MicroRNA-155靶向的放射性标记探针对乳腺癌小鼠模型的活体显像  

In vivo imaging of breast tumors by a ^(99m)Tc radiolabeled probe targeting microRNA-155 in mice models

作　　者：康磊[1] 霍焱[1] 王荣福[1] 张春丽[1] 闫平[1] 徐小洁[2] KANG Lei;HUO Yan;WANG Rong-fu;ZHANG Chun-li;YAN Ping;XU Xiao-jie(Department of Nuclear Medicine,Peking University First Hospital,Beijing 100034,China;Department of Medical Molecular Biology,Beijing Institute of Biotechnology,Academy of Military Medical Sciences,Beijing 100850,China)

机构地区：[1]北京大学第一医院核医学科,北京100034 [2]军事医学科学院生物工程研究所,北京100850

出　　处：《北京大学学报（医学版）》2018年第2期326-330,共5页Journal of Peking University:Health Sciences

基　　金：国家自然科学基金(81101065;81071183);高等学校博士学科点新教师专项科研基金(20110001120043);首都临床特色应用研究(Z141107002514159)资助~~

摘　　要：目的:microRNA-155(miR-155)显著高表达于乳腺癌、肺癌、肝癌等多种恶性肿瘤,本研究旨在构建靶向miR-155的放射性示踪探针对乳腺肿瘤的活体显像。方法:体外化学合成靶向miR-155的反义互补寡核苷酸探针(AMO-155),并对其进行5'端乙酰基修饰及2'-甲氧基修饰,进而与双功能螯合剂NHS-MAG3偶联后,在氯化亚锡的还原作用下对其标记99mTc,评价血清稳定性,并对乳腺癌荷瘤裸鼠进行活体显像,对比反义、无义及阻断组的显像差异,并通过实时定量PCR(quantitative real-time PCR,qRT-PCR)鉴定肿瘤的miR-155水平。结果:99mTc-AMO-155的制备标记率达97%(n=5),放射化学纯度大于98%(n=5),放射比活度约为3.75 GBq/μg。通过对比无义对照组及阻断组,^(99m)Tc-AMO-155能够在活体水平特异性地显示miR-155高表达的恶性肿瘤。此外,针对miR-155不同表达水平的肿瘤,^(99m)Tc-AMO-155亦可在活体水平反映其表达差异。结论:经化学修饰的~)99m_Tc标记的AMO-155探针具有良好的血清稳定性及活体肿瘤靶向识别作用,为肿瘤显像提供了潜在的新型探针。Objective:MicroRNA-155(miR-155)is significantly highly expressed in breast cancer,lung cancer,liver cancer and other malignant tumors.This study was to design and construct a radiolabeled probe targeting miR-155 for in vivo imaging in breast cancer.Methods:Anti-miR-155 oligonucleotide(AMO-155)was chemically synthesized with 2'-OMe modification.Its 5'end was linked with acetyl amine group.After chelated with a bifunctional chelator NHS-MAG3,AMO-155 was radiolabeled with 99mTc using stannous chloride.The serum stability was evaluated at cellular level.In vivo imaging was performed in MCF-7 tumor bearing mice after the administration of 99mTc radiolabeled AMO-155 and scramble control probes,respectively.Furthermore,the blocked imaging of tumor bearing mice was obtained after the injection of unlabeled AMO-155 2 hours ahead.MCF-7 and MDA-MB-231 tumor bearing mice with different expression level of miR-155 were imaged,respectively.Quantitative real-time PCR(qRT-PCR)was used to identify the expression level of miR-155 in the bearing tumors.Results:99mTc-AMO-155 was prepared with high radiolabeled efficiency(97%),radiochemical purity(greater than 98%),and radioactive specific activity(3.75 GBq/μg).99mTc-AMO-155 was stable in fresh human serum for 12 hours.After the administration via tail vein,99mTc-AMO-155 displayed significant accumulation in MCF-7 bearing tumors with high expression level of miR-155,whereas 99mTc-control showed little accumulation.After blocked with unlabeled AMO-155,the tumor could not be visualized clearly after the administration of 99mTc-AMO-155.Furthermore,99mTc-AMO-155 could show the differential expression of miR-155 in vivo.MCF-7 tumor was shown with significantly higher radioactive accumulation than MDAMB-231,based on its higher expression level of miR-155,which was verified by qRT-PCR.Conclusion:99mTc-labeled AMO-155 with chemical modification showed good serum stability and in vivo tumor targeting ability.This study provides a potential probe for in vivo imaging of breast cancer.

关 键 词：微RNAS 锝 乳腺肿瘤 寡核苷酸探针 放射性核素显像 小鼠 裸 

分 类 号：R817.4[医药卫生—影像医学与核医学]