Hasyeoui Mohamed, Lassagne Frédéric, Erb William, Nael Manal, Elokely Khaled M, Chaikuad Apirat, Knapp Stefan, Jorda Adrian, Vallés Soraya L, Quissac Emie, Verreault Maïté, Robert Thomas, Bach Stéphane, Samarat Ali, Mongin Florence
Univ Rennes, CNRS, ISCR (Institut des Sciences Chimiques de Rennes) - UMR 6226, F-35000 Rennes, France; University of Carthage, Faculty of Sciences of Bizerte, LR18ES11, Laboratory of Hetero-Organic Compounds and Nanostructured Materials, 7021 Bizerte, Tunisia.
Univ Rennes, CNRS, ISCR (Institut des Sciences Chimiques de Rennes) - UMR 6226, F-35000 Rennes, France.
Bioorg Chem. 2023 May;134:106456. doi: 10.1016/j.bioorg.2023.106456. Epub 2023 Mar 4.
The 2-(3-pyridyl)oxazolo[5,4-f]quinoxalines CD-07 and FL-291 are ATP-competitive GSK-3 kinase inhibitors. Here, we investigated the impact of FL-291 on neuroblastoma cell viability and showed that treatment at 10 μM (i.e. ∼500 times the IC against the GSK-3 isoforms) has no significant effect on the viability of NSC-34 motoneuron-like cells. A study performed on primary neurons (non-cancer cells) led to similar results. The structures co-crystallized with GSK-3β revealed similar binding modes for FL-291 and CD-07, with their hinge-oriented planar tricyclic system. Both GSK isoforms show the same orientations for the amino acids at the binding pocket except for Phe130 (α) and Phe67 (β), leading to a larger pocket on the opposite side of the hinge region for the α isoform. Calculations of the thermodynamic properties of the binding pockets highlighted the required features of potential ligands; these should have a hydrophobic core (which could be larger in the case of GSK-3β) surrounded by polar areas (a little more polar in the case of GSK-3α). A library of 27 analogs of FL-291 and CD-07 was thus designed and synthesized by taking advantage of this hypothesis. While the introduction of substituents at different positions of the pyridine ring, the replacement of the pyridine by other heterocyclic moieties, or the replacement of the quinoxaline ring by a quinoline moiety did not lead to any improvement, the replacement of the N-(thio)morpholino of FL-291/CD-07 by a slightly more polar N-thiazolidino led to a significant result. Indeed, the new inhibitor MH-124 showed clear selectivity for the α isoform, with IC values of 17 nM and 239 nM on GSK-3α and GSK-3β, respectively. Finally, the efficacy of MH-124 was evaluated on two glioblastoma cell lines. Although MH-124 alone did not have a significant impact on cell survival, its addition to temozolomide (TMZ) significantly reduced the TMZ IC values on the cells tested. The use of the Bliss model allowed a synergy to be evidenced at certain concentrations.
2-(3-吡啶基)恶唑并[5,4-f]喹喔啉类化合物CD-07和FL-291是ATP竞争性GSK-3激酶抑制剂。在此，我们研究了FL-291对神经母细胞瘤细胞活力的影响，结果表明，以10 μM的浓度进行处理（即约为针对GSK-3亚型的IC值的500倍）对NSC-34运动神经元样细胞的活力没有显著影响。一项针对原代神经元（非癌细胞）的研究也得出了类似结果。与GSK-3β共结晶的结构显示，FL-291和CD-07具有相似的结合模式，其铰链导向的平面三环系统。除了Phe130（α）和Phe67（β）外，两种GSK亚型在结合口袋处的氨基酸显示出相同的取向，这导致α亚型在铰链区域另一侧有一个更大的口袋。结合口袋热力学性质的计算突出了潜在配体所需的特征；这些配体应该有一个疏水核心（在GSK-3β的情况下可能更大），周围是极性区域（在GSK-3α的情况下极性稍强）。因此，利用这一假设设计并合成了一个包含27种FL-291和CD-07类似物的文库。虽然在吡啶环的不同位置引入取代基、用其他杂环部分取代吡啶或用喹啉部分取代喹喔啉环均未带来任何改善，但用极性稍强的N-噻唑烷取代FL-291/CD-07的N-（硫）吗啉则产生了显著效果。事实上，新抑制剂MH-124对α亚型表现出明显的选择性，对GSK-3α和GSK-3β的IC值分别为17 nM和239 nM。最后，在两种胶质母细胞瘤细胞系上评估了MH-124的疗效。虽然单独使用MH-124对细胞存活没有显著影响，但将其添加到替莫唑胺（TMZ）中可显著降低所测试细胞上的TMZ IC值。使用布利斯模型可以证明在某些浓度下存在协同作用。
