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 language | English |
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Pages (from-to) | 943-950 |
Number of pages | 8 |
Journal | Cell Cycle |
Volume | 6 |
Issue number | 8 |
Publication status | Published - Apr 15 2007 |
Keywords
- Anticancer drugs
- Cell cycle
- Cell kinetics
- Cisplatin
- Doxorubicin
- Flow cytometry
- Mathematical models
- p53
ASJC Scopus subject areas
- Biochemistry
- Cell Biology
- Molecular Biology