Abstract
This study investigated the diagnostic potential of serum small extracellular vesicle-derived long noncoding RNAs (EV-lncRNAs) for hepatocellular carcinoma (HCC). Driver oncogenic lncRNA candidates were selected by a comparative analysis of lncRNA expression profiles from two whole transcriptome human HCC datasets (Catholic_LIHC and TCGA_LIHC). Expression of selected lncRNAs in serum and small EVs was evaluated using quantitative reverse transcription PCR. Diagnostic power of serum EV-lncRNAs for HCC was determined in the test (n = 44) and validation (n = 139) cohorts. Of the six promising driver onco-lncRNAs, DLEU2, HOTTIP, MALAT1, and SNHG1 exhibited favorable performance in the test cohort. In the validation cohort, serum EV-MALAT1 displayed excellent discriminant ability, while EV-DLEU2, EV-HOTTIP, and EV-SNHG1 showed good discriminant ability between HCC and non-HCC. Furthermore, a panel combining EV-MALAT1 and EV-SNHG1 achieved the best area under the curve (AUC; 0.899, 95% CI = 0.816-0.982) for very early HCC, whereas a panel with EV-DLEU2 and alpha-fetoprotein exhibited the best positivity (96%) in very early HCC. Serum small EV-MALAT1, EV-DLEU2, EV-HOTTIP, and EV-SNHG1 may represent promising diagnostic markers for very early-stage HCC.