Circulating Epstein-Barr virus microRNA profile reveals novel biomarker for nasopharyngeal carcinoma diagnosis.

Nasopharyngeal carcinoma (NPC), a tumor quite prevalent in Asia, is closely associated with Epstein-Barr virus (EBV) infection status. Many NPC patients are not able to be treated in time when being diagnosed at an advanced stage. EBV-encoded microRNAs are reliable sources of biomarkers for NPC diagnosis. In this study, we conducted circulating EBV microRNAs profiling by quantitative reverse transcription polymerase chain reaction (qRT-PCR) among plasma samples of 159 NPC patients versus 145 normal controls (NCs) and serum samples of 60 NPC patients versus 60 NCs. Among the 44 mature EBV-encoded miRNAs, only miR-BART19-3p in plasma was proved to be significantly up-regulated in NPC patients (P< 0.05; fold change (FC) > 2.0). The area under the receiver operating characteristic curve (AUC) for the signature to discriminate NPC patients from NCs was 0.848 with the sensitivity and specificity being 71.7% and 72.3%, respectively. The identified biomarker was analyzed in tissue specimens (44 NPC VS. 32 NCs) and proved to be consistently up-regulated in NPC tumor tissues. Bioinformatics analysis was further conducted to predict the potential targets of miR-BART-19-3p, which provided some hints to its close relationship with NPC development. In conclusion, we identified a novel biomarker - plasma miR-BART19-3p for the detection of NPC.