원문정보
초록
영어
Aberrant glycosylation in serum proteins are associated with many human diseases, including various types of cancer. In this study, we developed a comprehensive glycomic approach involving immunoaffinity purification, lectin blotting, and advanced MS techniques to discover potential biomarkers for gastrointestinal cancer, especially focus on colon and gastric cancer. Haptoglobin (Hp), a target glycoprotein that displays aberrant glycosylation during cancer development, was initially screened by blotting with various lectins. To discover novel aberrant glycans in colon and gastric cancer, we have analyzed glycosylation status of haptoglobin by lectin blotting. In particular, aleuria aurantia lectin (AAL, which is specific to fucosyl residues) reactivity with cancer Hp was higher than control groups. Moreover, by LC/MS analysis following PNGaseF treatment for purified Hp, several aberrant glycans were detected in Hp from sera of colon and gastric cancer patients. Increased levels of antennary branching and reduced levels of high-mannose type structures were observed in cancer patients. In addition, enhanced fucosylation at Asn 241 of the four potential N-glycosylation sites of Hp in sera of cancer patients was especially identified by site-specific analysis. Our findings indicate that glycome profiling of Hp will be a useful platform for gastrointestinal cancer biomarker discovery, rapidly identifying a number of potential diagnostic markers for colon and gastric cancer.