Viral and Cellular MicroRNAs in Regulation of EBV Latency and Oncogenesis

Epstein-Barr virus (EBV), an oncogenic virus that ubiquitously establishes life-long persistence in humans, encodes viral miRNAs in two clusters, BHRF1 and BART. EBV also regulates expression of a large pool of cellular miRNAs, including miR-155, miR-146a, miR-21, miR-29, and miR-34a. These miRNAs targets both viral and cellular genes involved in the entire viral lifetime from lytic infection to oncogenesis, including viral replication, immune responses, cell cycle regulation, apoptosis, and cell proliferation, and are indispensable for persistent infection, latency establishment and maintenance, and cancer development. Among them, circulating miRNAs and unique miRNA profiles are promising diagnosis and prognosis biomarkers alone or with other traditional biomarkers. Elucidation of the precise mechanisms of action of these miRNAs in EBV latent infection will improve our knowlege of EBV persistence and oncogenesis, and may foster new strategies to target these miRNAs for treatments of EBV-associated cancers