Identification of prognosis-related proteins in gingival squamous cell carcinoma by twodimensional gel electrophoresis and mass spectrometry-based proteomics.

The aim of this study was to identify differentially expressed proteins in oral squamous carcinoma cells that could be potential prognosis-related cancer biomarkers. We compared protein expression patterns from gingival squamous cellc carcinoma (GSCC) tissues and adjacent non-cancerous matched tissues by proteomic analysis using two-dimensional gel electrophoresis coupled to mass spectrometry (2D-PAGE/MS). Seventeen protein spots were found to be over-expressed and eight were under-expressed in cancerous tissue compared to the normal counterpart. Of these, annexin A2 and ezrin were validated by Western blot. We also demonstrated by immunohistochemistry that POSTN is highly expressed in the neoplastic tissues examined. Among the differentially expressed proteins, we focused our attention on Chloride intracellular channel 1 (CLIC1). The 2D-PAGE/MS-based proteomics appears an efficient approach in detecting and identifying differentially expressed proteins that might function as potential biomarkers and/or molecular targets for early cancer diagnosis and prognosis and that might contribute to a innovative therapeutic strategies in GSCC. However, further validation and functional studies are needed to confirm and to support these promising, still preliminary data. Cancer biomarkers, Oral squamous cell carcinoma, Proteomics.