Evaluation and comparison of a new DOTA and DTPA-bombesin agonist in vitro and in vivo in low and high GRPR expressing prostate and breast tumor models. (February 2015)

• Record Type: Journal Article
• Authors: Pujatti, Priscilla B.; Foster, Julie M.; Finucane, Ciara; Hudson, Chantelle D.; Burnet, Jerome C.; Pasqualoto, Kerly F.M.; Mengatti, Jair; Mather, Stephen J.; de Araújo, Elaine B.; Sosabowski, Jane K.
• Is Part Of: Applied radiation and isotopes. Volume 96(2015:Feb.)
• Page Start: 91
• Page End: 101
• Publication Date: 2015-02
• Subjects: Bombesin -- DOTA -- DTPA -- GRPR -- Comparison; Radiology -- Periodicals; Radiation -- Industrial applications -- Periodicals; Nuclear chemistry -- Periodicals; Internet resource; Periodical; 660.298
• DOI: 10.1016/j.apradiso.2014.11.006
• Languages: English
• ISSNs: 0969-8043

Abstract

Abstract: We evaluated and compared a new bombesin analog [Tyr–Gly5, Nle 14 ]-BBN(6–14) conjugated to DOTA or DTPA and radiolabeled with In-111 in low and high GRPR expressing tumor models. Both peptides were radiolabeled with high radiochemical purity and specific activity. In vitro assays on T-47D, LNCaP and PC-3 cells showed that the affinity of peptides is similar and a higher binding and internalization of DOTA-peptide to PC-3 cells was observed. Both peptides could target PC-3 and LNCaP tumors in vivo and both tumor types could be visualized by microSPECT/CT. Highlights: A new DOTA or DTPA-bombesin analog was evaluated in GRPR expressing tumor models. The peptide could bind specifically only to T-47D, LNCaP and PC-3 cells in vitro. Saturation binding assays showed that the affinity of DOTA and DTPA peptide is similar. Greater internalization, but not efflux, of the DOTA-peptide was observed. Both peptides could target PC-3 and LNCaP tumors in vivo.