miR-205-5p regulates epithelial-mesenchymal transition by targeting PTEN via PI3K/AKT signaling pathway in cisplatin-resistant nasopharyngeal carcinoma cells

Epithelial-mesenchymal transition (EMT) symbolizes the predominant program of advanced-stage cancer, it is critical in cancer progression, metastasis, and chemotherapy resistance. In this study, the metastatic properties of nasopharyngeal carcinoma (NPC) cells were evaluated by morphological examination, wound healing assay, migration and invasion assay. Western blotting and qRT-PCR were used to ascertain the expression of markers which were associated with EMT. The effects of miR-205-5p on invasion, migration, EMT and proliferation of NPC cells were evaluated and the molecular mechanisms of their interaction were explored. In this study, we manifested firstly that the expression of miR-205-5p in cisplatin-resistant NPC cell line HNE1/DDP was obviously up-regulated than that in its parental cell line HNE1. Then we analyzed the specific role of miR-205-5p through functional assays by transfecting specific mimics and inhibitors. The results indicated that low expression of miR-205-5p restrained EMT progression of HNE1/DDP cells. Further studies on the mechanism of miR-205-5p manifested that PTEN was a downstream candidate gene of miR-205-5p, down-regulated PTEN expression could counteract the effect of miR-205-5p inhibitors, and the regulation of EMT by miR-205-5p on HNE1/DDP cells depended on the PI3K/AKT signaling pathway. Overall, our results indicated that miR-205-5p was targeting PTEN to regulate EMT through the PI3K/AKT pathway. This study will supply a new treatment target for advanced NPC.