Liang Guang-Quan, Liu Jing, Zhou Xiao-Xin, Lin Ze-Xiong, Chen Tao, Chen Guo, Wei Henry
Department of Cell Biology and Institute of Biomedicine, Guangdong Provincial Key Laboratory of Bioengineering Medicine, Guangdong Provincial Biotechnology Drug and Engineering Technology Research Center, National Engineering Research Center of Genetic Medicine, College of Life Science and Technology, Jinan University, Guangzhou, China.
Department of Medical Biochemistry and Molecular Biology, School of Medicine, Jinan University, Guangzhou, China.
Front Oncol. 2020 Dec 18;10:571194. doi: 10.3389/fonc.2020.571194. eCollection 2020.
Monoclonal antibodies (mAbs) are large and have limitations as cancer therapeutics. Human single-chain variable fragment (scFv) is a small antibody as a good alternative. It can easily enter cancer tissues, has no immunogenicity and can be produced in bacteria to decrease the cost. The chemokine receptor CXCR4 is overexpressed in different cancer cells. It plays an important role in tumor growth and metastasis. Its overexpression is associated with poor prognosis in cancer patients and is regarded as an attractive target for cancer treatment. In this study, a peptide on the CXCR4 extracellular loop 2 (ECL2) was used as an antigen for screening a human scFv antibody library by yeast two-hybrid method. Three anti-CXCR4 scFv antibodies were isolated. They could bind to CXCR4 protein and three cancer cell lines (DU145, PC3, and MDA-MB-231) and not to 293T and 3T3 cells as negative controls. These three scFvs could decrease the proliferation, migration, and invasion of these cancer cells and promote their apoptosis. The two scFvs were further examined in a mouse xenograft model, and they inhibited the tumor growth. Tumor immunohistochemistry also demonstrated that the two scFvs decreased cancer cell proliferation and tumor angiogenesis and increased their apoptosis. These results show that these anti-CXCR4 scFvs can decrease cancer cell proliferation and inhibit tumor growth in mice, and may provide therapy for various cancers.
单克隆抗体（mAb）体积较大，作为癌症治疗药物存在局限性。人单链可变片段（scFv）是一种小型抗体，是很好的替代品。它能轻易进入癌组织，无免疫原性，且可在细菌中生产以降低成本。趋化因子受体CXCR4在不同癌细胞中过度表达。它在肿瘤生长和转移中起重要作用。其过度表达与癌症患者的不良预后相关，被视为癌症治疗的一个有吸引力的靶点。在本研究中，将CXCR4细胞外环2（ECL2）上的一种肽用作抗原，通过酵母双杂交法筛选人scFv抗体文库。分离出三种抗CXCR4 scFv抗体。它们能与CXCR4蛋白以及三种癌细胞系（DU145、PC3和MDA-MB-231）结合，而不与作为阴性对照的293T和3T3细胞结合。这三种scFv可降低这些癌细胞的增殖、迁移和侵袭，并促进其凋亡。对其中两种scFv在小鼠异种移植模型中进行了进一步研究，它们抑制了肿瘤生长。肿瘤免疫组化也表明，这两种scFv降低了癌细胞增殖和肿瘤血管生成，并增加了其凋亡。这些结果表明，这些抗CXCR4 scFv可降低癌细胞增殖并抑制小鼠肿瘤生长，可能为多种癌症提供治疗方法。
