68Ga/177Lu-Labeled Bivalent Agents for Targeting Hypoxia and PSMA-Binding in Prostate Cancer

J Med Chem. 2024 Aug 8;67(15):13491-13506. doi: 10.1021/acs.jmedchem.4c01420. Epub 2024 Jul 28.

Abstract

Prostate-specific membrane antigen (PSMA) is an excellent target for cancer detection and therapy. Hypoxia is prevalent in solid tumors, and various nitroimidazole (NI) radioligands can be trapped inside hypoxic cells for diagnosis and therapy. To enhance tumor uptake and retention, we designed bivalent agents (compounds 1-8) incorporating a hypoxia-sensitive NI-moiety and a PSMA-targeting group. Ligands 1-8 were successfully prepared and labeled with 68Ga or 177Lu. Among them, [68Ga]Ga-8 ([68Ga]Ga-AAZTA-NI-PSMA-093) demonstrated significantly higher cellular accumulation under hypoxic conditions than under normoxic conditions, suggesting hypoxia-selective trapping by the introduction of NI group. PET/CT imaging at 60 min postinjection of [68Ga]Ga-8 revealed high tumor uptake (SUVmax: 10.68%ID/mL) in the tumor-bearing mice model. SPECT/CT imaging of [177Lu]Lu-8 at 24 and 48 h postinjection demonstrated excellent accumulation and retention. Preliminary studies indicate that [68Ga]Ga/[177Lu]Lu-8 may be promising bivalent agents targeting hypoxia and PSMA binding for diagnosis and radiotherapy.

MeSH terms

  • Animals
  • Antigens, Surface* / metabolism
  • Cell Line, Tumor
  • Gallium Radioisotopes* / chemistry
  • Glutamate Carboxypeptidase II* / metabolism
  • Humans
  • Lutetium* / chemistry
  • Male
  • Mice
  • Mice, Nude
  • Positron Emission Tomography Computed Tomography
  • Prostatic Neoplasms* / diagnostic imaging
  • Prostatic Neoplasms* / metabolism
  • Radioisotopes / chemistry
  • Radiopharmaceuticals / chemical synthesis
  • Radiopharmaceuticals / chemistry
  • Radiopharmaceuticals / pharmacokinetics
  • Tissue Distribution
  • Tumor Hypoxia

Substances

  • Gallium Radioisotopes
  • Glutamate Carboxypeptidase II
  • Antigens, Surface
  • Lutetium
  • FOLH1 protein, human
  • Lutetium-177
  • Radioisotopes
  • Gallium-68
  • Radiopharmaceuticals