Department of Bioscience and Biotechnology, Institute of Anticancer Medicine Development, Sejong University, 209 Neungdong-ro, Kwangjin-gu, Seoul 05006, Korea.
Center for Catalytic Hydrocarbon Functionalizations, Institute for Basic Science (IBS), Daejeon 34141, Korea.
Int J Mol Sci. 2020 Dec 7;21(23):9323. doi: 10.3390/ijms21239323.
Although the inhibitors of singly mutated epidermal growth factor receptor (EGFR) kinase are effective for the treatment of non-small cell lung cancer (NSCLC), their clinical efficacy has been limited due to the emergence of various double and triple EGFR mutants with drug resistance. It has thus become urgent to identify potent and selective inhibitors of triple mutant EGFRs resistant to first-, second-, and third-generation EGFR inhibitors. Herein, we report the discovery of potent and highly selective inhibitors of EGFR exon 19 p.E746_A750del/EGFR exon 20 p.T790M/EGFR exon 20 p.C797S (d746-750/T790M/C797S) mutant, which were derived via two-track virtual screening and de novo design. This two-track approach was performed so as to maximize and minimize the inhibitory activity against the triple mutant and the wild type, respectively. Extensive chemical modifications of the initial hit compounds led to the identification of several low-nanomolar inhibitors of the d746-750/T790M/C797S mutant. Among them, two compounds exhibited more than 10-fold selectivity in the inhibition of EGFR over the wild type. The formations of a hydrogen bond with the mutated residue Ser797 and the van der Waals contact with the mutated residue Met790 were found to be a common feature in the interactions between EGFR and the fourth-generation inhibitors. Such an exceptionally high selectivity could also be attributed to the formation of the hydrophobic contact with a Gly loop residue or the hydrogen bond with Asp855 in the activation loop. The discovery of the potent and selective EGFR inhibitors were actually made possible by virtue of the modified protein-ligand binding free energy function involving a new hydration free energy term with enhanced accuracy. The fourth-generation EGFR inhibitors found in this work are anticipated to serve as a new starting point for the discovery of anti-NSCLC medicines to overcome the problematic drug resistance.
尽管单突变表皮生长因子受体（EGFR）激酶抑制剂对非小细胞肺癌（NSCLC）的治疗有效，但由于出现了各种具有耐药性的双突变和三突变 EGFR，其临床疗效受到限制。因此，迫切需要发现对第一代、第二代和第三代 EGFR 抑制剂耐药的三突变 EGFR 的有效且选择性抑制剂。在此，我们报告了一种有效且高度选择性的 EGFR 外显子 19 p.E746_A750del/EGFR 外显子 20 p.T790M/EGFR 外显子 20 p.C797S（d746-750/T790M/C797S）突变体抑制剂的发现，该抑制剂是通过双轨道虚拟筛选和从头设计得到的。这种双轨道方法的目的是分别最大限度地提高和最小化对三突变体和野生型的抑制活性。对初始命中化合物进行广泛的化学修饰，导致鉴定出几种对 d746-750/T790M/C797S 突变体具有低纳摩尔抑制活性的抑制剂。其中，两种化合物在抑制 EGFR 方面比野生型具有超过 10 倍的选择性。发现与突变残基 Ser797 形成氢键和与突变残基 Met790 形成范德华接触是第四代抑制剂与 EGFR 相互作用的共同特征。这种异常高的选择性也可以归因于与激活环中的 Gly 环残基形成疏水接触或与 Asp855 形成氢键。由于修改后的蛋白配体结合自由能函数中包含了一个新的水合自由能项，因此能够实现高效且选择性的 EGFR 抑制剂的发现，从而提高了准确性。在这项工作中发现的第四代 EGFR 抑制剂有望成为发现抗 NSCLC 药物的新起点，以克服有问题的耐药性。
