Synthesis of a 68Ga-labeled bicyclic peptide targeting Nectin-4 and its application research in breast cancer imaging
10.3760/cma.j.cn321828-20240703-00244
- VernacularTitle:68Ga标记靶向Nectin－4双环肽的制备及乳腺癌显像研究
- Author:
Liqi LI
1
;
Yue XU
;
Donghui PAN
;
Junjie YAN
;
Xinyu WANG
;
Chongyang CHEN
;
Lizhen WANG
;
Min YANG
;
Yuping XU
Author Information
1. 江南大学附属医院甲状腺乳腺外科，无锡 214122
- Keywords:
Breast neoplasms;
Peptides, cyclic;
Isotope labeling;
Gallium radioisotopes;
Tumor cells, cultured;
Mice
- From:
Chinese Journal of Nuclear Medicine and Molecular Imaging
2024;44(12):741-747
- CountryChina
- Language:Chinese
-
Abstract:
Objective:To prepare a novel 68Ga-labeled bicyclic peptide targeting poliovirus receptor related protein 4 (PVRL4, Nectin-4), and evaluate its feasibility for breast cancer imaging via in vitro and in vivo experiments. Methods:A Biotin-modified bicyclic peptide targeting Nectin-4, Biotin-BMIC, was synthesized, and its targeting properties were preliminarily evaluated by in vitro cell staining experiments. BMIC was modified by 1, 4, 7-triazonane-1, 4-diacetic acid (NODA) and the labeling precursor NODA-BMIC was prepared. A potential PET probe targeting Nectin-4, 68Ga-NODA-BMIC was prepared by one-step labeling strategy. The imaging properties of the probe were investigated by in vivo microPET imaging and in vitro experiments in mice bearing breast tumors. Data were analyzed by independent-sample t test and repeated measures analysis of variance. Results:Fluorescence staining of the cells showed that the fluorescently labeled bicyclic peptide, Biotin-BMIC, was highly aggregated in Nectin-4 positive BT474 breast cancer cells compared to those in Nectin-4 negative MDA-MB-231 cells. The uncorrected yield of 68Ga-NODA-BMIC was (71.5±2.2)% and the radiochemical purity was greater than 95%. The specific activity was greater than 3 GBq/μmol. After incubation 10, 30, 60 and 120 min, higher radioactivity uptakes were found in BT474 breast cancer cells compared to those in MDA-MB-231 breast cancer cells respectively ( F=1 302.00, P<0.001). MicroPET imaging showed that the BT474 xenograft tumors were clearly visible with favorable contrast. A significant statistical difference in uptakes between BT474 and MDA-MB-231 xenograft tumor uptake at 10, 30, 60, and 120 min after probe injection respectively was existed ( F=1 826.00, P<0.001). At 60 min postinjection, the uptake value of BT474 tumors was (5.03±0.14) percentage activity of injection dose per gram of tissue (%ID/g), which was significantly higher than that of MDA-MB-231 tumors ((0.19±0.04) %ID/g; t=79.40, P<0.001). Meanwhile, the tumor-to-muscle ratios in the former were also greater than those in the latter ( F=222.00, P<0.001). At 60 min postinjection, the tumor-to-muscle ratio in the former was significantly higher than that in the latter (24.75±3.10 vs 1.30±0.15; t=14.31, P=0.002). The results were consistent with the immunohistochemistry staining. Conclusions:A novel bicyclic peptide PET probe targeting Nectin-4, 68Ga-NODA-BMIC, is easy to be synthesized and owns satisfactory labeling yield and radiological purity. The imaging performance is good and the target tissues could be visualized. It may play a unique role in the diagnosis and treatment of breast cancer.
