IκBζ, an atypical member of the inhibitor of nuclear factor kappa B family, is induced by γ-irradiation in glioma cells, regulating cytokine secretion and associated with poor prognosis

Int J Oncol. 2015 Nov;47(5):1971-80. doi: 10.3892/ijo.2015.3159. Epub 2015 Sep 14.

Abstract

The inhibitor of nuclear factor kappa B zeta (IκBζ) is an atypical member of the IκB protein family. Its function in regulating the activity of the transcription factor nuclear factor kappa B (NFκB) as well as its involvement in cancer-associated processes is poorly understood. In glioma patients, enhanced expression of IκBζ in tumor specimen is associated with poor prognosis. Here we report that IκBζ is upregulated in a glioma cell line resistant towards NFκB-dependent non-apoptotic cell death. Upon γ-irradiation of glioma cells, IκBζ expression is enhanced, and subsequently serves as a transcriptional activator of the tumor promoting cytokines interleukin (IL-6), IL-8 and chemokine (C-X-C motif) ligand 1 (CXCL1) that are known to be involved in glioma associated inflammatory processes. In contrast, shRNA-mediated knockdown of IκBζ reduces the expression of the aforementioned cytokines. We propose a previously unappreciated role of IκBζ in the inflammatory micromilieu as well as progression in glioma.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adaptor Proteins, Signal Transducing
  • Carcinogenesis / genetics*
  • Cell Death / radiation effects
  • Cell Line, Tumor
  • Chemokine CXCL1 / biosynthesis
  • Gamma Rays
  • Gene Expression Regulation, Neoplastic / radiation effects
  • Glioma / genetics*
  • Humans
  • I-kappa B Proteins / antagonists & inhibitors
  • I-kappa B Proteins / biosynthesis*
  • I-kappa B Proteins / genetics
  • Interleukin-6 / biosynthesis
  • Interleukin-8 / biosynthesis
  • NF-kappa B / biosynthesis
  • NF-kappa B / genetics*
  • Nuclear Proteins / antagonists & inhibitors
  • Nuclear Proteins / biosynthesis*
  • Nuclear Proteins / genetics
  • Prognosis
  • RNA, Small Interfering

Substances

  • Adaptor Proteins, Signal Transducing
  • CXCL1 protein, human
  • Chemokine CXCL1
  • I-kappa B Proteins
  • Interleukin-6
  • Interleukin-8
  • NF-kappa B
  • NFKBIZ protein, human
  • Nuclear Proteins
  • RNA, Small Interfering