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Oncogenic Ras-induced expression of Noxa and Beclin-1 promotes autophagic cell death and limits clonogenic survival

Mohamed Elgendy1, Clare Sheridan, Gabriela Brumatti

  • 1Molecular Cell Biology Laboratory, Department of Genetics, The Smurfit Institute, Trinity College, Dublin 2, Ireland.

Molecular Cell
|March 1, 2011
PubMed

Insights

Oncogenic H-Ras can trigger cell death via autophagy, involving Noxa and Beclin-1. This pathway limits Ras-driven cancer development by promoting cell death and reducing survival.

Area of Science:

  • Cell Biology
  • Molecular Oncology
  • Cancer Research

Background:

  • Oncogenes like MYC and RAS drive cancer but often require additional mutations for full transformation.
  • Cellular responses to oncogenic RAS include proliferation arrest, senescence, or cell death, varying by context.

Purpose of the Study:

  • To investigate the role of oncogenic H-Ras in inducing cell death.
  • To elucidate the mechanisms underlying Ras-induced cell death, particularly its relationship with autophagy.

Main Methods:

  • Analysis of caspase-independent cell death in cells with deregulated H-Ras.
  • Assessment of autophagy markers, including Noxa and Beclin-1 expression.
  • Gene silencing of Noxa and Beclin-1.
  • Investigation of Bcl-2 family member interactions with Beclin-1.

Main Results:

  • Deregulated H-Ras induced caspase-independent cell death with autophagic features.
  • Ras-induced autophagy correlated with increased Noxa and Beclin-1.
  • Silencing Noxa or Beclin-1 reduced autophagy and enhanced cell survival.
  • Bcl-2 family members inhibiting Beclin-1 function suppressed Ras-induced cell death.
  • Noxa mediated Mcl-1 displacement from Beclin-1, promoting autophagy.

Conclusions:

  • Ras-induced expression of Noxa and Beclin-1 promotes autophagic cell death.
  • This autophagic cell death mechanism acts as a barrier against the oncogenic potential of deregulated Ras.
  • Understanding this pathway offers insights into cancer prevention and therapy.

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