Mechanism of heme oxygenase-1 gene activation by cadmium in MCF-7 mammary epithelial cells. Role of p38 kinase and Nrf2 transcription factor. Academic Article uri icon

Overview

MeSH

  • Animals
  • Base Sequence
  • Breast Neoplasms
  • Cell Line
  • Enzyme Inhibitors
  • Female
  • Flavonoids
  • Gene Expression Regulation, Neoplastic
  • HeLa Cells
  • Heme Oxygenase-1
  • Humans
  • L Cells (Cell Line)
  • Membrane Proteins
  • Mice
  • Mitogen-Activated Protein Kinase 1
  • Mitogen-Activated Protein Kinase 3
  • Mitogen-Activated Protein Kinase 9
  • Molecular Sequence Data
  • NF-E2-Related Factor 2
  • Transcription Factors
  • Transcriptional Activation
  • Tumor Cells, Cultured
  • p38 Mitogen-Activated Protein Kinases

MeSH Major

  • Cadmium
  • DNA-Binding Proteins
  • Epithelial Cells
  • Gene Expression Regulation, Enzymologic
  • Heme Oxygenase (Decyclizing)
  • Mitogen-Activated Protein Kinases
  • Trans-Activators
  • Transcription, Genetic

abstract

  • The mouse heme oxygenase-1 (HO-1) gene, ho-1, contains two inducible enhancers, E1 and E2. Of several cell lines tested, induction of an E1/luciferase fusion construct, pE1-luc, by CdCl(2) is most pronounced in MCF-7 cells. In these cells, E1, but not E2, is necessary and sufficient for ho-1 gene activation. Exposure of MCF-7 cells to 10 micrometer CdCl(2) stimulates phosphorylation of ERK, JNK, and p38 mitogen-activated protein kinases, implicating one or more of these signaling pathways in ho-1 gene induction. SB203580, an inhibitor of p38, diminishes cadmium-stimulated pE1-luc expression and HO-1 mRNA levels by up to 70-80%. PD098059, an ERK pathway inhibitor, does not affect HO-1 mRNA induction at the highest concentration (40 micrometer) tested. Similarly, co-expression of a dominant-negative mutant of p38alpha, but not of ERK1, ERK2, JNK1, or JNK2, reduces basal and cadmium-induced pE1-luc activity. E1 contains binding sites for the activator protein-1 (Fos/Jun), Cap'n'Collar/basic leucine zipper (CNC-bZIP), and CCAAT/enhancer-binding protein (C/EBP) families of transcription factors. A dominant-negative mutant of Nrf2 (a CNC-bZIP member), but not of c-Jun or C/EBPbeta, inhibits pE1-luc activation by cadmium. Induction of the endogenous ho-1 gene is also inhibited by the Nrf2 mutant. Mutations of E1 that inhibit cadmium inducibility also suppress the trans-activation and DNA binding activities of Nrf2, and SB203580, but not PD098059, attenuates Nrf2-mediated trans-activation of pE1-luc. Taken together, these results indicate that cadmium induces ho-1 gene expression via sequential activation of the p38 kinase pathway and Nrf2.

publication date

  • September 8, 2000

has subject area

  • Animals
  • Base Sequence
  • Breast Neoplasms
  • Cadmium
  • Cell Line
  • DNA-Binding Proteins
  • Enzyme Inhibitors
  • Epithelial Cells
  • Female
  • Flavonoids
  • Gene Expression Regulation, Enzymologic
  • Gene Expression Regulation, Neoplastic
  • HeLa Cells
  • Heme Oxygenase (Decyclizing)
  • Heme Oxygenase-1
  • Humans
  • L Cells (Cell Line)
  • Membrane Proteins
  • Mice
  • Mitogen-Activated Protein Kinase 1
  • Mitogen-Activated Protein Kinase 3
  • Mitogen-Activated Protein Kinase 9
  • Mitogen-Activated Protein Kinases
  • Molecular Sequence Data
  • NF-E2-Related Factor 2
  • Trans-Activators
  • Transcription Factors
  • Transcription, Genetic
  • Transcriptional Activation
  • Tumor Cells, Cultured
  • p38 Mitogen-Activated Protein Kinases

Research

keywords

  • Journal Article

Identity

Language

  • eng

Digital Object Identifier (DOI)

  • 10.1074/jbc.M004729200

PubMed ID

  • 10874044

Additional Document Info

start page

  • 27694

end page

  • 27702

volume

  • 275

number

  • 36