Effect of ARF on the transcription of p53 target genes in homologous recombination deficient cells
Ontology highlight
ABSTRACT:
ORGANISM(S): Mus musculus
PROVIDER: GSE51354 | GEO | 2014/12/04
SECONDARY ACCESSION(S): PRJNA222809
REPOSITORIES: GEO
Similar Datasets
Project description:ARF is a tumour suppressor activated by oncogenic stress, which stabilizes p53. Although p53 is a key component of the response to DNA damage, a similar function for ARF has not been ascribed. In this work we show that homologous recombination (HR) -deficient primary mouse and human cells accumulate DNA damage, which triggers checkpoint signalling and ARF activation. We also show that in the absence of ARF p53 is induce in response to DNA damage, but surprisingly fails to trigger senescence. The hypothesis tested in this study was that ARF deficiency alters the spectrum of genes activated by p53 in response to HR deficiency. Using mRNA microarray analysis and expression profiling, we identified genes upregulated in wild type primary MEFs treated with RAD51 shRNA, whose expression was not induced in similarly treated Arf -/- primary MEFs. Clustering analysis of p53 transcriptional targets with increased expression in RAD51-depleted cells revealed three groups: genes requiring functional ARF for their expression, genes transcribed in an ARF-independent manner and genes that are upregulated in both ARF-proficient and ARF-deficient cells. Among the genes in the last group we found Cdkn1a(p21), encoding the p21 inhibitor of cyclindependent kinases and well-characterized effector of the p53 role in promoting senescence. The subset of p53 targets requiring ARF for their transcription was specifically upregulated in response to RAD51 inhibition in wild type, but not Arf -/- MEFs. Among these genes, two encoded the dual specificity phosphatase (DUSP) family members DUSP4 and DUSP7, which act as ERK phosphatases and negative regulators of the MAPK kinase pathway in mammalian cells. Four samples were analysed (WT or ARF negative cells transfected with GFP or RAD51 shRNAs) in duplicate. Samples treated with GFP shRNA are the reference samples and the ones treated with RAD51 shRNA are the experimental ones (RAD51 depletion leads to HR deficiency). The WT cell line is our control cell line to study the effect of HR deficiency on the transcription of p53 target genes
2014-12-04 | E-GEOD-51354 | biostudies-arrayexpress
Project description:Proctor2008 - p53/Mdm2 circuit - p53 stabilisation by ATM
This model is described in the article:
Explaining oscillations and
variability in the p53-Mdm2 system.
Proctor CJ, Gray DA.
BMC Syst Biol 2008; 2: 75
Abstract:
BACKGROUND: In individual living cells p53 has been found to
be expressed in a series of discrete pulses after DNA damage.
Its negative regulator Mdm2 also demonstrates oscillatory
behaviour. Attempts have been made recently to explain this
behaviour by mathematical models but these have not addressed
explicit molecular mechanisms. We describe two stochastic
mechanistic models of the p53/Mdm2 circuit and show that
sustained oscillations result directly from the key biological
features, without assuming complicated mathematical functions
or requiring more than one feedback loop. Each model examines a
different mechanism for providing a negative feedback loop
which results in p53 activation after DNA damage. The first
model (ARF model) looks at the mechanism of p14ARF which
sequesters Mdm2 and leads to stabilisation of p53. The second
model (ATM model) examines the mechanism of ATM activation
which leads to phosphorylation of both p53 and Mdm2 and
increased degradation of Mdm2, which again results in p53
stabilisation. The models can readily be modified as further
information becomes available, and linked to other models of
cellular ageing. RESULTS: The ARF model is robust to changes in
its parameters and predicts undamped oscillations after DNA
damage so long as the signal persists. It also predicts that if
there is a gradual accumulation of DNA damage, such as may
occur in ageing, oscillations break out once a threshold level
of damage is acquired. The ATM model requires an additional
step for p53 synthesis for sustained oscillations to develop.
The ATM model shows much more variability in the oscillatory
behaviour and this variability is observed over a wide range of
parameter values. This may account for the large variability
seen in the experimental data which so far has examined ARF
negative cells. CONCLUSION: The models predict more regular
oscillations if ARF is present and suggest the need for further
experiments in ARF positive cells to test these predictions.
Our work illustrates the importance of systems biology
approaches to understanding the complex role of p53 in both
ageing and cancer.
This model is hosted on
BioModels Database
and identified by:
BIOMD0000000188.
To cite BioModels Database, please use:
BioModels Database:
An enhanced, curated and annotated resource for published
quantitative kinetic models.
To the extent possible under law, all copyright and related or
neighbouring rights to this encoded model have been dedicated to
the public domain worldwide. Please refer to
CC0
Public Domain Dedication for more information.
2024-09-02 | BIOMD0000000188 | BioModels
Project description:Proctor2008 - p53/Mdm2 circuit - p53 stabilisation by p14ARF
This model is described in the article:
Explaining oscillations and
variability in the p53-Mdm2 system.
Proctor CJ, Gray DA.
BMC Syst Biol 2008; 2: 75
Abstract:
BACKGROUND: In individual living cells p53 has been found to
be expressed in a series of discrete pulses after DNA damage.
Its negative regulator Mdm2 also demonstrates oscillatory
behaviour. Attempts have been made recently to explain this
behaviour by mathematical models but these have not addressed
explicit molecular mechanisms. We describe two stochastic
mechanistic models of the p53/Mdm2 circuit and show that
sustained oscillations result directly from the key biological
features, without assuming complicated mathematical functions
or requiring more than one feedback loop. Each model examines a
different mechanism for providing a negative feedback loop
which results in p53 activation after DNA damage. The first
model (ARF model) looks at the mechanism of p14ARF which
sequesters Mdm2 and leads to stabilisation of p53. The second
model (ATM model) examines the mechanism of ATM activation
which leads to phosphorylation of both p53 and Mdm2 and
increased degradation of Mdm2, which again results in p53
stabilisation. The models can readily be modified as further
information becomes available, and linked to other models of
cellular ageing. RESULTS: The ARF model is robust to changes in
its parameters and predicts undamped oscillations after DNA
damage so long as the signal persists. It also predicts that if
there is a gradual accumulation of DNA damage, such as may
occur in ageing, oscillations break out once a threshold level
of damage is acquired. The ATM model requires an additional
step for p53 synthesis for sustained oscillations to develop.
The ATM model shows much more variability in the oscillatory
behaviour and this variability is observed over a wide range of
parameter values. This may account for the large variability
seen in the experimental data which so far has examined ARF
negative cells. CONCLUSION: The models predict more regular
oscillations if ARF is present and suggest the need for further
experiments in ARF positive cells to test these predictions.
Our work illustrates the importance of systems biology
approaches to understanding the complex role of p53 in both
ageing and cancer.
This model is hosted on
BioModels Database
and identified by:
BIOMD0000000188.
To cite BioModels Database, please use:
BioModels Database:
An enhanced, curated and annotated resource for published
quantitative kinetic models.
To the extent possible under law, all copyright and related or
neighbouring rights to this encoded model have been dedicated to
the public domain worldwide. Please refer to
CC0
Public Domain Dedication for more information.
2024-09-02 | BIOMD0000000189 | BioModels
Project description:Recently, more than a thousand large intergenic non-coding RNAs (lincRNAs) have been reported. These RNAs are evolutionarily conserved in mammalian genomes and thus presumably function in diverse biological processes. Here, we report the identification of lincRNAs that are regulated by p53. One of these lincRNAs (lincRNA-p21) serves as a repressor in p53-dependent transcriptional responses. Inhibition of lincRNA-p21 affects the expression of hundreds of gene targets enriched for genes normally repressed by p53. The observed transcriptional repression by lincRNA-p21 is mediated through the physical association with hnRNP-K. This interaction is required for proper genomic localization of hnRNP-K at repressed genes and regulation of p53 mediated apoptosis. We propose a model whereby transcription factors activate lincRNAs that serve as key repressors by physically associating with repressive complexes and modulating their localization to sets of previously active genes. Gene expression profiles of different p53 inducible mouse embryonic fibroblasts (p53LSL/LSL MEFs) across different time points after DNA damage. A large intergenic noncoding RNA induced by p53 mediates global gene repression in the p53 transcriptional response. [1] MEF profiling: p53 LSL/LSL MEFs were treated with adenoCRE for p53 restoration or adenoGFP as control for 24h and treated with 500nM doxorubicin for the indicated times. [2] hnRNPKKD profiling: p53 LSL/LSL MEFs were treated with adenoCRE for p53 restoration for 24h, transfected with siRNA oligos targeting different transcripts for 24h and then treated with 100nM doxorubicin for 13h. [3] lincP21KD profiling: p53 LSL/LSL MEFs were treated with adenoCRE for p53 restoration for 24h, transfected with siRNA oligos targeting different transcripts for 24h and then treated with 100nM doxorubicin for 13h. [4] RAS profiling: For p53 restoration, cultured tumor cell lines were incubated with 500nM 4-hydroxytamoxifen for the indicated times.
2010-08-09 | E-GEOD-21761 | biostudies-arrayexpress
Project description:Advanced colorectal cancer (CRC) is an unresolved clinical problem. Epigenetic drugs belonging to the group of histone deacetylase inhibitors (HDACi) may combat CRC in rationally designed treatment schedules. Unfortunately, there is sparse evidence on molecular mechanisms and markers that determine cellular sensitivity to HDACi. Irinotecan is widely used to treat CRC and causes replication stress (RS) and DNA damage as topoisomerase-I inhibitor. We applied irinotecan and the class I HDACi entinostat (MS-275) to isogenic p53-positive and -negative CRC cells. Combinations of irinotecan and MS-275 evoke mitochondrial damage, caspase-mediated apoptosis, and RS-associated DNA damage synergistically and p53-dependently. Targeted mass spectrometry and immunoblot show that irinotecan induces phosphorylation, acetylation, and accumulation of p53 and its target genes. Addition of MS-275 augments the irinotecan-induced acetylation of C-terminal lysine residues of p53 but decreases its phosphorylation and p53 target gene induction. Furthermore, MS-275 increases the amount of acetylated p53 at mitochondria and dysregulates the expression of pro- and anti-apoptotic BCL2 proteins in irinotecan-treated cells. Regarding DNA repair, we see that MS-275 represses the homologous recombination (HR) filament protein RAD51, which limits DNA damage and pro-apoptotic effects of irinotecan. These data suggest that key class I HDAC-dependent functions of p53 in cells with RS are linked to mitochondrial damage and a breakdown of HR. Most importantly, combinations of irinotecan plus MS-275 also kill short-term primary CRC cell cultures and organoids from CRC patients but spare organoids of adjacent matched normal tissue. Thus, irinotecan/HDACi treatment is a promising new approach for the therapy of p53-proficient tumors with clinically tractable inhibitors.
2022-02-15 | PXD019999 | Pride
Project description:The downstream events and target genes of p53 in senescence responses are not fully understood. Here, we report a novel function of the forkhead transcription factor Foxp3, a key player in mediating T cell inhibitory function, in p53-mediated cellular senescence. Overexpression of Foxp3 in mouse embryonic fibroblasts (MEFs) accelerates senescence, whereas Foxp3 knockdown leads to escape from p53-mediated senescence in p53-expressing MEFs. Consistently, Foxp3 expression resulted in the induction of senescence in epithelial cancer cells, including MCF7 and HCT116. Foxp3 overexpression also increased the intracellular levels of reactive oxygen species (ROS). The ROS inhibitor N-acetyl-L-cysteine rescued Foxp3 expression-induced senescence. Furthermore, the elevated ROS levels that accompanied Foxp3 overexpression were paralleled by an increase in p21 expression. Knockdown of p21 in Foxp3-expressing MEFs abrogated the Foxp3-dependent increase in ROS levels, indicating that Foxp3 acts through p21 induction and subsequent ROS elevation to trigger senescence. Collectively, these results suggest that Foxp3 is a downstream target of p53 that is sufficient to induce p21 expression and ROS production and is necessary for p53-mediated senescence. control and treated samples (human), young passage (p3) or old passage (p7) samples (mouse)
2015-08-13 | E-GEOD-71980 | biostudies-arrayexpress
Project description:The downstream events and target genes of p53 in the process of senescence are not fully understood. Here, we report a novel function of the forkhead transcription factor Foxp3, which is a key player in mediating T cell inhibitory functions, in p53-mediated cellular senescence. The overexpression of Foxp3 in mouse embryonic fibroblasts (MEFs) accelerates senescence, whereas Foxp3 knockdown leads to escape from p53-mediated senescence in p53-expressing MEFs. Consistent with these results, Foxp3 expression resulted in the induction of senescence in epithelial cancer cells, including MCF7 and HCT116 cells. Foxp3 overexpression also increased the intracellular levels of reactive oxygen species (ROS). The ROS inhibitor N-acetyl-L-cysteine rescued cells from Foxp3-expression-induced senescence. Furthermore, the elevated ROS levels that accompanied Foxp3 overexpression were paralleled by an increase in p21 expression. Knockdown of p21 in Foxp3-expressing MEFs abrogated the Foxp3-dependent increase in ROS levels, indicating that Foxp3 acts through the induction of p21 and the subsequent ROS elevation to trigger senescence. Collectively, these results suggest that Foxp3 is a downstream target of p53 that is sufficient to induce p21 expression and ROS production and is necessary for p53-mediated senescence.
2015-08-13 | GSE71980 | GEO
Project description:P53 inactivation occurs in about 50% of human cancers, where p53-driven p21 activity is devoid and p27 becomes essential for the establishment of the G1/S checkpoint upon DNA damage. Here, we show that the E2F1-responsive lncRNA LIMp27 selectively represses p27 expression and contributes to proliferation, tumorigenicity, and treatment resistance in p53-defective colon adenocarcinoma (COAD) cells. LIMp27 competes with p27 mRNA for binding to cytoplasmically localized hnRNA0, which otherwise stabilizes p27 mRNA leading to cell cycle arrest at the G0/G1 phase. In response to DNA damage, LIMp27 is upregulated in both wild-type and p53-mutant COAD cells, whereas cytoplasmic hnRNPA0 is only increased in p53-mutant COAD cells due to translocation from the nucleus. Moreover, high LIMp27 expression is associated with poor survival of p53-mutant but not wild-type p53 COAD patients. These results uncover a lncRNA mechanism that promotes p53-defective cancer pathogenesis and suggest that LIMp27 may constitute a target for the treatment of such cancers.
| MSV000090292 | MassIVE
Project description:Tumor cells require nominal increases in protein synthesis in order to maintain high proliferation rates. As such, tumor cells must acquire enhanced ribosome production. How many of the mutations in tumor cells ultimately achieve this aberrant production is largely unknown. The gene encoding ARF is the most commonly deleted gene in human cancer. ARF plays a significant role in regulating ribosomal RNA synthesis and processing, ribosome export into the cytoplasm, and global protein synthesis. Utilizing ribosome profiling, we show that 5’-terminal oligopyrimidine mRNA translation is upregulated following loss of ARF. Genes with increased translational efficiency following loss of ARF include many ribosomal proteins and translation factors. Knockout of p53 largely phenocopies ARF loss, with increased protein synthesis and expression of 5’-TOP encoded proteins. The 5’-TOP regulators eIF4G1 and LARP1 are upregulated in ARF and p53 null cells.
2020-12-20 | GSE156749 | GEO
Project description:The JmjC domain containing protein JMJD3/KDM6B catalyses H3K27me3 and H3K27me2 demethylation. JMJD3 appears to be highly regulated at the transcriptional level and is upregulated in response to diverse stimuli such as differentiation inducers and stress signals. Accordingly, JMJD3 has been linked to the regulation of different biological processes such as differentiation of embryonic stem cells, inflammatory responses in macrophages, and induction of cellular senescence via regulation of the INK4A-ARF locus. Here we show here that JMJD3 interacts with the tumour suppressor protein p53. We find that the interaction is dependent on the p53 tetramerization domain. Following DNA damage, JMJD3 is transcriptionally upregulated and by performing genome-wide mapping of JMJD3, we demonstrate that it binds genes involved in basic cellular processes, as well as genes regulating cell cycle, response to stress and apoptosis. Moreover, we find that JMJD3 binding sites show significant overlap with p53 bound promoters and enhancer elements. The binding of JMJD3 to p53 target sites is increased in response to DNA damage, and we demonstrate that the recruitment of JMJD3 to these sites is dependent on p53 expression. Therefore, we propose a model in which JMJD3 is recruited to p53 responsive elements via its interaction with p53 and speculate that JMJD3 could act as a fail-safe mechanism to remove low levels of H3K27me3 and H3K27me2 to allow for efficient acetylation of H3K27. Examination of JMJD3 and p53 genome-wide binding in untreated BJ cells or cells exposed to DNA damage (IR, 10 Gy)
2014-06-11 | E-GEOD-55912 | biostudies-arrayexpress