Purpose: Epithelial-to-mesenchymal transition (EMT)- related factors are known to contribute to the invasion and migration of multiple cancers. However, the expression levels of and the relationship between TWIST, E-cadherin, and beta-catenin in bladder cancer are not yet known. Therefore, this study investigated the relationship between TWIST, E-cadherin, and beta-catenin in tissue specimens and cell lines of bladder cancer.
Methods: Microarrays of bladder cancer tissue and bladder cancer cell lines were used to study the expression levels of TWIST, E-cadherin, and beta-catenin, with disease stage and grade using immunohistochemistry. Moreover, the siRNAs of TWIST, E-cadherin, and beta-catenin were transfected into the bladder cancer cell lines to study any relationship between these factors.
Results: The levels of TWIST and beta-catenin were upregulated with increasing grade of malignancy. In contrast, the corresponding results for E-cadherin were just the opposite. Furthermore, inhibition of the expression of TWIST elevated the expression of E-cadherin, but reduced the expression of beta-catenin. However, reduction of beta-catenin by siRNA had no influence on TWIST, but up-regulated the expression of E-cadherin.
Conclusion: TWIST may act upstream of E-cadherin, which can indirectly regulate the expression levels of beta-catenin. The EMT factors TWIST, E-cadherin, and beta-catenin may be a cluster of biomarkers for the metastatic progression of bladder cancer.