乳腺癌单链抗体制备及其在荷人乳腺癌裸鼠中的放免显像

Radioimmunoimaging in Human Breast Cancer Xenografted Nude Mice with Single Chain Antibody against Breast Cancer

目的:制备抗乳腺癌单链抗体,用于荷瘤裸鼠的放免显像研究。方法:提取乳腺癌膜抗原,制备抗乳腺癌单克隆抗体M4G3,用Pharmacia噬菌体单链抗体制备系统得到可溶性具有抗乳腺癌活性的ScFv抗体,利用环DTPA法标记核素99mTc,进行体外培养的乳腺癌细胞系MCF-7和荷瘤小鼠体内定位显像。结果:免疫组化显示单链抗体与乳腺癌膜抗原有较强的亲和力,并在体外培养的乳腺癌细胞及荷瘤小鼠体内显像成功,且在抗体注射第3～5天显像最清晰。结论:提示M4G3的ScFv可在乳腺癌的放射免疫显像和定位诊断研究中发挥作用,值得进一步研究。

Objective:The single chain antibody against breast cancer was prepared and radioimmunoimaging(RII)was studied in nude mice bearing human breast cancer using the antibody.Methods:The antigen was extracted from the breast cancer cell membrane for preparing the monoclonal antibody M4G3against breast cancer.On the basis of M4G3,the active ScFv antibody against breast cancer was prepared by the single chain antibody preparing system of phage of Pharmacia.The ScFv was labeled by 99m Tc with cycle DTPA method and radioimmunoimaging was performed in MCF-7and human breast cancer xenografted nude mice.Re sults:Immunohistochemistry study showed that the antibody had high specificity for breast cancer.RII study showed that radioimmunoimaging succeeded in cell line MCF-7and bearing tumor nude mice.The xenografted tumor was demonstrated clearly on the3rd and5th day after injection of antibody.Conclusion:Our results indicate that the antibody might be useful in the study of breast cancer and is worthful for further investigation.