MicroRNA-613 inhibits cell growth, migration and invasion of papillary thyroid carcinoma by regulating SphK2

Abstract

// Wangwang Qiu 1, * , Zhili Yang 1, * , Youben Fan 1 , Qi Zheng 1 1 Department of General Surgery, Shanghai Jiao Tong University Affiliated Sixth People’s Hospital, Shanghai 200233, P.R. China * These authors contributed equally to this work Correspondence to: Qi Zheng, email: zhengqi1957@aliyun.com Keywords: papillary thyroid cancer, miR-613, SphK2, cell growth, invasion Received: January 18, 2016      Accepted: April 26, 2016      Published: May 21, 2016 ABSTRACT MicroRNAs (miRNAs) have emerged as important gene regulators and are recognized as key players in carcinogenesis. In this study, we investigated the biological function and mechanism of miR-613 in the regulation of papillary thyroid cancer (PTC) development. We found that miR-613 was downregulated in PTC cell lines and tissues, and overexpression of miR-613 significantly suppressed PTC cell growth, migration and invasion in vitro and inhibited tumor growth in vivo . We identified the gene for sphingosine kinase 2 ( SphK2 ) as a direct target of miR-613. Overexpression of miR-613 significantly repressed SphK2 expression by directly targeting its 3′-untranslated regions (3′-UTR) and restoration of SphK2 reversed the inhibitory effects of miR-613 on PTC cell growth and invasion. Taken together, our results indicated that miR-613 functions as a tumor suppressor in PTC and its suppressive effect is mediated by repressing SphK2 expression.