Dataset Information

P53 dynamics in single cells are temperature-sensitive.

ABSTRACT: Cells need to preserve genome integrity despite varying cellular and physical states. p53, the guardian of the genome, plays a crucial role in the cellular response to DNA damage by triggering cell cycle arrest, apoptosis or senescence. Mutations in p53 or alterations in its regulatory network are major driving forces in tumorigenesis. As multiple studies indicate beneficial effects for hyperthermic treatments during radiation- or chemotherapy of human cancers, we aimed to understand how p53 dynamics after genotoxic stress are modulated by changes in temperature across a physiological relevant range. To this end, we employed a combination of time-resolved live-cell microscopy and computational analysis techniques to characterise the p53 response in thousands of individual cells. Our results demonstrate that p53 dynamics upon ionizing radiation are temperature dependent. In the range of 33?°C to 39?°C, pulsatile p53 dynamics are modulated in their frequency. Above 40?°C, which corresponds to mild hyperthermia in a clinical setting, we observed a reversible phase transition towards sustained hyperaccumulation of p53 disrupting its canonical response to DNA double strand breaks. Moreover, we provide evidence that mild hyperthermia alone is sufficient to induce a p53 response in the absence of genotoxic stress. These insights highlight how the p53-mediated DNA damage response is affected by alterations in the physical state of a cell and how this can be exploited by appropriate timing of combination therapies to increase the efficiency of cancer treatments.

SUBMITTER: Jentsch M

PROVIDER: S-EPMC6992775 | biostudies-literature | 2020 Jan

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

p53 dynamics in single cells are temperature-sensitive.

Jentsch Marcel M Snyder Petra P Sheng Caibin C Cristiano Elena E Loewer Alexander A

Scientific reports 20200130 1

Cells need to preserve genome integrity despite varying cellular and physical states. p53, the guardian of the genome, plays a crucial role in the cellular response to DNA damage by triggering cell cycle arrest, apoptosis or senescence. Mutations in p53 or alterations in its regulatory network are major driving forces in tumorigenesis. As multiple studies indicate beneficial effects for hyperthermic treatments during radiation- or chemotherapy of human cancers, we aimed to understand how p53 dyn ...[more]

PMID: 32001771

Similar Datasets

Project description:The p53 tumour suppressor is a transcription factor that can regulate the expression of numerous genes including many encoding proteins and microRNAs (miRNAs). The predominant outcomes of a typical p53 response are the initiation of apoptotic cascades and the activation of cell cycle checkpoints. HT29-tsp53 cells express a temperature sensitive variant of p53 and in the absence of exogenous DNA damage, these cells preferentially undergo G1 phase cell cycle arrest at the permissive temperature that correlates with increased expression of the cyclin-dependent kinase inhibitor p21WAF1. Recent evidence also suggests that a variety of miRNAs can induce G1 arrest by inhibiting the expression of proteins like CDK4 and CDK6. Here we used oligonucleotide microarrays to identify p53-regulated miRNAs that are induced in these cells undergoing G1 arrest. At the permissive temperature, the expression of several miRNAs was increased through a combination of either transcriptional or post-transcriptional regulation. In particular, miR-34a-5p, miR-143-3p and miR-145-5p were strongly induced and they reached levels comparable to that of reference miRNAs (miR-191 and miR-103). Importantly, miR-34a-5p and miR-145-5p are known to silence the Cdk4 and/or Cdk6 G1 cyclin-dependent kinases (cdks). Surprisingly, there was no p53-dependent decrease in the expression of either of these G1 cdks. To search for other potential targets of p53-regulated miRNAs, p53-downregulated mRNAs were identified through parallel microarray analysis of mRNA expression. Once again, there was no clear effect of p53 on the repression of mRNAs under these conditions despite a remarkable increase in p53-induced mRNA expression. Therefore, despite a strong p53 transcriptional response, there was no clear evidence that p53-responsive miRNA contributed to gene silencing. Taken together, the changes in cell cycle distribution in this cell line at the permissive temperature is likely attributable to transcriptional upregulation of the CDKN1A mRNA and p21WAF1 protein and not to the down regulation of CDK4 or CDK6 by p53-regulated miRNAs.

Project description:The tp53 gene is found to be mutated in 50% of all the cancers. The p53 protein, a product of tp53 gene, is a multi-domain protein. It consists of a core DNA binding domain (DBD) which is responsible for its binding and transcription of downstream target genes. The mutations in p53 protein are responsible for creating cancerous conditions and are found to be occurring at a high frequency in the DBD region of p53. Some of these mutations are also known to be temperature sensitive (ts) in nature. They are known to exhibit partial or strong binding with DNA in the temperature range (298-306 K). Whereas, at 310 K and above they show complete loss in binding. We have analyzed the changes in binding and conformational behavior at 300 K and 310 K for three of the ts-mutants viz., V143A, R249S and R175H. QM-MM simulations have been performed on the wild type and the above mentioned ts-mutants for 30 ns each. The optimal estimate of free energy of binding for a particular number of interface hydrogen bonds was calculated using the maximum likelihood method as described by Chodera et. al (2007). This parameter has been observed to be able to mimic the binding affinity of the p53 ts-mutants at 300 K and 310 K. Thus the correlation between MM-GBSA free energy of binding and hydrogen bonds formed by the interface residues between p53 and DNA has revealed the temperature dependent nature of these mutants. The role of main chain dihedrals was obtained by performing dihedral principal component analysis (PCA). This analysis, suggests that the conformational variations in the main chain dihedrals (? and ?) of the p53 ts-mutants may have caused reduction in the overall stability of the protein. The solvent exposure of the side chains of the interface residues were found to hamper the binding of the p53 to the DNA. Solvent Accessible Surface Area (SASA) also proved to be a crucial property in distinguishing the conformers obtained at 300 K and 310 K for the three ts-mutants from the wild type at 300 K.

Project description:ObjectiveMedical adhesives are used to secure wound care dressings and other critical devices to the skin. While high peel-strength adhesives provide more secure skin attachment, they are difficult to remove from the skin and are correlated with medical adhesive-related skin injuries (MARSI), including skin tears, and an increased risk of infection. Lower-adhesion medical tapes may be applied to avoid MARSI, leading to dressing or device dislodgement and further medical complications.MethodThis paper reports on the clinical testing of a new, high-adhesion medical tape, ThermoTape (University of Washington, US), designed for low skin trauma upon release. ThermoTape was benchmarked with Tegaderm (3M, US) and Kind Removal Tape (KRT) (3M, US). All three tapes were applied to both the left and right forearm of healthy volunteers and were removed 24 hours later-the right arm without applying heat and the left arm by applying a heat pack for 30 seconds before removal. Tape wear, self-reported pain (0-10 scale) and skin redness 15 minutes after removal were recorded.ResultsThis was a 53-subject comparative, single-blind clinical trial. There were clinically and statistically significant results supporting reduced pain during removal of ThermoTape with warming, with an average 58% decrease in pain, paired with a statistically significant 45% reduction in skin redness (p<0.01 for both values). In contrast, there were statistically insignificant differences in pain and redness for removal of Tegaderm and KRT with warming. ThermoTape after warming, in comparison with Tegaderm without warming, produced a reduced pain score of >1 on the 0-10 Wong-Baker/Face pain scale, which was statistically significant (p<0.01).ConclusionThese results provide compelling evidence that warming ThermoTape prior to removal can reduce pain and injury when compared with standard medical tapes. This could allow for stronger attachment of wound care dressings and critical medical devices while reducing cases of MARSI.

Dataset Information

P53 dynamics in single cells are temperature-sensitive.

Publications

p53 dynamics in single cells are temperature-sensitive.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets