Geldanamycin inhibits NF-kappaB activation and interleukin-8 gene expression in cultured human respiratory epithelium

Am J Respir Cell Mol Biol. 2001 Jul;25(1):92-7. doi: 10.1165/ajrcmb.25.1.4384.


Geldanamycin is a benzoquinone ansamycin with multiple pharmacologic properties. Recent data demonstrated that geldanamycin conferred protection in an animal model of inflammation-associated acute lung injury. In the current study, we investigated the effects of geldanamycin on interleukin (IL)-8 gene expression and nuclear factor (NF)-kappaB activation. Geldanamycin inhibited tumor necrosis factor (TNF)-alpha-mediated IL-8 gene expression in A549 human respiratory epithelial cells as measured by enzyme-linked immunosorbent assay and Northern blot analyses. In cells transiently transfected with an IL-8 promoter-luciferase reporter plasmid, geldanamycin inhibited TNF-alpha-mediated luciferase activity. Geldanamycin inhibited TNF-alpha-mediated NF-kappaB activation as measured by electromobility shift assays and transient transfections with a NF-kappaB-dependent luciferase reporter plasmid. In contrast, geldanamycin did not affect TNF-alpha-mediated degradation of the NF-kappaB inhibitory protein IkappaBalpha and did not block nuclear translocation of the NF-kappaB p65 subunit as measured by Western blot analyses. Geldanamycin added directly to nuclear extracts of TNF-alpha-treated cells reduced the formation of the NF-kappaB/DNA complex. These results demonstrate that geldanamycin inhibits TNF-alpha-mediated IL-8 gene expression in A549 cells by inhibiting activation of the IL-8 promoter. The mechanism of inhibition involves inhibition of NF-kappaB activation, which is independent of IkappaBalpha degradation or p65 nuclear translocation. Geldanamycin appears to directly inhibit the ability of NF-kappaB to bind DNA. The observed in vitro effects could account, in part, for the anti-inflammatory properties of geldanamycin observed in vivo.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Benzoquinones
  • Cell Nucleus / metabolism
  • Cells, Cultured
  • DNA Probes
  • Enzyme Inhibitors / pharmacology*
  • Epithelial Cells / drug effects
  • Epithelial Cells / metabolism
  • Gene Expression Regulation / drug effects*
  • Humans
  • Hydrolysis
  • Interleukin-8 / genetics*
  • Lactams, Macrocyclic
  • Lung / cytology
  • Lung / drug effects*
  • Lung / metabolism
  • NF-kappa B / antagonists & inhibitors*
  • NF-kappa B / metabolism
  • Protein Transport
  • Protein-Tyrosine Kinases / antagonists & inhibitors
  • Quinones / pharmacology*
  • RNA, Messenger / genetics
  • Tumor Necrosis Factor-alpha / antagonists & inhibitors
  • Tumor Necrosis Factor-alpha / pharmacology


  • Benzoquinones
  • DNA Probes
  • Enzyme Inhibitors
  • Interleukin-8
  • Lactams, Macrocyclic
  • NF-kappa B
  • Quinones
  • RNA, Messenger
  • Tumor Necrosis Factor-alpha
  • Protein-Tyrosine Kinases
  • geldanamycin