Prostaglandin E2 stimulates β1-integrin expression in hepatocellular carcinoma through the EP1 receptor/PKC/NF-κB pathway

Sci Rep. 2014 Oct 7:4:6538. doi: 10.1038/srep06538.

Abstract

Prostaglandin E2 (PGE2) has been implicated in cell invasion in hepatocellular carcinoma (HCC), via increased β1-integrin expression and cell migration; however, the mechanism remains unclear. PGE2 exerts its effects via four subtypes of the E prostanoid receptor (EP receptor 1-4). The present study investigated the effect of EP1 receptor activation on β1-integrin expression and cell migration in HCC. Cell migration increased by 60% in cells treated with 17-PT-PGE2 (EP1 agonist), which was suppressed by pretreatment with a β1-integrin polyclonal antibody. PGE2 increased β1-integrin expression by approximately 2-fold. EP1 receptor transfection or treatment with 17-PT-PGE2 mimicked the effect of PGE2 treatment. EP1 siRNA blocked PGE2-mediated β1-integrin expression. 17-PT-PGE2 treatment induced PKC and NF-κB activation; PKC and NF-κB inhibitors suppressed 17-PT-PGE2-mediated β1-integrin expression. FoxC2, a β1-integrin transcription factor, was also upregulated by 17-PT-PGE2. NF-κB inhibitor suppressed 17-PT-PGE2-mediated FoxC2 upregulation. Immunohistochemistry showed p65, FoxC2, EP1 receptor and β1-integrin were all highly expressed in the HCC cases. This study suggested that PGE2 upregulates β1-integrin expression and cell migration in HCC cells by activating the PKC/NF-κB signaling pathway. Targeting PGE2/EP1/PKC/NF-κB/FoxC2/β1-integrin pathway may represent a new therapeutic strategy for the prevention and treatment of this cancer.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Carcinoma, Hepatocellular / genetics*
  • Carcinoma, Hepatocellular / pathology
  • Cell Line, Tumor
  • Cell Movement / genetics
  • Dinoprostone / genetics
  • Dinoprostone / metabolism*
  • Gene Expression Regulation, Neoplastic / drug effects
  • Gene Expression Regulation, Neoplastic / genetics
  • Humans
  • Integrin beta1 / biosynthesis*
  • Integrin beta1 / genetics
  • Liver Neoplasms / genetics*
  • Liver Neoplasms / pathology
  • NF-kappa B / antagonists & inhibitors
  • NF-kappa B / genetics
  • Protein Kinase C / genetics
  • Receptors, Prostaglandin E, EP1 Subtype / genetics
  • Receptors, Prostaglandin E, EP1 Subtype / metabolism*
  • Signal Transduction / genetics

Substances

  • Integrin beta1
  • NF-kappa B
  • Receptors, Prostaglandin E, EP1 Subtype
  • Protein Kinase C
  • Dinoprostone