1. Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Miklukho-Maklaya, 16/10, Moscow, 117997, Russia;
Theranostics. 2013 Oct 12;3(11):831-40. doi: 10.7150/thno.6715. eCollection 2013.
Tumor-targeted delivery of cytotoxins presents considerable advantages over their passive transport. Chemical conjugation of cytotoxic module to antibody is limited due to insufficient reproducibility of synthesis, and recombinant immunotoxins are aimed to overcome this disadvantage. We obtained genetically encoded immunophotosensitizer 4D5scFv-miniSOG and evaluated its photocytotoxic effect in vitro. A single-chain variable fragment (scFv) of humanized 4D5 antibody was used as a targeting vehicle for selective recognition of the extracellular domain of human epidermal growth factor receptor 2 (HER2/neu) overexpressed in many human carcinomas. As a phototoxic module we used a recently described photoactivated fluorescent flavoprotein miniSOG. We found that recombinant protein 4D5scFv-miniSOG exerts a highly specific photo-induced cytotoxic effect on HER2/neu-positive human breast adenocarcinoma SK-BR-3 cells (IC50= 160 nM). We demonstrated that the 4D5scFv-miniSOG specifically binds to HER2-positive cells and internalizes via receptor-mediated endocytosis. Co-treatment of breast cancer cells with 4D5scFv-miniSOG and Taxol or junction opener protein JO-1 produced remarkable additive effects.
与毒素的被动转运相比，肿瘤靶向递药具有明显优势。由于合成的重现性不足，细胞毒素模块与抗体的化学偶联受到限制，而重组免疫毒素旨在克服这一缺点。我们获得了基因编码的免疫光感剂 4D5scFv-miniSOG，并评估了其体外光细胞毒性作用。人源化 4D5 抗体的单链可变片段 (scFv) 被用作选择性识别许多人类癌中过表达的人表皮生长因子受体 2 (HER2/neu) 的细胞外结构域的靶向载体。作为光毒性模块，我们使用了最近描述的光激活荧光黄素蛋白 miniSOG。我们发现重组蛋白 4D5scFv-miniSOG 对 HER2/neu 阳性的人乳腺腺癌 SK-BR-3 细胞具有高度特异性的光诱导细胞毒性作用 (IC50=160 nM)。我们证明 4D5scFv-miniSOG 特异性结合 HER2 阳性细胞，并通过受体介导的内吞作用内化。乳腺癌细胞与 4D5scFv-miniSOG 和 Taxol 或连接打开蛋白 JO-1 联合治疗产生了显著的相加作用。
