Author/Authors :
Sadeghzadeh، Nourollah نويسنده Department of Radiopharmacy, Faculty of Pharmacy, Mazandaran University of Medical Sciences, Sari, Iran , , Erfani، Mostafa نويسنده Nuclear Science Research School, Nuclear Science & Technology Research Institute (NSTRI), Atomic Energy Organization of Iran, Tehran, Iran. , , Omidi، Mahmoud نويسنده Department of Toxicology, Faculty of Pharmacy, Mazandaran University of Medical Sciences, Sari, Iran. ,
Abstract :
Background and Aim: Bombesin shows high affinity for Gastrin-releasing
peptide (GRP) receptors which over expressed on the cell surfaces of several
human tumors particularly in prostate and breast cancers. The aim of this study
was labeling of designed analogue with99mTc via HYNIC and Tricine /EDDA and
evaluation as potential targeted tumor scintigraphic agent.
Methods: HYNIC-Bombesin was prepared by solid phase synthesis using Fmoc
strategy and radiolabeled with 99mTc at 100 °C for 10 min by exchange method
and radiochemical analysis involved ITLC and HPLC methods. The stability of
radiopeptide was checked in the presence of human serum at 37 °C up to 24 h.
Internalization was studied with the human GRP receptor cell line PC-3.
Biodistribution study was performed in mice.
Results: Radiochemical purities of > 98% was obtained. Radiopeptide showed
high stability in serum. Radioligand internalization into PC-3 cells was high and
specific. Biodistribution study demonstrated that 99mTc-HYNIC peptide cleared
fast from blood and most non-targeted tissues and was excreted mainly by renal
pathway and was uptake significantly in GRPr positive tissues such as pancreas.
Conclusion: Easy radiolabeling of peptide conjugate together with favorable in
vitro and in vivo characteristics might be a useful peptide radiopharmaceutical in
diagnosis of GRPr positive tumors.
