The main goal of this project is to investigate the whether inactivation of E-cadherin, Beta and gamma-catenins can be used as biomarkers for bladder cancer initiation / progression or metastasis. Also investigate the molecular mechanisms of inactivation of E-cadherin, Beta and gamma-catenins in bladder cancer through mutation / CpG methylation pathways. We will also investigate the functional role of the E-cadherin, Beta, and gamma catenins genes in bladder cancer. Specific Hypotheses: We hypothesize that inactivation of E-cadherin, Beta, and gamma catenins is associated with stage and grades of bladder cancer. The mechanisms of inactivation of the E-cadherin, Beta, and gamma catenins gene are through mutation/hypermethylation pathways. Transfection of E-cadherin, Beta and gamma catenins genes will suppress growth of bladder cancer cells. To test these hypotheses, we will pursue the following specific aims. Specific Aim # 1. To analyze gene and protein expression of E-cadherin, Beta, and gamma catenins in different stages and grades of bladder cancer. This specific aim is based on the hypothesis that inactivation of E-cadherin, Beta, and gamma catenins genes can be detected in early stages of bladder cancer and that the frequency of loss of these genes increases with progression of the cancer process. Under this specific aim, we will determine the gene and protein expression of E-cadherin, Beta, and gamma catenins in normal and different stages and grades of bladder cancer. RNA expression will be analyzed by RT-PCR (for screening) and northern blot (for quantification). Protein expression will be analyzed by immunohistochemistry (for localization) and western blotting (for quantification). Specific Aim # 2. To investigate the mechanisms of inactivation of E-cadherin, Beta, and gamma catenins genes in bladder cancer. This specific aim is based on the hypothesis that mutation / hypermethylation pathways are involved in inactivation of E-cadherin, Beta, and gamma catenins genes in bladder cancer. Under this specific aim, we will first determine the mutation and CpG methylation of E-cadherin, Beta, and gamma catenins genes in different stages and grades of bladder cancer. CpG methylation will be analyzed by sodium bisulfite methylation techniques and confirm by direct DNA sequencing. Specific Aim # 3. To investigate the functional role of E-cadherin, Beta, and gamma catenins genes in bladder carcinogenesis. Under this specific aim, we will test the hypothesis that transfection of the E-cadherin, Beta, and gamma catenins genes in dominant-negative bladder cancer cells can suppress in vitro growth. Under this specific aim, we will transfect these genes and assess their in vitro growth and in vitro invasion assays. Accomplishment of these experiments will provide us with better biomarkers for detection of bladder cancer