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.

CREB（cAMP反应元件结合蛋白）结合蛋白（CBP）及其同系物EP300已成为治疗癌症和炎性疾病的新治疗靶标。在这里，我们将从基于片段的虚拟筛选（FBVS）开始，报告作为CBP / EP300抑制剂的1-（1 H-吲哚-1-基）乙酮衍生物的鉴定，优化和评估。抑制剂（22e）与CBP的共晶结构为进一步优化提供了坚实的结构基础。最有效的化合物32h与CBP溴结构域结合，在AlphaScreen分析中的IC ₅₀值为0.037μM，是我们手中报道的CBP溴结构域抑制剂SGC-CBP30的2倍。32小时与其他含溴结构域的蛋白质相比，CBP / EP300的选择性也高。值得注意的是，化合物32h的酯衍生物（29h）在包括LNCaP，22Rv1和LNCaP衍生的C4-2B的几种前列腺癌细胞系中显着抑制细胞生长。化合物29h抑制LNCaP细胞中全长AR（AR-FL），AR靶基因和其他癌基因的mRNA表达。29h还降低了前列腺癌生物标志物PSA的表达。CBP / EP300抑制剂29h代表了有前途的先导化合物，可用于开发治疗去势抵抗性前列腺癌的新疗法。