基于C797S共晶蛋白结构的新型蝶啶类EGFR激酶抑制剂的设计、合成及抗肿瘤活性研究

Non-small cell lung cancer is the most malignancy with the highest morbidity and mortality in our country. The commonly used treatment is EGFR kinase inhibitor. A number of small molecule inhibitors targeting EGFR have been marketed, with the third-generation inhibitor Osimertinib (AZD9291) being the most effective. However, with this drug long-term clinical application, EGFR kinase appears C797S mutation which significantly reduces the activity of the compound. In order to overcome the drug resistance, we studied the EGFR kinase inhibitors and introduced the pteridine structure to maintain the hydrogen bonding with the Met793 residue in the EGFR kinase. At the same time, the side chain NH bond and the substituted aryl group can form hydrogen bond or hydrophobic interaction with the residue Met790. Further, various substituted groups are added to the side chain which can interact with amino acid residues such as Ser797 and Asp855, in order to enhance the binding ability of compounds with the receptor protein. Finally, we used a scaffold hopping strategy and computational program drug design to obtain novel EGFR kinase inhibitors with the scaffold of pteridine. After that, we planed to evaluate the biological activities and study the antitumor mechanism of these compounds , hoping to obtain 1-2 clinical drug candidates which can overcome the resistance mechanism of C797S mutation.

肺癌是我国发病率和死亡率居首位的恶性肿瘤，常用治疗方案为EGFR激酶抑制剂。目前已有多个靶向EGFR小分子抑制剂上市，以第三代抑制剂Osimertinib (AZD9291)疗效最为显著。但随着临床的应用，激酶会发生C797S突变，使化合物活性显著降低，从而产生耐药性。为克服这种耐药性，我们在研究EGFR激酶抑制剂的基础上，针对EGFRC797S共晶蛋白结构特点，引入蝶啶类结构使其保持与残基Met793氢键作用的同时，其侧链NH键和取代的芳基基团能与残基Met790等形成氢键或疏水相互作用，在侧链上再增加可以与Ser797和ASP855等残基进行氢键作用的基团，增强分子与受体蛋白的结合能力。最终我们利用骨架跃迁和计算机辅助药物设计手段，得到具有蝶啶类的新型EGFR激酶抑制剂。开展体外活性研究、作用机制研究和体内抗肿瘤活性研究，期望得到1-2个可以克服C797S耐药的临床候选药物。

肺癌是严重威胁人类健康的恶性肿瘤之一，具有较高的发病率和死亡率。肺癌中约有80%为非小细胞肺癌（NSCLC），发生率高，生存率低。常用 EGFR 激酶抑制剂作为治疗方案。EGFR介导的信号转导通路影响细胞的增殖、分化、迁移、凋亡和细胞周期循环，与肿瘤的形成和恶化密切相关。目前已有多个小分子 EGFR 抑制剂上市，尤其以第三代抑制剂 Osimertinib (AZD9291)疗效最为显著。但随着临床的应用，EGFR 激酶会发生 C797S 突变，使药物活性显著降低，从而产生耐药性。根据AZD9291与EGFR激酶的结合模式，设计并合成了多种新型结构的化合物作为EGFR激酶抑制剂。研究发现最佳化合物A12是一种新型可逆抑制剂，与对照AZD9291相比，对EGFRL858R/T790M的选择性更好，是野生型EGFRWT的42倍。它对EGFRL858R/T790M的酶活性显示出强大的抑制作用，对EGFRL858R/T790M和EGFRWT激酶的抑制分别为 4.0 nM和170 nM。最重要的是，化合物A12对三突变的激酶EGFRL858R/T790M/C797S也显示出较好的抑制活性（IC50值为0.36 μM）。随后进行了机理研究，其活性通过细胞染色、细胞凋亡和迁移试验得到了很好的证明。并且预测出该化合物具有良好的“类药物”特性。因此，在未来的研究中，该化合物可以作为一种三突变激酶抑制剂被进一步研究，为下一代药物的研发奠定基础。