基于泛素化的TWIST1蛋白稳定性调控及其对乳腺癌侵袭转移作用的分子新通路研究

恶性肿瘤转移是威胁人类健康的主要杀手。TWIST1对乳腺癌转移起重要调控作用，而基于SPOP/RNF40的泛素-蛋白酶体对其降解不清楚。本课题结合前期基础，旨在分子、蛋白、细胞和小鼠成瘤模型等多层次进行：（1）鉴定新型调节TWIST1的E3连接酶SPOP/RNF40，研究其对TWIST1稳定性、相互作用及不同泛素化修饰位点及机制；(2) 阐明TWIST1泛素-蛋白酶体依赖的SPOP或RNF40调节对乳腺癌侵袭转移作用；(3) 揭示乳腺癌SPOP/TWIST1或RNF40/TWIST1之间表达及预后关系，SPOP/TWIST1/EMT或RNF40/TWIST1/EMT与乳腺癌特别是三阴性乳腺癌侵袭转移的新信号通路及关联性。本项目的成功实施，不仅有助于发现TWIST1调节新通路，为临床预后和治疗找到新靶标，而且有助于开发出潜在治疗药物来遏制乳腺癌的发生与转移，具有重要的科学意义和潜在临床价值。

The metastasis of malignant tumor is the major killer of human health threats. Regulation by transcriptional factor TWIST1 influences breast cancer metastasis, but its degradation based on SPOP/RNF40 for ubiquitin-proteasome is not fully understood. Therefore, based on our previous studies, in this study we design to investigate at the levels of molecule, protein, cell and experimental tumor model of mice as follows: (1) To screen novel E3 ligases, SPOP/RNF40, that regulate the stability of TWIST1, their interactions, and identify ubiquitin sites and mechanisms of TWIST1; (2) To elucidate the roles of ubiquitin-proteasome degradation-dependent SPOP/RNF40 regulating TWIST1 in breast cancer invasion and metastasis; (3) To reveal the expression relationship between the SPOP/TWIST1 or RNF40/TWIST1 and prognosis in breast cancer, and novel signaling pathways for SPOP/TWIST1/EMT or RNF40/TWIST1/EMT in breast cancer, particularly triple-negative breast cancer invasion and metastasis. For the successful implementation of this project, it will not only reveal TWIST1-regulated novel pathways, find novel targets for clinical prognosis and therapy, but also develop potential drugs for anti-cancer therapy bhy probably preventing breast cancer tumorigenesis and metastasis fundamentally, thus have important scientific significances and potential clinical values.