Background: Oral 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). Methods: Enzymatically hydrolyzed cell surface N-glycans were analyzed by MALDI-TOF mass spectrometry. Results: High 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). Conclusions: CD147 was discovered by glycoproteomic approaches and suggested to be a potential novel tumor marker for oral cancer diagnosis.

Background: Oral 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). Methods: Enzymatically hydrolyzed cell surface N-glycans were analyzed by MALDI-TOF mass spectrometry. Results: High 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). Conclusions: CD147 was discovered by glycoproteomic approaches and suggested to be a potential novel tumor marker for oral cancer diagnosis.

Glycoscience is important in many areas such as human health, energy and material science. Glycans have been shown to be involved in the pathophysiology of almost every major disease. Additional glycan structure knowledge is required to help advance personal medicine, and pharmaceutical developments, among others. For glycoscience to advance there is a need for large quantities of well-defined glycans and have quick access to glycosyltransferases for manipulating glycan synthesis. Herein, we will cover our efforts on studying the substrate specificities of human glycosyltransferases such as FUT8 and Gn-T V, and their application on N-glycan synthesis. Complex asymmetric N-glycan isomer structures have been related to many diseases such as breast cancer, among others. Synthesis of complex asymmetric N-glycan isomer structures including: alpha-1,6 core-fucosylated, and tri-antennary structures can be achieved by taking advantage of the high specificity of glycosyltransferases that can work as unique catalyst to generate well-defined glycan structures.