Nanoparticle-mediated knockdown of DNA repair sensitizes cells to radiotherapy and extends survival in a genetic mouse model of glioblastoma

Nanomedicine. 2017 Oct;13(7):2131-2139. doi: 10.1016/j.nano.2017.06.004. Epub 2017 Jun 11.

Abstract

Glioblastoma (GBM) remains incurable, and recurrent tumors rarely respond to standard-of-care radiation and chemo-therapies. Therefore, strategies that enhance the effects of these therapies should provide significant benefits to GBM patients. We have developed a nanoparticle delivery vehicle that can stably bind and protect nucleic acids for specific delivery into brain tumor cells. These nanoparticles can deliver therapeutic siRNAs to sensitize GBM cells to radiotherapy and improve GBM treatment via systemic administration. We show that nanoparticle-mediated knockdown of the DNA repair protein apurinic endonuclease 1 (Ape1) sensitizes GBM cells to radiotherapy and extend survival in a genetic mouse model of GBM. Specific knockdown of Ape1 activity by 30% in brain tumor tissue doubled the extended survival achieved with radiotherapy alone. Ape1 is a promising target for increasing the effectiveness of radiotherapy, and nanoparticle-mediated delivery of siRNA is a promising strategy for tumor specific knockdown of Ape1.

Keywords: Ape1/APEX1; Glioblastoma; Nanoparticle; Radiosensitization; siRNA.

MeSH terms

  • Animals
  • Brain / metabolism
  • Brain / pathology
  • Brain / radiation effects
  • Brain Neoplasms / genetics
  • Brain Neoplasms / pathology
  • Brain Neoplasms / radiotherapy*
  • Brain Neoplasms / therapy
  • Cell Line, Tumor
  • DNA Repair*
  • DNA-(Apurinic or Apyrimidinic Site) Lyase / genetics
  • Disease Models, Animal
  • Drug Carriers / chemistry*
  • Glioblastoma / genetics
  • Glioblastoma / pathology
  • Glioblastoma / radiotherapy*
  • Glioblastoma / therapy
  • Mice
  • Nanoparticles / chemistry*
  • RNA, Small Interfering / administration & dosage
  • RNA, Small Interfering / therapeutic use*
  • RNAi Therapeutics / methods

Substances

  • Drug Carriers
  • RNA, Small Interfering
  • Apex1 protein, mouse
  • DNA-(Apurinic or Apyrimidinic Site) Lyase