Stains & CD markers
RB1
Copyright: 2002-2024, PathologyOutlines.com, Inc.
PubMed Search: Rb[TI] review[ptyp]
RB1
Author: Nat Pernick, M.D.
Last author update: 1 July 2013
Last staff update: 29 December 2022
Copyright: 2002-2024, PathologyOutlines.com, Inc.
PubMed Search: Rb[TI] review[ptyp]
Table of Contents
Definition / general | Microscopic (histologic) images | Positive staining - normalCite this page: Pernick N. RB1. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/stainsrb.html. Accessed November 26th, 2024.
Definition / general
- Retinoblastoma gene / protein
- Tumor suppressor gene at 13q14
- Encodes a 110-114 kDa nuclear protein that plays a crucial role in cell cycle progression by regulating cell cycle arrest at G1-S
- Active form is hypophosphorylated and binds to E2F family of transcription factors, which bind to DNA to inhibit transcription
- Inactive form is phosphorylated via cyclin D-CDK4 / CDK6 complexes, which are inhibited by p16INK4a
- Rb inactivity (leading to transcription) caused by (a) loss of p16INK4a causing phosphorylation of Rb, making it inactive; (b) Rb mutations; (c) Rb hyperphosphorylation; (d) overexpression of cyclin D; (e) DNA tumor virus SV40 T antigen, adenovirus E1A and HPV-E7 protein
- Inactive Rb is reactivated by cell cycle specific phosphatase in M phase
- Germline mutations or loss predispose to retinoblastoma and osteosarcoma
- Somatic mutations cause various tumors
- Point mutations inhibits Rb1 and c-myc binding
- For thyroid neoplasms, follicular adenomas were usually positive, follicular and papillary carcinomas were usually negative (Mod Pathol 2000;13:562)
Microscopic (histologic) images
Images hosted on other servers:
Soft tissue, neck: spindle cell lipoma; right two: loss of Rb protein
Positive staining - normal
- Fibroblasts, endothelial cells and lymphoid cells within thyroid neoplasms
