نشان دار سازي آنتي بادي مونوكلونال PR81 با 99mTC به منظور توليد يك پرتوداروي بيولوژيك جهت تشخيص سرطان پستان به روش راديوايمونو سينتي گرافي

Radiolabeling of monoclonal antibody PR81 with Tc: production of a biologic radiopharmaceutical for early diagnosis of human breast cancer

Radioimmunoscintigraphy (RIS) has found widespread clinical application in tumor diagnosis. The antibody (Ab) PR81 is a new murine anti-MUCl monoclonal antibody (MAb) against human breast carcinoma and we have developed a very simple, rapid and efficient method for labeling of this MAb with 99mTc, particularly suitable for development of a ʹkitʹ. The Ab reduction was performed with 2-mercaptoethanol (2-ME) at a molar ratio of 2000:1 (2-ME:MAb) and reduced Ab was labeled with 99mTc via methylene diphosphonate (MDP) as a transchelator. The labeling efficiency determined by instant thin layer chromatography (ITLC) was 94.2%+2.3. Radiocolloides measured by cellulose nitrate electrophoresis were 2.5%+1.7. In vitro stability of labeled product in human serum measured by gel filtration chromatography (FPLC) was 70%+5.7 over 24 hr. The integrity of labeled MAb was checked by means of SDS-PAGE and no significant fragmentation was seen. The results of cell-binding studies showed that both labeled and unlabeled PR81 were able to compete for binding to MCF 7 cells. Biodistribution studies were performed in normal BALB/c mice at 4 and 24 hrs post-injection and no important accumulation was seen in vital organs. These results show that the new radiopharmaceutical can be considered as a promising candidate for imaging of breast cancer.