PSMA (FOLH1) as a Radioligand Therapy Target
PSMA (FOLH1), folate hydrolase 1, is a cell-surface protein. In Human Protein Atlas immunohistochemistry, PSMA staining is highest in prostate cancer (100% of samples positive), endometrial cancer (27% of samples positive) and pancreatic cancer (8% of samples positive). Published literature reports that PSMA internalizes after ligand binding, which helps retain a radionuclide inside tumor cells. Clinical status: FDA-approved radioligand therapy.
Is PSMA a good radioligand therapy target?
Scored against the six criteria that decide whether a protein can become a radioligand therapy:
- ✅ Cell-surface accessibility: Localized to the cell surface, so a radioligand can reach it from circulation.
- ✅ Tumor expression: High IHC staining in prostate cancer, 100% of samples positive.
- ✅ Internalization: Reported to internalize, which favors radionuclide retention.
- ✅ Clinical precedent: FDA-approved radioligand therapy
- ❔ Shedding: Not yet assessed.
- ❔ Normal-tissue dosimetry: Check kidney, liver, bone marrow and salivary expression in the Human Protein Atlas tissue atlas.
PSMA expression in cancer
Protein expression of PSMA across 20 cancer types from Human Protein Atlas immunohistochemistry. The score is a weighted staining intensity from 0 to 1; "% positive" is the share of patient samples with detectable staining.
| Cancer type | IHC score | Level | % positive |
|---|---|---|---|
| Prostate Cancer | 1.00 | High | 100% |
| Endometrial Cancer | 0.18 | Low | 27% |
| Pancreatic Cancer | 0.03 | Low | 8% |
Not detected by IHC in: skin cancer, colorectal cancer, head and neck cancer, ovarian cancer, lymphoma, breast cancer, melanoma, kidney cancer, thyroid cancer, bladder cancer, neuroendocrine tumors, cervical cancer, lung cancer, gastric cancer, testicular cancer, glioma, liver cancer.
Is PSMA internalized?
Yes. Cellular binding and internalization showed a time-dependent increase over 2 h at 37 °C in the PSMA-positive cells.
Sources: PMID 38856975 · PMID 27458033. AI-extracted from abstracts, so verify before citing.
PSMA clinical trials
FDA-approved radioligand therapy. Nuclens hasn't indexed trials for PSMA yet. Search ClinicalTrials.gov for PSMA trials.
PSMA normal tissue expression
Normal-tissue expression in dose-limiting organs (kidney, liver, bone marrow, salivary glands) drives radioligand dosimetry risk. Nuclens is re-validating its normal-tissue values, so they are not shown here yet. See PSMA in the Human Protein Atlas tissue atlas, and read how normal-tissue expression predicts radioligand dosimetry risk.
PSMA gene essentiality (DepMap)
CRISPR knockout effect across 1245 cancer cell lines: -0.17 (not essential). Radioligands kill by radiation, not by blocking the target, so essentiality matters less than for inhibitors. A non-essential target can still be an excellent radioligand target.
Related prostate cancer radioligand targets
HER3 (ERBB3) · c-MET (MET) · EGFR · EPCAM · FAP · B7-H3 (CD276) · STEAP2 · TMEFF2
See all radioligand therapy targets in prostate cancer.
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Subcellular localization: UniProt via Open Targets (CC BY 4.0 / CC0). Tumor immunohistochemistry: Human Protein Atlas (CC BY-SA 4.0). Clinical trials: ClinicalTrials.gov (public domain). Gene essentiality: DepMap (CC BY 4.0). Internalization and shedding: AI-extracted from PubMed abstracts, so verify against the cited papers before relying on them. Nuclens is a first-pass triage layer, not a substitute for wet-lab validation or clinical dosimetry. Derived expression data on this page is shared under CC BY-SA 4.0.