(99m)~Tc-Labeled Vasopressin Peptide as a Radiopharmaceutical for Small-Cell Lung Cancer (SCLC) Diagnosis

摘要

The (99m)~Tc-labeled conjugates of the vasopressin (AVP) peptide and of its analogue d(CH_2)_5[DTyr(Et~2)-Ile~4-Eda~9]AVP (AVP(an)) have been synthesized using the technetium complexes with tetradentate tripodal chelator (the tris(2-mercaptoethyl)amine (NS_3)) and the monodentate isocyanide ligand (CN-peptide). The conjugates exhibit high stability in the presence of 100 times the molar excess of standard amino acids cysteine or histidine and also satisfactory stability in human serum. The (99m)~Tc(NS_3)(CNAVP) and (99m)~Tc(NS_3)(CN-AVP(an)) ability of binding to small-cell lung cancer (SCLC) cell line H69 was studied in vitro. The results suggest that the novel vasopressin conjugate (99m)~Tc(NS_3)(CN-AVP(an)) is a desirable compound for imaging oncogene receptors overexpressed in SCLC cells and can be an important basis for further consideration the conjugate as a potential diagnostic radiopharmaceutical for patients suffering from small-cell lung cancer.