Reactivating HIF prolyl hydroxylases under hypoxia results in metabolic catastrophe and cell death

Oncogene. 2009 Nov 12;28(45):4009-21. doi: 10.1038/onc.2009.250. Epub 2009 Aug 31.

Abstract

Cells exposed to low-oxygen conditions (hypoxia) alter their metabolism to survive. This response, although vital during development and high-altitude survival, is now known to be a major factor in the selection of cells with a transformed metabolic phenotype during tumorigenesis. It is thought that hypoxia-selected cells have increased invasive capacity and resistance to both chemo- and radiotherapies, and therefore represent an attractive target for antitumor therapy. Hypoxia inducible factors (HIFs) are responsible for the majority of gene expression changes under hypoxia, and are themselves controlled by the oxygen-sensing HIF prolyl hydroxylases (PHDs). It was previously shown that mutations in succinate dehydrogenase lead to the inactivation PHDs under normoxic conditions, which can be overcome by treatment with alpha-ketoglutarate derivatives. Given that solid tumors contain large regions of hypoxia, the reactivation of PHDs in these conditions could induce metabolic catastrophe and therefore prove an effective antitumor therapy. In this report we demonstrate that derivatized alpha-ketoglutarate can be used as a strategy for maintaining PHD activity under hypoxia. By increasing intracellular alpha-ketoglutarate and activating PHDs we trigger PHD-dependent reversal of HIF1 activation, and PHD-dependent hypoxic cell death. We also show that derivatized alpha-ketoglutarate can permeate multiple layers of cells, reducing HIF1alpha levels and its target genes in vivo.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Cell Death / physiology
  • Cell Hypoxia / physiology
  • Enzyme Activation
  • Female
  • HCT116 Cells
  • Humans
  • Hypoxia-Inducible Factor 1 / genetics
  • Hypoxia-Inducible Factor 1 / metabolism*
  • Hypoxia-Inducible Factor 1, alpha Subunit / metabolism
  • Hypoxia-Inducible Factor-Proline Dioxygenases
  • Ketoglutaric Acids / metabolism
  • Ketoglutaric Acids / pharmacology
  • Metabolic Networks and Pathways
  • Mice
  • Mice, Inbred BALB C
  • Mice, Nude
  • Oxygen / metabolism
  • Procollagen-Proline Dioxygenase / metabolism*
  • Transfection
  • Von Hippel-Lindau Tumor Suppressor Protein / metabolism

Substances

  • HIF1A protein, human
  • Hypoxia-Inducible Factor 1
  • Hypoxia-Inducible Factor 1, alpha Subunit
  • Ketoglutaric Acids
  • EGLN1 protein, human
  • Procollagen-Proline Dioxygenase
  • Hypoxia-Inducible Factor-Proline Dioxygenases
  • Von Hippel-Lindau Tumor Suppressor Protein
  • VHL protein, human
  • Oxygen