Snail regulates Nanog status during the epithelial-mesenchymal transition via the Smad1/Akt/GSK3β signaling pathway in non-small-cell lung cancer

Oncotarget. 2014 Jun 15;5(11):3880-94. doi: 10.18632/oncotarget.2006.


The epithelial-mesenchymal transition (EMT), a crucial step in cancer metastasis, is important in transformed cancer cells with stem cell-like properties. In this study, we established a Snail-overexpressing cell model for non-small-cell lung cancer (NSCLC) and investigated its underlying mechanism. We also identified the downstream molecular signaling pathway that contributes to the role of Snail in regulating Nanog expression. Our data shows that high levels of Snail expression correlate with metastasis and high levels of Nanog expression in NSCLC. NSCLC cells expressing Snail are characterized by active EMT characteristics and exhibit an increased ability to migrate, chemoresistance, sphere formation, and stem cell-like properties. We also investigated the signals required for Snail-mediated Nanog expression. Our data demonstrate that LY294002, SB431542, LDN193189, and Noggin pretreatment inhibit Snail-induced Nanog expression during EMT. This study shows a significant correlation between Snail expression and phosphorylation of Smad1, Akt, and GSK3β. In addition, pretreatment with SB431542, LDN193189, or Noggin prevented Snail-induced Smad1 and Akt hyperactivation and reactivated GSK3β. Moreover, LY294002 pretreatment prevented Akt hyperactivation and reactivated GSK3β without altering Smad1 activation. These findings provide a novel mechanistic insight into the important role of Snail in NSCLC during EMT and indicate potentially useful therapeutic targets for NSCLC.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Carcinoma, Non-Small-Cell Lung / metabolism
  • Carcinoma, Non-Small-Cell Lung / pathology*
  • Epithelial-Mesenchymal Transition / physiology
  • Female
  • Glycogen Synthase Kinase 3 / metabolism
  • Glycogen Synthase Kinase 3 beta
  • Heterografts
  • Homeodomain Proteins / metabolism*
  • Humans
  • Lung Neoplasms / metabolism
  • Lung Neoplasms / pathology*
  • Male
  • Mice
  • Mice, Inbred BALB C
  • Mice, SCID
  • Middle Aged
  • Nanog Homeobox Protein
  • Neoplastic Stem Cells / pathology
  • Proto-Oncogene Proteins c-akt / metabolism
  • Signal Transduction
  • Smad1 Protein / metabolism
  • Snail Family Transcription Factors
  • Transcription Factors / antagonists & inhibitors
  • Transcription Factors / metabolism*
  • Transfection


  • Homeodomain Proteins
  • NANOG protein, human
  • Nanog Homeobox Protein
  • SMAD1 protein, human
  • Smad1 Protein
  • Snail Family Transcription Factors
  • Transcription Factors
  • GSK3B protein, human
  • Glycogen Synthase Kinase 3 beta
  • Gsk3b protein, mouse
  • Proto-Oncogene Proteins c-akt
  • Glycogen Synthase Kinase 3