Abstract 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 p interaction < 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 p trend < 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.
Abstract The detection of Epstein‐Barr virus (EBV) DNA load in nasopharyngeal (NP) brushing samples for diagnosis of nasopharyngeal carcinoma (NPC) has attracted great attention. Further improvements that eliminate the need for clinical settings will greatly extend its application. A total of 250 participants were recruited to obtain NP brushing samples. Brush sampling both with and without the guide of endoscopy was conducted in 38 NPC patients. EBV DNA load, EBV RNA transcript and EBV DNA C promoter methylation status were, respectively, evaluated. Typical latency II transcripts were observed in brushing samples from NPC patients but not controls. Unlike in tissues, multiple lytic gene transcripts were observed not only in NPC patients but also in controls. Apart from EBV RNA transcript, samples from NPC patients also showed higher levels of EBV DNA load and C promoter methylation degree than their controls. Qualitative analysis further showed that EBV DNA C promoter was methylated in all NPC patients but in only 18.4% of the control group. Combined analysis of EBV DNA methylated degree and EBV DNA load increased the sensitivity to 100% in the detection of NPC. Using qualitative methylated type as the criteria, up to 89.5% of samples collected via blind brushing showed consistent results with samples collected via endoscopy‐guided brushing from NPC patients. Detection of the methylation status of EBV DNA C promoter in NP brushing samples shows great potential in diagnosing NPC and may provide an appealing alternative for the non–invasive detection and screening of NPC without the need for clinical settings.
Abstract Human leukocyte antigen (HLA) molecules are essential for presenting Epstein−Barr virus (EBV) antigens and are closely related to nasopharyngeal carcinoma (NPC). This study aims to systematically investigate the association between HLA‐bound EBV peptides and NPC risk through in silico HLA‐peptide binding prediction. A total of 455 NPC patients and 463 healthy individuals in NPC endemic areas were recruited, and HLA‐target sequencing was performed. HLA‐peptide binding prediction for EBV, followed by peptidome‐wide logistic regression and motif analysis, was applied. Binding affinity changes for EBV peptides carrying high‐risk mutations were analyzed. We found that NPC‐associated EBV peptides were significantly enriched in immunogenic proteins and core linkage disequilibrium (LD) proteins related to evolution, especially those binding HLA‐A alleles ( p = 3.10 × 10 −4 for immunogenic proteins and p = 8.10 × 10 −5 for core LD proteins related to evolution). These peptides were clustered and showed binding motifs of HLA supertypes, among which supertype A02 presented an NPC‐risk effect ( p adj = 3.77 × 10 −4 ) and supertype A03 presented an NPC‐protective effect ( p adj = 4.89 × 10 −4 ). Moreover, a decreased binding affinity toward risk HLA supertype A02 was observed for the peptide carrying the NPC‐risk mutation BNRF1 V1222I ( p = 0.0078), and an increased binding affinity toward protective HLA supertype A03 was observed for the peptide carrying the NPC‐risk mutation BALF2 I613V ( p = 0.022). This study revealed the distinct preference of EBV peptides for binding HLA supertypes, which may contribute to shaping EBV population structure and be involved in NPC development.
Nasopharyngeal carcinoma (NPC) is highly incident in southern China, where 40% of world's new cases arise each year. Detection of Epstein-Barr virus (EBV) DNA load in nasopharyngeal (NP) brush/swab samples has gradually been established as a method for diagnosis of NPC. However, its applicable value in NPC diagnosis has never been investigated in southern China. It is important to explore whether such a test could be applicable to our local population. A total of 245 consecutive participants undergoing NP brushing examination were recruited to obtain the NP brushing samples in this study. Quantitative PCR assays were used to obtain the EBV DNA load. Mann-Whitney, ANOVA and receiver operating characteristic tests were used to analyze its diagnostic value. NP brushing samples from NPC patients showed extremely high levels of EBV DNA load (mean = 46360 copy/ng DNA) compared to its expression from non-NPC control (mean = 28 copy/ng DNA) and high-risk control (mean = 50 copy/ng DNA) groups. It produced 96% sensitivity and 97% specificity, at the COV = 225 copy/ng DNA. Furthermore, EBV DNA load could reflect disease progress. Our data showed a better performance of EBV DNA load in NP brushing samples compared with an initial biopsy, immunoglobulin A (IgA) antibody titers to viral capsid antigen in serum and EBV DNA load in plasma. Detection of EBV DNA load in NP brushing samples could be an effective supplement for NPC diagnosis. Being minimally invasive and low cost, NP brush sampling combined with EBV DNA detection demonstrates great potential for screening high-risk populations for NPC.
Tissue specimens for nasopharyngeal carcinoma (NPC) research are scarce because of sampling difficulties. Previous studies have suggested non-invasive nasopharyngeal brushing as an effective sampling method for NPC diagnosis. The present study aimed to evaluate the feasibility of nasopharyngeal brushing in the acquisition of NPC nucleic acids for research.Nasopharyngeal brushing samples were acquired from 24 healthy individuals and 48 NPC patients. Tissues from 48 NPC and 18 nasopharyngitis patients were collected by endoscopic biopsy. The expression levels of tumor suppressor genes (TSGs) and Epstein-Barr virus (EBV)-encoded microRNAs as well as EBV DNA copy number were measured by quantitative polymerase chain reaction in both types of samples.Among six TSGs examined, the expression levels of two genes were significantly decreased in nasopharyngeal brushing and tissue samples from NPC patients as compared with those from healthy/nasopharyngitis individuals. Four EBV-encoded microRNAs, mir-bart1-5p, mir-bart5, mir-bart6-5p, and mir-bart17-5p, were significantly up-regulated in both NPC brushing and tissue samples compared with those from healthy/nasopharyngitis controls (P < 0.001). EBV DNA was significantly increased in both nasopharyngeal brushing samples (P < 0.001) and tissue samples (P < 0.001) from NPC patients in comparison with those from healthy controls.Nasopharyngeal brushing can obtain sufficient tumoral materials for the analysis of viral nucleic acid, including EBV-encoded microRNAs and EBV DNA. For the detection of TSG expression, nasopharyngeal brushings was feasible but inferior to tissue samples. This study confirms nasopharyngeal brushing as an applicable sampling method that can aid in nucleic acid-based NPC research.
'/%3e%3cuse xlink:href='%23a' transform='rotate(23.036 .093 25.536)'/%3e%3cuse xlink:href='%23a' transform='rotate(45.87 1.273 16.18)'/%3e%3cuse xlink:href='%23a' transform='rotate(69.945 .996 12.078)'/%3e%3cuse xlink:href='%23a' transform='rotate(20.66 -19.689 31.932)'/%3e%3c/svg%3e)