NF-κB targets miR-16 and miR-21 in gastric cancer: involvement of prostaglandin E receptors

Carcinogenesis. 2011 Feb;32(2):240-5. doi: 10.1093/carcin/bgq240. Epub 2010 Nov 15.


Cigarette smoke is one of the risk factors for gastric cancer and nicotine has been reported to promote tumor growth. Deregulation of microRNA (miRNA) and cyclooxygenase-2 (COX-2) expressions are hallmarks of many cancers including gastric cancer. Here, we used an miRNA array platform covering a panel of 95 human miRNAs to examine the expression profile in nicotine-treated gastric cancer cells. We found that miR-16 and miR-21 were upregulated upon nicotine stimulation, transfection with anti-miR-16 or anti-miR-21 significantly abrogated cell proliferation. In contrast, ectopic miR-16 or miR-21 expression exhibited a similar stimulatory effect on cell proliferation as nicotine. Nicotine-mediated IkappaBα degradation and nuclear factor-kappa B (NF-κB) translocation dose-dependently. Knockdown of NF-κB by short interfering RNA (siRNA) or specific inhibitor (Bay-11-7085) markedly suppressed nicotine-induced cell proliferation and upregulation of miR-16 and miR-21. Interestingly, NF-κB-binding sites were located in both miR-16 and miR-21 gene transcriptional elements and we showed that nicotine enhanced the binding of NF-κB to the promoters of miR-16 and miR-21. Furthermore, activation of COX-2/prostaglandin E₂ (PGE₂) signaling in response to nicotine was mediated by the action of prostaglandin E receptors (EP2 and EP4). EP2 or EP4 siRNA or antagonists impaired the nicotine-mediated NF-κB activity, upregulation of miR-16 and miR-21 and cell proliferation. Taken together, these results suggest that miR-16 and miR-21 are directly regulated by the transcription factor NF-κB and yet nicotine-promoted cell proliferation is mediated via EP2/4 receptors. Perhaps this study may shed light on the development of anticancer drugs to improve the chemosensitivity in smokers.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Cell Line, Tumor
  • Cell Proliferation / drug effects
  • Humans
  • MicroRNAs / physiology*
  • NF-kappa B / physiology*
  • Nicotine / pharmacology
  • Receptors, Prostaglandin E, EP2 Subtype / physiology*
  • Receptors, Prostaglandin E, EP4 Subtype / physiology*
  • Signal Transduction
  • Stomach Neoplasms / pathology*


  • MIRN16 microRNA, human
  • MIRN21 microRNA, human
  • MicroRNAs
  • NF-kappa B
  • PTGER2 protein, human
  • Receptors, Prostaglandin E, EP2 Subtype
  • Receptors, Prostaglandin E, EP4 Subtype
  • Nicotine