Fluorescence-guided tumor detection with a novel anti-EpCAM targeted antibody fragment: Preclinical validation
Fluorescence-guided tumor detection with a novel anti-EpCAM targeted antibody fragment: Preclinical validation
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DOI：
10.1016/j.suronc.2018.10.004
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发表时间：
2019-03-01
影响因子：
2.3
通讯作者：
Vahrmeijer, Alexander L.
中科院分区：
文献类型：
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作者：
Boogerd, Leonora S. F.;Boonstra, Martin C.;Vahrmeijer, Alexander L.
肿瘤特异性荧光成像剂正在走向临床，为外科医生提供关于肿瘤位置的实时术中反馈。上皮细胞粘附分子（EpCAM）在上皮源性肿瘤中的高表达被认为是最有前途的肿瘤特异性蛋白之一。本研究描述了EpCAM-F800（一种新型荧光抗EpCAM抗体片段）用于术中肿瘤成像的开发和评价。使用HPLC、分光光度法和基于细胞的测定法测定和验证Fab产生、与荧光团IRDye 800 CW的缀合和结合能力。在体内，进行剂量递增、阻断、药代动力学和生物分布研究（使用荧光和放射性），然后对乳腺癌和结直肠癌的临床相关原位异种移植物进行成像。EpCAM-F800在体外以高特异性靶向EpCAM，这使用使用10倍更高剂量的未标记Fab的体内阻断实验来验证。在小鼠中进行荧光肿瘤检测的最佳剂量范围为1-5 nmol（52-260 μ g），相当于0.2-0.8 mg/kg的人体等效剂量。生物分布显示EpCAM-F800在肿瘤和代谢器官中的高积累。乳腺和结直肠肿瘤在注射后8小时内和长达96小时内可以清楚地可视化，而药剂在4小时内已经显示出均匀的肿瘤分布。血液半衰期为4.5 h。本研究描述了一种新型EpCAM靶向剂的开发和评价，以及在切除术期间通过荧光成像可视化乳腺和结直肠肿瘤的可行性。考虑到EpCAM-F800在广泛的肿瘤类型中的丰度，它将被转化用于临床应用。
Tumor-specific fluorescent imaging agents are moving towards the clinic, supporting surgeons with real-time intraoperative feedback about tumor locations. The epithelial cell adhesion molecule (EpCAM) is considered as one of the most promising tumor-specific proteins due its high overexpression on epithelial-derived cancers. This study describes the development and evaluation of EpCAM-F800, a novel fluorescent anti-EpCAM antibody fragment, for intraoperative tumor imaging. Fab production, conjugation to the fluorophore IRDye 800CW, and binding capacities were determined and validated using HPLC, spectrophotometry and cell-based assays. In vivo, dose escalation-, blocking-, pharmacokinetic- and biodistribution studies (using both fluorescence and radioactivity) were performed, next to imaging of clinically relevant orthotopic xenografts for breast and colorectal cancer. EpCAM-F800 targets EpCAM with high specificity in vitro, which was validated using in vivo blocking experiments with a 10x higher dose of unlabeled Fab. The optimal dose range for fluorescence tumor detection in mice was 1-5 nmol (52-260 mu g), which corresponds to a human equivalent dose of 0.2-0.8 mg/kg. Biodistribution showed high accumulation of EpCAM-F800 in tumors and metabolizing organs. Breast and colorectal tumors could clearly be visualized within 8h post-injection and up to 96 h, while the agent already showed homogenous tumor distribution within 4 h. The blood half-life was 4.5 h. This study describes the development and evaluation of a novel EpCAM-targeting agent and the feasibility to visualize breast and colorectal tumors by fluorescence imaging during resections. EpCAM-F800 will be translated for clinical use, considering its abundance in a broad range of tumor types.