Long Noncoding RNA LINC01554 Inhibits the Progression of NSCLC Progression by Functioning as a ceRNA for miR-1267 and Regulating ING3/Akt/mTOR Pathway.

Objectives: This study focused on the biological functions and mechanisms of action of LINC01554 in nonsmall cell lung cancer (NSCLC). Methods: The expression and prognostic values of LINC01554 in NSCLC were evaluated using The Cancer Genome Atlas datasets. MTT, colony formation, wound healing, transwell, and in vivo assays were performed to investigate the role of LINC01554 in NSCLC. The related protein expression levels were measured via western blotting. Bioinformatic analysis was conducted to predict targeted genes. The relationship between LINC01554, microRNA- (miR-) 1267, miR-1267, and inhibitor of growth family member 3 (ING3) was analysed via a dual-luciferase reporter assay. Results: LINC01554 expression was downregulated in NSCLC and associated with NSCLC prognosis. LINC01554 overexpression suppressed NSCLC cell proliferation, migration, invasion, and epithelial-mesenchymal transition (EMT). Bioinformatic and dual-luciferase reporter assays demonstrated that LINC01554 expression directly targeted miR-1267 expression, which in turn directly acted on ING3. An miR-1267 mimic significantly reduced ING3 expression, whereas an miR-1267 inhibitor observably elevated its expression. LINC01554 overexpression increased ING3 expression, whereas this effect was counteracted by the miR-1267 mimic. LINC01554 overexpression also significantly suppressed the expression of phosphorylated protein kinase B (Akt) and phosphorylated mammalian target of rapamycin (mTOR) expression; this effect was abrogated by the miR-1267 mimic. Mechanistically, LINC01554 overexpression repressed the growth, migration, invasion, and epithelial-mesenchymal transition (EMT) of NSCLC cells through the regulation of the miR-1267/ING3 axis via regulation of the Akt/mTOR signalling pathway. Conclusions: We provide the first evidence of the involvement of the LINC01554/miR-1267 axis in NSCLC proliferation and metastasis through the ING3Akt/mTOR pathway. Thus, LINC01554 may serve as a novel therapeutic target for NSCLC.