^99Tc^m-SHNH-AC133的制备及对荷结肠癌裸鼠的显像  

Preparation of 99Tcm-SHNH-AC133 and imaging on colon cancer bearing mice

作　　者：刘玉[1,2] 金雪艳[2] 兰晓莉 郎军涛[2] 文琼 安锐 

机构地区：[1]安徽省立医院放射科,合肥230001 [2]华中科技大学同济医学院附属协和医院核医学科、湖北省分子影像重点实验室,武汉430022

出　　处：《中华核医学与分子影像杂志》2018年第1期42-45,共4页Chinese Journal of Nuclear Medicine and Molecular Imaging

基　　金：国家自然科学基金（81371599）

摘　　要：目的制备99Tcm-6-肼基烟酸琥珀酰亚胺酯盐酸盐（SHNH）-AC133，通过γ显像研究其靶向CD133阳性结肠癌的能力，探讨其作为肿瘤干细胞（CSCs）靶向分子探针的可行性。方法采用免疫荧光法及流式细胞术检测人结肠癌Lovo细胞及肿瘤组织CD133的表达。以SHNH为双功能螯合剂，对CD133的特异性单克隆抗体AC133进行99Tcm标记，合成99Tcm -SHNH-AC133，检测其标记率及放化纯。建立荷结肠癌裸鼠模型，进行γ显像，利用感兴趣区技术获得肿瘤与对侧肌肉组织的肿瘤/正常组织放射性（T/NT）比值。注射标记物前，经荷瘤鼠尾静脉注射过量未标记的AC133进行阻断实验。采用两样本t检验分析数据。结果免疫荧光检测结果显示，CD133表达于Lovo细胞表面。流式细胞检测结果显示，Lovo结肠癌组织中CD133阳性细胞的占比为（29.5±3.4）%。99Tcm -SHNH-AC133标记率〉85%，放化纯为（97.7±2.4）%。γ显像示，99Tcm -SHNH-AC133对Lovo肿瘤有较好的靶向性，12 h后瘤体逐渐显影，24 h肿瘤部位放射性浓聚较明显，其T/NT比值为8.16±0.45。阻断实验中，肿瘤部位放射性摄取明显减少（3.52±0.13；t＝19.8，P〈0.05）。结论99Tcm -SHNH-AC133具有较高的标记率及放化纯，该标记物对CD133阳性结肠癌具有较强的靶向能力，有望用于CSCs的体内示踪。ObjectiveTo prepare 99Tcm-succinimidyl-6-hydrazinonicotinate hydrochloride （SHNH）-AC133 and evaluate its targeting ability on CD133 positive colon cancer by Gamma imaging, and to explore its feasibility as a molecular probe for cancer stem cells （CSCs）.MethodsCD133 expression was detected by immunofluorescence assay and flow cytometry on Lovo cell lines and tumor xenografts. CD133 specific monoclonal antibody （AC133） was conjugated with SHNH, and then labeled with 99Tcm to prepare 99Tcm-SHNH-AC133. The radiolabeled yield and radiochemical purity were investigated. Colon cancer xenografts were developed and Gamma imaging were performed. Region of interest （ROI） was drawn and the tumor/non-tumor （T/NT） ratio was calculated. For the blocking experiment, animals were pre-injected with excess unlabeled AC133. Two-sample t test was used to analyze the data.ResultsCD133 was expressed on the surface of Lovo cells. And the percentage of CD133 positive cells in Lovo tumor tissues was （29.5±3.4）%. The radiolabeled yield of 99Tcm-SHNH-AC133 was more than 85% and radiochemistry purity was （97.7±2.4）%. Gamma imaging demonstrated that 99Tcm-SHNH-AC133 could specifically target to Lovo tumors which could be gradually visible after 12 h. The tumor uptake was obvious at 24 h and T/NT ratio was 8.16±0.45. In blocking study, the tumor uptake was significantly reduced by pre-injection of excess unlabeled AC133 （3.52±0.13; t=19.8, P〈0.05）.Conclusions99Tcm-SHNH-AC133 has high labeling yield and radiochemistry purity. The excellent targeting properties of 99Tcm-SHNH-AC133 on CD133 positive colon cancer demonstrate that it is a promising imaging agent for CSCs tracking in vivo.

关 键 词：抗体 单克隆 琥珀酰亚胺类 锝 同位素标记 结肠肿瘤 放射性核素显像 小鼠 裸 

分 类 号：R730.44[医药卫生—肿瘤] R735.35[医药卫生—临床医学]