Objective methods for detecting and diagnosing bladder cancer (BLC) are described herein. In one embodiment, the diagnostic method involves determining the expression level of a BLC-associated gene that discriminates between BLC cells and normal cells. The present invention further provides means for predicting and preventing bladder cancer metastasis using BLC-associated genes having unique altered expression patterns in bladder cancer cells with lymph-node metastasis. The present invention provides methods of screening for therapeutic agents useful in the treatment of bladder cancer, methods of treating bladder cancer and method for vaccinating a subject against bladder cancer. Specifically, the present application provides novel human genes C2093, B5860Ns and C6055s whose expression is markedly elevated in bladder cancers. The genes and polypeptides encoded by the genes can be used, for example, in the diagnosis of bladder cancers, as target molecules for developing drugs against the disease, and for attenuating cell growth of bladder cancer.