Stabilization of p53 is a novel mechanism for proapoptotic function of NF-kappaB

J Biol Chem. 2004 Jun 25;279(26):27549-59. doi: 10.1074/jbc.M313435200. Epub 2004 Apr 21.

Abstract

Both pro- and antiapoptotic activities of NF-kappaB transcription factor have been observed; however, less is known about the mechanism by which NF-kappaB induces apoptosis. To elucidate how NF-kappaB regulates proapoptotic signaling, we performed functional analyses using wild-type, ikk1(-/-), ikk2(-/-), rela(-/-) murine fibroblasts, MDAPanc-28/Puro, MDAPanc-28/IkappaBalphaM, and HCT116/p53(+/+) and HCT116/p53(-/-) cells with investigational anticancer agent doxycycline as a superoxide inducer for generating apoptotic stimulus. In this report, we show that doxycycline increased superoxide generation and subsequently activated NF-kappaB, which in turn up-regulated p53 expression and increased the stability and DNA binding activity of p53. Consequently, NF-kappaB-dependent p53 activity induced the expression of p53-regulated genes PUMA and p21(waf1) as well as apoptosis. Importantly, lack of RelA, IKK, and p53 as well as expression of a dominant negative IkappaBalpha (IkappaBalphaM) inhibited NF-kappaB-dependent p53 activation and apoptosis. The doxycycline-induced NF-kappaB activation was not inhibited in HCT116/p53(-/-) cells. Our results demonstrate that NF-kappaB plays an essential role in activation of wild-type p53 tumor suppressor to initiate proapoptotic signaling in response to overgeneration of superoxide. Thus, these findings reveal a mechanism of NF-kappaB-regulated proapoptotic signaling.

Publication types

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

MeSH terms

  • Animals
  • Apoptosis / drug effects
  • Apoptosis / physiology*
  • Apoptosis Regulatory Proteins
  • Boronic Acids / pharmacology
  • Bortezomib
  • Cell Line, Tumor
  • Cyclin-Dependent Kinase Inhibitor p21
  • Cyclins / biosynthesis
  • Cyclins / genetics
  • Down-Regulation
  • Doxycycline / pharmacology
  • Fibroblasts / cytology
  • Fibroblasts / metabolism
  • Humans
  • I-kappa B Kinase
  • I-kappa B Proteins / genetics
  • I-kappa B Proteins / metabolism
  • Mice
  • NF-kappa B / deficiency
  • NF-kappa B / genetics
  • NF-kappa B / metabolism
  • NF-kappa B / physiology*
  • Nuclear Proteins / biosynthesis
  • Nuclear Proteins / genetics
  • Phosphorylation
  • Protease Inhibitors / pharmacology
  • Protein Serine-Threonine Kinases / deficiency
  • Protein Serine-Threonine Kinases / genetics
  • Protein Serine-Threonine Kinases / metabolism
  • Proto-Oncogene Proteins / biosynthesis
  • Proto-Oncogene Proteins / genetics
  • Proto-Oncogene Proteins c-mdm2
  • Pyrazines / pharmacology
  • Superoxides / metabolism
  • Transcription Factor RelA
  • Tumor Suppressor Protein p53 / biosynthesis
  • Tumor Suppressor Protein p53 / deficiency
  • Tumor Suppressor Protein p53 / genetics
  • Tumor Suppressor Protein p53 / metabolism*
  • Up-Regulation

Substances

  • Apoptosis Regulatory Proteins
  • BBC3 protein, human
  • Boronic Acids
  • CDKN1A protein, human
  • Cdkn1a protein, mouse
  • Cyclin-Dependent Kinase Inhibitor p21
  • Cyclins
  • I-kappa B Proteins
  • NF-kappa B
  • Nuclear Proteins
  • Protease Inhibitors
  • Proto-Oncogene Proteins
  • Pyrazines
  • Transcription Factor RelA
  • Tumor Suppressor Protein p53
  • Superoxides
  • Bortezomib
  • MDM2 protein, human
  • Mdm2 protein, mouse
  • Proto-Oncogene Proteins c-mdm2
  • Protein Serine-Threonine Kinases
  • CHUK protein, human
  • Chuk protein, mouse
  • I-kappa B Kinase
  • IKBKB protein, human
  • IKBKE protein, human
  • Ikbkb protein, mouse
  • Ikbke protein, mouse
  • Doxycycline