An epidemiological and molecular study of the relationship between smoking, risk of nasopharyngeal carcinoma, and Epstein-Barr virus activation

Host genetic variants, Epstein-Barr virus subtypes, and the risk of nasopharyngeal carcinoma: Assessment of interaction and mediation

Epstein-Barr virus (EBV) and human leukocyte antigen (HLA) polymorphisms are well-known risk factors for nasopharyngeal carcinoma (NPC). However, the combined effects between HLA and EBV on the risk of NPC are unknown. We applied a causal inference framework to disentangle interaction and mediation effects between two host HLA SNPs, rs2860580 and rs2894207, and EBV variant 163364 with a population-based case-control study in NPC-endemic southern China. We discovered the strong interaction effects between the high-risk EBV subtype and both HLA SNPs on NPC risk (rs2860580, relative excess risk due to interaction [RERI] = 4.08, 95% confidence interval [CI] = 2.03-6.14; rs2894207, RERI = 3.37, 95% CI = 1.59-5.15), accounting for the majority of genetic risk effects. These results indicate that HLA genes and the high-risk EBV have joint effects on NPC risk. Prevention strategies targeting the high-risk EBV subtype would largely reduce NPC risk associated with EBV and host genetic susceptibility.

The interaction and mediation effects between the host genetic factors and Epstein-Barr virus VCA-IgA in the risk of nasopharyngeal carcinoma

Previous studies have demonstrated strong associations between host genetic factors and Epstein-Barr virus (EBV) VCA-IgA with the risk of nasopharyngeal carcinoma (NPC). However, the specific interplay between host genetics and EBV VCA-IgA on NPC risk is not well understood. In this two-stage case-control study (N = 4804), we utilized interaction and mediation analysis to investigate the interplay between host genetics (genome-wide association study-derived polygenic risk score [PRS]) and EBV VCA-IgA antibody level in the NPC risk. We employed a four-way decomposition analysis to assess the extent to which the genetic effect on NPC risk is mediated by or interacts with EBV VCA-IgA. We consistently found a significant interaction between the PRS and EBV VCA-IgA on NPC risk (discovery population: synergy index [SI] = 2.39, 95% confidence interval [CI] = 1.85-3.10; replication population: SI = 3.10, 95% CI = 2.17-4.44; all pinteraction  < 0.001). Moreover, the genetic variants included in the PRS demonstrated similar interactions with EBV VCA-IgA antibody. We also observed an obvious dose-response relationship between the PRS and EBV VCA-IgA antibody on NPC risk (all ptrend  < 0.001). Furthermore, our decomposition analysis revealed that a substantial proportion (approximately 90%) of the genetic effects on NPC risk could be attributed to host genetic-EBV interaction, while the risk effects mediated by EBV VCA-IgA antibody were weak and statistically insignificant. Our study provides compelling evidence for an interaction between host genetics and EBV VCA-IgA antibody in the development of NPC. These findings emphasize the importance of implementing measures to control EBV infection as a crucial strategy for effectively preventing NPC, particularly in individuals at high genetic risk.

The risk of second primary cancer after nasopharyngeal cancer: a systematic review

PURPOSE

Second primary cancers (SPCs) after nasopharyngeal cancer (NPC) are rare, but have an impact on the follow-up of this patient population. The aim of this study is to systematically review the literature to determine the prevalence and most typical sites of SPCs after NPC.

METHODS

We searched the databases of PubMed, Web of Science, and Scopus for articles on SPCs after NPC. The Preferred Reporting Items for Systematic Review and Meta-Analyses guidelines were followed.

RESULTS

This review includes data on 89 168 patients with NPC from 21 articles. The mean occurrence for SPCs was 6.6% and varied from 4.9% in endemic areas to 8.7% in non-endemic areas. The most frequent locations of SPCs were oral cavity, pharynx, nose and paranasal sinuses, esophagus and lung.

CONCLUSION

There is an increased risk for a SPC after NPC management, especially in non-endemic areas. However, their mean rate is lower than after other head and neck carcinomas.

Epstein-Barr virus induced acute hepatitis with hyperferritinemia: A rare presentation

Elevated aminotransaminases and hyperbilirubinemia are common in primary Epstein-Barr Virus (EBV) infection in the adult and pediatric population and the disease course is usually subclinical and self-limited. However, EBV-induced hepatitis is an uncommon diagnosis, accounting for less than 1% of acute hepatitis causes. Acute EBV-hepatitis usually affects immunocompromised and older populations, with nearly half of patients being aged greater than 60 years. Significantly elevated ferritin levels correlate with severe infection and have been associated with EBV complications such as infectious mononucleosis, autoimmune hemolytic anemia, and hemophagocytic lymphohistiocytosis. We present a case of isolated acute cholestatic EBV-hepatitis and hyperferritinemia in an adult immunocompetent patient.

Risk factors for multiple sclerosis in the context of Epstein-Barr virus infection

Compelling evidence indicates that Epstein Barr virus (EBV) infection is a prerequisite for multiple sclerosis (MS). The disease may arise from a complex interplay between latent EBV infection, genetic predisposition, and various environmental and lifestyle factors that negatively affect immune control of the infection. Evidence of gene-environment interactions and epigenetic modifications triggered by environmental factors in genetically susceptible individuals supports this view. This review gives a short introduction to EBV and host immunity and discusses evidence indicating EBV as a prerequisite for MS. The role of genetic and environmental risk factors, and their interactions, in MS pathogenesis is reviewed and put in the context of EBV infection. Finally, possible preventive measures are discussed based on the findings presented.

Associations between serum trace elements and the risk of nasopharyngeal carcinoma: a multi-center case-control study in Guangdong Province, southern China

Background

Associations between trace elements and nasopharyngeal carcinoma (NPC) have been speculated but not thoroughly examined.

Methods

This study registered a total of 225 newly diagnosed patients with NPC and 225 healthy controls matched by sex and age from three municipal hospitals in Guangdong Province, southern China between 2011 and 2015. Information was collected by questionnaire on the demographic characteristics and other possibly confounding lifestyle factors. Eight trace elements and the level of Epstein-Barr virus (EBV) antibody were measured in casual (spot) serum specimens by inductively coupled plasma-mass spectrometry (ICP-MS) and enzyme-linked immunosorbent assay (ELISA), respectively. Restricted cubic splines and conditional logistic regression were applied to assess the relationship between trace elements and NPC risk through single-and multiple-elements models.

Results

Serum levels of chromium (Cr), cobalt (Co), nickel (Ni), arsenic (As), strontium (Sr) and molybdenum (Mo) were not associated with NPC risk. Manganese (Mn) and cadmium (Cd) were positively associated with NPC risk in both single-and multiple-element models, with ORs of the highest tertile compared with the reference categories 3.90 (95% CI, 1.27 to 7.34) for Mn and 2.30 (95% CI, 1.26 to 3.38) for Cd. Restricted cubic splines showed that there was a linear increasing trend between Mn and NPC risk, while for Cd there was a J-type correlation.

Conclusion

Serum levels of Cd and Mn was positively related with NPC risk. Prospective researches on the associations of the two trace elements with NPC ought to be taken into account within the future.

High-throughput identification of regulatory elements and functional assays to uncover susceptibility genes for nasopharyngeal carcinoma

Large-scale genetic association studies have identified multiple susceptibility loci for nasopharyngeal carcinoma (NPC), but the underlying biological mechanisms remain to be explored. To gain insights into the genetic etiology of NPC, we conducted a follow-up study encompassing 6,907 cases and 10,472 controls and identified two additional NPC susceptibility loci, 9q22.33 (rs1867277; OR = 0.74, 95% CI = 0.68-0.81, p = 3.08 × 10^-11) and 17q12 (rs226241; OR = 1.42, 95% CI = 1.26-1.60, p = 1.62 × 10^-8). The two additional loci, together with two previously reported genome-wide significant loci, 5p15.33 and 9p21.3, were investigated by high-throughput sequencing for chromatin accessibility, histone modification, and promoter capture Hi-C (PCHi-C) profiling. Using luciferase reporter assays and CRISPR interference (CRISPRi) to validate the functional profiling, we identified PHF2 at locus 9q22.33 as a susceptibility gene. PHF2 encodes a histone demethylase and acts as a tumor suppressor. The risk alleles of the functional SNPs reduced the expression of the target gene PHF2 by inhibiting the enhancer activity of its long-range (4.3 Mb) cis-regulatory element, which promoted proliferation of NPC cells. In addition, we identified CDKN2B-AS1 as a susceptibility gene at locus 9p21.3, and the NPC risk allele of the functional SNP rs2069418 promoted the expression of CDKN2B-AS1 by increasing its enhancer activity. The overexpression of CDKN2B-AS1 facilitated proliferation of NPC cells. In summary, we identified functional SNPs and NPC susceptibility genes, which provides additional explanations for the genetic association signals and helps to uncover the underlying genetic etiology of NPC development.

Phage display sequencing reveals that genetic, environmental, and intrinsic factors influence variation of human antibody epitope repertoire

Phage-displayed immunoprecipitation sequencing (PhIP-seq) has enabled high-throughput profiling of human antibody repertoires. However, a comprehensive overview of environmental and genetic determinants shaping human adaptive immunity is lacking. In this study, we investigated the effects of genetic, environmental, and intrinsic factors on the variation in human antibody repertoires. We characterized serological antibody repertoires against 344,000 peptides using PhIP-seq libraries from a wide range of microbial and environmental antigens in 1,443 participants from a population cohort. We detected individual-specificity, temporal consistency, and co-housing similarities in antibody repertoires. Genetic analyses showed the involvement of the HLA, IGHV, and FUT2 gene regions in antibody-bound peptide reactivity. Furthermore, we uncovered associations between phenotypic factors (including age, cell counts, sex, smoking behavior, and allergies, among others) and particular antibody-bound peptides. Our results indicate that human antibody epitope repertoires are shaped by both genetics and environmental exposures and highlight specific signatures of distinct phenotypes and genotypes.

Comparative Analysis of the Humoral Immune Response to the EBV Proteome across EBV-Related Malignancies

BACKGROUND

Epstein-Barr virus (EBV) is linked to multiple cancers, including classical Hodgkin lymphoma (cHL), endemic Burkitt lymphoma (eBL), nasopharyngeal carcinoma (NPC), and extranodal natural killer/T-cell lymphoma (NKTCL).

METHODS

Anti-EBV IgG and IgA antibody responses targeting 202 sequences from 86 EBV proteins were measured using the same EBV whole proteome array across four case-control studies investigating EBV-positive cHL, eBL, NPC, and NKTCL (407 cases/620 controls). We grouped EBV-targeted antibodies into pathways by immunoglobulin type (IgA and IgG) and life-cycle stage (latent, immediate early lytic, early lytic, late lytic, and glycoprotein) and evaluated their association with each cancer type. In an additional analysis, we focused on the subset of 46 individual antibodies representing the top candidates for each cancer and compared their associations across the four cancer types using multivariable linear regression models.

RESULTS

IgA antibody responses targeting all EBV life-cycle stages were associated with NPC but limited to anti-early lytic stage for cHL. NPC and eBL were associated with IgG antibodies across the viral life cycle; cHL with antibodies in the early lytic, late lytic and glycoprotein stages; and NKTCL with antibodies in the latent, immediate early lytic and early lytic phases. EBNA3A, BBLF1, BDLF4, and BLRF2 IgG antibodies were associated with all cancer types.

CONCLUSIONS

Our observed similarities and differences across four EBV-associated cancers may inform EBV-related oncogenesis.

IMPACT

Understanding the comparative humoral immune response across EBV-related cancers may aid in identifying shared etiologic roles of EBV proteins and inform unique pathogenic processes for each cancer.

Retrospective analysis of Porphyromonas gingivalis in patients with nasopharyngeal carcinoma in central China

Little is known about the presence and possible role of Porphyromonas gingivalis (P. gingivalis) in nasopharyngeal carcinoma (NPC), its co-infection with Epstein-Barr virus (EBV), or their association with clinical characteristics of patients with NPC in Central China, where NPC is non-endemic. A total of 45 NPC formalin-fixed paraffin-embedded (FFPE) tissues were retrospectively analyzed using immunohistochemistry (IHC) and a nested PCR combined with DNA sequencing to detect the presence of P. gingivalis, and using reverse transcription-quantitative PCR to detect the presence of EBV. Clinical data including EBV and P. gingivalis status were associated with overall survival (OS). All tumors were undifferentiated, non-keratinizing carcinomas, of which 40/45 (88.9%) were positive for EBV (EBV⁺), 26/45 (57.8%) were positive for P. gingivalis (by IHC), and 7/45 (15.6%) were positive for P. gingivalis DNA (P. gingivalis ⁺). All seven P. gingivalis DNA-positive NPCs were co-infected with EBV. The 5-year survival rates of the patients with EBV^-/P. gingivalis ^-, EBV⁺/P. gingivalis ^-, and EBV⁺/P. gingivalis ⁺ tumors were 60.0% (3/5), 39.4% (13/33) and 42.9% (3/7), respectively. No significant difference was found between the OS of NPC patients among the different infection groups (P=0.793). In conclusion, to the best of our knowledge, this is the first study to describe and confirm the presence of P. gingivalis in FFPE tissues from patients with NPC. P. gingivalis was found to co-exist with EBV in NPC tumor tissues, but is not etiologically relevant to NPC in non-endemic areas, such as Central China.

The Oral Microbiome as Mediator between Oral Hygiene and Its Impact on Nasopharyngeal Carcinoma

Oral hygiene and the alteration of the oral microbiome have been linked to nasopharyngeal carcinoma (NPC). This study aimed to investigate whether the oral microbiome plays a mediating role in the relationship between oral hygiene and NPC, and identify differential microbial taxonomies that potentially mediated this association. We conducted a case–control study that involved 218 NPC patients and 192 healthy controls. The 16S rRNA gene sequencing of the V4 region was performed to evaluate the composition of the oral microbiome. Mediation analysis was applied to explore the relationship among oral hygiene, the oral microbiome and NPC. We found that dental fillings and poor oral hygiene score were associated with increased risks of NPC (OR = 2.51 (1.52–4.25) and OR = 1.54 (1.02–2.33)). Mediation analysis indicated that dental fillings increased the risk of NPC by altering the abundance of Erysipelotrichales, Erysipelotrichaceae, Solobacterium and Leptotrichia wadei. In addition, Leptotrichia wadei also mediated the association between oral hygiene score and the risk of NPC. Our study confirmed that poor oral hygiene increased the risk of NPC, which was partly mediated by the oral microbiome. These findings might help us to understand the potential mechanism of oral hygiene influencing the risk of NPC via the microbiome.

Oral Microbiota Alteration and Roles in Epstein-Barr Virus Reactivation in Nasopharyngeal Carcinoma

Microbiota has recently emerged as a critical factor associated with multiple malignancies. Nasopharyngeal carcinoma (NPC) is highly associated with Epstein-Barr virus (EBV); the oncovirus resides and is transmitted in the oral cavity. However, the alternation of oral microbiota in NPC patients and its potential link to EBV reactivation and host cell response under the simultaneous existence of EBV and specific bacteria is largely unknown. Here, oral microbiota profiles of 303 NPC patients and controls with detailed clinical information, including serum EBV anti-virus capsid antigen (VCA) IgA level, were conducted. A distinct microbial community with lower diversity and imbalanced composition in NPC patients was observed. Notably, among enriched bacteria in patients, Streptococcus sanguinis was associated with anti-VCA IgA, an indicator of NPC risk and EBV reactivation. By measuring the concentration of its metabolite, hydrogen peroxide (H2O2), in the saliva of clinical patients, we found the detection rate of H2O2 was 2-fold increased compared to healthy controls. Further coculture assay of EBV-positive Akata cells with bacteria in vitro showed that S. sanguinis induced EBV lytic activation by its metabolite, H2O2. Host and EBV whole genome-wide transcriptome sequencing and EBV methylation assays showed that H2O2 triggered the host cell signaling pathways, notably tumor necrosis factor alpha (TNF-α) via NF-κB, and induced the demethylation of the global EBV genome and the expression of EBV lytic-associated genes, which could result in an increase of virus particle release and potential favorable events toward tumorigenesis. In brief, our study identified a characterized oral microbial profile in NPC patients and established a robust link between specific oral microbial alteration and switch of latency to lytic EBV infection status in the oral cavity, which provides novel insights into EBV's productive cycle and might help to further clarify the etiology of NPC. IMPORTANCE EBV is classified as the group I human carcinogen and is associated with multiple cancers, including NPC. The interplays between the microbiota and oncovirus in cancer development remain largely unknown. In this study, we investigate the interactions between resident microbes and EBV coexistence in the oral cavity of NPC patients. We identify a distinct oral microbial feature for NPC patients. Among NPC-enriched bacteria, we illustrated that a specific species, S. sanguinis, associated with elevated anti-IgA VCA in patients, induced EBV lytic activation by its by-product, H2O2, and activated the TNF-α/NF-κB pathway of EBV-positive B cells in vitro, together with increased detection rate of H2O2 in patients' oral cavities, which strengthened the evidence of bacteria-virus-host interaction in physiological circumstances. The effects of imbalanced microbiota on the EBV latent-to-lytic switch in the oral cavity might create the likelihood of EBV infection in epithelial cells at the nasopharynx and help malignant transition and cancer development.

The role of Epstein-Barr virus in nasopharyngeal carcinoma

Nasopharyngeal carcinoma (NPC) is a metastasis-prone malignancy closely associated with the Epstein-Barr virus (EBV). Despite ubiquitous infection of EBV worldwide, NPC incidences displayed predominance in certain ethnic groups and endemic regions. The majority of NPC patients are diagnosed with advanced-stage disease, as a result of anatomical isolation and non-specific clinical manifestation. Over the decades, researchers have gained insights into the molecular mechanisms underlying NPC pathogenesis as a result of the interplay of EBV infection with several environmental and genetic factors. EBV-associated biomarkers were also used for mass population screening for the early detection of NPC. EBV and its encoded products also serve as potential targets for the development of therapeutic strategies and tumour-specific drug delivery. This review will discuss the pathogenic role of EBV in NPC and efforts in exploiting the potential of EBV-associated molecules as biomarkers and therapeutic targets. The current knowledge on the role of EBV and its associated products in NPC tumorigenesis, development and progression will offer a new outlook and potential intervention strategy against this EBV-associated malignancy.

Mendelian randomisation identifies priority groups for prophylactic EBV vaccination

BACKGROUND

Epstein Barr virus (EBV) infects ~ 95% of the population worldwide and is known to cause adverse health outcomes such as Hodgkin's, non-Hodgkin's lymphomas, and multiple sclerosis. There is substantial interest and investment in developing infection-preventing vaccines for EBV. To effectively deploy such vaccines, it is vital that we understand the risk factors for infection. Why particular individuals do not become infected is currently unknown. The current literature, describes complex, often conflicting webs of intersecting factors-sociodemographic, clinical, genetic, environmental-, rendering causality difficult to decipher. We aimed to use Mendelian randomization (MR) to overcome the issues posed by confounding and reverse causality to determine the causal risk factors for the acquisition of EBV.

METHODS

We mapped the complex evidence from the literature prior to this study factors associated with EBV serostatus (as a proxy for infection) into a causal diagram to determine putative risk factors for our study. Using data from the UK Biobank of 8422 individuals genomically deemed to be of white British ancestry between the ages of 40 and 69 at recruitment between the years 2006 and 2010, we performed a genome wide association study (GWAS) of EBV serostatus, followed by a Two Sample MR to determine which putative risk factors were causal.

RESULTS

Our GWAS identified two novel loci associated with EBV serostatus. In MR analyses, we confirmed shorter time in education, an increase in number of sexual partners, and a lower age of smoking commencement, to be causal risk factors for EBV serostatus.

CONCLUSIONS

Given the current interest and likelihood of a future EBV vaccine, these factors can inform vaccine development and deployment strategies by completing the puzzle of causality. Knowing these risk factors allows identification of those most likely to acquire EBV, giving insight into what age to vaccinate and who to prioritise when a vaccine is introduced.

The short-term efficacy and safety of induction chemotherapy combined with PD-1 inhibitor or anti-EGFR in locoregionally advanced nasopharyngeal carcinoma

Purpose

This study aimed to investigate the short-term efficacy and safety of induction chemotherapy (IC) combined with PD-1 inhibitor or anti-EGFR in the treatment of locoregionally advanced nasopharyngeal carcinoma (LA-NPC).

Methods and materials

We retrospectively reviewed the clinical data of 206 patients with LA-NPC, including IC combined with anti-PD-1 (57 patients), IC combined with anti-EGFR (28 patients), and IC alone (121 patients). The short-term efficacy was assessed at the end of IC and one month after overall treatment. According to the RECIST v1.1, the short-term efficacy of cervical lymph nodes and primary nasopharynx foci was divided into complete remission (CR), partial remission (PR), stable disease (SD), and progressive disease (PD). The overall response (ORR) was defined as the sum of CR and PR. Acute toxicities were graded according to the CTCAE v5.0. One-way analysis of variance (ANOVA) was used to compare differences in the numerical variables among groups. Fisher Freeman-Halton test or Pearson Chi-square test was used to compare classified variables.

Results

The ORR rates of primary nasopharynx foci in IC, anti-EGFR, and anti-PD-1 group were 68.60%, 67.9%, and 94.7%, respectively, and the corresponding rates of ORR in cervical lymph nodes were 78.5%, 71.4%, and 93.0%, respectively. There was a statistical difference in the ORR between the three groups. Further analysis showed that after IC or overall treatment, the CR rate of primary nasopharynx foci in the anti-PD-1 group was significantly higher than the other two groups. The most common adverse effects were hematotoxicity, gastrointestinal toxicity, and transaminase elevation. However, there were no statistical differences in the frequency of any common adverse effects between the three groups.

Conclusions

The addition of anti-PD-1 based on IC significantly improved the short-term efficacy of LA-NPC and toxicities were tolerable.

Combination of smoking and Epstein-Barr virus DNA is a predictor of poor prognosis for nasopharyngeal carcinoma: a long-term follow-up retrospective study

BACKGROUND

This retrospective study was performed to determine the prognostic potential of smoking and its combination with pre-treatment plasma Epstein-Barr virus (EBV) DNA levels in patients with nasopharyngeal carcinoma (NPC).

METHODS

Medical records of 1080 non-metastatic NPC patients who received intensity-modulated radiotherapy were reviewed. Male patients were categorized as never and ever smokers, and the smoking amount, duration, and cumulative consumption were used to evaluate dose-dependent effects. Survival outcomes were assessed using Kaplan-Meier survival analysis and the multivariate Cox regression analysis. Propensity score matching (PSM) was constructed.

RESULTS

The 5-year overall survival (OS) was worse for ever smokers than never smokers, and significantly decreased with the increase of smoking amount, duration, and cumulative consumption. Compared with never smokers, the multivariate-adjusted hazard ratio (HR) of death was higher in ever smokers (HR = 1.361, P = 0.049), those smoked ≥20 cigarettes/day (HR = 1.473, P = 0.017), those smoked for ≥30 years (HR = 1.523, P = 0.023), and those cumulative smoked for ≥30 pack-years (HR = 1.649, P = 0.005). The poor prognostic effects of smoking was also confirmed in the PSM analysis. The combination of cumulative smoking consumption and pre-treatment EBV DNA levels was proven to be an independent poor prognostic factor for male NPC, and the risk of death, progression, and distant metastases gradually increased with both factors (P < 0.001).

CONCLUSIONS

Combination of smoking and pre-treatment EBV DNA levels as a predictor of poor prognosis could further improve the risk stratification and prognostication for NPC.

Epstein-Barr virus infection, B-cell dysfunction and other risk factors converge in gut-associated lymphoid tissue to drive the immunopathogenesis of multiple sclerosis: a hypothesis

Multiple sclerosis is associated with Epstein-Barr virus (EBV) infection, B-cell dysfunction, gut dysbiosis, and environmental and genetic risk factors, including female sex. A disease model incorporating all these factors remains elusive. Here, we hypothesise that EBV-infected memory B cells (MBCs) migrate to gut-associated lymphoid tissue (GALT) through EBV-induced expression of LPAM-1, where they are subsequently activated by gut microbes and/or their products resulting in EBV reactivation and compartmentalised anti-EBV immune responses. These responses involve marginal zone (MZ) B cells that activate CD4⁺ T-cell responses, via HLA-DRB1, which promote downstream B-cell differentiation towards CD11c⁺/T-bet⁺ MBCs, as well as conventional MBCs. Intrinsic expression of low-affinity B-cell receptors (BCRs) by MZ B cells and CD11c⁺/T-bet⁺ MBCs promotes polyreactive BCR/antibody responses against EBV proteins (e.g. EBNA-1) that cross-react with central nervous system (CNS) autoantigens (e.g. GlialCAM). EBV protein/autoantigen-specific CD11c⁺/T-bet⁺ MBCs migrate to the meningeal immune system and CNS, facilitated by their expression of CXCR3, and induce cytotoxic CD8⁺ T-cell responses against CNS autoantigens amplified by BAFF, released from EBV-infected MBCs. An increased abundance of circulating IgA⁺ MBCs, observed in MS patients, might also reflect GALT-derived immune responses, including disease-enhancing IgA antibody responses against EBV and gut microbiota-specific regulatory IgA⁺ plasma cells. Female sex increases MZ B-cell and CD11c⁺/T-bet⁺ MBC activity while environmental risk factors affect gut dysbiosis. Thus, EBV infection, B-cell dysfunction and other risk factors converge in GALT to generate aberrant B-cell responses that drive pathogenic T-cell responses in the CNS.

Human Papillomavirus-Related Carcinomas of the Sinonasal Tract

Purpose of review

The sinonasal tract is home to a uniquely heterogenous collection of malignant tumors. Human papillomavirus (HPV) has been detected in a number of these, but the virus' role as an oncogenic driver or coincidental finding remains unclear. We aim to highlight five sinonasal tumor types and synthesize the prevalence, etiologic role, and known clinicopathologic relevance of HPV in each.

Recent findings

The last decade has seen an expansion of investigation into HPV's oncogenic and prognostic significance within sinonasal malignancies. The sinonasal tract poses challenges to HPV detection where p16 lacks value as an accurate surrogate. A growing body of data supports a potentially favorable clinical profile for certain sinonasal HPV-positive lesions.

Summary

HPV represents a potential biologically and clinically relevant factor for some sinonasal malignancies. Definitive conclusions regarding HPV's role as a potential oncogenic agent require routine testing using validated methodologies, genomic interrogation, and large-scale prospective studies.

Are Viral Infections Key Inducers of Autoimmune Diseases? Focus on Epstein–Barr Virus

It is generally accepted that certain viral infections can trigger the development of autoimmune diseases. However, the exact mechanisms by which these viruses induce autoimmunity are still not understood. In this review, we first describe hypothetical mechanisms by which viruses induce some representative autoimmune diseases. Then, we focus on Epstein–Barr virus (EBV) and discuss its role in the pathogenesis of rheumatoid arthritis (RA). The discussion is mainly based on our own previous findings that (A) EBV DNA and its products EBV-encoded small RNA (EBER) and latent membrane protein 1 (LMP1) are present in the synovial lesions of RA, (B) mRNA expression of the signaling lymphocytic activation molecule-associated protein (SAP)/SH2D1A gene that plays a critical role in cellular immune responses to EBV is reduced in the peripheral T cells of patients with RA, and (C) EBV infection of mice reconstituted with human immune system components (humanized mice) induced erosive arthritis that is pathologically similar to RA. Additionally, environmental factors may contribute to EBV reactivation as follows: Porphyromonas gingivalis peptidylarginine deiminase (PAD), an enzyme required for citrullination, engenders antigens leading to the production of citrullinated peptides both in the gingiva and synovium. Anti-citrullinated peptides autoantibody is an important marker for diagnosis and disease activity of RA. These findings, as well as various results obtained by other researchers, strongly suggest that EBV is directly involved in the pathogenesis of RA, a typical autoimmune disease.

A polygenic risk score for nasopharyngeal carcinoma shows potential for risk stratification and personalized screening

Polygenic risk scores (PRS) have the potential to identify individuals at risk of diseases, optimizing treatment, and predicting survival outcomes. Here, we construct and validate a genome-wide association study (GWAS) derived PRS for nasopharyngeal carcinoma (NPC), using a multi-center study of six populations (6 059 NPC cases and 7 582 controls), and evaluate its utility in a nested case-control study. We show that the PRS enables effective identification of NPC high-risk individuals (AUC = 0.65) and improves the risk prediction with the PRS incremental deciles in each population (Ptrend ranging from 2.79 × 10-7 to 4.79 × 10-44). By incorporating the PRS into EBV-serology-based NPC screening, the test's positive predictive value (PPV) is increased from an average of 4.84% to 8.38% and 11.91% in the top 10% and 5% PRS, respectively. In summary, the GWAS-derived PRS, together with the EBV test, significantly improves NPC risk stratification and informs personalized screening.

Environmental factors for Epstein-Barr virus reactivation in a high-risk area of nasopharyngeal carcinoma: a population-based study

Background

Epstein-Barr virus (EBV) reactivation from latent to lytic infection has been considered as a key step in nasopharyngeal carcinoma oncogenesis. However, epidemiological evidence regarding environmental risk factors for EBV reactivation on a population level remains largely lacking.

Methods

We enrolled 1916 randomly selected adults from the general population of Guangdong and Guangxi, China, from 2010 to 2014. Information on environmental factors was collected via a structured interview. Serum immunoglobulin A antibodies against EBV viral capsid antigen and nuclear antigen 1 were measured by enzyme-linked immunosorbent assay to evaluate EBV reactivation status. We used logistic regression to calculate odds ratios (ORs) with 95% confidence intervals (CIs) for the associations of EBV reactivation with various environmental factors.

Results

No associations were observed between EBV reactivation and extensive environmental factors, including alcohol or tea drinking, a history of chronic ear/nose/throat diseases, use of medications or herbs, consumption of salted fish or preserved foods, oral hygiene, sibship structure, and various residential and occupational exposures. Only cigarette smoking was associated with EBV reactivation (current smokers vs never smokers; OR = 1.37; 95% CI = 1.02–1.83), with positive exposure-response trends with increasing intensity, duration, and pack-years of smoking.

Conclusions

Consistent with previous studies, we found an association between cigarette smoking and EBV reactivation. Other examined exposures were not associated with EBV reactivation. These null results could suggest either more complex interactions between exposures and EBV reactivation or a predominant role of host and/or viral genetic variation.

Epstein–Barr Virus Infection in Lung Cancer: Insights and Perspectives

Lung cancer (LC) is the leading cause of cancer death worldwide. Tobacco smoke is the most frequent risk factor etiologically associated with LC, although exposures to other environmental factors such as arsenic, radon or asbestos are also involved. Additionally, the involvement of some viral infections such as high-risk human papillomaviruses (HR-HPVs), Merkel cell polyomavirus (MCPyV), Jaagsiekte Sheep Retrovirus (JSRV), John Cunningham Virus (JCV), and Epstein–Barr virus (EBV) has been suggested in LC, though an etiological relationship has not yet been established. EBV is a ubiquitous gamma herpesvirus causing persistent infections and some lymphoid and epithelial tumors. Since EBV is heterogeneously detected in LCs from different parts of the world, in this review we address the epidemiological and experimental evidence of a potential role of EBV. Considering this evidence, we propose mechanisms potentially involved in EBV-associated lung carcinogenesis. Additional studies are warranted to dissect the role of EBV in this very frequent malignancy.

Prognostic Value of Oral Epstein–Barr Virus DNA Load in Locoregionally Advanced Nasopharyngeal Carcinoma

Background: Plasma Epstein–Barr virus (EBV) DNA load has been widely used for nasopharyngeal carcinoma (NPC) prognostic risk stratification. However, oral EBV DNA load, a non-invasive biomarker that reflects the EBV lytic replication activity, has not been evaluated for its prognostic value in NPC yet.

Methods: A total number of 1,194 locoregionally advanced NPC (LA-NPC) patients from south China were included from a prospective observational cohort (GARTC) with a median follow-up of 107.3 months. Pretreatment or mid-treatment mouthwashes were collected for EBV DNA detection by quantitative polymerase chain reaction (qPCR). The difference of pre- and mid-treatment oral EBV DNA load was tested by the Wilcoxon signed-rank test. The associations of oral EBV DNA load with overall survival (OS), progression-free survival (PFS), distant metastasis–free survival (DMFS), and locoregional relapse-free survival (LRFS) were assessed using the log-rank test and multivariate Cox regression.

Results: The high level of the oral EBV DNA load (>2,100 copies/mL) was independently associated with worse OS (HR = 1.45, 95% CI: 1.20–1.74, p < 0.001), PFS (HR = 1.38, 95% CI: 1.16–1.65, p < 0.001), DMFS (HR = 1.66, 95% CI: 1.25–2.21, p = 0.001), and LRFS (HR = 1.43, 95% CI: 1.05–1.96, p = 0.023). Similar and robust associations between oral EBV DNA load and prognosis were observed for patients in both the pretreatment and mid-treatment stages. The detection rate (71.7 vs. 48.6%, p < 0.001) and the median load of oral EBV DNA (13,368 vs. 382 copies/mL, p < 0.001) for patients in the pretreatment stage were significantly higher than those in the mid-treatment stage. The combination of the oral EBV DNA load and TNM staging provided a more precise risk stratification for the LA-NPC patients.

Conclusion: Oral EBV DNA load was an alternative non-invasive predictor of prognosis and may facilitate risk stratification for the LA-NPC patients.

Baicalein Inhibits Metastatic Phenotypes in Nasopharyngeal Carcinoma Cells via a Focal Adhesion Protein Integrin β8

Baicalein, a prominent flavonoid from the indigenous herbal plant Scutellaria baicalensis Georgi, possesses broad-spectrum anticancer activities. However, the biological effects of baicalein on nasopharyngeal carcinoma (NPC) and its underlying mechanisms remain unclarified. Thus, in this study, we examined the effects of baicalein on NPC cell lines and investigated the corresponding molecular mechanism through transcriptome profiling. In the study, four NPC cell lines were treated with various concentrations of baicalein at different time points. Cellular toxicity and proliferative inhibition of baicalein were examined by MTT assay. Metastatic phenotypes of NPC cells were investigated by wound healing, transwell, and adhesion assays. Additionally, microarray experiments were performed to determine the cellular pathways affected by baicalein. The expression and localization of the integrin β8 were validated by western immunoblotting and immunofluorescence. Our results revealed that baicalein exhibited its cytotoxicity and antiproliferative activity on all tested NPC cell lines. It also significantly inhibited metastatic phenotypes at sub-lethal concentrations. Transcriptomic analysis showed that baicalein significantly affected the focal adhesion pathway in NPC, where integrin β8 was greatly diminished. Thus, the present study results suggested that baicalein inhibits the metastatic phenotypes of NPC cells by modulating integrin β8, one of the major molecules in a focal adhesion pathway.

Radiotherapy for nasopharyngeal cancer

Nasopharyngeal cancers are a rarity in France. Radiotherapy is the cornerstone of treatment, frequently combined with chemotherapy. The technical modality of radiotherapy is complex in this disease, which is located in the vicinity of numerous organs at risk. In this article, we will present the updated guidelines of the French society for radiation oncology (Société française de radiothérapie oncologique, SFRO) on the indications, and technical details of radiotherapy in nasopharyngeal cancers.

Epstein–Barr Virus Epithelial Cancers—A Comprehensive Understanding to Drive Novel Therapies

Epstein–Barr virus (EBV) is a ubiquitous oncovirus associated with specific epithelial and lymphoid cancers. Among the epithelial cancers, nasopharyngeal carcinoma (NPC), lymphoepithelioma-like carcinoma (LELC), and EBV-associated gastric cancers (EBVaGC) are the most common. The role of EBV in the pathogenesis of NPC and in the modulation of its tumour immune microenvironment (TIME) has been increasingly well described. Much less is known about the pathogenesis and tumour–microenvironment interactions in other EBV-associated epithelial cancers. Despite the expression of EBV-related viral oncoproteins and a generally immune-inflamed cancer subtype, EBV-associated epithelial cancers have limited systemic therapeutic options beyond conventional chemotherapy. Immune checkpoint inhibitors are effective only in a minority of these patients and even less efficacious with molecular targeting drugs. Here, we examine the key similarities and differences of NPC, LELC, and EBVaGC and comprehensively describe the clinical, pathological, and molecular characteristics of these cancers. A deeper comparative understanding of these EBV-driven cancers can potentially uncover targets in the tumour, TIME, and stroma, which may guide future drug development and cast light on resistance to immunotherapy.

Characterization of the humoral immune response to the EBV proteome in extranodal NK/T-cell lymphoma

Extranodal natural killer/T-cell lymphoma (NKTCL) is an aggressive malignancy that has been etiologically linked to Epstein-Barr virus (EBV) infection, with EBV gene transcripts identified in almost all cases. However, the humoral immune response to EBV in NKTCL patients has not been well characterized. We examined the antibody response to EBV in plasma samples from 51 NKTCL cases and 154 controls from Hong Kong and Taiwan who were part of the multi-center, hospital-based AsiaLymph case–control study. The EBV-directed serological response was characterized using a protein microarray that measured IgG and IgA antibodies against 202 protein sequences representing the entire EBV proteome. We analyzed 157 IgG antibodies and 127 IgA antibodies that fulfilled quality control requirements. Associations between EBV serology and NKTCL status were disproportionately observed for IgG rather than IgA antibodies. Nine anti-EBV IgG responses were significantly elevated in NKTCL cases compared with controls and had ORs_{highest vs. lowest tertile} > 6.0 (Bonferroni-corrected P-values < 0.05). Among these nine elevated IgG responses in NKTCL patients, three IgG antibodies (all targeting EBNA3A) are novel and have not been observed for other EBV-associated tumors of B-cell or epithelial origin. IgG antibodies against EBNA1, which have consistently been elevated in other EBV-associated tumors, were not elevated in NKTCL cases. We characterize the antibody response against EBV for patients with NKTCL and identify IgG antibody responses against six distinct EBV proteins. Our findings suggest distinct serologic patterns of this NK/T-cell lymphoma compared with other EBV-associated tumors of B-cell or epithelial origin.

Nicotine-mediated OTUD3 downregulation inhibits VEGF-C mRNA decay to promote lymphatic metastasis of human esophageal cancer

Nicotine addiction and the occurrence of lymph node spread are two major significant factors associated with esophageal cancer's poor prognosis; however, nicotine's role in inducing lymphatic metastasis of esophageal cancer remains unclear. Here we show that OTU domain-containing protein 3 (OTUD3) is downregulated by nicotine and correlates with poor prognosis in heavy-smoking esophageal cancer patients. OTUD3 directly interacts with ZFP36 ring finger protein (ZFP36) and stabilizes it by inhibiting FBXW7-mediated K48-linked polyubiquitination. ZFP36 binds with the VEGF-C 3-'UTR and recruits the RNA degrading complex to induce its rapid mRNA decay. Downregulation of OTUD3 and ZFP36 is essential for nicotine-induced VEGF-C production and lymphatic metastasis in esophageal cancer. This study establishes that the OTUD3/ZFP36/VEGF-C axis plays a vital role in nicotine addiction-induced lymphatic metastasis, suggesting that OTUD3 may serve as a prognostic marker, and induction of the VEGF-C mRNA decay might be a potential therapeutic strategy against human esophageal cancer.

Masulili SL, Soeroso Y, Djoko Santoso W, S. Kusdhany L. Association between Epstein-Barr virus and periodontitis: A meta-analysis

Purpose

Previous studies have found that Epstein-Barr virus (EBV) is associated with periodontitis, though some controversy remains. This meta-analysis aimed to clarify and update the relationship between EBV and periodontitis as well as clinical parameters.

Methods

A comprehensive search was conducted in the PubMed and Scopus databases in December 2020. Original data were extracted according to defined inclusion and exclusion criteria. Outcomes were analyzed, including overall odds ratios (ORs) and 95% confidence intervals (CIs). A random-effects model was used, and publication bias was assessed by Egger’s and Begg’s tests. Sensitivity analysis was used to evaluate the stability of the outcome.

Results

Twenty-six studies were included in the present meta-analysis, involving 1354 periodontitis patients and 819 healthy controls. The included studies mostly showed high quality. The overall quantitative synthesis for the association between EBV and periodontitis was an increased odds ratio when subgingival EBV was detected OR = 7.069, 95% CI = 4.197–11.905, P<0.001). The results of subgroup analysis suggested that the association of EBV with periodontitis was significant in Asian, European, and American populations (P<0.001; P = 0.04; P = 0.003, respectively) but not in African populations (P = 0.29). Subgroup analysis by sample type showed that subgingival plaque (SgP), tissue and gingival crevicular fluid GCF were useful for EBV detection (P<0.001). EBV detection amplification methods included nested PCR, multiplex PCR and PCR (P<0.001; P = 0.05, P<0.001, respectively), but EBV detection by real-time PCR and loop-mediated isothermal amplification presented no significant result (P = 0.06; P = 0.3, respectively). For the clinical parameters of periodontitis, pocket depth (PD) and bleeding of probing (BOP) percentages were higher in the EBV-positive sites than in the EBV-negative sites (MD 0.47 [0.08, 0.85], P = 0.02; MD 19.45 [4.47, 34.43], P = 0.01).

Conclusions

A high frequency of EBV detection is associated with an increased risk of periodontitis. The EBV association was particularly significant in all populations except in African populations. Subgigival plaque (SgP), tissue and GCF were not significantly different useful material for detecting EBV in periodontitis. Nested PCR and multiplex PCR are reliable methods for this purpose. In the presence of EBV, PD and BOP are reliable clinical parameters for gingival inflammation. However, some caution in such interpretation is justified due to heterogeneity among studies. A suggested extension could assess the parallel influence of other human herpesviruses.

A comprehensive analysis of genetic diversity of EBV reveals potential high-risk subtypes associated with nasopharyngeal carcinoma in China

Epstein-Barr virus (EBV), a widespread oncovirus, is associated with multiple cancers including nasopharyngeal carcinoma (NPC), gastric cancer and diverse lymphoid malignancies. Recent studies reveal that specific EBV strains or subtypes are associated with NPC development in endemic regions. However, these NPC specific subtypes were only identified in a portion of infected individuals due possibly to the limited samples size studied or the complicated population structures of the virus. To identify additional high-risk EBV subtypes, we conducted a comprehensive genetic analysis of 22 critical viral proteins by using the largest dataset of 628 EBV genomes and 792 sequences of single target genes/proteins from GenBank. The phylogenetic, principal component and genetic structure analyses of these viral proteins were performed through worldwide populations. In addition to the general Asia-Western/Africa geographic segregation, population structure analysis showed a 'Chinese-unique' cluster (96.57% isolates from China) was highly enriched in the NPC patients, compared to the healthy individuals (89.6% vs. 44.5%, P < 0.001). The newly identified EBV subtypes, which contains four Chinese-specific NPC-associated amino acid substitutions (BALF2 V317M, BNRF1 G696R, V1222I and RPMS1 D51E), showed a robust positive association with the risk of NPC in China (Odds Ratio = 4.80, 20.00, 18.24 and 32.00 for 1, 2, 3 and 4 substitutions, respectively, P _trend <0.001). Interestingly, the coincidence of positively selected sites with NPC-associated substitutions suggests that adaptive nonsynonymous mutation on critical proteins, such as BNRF1, may interact with host immune system and contribute to the carcinogenesis of NPC. Our findings provide a comprehensive overview of EBV genetic structure for worldwide populations and offer novel clues to EBV carcinogenesis from the aspect of evolution.

Dose-Response Reduction in Risk of Nasopharyngeal Carcinoma From Smoking Cessation: A Multicenter Case-Control Study in Hong Kong, China

BACKGROUND

Cigarette smoking is associated with nasopharyngeal cancer (NPC) risk. Whether quitting reduces the risk is unclear. We investigated the associations of NPC with duration of and age at quitting in an endemic region.

METHODS

We investigated the associations between NPC and quitting in a multicenter case-control study in Hong Kong with 676 newly diagnosed NPC cases and 1,285 hospital controls between 2014 and 2017, using a computer-assisted self-administered questionnaire. Multivariable unconditional logistic regression yielded adjusted odds ratios (AORs) of NPC by quitting status, duration and age of quitting, combinations of duration and age of quitting, and quitting to smoking duration ratio, compared with current smoking.

RESULTS

Quitting (AOR: 0.72; 95% CI: 0.53-0.98) and never smoking (0.73, 0.56-0.95) were associated with lower NPC risk. NPC risk decreased with (i) longer quitting duration (p < 0.01), reaching significance after 11-20 (0.62, 0.39-0.99) and 21+ years (0.54, 0.31-0.92) of quitting; (ii) younger quitting age (p = 0.01), reaching significance for quitting at <25 years (0.49, 0.24-0.97); and (iii) higher quitting to smoking duration ratio (p < 0.01), reaching significance when the ratio reached 1 (0.60, 0.39-0.93). Quitting younger (age <25) appeared to confer larger reductions (49% for ≤10 years of quitting, 50% for 11+ years) in NPC risk than quitting at older ages (25+) regardless of quitting duration (16% for ≤10 years, 39% for 11+ years).

CONCLUSIONS

We have shown longer duration and younger age of quitting were associated with lower NPC risk, with dose-response relations. Our findings support including smoking as a cause of NPC. Stronger tobacco control measures and quitting services are needed to prevent NPC.

A direct negative feedback loop of miR-4721/FOXA1/Nanog promotes nasopharyngeal cell stem cell enrichment and metastasis

Objective

The recurrence and metastasis of nasopharyngeal cancer (NPC) may be mainly attributed to the persistence of cancer stem cells (CSCs); however, the linkage mechanism has yet to be fully elucidated.

Methods

The levels of miR-4721, FOXA1, and Nanog expression in NPC were detected by in situ hybridization and immunohistochemistry. In vivo and in vitro metastasis assays confirmed miR-4721 promotes cell migration and invasion. Tumor spheroid formation assay, side population (SP) assay, and ALDEFLUOR assay verified miR-4721 regulates cancer stem cell-like properties. Luciferase reporter assay showed that miR-4721 directly regulates FOXA1 and FOXA1 effects the promoter activity of miR-4721 and Nanog. Chromatin immunoprecipitation (ChIP) analysis and electrophoresis mobility shift assay (EMSA) revealed that FOXA1 combined the promoter region of human miR-4721 and Nanog and the possible mechanism was also analyzed.

Results

In this study, a new mechanism of NPC tumorigenesis related to miR-4721 was verified. We found that miR-4721, FOXA1 and Nanog control their expressions through a negative feedback loop and then activate the downstream regulator of stem cell signaling to promote the enrichment and metastasis of NPC stem cells.

Conclusion

These findings elucidate that the feedback loop of miR-4721/FOXA1/Nanog can regulate stemness and metastasis in NPC and may provide an experimental theoretical basis for metastasis and treatment resistance in NPC.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12967-021-03059-y.

Low vitamin D exposure and risk of nasopharyngeal carcinoma: Observational and genetic evidence from a multicenter case-control study

BACKGROUND & AIMS

Little is known about the risk of nasopharyngeal carcinoma (NPC) in relation to vitamin D exposure. The aim of this study was to examine the associations of NPC risk with serum level of 25-hydroxyvitamin D (25OHD) and genetic predicted 25OHD, and potential effect modification by several putative risk factors of NPC.

METHODS

Our multicenter case-control study in Hong Kong recruited 815 NPC cases and 1502 frequency-matched (by sex and age) hospital controls from five major regional hospitals, and recruited 299 healthy subjects from blood donation centers (2014-2017). Circulating level of 25-hydroxyvitamin D (25OHD) and genetic predicted 25OHD (rs12785878, rs11234027, rs12794714, rs4588 and rs6013897) were measured by validated enzyme immunoassay and the iPLEX assay on the MassARRAY System, respectively. Data were also collected on demographics, lifestyle factors, ultraviolet radiation exposure, and potential confounders using a computer-assisted, self-administered questionnaire with satisfactory test-retest reliability. Unconditional logistic regression models were used to estimate ORs and 95% CIs.

RESULTS

Despite no significant association of NPC risk with circulating 25OHD and genetic predicted 25OHD, there was evidence for an inverse association in participants with normal body mass index (between 18.5 and 27.5) across categories of 25OHD (P_trend = 0.003), and a positive association in those with low socioeconomic status across categories based on the genetic score (P_trend = 0.005). In addition, risk of NPC diagnosed at an early stage was higher for genetically lower 25OHD level (adjusted OR = 3.09, 95% CI = 1.04-9.21, P_trend = 0.022).

CONCLUSIONS

Findings of this first comprehensive study to investigate the positive association of NPC risk with vitamin D deficiency need to be confirmed and be best interpreted with results of further similar studies. Our findings may inform possible etiological mechanisms of the associations with several putative risk/protective factors of NPC.

A comprehensive risk score for effective risk stratification and screening of nasopharyngeal carcinoma

Using Epstein-Barr virus (EBV)-based markers to screen populations at high risk for nasopharyngeal carcinoma (NPC) is an attractive preventive approach. Here, we develop a comprehensive risk score (CRS) that combines risk effects of EBV and human genetics for NPC risk stratification and validate this CRS within an independent, population-based dataset. Comparing the top decile with the bottom quintile of CRSs, the odds ratio of developing NPC is 21 (95% confidence interval: 12-37) in the validation dataset. When combining the top quintile of CRS with EBV serology tests currently used for NPC screening in southern China, the positive prediction value of screening increases from 4.70% (serology test alone) to 43.24% (CRS plus serology test). By identifying individuals at a monogenic level of NPC risk, this CRS approach provides opportunities for personalized risk prediction and population screening in endemic areas for the early diagnosis and secondary prevention of NPC.

Central nervous system metastases: a rare presentation of nasopharyngeal carcinoma

We report a case of a male patient. He presented with nasal obstruction and epistaxis. The MRI of the brain showed a mass in the nasopharynx and enlarged cervical lymph nodes. Besides this, there was an extra-axial, dural-based lesion in brain and subcentimetre nodules in both lungs. He received induction chemotherapy followed by chemoradiation therapy to the primary site and dural-based metastatic deposit. He re-presented with bilateral lower limb weakness. The MRI of the spine showed metastatic deposits within the thoracic cord parenchyma and meningeal deposits at the lumbar region. Palliative radiation was used to treat spinal cord and meningeal metastases. He died a few months later because of systemic disease progression. Considering the rarity of this presentation in nasopharyngeal carcinoma and lack of clear guidelines for standard treatment, we report this case to share our experience of management.

Smoking and nasopharyngeal cancer: individual data meta-analysis of six prospective studies on 334 935 men

BACKGROUND

The role of smoking in nasopharyngeal carcinoma (NPC) remains uncertain, especially in endemic regions. We conducted an individual participant data (IPD) meta-analysis of prospective cohort studies to investigate the associations between smoking exposure and risk of NPC.

METHODS

We obtained individual participant data of 334 935 male participants from six eligible population-based cohorts in NPC-endemic regions, including two each in Guangzhou and Taiwan, and one each in Hong Kong and Singapore. We used one- and two-stage approaches IPD meta-analysis and Cox proportional hazard models to calculate hazard ratios (HRs) and 95% confidence intervals (CIs) of NPC for smoking exposure adjusting for age and drinking status.

RESULTS

During 2 961 315 person-years of follow-up, 399 NPC evens were ascertained. Risks of NPC were higher in ever versus never smokers (HRone-stage = 1.32, 95% CI = 1.07-1.63, P = 0.0088; HRtwo-stage = 1.27, 1.01-1.60, 0.04). These positive associations appeared to be stronger in ever smokers who consumed 16+ cigarettes/day (HRone-stage = 1.67, 95% CI = 1.29-2.16, P = 0.0001), and in those who started smoking at age younger than 16 (2.16, 1.33-3.50, 0.0103), with dose-response relationships (P-values for trend = 0.0028 and 0.0103, respectively). Quitting (versus daily smoking) showed a small reduced risk (stopped for 5+ years: HRone-stage = 0.91, 95% CI = 0.60-1.39, P = 0.66; for former smokers: HRtwo-stage = 0.84, 0.61-1.14, 0.26).

CONCLUSIONS

This first IPD meta-analysis from six prospective cohorts in endemic regions has provided robust observational evidence that smoking increased NPC risk in men. NPC should be added to the 12-16 cancer sites known to be tobacco-related cancers. Strong tobacco control policies, preventing young individuals from smoking, would reduce NPC risk in endemic regions.

Human Polycomb Protein 2 (hPC2) as a Novel Independent Prognostic Marker in Nasopharyngeal Carcinoma

Purpose

Human polycomb protein 2(hPC2) is a vital component of polycomb repressive complex 1(PRC1). It plays a critical role in tumorigenesis and progression. However, whether HPC2 expression affects the prognosis of patients with nasopharyngeal carcinoma (NPC) is currently unclear. In the present study, we investigated the expression of hPC2and elucidated its clinical prognostic significance in NPC.

Patients and Methods

The expression of hPC2 in 180 NPCs samples was examined by immunohistochemistry (IHC) and evaluated by H-score staining intensity. Receiver operator characteristic (ROC) curve analysis was performed to determine cut-off values of hPC2 expression. The chi-square test, Kaplan–Meier (Log rank test), and the Cox proportional hazards model were utilized to analyze the data.

Results

We found hPC2 is highly expressed in 48.3% of NPC specimens, which significantly correlated with T stage (p=0.032), N stage (p=0.006), and clinical stage (p=0.003). Kaplan–Meier analysis indicated that NPCs with high hPC2 expression tended to have a lower cumulative rates of overall survival (OS, p<0.001), recurrence-free survival (RFS, p=0.001), and distant metastasis-free survival (DMFS, p=0.003). In the NPCs subgroup, T3–T4, N2–N3, and stages III–IV, high hPC2 expression also had a prognostic impact on worse outcome in terms of OS, RFS, and DMFS. More importantly, multivariate analyses demonstrated that hPC2 expression was an independent prognostic factor for OS (hazard ratio [HR], 95% (confidence interval [CI]), p=0.001), RFS (HR, 95% CI, p=0.018), and DMFS (HR, 95% CI, p=0.022).

Conclusion

We present evidence that high expression of hPC2 correlated with poorer prognosis in NPC. hPC2 could serve as a novel prognostic biomarker and might be a promising therapeutic target for NPC.

Current Status and Future Perspectives about Molecular Biomarkers of Nasopharyngeal Carcinoma

Simple Summary

Nasopharyngeal carcinoma is a serious major public health problem in its endemic countries. Up to 80% of NPC patients with locally advanced disease or distant metastasis at diagnosis were associated with poor prognosis and with median survival less than 4 months. The mortality rate of NPC metastasis is up to 91%. To date, there is no available curative treatment or reliable early diagnosis or prognosis for NPC. Discovery and development of reliable early diagnosis and prognosis biomarkers for nasopharyngeal carcinoma are urgent needed. Hence, we have here listed the potential early diagnosis and prognosis biomarker candidates for nasopharyngeal carcinoma. This review will give an insight to readers on the progress of NPC biomarker discovery to date, as well as future prospective biomarker development and their translation to clinical use.

Abstract

Nasopharyngeal carcinoma (NPC) is an epithelial malignancy that shows a remarkable ethnic and geographical distribution. It is one of the major public health problems in some countries, especially Southern China and Southeast Asia, but rare in most Western countries. Multifactorial interactions such as Epstein–Barr virus infection, individual’s genetic susceptibility, as well as environmental and dietary factors may facilitate the pathogenesis of this malignancy. Late presentation and the complex nature of the disease have led it to become a major cause of mortality. Therefore, an effective, sensitive, and specific molecular biomarker is urgently needed for early disease diagnosis, prognosis, and prediction of metastasis and recurrence after treatment. In this review, we discuss the recent research status of potential biomarker discovery and the problems that need to be explored further for better NPC management. By studying the aberrant pattern of these candidate biomarkers that promote NPC development and progression, we are able to understand the complexity of this malignancy better, hence positing our stands better towards strategies that may provide a way forward to the discovery of more reliable and specific biomarkers for diagnosis and targeted therapeutic development.

Interplay between Epstein-Barr virus infection and environmental xenobiotic exposure in cancer

Epstein-Barr virus (EBV) is a herpesvirus associated with lymphoid and epithelial malignancies. Both B cells and epithelial cells are susceptible and permissive to EBV infection. However, considering that 90% of the human population is persistently EBV-infected, with a minority of them developing cancer, additional factors are necessary for tumor development. Xenobiotics such as tobacco smoke (TS) components, pollutants, pesticides, and food chemicals have been suggested as cofactors involved in EBV-associated cancers. In this review, the suggested mechanisms by which xenobiotics cooperate with EBV for carcinogenesis are discussed. Additionally, a model is proposed in which xenobiotics, which promote oxidative stress (OS) and DNA damage, regulate EBV replication, promoting either the maintenance of viral genomes or lytic activation, ultimately leading to cancer. Interactions between EBV and xenobiotics represent an opportunity to identify mechanisms by which this virus is involved in carcinogenesis and may, in turn, suggest both prevention and control strategies for EBV-associated cancers.

Impact of smoking on survival in nasopharyngeal carcinoma: A cohort study with 23,325 patients diagnosed from 1990 to 2016

BACKGROUND

We aimed to compare the survival outcomes of patients with nasopharyngeal carcinoma (NPC) who had different smoking behaviors and were treated with two- or three-dimensional radiotherapy (2D/3DRT) or intensity-modulated radiotherapy (IMRT) with a long-term follow up.

METHODS

From 1990 to 2016, 23,325 patients with NPC were included. The primary endpoint of this study was overall survival (OS). The log-rank test and Cox proportional hazards regression model were used to assess the patients' survival outcomes.

RESULTS

The 5-year OS rates in the entire cohort were 76.4%, 68.9%, and 79.8% in the former, current, and never smokers, respectively. In the IMRT cohort, the OS rates showed the same trend. Compared with the never smokers, the 5-year distant metastasis-free survival (DMFS) was lower in the former (P = 0.004) and current smokers (P < 0.001). In the multivariate analysis of the IMRT cohort, the risk of death (P = 0.003) and recurrence (P = 0.027) was higher in the current smokers, while the risk of metastasis was higher in the former and current smokers (P = 0.031 and P = 0.019, respectively) than the never smokers. A total of 53.9% of the effect of smoking status on OS was through sex, age, and Epstein-Barr virus DNA, which were significant mediators.

CONCLUSION

In the IMRT era, being a former smoker or current smoker was an independent risk factor for DMFS. The difference in OS and locoregional relapse-free survival was significant only between the current smokers and never smokers.

Association between HLA alleles and Epstein-Barr virus Zta-IgA serological status in healthy males from southern China

Background

Nasopharyngeal carcinoma (NPC), an Epstein–Barr virus (EBV) associated cancer, exhibits an extremely high incidence in southern Chinese. Given that human leukocyte antigen (HLA) plays critical roles in antigen presentation and relates to NPC susceptibility, it is speculated that certain HLA variants may affect EBV reactivation, which is a key pathogenic factor of NPC. Therefore, we attempted to identify HLA alleles associated with the indicator of EBV reactivation, Zta‐IgA, in healthy males from NPC endemic area.

Methods

HLA alleles of 1078 healthy males in southern China from the 21‐RCCP study were imputed using genome‐wide single nucleotide polymorphism data. EBV Zta‐IgA in blood samples were measured using an enzyme‐linked immunosorbent assay. Multiple logistic regression analysis was used to evaluate the effect of HLA allele on Zta‐IgA serological status and its potential joint association with smoking. The binding affinity for Zta‐peptide was predicted using NetMHCIIpan 4.0.

Results

HLA‐DRB1*09:01 was found to be associated with a higher risk of Zta‐IgA seropositivity (odds ratio = 1.80, 95% confidence interval = 1.32–2.45; p = 1.82 × 10⁻⁴). Compared with non‐smokers without HLA‐DRB1*09:01, the effect size increased to 2.19‐ and 3.70‐fold for the light and heavy smokers carrying HLA‐DRB1*09:01, respectively. Furthermore, HLA‐DRB1*09:01 showed a stronger binding affinity to Zta peptide than other HLA‐DRB1 alleles.

Conclusions

Our study highlighted the pivotal role of genetic HLA variants in EBV reactivation and the etiology of NPC. Smokers with HLA‐DRB1*09:01 have a significantly higher risk of being Zta‐IgA seropositive, which indicates the necessity of smoking cessation in certain high‐risk populations and also provide clues for further research on the etiology of NPC.

Advances in research on microRNAs related to the invasion and metastasis of nasopharyngeal carcinoma

Nasopharyngeal carcinoma (NPC), which is associated with latent Epstein-Barr virus infection in most cases, is a unique epithelial malignancy arising from the nasopharyngeal mucosal lining. Accumulating evidence provides insights into the genetic and molecular aberrations that likely drive nasopharyngeal tumor development and progression. We review recent analyses of microRNAs (miRNAs), including Epstein-Barr virus-encoded miRNAs (EBV-encoded miRNAs) and dysregulated cellular miRNAs, that may be related to the metastasis of nasopharyngeal carcinoma. The studies summarized herein have greatly expanded our knowledge of the molecular biology of NPC involving miRNAs, and they may provide new biological targets for clinical diagnosis and reveal the potential of microRNA therapeutics. However, much information remains to be uncovered.

High antibody levels against human herpesvirus-6A interact with lifestyle factors in multiple sclerosis development

BACKGROUND

Infection with human herpesvirus 6A (HHV-6A) has been suggested to increase multiple sclerosis (MS) risk. However, potential interactions between HHV-6A and environmental/lifestyle risk factors for MS have not previously been studied.

METHODS

We used two Swedish population-based case-control studies comprising 5993 cases and 5995 controls. Using logistic regression models, subjects with different HHV-6A antibody levels, environmental exposures, and lifestyle habits were compared regarding MS risk, by calculating odds ratios (ORs) with 95% confidence intervals (CIs). Potential interactions between high HHV-6A antibody levels and common environmental exposures and lifestyle factors were evaluated on the additive scale.

RESULTS

High HHV-6A antibody levels were associated with increased risk of developing MS (OR = 1.5, 95% CI = 1.4-1.6). Regarding MS risk, significant interactions were observed between high HHV-6A antibody levels and both smoking (attributable proportion (AP) = 0.2, 95% CI = 0.1-0.3), low ultraviolet radiation (UVR) exposure (AP = 0.3, 95% CI = 0.1-0.4), and low vitamin D levels (AP = 0.3, 95% CI = 0.0-0.6).

CONCLUSION

High HHV-6A antibody levels are associated with increased MS risk and act synergistically with common environmental/lifestyle risk factors for MS. Further research is needed to investigate potential mechanisms underlying the interactions presented in this study.

Nicotine-Induced ILF2 Facilitates Nuclear mRNA Export of Pluripotency Factors to Promote Stemness and Chemoresistance in Human Esophageal Cancer

Balancing mRNA nuclear export kinetics with its nuclear decay is critical for mRNA homeostasis control. How this equilibrium is aberrantly disrupted in esophageal cancer to acquire cancer stem cell properties remains unclear. Here we find that the RNA-binding protein interleukin enhancer binding factor 2 (ILF2) is robustly upregulated by nicotine, a major chemical component of tobacco smoke, via activation of JAK2/STAT3 signaling and significantly correlates with poor prognosis in heavy-smoking patients with esophageal cancer. ILF2 bound the THO complex protein THOC4 as a regulatory cofactor to induce selective interactions with pluripotency transcription factor mRNAs to promote their assembly into export-competent messenger ribonucleoprotein complexes. ILF2 facilitated nuclear mRNA export and inhibited hMTR4-mediated exosomal degradation to promote stabilization and expression of SOX2, NANOG, and SALL4, resulting in enhanced stemness and tumor-initiating capacity of esophageal cancer cells. Importantly, inducible depletion of ILF2 significantly increased the therapeutic efficiency of cisplatin and abrogated nicotine-induced chemoresistance in vitro and in vivo. These findings reveal a novel role of ILF2 in nuclear mRNA export and maintenance of cancer stem cells and open new avenues to overcome smoking-mediated chemoresistance in esophageal cancer. SIGNIFICANCE: This study defines a previously uncharacterized role of nicotine-regulated ILF2 in facilitating nuclear mRNA export to promote cancer stemness, suggesting a potential therapeutic strategy against nicotine-induced chemoresistance in esophageal cancer.

LncRNA EPB41L4A-AS2 represses Nasopharyngeal Carcinoma Metastasis by binding to YBX1 in the Nucleus and Sponging MiR-107 in the Cytoplasm

Nasopharyngeal carcinoma (NPC) is known for its potential to progress to the lymph nodes and distant metastases at an early stage. As an important regulator in tumorigenesis biological processes, the functions of lncRNA in NPC tumor development remain largely unclear. In this research, the expression of EPB41L4A-AS2 in NPC tissues and cells was analyzed via real-time quantitative polymerase chain reaction (qRT-PCR). CCK8, colony formation, and EDU experiments were used to determine the viability of NPC cells. Transwell and wound healing assays were performed to test NPC cell migration and invasion. RNA pull-down and mass spectrometry analysis were used to identify potential binding proteins. Then, a popliteal lymph node metastasis model was established to test NPC metastasis. EPB41L4A-AS2 is repressed by transforming growth factor-beta, which is downregulated in NPC cells and tissue. It is associated with the presence of distant metastasis and adverse outcomes. The univariate and multivariate survival assays confirmed that EPB41L4A-AS2 expression was an independent predictor of progression-free survival (PFS) in patients with NPC. Biological analyses showed that overexpression of EPB41L4A-AS2 reduced the metastasis and invasion of NPC in vitro and in vivo, but had no significant effect on cell proliferation. Mechanistically, in the nucleus we identified that EPB41L4A-AS2 relies on binding to YBX1 to reduce the stability of Snail mRNA to enhance the expression of E-cadherin and reverse the progression of epithelial-to-mesenchymal transition (EMT). In the cytoplasm, we found that EPB41L4A-AS2 blocked the invasion and migration of NPC cells by promoting LATS2 expression via sponging miR-107. In a whole, the findings of this study help to further understand the metastasis mechanism of NPC and could help in the prevention and treatment of NPC metastasis.

Macrophages Inhibit Ciliary Protein Levels by Secreting BMP-2 Leading to Airway Epithelial Remodeling Under Cigarette Smoke Exposure

Chronic obstructive pulmonary disease (COPD) is a chronic respiratory disease with high morbidity and mortality worldwide. So far, smoking is still its leading cause. The characteristics of COPD are emphysema and airway remodeling, as well as chronic inflammation, which were predominated by macrophages. Some studies have reported that macrophages were involved in emphysema and chronic inflammation, but whether there is a link between airway remodeling and macrophages remains unclear. In this study, we found that both acute and chronic cigarette smoke exposure led to an increase of macrophages in the lung and a decrease of ciliated cells in the airway epithelium of a mouse model. The results of in vitro experiments showed that the ciliary protein (β-tubulin-IV) levels of BEAS-2B cells could be inhibited when co-cultured with human macrophage line THP-1, and the inhibitory effect was augmented with the stimulation of cigarette smoke extract (CSE). Based on the results of transcriptome sequencing, we focused on the protein, bone morphogenetic protein-2 (BMP-2), secreted by the macrophage, which might mediate this inhibitory effect. Further studies confirmed that BMP-2 protein inhibited β-tubulin-IV protein levels of BEAS-2B cells under the stimulation of CSE. Coincidentally, this inhibitory effect could be nearly blocked by the BMP receptor inhibitor, LDN, or could be interfered with BMP-2 siRNA. This study suggests that activation and infiltration of macrophages in the lung induced by smoke exposure lead to a high expression of BMP-2, which in turn inhibits the ciliary protein levels of the bronchial epithelial cells, contributing to the remodeling of airway epithelium, and aggravates the development of COPD.

The Evolving Epidemiology of Nasopharyngeal Carcinoma

BACKGROUND

The epidemiology of nasopharyngeal carcinoma (NPC) has long been a source of fascination due to the malignancy's striking geographic distribution, the involvement of the oncogenic Epstein-Barr virus (EBV), the unique association with intake of Chinese-style salt-preserved fish, and etiologic heterogeneity by histologic subtype.

METHODS

This review summarizes the current epidemiologic literature on NPC, highlighting recent results from our population-based case-control study in southern China.

RESULTS

Findings from our case-control study provide new insight into the epidemiology of NPC, including a diminished role of Chinese-style salt-preserved fish, a profound impact of EBV genetic sequence variation, modest positive associations with passive smoking and household air pollution, and possible effects of oral health and the oral microbiome. Recent findings from other studies include a protective association with infectious mononucleosis, suggesting a causal role of early EBV infection; familial risk conferred by shared genetic variation in the host antibody-mediated immune response to EBV infection; and an unclear association with occupational exposure to formaldehyde.

CONCLUSIONS

To shed further light on the interplay of environmental, genetic, and viral causes of NPC, large pooled studies must accumulate sufficient cases with detailed exposure data.

IMPACT

New epidemiologic findings have reshaped the causal model for NPC.

Identification of potential plasma biomarkers in early-stage nasopharyngeal carcinoma-derived exosomes based on RNA sequencing

BACKGROUND

Early diagnosis of nasopharyngeal carcinoma (NPC) is vital to improve the prognosis of these patients. However, early diagnosis of NPC is typically challenging. Therefore, we explored the pathogenetic roles and associated mechanisms of exosomes in plasma of patients with early-stage NPC.

METHODS

Exosomes in plasma were extracted by ultra-high-speed centrifugation. Western blot and transmission electron microscopy (TEM) were used to verify the purity of exosomes. The sequencing data (6 plasma samples from healthy volunteers vs. 6 NPC plasma samples) were analyzed by principal component analysis (PCA), DESeq2, gene ontology (GO), Kyoto encyclopedia of genes and genomes (KEGG), and TargetScan. The differentially expressed miRNAs (DEmiRNAs) were obtained from the dataset (GSE118720) downloaded from the Gene Expression Omnibus (GEO) repository. Additionally, the datasets downloaded from the GEO database (GSE12452, GSE13597, GSE53819, GSE64634) were used to predict the target genes and functions of hsa-miR-1301-3p. qPCR was applied to verify the differences in the expressions of hsa-miR-1301-3p between 10 normal plasma and 10 NPC plasma samples.

RESULTS

Western blot, TEM, and Nanoparticle Tracking Analysis showed adequate purity of the extracted exosomes. RNA-seq analysis revealed 21 upregulated miRNAs, and 10 downregulated miRNAs in plasma exosomes of early-stage NPC patients. GO analysis showed that the target genes of DEmiRNAs were mainly enriched in DNA synthesis and transcription regulation. KEGG analysis revealed that DEmiRNAs were mainly enriched in PI3K-Akt and MAPK signaling pathways. Moreover, the expression of hsa-mir-1301-3p was verified to be significantly upregulated in enlarged samples of plasma exosomes.

CONCLUSIONS

We identified several DEmiRNAs extracted from tumor-derived exosomes between normal plasma and early-stage NPC plasma. Bioinformatics analyses indicated that these DEmiRNAs may be related to NPC development. Our study may provide novel insights into underlying biomarkers and mechanisms of plasma exosomes in early-stage NPC.

Prognostic Value of Serum Epstein-Barr Virus Antibodies and Their Correlation with TNM Classification in Patients with Locoregionally Advanced Nasopharyngeal Carcinoma

Purpose

This study assessed the correlation between Epstein-Barr virus (EBV) biomarkers and the eighth American Joint Committee on Cancer staging system and the prognostic values of IgG antibodies against replication and transcription activator (Rta-IgG), IgA antibodies against Epstein-Barr nuclear antigen 1, and BamH1 Z transactivator (Zta-IgA) in locoregionally advanced nasopharyngeal carcinoma (NPC) patients.

Materials and Methods

Serum EBV antibody levels were measured by enzyme-linked immunosorbent assay in 435 newly diagnosed stage III-IVA NPC patients administered intensity-modulated radiation therapy±chemotherapy. The primary endpoint was progression-free survival (PFS).

Results

Rta-IgG and Zta-IgA levels were positively correlated with the N category and clinical stage. Patients with high Rta-IgG levels (> 29.07 U/mL) showed a significantly inferior prognosis as indicated by PFS (77% vs. 89.8%, p=0.004), distant metastasis–free survival (DMFS) (88.3% vs. 95.8%, p=0.021), and local recurrence-free survival (LRFS) (91.2% vs. 98.3%, p=0.009). High Rta-IgG levels were also significantly associated with inferior PFS and LRFS in multivariable analyses. In the low-level EBV DNA group (≤ 1,500 copies/mL), patients with high Rta-IgG levels had significantly inferior PFS and DMFS (both p < 0.05). However, in the high-level EBV DNA group, Rta-IgG levels were not significantly associated with PFS, DMFS, and LRFS. In the advanced T category (T3–4) subgroup, high Rta-IgG levels were also significantly associated with inferior PFS, DMFS, and LRFS (both p < 0.05).

Conclusion

Rta-IgG and Zta-IgA levels were strongly correlated with the TNM classification. Rta-IgG level was a negative prognostic factor in locoregionally advanced NPC patients, especially those with advanced T category or low EBV DNA level.