Combined inhibition of NF-κB and Bcl-2 triggers synergistic reduction of viability and induces apoptosis in melanoma cells

Oncol Res. 2013;21(4):173-80. doi: 10.3727/096504014X13887748696707.

Abstract

Constitutive activation of nuclear factor κB (NF-κB) characterizes melanoma cells. To explore the molecular mechanism of melanoma cell survival by constitutive NF-κB activation, we used the NF-κB inhibitor dehydroxymethylepoxyquinomicin (DHMEQ), which directly binds to NF-κB. DHMEQ abrogated constitutive NF-κB activity, which included RelA (p65)/p50 in melanoma cell lines G361 and HMV-II; however, the reduction of the viability was marginal. Expression of c-FLIP was not observed in the melanoma cell lines tested, and DHMEQ could not repress the expression of the Bcl-2 family proteins Bcl-2 and Bcl-xL. Concomitant treatment with DHMEQ and the inhibitor of antiapoptotic Bcl-2 family proteins, GX15-070, triggered synergistic reduction of the viability and induced apoptosis of G361 cells. These results indicate that abrogation of the NF-κB pathway alone is not sufficient to suppress the survival of melanoma cells. The NF-κB and the antiapoptotic Bcl-2 pathways cooperatively support the survival, and the dual targeting triggers synergistic reduction of the viability and induces apoptosis of melanoma cells.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Antineoplastic Combined Chemotherapy Protocols / pharmacology*
  • Apoptosis / drug effects
  • Apoptosis / physiology
  • Benzamides / administration & dosage
  • Benzamides / pharmacology*
  • Cell Line, Tumor
  • Cell Survival
  • Cyclohexanones / administration & dosage
  • Cyclohexanones / pharmacology*
  • Drug Synergism
  • Humans
  • Indoles
  • Melanoma / drug therapy*
  • Melanoma / metabolism
  • Melanoma / pathology
  • NF-kappa B / antagonists & inhibitors*
  • NF-kappa B / metabolism
  • Proto-Oncogene Proteins c-bcl-2 / antagonists & inhibitors*
  • Proto-Oncogene Proteins c-bcl-2 / metabolism
  • Pyrroles / administration & dosage
  • Pyrroles / pharmacology*
  • Signal Transduction / drug effects
  • Tumor Cells, Cultured

Substances

  • Benzamides
  • Cyclohexanones
  • Indoles
  • NF-kappa B
  • Proto-Oncogene Proteins c-bcl-2
  • Pyrroles
  • dehydroxymethylepoxyquinomicin
  • obatoclax