99m Tc-HYNIC-(Ser)3 -J18 peptide: A radiotracer for non-small-cell lung cancer targeting.

Radiolabeled peptide could be a useful tool for the diagnosis of non-small-cell lung cancer (NSCLC). In this study, HYNIC-(Ser)3 -J18 peptide was labeled with 99m Tc using EDDA/tricine as coligands. The in vitro and in vivo studies of this radiolabeled peptide were performed for cellular-specific binding and tumor targeting in A-549 cells and tumor-bearing mice, respectively. The high radiochemical purity was obtained and this radiolabeled peptide exhibited high stability in buffer and serum. The radiolabeled peptide showed high affinity for the A-549 cells with a dissociation constant value (KD ) of 4.4 ± 0.8 nm. The tumor-muscles ratios were 2.7 and 4.4 at 1 and 2 hr after injection of 99m Tc-(EDDA/tricine)-HYNIC-(Ser)3 -J18 in tumor-bearing mice. The tumor uptake was decreased after preinjection with non-labeled peptide for this radiolabeled peptide in blocking experiment. The results of this study showed the 99m Tc-(EDDA/tricine)-(Ser)3 -HYNIC-J18 peptide might be a promising radiolabeled peptide for NSCLC targeting.