新型抗耐药性c-Met选择性抑制剂的设计、合成及生物活性研究

c-Met is one of the promising targets for developing antitumor agents due to its central role in tumorigenesis and metastasis, and its excessive expression, abnormal activation and mutation in various types of cancers. It was also reported to be closely associated with the resistance to certain kinase inhibitors and cytotoxic antitumor agents, and even with the cancer metastasis and relapse after radiotherapy. Besides, drug resistance to c-Met inhibitors was also found because of its various mutations. Therefore, it makes significant sense for solving the resistance to anticancer therapies and improving curative effects by developing novel c-Met inhibitors, especially those against c-Met mutations. A novel series of c-Met inhibitors with inhibitory activity against mutated c-Met were obtained through structure optimization of our novel c-Met inhibitors based on the scaffold of 5H-pyrimido[5,4-b]indole using fragment-based drug design approaches. This series of inhibitors have an absolutely novel binding mode as they extend into the new pocket emerged after biophosphorylation. The primary biological activity confirmed the rationality of methods for drug design. High c-Met selectivity was also found with these compounds in the kinase selectivity assays. This project will continue the study of these novel c-Met inhibitors, improving the activity against the mutated types and keeping the selectivity, to explore the solution of drug resistance due to anticancer therapies. Meanwhile, the novel compounds will be assessed at the level of kinase, cell and animal model to clarify their primary antitumor mechanism. Structure-activity relationship will be summarized for further structure optimization. Overall, this project will be a solid foundation for developing novel antitumor drugs of independent intellectual property rights.

c-Met激酶是目前抗肿瘤药物研究的热点靶标之一。而且HGF/c-Met信号转导通路与其他激酶抑制剂的耐药性，放疗后的转移和复发，以及细胞毒类抗肿瘤药物的耐药性密切相关。c-Met的突变等原因也导致了其抑制剂自身耐药性的发生。因此，开发新型尤其是具有突变型抑制活性的c-Met抑制剂对解决耐药性问题至关重要。本项目基于前期获得的嘧啶并吲哚类c-Met抑制剂，针对c-Met双磷酸化后新出现的结合口袋，运用基于片段的药物设计方法，对母核进行开环得到具有突变型抑制活性的新型c-Met抑制剂。初步活性结果确证了设计思路的合理性。实验还发现该类抑制剂具有c-Met高选择性，可降低毒副作用。本项目将继续提高对c-Met突变型的抑制活性，探索解决耐药性问题。同时，从分子、细胞和动物水平上评价目标化合物，初步阐明其抗肿瘤作用机制，总结构效关系，进一步优化结构，为最终获得具有自主知识产权的抗肿瘤新药打下基础。

细胞信号转导通路的改变是导致肿瘤形成的重要因素之一，肿瘤细胞中由基因突变引起高表达的蛋白激酶(Protein kinase)是导致信号转导通路异常的主要原因之一，以蛋白激酶作为抗肿瘤靶点的研究己经成为药物研发中最重要的领域。新型选择性c-Met小分子抑制剂的研究是其中主要方向之一。临床研究中发现c-Met激酶的突变会导致耐药性的产生，因此研发对突变型c-Met激酶有效的抑制剂同样至关重要。根据前期的研究成果，本项目以T1为先导化合物对其多个部位进行结构改造，结合类药性早期预测与计算机辅助药物设计，设计并合成了106个针对野生型和突变型c-Met激酶的小分子抑制剂，并通过HNMR、IR、MS 等方法进行了结构确证。化合物均已申请相关专利，具有完全的自主知识产权，为进一步的创新药物研究奠定基础。对目标化合物的生物活性测试结果表明，多个化合物具有很强的野生型和突变型c-Met抑制活性及肿瘤细胞增殖抑制活性。在此基础上我们深入分析并获得了针对c-Met激酶抑制活性有效的构效关系，为进一步开展该类化合物的结构修饰，提供了指导与帮助。在项目研究成果的基础上，已申请专利3项，发表与本项目相关的SCI论文7篇；培养博士生3人、硕士生4人。