具有抗耐药性的c-Met/IGF-1R双重抑制剂的设计、合成及抗肿瘤活性研究

Drug resistance usually lead to tumor recurrence and metastasis, and it is also the most common and difficult reason to overcome during the failed treatment process in which tumor patients used tyrosine kinase inhibitors for chemtherapy. c-Met is located in the intersection point of several signal transduction pathways in tumor, therefore inhibition of the phosphorylation of c-Met could induce stronger therapeutic effect. It is indicated that the amplification of MET and RAS mediated drug resistance to c-Met inhibitors. However, the mechanism of the activation and expression of RAS is exceptive. Thus, it is extremely difficult to develop direct inhibitors of RAS. In order to obtain a leading compound that could kill the c-Met-resistanced cancer cells, an idea developing c-Met/IGF-1R dual inhibitors was introduced. Thus, we incorporated a pharmacophore of IGF-1R inhibitor into the obtained c-Met/MEK dual inhibitors, and 18 c-Met/IGF-1R dual inhibitors were obtained, which could overcome drug resistance during the course of anti-c-Met therapy. Based on the above results, approximate 160 novel compounds will be designed, synthesized and evaluated for their bioactivities in this project. Furthermore, structure-activity relationships (SARs) and mechanism will be elucidated in order to obtain novel and more effetive c-Met/IGF-1R dual inhibitors that can overcome c-Met-resistance.

耐药性常导致肿瘤的复发和转移，也是患者使用酪氨酸激酶抑制剂化疗失败最常见和最难克服的原因。c-Met位于多条肿瘤信号转导通路的交叉点，抑制它的活性可产生较强的抗肿瘤作用。c-Met高表达的肿瘤细胞产生耐药性是与MET和RAS的过度表达有关的。然而，RAS的活化及表达有着特殊的机制，使得开发RAS直接抑制剂较为困难。为得到对耐药细胞具有杀伤作用的先导物，本课题提出以下研究思路：开发IGF-1R（RAS上游且对其有重要调控作用的信号因子）和c-Met的双重抑制剂。我们将IGF-1R抑制剂的药效团引入至已获得的c-Met/MEK双重抑制剂中，得到了18个对c-Met抑制剂耐药的肿瘤细胞具有杀伤作用的c-Met/IGF-1R双重抑制剂。基于以上，本项目拟继续设计合成约160个新化合物，并进行药理活性、构效关系及作用机制的研究，以期获得活性更好的、具有抗耐药性的c-Met/IGF-1R双重抑制剂。

c-Met（mesenchymal-epithelial transition）是肝细胞生长因子（hepatocyte growth factor，HGF）的高亲和受体，位于多条受体酪氨酸激酶信号通路的交点，作为肿瘤信号网络通路中的关键节点蛋白，它在肿瘤的发生、生长、转移及耐药性的出现等各个环节中均发挥了关键的作用。因此，以c-Met为靶点可相对容易地实现对多条信号通路的同时干扰，产生较好的抗肿瘤效果。但随着c-Met抑制剂在临床用药时间的延长，一些具有耐药性的突变型肿瘤细胞便会随之产生，使治疗效果下降。研究表明，c-Met高表达的肿瘤细胞产生耐药性是与MET和RAS的过度表达有关的。然而，RAS的活化及表达有着特殊的机制，使得开发RAS直接抑制剂较为困难。为得到对耐药肿瘤细胞具有杀伤作用的化合物，本研究基于课题组前期获得的c-Met激酶抑制剂的药效团模型，运用计算机辅助药物设计等手段，根据靶标及构效关系研究提供的反馈信息设计了4个系列共计145个化合物，拟开发得到IGF-1R（RAS上游且对其有重要调控作用的信号因子）和c-Met的双重抑制剂。综合运用有机合成方法，确定了化合物的合成路线，并经初步工艺优化，制得收率及纯度符合要求的目标化合物，并通过HRMS、1HNMR和13CNMR确证了其结构。酶活性测试结果表明，其作用靶点主要包括c-Met、Ron、IGF-1R、FLT3及c-Kit等。该类化合物对野生型和突变型的肿瘤细胞均表现出较好的体外抗肿瘤活性，明显优于先导物Cabozantinib。作用机制研究结果表明，该系列化合物对肿瘤细胞具有明显的杀伤作用，还可抑制肿瘤细胞的增殖及迁移过程，促进肿瘤细胞的凋亡；此外，它对c-Met及其下游信号通路的Akt及ERK等激酶的磷酸化过程也具有抑制作用。通过本项目的研究，将为自主创新药物研发工作积累丰富的经验，满足肿瘤患者对靶向抗肿瘤药物的需要，尤其是具有抗耐药性的抗肿瘤药物。