The contribution of p53 in the dynamics of cell cycle response to DNA damage interpreted by a mathematical model

Monica Lupi, Giada Matera, Claudia Natoli, Valentina Colombo, Paolo Ubezio

Research output: Contribution to journalArticle

Abstract

Despite numerous studies on the tumor suppressor p53, a complete picture of its role in cell arrest and killing in G1, S and G2M phases after drug treatment is lacking. We tackled the analysis of the complexity of cell cycle effects combining the time-course measures with different techniques with the aid of a computer program simulating cell cycle progression. This mixed experimental-simulation approach enabled us to decode the dynamics of the cytostatic and cytotoxic responses to cisplatin and doxorubicin treatments in a p53-proficient colon carcinoma cell line (HCT-116) and in its p53-deficient counterpart. We achieved a separate evaluation of the activity of each cell cycle control and we connected these results with measures of p53 level in G1, S and G2M. We confirmed the action of p53 in all cell cycle phases, but also the presence of strong p53-independent cytostatic and cytotoxic activities exerted by both drugs. In G1 phase, p53 was responsible for a medium/long term block, distinct from the short-term block, which was p53-independent. The delay in traversing S phase was reduced by the presence of p53. In G2M phase, despite a strong p53-independent block, there was a weaker but more persistent p53-dependent block. At cytotoxic concentrations, p53-dependent and p53-independent cell death was observed. The former was poorly phase-specific, occurred earlier and exploited the apoptotic mechanism more than p53-independent death. Computer simulation produced a framework where previous partial and sometimes apparently contradictory observations of the p53-mediated effects could be reconciled and explained.

Original languageEnglish
Pages (from-to)943-950
Number of pages8
JournalCell Cycle
Volume6
Issue number8
Publication statusPublished - Apr 15 2007

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Keywords

  • Anticancer drugs
  • Cell cycle
  • Cell kinetics
  • Cisplatin
  • Doxorubicin
  • Flow cytometry
  • Mathematical models
  • p53

ASJC Scopus subject areas

  • Biochemistry
  • Cell Biology
  • Molecular Biology

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