Polyploidy road to therapy-induced cellular senescence and escape

Int J Cancer. 2013 Apr 1;132(7):1505-15. doi: 10.1002/ijc.27810. Epub 2012 Nov 16.


Therapy-induced cellular senescence (TCS), characterized by prolonged cell cycle arrest, is an in vivo response of human cancers to chemotherapy and radiation. Unfortunately, TCS is reversible for a subset of senescent cells, leading to cellular reproliferation and ultimately tumor progression. This invariable consequence of TCS recapitulates the clinical treatment experience of patients with advanced cancer. We report the findings of a clinicopathological study in patients with locally advanced non-small cell lung cancer demonstrating that marker of in vivo TCS following neoadjuvant therapy prognosticate adverse clinical outcome. In our efforts to elucidate key molecular pathways underlying TCS and cell cycle escape, we have previously shown that the deregulation of mitotic kinase Cdk1 and its downstream effectors are important mediators of survival and cell cycle reentry. We now report that aberrant expression of Cdk1 interferes with apoptosis and promotes the formation of polyploid senescent cells during TCS. These polyploid senescent cells represent important transition states through which escape preferentially occurs. The Cdk1 pathway is in part modulated differentially by p21 and p27 two members of the KIP cyclin-dependent kinase inhibitor family during TCS. Altogether, these studies underscore the importance of TCS in cancer therapeutics.

Publication types

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

MeSH terms

  • Apoptosis / drug effects
  • Blotting, Western
  • CDC2 Protein Kinase / metabolism
  • Carcinoma, Non-Small-Cell Lung / drug therapy
  • Carcinoma, Non-Small-Cell Lung / genetics
  • Carcinoma, Non-Small-Cell Lung / mortality
  • Carcinoma, Non-Small-Cell Lung / pathology*
  • Cell Cycle Checkpoints / drug effects*
  • Cell Proliferation / drug effects
  • Cellular Senescence / drug effects*
  • Cyclin-Dependent Kinase Inhibitor p21 / antagonists & inhibitors
  • Cyclin-Dependent Kinase Inhibitor p21 / genetics
  • Cyclin-Dependent Kinase Inhibitor p21 / metabolism
  • Cyclin-Dependent Kinase Inhibitor p27 / antagonists & inhibitors
  • Cyclin-Dependent Kinase Inhibitor p27 / genetics
  • Cyclin-Dependent Kinase Inhibitor p27 / metabolism
  • Humans
  • Immunoprecipitation
  • Lung Neoplasms / drug therapy
  • Lung Neoplasms / genetics
  • Lung Neoplasms / mortality
  • Lung Neoplasms / pathology*
  • Neoadjuvant Therapy / adverse effects*
  • Neoplasm Staging
  • Polyploidy*
  • Prognosis
  • RNA, Small Interfering / genetics
  • Survival Rate
  • Tumor Cells, Cultured


  • CDKN1A protein, human
  • CDKN1B protein, human
  • Cyclin-Dependent Kinase Inhibitor p21
  • RNA, Small Interfering
  • Cyclin-Dependent Kinase Inhibitor p27
  • CDC2 Protein Kinase