Inhibition of SIRT2 in merlin/NF2-mutant Schwann cells triggers necrosis

Oncotarget. 2013 Dec;4(12):2354-65. doi: 10.18632/oncotarget.1422.

Abstract

Mutations in the NF2 gene cause Neurofibromatosis Type 2 (NF2), a disorder characterized by the development of schwannomas, meningiomas and ependymomas in the nervous system. Merlin, a tumor suppressor encoded by the NF2 gene, modulates activity of many essential signaling pathways. Yet despite increasing knowledge of merlin function, there are no NF2 drug therapies. In a pilot high-throughput screen of the Library of Pharmacologically Active Compounds, we assayed for compounds capable of reducing viability of mouse Schwann cells (MSC) with Nf2 inactivation as a cellular model for human NF2 schwannomas. AGK2, a SIRT2 (sirtuin 2) inhibitor, was identified as a candidate compound. SIRT2 is one of seven mammalian sirtuins that are NAD+-dependent protein deacetylases. We show that merlin-mutant MSC have higher expression levels of SIRT2 and lower levels of overall lysine acetylation than wild-type control MSC. Pharmacological inhibition of SIRT2 decreases merlin-mutant MSC viability in a dose dependent manner without substantially reducing wild-type MSC viability. Inhibition of SIRT2 activity in merlin-mutant MSC is accompanied by release of lactate dehydrogenase and high mobility group box 1 protein into the medium in the absence of significant apoptosis, autophagy, or cell cycle arrest. These findings suggest that SIRT2 inhibition triggers necrosis of merlin-mutant MSCs and that SIRT2 is a potential NF2 drug target.

Publication types

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

MeSH terms

  • Acetylation
  • Animals
  • Cell Line, Tumor
  • Drug Evaluation, Preclinical
  • Genes, Tumor Suppressor
  • High-Throughput Screening Assays
  • Humans
  • Mice
  • Necrosis
  • Neurofibromatosis 2 / drug therapy*
  • Neurofibromatosis 2 / genetics
  • Neurofibromatosis 2 / metabolism
  • Neurofibromatosis 2 / pathology*
  • Neurofibromin 2 / genetics*
  • Neurofibromin 2 / metabolism
  • Schwann Cells / drug effects
  • Schwann Cells / metabolism*
  • Schwann Cells / pathology*
  • Signal Transduction
  • Sirtuin 2 / antagonists & inhibitors*
  • Sirtuin 2 / metabolism

Substances

  • Neurofibromin 2
  • SIRT2 protein, human
  • Sirtuin 2