Cytoplasmic Localization of Prostate-Specific Membrane Antigen Inhibitors May Confer Advantages for Targeted Cancer...

Area of Science:

• Biochemistry
• Cell Biology
• Oncology

Background:

• Prostate-specific membrane antigen (PSMA) inhibitors are vital in advanced prostate cancer treatment.
• The internalization mechanism and subcellular fate of PSMA inhibitors are not fully understood.

Purpose of the Study:

• To investigate the intracellular distribution and fate of PSMA inhibitors and PSMA in prostate cancer cells.
• To elucidate the nanoscale mechanisms governing PSMA inhibitor internalization and trafficking.

Main Methods:

• Stimulated emission depletion (STED) nanoscopy was employed for high-resolution live-cell imaging.
• A novel nonstandard live cell staining protocol was developed and applied.

Main Results:

• PSMA inhibitors undergo clathrin-dependent endocytosis and follow the endosomal pathway.
• PSMA inhibitors accumulate within prostate cancer cells, reaching clinically relevant concentrations.
• Unlike PSMA, inhibitors distribute homogeneously in the cytoplasm, including perinuclear regions.

Conclusions:

• The homogeneous cytoplasmic distribution of PSMA inhibitors offers potential advantages for targeted radionuclide therapy.
• Understanding the subcellular fate of PSMA inhibitors can guide the development of improved prostate cancer diagnostics and therapeutics.