The experimental study of ^131I labeling prostate stem cell antigen monoclonal antibody in the treat-ment of nude mice bearing orthotopic implantation of prostate carcinomar

Abstract

Objective To study the distribution, radioimmunoimaging and anti-tumor effect of ^131I labeling prostate stem cell antigen monoclonal antibody （^131I-PSCA-McAb） in nude mice bearing orthotopic implantation of prostate carcinoma. Methods Thirty-six male nude mice were randomly divided into 2 groups： LNCap cell group （androgen dependent prostate cancer） and PC3 cell group （androgen independent prostate cancer）. Each group were then subdivided into 3 subgroups： experimental group （were intrave noused 1311-PSCA-McAb 200 μg）, monoclonal control group （were intravenoused PSCA-McAb 200 μg）, iodic control group （ were intravenoused 1311 200 μg）. Continuous images of nude mice bearing LNCap cell and PC3 cell were carried out respectively at 1, 4, 8, 12 and 24 h after drugs injection. Transplantation tumor images were then observed and the radioactivity ratio of tumor/non-tumor （T/NT） was calculated. 48 h later, nude mice were sacrificed and the apoptosis of tumor tissues were measured by TdT-mediated dUTP nick end labeling （TUNEL）. Results The models of nude mice bearing orthotopic implantation of prostate carcinoma were successfully established. The peak uptake of ^131I_PSCA.McAb in orthotopic tumor of prostate carcinoma was at 8h after injection with a T/NT ratio of 4.37 ± 0. 76 （LNCap cell group） and 4. 21±0. 71 （PC3 cell group） respectively. The number of TUNEL positive cells in experimental group was larger than that of the two other control groups. Conclusion ^131 I-PSCA-McAb could effectively target PSCA and inhibit the growth of tumor, therefore was a promising radioimmunotherapy radiophamaceutical for prostate carcinoma. Key words: Models of orthotopic implantation of prostate cancer; ^131I labeling prostate stem cellantigen monoclonal antibody; Cell apoptosis; Radioimmunotherapy