MiR-411-5p acts as a tumor suppressor in non-small cell lung cancer through targeting PUM1.

OBJECTIVE: The aim of this study was to investigate the expression of micro ribonucleic acid-411-5P (miR-411-5p) in non-small cell lung cancer (NSCLC), and to explore the effect of miR-411-5p on the biological behavior of NSCLC cells as well as the underlying molecular mechanism. PATIENTS AND METHODS: Quantitative Real Time- Polymerase Chain Reaction (qRT-PCR) was used to detect the expression level of miR-411-5p in NSCLC tissues and cells. MiR-411-5p mimics and relevant controls were transfected into NSCLC cells according to the instructions of Lipidosome 2000. Transfected cells were divided into the experimental group and the control group. The transfection efficiency of each group was detected by qRT-PCR. After miR-411-5p overexpression, methyl thiazolyl tetrazolium (MTT) assay, flow cytometry, and transwell assay were used to detect the biological changes of cells in each group. Bioinformatics predicted that pumilio homolog 1 (PUM1) was the target gene of miR-411-5p. Subsequently, the mRNA and protein expression level of PUM1 in each group was detected by qRT-PCR and Western blotting, respectively. Dual-luciferase reporter assay was used to validate the target regulatory relationship between miR-411-5p and PUM1.
RESULTS: The results of qRT-PCR showed that miR-411-5p was relatively lowly expressed in NSCLC tissues and cells. After miR-411-5p overexpression, MTT results revealed that the proliferation of NSCLC cells was decreased. Flow cytometry results indicated that the apoptosis rate of NSCLC cells was increased, and cell cycle was arrested in the G0-G1 phase. Meanwhile, the transwell assay demonstrated that the migration and invasion abilities of NSCLC cells were decreased. Bioinformatics predicted that PUM1 was the target gene of miR-411-5p. After miR-411-4p was overexpressed in NSCLC cells, qRT-PCR and Western blotting showed that both the mRNA and protein expression levels of PUM1 were up-regulated. Moreover, dual-luciferase reporter assay demonstrated that miR-411-5p could significantly inhibit the luciferase activity of wild-type PUM1-3'-untranslated region (3'-UTR). However, it exhibited no effect on the luciferase activity of cells transfected with mutant plasmids.
CONCLUSIONS: MiR-411-5p may be involved in regulating the biological function of NSCLC cells via targeting PUM1. In addition, miR-411-5p may serve as a potential target for the molecular therapy of NSCLC.