Etiology, cancer stem cells and potential diagnostic biomarkers for esophageal cancer

Nitric oxide synthase 1 inhibits the progression of esophageal cancer through interacting with nitric oxide synthase 1 adaptor protein

BACKGROUND

Esophageal cancer (ESCA) is among the most prevalent and lethal tumors globally. While nitric oxide synthase 1 (NOS1) is recognized for its important involvement in various cancers, its specific function in ESCA remains unclear.

AIM

To explore the potential role and underlying mechanisms of NOS1 in ESCA.

METHODS

Survival rates were analyzed using GeneCards and Gene Expression Profiling Interactive Analysis. The effects and mechanisms of NOS1 on ESCA cells were evaluated via the Cell Counting Kit-8 assay, scratch assay, Transwell assay, flow cytometry, quantitative polymerase chain reaction, western blotting, and terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate-biotin nick end labeling staining. The protein interaction network was used to screen the interacting proteins of NOS1 and validate these interactions through co-immunoprecipitation and dual luciferase assays. Additionally, a nude mouse xenograft model was established to evaluate the effect of NOS1 in vivo.

RESULTS

The survival rate of patients with ESCA with high NOS1 expression was higher than that of patients with low NOS1 expression. NOS1 expression in ESCA cell lines was lower than that in normal esophageal epithelial cells. Overexpression of NOS1 (oe-NOS1) inhibited proliferation, invasion, and migration abilities in ESCA cell lines, resulting in decreased autophagy levels and increased apoptosis, pyroptosis, and ferroptosis. Protein interaction studies confirmed the interaction between NOS1 and NOS1 adaptor protein (NOS1AP). Following oe-NOS1 and the silencing of NOS1AP, levels of P62 and microtubule-associated protein 1 light chain 3 beta increased both in vitro and in vivo. Furthermore, the expression levels of E-cadherin, along with the activation of phosphatidylinositol 3-kinase (PI3K) and protein kinase B (AKT), were inhibited in ESCA cell lines.

CONCLUSION

NOS1 and NOS1 proteins interact to suppress autophagy, activate the PI3K/AKT pathway, and exert anti-cancer effects in ESCA.

Recent advances in microfluidic-based photoelectrochemical (PEC) sensing platforms for biomedical applications

Photoelectrochemical (PEC) techniques seamlessly combine electrochemical and spectroscopic principles, offering a powerful platform for the detection of biomarkers and biological molecules in clinical and biomedical settings. This review provides a comprehensive overview of microfluidic PEC probes, emphasizing their potential for ultrasensitive detection through enhanced light absorption and charge transfer processes. Key advantages of microfluidic PEC include real-time monitoring of biological processes, non-invasive detection, and the possibility of multiplexing when integrated with various quantification modalities. However, the practical implementation of PEC faces challenges such as bulky setup, matrix interference, and stability of PEC-active materials. Also, this paper discusses the intricate mechanisms of PEC sensing, highlighting the roles of nanomaterials in enhancing microfluidic PEC systems. Additionally, the limitations inherent in PEC material selection, including stability and bandgap engineering, are critically discussed. Solutions such as doping and the development of composite materials are proposed to address these issues. Through presented examples of PEC applications in biomedical fields, this review elucidates the future potential of PEC-based methods as reliable and effective tools for diagnostic applications. Additionally, this review proposes the most effective probes for future investigations to develop commercial devices.

Potential biomarkers develop for predicting the prognosis of patients with esophageal squamous cell carcinoma after optimized chemoradiotherapy using serum metabolomics

BACKGROUND

Esophageal squamous cell carcinoma (ESCC), the most common type of esophageal cancer, characterized by low five-year survival rate, and concurrent chemoradiotherapy (CCRT) has been proposed to treat ESCC, while potential biomarkers for prognostic monitoring after optimized CCRT remains unknown.

METHODS

Serum samples from 45 patients with ESCC were collected and categorized into three groups: Control (pre-CCRT), CCRT (during CCRT), and CCRT-1 M (one-month post-CCRT). The therapeutic effect was evaluated using CT imaging and established evaluation criteria. Untargeted metabolomic analysis was performed on the serum samples to identify differential metabolites caused by CCRT treatment, assessing their potential for prognostic monitoring.

RESULTS

CCRT had significant therapeutic efficacy in patients with ESCC, as indicated by CT imaging and RECIST 1.1 solid tumor evaluation criteria. Notably, several metabolic markers were identified through non-targeted metabolomic analysis, highlighting changes following CCRT treatment. These differential metabolites are involved in the dysregulation of phenylalanine, tyrosine, and tryptophan biosynthesis, as well as histidine, arginine, and proline metabolism, and glycine, serine, and threonine metabolism, suggesting a reduction in glucose metabolism in patients with ESCC after CCRT. Additionally, ROC analysis indicated that the AUC of these metabolites exceeded 0.661, underscoring their diagnostic value for assessing CCRT efficacy and their potential use in prognostic monitoring. Comparative metabolomic analysis identified L-phenylalanine and lysine as promising serum biomarkers for predicting therapeutic outcomes.

CONCLUSIONS

CCRT shows considerable therapeutic benefit in patients with ESCC, with observed reductions in glucose metabolism post-treatment. L-phenylalanine and lysine may serve as potential serum biomarkers to predict CCRT efficacy.

Salivary Extracellular Vesicles in Detection of Cancers Other than Head and Neck: A Systematic Review

Cancer is one of the leading causes of death worldwide. Evidence indicates that extracellular vesicles are involved in cancer development and may be used as promising biomarkers in cancer detection. Concomitantly, saliva constitutes a non-invasive and inexpensive source of biomarkers. This systematic review investigates the use of salivary extracellular vesicles in detecting cancers located outside of the head and neck. PubMed, Web of Science, Scopus, and Embase were thoroughly searched from database inception to 16 July 2024. Data from sixteen eligible studies were analyzed, including glioblastoma, lung, esophageal, gastric, prostate, hepatocellular, breast, and pancreatobiliary tract cancers. The findings highlight strong diagnostic potential for lung and esophageal cancers, where specific exosomal RNAs and proteins demonstrated high accuracy in distinguishing cancer patients from healthy individuals. Additionally, biomarkers in glioblastoma showed prognostic value, while those in hepatocellular and pancreatobiliary cancers exhibited potential for early detection. However, gastric and prostate cancer biomarkers showed limited reliability, and breast cancer biomarkers require further validation. In conclusion, salivary extracellular vesicles present potential in non-invasive detection across multiple cancer types; however, their diagnostic power needs further research, including standardization and large-scale validation.

FOXD2-AS1 is modulated by METTL3 with the assistance of YTHDF1 to affect proliferation and apoptosis in esophageal cancer

This study aims to investigate the regulatory mechanisms of METTL3, YTHDF1, and the long non-coding RNA FOXD2-AS1 in the proliferation and apoptosis of esophageal cancer, with the goal of providing a basis for molecular diagnosis and targeted therapies. Gene expression was evaluated using qRT-PCR (METTL3/14) and Western blot analysis. The Cell Counting Kit-8 (CCK-8) assay, flow cytometry, and Transwell assay were employed to assess cell proliferation and apoptosis. The EpiQuik m6A RNA Methylation Quantification Kit was utilized to quantify total m6A levels. The interaction between YTHDF1, FOXD2-AS1, and METTL3 was confirmed using RNA Binding Protein Immunoprecipitation (RIP), Co-Immunoprecipitation (CO-IP), and RNA pull-down assays. Methylated RNA Immuno preci pitation (MeRIP) was employed to assess the m6A modification levels of FOXD2-AS1. Tissue samples from animal models were analyzed via Hematoxylin-eosin staining (HE) staining and immunohisto-chemistry to assess METTL3 expression. The expression of METTL3 was up-regulated in esophageal cancer tissues and cells. Flow cytometry and CCK-8 detection showed that silencing METTL3 could inhibit the proliferation of esophageal cancer cells but accelerate their apoptosis. MeRIP-qPCR and Prediction of m6A-modified sites indicated that METTL3 regulated the m6A modification of FOXD2-AS1. In vitro and in vivo experiments showed that YTHDF1 binds to METTL3 and regulates the m6A modification of FOXD2-AS1 to affect esophageal cancer. Our results indicate that METTL3 regulates FOXD2-AS1 in an m6A-dependent manner through its interaction with YTHDF1, thereby influencing EC proliferation and apoptosis. This suggests a potential therapeutic target for the treatment of esophageal cancer.

Exploratory analyses of the associations between Ki-67 expression, lymph node metastasis, and prognosis in patients with esophageal squamous cell cancer

Background

The relationships between Ki-67/MKI67 expression, lymph node metastasis (LNM), vascular invasion (VI), and perineural invasion (PI) in esophageal squamous cell cancer (ESCC) remain unclear. This retrospective cohort study was performed to evaluate the prognostic value of Ki-67 expression and its association with LNM in patients with resected ESCC.

Methods

The analysis included 168 patients with ESCC with available Ki-67 protein expression data. The patients were divided into Ki-67 high-expression group (Ki-67 High, 93 cases) and Ki-67 low-expression (Ki-67 Low, 75 cases) groups. Associations between Ki-67 expression and ESCC pathological features was assessed using chi-square test. Overall survival (OS) was compared between the two groups using Kaplan-Meier survival analysis and Cox proportional hazards model.

Results

Median follow-up duration was 33.5 months (range 3.0-60.0 months). High Ki-67 expression was significantly associated with poor OS in patients with ESCC compared to that of the low-expression in both univariate (hazard ratios (HR) = 3.42, 95% CI [2.22-5.27], P < 0.001) and multivariate analyses (HR = 1.98, 95% CI [1.33-2.94], P < 0.001). Furthermore, high Ki-67 expression was significantly associated with an increased risk of LNM (χ 2 = 11.219, P = 0.011), VI (χ 2 = 6.359, P = 0.012), and PI (χ 2 = 8.877, P = 0.003).

Conclusions

High Ki-67 protein expression is associated with poor prognosis in ESCC. Increased Ki-67 expression significantly increases the risk of LNM, VI, and PI in ESCC, and thus may serve as an indication for adjuvant therapy in ESCC management.

Pan-cancer and multi-omics analysis: NDUFA1 is a potential therapeutic target and prognostic marker for esophageal cancer

OBJECTIVES

The study examined the NDUFA1 expression and its prognostic value in pan-cancer, especially in esophageal cancer (ESCA). Its carcinogenic effect on ESCA was further elucidated.

MATERIALS AND METHODS

TCGA database was used to examine NDUFA1 expression and its prognostic value in 33 cancer types. GO and KEGG were performed for function and pathway enrichment of NDUFA1-related genes. The carcinogenic effect on ESCA was verified in both KYSE-30 cell and Xenograft mouse model.

RESULTS

Abnormal high expression of NDUFA1 was detected in pan-cancer, and related to immune cell infiltration. TCGA database indicated an elevated value of NDUFA1 in ESCA tumor tissues, which was linked to patients' poor prognosis. NDUFA1-related genes were mainly enriched in oxidative stress and immune response in ESCA. NDUFA1 knockdown significantly suppressed ESCA cell proliferation, migration and invasion. Similarly, tumor growth of ESCA xenograft mice was inhibited by NDUFA1 knockdown. Activated PI3K-Akt signaling was detected in both ESCA cell lines and tumor tissues, which was reversed by NDUFA1 knockdown.

CONCLUSION

Multi-omics analysis showed that NDUFA1 might be adopted as a potential therapeutic goal and prognostic indicator for a variety of cancers, especially for ESCA. NDUFA1 knockdown inhibited ESCA tumor growth, which may have the participation of the PI3K/Akt signaling pathway.

Pharmacological Modulation of Mutant TP53 with Oncotargets Against Esophageal Cancer and Therapy Resistance

The prevalence and deaths from esophageal cancer (EC) have recently increased. Although therapeutic strategies depend on the EC stage and recurrence, such as surgical intervention, chemotherapy, radiation therapy, chemoradiation therapy, targeted therapy, and immunotherapy, a more effective and novel treatment for EC is still required. This review briefly describes and summarizes some insightful oncotargets involved in the metabolic modulation of EC, including (1) cancer stem cells (CSCs) for EC progression, poor prognosis, tumor recurrence, and therapy resistance; (2) retinoic acid receptors (RARs) for esophageal carcinogenesis and regeneration; (3) phosphofructokinase (PFK) for EC-reprogrammed glycolysis; (4) lactate dehydrogenase (LDH) as an EC peripheral blood biomarker; and (5) hypoxia-inducible factor-1 alpha (HIF-1α) for the tumor microenvironment under hypoxic conditions. Moreover, the aforementioned oncotargets can be modulated by mutant TP53 and have their own features in the carcinogenesis, differentiation, proliferation, and metastasis of EC. Thus, the clarification of pharmacological mechanisms regarding the interaction between mutant TP53 and the abovementioned oncotargets could provide precise and perspective opinions for minimizing prediction errors, reducing therapy resistance, and developing novel drugs against EC.

Ultrasensitive detection of SCCA employing a graphene oxide integrated microfiber ring laser biosensor

Squamous cell carcinoma antigen (SCCA) is one of the most commonly detected cancer biomarkers for a variety of cancers. In this paper, a microfiber ring laser biosensor with a graphene oxide linking layer for SCCA detection was proposed and experimentally demonstrated. SCCA antibody immobilized on graphene oxide surface binds specifically to SCCA, and induces refractive index variation over the surface of the microfiber biosensor, which leads to a wavelength shift of the microfiber ring laser biosensor. The experimental results show that the proposed laser biosensor can detect SCCA with concentrations from 0.01 to 50 ng/mL, and the calculated detection limit can be as low as 1.3 pg/mL. Additionally, the label-free quantitative detection of SCCA using the proposed microfiber biosensor was verified experimentally according to the corresponding regression equation, and the results agree well with clinical examination detection. This constructed microfiber biosensor may have promising practical applications in analytical detection, medical diagnostics, etc.

Synthesis, characterisation, and anti-tumour activity of nano-immuno-conjugates for enhanced photodynamic therapy of oesophageal cancer stem cells

In recent times, oesophageal cancer has been listed as the eleventh most prevalent type of cancer. It is a lethal disease attributed to a high mortality rate, tumour metastasis and poor treatment outcome. A subset of oesophageal cancer referred to as stem cells (CSCs) has been revealed to drive carcinogenesis, metastasis, and treatment failure. Therefore, it is essential to target these CSCs to improve the efficacy of treatment for oesophageal cancer. In this present study, we employed a strategy to target oesophageal CSCs with a nano-immuno-conjugate (NIC) consisting of AlPcS4Cl, gold nanoparticle (AuNPs) and anti-CD271 antibody synthesised using a chemical reaction. The synthesised NIC was characterised using ultraviolet-visible spectroscopy, transmission electron microscope (TEM), Fourier transform infra-red (FTIR) spectroscopy, dynamic light scattering (DLS), and zeta potential (ZP). The in vitro anti-tumour action of NIC-mediated photodynamic therapy (PDT) was performed on oesophageal CSCs using cell viability/cytotoxicity assays and morphological examination via light microscopy. The characterisation analysis confirmed the successful synthesis of the NIC. The synthesised nano-immuno-conjugates showed significant cytotoxicity and reduction in cell viability in the HKESC-1 oesophageal CSCs. Fluorescence microscopy confirmed the rapid internalisation of the targeted NIC in key cellular organelles of the CSCs, resulting in enhanced effects. Interestingly, NIC exhibited cytocompatibility with non-tumour WS1 cells, thus supporting its clinical application as a safe anti-tumour agent for enhanced PDT. The study demonstrates the improved effects of NIC-mediated PDT as targeted therapeutics against oesophageal CSCs.

A novel disulfidptosis-related LncRNA prognostic risk model: predicts the prognosis, tumor microenvironment and drug sensitivity in esophageal squamous cell carcinoma

BACKGROUND

Disulfidptosis is a newly discovered type of cell death that differs from apoptosis, necrosis, ferroptosis and other death modes and is closely related to the occurrence and progression of tumors. However, the predictive potential and biological characteristics of disulfidptosis-related lncRNAs (DRGs-lncRNAs) in esophageal squamous cell carcinoma (ESCC) are unclear.

METHODS

RNA transcriptome data, clinical information and mutation data for ESCC patients were obtained from The Cancer Genome Atlas (TCGA) database. Pearson correlation and Cox regression analyses were used to identify the DRGs-lncRNAs associated with overall survival (OS). LASSO regression analysis was used to construct the prognostic model. A nomogram was created to predict the prognosis of patients with ESCC. Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG), and gene set enrichment analysis (GSEA) were used to identify the signaling pathways associated with the model. TIMER, CIBERSORT, ESTIMATE and other methods were used to analyze immune infiltration, immune function, immune checkpoints and drug sensitivity. The tumor mutation burden (TMB) were assessed between different risk groups. Real-time polymerase chain reaction (RT‒PCR) was used to detect the expression of DRGs-lncRNAs in ESCC cell lines.

RESULTS

A total of 155 lncRNAs significantly associated with disulfidptosis were identified. Through univariate Cox regression analysis, LASSO regression analysis and multivariate Cox regression analysis, 9 lncRNAs with independent prognostic significance were selected, and a prognosis model was established. Survival analysis with the prognostic model revealed that there were obvious differences in survival between the high- and low-risk groups. Further analysis revealed that the immune microenvironment, immune infiltration, immune function, immune checkpoints, and drug sensitivity significantly differed between the high-risk and low-risk groups. Patients who exhibited both high risk and high tumor mutation burden (TMB) survived shorter, while those who fell into the low risk and low TMB categories survived longer. In addition, RT‒PCR analysis revealed differential expression of DRG lncRNAs between ESCC cell lines and esophageal epithelial cell lines.

CONCLUSIONS

We established a DRG-lncRNA prognostic model that can be used to predict the prognosis, tumor mutation burden, immune cell infiltration, and drug sensitivity of ECSS patients. The results of this study provide valuable insights into the understanding of ESCC and provide valuable assistance for the individualized treatment of ESCC patients.

Predictive factors for intrathoracic anastomotic leakage and postoperative mortality after esophageal cancer resection

BACKGROUND

Esophageal cancer is currently one of the high-risk malignant tumors worldwide, posing a serious threat to human health. This study aimed to analyse the causes of postoperative mortality and intrathoracic anastomotic leakage(IAL) after esophagectomy.

METHODS

A retrospective analysis was conducted on 172 patients with esophageal cancer resection and focused on the preoperative and postoperative indicators. Cox regression analysis was performed to identify factors affected IAL and evaluated the potential factors on postoperative mortality. The Kaplan-Meier curve was applied to evaluate the effect of leakage on postoperative mortality after propensity score matching.

RESULTS

Univariable and multivariable Cox regression analysis showed that infection and high BMI were significant risk factors for IAL, patients with BMI over 24 kg/m2 in IAL group was two times higher than that of the group without IAL (95% CI = 1.01-6.38; P = 0.048). When patients were infected, the hazard ratios(HRs) of anastomotic leakage was twice that of patients without infection (95% CI = 1.22-4.70; P = 0.011). On the other hand, IAL was a significant cause of postoperative mortality, the 40-day postoperative mortality rate in the leakage group was significantly higher than the non leakage group (28.95% in leakage group vs. 7.46% in non leakage group, P<0.01). After propensity score matching, IAL still significantly affected postoperative mortality. The total length of hospital stay of the leakage group was inevitably longer than that of the non leakage group (22.19 ± 10.79 vs. 15.27 ± 8.59).

CONCLUSION

IAL was a significant cause of death in patients underwent esophageal cancer resection. Patients with high BMI over 24 kg/m2 and infection may be more prone to developing IAL after esophagectomy. IAL inevitably prolonged the length of hospital stay and increased postoperative mortality.

Extracellular glypican-1 affects tumor progression and prognosis in esophageal cancer

INTRODUCTION

Cells are covered with a glycan surface layer that is referred to as the glycocalyx (GCX). It has been reported that the formation of the GCX is promoted on cancer cells and is associated with tumor growth and metastasis. Heparan sulfate proteoglycan glypican-1 (GPC1) is a core protein of the GCX that is overexpressed in esophageal squamous cell carcinoma (ESCC) and is involved in the development and progression of cancer cells. The purpose of the present study is to analyze the utility of GPC1 as a new biomarker ralated to glycocalyx that reflects therapeutic effect and prognosis of ESCC.

METHODS

We measured the concentration of GPC1 protein in preoperative plasma from advanced esophageal cancer patients and examined its relationships with clinicopathological factors and therapeutic efficacy, and the effects of extracellular GPC1 were investigated.

RESULTS

The following clinical factors were significantly correlated with the preoperative high GPC1 concentration: male, tumor size ≥30 mm, venous invasion, pT factor ≥2, pStage ≥3, residual tumor, and distant metastatic recurrence. Both overall and recurrence-free survival were significantly worse in the high GPC1 group. Extracellular GPC1 protein concentration reflected intracellular GPC1 expression. Furthermore, we examined the effects of extracellular recombinant human (rh)GPC1 on ESCC cells, and found that extracellular rhGPC1 affects cell motility, including migration and invasion.

CONCLUSIONS

These results demonstrated the utility of extracellular GPC1 as a biomarker, which can be assayed from a less invasive blood sample-based liquid biopsy. Extracellular GPC1 protein plays a role in both tumor cell motility and cancer progression. Thus, plasma GPC1 is a useful biomarker for esophageal cancer progression and may be a potential candidate of therapeutic target.

ESCCPred: a machine learning model for diagnostic prediction of early esophageal squamous cell carcinoma using autoantibody profiles

BACKGROUND

Esophageal squamous cell carcinoma (ESCC) is a deadly cancer with no clinically ideal biomarkers for early diagnosis. The objective of this study was to develop and validate a user-friendly diagnostic tool for early ESCC detection.

METHODS

The study encompassed three phases: discovery, verification, and validation, comprising a total of 1309 individuals. Serum autoantibodies were profiled using the HuProtTM human proteome microarray, and autoantibody levels were measured using the enzyme-linked immunosorbent assay (ELISA). Twelve machine learning algorithms were employed to construct diagnostic models, and evaluated using the area under the receiver operating characteristic curve (AUC). The model application was facilitated through R Shiny, providing a graphical interface.

RESULTS

Thirteen autoantibodies targeting TAAs (CAST, FAM131A, GABPA, HDAC1, HDGFL1, HSF1, ISM2, PTMS, RNF219, SMARCE1, SNAP25, SRPK2, and ZPR1) were identified in the discovery phase. Subsequent verification and validation phases identified five TAAbs (anti-CAST, anti-HDAC1, anti-HSF1, anti-PTMS, and anti-ZPR1) that exhibited significant differences between ESCC and control subjects (P < 0.05). The support vector machine (SVM) model demonstrated robust performance, with AUCs of 0.86 (95% CI: 0.82-0.89) in the training set and 0.83 (95% CI: 0.78-0.88) in the test set. For early-stage ESCC, the SVM model achieved AUCs of 0.83 (95% CI: 0.79-0.88) in the training set and 0.83 (95% CI: 0.77-0.90) in the test set. Notably, promising results were observed for high-grade intraepithelial neoplasia, with an AUC of 0.87 (95% CI: 0.77-0.98). The web-based implementation of the early ESCC diagnostic tool is publicly accessible at https://litdong.shinyapps.io/ESCCPred/ .

CONCLUSION

This study provides a promising and easy-to-use diagnostic prediction model for early ESCC detection. It holds promise for improving early detection strategies and has potential implications for public health.

Human esophageal cancer stem-like cells escape the cytotoxicity of natural killer cells via down-regulation of ULBP-1

BACKGROUND

Cancer stem-like cells (CSCs) play an important role in initiation and progression of aggressive cancers, including esophageal cancer. Natural killer (NK) cells are key effector lymphocytes of innate immunity that directly attack a wide variety of cancer cells. NK cell-based therapy may provide a new treatment option for targeting CSCs. In this study, we aimed to investigate the sensitivity of human esophageal CSCs to NK cell-mediated cytotoxicity.

METHODS

CSCs were enriched from human esophageal squamous cell carcinoma cell lines via sphere formation culture. Human NK cells were selectively expanded from the peripheral blood of healthy donors. qRT-PCR, flow cytometry and ELISA assays were performed to examine RNA expression and protein levels, respectively. CFSE-labeled target cells were co-cultured with human activated NK cells to detect the cytotoxicity of NK cells by flow cytometry.

RESULTS

We observed that esophageal CSCs were more resistant to NK cell-mediated cytotoxicity compared with adherent counterparts. Consistently, esophageal CSCs showed down-regulated expression of ULBP-1, a ligand for NK cells stimulatory receptor NKG2D. Knockdown of ULBP-1 resulted in significant inhibition of NK cell cytotoxicity against esophageal CSCs, whereas ULBP-1 overexpression led to the opposite effect. Finally, the pro-differentiation agent all-trans retinoic acid was found to enhance the sensitivity of esophageal CSCs to NK cell cytotoxicity.

CONCLUSIONS

This study reveals that esophageal CSCs are more resistant to NK cells through down-regulation of ULBP-1 and provides a promising approach to promote the activity of NK cells targeting esophageal CSCs.

Discovery and validation of combined biomarkers for the diagnosis of esophageal intraepithelial neoplasia and esophageal squamous cell carcinoma

Early diagnosis and intervention of esophageal squamous cell carcinoma (ESCC) can improve the prognosis. The purpose of this study was to identify biomarkers for ESCC and esophageal precancerous lesions (intraepithelial neoplasia, IEN). Based on the proteomic and genomic data of esophageal tissue including previously reported data, up-regulated proteins with copy number amplification in esophageal cancer were screened as candidate biomarkers. Five proteins, including KDM2A, RAD9A, ECT2, CYHR1 and TONSL, were confirmed by immunohistochemistry on ESCC and normal esophagus (NE). Then, we investigated the expression of 5 proteins in 236 participants (60 NEs, 93 IENs and 83 ESCCs) which were randomly divided into training set and test set. When distinguishing ESCC from NE, the area under curve (AUC) of the multiprotein model was 0.940 in the training set, while the lowest AUC of a protein was 0.735. In the test set, the results were similar. When distinguishing ESCC from IEN or distinguishing IEN from NE, the diagnostic efficiency of the multi-protein models were also improved compared with that of single protein. Our findings suggest that combined detection of KDM2A, RAD9A, ECT2, CYHR1 and TONSL can be used as potential biomarkers for the early diagnosis of ESCC and precancerous lesion development prediction. SIGNIFICANCE: Candidate biomarkers including KDM2A, RAD9A, ECT2, CYHR1 and TONSL screened by integrating genomic and proteomic data from the esophagus can be used as potential biomarkers for the early diagnosis of esophageal squamous cell carcinoma and precancerous lesion development prediction.

Metabolic reprogramming in esophageal squamous cell carcinoma

Esophageal squamous cell carcinoma (ESCC) is a malignancy with high incidence in China. Due to the lack of effective molecular targets, the prognosis of ESCC patients is poor. It is urgent to explore the pathogenesis of ESCC to identify promising therapeutic targets. Metabolic reprogramming is an emerging hallmark of ESCC, providing a novel perspective for revealing the biological features of ESCC. In the hypoxic and nutrient-limited tumor microenvironment, ESCC cells have to reprogram their metabolic phenotypes to fulfill the demands of bioenergetics, biosynthesis and redox homostasis of ESCC cells. In this review, we summarized the metabolic reprogramming of ESCC cells that involves glucose metabolism, lipid metabolism, and amino acid metabolism and explore how reprogrammed metabolism provokes novel opportunities for biomarkers and potential therapeutic targets of ESCC.

RSPO2-associated mitochondrial metabolism defines molecular subtypes with distinct clinical and immune features in esophageal cancer

BACKGROUND

Esophageal cancer is a highly aggressive malignancy with limited treatment options and poor prognosis. The identification of novel molecular subtypes and therapeutic targets is crucial for improving clinical outcomes.

METHOD

In this study, we investigated the role of R-spondin 2 (RSPO2) in esophageal cancer and its association with mitochondrial metabolism. Using bioinformatics analysis of publicly available datasets, we identified a panel of RSPO2-related mitochondrial metabolism genes and their expression patterns in esophageal cancer. Based on these genes, we stratified esophageal cancer patients into distinct molecular subtypes with different survival rates, immune cell infiltration profiles, and drug sensitivities.

RESULTS

Our findings suggest that RSPO2-related mitochondrial metabolism genes may serve as potential therapeutic targets and prognostic markers for esophageal cancer. These genes play an important role in the prognosis, immune cell infiltration and drug sensitivity of esophageal cancer.

CONCLUSION

The identified molecular subtypes provide valuable insights into the underlying molecular mechanisms of esophageal cancer and could guide personalized treatment strategies in the future.

Purine salvage-associated metabolites as biomarkers for early diagnosis of esophageal squamous cell carcinoma: a diagnostic model-based study

Esophageal squamous cell carcinoma (ESCC) remains an important health concern in developing countries. Patients with advanced ESCC have a poor prognosis and survival rate, and achieving early diagnosis remains a challenge. Metabolic biomarkers are gradually gaining attention as early diagnostic biomarkers. Hence, this multicenter study comprehensively evaluated metabolism dysregulation in ESCC through an integrated research strategy to identify key metabolite biomarkers of ESCC. First, the metabolic profiles were examined in tissue and serum samples from the discovery cohort (n = 162; ESCC patients, n = 81; healthy volunteers, n = 81), and ESCC tissue-induced metabolite alterations were observed in the serum. Afterward, RNA sequencing of tissue samples (n = 46) was performed, followed by an integrated analysis of metabolomics and transcriptomics. The potential biomarkers for ESCC were further identified by censoring gene-metabolite regulatory networks. The diagnostic value of the identified biomarkers was validated in a validation cohort (n = 220), and the biological function was verified. A total of 457 dysregulated metabolites were identified in the serum, of which 36 were induced by tumor tissues. The integrated analyses revealed significant alterations in the purine salvage pathway, wherein the abundance of hypoxanthine/xanthine exhibited a positive correlation with HPRT1 expression and tumor size. A diagnostic model was developed using two purine salvage-associated metabolites. This model could accurately discriminate patients with ESCC from normal individuals, with an area under the curve (AUC) (95% confidence interval (CI): 0.680-0.843) of 0.765 in the external cohort. Hypoxanthine and HPRT1 exerted a synergistic effect in terms of promoting ESCC progression. These findings are anticipated to provide valuable support in developing novel diagnostic approaches for early ESCC and enhance our comprehension of the metabolic mechanisms underlying this disease.

Expression and Clinicopathological Significance of Extracellular Matrix Remodeling Markers in Esophageal Squamous Carcinoma

Esophageal squamous cell carcinoma (ESCC) is a common malignancy of the gastrointestinal tract with a single therapeutic option and a lack of effective clinical therapeutic biomarkers. Extracellular matrix (ECM) remodeling plays a pro-carcinogenic role in a variety of malignancies, but its role in esophageal squamous carcinoma remains to be elucidated. In this study, we examined the expression levels of ECM remodeling markers in 71 pairs of esophageal squamous carcinoma tissues and normal tissues adjacent to the carcinoma using immunohistochemical staining, and analyzed their relationship with clinicopathological features and prognosis. The results suggested that extracellular matrix remodeling markers (integrin αV, fibronectin, MMP9) were abnormally highly expressed in esophageal squamous carcinoma tissues. There was a statistically significant difference between the positive expression of ECM remodeling and the TNM stage of esophageal squamous carcinoma, and there was no statistically significant correlation with age, gender and carcinoembryonic antigen expression, differentiation degree, T stage, and lymph node metastasis. Overall survival rate and overall survival time were significantly lower in patients with positive ECM remodeling expression, which was an independent risk factor for poor prognosisof esophageal squamous carcinoma.

The Role of Pentraxin 3 in Gastrointestinal Cancers

Gastrointestinal cancers have become a huge problem worldwide as the number of new cases continues to increase. Due to the growing need to explore new biomarkers and therapeutic targets for the detection and treatment of cancerous lesions, we sought to elucidate the role of Pentraxin-3 in the progression of cancerous lesions, as it is involved in the process of angiogenesis and inflammation. Statistically significant changes in the concentration of this parameter have emerged in many gastrointestinal cancer patients. Moreover, it is related to the advancement of cancer, as well as processes leading to the development of those changes. In the case of studies concerning tissue material, both increased and decreased tissue expression of the tested parameter were observed and were dependent on the type of cancer. In the case of cell lines, both human and animal, a significant increase in Pentraxin 3 gene expression was observed, which confirmed the changes observed at the protein level. In conclusion, it can be assumed that PTX3, both at the level of gene expression and protein concentrations, is highly useful in the detection of gastrointestinal cancers, and its use as a biomarker and/or therapeutic target may be useful in the future.

Licochalcone A induces G2/M phase arrest and apoptosis via regulating p53 pathways in esophageal cancer: In-vitro and in-vivo study

Licochalcone A (LCA) is a flavonoid isolated from Glycyrrhiza uralensis Fisch that has shown promising therapeutic effects in various cancers. This study attempted to analyze its therapeutic potential for esophageal cancer (EC). Combining multiple databases and network pharmacology, we found that the mechanism of LCA inhibiting EC may be closely related to p53 signaling pathway, cell cycle regulation and apoptosis. Molecular docking was then used to predict the affinity between LCA and key targets. Subsequently, we selected three common EC cell lines for in vitro validation. LCA treatment significantly inhibited EC cell proliferation and colony formation. Wound healing and transwell assay showed that LCA can reduce the migration and invasion of EC cells, and down-regulated the expression of matrix metalloproteinases (MMP). LCA promoted excessive ROS production, decreased mitochondrial membrane potential, and upregulated the expression of Bax, Caspase3 and Caspase-9, all of which are involved in apoptosis. LCA treatment blocked the cell cycle in G2/M phase and decreased the expression of cyclin D1, cyclin B1, and CDK1. LCA significantly up-regulated p53 protein and gene expression, thereby inducing apoptosis and cycle arrest. Finally, the xenograft tumor model was established by subcutaneous injection of Eca-109 cells. LCA administration inhibited tumor growth by activating p53 signaling pathways and apoptosis. Meanwhile, there was no significant weight loss and few major organotoxicity and hematotoxicity. In conclusion, LCA is an excellent candidate for EC treatment by regulating p53 pathway to induce G2/M phase arrest and apoptosis.

Vegetarian diets and the risk of gastrointestinal cancers: a meta-analysis of observational studies

The systematic review aimed to assess the association between vegetarian diet and the risk of gastrointestinal tumorigenesis. PubMed, Embase, Cochrane Library, and Web of Science were searched from inception to August 2022 for observational studies on vegetarian diets and the risk of gastrointestinal tumorigenesis. The primary outcome was morbidity due to gastrointestinal cancer. The Newcastle-Ottawa Scale was used to assess the quality of included studies. Pooled effects were analyzed using a random-effects model. The study protocol was registered in PROSPERO (no. CRD42022310187). Eight original studies (seven cohorts and one case-control), involving 686 691 participants, were included. Meta-analysis showed a negative correlation between vegetarian diets and gastrointestinal tumorigenesis risk [relative risk (RR) equals 0.77, 95% confidence interval (CI) is (0.65-0.90)], compared with non-vegetarian diets. Subgroup analysis indicated that vegetarian diets were negatively correlated with the risks of gastric cancer [RR = 0.41, 95% CI (0.28-0.61)] and colorectal cancer [RR = 0.85, 95% CI (0.76-0.95)], but not with that of upper gastrointestinal cancer (excluding stomach) [RR = 0.93, 95% CI (0.61-1.42)]. Vegetarian diets were negatively correlated with the risk of gastrointestinal tumorigenesis in men [RR = 0.57, 95% CI (0.36-0.91)], but were uncorrelated in women [RR = 0.89, 95% CI (0.71-1.11)]. Vegetarian diets were negatively correlated with the risk of gastrointestinal tumorigenesis in North American [RR = 0.76, 95% CI (0.61-0.95)] and Asian populations [RR = 0.43, 95% CI (0.26-0.72)] and were uncorrelated in the European population [RR = 0.83, 95% CI (0.68-1.01)]. Adhering to vegetarian diets reduces the risk of gastrointestinal tumorigenesis. More data from well-conducted cohort and other studies are needed.

Targeting the SOX2/CDP protein complex with a peptide suppresses the malignant progression of esophageal squamous cell carcinoma

Emerging evidence indicates that SOX2 is an oncogene for esophageal squamous cell carcinoma (ESCC). However, direct targeting of SOX2 is not feasible given that this transcription factor plays important roles in the maintenance of tissues such as the brain. Here, we identified CDP (Homeobox protein cut-like 1 or CASP) as a unique SOX2 binding partner enriched in ESCC with Duolink proximity ligation assay, bimolecular fluorescence complementation (BiFc) and immunoprecipitation. We then screened a peptide aptamer library using BiFc and immunoprecipitation and identified several peptide aptamers, including P58, that blocked the CDP/SOX2 interaction, leading to the inhibition of ESCC progress in vitro and in vivo. Upon administration, synthetic peptide P58, containing the YGRKKRRQRRR cell-penetrating peptide and the fluorophore TAMRA, also blocked the growth and metastasis of ESCC in both mice and zebrafish. Therefore, targeting the SOX2 binding partner CDP with peptide P58 offers an alternative avenue to treat ESCC with increased SOX2 levels.

HOXC10 promotes esophageal squamous cell carcinoma progression by targeting FOXA3 and indicates poor survival outcome

Background

Esophageal cancer is one of the most unknown and deadliest cancers in the world. Although recent studies have identified some mutations linked to the development of squamous cell carcinoma of the esophagus (ESCC), the specific role of HomeoboxC10 (HOXC10) in the pathogenesis still requires further investigation.

Methods

Agilent mRNA single-channel gene expression was employed to identify genome-wide gene signatures in ESCC. These signatures were also verified using qRT-PCR, immunohistochemical staining as well as Western blot. The biological functions of HOXC10 were further investigated through cellular studies conducted on ESCC cells. Survival analysis was conducted utilizing the Kaplan-Meier method. The GEPIA database and the STRING website were utilized to predict the potential targets that bind to HOXC10. Co-immunoprecipitation assays were performed to investigate the binding interaction between HOXC10 and Forkhead Box A3 (FOXA3). Animal models were established to analyze the effects of HOXC10 silencing on tumorigenesis in vivo.

Results

The expression levels of HOXC10 mRNA were found to be upregulated in ESCC. Survival analysis revealed a significant association between abnormally elevated levels of HOXC10 mRNA and an unfavorable prognosis in patients with ESCC. In vitro studies revealed that the knockdown of HOXC10 expression resulted in the inhibition of the proliferation, invasion, and migrating ability of ESCC cells through the upregulation of FOXA3. Furthermore, tumor-bearing mouse models studies demonstrated that HOXC10 through knockdown techniques significantly suppressed ESCC tumor growth. HOXC10 was found to enhance the activation of the MAPK signaling pathway by regulating FOXA3 in ESCC cells.

Conclusion

These results support a key role for HOXC10 in the tumorigenesis of ESCC by upregulating FOXA3 via the MAPK pathway and highlight its potential as a promising diagnostic and prognostic marker for ESCC.

HPV16 infection promotes the malignant transformation of the esophagus and progression of esophageal squamous cell carcinoma

Esophageal squamous cell carcinoma (ESCC) may be correlated with HPV infection, and the mechanism underlying the ESCC formation induced by HPV16 infection remains elusive. Here, we overexpressed HPV16 E6 and E7 and coordinated the overexpression of these two genes in EPC2 and ESCC cells. We found that E7 and coordinated expression of E6 and E7 promoted the proliferation of EPC2 cells, and upregulation of shh was responsible for cell proliferation since the use of vismodegib led to the failure of organoid formation. Meanwhile, overexpression of E6 and E7 in ESCC cells promoted cell proliferation, migration, and invasion in vitro. Importantly, E6 and E7 coordinately increased the capability of tumor growth in nude mice, while vismodegib slowed the growth of tumors in NCG mice. Moreover, a series of genes and proteins changed in cell lines after overexpression of the E6 and E7 genes, the potential biological processes and pathways were systematically analyzed using a bioinformatics assay. Together, these findings suggest that the activation of the hedgehog pathway induced by HPV16 infection may initially transform basal cells in the esophagus and promote following malignant processes in ESCC cells. The application of hedgehog inhibitors may represent a therapeutic avenue for ESCC treatment.

Methyltransferase-like 3 facilitates the stem cell properties of esophageal cancer by upregulating patched homolog 1 via N6-methyladenosine methylation

Patched homolog 1 (PTCH1) has been proven to facilitate cell proliferation and self-renewal in esophageal cancer (EC). The present study intended to exploit the influence of PTCH1 on EC cells and the potential mechanisms. PTCH1 and methyltransferase-like 3 (METTL3) expression were examined by quantitative real-time polymerase chain reaction (qRT-PCR) and Western blot in EC cell lines. Following the loss- and gain-of-function assays, cell proliferation was examined by cell counting kit (CCK)-8 and clone formation assays, invasion and migration by Transwell and scratch assays, and the sphere-forming ability of stem cells by cell sphere-forming assay. The expression of stemness genes NANOG homeobox protein (NANOG), octamer-binding transcription factor 4 (Oct4), and sex-determining region Y-box 2 (SOX2) was detected by Western blot. Methylated RNA immunoprecipitation (Me-RIP) assay was performed to test N6-methyladenosine (m6A) modification levels of PTCH1 mRNA, RIP and photoactivatable ribonucleoside-enhanced crosslinking and immunoprecipitation (PAR-CLIP) assays to assess the binding of METTL3 to PTCH1, and actinomycin D treatment to examine PTCH1 mRNA stability. A xenograft tumor model in nude mice was established for further in vivo verification. PTCH1 and METTL3 expression was high in EC cells. Knockdown of METTL3 reduced m6A level and stability of PTCH1 mRNA. Knockdown of PTCH1 or METTL3 declined invasion, proliferation, migration, and NANOG, Oct4, and SOX2 levels in EC cells, and reduced sphere-forming abilities of EC stem cells. Overexpression of PTCH1 abolished the suppressive effect of METTL3 knockdown on EC cells in vitro. METTL3 knockdown repressed tumor growth in nude mice, which was negated by further overexpressing PTCH1. METTL3 facilitated growth and stemness of EC cells via upregulation of PTCH1 expression by enhancing PTCH1 m6A modification.NEW & NOTEWORTHY PTCH1 has been proved to facilitate cell proliferation and self-renewal in esophageal cancer. We studied the upstream regulation mechanism of PTCH1 by METTL3 through m6A modification. Our results provide a new target and theoretical basis for the treatment of esophageal cancer.

Esophageal cancer stem cells reduce hypoxia-induced apoptosis by inhibiting the GRP78-perk-eIF2α-ATF4-CHOP pathway in vitro

Background

Due to the abnormal angiogenesis, cancer stem cells (CSCs) in esophageal cancer (EC) have the characteristics of a hypoxic microenvironment. However, they can resist hypoxia-induced apoptosis. the molecular mechanism underlying the resistance of esophageal CSCs to hypoxia-induced apoptosis is currently unclear. Therefore, this study will investigate the molecular mechanism based on CHOP-mediated endoplasmic reticulum stress.

Methods

CD44+CD24- cells in EC9706 cells were screened by fluorescence-activated cell sorting (FACS). To clarify which apoptosis pathway esophageal CSCs resist hypoxia-induced cell apoptosis through, the effects of hypoxia on apoptosis were detected by nuclear staining, flow cytometry, and JC-1 reagent, the effects of hypoxia on the expression of apoptosis-related proteins were detected by western blotting (WB) assay and quantitative polymerase chain reaction (qPCR) assay. To clarify the mechanisms of CD44+CD24- cells resistance to hypoxia-induced apoptosis is achieved by inhibiting the activation of endoplasmic reticulum stress (ERS) pathway, silenced CHOP and PERK cell lines of EC9706 cells and overexpressed CHOP and PERK cell lines of CD44+CD24- cells were constructed, the effects of hypoxia on apoptosis, cell cycle, and mitochondrial membrane potential were detected by flow cytometry and JC-1 reagent. WB assay and qPCR assay were used to detect the expressions of apoptosis-related proteins and ERS-related proteins.

Results

Hypoxia significantly induce apoptosis and cycle arrest of EC9706 cells (P<0.05), but did not affect apoptosis and cycle of CD44+CD24- cells (P>0.05). Hypoxia considerably induced the activation of mitochondrial and ERS apoptosis pathways in EC9706 cells (P<0.05), but did not affect Fas receptor apoptosis pathways (P>0.05). The three apoptosis pathways were not affected by hypoxia in CD44+CD24- cells (P>0.05). Silencing the CHOP and PERK gene inhibited hypoxia-induced apoptosis of EC9706 cells (P<0.05). CHOP and PERK overexpression promoted hypoxia-induced apoptosis of CD44+CD24- cells (P<0.05), whereas mitochondrial membrane permeability inhibitors inhibited hypoxia-induced apoptosis of CD44+CD24- cells overexpressed CHOP gene.

Conclusions

CD44+CD24- tumor stem cells in EC resist to hypoxia-induced apoptosis by the inhibition of ERS-mediated mitochondrial apoptosis pathway, which suggested that ERS pathway can serve as a potential target for reducing EC treatment resistance in clinical treatment.

Developing a novel necroptosis-related signature to evaluate the prognostic and therapeutic characteristics of esophageal cancer

BACKGROUND

The prognostic assessment and therapeutic interventions of esophageal cancer (ESCA) require novel molecular targets. The prognostic value of necroptosis, a specific mode of programmed cell death strongly linked to cancer progression, remains largely unexplored in ESCA. The primary goal of this research is to develop a necroptosis-based prognostic signature, which will represent the microenvironmental characteristics and prognosis of individuals diagnosed with ESCA.

METHODS

Transcriptome data of ESCA samples from The Cancer Genome Atlas were utilized to screen for necroptosis-related long non-coding RNAs (NR-lncRNAs) and genes (NRGs). The research employed the least absolute shrinkage and selection operator (LASSO) regression and univariate Cox regression analysis to identify prognostic candidates. Based on these analyses, a signature was developed in the training set and subsequently verified in the testing and entire sets. A clinicopathologic relevance assessment was carried out, after which a nomogram was established. The features of the immune microenvironment, functional pathways, mutational burden, checkpoint expression, and stemness of tumors were analyzed. Moreover, the sensitivity of individuals to immunotherapy and chemotherapy was compared for therapeutic guidance.

RESULTS

A necroptosis-associated signature comprising two genes and eleven lncRNAs was constructed. High-risk patients showed worse prognosis and clinicopathologic features, with more tumor-infiltrating naïve B cells, CD4+ memory resting T cells, and regulatory T cells. Furthermore, stromal and ESTIMATE scores were decreased along with increased stemness scores and tumor mutational burden in high-risk individuals. For the quantitative prediction of the outcomes of individuals, a nomogram was established. High-risk individuals showed greater sensitivity to immunotherapy while low-risk individuals benefited more from conventional chemotherapeutic or targeted therapy.

CONCLUSION

A necroptosis-related prognostic signature was developed to study the tumor microenvironment, mutational burden, clinical features, and the treatment response of ESCA patients. This may contribute to precision medicine for ESCA.

MIAT shuttled by tumor-secreted exosomes promotes paclitaxel resistance in esophageal cancer cells by activating the TAF1/SREBF1 axis

Chemoresistance remains a major obstacle to the treatment of esophageal cancer (EC). Exosome-mediated transfer of long noncoding RNAs (lncRNAs) has recently been unveiled to correlate with the regulation of drug resistance in EC. This study aimed to investigate the physiological mechanisms by which exosome-encapsulated lncRNA myocardial infarction-associated transcript (MIAT) derived from tumor cells might mediate the paclitaxel (PTX) resistance of EC cells. First, MIAT was experimentally determined to be upregulated in PTX nonresponders and PTX-resistant EC cells. Silencing of MIAT in PTX-resistant EC cells decreased cell viability and enhanced apoptosis, corresponding to a reduced half-maximal inhibitory concentration (IC50 ) value. Next, exosomes were isolated from EC109 and EC109/T cells, and EC109 cells were cocultured with EC109/T-cell-derived exosomes. Accordingly, MIAT was revealed to be transmitted through exosomes from EC109/T cells to EC109 cells. Tumor-derived exosomes carrying MIAT increased the IC50 value of PTX and suppressed apoptosis in EC109 cells to promote PTX resistance. Furthermore, MIAT promoted the enrichment of TATA-box binding protein-associated Factor 1 (TAF1) in the promoter region of sterol regulatory element binding transcription factor 1 (SREBF1), as shown by a chromatin immunoprecipitation assay. This might be the mechanism by which MIAT could promote PTX resistance. Finally, in vivo experiments further confirmed that the knockdown of MIAT attenuated the resistance of EC cells to PTX. Collectively, these results indicate that tumor-derived exosome-loaded MIAT activates the TAF1/SREBF1 axis to induce PTX resistance in EC cells, providing a potential therapeutic target for overcoming PTX resistance in EC.

Esophageal organoids: applications and future prospects

Organoids have been developed in the last decade as a new research tool to simulate organ cell biology and disease. Compared to traditional 2D cell lines and animal models, experimental data based on esophageal organoids are more reliable. In recent years, esophageal organoids derived from multiple cell sources have been established, and relatively mature culture protocols have been developed. Esophageal inflammation and cancer are two directions of esophageal organoid modeling, and organoid models of esophageal adenocarcinoma, esophageal squamous cell carcinoma, and eosinophilic esophagitis have been established. The properties of esophageal organoids, which mimic the real esophagus, contribute to research in drug screening and regenerative medicine. The combination of organoids with other technologies, such as organ chips and xenografts, can complement the deficiencies of organoids and create entirely new research models that are more advantageous for cancer research. In this review, we will summarize the development of tumor and non-tumor esophageal organoids, the current application of esophageal organoids in disease modeling, regenerative medicine, and drug screening. We will also discuss the future prospects of esophageal organoids.

The possible molecular mechanism underlying the involvement of the variable shear factor QKI in the epithelial-mesenchymal transformation of oesophageal cancer

OBJECTIVE

Based on the GEO, TCGA and GTEx databases, we reveal the possible molecular mechanism of the variable shear factor QKI in epithelial mesenchymal transformation (EMT) of oesophageal cancer.

METHODS

Based on the TCGA and GTEx databases, the differential expression of the variable shear factor QKI in oesophageal cancer samples was analysed, and functional enrichment analysis of QKI was performed based on the TCGA-ESCA dataset. The percent-spliced in (PSI) data of oesophageal cancer samples were downloaded from the TCGASpliceSeq database, and the genes and variable splicing types that were significantly related to the expression of the variable splicing factor QKI were screened out. We further identified the significantly upregulated circRNAs and their corresponding coding genes in oesophageal cancer, screened the EMT-related genes that were significantly positively correlated with QKI expression, predicted the circRNA-miRNA binding relationship through the circBank database, predicted the miRNA-mRNA binding relationship through the TargetScan database, and finally obtained the circRNA-miRNA-mRNA network through which QKI promoted the EMT process.

RESULTS

Compared with normal control tissue, QKI expression was significantly upregulated in tumour tissue samples of oesophageal cancer patients. High expression of QKI may promote the EMT process in oesophageal cancer. QKI promotes hsa_circ_0006646 and hsa_circ_0061395 generation by regulating the variable shear of BACH1 and PTK2. In oesophageal cancer, QKI may promote the production of the above two circRNAs by regulating variable splicing, and these circRNAs further competitively bind miRNAs to relieve the targeted inhibition of IL-11, MFAP2, MMP10, and MMP1 and finally promote the EMT process.

CONCLUSION

Variable shear factor QKI promotes hsa_circ_0006646 and hsa_circ_0061395 generation, and downstream related miRNAs can relieve the targeted inhibition of EMT-related genes (IL11, MFAP2, MMP10, MMP1) and promote the occurrence and development of oesophageal cancer, providing a new theoretical basis for screening prognostic markers of oesophageal cancer patients.

Advances in the Theranostics of Oesophageal Squamous Carcinoma

Oesophageal squamous carcinoma (ESCC) is one of the most lethal human malignancies, and it is a more aggressive form of oesophageal cancer (EC) that comprises over 90% of all EC cases in China compared with oesophageal adenocarcinoma (EAC). The high mortality of ESCC is attributed to the late‐stage diagnosis, chemoradiotherapy resistance, and lack of appropriate therapeutic targets and corresponding therapeutic formulations. Recently, emerging clinical and translational investigations have involved genome analyses, diagnostic biomarkers, and targeted therapy for ESCC, and these studies provide a new horizon for improving the clinical outcomes of patients with ESCC. Here, the latest research advances in the theranostics of ESCC are reviewed and the unique features of ESCC (including differences from EAC, genomic alterations, and microbe infections), tissue and circulating biomarkers, chemoradiotherapy resistance, clinical targeted therapy for ESCC, identification of novel therapeutic targets, and designation of nanotherapeutic systems for ESCC are particularly focused on. Finally, the perspectives for future clinical and translational theranostic research of ESCC are discussed and the obstacles that must be overcome in ESCC theranostics are described.

Global incidence, mortality, and burden of esophageal cancer, and its correlation with SDI, metabolic risks, fasting plasma glucose, LDL cholesterol, and body mass index: An ecological study

BACKGROUND AND AIMS

Esophageal cancer (EC) is one of the most common gastrointestinal malignancies. The geographical variation shows the influence of genetic factors, ethnicity, and distribution of various risk factors. Accurate knowledge of EC epidemiology at the global level will help to develop management strategies. Therefore, the present study was conducted to investigate the global and regional disease burden of EC, including the incidence, mortality, and burden of this cancer in 2019.

METHODS

Incidence, mortality, disability-adjusted life years (DALYs), and age-standardized rates (ASRs) associated with EC in 204 countries in different classifications were extracted from the global burden of disease study. After collecting information on metabolic risks, fasting plasma glucose (FPG), low-density lipoprotein (LDL) cholesterol, and body mass index (body mass index), the relationship between age-standardized incidence rate (ASIR), mortality rate, and DALYs with these variables was determined.

RESULTS

In 2019, 534,563 new cases of EC were reported worldwide. The highest ASIR is related to regions with medium sociodemographic index (SDI), and high middle income according to the World Bank, the Asian continent, and the western Pacific region. In 2019, a total of 498,067 deaths from EC were recorded. The highest mortality rate due to ASR is in countries with medium SDI and countries with upper middle income of the World Bank. In 2019, 1,166,017 DALYs were reported due to EC. The ASIR, ASDR, and DALYS ASR of EC showed a significant negative linear correlation with SDI, metabolic risks, high FPG, high LDL cholesterol, and high BMI (p < 0.05).

CONCLUSIONS

The results of this study showed significant gender and geographic variation in the incidence, mortality, and burden of EC. It is recommended to design and implement preventive approaches based on known risk factors and improve quality and access to efficient and appropriate treatments.

DUSP4 promotes esophageal squamous cell carcinoma progression by dephosphorylating HSP90β

The molecular and pathogenic mechanisms of esophageal squamous cell carcinoma (ESCC) development are still unclear, which hinders the development of effective treatments. In this study, we report that DUSP4 is highly expressed in human ESCC and is negatively correlated with patient prognosis. Knockdown of DUSP4 suppresses cell proliferation and patient-derived xenograft (PDX)-derived organoid (PDXO) growth and inhibits cell-derived xenograft (CDX) development. Mechanistically, DUSP4 directly binds to heat shock protein isoform β (HSP90β) and promotes the ATPase activity of HSP90β by dephosphorylating HSP90β on T214 and Y216. These dephosphorylation sites are critical for the stability of JAK1/2-STAT3 signaling and p-STAT3 (Y705) nucleus translocation. In vivo, Dusp4 knockout in mice significantly inhibits 4-nitrochinoline-oxide-induced esophageal tumorigenesis. Moreover, DUSP4 lentivirus or treatment with HSP90β inhibitor (NVP-BEP800) significantly impedes PDX tumor growth and inactivates the JAK1/2-STAT3 signaling pathway. These data provide insight into the role of the DUSP4-HSP90β-JAK1/2-STAT3 axis in ESCC progression and describe a strategy for ESCC treatment.

Phosphorylation of AKT by lysyl oxidase-like 2 activates the PI3K/AKT signaling pathway to promote proliferation, invasion and metastasis in esophageal squamous carcinoma

OBJECTIVE

Esophageal squamous cell carcinoma (ESCC) is a common and aggressive malignancy of the gastrointestinal tract for which therapeutic options are scarce. This study screens for LOXL2, a key gene in ESCC, and explains the molecular mechanism by which it promotes the progression of ESCC.

METHODS

Immunohistochemical staining was performed to detect the expression level of LOXL2 in ESCC tissues and paraneoplastic tissues. CCK-8 and Transwell assays were performed to assess the effects of LOXL2 knockdown and overexpression on the proliferation, apoptosis, migration and invasion ability of ESCC cells. High-throughput sequencing analysis screens for molecular mechanisms of action by which LOXL2 promotes ESCC progression. Western blotting and qRT-PCR were used to determine the expression levels of relevant markers.

RESULTS

LOXL2 is positively expressed in ESCC and highly correlated with poor prognosis. Silencing LOXL2 significantly inhibited the proliferation, migration and invasive ability of ESCC cells, whereas overexpression showed the opposite phenotype. High-throughput sequencing suggested that LOXL2-associated differentially expressed genes were highly enriched in the PI3K/AKT signaling pathway. In vitro cellular assays confirmed that silencing LOXL2 significantly reduced PI3K, p-AKT^Thr308 and p-AKT^Ser473 gene and protein expression levels, while overexpression increased all three gene and protein levels, while AKT gene and protein expression levels were not significantly different.

CONCLUSION

This study found that LOXL2 may regulate the PI3K/AKT signaling pathway and exert protumor effects on ESCC cells through phosphorylation of AKT. LOXL2 may be a key clinical warning biomarker or therapeutic target for ESCC.

Biomaterial-based platforms for modulating immune components against cancer and cancer stem cells

Immunotherapy involves the therapeutic alteration of the patient's immune system to identify, target, and eliminate cancer cells. Dendritic cells, macrophages, myeloid-derived suppressor cells, and regulatory T cells make up the tumor microenvironment. In cancer, these immune components (in association with some non-immune cell populations like cancer-associated fibroblasts) are directly altered at a cellular level. By dominating immune cells with molecular cross-talk, cancer cells can proliferate unchecked. Current clinical immunotherapy strategies are limited to conventional adoptive cell therapy or immune checkpoint blockade. Targeting and modulating key immune components presents an effective opportunity. Immunostimulatory drugs are a research hotspot, but their poor pharmacokinetics, low tumor accumulation, and non-specific systemic toxicity limit their use. This review describes the cutting-edge research undertaken in the field of nanotechnology and material science to develop biomaterials-based platforms as effective immunotherapeutics. Various biomaterial types (polymer-based, lipid-based, carbon-based, cell-derived, etc.) and functionalization methodologies for modulating tumor-associated immune/non-immune cells are explored. Additionally, emphasis has been laid on discussing how these platforms can be used against cancer stem cells, a fundamental contributor to chemoresistance, tumor relapse/metastasis, and failure of immunotherapy. Overall, this comprehensive review strives to provide up-to-date information to an audience working at the juncture of biomaterials and cancer immunotherapy. STATEMENT OF SIGNIFICANCE: Cancer immunotherapy possesses incredible potential and has successfully transitioned into a clinically lucrative alternative to conventional anti-cancer therapies. With new immunotherapeutics getting rapid clinical approval, fundamental problems associated with the dynamic nature of the immune system (like limited clinical response rates and autoimmunity-related adverse effects) have remained unanswered. In this context, treatment approaches that focus on modulating the compromised immune components within the tumor microenvironment have garnered significant attention amongst the scientific community. This review aims to provide a critical discussion on how various biomaterials (polymer-based, lipid-based, carbon-based, cell-derived, etc.) can be employed along with immunostimulatory agents to design innovative platforms for selective immunotherapy directed against cancer and cancer stem cells.

Associations of trace element levels in paired serum, whole blood, and tissue: an example of esophageal squamous cell carcinoma

Previous studies have extensively explored impacts of trace elements on human beings and complex relationships with cancers. However, contradictory conclusions may be more challenging to explain due to biological specimen differences. To investigate the distribution of trace elements inside body, we collected serum, whole blood and tissues from 77 patients with esophageal squamous cell carcinoma (ESCC), as well as serum and whole blood from 100 healthy individuals, and determined the concentrations of 13 elements (Al, V, Cr, Mn, Co, Ni, Cu, Zn, As, Se, Sr, Cd, and Pb) with inductively coupled plasma-mass spectrometry (ICP-MS). Al, Ni, Cu, Sr, and Cd variations between patients and controls were found to be inconsistent in serum and blood. Concentrations of Cu, As, Se, and Sr in serum were positively correlated with that in whole blood in both case and control group (r_s >0.450, P <0.01). Elements in serum had a higher accuracy (87.0%) than whole blood (74.0%) in classifying ESCC patients and healthy individuals with discriminant analysis. As, Cd, and Pb concentrations in cancerous tissues were positively correlated with those in normal epithelium (r_s =0.397, 0.571, and 0.542, respectively), while Mn, Cu, and Se accumulated in malignant tissues, with V, Cr, Co, Ni, Sr, and Cd partitioning in normal epithelium (all P <0.05). Thus, certain elements in blood, such as Cu, As, Se, and Sr, were useful in assessing element exposure burdens and accumulation tendency of some elements (Mn, Cu and Se, etc.) was uncovered in tumors. Our investigation demonstrated the variations in trace element distribution for frequently used specimens and further evidence of etiological mechanism is necessary.

Comparison of Efficacy and Safety of First-Line Chemoimmunotherapy in Advanced Esophageal Squamous Cell Carcinoma: A Systematic Review and Network Meta-Analysis

Background. Chemoimmunotherapy has become the first-line treatment for advanced esophageal squamous cell carcinoma (ESCC). We aimed to compare the efficacy and toxicity of different chemoimmunotherapy combinations to determine the optimal treatment option. Methods. PubMed, Web of Science, Cochrane Library, Embase, and abstracts of recent relevant meetings were searched to identify phase III randomized controlled trials (RCTs) of first-line programmed cell death-1 (PD-1)/its receptor (PD-L1) inhibitors plus chemotherapy for ESCC up to July 2022. A network meta-analysis (NMA) following Bayesian approaches was conducted in R software. Result. Our study included six RCTs and 3,611 patients. According to the NMA, toripalimab plus chemotherapy ranked first to prolong overall survival (OS). Sintilimab plus chemotherapy and camrelizumab plus chemotherapy consistently yielded the greatest benefits regarding progression-free survival (PFS). The maximal complete response rate (CRR) and objective response rate (ORR) were achieved with nivolumab plus chemotherapy. Tislelizumab plus chemotherapy attained the highest likelihood of achieving a disease control rate (DCR). The addition of immunotherapy to chemotherapy was associated with improved survival and increased adverse events. Subgroup analysis revealed that patients with PD-L1 tumor positive score (TPS) ≥10% showed a better OS than those with lower values when undergoing first-line chemoimmunotherapy. Anti-PD-1 inhibitor with platinum plus paclitaxel (TP) regimen showed a superior PFS benefit over anti-PD-1 inhibitor with platinum plus fluorouracil (FP) regimen. Conclusion. The NMA analysis suggested that sintilimab plus chemotherapy was the preferred regimen for treatment-naive advanced ESCC patients with the best balance between efficacy and safety. Anti-PD-1 inhibitors with the TP regimen were associated with more favorable PFS than those with the FP regimen.

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].

HPV 16 E6 promotes growth and metastasis of esophageal squamous cell carcinoma cells in vitro

BACKGROUND

Esophageal squamous cell carcinoma (ESCC) is one of the most lethal malignancies worldwide. Increasing evidence suggests that human papillomavirus (HPV) infection may be associated with the etiology of ESCC. However, the precise role of HPV in ESCC remains unclear.

METHODS AND RESULTS

Proliferation and apoptosis of ESCC cells upon infection with HPV16 E6 were detected using CCK-8 assays and Western blot analyses. The migration rate was measured with a wound healing assay, and a Transwell Matrigel invasion assay was used to detect the invasive ability. RT-qPCR was performed to detect the expression of E6AP, p53, and miR-34a. The proliferation rates were significantly higher in HPV16E6-transfected cell groups compared with the negative control groups. Bax protein expression was downregulated in HPV16E6-treated groups compared to the controls. The wound healing and Transwell Matrigel invasion assays indicated that HPV16 E6 infection could increase ESCC cell migration and invasion. Furthermore, E6AP, p53 and miR-34a expression were decreased in HPV16 E6-transfected cell lines.

CONCLUSION

Our results not only provide evidence that HPV16 E6 promotes cell proliferation, migration, and invasion in ESCC, but also suggests a correlation between HPV infection and E6AP, p53 and miR-34a expression. Consequently, HPV16 E6 may play an important role in ESCC development.

Revisiting Inhibition Effects of miR-28 as a Metastasis Suppressor in Gastrointestinal Cancers

MicroRNAs are critical epigenetic regulators that can be used as diagnostic, prognostic, and therapeutic biomarkers for the treatment of various diseases, including gastrointestinal cancers, among a variety of cellular and molecular biomarkers. MiRNAs have also shown oncogenic or tumor suppressor roles in tumor tissue and other cell types. Studies showed that the dysregulation of miR-28 is involved in cell growth and metastasis of gastrointestinal cancers. MiR-28 plays a key role in controlling the physiological processes of cancer cells including growth and proliferation, migration, invasion, apoptosis, and metastasis. Therefore, miR-28 expression patterns can be used to distinguish patient subgroups. Based on the previous studies, miR-28 expression can be a suitable biomarker to detect tumor size and predict histological grade metastasis. In this review, we summarize the inhibitory effects of miR-28 as a metastasis suppressor in gastrointestinal cancers. miR-28 plays a role as a tumor suppressor in gastrointestinal cancers by regulating cancer cell growth, cell differentiation, angiogenesis, and metastasis. As a result, using it as a prognostic, diagnostic, and therapeutic biomarker in the treatment of gastrointestinal cancers can be a way to solve the problems in this field.

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.

SOX2 inhibits LLGL2 polarity protein in esophageal squamous cell carcinoma via miRNA-142-3p

ABBREVIATIONS

CCK-8, Cell Counting Kit 8; Chip, Chromatin Immunoprecipitation; EC, Esophageal cancer; EMT, epithelial-to-mesenchymal transition; ESCC, Esophageal squamous cell carcinomas; LLGL2, lethal (2) giant larvae protein homolog 2; LLGL2ov, LLGL2 overexpression; MET, mesenchymal-epithelial transition; miRNAs, MicroRNAs; PRM-MS, Parallel reaction monitoring-Mass spectrometry; SD, Standard deviation; SOX, sex determining region Y (SRY)-like box; SOX2-Kd, SOX2-knockdwon; TUNEL, TdT-mediated dUTP Nick-End Labeling.

Challenges in precision medicine in pancreatic cancer: A focus in cancer stem cells and microbiota

Pancreatic cancer adenocarcinoma (PDAC) is a lethal disease, with the lowest 5-years survival rate of all cancers due to late diagnosis. Despite the advance and success of precision oncology in gastrointestinal cancers, the frequency of molecular-informed therapy decisions in PDAC is currently neglectable. The reasons for this dismal situation are mainly the absence of effective early diagnostic biomarkers and therapy resistance. PDAC cancer stem cells (PDAC-SC), which are regarded as essential for tumor initiation, relapse and drug resistance, are highly dependent on their niche i.e. microanatomical structures of the tumor microenvironment. There is an altered microbiome in PDAC patients embedded within the highly desmoplastic tumor microenvironment, which is known to determine therapeutic responses and affecting survival in PDAC patients. We consider that understanding the communication network that exists between the microbiome and the PDAC-SC niche by co-culture of patient-derived organoids (PDOs) with TME microbiota would recapitulate the complexity of PDAC paving the way towards a precision oncology treatment-response prediction.

HA-ADT suppresses esophageal squamous cell carcinoma progression via apoptosis promotion and autophagy inhibition

Esophageal squamous cell carcinoma (ESCC) is a major cause of cancer-related deaths. We have previously connected a non-sulfated glycosaminoglycan, hyaluronic acid (HA), with a common hydrogen sulfide (H₂S) donor, 5-(4-hydroxyphenyl)-3H-1,2-dithiol-3-thione (ADT-OH), to reconstruct a novel conjugate, HA-ADT. In this study, we determined the effect of HA-ADT on the growth of ESCC. Our data suggested that HA-ADT exerted more potent effects than sodium hydrosulfide (NaHS, a fast H₂S-releasing donor) and morpholin-4-ium (4-methoxyphenyl)-morpholin-4-ylsulfanylidenesulfido-λ5-phosphane (GYY4137, a slow H₂S-releasing donor) on inhibiting the viability, proliferation, migration, and invasion of human ESCC cells. HA-ADT increased apoptosis by suppressing the protein expressions of phospho (p)-Ser473-protein kinase B (PKB/AKT), p-Tyr199/Tyr458-phosphatidylinositol 3-kinase (PI3K), and p-Ser2448-mammalian target of rapamycin (mTOR), but suppressed autophagy through the inhibition of the protein levels of p-Ser552-β-catenin, p-Ser9-glycogen synthase kinase-3β (GSK-3β), and Wnt3a in human ESCC cells. In addition, HA-ADT was more effective in terms of the growth inhibition of human ESCC xenograft tumor than NaHS and GYY4137. In conclusion, HA-ADT can suppress ESCC progression via apoptosis promotion and autophagy inhibition. HA-ADT might be efficacious for the treatment of cancer.

[MC1R is highly expressed in esophageal squamous cell carcinoma]

OBJECTIVE

To investigate the expression of MC1R in esophageal squamous cell carcinoma and its correlation with the clinicopathological parameters.

METHODS

We analyzed the expression of MC1R in esophageal cancer based on data from TCGA databse and examined its expression levels using RT-PCR and Western blotting in a human esophageal epithelial cell line BAr-T, human esophageal squamous cell carcinoma cell lines ECA109, KYSE30, KYSE150, KYSE510, TE-1, TE-13, and EC9706, a human gastric cancer cell line SGC7901 and 19 pairs of esophageal squamous cell carcinoma tissues and adjacent tissues.Immunohistochemistry was used to detect MC1R expression levels in 32 pairs of paraffin-embedded sections of esophageal squamous cell carcinoma and adjacent tissues, and the correlation of MC1R expression and the patients'clinicopathological characteristics was analyzed.

RESULTS

Bioinformatics analysis showed that MC1R was significantly overexpressed in esophageal cancer tissues (P < 0.05).MC1R expression was also increased in 5 esophageal squamous cell carcinoma cell lines ECA109, KYSE30, KYSE510, TE-13, EC9706 and the gastric cancer cell line SGC7901 as compared with that in esophageal epithelial cells (P < 0.05).Immunohistochemistry revealed significantly increased MC1R expression in esophageal squamous cell carcinoma tissue sections in comparison with the adjacent tissue sections (P < 0.05).In patients with esophageal squamous cell carcinoma, a high MC1R expression was detected mainly in those with an old age, positive for middle-thoracic involvement, and with moderately differentiated tumor cells, and showed a correlation with T stage of tumor (P < 0.05), but not with the other clinicopathological parameters such as gender, age, degree of cell differentiation, primary tumor site, or TNM stage (P>0.05).

CONCLUSION

MC1R is highly expressed in esophageal squamous cell carcinoma and may serve as a molecular biomarker to assist in the diagnosis of esophageal squamous cell carcinoma.

Single-Cell Transcriptomics of Endothelial Cells in Upper and Lower Human Esophageal Squamous Cell Carcinoma

Esophageal squamous cell carcinoma (ESCC) is a type of progressive and distant metastatic tumor. Targeting anti-angiogenic genes could effectively hinder ESCC development and metastasis, whereas ESCC locating on the upper or the lower esophagus showed different response to the same clinical treatment, suggesting ESCC location should be taken into account when exploring new therapeutic targets. In the current study, to find novel anti-angiogenic therapeutic targets, we identified endothelial cell subsets in upper and lower human ESCC using single-cell RNA sequencing (scRNA-seq), screened differentially expressed genes (DEGs), and performed gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis. The results showed that common DEGs shared in the upper and the lower endothelial cells mainly are involved in vessel development, angiogenesis, and cell motility of endothelial cells by regulating PI3K-AKT, Rap1, Ras, TGF-beta, and Apelin signaling pathways. The critical regulatory genes were identified as ITGB1, Col4A1, Col4A2, ITGA6, LAMA4, LAMB1, LAMC1, VWF, ITGA5, THBS1, PDGFB, PGF, RHOC, and CTNNB1. Cell metabolism-relevant genes, e.g., MGST3, PNP, UPP1, and HYAL2 might be the prospective therapeutic targets. Furthermore, we found that DEGs only in the upper endothelial cells, such as MAPK3, STAT3, RHOA, MAPK11, HIF1A, FGFR1, GNG5, GNB1, and ARHGEF12, mainly regulated cell adhesion, structure morphogenesis, and motility through Phospholipase D, Apelin, and VEGF signaling pathways. Moreover, DEGs only in the lower endothelial cells, for instance PLCG2, EFNA1, CALM1, and RALA, mainly regulated cell apoptosis and survival by targeting calcium ion transport through Rap1, Ras, cAMP, Phospholipase D, and Phosphatidylinositol signaling pathways. In addition, the upper endothelial cells showed significant functional diversity such as cytokine-responsive, migratory, and proliferative capacity, presenting a better angiogenic capacity and making it more sensitive to anti-angiogenic therapy compared with the lower endothelial cells. Our study has identified the potential targeted genes for anti-angiogenic therapy for both upper and lower ESCC, and further indicated that anti-angiogenic therapy might be more effective for upper ESCC, which still need to be further examined in the future.

miR-18a-5p and ATM Expression in Esophageal Squamous Cell Carcinoma and Their Correlations with Clinicopathological Features

Objective. To investigate miR-18a-5p and ataxia telangiectasia muted (ATM) expression in esophageal squamous cell carcinoma (ESCC) and their correlations with clinicopathological features. Methods. The subjects of this study were 62 ESCC patients (research group, RG) and 57 healthy controls (control group, CG) presented to our hospital between July 2019 and April 2020. Peripheral blood (PB) miR-18a-5p and ATM levels in these participants were quantified via qRT-PCR, and the correlations of the two genes with ESCC patients’ clinicopathological characteristics were investigated. In addition, a two-year follow-up was performed on ESCC patients to understand their survival, so as to further determine the prognostic utility of miR-18a-5p and ATM in ESCC. Factors influencing patient outcomes were identified by COX analysis. Results. PB miR-18a-5p expression was higher in RG compared with CG, while ATM was lower, suggesting an inverse connection between the two genes in ESCC ( $P<0.001$ ). miR-18a-5p and ATM levels were determined to be strongly linked to TNM stage, differentiation degree, and lymph node metastasis in ESCC patients ( $P<0.001$ and $P=0.007$ ). The patients who succumbed to the disease exhibited higher miR-18a-5p and lower ATM than the survival ( $P<0.05$ ). ROC analysis suggested favorable evaluation effects of miR-18a-5p and ATM on the occurrence and prognostic death of ESCC ( $P<0.001$ ). Further, these two genes were identified by the COX analysis to be factors independently affecting the prognosis of ESCC. Conclusion. miR-18a-5p is highly expressed in ESCC, and ATM is underexpressed, both of which are closely linked to the pathological process of ESCC and have a good evaluation effect on the occurrence and prognosis of ESCC, which may become a breakthrough in future diagnosis and treatment of ESCC.

Identification of clinical prognostic features of esophageal cancer based on m6A regulators

Background

Esophageal cancer (ESCA) is a common malignancy with high morbidity and mortality. n6-methyladenosine (m6A) regulators have been widely recognized as one of the major causes of cancer development and progression. However, for ESCA, the role of regulators is unclear. The aim of this study was to investigate the role of m6A RNA methylation regulators in the immune regulation and prognosis of ESCA.

Methods

RNA-seq data were downloaded using the Cancer Genome Atlas (TCGA) database, and the expression differences of m6A RNA methylation regulators in ESCA were analyzed. Further m6A methylation regulator markers were constructed, and prognostic and predictive values were assessed using survival analysis and nomograms. Patients were divided into low-risk and high-risk groups. The signature was evaluated in terms of survival, single nucleotide polymorphism (SNP), copy number variation (CNV), tumor mutation burden (TMB), and functional enrichment analysis (TMB). The m6A expression of key genes in clinical specimens was validated using quantitative reverse transcription polymerase chain reaction (qRT-PCR).

Results

In ESCA tissues, most of the 23 regulators were significantly differentially expressed. LASSO regression analysis included 7 m6A-related factors (FMR1, RBMX, IGFBP1, IGFBP2, ALKBH5, RBM15B, METTL14). In addition, this study also identified that the risk model is associated with biological functions, including base metabolism, DNA repair, and mismatch repair. In this study, a nomogram was created to predict the prognosis of ESCA patients. Bioinformatics analysis of human ESCA and normal tissues was performed using qRT-PCR. Finally. Seven genetic features were found to be associated with m6A in ESCA patients. The results of this study suggest that three different clusters of m6A modifications are involved in the immune microenvironment of ESCA, providing important clues for clinical diagnosis and treatment.