Objective: This study aimed at detecting Pokemon expression in bladder cancer cell and investigating the relationship between Pokemon and epithelial-mesenchymal transition. Furthermore, we investigated the functions of Pokemon in the carcinogenesis and development of bladder cancer. This study was also designed to observe the inhibitory effects of siRNA expression vector on Pokemon in bladder cancer cell. Methods: The siRNA expression vectors which were constructed to express a short hairpin RNA against Pokemon were transfected to the bladder cancer cells T24 with a liposome. Levels of Pokemon, E-cadherin and beta-catenin mRNA and protein were examined by real-time quantitative-fluorescent PCR and Western blot analysis, respectively. The effects of Pokemon silencing on epithelial-mesenchymal transition of T24 cells were evaluated with wound-healing assay. Results: Pokemon was strongly inhibited by siRNA treatment, especially siRNA3 treatment group, as it was reflected by Western blot and real-time PCR. The gene and protein of E-cadherin expression level showed increased markedly after Pokemon was inhibited by RNA interference. While there were no differences in the levels of gene and protein of beta-catenin among five groups. The bladder cancer cell after Pokemon siRNA interference showed a significantly reduced wound-closing efficiency at 6, 12 and 24 h. Conclusions: Our findings suggest Pokemon may inhibit the expression of E-cadherin. The low expression of E-cadherin lead to increasing the phenotype and apical-base polarity of epithelial cells. These changes of cells may result in the recurrence and progression of bladder cancer at last. (C) 2013 Elsevier Inc. All rights reserved.