摘要
碳酸酐酶IX(CA IX)在多种实体肿瘤中过表达,而在相应的正常组织中没有表达或表达水平很低,是肿瘤诊断和治疗中的一个潜在靶点。利用99Tcm直接标记抗CA IX单克隆抗体(MAb),在最佳的标记条件下可以得到标记率为85%的目标产物99Tcm-MAb。此标记物在新生牛血清和PBS中稳定性良好。99Tcm-MAb通过尾静脉注入到荷HT-29肿瘤鼠进行显像,注射24 h后在肿瘤处没有看到明显的放射性浓集。注射24 h后的体内分布实验显示99Tcm-MAb在肿瘤内的摄取率较低。将125I-MAb注入到荷HT-29肿瘤鼠进行显像,注射48 h后在肿瘤处可以看到明显的放射性浓集。由于抗体在体内循环代谢速度较慢,而99Tcm的半衰期相对较短,故99Tcm标记抗CA IX单抗不适用于靶向CA IX的肿瘤显像。
CA IX （carbonic anhydrase IX）, which is highly overexpressed in several solid tumors with limited distribution in normal tissues, is a drug target in the diagnosis and treatment of tumors. In this work, anticarbonic anhydrase IX （CA IX） monoclonal antibody （MAb） was labeled with 9^99Tc^m. Under the optimized conditions, the labeling yield and the radiochemical purity of ^99Tc^m-MAb were 85%. ^99Tc^m-MAb was stable in NBCS and PBS. ^99Tc^m-MAb was injected into tail vein of three nude mice bearing HT-29 tumor for planar imaging. The radioactivity was not observed in the tumor 24 h post injection （p.i.）. Biodistribution at 24 h p.i. in the mice showed a little uptake of ^99Tc^m-MAb in tumors. The planar imaging with ^125I-MAb at 48 h p.i. showed high concentration of radioactivity in the tumor. Because of slow metabolic cycle of Ab in the body and the short half-life of ^99Tc^m, ^99Tc^m-MAb is not suitable for tumor imaging for targeting CA IX.
出处
《核技术》
CAS
CSCD
北大核心
2012年第7期535-538,共4页
Nuclear Techniques
基金
国家自然科学基金(No.10875163)资助
