Oridonin inhibits epithelial-mesenchymal transition of human nasopharyngeal carcinoma cells by negatively regulating AKT/STAT3 signaling pathway

Oridonin, derived from Rabdosia rubescens, has exhibited anticancer activity in a variety of cancers. However, few studies have explored the effect of oridonin (ORI) on migration, invasion and epithelial-mesenchymal transition (EMT) in nasopharyngeal carcinoma. In our study, the results demonstrated that oridonin significantly inhibited migration and invasion of human nasopharyngeal carcinoma CNE-2Z and HNE-1 cell lines, as depicted by wound healing and Transwell assays. In addition, oridonin increased the expression of E-Cadherin while decreased the expressions of vimentin and twist1 at the mRNA and protein levels in a dose-dependent manner. Interestingly, oridonin also decreased cell mobility in nasopharyngeal carcinoma. The subsequent results of western blotting uncovered that the phosphorylation levels of AKT and signal transducer and activator of transcription 3 (STAT3) were decreased upon oridonin treatment. Furthermore, co-treatment with the AKT activator SC-79 attenuated the anti-metastatic effect of oridonin on nasopharyngeal carcinoma and partially abolished the high expression of E-cadherin and the low expression of twist1 mediated by oridonin. In conclusion, the results revealed that oridonin could repress metastatic phenotype and reverse epithelial-mesenchymal transition (EMT) in nasopharyngeal carcinoma by negatively regulating AKT/STAT3 signaling pathway, suggesting that AKT/STAT3 signaling may be the potential therapeutic target of oridonin against nasopharyngeal carcinoma.