Department of Chemistry and Molecular Biology, University of Gothenburg, SE, 41296, Gothenburg, Sweden.
Department of Molecular and Clinical Medicine, Institute of Medicine, Sahlgrenska Academy at University of Gothenburg, SE, 41345, Gothenburg, Sweden.
Eur J Med Chem. 2022 Apr 15;234:114226. doi: 10.1016/j.ejmech.2022.114226. Epub 2022 Mar 10.
REarranged during Transfection (RET) is a transmembrane receptor tyrosine kinase that is required for development of multiple human tissues, but which is also an important contributor to human cancers. RET activation through rearrangement or point mutations occurs in thyroid and lung cancers. Furthermore, activation of wild type RET is an increasingly recognized mechanism promoting tumor growth and dissemination of a much broader group of cancers. RET is therefore an attractive therapeutic target for small-molecule kinase inhibitors. Non-invasive control of RET signaling with light offers the promise of unveiling its complex spatiotemporal dynamics in vivo. In this work, photoswitchable DFG-out RET kinase inhibitors based on heterocycle-derived azobenzenes were developed, enabling photonic control of RET activity. Based on the binding mode of DFG-out kinase inhibitors and using RET kinase as the test model, we developed a photoswitchable inhibitor with a quinoline "head" constituting the azoheteroarene. This azo compound was further modified by three different strategies to increase the difference in biological activity between the E-isomer and the light enriched Z-isomer. Stilbene-based derivatives were used as model compounds to guide in the selection of substituents that could eventually be introduced to the corresponding azo compounds. The most promising quinoline-based compound showed more than a 15-fold difference in bioactivity between the two isomers in a biochemical assay. However, the same compound showed a decreased Z/E (IC) ratio in the cellular assay, tentatively assigned to stability issues. The corresponding stilbene compound gave a Z/E (IC) ratio well above 100, consistent with that measured in the biochemical assay. Ultimately, a 7-azaindole based photoswitchable DFG-out kinase inhibitor was shown to display more than a 10-fold difference in bioactivity between the two isomers, in both a biochemical and a cell-based assay, as well as excellent stability even under reducing conditions.
转染重排（RET）是一种跨膜受体酪氨酸激酶，它是人类多种组织发育所必需的，但也是人类癌症的重要贡献者。通过重排或点突变激活 RET 会发生在甲状腺癌和肺癌中。此外，野生型 RET 的激活是促进肿瘤生长和更广泛的癌症扩散的一种日益被认可的机制。因此，RET 是小分子激酶抑制剂的一个有吸引力的治疗靶点。用光线对 RET 信号进行非侵入性控制，有望揭示其在体内的复杂时空动力学。在这项工作中，基于杂环衍生的偶氮苯开发了可光切换的 DFG-out RET 激酶抑制剂，从而实现了对 RET 活性的光子控制。基于 DFG-out 激酶抑制剂的结合模式，并使用 RET 激酶作为测试模型，我们开发了一种带有喹啉“头”的可光切换抑制剂，该“头”构成了偶氮杂芳烃。该偶氮化合物通过三种不同的策略进一步修饰，以增加 E-异构体和富含光的 Z-异构体之间的生物活性差异。二苯乙烯基衍生物被用作模型化合物，以指导选择最终可以引入相应偶氮化合物的取代基。最有前途的基于喹啉的化合物在生化测定中两种异构体之间的生物活性差异超过 15 倍。然而，相同的化合物在细胞测定中显示出 Z/E（IC）比值降低，推测这是由于稳定性问题。相应的二苯乙烯基化合物的 Z/E（IC）比值远远高于 100，与生化测定中测量的值一致。最终，基于 7-氮杂吲哚的可光切换 DFG-out 激酶抑制剂在生化和基于细胞的测定中，两种异构体之间的生物活性差异超过 10 倍，即使在还原条件下也具有极好的稳定性。
