Linc00221 modulates cisplatin resistance in non-small-cell lung cancer via sponging miR-519a.

Cisplatin resistance has been long considered an obstacle to the efficacy of chemotherapy in non-small-cell lung cancer (NSCLC). Long non-coding RNAs (lncRNAs) have been widely reported to participate in the various biological process including cancer. In the present study, we aim to explore the functions of Linc00221 and miR-519a in the sensitivity and the resistance of NSCLC to cisplatin. The levels of Linc00221, miR-519a, and zinc finger and BTB domain-containing five (ZBTB5) in NSCLC tissues were detected by qRT-PCR and Western blot. Colony formation and MTT assays were applied to detect the viability of cells after cisplatin treatment. Dual luciferase reporter assays were used to detect the inhibitory effect of miR-519a on ZBTB5 and Linc00221, and pull down experiments were employed to determine the direct interaction between Linc00221 and miR-519a. Our results showed that Linc00221 was highly expressed in cisplatin-resistant NSCLC tissues and cells and closely associated with poor prognosis. Linc00221 promoted the cisplatin resistance of NSCLC and miR-519a was a direct target of Linc00221. In addition, miR-519a could promote cisplatin sensitivity in NSCLC cells by targeting ZBTB5. Linc00221 could mediate the cisplatin sensitivity in NSCLC by adsorbing miR-519a to prevent its down-regulation of ZBTB5. In conclusion, Linc00221 promotes cisplatin resistance in NSCLC through the downstream miR-519a/ZBTB5 signaling axis, which could be used as a potential diagnostic and therapeutic target for clinical cisplatin-resistant NSCLC patients.