Role of NF-κB signaling in hepatocyte growth factor/scatter factor-mediated cell protection

Saijun Fan, Min Gao, Qinghui Meng, John J. Laterra, Marc H. Symons, Sal Coniglio, Richard G. Pestell, Itzhak D. Goldberg, Eliot M. Rosen

Research output: Contribution to journalArticle

Abstract

The cytokine scatter factor/hepatocyte growth factor (HGF/SF) protects epithelial, carcinoma, and other cell types against cytotoxicity and apoptosis induced by DNA-damaging agents such as ionizing radiation and adriamycin (ADR, a topoisomerase IIα inhibitor). We investigated the role of nuclear factor kappa B (NF-κB) signaling in HGF/SF-mediated protection of human prostate cancer (DU-145) and Madin-Darby canine kidney (MDCK) epithelial cells against ADR. HGF/SF caused the rapid nuclear translocation of the p65 (RelA) subunit of NF-κB associated with the transient loss of the inhibitory subunit IκB-α. Exposure to HGF/SF caused the activation of an NF-κB luciferase reporter that was blocked or attenuated by the expression of a mutant 'super-repressor' IκB-α. Electrophoretic mobility shift assay supershift assays revealed that HGF/SF treatment induced the transient binding of various NF-κB family proteins (p65, p50, c-Rel, and RelB) with radiolabeled NF-κB-binding oligonucleotides. The HGF/SF-mediated protection of DU-145 and MDCK cells against ADR (demonstrated using MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assays) was abrogated by the IκB-α super-repressor. The ability of HGF/SF to activate NF-κB signaling was dependent on c-Akt→Pak1 (p21-associated kinase-1) signaling (with Pak1 downstream of c-Akt) and was inhibited by the tumor suppressor PTEN (phosphatase and tensin homolog). Inhibitors of phosphatidylinositol-3′-kinase and Src family kinases significantly inhibited HGF/SF-mediated activation of NF-κB, while inhibitors of MEK, protein kinase C, and p70 S6 kinase had a modest effect or no effect on NF-κB activity. HGF/ SF induced the expression of several known NF-κB target genes (cIAP-1 (cellular inhibitor of apoptosis-1), cIAP-2, and TRAF-2 (TNF receptor-associated factor-2)) in an NF-κB-dependent manner; HGF/SF blocked the inhibition of expression of these genes by ADR. Experimental manipulation of expression of these genes suggests that they (particularly TRAF-2 and cIAP-2) contribute to the protection against ADR by HGF/SF. These findings suggest that HGF/SF activates NF-κB through a c-Akt → Pak1 signaling pathway that is also dependent on Src, and that NF-κB contributes to HGF/SF-mediated protection against ADR.

Original languageEnglish (US)
Pages (from-to)1749-1766
Number of pages18
JournalOncogene
Volume24
Issue number10
DOIs
StatePublished - Mar 3 2005

Keywords

  • Hepatocyte growth factor (HGF)
  • IκB
  • NF-κB
  • Scatter factor (SF)
  • Super-repressor
  • p65

ASJC Scopus subject areas

  • Molecular Biology
  • Genetics
  • Cancer Research

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  • Cite this

    Fan, S., Gao, M., Meng, Q., Laterra, J. J., Symons, M. H., Coniglio, S., Pestell, R. G., Goldberg, I. D., & Rosen, E. M. (2005). Role of NF-κB signaling in hepatocyte growth factor/scatter factor-mediated cell protection. Oncogene, 24(10), 1749-1766. https://doi.org/10.1038/sj.onc.1208327