Tolmachev Vladimir, Orlova Anna
Department of Immunology, Genetics and Pathology, Uppsala University, 75185 Uppsala, Sweden.
Research Centrum for Oncotheranostics, Research School of Chemistry and Applied Biomedical Sciences, Tomsk Polytechnic University, 634050 Tomsk, Russia.
Cancers (Basel). 2020 Mar 11;12(3):651. doi: 10.3390/cancers12030651.
Affibody molecules are small (58 amino acids) engineered scaffold proteins that can be selected to bind to a large variety of proteins with a high affinity. Their small size and high affinity make them attractive as targeting vectors for molecular imaging. High-affinity affibody binders have been selected for several cancer-associated molecular targets. Preclinical studies have shown that radiolabeled affibody molecules can provide highly specific and sensitive imaging on the day of injection; however, for a few targets, imaging on the next day further increased the imaging sensitivity. A phase I/II clinical trial showed that Ga-labeled affibody molecules permit an accurate and specific measurement of HER2 expression in breast cancer metastases. This paper provides an overview of the factors influencing the biodistribution and targeting properties of affibody molecules and the chemistry of their labeling using positron emitters.
亲和体分子是小型（58个氨基酸）的工程化支架蛋白，可被筛选出与多种蛋白质高亲和力结合。它们的小尺寸和高亲和力使其成为分子成像的有吸引力的靶向载体。已经针对几种癌症相关分子靶点筛选出了高亲和力的亲和体结合剂。临床前研究表明，放射性标记的亲和体分子在注射当天可提供高度特异性和灵敏的成像；然而，对于少数靶点，第二天成像进一步提高了成像灵敏度。一项I/II期临床试验表明，镓标记的亲和体分子能够准确、特异性地测量乳腺癌转移灶中的HER2表达。本文概述了影响亲和体分子生物分布和靶向特性的因素以及使用正电子发射体进行标记的化学方法。
