使用新型放射性示踪剂（68）Ga-NOTA-c（NGR）对实验性肾肿瘤中的氨肽酶N（CD13）受体进行体内成像。

In vivo imaging of Aminopeptidase N (CD13) receptors in experimental renal tumors using the novel radiotracer (68)Ga-NOTA-c(NGR).

作者信息

Máté Gábor, Kertész István, Enyedi Kata Nóra, Mező Gábor, Angyal János, Vasas Nikolett, Kis Adrienn, Szabó Éva, Emri Miklós, Bíró Tamás, Galuska László, Trencsényi György

机构信息

Department of Nuclear Medicine, University of Debrecen, Hungary.

MTA-ELTE, Research Group of Peptide Chemistry, Hungarian Academy of Sciences, Eötvös L. University, Budapest, Hungary.

出版信息

Eur J Pharm Sci. 2015 Mar 10;69:61-71. doi: 10.1016/j.ejps.2015.01.002. Epub 2015 Jan 13.

DOI:10.1016/j.ejps.2015.01.002

PMID:25592229

Abstract

PURPOSE

Aminopeptidase N (APN/CD13) plays an important role in tumor neoangiogenic process and the development of metastases. Furthermore, it may serve as a potential target for cancer diagnosis and therapy. Previous studies have already shown that asparagine-glycine-arginine (NGR) peptides specifically bind to APN/CD13. The aim of the study was to synthesize and investigate the APN/CD13 specificity of a novel (68)Ga-labeled NOTA-c(NGR) molecule in vivo using miniPET.

METHODS

c[KNGRE]-NH2 peptide was conjugated with p-SCN-Bn-NOTA and was labeled with Ga-68 ((68)Ga-NOTA-c(NGR)). Orthotopic and heterotopic transplanted mesoblastic nephroma (NeDe) bearing Fischer-344 rats were prepared, on which biodistribution studies and miniPET scans were performed for both (68)Ga-NOTA-c(NGR) and ανβ3 integrin selective (68)Ga-NODAGA-[c(RGD)]2 tracers. APN/CD13 receptor expression of NeDe tumors and metastases was analyzed by western blot.

RESULTS

(68)Ga-NOTA-c(NGR) was produced with high specific activity (5.13-5.92GBq/μmol) and with excellent radiochemical purity (95%<), at all cases. Biodistribution studies in normal rats showed that uptake of the (68)Ga-NOTA-c(NGR) was significantly (p⩽0.05) lower in abdominal organs in comparison with (68)Ga-NODAGA-[c(RGD)]2. Both radiotracers were mainly excreted from the kidney. In NeDe tumor bearing rats higher (68)Ga-NOTA-c(NGR) accumulation was found in the tumors than that of the (68)Ga-NODAGA-[c(RGD)]2. Using orthotopic transplantation, metastases were developed which showed specific (68)Ga-NOTA-c(NGR) uptake. Western blot analysis confirmed the presence of APN/CD13 expression in NeDe tumors and metastases.

CONCLUSION

Our novel radiotracer (68)Ga-NOTA-c(NGR) showed specific binding to the APN/CD13 expressed ortho- and heterotopic transplanted NeDe tumors. Therefore, (68)Ga-NOTA-c(NGR) is a suitable tracer for the detection of APN/CD13 positive tumors and metastases in vivo.

摘要

目的

氨肽酶N（APN/CD13）在肿瘤新生血管形成过程和转移发展中起重要作用。此外，它可能作为癌症诊断和治疗的潜在靶点。先前的研究已经表明，天冬酰胺-甘氨酸-精氨酸（NGR）肽能特异性结合APN/CD13。本研究的目的是使用微型PET在体内合成并研究一种新型的（68）Ga标记的NOTA-c（NGR）分子对APN/CD13的特异性。

方法

将c[KNGRE]-NH2肽与p-SCN-Bn-NOTA偶联，并用Ga-68进行标记（（68）Ga-NOTA-c（NGR））。制备携带原位和异位移植中胚层肾瘤（NeDe）的Fischer-344大鼠，对（68）Ga-NOTA-c（NGR）和αvβ3整合素选择性的（68）Ga-NODAGA-[c（RGD）]2示踪剂进行生物分布研究和微型PET扫描。通过蛋白质印迹法分析NeDe肿瘤和转移灶中APN/CD13受体的表达。

结果

（68）Ga-NOTA-c（NGR）的比活度高（5.13-5.92GBq/μmol），在所有情况下放射化学纯度均优异（>95%）。正常大鼠的生物分布研究表明，与（68）Ga-NODAGA-[c（RGD）]2相比，（68）Ga-NOTA-c（NGR）在腹部器官中的摄取显著降低（p⩽0.05）。两种放射性示踪剂均主要经肾脏排泄。在携带NeDe肿瘤的大鼠中，肿瘤内（68）Ga-NOTA-c（NGR）的蓄积高于（68）Ga-NODAGA-[c（RGD）]2。采用原位移植法形成转移灶，其显示出对（68）Ga-NOTA-c（NGR）的特异性摄取。蛋白质印迹分析证实NeDe肿瘤和转移灶中存在APN/CD13表达。