Identification of novel tumor markers for oral squamous cell carcinoma using glycoproteomic analysis

BackgroundOral cancer, the largest subset of head and neck cancer, has become one of the most lethal malignancies during the last two decades. Although several diagnostic tools have been applied for the early detection of oral malignancies, it is still urgent to identify novel tumor markers. In this study, we explored the cell surface N-glycomes of primary cultured human oral keratinocytes (HOK), immortalized human gingival keratinocytes (SG cells), and oral squamous cell carcinoma (OC2).MethodsEnzymatically hydrolyzed cell surface N-glycans were analyzed by MALDI-TOF mass spectrometry.ResultsHigh levels of fucosylated N-glycans, especially core-fucosylated N-glycans, were observed on the OC2 cell surface whereas the major N-glycans on SG and HOK cells were high mannose type. In addition, the mRNA expression level of fucosyltransferase 8 was elevated significantly in OC2 cells than in SG and HOK cells. Core-fucosylated glycoproteins of OC2 cells were then purified with lectin affinity chromatography and a key adhesion molecule in cancer cells, CD147, was identified. Finally, overexpression of cell surface CD147 was confirmed on OC2 cells and oral cancer tissues (tissue array).ConclusionsCD147 was discovered by glycoproteomic approaches and suggested to be a potential novel tumor marker for oral cancer diagnosis.

► Cell surface N-glycan profiling of HOK, SG, and OC2 cells are characterized. ► Core-fucosylation and the expression of FUT8 gene are elevated in OSCC cells. ► CD147 is identified and confirmed as potential tumor marker for oral cancer.