恶性肿瘤是细胞增殖与死亡失衡的疾病，其导致患者死亡的首要原因是复发与转移。肿瘤炎症微环境中的炎症因子TNFa是促发肿瘤转移的关键因子。目前，商品化TNFa拮抗剂对肿瘤治疗的效果并不显著。项目组前期研究发现，自主研发的TNFa小型化纳米抗体在肿瘤部位有效聚集，并且能够显著抑制乳腺癌肿瘤生长及EMT发生。近年发现，肿瘤细胞表面过表达的整合素αvβ3与肿瘤炎症性环境中TNFα关系密切：TNFα促进αvβ3的表达，通过αVβ3-FAK信号通路途径诱导肿瘤转移；同时αvβ3单克隆抗体能够调控TNFa抑制其促肿瘤作用。鉴于TNFα与αvβ3的拮抗剂能够协同抑制肿瘤的增殖、转移，本项目利用酵母表达系统将TNFa纳米抗体与RGD4C蛋白进行融合表达，靶向肿瘤部位，实现对乳腺癌细胞增殖、转移、EMT及肿瘤血管生成的抑制作用，进一步阐明其作用机制。为建立针对炎症因子抗体的肿瘤治疗新策略提供理论依据。

Malignant tumor is the imbalance between cell proliferation and death disease, recurrence and metastasis is the leading cause of death. TNFa inflammatory factors in tumor microenvironment is the key factor of the promotion of tumor metastasis. At present, the commercial TNFa antagonists for tumor treatment have not significant effect . In preliminary study, self-developed TNFa minimized nanobody gathered in tumor site effectively, and can significantly inhibit breast cancer cell proliferation and EMT. In recent years, study found that integrin αvβ3 expressing on tumor cell surface was related with TNFa in inflammatory environment of tumor, TNFa promotes the expression of αvβ3, by αvβ3- FAK signaling pathways induced tumor metastasis; αvβ3 can regulate the effect of TNFa on tumor , integrin monoclonal antibody can inhibit TNFa mediating cell migration. Above all, this project the yeast expression system will be used to express the TNFa and RGD4C nanobody fusion protein, targeting to tumor site, synergistic inhibiting sTNFa and αvβ3, study the function and mechanism of breast cancer cell proliferation, metastasis, EMT and angiogenesis. In order to establish new tumor treatment strategy of antibodies against inflammatory factor to provide theoretical foundation.