Combined proteasome and histone deacetylase inhibition in non-small cell lung cancer

J Thorac Cardiovasc Surg. 2004 Apr;127(4):1078-86. doi: 10.1016/s0022-5223(03)01321-7.


Objective: Inhibitors of histone deacetylases are potent inducers of cell-cycle arrest and apoptosis in certain malignancies. We have previously demonstrated that chemotherapy activates the antiapoptotic transcription factor nuclear factor kappa B in non-small cell lung cancer and fails to induce significant levels of apoptosis. We hypothesize that nuclear factor kappa B inhibition with the proteasome inhibitor bortezomib (formerly known as PS-341) will sensitize non-small cell lung cancer cells to histone deacetylase inhibitor-mediated apoptosis.

Methods: Tumorigenic non-small cell lung cancer cells (A549, H358, and H460) were treated with bortezomib, followed by the histone deactylase inhibitor sodium butyrate. After treatment, nuclear factor kappa B transcriptional activity was measured by using a luciferase reporter assay and transcription of the nuclear factor kappa B-dependent gene IL8. Apoptosis was determined on the basis of caspase-3 activation and DNA fragmentation. Western blot analyses for the cell-cycle regulatory proteins p21 and p53 were performed, and cell-cycle alterations were determined by means of FACS analysis. Experiments were performed in triplicate, and statistical significance was determined by using unpaired t tests.

Results: Butyrate increased nuclear factor kappa B transcriptional activity 4-fold relative to that seen in control cells (P =.05) in all non-small cell lung cancer cell lines. Treatment with bortezomib reduced butyrate-induced activation of nuclear factor kappa B to baseline levels. The proteins p21 and p53 were stabilized after treatment with bortezomib, correlating with a G(2)/M cell-cycle arrest. Treatment with butyrate alone resulted in minimal apoptosis, but combined histone deacetylase and proteasome inhibition increased apoptosis 3- to 4-fold (P =.02).

Conclusions: Combined molecular targeting of histone deacteylases and proteasomes synergistically induced apoptosis in non-small cell lung cancer. Pharmacologic nuclear factor kappa B suppression through proteasome inhibition, followed by treatment with histone deacetylase inhibitors, might represent a novel treatment strategy for patients with non-small cell lung cancer.

Publication types

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

MeSH terms

  • Antineoplastic Combined Chemotherapy Protocols / therapeutic use*
  • Apoptosis / drug effects
  • Boronic Acids / administration & dosage
  • Bortezomib
  • Butyrates / administration & dosage
  • Carcinoma, Non-Small-Cell Lung / drug therapy*
  • Carcinoma, Non-Small-Cell Lung / physiopathology
  • Cell Cycle / drug effects
  • Cell Survival / drug effects
  • Cysteine Endopeptidases / administration & dosage
  • Histone Deacetylases / administration & dosage
  • Humans
  • Interleukin-8 / genetics
  • Lung Neoplasms / drug therapy*
  • Lung Neoplasms / physiopathology
  • Multienzyme Complexes / administration & dosage
  • NF-kappa B / drug effects
  • NF-kappa B / metabolism
  • Protease Inhibitors / administration & dosage
  • Proteasome Endopeptidase Complex
  • Pyrazines / administration & dosage
  • Transcription, Genetic / drug effects
  • Transcriptional Activation / drug effects
  • Treatment Outcome
  • Tumor Cells, Cultured


  • Boronic Acids
  • Butyrates
  • Interleukin-8
  • Multienzyme Complexes
  • NF-kappa B
  • Protease Inhibitors
  • Pyrazines
  • Bortezomib
  • Cysteine Endopeptidases
  • Proteasome Endopeptidase Complex
  • Histone Deacetylases