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Malachite Green Assay for the Discovery of Heat-Shock Protein 90 Inhibitors
07:57

Malachite Green Assay for the Discovery of Heat-Shock Protein 90 Inhibitors

Published on: January 20, 2023

Genes and proteins governing the cellular sensitivity to HSP90 inhibitors: a mechanistic perspective

Alison Maloney1, Paul A Clarke, Paul Workman

  • 1Cancer Research UK Centre for Cancer Therapeutics, Institute of Cancer Research, 15 Cotswold Rd, Sutton, Surrey, SM2 5NG, UK.

Current Cancer Drug Targets
|October 8, 2003
PubMed

Insights

HSP90 inhibitors like 17AAG show broad anti-cancer effects by targeting multiple oncogenic pathways. Understanding factors influencing cellular sensitivity is key to predicting patient response to these promising cancer therapies.

Area of Science:

  • Oncology
  • Molecular Biology
  • Pharmacology

Background:

  • Heat shock protein 90 (HSP90) inhibitors, exemplified by 17AAG, offer a therapeutic advantage by targeting multiple oncogenic client proteins.
  • This broad-spectrum approach inhibits critical cancer-promoting pathways and can modulate hallmarks of malignancy.
  • Despite broad anti-tumor activity in preclinical models, variable sensitivity among cancer cell lines necessitates investigation into response determinants.

Purpose of the Study:

  • To investigate the genes and proteins involved in the mechanism of action of HSP90 inhibitors.
  • To elucidate the significance of these factors for cellular sensitivity to HSP90 inhibitors.
  • To discuss the potential relevance of these determinants to cancer patient response.

Main Methods:

  • Utilized conventional cell and molecular biology techniques.
  • Applied high-throughput global technologies including gene expression microarrays and proteomics.
  • Analyzed expression of HSP90 client proteins, HSP90 family members, co-chaperones, and cell cycle/apoptotic regulators.

Main Results:

  • Identified key determinants of cellular sensitivity to HSP90 inhibitors.
  • Demonstrated that dependence on HSP90 client proteins (e.g., ERBB2, steroid hormone receptors, AKT/PKB) influences response.
  • Highlighted the role of HSP90 family member and co-chaperone levels (e.g., HSP70, AHA1) and regulators of cell cycle and apoptosis.

Conclusions:

  • Cellular sensitivity to HSP90 inhibitors is multifactorial.
  • Factors such as client protein dependence, HSP90 machinery levels, and cell cycle/apoptotic regulators are critical.
  • For 17AAG, metabolic enzymes (e.g., NQO1) and efflux pumps also impact sensitivity, informing clinical applicability.

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