Exosomal miRNAs are potential diagnostic biomarkers between malignant and benign thyroid nodules based on next-generation sequencing.

An accurate biomarker or method for diagnosis of thyroid nodule with indeterminate fine-needle aspiration result is essential for clinical treatment. Micro RNAs (miRNAs) of exosomes are advantageous in the diagnosis of tumors because they are highly stable, and be protected by a bilayer membrane structure. Exosomes were isolated from 13 papillary thyroid carcinoma (PTC) and 7 nodular goiter (NG) patients' plasma. Small RNA sequencing was performed on exosomes' RNA in next-generation sequencing (NGS) platform. Then, we performed comprehensive analysis on miRNA expression profile in exosome of two groups. One hundred and twenty-nine differentially expressed miRNAs were identified in plasma exosomes between PTC and NG patients. Forty-nine miRNAs were up-regulated, and 80 miRNAs were down-regulated in PTC patients. Receiver operating characteristic (ROC) curves of 129 miRNAs were plotted. Area under curve (AUC) of 129 miRNAs was 0.571-0.951, with distribution peak of 0.82-0.86. AUC of 11 miRNAs was above 0.9, miR-5189-3p had the most optimal performance for diagnosis between PTC and NG, with 0.951 of AUC. Target genes of 129 miRNAs were enriched into 7 cancer-related signaling pathways, including mitogen-activated protein kinase (MAPK), tumor necrosis factor (TNF), NF-kappa B signaling pathway and so on. This study profiled the miRNA signature of exosomes from PTC patients and NG patients. We proposed a group of miRNAs in plasma exosomes as candidate biomarkers for thyroid nodule diagnosis.