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Methods to Classify Cytoplasmic Foci as Mammalian Stress Granules
09:33

Methods to Classify Cytoplasmic Foci as Mammalian Stress Granules

Published on: May 12, 2017

The chemotherapeutic agent bortezomib induces the formation of stress granules

Marie-Josée Fournier1, Cristina Gareau, Rachid Mazroui

  • 1Centre de recherche de l'hôpital St-François d'Assise (CHUQ/CRSFA), 10 rue de l'Espinay, Quebec, QC G1L 3L5, Canada. rachid.mazroui@crsfa.ulaval.ca.

Cancer Cell International
|May 1, 2010
PubMed
Abstract

Insights

Bortezomib triggers stress granule formation in cancer cells, involving heme-regulated inhibitor kinase (HRI). This SG formation may be a resistance mechanism against bortezomib-induced cell death.

Area of Science:

  • Cell Biology
  • Cancer Research
  • Pharmacology

Background:

  • Cytoplasmic stress granules (SGs) sequester untranslated mRNAs, aiding cell survival under stress.
  • Stress conditions like hypoxia and viral infections induce SG formation.
  • Bortezomib, a proteasome inhibitor, treats hematological tumors but is less effective against solid tumors.

Purpose of the Study:

  • Investigate stress granule formation induced by bortezomib treatment.
  • Explore the role of heme-regulated inhibitor kinase (HRI) in this process.
  • Determine the implications of SG formation for cancer cell survival under bortezomib therapy.

Main Methods:

  • Treatment of cancer cells with bortezomib.
  • Analysis of stress granule formation.
  • Investigation of eIF2alpha phosphorylation and HRI activity.
  • HRI depletion experiments.

Main Results:

  • Bortezomib effectively induces stress granule formation in cancer cells.
  • Heme-regulated inhibitor kinase (HRI) mediates bortezomib-induced SG formation via eIF2alpha phosphorylation.
  • Depletion of HRI inhibits SG formation and enhances apoptosis.

Conclusions:

  • Bortezomib is the first chemotherapeutic agent shown to induce stress granules.
  • HRI activation and subsequent SG formation may represent a cancer cell resistance mechanism against bortezomib.
  • Understanding this pathway could inform strategies to overcome bortezomib resistance.

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