Dynamic equilibrium between cancer stem cells and non-stem cancer cells in human SW620 and MCF-7 cancer cell populations

Br J Cancer. 2012 Apr 24;106(9):1512-9. doi: 10.1038/bjc.2012.126.


Background: Cancer stem cells (CSCs) paradigm suggests that CSCs might have important clinical implications in cancer therapy. Previously, we reported that accumulation efficiency of CSCs is different post low- and high-LET irradiation in 48 h.

Methods: Cancer stem cells and non-stem cancer cells (NSCCs) were sorted and functionally identified through a variety of assays such as antigen profiles and sphere formation. Inter-conversion between CSCs and NSCCs were in situ visualised. Cancer stem cells proportions were assayed over multiple generations under normal and irradiation surroundings. Supplement and inhibition of TGF-β1, as well as immunofluorescence assay of E-cadherin and Vimentin, were performed.

Results: Surface antigen markers of CSCs and NSCCs exist in an intrinsic homoeostasis state with spontaneous and in situ visualisable inter-conversions, irrespective of prior radiations. Supplement with TGF-β1 accelerates the equilibrium, whereas inhibition of TGF-β signalling disturbs the equilibrium and significantly decreases CSC proportion. Epithelial mesenchymal transition (EMT) might be activated during the process.

Conclusion: Our results indicate that the intrinsic inter-conversion and dynamic equilibrium between CSCs and NSCCs exist under normal and irradiation surroundings, and TGF-β might have important roles in the equilibrium through activating EMT.

Publication types

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

MeSH terms

  • Biomarkers, Tumor / metabolism*
  • Breast Neoplasms / metabolism
  • Breast Neoplasms / pathology*
  • Cadherins / metabolism
  • Cell Movement / physiology*
  • Cell Movement / radiation effects
  • Colonic Neoplasms / metabolism
  • Colonic Neoplasms / pathology*
  • Colony-Forming Units Assay
  • Epithelial-Mesenchymal Transition
  • Female
  • Fluorescent Antibody Technique
  • Humans
  • Neoplastic Stem Cells / metabolism
  • Neoplastic Stem Cells / pathology*
  • Neoplastic Stem Cells / radiation effects
  • Signal Transduction
  • Stem Cells / cytology*
  • Stem Cells / metabolism
  • Stem Cells / radiation effects
  • Transforming Growth Factor beta1 / metabolism
  • Vimentin / metabolism


  • Biomarkers, Tumor
  • Cadherins
  • Transforming Growth Factor beta1
  • Vimentin