MiR-139-5p Targetedly Regulates YAF2 and Mediates the AKT/P38 MAPK Signaling Pathway to Alleviate the Metastasis of Non-Small Cell Lung Cancer Cells and Their Resistance Against Cisplatin

OBJECTIVE: To explore relevant mechanisms of miR-139-5p in alleviating the metastasis of non-small cell lung cancer cells (NSCLC) and their resistance against cisplatin. METHODS: Quantitative real-time polymerase chain reaction (qRT-PCR) and Western blot (WB) assays were carried out to determine the protein levels of miR-139-5p and YAF2, and cisplatin (DDP)-resistant NSCLC cell strains were established. Subsequently, an MTT assay was employed to evaluate the viability of the cell strains, a Transwell assay to evaluate cell invasion activity, and flow cytometry to analyze cell apoptosis rate. Finally, a Western blot assay was carried out to determine the protein levels of P-PI3K and p-p38. RESULTS: NSCLC tissues showed lower miR-139-5p expression and higher YAF2 expression than paracancerous tissues and human normal lung epithelial cells, and miR-139-5p was related to the prognosis of NSCLC patients. Overexpression of miR-139-5p or knock-down of YAF2 inhibited the proliferation and invasion of NSCLC cells and induced their apoptosis. Additionally, the dual-luciferase reporter assay verified a targeting relationship between miR-139-5p and YAF2. Overexpression of miR-139-5p and knockdown of YAF2 reversed the resistance of A549/DDP cells against DDP, inactivated p38 and Akt proteins, and inhibited the AKT/p38 MAPK signaling pathway. Furthermore, inhibiting the AKT/p38 MAPK signaling pathway with MK2206 resisted the effects of knock-down of miR-139-5p on DDP resistance in NSCLC cells. CONCLUSION: MiR-139-5p targetedly regulates YAF2 and mediates the AKT/p38 MAPK signaling pathway to alleviate the metastasis of NSCLC cells and their resistance against cisplatin, which may be a novel target for improving the therapeutic effect on NSCLC.