Comprehensive Clinico-Glycomic Study of 16 Colorectal Cancer Specimens: Elucidation of Aberrant Glycosylation and Its Mechanistic Causes in Colorectal Cancer Cells

The structures of neutral and acidic glycosphingolipids from both normal colorectal epithelial cells and colorectal cancer cells, which were highly purified with the epithelial cell marker CD326, have been analyzed. The analysis was performed on samples from 16 patients. The carbohydrate moieties from glycosphingolipids were released by endoglycoceramidase II, labeled by pyridylamination, and identified using two-dimensional mapping and mass spectrometry. The structures from normal colorectal epithelial cells are characterized by dominant expression of neutral type-1 chain oligosaccharides. Three specific alterations were observed in malignant transformation; increased ratios of type-2 oligosaccharides, increased α2−3 and/or α2−6 sialylation and increased α1−2 fucosylation. Although the degree of alteration varies case to case, we found that two characteristic alterations tend to be associated with clinical features. One is a shift from type-1 dominant normal colorectal epithelial cells to type-2 dominant...