Up-regulation of the tumor promoter Glyoxalase-1 indicates poor prognosis in breast cancer.

Glyoxalase 1 (Glo1) is an enzyme that plays a role to metabolize and inactivate methylglyoxal. Previous studies also have confirmed that Glo1 is closely related with tumorigenesis, metastasis, and drug-resistant, but its prognostic value in breast cancer has never been explored. In this study, we investigated the expression of Glo1 in breast cancer cell lines and tissues using real-time PCR, western blot and immunohistochemical analysis. We found Glo1 was frequently up-regulated in human breast cancer cells and tissues, and high expression of Glo1 was associated with positive lymph node, lymphovascular invasion, and TNM stage (all <0.05). The Kaplan-Meier survival curve demonstrated that patients with high Glo1 expression had a shorter overall survival (OS) and recurrence-free survival (RFS) (Both <0.001) than those with low Glo1 expression. Moreover, the univariate and further multivariate analysis revealed that Glo1 expression was an independent prognostic factor for both OS and RFS of breast cancer patients. Next, with CCK-8 assay, cell apoptosis analysis, colony formation assay, transwell invasion/migration assay, and wound-healing assay, we validated knock-down of Glo1 suppressed invasion and migration and promoted apoptosis of breast cancer cells. Taken together, we demonstrated the tumor-promoter Glo1 may serve as a prognostic biomarker for breast cancer.