A potent CBP/p300-Snail interaction inhibitor suppresses tumor growth and metastasis in wild-type p53-expressing cancer.

The zinc finger transcription factor Snail is aberrantly activated in many human cancers and associated with poor prognosis. Therefore, targeting Snail is expected to exert therapeutic benefit in patients with cancer. However, Snail has traditionally been considered "undruggable," and no effective pharmacological inhibitors have been identified. Here, we found a small-molecule compound CYD19 that forms a high-affinity interaction with the evolutionarily conserved arginine-174 pocket of Snail protein. In aggressive cancer cells, CYD19 binds to Snail and thus disrupts Snail's interaction with CREB-binding protein (CBP)/p300, which consequently impairs CBP/p300-mediated Snail acetylation and then promotes its degradation through the ubiquitin-proteasome pathway. Moreover, CYD19 restores Snail-dependent repression of wild-type p53, thus reducing tumor growth and survival in vitro and in vivo. In addition, CYD19 reverses Snail-mediated epithelial-mesenchymal transition (EMT) and impairs EMT-associated tumor invasion and metastasis. Our findings demonstrate that pharmacologically targeting Snail by CYD19 may exert potent therapeutic effects in patients with cancer.