PTPRB as a Radioligand Therapy Target
PTPRB, protein tyrosine phosphatase receptor type B, is a cell-surface protein (membrane receptor). In Human Protein Atlas immunohistochemistry, PTPRB staining is highest in prostate cancer (100% of samples positive), thyroid cancer (100% of samples positive) and glioma (100% of samples positive). Published literature reports that PTPRB internalizes after ligand binding, which helps retain a radionuclide inside tumor cells. Clinical status: Clinical-stage (up to phase 2, any modality).
Is PTPRB 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: Clinical-stage (up to phase 2, any modality)
- ❔ Shedding: Not yet assessed.
- ❔ Normal-tissue dosimetry: Check kidney, liver, bone marrow and salivary expression in the Human Protein Atlas tissue atlas.
PTPRB expression in cancer
Protein expression of PTPRB 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 | 0.97 | High | 100% |
| Thyroid Cancer | 0.92 | High | 100% |
| Glioma | 0.88 | High | 100% |
| Neuroendocrine Tumors | 0.67 | High | 67% |
| Lymphoma | 0.39 | Medium | 58% |
| Gastric Cancer | 0.27 | Medium | 40% |
| Pancreatic Cancer | 0.25 | Medium | 33% |
| Kidney Cancer | 0.21 | Medium | 36% |
| Endometrial Cancer | 0.19 | Low | 42% |
| Bladder Cancer | 0.18 | Low | 27% |
| Melanoma | 0.17 | Low | 25% |
| Testicular Cancer | 0.14 | Low | 25% |
| Cervical Cancer | 0.09 | Low | 18% |
| Ovarian Cancer | 0.06 | Low | 18% |
| Lung Cancer | 0.06 | Low | 8% |
| Breast Cancer | 0.03 | Low | 8% |
| Liver Cancer | 0.03 | Low | 8% |
Not detected by IHC in: skin cancer, colorectal cancer, head and neck cancer.
Is PTPRB internalized?
Yes. VE-PTP undergoes downstream polarization and endocytosis in endothelial cells exposed to laminar flow and high shear stress.
Sources: PMID 38032480. AI-extracted from abstracts, so verify before citing.
PTPRB clinical trials
Clinical-stage (up to phase 2, any modality). Nuclens hasn't indexed trials for PTPRB yet. Search ClinicalTrials.gov for PTPRB trials.
PTPRB 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 PTPRB in the Human Protein Atlas tissue atlas, and read how normal-tissue expression predicts radioligand dosimetry risk.
PTPRB gene essentiality (DepMap)
CRISPR knockout effect across 1258 cancer cell lines: -0.01 (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
PSMA (FOLH1) · HER3 (ERBB3) · c-MET (MET) · EGFR · EPCAM · FAP · B7-H3 (CD276) · STEAP2
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.