Despite still investigational, the bombesin-based radiotracers and antagonist of gastrin releasing-peptide receptor (GRP) (RM2) and anti1-amino-3-18Ffluorocyclobutane-1-carboxylic acid (18F-FACBC) are emerging as possible alternatives for investigating PCa.
Of these, radiolabeled PSMA-PET agents have shown the most encouraging results in terms of sensitivity and are likely to become universally available for imaging PCa within a few years Other PET radiotracers such as bombesin-based radiotracers and antagonist of gastrin releasing-peptide receptor (RM2) are emerging as possible alternatives for PCa imaging.
This study indicates the safety and efficiency of a new type of dual integrin α<sub>v</sub>β<sub>3</sub>- and GRPR-targeting PET radiotracer in prostate cancer diagnosis and staging.
We review the preclinical and clinical literatures on the use of GRPRs as targets for imaging and therapy of prostate cancer, with a focus on the newer developments and theranostic potential of GRPR peptides.
These findings constitute a caveat for the use of GRPR as a target for diagnostic or therapeutic approaches to high grade or progressed prostate cancer.
Gastrin-Releasing Peptide Receptor- and Prostate-Specific Membrane Antigen-Specific Ultrasmall Gold Nanoparticles for Characterization and Diagnosis of Prostate Carcinoma via Fluorescence Imaging.
Immunohistochemical analysis of gastrin-releasing peptide receptor (GRPR) and possible regulation by estrogen receptor βcx in human prostate carcinoma.
MicroPET/CT and microSPECT/CT scans confirmed biodistribution data, suggesting that <sup>68</sup>Ga-NOTA-DUPA-RM26 and <sup>111</sup>In-NOTA-DUPA-RM26 are suitable candidates for the imaging of GRPR and PSMA expression in PCa shortly after administration.
Considering their adequate imaging characteristics, [<sup>64</sup> Cu]-NOTA-LK-RM26 bearing APCA- and AHDA-linkers are promising candidates for GRPR-targeted PET imaging prostate cancer.
The GRPR antagonist radioligands <sup>67</sup>Ga-, <sup>111</sup>In-, and <sup>177</sup>Lu-NeoBOMB1, independent of the radiometal applied, have shown comparable behavior in prostate cancer models, in favor of future theranostic use in GRPR-positive cancer patients.
Of the 22 prostate cancer specimens analyzed by RT-PCR, 20 (91%) expressed GRPR mRNA, 3 (14%) showed NMBR mRNA, and 2 ( approximately 9%) revealed BRS-3 mRNA.
The gastrin-releasing peptide receptor (GRPR), a G protein-coupled receptor, is overexpressed in solid malignancies and particularly in prostate cancer.
We sought to evaluate the tumor binding and imaging potential of (177)Lu-AMBA in low GRP-R models of prostate cancer and determine how reduced expression affects (177)Lu-AMBA radiotherapy efficacy.