Up-regulation of glyceraldehyde-3-phosphate dehydrogenase gene expression by HIF-1 activity depending on Sp1 in hypoxic breast cancer cells

Arch Biochem Biophys. 2011 May 1;509(1):1-8. doi: 10.1016/j.abb.2011.02.011. Epub 2011 Feb 19.

Abstract

Hypoxia up-regulates the expression of glyceraldehyde-3-phosphate dehydrogenase (GAPDH) in a cell type-specific manner. It is unknown whether this occurs in breast cancer. Here, we report that hypoxia up-regulates the GAPDH gene expression through breast cancer-specific molecular mechanisms in MCF-7 cells. Mutation analysis identified a novel hypoxia response element (HRE), in addition to the HRE found previously in prostate cancer LNCaP cells. Knockdown and overexpression of hypoxia-inducible factor (HIF)-1α indicated that HIF-1 contributed to the up-regulation of GAPDH gene expression by hypoxia. Although chromatin immunoprecipitation (ChIP) and plasmid immunoprecipitation analyses revealed the presence of HIF-1α on the novel HRE in both hypoxic cell lines, a mutation in either the novel HRE or its 3'-flanking GC-box resulted in a reduction of hypoxia-increased GAPDH promoter activity only in MCF-7 cells. ChIP analysis showed that Sp1 bound to the GC-box in MCF-7 cells, but not in LNCaP cells, in normoxia and hypoxia. Knockdown of Sp1 reduced hypoxia-increased promoter activity and expression level of GAPDH in MCF-7 cells. These results indicate that in MCF-7 cells, the activation of HIF-1 on the novel HRE contributes to the breast cancer-specific hypoxic induction of GAPDH gene expression and absolutely depends on the presence of Sp1 on the GC-box.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Breast Neoplasms / genetics*
  • Breast Neoplasms / metabolism
  • Cell Hypoxia*
  • Cell Line, Tumor
  • Female
  • Gene Expression Regulation, Neoplastic*
  • Glyceraldehyde-3-Phosphate Dehydrogenases / genetics*
  • Humans
  • Hypoxia-Inducible Factor 1 / metabolism*
  • Male
  • Prostatic Neoplasms / genetics
  • Prostatic Neoplasms / metabolism
  • Response Elements
  • Sp1 Transcription Factor / metabolism*
  • Transcriptional Activation
  • Up-Regulation

Substances

  • Hypoxia-Inducible Factor 1
  • Sp1 Transcription Factor
  • Glyceraldehyde-3-Phosphate Dehydrogenases