Structure-based design and optimization were performed to develop small-molecule β-catenin/B-cell lymphoma 9 (BCL9) inhibitors and improve their inhibitory activities. Compound ZL3138 with a novel 1-benzoyl 4-phenoxypiperidine scaffold was discovered to disrupt the β-catenin/BCL9 protein–protein interaction (PPI) with a K_i of 0.96 μM in AlphaScreen competitive inhibition assays and displayed good selectivity for β-catenin/BCL9 over β-catenin/E-cadherin PPIs. The binding mode of new inhibitors was characterized by structure–activity relationship and site-directed mutagenesis studies. Protein pull-down assays indicate that this series of compounds directly binds with β-catenin. Cellular target engagement and co-immunoprecipitation experiments demonstrate that ZL3138 binds with β-catenin and disrupts the β-catenin/BCL9 interaction without affecting the β-catenin/E-cadherin interaction in living cells. Further cell-based studies show that ZL3138 selectively suppresses transactivation of Wnt/β-catenin signaling, regulates transcription and expression of Wnt target genes, and inhibits the growth of Wnt/β-catenin-dependent cancer cells.

中文翻译：

---

发现 1-苯甲酰基 4-苯氧基哌啶作为 β-连环蛋白/B 细胞淋巴瘤 9 蛋白质-蛋白质相互作用的小分子抑制剂

进行基于结构的设计和优化以开发小分子 β-连环蛋白/B 细胞淋巴瘤 9 (BCL9) 抑制剂并提高其抑制活性。发现具有新型 1-苯甲酰基 4-苯氧基哌啶支架的化合物ZL3138在 AlphaScreen 竞争性抑制试验中以 0.96 μM的K _i破坏 β-连环蛋白/BCL9 蛋白-蛋白相互作用 (PPI)，并显示出对 β-连环蛋白/ BCL9 超过 β-连环蛋白/E-钙粘蛋白 PPI。新抑制剂的结合模式以构效关系和定点诱变研究为特征。蛋白质下拉分析表明这一系列化合物直接与 β-catenin 结合。细胞靶标参与和免疫共沉淀实验表明ZL3138与 β-catenin 结合并破坏 β-catenin/BCL9 相互作用而不影响活细胞中的 β-catenin/E-cadherin 相互作用。进一步的基于细胞的研究表明，ZL3138选择性地抑制 Wnt/β-catenin 信号传导的反式激活，调节 Wnt 靶基因的转录和表达，并抑制 Wnt/β-catenin 依赖性癌细胞的生长。