Background: T cell immunoglobulin mucin-3 (Tim-3) was initially recognized as a pivotal immune checkpoint inhibitor that maintains immune homeostasis and tolerance. Recently, Tim-3 has been demonstrated to play an important role in tumor-associated immune suppression and aberrant Tim-3 expression has been reported in several human malignancies. However, the role of Tim-3 in bladder urothelial carcinoma (BUC) remains largely unknown. The present study aims to investigate Tim-3 expression in BUC and analyze correlations with clinicopathologic outcomes and postoperative survival.
Methods: Tim-3 protein expressions were detected in paraffin embedded sections from 100 patients with BUC by immunohistochemistry. Expressions were correlated with clinicopathologic outcomes and postoperative survival.
Results: Tim-3 protein was over-expressed in bladder cancer cells, tumor infiltrating lymphocytes and endothelial cells from patients with BUC. The expression levels of Tim-3 were significantly correlated with advanced pathological grade and T stage. Moreover, another immune checkpoint molecule programmed death receptor-1(PD-1) was also over- expressed in BUC tissues and had a significant correlation with Tim-3. Multivariate analysis showed that Tim-3 expression, as well as PD-1 expression was both independent predictors of disease-free survival and overall survival in patients with BUC.
Conclusion: Tim-3 over-expression implies adverse clinical outcomes for BUC, which suggests it is a potential prognostic biomarker and a novel therapeutic target in BUC.
Keywords: PD-1; Tim-3; bladder urothelial carcinoma; prognosis.
© 2015 Wiley Periodicals, Inc.