Endocyte, Inc. , 3000 Kent Avenue, Suite A1-100 , West Lafayette , Indiana 47906 , United States.
Mol Pharm. 2019 Sep 3;16(9):3985-3995. doi: 10.1021/acs.molpharmaceut.9b00624. Epub 2019 Aug 13.
Folate-based small molecule drug conjugates (SMDCs) are currently under development and have shown promising preclinical and clinical results against various cancers and polycystic kidney disease. Two requisites for response to a folate-based SMDC are (i) folate receptor alpha (FRα) protein is expressed in the diseased tissues, and (ii) FRα in those tissues is accessible and functionally competent to bind systemically administered SMDCs. Here we report on the development of a small molecule reporter conjugate (SMRC), called EC2220, which is composed of a folate ligand for FRα binding, a multilysine containing linker that can cross-link to FRα in the presence of formaldehyde fixation, and a small hapten (fluorescein) used for immunohistochemical detection. Data show that EC2220 produces a far greater IHC signal in FRα-positive tissues over that produced with EC17, a folate-fluorescein SMRC that is released from the formaldehyde-denatured FRα protein. Furthermore, the extent of the EC2220 IHC signal was proportional to the level of FRα expression. This EC2220-based assay was qualified both and using normal tissue, cancer tissue, and polycystic kidneys. Overall, EC2220 is a sensitive and effective reagent for evaluating functional and accessible receptor expression and .
叶酸小分子药物偶联物（SMDC）目前正在开发中，针对各种癌症和多囊肾病显示出有希望的临床前和临床结果。对叶酸基 SMDC 产生反应的两个必要条件是：(i)在患病组织中表达叶酸受体α (FRα)蛋白，(ii)在这些组织中 FRα可及且功能健全以结合系统性给予的 SMDC。在这里，我们报告了一种小分子报告偶联物 (SMRC) 的开发，称为 EC2220，它由叶酸配体与 FRα 结合组成，在存在甲醛固定的情况下，多赖氨酸连接子可以交联到 FRα，以及用于免疫组织化学检测的小半抗原（荧光素）。数据表明，EC2220 在 FRα 阳性组织中产生的免疫组织化学信号远大于 EC17 产生的信号，EC17 是一种从甲醛变性的 FRα 蛋白释放的叶酸-荧光素 SMRC。此外，EC2220 的 IHC 信号的程度与 FRα 表达水平成正比。该基于 EC2220 的测定方法使用正常组织、癌症组织和多囊肾进行了 和 资格认证。总的来说，EC2220 是一种敏感有效的试剂，用于评估功能性和可及的受体表达。
