Pharmaceutical Organic Chemistry Department, Faculty of Pharmacy, Suez Canal University, Ismailia 41522, Egypt.
Department of Chemistry, Faculty of Science, Alexandria University, P.O. Box 426, Ibrahimia, Alexandria 21321, Egypt.
Bioorg Chem. 2021 Dec;117:105427. doi: 10.1016/j.bioorg.2021.105427. Epub 2021 Oct 13.
Despite the achieved progress in developing efficient MDM2-p53 protein-protein interaction inhibitors (MDM2 inhibitors), the acquired resistance of tumor cells to such p53 activators posed an argument about the druggability of the pathway. Combination studies disclosed that concomitant inhibition of MDM2 and BCL2 functions can sensitize the tumor cells and synergistically induce apoptosis. Herein, we employed a rapid combinatorial approach to generate a novel series of hybrid spirooxindole-based MDM2 inhibitors (5a-s) endowed with BCL2 signaling attenuation. The adducts were designed to mimic the thematic features of the chemically stable potent spiro[3H-indole-3,2'-pyrrolidin]-2(1H)-ones MDM2 inhibitors while installing a pyrrole ring on the core via a carbonyl spacer inspired by the natural product marinopyrrole A that efficiently inhibits BCL2 family functions by various mechanisms. NCI 60 cell-line panel screening revealed their promising broad-spectrum antiproliferative activities. The NCI-selected derivatives were screened for cytotoxic activities against normal fibroblasts, MDA-MB 231, HepG-2, and Caco-2 cells via MTT assay, subjected to mechanistic apoptosis studies for assessment of p53, BCL2, p21, and caspase 3/7 status, then evaluated for potential MDM2 inhibition utilizing MST assay. The most balanced potent and safe derivatives; 5i and 5q were more active than 5-fluorouracil, exhibited low μmrange MDM2 binding (K=1.32and 1.72 μm, respectively), induced apoptosis-dependent anticancer activities up to 50%, activated p53 by 47-63%, downregulated the BCL2 gene to 59.8%, and reduced its protein level (13.75%) in the treated cancer cells. Further downstream p53 signaling studies revealed > 2 folds p21 upregulation and > 3 folds caspase 3/7 activation. Docking simulations displayed that the active MDM2 inhibitors resided well into the p53 binding sites of MDM2, and shared key interactions with the co-crystalized inhibitor posed by the indolinone scaffold (5i, 5p, and 5q), the halogen substituents (5r), or the installed spiro ring (5s). Finally, in silico ADMET profiling predicted acceptable drug-like properties with full accordance to Lipinski's, Veber's, and Muegge's bioavailability parameters for 5i and a single violation for 5q.
尽管在开发高效的 MDM2-p53 蛋白-蛋白相互作用抑制剂（MDM2 抑制剂）方面取得了进展，但肿瘤细胞对这种 p53 激活剂的获得性耐药性引发了关于该途径可成药性的争论。联合研究表明，同时抑制 MDM2 和 BCL2 的功能可以使肿瘤细胞敏感，并协同诱导细胞凋亡。在此，我们采用快速组合方法生成了一系列新型杂合螺噁吲哚基 MDM2 抑制剂（5a-s），具有 BCL2 信号衰减作用。这些加合物的设计旨在模拟化学稳定的强效螺[3H-吲哚-3,2'-吡咯烷]-2(1H)-酮 MDM2 抑制剂的主题特征，同时通过受天然产物 marinopyrrole A 启发的羰基间隔基在核心上安装一个吡咯环，该天然产物通过多种机制有效地抑制 BCL2 家族功能。NCI 60 细胞系小组筛选显示它们具有有希望的广谱抗增殖活性。通过 MTT 测定法对 NCI 选择的衍生物进行了针对正常成纤维细胞、MDA-MB 231、HepG-2 和 Caco-2 细胞的细胞毒性活性筛选，进行了机制凋亡研究以评估 p53、BCL2、p21 和 caspase 3/7 状态，然后利用 MST 测定法评估潜在的 MDM2 抑制作用。最平衡的有效且安全的衍生物；5i 和 5q 比 5-氟尿嘧啶更活跃，表现出低 μm 范围的 MDM2 结合（K=1.32 和 1.72μm，分别），诱导高达 50%的凋亡依赖性抗癌活性，使 p53 激活 47-63%，下调 BCL2 基因至 59.8%，并降低治疗癌细胞中的蛋白水平（13.75%）。进一步的下游 p53 信号研究表明，p21 上调超过 2 倍，caspase 3/7 激活超过 3 倍。对接模拟显示，活性 MDM2 抑制剂很好地位于 MDM2 的 p53 结合部位，并与由 indolinone 支架（5i、5p 和 5q）、卤素取代基（5r）或安装的螺环（5s）构成的共结晶抑制剂共享关键相互作用。最后，计算机 ADMET 分析预测 5i 具有可接受的类药性，完全符合 Lipinski、Veber 和 Muegge 的生物利用度参数，而 5q 只有一个违反。
