Kang Lei, Rosenkrans Zachary T, Cai Weibo
Department of Nuclear Medicine, Peking University First Hospital, Beijing, China.
Department of Radiology, University of Wisconsin-Madison, Madison, WI, USA.
Methods Mol Biol. 2019;1974:223-231. doi: 10.1007/978-1-4939-9220-1_17.
Aptamers are a class of oligonucleotides with high binding affinity and specificity with their targets. Additionally, aptamers are nontoxic, very thermally stable, and able to reversibly undergo denaturation and have a small size. Cancer-related aptamers can be used for tumor-targeted drug delivery, such as to deliver diagnostic and therapeutic radionuclides to target cancers. We describe the process for preparing a Cu-labeled modified A10 aptamer to target prostate cancer by conjugating and radiolabeling. The modified A10 aptamer was conjugated with p-SCN-Bn-NOTA as the chelator. Following this, the aptamer can be radiolabeled with the Cu radioisotope. NOTA was selected as the chelator of choice due to its commercial availability and widely demonstrated in vivo stability with the Cu radioisotope. Using this system, prostate cancer could potentially be targeted for noninvasive imaging using positron emission tomography (PET). Closely following this protocol allows many aptamers to be successfully radiolabeled to accurately and quantitatively trace their distribution in vivo for a wide range of medical applications.
适配体是一类对其靶标具有高结合亲和力和特异性的寡核苷酸。此外，适配体无毒、热稳定性高、能够可逆地发生变性且尺寸小。与癌症相关的适配体可用于肿瘤靶向药物递送，例如将诊断和治疗性放射性核素递送至靶向癌症。我们描述了通过共轭和放射性标记制备用于靶向前列腺癌的铜标记修饰A10适配体的过程。修饰的A10适配体与作为螯合剂的对氨基苯硫氰基苄基氮杂环三乙酸（p-SCN-Bn-NOTA）共轭。在此之后，该适配体可用铜放射性同位素进行放射性标记。选择氮杂环三乙酸（NOTA）作为螯合剂是因为其可商购且已广泛证明其与铜放射性同位素在体内的稳定性。使用该系统，前列腺癌有可能通过正电子发射断层扫描（PET）进行无创成像。严格遵循该方案可使许多适配体成功进行放射性标记，以准确和定量地追踪它们在体内的分布，用于广泛的医学应用。
