基于新型不可逆微管稳定剂TAJ构建基因工程化Thiol-DDR1抗体偶联物靶向治疗结肠癌及其机制研究

TAJ是源于箭根薯科植物的天然/半合成甾体化合物，为一种新型的微管稳定剂，抗肿瘤活性强于紫杉醇，与紫杉醇不同的是，其与微管为共价结合，并能克服紫杉醇耐药，单独使用毒副作用明显，如果将其研制成靶向药物，则具有潜在的应用前景。在最近的研究中，我们通过冷冻电镜技术明确了TAJ的绝对构型和TAJ-微管超分子复合物的结构，阐明了TAJ与微管作用的分子机制，三维结构信息有利于构造科学的修饰位点。同时，团队还研发了能靶向结肠癌的高亲合力、内化型Thiol-DDR1基因工程化突变抗体，使之可以定向偶联，提高其安全性。本项目拟在冷冻电镜和探针数据的指导下，对TAJ的C6位进行修饰，并通过三种双功能连接子与Thiol-DDR1基因工程化抗体定向偶联，构建和筛选一种新型的靶向药物，将不可逆微管稳定剂TAJ靶向递送到肿瘤细胞而杀伤之，在细胞和动物水平上阐明其抗肿瘤作用和机理，为结肠癌靶向治疗药物的研究奠定基础。

TAJ, a natural / semi-synthetic steroid compound isolated from a plant of the genus Tacca, is a new type of microtubule-stabilizing agent with stronger antitumor activity than paclitaxel. Unlike paclitaxel, the covalent binding of TAJ to microtubules provided the advantage of overcoming drug resistance. When used alone, TAJ has obvious toxic side effects, but has great potential if it developed into a targeted drug. Using cryo-electron microscopy, we confirmed the absolute configuration of TAJ and the structure of TAJ-microtubule supramolecular complex, clarified the molecular mechanism of TAJ-microtubule interaction in our previous study. And through the study of three-dimensional structure of TAJ can provide information about the modification sites.Moreover, our team also developed a genetically engineered high-affinity, internalizing Thiol-DDR1 antibody that targets colon cancer. This project intends to modify the C6 position of TAJ under the guidance of cryo-electron microscopy and probe data. Then Site-specific conjugation through genetically engineered sites of Thiol-DDR1 antibody by utilizing three dual function cross-link linkers to construct a novel antibody-drug conjugate. Through Antibody-Mediated Delivery of TAJ into tumor cells and kill them. We’ll elucidate the underlying antitumor mechanisms in vitro and in vivo and lay the foundation for targeted therapy drugs to treat colon cancer.