Periostin Plays a Key Role in Radioresistance of Head and Neck Cancer Cells Via Epithelial-to-Mesenchymal Transition.

Background/Aim: Head and neck squamous cell carcinoma (HNSCC) is an aggressive head and neck malignancy. The aim of this study was to elucidate the role of periostin (POSTN) in the epithelial-to-mesenchymal transition (EMT) process mediating the acquisition of radioresistance in HNSCC. Materials and Methods: The expression levels of EMT hallmark genes including POSTN and Erk/Akt signaling pathways were compared between radiosensitive and radioresistant HNSCC cells. Results: POSTN mRNA expression was higher in radioresistant HNSCC cells, and silencing POSTN significantly impaired their invasiveness under the effect of EMT process represented by up-regulation of mesenchymal markers and down-regulation of an epithelial marker. Expression levels of Erk and Akt were higher in radioresistant cells. Conclusion: POSTN in association with the Erk and Akt signaling pathways was up-regulated during the EMT process, leading to the conversion of radiosensitive to radioresistant HNSCC cells. POSTN may be a key marker for predicting the radioresistance and therapeutic target of HNSCC.