Objective: To analyze the impact of expression of miR-504-3p on the proliferation, migration, cell cycle transit and rate of apoptosis of NSCLC cells and explore the underlying mechanisms. Methods: The Cancer Genome Atlas (TCGA) database was used to compare the expression levels of miR-504 between NSCLC tissues and normal lung tissues. NSCLC cells were transfected with lentiviral vectors that either overexpressed or knocked down miR-504-3p to evaluate its effects on NSCLC biological behavior. Quantitative Real Time Polymerase Chain Reaction was used to measure the levels of miR-504-3p and Interferon-Induced Transmembrane Protein 1 (IFITM1). A luciferase reporter array was used to reveal whether miR-504-3p directly targets IFITM1. Results: The expression of miR-504 was significantly down-regulated in lung cancer tissues compared to normal lung tissues. Overexpression of miR-504-3p in NSCLC cell lines inhibited cell proliferation, migration and promoted cell apoptosis. Meanwhile, changes in the expression level of miR-504-3p had no significant effect on NSCLC cell cycle progression. Moreover, over-expressed miR-504-3p following its transfection significantly decreased the expression of IFITM1 in NSCLC cell lines and suppressed the activity of the luciferase reporter containing wild type but not mutant IFITM1 3' -UTR. Conclusion: miR-504-3p inhibits cell proliferation and migration and promotes cell apoptosis in NSCLC cells. MiR-504-3p decreases IFITM1 expression in NSCLC cells, which may be a potential mechanism of its tumor-suppressive functions in NSCLC.
Keywords: interferon-induced transmembrane protein 1; miR-504-3p; migration and invasion; non-small cell lung cancer; proliferation.