HIF-1α stimulates the progression of oesophageal squamous cell carcinoma by activating the Wnt/ß-catenin signalling pathway.

BACKGROUND: This study aimed to clarify the significance of the crosstalk between hypoxia-inducible factor-1α (HIF-1α) and the Wnt/ß-catenin pathway in oesophageal squamous cell carcinoma (ESCC). METHODS: The oncogenic role of HIF-1α in ESCC was investigated using in vitro and in vivo assays. The clinicopathological significance of HIF-1α, ß-catenin and TCF4/TCF7L2 in ESCC were evaluated using quantitative real-time PCR and immunohistochemistry. RESULTS: The expression level of HIF-1α, ß-catenin, and TCF4/TCF7L2 in T.Tn and TE1 cell lines were elevated under hypoxia in vitro. HIF-1α knockdown suppressed proliferation, migration/invasion and epithelial-mesenchymal transition (EMT) progression, induced G0/G1 cell cycle arrest, promoted apoptosis and inhibited 5-fluorouracil chemoresistance in vitro. In vivo assays showed that HIF-1α is essential in maintaining tumour growth, angiogenesis, and 5-fluorouracil chemoresistance. Mechanically, we identified the complex between HIF-1α and ß-catenin, HIF-1α can directly bind to the promoter region of TCF4/TCF7L2. The mRNA level of HIF-1α, ß-catenin and TCF4/TCF7L2 were increased in ESCC tumour tissues compared to the corresponding non-tumour tissues. High levels of HIF-1α and TCF4/TCF7L2 expression were correlated with aggressive phenotypes and poor prognosis in ESCC patients. CONCLUSIONS: HIF-1α serves as an oncogenic transcriptional factor in ESCC, probably by directly targeting TCF4/TCF7L2 and activating the Wnt/ß-catenin pathway.

Soluble PD-L1 Concentration Is Proportional to the Expression of PD-L1 in Tissue and Is Associated with a Poor Prognosis in Esophageal Squamous Cell Carcinoma.

INTRODUCTION: We determined the soluble programmed cell death-1 ligand-1 (sPD-L1) concentration in patients with esophageal squamous cell carcinoma (ESCC), and confirmed the PD-L1 expression in resected specimens. METHODS: Blood samples were collected from 73 patients with histologically proven ESCC. The serum levels of sPD-L1 were measured using an enzyme-linked immunosorbent assay. The correlations between the sPD-L1 concentration and the expression of PD-L1 in tumor specimens and tumor depth, lymph node metastasis, disease stage, and various laboratory data were assessed. RESULTS: sPD-L1 levels in patients with high PD-L1 expression levels in tumor tissue were significantly higher than in patients with low PD-L1 expression levels (p = 0.042). The OS of the sPD-L1-high group was significantly worse than that of the low group (p = 0.028). Similarly, patients in whom a tissue specimen was PD-L1-positive group showed significantly poorer OS. CONCLUSION: The sPD-L1 concentration was correlated with the PD-L1 expression in tissues. Patients with PD-L1-positive tissue specimens showed significantly higher sPD-L1 levels in comparison to PD-L1-negative cases. Furthermore, patients with high sPD-L1 expression levels had a significantly worse prognosis than those with low sPD-L1 expression levels, and patients with a PD-L1-positive tissue specimen had a significantly worse prognosis than patients in whom the tissue specimen showed a low PD-L1 expression level.

Metformin-Induced Heat Shock Protein Family A Member 6 Is a Promising Biomarker of Esophageal Squamous Cell Carcinoma.

INTRODUCTION: Antidiabetic drug metformin exerts various antitumor effects on different cancers. Esophageal squamous cell carcinoma (ESCC) is an intractable digestive organ cancer and new treatment strategy is required. In this study, we performed a comprehensive gene expression analysis of ESCC cell lines treated with metformin, which provided helpful information on the antitumor effects of metformin in ESCC. Next, we selected a promising gene among them and examined its effects on ESCC properties. METHODS: We examined metformin-induced mRNA expression changes in two human ESCC cell lines by performing next-generation sequencing (NGS) and pathway analysis. Heat shock protein family A (Hsp70) member 6 (HSPA6) expression in surgical specimens obtained from 83 ESCC patients who underwent curative operations was evaluated immunohistochemically and analyzed. RESULTS: Metformin upregulated mRNA expression of the many genes, including HSPA6, a cancer immune-related gene, and inhibited mRNA expression of the other many genes. Pathway analysis indicated major canonical pathways and upstream regulators related to metformin. The result indicated HSPA6 as a promising biomarker. HSPA6 expression correlated with disease-free survival (DFS) of the patients with all stage ESCC (p = 0.021), especially with stage I/II ESCC (p < 0.001). With stage III, low HSPA6 expression was not associated with poor DFS (p = 0.918). Multivariate analysis indicated that independent low HSPA6 expression was an independent poor prognostic factor of stage I/II ESCC (p < 0.001). However, HSPA6 expression did not correlate with the clinicopathological characteristics, including age, sex, tumor depth, lymph node metastasis, tumor stage, and tumor markers of the patients with stage I/II ESCC. CONCLUSIONS: This NGS analysis detected prospective candidate genes, including HSPA6. Our results indicate that HSPA6 is a promising biomarker of the recurrence risk of stage I/II ESCC. Further studies on HSPA6 would lead to better treatment.

Tumor-derived exosomes influence the cell cycle and cell migration of human esophageal cancer cell lines.

Our laboratory previously reported the usefulness as biomarkers of exosomes in the plasma of esophageal squamous cell carcinoma (ESCC) patients. However, the influence of tumor-derived exosomes on the tumor itself and underlying mechanisms remain unclear. We here report changes in the phenotype and gene expression when cancer cells exist in an environment with tumor-derived exosomes. The exosomes were isolated from the culture medium of human ESCC cells (TE2, T.Tn) by ultracentrifugation; cell proliferation assay, wound-healing assay, and fluorescence imaging of the cell cycle were performed to clarify the phenotypic changes in the high concentration of tumor-derived exosomes. Gene expression changes were also assessed by mRNA microarray, and the data were analyzed by gene set enrichment analysis (GSEA). The data revealed that the proliferation of both TE2 and T.Tn was inhibited, and cell migration ability was upregulated in the exosome exposure group (P < .05). Fluorescence imaging using a fluorescent ubiquitination-based cell cycle indicator expressing ESCC cells revealed that the ratio of G1-phase cells was significantly increased in the exosome exposure group (P < .05). Findings of the GSEA clarified that high-density exposure of cancer-derived exosomes to their parent cancer cells downregulated the expression of genes related to cell proliferation and cell cycle, and upregulated the expression of genes related to actin filament length and extracellular structure organization. In conclusion, an environment of high-density tumor-derived exosomes induces changes in the gene expression and phenotype of tumor cells and may lead to tumor progression or malignant transformation.

[A Case of Primary Amelanotic Malignant Melanoma of the Esophagus, Wherein Pseudoprogression Was Suspected during Immune Checkpoint Inhibitor Treatment].

A 78-year-old man was admitted to our hospital with a diagnosis of esophageal cancer and gastric cancer. Gastroscopy showed a type 2 tumor located in the cardia from the lower esophagus, and a pathological examination showed malignant melanoma. Based on the physical examination and other imaging tests, the patient was diagnosed with primary amelanotic malignant melanoma of the esophagus, but the tumor was unresectable due to extensive lymph node metastasis. According to the guideline, immune checkpoint inhibitor(nivolumab)was used for treatment, but because the tumor progressed after 2 courses and the performance status of the patient worsened, aggressive treatment was ended. Six weeks after finishing treatment, computed tomography showed that the tumor had shrunk to some extent. The patient ultimately died from aspiration pneumonia 4 months after the first consultation. The patient was thought to have had an immune-related adverse event, with the tumor showing pseudoprogression.

Apparent diffusion coefficient by magnetic resonance cholangiopancreatography is useful for grading cholecystitis and surgery planning.

INTRODUCTION: Laparoscopic cholecystectomy is a standard procedure for treating cholescytitis, but severe inflammation may cause complications. Our previous study showed that the apparent diffusion coefficient (ADC) values could predict difficult surgery. In the present study, relevance of ADC values in grading the severity of cholecystitis was pathologically investigated. METHODS: We retrospectively analyzed a total of 50 patients who underwent laparoscopic cholecystectomy or laparotomic cholecystectomy/choledocholithotomy. The degree of inflammation in the neck of the gall bladder was pathologically graded into three tiers (grade 1, mild; grade 2, moderate; grade 3, severe), and ulceration, lymphoid follicle formation, and wall thickness of the gallbladder neck were recorded. All factors were statistically compared with the measured ADC values. RESULTS: The ADC value was significantly lower in the severe inflammation group ( grade 3) than in the weak inflammation group (grades 1 and 2) (1.93 ± 0.22 vs 2.38 ± 0.67, respectively; P = .02). Ulceration and wall thickness in the gallbladder neck were significantly correlated with ADC values (P = .04 and .006, respectively), and lymphoid follicle formation was marginally correlated with ADC values (P = .06). The diagnostic utility of the ADC values decreased as the interval between imaging and cholecystectomy increased. [Correction added on 19 October 2022, after first online publication: [On the first sentence of the Results section, (grades 2 and 3) for weak inflammation group has been changed to (grades 1 and 2).] CONCLUSION: ADC values were inversely associated with the pathologic intensity of cholecystitis. We recommend that the ADC value be measured before surgery, so that the procedure can be accordingly planned.

SIRT1 Expression Is a Promising Prognostic Biomarker in Esophageal Squamous Cell Carcinoma: A Systematic Review and Meta-analysis.

Background/Aim: Several articles have assessed the prognostic significance of the expression of sirtuin 1 (SIRT1) in esophageal squamous cell carcinoma (ESCC). However, evidence in this field is insufficient. Thus, we conducted a meta-analysis to investigate the prognostic and clinical impact of SIRT1 expression in ESCC. Materials and Methods: We searched the PubMed, Cochrane Library, and Web of Science databases for articles on the expression of SIRT1 and clinicopathological features in patients with ESCC. A meta-analysis was conducted. Results: Four studies with 429 patients were included. The meta-analysis revealed a significant relationship between the high expression of SIRT1 and higher T-stage (odds ratio=2.39. 95% confidence interval=1.12-5.13, p=0.02), more advanced TNM stage (odds ratio=2.35. 95% confidence interval=1.20-4.60, p=0.01), and a poor overall survival (hazard ratio=1.90, 95% confidence interval=1.45-2.47, p<0.00001). Conclusion: SIRT1 expression may be a promising prognostic biomarker for patients with ESCC.