Piperlongumine conjugates induce targeted protein degradation.

Area of Science:

• Biochemistry
• Molecular Biology
• Medicinal Chemistry

Background:

• Proteolysis targeting chimeras (PROTACs) are bifunctional molecules for targeted protein degradation.
• Current PROTAC applications are limited by the scarcity of E3 ligase ligands.

Purpose of the Study:

• To identify novel E3 ligase recruiters for targeted protein degradation.
• To develop new PROTACs with enhanced efficacy and broader applicability.

Main Methods:

• Conjugation of piperlongumine (PL) with SNS-032, a CDK9 inhibitor, to create conjugate 955.
• Assessment of CDK9 degradation and anti-tumor activity in vitro.
• Identification of the recruited E3 ligase using TurboID-based proteomics, KEAP1 knockout, and nanoBRET assays.

Main Results:

• Conjugate 955 potently degrades CDK9 via the ubiquitin-proteasome pathway.
• Conjugate 955 exhibits superior potency against tumor cells compared to SNS-032 alone.
• KEAP1 was identified as the E3 ligase recruited by 955 for CDK9 degradation.
• PL-ceritinib conjugate demonstrated degradation of EML4-ALK fusion oncoprotein.

Conclusions:

• Piperlongumine serves as a novel covalent E3 ligase ligand for targeted protein degradation.
• PL-based PROTACs offer a promising strategy for degrading various target proteins, including oncoproteins.
• This approach expands the utility of PROTAC technology in cancer treatment.