Real-time,noninvasive programmed death-ligand 1(PD-L1)testing using molecular imaging has enhanced our understanding of the immune environments of neoplasms and has served as a guide for immunotherapy.However,the util...Real-time,noninvasive programmed death-ligand 1(PD-L1)testing using molecular imaging has enhanced our understanding of the immune environments of neoplasms and has served as a guide for immunotherapy.However,the utilization of radiotracers in the imaging of human brain tumors using positron emission tomography/computed tomography(PET/CT)remains limited.This investigation involved the synthesis of[18F]AlF-NOTA-PCP2,which is a novel peptide-based radiolabeled tracer that targets PD-L1,and evaluated its imaging capabilities in orthotopic glioblastoma(GBM)models.Using this tracer,we could noninvasively monitor radiation-induced PD-L1 changes in GBM.[18F]AlF-NOTA-PCP2 exhibited high radiochemical purity(>95%)and stability up to 4 h after synthesis.It demonstrated specific,high-affinity binding to PD-L1 in vitro and in vivo,with a dissociation constant of 0.24 nM.PET/CT imaging,integrated with contrast-enhanced magnetic resonance imaging,revealed significant accumulation of[18F]AlF-NOTA-PCP2 in orthotopic tumors,correlating with blood-brain barrier disruption.After radiotherapy(15 Gy),[18F]AlF-NOTA-PCP2 uptake in tumors increased from 9.51%±0.73%to 12.04%±1.43%,indicating enhanced PD-L1 expression consistent with immunohistochemistry findings.Fractionated radiation(5 Gy×3)further amplified PD-L1 upregulation(13.9%±1.54%ID/cc)compared with a single dose(11.48%±1.05%ID/cc).Taken together,[18F]AlF-NOTA-PCP2 may be a valuable tool for noninvasively monitoring PD-L1 expression in brain tumors after radiotherapy.展开更多
基金support from the National Natural Science Foundation of China(Grant Nos.:82272751 and 82202958)the Natural Science Foundation of Shandong,China(Grant No.:ZR2021LSW002)+6 种基金the Science and Technology Program of Jinan,China(Grant Nos.:202225019 and 202225013)to Man Huthe Shandong Postdoctoral Innovation Program,China(Grant No.:SDCX-ZG-202302011)Beijing Science and Technology Innovation Medical Development Foundation,China(Grant No.:KC2023-JX-0288-BQ26)to Yong Wangthe Natural Science Foundation of China(Grant No.:NSFC82303676)the Natural Science Foundation of Shandong(Grant No.:ZR2023QH208)the China Postdoctoral Science Foundation(Grant No.:2023M732125)the Taishan Scholar Project Special Fund(Grant No.:tsqn202312368)to Kewen He.
文摘Real-time,noninvasive programmed death-ligand 1(PD-L1)testing using molecular imaging has enhanced our understanding of the immune environments of neoplasms and has served as a guide for immunotherapy.However,the utilization of radiotracers in the imaging of human brain tumors using positron emission tomography/computed tomography(PET/CT)remains limited.This investigation involved the synthesis of[18F]AlF-NOTA-PCP2,which is a novel peptide-based radiolabeled tracer that targets PD-L1,and evaluated its imaging capabilities in orthotopic glioblastoma(GBM)models.Using this tracer,we could noninvasively monitor radiation-induced PD-L1 changes in GBM.[18F]AlF-NOTA-PCP2 exhibited high radiochemical purity(>95%)and stability up to 4 h after synthesis.It demonstrated specific,high-affinity binding to PD-L1 in vitro and in vivo,with a dissociation constant of 0.24 nM.PET/CT imaging,integrated with contrast-enhanced magnetic resonance imaging,revealed significant accumulation of[18F]AlF-NOTA-PCP2 in orthotopic tumors,correlating with blood-brain barrier disruption.After radiotherapy(15 Gy),[18F]AlF-NOTA-PCP2 uptake in tumors increased from 9.51%±0.73%to 12.04%±1.43%,indicating enhanced PD-L1 expression consistent with immunohistochemistry findings.Fractionated radiation(5 Gy×3)further amplified PD-L1 upregulation(13.9%±1.54%ID/cc)compared with a single dose(11.48%±1.05%ID/cc).Taken together,[18F]AlF-NOTA-PCP2 may be a valuable tool for noninvasively monitoring PD-L1 expression in brain tumors after radiotherapy.
