V600EBRAF is associated with disabled feedback inhibition of RAF-MEK signaling and elevated transcriptional output of the pathway Academic Article uri icon


MeSH Major

  • Feedback, Physiological
  • Mitogen-Activated Protein Kinase Kinases
  • Mutation, Missense
  • Proto-Oncogene Proteins B-raf
  • Signal Transduction
  • raf Kinases


  • Tumors with mutant BRAF and those with receptor tyrosine kinase (RTK) activation have similar levels of phosphorylated ERK, but only the former depend on ERK signaling for proliferation. The mitogen-activated protein kinase, extracellular signal-regulated kinase kinase (MEK)/ERK-dependent transcriptional output was defined as the genes whose expression changes significantly 8 h after MEK inhibition. In (V600E)BRAF cells, this output is comprised of 52 genes, including transcription factors that regulate transformation and members of the dual specificity phosphatase and Sprouty gene families, feedback inhibitors of ERK signaling. No such genes were identified in RTK tumor cells, suggesting that ERK pathway signaling output is selectively activated in BRAF mutant tumors. We find that RAF signaling is feedback down-regulated in RTK cells, but is insensitive to this feedback in BRAF mutant tumors. Physiologic feedback inhibition of RAF/MEK signaling down-regulates ERK output in RTK cells; evasion of this feedback in mutant BRAF cells is associated with increased transcriptional output and MEK/ERK-dependent transformation.

publication date

  • March 17, 2009



  • Academic Article



  • eng

PubMed Central ID

  • PMC2649208

Digital Object Identifier (DOI)

  • 10.1073/pnas.0900780106

PubMed ID

  • 19251651

Additional Document Info

start page

  • 4519

end page

  • 24


  • 106


  • 11