Oncometabolite D-2-Hydroxyglutarate Inhibits ALKBH DNA Repair Enzymes and Sensitizes IDH Mutant Cells to Alkylating Agents

Cell Rep. 2015 Dec 22;13(11):2353-2361. doi: 10.1016/j.celrep.2015.11.029. Epub 2015 Dec 10.

Abstract

Chemotherapy of a combination of DNA alkylating agents, procarbazine and lomustine (CCNU), and a microtubule poison, vincristine, offers a significant benefit to a subset of glioma patients. The benefit of this regimen, known as PCV, was recently linked to IDH mutation that occurs frequently in glioma and produces D-2-hydroxyglutarate (D-2-HG), a competitive inhibitor of α-ketoglutarate (α-KG). We report here that D-2-HG inhibits the α-KG-dependent alkB homolog (ALKBH) DNA repair enzymes. Cells expressing mutant IDH display reduced repair kinetics, accumulate more DNA damages, and are sensitized to alkylating agents. The observed sensitization to alkylating agents requires the catalytic activity of mutant IDH to produce D-2-HG and can be reversed by the deletion of mutant IDH allele or overexpression of ALKBH2 or AKLBH3. Our results suggest that impairment of DNA repair may contribute to tumorigenesis driven by IDH mutations and that alkylating agents may merit exploration for treating IDH-mutated cancer patients.

Publication types

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

MeSH terms

  • AlkB Homolog 2, Alpha-Ketoglutarate-Dependent Dioxygenase
  • AlkB Homolog 3, Alpha-Ketoglutarate-Dependent Dioxygenase
  • Alkylating Agents / toxicity*
  • Busulfan / toxicity
  • Cell Line, Tumor
  • DNA Damage / drug effects*
  • DNA Repair / drug effects
  • DNA Repair Enzymes / antagonists & inhibitors
  • DNA Repair Enzymes / genetics
  • DNA Repair Enzymes / metabolism*
  • Dioxygenases / antagonists & inhibitors
  • Dioxygenases / genetics
  • Dioxygenases / metabolism
  • Glutarates / metabolism
  • Glutarates / pharmacology*
  • Humans
  • Isocitrate Dehydrogenase / genetics
  • Isocitrate Dehydrogenase / metabolism*
  • Ketoglutaric Acids / metabolism
  • Mutation
  • Protein Binding
  • RNA Interference
  • RNA, Small Interfering / metabolism

Substances

  • Alkylating Agents
  • Glutarates
  • Ketoglutaric Acids
  • RNA, Small Interfering
  • alpha-hydroxyglutarate
  • Isocitrate Dehydrogenase
  • Dioxygenases
  • ALKBH3 protein, human
  • AlkB Homolog 3, Alpha-Ketoglutarate-Dependent Dioxygenase
  • ALKBH2 protein, human
  • AlkB Homolog 2, Alpha-Ketoglutarate-Dependent Dioxygenase
  • DNA Repair Enzymes
  • Busulfan