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Updated: Jun 25, 2026
06:51
Studies of Chaperone-Cochaperone Interactions using Homogenous Bead-Based Assay
Published on: July 21, 2021
Death by chaperone: HSP90, HSP70 or both?
Marissa V Powers1, Paul A Clarke, Paul Workman
1Signal Transduction and Molecular Pharmacology Team, Cancer Research UK Centre for Cancer Therapeutics, The Institute of Cancer Research, Haddow Laboratories, Sutton, UK.
Cell Cycle (Georgetown, Tex.)
|February 7, 2009
Summary
Dual silencing of heat shock protein 70 (HSP70) isoforms in cancer cells inhibits HSP90 clients, inducing tumor-specific apoptosis. This suggests HSP70 modulators could target both HSP70 and HSP90 for cancer therapy.
Area of Science:
- Molecular Biology
- Cell Biology
- Oncology
Background:
- Heat shock protein 70 (HSP70) family members are conserved molecular chaperones crucial for protein folding, localization, and cell survival.
- HSP70 isoforms inhibit apoptosis and are often overexpressed in malignant cells.
- HSP70 functions with the HSP90 chaperone system, aiding in substrate recruitment.
Purpose of the Study:
- To investigate the effects of dual silencing of HSP70 isoforms (HSC70 and HSP72) in cancer cells.
- To explore the potential of HSP70 modulators as a dual-targeting cancer therapy.
Main Methods:
- Dual silencing of constitutive (HSC70) and inducible (HSP72) HSP70 isoforms in cancer cells.
- Assessing the impact on HSP90 client proteins (CRAF, CDK4, ERBB2) and proteasome-dependent degradation.
- Evaluating cell cycle progression (G1 arrest) and apoptosis induction.
- Comparing effects in cancer cells versus non-tumorigenic human cell lines.
Main Results:
- Dual HSP70 silencing phenocopied HSP90 inhibition, leading to proteasome-dependent degradation of HSP90 client proteins.
- Cancer cells exhibited G1 cell cycle arrest and extensive apoptosis.
- Non-tumorigenic cell lines did not show these effects, indicating tumor specificity.
Conclusions:
- Simultaneous inhibition of HSP70 and HSP90 via HSP70 modulators can induce extensive tumor-specific apoptosis.
- This dual-targeting strategy holds promise for novel cancer therapeutics.
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