Our project is focused on bispecific targeting of prostate cancer cells. We are evaluating a heterodimer which includes PSMA-617 and DOTA-RM2 in its structure and targets both Prostate-Specific Membrane Antigen (PSMA) and Gastrin- Releasing Peptide Receptors (GRPr) (receptors that exist on prostate cancer cells). All three molecules, the heterodimer and both monomers, are radiolabeled with the diagnostic radionuclide Ga-68 and show high labeling levels (>93%). We are performing internalization assays, specific binding and inhibition potency assays (by calculation of IC50). Two different types of cells are used in these in vitro assays, LNCaP (PSMA+, GRPr -) and PC3 (PSMA-, GRPr+). Our future project involves biodistribution studies on healthy experimental animals and pathological tumor models bearing LNCaP and PC3 tumors.