Galectin-1 dysregulation independently predicts disease specific survival in bladder urothelial carcinoma

Galectin-1 is highly expressed in various tumors and participates in various oncogenic processes. Our previous proteomics investigation demonstrated that galectin-1 is up-regulated in high compared to nonhigh grade lesions. Thus, in the current cohort study we clarified the correlation of galectin-1 over expression with various clinicopathological features and prognosis.

We selected 185 cases of consecutively treated primary localized bladder urothelial carcinoma for study. Transurethral resection of bladder tumor was performed in all patients followed by radical cystectomy in those with T2 to T4 tumors. Pathological slides were examined to determine cytoplasmic galectin-1 immuno-expression and correlate galectin-1 dysregulation with various clinicopathological factors and disease specific survival.

Positive galectin-1 immuno-expression in tumors was significantly linked to pT status (p = 0.0295), histological grade (p = 0.037), vascular invasion (p = 0.0287) and nodal status (p = 0.0012). Galectin-1 over expression in tumors significantly predicted disease specific survival at the univariate (p = 0.0002) and multivariate levels (p = 0.03, HR 2.438, 95% CI 1.090-5.451). In situ hybridization indicated that the LGALS1 gene was amplified in 43 specimens in an independent cohort of 56 snap frozen tumor specimens. Association analysis showed that an increased LGALS1 mRNA level was linked to bladder urothelial carcinoma invasiveness (p = 0.016) and LGALS1 gene amplification was significantly associated the amount of GAL-1 protein in tumors (p <0.0001). On the univariate level gene amplification was also closely linked to disease specific survival (p = 0.0006).

These results reveal that galectin-1 over expression is a possible independent factor for bladder cancer prognosis.