Abstract
The aim of the present study was to examine the characteristics of bladder transitional cell carcinoma with E-cadherin and N-cadherin double-negative expression. An immunofluorescence assay was used to detect E-cadherin and N-cadherin expression in infiltrative bladder cancer tissues, and immunofluorescence and western blot analysis were used to detect E-cadherin and N-cadherin expression in human urinary bladder grade II carcinoma 5637, transitional cell carcinoma UMUC-3 and invasive bladder carcinoma EJ cells. Cell proliferation, migration, invasion and plate colony formation assays were used to detect the proliferative, migratory and invasive abilities and the efficiency of plate colony formation of 5637, UMUC3 and EJ cells. A tumor xenograft formation assay was used to evaluate the tumorigenic abilities of 5637, UMUC-3 and EJ cells in vivo. E-cadherin and N-cadherin double-negative expression was identified in various pathological grades of infiltrative bladder cancers. E-cadherin positive and N-cadherin negative expression was exhibited by 5637 cells. By contrast, E-cadherin negative and N-cadherin positive expression was exhibited by EJ cells, and E-cadherin and N-cadherin double-negative expression was exhibited by UMUC-3 cells. The ability of cells to proliferate, migrate, invade, and the efficiency of plate colony formation and tumorigenic abilities of the cells were significantly different among 5637, UMUC-3 and EJ cells. These cell characteristics were significantly increased in UMUC-3 cells compared with 5637 cells; however, the characteristics were significantly decreased compared with EJ cells. The biological characteristics of bladder cancer cells with E-cadherin and N-cadherin double-negative expression was between bladder cancer cells that exhibited a E-cadherin positive and N-cadherin negative expression, and bladder cancer cells that exhibited E-cadherin negative and N-cadherin positive expression. The present study deduces that the status of E-cadherin and N-cadherin double-negative expression may participate in the process of epithelial-mesenchymal transition in the pathogenesis of bladder urothelial carcinoma.