Proteomic analysis of a nasopharyngeal carcinoma cell line and a nasopharyngeal epithelial cell line.

Abstract Nasopharyngeal carcinoma (NPC) is an epithelial malignancy exhibiting a strong geographic preference and a close association with Epstein-Barr virus (EBV). The aim of this study was to investigate the precise mechanism of nasopharyngeal epithelial-to-NPC tumorigenesis and to identify possible biomarkers and targets for therapy. Proteomic analysis was performed on the immortalized nasopharyngeal epithelial cell line NP69 and the NPC cell line C666. A comparative analysis of total lysates from the cell lines using 2-D gel electrophoresis-mass spectrometry resulted in the identification of 87 different protein spots. The different proteins were grouped into 5 main categories: (i) energy production and general metabolism, (ii) adaptation/stress tolerance, (iii) cell proliferation, (iv) cell structure and (v) epithelial-mesenchymal transition. The detection of metabolism-related proteins indicated that the NPC cells relied on aerobic glycolysis, with reduced use of the citric acid cycle. Glucose uptake and lactate secretion increased in the medium of C666 compared with NP69. The present study revealed that glycolysis was up-regulated in the NPC cell lines compared with nasopharyngeal epithelial cells. A number of molecules involved in metabolism were identified, and further investigations will be needed to validate these potential biomarkers or targets.