The present invention provides therapeutic agents and methods for treating cancer using the polypeptides composed of an amino acid sequence which includes a polypeptide fragment of DEPDC1. The polypeptides of the present invention can be introduced into cancer cells by modifying the polypeptides with transfection agents such as poly-arginine. Furthermore, the present invention provides methods of screening for therapeutic agents or compounds useful in inhibition of the DEPDC1/ZN-F224 complex formation or the treatment of cancer. The present invention also provides siRNAs targeting the ZNF224 gene, which are suggested to be useful in the treatment of bladder cancer.
