Structure-based optimization of a series of selective BET inhibitors containing aniline or indoline groups

• DOI: 10.1016/j.ejmech.2018.02.070
• Publication Date: 2018-02-24T12:48:00Z
• Authors: Jianping Hu; Yingqing Wang; Yanlian Li; Danyan Cao; Lin Xu; ShanShan Song; Mohammadali Solei...; Jian Li; Yuelei Chen; Xin Wang; Lin Chen; Jingkang Shen; Zehong Miao; Bing Xiong
• Keywords: 0303 health sciences; Aniline Compounds; Indoles; Dose-Response Relationship, Drug; Molecular Structure; Nuclear Proteins; Cell Cycle Proteins; B7-H1 Antigen; 3. Good health; Proto-Oncogene Proteins c-myc; Structure-Activity Relationship; 03 medical and health sciences; Humans; Transcription Factors

Recently, several kinase inhibitors were found to also inhibit bromodomains, providing a new strategy for the discovery of bromodomain inhibitors. Along this line, starting from PLK1-BRD4 dual inhibitor BI-2536, we discovered a new series of dihydroquinoxalin-2(1H)-one with aniline and indoline WPF binders as selective BRD4 inhibitors. They showed better BRD4-BD1 potency and negligible PLK1 kinase activity comparing with BI-2536. Additionally, dihydroquinoxalin-2(1H)-ones containing indoline group showed profound activities in molecular and cellular based assays. Throughout the study, compounds 9, 28 and 37 showed significant inhibitory activity for c-Myc or PD-L1 protein expression and mRNA transcription both at concentration of 0.2 and 1 μM. Compound 9 was found possessing the best balance of binding affinity, in vitro metabolic stability and in vivo pharmacokinetic properties. Therefore, it was selected for in vivo pharmacological study. By using MM.1S cell derived xenograft model, we confirmed compound 9 showed comparable in vivo tumor inhibition to phase II investigation drug I-BET762, which, together with the novel WPF binder, further indicated the utility of this series of BRD4 inhibitors.