Radiopharmacy, KULeuven, Belgium.
Nucl Med Biol. 2011 Apr;38(3):381-92. doi: 10.1016/j.nucmedbio.2010.09.008. Epub 2010 Dec 3.
Two variants of Annexin A5 (Cys2-AnxA5 and Cys165-AnxA5) were labelled with Gallium-68 in order to evaluate their biological properties.
Biodistribution and pharmacokinetics of the radiotracers were studied with μPET in healthy mice and in a mouse model of hepatic apoptosis. μPET imaging after IV injection of the tracers in combination with μMRI was performed in Daudi tumor bearing mice before and after treatment with a combination of chemotherapy and radiotherapy.
The biodistribution data indicated a fast urinary clearance with only minor hepatobilliary clearance, although a high retention in the kidneys was observed. Animals treated with anti-Fas showed a 3 to 8 times higher liver uptake as compared to healthy animals. Tumor uptake of (68)Ga-Cys2-AnxA5 and (68)Ga-Cys165-AnxA5 was low but significantly increased after therapy.
Both (68)Ga-Cys2-AnxA5 and (68)Ga-Cys165-AnxA5 show a clear binding to apoptotic cells and are promising tracers for rapid evaluation of cancer therapy.
用镓-68 对 Annexin A5 的两种变体（Cys2-AnxA5 和 Cys165-AnxA5）进行标记，以评估它们的生物学特性。
通过 μPET 在健康小鼠和肝细胞凋亡模型中研究了放射性示踪剂的生物分布和药代动力学。在接受化疗和放疗联合治疗前后，用携带 Daudi 肿瘤的小鼠进行了 μPET 成像与 μMRI 相结合的静脉注射示踪剂的实验。
生物分布数据表明，放射性示踪剂具有快速的尿液清除率，只有少量的肝胆清除率，但肾脏的清除率很高。与健康动物相比，用抗 Fas 处理的动物的肝脏摄取率高 3 到 8 倍。（68）Ga-Cys2-AnxA5 和（68）Ga-Cys165-AnxA5 的肿瘤摄取量较低，但治疗后明显增加。
（68）Ga-Cys2-AnxA5 和（68）Ga-Cys165-AnxA5 均与凋亡细胞有明显的结合，是快速评估癌症治疗的有前途的示踪剂。
