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RB1-Funktionsverlust (Retinoblastomprotein)

Deterministische Ansicht der Quelle YAML Entität. Klinische Autorität bleibt mit den zitierten Quell-IDs und Rezensenten Sign-off Zustand.

IDBIO-RB1
ArtBiomarker
Aliase
RB1-Verlust / Genmutation des RetinoblastomsВтрата функції RB1 (ретинобластомний білок)
Statusreviewed 2026-05-04 | pending_clinical_signoff
ErkrankungenDIS-SCLC DIS-UROTHELIAL
QuellenSRC-EAU-BLADDER-2024 SRC-NCCN-SCLC-2025

Biomarker-Fakten

Biomarker-Typgene_mutation
Angaben zur Mutation{"exon": "multiple (exons 1–27)", "functional_impact": "loss-of-function", "gene": "RB1", "variant_type": "loss-of-function (deletion, frameshift, nonsense, splice, missense inactivating)"}
Messung
VerfahrenTumor-NGS; IHC (Rb-Proteinverlust durch IHC — klinisch in SCLC-Diagnose verwendet); FISH für 13q14 Löschen (Retinoblastom)
Nachschlagewerk für die Aktionsfähigkeit{"gene": "RB1", "variant": "loss_of_function"}
Verwandte BiomarkerBIO-CDKN2A

Anmerkungen

RB1 encodes the retinoblastoma protein (pRb), the master G1/S checkpoint regulator. pRb normally sequesters E2F transcription factors to prevent S-phase entry; loss of pRb → uncontrolled cell cycle progression. Clinical contexts: (1) Hereditary retinoblastoma: germline RB1 mutation → bilateral/multifocal retinoblastoma in childhood; lifetime elevated risk of osteosarcoma, SCLC, melanoma. (2) SCLC: biallelic RB1 loss + TP53 mutation defines the SCLC molecular signature (~95% of SCLC). pRb loss by IHC is used in pathologic diagnosis. No targeted therapy for RB1 deficiency per se; SCLC treatment is chemotherapy (EP/EC) ± atezolizumab. (3) Urothelial carcinoma: RB1 alterations in ~30% of muscle-invasive bladder cancer; associated with basal/squamous subtype; not currently targeted. (4) Breast cancer: RB1 mutations occur in ~10% of TNBC; RB1 loss predicts resistance to CDK4/6 inhibitors (palbociclib, ribociclib, abemaciclib) — pRb is the substrate for CDK4/6 that drives cell cycle entry; without pRb, CDK4/6 inhibition is ineffective. (5) Osteosarcoma: RB1 alterations in ~30%. Therapeutic implication of RB1 loss in HR+ breast cancer: CDK4/6 inhibitors are essentially non-functional with...

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Therapeutische Relevanz

Biomarker

Erkrankung