Emerging roles of circular RNAs in thyroid cancer.

As the most common endocrine-related malignant tumor, the prevalence of thyroid cancer (TC) has soared strikingly over the past thirty years then verged to stabilization or even descension temporally. Distributed in a cell-specific manner, circular RNAs (circRNAs) is a novel class of non-coding RNAs characterized by its covalently closed loop without 5'-terminal cap and 3'-terminal poly A tail, which guarantee its distinctive evolutionary conservation and exonucleases resistance. Emerging evidence indicates that circRNA participates in the pathogenesis and carcinogenesis of several cancers including thyroid cancer. In this review, we concentrated on the connection between circRNAs and thyroid cancer so as to obtain a more profound understanding. We aim to discuss this relationship between TC and circRNAs by summarizing the effect of various circRNAs on tumor biological behaviors and clinical application, and systematically outlook the conceivable application of circRNAs in TC diagnosis and therapy.