mediated FNDC3B expression regulation.

Molecular basis of the anticancer, apoptotic and antibacterial activities of Bombyx mori Cecropin A

As Cecropin XJ, Cecropin A from Bombyx mori is one of the very few antimicrobial peptides having shown activity against esophageal cancer cells. It displays remarkable sequence-similarity to Cecropin XJ but slightly enhanced activity. In this work we show by NMR that both peptides are unstructured in solution but get structured in the presence of DPC micelles, mimicking the surface of biological membranes. In order to get insight into the molecular basis of its anticancer, antimicrobial and antifungal activity, we have investigated by MD simulations their interaction with a large variety of lipid bilayers mimicking cancer, mitochondrial, bacterial and fungal membranes. At variance with CecXJ, organized in two main helices, CecA tends to form a three helix bundle resulting in enhanced adaptability to its membrane targets. A specificity for the headgroup of phosphatidylserine and affinity for phosphatidylglycerol and cardiolipin may account for its selective targeting of cancer, bacterial and mitochondrial membranes, respectively.

Glycolysis Changes the Microenvironment and Therapeutic Response Under the Driver of Gene Mutation in Esophageal Adenocarcinoma

Background: Esophageal cancer is one of the most leading and lethal malignancies. Glycolysis and the tumor microenvironment (TME) are responsible for cancer progressions. We aimed to study the relationships between glycolysis, TME, and therapeutic response in esophageal adenocarcinoma (EAC). Materials and Methods: We used the ESTIMATE algorithm to divide EAC patients into ESTIMATE ^high and ESTIMATE ^low groups based on the gene expression data downloaded from TCGA. Weighted gene co-expression network analysis (WGCNA) and Gene Set Enrichment Analysis (GSEA) were performed to identify different glycolytic genes in the TME between the two groups. The prognostic gene signature for overall survival (OS) was established through Cox regression analysis. Impacts of glycolytic genes on immune cells were assessed and validated. Next, we conducted the glycolytic gene mutation analysis and drug therapeutic response analysis between the two groups. Finally, the GEO database was employed to validate the impact of glycolysis on TME in patients with EAC. Results: A total of 78 EAC patients with gene expression profiles and clinical information were included for analysis. Functional enrichment results showed that the genes between ESTIMATE ^high and ESTIMATE ^low groups (N = 39, respectively) were strongly related with glycolytic and ATP/ADP metabolic pathways. Patients in the low-risk group had probabilities to survive longer than those in the high-risk group (p < 0.001). Glycolytic genes had significant impacts on the components of immune cells in TME, especially on the T-cells and dendritic cells. In the high-risk group, the most common mutant genes were TP53 and TTN, and the most frequent mutation type was missense mutation. Glycolysis significantly influenced drug sensitivity, and high tumor mutation burden (TMB) was associated with better immunotherapeutic response. GEO results confirmed that glycolysis had significant impacts on immune cell contents in TME. Conclusion: We performed a comprehensive study of glycolysis and TME and demonstrated that glycolysis could influence the microenvironment and drug therapeutic response in EAC. Evaluation of the glycolysis pattern could help identify the individualized therapeutic regime.

METTL3-mediated m6A mRNA modification promotes esophageal cancer initiation and progression via Notch signaling pathway

Esophageal cancer is a lethal malignancy with a high mortality rate, while the molecular mechanisms underlying esophageal cancer pathogenesis are still poorly understood. Here, we found that the N6-methyladenosine (m⁶A) methyltransferase-like 3 (METTL3) is significantly upregulated in esophageal squamous cell carcinoma (ESCC) and associated with poor patient prognosis. Depletion of METTL3 results in decreased ESCC growth and progression in vitro and in vivo. We further established ESCC initiation and progression models using Mettl3 conditional knockout mouse and revealed that METTL3-mediated m⁶A modification promotes ESCC initiation and progression in vivo. Moreover, using METTL3 overexpression ESCC cell model and Mettl3 conditional knockin mouse model, we demonstrated the critical function of METTL3 in promoting ESCC tumorigenesis in vitro and in vivo. Mechanistically, METTL3-catalyzed m⁶A modification promotes NOTCH1 expression and the activation of the Notch signaling pathway. Forced activation of Notch signaling pathway successfully rescues the growth, migration, and invasion capacities of METTL3-depleted ESCC cells. Our data uncovered important mechanistical insights underlying ESCC tumorigenesis and provided molecular basis for the development of novel strategies for ESCC diagnosis and treatment.

A concise review towards defining the exposome of oesophageal cancer in sub-Saharan Africa

CONTEXT

Oesophageal cancer (EC) is among the common causes of illness and death among all cancers worldwide. Advanced EC has a poor prognosis, with worse outcomes observed in low-income settings. Oesophageal squamous cell carcinoma (ESCC) is the most common EC histology reported globally, with the highest ESCC incidence rates in the 'Asian Belt' and the African EC corridor. While the aetiology of ESCC is well-documented in the 'Asian belt', data for the African EC corridor and the entirety of sub-Saharan Africa (SSA) are fewer.

OBJECTIVE

To help address gaps in ESCC aetiology in SSA, we critically evaluated evidence of lifestyle, environmental, and epigenetic factors associated with ESCC risk and discussed prospects of defining ESCC exposome.

DATA INCLUSION

Unlimited English and non-English articles search were made on PubMed Central and Web of Science databases from January 1970 to August 2021. In total, we retrieved 999 articles and considered meta-analyses, case-control, and cohort studies. The quality of individual studies was assessed using the Newcastle-Ottawa scale.

DATA EXTRACTION

Details extracted include the year of publication, country of origin, sample size, comparators, outcomes, study subjects, and designs.

DATA ANALYSIS

Together, we assessed 13 case-control studies and two meta-analyses for the effect of lifestyle or environmental exposures on ESCC risk. Again, we evaluated seven case-control studies and one meta-analysis regarding the role of epigenetics in ESCC tumorigenesis.

RESULTS

In general, evidence of ESCC aetiology points to essential contributions of alcohol, tobacco, hot beverages, biomass fuel, and poor oral health/hygiene, although more precise risk characterisation remains necessary.

CONCLUSION

We conclude that ESCC in SSA is a multifactorial disease initiated by several external exposures that may induce aberrant epigenetic changes. The expanding aetiological research in this domain will be enhanced by evidence synthesis from classical and molecular epidemiological studies spanning the external and internal exposome.

Integrated genomic profiling and modelling for risk stratification in patients with advanced oesophagogastric adenocarcinoma

OBJECTIVE

Prognosis of patients with advanced oesophagogastric adenocarcinoma (mEGAC) is poor and molecular determinants of shorter or longer overall survivors are lacking. Our objective was to identify molecular features and develop a prognostic model by profiling the genomic features of patients with mEGAC with widely varying outcomes.

DESIGN

We profiled 40 untreated mEGACs (20 shorter survivors <13 months and 20 longer survivors >36 months) with whole-exome sequencing (WES) and RNA sequencing and performed an integrated analysis of exome, transcriptome, immune profile and pathological phenotypes to identify the molecular determinants, developing an integrated model for prognosis and comparison with The Cancer Genome Atlas (TCGA) cohorts.

RESULTS

KMT2C alterations were exclusively observed in shorter survivors together with high level of intratumour heterogeneity and complex clonal architectures, whereas the APOBEC mutational signatures were significantly enriched in longer survivors. Notably, the loss of heterozygosity in chromosome 4 (Chr4) was associated with shorter survival and 'cold' immune phenotype characterised by decreased B, CD8, natural killer cells and interferon-gamma responses. Unsupervised transcriptomic clustering revealed a shorter survivor subtype with distinct expression features (eg, upregulated druggable targets JAK2, MAP3K13 and MECOM). An integrated model was then built based on clinical variables and the identified molecular determinants, which significantly segregated shorter and longer survivors. All the above features and the integrated model have been validated independently in multiple TCGA cohorts.

CONCLUSION

This study discovered novel molecular features prognosticating overall survival in patients with mEGAC and identified potential novel targets in shorter survivors.

Prognostic Value of Immune-Related Multi-IncRNA Signatures Associated With Tumor Microenvironment in Esophageal Cancer

Esophageal cancer is the eighth most common cancer and the sixth leading cause of cancer death worldwide. Hence, for a better understanding of tumor microenvironment and to seek for novel molecular targets for esophageal cancer, we performed related studies on two histopathological subtypes of esophageal cancer: esophageal squamous cell carcinoma (ESCC) and esophageal adenocarcinoma (EAC). Bioinformatic analyses were conducted based on the RNA-seq, genomic mutation, and clinical data from TCGA and GEO cohorts. We clustered patients into high-immunity and low-immunity groups through the ssGSEA results. The ESTIMATE algorithm was used to evaluate the tumor microenvironment. Patients with high immunity in both ESCC and EAC had lower tumor purity and poor survival. Subsequently, CIBERSORT was performed to learn about the detailed difference of tumor-infiltrating lymphocytes (TILs) between high- and low-immunity patients. Specific increase of M2 macrophages and decrease of activated dendric cells can be observed in ESCC and EAC, respectively. The most enriched functions and pathways of high-immunity patients were immunoglobulin complex, MHC class II protein complex, and allograft rejection according to the GO terms and KEGG. Two prognostic immune-related multi-lncRNA risk models were constructed and validated by ROC curve and PCA in ESCC and EAC. High-risk patients in both subtypes had poor survival, advanced clinical characteristics, and higher drug susceptibility except cisplatin and sorafenib. In addition, the tumor mutation burden (TMB) was positively correlated with the risk level in the ESCC and EAC and showed distinct differences between the two subtypes. In summary, we comprehensively analyzed the tumor microenvironment for two subtypes of esophageal cancer, identified two multi-lncRNA signatures predictive for the prognosis, and explored the possibility of the signatures to forecast drug susceptibility as well as TMB for the first time. The findings may serve as a conceptual basis for innovative strategy of individualized immunotherapy for esophageal cancer.

Detection of Incidental Esophageal Cancers on Chest CT by Deep Learning

Objective

To develop a deep learning-based model using esophageal thickness to detect esophageal cancer from unenhanced chest CT images.

Methods

We retrospectively identified 141 patients with esophageal cancer and 273 patients negative for esophageal cancer (at the time of imaging) for model training. Unenhanced chest CT images were collected and used to build a convolutional neural network (CNN) model for diagnosing esophageal cancer. The CNN is a VB-Net segmentation network that segments the esophagus and automatically quantifies the thickness of the esophageal wall and detect positions of esophageal lesions. To validate this model, 52 false negatives and 48 normal cases were collected further as the second dataset. The average performance of three radiologists and that of the same radiologists aided by the model were compared.

Results

The sensitivity and specificity of the esophageal cancer detection model were 88.8% and 90.9%, respectively, for the validation dataset set. Of the 52 missed esophageal cancer cases and the 48 normal cases, the sensitivity, specificity, and accuracy of the deep learning esophageal cancer detection model were 69%, 61%, and 65%, respectively. The independent results of the radiologists had a sensitivity of 25%, 31%, and 27%; specificity of 78%, 75%, and 75%; and accuracy of 53%, 54%, and 53%. With the aid of the model, the results of the radiologists were improved to a sensitivity of 77%, 81%, and 75%; specificity of 75%, 74%, and 74%; and accuracy of 76%, 77%, and 75%, respectively.

Conclusions

Deep learning-based model can effectively detect esophageal cancer in unenhanced chest CT scans to improve the incidental detection of esophageal cancer.

FoXA2 promotes esophageal squamous cell carcinoma progression by ZEB2 activation

Background

It has been reported that Forkhead transcription family member (FOXA2) regulates esophageal squamous cell carcinoma (ESCC) progression. However, the specific mechanism, by which FOXA2 promotes ESCC malignant progression, remains unclear.

Materials and methods

QRT-PCR and western blotting were applied to measure FOXA2 expression in ESCC tissues, while CCK-8 assay and Transwell assays were used to investigate the effect of FOXA2 on ESCC. Luciferase reporter assay, followed by fast chromatin immunoprecipitation (ChIP) assay, was used to study the relationship between FOXA2 and ZEB2.

Results

FOXA2 was significantly increased in ESCC tissues, when compared to normal tissues. Moreover, high expression of FOXA2 was also found in ESCC cells. Knockdown of FOXA2 inhibited ESCC cell proliferation, invasion, and migration. Mechanically, FOXA2 was verified to regulate ZEB2 expression at transcription level. Moreover, ZEB2 reversed the inhibitory effect of FOXA2 on ESCC proliferation, invasion, and migration. The relationship between ZEB2 and FOXA2 in ESCC tissues was negative.

Conclusions

These results indicate that FOXA2 plays a critical role in ESCC progression and may become a potential candidate target for ESCC treatment.

The upregulated expression of RFC4 and GMPS mediated by DNA copy number alteration is associated with the early diagnosis and immune escape of ESCC based on a bioinformatic analysis

Esophageal squamous cell carcinoma (ESCC) is a malignant tumor that commonly occurs worldwide. Usually, Asia, especially China, has a high incidence of esophageal cancer. ESCC often has a poor outcome because of a late diagnosis and lack of effective treatments.

To build foundations for the early diagnosis and treatment of ESCC, we used the gene expression datasets GSE20347 and GSE17351 from the GEO database and a private dataset to uncover differentially expressed genes (DEGs) and key genes in ESCC. Notably, we found that replication factor C subunit 4 (RFC4) and guanine monophosphate synthase (GMPS) were upregulated but have been rarely studied in ESCC. In particular, to the best of our knowledge, our study is the first to explore GMPS and ESCC. Furthermore, we found that high levels of RFC4 and GMPS expression may result from an increase in DNA copy number alterations. Furthermore, RFC4 and GMPS were both upregulated in the early stage and early nodal metastases of esophageal carcinoma. The expression of RFC4 was strongly correlated with GMPS. In addition, we explored the relationship between RFC4 and GMPS expression and tumor-infiltrating immune cells (TILs) in esophageal carcinoma. The results showed that the levels of RFC4 and GMPS increased with a decrease in some tumor-infiltrating cells. Upregulated RFC4 and GMPS with high TILs indicate a worse prognosis.

In summary, our study shows that RFC4 and GMPS have potential as biomarkers for the early diagnosis of ESCC and may played a crucial role in the process of tumor immunity in ESCC.

Long non-coding RNA DDX11-AS1 promotes esophageal carcinoma cell proliferation and migration through regulating the miR-514b-3p/RBX1 axis

Esophageal carcinoma (ESCA) is one of the most aggressive malignancies with extremely high morbidity and mortality. At present, limited advancement in ESCA treatment has achieved. Therefore, it is urgent to explore the pathogenesis and progression mechanism of ESCA to provide the basis for the formulation of novel therapeutic strategies. Previous studies have found that long non-coding RNA (lncRNA) DDX11-AS1 expression enhances the paclitaxel resistance of ESCA cells. However, the mechanisms underlying the drug resistance conferred by lncRNA DDX11-AS1 in ESCA remains to be elucidated. Our research aims to clarify the role and mechanism of lncRNA DDX11-AS1 in regulating the progression of ESCA. We found that the expression of lncRNA DDX11-AS1 in ESCA tissues and cell lines was significantly upregulated. Subsequently, silencing lncRNA DDX11-AS1 significantly inhibited the proliferation, migration and invasion of ESCA cells, and induced the level of cell apoptosis. In terms of mechanism, our data showed that miR-514b-3p/RING box protein 1 (RBX1) axis played a crucial role in the oncogenic function of lncRNA DDX11-AS1. LncRNA DDX11-AS1 expression impaired the inhibitory function of miR-514b-3p on RBX1 through sponging effect. Taken together, our data support the notion that lncRNA DDX11-AS1 promotes the progression of ESCA through miR-514b-3p/RBX1 axis. Our research uncovers the novel regulatory role of lncRNA DDX11-AS1 in ESCA and lays a theoretical basis for developing novel treatment strategy of ESCA.

LINC00657/miR-26a-5p/CKS2 ceRNA network promotes the growth of esophageal cancer cells via the MDM2/p53/Bcl2/Bax pathway

LncRNA LINC00657 has oncogenic or anti-carcinoma roles in different cancers, and yet its detailed molecular mechanism in esophageal cancer (EC) remains unclear. In addition, competitive endogenous RNA (ceRNA) regulatory lncRNA–miRNA–mRNA networks are critical for tumorigenesis and progression. Hence, the present study explored the roles of LINC00657 in EC and identified its relevant ceRNA network. We first detected the expression of LINC00657 in EC. Then, we applied starBase and TargetScan websites to find miR-26a-5p binding to LINC00657 and obtain CKS2 as a target of miR-26a-5p. The roles of LINC00657, miR-26a-5p or CKS2 in the proliferation, migration, invasion, and apoptosis of EC cells were respectively assessed by CCK-8, wound healing assay, transwell invasion assay, and flow cytometry. The changes of the MDM2/p53/Bcl2/Bax pathway were measured via Western blot. The results revealed that LINC00657 showed an aberrant high expression in EC cells, which promoted the growth of EC cells. Additionally, LINC00657 functioned as a sponge of miR-26a-5p, and LINC00657 negatively mediated miR-26a-5p to regulate the growth of EC cells. Furthermore, CKS2 was observed as a direct target of miR-26a-5p, and CKS2 controlled the growth of EC cells via the MDM2/p53/Bcl2/Bax pathway. Moreover, there was a positive correlation between LINC00657 and CKS2. LINC00657 knockdown inhibited CKS2 expression to suppress the proliferation, migration, and invasion of EC cells and induced apoptosis via regulating the MDM2/p53/Bcl2/Bax pathway. Collectively, LINC00657/miR-26a-5p/CKS2 ceRNA network could promote the progression of EC, which is good for understanding the molecular mechanism of EC and offers novel biomarkers for EC diagnosis and therapy.

ACTL6A Promotes the Proliferation of Esophageal Squamous Cell Carcinoma Cells and Correlates with Poor Clinical Outcomes

Background

ACTL6A, a regulatory subunit of ATP-dependent chromatin-remodeling complexes SWI/SNF, has been identified as a central oncogenic driver in many tumor types.

Materials and Methods

We used immunohistochemistry (IHC) to detect ACTL6A expression in esophageal squamous cell carcinoma (ESCC) tissues. Then, the effect of ACTL6A on proliferation and DNA synthesis was explored by using cell counting kit 8 (CCK8) and EdU retention assays. The potential oncogenic mechanism of ACTL6A in ESCC cells was also analyzed by flow cytometry and Western blotting. We further established an ESCC xenograft mouse model to validate the in vitro results.

Results

ACTL6A expression, localized in cancer cell nuclei, was markedly higher in ESCC tissues than in the corresponding noncancerous tissues (P<0.001) and was positively associated with tumor size, histological differentiation, T stage and tumor-node-metastasis (TNM) stage. Kaplan–Meier analysis revealed that high ACTL6A expression was significantly associated with poor overall survival (OS) (P = 0.008, HR= 2.562, 95% CI: 1.241–5.289), and decision curve analysis (DCA) demonstrated that ACTL6A could increase the clinical prognostic efficiency of the original clinical prediction model. Further in vitro experiments showed that ACTL6A knockdown led to inhibition of cell proliferation and DNA synthesis in ESCC cell lines, while overexpression of ACTL6A had the opposite effects. ACTL6A knockdown resulted in G1 phase arrest, with downregulation of cyclin D1, CDK2 and S6K1/pS6 pathway proteins and upregulation of p21 and p27, while overexpression of ACTL6A facilitated the entry of more cells into S phase with upregulated cyclin D1, CDK2 and S6K1/pS6 pathway proteins and downregulated p21 and p27. Finally, a xenograft mouse model of ESCC cells validated the results in vitro.

Conclusion

ACTL6A expression may affect the proliferation and DNA synthesis of ESCC cells by facilitating ESCC cell cycle redistribution via the S6K1/pS6 pathway. Therefore, ACTL6A may potentially become an alternative therapeutic target for ESCC.

Molecular Basis of the Anticancer and Antibacterial Properties of CecropinXJ Peptide: An In Silico Study

Esophageal cancer is an aggressive lethal malignancy causing thousands of deaths every year. While current treatments have poor outcomes, cecropinXJ (CXJ) is one of the very few peptides with demonstrated in vivo activity. The great interest in CXJ stems from its low toxicity and additional activity against most ESKAPE bacteria and fungi. Here, we present the first study of its mechanism of action based on molecular dynamics (MD) simulations and sequence-property alignment. Although unstructured in solution, predictions highlight the presence of two helices separated by a flexible hinge containing P24 and stabilized by the interaction of W2 with target biomembranes: an amphipathic helix-I and a poorly structured helix-II. Both MD and sequence-property alignment point to the important role of helix I in both the activity and the interaction with biomembranes. MD reveals that CXJ interacts mainly with phosphatidylserine (PS) but also with phosphatidylethanolamine (PE) headgroups, both found in the outer leaflet of cancer cells, while salt bridges with phosphate moieties are prevalent in bacterial biomimetic membranes composed of PE, phosphatidylglycerol (PG) and cardiolipin (CL). The antibacterial activity of CXJ might also explain its interaction with mitochondria, whose phospholipid composition recalls that of bacteria and its capability to induce apoptosis in cancer cells.

Mutational Characterization and Potential Prognostic Biomarkers of Chinese Patients with Esophageal Squamous Cell Carcinoma

Purpose

Esophageal squamous cell carcinoma (ESCC) is the most common type of esophageal cancer in China and the 5-year mortality rate is up to 70%. Studies on the ESCC genetic landscape are needed to further explore clinical therapeutic strategies. In this study, we evaluated the genetic landscape of ESCC to aid the search for clinical therapeutic strategies.

Patients and Methods

A total of 225 ESCC patients were enrolled in this study. Deep sequencing of 450 cancer genes was performed on formalin-fixed paraffin-embedded tumor biopsies and matched blood samples from patients. Tumor mutational burden (TMB) was calculated using an algorithm developed in-house.

Results

Our results showed that the most commonly mutated genes in ESCC were TP53 (96%), CCND1 (46%), FGF4 (44%), FGF19 (44%), FGF3 (44%), CDKN2A (31%), PIK3CA (26%), NOTCH1 (24%), KMT2D (18%), FAT1 (16%), and LRP1B (16%). We found that TMB correlated with patient drinking status. We identified mutations associated with sex, early ESCC, high TMB, and metastasis lymph nodes. KMT2D mutations associated with sex (P = 0.035), tumor stage (P = 0.016), high TMB (P = 0.0072), and overall survival of patients (P = 0.0026). SPEN mutations associated with high TMB (P = 0.0016) and metastasis-positive lymph nodes (P = 0.027). These results suggested that SPEN and KMT2D could be potential prognosis biomarkers for Chinese patients with ESCC. We also found that the number of positive lymph nodes was associated with disease-free survival. Clinical target gene analysis indicated that nearly half of Chinese ESCC patients might benefit from treatment with gene-specific target drugs.

Conclusion

Our study revealed the ESCC mutational landscape in 225 Chinese patients and uncovered the potential prognosis biomarker for Chinese patients with ESCC.

Liquid biopsy for esophageal cancer: Is detection of circulating cell-free DNA as a biomarker feasible?

Esophageal cancer (EC) is a common cancer and is histopathologically classified into esophageal squamous cell carcinoma and esophageal adenocarcinoma. EC is a worldwide public health issue because of late diagnosis and lack of effective therapy. In contrast to standard tumor biopsies, liquid biopsies are emerging as a tool which is minimally invasive that can complement or even substitute more classical approaches. Specifically, cell-free DNA (cfDNA) has shown promise in cancer-related clinical applications. Indeed, cfDNA has been shown to be an effective circulating biomarker for non-invasive cancer diagnosis and monitoring of cancer patients. Although the clinical application of cfDNA has been reported on other cancers, few studies have evaluated its use in EC. Here, we review this relevant literature and discuss limitations and advantages of its application in the diagnosis and monitoring of EC.

Elevated DHODH expression promotes cell proliferation via stabilizing β-catenin in esophageal squamous cell carcinoma

As a key enzyme in de novo pyrimidine biosynthesis, the expression level of dihydroorotate dehydrogenase (DHODH) has been reported to be elevated in various types of malignant tumors and its tumor-promoting effect was considered to relate to its pyrimidine synthesis function. Here, we revealed one intriguing potential mechanism that DHODH modulated β-catenin signaling in esophageal squamous cell carcinoma (ESCC). We demonstrated that DHODH directly bound to the NH2 terminal of β-catenin, thereby, interrupting the interaction of GSK3β with β-catenin and leading to the abrogation of β-catenin degradation and accumulation of β-catenin in the nucleus, which in turn, resulted in the activation of β-catenin downstream genes, including CCND1, E2F3, Nanog, and OCT4. We further demonstrated that the regulation of β-catenin by DHODH was independent of DHODH catalyzing activity. Univariate and multivariate analyses suggested that DHODH expression might be an independent prognostic factor for ESCC patients. Collectively, our study highlights the pivotal role of DHODH mediated β-catenin signaling and indicates that DHODH may act as a multi-functional switcher from catalyzing pyrimidine metabolism to regulating tumor-related signaling pathways in ESCC.

MicroRNA‑216a‑5p suppresses esophageal squamous cell carcinoma progression by targeting KIAA0101

The KIAA0101 protein (also referred to as NS5ATP9 or Paf15) is overexpressed in esophageal squamous cell carcinoma (ESCC) and is associated with disease progression and poor patient survival, but how KIAA0101 expression is regulated remains unknown. The relationship between tumor miR-216a-5p expression and prognosis in patients with ESCC was revealed by survival analyses. Quantitative reverse-transcriptase PCR and western blot analysis were used to evaluate miR-216a-5p and KIAA0101 expression in human ESCC tissues and cell lines. The targeting of KIAA0101 by miR-216a-5p was verified by dual-luciferase reporter assays. The EC9706 and TE1 cell lines were transfected with miR-216a-5p mimics and inhibitor, or KIAA0101-specific shRNA and KIAA0101-expressing plasmids, in order to evaluate the effect of manipulating miR-216a-5p and KIAA0101 expression on ESCC cell proliferation, cell cycle progression, migration, and invasion. miR-216a-5p was lowly expressed and inversely correlated with KIAA0101 protein expression in ESCC tissues and cell lines. Lower miR-216a-5p expression was associated with worse prognosis in patients with ESCC. miR-216a-5p negatively regulated KIAA0101 expression by directly targeting the 3′-untranslated region of the KIAA0101 mRNA. Overexpression of miR-216a-5p suppressed the proliferation, migration, and invasion of the ESCC cell lines, whereas inhibition of miR-216a-5p had the opposite effects. Meanwhile, KIAA0101 promoted ESCC migration and invasion, and its overexpression abolished the antitumor effects of miR-216a-5p mimics. As a tumor suppressor, miR-216a-5p targets KIAA0101 to inhibit the proliferation, migration, and invasion of ESCC. Therefore, the miR-216a-5p/KIAA0101 axis may be a potential target for ESCC treatment.

Minichromosome maintenance 6 complex component identified by bioinformatics analysis and experimental validation in esophageal squamous cell carcinoma

Esophageal squamous cell carcinoma (ESCC), the main subtype of esophageal cancer (EC), is a common lethal type of cancer with a high mortality rate. The aim of the present study was to select key relevant genes and identify potential mechanisms involved in the development of ESCC based on bioinformatics analysis. Minichromosome maintenance 6 complex component (MCM6) has been identified to be upregulated in multiple malignancies; however, its contributions to ESCC remain unclear. For the purposes of the present study, four datasets were downloaded from the Gene Expression Omnibus (GSE63941, GSE26886, GSE17351 and GSE77861), and the intersection of the differentially expressed genes was obtained using a Venn diagram. The protein‑protein interaction was then constructed, and the modules were verified by Cytoscape, in which the key genes have a high connectivity degree with other genes. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathway were subsequently filtered out to analyze the development of ESCC. MCM6, an upregulated gene, was selected and connected with most of the other genes, for further research validation. The expression levels of MCM6 were then assessed using the Oncomine, GEPIA and UALCAN databases and validated in both ESCC tissues samples and cell lines by immunohistochemistry and RT‑qPCR. Cell counting kit‑8 (CCK‑8), flow cytometry, wound healing and Transwell assays were used to determine the proliferation, apoptosis, cell cycle, migration and invasion of ESCC cells. A total of 24 genes were identified by a series of bioinformatics analyses and the results revealed that the genes were associated with DNA replication and cell cycle. Experimental validation revealed that MCM6 expression was significantly elevated in both ESCC tissues and cell lines. The results were consistent with those of bioinformatics analysis. Furthermore, the knockdown of MCM6 inhibited cell proliferation, migration and invasion and promoted cell apoptosis, and made cells arrested in S stage. In summary, the findings of bioinformatics analysis provided a novel hypothesis for ESCC progression. In particular, the aberrantly elevated expression of MCM6 is a potential biomarker for ESCC diagnosis and treatment.

Functional Significance and Therapeutic Potential of miRNA-20b-5p in Esophageal Squamous Cell Carcinoma

Novel therapies tailored to the molecular composition mechanism of esophageal squamous cell carcinoma (ESCC) are needed to improve patient survival. miR-20b-5p expression was significantly upregulated in cancerous tissues and associated with lymph node metastasis, clinical stage, and overall survival (OS). An analysis of the methylation status of the miR-20b-5p gene indicated that the hypomethylation of the CpG sites located upstream of the miR-20b-5p gene in the ESCC tissues was more frequent than in the adjacent normal tissues, and the methylation status of miR-20b-5p correlated inversely with its expression levels. Notably, a series of gain- and loss-of-function assays elucidated that miR-20b-5p promoted ESCC cell proliferation, migration, and invasion both in vitro and in vivo. Luciferase reporter assays, western blot, and qRT-PCR revealed that RB1 and TP53INP1 were the direct targets of miR-20b-5p. Moreover, the effects of ectopic miR-20b-5p expression were abrogated by RB1 and TP53INP1 overexpression. In contrast, the effects of miR-20b-5p depletion were impaired by RB1 and TP53INP1 knockdown. Treatment with a miR-20b-5p antagomir dramatically increased tumor growth and inhibited RB1 and TP53INP1 protein expression in nude mice. This work provided novel insights on the molecular mechanism of ESCC and further provided suggestions for therapy development.

(Patho-)Physiology of Na+/H+ Exchangers (NHEs) in the Digestive System

Na⁺/H⁺ exchangers (NHEs) are expressed in virtually all human tissues and organs. Two major tasks of those NHE isoforms that are located in plasma membranes are cell volume control by Na⁺-uptake and cellular pH regulation by H⁺-extrusion. Several NHEs, particularly NHE 1–4 and 8, are involved in the pathogenesis of diseases of the digestive system such as inflammatory bowel disease (ulcerative colitis, Crohn’s disease) and gastric and colorectal tumorigenesis. In the present review, we describe the physiological purposes, possible malfunctions and pathophysiological effects of the different NHE isoforms along the alimentary canal from esophagus to colon, including pancreas, liver and gallbladder. Particular attention is paid to the functions of NHEs in injury repair and to the role of NHE1 in Barrett’s esophagus. The impact of NHEs on gut microbiota and intestinal mucosal integrity is also dealt with. As the hitherto existing findings are not always consistent, sometimes even controversial, they are compared and critically discussed.

Combination of checkpoint inhibitors with radiotherapy in esophageal squamous cell carcinoma treatment: A novel strategy

Despite the rapid development of numerous types of treatment, including radiotherapy (RT) as the main strategy, esophageal squamous cell carcinoma (ESCC) has a poor prognosis. Recent studies demonstrated that immunotherapy can improve the survival of patients with locally advanced and metastatic ESCC. Furthermore, previous studies reported that the expression of programmed death-ligand 1 is significantly associated with esophageal cancer prognosis. At present, several ongoing clinical trials have extended the use of immunotherapy from palliative and salvage treatments to neoadjuvant treatment with concurrent chemoradiation. The first- or second-line treatments were used to explore antitumor efficacy with reduced adverse events. The combination of RT and immunotherapy can exert a local therapeutic effect and improve the function of the immune system, enhancing antitumor efficacy. This review investigated the role of immunotherapy and radiotherapy in ESCC and described the potential efficacy of combining immunotherapy with radiotherapy in ESCC.

The Prominent Role of HMGA Proteins in the Early Management of Gastrointestinal Cancers

GI tumors represent a heterogeneous group of neoplasms concerning their natural history and molecular alterations harbored. Nevertheless, these tumors share very high incidence and mortality rates worldwide and patients' poor prognosis. Therefore, the identification of specific biomarkers could increase the development of personalized medicine, in order to improve GI cancer management. In this sense, HMGA family members (HMGA1 and HMGA2) comprise an important group of genes involved in the genesis and progression of malignant tumors. Additionally, it has also been reported that HMGA1 and HMGA2 display an important role in the detection and progression of GI tumors. In this way, HMGA family members could be used as reliable biomarkers able to efficiently track not only the tumor per se but also the main risk conditions related with their development of GI cancers in the future. Finally, it shall be a promising option to revert the current scenario, once HMGA genes and proteins could represent a convergence point in the complex landscape of GI tumors.