Synthesis and Evaluation of [64Cu]Cu-NOTA-HFn for PET Imaging of Transferrin Receptor 1 Expression in Nasopharyngeal Carcinoma

Yanfang Shen; Renwei Zhou; Lei Bi; Guolong Huang; Min Yang; Zhijun Li; Jijin Yao; Jianzhong Xian; Yifan Qiu; Peizhen Ye; Yongshan Liu; Yuyi Hou; Hongjun Jin; Ying Wang

doi:10.1021/acsomega.4c00187

Synthesis and Evaluation of [⁶⁴Cu]Cu-NOTA-HFn for PET Imaging of Transferrin Receptor 1 Expression in Nasopharyngeal Carcinoma

ACS Omega. 2024 Apr 5;9(15):17423-17431. doi: 10.1021/acsomega.4c00187. eCollection 2024 Apr 16.

Authors

Yanfang Shen^{1

2

3}, Renwei Zhou^{1

2

3}, Lei Bi^{2

3}, Guolong Huang^{2

3}, Min Yang^{1

2

3}, Zhijun Li^{2

3}, Jijin Yao^{2

3}, Jianzhong Xian^{2

3}, Yifan Qiu^{2

3}, Peizhen Ye^{2

3}, Yongshan Liu^{2

3}, Yuyi Hou^{2

3}, Hongjun Jin^{2

3}, Ying Wang¹

Affiliations

¹ Department of Nuclear Medicine, The Fifth Affiliated Hospital, Sun Yat-sen University, Zhuhai 519000, China.
² Guangdong Provincial Engineering Research Center of Molecular Imaging, The Fifth Affiliated Hospital, Sun Yat-sen University, Zhuhai 519000, China.
³ Guangdong-Hong Kong-Macao University Joint Laboratory of Interventional Medicine, The Fifth Affiliated Hospital, Sun Yat-sen University, Zhuhai 519000, China.

Abstract

As recurrent and metastatic nasopharyngeal carcinoma (NPC) is the most common cause of death among patients with NPC, there is an urgent clinical need for the development of precision diagnosis to guide personalized treatment. Recent emerging evidence substantiates the increased expression of transferrin receptor 1 (also known as cluster of differentiation 71, CD71) within tumor tissues and the inherent targeting capability of natural heavy-chain ferritin (HFn) toward CD71. This study aimed to synthesize and assess a radiotracer ([⁶⁴Cu]Cu-NOTA-HFn) designed to target CD71 for positron emission tomography (PET) imaging in an NPC tumor-bearing mouse model. The entire radiolabeling process of [⁶⁴Cu]Cu-NOTA-HFn was completed within 15 min with high yield (>98.5%) and high molar activity (72.96 ± 21.33 GBq/μmol). The in vitro solubility and stability experiments indicated that [⁶⁴Cu]Cu-NOTA-HFn had a high water solubility (log P = -2.42 ± 0.52, n = 6) and good stability in phosphate-buffered saline (PBS) for up to 48 h. The cell saturation binding assay indicated that [⁶⁴Cu]Cu-NOTA-HFn had a nanomolar affinity (K_d = 10.9 ± 6.1 nM) for CD71-overexpressing C666-1 cells. To test the target engagement in vivo, prolonged-time PET imaging was performed at 1, 6, 12, 24, and 36 h postinjection (p.i.) of [⁶⁴Cu]Cu-NOTA-HFn to C666-1 NPC tumor-bearing mice. The C666-1 tumors could be visualized by [⁶⁴Cu]Cu-NOTA-HFn and blocked by nonradiolabeled HFn. PET imaging quantitative analysis demonstrated that the uptake of [⁶⁴Cu]Cu-NOTA-HFn in C666-1 tumors peaked at 6 h p.i. and the best radioactive tumor-to-muscle ratio was 10.53 ± 3.11 (n = 3). Ex vivo biodistribution assay at 6 h p.i. showed that the tumor uptakes were 1.43 ± 0.23%ID/g in the nonblock group and 0.92 ± 0.2%ID/g in the block group (n = 3, p < 0.05). Immunohistochemistry and immunofluorescence staining confirmed positive expression of CD71 and the uptake of HFn in C666-1 tumor tissues. In conclusion, our experiments demonstrated that [⁶⁴Cu]Cu-NOTA-HFn possesses a very high target engagement for CD71-positive NPC tumors and provided a fundamental basis for further clinical translation.