Preparation and preliminary studies of [64Cu]-antiMUC-1 for breast cancer targeting

PR81 is a monoclonal antibody that binds with high affinity to MUC1 that over expressed on breast tumors. PR81 is considered a suitable targeting molecule that was radiolabeled using Cu-64 for positron imaging studies. The monoclonal antibody was conjugated with DOTA moiety and after purification was evaluated for radiochemical purity, immunoreactivity, cell toxicity and structure integrity as well as biodistribution study in normal rats. The radiolabeled antibody prepared with acceptable radiochemical purity (> 93.2 ± 0.6 %, ITLC; specific activity; 4.6 µCi/µg), protein structure integration, significant cytotoxicity and significant immunoreactivity retention was assessed by radioimmunoassay (RIA). Animal biodistribution of the 64Cu-DOTA-PR81 was consistent with other radiolabeled antibodies. The results showed that 64Cu-DOTA-PR81 may be considered for tumor imaging for ultimate diagnosis and follow-up of MUC1 expression in oncology.