Expression of PDZ-binding kinase/T-LAK cell-originated protein kinase (PBK/TOPK) in human urinary bladder transitional cell carcinoma

The objective of this study was to evaluate the expression pattern of PDZ-binding kinase/T-LAK cell-originated protein kinase (PBK/TOPK) and its clinical significance in human bladder cancer (BC).We detected PBK/TOPK mRNA overexpression in BC and human normal testis tissues using RT-PCR. Using qRT-PCR revealed a higher expression of PBK/TOPK in BC tissues than their adjacent noncancerous tissues (ANCTs) (p < 0.0001). Cytoplasmic expression of PBK/TOPK protein was found to be positive in 64.6% (42 of 65) BC patients. Expression of PBK/TOPK protein was found to be significantly higher in muscle-invasive bladder cancer (MIBC) than in non-muscle-invasive bladder cancer (NMIBC) (86.1% vs. 37.9%, p < 0.001). The immunohistochemical (IHC) expression of PBK/TOPK was found to be significantly (p < 0.001) associated with the stage of disease.Study findings suggest that the PBK/TOPK mRNA/protein expression is specific to human BC and might be used as a novel target for development of cancer immunotherapy and diagnostic biomarker.