Circulating Exosomal miR-27a and miR-130a Act as Novel Diagnostic and Prognostic Biomarkers of Colorectal Cancer

Background: Colorectal cancer is one of the most common cancers worldwide usually is associated with poor prognosis due to the advanced stage when diagnosed. This study aimed to investigate whether specific circulating exosomal miRNAs could act as biomarkers for early diagnosis of colorectal cancer. Methods: A total of 369 peripheral Hood samples were included in this study. In the discovery phase, circulating exosomal miR-27a and miR-130a were selected after synthetical analysis of two GEO datasets and TCGA database, The differential expression and diagnostic utility of miR-27a and miR-110a panel were validated using qRT-PCR and ROC curve analysis in subsequent training phase, validation phase, and external validation phase. The prognosis of circulating exosomal miR-27a and miR-130a were investigated using the Kaplan-Meier method. Results: The expression of exosomal miR-27a and miR-130a in plasma significantly increased in colorectal cancer. The area wider ROC curves (ALIC) of miR-27a (miR-130a) were 0.773 (0.742) in the training phase, 0.82 (0.787) in the validation phase, and 0.746 (0.697) in the external validation phase. The combination of two miRNAs presented higher diagnostic utility for colorectal cancer (AUCs = 0.846, 0.898, and 0.801 for the training, validation, and external validation phases, respectively). Patients with colorectal cancer with high expression of circulating exosomal miR-27a or milt-130a underwent poorer prognosis. Conclusions: We identified a circulating exosomal miRNAs panel for the detection of colorectal cancer. Impact: The exosomal miR-27a and miR-130a panel in plasma may act as a noninvasive biomarker for early detection and predicting prognosis of colorectal cancer. (C)2018 AAGR.