Maternal cigarette smoking during pregnancy is associated with downregulation of miR-16, miR-21, and miR-146a in the placenta

Epigenetics. 2010 Oct 1;5(7):583-9. doi: 10.4161/epi.5.7.12762. Epub 2010 Oct 1.


Maternal cigarette smoking during pregnancy is associated with poor fetal outcome and aberrant miRNA expression is associated with adverse pregnancy outcomes. In 25 human placentas, we analyzed the expression of four candidate miRNA previously implicated in growth and developmental processes: miR-16, miR-21, miR-146a, and miR-182, and used three immortalized placental cell lines to identify if specific components of cigarette smoke were responsible for alterations to miRNA expression. miR-16, miR-21, and miR-146a were significantly downregulated in cigarette smoke-exposed placentas compared to controls. TCL-1 cells exposed to both nicotine and benzo(a)pyrene exhibited significant, dose-dependent downregulation of miR-146a. These results suggest that miR-146a is particularly responsive to exposures, and that smoking may elicit some of its downstream effects through alteration of miRNA expression.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Benzo(a)pyrene / toxicity
  • Case-Control Studies
  • Cell Line
  • Down-Regulation / drug effects
  • Female
  • Humans
  • Infant, Newborn
  • Male
  • MicroRNAs / genetics*
  • MicroRNAs / metabolism
  • Nicotine / toxicity
  • Placenta / drug effects
  • Placenta / metabolism*
  • Pregnancy
  • Pregnancy Outcome
  • Smoking / adverse effects*
  • Smoking / genetics*
  • Smoking / metabolism
  • Young Adult


  • MIRN146 microRNA, human
  • MIRN16 microRNA, human
  • MIRN21 microRNA, human
  • MicroRNAs
  • Mirn182 microRNA, human
  • Benzo(a)pyrene
  • Nicotine