Hepatocyte growth factor-mediated gastrin-releasing peptide induces IL-8 expression through Ets-1 in gastric cancer cells

Oncol Res. 2013;20(9):393-402. doi: 10.3727/096504013X13657689382770.

Abstract

Gastric cancer cells secrete a variety of proangiogenic molecules, including IL-8 and VEGF. However, factors regulating the expression of proangiogenic genes for gastric cancer remain largely undefined. We investigated the role of HGF-induced activation of GRP and Ets-1 transcription factor in expression of the proangiogenic factor IL-8. The genes associated with angiogenesis induced by HGF were screened using cDNA micro-array technology in two gastric cancer cell lines (NUGC-3 and MKN-28). First, GRP RNA and protein were confirmed to be upregulated. Then, expression of GRP, Ets-1, and IL-8 were further estimated by Western blot analysis. A role for Ets-1 in HGF-induced upregulation of IL-8 was determined by knockdown of Ets-1 with Ets-1 sh-RNA and a chromatin immune precipitation assay. The levels of GRP, Ets-1, and IL-8 were upregulated in cells treated with HGF in a dose-dependent manner. HGF-induced expression of Ets-1 and IL-8 was increased more by GRP treatment and inhibited by pretreatment with an ERK 1/2 inhibitor (PD098059). HGF-induced upregulation of IL-8 was repressed by Ets-1 knockdown. HGF enhanced the binding activity of Ets-1 to the IL-8 promoter in control cells, but not in the Ets-1 shRNA cells. We confirmed the functional role of HGF-induced Ets-1 in activation of the IL-8 promoter by the reporter gene assay. Downregulation of IL-8 also decreased in vitro cell invasion. In conclusion, HGF mediated the GRP induction of IL-8 expression through Ets-1, which thus might serve as a promising target for gastric cancer therapy.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adenocarcinoma / blood supply
  • Adenocarcinoma / genetics*
  • Adenocarcinoma / pathology
  • Base Sequence
  • Cell Line, Tumor / pathology
  • Extracellular Signal-Regulated MAP Kinases / antagonists & inhibitors
  • Extracellular Signal-Regulated MAP Kinases / physiology
  • Flavonoids / pharmacology
  • Gastrin-Releasing Peptide / physiology*
  • Gene Expression Regulation, Neoplastic* / drug effects
  • Gene Knockdown Techniques
  • Genes, Reporter
  • Genes, fos
  • Genes, jun
  • Hepatocyte Growth Factor / physiology*
  • Humans
  • Interleukin-8 / biosynthesis*
  • Interleukin-8 / genetics
  • MAP Kinase Signaling System / drug effects
  • Molecular Sequence Data
  • Neoplasm Invasiveness
  • Neoplasm Proteins / biosynthesis
  • Neoplasm Proteins / genetics
  • Neoplasm Proteins / physiology*
  • Neovascularization, Pathologic / genetics*
  • Promoter Regions, Genetic
  • Proto-Oncogene Protein c-ets-1 / genetics
  • Proto-Oncogene Protein c-ets-1 / physiology*
  • RNA, Small Interfering / pharmacology
  • Stomach Neoplasms / blood supply
  • Stomach Neoplasms / genetics*
  • Stomach Neoplasms / pathology

Substances

  • ETS1 protein, human
  • Flavonoids
  • HGF protein, human
  • Interleukin-8
  • Neoplasm Proteins
  • Proto-Oncogene Protein c-ets-1
  • RNA, Small Interfering
  • Hepatocyte Growth Factor
  • Gastrin-Releasing Peptide
  • Extracellular Signal-Regulated MAP Kinases
  • 2-(2-amino-3-methoxyphenyl)-4H-1-benzopyran-4-one