Gene variations of Epstein-Barr virus nuclear antigen 3A in nasopharyngeal carcinomas, gastric carcinomas and healthy carriers in northern China

Essential Genes to Consider in Epstein-Barr Virus-Associated Gastric Cancer: A Systematic Review

Gastric cancer (GC) is a prevalent malignancy worldwide; the Epstein-Barr Virus (EBV) also affects many people worldwide. An important association has been seen in these two diseases that could explain causality and a possible viral etiology of GC as has been seen with Helicobacter pylori. This study aims to identify genes expressed in malignant cells that are infected with EBV and see if one could be more oncogenic than the other. We conducted a systematic review based on the preferred reporting items for systematic reviews and meta-analysis (PRISMA) guidelines. We had 29 observational studies after inclusion/exclusion criteria and quality assessment for every single study. A total of 1022 patients were evaluated for different types of genes in 29 papers. It was demonstrated that the most expressed genes or the gene most involved were genes that are seen in Epstein-Barr virus-associated gastric cancer (EBVaGC) as latent genes of the EBV-infected cells, which are found in tumor cells. The genes that were mostly involved were LMP2, BNLF2a, and the absence of LMP1 that lead to the expression of BARF1, among other genes. These studies were made on mostly Asian populations, so it is still unknown if these genes involved have a geographical association more than an EBV and GC association.

Epstein-Barr Virus Epidemiology, Serology, and Genetic Variability of LMP-1 Oncogene Among Healthy Population: An Update

The Epstein-Barr virus (EBV) is a DNA lymphotropic herpesvirus and the causative agent of infectious mononucleosis. EBV is highly prevalent since it affects more than 90% of individuals worldwide and has been linked to several malignancies including PTLDs, which are one of the most common malignancies following transplantation. Among all the EBV genes, most of the recent investigations focused on studying the LMP-1 oncogene because of its high degree of polymorphism and association with tumorigenic activity. There are two main EBV genotypes, Type 1 and 2, distinguished by the differences in the EBNA-2 gene. Further sub genotyping can be characterized by analyzing the LMP-1 gene variation. The virus primarily transmits through oral secretions and persists as a latent infection in human B-cells. However, it can be transmitted through organ transplantations and blood transfusions. In addition, symptoms of EBV infection are not distinguishable from other viral infections, and therefore, it remains questionable whether there is a need to screen for EBV prior to blood transfusion. Although the process of leukoreduction decreases the viral copies present in the leukocytes, it does not eliminate the risk of EBV transmission through blood products. Here, we provide a review of the EBV epidemiology and the genetic variability of the oncogene LMP-1. Then, we underscore the findings of recent EBV seroprevalence and viremia studies among blood donors as a highly prevalent transfusion transmissible oncovirus.