Prognostic significance of UDP-N-acetyl-alpha-D-galactosamine:polypeptide N-acetylgalactosaminyltransferase-3 (GalNAc-T3) expression in patients with gastric carcinoma.

Aberrant glycosylation occurs during development of gastric carcinomas. The initiation of mucin-type O-glycosylation is regulated by GalNAc-T3 (UDP-N-acetylgalactosamine:polypeptide N-acetylgalactosaminyltransferase-3). However, the clinical significance of GalNAc-T3 expression in human gastric carcinoma has not yet been demonstrated. In the present study, we investigated the relationship between immunohistochemical GalNAc-T3 expression and various clinicopathologic factors, including prognosis, in 117 gastric carcinoma patients. Of 117 gastric carcinomas examined, 59 (50.4%) showed strong expression of GalNAc-T3. Strong expression was detected in 38 of 59 (64.4%) differentiated type and in 21 of 58 (36.2%) undifferentiated gastric carcinomas, indicating that the expression of GalNAc-T3 correlated significantly with tumor differentiation (P=0.0023, chi2 test). Overall 5-year survival rate in patients with strong GalNAc-T3 expression (71.0%) was significantly better than that of patients with weak expression (49.3%) (P=0.0197, log-rank test). Multivariate analysis identified GalNAc-T3 expression as an independent prognostic factor (P=0.0158, Cox proportional hazards model). Our data suggest that GalNAc-T3 expression may be a useful marker for prognosis and differentiation of gastric carcinomas.