MST1R as a Radioligand Therapy Target
MST1R, macrophage stimulating 1 receptor, is a cell-surface protein (membrane receptor). In Human Protein Atlas immunohistochemistry, MST1R staining is highest in melanoma (100% of samples positive), thyroid cancer (100% of samples positive) and endometrial cancer (100% of samples positive). Published literature reports that MST1R internalizes after ligand binding, which helps retain a radionuclide inside tumor cells. Clinical status: Clinical-stage (up to phase 2, any modality).
Is MST1R 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 melanoma, 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.
MST1R expression in cancer
Protein expression of MST1R 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 |
|---|---|---|---|
| Melanoma | 0.94 | High | 100% |
| Thyroid Cancer | 0.67 | High | 100% |
| Endometrial Cancer | 0.67 | High | 100% |
| Liver Cancer | 0.67 | High | 100% |
| Ovarian Cancer | 0.64 | High | 100% |
| Breast Cancer | 0.64 | High | 100% |
| Colorectal Cancer | 0.58 | High | 91% |
| Lung Cancer | 0.56 | High | 92% |
| Pancreatic Cancer | 0.53 | High | 100% |
| Bladder Cancer | 0.52 | High | 100% |
| Cervical Cancer | 0.50 | Medium | 100% |
| Skin Cancer | 0.50 | Medium | 92% |
| Prostate Cancer | 0.44 | Medium | 100% |
| Gastric Cancer | 0.44 | Medium | 100% |
| Head and Neck Cancer | 0.42 | Medium | 100% |
| Neuroendocrine Tumors | 0.42 | Medium | 75% |
| Glioma | 0.39 | Medium | 100% |
| Testicular Cancer | 0.36 | Medium | 100% |
| Lymphoma | 0.31 | Medium | 58% |
| Kidney Cancer | 0.22 | Medium | 58% |
Is MST1R internalized?
Yes. Homodimerization of RON (MST1R), a receptor tyrosine kinase, usually occurs in cells stimulated by a ligand and leads to the downstream activation of signaling pathways. Time-course studies indicated that RON migrated directly from the membrane to the nucleus of bladder cancer cells.
Sources: PMID 20498137. AI-extracted from abstracts, so verify before citing.
MST1R clinical trials
Clinical-stage (up to phase 2, any modality). Nuclens hasn't indexed trials for MST1R yet. Search ClinicalTrials.gov for MST1R trials.
MST1R 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 MST1R in the Human Protein Atlas tissue atlas, and read how normal-tissue expression predicts radioligand dosimetry risk.
MST1R gene essentiality (DepMap)
CRISPR knockout effect across 1258 cancer cell lines: -0.06 (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 melanoma radioligand targets
HER3 (ERBB3) · c-MET (MET) · STEAP2 · SSTR2 · B7-H3 (CD276) · ITGAV · TMEFF2 · FAP
See all radioligand therapy targets in melanoma.
See how MST1R ranks against 15,000 targets for your indication.
Run a free analysisData 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.