Discovery of Norbornene as a Novel Hydrophobic Tag Applied in Protein Degradation
Shaowen Xie, Feiyan Zhan, Jingjie Zhu, Yuan Sun, Huajian Zhu, Jie Liu, Jian Chen, Zheying Zhu, Dong‐Hua Yang, Zhe‐Sheng Chen, Hong Yao, Jinyi Xu, Shengtao Xu
Abstract
Hydrophobic tagging (HyT) is a potential therapeutic strategy for targeted protein degradation (TPD). Norbornene was discovered as an unprecedented hydrophobic tag in this study and was used to degrade the anaplastic lymphoma kinase (ALK) fusion protein by linking it to ALK inhibitors. The most promising degrader, Hyt-9, potently reduced ALK levels through Hsp70 and the ubiquitin-proteasome system (UPS) in vitro without compensatory upregulation of ALK. Furthermore, Hyt-9 exhibited a significant tumor-inhibiting effect in vivo with moderate oral bioavailability. More importantly, norbornene can also be used to degrade the intractable enhancer of zeste homolog 2 (EZH2) when tagged with the EZH2 inhibitor tazemetostat. Thus, the discovery of novel hydrophobic norbornene tags shows promise for the future development of TPD technology.