5-Lipoxygenase is a direct p53 target gene in humans

Biochim Biophys Acta. 2015 Aug;1849(8):1003-16. doi: 10.1016/j.bbagrm.2015.06.004. Epub 2015 Jun 9.


The p53 tumor suppressor plays a critical role in cancer, and more than 50% of human tumors contain mutations or deletions of the TP53 gene. p53 can transactivate or repress target genes in response to diverse stress signals, such as transient growth arrest, DNA repair, cellular differentiation, senescence and apoptosis. Through an unbiased genome-wide ChIP-seq analysis, we have found that 5-lipoxygenase (ALOX5, 5-LO) which is a key enzyme of leukotriene (LT) biosynthesis, is a direct target gene of p53 and its expression is induced by genotoxic stress via actinomycin D (Act.D) or etoposide (Eto) treatment. 5-LO and LTs play a role in immunological diseases as well as in tumorigenesis and tumor growth. p53 binds to a specific binding site consisting of a complete p53 consensus-binding motif in ALOX5 intron G which is located about 64kbp downstream of the transcriptional start site. We confirmed the strong binding of p53 to the 5-LO target site in ChIP-qPCR experiments. Expression analyses by qRT-PCR and immunoblot further revealed that genotoxic stress induces the ALOX5 mRNA and protein expression in a p53-dependent manner. Knockdown of p53 in U2OS cells leads to a downregulation of 5-LO mRNA and protein expression. In addition, immunofluorescence and immunoprecipitation assays indicate the direct binding of 5-LO to p53 protein. Furthermore, we found that 5-LO can inhibit the transcriptional activity of p53 suggesting that 5-LO acts in a negative feedback loop to limit induction of p53 target genes.

Keywords: 5-Lipoxygenase; Chromatin immunoprecipitation; Leukemia; Leukotriene; p21; p53.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Arachidonate 5-Lipoxygenase / genetics*
  • Binding Sites
  • DNA Damage / drug effects
  • DNA Damage / physiology
  • Dactinomycin / pharmacology
  • Etoposide / pharmacology
  • Gene Expression Regulation, Enzymologic*
  • Gene Expression Regulation, Neoplastic*
  • HCT116 Cells
  • HEK293 Cells
  • HeLa Cells
  • Humans
  • Promoter Regions, Genetic / drug effects
  • Tumor Cells, Cultured
  • Tumor Suppressor Protein p53 / physiology*


  • TP53 protein, human
  • Tumor Suppressor Protein p53
  • Dactinomycin
  • Etoposide
  • Arachidonate 5-Lipoxygenase
  • ALOX5 protein, human