EphB4在所有乳腺癌中表达，但EphB4与ER之间的研究鲜有报道。申请人在青年-面上连续资助项目支持下，发现新型结构母核的塔斯品碱衍生物TaD1822-7能够抑制EphB4激酶活性和ER+乳腺癌增殖；沉默EphB4后，抑制作用明显减弱。故本课题将继续深入研究TaD1822-7对ER依赖的乳腺癌抑制作用及与EphB4关系。通过构建多种不同表达ER的细胞株，分析TaD1822-7调控的ER基因组和非基因组作用模式以及ER核心启动子区，系统研究TaD1822-7对ER依赖的乳腺癌抑制作用；再利用构建不同表达EphB4的细胞株，突变EphB4激酶区活性位点和EphB4-Mutation移植瘤实验等分析研究TaD1822-7对EphB4调控的PI3K/Akt信号通路与ER相关性，从多靶点角度阐明TaD1822-7抑制ER+乳腺癌的分子机制，为TaD1822-7开发成多靶点RTK抑制剂奠定实验基础。

Eph is the biggest one of tyrosine kinase receptors (RTKs), and EphB4 is expressed in all breast cancers. However, there are few studies on relation between EphB4 and ER. The study of molecular target inhibitors on multi-targets is an important way to the research and development of anti-cancer drugs. Under the continuous funding projects supported by National Natural Science Foundation of China, the applicant has found the compound TaD1822-7 with a new chemical structure derived from the natural product taspine. TaD1822-7 could regulate the EphB4 reverse signaling, and inhibit the EphB4 kinase activity as well as growth of breast cancer with ER. The inhibitory action of TaD1822-7 decreased when the EphB4 was knockdown. To be specific, this project will proceed to study the inhibition on breast cancer with ER regulated by TaD1822-7 and analyze the its relation with EphB4. By constructing different cells of over-expressed or low-expressed ER, the mode of action of the genome and non-genome and core promoter region of ER will be investigated after treatment with TaD1822-7. The project will also investigate the effect of TaD1822-7 on the correlation between ER and EphB4 regulated by PI3K/Akt signal pathway, by constructing different cells of over-expressed or low-expressed EphB4, screening the mutation site of EphB4 kinase domain, and establishing transplant tumor model with mutation site of EphB4. The mechanism of breast cancer inhibition with ER by TaD1822-7 will be expounded. This project may lay a solid foundation for the research and development of TaD1822-7 as a new multi-targets RTK inhibitor.