lncRNA‑NEF is downregulated in osteosarcoma and inhibits cancer cell migration and invasion by downregulating miRNA‑21

Long non‑coding RNA (lncRNA)‑NEF inhibits cancer metastasis in hepatocellular carcinoma; however, its role in other malignancies is unknown. The present study revealed that plasma lncRNA‑NEF was downregulated, while miRNA‑21 was upregulated in patients with osteosarcoma compared with healthy controls. Plasma lncRNA‑NEF and miRNA‑21 were negatively correlated in patients with osteosarcoma and healthy controls. Downregulation of lncRNA‑NEF and upregulation of miRNA‑21 distinguished patients with osteosarcoma from healthy controls. lncRNA‑NEF overexpression mediated the inhibition of miRNA‑21 expression in osteosarcoma cell lines, while miRNA‑21 overexpression did not significantly affect the expression of lncRNA‑NEF. lncRNA‑NEF overexpression inhibited, while miRNA‑21 overexpression promoted, migration and invasion of osteosarcoma cell lines in vitro. miRNA‑21 overexpression partially compensated the inhibitory effects of lncRNA‑NEF overexpression on osteosarcoma cell migration and invasion. Therefore, lncRNA‑NEF may inhibit cancer cell migration and invasion in osteosarcoma by downregulating miRNA‑21.