^(131)I标记PDL1抗体在人乳腺癌荷瘤小鼠模型中分子成像的研究  

Molecular imaging of 131I‐labeled PD‐L1 antibody in mice bearing human breast cancer tumor

作　　者：严小平 邵晨旭 年娣 任丽 袁超[3] 李辉[3] 孙俊杰 Yan Xiaoping;Shao Chenxu;Nian Di;Ren Li;Yuan Chao;Li Hui;Sun Junjie(School of Medical Imaging,Bengbu Medical College,Bengbu 233030,China;Laboratory Medical College of Bengbu Medical College,Bengbu 233030,China;Department of Nuclear Medicine,the First Affiliated Hospital of Bengbu Medical College,Bengbu 233004,China)

机构地区：[1]蚌埠医学院医学影像学院,蚌埠233030 [2]蚌埠医学院检验医学院,蚌埠233030 [3]蚌埠医学院第一附属医院核医学科,蚌埠233004

出　　处：《中华解剖与临床杂志》2023年第10期679-685,共7页Chinese Journal of Anatomy and Clinics

基　　金：蚌埠医学院自然科学基金(BYKY18110);蚌埠医学院研究生科研创新项目(Byycx22032);安徽省大学生创新训练项目(S202110367092)。

摘　　要：目的探讨放射性核素^(131)I标记的程序性死亡受体配体1单克隆抗体(PD-L1 McAb)的物理性质及其在人乳腺癌荷瘤小鼠模型中进行分子成像的可行性。方法采用氯胺T法以放射性核素^(131)I标记PD-L1 McAb,采用纸层析法测定^(131)I标记PD-L1 McAb的标记率,并计算放射性比活度;标记产物^(131)I-PD-L1 McAb采用葡聚糖凝胶G-25层析柱分离纯化,采用纸层析法测定^(131)I-PD-L1 McAb的放射性化学纯度,以及^(131)I-PD-L1 McAb在生理盐水和健康成人血浆中的稳定性。培养人乳腺癌PD-L1阳性细胞株MDA-MB-231细胞,随机分为总结合实验(TB)组和非特异性结合实验(NSB)组,每组又分为6个亚组,各亚组在PH 7.4的磷酸盐缓冲液中分别加入不同体积的^(131)I-PD-L1 McAb溶液和PD-L1 McAb溶液,配制总量500μL,使用GC-300型免疫γ-计数器测量各组细胞中^(131)I-PD-L1 McAb的每分钟计数(cpm)值。根据TB组与NSB组各亚组之间cpm值的差值,使用Scatchard作图分析方法计算^(131)I-PD-L1 McAb的平衡解离常数KD值,评估^(131)I-PD-L1 McAb与MDA-MB-231细胞亲和力。取裸鼠3只,于右前肢前臂皮下接种MDA-MB-231细胞悬液制备人乳腺癌荷瘤小鼠模型,观察接种部位成瘤情况并计算肿瘤体积。裸鼠肿瘤接种后第15天按200 MBq/kg尾静脉注射^(131)I-PD-L1 McAb溶液,分别于注射后5 min、30 min、60 min、24 h、48 h、72 h使用小动物活体成像仪进行放射性核素成像检查,观察^(131)I-PD-L1 McAb在荷瘤鼠体内浓聚情况;在小动物活体成像检查图像上选择肿瘤部位、对侧前肢相应部位为感兴趣区,计算相应的放射性计数靶(T)值和放射性计数非靶(NT)值,比较不同时间点肿瘤部位与非肿瘤部位的放射性活度比值(T/NT)的变化情况。结果^(131)I标记PD-L1 McAb的标记率为80.10%~82.20%(81.07%±1.06%),标记产物^(131)I-PD-L1 McAb的放射性比活度为(2.78±0.23)MBq/μg,放射性化学纯度为99.10%~99.60%(99.37%±0.25%)。^(131)I-PD-L1 McAb�Objective This study aims to explore the physical properties of programmed death‐ligand 1(PD‐L1)monoclonal antibody(McAb)labeled with radionuclide ^(131)I and the feasibility of molecular imaging in mice bearing human breast cancer tumor.Methods Radionuclide ^(131)I was labeled with PD‐L1 McAb by chloramine T method.The labeling rate of ^(131)I‐labeled PD‐L1 McAb was determined by paper chromatography,and specific radioactivity was calculated.The labeled product ^(131)I-PD-L1 McAb was separated and purified by dextran gel chromatography 25 column.The radiochemical purity of ^(131)I-PD-L1 McAb and its stability in normal saline and healthy adult plasma were determined by paper chromatography.Human breast cancer PD‐L1‐positive MDA‐MB‐231 cells were randomly divided into total binding test(TB)and non‐specific binding test(NSB)groups.Each group was subdivided into six subgroups.In each subgroup,different volumes of ^(131)I‐PD‐L1 McAb and PD‐L1 McAb solutions were added to phosphate buffer solution with PH 7.4,respectively,with a total of 500μL.The count per minute(cpm)of ^(131)I‐PD‐L1 McAb in cells of each group was measured by GC‐300 immuneγ‐counter.According to the difference in the cpm value between TB and NSB groups,the equilibrium dissociation constant(KD)of ^(131)I-PD-L1 McAb was calculated by Scatchard mapping analysis,and the affinity of ^(131)I‐PD‐L1 McAb with MDA‐MB‐231 cells was evaluated.Three nude mice were subcutaneously inoculated with MDA-MB-231 cell suspension into the forearm of the right forelimb to establish a mouse model of human breast cancer.The tumor formation at the inoculation site was observed,and tumor volume was calculated.On the 15th day after tumor inoculation,nude mice were injected with ^(131)I‐PD‐L1 McAb solution according to 200 MBq/kg tail vein.At 5 min,30 min,60 min,24 h,48 h,and 72 h after injection,the mice were examined by living animal imager to observe the concentration of ^(131)I-PD-L1 McAb.The tumor site and the corresponding

关 键 词：乳腺肿瘤 模型 动物 小鼠 裸 ^(131)碘 程序性死亡受体配体1 分子显像 

分 类 号：R737.9[医药卫生—肿瘤] R-332[医药卫生—临床医学]