Knockdown of the TP53-Induced Glycolysis and Apoptosis Regulator (TIGAR) Sensitizes Glioma Cells to Hypoxia, Irradiation and Temozolomide

Int J Mol Sci. 2019 Mar 1;20(5):1061. doi: 10.3390/ijms20051061.

Abstract

The TP53-induced glycolysis and apoptosis regulator (TIGAR) has been shown to decrease glycolysis, to activate the pentose phosphate pathway, and to provide protection against oxidative damage. Hypoxic regions are considered characteristic of glioblastoma and linked with resistance to current treatment strategies. Here, we established that LNT-229 glioma cell lines stably expressed shRNA constructs targeting TIGAR, and exposed them to hypoxia, irradiation and temozolomide. The disruption of TIGAR enhanced levels of reactive oxygen species and cell death under hypoxic conditions, as well as the effectiveness of irradiation and temozolomide. In addition, TIGAR was upregulated by HIF-1α. As a component of a complex network, TIGAR contributes to the metabolic adjustments that arise from either spontaneous or therapy-induced changes in tumor microenvironment.

Keywords: TP53-induced glycolysis and apoptosis regulator; glioma; hypoxia; hypoxia-inducible factor; irradiation; reactive oxygen species; temozolomide.

MeSH terms

  • Antineoplastic Agents / toxicity*
  • Apoptosis Regulatory Proteins
  • Cell Hypoxia
  • Cell Line, Tumor
  • Drug Resistance, Neoplasm
  • Glioma / metabolism*
  • Humans
  • Intracellular Signaling Peptides and Proteins / genetics*
  • Intracellular Signaling Peptides and Proteins / metabolism
  • Neurons / drug effects
  • Neurons / metabolism*
  • Neurons / radiation effects
  • Phosphoric Monoester Hydrolases
  • Radiation Tolerance*
  • Temozolomide / toxicity*

Substances

  • Antineoplastic Agents
  • Apoptosis Regulatory Proteins
  • Intracellular Signaling Peptides and Proteins
  • Phosphoric Monoester Hydrolases
  • TIGAR protein, human
  • Temozolomide