The cell cycle inhibitor p27Kip¹ controls self-renewal and pluripotency of human embryonic stem cells by regulating the cell cycle, Brachyury and Twist

Cell Cycle. 2011 May 1;10(9):1435-47. doi: 10.4161/cc.10.9.15421. Epub 2011 May 1.


The continued turn over of human embryonic stem cells (hESC) while maintaining an undifferentiated state is dependent on the regulation of the cell cycle. Here we asked the question if a single cell cycle gene could regulate the self-renewal or pluripotency properties of hESC. We identified that the protein expression of the p27(Kip)¹ cell cycle inhibitor is low in hESC cells and increased with differentiation. By adopting a gain and loss of function strategy we forced or reduced its expression in undifferentiating conditions to define its functional role in self-renewal and pluripotency. Using undifferentiation conditions, overexpression of p27(Kip)¹ in hESC lead to a G₁phase arrest with an enlarged and flattened hESC morphology and consequent loss of self-renewal ability. Loss of p27(Kip)¹ caused an elongated/scatter cell-like phenotype involving up-regulation of Brachyury and Twist gene expression. We demonstrate the novel finding that p27(Kip)¹ protein occupies the Twist1 gene promoter and manipulation of p27(Kip)¹ by gain and loss of function is associated with Twist gene expression changes. These results define p27(Kip)¹ expression levels as critical for self-renewal and pluripotency in hESC and suggest a role for p27(Kip)¹ in controlling an epithelial to mesenchymal transition (EMT) in hESC.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Apoptosis / genetics
  • Cell Cycle / genetics*
  • Cell Differentiation / genetics*
  • Cells, Cultured
  • Cyclin-Dependent Kinase Inhibitor p27 / biosynthesis
  • Cyclin-Dependent Kinase Inhibitor p27 / deficiency
  • Cyclin-Dependent Kinase Inhibitor p27 / physiology*
  • Embryonic Stem Cells / cytology*
  • Embryonic Stem Cells / metabolism*
  • Embryonic Stem Cells / physiology
  • Epithelial-Mesenchymal Transition / physiology
  • Fetal Proteins / biosynthesis
  • Fetal Proteins / genetics
  • Fetal Proteins / metabolism*
  • Gene Expression Regulation, Developmental / physiology
  • Gene Knockdown Techniques / methods
  • Growth Inhibitors / physiology*
  • Humans
  • Induced Pluripotent Stem Cells / cytology
  • Induced Pluripotent Stem Cells / physiology
  • Keratinocytes / cytology
  • Keratinocytes / physiology
  • Nuclear Proteins / genetics
  • Nuclear Proteins / metabolism*
  • Promoter Regions, Genetic
  • T-Box Domain Proteins / biosynthesis
  • T-Box Domain Proteins / genetics
  • T-Box Domain Proteins / metabolism*
  • Twist-Related Protein 1 / genetics
  • Twist-Related Protein 1 / metabolism*
  • Up-Regulation / genetics


  • CDKN1B protein, human
  • Fetal Proteins
  • Growth Inhibitors
  • Nuclear Proteins
  • T-Box Domain Proteins
  • TWIST1 protein, human
  • Twist-Related Protein 1
  • Cyclin-Dependent Kinase Inhibitor p27
  • Brachyury protein