OBJECTIVE: To explore the potential role of mRNA m7G modification in the pathogenesis of human adenocarcinoma of esophagogastric junction (AEG). METHODS: Pathological tissue specimens from four AEG patients who underwent surgical treatment at the People's Hospital Affiliated to Jiangsu University between 2018 and 2019 were selected. Tumor tissues and adjacent normal tissues were collected from these patients. RNA was extracted from both tissue types and subjected to m7G methylated RNA immunoprecipitation sequencing (m7G-MeRIP-seq) to analyze the patterns of m7G modification, the characteristics of differential m7G modification sites, the differentially expressed mRNA, and the correlation between m7G modification and mRNA expression levels. Differential m7G-modified genes (MSH6, BRCA1, and SOX9) were further validated using methylated RNA immunoprecipitation quantitative PCR (MeRIP-qPCR), while the expression of METTL1 and WDR4 genes was examined by real-time quantitative PCR (RT-qPCR). This study was approved by the Medical Ethics Committee of the People's Hospital Affiliated to Jiangsu University (Ethics No. 20150083). RESULTS: m7G-MeRIP-seq analysis revealed that m7G modifications in both AEG and adjacent normal tissues were predominantly located in the GC-rich region surrounding the internal start codon of mRNA. Differential m7G modification sites between the two groups were closely associated with cancer-related genes. mRNA library analysis showed that differentially expressed mRNA were predominantly upregulated in AEG tissues and downregulated in adjacent normal tissues. Cross-analysis indicated that genes with hypermethylation tended to exhibit upregulated expression, while genes with hypomethylation were typically downregulated in AEG tissues. MeRIP-qPCR validation confirmed that the mRNA expression of MSH6, BRCA1, and SOX9 were significantly upregulated in AEG tissues compared to adjacent normal tissues (AEG vs. normal, P < 0.05). RT-qPCR results demonstrated that the mRNA expression levels of METTL1 and WDR4 were also upregulated in AEG tissues (AEG vs. normal, P < 0.000 5). CONCLUSION These findings suggest that mRNA m7G modification plays a significant role in the development of AEG. Furthermore, proteins as METTL1 and WDR4 may facilitate AEG progression by regulating mRNA m7G modification. These results provide valuable insights into the molecular mechanisms underlying AEG and may inform future therapeutic strategies for this malignancy.
Humans ; RNA, Messenger/metabolism* ; Adenocarcinoma/pathology* ; Esophagogastric Junction/metabolism* ; Esophageal Neoplasms/metabolism* ; Gene Expression Regulation, Neoplastic ; Female ; Male ; Middle Aged ; DNA Methylation ; Methyltransferases/metabolism* ; Stomach Neoplasms/genetics*

OBJECTIVES: To investigate the effect of BRD4 inhibition on migration of esophageal squamous cell carcinoma (ESCC) cells with low acetyl-CoA carboxylase 1 (ACC1) expression. METHODS: ESCC cell lines with lentivirus-mediated ACC1 knockdown or transfected with a negative control sequence (shNC) were treated with DMSO, JQ1 (a BRD4 inhibitor), co-transfection with shNC-siBRD4 or siNC with additional DMSO or C646 (an ahistone acetyltransferase inhibitor) treatment, or JQ1combined with 3-MA (an autophagy inhibitor). BRD4 mRNA expression in the cells was detected using RT-qPCR. The changes in cell proliferation, migration, autophagy, and epithelial-mesenchymal transition (EMT) were examined with CCK8 assay, Transwell migration assay, and Western blotting. RESULTS: ACC1 knockdown did not significantly affect BRD4 expression in the cells but obviously increased their sensitivity to JQ1. JQ1 treatment at 1 and 2 μmol/L significantly inhibited ESCC cell proliferation, while JQ1 at 0.2 and 2 μmol/L promoted cell migration. The cells with ACC1 knockdown and JQ1 treatment showed increased expresisons of vimentin and Slug and decreased expression of E-cadherin. BRD4 knockdown promoted migration of ESCC cells, and co-transfection with shACC1 and siBRD4 resulted in increased vimentin and Slug expressions and decreased E-cadherin expression in the cells. C646 treatment of the co-transfected cells reduced acetylation levels, decreased vimentin and Slug expressions, and increased E-cadherin expression. Treatment with JQ1 alone obviously increased LC3A/B-II levels in the cells either with or without ACC1 knockdown. In the cells with ACC1 knockdown and JQ1 treatment, additional 3-MA treatment significantly decreased the expressions of vimentin, Slug and LC3A/B-II and increased the expression of E-cadherin. CONCLUSIONS BRD4 inhibition promotes autophagy of ESCC cells via a histone acetylation-dependent mechanism, thereby enhancing EMT and ultimately increasing cell migration driven by ACC1 deficiency.
Humans ; Cell Movement ; Transcription Factors/metabolism* ; Esophageal Neoplasms/metabolism* ; Cell Line, Tumor ; Cell Cycle Proteins ; Azepines/pharmacology* ; Epithelial-Mesenchymal Transition ; Carcinoma, Squamous Cell/metabolism* ; Esophageal Squamous Cell Carcinoma ; Triazoles/pharmacology* ; Nuclear Proteins/genetics* ; Cell Proliferation ; Acetyl-CoA Carboxylase/genetics* ; Transfection ; Autophagy ; Bromodomain Containing Proteins

Objective To elucidate the molecular mechanism by which exosomes (Exo) derived from cancer-associated fibroblasts (CAF) carrying HOX transcript antisense intergenic RNA (lncRNA HOTAIR) promote the metastasis of esophageal squamous cell carcinoma (ESCC). Methods CAFs were collected from tumor tissues, and non-cancer associated fibroblasts (NFs) were obtained from adjacent normal tissues at least 5 cm away from the tumor. Exosomes (CAFs-Exo and NFs-Exo) were isolated from conditioned media collected from CAFs or NFs. CAFs-Exo and NFs-Exo were incubated with human ESCC cell line TE-1 for 24 hours, and CCK-8 was used to determine the cell proliferation ability. Scratch test and Transwell test were performed to determine the cell migration and invasion ability. TE-1 cells were divided into the following two groups: NC group and KD group. The NC group and KD group were transfected with control siRNAs or siRNAs targeting HOTAIR respectively. The effects of HOTAIR knock-down on cell proliferation, migration, invasion and glycolysis were determined. Results CAFs-Exo promoted the proliferation of TE-1 cells more significantly than NFs-Exo. Compared with NFs-Exo group, the migration and invasion ability of TE-1 cells treated with CAFs-Exo were improved significantly. In addition, CAFs-Exo treatment inhibited the expression of E-cadherin and enhanced the expression of N-cadherin. The expression of HOTAIR in CAFs was significantly higher than that in NFs. Compared with NFs-Exo, the expression level of HOTAIR in CAFs-Exo increased significantly. Compared with NC group, the proliferation, migration and invasion of TE-1 cells in KD group decreased significantly. Compared with NC group, hexokinase 2 (HK2), extracellular acidification rate (ECAR) and ATP/ADP ratio of TE-1 cells in KD group decreased significantly. Conclusion HOTAIR, an exosome derived from CAFs, may be involved in metastasis and EMT by regulating glycolysis in ESCC cells.
Humans ; RNA, Long Noncoding/metabolism* ; Esophageal Neoplasms/metabolism* ; Cell Movement/genetics* ; Cell Proliferation/genetics* ; Cell Line, Tumor ; Esophageal Squamous Cell Carcinoma ; Exosomes/genetics* ; Neoplasm Metastasis ; Neoplasm Invasiveness ; Gene Expression Regulation, Neoplastic ; Glycolysis/genetics* ; Cancer-Associated Fibroblasts/metabolism* ; Carcinoma, Squamous Cell/metabolism* ; Cadherins/genetics*

OBJECTIVES: Esophageal squamous cell carcinoma (ESCC) is characterized by complex pathogenesis and poor prognosis. In recent years, epithelial-mesenchymal transition (EMT) in tumor initiation and progression has attracted increasing attention. Enhancer of zeste homolog 2 (EZH2), which is aberrantly expressed in various tumors, may be closely related to the EMT process. This study aims to examine the expression and correlation of EZH2 and EMT markers in ESCC cells and tissues, evaluate the effects of EZH2 knockdown on ESCC cell proliferation, invasion, and migration, and explore how EZH2 contributes to the malignant biological behavior of ESCC. METHODS: Bioinformatics analyses were used to assess EZH2 expression levels in ESCC. Small interfering RNA was used to knock down EZH2 in ESCC cell lines EC109 and EC9706. Cell proliferation, invasion, and migration were evaluated using cell counting kit-8 (CCK-8), wound healing, and Transwell assays. Protein and mRNA expression levels of EZH2, E-cadherin (E-cad), and vimentin (Vim) were detected by Western blotting and real time fluorogenic quantitative PCR (RT-qPCR), respectively. Immunohistochemical (IHC) staining was performed on 70 ESCC tissue samples and 40 paired adjacent normal tissues collected from the First Affiliated Hospital of Shihezi University between 2010 and 2016 to assess the expression of EZH2, E-cad, and Vim, and to analyze their associations with clinicopathological feature and patient prognosis. RESULTS: Bioinformatics analysis showed that EZH2 was highly expressed in ESCC (P<0.001), and high EZH2 expression was associated with worse prognosis (P<0.001). CCK-8, wound healing, and Transwell assays demonstrated that EZH2 knockdown significantly suppressed the proliferation, invasion, and migration of ESCC cells (P<0.001). In addition, Vim expression was significantly reduced, while E-cad expression was significantly increased at both protein and mRNA levels in EZH2-silenced cells (all P<0.05). IHC staining analysis revealed higher expression of EZH2 and Vim and lower expression of E-cad in ESCC tissues compared to adjacent normal tissues. Kaplan-Meier survival analysis showed that low expression of EZH2 and Vim and high expression of E-cad were associated with longer survival (all P<0.05). CONCLUSIONS EZH2 promotes malignant biological behavior in ESCC by mediating EMT. Elevated EZH2 expression is associated with poor prognosis in ESCC patients.
Humans ; Enhancer of Zeste Homolog 2 Protein/physiology* ; Esophageal Squamous Cell Carcinoma/pathology* ; Epithelial-Mesenchymal Transition/genetics* ; Esophageal Neoplasms/metabolism* ; Cell Proliferation ; Cell Line, Tumor ; Cell Movement ; Cadherins/genetics* ; Vimentin/genetics* ; Male ; Female ; Middle Aged ; Neoplasm Invasiveness ; Prognosis ; RNA, Small Interfering/genetics* ; Gene Expression Regulation, Neoplastic

Dysregulated RNA splicing events produce transcripts that facilitate esophageal squamous cell carcinoma (ESCC) progression, but how this splicing process is abnormally regulated remains elusive. Here, we unveiled a novel alternative splicing axis of BOLA3 transcripts and its regulator HNRNPC in ESCC. The long-form BOLA3 (BOLA3-L) containing exon 3 exhibited high expression levels in ESCC and was associated with poor prognosis. Functional assays demonstrated the protumorigenic function of BOLA3-L in ESCC cells. Additionally, HNRNPC bound to BOLA3 mRNA and promoted BOLA3 exon 3 inclusion forming BOLA3-L. High HNRNPC expression was positively correlated with the presence of BOLA3-L and associated with an unfavorable prognosis. HNRNPC knockdown effectively suppressed the malignant biological behavior of ESCC cells, which were significantly rescued by BOLA3-L overexpression. Moreover, BOLA3-L played a significant role in mitochondrial structural and functional stability. E2F7 acted as a key transcription factor that promoted the upregulation of HNRNPC and inclusion of BOLA3 exon 3. Our findings provided novel insights into how alternative splicing contributes to ESCC progression.
Female ; Humans ; Male ; Mice ; Alternative Splicing ; Cell Line, Tumor ; Disease Progression ; Esophageal Neoplasms/pathology* ; Esophageal Squamous Cell Carcinoma/pathology* ; Exons/genetics* ; Gene Expression Regulation, Neoplastic ; Heterogeneous-Nuclear Ribonucleoprotein Group C/metabolism* ; Prognosis ; RNA, Long Noncoding/metabolism* ; Animals

In recent years, immunotherapy represented by immune checkpoint inhibitors programmed death 1 (PD-1) has made great progress in the treatment of esophageal cancer and is rewriting the global paradigm for the treatment of esophageal cancer. According to current data, only a small number of patients with esophageal cancer could benefit from immunotherapy. Therefore, it is a challenge to screen the potential beneficiaries of PD-1 inhibitors. Studies have shown that the expression level of programmed death-ligand 1 (PD-L1) in esophageal cancer is closely associated with the efficacy of PD-1 inhibitors, and PD-L1 is the most important predictive biomarker of the efficacy of PD-1 inhibitors. With the clinical application of different PD-1 inhibitors and PD-L1 protein expression detection platforms, clarifying the clinical significance and timing of detection of PD-L1 protein expression in esophageal cancer, and establishing a standardized PD-L1 testing procedure, are of great significance to improve the accuracy of detection and reduce the difference between laboratories, so as to maximize the therapeutic benefits for patients. This consensus was finally reached, based on the combination of literature, expert experience, and internal discussion and voting of committee members, to provide an accurate and reliable evidence for clinicians to make decisions.
Humans ; B7-H1 Antigen/metabolism* ; Immune Checkpoint Inhibitors/therapeutic use* ; Consensus ; Esophageal Neoplasms/drug therapy* ; Immunotherapy/methods* ; Lung Neoplasms/pathology*

Objective: To investigate the effect of acetyl-CoA carboxylase 1 (ACC1) knockdown on the migration of esophageal squamous cell carcinoma (ESCC) KYSE-450 cell and underlying mechanism. Methods: Lentiviral transfection was conducted to establish sh-NC control cell and ACC1 knocking down cell (sh-ACC1). Human siRNA HSP27 and control were transfected by Lipo2000 to get si-HSP27 and si-NC. The selective acetyltransferase P300/CBP inhibitor C646 was used to inhibit histone acetylation and DMSO was used as vehicle control. Transwell assay was performed to detect cell migration. The expression of HSP27 mRNA was examined by reverse transcription-quantitative real-time polymerase chain reaction (RT-qPCR) and the expressions of ACC1, H3K9ac, HSP27 and epithelial-mesenchymal transition-related proteins E-cadherin and Vimentin were detected by western blot. Results: The expression level of ACC1 in sh-NC group was higher than that in sh-ACC1 group (P<0.01). The number of cell migration in sh-NC group was (159.00±24.38), lower than (361.80±26.81) in sh-ACC1 group (P<0.01). The protein expression levels of E-cadherin and Vimentin in sh-NC group were statistically significant compared with sh-AAC1 group (P<0.05). The migrated cell number in sh-NC+ si-NC group was (189.20±16.02), lower than (371.60±38.40) in sh-ACC1+ si-NC group (P<0.01). The migrated cell number in sh-NC+ si-NC group was higher than that in sh-NC+ si-HSP27 group (152.40±24.30, P<0.01), and the migrated cell number in sh-ACC1+ si-NC group was higher than that in sh-ACC1+ si-HSP27 group (P<0.01). The protein expression levels of E-cadherin and Vimentin in sh-NC+ si-NC group were significantly different from those in sh-ACC1+ si-NC and sh-NC+ si-HSP27 groups (P<0.01). The protein expression levels of E-cadherin and Vimentin in sh-ACC1+ si-NC group were significantly different from those in sh-ACC1+ si-HSP27 group (P<0.01). After 24 h treatment with C646 at 20 μmmo/L, the migrated cell number in sh-NC+ DMSO group was (190.80±11.95), lower than (395.80±17.10) in sh-ACC1+ DMSO group (P<0.01). The migrated cell number in sh-NC+ DMSO group was lower than that in sh-NC+ C646 group (256.20±23.32, P<0.01). The migrated cell number in sh-ACC1+ DMSO group was higher than that in sh-ACC1+ C646 group (87.80±11.23, P<0.01). The protein expressions of H3K9ac, HSP27, E-cadherin and Vimentin in sh-NC+ DMSO group were significantly different from those in sh-ACC1+ DMSO group and sh-NC+ C646 group (P<0.01). The protein expression levels of H3K9ac, HSP27, E-cadherin and Vimentin in sh-ACC1+ DMSO group were significantly different from those in sh-ACC1+ C646 group (P<0.01). Conclusion: Knockdown of ACC1 promotes the migration of KYSE-450 cell by up-regulating HSP27 and increasing histone acetylation.
Humans ; Esophageal Neoplasms/pathology* ; Esophageal Squamous Cell Carcinoma/genetics* ; Vimentin/metabolism* ; Dimethyl Sulfoxide ; HSP27 Heat-Shock Proteins/metabolism* ; Histones/metabolism* ; Cadherins/metabolism* ; Cell Movement ; Cell Line, Tumor ; Cell Proliferation/genetics* ; Epithelial-Mesenchymal Transition/genetics* ; Gene Expression Regulation, Neoplastic

Objective To screen antigen targets for immunotherapy by analyzing over-expressed genes, and to identify significant pathways and molecular mechanisms in esophageal cancer by using bioinformatic methods such as enrichment analysis, protein-protein interaction (PPI) network, and survival analysis based on the Gene Expression Omnibus (GEO) database.Methods By screening with highly expressed genes, we mainly analyzed proteins MUC13 and EPCAM with transmembrane domain and antigen epitope from TMHMM and IEDB websites. Significant genes and pathways associated with the pathogenesis of esophageal cancer were identified using enrichment analysis, PPI network, and survival analysis. Several software and platforms including Prism 8, R language, Cytoscape, DAVID, STRING, and GEPIA platform were used in the search and/or figure creation.Results Genes MUC13 and EPCAM were over-expressed with several antigen epitopes in esophageal squamous cell carcinoma (ESCC) tissue. Enrichment analysis revealed that the process of keratinization was focused and a series of genes were related with the development of esophageal cancer. Four genes including ALDH3A1, C2, SLC6A1,and ZBTB7C were screened with significant P value of survival curve.Conclusions Genes MUC13 and EPCAM may be promising antigen targets or biomarkers for esophageal cancer. Keratinization may greatly impact the pathogenesis of esophageal cancer. Genes ALDH3A1, C2, SLC6A1,and ZBTB7C may play important roles in the development of esophageal cancer.
Humans ; Esophageal Neoplasms/metabolism* ; Esophageal Squamous Cell Carcinoma/metabolism* ; Epithelial Cell Adhesion Molecule/metabolism* ; Gene Expression Profiling/methods* ; Gene Regulatory Networks ; Gene Expression ; Gene Expression Regulation, Neoplastic ; Intracellular Signaling Peptides and Proteins

Objective To investigate the effects of natural killer (NK)-cell-derived miR-30e-3p-containing exosomes (Exo) on esophageal squamous cell carcinoma (ESCC) cell proliferation, apoptosis and invasion. Methods NK cells were isolated and amplified from the peripheral blood of healthy donors, and NK cell-derived Exo was isolated and identified, which were further co-cultured with NEC cells and were randomly grouped into Exo1 and Exo2 groups. Transmission electron microscopy (TEM) was used to observe the morphology and size of exosomes. Western blot analysis was used to detect the expression levels of exosome markers apoptosis related gene 2- interacting protein X(ALIX), tumor susceptibility gene 101(TSG101), CD81 and calnexin. The NC plasmids, mimics and inhibitors of miR030e-3p were respectively delivered into the NK cells, and the corresponding NK cells-derived Exo were co-cultured with NEC cells, which were divided into NC, Exo, mimic and inhibitor groups. CCK-8 assay was used to evaluate cell proliferation, flow cytometry was conducted to determine cell cycle, annexin V-FITC/PI double staining was employed to detect cell apoptosis, and Transwell^TM assay was performed to detect cell invasion abilities. Real-time quantitative PCR was used to detect the expression of miR-23b, miR-422a, miR-133b, miR-124, miR-30e-3p and miR-99a in NCE cells and exosomes. Results The percentages of CD56⁺CD3⁺ cells and CD56⁺CD16⁺ cells in NK cells were (0.071±0.008)% and (90.6±10.6)%, respectively. Exosome isolated from NK cells ranged from 30 nm to 150 nm, and was positive for ALIX, TSG101 and CD81, while negative for calnexin. NK cell-derived Exos inhibited the proliferation, reduced the proportion of S-phase cells and the number of invaded cells of NEC cells, and promoted the apoptosis and the proportion of G1 phase cells. Overexpression of miR-30E-3p in NK cell-derived exosome inhibited the proliferation and invasion of NEC cells, and blocked cell cycle and promoted apoptosis, while knockdown miR-30e-3p in NK cell-derived exosomes did the opposite. Conclusion miR-30e-3p in NK cell-derived exosomes can inhibit the proliferation and invasion of ESCC cells, block their cell cycle and induce their apoptosis.
Humans ; Esophageal Squamous Cell Carcinoma/genetics* ; Esophageal Neoplasms/genetics* ; Exosomes/metabolism* ; Calnexin/metabolism* ; Cell Movement/genetics* ; MicroRNAs/metabolism* ; Cell Proliferation/genetics* ; Killer Cells, Natural ; Cell Line, Tumor ; Apoptosis/genetics*

Objective To clarify the effect and mechanism of tumor antigen-loaded dendritic cells (Ag-DCs) combined with cytokine-induced killers (CIKs) on the killing of esophageal cancer tumor cells. Methods Peripheral blood DCs and CIKs were induced and cultured, and the DCs were loaded with tumor antigen to obtain Ag-DCs, and Ag-DCs were co-cultured with CIKs. The experiment was divided into CIK group, DC combined with CIK group, Ag-DC combined with CIK group. Flow cytometry was used to detect the phenotype of cells. MTT assay was employed to determine the killing activity against EC9706 cells. Annexin V-FITC/PI double staining was used to detect the apoptosis rate of cells, immunofluorescence staining to detect the expression of phosphorylated apoptotic signal-regulated kinase 1 (p-ASK1) and Western blot analysis to detect the expression of ASK1 pathway related proteins. A nude mouse model of esophageal cancer transplantation tumor was constructed and divided into control group, DC combined with CIK group and Ag-DC combined with CIK group. The corresponding immune cells were injected into the tail vein for treatment and the tumor volume was measured every 2 days. After 21 days, all nude mice were sacrificed with the tumors taken out. HE staining was used to observe the tumor pathological changes and immunohistochemical staining was performed to detect the expression of ki67 and ASK1 in the tumor tissue. Results Comparedwith the CIK group alone and the DC combined with CIK group, the ratio of CD3⁺ CD8⁺ and CD3⁺ CD56⁺ in the cells significantly increased after Ag-DCs and CIKs co-culture, along with the increased killing rate of EC9706 cells, increased apoptosis rate of EC9706 cells, and the improved activation level of ASK1. Compared with the CIK group and the DC combined with CIK group, the growth of the transplanted tumor in nude mice treated with Ag-DCs combined with CIKs was significantly inhibited, and after 21 days, it was observed that the tumor tissue mass in this group was relatively smaller, with sparsely arranged cells in the tumor tissue and a decline in the positive rate of ki67 in tumor tissue, while the positive rate of ASK1 was significantly increased. Conclusion Co-cultivation of tumor antigen-loaded DCs with CIKs can significantly increase the killing activity of esophageal cancer tumor cells. The mechanism of action may be related to the activation of the ASK1 pathway.
Animals ; Humans ; Mice ; Antigens, Neoplasm ; Cytokine-Induced Killer Cells ; Cytokines/metabolism* ; Cytotoxicity, Immunologic ; Dendritic Cells ; Esophageal Neoplasms/therapy* ; Ki-67 Antigen ; Mice, Nude