Reactive oxygen species from NAD(P)H:quinone oxidoreductase constitutively activate NF-kappaB in malignant melanoma cells.


Journal Article

The transcription factor nuclear factor-kappaB (NF-kappaB) is constitutively activated in malignancies from enhanced activity of inhibitor of NF-kappaB (IkappaB) kinase, with accelerated IkappaBalpha degradation. We studied whether redox signaling might stimulate these events. Cultured melanoma cells generated superoxide anions (O(2)(-)) without serum stimulation. O(2)(-) generation was reduced by the NAD(P)H:quinone oxidoreductase (NQO) inhibitor dicumarol and the quinone analog capsaicin, suggesting that electron transfer from NQO through a quinone-mediated pathway may be an important source of endogenous reactive oxygen species (ROS) in tumor cells. Treatment of malignant melanoma cells with the H(2)O(2) scavenger catalase, the sulfhydryl donor N-acetylcysteine, the glutathione peroxidase mimetic ebselen, or dicumarol decreased NF-kappaB activation. Catalase, N-acetylcysteine, ebselen, dicumarol, and capsaicin also inhibited growth of melanoma and other malignant cell lines. These results raise the possibility that ROS produced endogenously by mechanisms involving NQO can constitutively activate NF-kappaB in an autocrine fashion and suggest the potential for new antioxidant strategies for interruption of oxidant signaling of melanoma cell growth.

Full Text

Cited Authors

  • Brar, SS; Kennedy, TP; Whorton, AR; Sturrock, AB; Huecksteadt, TP; Ghio, AJ; Hoidal, JR

Published Date

  • March 2001

Published In

Volume / Issue

  • 280 / 3

Start / End Page

  • C659 - C676

PubMed ID

  • 11171586

Pubmed Central ID

  • 11171586

Electronic International Standard Serial Number (EISSN)

  • 1522-1563

International Standard Serial Number (ISSN)

  • 0363-6143

Digital Object Identifier (DOI)

  • 10.1152/ajpcell.2001.280.3.c659


  • eng