Bromodomain protein 4 (BRD4) is an attractive epigenetic target that regulating diverse cellular processes, and the discovery of dual-target inhibitors including BRD4 is an effective approach in cancer treatment to increase potency and reduce drug resistance. Based on the multifunctional drug development strategy, a series of new derivatives of nitrooxy (ONO₂) or furoxan (1,2,5-oxadiazole 2-oxide) with BRD4 inhibitor capable of inhibiting BRD4 and simultaneously releasing NO were designed and synthesized. When NO concentrations were measured with Griess reagent under physiological conditions, all compounds released NO at micromolar levels, reaching effective antitumor concentrations. Biological studies showed that the most potent BRD4/NO hybrid 11a exhibited good BRD4 inhibitory activity and selectivity. Further mechanistic studies revealed that 11a significantly decreased the expression of BRD4 and c-Myc, as well as induced cellular apoptosis and autophagic cell death both in vitro and in vivo. In summary, we optimized the chimeric BRD4-inhibitor/NO-donor based on our previous studies, and it should be a lead compound for targeted therapy of OC (ovarian cancer) in the future. This interesting strategy could expand the usage of BRDi in human malignancies and endogenous gastro-transmitters.

溴结构域蛋白 4 (BRD4) 是一个有吸引力的表观遗传靶点，可调节多种细胞过程，发现包括 BRD4 在内的双靶点抑制剂是癌症治疗中提高效力和降低耐药性的有效方法。基于多功能药物开发策略，设计并合成了一系列新的硝基氧基（ONO ₂）或呋喃（1,2,5-恶二唑2-氧化物）衍生物与BRD4抑制剂能够抑制BRD4并同时释放NO。当在生理条件下用 Griess 试剂测量 NO 浓度时，所有化合物都以微摩尔水平释放 NO，达到有效的抗肿瘤浓度。生物学研究表明，最有效的 BRD4/NO 杂种11a表现出良好的 BRD4 抑制活性和选择性。进一步的机制研究表明，11a显着降低 BRD4 和 c-Myc 的表达，并在体外和体内诱导细胞凋亡和自噬细胞死亡。总之，我们在前期研究的基础上优化了嵌合BRD4-抑制剂/NO-供体，它应该是未来卵巢癌靶向治疗的先导化合物。这种有趣的策略可以扩大 BRDi 在人类恶性肿瘤和内源性胃递质中的应用。