Stains
Nucleophosmin (NPM)
Copyright: 2002-2015, PathologyOutlines.com, Inc.
PubMed Search: Nucleophosmin [title]
Nucleophosmin (NPM)
Author: Nat Pernick, M.D.
Topic Completed: 1 June 2005
Minor changes: 7 March 2019
Copyright: 2002-2015, PathologyOutlines.com, Inc.
PubMed Search: Nucleophosmin [title]
Table of Contents
Definition / generalCite this page: Pernick N. Nucleophosmin (NPM). PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/stainsnucleophosmin.html. Accessed June 2nd, 2020.
Definition / general
- Also called B23, numatrin; gene at 5q35
- Highly conserved non-ribosomal nucleolar phosphoprotein involved in assembling preribosomal particles into small and large ribosomal subunits
- Binds with high affinity to ss nucleic acids, exhibits activity that destabilizes the RNA helix and is associated with the most mature nucleolar preribosomal ribonucleoproteins
- May contribute active promoter to NPM-ALK
- ALK promoter is normally silent in lymphoid cells
- Hypothesis
- IL-2 or T-cell mediated signals activate substrates; with NPM-ALK, get constitutive activation (note ALCL arises from activated T lymphocytes, which depend on IL-2 for growth and viability)
- Fusion protein found in anaplastic large cell lymphoma (13-50%)
- When present, can be used to differentiate from Hodgkin lymphoma
