SMO: IHC Expression in Cancer and Radioligand Target Profile
SMO, smoothened, frizzled class receptor, is a cell-surface protein (GPCR). In Human Protein Atlas immunohistochemistry, SMO staining is highest in prostate cancer (100% of samples positive), melanoma (100% of samples positive) and thyroid cancer (100% of samples positive). Evidence on whether SMO internalizes is mixed. Clinical status: FDA-approved drug (any modality).
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Analyze SMO freeIs SMO 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: Mixed evidence.
- ✅ Clinical precedent: FDA-approved drug (any modality)
- ❔ Shedding: Not yet assessed.
- ❔ Normal-tissue dosimetry: Check kidney, liver, bone marrow and salivary expression in the Human Protein Atlas tissue atlas.
SMO IHC staining by cancer type
Protein expression of SMO 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 | 0.67 | High | 100% |
| Melanoma | 0.64 | High | 100% |
| Thyroid Cancer | 0.58 | High | 100% |
| Kidney Cancer | 0.56 | High | 100% |
| Neuroendocrine Tumors | 0.50 | Medium | 75% |
| Breast Cancer | 0.46 | Medium | 100% |
| Endometrial Cancer | 0.46 | Medium | 82% |
| Liver Cancer | 0.44 | Medium | 92% |
| Pancreatic Cancer | 0.44 | Medium | 83% |
| Ovarian Cancer | 0.36 | Medium | 100% |
| Bladder Cancer | 0.36 | Medium | 82% |
| Head and Neck Cancer | 0.33 | Medium | 100% |
| Testicular Cancer | 0.31 | Medium | 67% |
| Colorectal Cancer | 0.28 | Medium | 83% |
| Lung Cancer | 0.25 | Medium | 67% |
| Cervical Cancer | 0.25 | Medium | 58% |
| Skin Cancer | 0.19 | Low | 58% |
| Gastric Cancer | 0.18 | Low | 46% |
| Glioma | 0.11 | Low | 33% |
Not detected by IHC in: lymphoma.
Is SMO internalized?
Uncertain. The abstract does not provide specific information regarding receptor internalization or endocytosis related to SMO upon ligand or antibody binding.
Sources: PMID 40551010 · PMID 40393597 · PMID 39180250 · PMID 38886055 · PMID 36083801. AI-extracted from abstracts, so verify before citing.
SMO clinical trials
FDA-approved drug (any modality). Nuclens hasn't indexed trials for SMO yet. Search ClinicalTrials.gov for SMO trials.
SMO 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 SMO in the Human Protein Atlas tissue atlas, and read how normal-tissue expression predicts radioligand dosimetry risk.
SMO gene essentiality (DepMap)
CRISPR knockout effect across 1256 cancer cell lines: -0.09 (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.
See how SMO ranks against 15,000 targets for your indication.
Analyze SMO freeData sources
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.