miR-199a-5p inhibits malignant progression and enhances cisplatin sensitivity of nasopharyngeal carcinoma by targeting SLC1A5.

OBJECTIVE: The prevalence of Nasopharyngeal Carcinoma (NPC) is increasing, and the mortality of patients with cisplatin resistance is high. In this study, we aimed to elucidate several potential mechanisms of miR-199a-5p in regulating the progression and cisplatin resistance of NPC.

METHODS: Relevant datasets were downloaded from the Gene Expression Omnibus (GEO) database to verify miR-199a-5p expression in NPC. The miR-199a-5p level was evaluated by RT-qPCR, and the prognostic significance was analyzed by K-M curve. Cell proliferation, migration, invasion and apoptosis were detected in vitro. The contents of Epithelial-Mesenchymal Transition (EMT) protein, apoptosis protein and SLC1A5 protein were detected by Western immunoblotting. DLR assay elucidated that miR-199a-5p targets SLC1A5. The effect of miR-199a-5p on subcutaneous tumor in nude mice was detected in vivo.

RESULTS: We found that miR-199a-5p was differentially expressed in nasopharyngeal carcinoma, and patients with high expression showed good prognosis. It was also found to be associated with cisplatin resistance and showed low expression in HNE1/DDP cells. The up-regulation of miR-199a-5p can inhibit the proliferation, migration and invasion of NPC cells, and enhance cell apoptosis. The mechanism may be achieved by targeting SLC1A5.

CONCLUSION: The high expression of miR-199a-5p can inhibit SLC1A5 and thus the progression of NPC. At the same time, the high expression of miR-199a-5p can increase the sensitivity of NPC to cisplatin.

LEVEL OF EVIDENCE: Level 5.