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Updated: Jun 4, 2025
Kinase Inhibitor Screening In Self-assembled Human Protein Microarrays
Published on: October 23, 2019
Advanced PROTAC and Quantitative Proteomics Strategy Reveals Bax Inhibitor-1 as a Critical Target of Icaritin in
Peixi Zhang1, Ziqing Zhang1, Jie Li1
1School of Medicine, Huaqiao University, Quanzhou 362021, China.
Abstract:
Understanding the molecular targets of natural products is crucial for elucidating their mechanisms of action, mitigating toxicity, and uncovering potential therapeutic pathways. Icaritin (ICT), a bioactive flavonoid, demonstrates significant anti-tumor activity but lacks defined molecular targets. This study employs an advanced strategy integrating proteolysis targeting chimera (PROTAC) technology with quantitative proteomics to identify ICT's key targets. A library of 22 ICT-based PROTAC derivatives were synthesized, among which LJ-41 exhibited a superior IC50 of 5.52 μM against Burkitt lymphoma (CA-46) cells. Then, differential proteomic analysis identified Bax inhibitor-1 (BI-1) as a potential target. Target validation techniques, including cellular thermal shift assay (CETSA), drug affinity responsive target stability (DARTS) assay, surface plasmon resonance (SPR) assay, and molecular docking, confirmed LJ-41's high specificity for BI-1. Mechanistic investigations revealed that LJ-41 induces apoptosis through BI-1 degradation, triggering endoplasmic reticulum stress and activating inositol-requiring enzyme 1 α (IRE1α), activating transcription factor 6 (ATF6), and nuclear factor erythroid 2-related factor transcription factor heme oxygenase 1 (NRF2-HO-1) signaling pathways. This study establishes a refined methodological framework for natural product target discovery and highlights ICT-PROTAC derivatives' potential for clinical application in Burkitt lymphoma treatment.
Insights
This study identified Bax inhibitor-1 (BI-1) as a molecular target of icaritin (ICT) using PROTAC technology. The novel compound LJ-41 induces apoptosis in Burkitt lymphoma cells by degrading BI-1.
Area of Science:
- Biochemistry
- Molecular Biology
- Pharmacology
Background:
- Natural products like icaritin (ICT) show anti-tumor potential but require defined molecular targets for therapeutic development.
- Identifying molecular targets is key to understanding drug mechanisms, reducing toxicity, and discovering new treatments.
Purpose of the Study:
- To identify the molecular targets of icaritin (ICT) using a novel proteolysis targeting chimera (PROTAC) and quantitative proteomics approach.
- To validate the identified target and elucidate the mechanism of action of ICT-based PROTAC derivatives in Burkitt lymphoma cells.
Main Methods:
- Synthesis of 22 icaritin-based PROTAC derivatives, including LJ-41.
- Differential proteomic analysis, cellular thermal shift assay (CETSA), drug affinity responsive target stability (DARTS), surface plasmon resonance (SPR), and molecular docking.
- Investigation of apoptosis induction, endoplasmic reticulum stress, and associated signaling pathways (IRE1α, ATF6, NRF2-HO-1).
Main Results:
- LJ-41 demonstrated potent anti-cancer activity against Burkitt lymphoma cells (IC50 = 5.52 μM).
- Bax inhibitor-1 (BI-1) was identified as a specific molecular target of LJ-41.
- LJ-41 induces apoptosis via BI-1 degradation, leading to endoplasmic reticulum stress and activation of IRE1α, ATF6, and NRF2-HO-1 signaling.
Conclusions:
- This study establishes a robust framework for natural product target discovery using PROTAC technology.
- Icaritin-PROTAC derivatives, exemplified by LJ-41 targeting BI-1, show significant potential for Burkitt lymphoma treatment.
