The Experimental Study Of Biodistribution And Radioimmunotheraphy Growth Suppression Eafter On Tumor Tissue Of ～(131)I0-labeled Anti-KDR Monoclonal Antibody In SCID Mice Bearing Human Bladder Cancer

Objective　To study the Biodistribution and growth suppression effect of 131I-labeled anti-KDR monoclonal antibody(3G9) on the tumor tissue in SCID mice bearing Human Bladder cancer.To explore the feasibility of 131I-3G9 to therapy human bladder cancer.Methods　 Ⅰ.T24 cells was cultivated by conventional method and SCID mice model bearing T24 cells derived from human bladder cancer was established. Ⅱ. Anti-KDR McAb(3G9) was used to measure the expression of KDR (kinase insert domain-containing receptor) in T24 cells and tumor tissue by immunofluorescence and immunohistochemistry. Ⅲ. anti-KDR McAb(3G9) was labeled with Na131I using the Iodogen method, and evaluated immune activity of labeled antibody by cell-combine analyzing method. Ⅳ. 131I-3G9 was injected into the mice. Then, assayed the radioactivity T/NT value of the important viscera or tissue and blood after 24,48,96hours.Ⅴ. The mice which 131I-3G9 were injected by caudal vein as the experimental group ,which were injected unlabeled 3G9 as the contrast group and the same volume of saline as the vacuity group.Ⅶ. The growth suppression effect of 131I-3G9 on the tumor tissue in SCIDmice bearing human bladder cancer was observed.Results Ⅰ. All of the 26 SCID mouse were successfully transplanted human bladder cancer;The T24 human bladder cancer cells and tumor xenograft expressed KDR positively.Ⅱ. The specific binding rate of 131I-3G9 to T24 cell in vitro was 61.2%; The biodistribution experiment showed that the time of 131I-3G9 concentrating in the xenograft was about 48h after injected, and the highest radioactive ratio between tumor and various tissues was 8.9. Ⅲ. 3 weeks after 131I-3G9 was injected into the mice by caudal vein, most parts tumor tissue necrosis of human bladder subcutaneous transplantation cancer in SCID mice was observed Contrasting with the vacuity section the growth suppression ratio of the experimental section and the contrast section were 96.5% and 82.5%.Conclusion Ⅰ. We confirmed that T24 human bladder cancer express KDR , and the tumor xenograft has the similar character . Ⅱ. The present study shows that the maintaining immune activity of the 131I-3G9 in vivo is suitable for RII. Ⅲ. The results of the biodistribution experiment shows that the 131I-3G9 can be used as a better radioimmunoguiding agent . The results also laid a foundation for the experimental study of using 131I-3G9 radioimmunotherapy of bladder cancer. Ⅳ. The results of present study shows that 131I-3G9 can be used in anti- angiogenesis therapy for the human cancer.