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Discovery of a potent and selective PROTAC degrader for STAT3
Kefeng Wang1, Yuxin Zheng1, Wenli Mao1
1Department of Pharmacology, School of Medicine, Southern University of Science and Technology Shenzhen 518055 China wangyk@sustech.edu.cn.
Abstract:
The signal transducer and activator of transcription 3 (STAT3) protein and the p53 protein play opposite roles in the regulation of cell pathways. Activation of STAT3 upregulates survival pathways, while activation of p53 triggers apoptosis pathways. Therefore, STAT3 inhibition of p53 expression may play a central role in tumor development, and targeting STAT3 represents a promising therapeutic method for p53 reactivation in many cancers. Here, we report the design of S3D5, a BP-1-102-based proteolysis targeting chimera (PROTAC) that induces time- and dose-dependent degradation of STAT3 in HepG2 cells without significant effects on other STAT proteins. Preliminary mechanism studies show that S3D5 degradation of the STAT3 protein is mediated by the ubiquitin-proteasome system (UPS). S3D5 exhibits good anti-hepatocellular carcinoma cell proliferation activity, which can be explained by activating the p53 pathway. These findings demonstrate the utility and importance of PROTACs as preliminary chemical tools to investigate the function of the STAT3 protein. Further, S3D5 may serve as a potential anti-hepatocellular carcinoma agent, laying a practical foundation for further development of potent STAT3-targeting PROTACs.
Insights
Researchers developed S3D5, a novel PROTAC, to degrade STAT3, a protein promoting cancer cell survival. This approach reactivates the p53 pathway, inhibiting hepatocellular carcinoma cell proliferation and offering a potential new cancer therapy.
Area of Science:
- Oncology
- Molecular Biology
- Biochemistry
Background:
- Signal transducer and activator of transcription 3 (STAT3) and p53 proteins have opposing roles in cell survival and apoptosis.
- STAT3 activation promotes cancer cell survival, while p53 activation induces apoptosis.
- STAT3's inhibition of p53 is implicated in tumor development, making STAT3 a therapeutic target.
Purpose of the Study:
- To design and characterize a novel proteolysis targeting chimera (PROTAC) to degrade STAT3.
- To investigate the potential of STAT3 degradation as a therapeutic strategy for hepatocellular carcinoma (HCC).
- To explore the mechanism of STAT3 degradation and its effect on the p53 pathway.
Main Methods:
- Design and synthesis of S3D5, a BP-1-102-based PROTAC targeting STAT3.
- Assessment of STAT3 degradation in HepG2 cells using time- and dose-dependent assays.
- Investigation of the degradation mechanism via the ubiquitin-proteasome system (UPS).
- Evaluation of S3D5's anti-proliferative activity against HCC cells and its effect on p53 pathway activation.
Main Results:
- S3D5 effectively induced time- and dose-dependent degradation of STAT3 in HepG2 cells.
- STAT3 degradation by S3D5 was confirmed to be mediated by the UPS.
- S3D5 demonstrated significant anti-proliferative activity against HCC cells.
- The anti-cancer effect of S3D5 was associated with the activation of the p53 pathway.
Conclusions:
- PROTACs are valuable chemical tools for studying STAT3 function.
- S3D5 is a potent PROTAC capable of degrading STAT3 and reactivating the p53 pathway.
- S3D5 shows promise as a potential therapeutic agent for hepatocellular carcinoma.
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