生理流动条件下CD82-EWI2介导的乳腺癌细胞粘附转移的机制研究

Breast cancer is the most lethal malignancy in female worldwide. It has been demonstrated that mortality of beast cancer patients is mostly induced by tumor metastasis. The adhesion and extravasation of breast cancer cells with endothelial cells are the key steps during the process of metastasis. In our previous works, we illustrated that 1) adhesion between breast cancer cells and endothelial cells was mediated by CD82; 2) CD82 exerted its function in the form of a protein complex with the interaction of EWI2; 3) the adhesion efficiency between breast cancers and endothelial cells was affected by the flow conditions, and it didn’t monotonically decline with the increasing shear rates. Thus, we hypothesized that during the metastasis of breast cancer cells, the adhesion and extravasation between cancer cells and endothelial cells were mediated by CD82-EWI2 complex which was induced by the elevated expression level of CD82 triggered by a certain flow range. In this project, we plan to investigate the mechanism by which CD82-EWI2 complex mediated the adhesion and extravasation of cancer cells and endothelial cells via mathematical modeling, flow chamber technique, biological engineering, gene array technology and bioinformatics. Furthermore, we also intend to elucidate the signaling pathway underlying the function of CD82-EWI2 complex. We hope our research could provide potential drug target for the treatment of breast cancer metastasis.

乳腺癌发病率位居女性恶性肿瘤首位，肿瘤转移是导致患者死亡最主要原因。循环肿瘤细胞与内皮细胞发生粘附及外渗是导致肿瘤远处转移的关键步骤。申请人前期工作发现：1）CD82介导了乳腺癌细胞与内皮细胞间的粘附；2）CD82能与EWI2相互结合，形成复合物发挥功能；3）乳腺癌细胞与内皮细胞的粘附效率受到流动条件的调控，且不随剪切率的增大而单调下降。基于此，提出如下假说：乳腺癌细胞在远处转移过程中，在一定生理流动条件下，细胞表面CD82分子表达升高，促进了CD82-EWI2复合物形成，从而介导癌细胞与内皮细胞的粘附与外渗转移。为验证上述假说，本项目将结合数学建模、流动腔技术、生物工程技术、基因芯片技术、生物信息学等多种研究手段，研究生理流动条件下CD82-EWI2介导的乳腺癌细胞粘附转移的生物力学机制，构建CD82-EWI2介导的下游分子信号通路，为未来开发抑制乳腺癌转移的靶向药物提供潜在的分子靶点。

乳腺癌发病率及死亡率皆位居女性恶性肿瘤首位。肿瘤转移是导致患者死亡的最主要原因。循环肿瘤细胞与内皮细胞发生粘附及外渗是导致肿瘤远处转移的关键步骤。本项目充分发挥交叉学科优势，融合了流体力学、细胞力学、分子生物学和生物信息学等多学科研究手段，针对乳腺癌细胞的粘附转移过程进行了深入研究：(1)结合乳腺癌生理学、临床影像学等资料，建立乳腺癌细胞转移的血液动力学模型，数值模拟获取流动信息；（2）结合流动腔实验、高通量基因芯片筛选、生物信息学分析等手段，通过多维度实验验证，证实了CD82能与EWI2形成复合物，共同介导乳腺癌细胞的粘附与外渗转移；（3）结合微流控和生物检测技术，定量评价了流动环境对乳腺癌细胞表面粘附分子表达、细胞生物学特性与力学行为、癌细胞粘附与外渗效率的调控作用；（4）通过高通量基因芯片与蛋白芯片技术，结合生物信息学分析手段，确定了CD82-EWI2粘附分子间的分子作用机制，构建了下游分子信号网络；（5）基于高通量研究数据，构建了乳腺癌细胞内与转移相关的ceRNA调控网络及基因组内甲基化修饰图谱。以上研究结果，有助于深刻理解乳腺癌细胞发生粘附和外渗转移的分子机制和信号调控网络，及生理流动条件在其中起到的调控作用，并挖掘到潜在的药物靶点，为开发针对乳腺癌转移的靶向药物奠定扎实的理论基础。