Glycoproteomics analysis to identify a specific glyco- biomarker on haptoglobin associated with lung cancer

• Main Authors: Hsien-Yu Tsai, 蔡顯裕
• Other Authors: Shui-Tein Chen
• Format: Others
• Language: en_US
• Published: 2011
• Online Access: http://ndltd.ncl.edu.tw/handle/92861972691831914305

博士 === 國立臺灣大學 === 生化科學研究所 === 99 === Glycosylation is a common protein modification that is of interest in current cancer research because altered carbohydrate moieties are often found during cancer progress. Lung cancer is the major cause of cancer death in the world and the survival rate is less than 15%. A search for biomarkers in human lung cancer serum samples using proteomic approaches, e.g., 2-DE and 2-D DIGE, identified haptoglobin as a protein that is expressed more highly in lung cancer serum samples than in normal serum samples. Western blot analysis and AAL lectin staining were used to validate the expression level and the glycan modification of haptoglobin, respectively. The degree of haptoglobin fucosylation was significantly increased in serum samples from subjects with subtypes of lung cancer compared to normal serum samples. In addition, mass spectrometry provided evidence of an increase of haptoglobin fucosylation; the glycan structure was determined to be an α2,6-linked tri-sialylated triantennary glycan containing α1,3-linked fucose attached to the 4-linked position of the 3-arm mannose of N-linked core pentasaccharide, which is different from the common glycoform , sialyl Lewis X. These preliminary findings suggested that the specific glycoform of haptoglobin may be useful as a marker to monitor lung cancer progression.