Tokyo Tech World Research Hub Initiative, Institute of Innovative Research, Tokyo Institute of Technology, Yokohama, Japan.
Key Laboratory of Biological Medicines in Universities of Shandong Province, Weifang Key Laboratory of Antibody Medicines, School of Bioscience and Technology, Weifang Medical University, Shandong, China.
Biotechnol Bioeng. 2020 May;117(5):1259-1269. doi: 10.1002/bit.27302. Epub 2020 Feb 17.
Ultra Quenchbody (UQ-body) is a biosensor that utilizes the quenching behavior of the fluorescent dye linked to the antibody V region. When the corresponding antigen is bound to the UQ-body, the fluorescence is restored and allows the detection of target molecules easily and sensitively. In this paper, we constructed UQ-bodies to sensitively detect the human epidermal growth factor receptor 2 (HER2) cancer marker in solution or on cancer cells, which was further used to kill the cancer cells. A synthetic Fab fragment of anti-HER2 antibody Fab37 with many Trp residues at hypervariable region was prepared and labeled with fluorescent dyes to obtain the UQ-bodies. The UQ-body could detect HER2 in solution at concentrations as low as 20 pM with an EC of 0.3 nM with a fourfold response. Fluorescence imaging of HER2-positive cells was successfully performed without any washing steps. To deliver small interfering RNA (siRNA) to cancer cells, a modified UQ-body with C-terminal 9R sequence was also prepared. HER2-positive cancer cells were effectively killed by polo-like kinase 1 siRNA intracellularly delivered by the UQ-body-9R. The novel approach employing siRNA-empowered UQ-body could detect and image the HER2 antigen easily and sensitively, and effectively kill the HER2-positive cancer cells.
超淬灭体 (UQ-body) 是一种利用与抗体 V 区连接的荧光染料淬灭行为的生物传感器。当相应的抗原与 UQ-body 结合时，荧光会恢复，从而可以轻松、灵敏地检测到靶分子。在本文中，我们构建了 UQ-body，以灵敏地检测溶液或癌细胞中的人表皮生长因子受体 2 (HER2) 癌症标志物，进一步用于杀死癌细胞。制备了具有许多超变区色氨酸残基的抗 HER2 抗体 Fab37 的合成 Fab 片段，并将其用荧光染料标记以获得 UQ-body。UQ-body 可以在溶液中检测到低至 20 pM 的 HER2，EC 为 0.3 nM，响应提高了四倍。无需任何洗涤步骤即可成功进行 HER2 阳性细胞的荧光成像。为了将小干扰 RNA (siRNA) 递送至癌细胞，还制备了带有 C 末端 9R 序列的修饰 UQ-body。由 UQ-body-9R 体内递送至癌细胞的 Polo 样激酶 1 siRNA 有效地杀死了 HER2 阳性癌细胞。该新型方法采用了 siRNA 增强的 UQ-body，可以轻松、灵敏地检测和成像 HER2 抗原，并有效地杀死 HER2 阳性癌细胞。
