~(99m)Tc-转铁蛋白在乳腺癌裸鼠的放射性核素显像研究

目的:探讨99mTc-转铁蛋白(Tf)诊断乳腺癌的价值。方法:以99mTc标记转铁蛋白,测定人乳腺癌MCF7细胞膜转铁蛋白受体数及99mTc-Tf与转铁蛋白受体结合的解离常数(Kd)。对人乳腺癌细胞系MCF7裸鼠进行显像研究,获取肿瘤与肌肉、肿瘤与血的单位像素放射性比值。观察99mTc-Tf在BALB/c小鼠体内生物分布。结果:人乳腺癌MCF7细胞膜转铁蛋白受体数为1.95×105/cell,Kd为4.13 nmol/L。人乳腺癌MCF7裸鼠注入99mTc-Tf后12 h,肿瘤/肌肉及肿瘤/血比值分别为4.42±0.46和3.06±0.579。9mTc-Tf主要分布于肝、血及肾脏。结论:99mTc-Tf制备简便,在高表达转铁蛋白受体的肿瘤病变部位聚积。99mTc-Tf为乳腺癌的诊断提供了一种可能的新方法。

Radionuclide Imaging of Breast Carcinoma in nude mice with 99mTc-transferrin

Objective To evaluate the advantages of ~(99m)Tc-transferrin as a tracer in nude mice bearing breast MCF7 tumor.Methods Transferrin was modified with 2-iminotholane and labeled with ~(99m)Tc.The numbers of receptor and the K_d were measured with the receptor radioligand binding assay and Scatchard analysis.Imagings with ~(99m)Tc-Tf at different time were performed in nude mice bearing human breast carcinoma MCF7 xenografts,and the tissue distribution of ~(99m)Tc-Tf in BALB/c mice were carried out as well.Results The numbers of receptor per cell were 1.95×10~5 and the K_d was 4.13 nmol/L.Tumor lesions were clearly visible 12 hours post injection and the ratios of tumor to muscle and tumor to blood were 4.42±0.46 and 3.06±0.57,respectively.The tissue distribution in BALB/c mice showed that ~(99m)Tc-Tf was mainly distributed in liver,blood,and kidneys.Conclusions All these results indicate that the labelling procedure of ~(99m)Tc-Tf is simple and ~(99m)TcTf specifically localizes in tumor lesions of nude mice.It is a promising method of ~(99m)Tc-Tf to detect breast carcinoma.