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.
Qiu, W., Yang, Z., Fan, Y., & Zheng, Q. (2016). MicroRNA-613 inhibits cell growth, migration and invasion of papillary thyroid carcinoma by regulating SphK2. Oncotarget, 7(26), 39907–39915. https://doi.org/10.18632/oncotarget.9530