^131I标记抗神经纤毛蛋白－2单克隆抗体在荷肺腺癌裸鼠中的生物分布及显像  

Imaging and biodistribution of 131I labeled anti-neuropilin-2 monoclonal antibody in lung adenocarcinoma-bearing mice

作　　者：陈丽春[1] 王亮亮 苏新辉[1] 颜江华[2] 马超[1] 陈国强[1] 陈盛优 

机构地区：[1]厦门大学附属中山医院核医学科,361004 [2]厦门大学医学院抗癌中心,361102

出　　处：《中华核医学与分子影像杂志》2018年第1期37-41,共5页Chinese Journal of Nuclear Medicine and Molecular Imaging

摘　　要：目的制备131I标记的抗神经纤毛蛋白（NPR）－2单克隆抗体（mAb）（131I－anti－NRP－2－mAb），在体内外观察其与NRP－2表达阳性肿瘤的结合特性，以探讨其应用于NRP－2表达阳性肿瘤显像的可能性。方法（1）采用氯胺T法制备131I－anti－NRP－2－mAb，经Sephadex G25柱纯化，用薄层色谱法测定放化纯和稳定性。（2）利用A549细胞进行体外实验，测定131I－anti－NRP－2－mAb的结合率和受体的亲和力。（3）将A549荷瘤裸鼠以随机抽样法随机分为4组，每组4只，分别于尾静脉注射0.37 MBq 131I－anti－NRP－2－mAb，6、24、48和72 h后，测定并计算主要器官及组织的放射性摄取值[每克组织百分注射剂量率（%ID/g）]、肿瘤/肌肉放射性（T/M）比值和肿瘤/血液放射性（T/B）比值。（4）将A549荷瘤裸鼠以随机抽样法分为未阻断组和竞争性阻断组，每组3只，未阻断组经尾静脉注射3.7 MBq 131I－anti－NRP－2－mAb，竞争性阻断组经尾静脉注射同等剂量的标记物和100 μg未标记的抗NRP－2 mAb，均分别于注射后6、24、48和72 h行γ显像，观察肿瘤放射性浓聚状况。采用两样本t检验分析数据。结果（1）131I－anti－NRP－2－mAb标记率为（94.69±3.63）%，放化纯为（98.56±0.48）%；室温下磷酸盐缓冲液中放置72 h，其标记率仍〉85%。（2）131I－anti－NRP－2－mAb与A549细胞特异性结合率，在60、120、180和240 min时分别为（3.95±0.18）%、（5.19±0.65）%、（6.60±0.36）%和（5.58±0.63）%；加入过量未标记的anti－NRP－2－mAb后，下降至（0.94±0.31）%、（1.12±0.17）%、（1.24±0.25）%和（1.04±0.18）%，阻断组与未阻断组4个时间点细胞结合率间的差异具有统计学意义（t值：11.22、9.89、19.66和9.95，均P〈0.05）；与A549细胞表面受体结合的半抑制浓度（IC50）值为（410.8±1.2） nmol/L。（3）注射131I－anti－NRP－2－mAb后，T/B比值和T/M比值�ObjectiveTo prepare 131I-anti-neuropilin-2-monoclonal antibody （131I-anti-NRP-2-mAb）, and investigate its biodistribution and imaging in nude mice bearing xenografted lung adenocarcinoma, in order to evaluate its feasibility as an imaging agent targeting to NRP-2 positive tumors.Methods（1） 131I-anti-NRP-2-mAb was prepared by Chloramine-T method under the optimum labeling conditions, then the labeling efficiency, radiochemical purity and stability were determined in vitro. （2） The binding fraction and receptor binding affinity of 131I-anti-NRP-2-mAb were measured in A549 human lung cancer cells by cell uptaking and binding experiments. （3） The A549 tumor-bearing mice were randomly divided into 4 groups with direct sampling method and were sacrificed at 6, 24, 48, and 72 h, respectively, after tail intravenous injection of 0.37 MBq 131I-anti-NRP-2-mAb. The distribution was measured, and the ratios of tumor/muscle （T/M） and tumor/blood （T/B） were calculated. （4） Gamma imaging was performed in 6 mice, including 3 in the competitive inhibition control group （injected with 3.7 MBq 131I-anti-NRP-2-mAb and 100 μg atni-NRP-2-mAb）, at 6, 24, 48, and 72 h post-injection to observe the radioactivity in tumor. Two-sample t test was used for data analysis.Results（1） The labeling yield and radiochemical purity of 131I-anti-NRP-2-mAb were （94.69±3.63）% and （98.56±0.48）%, respectively. The radiochemical purity was more than 85% after incubating in phosphate-buffered solution at room temperature for 72 h. （2） At 60, 120, 180 and 240 min post-injection, the binding ratios of 131I-anti-NRP-2-mAb in A549 cells were （3.95±0.18）%, （5.19±0.65）%, （6.60±0.36）% and （5.58±0.63）%, respectively. When excessive anti-NRP-2-mAb were added, the binding ratios were reduced to （0.94±0.31）%, （1.12±0.17）%, （1.24±0.25）% and （1.04±0.18）%, respectively, which were significantly lower than those of non-inhibited group （t values： 9.89-19.66, all P〈0.05）. 131

关 键 词：神经纤毛蛋白质2 抗体 单克隆 同位素标记 碘放射性同位素 放射性核素显像 肺肿瘤 小鼠 裸 

分 类 号：R730.44[医药卫生—肿瘤] R734.2[医药卫生—临床医学]