Identification of bicyclic compounds that act as dual inhibitors of Bcl-2 and Mcl-1
作者:Abhay Uthale、Aarti Anantram、Prasad Sulkshane、Mariam Degani、Tanuja Teni
DOI:10.1007/s11030-022-10494-6
日期:——
Elevated expression of anti-apoptotic proteins, such as Bcl-2 and Mcl-1 contributes to poor prognosis and resistance to current treatment modalities in multiple cancers. Here, we report the design, synthesis and characterization of benzimidazole chalcone and flavonoid scaffold-derived bicyclic compounds targeting both Bcl-2 and Mcl-1 by optimizing the structural differences in the binding sites of both these proteins. Initial docking screen of Bcl-2 and Mcl-1 with pro-apoptotic protein Bim revealed possible hits with optimal binding energies. All the optimized bicyclic compounds were screened for their in vitro cytotoxic activity against two oral cancer cell lines (AW8507 and AW13516) which express high levels of Bcl-2 and Mcl-1. Compound 4d from the benzimidazole chalcone series and compound 6d from the flavonoid series exhibited significant cytotoxic activity (IC50 7.12 μM and 17.18 μM, respectively) against AW13516 cell line. Time Resolved-Fluorescence Resonance Energy Transfer (TR-FRET) analysis further demonstrated that compound 4d and compound 6d could effectively inhibit the Bcl-2 and Mcl-1 proteins by displacing their BH3 binding partners. Both compounds exhibited potent activation of canonical pathway of apoptosis evident from appearance of cleaved Caspase-3 and PARP. Further, treatment of oral cancer cells with the inhibitors induced dissociation of the BH3 only protein Bim from Mcl-1 and Bak from Bcl-2 but failed to release Bax from Bcl-xL thereby confirming the nature of compounds as BH3-mimetics selectively targeting Bcl-2 and Mcl-1. Our study thus identifies bicyclic compounds as promising candidates for anti-apoptotic Bcl-2/Mcl-1 dual inhibitors with a potential for further development.
抗凋亡蛋白(如Bcl-2和Mcl-1)的表达升高会导致多种癌症预后不良,并导致对现有治疗方式的耐药性。在此,我们报告了苯并咪唑查尔酮和黄酮类化合物骨架衍生物双环化合物的设计、合成和表征,这些化合物通过优化Bcl-2和Mcl-1结合位点的结构差异,同时靶向这两种蛋白。通过将Bcl-2和Mcl-1与促凋亡蛋白Bim进行初步对接筛选,我们发现了具有最佳结合能的可能的靶向化合物。对所有优化后的双环化合物进行了体外细胞毒性活性筛选,以检测其对两种表达高水平Bcl-2和Mcl-1的口腔癌细胞系(AW8507和AW13516)的细胞毒性活性。苯并咪唑查尔酮系列中的化合物4d和黄酮类化合物系列中的化合物6d对AW13516细胞系表现出显著的细胞毒性活性(IC50分别为7.12 μM和17.18 μM)。时间分辨荧光共振能量转移(TR-FRET)分析进一步表明,化合物4d和化合物6d可通过置换其BH3结合伴侣来有效抑制Bcl-2和Mcl-1蛋白。从裂解的Caspase-3