Fusobacterium nucleatum confers chemoresistance by modulating autophagy in oesophageal squamous cell carcinoma

Background Fusobacterium nucleatum (F. nucleatum) is a gut microbe implicated in gastrointestinal tumorigenesis. Predicting the chemotherapeutic response is critical to developing personalised therapeutic strategies for oesophageal cancer patients. The present study investigated the relationship between F. nucleatum and chemotherapeutic resistance in oesophageal squamous cell carcinoma (ESCC).Methods We examined the relationship between F. nucleatum and chemotherapy response in 120 ESCC resected specimens and 30 pre-treatment biopsy specimens. In vitro studies using ESCC cell lines and co-culture assays further uncovered the mechanism underlying chemotherapeutic resistance.Results ESCC patients with F. nucleatum infection displayed lesser chemotherapeutic response. The infiltration and subsistence of F. nucleatum in the ESCC cells were observed by transmission electron microscopy and laser scanning confocal microscopy. We also observed that F. nucleatum modulates the endogenous LC3 and ATG7 expression, as well as autophagosome formation to induce chemoresistance against 5-FU, CDDP, and Docetaxel. ATG7 knockdown resulted in reversal of F. nucleatum-induced chemoresistance. In addition, immunohistochemical studies confirmed the correlation between F. nucleatum infection and ATG7 expression in 284 ESCC specimens.Conclusions F. nucleatum confers chemoresistance to ESCC cells by modulating autophagy. These findings suggest that targeting F. nucleatum, during chemotherapy, could result in variable therapeutic outcomes for ESCC patients.Subject terms: Tumour biomarkers, Oesophageal cancer     

Comprehensive analysis of gene expression of isolated pancreatic islets during pretransplant culture

Background: The aim of this study was to investigate the effect of pretransplant culture on the survival of pancreatic islet grafts, and to determine the biological characteristics of isolated islets during pretransplant culture. Methods: The survival of islets from Wistar rats, transplanted to diabetic C57BL/B6 mice, was compared between fresh islets and cultured islets. A comprehensive gene expression analysis was employed to investigate biological processes during pretransplant culture, and in vitro validation studies were performed. Results: Survival of cultured xenografts was significantly prolonged as compared to that of fresh islets (fresh: 12.5 ± 1.9 days, 1-day cultured: 16.0 ± 1.3 days (p= 0.017), 3-day cultured: 17.0 ± 2.6 days (p= 0.014)). Comprehensive gene expression analysis identified significant upregulation of annotated functions associated with inflammation in cultured groups. Six proinflammatory genes, including heme oxygenase 1 (HO-1) and IL-6, were significantly upregulated during culture. Validation studies revealed significantly higher levels of IL-6 in the supernatant of cultured islets and HO-1 in the cultured islets when compared with fresh islets. Conclusion: Transplantation of cultured islets induced significant but minimal prolongation of graft survival in xenogeneic combinations. Comprehensive analysis of gene expression in cultured islets showed biological processes associated with proinflammation during culture.     

Clinical characteristic of esophageal cancer without lugol-voiding lesions in the background esophagus

Lugol chromoendoscopy is useful for the detection of early esophageal squamous cell cancer (ESCC). Multiple lugol-voiding lesions (LVLs) on lugol chromoendoscopy are associated with a very high risk of multiple cancers arising in the esophagus. Due to the widespread use of narrow band image technology in many institutions, esophageal cancer without LVLs in the background esophagus is sometimes detected. This retrospective study aims to clarify the clinical characteristic of esophageal cancer without LVLs in the background esophagus. A total of 191 consecutive patients with 204 ESCCs had undergone endoscopic submucosal dissection (ESD) from 2011 and 2014. Amongst these lesions, the number of LVLs in the background esophagus per endoscopic view was counted excluding main lesion, and the grading was divided into no LVLs ESCC (nL-ESCC) group and LVLs ESCC (L-ESCC) group. This study evaluated the clinical characteristics and the cumulative incidence of metachronous ESCC after ESD in both groups. Thirty-six patients with 36 lesions and 155 patients with 168 lesions were separated into the nL-ESCC group and L-ESCC group, respectively. On multivariate analysis, the nL-ESCC group was found to be more common in females, who were non-drinkers, or with erosive esophagitis. During follow-up periods, the cumulative incidence of metachronous ESCC at 3-years was 14.4% and 0.00% in the L-ESCC and nL-ESCC groups, respectively (P < 0.01). Our study showed that esophageal cancer without LVLs in the background esophagus was mostly occurred in females, who were non-drinkers, or with erosive esophagitis, which are uncommon features of ESCC.     

Acute Hypertriglyceridaemia Caused by Tocilizumab in a Patient with Severe COVID-19

Treatment with tocilizumab (TCZ) to block interleukin-6 (IL-6) signalling is predicted to mitigate cytokine release syndrome (CRS) caused by coronavirus disease 2019 (COVID-19). However, the adverse effects of TCZ on patients with COVID-19 remain unclear. We herein report a patient with COVID-19 treated with TCZ who developed acute hypertriglyceridaemia. Despite favipiravir treatment, acute respiratory distress syndrome developed in a 45-year-old patient with COVID-19; thus, TCZ was initiated. The triglyceride levels greatly increased after TCZ administration. Physicians should consider the negative impact of TCZ on the lipid profile in patients with COVID-19, although COVID-19-induced CRS itself may be an aggravating factor.