In vivo evaluation of 99mTc/188Re-labeled linear alpha-melanocyte stimulating hormone analogs for specific melanoma targeting.
Radiolabeled alpha-melanocyte stimulating hormone (alpha-MSH) analogs were examined in melanoma-bearing mice to determine the effects of peptide length, structure, and radiometal chelation chemistry on tumor targeting and in vivo biodistribution. The linear alpha-MSH analogs [Nle4,D-Phe7]alpha-MSH (NDPMSH) and [D-Phe7]alpha-MSH(5-10) (DPMSH) were radiolabeled with 99mTc and 188Re via the addition of tetrafluorophenyl mercapto-acetylglycylglycyl-gamma-aminobutyrate (MAG2) or tetrapeptide Ac-Cys-Gly-Cys-Gly (CGCG) chelation moieties. 125I-Tyr2-NDPMSH was obtained by direct iodination of the Tyr2 residue. Tumor uptake of 99mTc-labeled CGCG- and MAG2-NDPMSH analogs at 30 min postinjection were 6.52 +/- 1.11 %ID/g and 4.17 +/- 1.34 %ID/g, respectively, resulting in a significantly higher tumor-to-blood uptake ratio than that of 125I-NDPMSH or a shorter alpha-MSH analog, 99mTc-CGCG-DPMSH. The combination of radiolabeling efficacy and in vivo tumor uptake highlights the potential of 99mTc-CGCG-NDPMSH as a melanoma imaging agent.
Chen
J
J
Department of Biochemistry, University of Missouri-Columbia, 65211, USA.
Giblin
M F
MF
Wang
N
N
Jurisson
S S
SS
Quinn
T P
TP
D000818:Animals; D005260:Female; D007202:Indicators and Reagents; D007700:Kinetics; D009074:Melanocyte-Stimulating Hormones / Q000138:chemical synthesis / Q000493:pharmacokinetics; D008546:Melanoma, Experimental / Q000000981:diagnostic imaging*; D051379:Mice; D008810:Mice, Inbred C57BL; D011877:Radionuclide Imaging; D019275:Radiopharmaceuticals / Q000138:chemical synthesis / Q000493:pharmacokinetics; D012211:Rhenium / Q000493:pharmacokinetics; D013667:Technetium / Q000493:pharmacokinetics; D014018:Tissue Distribution; D000521:alpha-MSH / Q000031:analogs & derivatives* / Q000138:chemical synthesis / Q000493:pharmacokinetics
D007202:Indicators and Reagents; D019275:Radiopharmaceuticals; C402167:alpha-MSH (5-10), Phe(7)-; D000521:alpha-MSH; D012211:Rhenium; D013667:Technetium; C027756:MSH, 4-Nle-7-Phe-alpha-; D009074:Melanocyte-Stimulating Hormones