采用靶向人表皮生长因子受体2分子探针行体外乳腺癌细胞株 MRI 的可行性  

Preparation of MRI molecular probe targeting human epidermal growth factor receptor 2 and the ;preliminary study of breast cancer cell in vitro

作　　者：朱媛[1] 王瑞峰[1] 尚进[1] 邓蕾[1] 于楠[1] 樊钢练[2] 郭佑民[1] 段小艺[1] 

机构地区：[1]西安交通大学医学院第一附属医院PETCT室710061 [2]西安交通大学医学院第一附属医院影像科,710061

出　　处：《中华放射学杂志》2014年第5期358-362,共5页Chinese Journal of Radiology

基　　金：国家自然科学基金面上资助项目（81171397）

摘　　要：目的探讨特异靶向人表皮生长因子受体2（ HER2）七肽分子LTVSPYW偶联超顺磁性氧化铁（ SPIO）纳米颗粒分子探针的构建方法及其表征，以及对体外乳腺癌细胞行靶向MR成像的可行性。方法（1）通过共沉淀法合成表面包被聚乳酸的 SPIO （ PS ）；将 PS 与异硫氰酸荧光素（FITC）标记的七肽分子LTVSPWY（FITC-LTVSPWY）偶联构建分子靶向探针（FITC-LTVSPWY-PS），用透射电子显微镜分别测量PS和FITC-LTVSPWY-PS粒径大小，动态光散射仪检测其粒径分布及表面电位，3.0 T MRI检测弛豫率。（2）制备高表达HER2的人乳腺癌细胞株MCF-7爬片，与FITC-LTVSPWY-PS进行孵育，荧光显微镜观察细胞与探针的结合情况，并行普鲁士蓝染色验证。（3）将合成的2种探针分别与HER2高表达的MCF-7细胞及HER2阴性的MDA-MB-231细胞孵育，消化离心后置入1.5 ml Eppendorf管。 FITC-LTVSPWY-PS与MCF-7孵育作为实验组，PS与MCF-7孵育作为对照组，不添加探针的MCF-7细胞为空白组，每种处理设立3管，采用3.0 T MR扫描1次，采集T2 WI序列图像，观察各组细胞MR信号并测出T2信号值，检测分子探针的靶向增强作用。各组间T2信号值的比较采用单因素方差分析法。结果分子靶向探针构建成功，电子透射显微镜测得PS纳米粒子的核心粒径大小为（13.9±1.6） nm，动态光散射仪测得PS的表面粒径为（122.0±5.5） nm。 FITC-LTVSPWY-PS探针的表面电位与弛豫率分别为（-30.7±2.2） mV和70.7 m· M-1· s-1，PS的表面电位与弛豫率分别为（28.1±2.8） mV和72.1 m· M-1· s-1。25μg/ml FITC-LTVSPWY-PS与MCF-7细胞孵育1 h后体外细胞MRI显示，实验组呈短T2低信号，对照组与空白细胞组呈等信号。实验组、对照组和空白组T2信号值分别为（61.8±5.7）、（101.6±2.5）和（103.5±1.9）ms，差异有统计学意义（ F＝355.698，P＜0.05）。结论针对HER2与聚乳酸修饰的SPIO耦联后获得的MR�Objective To develop a superparamagnetic iron oxide nanoparticles （ SPIO ） based on MRI probe specifically targeting human epidermal growth factor receptor 2 （HER2） and explore its value as MRI positive contrast agents in vitro.Methods （1） The superparamagnetic iron oxide （ PS） was obtained by means of classical coprecipitation in polylactic acid solution , then coupled with fluorescein isothiocyanate （FITC） labeled LTVSPYW to develop the targeted probe （ FITC-LTVSPWY-PS）.The particle size was measured under transmission electron microscope.Relaxation rate was detected by 3.0 T MR scanner.（2） Climbing films of human breast cancer cell MCF-7 were prepared and incubated with FITC-LTVSPWY-SPIO, then fluorescence distribution was observed under inverted microscope.And distribution of iron particles was confirmed by prussian blue staining.（3） MCF-7 and MDA-MB-231 cells were incubated with＆amp;nbsp;FITC-LTVSPWY-SPIO and PS, respectively.MCF-7 incubated with FITC-LTVSPWY-PS were used as experimental group, MCF-7 treated with PS as control group , and cells added with nothing as blank group.There were 3 samples in each group.The MR imaging was performed only once and T 2 WI signal intensity of cells was recorded.The comparison of T 2 signal intensity among groups was conducted by using one-way ANOVA.Results The core and surface size of nanoparticles were （13.9 ±1.6） nm and （122.0 ±5.5） nm respectively.Zeta potential and relaxation rate of the FITC-LTVSPWY-PS were （ -30.7 ±2.2 ） mV and 70.7 m· M-1 · s-1 respectively, and the PS were （28.1 ±2.8） mV and 72.1 m· M-1 · s-1 respectively.The fluorescence could be seen on the surface of MCF-7 cells, and the prussian blue staining showed that FITC-LTVSPWY-PS could specifically target HER 2-positive cells.The low signal on T 2 WI was observed in MCF-7 cells incubated with FITC-LTVSPWY-PS, whereas cells treated with PS and blank group showed equal signals , the T2 values were （ 61.8 ±5.7 ） , （ 101.6 ±2.5 ） and （

关 键 词：乳腺肿瘤 分子探针 磁共振成像 

分 类 号：R737.9[医药卫生—肿瘤] R730.44[医药卫生—临床医学]