N-Acetylglucosaminyltransferase III (GnT-III) but not N-Acetylgalactosaminyltransferase-6 and 8 are Differentially Expressed in Invasive and In Situ Ductal Carcinoma of the Breast.

Mammary carcinoma is the most common malignant tumor in women, and it is the leading cause of mortality. In tumor context, glycosylation promotes post translational modifications necessary for cell progression, emerging as a relevant tumor hallmarker. This study aimed to analyze the association between polypeptide N-acetylgalactosaminyltransferase-6 (ppGalNAc-T6), -T8, N-acetylglucosaminyltransferase III (GnT-III) expression, Phaseolus vulgaris-leucoagglutinin (PHA-L), wheat germ agglutinin (WGA) and peanut agglutinin (PNA) staining with clinic-histopathological factors from patients with pure ductal carcinoma in situ (DCIS) and DCIS with invasive ductal carcinoma (DCIS-IDC) of breast. Formalin-fixed and paraffin-embedded samples (n = 109) were analyzed. In pure DCIS samples GnT-III was over-expressed in comedo lesions (p = 0.007). In DCIS-IDC, GnT-III expression was associated with high nuclear grade tumors (p = 0.039) while the presence of PHA-L and WGA were inversely related to HER-2 expression (p = 0.001; p = 0.036, respectively). These findings pointed to possible involvement of GnT-III, ppGalNAc-T8, L-PHA and WGA as probes in prognostic evaluation of DCIS.