title: Dynamic equilibrium between cancer stem cells and non-stem cancer cells in human SW620 and MCF-7 cancer cell populations.
abstract: 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.
  
  
  CONCLUSIONS
  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.
authors.affiliation: State Key Laboratory of Nuclear Physics and Technology, School of Physics, Peking University, Beijing, People's Republic of China.
authors.forename: G
authors.initials: G
authors.lastname: Yang
authors.forename: Y
authors.initials: Y
authors.lastname: Quan
authors.forename: W
authors.initials: W
authors.lastname: Wang
authors.forename: Q
authors.initials: Q
authors.lastname: Fu
authors.forename: J
authors.initials: J
authors.lastname: Wu
authors.forename: T
authors.initials: T
authors.lastname: Mei
authors.forename: J
authors.initials: J
authors.lastname: Li
authors.forename: Y
authors.initials: Y
authors.lastname: Tang
authors.forename: C
authors.initials: C
authors.lastname: Luo
authors.forename: Q
authors.initials: Q
authors.lastname: Ouyang
authors.forename: S
authors.initials: S
authors.lastname: Chen
authors.forename: L
authors.initials: L
authors.lastname: Wu
authors.forename: T K
authors.initials: TK
authors.lastname: Hei
authors.forename: Y
authors.initials: Y
authors.lastname: Wang
mesh_terms: D014408:Biomarkers, Tumor / Q000378:metabolism*; D001943:Breast Neoplasms / Q000378:metabolism / Q000473:pathology*; D015820:Cadherins / Q000378:metabolism; D002465:Cell Movement / Q000502:physiology* / Q000528:radiation effects; D003110:Colonic Neoplasms / Q000378:metabolism / Q000473:pathology*; D003114:Colony-Forming Units Assay; D058750:Epithelial-Mesenchymal Transition; D005260:Female; D005455:Fluorescent Antibody Technique; D006801:Humans; D014411:Neoplastic Stem Cells / Q000378:metabolism / Q000473:pathology* / Q000528:radiation effects; D015398:Signal Transduction; D013234:Stem Cells / Q000166:cytology* / Q000378:metabolism / Q000528:radiation effects; D053773:Transforming Growth Factor beta1 / Q000378:metabolism; D014746:Vimentin / Q000378:metabolism
chemical_list: D014408:Biomarkers, Tumor; D015820:Cadherins; D053773:Transforming Growth Factor beta1; D014746:Vimentin