Cooke S P, Boxer G M, Lawrence L, Pedley R B, Spencer D I, Begent R H, Chester K A
CRC Targeting and Imaging Group, Department of Oncology, Royal Free and University College Medical School, University College London, NW3 2PF, United Kingdom.
Cancer Res. 2001 May 1;61(9):3653-9.
Vascular endothelial growth factor (VEGF) is produced by cancer cells in response to hypoxia and is the primary stimulant of vascularization in solid tumors. Endothelial cells lining the blood vessels of these tumors have a high concentration of receptor-bound VEGF on their surface, providing a target for antibody- directed cancer therapy. To obtain a cloned antibody to this target when bound to its receptor on tumor endothelium, we used phage display technology to create a single-chain Fv (sFv) antibody library from mice immunized with the 165-amino acid isoform of human VEGF-A. We selected, purified, and characterized LL4, an anti-VEGF sFv that was shown to react with receptor-bound VEGF. LL4 bound selectively to blood vessel endothelium, as shown by immunohistochemistry on tissue sections of human tumors. Furthermore, using autoradiography and grain counting of histological sections, systemically administered LL4 was shown to localize selectively to the endothelial lining of tumor blood vessels in human colorectal carcinoma xenografts in vivo. This study demonstrates the feasibility of targeting tumor vasculature using recombinant antibodies to the VEGF:receptor complex.
血管内皮生长因子（VEGF）由癌细胞在缺氧反应中产生，是实体瘤血管生成的主要刺激物。这些肿瘤血管内衬的内皮细胞表面有高浓度的受体结合型VEGF，为抗体导向的癌症治疗提供了靶点。为了获得与肿瘤内皮细胞上的受体结合时针对该靶点的克隆抗体，我们利用噬菌体展示技术，从用人VEGF-A的165个氨基酸异构体免疫的小鼠中创建了一个单链Fv（sFv）抗体文库。我们筛选、纯化并鉴定了LL4，一种抗VEGF的sFv，它被证明能与受体结合型VEGF发生反应。免疫组化显示，LL4在人肿瘤组织切片上能选择性地结合血管内皮。此外，通过对组织学切片进行放射自显影和颗粒计数，结果表明，在体内，系统给药的LL4能选择性地定位于人结直肠癌异种移植瘤的肿瘤血管内皮。这项研究证明了使用针对VEGF：受体复合物的重组抗体靶向肿瘤血管系统的可行性。
