Abstract
Increased expression levels of transforming growth factor-β1 (TGF-β1) are associated with metastasis in papillary thyroid carcinoma (PTC), although the mechanisms involved remain unknown. The present study aimed to investigate these mechanisms. The results demonstrated that the expression levels of TGF-β1 mRNA were higher and those of lncRNA-NEF were lower in tumor tissues compared with in healthy tissues. High levels of TGF-β1 mRNA and low levels of lncRNA-NEF were also detected in the serum of patients with PTC compared with in healthy controls. Serum levels of TGF-β1 and lncRNA-NEF were significantly associated with lymph node metastasis. Furthermore, TGF-β1 promoted cell migration and invasion of PTC cell lines, but not the normal cell line, whereas lncRNA-NEF overexpression inhibited these phenomena. TGF-β1 also inhibited lncRNA-NEF expression in PTC cell lines, but not in the normal cell line. Conversely, lncRNA-NEF overexpression exhibited no effects on TGF-β1. In conclusion, the present study suggested that TGF-β1 may promote the invasion and migration of PTC cells by inhibiting the expression of lncRNA-NEF.