A novel β1,3‐ N ‐acetylglucosaminyltransferase (β3Gn‐T8), which synthesizes poly‐ N ‐acetyllactosamine, is dramatically upregulated in colon cancer

A new member of the UDP‐ N ‐acetylglucosamine: β‐galactose β1,3‐ N ‐acetylglucosaminyltransferase (β3Gn‐T) family having the β3‐glycosyltransferase motifs was identified using an in silico method. This novel β3Gn‐T was cloned from a human colon cancer cell line and named β3Gn‐T8 based on its position in a phylogenetic tree and enzymatic activity. β3Gn‐T8 transfers GlcNAc to the non‐reducing terminus of the Galβ1–4GlcNAc of tetraantennary N ‐glycan in vitro. HCT15 cells transfected with β3Gn‐T8 cDNA showed an increase in reactivity to both LEA and PHA‐L4 in a flow cytometric analysis. These results indicated that β3Gn‐T8 is involved in the biosynthesis of poly‐ N ‐acetyllactosamine chains on tetraantennary (β1,6‐branched) N ‐glycan. In most of the colorectal cancer tissues examined, the level of β3Gn‐T8 transcript was significantly higher than in normal tissue. β3Gn‐T8 could be an enzyme involved in the synthesis of poly‐ N ‐acetyllactosamine on β1–6 branched N ‐glycans in colon cancer.