Stains
MYB

Author: Angela Chan, MSc and Emeka Enwere, PhD (see Authors page)

Revised: 10 May 2016, last major update May 2016

Copyright: (c) 2002-2016, PathologyOutlines.com, Inc.

PubMed Search: MYB [title]

Cite this page: MYB. PathologyOutlines.com website. http://pathologyoutlines.com/topic/stainsmyb.html. Accessed June 29th, 2017.
Definition / general
  • A proto-oncogene
  • The canonical member of the MYB family of transcription factor proteins
  • Important regulator of hematopoiesis
  • Significant contributing factor to induction of leukemia in humans (Leukemia 2013;27:269)
Essential features
  • Essential for hematopoiesis and lymphoid development
  • Expressed in nuclei of proliferating epithelial, endothelial and hematopoietic progenitor cells (erythroid, myeloid, lymphoid); as these mature and differentiate, MYB transcription levels decrease dramatically (Mol Biol Evol 2008;25:2189)
  • Has hundreds of transcriptional targets, including genes involved in development, cell survival, proliferation and homeostasis (Nat Rev Cancer 2008;8:523)
  • Oncogenic mutations in MYB alter the spectrum of its transcriptional targets
Terminology
  • Also referred to as C - Myb, Cmyb, V - Myb avian myeloblastosis viral oncogene homolog, Efg
Pathophysiology
  • MYB family proteins have three domains:
    • Highly conserved N terminal DNA binding domain, which specifically recognizes the consensus sequence 5’-YAAC[GT]G-3’, where Y is any pYrimidine
    • Transcriptional activation domain
    • A less conserved C terminal domain mostly involved in transcriptional silencing
      • Contains a leucine zipper - like motif that regulates MYB activity
      • Disruption enhances the protein activity (Genes Dev 1996;10:1858)
  • MYB knockout mice die in utero from severe anemia resulting from impaired hepatic hematopoiesis (Cell 1991;65:677)
  • One study showed only 10 – 15% expression of MYB is required to allow 60% survival of mice for several months (EMBO J 2003;22:4478)
Clinical features
Microscopic (histologic) images

Images hosted on other servers:

C - MYB immunostain positive in
adenoid cystic carcinoma component (figure D)

Positive staining - normal
  • Colon, rectum, hematopoietic stem cells
Positive staining - disease
  • Adenoid cystic carcinoma
  • Pancreatic, colon and breast cancer
  • Leukemia and lymphoma
  • Negative stains
    • Adipose tissue and skin