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Standardized Methods for Measuring Induction of the Heat Shock Response in Caenorhabditis elegans
06:01

Standardized Methods for Measuring Induction of the Heat Shock Response in Caenorhabditis elegans

Published on: July 3, 2020

Heat shock-independent induction of multidrug resistance by heat shock factor 1

Thierry Tchénio1, Marilyne Havard, Luis A Martinez

  • 1Unité de Génétique Moléculaire et Intégrations des Fonctions Cellulaires, CNRS-UPR1983, 7 rue Guy Moquet, BP8, 94801 Villejuif Cedex, France. tchenio@infobiogen.fr

Molecular and Cellular Biology
|December 31, 2005
PubMed

Insights

Heat shock factor 1 (HSF1) confers constitutive doxorubicin resistance by activating the multidrug resistance gene 1 (MDR-1) independently of heat shock. This suggests a novel role for HSF1 in stress-independent drug resistance and gene regulation.

Area of Science:

  • Molecular Biology
  • Cellular Biology
  • Genetics

Background:

  • Multidrug resistance (MDR) is a significant challenge in cancer therapy.
  • Heat shock factor 1 (HSF1) is a transcription factor typically activated by cellular stress to induce heat shock proteins (HSPs).

Purpose of the Study:

  • To identify genes conferring constitutive doxorubicin resistance.
  • To investigate the role of HSF1 in multidrug resistance independent of cellular stress.

Main Methods:

  • Screening of retroviral cDNA expression libraries for doxorubicin resistance.
  • Analysis of HSF1 activity, MDR-1 expression, and HSP gene expression.
  • Characterization of HSF1 mutants and phosphorylation status.

Main Results:

  • HSF1 was isolated as a gene conferring constitutive doxorubicin resistance.
  • HSF1 induced MDR in a stress-independent manner, partly via MDR-1 activation.
  • This resistance did not correlate with increased HSP expression, and HSF1 mutants lacking HSP activation retained resistance.
  • Hypophosphorylated HSF1 complexes accumulated, suggesting a non-canonical role.

Conclusions:

  • HSF1 activates MDR-1 expression in a stress-independent pathway, distinct from canonical heat shock responses.
  • HSF1 plays a novel role in posttranscriptional gene regulation, specifically in MDR-1 induction.

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