论文部分内容阅读
目的 探讨1 5 3Sm标记亲和素 生物素系统 (ABS)在荷人结肠癌裸鼠模型中进行抗CEA单克隆抗体 (McAb)预定位放免显像的可行性。方法 首先用1 5 3Sm标记螯合DTPA生物素 (DB2 ) ,然后利用生物素与亲和素 (AV)的高亲和力特性 ,对链霉亲和素 (SA)进行1 5 3 Sm标记 ,通过DTPA环酐法将1 5 3Sm标记到抗CEAMcAb上。应用三步法方法A(生物素化CEAMcAb AV 1 5 3 Sm标记DB2 )和方法B(链霉亲和素化CEAMcAb 生物素 1 5 3Sm标记SA)以及二步法方法A(生物素化CEAMcAb 1 5 3Sm标记SA)和方法B(链霉亲和素化CEAMcAb 1 5 3Sm标记DB2 )预定位于荷人结肠癌裸鼠 ,分别于注射放射性标记物后 4～ 72h进行γ显像和体内分布测定。以1 5 3 Sm CEAMcAb、1 5 3Sm SA、1 5 3Sm DB2 和生物素化正常鼠IgG AV 1 5 3 Sm标记DB2 作为对照组。结果 三步法 :方法A在标记物引入后 4h肿瘤即显影 ,其肿瘤 %ID g在 4和 2 4h分别为 1 78和 1 36 ,而血T NT分别为 5 76和 12 94,血T NT均显著高于各对照组 ;方法B肿瘤部位未见明显放射性摄取 ,其肿瘤 %ID g和血T NT与1 5 3 Sm SA对照组相近。二步法 :方法A在标记物引入 2 4h肿瘤即有放射性聚集 ,血T NT为 2 0 3,肿瘤的 %ID g为 2 10 ,且随预定位时间增加未见明显降低 ;方法B肿瘤部位未见放射性摄取
Objective To investigate the feasibility of anti-CEA monoclonal antibody (McAb) pre-location radioimmunoimaging in human colon cancer nude mice model with 153Sm labeled avidin biotin system (ABS). METHODS: The chelated DTPA biotin was first labeled with 153Sm, and then the streptavidin (SA) was labeled with 1 5 3 Sm through the high affinity of biotin and avidin (AV) The cyclic anhydride method labeled 153Sm against anti-CEAMcAb. Three-step method A (biotinylated CEAMcAb AV 1 5 3 Sm labeled DB2) and method B (streptavidin-CEAMcAb biotin 153Sm-labeled SA) as well as two-step method A (biotinylated CEAMcAb 1 5 3Sm-labeled SA) and method B (streptavidin-immobilized CEAMcAb 1 5 3Sm-labeled DB2) were pre-located in nude mice bearing human colon cancer and were respectively subjected to γ imaging and in vivo distribution measurement 4 to 72 hours after radiolabeling. DB2 was used as a control group with 1 5 3 Sm CEAMcAb, 1 5 3Sm SA, 1 5 3Sm DB2 and biotinylated normal murine IgG AV 1 5 3 Sm. Results Three-step method: Method A developed a tumor 4 h after the introduction of the marker with a tumor% ID g of 1 78 and 1 36 at 4 and 24 h, respectively, and blood T NT of 5 76 and 12 94, respectively, and blood T NT Were significantly higher than that of the control group. There was no obvious radioactive uptake in the tumor of method B. The% ID g of tumor and T NT of blood were similar to the control group of 153 Sm SA. Two-step method: method A 24 h tumor in the marker that is radioactive aggregation, blood T NT was 20 3, the tumor% ID g 2 10, and with the pre-positioning time increased no significant reduction; Method B tumor site No radioactive ingestion