CLDN3 as a Radioligand Therapy Target
CLDN3, claudin 3, is a cell-surface protein. In Human Protein Atlas immunohistochemistry, CLDN3 staining is highest in colorectal cancer (100% of samples positive), thyroid cancer (100% of samples positive) and endometrial cancer (100% of samples positive). Clinical status: Discovery-stage (no clinical drug program).
Is CLDN3 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 colorectal cancer, 100% of samples positive.
- ❔ Internalization: Not yet assessed.
- ⚠️ Clinical precedent: Discovery-stage (no clinical drug program)
- ❔ Shedding: Not yet assessed.
- ❔ Normal-tissue dosimetry: Check kidney, liver, bone marrow and salivary expression in the Human Protein Atlas tissue atlas.
CLDN3 expression in cancer
Protein expression of CLDN3 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 |
|---|---|---|---|
| Colorectal Cancer | 1.00 | High | 100% |
| Thyroid Cancer | 1.00 | High | 100% |
| Endometrial Cancer | 0.94 | High | 100% |
| Prostate Cancer | 0.92 | High | 100% |
| Ovarian Cancer | 0.89 | High | 100% |
| Cervical Cancer | 0.82 | High | 100% |
| Lung Cancer | 0.75 | High | 92% |
| Head and Neck Cancer | 0.67 | High | 100% |
| Pancreatic Cancer | 0.67 | High | 90% |
| Liver Cancer | 0.61 | High | 100% |
| Bladder Cancer | 0.61 | High | 91% |
| Skin Cancer | 0.58 | High | 82% |
| Breast Cancer | 0.56 | High | 67% |
| Gastric Cancer | 0.47 | Medium | 70% |
| Neuroendocrine Tumors | 0.25 | Medium | 50% |
| Glioma | 0.25 | Medium | 50% |
| Melanoma | 0.11 | Low | 17% |
| Kidney Cancer | 0.11 | Low | 17% |
| Testicular Cancer | 0.09 | Low | 27% |
Not detected by IHC in: lymphoma.
Is CLDN3 internalized?
Nuclens has not yet extracted internalization evidence for CLDN3. Internalization matters for radioligands because an internalizing receptor traps the radionuclide inside the tumor cell. Run a full analysis to pull the latest literature.
CLDN3 clinical trials
Discovery-stage (no clinical drug program). Nuclens hasn't indexed trials for CLDN3 yet. Search ClinicalTrials.gov for CLDN3 trials.
CLDN3 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 CLDN3 in the Human Protein Atlas tissue atlas, and read how normal-tissue expression predicts radioligand dosimetry risk.
CLDN3 gene essentiality (DepMap)
CRISPR knockout effect across 1252 cancer cell lines: 0.10 (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 colorectal cancer radioligand targets
c-MET (MET) · HER3 (ERBB3) · FAP · EGFR · CEA (CEACAM5) · EPCAM · SSTR2 · STEAP2
See all radioligand therapy targets in colorectal cancer.
See how CLDN3 ranks against 15,000 targets for your indication.
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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.