Expression and prognostic significance of the PD-1/PD-L1 pathway in AIDS-related non-Hodgkin lymphoma.

OBJECTIVE: Immune tolerance and evasion play a critical role in virus-driven malignancies. However, the phenotype and clinical significance of programmed cell death 1 (PD-1) and its ligands, PD-L1 and PD-L2, in aggressive acquired immunodeficiency syndrome (AIDS)-related non-Hodgkin lymphoma (AR-NHL) remain poorly understood, particularly in the Epstein-Barr virus (EBV)-positive subset. METHODS: We used in situ hybridization with EBV-encoded RNA (EBER) to assess the EBV status. We performed immunohistochemistry and flow cytometry analysis to evaluate components of the PD-1/PD-L1/L2 pathway in a multi-institutional cohort of 58 patients with AR-NHL and compared EBV-positive and EBV-negative cases. RESULTS: The prevalence of EBV+ in AR-NHL was 56.9% and was associated with a marked increase in the expression of PD-1/PD-L1/PD-L2 in malignant cells. Patients with AR-NHLs who tested positive for both EBER and PD-1 exhibited lower survival rates compared to those negative for these markers (47.4% vs. 93.8%, p = 0.004). Similarly, patients positive for both EBER and PD-L1 also demonstrated poorer survival (56.5% vs. 93.8%, p = 0.043). Importantly, PD-1 tissue-expression demonstrated independent prognostic significance for overall survival in multivariate analysis and was correlated to elevated levels of LDH (r = 0.313, p = 0.031), increased PD-1+ Tregs (p = 0.006), and robust expression of EBER (r = 0.541, p < 0.001) and PD-L1 (r = 0.354, p = 0.014) expression. CONCLUSIONS: These data emphasize the importance of PD-1-mediated immune evasion in the complex landscape of immune oncology in AR-NHL co-infected with EBV, and contribute to the diagnostic classification and possible definition of immunotherapeutic strategies for this unique subgroup.

[Clinical study of the efficacies of ruxolitinib plus low-dose PTCY for acute GVHD prevention after haploidentical transplantation in malignant hematological diseases].

Objective: To investigate and verify a novel acute graft versus host disease (aGVHD) prevention protocol in the context of haploidentical hematopoietic stem cell transplantation (haplo-HSCT) . Methods: Patients who underwent haplo-HSCT in our center between January 2022 and December 2022 were included. All patients received reduced doses of cyclophosphamide, Rabbit anti-human tymoglobulin, ruxolitinib, methotrexate, cyclosporine, and MMF to prevent aGVHD. The transplantation outcomes, complications, and survival rate of all patients were investigated. Results: A total of 52 patients with haplo-HSCT were enrolled, 29 (55.8%) male and 23 (44.2%) female, with a median age of 28 (5-59) years. There were 25 cases of acute myeloid leukemia, 17 cases of acute lymphocyte leukemia, 6 cases of myelodysplastic syndrome, 2 cases of chronic myeloid leukemia and 2 cases of myeloproliferative neoplasms. 98.1% of patients had successful engraftment. The incidence of Ⅱ-Ⅳ aGVHD and Ⅲ-Ⅳ aGVHD was 19.2% (95% CI 8.2% -30.3% ) and 7.7% (95% CI 0.2% -15.2% ), respectively. No patients experienced severe gastrointestinal mucositis. The Epstein-Barr virus and CMV reactivation rates were 40.4% and 21.3%, respectively. 9.6% of patients relapsed during followup, with 1-year overall survival, progression-free survival, and non-relapse mortality rates of 86.5% (95% CI 76.9% -96.1% ), 78.8% (95% CI 67.4% -90.3% ) and 11.5% (95% CI 2.6% -20.5% ), respectively. Conclusion: Ruxolitinib combined with a low dose of PTCY is a safe and effective first-line aGVHD prevention strategy.

Epstein-Barr Virus in the Cerebrospinal Fluid and Blood Compartments of Patients With Multiple Sclerosis and Controls.

BACKGROUND AND OBJECTIVES: Epstein-Barr virus (EBV) infection is a major risk factor of multiple sclerosis (MS). We examined the presence of EBV DNA in the CSF and blood of patients with MS and controls. We analyzed whether EBV DNA is more common in the CSF of patients with MS than in controls and estimated the proportions of EBV-positive B cells in the CSF and blood. METHODS: CSF supernatants and cells were collected at diagnostic lumbar punctures from 45 patients with MS and 45 HLA-DR15 matched controls with other conditions, all participants were EBV seropositive. Cellular DNA was amplified by Phi polymerase targeting both host and viral DNA, and representative samples were obtained in 28 cases and 28 controls. Nonamplified DNA from CSF cells (14 cases, 14 controls) and blood B cells (10 cases, 10 controls) were analyzed in a subset of participants. Multiple droplet digital PCR (ddPCR) runs were performed per sample to assess the cumulative EBV positivity rate. To detect viral RNA as a sign of activation, RNA sequencing was performed in blood CD4-positive, CD8-positive, and CD19-positive cells from 21 patients with MS and 3 controls. RESULTS: One of the 45 patients with MS and none of the 45 controls were positive for EBV DNA in CSF supernatants (1 mL). CSF cellular DNA was analyzed in 8 independent ddPCRs: EBV DNA was detected at least once in 18 (64%) of the 28 patients with MS and in 15 (54%) of the 28 controls (p = 0.59, Fisher test). The cumulative EBV positivity increased steadily up to 59% in the successive ddPCRs, suggesting that all individuals would have reached EBV positivity in the CSF cells, if more DNA would have been analyzed. The estimated proportion of EBV-positive B cells was >1/10,000 in both the CSF and blood. We did not detect viral RNA, except from endogenous retroviruses, in the blood lymphocyte subpopulations. DISCUSSION: EBV-DNA is equally detectable in the CSF cells of both patients with MS and controls with ddPCR, and the probabilistic approach indicates that the true positivity rate approaches 100% in EBV-positive individuals. The proportion of EBV-positive B cells seems higher than previously estimated.

Effect of pre-emptive rituximab on EBV DNA levels and prevention of post-transplant lymphoproliferative disorder in pediatric kidney transplant recipients: A case series from the pediatric nephrology research consortium.

BACKGROUND: There are scant data on the effect of rituximab on EBV DNA levels and prevention of post-transplant lymphoproliferative disorder (PTLD) in pediatric kidney transplant recipients with EBV DNAemia. METHODS: Kidney transplant recipients with EBV DNAemia treated with rituximab to prevent PTLD between 7/1999 and 7/2019 at five pediatric centers were included. Those with confirmed PTLD at the onset of rituximab were excluded. Primary outcomes included percentage change in EBV DNAemia and occurrence of PTLD post rituximab. RESULTS: Twenty-six pediatric kidney transplant recipients were included. Median age at transplant was 4 years (IQR 2.1-10.3). EBV DNA load monitoring by qPCR was performed at 1-3 month intervals. EBV DNAemia onset occurred at a median of 73 days post-transplant (IQR 52-307), followed by DNAemia peak at a median of 268 days (IQR 112-536). Rituximab was administered at a median of 9 days post peak (IQR 0-118). Rituximab regimens varied; median dose 375 mg/m2 (IQR 375-439) weekly for 1-4 doses per course. Following rituximab, EBV DNA load decreased to <10% of baseline at 120 days in 20/26 patients; however, only 30% achieved complete resolution at last follow-up (median 2094 days post-transplant [IQR 1538-3463]). Two (7%) developed PTLD at 915 and 1713 days post rituximab. All recipients had functioning grafts. One death occurred in a child with PTLD following remission due to unrelated reasons. CONCLUSIONS: In the largest pediatric kidney transplant recipient case series with EBV DNAemia given rituximab to prevent PTLD, rituximab achieved a short-term reduction in DNA load; however, recurrent DNAemia is common.

Evaluation of serum Epstein-Barr virus envelope glycoproteins antibodies and their association with systemic autoimmune diseases.

Systemic autoimmune diseases (SADs) are a growing spectrum of autoimmune disorders that commonly affect multiple organs. The role of Epstein-Barr virus (EBV) infection or reactivation as a trigger for the initiation and progression of SADs has been established, while the relationship between EBV envelope glycoproteins and SADs remains unclear. Here, we assessed the levels of IgG, IgA, and IgM against EBV glycoproteins (including gp350, gp42, gHgL, and gB) in serum samples obtained from patients with rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE), and found that RA and SLE patients exhibited a statistically significant increase in the levels of 8 and 11 glycoprotein antibodies, respectively, compared to healthy controls (p < 0.05). The LASSO model identified four factors as significant diagnostic markers for RA: gp350 IgG, gp350 IgA, gHgL IgM, and gp42 IgA; whereas for SLE it included gp350 IgG, gp350 IgA, gHgL IgA, and gp42 IgM. Combining these selected biomarkers yielded an area under the curve (AUC) of 0.749 for RA and 0.843 for SLE. We subsequently quantified the levels of autoantibodies associated with SADs in mouse sera following immunization with gp350. Remarkably, none of the tested autoantibody levels exhibited statistically significant alterations. Elevation of glycoprotein antibody concentration suggests that Epstein-Barr virus reactivation and replication occurred in SADs patients, potentially serving as a promising biomarker for diagnosing SADs. Moreover, the absence of cross-reactivity between gp350 antibodies and SADs-associated autoantigens indicates the safety profile of a vaccine based on gp350 antigen.

Role of plasma EBV-DNA load and EBER status on newly diagnosed peripheral T-cell lymphoma.

PURPOSE: To explore the prognostic and therapeutic role of Epstein-Barr Virus (EBV) on peripheral T-cell lymphoma (PTCL). METHODS: Totally 262 newly diagnosed PTCL patients who were hospitalized from January 2014 to December 2022 were retrospectively enrolled. Molecular analysis included 31 eligible patients. EBV-encoded RNA (EBER) presence in tumor tissue and EBV DNA levels in patients at baseline (DNA1) and after 4 cycles of chemotherapy (DNA4) were assessed. RESULTS: Our findings revealed that the EBER-positive cohort exhibited significant differences compared to counterparts in overall survival (OS, P = 0.047) and progression-free survival (PFS, P = 0.009). Both DNA1 and DNA4 were significantly associated with inferior OS. Multivariate analysis demonstrated that DNA4 independently affected PTCL prognosis for OS (hazard ratio = 5.1617; 95% confidence interval 1.1017-24.1831; P = 0.037). Treatment with the cyclophosphamide, doxorubicin, vincristine, and prednisone (CHOP) plus azacytidine regimen showed a better OS compared to CHOP or CHOP plus etoposide for patients with partially positive EBER and EBER positive statuses (P = 0.192), although the improvement was not statistically significant. This study delineated the genetic paradigm of PTCL, comparing genetic differences by EBV status and found that EBER partially positive plus positive patients were more likely to have DNMT3A (P = 0.002), RHOAG17V (P = 0.023), and TET2 mutations (P = 0.032). CONCLUSION: EBER, DNA1, and DNA4 emerged as sensitive markers for prognosis. CHOP plus azacytidine might present a preferable option for PTCL patients with DNA methylation due to EBV infection.

BCR signaling is required for posttransplant lymphoproliferative disease in immunodeficient mice receiving human B cells.

Posttransplant lymphoproliferative disease (PTLD) is a major therapeutic challenge that has been difficult to study using human cells because of a lack of suitable models for mechanistic characterization. Here, we show that ex vivo-differentiated B cells isolated from a subset of healthy donors can elicit pathologies similar to PTLD when transferred into immunodeficient mice. The primary driver of PTLD-like pathologies were IgM-producing plasmablasts with Epstein-Barr virus (EBV) genomes that expressed genes commonly associated with EBV latency. We show that a small subset of EBV+ peripheral blood-derived B cells expressing self-reactive, nonmutated B cell receptors (BCRs) expand rapidly in culture in the absence of BCR stimulation. Furthermore, we found that in vitro and in vivo expansion of EBV+ plasmablasts required BCR signaling. Last, treatment of immunodeficient mice with the BCR pathway inhibitor, ibrutinib, delays onset of PTLD-like pathologies in vivo. These data have implications for the diagnosis and care of transplant recipients who are at risk of developing PTLD.

Aflatoxin B1 and Epstein-Barr virus-induced CCL22 expression stimulates B cell infection.

Epstein-Barr Virus (EBV) infects more than 90% of the adult population worldwide. EBV infection is associated with Burkitt lymphoma (BL) though alone is not sufficient to induce carcinogenesis implying the involvement of co-factors. BL is endemic in African regions faced with mycotoxins exposure. Exposure to mycotoxins and oncogenic viruses has been shown to increase cancer risks partly through the deregulation of the immune response. A recent transcriptome profiling of B cells exposed to aflatoxin B1 (AFB1) revealed an upregulation of the Chemokine ligand 22 (CCL22) expression although the underlying mechanisms were not investigated. Here, we tested whether mycotoxins and EBV exposure may together contribute to endemic BL (eBL) carcinogenesis via immunomodulatory mechanisms involving CCL22. Our results revealed that B cells exposure to AFB1 and EBV synergistically stimulated CCL22 secretion via the activation of Nuclear Factor-kappa B pathway. By expressing EBV latent genes in B cells, we revealed that elevated levels of CCL22 result not only from the expression of the latent membrane protein LMP1 as previously reported but also from the expression of other viral latent genes. Importantly, CCL22 overexpression resulting from AFB1-exposure in vitro increased EBV infection through the activation of phosphoinositide-3-kinase pathway. Moreover, inhibiting CCL22 in vitro and in humanized mice in vivo limited EBV infection and decreased viral genes expression, supporting the notion that CCL22 overexpression plays an important role in B cell infection. These findings unravel new mechanisms that may underpin eBL development and identify novel pathways that can be targeted in drug development.

Single-Cell Transcriptomic Analysis of Epstein-Barr Virus-Associated Hemophagocytic Lymphohistiocytosis.

Epstein-Barr virus (EBV) infection can lead to infectious mononucleosis (EBV-IM) and, more rarely, EBV-associated hemophagocytic lymphohistiocytosis (EBV-HLH), which is characterized by a life-threatening hyperinflammatory cytokine storm with immune dysregulation. Interferon-gamma (IFNγ) has been identified as a critical mediator for primary HLH; however, the detailed role of IFNγ and other cytokines in EBV-HLH is not fully understood. In this study, we used single-cell RNA sequencing to characterize the immune landscape of EBV-HLH and compared it with EBV-IM. Three pediatric patients with EBV-HLH with different backgrounds, one with X-linked lymphoproliferative syndrome type 1 (XLP1), two with chronic active EBV disease (CAEBV), and two patients with EBV-IM were enrolled. The TUBA1B + STMN1 + CD8 + T cell cluster, a responsive proliferating cluster with rich mRNA detection, was explicitly observed in EBV-IM, and the upregulation of SH2D1A-the gene responsible for XLP1-was localized in this cluster. This proliferative cluster was scarcely observed in EBV-HLH cases. In EBV-HLH cases with CAEBV, upregulation of LAG3 was observed in EBV-infected cells, which may be associated with an impaired response by CD8 + T cells. Additionally, genes involved in type I interferon (IFN) signaling were commonly upregulated in each cell fraction of EBV-HLH, and activation of type II IFN signaling was observed in CD4 + T cells, natural killer cells, and monocytes but not in CD8 + T cells in EBV-HLH. In conclusion, impaired responsive proliferation of CD8 + T cells and upregulation of type I IFN signaling were commonly observed in EBV-HLH cases, regardless of the patients' background, indicating the key features of EBV-HLH.

Characterization of the brain virome in human immunodeficiency virus infection and substance use disorder.

Viruses can infect the brain in individuals with and without HIV-infection: however, the brain virome is poorly characterized. Metabolic alterations have been identified which predispose people to substance use disorder (SUD), but whether these could be triggered by viral infection of the brain is unknown. We used a target-enrichment, deep sequencing platform and bioinformatic pipeline named "ViroFind", for the unbiased characterization of DNA and RNA viruses in brain samples obtained from the National Neuro-AIDS Tissue Consortium. We analyzed fresh frozen post-mortem prefrontal cortex from 72 individuals without known viral infection of the brain, including 16 HIV+/SUD+, 20 HIV+/SUD-, 16 HIV-/SUD+, and 20 HIV-/SUD-. The average age was 52.3 y and 62.5% were males. We identified sequences from 26 viruses belonging to 11 viral taxa. These included viruses with and without known pathogenic potential or tropism to the nervous system, with sequence coverage ranging from 0.03 to 99.73% of the viral genomes. In SUD+ people, HIV-infection was associated with a higher total number of viruses, and HIV+/SUD+ compared to HIV-/SUD+ individuals had an increased frequency of Adenovirus (68.8 vs 0%; p<0.001) and Epstein-Barr virus (EBV) (43.8 vs 6.3%; p=0.037) as well as an increase in Torque Teno virus (TTV) burden. Conversely, in HIV+ people, SUD was associated with an increase in frequency of Hepatitis C virus, (25 in HIV+/SUD+ vs 0% in HIV+/SUD-; p=0.031). Finally, HIV+/SUD- compared to HIV-/SUD- individuals had an increased frequency of EBV (50 vs 0%; p<0.001) and an increase in TTV viral burden, but a decreased Adenovirus viral burden. These data demonstrate an unexpectedly high variety in the human brain virome, identifying targets for future research into the impact of these taxa on the central nervous system. ViroFind could become a valuable tool for monitoring viral dynamics in various compartments, monitoring outbreaks, and informing vaccine development.

EBER-negative inflammatory pseudotumor-like follicular dendritic cell sarcoma of liver: A case report.

RATIONALE: Inflammatory pseudotumor-like follicular dendritic cell sarcoma (IPT-like FDCS) of the liver is rare. It was previously believed that Epstein-Barr virus (EBV) positivity was a necessary criterion for pathological diagnosis. However, we found that there were also cases of EBV negativity. Therefore, clinicians and pathologists are reminded that EBV positivity is not a necessary condition for diagnosis. PATIENT CONCERNS: A 70-year-old female underwent computed tomography (CT) examination for upper abdominal discomfort, which revealed the presence of a liver tumor. Follow-up revealed that the tumor had progressively increased in size. DIAGNOSIS: The final diagnosis was an IPT-like follicular cell sarcoma, based on CT, MRI, HE staining, and immunohistochemical staining. INTERVENTIONS: The patient underwent a laparoscopic left hemihepatectomy. OUTCOMES: The patient has not undergone any special treatment, such as radiotherapy and chemotherapy, and has been followed up for over 3 years without experiencing any recurrence. LESSONS: IPT-like FDCS is a rare tumor that lacks definitive criteria, and its diagnosis mainly relies on pathological findings. Previously, it was believed that being EBV-positive was an important condition for diagnosis. Primary IPT-like FDCS in the liver is even rarer, and the patient in this case tested negative for EBV. It may be necessary for pathologists to consider the role of EBV in the diagnosis of IPT-like FDCS.

Risk Factors Associated with PTLD Related Mortality in Adult Multivisceral Transplant Recipients - A Single Centre Cohort Study.

Background: PTLD is a heterogeneous group of lymphoproliferative diseases which can add significant mortality following multivisceral transplantation (MVTx). Our study aimed to identify potential risk factors of mortality in adult MVTx recipients who developed PTLD. Methods: All adult recipients of intestinal-containing grafts transplanted in our institution between 2013 and 2022, and who developed PTLD, were included in the study. Results: PTLD-associated mortality was 28.6% (6/21). Increased relative risk of mortality was associated with Stage 3 ECOG performance score (p=0.005; HR 34.77; 95%CI 2.94-410.91), if the recipients had a splenectomy (p=0.036; HR 14.36; 95%CI 1.19-172.89), or required retransplantation (p=0.039; HR 11.23; 95% CI 1.13-112.12). There was a significant trend for increased risk of PTLD mortality with higher peak EBV load (p=0.008), longer time from MVTx to PTLD diagnosis (p=0.008), and higher donor age (p 0.001). Peak LDH before treatment commencement was significantly higher in the mortality group vs the survival group (520.3 +- 422.8 IU/L vs 321.8 +- 154.4 IU/L; HR 1.00, 95%CI 1.00 to 1.01, p=0.019). Peak viral load prior to treatment initiation (Cycle Threshold (CT) cutoff = 32) correlated with the relative risk of death in MVTx patients who developed PTLD [29.4 (3.5) CTs in survivors compared to 23.0 (4.0) CTs in the mortality group]. Conclusions: This is the first study to identify risk factors for PTLD-associated mortality in an adult MVTx recipient cohort. Validation in larger multicentre studies and subsequent risk stratification according to these risk factors may contribute to better survival in this group of patients.

Risk of multiple sclerosis in individuals with infectious mononucleosis: a national population-based cohort study using hospital records in England, 2003-2023.

BACKGROUND: Epstein-Barr virus (EBV) is thought to be a necessary causative agent in the development of multiple sclerosis (MS). Infectious mononucleosis (IM), which occurs up to 70% of adolescents and young adults with primary EBV infection, appears to be a further risk factor but few studies have been highly powered enough to explore this association by time since IM diagnosis. OBJECTIVE: The objective was to quantify the risk of MS in individuals with IM compared with the general population, with particular focus on time since IM diagnosis. METHODS: In this retrospective cohort study using English national Hospital Episode Statistics from 2003 to 2023, patients with a hospital diagnosis of IM were compared with the general population for MS incidence. RESULTS: MS incidence in patients with IM was nearly three times higher than the general population after multivariable adjustment (adjusted hazard ratio = 2.8, 95% confidence interval (CI = 2.3-3.4), driven by strong associations at long time intervals (>5 years) between IM diagnosis and subsequent MS diagnosis. CONCLUSION: While EBV infection may be a prerequisite for MS, the disease process of IM (i.e. the body's defective immune response to primary EBV infection) seems to be, in addition, implicated over the long term.

A retrospective cohort study of Epstein-Barr virus infection status and systemic lupus erythematosus.

OBJECTIVES: Systemic lupus erythematosus (SLE) and the Epstein-Barr virus (EBV) are very closely related. This study estimated the impact of EBV infection status on clinical manifestations and disease remission in patients with SLE. METHOD: A retrospective study was performed using electronic health records of patients with SLE. The SLE disease activity index (SLEDAI-2 K) was used to assess disease activity. VCAIgM or EAIgM positive or EBVDNA copies ≥ 50 IU/mL were defined as lytic infection group, EBNA-IgG or VCAIgG-positive and who were negative for both VCAIgM and EAIgM with EBVDNA copies < 50 IU/mL were defined as the latent infection group. The endpoint (disease remission) was defined as a decrease in SLEDAI-2 K score of ≥ 1 grade or ≥ 4 points from baseline. The association between EBV infection status and disease remission was assessed using propensity score weighting and multivariable Cox regression models. RESULTS: There were 75 patients with SLE in the EBV lytic infection group and 142 patients in the latent infection group. The SLEDAI-2 K score was higher in the lytic infection group (10.00 (6.25, 16.00) vs. 8.00 (5.00, 10.00), Z = 3.96, P < 0.001). There was a significant difference in the effect of EBV lytic infection on disease remission compared to latent infection (HR 0.30, 95% CI 0.19-0.49, P < 0.001). CONCLUSIONS: Patients with SLE with lytic EBV infection have higher disease activity and take longer to achieve remission. Our study furthers our understanding of the relationship between SLE and EBV infection and may inform better treatment practices in the future.

The Role of Epstein-Barr Virus (EBV) Infected Gastric Cancer in Increasing microRNA124 (miR-124) Promoter Methylation and Enhancer of Zeste Homolog 2 (EZH2) Gene Expression.

The tumor suppressor microRNAs, miR-21, miR-124, and miR-494, participate in the controlling several cellular processes. To assess target miRNAs promoter methylation levels, we investigated 304 pairs of gastric cancer (GC) tissues and non-tumor tissues. We used a commercial real-time polymerase chain reaction (RT-PCR) for Epstein-Barr virus (EBV) and Helicobacter pylori kit to detect EBV and H. pylori DNA in GC tissues. After finding hypermethylation in the promoter of the miR-124 gene, we evaluated its expression level using quantitative PCR (qPCR). Bioinformatics analysis confirmed miR-124 as a target of enhancer of Zeste homolog 2 (EZH2). Additionally, qPCR confirmed the association between EZH2 and miR-124. EBV and H. pylori DNA were detected in 9.5% and 15.1% of GC patients, respectively. Our findings also revealed significant differences in the miR-124 methylation levels among EBV-infected GC patients, H. pylori infected GC patients, GC patients without EBV and H. pylori infection, and non-tumor tissue. Bioinformatics and qPCR assays suggested an inverse relationship between the expression levels of EZH2 and miR-124 in EBV-infected GC patients. Our data revealed hypermethylation of the miR-124 promoter and significant reduction in its expression in EBV-infected GC tissues. It is possible that miR-124 may target EZH2 by binding to the 3'-UTR of the EZH2 gene, thus potentially contributing to the development of EBV-infected GC.

Role of Peroxiredoxin 1 Induced by Epstein-Barr Virus Infection in Nasopharyngeal Carcinoma.

BACKGROUND/AIM: Nasopharyngeal carcinoma (NPC), a common cancer in Southern China, is associated with Epstein-Barr Virus (EBV) infection. Although many therapies for NPC have been established, the definite role of EBV in NPC remains unclear. Therefore, this work focuses on LMP2A, a latent EBV gene, and investigates whether LMP2A is related to peroxiredoxin 1 (PRDX1) in EBV-positive NPC. MATERIALS AND METHODS: The mRNA and protein expression levels of LMP2A, PRDX1, and beta-catenin were compared in patient samples. To identify molecular mechanisms, EBV-negative NP69 and EBV-positive C666-1 NPC cell lines were used. After making an agar cell block for cell slides, the intensity of LMP2A expression was observed visually. To measure the level of reactive oxygen species, both fluorescence microscope and flow cytometry were used. To investigate the intracellular signaling molecular mechanisms with and without the LMP2A gene, reverse transcription polymerase chain reaction and western blotting were used. RESULTS: Both patient samples and cells of nasopharyngeal carcinoma infected with EBV had increased expression of LMP2A compared with controls, and high ROS levels were identified. Cell viability assay showed that LMP2A promoted cell growth by regulating gene expression. Furthermore, LMP2A induced the expression of PRDX1 and beta-catenin. LMP2A also increased the expression of both cyclin B1 and cyclin D1. CONCLUSION: In NPC cells, PRDX1 and beta-catenin were regulated through LMP2A expression, which reduced cell growth through cell cycle-related gene expression. This study suggests that LMP2A could be a target molecule for inhibiting cancer progression in NPC cells infected with EBV.