Evaluation of a Novel Pb-203-Labeled Lactam-Cyclized Alpha-Melanocyte-Stimulating Hormone Peptide for Melanoma Targeting

The purpose of this study is to examine the melanocortin-1 receptor (MC1R) targeting and specificity of Pb-203-DOTA-GGN1e-CycMSH(hex) in melanoma cells and tumors to facilitate its potential therapeutic application when labeled with Pb-212. The MC1R-specific targeting and imaging properties of Pb-203-DOTA-GGN1e-CycMSHhe. were determined on B16/F1 and B16/F10 murine melanoma cells and in B16/F1 flank melanoma-, B16/F10 flank melanoma-, and B16/F10 pulmonary metastatic melanoma-bearing C57 mice. Pb-203-DOTA-GGN1e-CycMSH(hex) displayed MC1R-specific binding on B16/F1 and B16/F10 melanoma cells and tumors. B16/F1 flank melanoma, B16/F10 flank melanoma, and B16/F10 pulmonary metastatic melanoma lesions could be clearly imaged by single photon emission computed tomography (SPECT) using Pb-203-DOTA-GGN1e-CycMSHhe. as an imaging probe. The favorable melanoma targeting and imaging properties highlighted the potential of (203)pb-DOTA-GGN1e-CycMSH(hex) as a MC1R-targeting melanoma imaging probe and warranted the evaluation of Pb-212-DOTA-GGN1e-CycMSH(hex) for melanoma therapy in future studies.