99mTc-(tricine)-HYNIC-Lys-FROP Peptide for Breast Tumor Targeting

Background: Breast cancer is a malignant disease with high mortality rate among women in the world. It is necessary to diagnose breast cancer at the early stage before it metastasizes in patients. Objective: The aim of this study is the evaluation of 99mTc-(tricine)-HYNIC-Lys-FROP for breast tumor imaging. Method: Lys-FROP peptide was labeled with 99mTc using HYNIC as chelator and tricine as co-ligand. Specific binding of this radiolabeled peptide on breast cancerous cell was assessed in different cell lines as well as in tumor-bearing mice. Results: HYNIC-Lys-FROP peptide was labeled with 99mTc at radiochemical purity more than 99%. It was observed high stability in normal saline and serum about 95%. The highest cellular uptake was observed in MCF-7 breast tumor cells treated with 99mTc-(tricine)-HYNIC-Lys-FROP as compared to other cell lines (lung, ovarian, T47D breast cancer cell lines). Biodistribution results in female MCF-7 tumor-bearing mice showed the relatively high tumor uptake and tumor-muscle ratio as 3.82 ± 0.66 after 15 min post-injection of 99mTc-(tricine)- HYNIC-Lys-FROP. Tumor uptake was reduced in mice that were co-injected with excess of unlabeled peptide to be 0.91 ± 0.08. Conclusion: Findings showed this radiolabeled peptide is a promising candidate for tumor targeting and molecular imaging of breast cancer.