LncRNA NORAD promotes thyroid carcinoma progression through targeting miR-202-5p

Long noncoding RNAs (lncRNAs) have been shown to have several functional roles in tumor biology, and they are deregulated in many types of cancer. The role of a novel lncRNA, NORAD, in papillary thyroid carcinoma (PTC) is still unknown. In this study, we demonstrated that NORAD expression was upregulated in PTC cell lines and samples. Ectopic expression of NORAD promoted PTC cell growth, invasion and migration. Overexpression of NORAD promotes epithelial-to-mesenchymal transition (EMT) progression in the PTC cell. Furthermore, overexpression of NORAD suppressed miR-202-5p expression in PTC cells. The data suggested that miR-202-5p expression was downregulated in PTC cell lines and samples and was negatively correlated with NORAD expression in PTC tissues. Overexpression of miR-202-5p suppressed PTC cell growth, invasion and migration. In addition, we demonstrated that elevated expression of NORAD promoted PTC cell growth, invasion and migration by inhibiting miR-202-5p expression. These results suggested that the lncRNA NORAD acts as an oncogene in PTC progression, partly by regulating miR-202-5p expression.