Conditionally reprogrammed cells represent a stem-like state of adult epithelial cells

Proc Natl Acad Sci U S A. 2012 Dec 4;109(49):20035-40. doi: 10.1073/pnas.1213241109. Epub 2012 Nov 19.


The combination of irradiated fibroblast feeder cells and Rho kinase inhibitor, Y-27632, conditionally induces an indefinite proliferative state in primary mammalian epithelial cells. These conditionally reprogrammed cells (CRCs) are karyotype-stable and nontumorigenic. Because self-renewal is a recognized property of stem cells, we investigated whether Y-27632 and feeder cells induced a stem-like phenotype. We found that CRCs share characteristics of adult stem cells and exhibit up-regulated expression of α6 and β1 integrins, ΔNp63α, CD44, and telomerase reverse transcriptase, as well as decreased Notch signaling and an increased level of nuclear β-catenin. The induction of CRCs is rapid (occurs within 2 d) and results from reprogramming of the entire cell population rather than the selection of a minor subpopulation. CRCs do not overexpress the transcription factor sets characteristic of embryonic or induced pluripotent stem cells (e.g., Sox2, Oct4, Nanog, or Klf4). The induction of CRCs is also reversible, and removal of Y-27632 and feeders allows the cells to differentiate normally. Thus, when CRCs from ectocervical epithelium or tracheal epithelium are placed in an air-liquid interface culture system, the cervical cells form a well differentiated stratified squamous epithelium, whereas the tracheal cells form a ciliated airway epithelium. We discuss the diagnostic and therapeutic opportunities afforded by a method that can generate adult stem-like cells in vitro without genetic manipulation.

Publication types

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

MeSH terms

  • Adult Stem Cells / cytology*
  • Adult Stem Cells / drug effects
  • Amides / pharmacology*
  • Antigens, Surface / metabolism
  • Blotting, Western
  • Cell Proliferation / drug effects*
  • Cellular Reprogramming / drug effects
  • Cellular Reprogramming / physiology*
  • Enzyme Inhibitors / pharmacology*
  • Epithelial Cells / cytology*
  • Epithelial Cells / drug effects
  • Feeder Cells
  • Flow Cytometry
  • Humans
  • Hyaluronan Receptors / metabolism
  • Immunohistochemistry
  • Integrin beta1 / metabolism
  • Karyotyping
  • Kruppel-Like Factor 4
  • Pyridines / pharmacology*
  • Real-Time Polymerase Chain Reaction
  • Telomerase / metabolism
  • Transcription Factors / metabolism
  • Tumor Suppressor Proteins / metabolism


  • Amides
  • Antigens, Surface
  • Enzyme Inhibitors
  • Hyaluronan Receptors
  • Integrin beta1
  • KLF4 protein, human
  • Kruppel-Like Factor 4
  • Pyridines
  • TP63 protein, human
  • Transcription Factors
  • Tumor Suppressor Proteins
  • alpha 6p integrin
  • Y 27632
  • Telomerase