Abstract: Objective To study the inhibitory effect of CD133 monoclonal antibody labeled with 131I (131I-CD133mAb) on Huh-7
human liver cancer cell line overexpressing CD133 antigen in vitro and in mouse models bearing the tumor cell xenograft.
Methods 131I-CD133mAb was prepared by chloramines-T method and evaluated for its stability. Flow cytometry and
immunohistochemistry were used to detect the expression of CD133 in Huh-7 cells and in Huh-7 cell-derived tumors,
respectively. Huh-7 cells treated with 131I-CD133mAb plus cisplatin (DDP), 131I -CD133mAb, DDP, or no treatment (blank
control) were examined for cell proliferation suppression by MTT assay with the IC50 calculated. BALB/c mice bearing
subcutaneous Huh-7 cell xenograft in the right forelegs were treated with 131I -CD133mAb, DDP, or both every two days for
two weeks. The tumor size and volume were measured twice a week, and pathological examination of the tumor was carried
out after the treatments. The tumor inhibition rate was calculated and tumor cell apoptosis observed with HE staining. Results
The labeling ratio of 131I-CD133mAb was 90.25% and the radiochemical purity was 97.78%. Huh-7 cells showed obviously
higher CD133 expression than HepG2 cells. 131I-CD133mAb combined with DDP group resulted in a significantly higher tumor
inhibition rate than other treatments in the tumor-bearing mice. Conclusion 131I-CD133mAb can inhibit the growth of liver
cancer cells with a high CD133 expression both in vivo and in vitro.