Therapy to target renal cell carcinoma using (131)I-labeled B7-H3 monoclonal antibody

B7-H3 is a tumor-associated antigen that plays a critical role in potential tumor-targeted therapy. In this study, we aimed to assess the radiobiological effect of (131)I-labeled B7-H3 monoclonal antibody ((131)I-4H7) in nude mice with human renal cell carcinoma (RCC) and evaluate the effect of (131)I-4H7 on RCC treatment. The radiobiological activity and tumor uptake of (131)I-4H7, and its effect on tumor growth were measured. (131)I-4H7 was absorbed by the tumor and reached its maximal uptake rate (3.32% injected dose [ID]/g) at 24 h, at which point the drug concentration in the tumor was 7.36-, 2.06-, 1.80-, and 2.78-fold higher than that in muscle, kidneys, liver, and heart, respectively. Measurements and positron emission tomography–computed tomography imaging showed that tumor development was significantly inhibited by (131)I-4H7. HE staining revealed that (131)I-4H7 significantly injures tumor cells. Our results suggest that (131)I-4H7 is markedly absorbed by the tumor and did suppress the development of RCC xenografted tumors in nude mice, which might provide a new candidate for antibody-mediated targeted radiotherapy in human RCC.