SSTR5 as a Radioligand Therapy Target

SSTR5, somatostatin receptor 5, is a cell-surface protein (GPCR). No tumor protein staining is recorded for it in Human Protein Atlas immunohistochemistry. Published literature reports that SSTR5 internalizes after ligand binding, which helps retain a radionuclide inside tumor cells. Clinical status: Clinical-stage (up to phase 3, any modality).

Is SSTR5 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: No tumor staining in HPA immunohistochemistry.
• ✅ Internalization: Reported to internalize, which favors radionuclide retention.
• ✅ Clinical precedent: Clinical-stage (up to phase 3, any modality)
• ❔ Shedding: Not yet assessed.
• ❔ Normal-tissue dosimetry: Check kidney, liver, bone marrow and salivary expression in the Human Protein Atlas tissue atlas.

SSTR5 expression in cancer

No Human Protein Atlas tumor immunohistochemistry data is available for SSTR5.

Is SSTR5 internalized?

Yes. ITF2984 induces receptor internalization and phosphorylation, and triggers G-protein signaling at pharmacologically relevant concentrations.

Sources: PMID 37444563 · PMID 36804512 · PMID 32383089 · PMID 27984180 · PMID 24523912. AI-extracted from abstracts, so verify before citing.

SSTR5 clinical trials

Clinical-stage (up to phase 3, any modality). Nuclens hasn't indexed trials for SSTR5 yet. Search ClinicalTrials.gov for SSTR5 trials.

SSTR5 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 SSTR5 in the Human Protein Atlas tissue atlas, and read how normal-tissue expression predicts radioligand dosimetry risk.

SSTR5 gene essentiality (DepMap)

CRISPR knockout effect across 1242 cancer cell lines: 0.03 (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.

Data 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.