Modeling the role of p53 pulses in DNA damage- induced cell death decision

• Published in: BMC bioinformatics Vol. 10; no. 1; p. 190
• Main Authors: Sun, Tingzhe, Chen, Chun, Wu, Yuanyuan, Zhang, Shuai, Cui, Jun, Shen, Pingping
• Format: Journal Article
• Language: English
• Published: England BioMed Central Ltd 22.06.2009; BioMed Central; BMC
• Subjects: Animals; Ataxia Telangiectasia Mutated Proteins; bcl-2-Associated X Protein - chemistry; Cell Cycle Proteins - chemistry; Cell Death; Computational biology; Computer simulation; Computer-generated environments; DNA Damage; DNA-Binding Proteins - chemistry; Humans; Models, Theoretical; Physiological aspects; Protein-Serine-Threonine Kinases - chemistry; Proto-Oncogene Proteins c-mdm2 - chemistry; Tumor suppressor genes; Tumor Suppressor Protein p53 - genetics; Tumor Suppressor Proteins - chemistry; China
• ISSN: 1471-2105; 1471-2105
• DOI: 10.1186/1471-2105-10-190

The tumor suppressor p53 plays pivotal roles in tumorigenesis suppression. Although oscillations of p53 have been extensively studied, the mechanism of p53 pulses and their physiological roles in DNA damage response remain unclear. To address these questions we presented an integrated model in which Ataxia-Telangiectasia Mutated (ATM) activation and p53 oscillation were incorporated with downstream apoptotic events, particularly the interplays between Bcl-2 family proteins. We first reproduced digital oscillation of p53 as the response of normal cells to DNA damage. Subsequent modeling in mutant cells showed that high basal DNA damage is a plausible cause for sustained p53 pulses observed in tumor cells. Further computational analyses indicated that p53-dependent PUMA accumulation and the PUMA-controlled Bax activation switch might play pivotal roles to count p53 pulses and thus decide the cell fate. The high levels of basal DNA damage are responsible for generating sustained pulses of p53 in the tumor cells. Meanwhile, the Bax activation switch can count p53 pulses through PUMA accumulation and transfer it into death signal. Our modeling provides a plausible mechanism about how cells generate and orchestrate p53 pulses to tip the balance between survival and death.