SA-gal在肿瘤放免治疗中清除作用的实验研究  

The utilization of SA-gal in pretargeting RIT of colon carcinoma xenograft models

作　　者：吴湖炳[1] 黄祖汉[1] 彭武和[1] 高晓[1] GAO Xiao 

机构地区：[1]第一军医大学附属南方医院,广州510515 [2]Nanfang Hospital, First Military Medical University,

出　　处：《核技术》2001年第5期403-407,共5页Nuclear Techniques

摘　　要：研究半乳糖化链霉亲和素 (Streptavidin -gal,SA -gal)和亲和素 (Avidin ,Av)在大肠癌预定位放免显像中对血中标记生物素化单抗的“清除”作用。从荷瘤鼠的尾静脉内注射131I标记的生物素化单抗 ( 131I-bt-McAb)预定位于肿瘤靶位 ,2 4h后 2组实验组分别给予SA -gal和Av ,再过 6h分别行体内分布测定和显像。对照组未给予清除剂。结果表明 ,SA -gal、Av使用后 6h ,血中131I -bt-McAb水平都明显降低 ,肿瘤 血比值明显提高 (对照组、Av清除组、SA -gal清除组的肿瘤 血比值分别为 0 .4 2、2 .0 9、5.2 3,3组之间P <0 .0 5) ;与Av相比 ,SA -gal清除作用更强 ,而且在体内脏器分布上 ,其非特异性摄取也明显地较Av少。实验结果提示 ,SA -gal和Av作为清除剂在肿瘤预定位放免治疗中能有效地加快血中标记单抗的清除 ,使肿瘤靶 非靶比值得以明显地提高 ;两者相比 ,SA -gal优于Av。To investigate the improved clearance effect of avidin(Av) and streptavidin-gal (SA-gal) for blood radiolabeled biotinylated antibody in pretargeting radioimmuno therapy (RIT) of colon carcinoma xenograft models. Biotinylated antibody radiolabeled with 131 I was injected into the nude mice bearing the colon carcinoma via the tail vein. 24h later, in 2 test groups, SA-gal or Av at a 10-fold molar excess of antibody was intraperitoneally injected into the animals whereas no any chase agents were given to the control animals. Animals were killed for biodistribution study at 30h after 131 I-labeled biotinylated antibody administration. Results showed that Av and SA-gal took the effect of chase very fast. At 6h after injection, the blood level of radioactivity decreased very fast. The tumor/blood raios of control group, Av chase group, SA-gal chase group were 0.42, 2.09, 5.23 respectively, P <0.05 and P <0.01 for the latter two groups as compared other control groups. Compared with Av, SA-gal showed better chase effect, its T/B ratios was 5.23, significantly higher than 2.09 of Av ( P <0.01). In the tissue biodistributions, relatively high non-specific radioactivity uptakes in non-liver organs were seen in Av chase group. Utilized in pretargeting RIT, both Av and SA-gal could make the blood level of radioactivity decrease quickly and considerably improves tumor T/NT ratios. The chase effect of SA-gal was superior to that of avidin.

关 键 词：半乳糖化链霉亲和素 亲和素 预定位放射免疫治疗 大肠癌 生物素化单体 清除作用 碘131标记 

分 类 号：R735.34[医药卫生—肿瘤] R730.55[医药卫生—临床医学]