Polypeptide-GalNAc-T6 expression predicts better overall survival in patients with colon cancer

Colorectal carcinoma (CRC) is the second leading cause of cancer mortality worldwide. O-glycosylated mucins at the cell surface of colonic mucosa exhibit alterations in cancer and are involved in fundamental biological processes, including invasion and metastasis. Certain members of the GalNAc-transferase family may be responsible for these changes and are being investigated as novel biomarkers of cancer. In the present study the prognostic significance of GalNAc-T6 was investigated in patients with CRC patients. GalNAc-T6 expression was observed in all three colon cancer cell lines analyzed by reverse transcription-polymerase chain reaction, immunofluorescence and flow cytometry. A cohort of 81 colon cancer specimens was analyzed by immunohistochemical staining using MAb T6.3. It was demonstrated that GalNAc-T6 was expressed in 35/81 (43%) cases of colon cancer but not in the normal colonic mucosa. No association was observed with the clinical-pathologic parameters. However, patients expressing GalNAc-T6 had a significantly increased overall survival (median, 58 months; P<0.001) compared with GalNAc-T6 negative patients, especially those with advanced disease. These results suggest that GalNAc-T6 expression predicts an improved outcome in patients with CRC. The molecular mechanism underlying the less aggressive behavior of colon cancer cells expressing GalNAc-T6 remains to be elucidated.

Polypeptide N-acetylgalactosaminyltransferase-6 expression independently predicts poor overall survival in patients with lung adenocarcinoma after curative resection

Background

Polypeptide N-acetylgalactosaminyltransferases (GalNAc-Ts) are important glycosyltransferases in cancer, but the clinical role of its individual isoforms is unclear. We investigated the clinical significance and survival relevance of one isoform, GalNAc-T6 in lung adenocarcinoma after curative resection.

Results

GalNAc-T6 was identified in 27.8% (55/198) of patients, and statistically indicated advanced TNM stage (P = 0.069). Multivariate analysis showed GalNAc-T6 to be an independent predictor for reduced overall survival of patients (P = 0.027), and the result was confirmed with bootstraping techniques, and on line “Kaplan-Meier Plotter” and “SurvExpress” database analysis, respectively. Moreover, ROC curve demonstrated that GalNAc-T6 expression significantly improved the accuracy of survival prediction.

Methods

With 198 paraffin-embedded tumor samples from lung adenocarcinoma patients, GalNAc-T6 expression was immunohistochemically assessed for the association with clinicopathological parameters. The prognostic significance was evaluated by Cox proportional hazards regression analysis with 1000 bootstraping. “Kaplan-Meier Plotter”, “SurvExpress” database analysis, and receiver-operating characteristic (ROC) curve were performed to provide further validation.

Conclusions

GalNAc-T6 expression correlated significantly with advanced TNM stage, and independently predicted worse OS for lung adenocarcinoma.

Expression of Polypeptide N-Acetylgalactosaminyltransferase-6 in Epithelial Ovarian Carcinoma

BACKGROUND

The family of polypeptide N-acetylgalactosanimyltransferases (GalNAc-Ts) are important factors in glycosylation in carcinomas. The purpose of this study was to investigate the clinical significance of GalNAc-T6 and its correlation with the prognosis of epithelial ovarian carcinoma.

MATERIALS AND METHODS

A total of 150 patients with epithelial ovarian carcinoma were enrolled and the relationship between GalNAc-T6 expression by immunohistochemistry and long-term survival was evaluated.

RESULTS

The expression of GalNAc-T6 was positive in 57.6% (34/59) of those with serous carcinoma, 85.3% (29/34) in mucinous carcinoma, 15.6% (5/27) in clear cell carcinoma, and 44% (14/25) in endometrioid carcinoma. In a Kaplan-Meier analysis of patients with grade 1 or 2 serous carcinoma, the 10-year overall survival rates were 47.4% in the GalNAc-T6-positive and 9.1% in the GalNAc-T6-negative groups (p=0.047).

CONCLUSION

GalNAc-T6 expression in epithelial ovarian carcinoma was different according to pathological type. In low-grade serous carcinoma, GalNAc-T6 expression may contribute to improved long-term survival.

Correlation of polypeptide N-acetylgalactosamine transferases-3 and -6 to different stages of endometriosis

PURPOSE

To investigate the expression patterns of N-acetyl galactosamine transferases (GalNAc-Ts)-3 and GalNAc-T6 in clinicopathologically characterized endometriosis (EMS), and to explore their clinical significance.

METHODS

Ectopic and eutopic endometrial tissue samples were obtained and confirmed with CD-10 immunohistochemistry in patients with EMS (n = 12), whereas normal control endometrium was obtained from patients with uterine septum (n = 12). The mRNA and protein levels of GalNAc-T3 and GalNAc-T6 were detected in these samples using quantitative real-time PCR, immunohistochemistry, and western blotting.

RESULTS

GalNAc-T3 and GalNAc-T6 were expressed in the endometrium of all groups, with no significant changes observed during the menstrual cycle. The expression of GalNAc-T3 and GalNAc-T6 in ectopic endometrium was significantly lower than that in eutopic (P < 0.05) or control endometrium (P < 0.05), whereas there were no significant differences (P > 0.05) between eutopic and control endometria. Furthermore, the expression of GalNAc-T3 and GalNAc-T6 was significantly lower in patients with stage III/IV EMS compared to patients with stage I/II (P < 0.05).

CONCLUSIONS

Both GalNAc-T3 and GalNAc-T6 expression levels were downregulated in ectopic endometrium, which may increase the adhesion and invasion of endometrial cells and contribute to the development of EMS. Moreover, we found a strong correlation between the expression of GalNAc-T3 and GalNAc-T6 and different stages of EMS.