Background: D4 small peptide (Leu-Ala-Arg-Leu-Leu-Thr) was selected as an appropriate
agent for specific targeting of epidermal growth factor receptor (EGFR).
Objective: The aim of study was to investigate the 99mTc-labeled D4 peptide for non-small cell
lung tumor targeting.
Method: HYNIC-(Ser)3-D4 peptide was labeled with 99m
Tc using mixture of tricine and ethylenediamine
diacetic acid (EDDA) as co-ligands. The in vitro cellular uptake of radiolabeled peptide
was evaluated by blocking test on human non-small cell lung cancer (A-549) cell line and its
biodistribution was evaluated in A-549 xenografted nude mice.
Results: This conjugated peptide was labeled with 99mTc in high radiochemical purity and it was
highly stable in buffer and serum. The un-blocked to blocked cellular radioactivity ratio was 4-
fold that showed a specific binding of this radiolabeled peptide on A-549 cell. Animal biodistribution
in A-549 xenografted nude mice showed rapid clearance from blood and other non-target organs.
Tumor uptake values as %ID/g (percentage of injection dose per gram of tissue) were 2.47%
and 1.30% at 1 and 4 h after injection.
Conclusion: This study showed the 99m
Tc-EDDA/tricine-HYNIC-(Ser)3-D4 peptide had tumor
targeting on the non-small cell lung tumor.