Department of Radiology, University of Missouri School of Medicine, and Harry S. Truman Memorial Veterans' Hospital, One Hospital Drive, Columbia, MO 65211, USA.
In Vivo. 2012 Jul-Aug;26(4):583-92.
The present study adds scientific support to the growing debate regarding the superiority of radiolabeled bombesin-based antagonist peptides over agonists for molecular imaging and therapy of human tumors overexpressing the gastrin-releasing peptide receptor (GRPR) and describes a detailed in vitro and in vivo comparison of 64Cu-NODAGA-6-Ahx-BBN(7-14)NH2 agonist and 64Cu-NODAGA-6-Ahx-DPhe6-BBN(6-13)NHEt antagonist ligands.
Conjugates were synthesized by solid-phase peptide synthesis, purified by reversed-phase high-performance liquid chromatography, and characterized by electrospray ionization-mass spectroscopy. The conjugates were radiolabeled with 64Cu.
In vitro and in vivo data support the hypothesis for targeting of the GRPR by these tracer molecules. Maximum-intensity micro Positron Emission Tomography (microPET) imaging studies show the agonist ligand to provide high-quality, high-contrast images with very impressive tumor uptake and background clearance, with virtually no residual gastrointestinal or renal-urinary radioactivity.
Based on microPET imaging experiments, we conclude the agonist peptide ligand to be a superior molecular imaging agent for targeting GRPR.
本研究为关于放射性标记的蛙皮素拮抗剂肽优于激动剂在高表达胃泌素释放肽受体（GRPR）的人类肿瘤的分子成像和治疗的日益激烈的争论提供了科学依据，并描述了 64Cu-NODAGA-6-Ahx-BBN（7-14）NH2 激动剂和 64Cu-NODAGA-6-Ahx-DPhe6-BBN（6-13）NHEt 拮抗剂配体的详细体外和体内比较。
通过固相肽合成合成缀合物，通过反相高效液相色谱法纯化，并通过电喷雾电离质谱法进行表征。用 64Cu 对缀合物进行放射性标记。
体外和体内数据支持这些示踪分子靶向 GRPR 的假设。最大强度微正电子发射断层扫描（microPET）成像研究表明，激动剂配体提供高质量、高对比度的图像，具有非常令人印象深刻的肿瘤摄取和背景清除，几乎没有残留的胃肠道或肾-尿放射性。
基于 microPET 成像实验，我们得出结论，激动肽配体是一种用于靶向 GRPR 的优越的分子成像剂。
