Regulation network and expression profiles of Epstein-Barr virus-encoded microRNAs and their potential target host genes in nasopharyngeal carcinomas.

Epstein-Barr virus (EBV) is associated with nasopharyngeal carcinoma (NPC) tumorigenesis. However, the mechanism(s) connecting EBV infection and NPC remain unclear. Recently, a new class of EBV microRNAs (miRNAs) has been described. To determine how EBV miRNAs control the expression of host genes, and to understand their potential role in NPC tumorigenesis, we profiled the expression of 44 mature EBV miRNAs and potential host genes in NPC and non-tumor nasopharyngeal epithelial tissues. We found that 40 EBV miRNAs from the BART transcript were highly expressed in NPC. Analysis of potential BART miRNA target genes revealed that 3140 genes and several important pathways might be involved in the carcinogenesis of NPC. A total of 105 genes with potential EBV miRNA binding sites were significantly downregulated, suggesting that EBV miRNAs may regulate these genes and contribute to NPC carcinogenesis. An EBV miRNA and host gene regulation network was generated to provide useful clues for validating of EBV miRNA functions in NPC tumorigenesis.