Cofilin在Erucin诱导的乳腺癌细胞线粒体分裂和细胞凋亡中的作用及分子机制研究

Development of the novel therapeutic targets and drugs for treatment of breast cancer has attracted attention worldwidly. Our preliminary study suggest that a biologically active constituent extracted from cruciferous vegetables, Erucin,could induces apoptosis in human breast cancer cells markedly. Cofilin-mediated mitochondrial fission play an important roles in Ercuin-induced apoptosis in breast cancer cells. We will investigate the effects of Erucin induced mitochondrial fission and apoptosis in a variety of breast cancer cell lines. We will also study the molecular mechanism of Erucin-mediated mitochondrial fission using Rho/ROCK1 pathway inhibitors and Actin polymerization inhibitor, as well as genetic approaches (point mutation of Cofilin and Drp1 phosphorylation site or siRNA of Cofilin, Drp1 and ROCK1). Finally, we will evaluate the mechanism and Erucin induced apoptosis on the breast cancer xenograft mouse model and primary breast cancer cells. Our studies reveal for the first time that Cofilin is involved in Erucin-induced mitochondrial fission and will elucidate the mechanism for the anti-breast cancer effect of Erucin. Our studies will also provide the novel therapeutic targets for breast cancer and support the potential application of Erucin in cancer chemotherapy and chemoprevention.

乳腺癌新靶点和新药物的筛选一直是乳腺癌研究的热点。我们前期研究发现，从十字花科蔬菜中提取的有效成分甘油三介酸酯（Erucin）可显著诱导乳腺癌细胞凋亡，而Cofilin参与的线粒体分裂是Erucin诱导凋亡的重要特征。本项目拟进一步确认Erucin对不同类型乳腺癌细胞的诱导凋亡和线粒体分裂作用，并采用Rho/ROCK1通路抑制剂、Actin聚合抑制剂，敲降Cofilin、Drp1、ROCK1及点突变Cofilin和Drp1深入研究Cofilin介导的线粒体分裂在Erucin诱导乳腺癌细胞凋亡中的分子机制，并采用裸鼠移植瘤模型、乳腺癌原代细胞证实Erucin的抗乳腺癌作用和上述机制的参与。本研究首次提出Cofilin参与Erucin诱导乳腺癌细胞线粒体分裂的调控，将明确Erucin的抗乳腺癌机理，为乳腺癌的治疗提供新的干预靶点；为将Erucin开发为高效、低毒的抗癌新药奠定重要的药理学基础。

乳腺癌位于女性癌症死亡率第一位，严重危害女性身心健康。寻找治疗乳腺癌新的靶点和药物一直是国内外关注的热点。我们前期研究发现，从十字花科蔬菜中提取的有效成分甘油三介酸酯（Erucin）可显著诱导乳腺癌细胞凋亡，而Cofilin参与的线粒体分裂是Erucin诱导凋亡的重要特征。本项目采用多种乳腺癌细胞明确了Erucin可显著诱导Cofilin和Drp1发生线粒体转位和线粒体损伤途径细胞凋亡。进一步研究发现Erucin诱导了明显的线粒体分裂，Cofilin和Drp1线粒体转位后在线粒体外膜发生了直接共定位，敲降Cofilin或Drp1均可阻断Erucin诱导的线粒体分裂和细胞凋亡。采用Cofilin和Drp1的磷酸化位点突变质粒明确Erucin诱导的Cofilin和Drp1线粒体转位调控的线粒体分裂依赖于Cofilin（Ser 3）和Drp1 （Ser 637）位点去磷酸化。并发现ROCK1通路抑制剂Y-27632和基因敲降ROCK1均能阻断Erucin诱导的Cofilin和Drp1线粒体转位，线粒体损伤和细胞凋亡。最后在裸鼠移植瘤体内水平明确了Erucin的抗乳腺癌作用以及诱导ROCK1激活、Cofilin和Drp1线粒体转位介导的线粒体分裂作用。本研究首次阐明了Cofilin参与调控了线粒体分裂，明确了Erucin的抗乳腺癌机理，为线粒体分裂提出新的理论认识，为乳腺癌的治疗提供新的干预靶点和治疗途径。