Abstract
MicroRNAs (miRNAs) are involved in the development of non-small cell lung cancer (NSCLC). However, the biological roles of several aberrantly expressed miRNAs have not been explored yet. In the present study, miR-4491 was identified as a novel upregulated miRNA in NSCLC tissues and cell lines. Downregulation of miR-4491 by a miR-4491 inhibitor inhibited the proliferation and triggered the apoptosis of NSCLC cells. Tripartite motif containing 7 (TRIM7), a tumor suppressor gene expressed in NSCLC, was demonstrated in the present study to be directly targeted by miR-4491. This finding was verified by bioinformatics analysis, reverse transcription-quantitative PCR, western blotting and dual luciferase reporter assays. Furthermore, downregulation of miR-4491 inactivated nuclear factor-κB signaling via induction of TRIM7. In addition, TRIM7 silencing attenuated the effect of miR-4491 inhibitor in NSCLC cells. The decreased TRIM7 level in NSCLC tissues was negatively correlated with miR-4491 expression in NSCLC tissues. In conclusion, the findings from this study demonstrated that miR-4491 expression was upregulated in NSCLC tissues and cells and that miR-4491 may promote NSCLC progression via targeting TRIM7.