| Radiolabeled monoclonal antibodies (MAb) against tumor associated antigens (TAA) are used to immunolocalize occult tumors; and as scouting agents before 131I-radioimmunotherapy. Herein, 124I-JAA-F11 to Thomsen-Friedenreich antigen (TF-Ag), a carcinoma specific cell-surface TAA, is utilized in in vivo imaging experiments. Immunolocalization was performed in mice bearing the mammary adenocarcinoma metastatic line, 4T1. JAA-F11 was indirectly radioiodinated with 124I for imaging with micro-positron emission tomography (microPET) and biodistribution, which were performed at 72h, 144h, 240h, 360h, and 480h after injection and tumor tissue, blood and all organs were collected for gamma-counting. MicroPET images with high tumor-to-background contrast showed localization of the primary tumor, which remained localized until 20 days, were obtained in 100% of the mice (n=8). Biodistribution studies showed higher uptake (percentage injected dose per gram of the tissue, %ID/g) in tumors compared to other organs and blood. These results further evaluation of 131I-JAA-F11 as a radioimmunotherapy drug for clinical applications. |
