Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
10594784 | Bioorganic & Medicinal Chemistry Letters | 2014 | 6 Pages |
Abstract
The purpose of this study was to examine whether the introduction of d-Phe could improve the GnRH receptor binding affinities of DOTA-conjugated d-Lys6-GnRH peptides. Building upon the construct of DOTA-Ahx-(d-Lys6-GnRH1) we previously reported, an aromatic amino acid of d-Phe was inserted either between the DOTA and Ahx or between the Ahx and d-Lys6 to generate new DOTA-d-Phe-Ahx-(d-Lys6-GnRH) or DOTA-Ahx-d-Phe-(d-Lys6-GnRH) peptides. Compared to DOTA-Ahx-(d-Lys6-GnRH1) (36.1Â nM), the introduction of d-Phe improved the GnRH receptor binding affinities of DOTA-d-Phe-Ahx-(d-Lys6-GnRH) (16.3Â nM) and DOTA-Ahx-d-Phe-(d-Lys6-GnRH) (7.6Â nM). The tumor targeting and pharmacokinetic properties of 111In-DOTA-Ahx-d-Phe-(d-Lys6-GnRH) was determined in MDA-MB-231 human breast cancer-xenografted nude mice. Compared to 111In-DOTA-Ahx-(d-Lys6-GnRH1), 111In-DOTA-Ahx-d-Phe-(d-Lys6-GnRH) exhibited comparable tumor uptake with faster renal and liver clearance. The MDA-MB-231 human breast cancer-xenografted tumors were clearly visualized by single photon emission computed tomography (SPECT) using 111In-DOTA-Ahx-d-Phe-(d-Lys6-GnRH) as an imaging probe, providing a new insight into the design of new GnRH peptides in the future.
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Authors
Jie Lu, Helen J. Hathaway, Melanie E. Royce, Eric R. Prossnitz, Yubin Miao,