64Cu-labeled minibody D2101 visualizes CDH17-positive gastric cancer xenografts with short waiting time
64Cu-labeled minibody D2101 visualizes CDH17-positive gastric cancer xenografts with short waiting time
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DOI：
10.1097/mnm.0000000000001203
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发表时间：
2020-07-01
影响因子：
1.5
通讯作者：
Higashi, Tatsuya
中科院分区：
文献类型：
--
作者：
Fujiwara, Kentaro;Akiba, Hiroki;Higashi, Tatsuya
目的应用（111）In标记的抗钙粘附素17（CDH 17）抗体（IgG）对CDH 17阳性的胃癌移植瘤进行显像。不幸的是，由于血液滞留时间长（血液半衰期：26小时），需要长时间等待才能获得高对比度图像。为了加速血液清除，我们开发了抗CDH 17微抗体（D2101微抗体），并在胃癌小鼠模型中评估了药代动力学。方法分别从亲本IgG中制备D2101突变体和D2111突变体单链抗体。评价了与CDH 17的结合能力和在血浆中的稳定性。以D2101突变体scFv为基础构建D2101微抗体，用（64）Cu标记（Cu-64-D2101微抗体），通过细胞ELISA、生物分布实验和PET成像评价其在CDH 17阳性AGS和CDH 17阴性MKN 74荷瘤小鼠体内和体外的特性。结果D2101突变体和D2111单链抗体与CDH 17的亲和力相似。D2101突变体scFv在血浆中的稳定性优于D2111 scFv。通过螯合物缀合和放射性标记程序，未观察到D2101微抗体的结合亲和力损失。（64）Cu-D2101微抗体的生物分布显示在AGS肿瘤中高摄取，在MKN 74中低摄取。（64）Cu-D2101微抗体的血液半衰期为6.5h。与亲本IgG在AGS异种移植小鼠中的先前结果相比，（64）Cu-D2101微抗体的改善的血液清除提供了高的肿瘤-血液比。PET研究显示与生物分布研究一致的结果。结论Cu-64-D2101微抗体在较早的时间点具有较高的肿瘤/血液比值，Cu-64-D2101微抗体可作为CDH 17阳性肿瘤的免疫显像剂。
Objective We previously reported(111)In-labeled anti-cadherin17 (CDH17) IgG visualized CDH17-positive gastric cancer xenografts. Unfortunately, a long waiting time was required to obtain high-contrast images due to long blood retention (blood half-life: 26 h). To accelerate blood clearance, we have developed anti-CDH17 minibody (D2101 minibody) and evaluated the pharmacokinetics in gastric cancer mouse models. Methods Two different single chain Fvs (scFvs), D2101 mutant and D2111, were developed from each parental IgG. The binding ability to CDH17 and stability in plasma were evaluated. D2101 minibody, constructed based on D2101 mutant scFv, was labeled with(64)Cu (Cu-64-D2101 minibody), and the in-vitro and in-vivo properties were evaluated by cell ELISA, biodistribution experiments, and PET imaging in mice bearing CDH17-positive AGS and CDH17-negative MKN74 tumors. Results D2101 mutant and D2111 scFvs showed similar affinities to CDH17. D2101 mutant scFv was more stable than D2111 scFv in plasma. No loss of binding affinity of the D2101 minibody by chelate conjugation and radiolabeling procedures was observed. The biodistribution of(64)Cu-D2101 minibody showed high uptake in AGS tumors and low uptake in MKN74. The blood half-life of(64)Cu-D2101 minibody was 6.5 h. Improved blood clearance of(64)Cu-D2101 minibody provided high tumor-to-blood ratios compared with the previous results of parental IgG in AGS xenograft mice. PET studies showed consistent results with biodistribution studies. Conclusions Cu-64-D2101 minibody exhibited higher tumor-to-blood ratios at earlier time points than those of the radiolabeled parental IgG.Cu-64-D2101 minibody has potential as an immunoimaging agent for CDH17-positive tumors.