Volume 64, Issue 28 e202424832
Research Article

Lysine-Targeting, Covalent Inhibitors of Bromodomain BD1 of BET Proteins in Live Cells and Animals

Tao Li

Tao Li

Department of Pharmacology, School of Basic Medical Sciences, Cheeloo College of Medicine, Shandong University, Jinan, 250012 China

These authors contributed equally to this work.

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Wenjie Zhang

Wenjie Zhang

Department of Pharmacology, School of Basic Medical Sciences, Cheeloo College of Medicine, Shandong University, Jinan, 250012 China

These authors contributed equally to this work.

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Yiqing Wang

Yiqing Wang

State Key Laboratory of Bioactive Molecules and Druggability Assessment, School of Pharmacy, Jinan University, Guangzhou, 511436 China

These authors contributed equally to this work.

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Guangyu Xu

Guangyu Xu

Department of Pharmacology, School of Basic Medical Sciences, Cheeloo College of Medicine, Shandong University, Jinan, 250012 China

These authors contributed equally to this work.

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Fengfei Miao

Fengfei Miao

Department of Chemistry, National University of Singapore, 4 Science Drive 2, Singapore, 117544 Singapore

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Peng Chen

Peng Chen

Department of Chemistry, National University of Singapore, 4 Science Drive 2, Singapore, 117544 Singapore

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Guanghui Tang

Guanghui Tang

Department of Chemistry, National University of Singapore, 4 Science Drive 2, Singapore, 117544 Singapore

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Xiaotong Ze

Xiaotong Ze

Department of Pharmacology, School of Basic Medical Sciences, Cheeloo College of Medicine, Shandong University, Jinan, 250012 China

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Jing Xiang

Jing Xiang

Department of Pharmacology, School of Basic Medical Sciences, Cheeloo College of Medicine, Shandong University, Jinan, 250012 China

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Jiaqian Yan

Jiaqian Yan

Department of Pharmacology, School of Basic Medical Sciences, Cheeloo College of Medicine, Shandong University, Jinan, 250012 China

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Dr. Miaomiao Wang

Dr. Miaomiao Wang

Department of Clinical Laboratory, The Second Hospital of Shandong University, Jinan, Shandong, 250033 China

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Min Liu

Min Liu

Department of Pharmacology, School of Basic Medical Sciences, Cheeloo College of Medicine, Shandong University, Jinan, 250012 China

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Xiaojie Wang

Xiaojie Wang

Department of Pharmacology, School of Basic Medical Sciences, Cheeloo College of Medicine, Shandong University, Jinan, 250012 China

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Wei Tang

Wei Tang

Department of Pharmacology, School of Basic Medical Sciences, Cheeloo College of Medicine, Shandong University, Jinan, 250012 China

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Prof. Dr. Fan Yi

Prof. Dr. Fan Yi

Department of Pharmacology, School of Basic Medical Sciences, Cheeloo College of Medicine, Shandong University, Jinan, 250012 China

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Prof. Dr. Zhi-Min Zhang

Corresponding Author

Prof. Dr. Zhi-Min Zhang

State Key Laboratory of Bioactive Molecules and Druggability Assessment, School of Pharmacy, Jinan University, Guangzhou, 511436 China

E-mail: [email protected]; [email protected]; [email protected]; [email protected]

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Dr. Rui Wang

Corresponding Author

Dr. Rui Wang

Pingshan Translational Medicine Center, Shenzhen Bay Laboratory, Shenzhen, 518118 China

E-mail: [email protected]; [email protected]; [email protected]; [email protected]

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Prof. Dr. Shao Q Yao

Corresponding Author

Prof. Dr. Shao Q Yao

Department of Chemistry, National University of Singapore, 4 Science Drive 2, Singapore, 117544 Singapore

E-mail: [email protected]; [email protected]; [email protected]; [email protected]

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Prof. Dr. Yusheng Xie

Corresponding Author

Prof. Dr. Yusheng Xie

Department of Pharmacology, School of Basic Medical Sciences, Cheeloo College of Medicine, Shandong University, Jinan, 250012 China

E-mail: [email protected]; [email protected]; [email protected]; [email protected]

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First published: 01 May 2025

Graphical Abstract

We successfully developed the first BD1-targted covalent inhibitor (TCI), BDS4, by utilizing 2-ethynylbenzaldehyde (EBA). Importantly, BDS4 retained robust activity against fibrosis in cells and animals when compared to the marginal effects of BD2 inhibitor RVX-208. Our developed tool showed clear advantages of long-lasting domain-selective TCI in delineating the district function of BD1 and BD2.

Abstract

The bromodomain extra-terminal (BET) family of proteins are valuable therapeutic targets for cancer and other diseases. The adverse events of current pan-BET inhibitors (BETi) make the development of BET BD1- or BD2-selective inhibitors as a fresh avenue to overcome safety challenges. On the basis of various lysine-reactive covalent warheads herein we report a set of activity-based probes (ABPs; P3P7) capable of global profiling of ligandable lysines within bromodomains (BRDs) in live cells and animals. Chemoproteomic experiments with P7, which utilizes 2-ethynylbenzaldehyde (EBA), identified 16 endogenous BRDs, thus giving a global landscape of ligandable lysines in BRDs. By further introducing EBA and salicylaldehyde into PLX51107 (a noncovalent BETi), we generated lysine-reactive, irreversible (BDS14) and reversible (BDS56) BD1 covalent inhibitors. Mass spectrometry and X-ray crystallography confirmed the successful covalent engagement between EBA and K91 near the acetylated lysine (Kac)-binding site of BD1 in BRD4. BDS4 showed 104-fold selectivity for BD1 over BD2 with prolonged anticancer effects. Importantly, BDS4 retained robust activity against fibrosis in cells and animals when compared to RVX-208 (a reported BD2-selective noncovalent inhibitor), which showed only marginal effects. Our work serves as a useful tool to delineate distinct functions of BD1 and BD2 in future studies.

Conflict of Interests

Y.X., S.Y., M.W., T.L., W.Z., X.Z., and J.Y. are inventors on provisional patents (China Provisional Patent Application no.: 2024117297803, 2024117641745) related to this work.

Data Availability Statement

The data that support the findings of this study are available in the Supporting Information of this article.

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