Epstein-Barr virus BART microRNAs in EBV- associated Hodgkin lymphoma and gastric cancer

Bibliometric analysis of research trends and topic areas in traditional Chinese medicine therapy for lymphoma

CONTEXT

Traditional Chinese Medicine (TCM) is effective as a cancer treatment modality. However, this is the first bibliometric analysis of TCM in lymphoma treatment.

OBJECTIVE

This study explores the current trends and research topics of TCM in treating lymphoma from 2000 to 2023.

MATERIALS AND METHODS

We searched within the Web of Science Core Collection (WoSCC) for publications on TCM in lymphoma treatment, spanning 2000 to 2023. Subsequently, we employed a comprehensive approach utilizing CiteSpace software and VOSviewer to visually analyze research trends, authors, institutions, co-cited references, and keywords.

RESULTS

From January 1, 2000, to August 31, 2023, annual scientific publications on TCM for lymphoma treatment have steadily increased. Among the leading institutions in this field, the Beijing University of Chinese Medicine and the Fujian Medical University occupied the top positions. Regarding the authors, Jun Peng, Jiumao Lin, and Hongwei Chen emerged as the top three contributors. In the co-citation analysis of references, the top three co-cited references were authored by Hanahan D, Elmore S, and Livak KJ with citations numbered 13, 14, and 17, respectively. In particular, keywords reflecting current emerging trends included 'pathway', 'traditional Chinese medicine', 'oxidative stress', and 'macrophage polarization'.

DISCUSSION AND CONCLUSIONS

This bibliometric analysis provides a comprehensive overview of TCM for lymphoma treatment. This analysis identified the predominant trends and research topics in the field. The findings are expected to be of significant value for researchers who focus on TCM in lymphoma treatment, helping them better understand the development of this field.

HIV-associated cancers and lymphoproliferative disorders caused by Kaposi sarcoma herpesvirus and Epstein-Barr virus

SUMMARYWithin weeks of the first report of acquired immunodeficiency syndrome (AIDS) in 1981, it was observed that these patients often had Kaposi sarcoma (KS), a hitherto rarely seen skin tumor in the USA. It soon became apparent that AIDS was also associated with an increased incidence of high-grade lymphomas caused by Epstein-Barr virus (EBV). The association of AIDS with KS remained a mystery for more than a decade until Kaposi sarcoma-associated herpesvirus (KSHV) was discovered and found to be the cause of KS. KSHV was subsequently found to cause several other diseases associated with AIDS and human immunodeficiency virus (HIV) infection. People living with HIV/AIDS continue to have an increased incidence of certain cancers, and many of these cancers are caused by EBV and/or KSHV. In this review, we discuss the epidemiology, virology, pathogenesis, clinical manifestations, and treatment of cancers caused by EBV and KSHV in persons living with HIV.

Exploring the anti-EBV potential of suberoylanilide hydroxamic acid: Induction of apoptosis in infected cells through suppressing BART gene expression and inducing lytic infection

Epstein-Barr virus (EBV) is linked to lymphoma and epithelioma but lacks drugs specifically targeting EBV-positive tumors. BamHI A Rightward Transcript (BART) miRNAs are expressed in all EBV-positive tumors, suppressing both lytic infection and host cell apoptosis. We identified suberoylanilide hydroxamic acid (SAHA), an inhibitor of histone deacetylase enzymes, as an agent that suppresses BART promoter activity and transcription of BART miRNAs. SAHA treatment demonstrated a more pronounced inhibition of cell proliferation in EBV-positive cells compared to EBV-negative cells, affecting both p53 wild-type and mutant gastric epithelial cells. SAHA treatment enhanced lytic infection in wild-type EBV-infected cells, while also enhancing cell death in BZLF1-deficient EBV-infected cells. It reduced BART gene expression by 85% and increased the expression of proapoptotic factors targeted by BART miRNAs. These findings suggest that SAHA not only induces lytic infection but also leads to cell death by suppressing BART miRNA transcription and promoting the apoptotic program.

Epstein-Barr virus-encoded BART9 and BART15 miRNAs are elevated in exosomes of cerebrospinal fluid from relapsing-remitting multiple sclerosis patients

Epstein-Barr virus (EBV) infection is approved as the main environmental trigger of multiple sclerosis (MS). In this path, we quantified ebv-miR-BART9-3p and ebv-miR-BART15 in exosomes of cerebrospinal fluid (CSF) of untreated relapsing-remitting MS (RRMS) patients in comparison with the control group. Interestingly, patients displayed significant upregulation of ebv-miR-BART9-3p (18.4-fold) and ebv-miR-BART15 (3.1-fold) expression in CSF exosomes. Moreover, the expression levels of hsa-miR-21-5p and hsa-miR-146a-5p were found to be significantly elevated in the CSF samples obtained from the patient group compared to those obtained from the HC group. The levels of Interferon-gamma (IFN-γ), interleukin-1β (IL-1β), interleukin-6 (IL-6), interleukin-17 (IL-17), interleukin-23 (IL-23), transforming growth factor beta (TGF-β), and tumor necrosis factor-alpha (TNF-α) were observed to be significantly elevated in the serum and CSF exosomes of the patients. The highest increase was observed in TGF-β (8.5-fold), followed by IL-23 (3.9-fold) in CSF exosomes. These findings are in agreement with the association between EBV infection and inflammatory cytokines induction. Furthermore, the ratios of TGF-β: TNF-α and TGF-β: IFN-γ attained values of 4 to 16.4 and 1.3 to 3.6, respectively, in the CSF exosomes of the patients, in comparison to those of the control group. These findings show EBV activity in RRMS patients is different from that of healthy ones. Elevation of ebv-miR-BART9-3p, ebv-miR-BART15, and inflammatory cytokines expression in CSF exosomes in RRMS patients provides a substantial link between EBV activity and the onset of the disease, as well as the transition from EBV infection to MS.

Epstein-Barr Virus miR-BARTs 7 and 9 modulate viral cycle, cell proliferation, and proteomic profiles in Burkitt lymphoma

The Epstein-Barr Virus (EBV) encodes viral microRNAs (miRs) that have been implicated in the pathogenesis of nasopharyngeal and gastric carcinomas, yet their potential roles in lymphomas remain to be fully elucidated. This study evaluated the impact of CRISPR/Cas9-mediated knockdown of EBV miRs BART-7 and BART-9 in EBV-positive Burkitt lymphoma cells Akata. As anticipated, the Akata cells subjected to CRISPR/Cas9-mediated knockdown of either EBV BART-7 or BART-9 exhibited a significant reduction in the expression of these viral miRs compared to cells with wild-type (wt) EBV genomes. This outcome effectively validates the experimental model employed in this study. Knocking down either BART-7 or BART-9 resulted in a notable reduction in cell viability and proliferation rates, alongside an elevation in the expression of EBV lytic genes. Global proteomic analysis revealed that the knockdown of EBV BART-7 significantly decreased the expression of ubiquitin/proteasome proteins while concurrently increasing RNA binding proteins (RBPs). Conversely, BART-9 knockdown reduced proteins associated with oxidoreductase activity, particularly those involved in fatty acid metabolism. Our findings unveil previously undiscovered EBV miRs BARTs 7 and 9 roles in cellular pathways relevant to both viral biology and lymphomagenesis.

The Epstein-Barr virus-miRNA-BART6-5p regulates TGF-β/SMAD4 pathway to induce glycolysis and enhance proliferation and metastasis of gastric cancer cells

Background

EBV-miR-BARTs exhibit significant relevance in epithelial tumors, particularly in EBV-associated gastric and nasopharyngeal cancers. However, their specific mechanisms in the initiation and progression of gastric cancer remain insufficiently explored.

Material and Methods

Initially, EBV-miRNA-BART6-5p and its target gene SMAD4 expression were assessed in EBV-associated gastric cancer tissues and cell lines. Subsequent transfection induced overexpression of EBV-miRNA-BART6-5p in AGS and MKN-45, and downregulation in EBV-positive cells (SUN-719). The subsequent evaluation aimed to observe their impact on gastric cancer cell proliferation, migration, and glycolytic processes, with the TGF-β/SMAD4 signaling pathway value clarified using a TGF-β inhibitor.

Results

EBV-miRNA-BART6-5p exhibits pronounced upregulation in EBV-associated gastric cancer tissues and EBV-positive cells, while its target gene SMAD4 demonstrates downregulated expression. Upregulation of it can promote the proliferation and migration of gastric cancer cells. Additionally, We found EBV-miRNA-BART6-5p promotes glycolysis of gastric cancer cells. Inhibition of the TGF-β/SMAD4 signaling pathway resulted in suppressed proliferation and migration of gastric cancer cells, concomitant with a diminished glycolytic capacity.

Conclusion

In this study, we found that EBV-miRNA-BART6-5p can target SMAD4, effectively increasing glycolysis in gastric cancer cells by regulating the TGF-β/SMAD4 signaling pathway, thereby enhancing the proliferation and metastasis of gastric cancer cells. Our findings may offer new insights into the metabolic aspects of gastric cancer.

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.

Epigenetic Mechanisms in Latent Epstein-Barr Virus Infection and Associated Cancers

The Epstein-Barr Virus (EBV) is a double-stranded DNA-based human tumor virus that was first isolated in 1964 from lymphoma biopsies. Since its initial discovery, EBV has been identified as a major contributor to numerous cancers and chronic autoimmune disorders. The virus is particularly efficient at infecting B-cells but can also infect epithelial cells, utilizing an array of epigenetic strategies to establish long-term latent infection. The association with histone modifications, alteration of DNA methylation patterns in host and viral genomes, and microRNA targeting of host cell factors are core epigenetic strategies that drive interactions between host and virus, which are necessary for viral persistence and progression of EBV-associated diseases. Therefore, understanding epigenetic regulation and its role in post-entry viral dynamics is an elusive area of EBV research. Here, we present current outlooks of EBV epigenetic regulation as it pertains to viral interactions with its host during latent infection and its propensity to induce tumorigenesis. We review the important epigenetic regulators of EBV latency and explore how the strategies involved during latent infection drive differential epigenetic profiles and host-virus interactions in EBV-associated cancers.

Serum and Saliva Level of miR-31-5p and miR-let 7a in EBV Associated Oropharyngeal Cancer

Epstein-Barr virus (EBV) has a well-documented association with head and neck neoplasms, including nasopharyngeal carcinoma (NPC). In the last few years, research aimed at elucidating the role of the miRs in the pathogenesis of head and neck cancer (HNC) has gained importance. The study of miRs expression has set new directions in the search for biomarkers with diagnostic and prognostic value, and even in the search for new therapeutic targets for various tumors, including HNC. The aim of current study was to approximate the importance of miR-31-5p and miR-let 7a in the pathogenesis of EBV associated oropharyngeal cancer. For this purpose, experiments were carried out to determine the level of mentioned miRs in serum among patients diagnosed with oropharyngeal cancer linked to EBV infection, depending on histological differentiation-grading (G1-G3) and TNM classification. All clinical specimens stratified by HPV status were HPV negative. The level of antibodies EBNA and EBVCA was also assessed. The obtained results showed a significantly increased serum level of miR-31-5p but decreased level of miR-let 7a in EBV positive oropharyngeal cancer patients. We demonstrated association between the level of tested miRs and clinical stage. Our findings showed that miR-31-5p and miR-let-7a may be involved in development and progression of EBV associated oropharyngeal cancer. Therefore, it seems important to further study these molecules, as well as to determine whether they could be important biomarkers in the diagnosis of oropharyngeal cancer associated with EBV infection.

Differences in the Tumor Microenvironment of EBV-Associated Gastric Cancers Revealed Using Single-Cell Transcriptome Analysis

Epstein-Barr virus (EBV) is a gamma-herpesvirus associated with nearly 10% of gastric cancers (GCs). These EBV-associated GCs (EBVaGCs) are molecularly, histopathologically, and clinically distinct from EBV-negative GCs (EBVnGCs). While viral genes in EBVaGCs contribute to the carcinogenesis process, viral proteins also represent foreign antigens that could trigger enhanced immune responses compared to EBVnGCs. Despite prior investigations of the EBVaGC tumor microenvironment (TME), the cellular composition has not been thoroughly explored. In this study, cellular subpopulations overrepresented in EBVaGCs were identified and molecularly characterized. Genes consistently expressed across both bulk tumor and single-cell RNA sequencing data were highlighted, with the expression across the identified cellular subpopulations analyzed. As expected, based on existing histopathological analysis, EBVaGC is characterized by abundant lymphocytic infiltration of the stroma. Our molecular analysis identified three unique immune cell subpopulations in EBVaGC: T and B cells expressing high levels of proliferation markers and B cells expressing T cell features. The proliferating T cell cluster also expressed markers of follicular T helper cells. Overall, EBVaGC also exhibited unique features indicative of a higher inflammatory response. These substantial differences within the TME suggest that further detailed exploration of the cellular composition of EBVaGCs is needed, which may identify cellular subpopulations and phenotypes associated with patient outcomes.

The EBV Gastric Cancer Resource (EBV-GCR): A Suite of Tools for Investigating EBV-Associated Human Gastric Carcinogenesis

Epstein-Barr virus (EBV) causes lifelong infection in over 90% of the world’s population. EBV infection leads to several types of B cell and epithelial cancers due to the viral reprogramming of host-cell growth and gene expression. EBV is associated with 10% of stomach/gastric adenocarcinomas (EBVaGCs), which have distinct molecular, pathological, and immunological characteristics compared to EBV-negative gastric adenocarcinomas (EBVnGCs). Publicly available datasets, such as The Cancer Genome Atlas (TCGA), contain comprehensive transcriptomic, genomic, and epigenomic data for thousands of primary human cancer samples, including EBVaGCs. Additionally, single-cell RNA-sequencing data are becoming available for EBVaGCs. These resources provide a unique opportunity to explore the role of EBV in human carcinogenesis, as well as differences between EBVaGCs and their EBVnGC counterparts. We have constructed a suite of web-based tools called the EBV Gastric Cancer Resource (EBV-GCR), which utilizes TCGA and single-cell RNA-seq data and can be used for research related to EBVaGCs. These web-based tools allow investigators to gain in-depth biological and clinical insights by exploring the effects of EBV on cellular gene expression, associations with patient outcomes, immune landscape features, and differential gene methylation, featuring both whole-tissue and single-cell analyses.

Role of Exosomes and Their Potential as Biomarkers in Epstein-Barr Virus-Associated Gastric Cancer

Exosomes are a subtype of extracellular vesicles ranging from 30 to 150 nm and comprising many cellular components, including DNA, RNA, proteins, and metabolites, encapsulated in a lipid bilayer. Exosomes are secreted by many cell types and play important roles in intercellular communication in cancer. Viruses can hijack the exosomal pathway to regulate viral propagation, cellular immunity, and the microenvironment. Cells infected with Epstein-Barr virus (EBV), one of the most common oncogenic viruses, have also been found to actively secrete exosomes, and studies on their roles in EBV-related malignancies are ongoing. In this review, we focus on the role of exosomes in EBV-associated gastric cancer and their clinical applicability in diagnosis and treatment.

Tumor-Infiltrating T Cells in EBV-Associated Gastric Carcinomas Exhibit High Levels of Multiple Markers of Activation, Effector Gene Expression, and Exhaustion

Epstein-Barr virus (EBV) is a gamma-herpesvirus associated with 10% of all gastric cancers (GCs) and 1.5% of all human cancers. EBV-associated GCs (EBVaGCs) are pathologically and clinically distinct entities from EBV-negative GCs (EBVnGCs), with EBVaGCs exhibiting differential molecular pathology, treatment response, and patient prognosis. However, the tumor immune landscape of EBVaGC has not been well explored. In this study, a systemic and comprehensive analysis of gene expression and immune landscape features was performed for both EBVaGC and EBVnGC. EBVaGCs exhibited many aspects of a T cell-inflamed phenotype, with greater T and NK cell infiltration, increased expression of immune checkpoint markers (BTLA, CD96, CTLA4, LAG3, PD1, TIGIT, and TIM3), and multiple T cell effector molecules in comparison with EBVnGCs. EBVaGCs also displayed a higher expression of anti-tumor immunity factors (PDL1, CD155, CEACAM1, galectin-9, and IDO1). Six EBV-encoded miRNAs (miR-BARTs 8-3p, 9-5p, 10-3p, 22, 5-5p, and 14-3p) were strongly negatively correlated with the expression of immune checkpoint receptors and multiple markers of anti-tumor immunity. These profound differences in the tumor immune landscape between EBVaGCs and EBVnGCs may help explain some of the observed differences in pathological and clinical outcomes, with an EBV-positive status possibly being a potential biomarker for the application of immunotherapy in GC.

Extracellular Vesicles and Viruses: Two Intertwined Entities

Viruses share many attributes in common with extracellular vesicles (EVs). The cellular machinery that is used for EV production, packaging of substrates and secretion is also commonly manipulated by viruses for replication, assembly and egress. Viruses can increase EV production or manipulate EVs to spread their own genetic material or proteins, while EVs can play a key role in regulating viral infections by transporting immunomodulatory molecules and viral antigens to initiate antiviral immune responses. Ultimately, the interactions between EVs and viruses are highly interconnected, which has led to interesting discoveries in their associated roles in the progression of different diseases, as well as the new promise of combinational therapeutics. In this review, we summarize the relationships between viruses and EVs and discuss major developments from the past five years in the engineering of virus-EV therapies.

Viral miRNA regulation of host gene expression

Viruses have evolved a multitude of mechanisms to combat barriers to productive infection in the host cell. Virally-encoded miRNAs are one such means to regulate host gene expression in ways that benefit the virus lifecycle. miRNAs are small non-coding RNAs that regulate protein expression but do not trigger the adaptive immune response, making them powerful tools encoded by viruses to regulate cellular processes. Diverse viruses encode for miRNAs but little sequence homology exists between miRNAs of different viral species. Despite this, common cellular pathways are targeted for regulation, including apoptosis, immune evasion, cell growth and differentiation. Herein we will highlight the viruses that encode miRNAs and provide mechanistic insight into how viral miRNAs aid in lytic and latent infection by targeting common cellular processes. We also highlight how viral miRNAs can mimic host cell miRNAs as well as how viral miRNAs have evolved to regulate host miRNA expression. These studies dispel the myth that viral miRNAs are subtle regulators of gene expression, and highlight the critical importance of viral miRNAs to the virus lifecycle.

Small extracellular vesicles as key players in cancer development caused by human oncogenic viruses

Background

Exosomes are the smallest group of extracellular vesicles in size from 30 to 150 nm, surrounded by a lipid bilayer membrane, and originate from multivesicular bodies secreted by different types of cells, such as virus-infected cells. The critical role of exosomes is information transfer among cells, representing a unique way for intercellular communication via a load of many kinds of molecules, including various signaling proteins and nucleic acids. In this review, we aimed to comprehensively investigate the role of exosomes in promoting human oncogenic viruses-associated cancers.

Methods

Our search was conducted for published researches between 2000 and 2022 by using several international databases includeing Scopus, PubMed, and Web of Science as well as Google scholar. We also reviewed additional evidence from relevant published articles.

Results

It has been shown that exosomes can create the conditions for viral spread in viral infections. Exosome secretion in a human tumor virus can switch on the cell signaling pathways by transferring exosome-encapsulated molecules, including viral oncoproteins, signal transduction molecules, and virus-encoded miRNAs, into various cells.

Conclusion

Given the role of exosomes in viruses-associated cancers, they can also be considered as molecular targets in diagnosis and treatment.

Promising drugs and treatment options for pediatric and adolescent patients with Hodgkin lymphoma

Currently-available therapies for newly-diagnosed pediatric and adolescent patients with Hodgkin lymphoma result in >95% survival at 5 years. Long-term survivors may suffer from long-term treatment-related side effects, however, so the past 20 years have seen clinical trials for children and adolescents with HL gradually abandon the regimens used in adults in an effort to improve this situation. Narrower-field radiotherapy can reduce long-term toxicity while maintaining good tumor control. Various risk-adapted chemo-radiotherapy strategies have been used. Early assessment of tumor response with interim positron emission tomography and/or measuring metabolic tumor volume has been used both to limit RT in patients with favorable characteristics and to adopt more aggressive therapies in patients with a poor response. Most classical Hodgkin's lymphoma relapses occur within 3 years of initial treatment, while relapses occurring 5 years or more after diagnosis are rare. As the outcome for patients with relapsed/refractory classical Hodgkin lymphoma remains unsatisfactory, new drugs have been proposed for its prevention or treatment. This review summarizes the important advances made in recent years in the management of pediatric and adolescent with classical Hodgkin lymphoma, and the novel targeted treatments for relapsed and refractory classical Hodgkin lymphoma.

Novel Approaches in Molecular Characterization of Classical Hodgkin Lymphoma

Simple Summary

The unique tumor composition of classical Hodgkin lymphoma (cHL), with only a small fraction of malignant Hodgkin and Reed–Sternberg cells within the tumor tissue, has created many challenges to characterize the genetic alterations that drive this lymphoid malignancy. Major advances in sequencing technologies and detailed analysis of circulating tumor DNA in blood samples of patients have provided important contributions to enhance our understanding of the pathogenesis of cHL. In this review, we provide an overview of the recent advances in genotyping the clonal and mutational landscape of cHL. In addition, we discuss different next-generation sequencing applications to characterize tumor tissue and cell-free DNA, which are now available to improve the diagnosis of cHL, and to monitor therapeutic response or disease progression during treatment and follow up of cHL patients.

Abstract

Classical Hodgkin lymphoma (cHL) represents a B-cell lymphoproliferative disease characterized by clonal immunoglobulin gene rearrangements and recurrent genomic aberrations in the Hodgkin Reed–Sternberg cells in a reactive inflammatory background. Several methods are available for the molecular analysis of cHL on both tissue and cell-free DNA isolated from blood, which can provide detailed information regarding the clonal composition and genetic alterations that drive lymphoma pathogenesis. Clonality testing involving the detection of immunoglobulin and T cell receptor gene rearrangements, together with mutation analysis, represent valuable tools for cHL diagnostics, especially for patients with an atypical histological or clinical presentation reminiscent of a reactive lesion or another lymphoma subtype. In addition, clonality assessment may establish the clonal relationship of composite or subsequent lymphoma presentations within one patient. During the last few decades, more insight has been obtained on the molecular mechanisms that drive cHL development, including recurrently affected signaling pathways (e.g., NF-κB and JAK/STAT) and immune evasion. We provide an overview of the different approaches to characterize the molecular composition of cHL, and the implementation of these next-generation sequencing-based techniques in research and diagnostic settings.

Virus-Mediated Inhibition of Apoptosis in the Context of EBV-Associated Diseases: Molecular Mechanisms and Therapeutic Perspectives

Epstein-Barr virus (EBV), the representative of the Herpesviridae family, is a pathogen extensively distributed in the human population. One of its most characteristic features is the capability to establish latent infection in the host. The infected cells serve as a sanctuary for the dormant virus, and therefore their desensitization to apoptotic stimuli is part of the viral strategy for long-term survival. For this reason, EBV encodes a set of anti-apoptotic products. They may increase the viability of infected cells and enhance their resistance to chemotherapy, thereby contributing to the development of EBV-associated diseases, including Burkitt’s lymphoma (BL), Hodgkin’s lymphoma (HL), gastric cancer (GC), nasopharyngeal carcinoma (NPC) and several other malignancies. In this paper, we have described the molecular mechanism of anti-apoptotic actions of a set of EBV proteins. Moreover, we have reviewed the pro-survival role of non-coding viral transcripts: EBV-encoded small RNAs (EBERs) and microRNAs (miRNAs), in EBV-carrying malignant cells. The influence of EBV on the expression, activity and/or intracellular distribution of B-cell lymphoma 2 (Bcl-2) protein family members, has been presented. Finally, we have also discussed therapeutic perspectives of targeting viral anti-apoptotic products or their molecular partners.

Prognostic Epstein-Barr Virus (EBV) miRNA biomarkers for survival outcome in EBV-associated epithelial malignancies: Systematic review and meta-analysis

Background

The EBV-associated epithelial tumours consist 80% of all EBV-associated cancer, where the nasopharyngeal cancer (NPC) and EBV-associated gastric carcinoma (EBVaGC) are considered as the most frequent EBV-associated epithelial tumours. It has been shown that the BART-encoded miRNAs are abundantly expressed in EBV-associated epithelial tumours, hence, these miRNAs may serve as diagnostic and prognostic biomarkers for EBV-associated epithelial tumours. Therefore, the purpose of this systematic review and meta-analysis is to assess these EBV miRNAs as prognostic biomarkers for NPC and GC.

Method

This systematic review was developed based on PRISMA guidelines and utilizing PubMed, Web of Science, Scopus, Cochrane, and Google scholar databases. The retrieved articles were thoroughly screened in accordance with the selection criteria. The hazard ratio (HR) and 95% confidence interval (CI) for patient survival outcomes were used to evaluate EBV miRNA expression levels. To assess the risk of bias, funnel plot symmetry and Egger’s bias test were employed.

Result

Eleven studies met the selection criteria for inclusion, and four were included in the meta-analysis. Most of the articles considered in this study were from China, with one study from South Korea. The overall pooled effect size estimation (HR) for upregulated EBV miRNAs was 3.168 (95% CI: 2.020–4.969), demonstrating that upregulated EBV miRNA expression enhanced the mortality risk in NPC and GC patients by three times.

Conclusion

To the best of our knowledge, this is the first meta-analysis that investigates the significance of EBV miRNAs as prognostic biomarkers in NPC and GC patients. The pooled effect estimates of HR of the various studies revealed that higher EBV miRNA expression in NPC and GC may result in a worse survival outcome. To assess the clinical significance of EBV miRNAs as prognostic biomarkers, larger-scale prospective studies are needed.

Correlation of SARS‑CoV‑2 to cancer: Carcinogenic or anticancer? (Review)

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is highly infectious and pathogenic. Among patients with severe SARS-CoV-2-caused by corona virus disease 2019 (COVID-19), those complicated with malignant tumor are vulnerable to COVID-19 due to compromised immune function caused by tumor depletion, malnutrition and anti-tumor treatment. Cancer is closely related to the risk of severe illness and mortality in patients with COVID-19. SARS-CoV-2 could promote tumor progression and stimulate metabolism switching in tumor cells to initiate tumor metabolic modes with higher productivity efficiency, such as glycolysis, for facilitating the massive replication of SARS-CoV-2. However, it has been shown that infection with SARS-CoV-2 leads to a delay in tumor progression of patients with natural killer cell (NK cell) lymphoma and Hodgkin's lymphoma, while SARS-CoV-2 elicited anti-tumor immune response may exert a potential oncolytic role in lymphoma patients. The present review briefly summarized potential carcinogenicity and oncolytic characteristics of SARS-CoV-2 as well as strategies to protect patients with cancer during the COVID-19 pandemic.

Adoptive T-cell Immunotherapy: Perfecting Self-Defenses

As an important part of the immune system, T lymphocytes exhibit undoubtedly an important role in targeting and eradicating cancer. However, despite these characteristics, their natural antitumor response may be insufficient. Numerous clinical trials in terminally ill cancer patients testing the design of novel and efficient immunotherapeutic approaches based on the adoptive transfer of autologous tumor-specific T lymphocytes have shown encouraging results. Moreover, this also led to the approval of engineered T-cell therapies in patients. Herein, we will expand on the development and the use of such strategies using tumor-infiltrating lymphocytes or genetically engineered T-cells. We will also comment on the requirements and potential hurdles encountered when elaborating and implementing such treatments as well as the exciting prospects for this kind of emerging personalized medicine therapy.

MicroRNAs Encoded by Virus and Small RNAs Encoded by Bacteria Associated with Oncogenic Processes

Cancer is a deadly disease and, globally, represents the second leading cause of death in the world. Although it is a disease where several factors can help its development, virus induced infections have been associated with different types of neoplasms. However, in bacterial infections, their participation is not known for certain. Among the proposed approaches to oncogenesis risks in different infections are microRNAs (miRNAs). These are small molecules composed of RNA with a length of 22 nucleotides capable of regulating gene expression by directing protein complexes that suppress the untranslated region of mRNA. These miRNAs and other recently described, such as small RNAs (sRNAs), are deregulated in the development of cancer, becoming promising biomarkers. Thus, resulting in a study possibility, searching for new tools with diagnostic and therapeutic approaches to multiple oncological diseases, as miRNAs and sRNAs are main players of gene expression and host–infectious agent interaction. Moreover, sRNAs with limited complementarity are similar to eukaryotic miRNAs in their ability to modulate the activity and stability of multiple mRNAs. Here, we will describe the regulatory RNAs from viruses that have been associated with cancer and how sRNAs in bacteria can be related to this disease.

Fibrogenic signals persist in DAA-treated HCV patients after sustained virological response

BACKGROUND & AIMS

Patients with HCV who achieve a sustained virological response (SVR) on direct-acting antiviral (DAA) therapy still need to be monitored for signs of liver disease progression. To this end, the identification of both disease biomarkers and therapeutic targets is necessary.

METHODS

Extracellular vesicles (EVs) purified from plasma of 15 healthy donors (HDs), and 16 HCV-infected patients before (T0) and after (T6) DAA treatment were utilized for functional and miRNA cargo analysis. EVs purified from plasma of 17 HDs and 23 HCV-infected patients (T0 and T6) were employed for proteomic and western blot analyses. Functional analysis in LX2 cells measured fibrotic markers (mRNAs and proteins) in response to EVs. Structural analysis was performed by qPCR, label-free liquid chromatography-mass spectrometry and western blot.

RESULTS

On the basis of observations indicating functional differences (i.e. modulation of FN-1, ACTA2, Smad2/3 phosphorylation, collagen deposition) of plasma-derived EVs from HDs, T0 and T6, we performed structural analysis of EVs. We found consistent differences in terms of both miRNA and protein cargos: (i) antifibrogenic miR204-5p, miR181a-5p, miR143-3p, miR93-5p and miR122-5p were statistically underrepresented in T0 EVs compared to HD EVs, while miR204-5p and miR143-3p were statistically underrepresented in T6 EVs compared to HD EVs (p <0.05); (ii) proteomic analysis highlighted, in both T0 and T6, the modulation of several proteins with respect to HDs; among them, the fibrogenic protein DIAPH1 was upregulated (Log₂ fold change of 4.4).

CONCLUSIONS

Taken together, these results highlight structural EV modifications that are conceivably causal for long-term liver disease progression in patients with HCV despite DAA-mediated SVR.

LAY SUMMARY

Direct-acting antivirals lead to virological cure in the majority of patients with chronic hepatitis C virus infection. However, the risk of liver disease progression or complications in patients with fibrosis and cirrhosis remains in some patients even after virological cure. Herein, we show that extracellular vesicle modifications could be linked to long-term liver disease progression in patients who have achieved virological cure; these modifications could potentially be used as biomarkers or treatment targets in such patients.

New insights into Epstein‑Barr virus‑associated tumors: Exosomes (Review)

Epstein-Barr virus (EBV) is endemic worldwide and is associated with a number of human tumors. EBV-associated tumors have unique mechanisms of tumorigenesis. EBV encodes multiple oncogenic molecules that can be loaded into exosomes released by EBV⁺ tumor cells to mediate intercellular communication. Moreover, different EBV⁺ tumor cells secrete exosomes that act on various target cells with various biological functions. In addition to oncogenicity, EBV⁺ exosomes have potential immunosuppressive effects. Investigating EBV⁺ exosomes could identify the role of EBV in tumorigenesis and progression. The present review summarized advances in studies focusing on exosomes and the functions of EBV⁺ exosomes derived from different EBV-associated tumors. EBV⁺ exosomes are expected to become a new biomarker for disease diagnosis and prognosis. Therefore, exosome-targeted therapy displays potential.

Stress-Induced Epstein-Barr Virus Reactivation

Epstein-Barr virus (EBV) is typically found in a latent, asymptomatic state in immunocompetent individuals. Perturbations of the host immune system can stimulate viral reactivation. Furthermore, there are a myriad of EBV-associated illnesses including various cancers, post-transplant lymphoproliferative disease, and autoimmune conditions. A thorough understanding of this virus, and the interplay between stress and the immune system, is essential to establish effective treatment. This review will provide a summary of the interaction between both psychological and cellular stressors resulting in EBV reactivation. It will examine mechanisms by which EBV establishes and maintains latency and will conclude with a brief overview of treatments targeting EBV.

Recent advances in immune therapies for gastric cancer

Gastric cancer (GC) is an aggressive malignancy that is the third leading cause of cancer mortality worldwide. Localized GC can be cured with surgery, but most patients present with more advanced non-operable disease. Until recently, treatment options for relapsed and refractory advanced GC have been limited to combination chemotherapy regimens, HER-2 directed therapy, and radiation, which lead to few durable responses. Over the past decade, there have been significant advances in our understanding of the molecular and immune pathogenesis of GC. The infectious agents Epstein-Barr virus and Helicobacter pylori perturb the gastric mucosa immune equilibrium, which creates a microenvironment that favors GC tumorigenesis and evasion of immune surveillance. Insights into immune mechanisms of GC have translated into novel therapeutics, including immune checkpoint inhibitors, which have become a treatment option for select patients with GC. Furthermore, chimeric antigen receptor T-cell therapies have emerged as a breakthrough treatment for many cancers, with recent studies showing this to be a potential therapy for GC. In this review, we summarize the current state of knowledge on immune mechanisms of GC and the status of emerging immunotherapies to treat this aggressive cancer, as well as outline current challenges and directions for future research.

Overview of Epstein-Barr-Virus-Associated Gastric Cancer Correlated with Prognostic Classification and Development of Therapeutic Options

Gastric cancer (GC) is a deadly disease with poor prognosis that is characterized by heterogeneity. New classifications based on histologic features, genotypes, and molecular phenotypes, for example, the Cancer Genome Atlas subtypes and those by the Asian Cancer Research Group, help understand the carcinogenic differences in GC and have led to the identification of an Epstein-Barr virus (EBV)-related GC subtype (EBVaGC), providing new indications for tailored treatment and prognostic factors. This article provides a review of the features of EBVaGC and an update on the latest insights from EBV-related research with a particular focus on the strict interaction between EBV infection and the gastric tumor environment, including the host immune response. This information may help increase our knowledge of EBVaGC pathogenesis and the mechanisms that sustain the immune response of patients since this mechanism has been demonstrated to offer a survival advantage in a proportion of patients with GC.