Synthesis and Evaluation of a Novel 64Cu- and 67Ga-Labeled Neurokinin 1 Receptor Antagonist for in Vivo Targeting of NK1R-Positive Tumor Xenografts.
Synthesis and Evaluation of a Novel 64Cu- and 67Ga-Labeled Neurokinin 1 Receptor Antagonist for in Vivo Targeting of NK1R-Positive Tumor Xenografts.
复制标题
用于体内靶向 NK1R 阳性肿瘤异种移植物的新型 64Cu 和 67Ga 标记神经激肽 1 受体拮抗剂的合成和评估。
DOI：
10.1021/acs.bioconjchem.8b00063
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发表时间：
2018
影响因子：
4.7
通讯作者：
Low,PhilipS
中科院分区：
文献类型：
--
作者：
Zhang,Hanwen;Kanduluru,AnandaKumar;Desai,Pooja;Ahad,Afruja;Carlin,Sean;Tandon,Nidhi;Weber,WolfgangA;Low,PhilipS
Neurokinin 1 receptor (NK1R) is expressed in gliomas and neuroendocrine malignancies and represents a promising target for molecular imaging and targeted radionuclide therapy. The goal of this study was to synthesize and evaluate a novel NK1R ligand (NK1R-NOTA) for targeting NK1R-expressing tumors. Using a carboxymethyl moiety linked to L-733060 as a starting reagent, NK1R-NOTA was synthesized in a three-step reaction and then labeled with64Cu (or67Ga forin vitrostudies) in the presence of CH3COONH4buffer. The radioligand affinity and cellular uptake were evaluated with NK1R-transduced HEK293 cells (HEK293-NK1R) and NK1R nontransduced HEK293 cells (HEK293-WT) and their xenografts. Radiolabeled NK1R-NOTA was obtained with a radiochemical purity of >95% and specific activities of >7.0 GBq/μmol for64Cu and >5.0 GBq/μmol for67Ga. Both64Cu- and67Ga-labeled NK1R-NOTA demonstrated high levels of uptake in HEK293-NK1R cells, whereas co-incubation with an excess of NK1R ligand L-733060 reduced the level of uptake by 90%. Positron emission tomography (PET) imaging showed that [64Cu]NK1R-NOTA had a accumulated rapidly in HEK293-NK1R xenografts and a 10-fold lower level of uptake in HEK293-WT xenografts. Radioactivity was cleared by gastrointestinal tract and urinary systems. Biodistribution studies confirmed that the tumor-to-organ ratios were ≥5 for all studied organs at 1 h p.i., except kidneys, liver, and intestine, and that the tumor-to-intestine and tumor-to-kidney ratios were also improved 4 and 20 h post-injection. [64Cu]NK1R-NOTA is a promising ligand for PET imaging of NK1R-expressing tumor xenografts. Delayed imaging with [64Cu]NK1R-NOTA improves image contrast because of the continuous clearance of radioactivity from normal organs.
