Chen Lixing, Cheng Siyuan, Zhu Dongling, Bao Guangfa, Wang Ziqiang, Deng Xiaoyun, Liu Xiaoguang, Ma Xiang, Zhao Jun, Zhu Lei, Zhu Xiaohua
Department of Nuclear Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430000, China.
School of Pharmacy, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China.
Mol Pharm. 2025 Jan 6;22(1):209-220. doi: 10.1021/acs.molpharmaceut.4c00838. Epub 2024 Dec 10.
Positron emission tomography (PET) is a promising modality for early diagnosis, accurate detection, and staging of hepatocellular carcinoma (HCC). Hereby, a dual-specific probe targeting Glypican-3 (GPC3) and prostate-specific membrane antigen (PSMA) was evaluated for HCC PET imaging. The probe was prepared by conjugating TJ12P2, a GPC3-targeting peptide previously reported by our group, to a highly potent PSMA inhibitor via a polyethylene glycol linker and further tethered to the 1,4,7-triazacyclononane-1,4,7-triacetic acid (NOTA) chelator. The resultant probe, NOTA-TJ12P2-PSMA, abbreviated as T2P, was labeled with gallium-68 and fluorine-18, respectively, and evaluated in murine HCC models of various levels of GPC3 and PSMA expression. Targeting specificity was confirmed by blocking studies. The synthesized [Ga]Ga-T2P and [F]AlF-T2P were stable in saline and fetal bovine serum for over 2 h, and bound to their respective targets with high affinity and specificity in cell assays. PET imaging at 60 min postinjection (p.i.) showed that [Ga]Ga-T2P exhibited higher uptake (1.75 ± 0.16%ID/g) in Huh7 models with high expression of GPC3 and PSMA than gallium-68 labeled TJ12P2 (1.25 ± 0.07%ID/g, < 0.01) or gallium-68 labeled PSMA-617 (1.07 ± 0.06%ID/g, ). The uptake of [Ga]Ga-T2P in Huh7 tumors was higher than that in PC-3 tumors with low expression of GPC3 or PSMA (0.55 ± 0.24%ID/g, < 0.01). The uptake of [F]AlF-T2P or [Ga]Ga-T2P in the Huh7 tumor was substantially blocked by TJ12P2, TJ12P2 + PSMA, or T2P, but only partially blocked by PSMA. And the PSMA and TJ12P2 monomer blocking effect was less than that of TJ12P2 + PSMA and T2P. [F]AlF-T2P had higher tumor-to-muscle ratios than [Ga]Ga-T2P at 90 min postinjection (4.31 ± 0.10 vs 3.80 ± 0.17, ) in Huh7 tumor models. To conclude, radiolabeled T2P exhibited a higher uptake and longer retention in Huh7 tumors than its monomeric counterparts. PET imaging via gallium-68 and fluorine-18 labeled T2P showed a similar imaging quality with comparable signal-to-background ratios. Our results demonstrate that T2P is a promising tool for future clinical diagnosis of HCC.
正电子发射断层扫描（PET）是一种用于肝细胞癌（HCC）早期诊断、准确检测和分期的有前景的检查方法。在此，评估了一种靶向磷脂酰肌醇蛋白聚糖-3（GPC3）和前列腺特异性膜抗原（PSMA）的双特异性探针用于HCC的PET成像。该探针是通过将我们小组先前报道的靶向GPC3的肽TJ12P2通过聚乙二醇连接子与一种高效的PSMA抑制剂偶联，然后进一步连接到1,4,7-三氮杂环壬烷-1,4,7-三乙酸（NOTA）螯合剂上制备而成。所得探针NOTA-TJ12P2-PSMA，简称为T2P，分别用镓-68和氟-18标记，并在不同GPC3和PSMA表达水平的小鼠HCC模型中进行评估。通过阻断研究证实了靶向特异性。合成的[Ga]Ga-T2P和[F]AlF-T2P在生理盐水和胎牛血清中2小时以上稳定，并且在细胞试验中以高亲和力和特异性与其各自的靶点结合。注射后60分钟（p.i.）的PET成像显示，在GPC3和PSMA高表达的Huh7模型中，[Ga]Ga-T2P的摄取（1.75±0.16%ID/g）高于镓-68标记的TJ12P2（1.25±0.07%ID/g，P<0.01）或镓-68标记的PSMA-617（1.07±0.06%ID/g）。[Ga]Ga-T2P在Huh7肿瘤中的摄取高于GPC3或PSMA低表达的PC-3肿瘤（0.55±
