Knockdown of long non-coding RNA inhibits autophagy in lung cancer.

Objective: Long non-coding RNAs (lncRNAs) are involved in numerous biological processes in lung cancer cells. In our previous studies, we identified a lncRNA, ENST00000439577, which is highly expressed in lung carcinomas, and termed it lung cancer progression-associated transcript 1 (LCPAT1). To characterize the role of LCPAT1 in lung cancer, we conducted the current study. Methods: Expression of LCPAT1 and autophagy-associated markers in tumor tissues and lung cancer cell lines was determined by real-time quantitative polymerase chain reaction (qPCR). Hematoxylin and eosin (HE) staining, qPCR, Western blot, and immunohistochemistry were performed to evaluate xenografted tumor tissues. Autophagy induced by rapamycin was detected by Western blot and immunofluorescence in lung cancer cell lines. Results: Expression of LCPAT1 and microtubule-associated protein 1 light chain 3 beta (LC3B) was positively correlated in lung cancer. Knockdown of LCPAT1 inhibited tumor growth and suppressed cell autophagy in vivo. Moreover, LCPAT1 knockdown in lung cancer cell lines resulted in decreased autophagy-associated gene expression and alleviated the cell autophagy induced by rapamycin. Conclusions: We speculate that LCPAT1 plays a crucial role in regulating autophagy in lung cancer.