Discovery and optimization of 1-(1H-indol-1-yl)ethanone derivatives as CBP/EP300 bromodomain inhibitors for the treatment of castration-resistant prostate cancer.

Abstract

The CREB (cAMP responsive element binding protein) binding protein (CBP) and its homolog EP300 have emerged as new therapeutic targets for the treatment of cancer and inflammatory diseases. Here we report the identification, optimization and evaluation of 1-(1H-indol-1-yl)ethanone derivatives as CBP/EP300 inhibitors starting from fragment-based virtual screening (FBVS). A cocrystal structure of the inhibitor (22e) in complex with CBP provides a solid structural basis for further optimization. The most potent compound 32h binds to the CBP bromodomain and has an IC50 value of 0.037 μM in the AlphaScreen assay which was 2 times more potent than the reported CBP bromodomain inhibitor SGC-CBP30 in our hands. 32h also exhibit high selectivity for CBP/EP300 over other bromodomain-containing proteins. Notably, the ester derivative (29h) of compound 32h markedly inhibits cell growth in several prostate cancer cell lines including LNCaP, 22Rv1 and LNCaP derived C4-2B. Compound 29h suppresses the mRNA expression of full length AR (AR-FL), AR target genes and other oncogene in LNCaP cells. 29h also reduces the expression of PSA, the biomarker of prostate cancer. CBP/EP300 inhibitor 29h represents a promising lead compound for the development of new therapeutics for the treatment of castration-resistant prostate cancer.

• Authors: Qiuping Xiang, Chao Wang, Yan Zhang, Xiaoqian Xue, Ming Song, Cheng Zhang, Chenchang Li, Chun Wu, Kuai Li, Xiaoyan Hui, Yulai Zhou, Jeff B Smaill, Adam V Patterson, Donghai Wu, Ke Ding, Yong Xu
• Journal: European journal of medicinal chemistry (Eur J Med Chem) Vol. 147 Pg. 238-252 (Mar 10 2018) ISSN: 1768-3254 [Electronic] France
• PMID: 29448139 (Publication Type: Journal Article)
• Copyright: Copyright © 2018 Elsevier Masson SAS. All rights reserved.

Chemical References

• Antineoplastic Agents
• Indoles
• Peptide Fragments
• Sialoglycoproteins
• bone sialoprotein (35-62), human
• E1A-Associated p300 Protein
• EP300 protein, human

Topics

• Antineoplastic Agents (chemical synthesis, chemistry, pharmacology)
• Cell Proliferation (drug effects)
• Cell Survival (drug effects)
• Dose-Response Relationship, Drug
• Drug Discovery
• Drug Screening Assays, Antitumor
• E1A-Associated p300 Protein (antagonists & inhibitors, isolation & purification, metabolism)
• Humans
• Indoles (chemical synthesis, chemistry, pharmacology)
• Male
• Molecular Structure
• Peptide Fragments (antagonists & inhibitors, isolation & purification, metabolism)
• Prostatic Neoplasms, Castration-Resistant (drug therapy, metabolism, pathology)
• Sialoglycoproteins (antagonists & inhibitors, isolation & purification, metabolism)
• Structure-Activity Relationship
• Tumor Cells, Cultured