Design, synthesis and iodination of an Arg-Arg-Leu peptide for potential use as an imaging agent for human prostate carcinoma

Abstract

The aim of this work was to design and synthesize a radioiodinated peptide containing arginine-arginine-leucine (RRL) functionality as a potential imaging agent of tumor angiogenesis. The RRL peptide was synthesized using the Fmoc solid phase method and identified by MS analysis after purification by HPLC. The RRL peptide was labeled with (131)I by the Chloramine-T method and purified through Sephadex G-25 column. Furthermore, the (131)I labeled peptide was used to evaluate its biodistribution. SPECT imaging was carried out at 24h after the (131)I labeled RRL peptide was injected into BALB/c nude mice bearing human prostate carcinoma. For the first time we have shown that a radiolabelled RRL peptide appears to be useful as a tumor angiogenic endothelium imaging agent for the diagnosis of the human prostate carcinoma.