Glycine N-methyltransferase is a favorable prognostic marker for human cholangiocarcinoma.

BACKGROUND AND AIM

Glycine N-methyltransferase (GNMT) is a susceptibility gene for human hepatocellular carcinoma (HCC). We previously reported that GNMT expression is diminished in HCC. Here we report our examination of GNMT expression patterns in cholangiocarcinoma and the relationship between its expression and prognosis.

METHODS

We analyzed GNMT expression in tumor tissues from 33 cholangiocarcinoma patients (19 male) using immunohistochemistry (IHC) procedures with a GNMT monoclonal antibody (mAb 4-17). GNMT expression intensity and percentages were scored on a scale of 0 to 6. The association between GNMT expression and survival was analyzed using the Kaplan-Meier method, and prognostic factors were evaluated with a multivariate Cox proportional hazards regression model.

RESULTS

High GNMT expression was found in epithelial cells of normal bile ducts. Six of 33 (18.2%) cholangiocarcinoma tissues had no GNMT expression. A statistically significant difference was noted in GNMT expression between male and female patients (68.4% vs 100%, P < 0.05). Compared to patients with GNMT expression scores > 3, the death hazard ratio for patients with GNMT scores <or= 3 was 3.68 (95% confidence interval = 1.17-11.59, P < 0.05).

CONCLUSIONS

GNMT expression is a favorable prognosis predictor for cholangiocarcinoma.