Autophagy facilitates glycolysis during Ras-mediated oncogenic transformation

Mol Biol Cell. 2011 Jan 15;22(2):165-78. doi: 10.1091/mbc.E10-06-0500. Epub 2010 Nov 30.

Abstract

The protumorigenic functions for autophagy are largely attributed to its ability to promote cancer cell survival in response to diverse stresses. Here we demonstrate an unexpected connection between autophagy and glucose metabolism that facilitates adhesion-independent transformation driven by a strong oncogenic insult-mutationally active Ras. In cells ectopically expressing oncogenic H-Ras as well as human cancer cell lines harboring endogenous K-Ras mutations, autophagy is induced following extracellular matrix detachment. Inhibiting autophagy due to the genetic deletion or RNA interference-mediated depletion of multiple autophagy regulators attenuates Ras-mediated adhesion-independent transformation and proliferation as well as reduces glycolytic capacity. Furthermore, in contrast to autophagy-competent cells, both proliferation and transformation in autophagy-deficient cells expressing oncogenic Ras are insensitive to reductions in glucose availability. Overall, increased glycolysis in autophagy-competent cells facilitates Ras-mediated adhesion-independent transformation, suggesting a unique mechanism by which autophagy may promote Ras-driven tumor growth in specific metabolic contexts.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Anoikis
  • Autophagy*
  • Autophagy-Related Protein 12
  • Autophagy-Related Protein 7
  • Cell Adhesion
  • Cell Line, Transformed
  • Cell Proliferation
  • Cell Transformation, Neoplastic / metabolism*
  • Cell Transformation, Neoplastic / pathology
  • Female
  • Glycolysis
  • Humans
  • Mice
  • Proto-Oncogene Proteins c-bcl-2 / biosynthesis
  • RNA Interference
  • Small Ubiquitin-Related Modifier Proteins / biosynthesis
  • Small Ubiquitin-Related Modifier Proteins / genetics
  • Tumor Cells, Cultured
  • Ubiquitin-Activating Enzymes / biosynthesis
  • Ubiquitin-Activating Enzymes / genetics
  • ras Proteins / biosynthesis
  • ras Proteins / genetics
  • ras Proteins / physiology*

Substances

  • ATG12 protein, human
  • Autophagy-Related Protein 12
  • Proto-Oncogene Proteins c-bcl-2
  • Small Ubiquitin-Related Modifier Proteins
  • ras Proteins
  • ATG7 protein, human
  • Autophagy-Related Protein 7
  • Ubiquitin-Activating Enzymes