Preliminary radioimmunoimaging and biodistribution of ^131iodine-labeled single-chain antibody fragment against progastrin-releasing peptide（31-98） in small cell lung cancer xenografts  

作　　者：Hong Zhihui Shi Yizhen Liu Zengli Zhou Xiaolin Yang Yi Tang Jun 

机构地区：[1]Department of Nuclear Medicine, the Second Affiliated Hospital of Soochow University, Suzhou, Jiangsu 215004, China [2]Department of Radiology and Nuclear Medicine, China Institute for Radiation Protection, Taiyuan, Shanxi 030006, China

出　　处：《Chinese Medical Journal》2014年第11期2007-2011,共5页中华医学杂志（英文版）

摘　　要：Background Monoclonal antibodies （mAbs） such as DD3,raised against progastrin-releasing peptide（31-98） （ProGRP（31-98）） antigen,have been used to target small cell lung cancer （SCLC）.However,as an intact mAb,DD3 is cleared slowly from the body,with an optimal radioimmunoimaging time of 72 hours.More recently,a singlechain antibody fragment has demonstrated reduced excretion time in blood and normal tissues and is increasingly used in diagnostic cancer research.Thereby,it potentially increases the radioimmunoimaging efficacy.However,there have been few studies with this antibody fragment.The aim of this study was to characterize the preliminary radioimmunoimaging and biodistribution of 1311I-anti-ProGRP（31-98）scFv in nude mice bearing SCLC xenografts.Methods Anti-ProGRP（31-98） scFv was used to detect ProGRP expression by flow cytometry analysis and immunohistochemistry.131I-anti-ProGRP（31-98） scFv was injected intravenously into healthy Kunming mice and the percentage injected dose per gram （%ID/g） in various organs was calculated.Similarly,the %ID/g and tumor/non-tumor ratio in xenograft-bearing mice was calculated.After injection of 131I-anti-ProGRP（31-98） scFv,treated mice were imaged at 1,24,and 30 hours.Then the tumor/base ratios were calculated.Results ProGRP was highly expressed in NCI-H446 cells and xenograft tissue.The metabolism of 131I-anti-ProGRP（31-98） scFv in healthy mice was consistent with a first-order and two-compartment model; T1/2α and T1/2β were 10.2 minutes and 5 hours 18 minutes,respectively.The %ID/g of 131I-anti-ProGRP（31-98） scFv in xenografts was much higher than in healthy tissues at 12 hours after injection,reaching a maximum of （5.38±0.92） %ID/g at 24 hours.Successful imaging of xenograft tissue was achieved as early as 1 hour post-injection and persisted until 30 hours,with 24 hours proving optimal.Conclusion 131I-anti-ProGRP（31-98）scFv shows highly selective tumor uptake with low accumulation in normal tissues and rapid bloodBackground Monoclonal antibodies （mAbs） such as DD3,raised against progastrin-releasing peptide（31-98） （ProGRP（31-98）） antigen,have been used to target small cell lung cancer （SCLC）.However,as an intact mAb,DD3 is cleared slowly from the body,with an optimal radioimmunoimaging time of 72 hours.More recently,a singlechain antibody fragment has demonstrated reduced excretion time in blood and normal tissues and is increasingly used in diagnostic cancer research.Thereby,it potentially increases the radioimmunoimaging efficacy.However,there have been few studies with this antibody fragment.The aim of this study was to characterize the preliminary radioimmunoimaging and biodistribution of 1311I-anti-ProGRP（31-98）scFv in nude mice bearing SCLC xenografts.Methods Anti-ProGRP（31-98） scFv was used to detect ProGRP expression by flow cytometry analysis and immunohistochemistry.131I-anti-ProGRP（31-98） scFv was injected intravenously into healthy Kunming mice and the percentage injected dose per gram （%ID/g） in various organs was calculated.Similarly,the %ID/g and tumor/non-tumor ratio in xenograft-bearing mice was calculated.After injection of 131I-anti-ProGRP（31-98） scFv,treated mice were imaged at 1,24,and 30 hours.Then the tumor/base ratios were calculated.Results ProGRP was highly expressed in NCI-H446 cells and xenograft tissue.The metabolism of 131I-anti-ProGRP（31-98） scFv in healthy mice was consistent with a first-order and two-compartment model; T1/2α and T1/2β were 10.2 minutes and 5 hours 18 minutes,respectively.The %ID/g of 131I-anti-ProGRP（31-98） scFv in xenografts was much higher than in healthy tissues at 12 hours after injection,reaching a maximum of （5.38±0.92） %ID/g at 24 hours.Successful imaging of xenograft tissue was achieved as early as 1 hour post-injection and persisted until 30 hours,with 24 hours proving optimal.Conclusion 131I-anti-ProGRP（31-98）scFv shows highly selective tumor uptake with low accumulation in normal tissues and rapid blood

关 键 词：131I-anti-ProGRP（31-98）scFv ProGRP（31-98） small cell lung cancer BIODISTRIBUTION RADIOIMMUNOIMAGING 

分 类 号：Q78[生物学—分子生物学] S188[农业科学—农业基础科学]