Abstract
DEDD, a member of a family of death effector domain-containing proteins, plays crucial roles in mediating apoptosis, regulating cell cycle, and inhibiting cell mitosis. Our recent work demonstrates that DEDD is a novel tumor repressor, which impedes metastasis by reversing the epithelial-mesenchymal transition (EMT) process in breast and colon cancers. DEDD expression therefore may represent a prognostic marker and potential therapeutic target for the prevention and treatment of cancer metastasis. To reveal the anti-metastatic roles of DEDD in these cancer cells, a number of experiments, including immunohistochemistry, the establishment of stably overexpressing or silencing cancer cells, chemoinvasion assay, soft agar assay, protein degradation, and protein-protein interaction were used in our in vitro and in vivo studies. This chapter focuses on the details of these experiments to provide references for the researchers to investigate the function of a gene in the regulation of tumor metastasis.