EBV-Induced CXCL8 Upregulation Promotes Vasculogenic Mimicry in Gastric Carcinoma via NF-κB Signaling

EBV DNA methylation profiles and its application in distinguishing nasopharyngeal carcinoma and nasal NK/T-cell lymphoma

BACKGROUND

As an oncovirus, EBV is associated with multiple cancers, including solid tumors and hematological malignancies. EBV methylation plays an important role in regulating tumor occurrence. However, the EBV methylation profiles in EBV-associated tumor tissues are poorly understood.

RESULTS

In this study, EBV methylation capture sequencing was conducted in several different tumor tissue samples, including NPC, EBVaGC, lung LELC and parotid LELC. Besides, EBV capture sequencing and following qMSP were performed on nasopharyngeal brushing samples from NPC and nasal NKTCL patients. Our results showed that the EBV genome among different types of tumors displayed specific methylation patterns. Among the four types of tumors from epithelial origin (NPC, EBVaGC, lung LELC and parotid LELC), the most significant differences were found between EBVaGC and the others. For example, in EBVaGC, all CpG sites within 1,44,189-1,45,136 bp of the EBV genome sequence on gene RPMS1 were hyper-methylated compared to the others. Differently, significant differences of EBV CpG sites, particularly those located on gene BILF2, were observed between NPC and nasal NKTCL patients in nasopharyngeal brushing samples. Further, the methylated level of BILF2 was further detected using qMSP, and a diagnostic model distinguishing NPC and nasal NKTCL was established. The AUC of the model was 0.9801 (95% CI 0.9524-1.0000), with the sensitivity and specificity of 98.81% (95% CI 93.63-99.94%) and 76.92% (95% CI 49.74-91.82%), respectively.

CONCLUSIONS

Our study reveals more clues for further understanding the pathogenesis of EBV, and provides a possibility for distinguishing EBV-related tumor by detecting specific EBV CpG sites.

Establishment and characterization of two Epstein-Barr virus-positive gastric cancer cell lines with epitheliotropic M81 strain undergoing distinct viral and altered cellular expression profiles

Epstein-Barr virus (EBV)-associated gastric cancer (EBVaGC) is a distinct subtype of gastric cancer (GC) distinguished by the presence of the EBV genome and limited viral gene expression within malignant epithelial cells. EBV infection is generally thought to be a relatively late event following atrophic gastritis in carcinogenesis, which implies the heterogeneity of EBVaGC. To facilitate the study of the role of EBV in EBVaGC, we established two EBV-positive GC cell lines (AGS-EBV and HGC27-EBV) with an epitheliotropic EBV strain M81 and characterized viral and cellular gene expression profiles in comparison to SNU719, a naturally derived EBV-positive GC cell line. Like SNU719, AGS-EBV and HGC27-EBV stably maintained their EBV genomes and expressed EBV-encoded small RNAs and nuclear antigen EBNA1. Comprehensive analysis of the expression of EBV-encoded miRNAs within the BamHI-A region rightward transcript region, and the transcripts of EBV latent and lytic genes in cell lines, as well as xenografts, reveals that AGS-EBV and HGC27-EBV cells undergo distinct viral expression profiles. A very small fraction of AGS-EBV and SNU719 cells can spontaneously produce infectious progeny virions, while HGC27-EBV does not. AGS-EBV (both M81 and Akata) cells largely mimic SNU719 cells in viral gene expression profiles, and altered cellular functions and pathways perturbed by EBV infection. Phylogenetic analysis of the EBV genome shows both M81 and Akata EBV strains are closely related to clinical EBVaGC isolates. Taken together, these two newly established EBV-positive GC cell lines can serve as models to further investigate the role of EBV in different contexts of gastric carcinogenesis and identify novel therapeutics against EBVaGC.

Herpesvirus Screening in Childhood Hematopoietic Transplant Reveals High Systemic Inflammation in Episodes of Multiple Viral Detection and an EBV Association with Elevated IL-1β, IL-8 and Graft-Versus-Host Disease

Infections remain a major cause of morbidity and mortality among hematopoietic stem cell transplant (HSCT) recipients. Unlike Epstein–Barr Virus (EBV) and Human Cytomegalovirus (HCMV), Human Herpesvirus (HHV) 6, HHV7 and HHV8 are not routinely monitored in many centers, especially in the pediatric population of low–medium income countries. We screened EBV, HCMV, HHV6, HHV7 and HHV8 in 412 leukocytes-plasma paired samples from 40 pediatric patients assisted in a tertiary hospital in Mexico. Thirty-two underwent allo-HSCT, whereas eight received auto-HSCT. Overall viral detection frequencies in allo- and auto-HSCT were: EBV = 43.7% and 30.0%, HCMV = 5.0% and 6.7%, HHV6 = 7.9% and 20.0% and HHV7 = 9.7% and 23.3%. HHV8 was not detected in any sample. Interestingly, HHV6 and HHV7 were more frequent in auto-HSCT, and HHV6 was observed in all episodes of multiple detection in auto-HSCT patients. We found EBV DNA in plasma samples, whereas HCMV, HHV6 and HHV7 DNA were predominantly observed in leukocytes, indicative of their expansion in cellular compartments. We also found that IL-1β, IL-2, IL-6 and IL-8 were significantly increased in episodes in which multiple viruses were simultaneously detected, and samples positive for EBV DNA and graft-versus-host disease had a further increase of IL-1β and IL-8. In conclusion, the EBV, HCMV, HHV6 and HHV7 burdens were frequently detected in allo- and auto-HSCT, and their presence associated with systemic inflammation.