Functional Implications of Epstein-Barr Virus Lytic Genes in Carcinogenesis

Simple Summary Epstein-Barr virus (EBV) was the first human tumor virus to be discovered and is a causative agent for several cancer types of epithelial and lymphoid origin. EBV has two life cycles comprised of latent and lytic phases. The lytic cycle is when new virions are produced, whereas the latent cycle is a state of persistent infection without productive viral replication. It has been recognized that latent infection is the predominant mode of infection in EBV-associated cancers and the expression of a restricted set of latent genes drives disease development. However, we now know that several lytic genes are also expressed in EBV tumors, suggesting a critical role for these genes in tumorigenesis. Here, we summarize the current evidence as to how EBV lytic genes might contribute to EBV-driven oncogenesis. Epstein-Barr virus (EBV) is associated with a diverse range of tumors of both lymphoid and epithelial origin. Similar to other herpesviruses, EBV displays a bipartite life cycle consisting of latent and lytic phases. Current dogma indicates that the latent genes are key drivers in the pathogenesis of EBV-associated cancers, while the lytic genes are primarily responsible for viral transmission. In recent years, evidence has emerged to show that the EBV lytic phase also plays an important role in EBV tumorigenesis, and the expression of EBV lytic genes is frequently detected in tumor tissues and cell lines. The advent of next generation sequencing has allowed the comprehensive profiling of EBV gene expression, and this has revealed the consistent expression of several lytic genes across various types of EBV-associated cancers. In this review, we provide an overview of the functional implications of EBV lytic gene expression to the oncogenic process and discuss possible avenues for future investigations.

Automated summary

Epstein-Barr virus (EBV) is a human tumor virus that plays a critical role in the development of various cancers. It has two life cycles, latent and lytic, with latent genes driving disease development and lytic genes responsible for viral transmission. Recent studies have shown that EBV lytic genes are expressed in tumor tissues and cell lines, suggesting their significant involvement in tumorigenesis.