High expression of N-acetylglucosaminyltransferase V in mucinous tumors of the ovary

N-acetylglucosaminyltransferase V (GnT-V) is an enzyme that catalyzes β1-6 branching of N-acetylglucosamine (GlcNAc) on asparagine-linked oligosaccharides of cell proteins. The present study aimed to investigate GnT-V expression and its prognostic significance in epithelial ovarian cancer. GnT-V expression was studied by immunohistochemistry in 83 surgically resected ovarian cancers, and the staining intensity was evaluated. High GnT-V expression in cancer cells was found in 17 (20.5%) of the 83 cases, and was positively correlated with early FIGO staging. In the histological type, mucinous adenocarcinoma showed significantly strong immunostaining compared to the non-mucinous type (P<0.001). In 36 mucinous tumors, the GnT-V immunostaining score was significantly higher in cancer than in benign and borderline tumors (P<0.001). NOM-1, a human ovarian mucinous adenocarcinoma cell line, expressed strong GnT-V protein and swainsonine treatment suppressed β1-6GlcNAc branching and reduced migration ability significantly (P<0.001). These results suggested that GnT-V might be involved in the malignant potential of mucinous ovarian cancer.