Influence of chelator and near-infrared dye labeling on biocharacteristics of dual-labeled trastuzumab-based imaging agents

作     者：Xuejuan Wang Melissa B Aldrich Zhi Yang Nina Zhou Qing Xie Chen Liu Eva Sevick-Muraca 

作者机构：Key Laboratory of Carcinogenesis and Translational Research(Ministry of Education/Beijing)Department of Nuclear MedicinePeking University Cancer Hospital&InstituteBeijing 100142China Center for Molecular Imagingthe Brown Foundation Institute of Molecular MedicineUniversity of Texas Health Science Center at HoustonHouston TX 77030USA 

出 版 物：《Chinese Journal of Cancer Research》 (中国癌症研究（英文版）)

年 卷 期：2016年第28卷第3期

页      面：362-369页

核心收录：

学科分类：1002[医学-临床医学] 100214[医学-肿瘤学] 10[医学] 

基　　金：supported by Beijing Natural Science Foundation(No.7132037) the National Cancer Institute Network for Translational Research U54 CA136404-01 

主　　题：Influence near infrared dye trastuzumab human epidermal growth factor receptor 2 dual-labeled 

摘      要：Objective： To investigate the effect of fluorescent dye labeling on the targeting capabilities of 111 In- （DTPA）.-trastuzumab-（IRDye 800）m. Methods： Trastuzumab-based conjugates were synthesized and conjugated with diethylenetriaminepentaacetic acid （DTPA） at molar ratios of I, 2, 3 and 5 and with a fluorescent dye （IRDye 800CW） at molar ratios of 1, 3 and 5. Immunoreactivity and internalization were assessed on SKBR-3 cells, overexpressing human epidermal growth factor receptor 2. The stability in human serum and phosphate-buffered saline （PBS） was evaluated. The biodistribution of dual-labeled conjugates was compared with that of 111In-（DTPA）2-trastuzumab in a SKBR-3 xenograft model to evaluate the effect of dye-to-protein ratio. Results： All trastuzumab-based conjugates exhibited a high level of chemical and optical purity. Flow cytometry results showed that increasing dye-to-protein ratios were associated with decreased immunoreactivity. Stability studies revealed that the conjugate was stable in PBS, while in human serum, increased degradation and protein precipitation were observed with increasing dye-to-protein ratios. At 4 h, the percentages of internalization of dual-labeled conjugates normalized by dye-to-protein ratio （m） were 24.88%±2.10%, 19.99%±0.59%, and 17.47%±1.26% for ＂m＂ equal to 1, 3, and 5, respectively. A biodistribution study revealed a progressive decrease in tumor uptake with an increase in the dye-to-protein ratios. The liver, spleen and kidney showed a marked uptake with increased dye-to-protein ratios, particularly in the latter. Conclusions： With non-specific-site conjugation of the fluorescent dye with a protein based on imaging agent, the increase in dye-to-protein ratios negatively impacted the immunoreactivity and stability, indicating a reduced tumor uptake.