Coordinated autophagy modulation overcomes glioblastoma chemoresistance through disruption of mitochondrial bioenergetics

Sci Rep. 2018 Jul 9;8(1):10348. doi: 10.1038/s41598-018-28590-9.

Abstract

Glioblastoma Multiforme (GBM) is known to be one of the most malignant and aggressive forms of brain cancer due to its resistance to chemotherapy. Recently, GBM was found to not only utilise both oxidative phosphorylation (OXPHOS) and aerobic glycolysis, but also depend on the bulk protein degradation system known as macroautophagy to uphold proliferation. Although autophagy modulators hold great potential as adjuvants to chemotherapy, the degree of upregulation or inhibition necessary to achieve cell death sensitisation remains unknown. Therefore, this study aimed to determine the degree of autophagy modulation necessary to impair mitochondrial bioenergetics to the extent of promoting cell death onset. It was shown that coordinated upregulation of autophagy followed by its inhibition prior to chemotherapy decreased electron transfer system (ETS) and oxidative phosphorylation (OXPHOS) capacity, impaired mitochondrial fission and fusion dynamics and enhanced apoptotic cell death onset in terms of cleaved caspase 3 and cleaved PARP expression. Therefore, coordinated autophagy modulation may present a favourable avenue for improved chemotherapeutic intervention in the future.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Antineoplastic Agents / pharmacology
  • Autophagy* / drug effects
  • Autophagy-Related Protein 5 / antagonists & inhibitors
  • Autophagy-Related Protein 5 / genetics
  • Autophagy-Related Protein 5 / metabolism
  • Brain Neoplasms / metabolism
  • Brain Neoplasms / pathology
  • Cell Line, Tumor
  • Cell Survival / drug effects
  • Drug Resistance, Neoplasm* / drug effects
  • Electron Transport Complex I / metabolism
  • Glioblastoma / metabolism
  • Glioblastoma / pathology
  • Humans
  • Lactic Acid / metabolism
  • Mitochondria / metabolism*
  • Mitochondrial Dynamics / drug effects
  • Oxidative Phosphorylation / drug effects
  • RNA Interference
  • RNA, Small Interfering / metabolism
  • Temozolomide / pharmacology

Substances

  • ATG5 protein, human
  • Antineoplastic Agents
  • Autophagy-Related Protein 5
  • RNA, Small Interfering
  • Lactic Acid
  • Electron Transport Complex I
  • Temozolomide