Center for Radiopharmaceutical Sciences ETH-PSI-USZ, Paul Scherrer Institute.
Curr Pharm Des. 2012;18(8):1058-83. doi: 10.2174/138161212799315777.
Frequent overexpression of the folate receptor (FR) on a variety of tumor types and on activated macrophages makes this receptor an interesting target for both imaging and therapy of cancer and inflammation. The FR is a glycosylphophatidylinositol-anchored protein that binds the vitamin folic acid with high affinity and internalizes it via endocytosis. In normal tissues and organs, FR-expression is restricted to only a few sites where it is confined to the luminal surface of polarized epithelia and hence does not have access to intra-venously administered folic acid conjugates. Thus, using folic acid as a molecular "Trojan horse" to deliver attached probes to the diseased tissue has emerged as a powerful strategy. A variety of folic acid radioconjugates for potential application in nuclear medicine have been developed and (pre)clinically evaluated during the last two decades. Herein we report on folate receptor targeted tracer design and in vitro/in vivo investigations using folic acid -targeted radioconjugates suitable for SPECT and PET imaging as well as for potential therapeutic purposes.
叶酸受体（FR）在多种肿瘤类型和活化的巨噬细胞上频繁过表达，使其成为癌症和炎症成像和治疗的一个有趣靶点。FR 是一种糖基磷脂酰肌醇锚定蛋白，它与维生素叶酸具有高亲和力结合，并通过内吞作用将其内化。在正常组织和器官中，FR 的表达仅限于少数几个部位，仅限于极化上皮的腔面，因此无法接触到静脉内给予的叶酸缀合物。因此，使用叶酸作为分子“特洛伊木马”将附着的探针递送到患病组织已成为一种强大的策略。在过去的二十年中，已经开发出多种用于核医学潜在应用的叶酸放射性缀合物，并进行了（临床前）评估。在此，我们报告了叶酸受体靶向示踪剂的设计以及使用叶酸靶向放射性缀合物的体外/体内研究，这些放射性缀合物适用于 SPECT 和 PET 成像以及潜在的治疗目的。
