Identification of Radioresistance-Associated Proteins in Human Nasopharyngeal Carcinoma Cell Lines by Proteomic Analysis

Background and Purpose: Radiotherapy is the mainstay of treatment modality for human nasopharyngeal carcinoma (NPC), but in some cases, the disease is radioresistant. This study aimed to identify proteins potentially responsible for radioresistance of NPC by a proteomic approach. Material and Methods: The radioresistant human NPC cell line CNE-2R and its parental cell line CNE-2 were analyzed by two-dimensional gel electrophoresis and matrix-assisted laser desorption/time-of-flight mass spectrometry analysis. The candidate proteins were validated by Western blot analysis. Results: In total, 16 differentially expressed proteins were identified; among them, Nm23 H1 was significantly increased, while Annexin A3 was significantly downregulated in CNE-2R cells, compared to CNE-2 cells. Conclusions: Our findings provide a platform for further characterization of the proteins implicated in radioresistance and suggest that these proteins could be exploited as a biomarker for predicting the NPC response to radiotherapy in the clinic.