SIRT1 promotes chemoradiotherapy resistance in esophageal squamous cell carcinoma.

Introduction Identifying accurate biomarkers for predicting response to chemoradiotherapy (CRT) in patients with esophageal squamous cell carcinoma (ESCC) is a critical challenge. The protein SIRT1, recognized for its implications in longevity, has been associated with tumor promotion in ESCC. However, data regarding its correlation with CRT sensitivity remains unreported. Therefore, in this study, we aimed to investigate the relationship between SIRT1 expression and CRT sensitivity and concurrently assess the effect of SIRT1 knockdown on CRT sensitivity in ESCC. Methods This study included 73 patients who underwent radical esophagectomy after CRT. SIRT1 expression in pre-treatment endoscopic biopsies was assessed through immunostaining, followed by a comparative analysis of CRT effects on surgical specimens. Small interfering RNA was used to attenuate SIRT1 expression in TE5 and TE10 cells, which were then subjected to cisplatin treatment at varying doses and concentrations and irradiation with X-rays, respectively. Results High SIRT1 tissue expression was significantly associated with CRT resistance. Multivariate analysis identified high SIRT1 expression as an independent biomarker for poor CRT response. In TE-5 and TE-10 cells, SIRT1 knockdown significantly decreased cell viability and increased sensitivity to cisplatin and radiation treatment compared to that of the negative control. Conclusion Our study results demonstrate the potential of SIRT1 as a predictive biomarker for CRT response in ESCC, highlighting the heightened sensitivity to CRT upon the transcriptional inactivation of SIRT1. Targeting SIRT1 emerges as a promising strategy for enhancing the efficacy of CRT for ESCC.

Establishment of a novel small bowel adenocarcinoma cell line using patient­derived xenografts, which produces CEA and CA19­9.

Small bowel adenocarcinoma (SBA) is a rare tumor with a poor prognosis. Due to its rarity, the research infrastructure for SBA, including cell lines, is inadequate. The present study established a novel SBA cell line, SiCry-15X, using patient-derived xenografts of SBA. The following criteria were defined for establishment: Long-term culturability, tumorigenicity and similarity with the original tumor. The biological characteristics of the cell line, its sensitivity to anticancer drugs and its ability to produce tumor markers carcinoembryonic antigen (CEA) and carbohydrate antigen 19-9 (CA19-9) were evaluated. SiCry-15X cells adhered and grew as a monolayer, with a population doubling time of 37 h. Polymerase chain reaction results confirmed the human origin of the cell line, and short tandem repeat analysis revealed that the cells were genetically identical to the original tumor. The 50% inhibitory concentrations of 5-fluorouracil, paclitaxel, irinotecan, oxaliplatin and cisplatin for SiCry-15X were 104.05, 0.24, 63.3, 146.55 and 49.29 µM, respectively. CEA and CA19-9 concentrations in the culture media were markedly elevated. In addition, CEA and CA19-9 levels in the serum of cell-derived xenograft model mice were elevated. Moreover, CEA and CA19-9 were produced by SiCry-15X cells and distributed throughout the blood. Furthermore, increases in serum CEA and CA19-9 of cell-derived xenograft model mice were consistent with the clinical course of the disease. The newly established SBA cell line, SiCry-15X, could be an effective tool for conducting further studies on SBA.

Hypoxia­regulated exosomal miR­185 inhibits esophageal squamous cell carcinoma progression and predicts prognosis.

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

[Chemotherapy Strategy in a Case of MSI-High Patients with Gastric Cancer-Case Report].

A 73-year-old woman was referred to our hospital with a chief complaint of black stools and abdominal distention. She was diagnosed with advanced gastric cancer with pyloric stenosis and multiple lymph node metastasis(cT4aN3M0, cStage Ⅲ)and was administered preoperative chemotherapy after laparoscopy and gastric jejunal bypass surgery. The surgical diagnosis was sT4aN3M0P0CY0. After surgery, 2 courses of DS therapy were administered. However, a new liver metastatic lesion was found, and XELOX therapy was selected as the second-line of treatment. Subsequently, enlarged hepatic hilar lymph nodes were found; microsatellite instability testing confirmed MSI-High cancer. Nivolumab was selected as the third- line therapy. After 15 courses, a new liver metastatic lesion appeared. Although Ram+nab-PTX therapy was chosen as the fourth-line therapy, the patient developed myelosuppression after 3 courses. Two years and 4 months after the initial treatment, the patient was considered to have achieved CR. Because drug-induced liver injury had occurred, the Ram therapy was discontinued. The patient has remained in CR for 1 year without receiving any anticancer drugs. This case suggests that for MSI-high patients with gastric cancer, the consideration of treatment strategy should be based on the molecular biological background.

CT-derived skeletal muscle change before immunotherapy predicts survival of advanced gastric cancer: associations with inflammatory markers and liver lipid metabolism.

BACKGROUND: Skeletal muscle (SM) is a key factor in cancer treatment. However, it is unclear whether pretreatment SM change affects the outcome of immune checkpoint inhibitors (ICIs) therapy in gastric cancer (GC). METHODS: Advanced GCs treated with ICIs were retrospectively investigated. SM evaluated by psoas muscle area at the third lumbar vertebra was measured on CT acquired within 1 month from the start of ICIs therapy (CT-1), and on CT acquired 2.8 ± 0.84 months before CT-1. Monthly change rate of SM (MCR-SM) was defined as the change rate of SMs between those two CTs divided by the period between those CTs (month). Monthly change rate of body weight (MCR-BW) during the same period was also calculated. They were compared with disease-specific survival (DSS) and progression-free survival (PFS). MCR-SM was compared with pretreatment markers including neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), monocyte-to-lymphocyte ratio (MLR), C-reactive protein (CRP), and liver-to-spleen CT attenuation ratio (LSR) as a marker of liver lipid metabolism. RESULTS: This study enrolled eighty-three GC patients. MCR-SM significantly correlated with DSS and PFS (P < 0.0001, 0.001, respectively), whereas MCR-BW did not. Kaplan-Meier analyses demonstrated that higher MCR-SM (MCR-SM ≥ -0.7185%) significantly associated with better DSS and PFS (P = 0.0002, 0.03, respectively). Patients with positive MCR-SM showed significantly lower NLR, MLR, and CRP than those with negative (P = 0.01, 0.006, 0.003, respectively). MCR-SM showed a significant positive correlation with LSR (P = 0.007, R = 0.30). CONCLUSIONS: Pretreatment SM loss, associated with high systemic inflammation and hepatic fat accumulation, related to poor outcome of ICIs therapy in GC.

A case of laparoscopic revision surgery 30 years after vertical banded gastroplasty for morbid obesity.

As the number of bariatric and metabolic surgeries being performed is increasing, the importance of revision surgeries is escalating. In this report, we describe a case of revision surgery performed 30 years after vertical banded gastroplasty (VBG), including a review of the surgical techniques. The patient was a male in his 50s who had previously undergone VBG for morbid obesity (body mass index of 72.6 kg/m2 ), resulting in gradual weight loss. Twenty-eight years later, reflux symptoms due to stenosis of the mesh area developed. Despite conservative treatment, the symptoms recurred, and aspiration pneumonia developed. Gastrojejunal and Y-anastomoses were performed laparoscopically. Postoperatively, the patient progressed well with no weight regain. In revision surgery, it is essential to accurately assess the patient's pathophysiology, as the surgical technique must consider improvement in symptoms, risk of weight regain, and the need for observation of the residual stomach.

Intraoperative assessment of blood flow using transabdominal ultrasound during laparoscopic surgery of celiac artery compression syndrome.

Surgical treatment of celiac artery (CA) compression syndrome (CACS) is to release the median arcuate ligament (MAL) by removing the abdominal nerve plexus surrounding CA. In laparoscopic surgery of CACS, objective intraoperative assessment of blood flow in CA is highly desirable. We herein demonstrate a case of laparoscopic surgery of CACS with use of intraoperative transabdominal ultrasound. A 52-year-old woman was presented with epigastric pain and vomiting after eating. Contrast-enhanced computed tomography demonstrated significant stenosis at the origin of CA. Doppler study of CA was also performed, and she was diagnosed as CACS. Laparoscopic surgery was performed, and the MAL was divided. And then, Doppler study using intraoperative transabdominal ultrasound confirmed the successful decompression of CA. This patient was discharged on postoperative day 11, and her symptoms was improved. Intraoperative assessment of blood flow in CA using transabdominal ultrasound was a simple and useful method for laparoscopic surgery of CACS.

Use of inducible and limiting fluorescence in laparoscopic endoscopic cooperative surgery.

Video 1Demonstration of the special use of the near-infrared fluorescent clip in laparoscopic endoscopic cooperative surgery.

Peripherally inserted central catheter securement with cyanoacrylate glue and bloodstream infection: A retrospective cohort study.

BACKGROUND: Treatment via a peripherally inserted central venous catheter is important for anticancer treatment, perioperative management, and nutrition management. In this study, we aimed to investigate the usefulness of cyanoacrylate glue (CG) in managing peripherally inserted central venous catheters in adults. METHODS: This retrospective cohort study enrolled 411 adults requiring a central venous catheter for treatment in the Chiba University Esophageal-Gastro-Intestinal Surgery department between January 2021 and October 2022. The preventive effect of CG in reducing adverse events, including infection, tip migration, and thrombus formation, was evaluated by reviewing electronic medical records, chest radiographs, and contrast-enhanced computed tomography scans. RESULTS: CG and other dressings were used in 158 (CG group) and 253 (control group) patients, respectively. The incidence of catheter infection based on the clinical course was lower in the CG group (3.2%) than in the control group (9.1%; P = 0.03). However, cases of infection confirmed by blood or catheter cultures did not differ between the CG (1.3%) and control (1.9%) groups (P = 1.0). Chest radiographs revealed that catheter tip migration (mean ± SD) was lesser in the CG group (8.2 ± 6.7 mm) than in the control group (15.0 ± 15.8 mm; P < 0.01). There were two cases of venous thrombus formation in the control group. CONCLUSION: In a population dominated by esophago-gastroenterological malignancy, peripherally inserted central catheter securement via CG was associated with decreased catheter removal because of suspected catheter infection. Further research on larger cohorts is needed to determine if other adverse events decrease following peripherally inserted central catheter securement via CG.

Inflammatory and Nutritional Indices as Prognostic Markers in Elderly Patients With Gastric Cancer.

BACKGROUND/AIM: Peripheral blood inflammatory and nutritional indices are independent prognostic factors for various cancers. However, as society's longevity and the demand for surgery in the elderly increase, it remains unclear whether these indices are valuable for patients aged ≥80 years. This study aimed to assess the utility of peripheral blood indices as prognostic markers in elderly patients with gastric cancer (GC). PATIENTS AND METHODS: This study included 103 elderly patients (aged ≥80 years) who underwent radical gastrectomy at our hospital between 2008 and 2020. Preoperative systemic inflammatory and nutritional indices, including the neutrophil-lymphocyte ratio (NLR), platelet-lymphocyte ratio (PLR), lymphocyte-monocyte ratio (LMR), and prognostic and nutritional index (PNI), were evaluated. Prognostic evaluation was performed using Kaplan-Meier analysis and Cox regression. RESULTS: There were no statistically significant differences in NLR, PLR, and LMR regarding overall survival (OS) and relapse-free survival (RFS). However, patients with low PNI had a markedly worse prognosis (3-year OS: 63.9% vs. 81.2%, p=0.002; 3-year RFS: 55.3% vs. 77.6%, p=0.002). Multivariate analysis revealed that male sex and low PNI were independent predictors of OS (p=0.007p=0.003, respectively) and RFS, with only PNI showing significance (p=0.023). CONCLUSION: Preoperative PNI is an independent prognostic factor for survival in elderly patients with GC who undergo radical gastrectomy.

Small bowel adenocarcinomas with favorable prognoses by radical resection and adjuvant chemotherapy: a case series of five cases.

BACKGROUND: Small bowel cancer is very rare, accounting for less than 5% of all gastrointestinal cancers, and small bowel adenocarcinoma accounts for approximately 40% of all small bowel cancers. Small bowel adenocarcinoma is often found in advanced stages, with only 40-65% of cases being curatively resectable. The prognosis is poor, with a 5-year survival rate of 14-33% for all patients and 40-60% for those who are curatively resectable. In Japan, practice guidelines for duodenal cancer were instituted in 2021. However, evidence-based standard treatments have not been established for jejunal and ileal cancers. In particular, chemotherapeutic options are limited, and there are only a few reports on multidisciplinary treatments, including adjuvant chemotherapy. CASE PRESENTATION: We report five cases of jejunal or ileal lesions that were treated with adjuvant chemotherapy after radical resection. Three patients were male and two were female, with a median age of 67 years. Tumor localization was observed in the jejunum in all cases. Clinical staging was as follows: stage IIIA in two cases and stage IIIB in three cases. Laparotomy was then performed in all cases, employing partial resection with lymph node dissection. Pathological staging in all cases was as follows: stage IIB in two cases, stage IIIA in one case, and stage IIIB in two cases. In all cases, the regimen for adjuvant chemotherapy was selected based on the colorectal cancer guidelines. No serious complications arose from adjuvant therapy; however, adverse events occurred in patients receiving multi-agent chemotherapy. No recurrence was observed in any of the cases, and all the patients survived, with a median survival time of 32 months. As a representative case, we present a case of adjuvant chemotherapy for jejunal adenocarcinoma staged as pT3N2M0, pStage IIIB, with no recurrence at 32 months postoperatively. CONCLUSIONS: In general, favorable outcomes were achieved with adjuvant therapy applied in accordance with the criteria for colorectal cancer. These favorable outcomes suggest that it is necessary to identify the risk factors and indications for adjuvant therapy, specifically for small bowel adenocarcinoma.

[A Case of Primary Duodenal Adenocarcinoma in the Third Portion Treated with Partial Duodenectomy and Adjuvant Chemotherapy].

A 69-year-old man was referred for vomiting. CT and upper gastrointestinal endoscopy revealed a circumferential stenotic lesion in the third portion of the duodenum, and partial duodenectomy and lymph node dissection were performed for the diagnosis of duodenal adenocarcinoma. The histopathological diagnosis was pT3, pN0, pStage ⅡA(UICC 8th)well differentiated tubular adenocarcinoma. The patient was treated with FOLFOX as adjuvant chemotherapy and is alive 2 years and 4 months postoperatively without recurrence. Primary duodenal adenocarcinoma in the third portion is rare, and further case experience is required for selection of the operation and adjuvant therapy.

Soluble PD­L1 reflects cachexia status in patients with gastric cancer and is an independent prognostic marker for relapse­free survival after radical surgery.

Soluble programmed death-ligand 1 (sPD-L1) levels can be used as a biomarker for gastric cancer (GC). However, comprehensive information regarding the sPD-L1 expression profiles and their association with cachexia in GC is lacking. Therefore, the present study evaluated the association between clinicopathological findings and sPD-L1 levels in patients with GC. Serum samples were collected from patients with GC during their first visit to Department of Esophageal-Gastro-Intestinal Surgery, Chiba University Hospital, Chiba, Japan (January 2012-December 2017; n=173), and sPD-L1 levels were measured using an enzyme-linked immunosorbent assay. Survival rates among 116 patients, excluding cases with preoperative chemotherapy or no radical procedures, were analyzed. sPD-L1 levels were associated with factors such as neutrophil-to-lymphocyte ratio, hemoglobin (Hb) and albumin (Alb) levels, total cholesterol and C-reactive protein (CRP) levels, and related to inflammation and nutrition in patients. Notably, the higher the number of applicable indicators related to cachexia (Hb <12 g/dl, Alb <3.2 g/dl, CRP >0.5 mg/dl and low body mass index) was, the higher the sPD-L1 value was. However, the pathological stage did not significantly differ between the groups. Clinicopathologically, there was no association with tumor depth, lymph node metastasis or vascular invasion; however, patients with the intestinal type had significantly higher sPD-L1 levels than patients with the diffuse type (P=0.032; Wilcoxon test). The overall survival did not significantly differ between the groups with low and high sPD-L1 levels; however, among patients who received radical treatment, the relapse-free survival was significantly worse in the high-sPD-L1-level group than in the low-sPD-L1-level group (P=0.025; log-rank test). Multivariate Cox regression analysis revealed that a high sPD-L1 concentration was a sign of poor prognosis, independent of pathological stage and cancer antigen CA19-9 (P=0.0029). Therefore, the present findings suggest that sPD-L1 can reflect cachexia status in patients with GC and may serve as a prognostic marker for relapse-free survival after radical GC surgery.

Gut microbiome can predict chemoradiotherapy efficacy in patients with esophageal squamous cell carcinoma.

PURPOSE: The gut microbiome plays an important role in cancer pathogenesis and therapy. Some studies have reported that specific bacteria in tumor tissues may contribute to the prognosis and treatment of esophageal squamous cell carcinoma (ESCC). However, there is limited evidence that the gut microbiome is associated with ESCC. This study assessed the utility of the gut microbiome as a predictive marker of the therapeutic effect in patients with ESCC undergoing chemo-radiotherapy (CRT). PATIENTS AND METHODS: Fecal samples were collected from 51 patients with ESCC who had never undergone treatment between April 2021 and May 2022 in the Department of Frontier Surgery, Chiba University. The gut microbiome was analyzed using 16S metagenomics sequencing. The association between the gut microbiome composition and stage according to the TNM classification (American Joint Committee on Cancer 7.0) and CRT response according to the RECIST criteria was evaluated. RESULTS: The relative abundance of Fusobacteriaceae was enriched in cStage III-IVb group. Among the 27 patients who received CRT, the relative abundance of Lactobacillaceae was enriched in those with a partial and complete response. Lactobacillaceae also did not correlate with any clinical data, but the high Lactobacillales group had a higher LMR (P = 0.032) and lower PLR (P = 0.045) than in the low Lactobacillales group. CONCLUSIONS: In conclusion, we found that the relative abundance of Lactobacillaceae was enriched in patients with a partial or complete response among CRT those with ESCC, thus suggesting that the relative abundance of Lactobacillaceae can predict the effect of CRT.

ypTNM staging is a potentially useful prognostic stratification tool in patients with advanced gastric cancer after preoperative chemotherapy.

PURPOSE: Although the usefulness of the ypStage in neoadjuvant chemotherapy for advanced gastric cancer (GC) has been reported, whether or not the ypStage is applicable to all GC patients who receive preoperative chemotherapy, including conversion surgery cases, is unclear. Therefore, this retrospective study evaluated the value of the ypTNM staging system in all advanced GC patients who received chemotherapy prior to gastrectomy. METHODS: A total of 66 patients who underwent chemotherapy prior to gastrectomy for advanced GC at Chiba University Hospital from January 2008 to December 2020 were enrolled in the current study. The prognostic impact of the ypStage on the overall survival (OS) and relapse-free survival (RFS) were examined via univariate and multivariate analyses. RESULTS: The 5-year OS rates for ypStage I, II, III, and IV were 87.5%, 64.7%, 52.9%, and 28.6%, respectively, while the 5-year RFS rates were 81.3%, 57.4%, 44.4%, and 28.6%, respectively. The univariate analysis revealed that the ypStage was significantly correlated with the OS (p = 0.037) and the ypT status and ypStage showed a significant correlation with the RFS (p = 0.043 and p = 0.021, respectively). The multivariate analysis demonstrated that only the ypStage was an independent prognostic factor for the OS and RFS (p = 0.024 and p = 0.018, respectively). CONCLUSION: The ypTNM stage may be a useful tool for the risk stratification of all advanced GC patients treated with chemotherapy followed by gastrectomy, including not only neoadjuvant but also conversion surgery cases.

Serum Versus Tissue SIRT1 as Potentially Valuable Biomarkers in Gastric Cancer.

BACKGROUND/AIM: We lack reports on the clinicopathological characteristics and prognostic value of serum sirtuin 1 (SIRT1) levels and their association with SIRT1 expression in tissues of patients with gastric cancer (GC). Thus, we investigated the pathological characteristics and prognostic values of SIRT1 tissue expression and its serum concentration in GC. Moreover, we investigated the correlation between these two factors. MATERIALS AND METHODS: A total of 78 patients with GC who underwent curative gastrectomy were evaluated in this study. The expression of SIRT1 in the surgical specimens was assessed using immunohistochemistry. Serum levels of SIRT1 were measured using an enzyme-linked immunosorbent assay. The association of tissue and serum SIRT1 with the clinicopathological features and prognosis were evaluated. RESULTS: Positive SIRT1 tissue expression was significantly related to an advanced cancer stage (p=0.017). Furthermore, a significant relationship existed between a positive SIRT1 tissue expression and poorer overall survival (OS) and relapse-free survival (RFS) (p=0.033 and p=0.033, respectively). In contrast, serum SIRT1 levels showed no significant association with clinicopathological characteristics besides age. In addition, no significant correlation was observed between tissue SIRT1 expression and serum SIRT1 concentration. CONCLUSION: Tissue SIRT1 expression may be a valuable novel prognostic biomarker; nonetheless, further studies are required to clarify the relationship between tissue SIRT1 expression and serum SIRT1 levels in GC.

Prognostic Impact of Hepatic Steatosis Evaluated by CT on Immunotherapy for Gastric Cancer: Associations with Sarcopenia, Systemic Inflammation, and Hormones.

INTRODUCTION: Immune checkpoint inhibitors (ICIs) are expected to improve the prognosis of gastric cancer (GC). Also, hepatic steatosis has been reported to be associated with cancer cachexia and is expected to be a cancer biomarker. The purpose of this study was to evaluate prognostic impact of hepatic steatosis in ICI therapy for GC. METHODS: Unresectable or recurrent GC treated with ICIs was investigated. Using unenhanced CT, the liver-to-spleen CT attenuation ratio (LSR) was calculated as a parameter of hepatic steatosis. LSR was compared with the presence of sarcopenia and inflammatory markers including neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), and monocyte-to-lymphocyte ratio (MLR). These parameters were also compared with disease-specific survival (DSS) and progression-free survival (PFS). Associations of LSR with insulin-like growth factor 1 (IGF-1) and growth hormone were also evaluated. RESULTS: A total of 70 patients were investigated. LSR of sarcopenia patients was significantly lower than that of non-sarcopenic ones (p = 0.02). LSR showed significant negative correlations with NLR, PLR, and MLR (p = 0.003, 0.03, 0.01, respectively). Lower LSR was significantly associated with a higher level of serum IGF-1 (p = 0.03). In univariate analysis, LSR was significantly correlated with DSS and PFS (both p < 0.0001), and multivariate analysis demonstrated that LSR was the independent prognostic factor for both DSS and PFS (both p = 0.01). ROC analysis demonstrated that LSR >1.263 was a good predictive marker for favorable DSS (>5.3 months) with an AUC of 0.80. CONCLUSION: Hepatic steatosis can be a promising prognostic biomarker for ICI therapy of GC, associated with sarcopenia and the elevation of inflammatory markers. Our data suggested that GC with steatohepatitis might be less responsive to ICI therapy.

An anti-alcoholism drug, disulfiram and copper complex improves radio-resistance of tumor-initiating cells in esophageal squamous cell carcinoma.

BACKGROUND: Esophageal squamous cell carcinoma (ESCC) is a malignant cancer with a poor prognosis. Chemoradiotherapy is one of the most important strategies for patients with locally advanced unresectable ESCC; however, its therapeutic effect is unsatisfactory. Tumor-initiating cells (TICs) have been reported to be resistant to conventional chemotherapy and radiotherapy so far. Therefore, we aimed to develop a treatment strategy targeting TICs in ESCC to improve radiosensitivity. METHODS: First, we validated aldehyde dehydrogenase 1 (ALDH1) as a TIC marker and investigated its ability to mediate resistance in human ESCC cell lines using flow cytometry, Western blotting, and functional analyses. Then, we focused on disulfiram (DSF), an aldehyde dehydrogenase inhibitor, used to treat alcohol use disorder. We investigated the effect of DSF and copper (II) D-gluconate (Cu) on the radiosensitivity of ESCC in xenograft mouse models. RESULTS: ALDH1-positive cells showed an upregulation of SOX2 and Nanog, exhibiting much stronger tumor-initiating properties than ALDH1-negative cells. Furthermore, inhibition of ALDH1 attenuated the tumor-initiating properties of ESCC cell lines. Our results also showed that ALDH1-positive cells were resistant to chemotherapy and radiotherapy, and the inhibition of ALDH1 led to the mitigation of therapeutic resistance. Our in vitro and in vivo studies revealed that the DSF/Cu complex could radiosensitize ALDH1-positive ESCC cells and downregulate the phosphoinositide 3-kinase/Akt pathway. CONCLUSION: ALDH1 inhibition by the DSF/Cu complex enhances the radiosensitivity of TICs in ESCC. The drug repositioning approach using disulfiram is a potential treatment option to overcome radioresistance in patients with locally advanced ESCC.

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.

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.