乳腺癌PET/CT成像探针18F-NOTA-Gly3-E（2PEG4-RGD-WH701）的合成及初步评价

Preliminary study on developing and evaluating the PET/CT imaging probe 18F-NOTA-Gly3-E（2PEG4-RGD-WH701） for the diagnosis of breast cancer

目的开发一个靶向双受体(TNFR1和ανβ3)的18F标记融合肽探针18F-NOTA-Gly3-E(2PEG4-RGD-WH701),并且在MDA-MB-231和MCF-7异种移植裸鼠模型中评估放射性探针的诊断效果。方法利用NOTA修饰RGD-WH701化合物,采用NOTA-AlF螯合法进行18F的放射性标记。采用两个聚乙二醇(PEG4)分子和一个谷氨酸(Glu)分子与WH701和c(RGDyK)共价连接,并加入甘氨酸(Gly)以进一步改善探针的水溶性和药代动力学特性。采用免疫印迹分析(WB)和免疫荧光染色检测TNFR1和整合素ανβ3在MCF-7和MDA-MB-231细胞的表达。通过MDA-MB-231和MCF-7异种移植裸鼠模型评估18F-NOTA-Gly3-E(2PEG4-RGD-WH701)的体内靶向特性及Micro PET/CT成像性能。结果 18F-NOTAGly3-E(2PEG4-RGD-WH701)经衰减校正后的放射性化学产率约为33.5﹪±2.8﹪(n=5),放射化学纯度在95﹪以上。尾静脉注射18F-NOTA-Gly3-E(2PEG4-RGD-WH701)后40 min,Micro PET/CT测定MCF-7肿瘤摄取值为(1.22±0.11)﹪ID/g,MDA-MB-231肿瘤值摄取为(1.14±0.14)﹪ID/g。而单靶点肽18F-NOTA-RGD和18F-NOTA-WH701在MCF-7肿瘤中摄取值分别为(0.99±0.18)﹪ID/g、(0.57±0.08)﹪ID/g,在MDA-MB-231肿瘤中的摄取值分别为(0.96±0.13)﹪ID/g、(0.93±0.28)﹪ID/g。结论成功合成18F标记的双靶点融合肽18F-NOTA-Gly3-E(2PEG4-RGD-WH701),并在MDA-MB-231和MCF-7异种移植裸鼠模型中均获得了良好的成像效果。相对于分别针对对应单靶点整合素ανβ3和TNFR1的探针18F-NOTA-RGD和18F-NOTA-WH701,融合肽探针具有更高的肿瘤摄取。

Objective To develop an 18F-labeled fusion peptide probe 18F-NOTA-Gly3-E(2 PEG4-RGDWH701)targeting dual receptors(TNFR1 and ανβ3), and to evaluate the diagnostic potential of it in xenografted nude mice models of MDA-MB-231 and MCF-7. Methods The NOTA-conjugated RGD-WH701 analog was radiolabeled with 18F using NOTA-AlF chelation method. We used two PEG4 molecules and one glutamic acid(Glu)to covalently link c(RGDyK)with WH701. Gly3 was also added to further improve the water solubility and pharmacokinetic properties of the probe. The expression of TNFR1 and integrin ανβ3 in MCF-7 and MDAMB-231 cells were detected by western blot analysis and immunofluorescence staining. The tumor-targeting characteristics and PET/CT imaging properties of 18F-NOTA-Gly3-E(2 PEG4-RGD-WH701) were assessed in nude mice bearing MDA-MB-231 and MCF-7 xenografts. Results The radiochemical yield after attenuation correction was approximately 33.5 ﹪ ± 2.8 ﹪(n = 5), and the radiochemical purity was above 95 ﹪. The MCF-7 tumor uptake of 18F-NOTA-Gly3-E(2 PEG4-RGD-WH701) were(1.22 ± 0.11) ﹪ ID/g, as measured by Micro PET/CT at 40 min post injection. In comparison, the tumor uptake of 18F-NOTA-RGD and 18F-NOTAWH701 in MCF-7 xenografts were(0.99 ± 0.18)﹪ ID/g and(0.57 ± 0.08)﹪ ID/g, respectively. The MDAMB-231 tumor uptake of 18F-NOTA-Gly3-E(2 PEG4-RGD-WH701) was(1.14 ± 0.14)﹪ ID/g, as measured by PET/CT at 40 min post injection. In comparison, the tumor uptake of 18F-NOTA-RGD and 18F-NOTA-WH701 in MDA-MB-231 xenografts were(0.96 ± 0.13)﹪ ID/g and(0.93 ± 0.28)﹪ ID/g, respectively. Conclusions The 18F-labeled double-targeting fusion peptide 18F-NOTA-Gly3-E(2 PEG4-RGD-WH701) was successfully developed, and good imaging results were obtained in MDA-MB-231 and MCF-7 xenograft nude mouse models. Fusion peptide probes 18F-NOTA-Gly3-E(2 PEG4-RGD-WH701) have a higher tumor uptake than probes 18F-NOTA-RGD and 18F-NOTA-WH701 that targeting single-target integrin ανβ3 and TNFR1, respectively.