Circular RNA Expression Profiling and the Potential Role of hsa_circ_0089172 in Hashimoto's Thyroiditis via Sponging miR125a-3p

Circular RNA (circRNA) is a novel subclass of noncoding-RNA molecules that participate in development and progression of a variety of human diseases via sponging microRNAs (miRNAs), but the role of circRNAs in Hashimoto's thyroiditis (HT) has not been defined. In this study, peripheral blood samples from five patients with HT and five healthy volunteers were investigated by Illumina HiSeq Sequencer. A total of 627 differentially expressed circRNAs including 370 upregulated and 257 downregulated ones were identified in HT patients. Four upregulated circRNAs indicated the same rising tendency toward sequencing results. The expression of hsa_circ_0089172 was upregulated and correlated positively with the serum level of the thyroid peroxidase antibody. Two perfectly matched binding sites of miR-125a-3p were found in hsa_circ_0089172 sequences with bioinformatics tools. The expression of miR-125a-3p was decreased in the HT patients and correlated inversely with an elevated level of hsa_circ_0089172. Moreover, knockdown of hsa_circ_0089172 resulted in an increase of the expression of miR-125a-3p in vitro. Receiver operating characteristic (ROC) curve analysis suggested that hsa_circ_0089172 had significant value in HT diagnosis. Taken together, these results demonstrate that hsa_circ_0089172 as a potential diagnostic biomarker of HT and may play a crucial role in the pathogenesis of HT via sponging miR-125a-3p.