N6-methyladenosine methylation regulates the tumor microenvironment of Epstein-Barr virus-associated gastric cancer.

BACKGROUND: N6-methyladenosine (m6A) methylation modification exists in Epstein-Barr virus (EBV) primary infection, latency, and lytic reactivation. It also modifies EBV latent genes and lytic genes. EBV-associated gastric cancer (EBVaGC) is a distinctive molecular subtype of GC. We hypothesized EBV and m6A methylation regulators interact with each other in EBVaGC to differentiate it from other types of GC. AIM: To investigate the mechanisms of m6A methylation regulators in EBVaGC to determine the differentiating factors from other types of GC. METHODS: First, The Cancer Gene Atlas and Gene Expression Omnibus databases were used to analyze the expression pattern of m6A methylation regulators between EBVaGC and EBV-negative GC (EBVnGC). Second, we identified Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) functional enrichment of m6A-related differentially expressed genes. We quantified the relative abundance of immune cells and inflammatory factors in the tumor microenvironment (TME). Finally, cell counting kit-8 cell proliferation test, transwell test, and flow cytometry were used to verify the effect of insulin-like growth factor binding protein 1 (IGFBP1) in EBVaGC cell lines. RESULTS: m6A methylation regulators were involved in the occurrence and development of EBVaGC. Compared with EBVnGC, the expression levels of m6A methylation regulators Wilms tumor 1-associated protein, RNA binding motif protein 15B, CBL proto-oncogene like 1, leucine rich pentatricopeptide repeat containing, heterogeneous nuclear ribonucleoprotein A2B1, IGFBP1, and insulin-like growth factor 2 binding protein 1 were significantly downregulated in EBVaGC (P < 0.05). The overall survival rate of EBVaGC patients with a lower expression level of IGFBP1 was significantly higher (P = 0.046). GO and KEGG functional enrichment analyses showed that the immunity pathways were significantly activated and rich in immune cell infiltration in EBVaGC. Compared with EBVnGC, the infiltration of activated CD4+ T cells, activated CD8+ T cells, monocytes, activated dendritic cells, and plasmacytoid dendritic cells were significantly upregulated in EBVaGC (P < 0.001). In EBVaGC, the expression level of proinflammatory factors interleukin (IL)-17, IL-21, and interferon-γ and immunosuppressive factor IL-10 were significantly increased (P < 0.05). In vitro experiments demonstrated that the expression level of IGFBP1 was significantly lower in an EBVaGC cell line (SNU719) than in an EBVnGC cell line (AGS) (P < 0.05). IGFBP1 overexpression significantly attenuated proliferation and migration and promoted the apoptosis levels in SNU719. Interfering IGFBP1 significantly promoted proliferation and migration and attenuated the apoptosis levels in AGS. CONCLUSION: m6A regulators could remodel the TME of EBVaGC, which is classified as an immune-inflamed phenotype and referred to as a "hot" tumor. Among these regulators, we demonstrated that IGFBP1 affected proliferation, migration, and apoptosis.

Global research trends and hotspots of Helicobacter pylori eradication based on clinical trial registration platforms: A cross-sectional analysis.

BACKGROUND: This study aimed to obtain an overview of clinical trials on Helicobacter pylori (H. pylori) eradication and analyze the global trends and hotspots in this field. METHODS: We collected the data from clinical trials focused on H. pylori eradication in the primary clinical trial registries from 2000 to 2022 in the world. Then we analyzed the research trends and hotspots in H. pylori eradication regimens in different regions at different periods. RESULTS: A total of 780 clinical trials were included, which were mainly conducted in Asia (682), followed by Europe (59), Africa (20), North America (16), South America (7), Oceania (2). The most active countries were China (343), Iran (140), South Korea (63), and Japan (73). "Bismuth-containing quadruple therapy (BQT)" was the most studied regimen (159, 20.38 %). Additionally, clinical trials focused on potassium-competitive acid blockers (P-CABs)-based therapy, probiotics, and high-dose dual therapy (HDDT) were constantly increasing. BQT received the most attention in China (26.53 %) and Iran (22.14 %), while it was tailored therapy in South Korea (23.29 %). P-CABs-based therapy was the main reseach hotspot in Japan (61.90 %). CONCLUSION: How to eradicate H. pylori infection has been a heated research topic. BQT, P-CABs-based therapy, probiotics, and HDDT attracted the most attention in recent years.

Determination of an Appropriate Endoscopic Monitoring Interval for Patients with Gastric Precancerous Conditions in China.

OBJECTIVE: Gastric precancerous conditions such as atrophic gastritis (AG) and intestinal metaplasia (IM) are considered independent risk factors for gastric cancer (GC). The suitable endoscopic monitoring interval is unclear when we attempt to prevent GC development. This study investigated the appropriate monitoring interval for AG/IM patients. METHODS: Totally, 957 AG/IM patients who satisfied the criteria for evaluation between 2010 and 2020 were included in the study. Univariate and multivariate analyses were used to determine the risk factors for progression to high-grade intraepithelial neoplasia (HGIN)/GC in AG/IM patients, and to determine an appropriate endoscopic monitoring scheme. RESULTS: During follow-up, 28 AG/IM patients developed gastric neoplasia lesions including gastric low-grade intraepithelial neoplasia (LGIN) (0.7%), HGIN (0.9%), and GC (1.3%). Multivariate analysis identified H. pylori infection (P=0.022) and extensive AG/IM lesions (P=0.002) as risk factors for HGIN/GC progression (P=0.025). CONCLUSION: In our study, HGIN/GC was present in 2.2% of AG/IM patients. In AG/IM patients with extensive lesions, a 1-2-year surveillance interval is recommended for early detection of HIGN/GC in AG/IM patients with extensive lesions.

Impact of body size on efficacy of high-dose dual therapy for Helicobacter pylori eradication.

BACKGROUND: High-dose dual therapy (HDDT) is an emerging and promising therapeutic regime for Helicobacter pylori (H. pylori) eradication. However, the pharmacokinetics of the components of HDDT, amoxicillin and proton pump inhibitor, are likely to be affected by body size. In this study, we aimed to find out the impact of body size on the efficacy of HDDT. METHODS: We collected the medical data of 385 treatment-naive patients infected with H. pylori who received HDDT (esomeprazole 20 mg and amoxicillin 750 mg four times daily) for 14 days from July 2020 to December 2021. The associations among the eradication efficacy, adverse events, and variables (sex, age, height, body weight, body mass index (BMI), body surface area (BSA), smoking, drinking, etc.) were analyzed respectively in our study. Among these factors, continuous variables were classified into categorical variables using the cut-off values which were calculated by receiver operating characteristic analysis. RESULTS: The eradication rate of HDDT was 89.9%. There were 55 (14.3%) patients who occurred adverse events during the treatment. Patients with height <170.5 cm, body weight <60.5 kg, BMI <20.55 kg/m2 , BSA <1.69 m2 had a higher eradication rate (92.1% vs. 84.0%, 93.1% vs. 86.8%, 96.0% vs. 87.8%, 93.4% vs. 84.8%, all p < .05). The multivariate analysis showed that BSA ≥1.69 m2 (OR 2.53, 95% CI: 1.28-4.99, p = .007) was the only independent predictor of eradication failure. CONCLUSION: HDDT could achieve better eradication efficacy in patients with small BSA. Clinicians should be aware of the impact of BSA on the H. pylori eradication rate and pay more attention to patients with large BSA.

Facile Synthesis of Highly Dispersed and Well-Alloyed Bimetallic Nanoparticles on Oxide Support.

Supported alloy catalysts play a pivotal role in many heterogeneous catalytic processes of socioeconomic and environmental importance. But the controlled synthesis of supported alloy nanoparticles with consistent composition and tight size distribution remains a challenging issue. Herein, a simple yet effective method for preparation of highly dispersed, homogeneously alloyed bimetallic nanoparticles on oxide supports is reported. This method is based on solid solution of metal cations in parent oxide and strong electrostatic adsorption of a secondary metal species onto the oxide surface. In the reductive annealing process, hydrogen spillover occurs from the surface metal with a higher reduction potential to the solute metal in solid solution, leading to metal exsolution and homogenous alloying of the metals on the oxide surface. The ceria-supported Ni-Pt alloy is chosen as a model catalyst and hydrazine monohydrate decomposition is chosen as a probe reaction to demonstrate this method, and particularly its advantages over the conventional impregnation and galvanic replacement methods. A systematic application of this method using different oxides and base-noble metal pairs further elucidates its applicability and generality.