Histone deacetylase inhibitor induced pVHL-independent degradation of HIF-1α and hierarchical quality control of pVHL via chaperone system

PLoS One. 2021 Jul 30;16(7):e0248019. doi: 10.1371/journal.pone.0248019. eCollection 2021.

Abstract

The mortality rate of ovarian cancer is increasing and the role of hypoxia inducible factor-1α (HIF-1α) in tumor progression has been confirmed. von Hippel-Lindau tumor suppressor protein (pVHL) binds HIF-1α and mediates proteasome degradation of HIF-1α. Besides, histone deacetylase inhibitor (HDACi) mitigates tumor growth via targeting HIF-1α, whereas underlying mechanism still requires investigation. In this research, we exposed ovarian cancer cell lines OV-90 and SKOV-3 to escalating concentrations of HDACi LBH589. As a result, cell viability was significantly suppressed and expression of HIF-1α was remarkably reduced along with decreased levels of signal molecules, including phosphoinositide 3-kinase (PI3K) and glycogen synthase kinase 3β (GSK3β) (P = 0.000). Interestingly, pVHL was expressed in a notably declining tendency (P = 0.000). Chaperone heat shock protein-70 (HSP70) was expressed in an ascending manner, whereas expression of chaperonin TCP-1α was reduced clearly (P = 0.000). Besides, co-inhibition of pVHL plus HDAC did not contribute to a remarkable difference in HIF-1α expression as compared with single HDAC inhibition. Furthermore, both cell lines were transfected with plasmids of VHL plus VHL binding protein-1 (VBP-1). Consequently, the expression of HIF-1α as well as lactate dehydrogenase-A (LDHA) was remarkably decreased (P = 0.000). These findings indicate HDACi may repress expression of HIF-1α via inhibiting PI3K and GSK3β and promote degradation of HIF-1α via HSP70, independent of pVHL. Additionally, a sophisticated network of HDAC and chaperones may involve in pVHL quality control.

MeSH terms

  • Cell Line, Tumor
  • Cell Survival / drug effects
  • Cytoskeletal Proteins / genetics
  • Cytoskeletal Proteins / metabolism
  • Down-Regulation / drug effects*
  • Glycogen Synthase Kinase 3 beta / metabolism
  • HSP90 Heat-Shock Proteins / metabolism
  • Histone Deacetylase Inhibitors / pharmacology*
  • Humans
  • Hypoxia-Inducible Factor 1, alpha Subunit / genetics
  • Hypoxia-Inducible Factor 1, alpha Subunit / metabolism*
  • Molecular Chaperones / genetics
  • Molecular Chaperones / metabolism
  • Phosphatidylinositol 3-Kinases / metabolism
  • Proteolysis / drug effects
  • Up-Regulation / drug effects*
  • Von Hippel-Lindau Tumor Suppressor Protein / genetics
  • Von Hippel-Lindau Tumor Suppressor Protein / metabolism*

Substances

  • Cytoskeletal Proteins
  • HIF1A protein, human
  • HSP90 Heat-Shock Proteins
  • Histone Deacetylase Inhibitors
  • Hypoxia-Inducible Factor 1, alpha Subunit
  • Molecular Chaperones
  • VBP1 protein, human
  • Von Hippel-Lindau Tumor Suppressor Protein
  • Glycogen Synthase Kinase 3 beta
  • VHL protein, human

Grants and funding

The authors received no specific funding for this work.