EBV-associated Gastric Carcinoma Research Articles

Epstein Barr virus: A cellular hijacker in cancer.

Numerous studies have demonstrated the importance of the Epstein-Barr Virus (EBV), which was initially identified in 1964 while studying Burkitt's lymphoma, in the development of a number of cancers, including nasopharyngeal carcinoma, Hodgkin's lymphoma, Burkitt's lymphoma, and EBV-associated gastric carcinoma. Gammaherpesvirus EBV is extremely common; by adulthood, over 90 % of people worldwide have been infected. Usually, the virus causes a permanent latent infection in B cells, epithelial cells, and NK/T cells. It then contributes to oncogenesis by inhibiting apoptosis and promoting unchecked cell proliferation through its latent proteins, which include EBNA-1, LMP1, and LMP2A. Tumor progression further accelerated by EBV's capacity to transition between latent and lytic phases, especially in cases of nasopharyngeal carcinoma. Although our understanding of the molecular underpinnings of EBV has advanced, there are still difficulties in identifying latent infections and creating targeted therapeutics. To tackle EBV-associated malignancies, current research efforts are concentrated on developing vaccines, developing better diagnostic tools, and developing targeted treatments. In order to improve treatment approaches and lower the incidence of EBV-related cancers worldwide, more research into the relationship between EBV and immune evasion and cancer formation is necessary.

Clinicopathological Characteristics and Perioperative Treatment of Epstein-Barr Virus-Associated Gastric Cancer: A Retrospective Study.

The clinicopathological characteristics and perioperative treatment outcomes of patients with EBVaGC who underwent radical gastrectomy in Tianjin Medical University Cancer Hospital from September 2016 to May 2022 were retrospectively reviewed. Disease-free survival (DFS) was analyzed and Cox regression analysis was performed to identify risk factors. The study cohort included 128 patients with EBVaGC. Histologically, 126 (98.4%) patients had adenocarcinoma and only 2 (1.6%) had adenosquamous carcinoma. In addition, 18 (14.1%) had nerve invasion and 29 (22.7%) had vascular invasion. Notably, 41 (32.0%) patients had tumors in the proximal stomach and 69 (53.9%) had no lymph node metastasis. Proficient mismatch repair was confirmed in all 104 patients with available results. Overall, 16 (12.5%) patients received neoadjuvant therapy, 81 (63.3%) received adjuvant therapy, and 10 (7.8%) received perioperative immunotherapy combined with chemotherapy. In total, 22 patients experienced disease progression or had died. The 3-year DFS rate was 75.0%. DFS was relatively poorer for patients with advanced tumor (T) stage, lymph node (N) stage, disease stage, and vascular invasion. EBVaGC had unique clinicopathological characteristics and prognosis. Advanced T, N, and disease stages, in addition to vascular invasion, were predictive of poorer DFS. However, the efficacy of perioperative treatment of EBVaGC remains uncertain.

Molecular detection of Epstein-Barr virus in paraffin-embedded tissue samples of patients suffering gastric cancer in Ahvaz, Iran: a case-control study.

Gastric cancer (GC) is the third most common cause of cancer-related mortality. Epstein-Barr virus (EBV) is associated with several human tumors. The present research was performed to investigate the prevalence of EBV-associated gastric cancer (EBVaGC) among Iranian patients. Seventy cases of gastric cancer and 30 cases of gastric ulcer, all preserved in formalin-fixed paraffin-embedded (FFPE), were examined in a case-control study conducted between 2011 and 2018. The specimens underwent analysis to detect the presence of the EBV genome using a Nested-PCR method targeting EBNA1. Subsequently, samples testing positive for the EBNA1 underwent further testing for the presence of the EBER gene using PCR. Finally, Positive samples were subjected to sequencing. Five out of 70 cases (7%) were found to be positive for EBV based on EBNA1 testing, while all EBNA1 positive samples were negative for EBER. Notably, EBV was not detected in patients with gastric ulcer. The mean age of EBV-positive gastric carcinomas pateints was 64.5 years. Within this group, 60% were male and 40% were female. A higher prevalence of EBV association was observed in diffuse-type cases, with 60% (3 out of 24) testing positive, compared to intestinal-type cases where 40% (2 out of 46) were EBV-positive. Most cases of EBVaGC belonged to grade Ⅰ. This research demonstrates a low prevalence of EBVaGC in Iran. Discrepancies in EBVaGC occurrence among countries could be attributed to epidemiological variables and dietary practices. A comprehensive studies will provide significant contributions to understanding of its etiology.

P9-1 Deep learning in detection of Epstein-Barr virus-associated gastric cancer in histology slides: systematic review

P9-1 Deep learning in detection of Epstein-Barr virus-associated gastric cancer in histology slides: systematic review

Epstein-Barr Virus BARF1 Is Expressed in Lung Cancer and Is Associated with Cancer Progression.

Epstein-Barr virus (EBV) is involved in the development of lymphomas, nasopharyngeal carcinomas (NPC), and a subgroup of gastric carcinomas (GC), and has also been detected in lung carcinomas, even though the role of the virus in this malignancy has not yet been established. BamH1-A Rightward Frame 1 (BARF1), a suggested exclusive epithelial EBV oncoprotein, is detected in both EBV-associated GCs (EBVaGC) and NPC. The expression and role of BARF1 in lung cancer is unknown. A total of 158 lung carcinomas including 80 adenocarcinomas (AdCs) and 78 squamous cell carcinomas (SQCs) from Chilean patients were analyzed for EBV presence via polymerase chain reaction (PCR), Immunohistochemistry (IHC), or chromogenic in situ hybridization (CISH). The expression of BARF1 was evaluated using Reverse Transcription Real-Time PCR (RT-qPCR). Additionally, A549 and BEAS-2B lung epithelial cells were transfected with a construct for ectopic BARF1 expression. Cell proliferation, migration, invasion, and epithelial-mesenchymal transition (EMT) were evaluated. We found that EBV was present in 37 out of 158 (23%) lung carcinomas using PCR. Considering EBV-positive specimens using PCR, IHC for Epstein-Barr nuclear antigen 1 (EBNA1) detected EBV in 24 out of 30 (80%) cases, while EBERs were detected using CISH in 13 out of 16 (81%) cases. Overall, 13 out of 158 (8%) lung carcinomas were shown to be EBV-positive using PCR/IHC/CISH. BARF1 transcripts were detected in 6 out of 13 (46%) EBV-positive lung carcinomas using RT qPCR. Finally, lung cells ectopically expressing BARF1 showed increased migration, invasion, and EMT. EBV is frequently found in lung carcinomas from Chile with the expression of BARF1 in a significant subset of cases, suggesting that this viral protein may be involved in EBV-associated lung cancer progression.

Unlocking the Potential: Epstein-Barr Virus (EBV) in Gastric Cancer and Future Treatment Prospects, a Literature Review.

Gastric cancer (GC) is a complex disease with various etiologies. While Helicobacter pylori infection is still one of the leading risk factors for GC, increasing evidence suggests a link between GC and other infective agents such as Epstein Bar Virus (EBV). EBV-associated gastric cancer (EBVaGC) is now recognized as a distinct subgroup of GC, and the complex interactions between the virus and gastric mucosa may influence its development. A recent integrative analysis of the genome and proteome of GC tissues by The Cancer Genome Atlas project has identified EBVaGC as a specific subtype characterized by PIK3CA and ARID1A mutations, extensive DNA hyper-methylation, and activation of immune signaling pathways. These molecular characteristics are markers of the unique molecular profile of this subset of GC and are potential targets for therapy. This review aims to provide an overview of the current knowledge on EBVaGC. It will focus on the epidemiology, clinic-pathological features, and genetic characteristics of EBVaGC. Additionally, it will discuss recent data indicating the potential use of EBV infection as a predictive biomarker of response to chemotherapy and immune checkpoint inhibitors. The review also delves into potential therapeutic approaches for EBVaGC, including targeted therapies and adoptive immunotherapy, highlighting the promising potential of EBV as a therapeutic target.

Stearoyl-CoA desaturase 1 is targeted by EBV-encoded miR-BART20-5p and regulates cell autophagy, proliferation, and migration in EBV-associated gastric cancer.

Epstein-Barr virus (EBV) is the first human oncogenic virus known to express microRNAs (miRNAs), which are closely associated with the development of various tumors, including nasopharyngeal and gastric cancers. Stearoyl-CoA Desaturase 1 (SCD1) is a key enzyme in fatty acid synthesis, highly expressed in numerous tumors, promoting tumor growth and metastasis, making it a potential therapeutic target. In this study, we found that SCD1 expression in EBV-associated gastric cancer (EBVaGC) was significantly lower than in EBV-negative gastric cancer (EBVnGC) at both cellular and tissue levels. In addition, EBV-miR-BART20-5p targets the 3'-UTR of SCD1, downregulating its expression. Moreover, overexpression of SCD1 in EBVaGC cells promoted cell migration and proliferation while inhibiting autophagy. These results suggest that EBV-encoded miRNA-BART20-5p may contribute to EBVaGC progression by targeting SCD1.

The impact of CLDN18.2 expression on effector cells mediating antibody-dependent cellular cytotoxicity in gastric cancer

Activating antibody-dependent cellular cytotoxicity (ADCC) by targeting claudin-18 isoform 2 (CLDN18.2) using zolbetuximab, a monoclonal antibody against CLDN18.2, has been considered a promising novel therapeutic strategy for gastric cancer (GC). However, the impact of CLDN18.2 expression on natural killer (NK) cells and monocytes/macrophages—crucial effector cells of ADCC—in GC has not been fully investigated. In the present study, we assessed the impact of CLDN18.2 expression on clinical outcomes, molecular features, and the frequencies of tumor-infiltrating NK cells and macrophages, as well as peripheral blood NK cells and monocytes, in GC by analyzing our own GC cohorts. The expression of CLDN18.2 did not significantly impact clinical outcomes of GC patients, while it was significantly and positively associated with Epstein–Barr virus (EBV) status and PD-L1 expression. The frequencies of tumor-infiltrating NK cells and macrophages, as well as peripheral blood NK cells and monocytes, were comparable between CLDN18.2-positive and CLDN18.2-negative GCs. Importantly, both CLDN18.2 expression and the number of tumor-infiltrating NK cells were significantly higher in EBV-associated GC compared to other molecular subtypes. Our findings support the effectiveness of zolbetuximab in CLDN18.2-positive GC, and offer a novel insight into the treatment of this cancer type, highlighting its potential effectiveness for CLDN18.2-positive/EBV-associated GC.

Can Machine Learning Models Based on Computed Tomography Radiomics and Clinical Characteristics Provide Diagnostic Value for Epstein-Barr Virus-Associated Gastric Cancer?

The aim of this study was to explore whether machine learning model based on computed tomography (CT) radiomics and clinical characteristics can differentiate Epstein-Barr virus-associated gastric cancer (EBVaGC) from non-EBVaGC. Contrast-enhanced CT images were collected from 158 patients with GC (46 EBV-positive, 112 EBV-negative) between April 2018 and February 2023. Radiomics features were extracted from the volumes of interest. A radiomics signature was built based on radiomics features by the least absolute shrinkage and selection operator logistic regression algorithm. Multivariate analyses were used to identify significant clinicoradiological variables. We developed 6 ML models for EBVaGC, including logistic regression, Extreme Gradient Boosting, random forest (RF), support vector machine, Gaussian Naive Bayes, and K-nearest neighbor algorithm. The area under the receiver operating characteristic curve (AUC), the area under the precision-recall curves (AP), calibration plots, and decision curve analysis were applied to assess the effectiveness of each model. Six ML models achieved AUC of 0.706-0.854 and AP of 0.480-0.793 for predicting EBV status in GC. With an AUC of 0.854 and an AP of 0.793, the RF model performed the best. The forest plot of the AUC score revealed that the RF model had the most stable performance, with a standard deviation of 0.003 for AUC score. RF also performed well in the testing dataset, with an AUC of 0.832 (95% confidence interval: 0.679-0.951), accuracy of 0.833, sensitivity of 0.857, and specificity of 0.824, respectively. The RF model based on clinical variables and Rad_score can serve as a noninvasive tool to evaluate the EBV status of gastric cancer.

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

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. To investigate the mechanisms of m6A methylation regulators in EBVaGC to determine the differentiating factors from other types of GC. 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. 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. 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.

Viral Infection in Upper Gastrointestinal Tract

Viral infections of the upper gastrointestinal (GI) tract are not uncommon in clinical practice; however, these are frequently observed in immunocompromised patients and rarely in immunocompetent hosts. Compared with esophagitis, which may be associated with clinically significant outcomes, the stomach is a relatively rare site for opportunistic infections in immunocompetent patients. The most common clinically relevant upper GI tract viral infections include cytomegalovirus (CMV), Epstein-Barr virus (EBV), and herpes simplex virus infections. CMV esophagitis and gastritis, which primarily occur in immunocompromised patients, necessitate antiviral treatment, whereas immunocompetent patients typically respond to proton pump inhibitor administration. Most EBV-induced gastric infections are asymptomatic. However, EBV infection is a known etiological contributor to stomach cancer. EBV-associated gastric cancer shows distinctive clinical, pathological, genetic, and post-genetic mutation features and is therefore a clinically significant entity. Herpetic esophagitis usually affects immunocompromised patients and is uncommon in immunocompetent individuals. In this review, we discuss the general aspects and recent studies that have reported esophageal and gastric infections in immunocompromised patients.

EBV promotes TCR-T-cell therapy resistance by inducing CD163+M2 macrophage polarization and MMP9 secretion

BackgroundEpstein-Barr virus (EBV) is a double-stranded DNA oncogenic virus. Several types of solid tumors, such as nasopharyngeal carcinoma, EBV-associated gastric carcinoma, and lymphoepithelioma-like carcinoma of the lung, have been linked...

Clinicopathological characteristics and prognosis of Epstein-Barr virus-associated gastric cancer.

Epstein-Barr virus (EBV)-associated gastric cancer (EBVaGC) is a distinct molecular subtype of gastric cancer (GC). At present, the clinical characteristics and prognostic implications of EBV infection and the potential clinical benefits of immune checkpoint blockade in GC remain to be clarified. Hence, this study was designed to analyze the clinical and pathological characteristics of GC patients with varying EBV infection states and compare their overall survival (OS). A retrospective study was performed on 1031 consecutive GC patients who underwent gastrectomy at the Affiliated Hospital of Xuzhou Medical University from February 2018 to November 2022. EBV-encoded RNA (EBER) in situ hybridization (ISH) was used for EBV assessment, and immunohistochemical staining was used for evaluation of human epidermal growth factor receptor 2 (HER2), programmed death ligand 1 (PD-L1), and Ki67 expression. EBVaGC was defined as tumors with EBV positivity. In addition, EBV-negative GC (EBVnGC) patients were matched with EBVaGC patients based on seven clinicopathological parameters (age, gender, anatomic subsite, tumor size, Lauren classification, degree of differentiation, and tumor-node-metastasis [TNM] stage). The correlations of clinical features with HER2, PD-L1, and Ki67 expression were evaluated statistically. The survival of patients was assessed through medical records, telephone, or WeChat communication, and prognostic analysis was performed using the logrank test as well as univariable and multivariable regression analysis. Out of 1031 GC patients tested, 35 (3.4%) were diagnosed with EBVaGC. Notably, the EBVaGC group exhibited a distinct predominance of males and younger patients, significantly higher Ki67 and PD-L1 expression levels, and a lower prevalence of pericancerous nerve invasion than the EBVnGC group (P < 0.01). In the 35 EBVaGC cases, Ki67 expression was negatively correlated with age (P < 0.05), suggesting that a younger onset age was associated with higher Ki67 expression. In addition, PD-L1 expression was correlated with the degree of differentiation, T-stage, and clinical stage of the patient. Furthermore, PD-L1 expression was elevated in tumors with lower differentiation or at later stages (P < 0.05). Using univariate analysis, Ki67, PD-L1, and clinical stage were identified as significant factors influencing the overall survival (OS) of EBVaGC patients (P < 0.05). Moreover, multivariate survival analysis revealed that clinical stage and Ki67 expression were independent risk factors for the OS of the patients (P < 0.05), and the three-year OS rate of EBVaGC patients was 64.2%. EBV-ISH is a practical and valuable method to identify EBVaGC. Owing to its unique etiological, pathological, and clinical characteristics, patients with EBVaGC might benefit from immune checkpoint blockade therapy.

Prognostic Effect of Tertiary Lymphoid Structures in Epstein–Barr Virus–Associated Gastric Carcinomas Measured by Digital Image Analysis

Epstein–Barr virus–associated gastric carcinoma (EBVaGC) is characterized by prominent tumor-infiltrating lymphocytes (TILs) and has a favorable prognosis. Tertiary lymphoid structures (TLS), characterized by ectopic aggregated lymphocytes with high-endothelial venules (HEV), are associated with favorable outcomes in various solid tumors. We hypothesized that EBVaGC, characterized by intense TILs, may be closely associated with TLS or HEV. To test this hypothesis, we digitally analyzed the TLS, HEV, and TILs in 73 surgically resected advanced EBVaGCs. For HEV, dual MECA-79 and CD31 dual immunohistochemistry were performed, and the ectopic expression of MECA-79 in tumor cells was measured. In 73 patients with EBVaGC, a high-TLS ratio was found in 29 (39.7%) cases, high-tumor-associated HEV density in 44 (60.3%) cases, and high-CD8+ TIL density in 38 (52.1%) cases. Ectopic tumor expression of MECA-79 was observed in 36 patients (49.3%) cases. A low-TLS ratio and tumor-associated HEV density were significantly associated with lymph node metastasis (P = .005 and .042, respectively). Ectopic MECA-79 expression was significantly associated with lymph node metastasis (P = .003). Patients with a low-TLS ratio (P = .038), low-HEV density (P = .042), and ectopic tumor MECA-79 expression (P = .032) had significantly worse prognoses. In conclusion, TLS ratio and HEV density affect the survival of patients with EBVaGC and may be related to the immune response that interrupts lymph node metastasis.

EBV-Associated Gastric Cancer; An In Situ Hybridization Assay on Tissue Microarray: A Multi-Region Study from Four Major Provinces of Iran.

Gastric cancer is the fourth leading cause of cancer-related deaths in the world. The identification of gastric cancer subtypes related to recognizable microbial agents may play a pivotal role in the targeted prevention and treatment of this cancer. The current study is conducted to define the frequency of Epstein-Barr virus (EBV) infection in gastric cancers of four major provinces, with different incidence rates of gastric cancers, in Iran. Paraffin blocks of 682 cases of various types of gastric cancer from Tehran, South and North areas of Iran were collected. Twelve tissue microarray (TMA) blocks were constructed from these blocks. Localization of EBV in tumors was assessed by in situ hybridization (ISH) for EBV-encoded RNA (EBER). Chi-squared test was used to evaluate the statistical significance between EBV-associated gastric cancer (EBVaGC) and clinicopathologic tumor characteristics. Fourteen out of 682 cases (2.1%) of gastric adenocarcinoma were EBER-positive. EBER was positive in 8 out of 22 (36.4%) of medullary carcinomas and 6 out of 660 (0.9%) of non-medullary type, which was a statistically significant difference (P<0.001). The EBVaGCs were more frequent in younger age (P=0.009) and also showed a trend toward the lower stage of the tumor (P=0.075). EBV-associated gastric adenocarcinoma has a low prevalence in Iran. This finding can be due to epidemiologic differences in risk factors and exposures, and the low number of gastric medullary carcinomas in the population. It may also be related to gastric tumor heterogeneity not detected with the TMA technique.

The viral etiology of EBV-associated gastric cancers contributes to their unique pathology, clinical outcomes, treatment responses and immune landscape.

Epstein-Barr virus (EBV) is a pathogen known to cause a number of malignancies, often taking years for them to develop after primary infection. EBV-associated gastric cancer (EBVaGC) is one such malignancy, and is an immunologically, molecularly and pathologically distinct entity from EBV-negative gastric cancer (EBVnGC). In comparison with EBVnGCs, EBVaGCs overexpress a number of immune regulatory genes to help form an immunosuppressive tumor microenvironment (TME), have improved prognosis, and overall have an "immune-hot" phenotype. This review provides an overview of the histopathology, clinical features and clinical outcomes of EBVaGCs. We also summarize the differences between the TMEs of EBVaGCs and EBVnGCs, which includes significant differences in cell composition and immune infiltration. A list of available EBVaGC and EBVnGC gene expression datasets and computational tools are also provided within this review. Finally, an overview is provided of the various chemo- and immuno-therapeutics available in treating gastric cancers (GCs), with a focus on EBVaGCs.

Regulation mechanism of EBV-encoded EBER1 and LMP2A on YAP1 and the impact of YAP1 on the EBV infection status in EBV-associated gastric carcinoma

This study aims to explore the role and regulatory mechanism of Yes-associated protein 1 (YAP1) in the development of Epstein-Barr virus-associated gastric cancer (EBVaGC). Here we showed that EBV can upregulate the expression and activity of YAP1 protein through its encoded latent products EBV-encoded small RNA 1 (EBER1) and latent membrane protein 2A (LMP2A), enhancing the malignant characteristics of EBVaGC cells. In addition, we also showed that overexpression of YAP1 induced the expression of EBV encoding latent and lytic phase genes and proteins in the epithelial cell line AGS-EBV infected with EBV, and increased the copy number of the EBV genome, while loss of YAP1 expression reduced the aforementioned indicators. Moreover, we found that YAP1 enhanced EBV lytic reactivation induced by two known activators, 12-O-tetradecanoylhorbol-13-acetate (TPA) and sodium butyrate (NaB). These results indicated a bidirectional regulatory mechanism between EBV and YAP1 proteins, providing new experimental evidence for further understanding the regulation of EBV infection patterns and carcinogenic mechanisms in gastric cancer.

Comprehensive Analysis Based on the TCGA Database Identified SCIN as a Key DNA Methylation-Driver Gene in Epstein-Barr Virus-Associated Gastric Cancer.

An important feature of EBV-associated gastric cancer (EBVaGC) is extensive methylation of viral and host genomes. This study aims to analyze DNA methylation-driven genes (DMDG) in EBVaGC through bioinformatics methods, providing an important bioinformatics basis for the differential diagnosis and treatment of potential methylation biomarkers in EBVaGC. We downloaded the mRNA expression profiles and methylation datasets of EBVaGC and EBV-negative gastric cancer (EBVnGC) through the TCGA database to screen methylated-differentially expressed genes (MDEGs). DNA methylation-driver genes were identified based on MethylMix algorithm and key genes were further identified by LASSO regression and Random Forest algorithm. Then, we performed gene enrichment analysis for key genes and validated them by GEO database. Gene expression differences in EBVaGC and EBVnGC cell lines was determined by quantitative real-time PCR (qRT-PCR) and western blotting and in GT38 cell and SNU719 cell which all treated by 5-Aza-CdR. Finally, the effect of key gene on the migration and proliferation capacity of EBVaGC cells was determined by Transwells assay and Cell counting Kit-8 (CCK-8) assay. We obtained a total of 687 hypermethylation-low expression genes (Hyper-LGs) and further obtained 53 DNA methylation-driver genes based on the MethylMix algorithm. A total of six key genes (SCIN, ETNK2, PCDH20, PPP1R3C, MATN2, and HOXA5) were identified by LASSO regression and Random Forest algorithm. Among them, SCIN expression was significantly lower in EBVaGC cell lines than in EBVnGC cell lines, and its expression was significantly recovered in EBVaGC cell lines treated with 5-Aza-CdR. Overexpression of SCIN can promote the proliferation and migration capacity of EBVaGC cells. Our study will provide some bioinformatics basis for the study of EBVaGC-related methylation. SCIN may be used as potential methylation biomarkers for the diagnosis and treatment of EBVaGC.

Tremella fuciformis polysaccharides induce ferroptosis in Epstein-Barr virus-associated gastric cancer by inactivating NRF2/HO-1 signaling.

Approximately 10% of gastric cancers are associated with Epstein-Barr virus (EBV). Tremella fuciformis polysaccharides (TFPs) are characterized by antioxidative and anti-inflammatory effects in different diseases. However, whether TFP improves EBV-associated gastric cancer (EBVaGC) has never been explored. The effects of TFP on EBV-infected GC cell viability were determined using a CCK-8 assay and flow cytometry. Western blotting and RT-qPCR were performed to explore the expression of ferroptosis-related proteins. The CCK-8 assay showed that TFP decreased EBV-infected GC cell viability in a dose- and time-dependent manner. Flow cytometry assays indicated that TFP significantly induced EBV-infected GC cell death. TFP also reduced the migratory capacity of EBV-infected GC cells. Furthermore, treatment with TFP significantly increased the mRNA levels of PTGS2 and Chac1 in EBV-infected GC cells. Western blot assays indicated that TFP suppressed the expression of NRF2, HO-1, GPX4 and xCT in EBV-infected GC cells. More importantly, overexpression of NRF2 could obviously rescue TFP-induced downregulation of GPX4 and xCT in EBV-infected GC cells. In summary, we showed novel data that TFP induced ferroptosis in EBV-infected GC cells by inhibiting NRF2/HO-1 signaling. The current findings may shed light on the potential clinical application of TFP in the treatment of EBVaGC.

Sex-dependent different clinicopathological characterization of Epstein-Barr virus-associated gastric carcinoma: a large-scale study.

Epstein-Barr virus (EBV)-associated gastric cancer (EBVaGC) has been reported to account for approximately 5-16% of all GCs with good prognosis compared to EBV-negative GC. We evaluated the clinicopathological characteristics of EBVaGC including survival rate in South Korea. A total of 4,587 patients with GC who underwent EBV in situ hybridization (EBV-ISH) were prospectively enrolled at the Seoul National University Bundang Hospital from 2003 to 2021. Age, sex, smoking status, cancer type and stage, tumor size and location, histological type, molecular features and survival information were analyzed. A total of 456 patients with GC (9.9%) were positive for EBV. The EBVaGC group displayed a higher proportion of males (P < 0.001), a predominant presence in the proximal stomach (P < 0.001), a higher proportion of undifferentiated cancer (P < 0.001), and a lower cancer stage (P = 0.004) than the EBV-negative group. Cox multivariate analyses revealed age (hazard ratio [HR] = 1.025, P < 0.001), tumor size (HR = 1.109, P < 0.001), and cancer stage (stage2 HR = 4.761, P < 0.001; stage3 HR = 13.286, P < 0.001; stage4 HR = 42.528, P < 0.001) as significant risk factors for GC-specific mortality, whereas EBV positivity was inversely correlated (HR = 0.620, P = 0.022). Furthermore, the EBVaGC group displayed statistically significant survival advantages over the EBV-negative cancer group in terms of both overall (P = 0.021) and GC-specific survival (P = 0.007) on the Kaplan-Meier survival curve. However, this effect was evident only in males. EBVaGC patients showed better prognoses despite their association with proximal location and poorly differentiated histology in male, probably due to the difference in immunity between males and females.