αGlcNAc and its catalyst α4GnT are diagnostic and prognostic markers in uterine cervical tumor, gastric type

Cervical adenocarcinoma, gastric type (GAS) is not associated with human papilloma virus (HPV) infection. GAS patients prognoses are significantly worse compared with cervical adenocarcinoma associated with HPV infection, as their tumors exhibit resistance to conventional chemotherapy and radiotherapy. GAS is often associated with lobular endocervical glandular hyperplasia (LEGH), which is regarded as a precursor to GAS in the latest WHO classification. Recently, we reported that a decrease in expression of terminal α1,4-linked N-acetylglucosamine (αGlcNAc) relative to that of MUC6 was already apparent in atypical LEGH in the LEGH-GAS sequence. Here, we analyzed expression of α1,4-N-acetylglucosaminyltransferase (α4GnT), the sole enzyme catalyzing αGlcNAc biosynthesis, and that of αGlcNAc and MUC6 in cases representing non-neoplastic endocervical gland (NNEG) (11 cases), LEGH (26 cases) and GAS (12 cases). α4GnT protein was detected in a “dot-like” pattern, indicating localization in the Golgi apparatus in all 26 LEGH cases and 5 of 12 GAS cases. α4GnT- and αGlcNAc-positive cells largely overlapped, suggesting that α4GnT gene expression regulates αGlcNAc biosynthesis. Interestingly, all NNEG cases were negative for α4GnT and αGlcNAc expression, but 7 of 11 NNEG and all LEGH cases were MUC6-positive. In GAS cases, patients whose tumors were α4GnT- and αGlcNAc-positive had more favorable prognosis than others. Multivariate analysis revealed that positive expressions of α4GnT and αGlcNAc were independent prognostic indicators. These results indicate that α4GnT and αGlcNAc could serve as useful markers not only to distinguish LEGH from NNEG but to evaluate prognoses of GAS patients.