title: Biphasic modulation of cancer stem cell-driven solid tumour dynamics in response to reactivated replicative senescence.
abstract: OBJECTIVE
  Cell senescence is a physiological programme of irreversible mitotic arrest that is triggered after a variety of intracellular and extracellular events. Its purpose is to protect tissue integrity by disabling mitosis in stressed or damaged cells. The senescence program serves as a tumour suppressor, and cancer cells are believed to bypass senescence to advance to malignancy. Recent studies have shown that senescence can be reactivated in cancer cells through a number of external perturbations, including oncogene activation, tumour suppressor gene withdrawal and irradiation.
  
  
  METHODS
  We have developed an agent-based model of solid tumour growth whose input population composition is based on the cancer stem-cell hypothesis. It is used to show how cancer stem cells can drive tumour progression, while non-stem cancer cells (CCs) interfere with this by impeding cancer stem-cell dynamics.
  
  
  RESULTS
  Here we show that intratumoural competition between the two cell types may arise to modulate tumour progression and ultimately cancer presentation risk. Model simulations reveal that reactivation of the replicative senescence programme in CCs initially increases total tumour burden, as attrition from cell death is partially averted, but evolves to provide tumour control in the long-term through increasing constraints on stem-cell compartment kinetics.
  
  
  CONCLUSIONS
  Reactivation of replicative senescence can prolong CC competition with cancer stem cells, thereby ultimately inhibiting malignant progression regardless of tumour size.
authors.affiliation: Center of Cancer Systems Biology, GRI, Tufts University School of Medicine, Boston, MA, 02135, USA; College of Inter-faculty Individual Studies in Mathematics and Natural Sciences, University of Warsaw, Warsaw, 02-089, Poland.
authors.forename: J
authors.initials: J
authors.lastname: Poleszczuk
authors.forename: P
authors.initials: P
authors.lastname: Hahnfeldt
authors.forename: H
authors.initials: H
authors.lastname: Enderling
mesh_terms: D000465:Algorithms; D017209:Apoptosis; D049109:Cell Proliferation; D016922:Cellular Senescence; D006801:Humans; D008954:Models, Biological; D009369:Neoplasms / Q000473:pathology*; D014411:Neoplastic Stem Cells / Q000166:cytology / Q000502:physiology*