Overall, the antagonistic GRPR targeted probe <sup>68</sup>Ga-NOTA-PEG<sub>3</sub>-RM26 is a more-promising candidate than the agonist <sup>68</sup>Ga-NOTA-Aca-BBN<sub>7-14</sub> for the PET imaging of prostate cancer patients.
We have further investigated the effect of androgen modulation on GRPR-expression in three androgen-dependent human PC-bearing xenografts: PC295, PC310 and PC82 using the androgen-independent PC3-model as a reference.
<sup>68</sup>Ga-RM2 is a gastrin releasing peptide receptor (GRPR) antagonist PET (positron emission tomography) radiotracer which is being investigated in clinical trials as a potential prostate cancer imaging agent.
This study aimed to synthesize and characterize the Lu-DOTA-PSMA(inhibitor)-Lys-bombesin (Lu-DOTA-iPSMA-Lys-BN) heterodimer and to evaluate its potential to target prostate-specific membrane antigen (PSMA) and gastrin-releasing peptide receptor (GRPr) overexpressed in prostate cancer.