Expression and Function of Kaposi’s Sarcoma-Associated Herpesvirus Non-coding RNAs

Purpose of Review Herpesviruses are large DNA viruses whose genomes contain a number of genes producing non-coding RNAs, such as small RNA and long non-coding RNA. In this review, the expression and function of Kaposi’s sarcoma-associated herpesvirus (KSHV) non-coding RNAs are discussed. Recent Findings The KSHV genome contains at least 12 genes from which pre-microRNAs (miRNAs) are transcribed, and several genes producing long non-coding RNAs (lncRNAs). Polyadenylated nuclear RNA is a highly expressed viral lncRNA molecule in KSHV-infected cells and is necessary for KSHV replication. KSHV miRNAs are expressed predominantly during the latent phase of KSHV infection not only in cells but also in extracellular vesicles such as exosomes and virions. Identification of viral miRNA targets has revealed that KSHV miRNAs have various functions relating to oncogenesis, anti-apoptosis, angiogenesis, and migration of KSHV-infected cells. Some KSHV miRNAs regulate KSHV replication to maintain viral latency. Summary KSHV non-coding RNAs play significant roles in the pathogenesis of KSHV-associated diseases.