CD45 (PTPRC) as a Radioligand Therapy Target
CD45 (PTPRC), protein tyrosine phosphatase receptor type C, is a cell-surface protein (membrane receptor). In Human Protein Atlas immunohistochemistry, CD45 staining is highest in lymphoma (83% of samples positive) and prostate cancer (8% of samples positive). Published literature suggests CD45 does not readily internalize, so radionuclide retention may rely on surface binding. Clinical status: Clinical-stage (up to phase 2, any modality).
Is CD45 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 lymphoma, 83% of samples positive.
- ❌ Internalization: Reported not to internalize.
- ✅ 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.
CD45 expression in cancer
Protein expression of CD45 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 |
|---|---|---|---|
| Lymphoma | 0.72 | High | 83% |
| Prostate Cancer | 0.03 | Low | 8% |
Not detected by IHC in: skin cancer, colorectal cancer, head and neck cancer, ovarian cancer, breast cancer, melanoma, kidney cancer, thyroid cancer, bladder cancer, neuroendocrine tumors, cervical cancer, lung cancer, pancreatic cancer, gastric cancer, testicular cancer, endometrial cancer, glioma, liver cancer.
Is CD45 internalized?
No. The study focuses on biosurfactants and does not provide evidence of PTPRC undergoing receptor internalization or endocytosis. There is no mention of internalization in the context of PTPRC and the relevant signaling pathways discussed.
Sources: PMID 36671206 · PMID 30196744. AI-extracted from abstracts, so verify before citing.
CD45 clinical trials
Clinical-stage (up to phase 2, any modality). Nuclens hasn't indexed trials for CD45 yet. Search ClinicalTrials.gov for CD45 trials.
CD45 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 CD45 in the Human Protein Atlas tissue atlas, and read how normal-tissue expression predicts radioligand dosimetry risk.
CD45 gene essentiality (DepMap)
CRISPR knockout effect across 393 cancer cell lines: -0.12 (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 lymphoma radioligand targets
c-MET (MET) · CD20 (MS4A1) · HER3 (ERBB3) · CD19 · SSTR2 · STEAP2 · CD22 · TMEFF2
See all radioligand therapy targets in lymphoma.
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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.