LINK-A lncRNA is upregulated in metastatic non-small cell lung cancer and is associated with poor prognosis

Long intergenic non-coding RNA for kinase activation (LINK-A) has been characterized as an oncogenic long non-coding RNA (lncRNA) in triple-negative breast cancer. However, its involvement in non-small cell lung cancer (NSCLC) remains unknown. The aim of the present study was to investigate the involvement of LINK-A in NSCLC. Expression of LINK-A lncRNA in the plasma of patients with NSCLC collected on the day of admission and the day of discharge, and in the plasma of healthy controls, was detected by reverse transcription-quantitative PCR. Diagnostic values of plasma LINK-A for metastatic NSCLC were evaluated by receiver operating characteristic curve analysis. A LINK-A lncRNA expression vector was constructed and transfected into human NSCLC cell lines, and the effects on cell migration and invasion, and Akt activation were detected by Transwell and Matrigel assays, and western blotting, respectively. Plasma levels of LINK-A were found to be significantly higher in patients with different types of metastatic NSCLC than in patients with non-metastatic NSCLC and healthy controls. Plasma levels of LINK-A were lower in patients with metastatic NSCLC on the day of discharge than on the day of admission. Patients with high plasma LINK-A had a higher mortality rate and lower progression-free survival rate within 2 years of discharge. In conclusion, LINK-A is overexpressed in metastatic NSCLC, and may promote the migration and invasion of NSCLC by activating Akt signaling.