肿瘤相关巨噬细胞MR成像可行性的实验研究  

Experimental study on the feasibility of MR imaging for tumor-associated macrophages

作　　者：王进华[1] 龚洪翰[1] 

机构地区：[1]南昌大学第一附属医院放射科,330006

出　　处：《中华放射学杂志》2010年第7期753-759,共7页Chinese Journal of Radiology

基　　金：志谢 国家留学基金委及斯坦福大学分子影像中心ShawnChen教授,博士后谢晋及刘刚对本实验的指导和帮助

摘　　要：目的 探讨肿瘤相关巨噬细胞（TAMs）MR成像的可行性。方法BALB／c小鼠和BALB／c（nu／nu）裸鼠按数字表法随机分组，每组3只，小鼠分为6个组（分别为注射前组，注射后6、24、48、72h、7d组）和裸鼠5个组（分别为注射前，注射后6、24、48、72h）。用含20μgFe／ml人血清白蛋白和多巴胺包裹的铁氧颗粒（HSA-IONPs）标记巨噬细胞系（RAW264．7）24h，收集细胞，经尾静脉注射5×10^6RAW264．7至皮下4T1荷瘤小鼠和22B移植瘤裸鼠，分别在上述不同时间点应用7．0TMR扫描仪行横断面、冠状面T2WI，动物处死后行病理检查。细胞毒性试验应用SPSS11．5软件行单因素方差分析；MRI信号强度采用ImageJ1．42软件测量。结果普鲁士蓝染色及电镜证实细胞标记有效，单个细胞吸入的铁量为6．19pg。HSA—IONPs孵育细胞24h后，不同浓度HSA-IONPs（5、10、20、40、80、160μg／ml）每组细胞平均吸光度A值分别为1．95±0．19、1．82±0．29、2．10±0．14、1．96±0．18、2．05±0．27、2．17±0．22，与对照组（2．00±0．07）相比，细胞吸光度A值差异无统计学意义（F=1．24，P〉0．05）。标记HSA-IONPs细胞数与MRR，值呈线性正相关，r=0．99，P〈0．05。4T1肿瘤：注射后6hT2WI坏死囊变周围呈明显低信号，信号强度下降率为59．4％，肿瘤实质区信号未见明显改变，下降率为4．8％。注射后24h坏死与肿瘤实质交界部位见不规则环形低信号影，下降率为46．8％，肿瘤坏死囊变周围T2WI信号恢复，恢复96．8％。22B肿瘤：注射后6hMRI见多发散在灶性低信号影，下降率为64．3％，24h见点片状低信号影缩小。2种肿瘤注射后48、72h或7dMRT2WI形态、位置和注射后24h相似，但信号强度递减。病理与影像结果一致。结论TAMsMR成像可行。注射后24hT2WI是显示肿瘤巨噬细胞迁移、浸润及定位肿瘤内的最佳时机，注射后6h可能反映病变局部�Objective To explore the feasibility of MR imaging for tumor-associated macrophages. Methods BALB/c mice and BALB/c （nu/nu） nude mice were randomly divided into 6 groups （before injection, 6, 24, 48, 72 hours and 7 days after injection） and 5 groups （before injection, 6, 24, 48 and 72 hours after injection） with each group of 3 animals, respectively. Macrophages （ RAW 264.7 ） were incubated with HSA-IONPs （dopamine/HSA coating iron oxide nanoparticle） containing 20μg Fe/ml for 24 hours. Then, 5 × 10^6 labeled macrophages were collected and injected into subcutaneous 4T1 tumorbearing BALB/c mice and 22B tumor-bearing nude mice via tail vein. At different time points described above, all animals performed transverse and coronal T2-weighted MR scans using a 7.0 T MR imaging unit. After sacrifice at different time points, tumor, liver and other organs were removed and processed for histological examination. Cytotoxicity of HSA-IONPs were assayed by MTT test, Statistics analysis adopt SPSS 11.5, the differences among groups were analyzed by one-way ANOVA. The difference was regarded as statistically significant when P 〈 0. 05. Image J 1.42 software was used for the quantitative measurement of MR signal intensity. Results Effective cell labeling was confirmed by Prussian blue staining and transmission electron microscopy （TEM）. Iron uptake of single cell was 6. 19 pg. The mean absorbance values of cells incubated with HSA-IONPs for 24 hours in each group were 1.95 ± 0. 19, 1.82 ±0. 29, 2. 10 ± 0. 14, 1.96 ±0. 18, 2.05 ± 0.27 and 2. 17 ± 0. 22 respectively at different concentrations （5, 10, 20, 40, 80, 160 μg/ml）. Compared with that in control group（2. 00 ± 0. 07）, the absorbance values of cells in each group were not significantly different （ F = 1.24, P 〉 0. 05 ）. There was a significant linear positive correlation between the labelled macrophage numbers and MR R2 values （ r = 0.99, P 〈 0. 05）. In 4T1 tumor model, significant low signal intensity was found on T2

关 键 词：巨噬细胞 肿瘤 磁共振成像 

分 类 号：R445.2[医药卫生—影像医学与核医学]