Homo sapiens
Ontology highlight
ABSTRACT:
PROVIDER: PRJNA260290 | ENA |
REPOSITORIES: ENA
Similar Datasets
Project description:Targeting “oncogene addiction” is a promising strategy for anti-cancer therapy. Here, we report a potent inhibition of crucial oncogenes by p53 upon reactivation with small molecule RITA in vitro and in vivo. RITA-activated p53 unleashes transcriptional repression of anti-apoptotic proteins Mcl-1, Bcl-2, MAP4, and survivin, blocks Akt pathway on several levels and downregulates c-Myc, cyclin E and B-catenin. p53 ablates c-Myc expression via several mechanisms at transcriptional and posttranscriptional level. We show that transrepression of oncogenes correlated with higher level of p53 bound to chromatin-bound p53 than transactivation of pro-apoptotic targets. Inhibition of oncogenes by p53 reduces the cell’s ability to buffer pro-apoptotic signals and elicits robust apoptosis. Our study highlights the role of transcriptional repression for p53-mediated tumor suppression. Experiment Overall Design: Breast carcinoma cell-line MCF7 was treated with the small-molecule p53 activator RITA for 2h, 8h, 16h and 24h.
2009-05-15 | E-GEOD-13291 | biostudies-arrayexpress
Project description:TFIIS.h, a new target of p53, regulates transcription efficiency of pro-apoptotic bax gene
| PRJNA311176 | ENA
Project description:Mutant p53 (mtp53) promotes chemotherapy resistance through multiple mechanisms including disabling pro-apoptotic proteins and by regulating gene expression. Analysis of promoter regions identified through CHIP-on-CHIP and CHIP-SEQ platforms reveal that the ETS motif (EBS) is prevalent within predicted mtp53 binding sites. We demonstrate that mtp53 regulates gene expression through EBS in promoters, and that ETS2 mediates the interaction with this motif. Importantly, we identified TDP2, a 5’-tyrosyl DNA phosphodiesterase involved in the repair of DNA damage caused by etoposide, as a transcriptional target of mtp53. We demonstrate that suppression of TDP2 sensitizes mtp53 expressing cells to etoposide, and that mtp53 and TDP2 are frequently overexpressed in human lung cancer; thus, our analysis identifies a potentially “druggable” component of mtp53’s gain-of-function activity. Comparison of two different transcriptional binding analysis (ChIP-on-ChIP and ChIP-Seq) for the identification of novel mutant p53 binding.
2012-05-02 | E-GEOD-36749 | biostudies-arrayexpress
Project description:Mutant p53 (mtp53) promotes chemotherapy resistance through multiple mechanisms including disabling pro-apoptotic proteins and by regulating gene expression. Analysis of promoter regions identified through CHIP-on-CHIP and CHIP-SEQ platforms reveal that the ETS motif (EBS) is prevalent within predicted mtp53 binding sites. We demonstrate that mtp53 regulates gene expression through EBS in promoters, and that ETS2 mediates the interaction with this motif. Importantly, we identified TDP2, a 5’-tyrosyl DNA phosphodiesterase involved in the repair of DNA damage caused by etoposide, as a transcriptional target of mtp53. We demonstrate that suppression of TDP2 sensitizes mtp53 expressing cells to etoposide, and that mtp53 and TDP2 are frequently overexpressed in human lung cancer; thus, our analysis identifies a potentially “druggable” component of mtp53’s gain-of-function activity. Comparison of two different transcriptional binding analysis (ChIP-on-ChIP and ChIP-Seq) for the identification of novel mutant p53 (R248W) binding.
2012-05-02 | E-GEOD-36751 | biostudies-arrayexpress
Project description:Targeting “oncogene addiction” is a promising strategy for anti-cancer therapy. Here, we report a potent inhibition of crucial oncogenes by p53 upon reactivation with small molecule RITA in vitro and in vivo. RITA-activated p53 unleashes transcriptional repression of anti-apoptotic proteins Mcl-1, Bcl-2, MAP4, and survivin, blocks Akt pathway on several levels and downregulates c-Myc, cyclin E and B-catenin. p53 ablates c-Myc expression via several mechanisms at transcriptional and posttranscriptional level. We show that transrepression of oncogenes correlated with higher level of p53 bound to chromatin-bound p53 than transactivation of pro-apoptotic targets. Inhibition of oncogenes by p53 reduces the cell’s ability to buffer pro-apoptotic signals and elicits robust apoptosis. Our study highlights the role of transcriptional repression for p53-mediated tumor suppression. Keywords: time course
2009-05-12 | GSE13291 | GEO
Project description:In colorectal cancer, p53 is commonly inactivated, associated with chemo-resistance, and marks the transition from non-invasive to invasive disease. Cancers, including colorectal cancer, are thought to be diseases of aberrant stem cell populations, as stem cells are able to self-renew, making them long-lived enough to acquire mutations necessary to manifest the disease. We have shown that extracts from sweet sorghum stalk components eliminate colon cancer stem cells (CCSC) in a partial p53-dependent fashion. However, the underlying mechanisms are unknown. In the present study, CCSC were transfected with short hairpin-RNA against p53 (CCSC p53 shRNA) and treated with sweet sorghum phenolics extracted from different plant components (dermal layer, leaf, seed head and whole plant). While all components demonstrated anti-proliferative and pro-apoptotic effects in CCSC, phenolics extracted from the dermal layer and seed head were more potent in eliminating CCSC by elevating caspases 3/7 activity, PARP cleavage, and DNA fragmentation in a p53-dependent and p53-independent fashion, respectively. Further investigations revealed that the anti-proliferative and pro-apoptotic effects were associated with decreases in beta-catenin protein levels, and beta-catenin targets cyclin D1, cMyc, and survivin. These results suggest that the anti-proliferative and pro-apoptotic effects of sweet sorghum extracts against human colon cancer stem cells are via suppression of Wnt/beta-catenin pro-survival signaling in a p53-dependent (dermal layer) and partial p53-independent (seed head) fashion. LCMS used to identify phenolic compounds associated with extract activity
2014-05-01 | MTBLS69 | MetaboLights
Project description:The tumor suppressor p53 is mainly involved in the transcriptional regulation of a large number of growth-arrest- and apoptosis-related genes. However, a clear understanding of which factor/s influences the choice between these two opposing p53- dependent outcomes remains largely elusive. We have previously described that in response to DNA damage, the RNA polymerase II binding protein Che-1/AATF transcriptionally activates p53. Here, we show that Che-1 binds directly p53. This interaction essentially occurs in the first hours of DNA damage, whereas it is lost when cells undergo to apoptosis in response to post-transcriptional modifications. Moreover, Che-1 sits in a ternary complex with p53 and the oncosuppressor Brca1. Accordingly, our analysis of genome-wide chromatin occupancy by p53 revealed that p53/Che1 interaction results in preferential transactivation of growth-arrest p53 target genes over its pro-apoptotic target genes. Notably, exposure of Che-1+/- mice to ionizing radiations resulted in enhanced apoptosis of thymocytes, compared to wild-type mice. These results confirm Che-1 as an important regulator of p53 activity and suggest Che-1 to be a promising yet attractive drug target for cancer therapy.
2015-06-01 | GSE60267 | GEO
Project description:The tumor suppressor protein p53, encoded by TP53, inhibits tumorigenesis by inducing cell cycle arrest, senescence and apoptosis. Several genetic polymorphisms exist in TP53, including a proline to arginine variant at amino acid 72 (P72 and R72, respectively); this polymorphism alters p53 function. In general, the P72 variant shows increased ability to induce cell cycle arrest, while the R72 variant possesses increased ability to induce apoptosis, relative to P72. At present, the underlying mechanisms for these functional differences are not fully understood. Toward elucidating the molecular basis for these differences a gene expression microarray analysis was conducted on normal human fibroblast cells that are homozygous for P72 and R72 variants, along with subclones of these lines that express a p53 short hairpin (shp53). Approximately three dozen genes were identified whose transactivation is affected by the codon 72 polymorphism. One of these is the tripartite motif family-like 2 (TRIML2) gene, which is preferentially induced by the R72 variant. Importantly, the accumulated data indicate that TRIML2 interacts with p53, and facilitates the modification of p53 with SUMO2. TRIML2 also enhances the ability of p53 to transactivate a subset of pro-apoptotic target genes associated with prolonged oxidative stress, including PIDD, PIG3 (TP53I3) and PIG6 (PRODH). These data indicate that TRIML2 is part of a feed-forward loop that activates p53 in cells expressing the R72 variant, particularly after prolonged stress.
2014-12-01 | GSE61124 | GEO
Project description:A better understanding of how p53 differentially activates cell cycle arrest or cell death is important to maximize benefits of therapeutic strategies dependant by wild-type p53. Here, we report that activation of pro-apoptotic p53 transcriptional targets in colorectal cancer cells imposes a critical, targetable dependence on the long splice form of the caspase-8 regulator FLIP (FLIPL) for survival. Upon Nutlin-3A induced stabilisation p53 directly upregulates FLIPL expression in a manner dependent on Class-I HDAC activity. Preventing FLIPL upregulation with the clinically relevant Class-I selective inhibitor Entinostat promotes apoptosis in response to Nutlin-3A , which predominantly induces growth arrest despite upregulating a range of pro-apoptotic target genes. Cell death in response to Nutlin-3A in FLIPL-depleted cells is mediated through two of p53's canonical transcriptional targets TRAIL-R2 and BAX and is caspase-8-dependent. This work uncovers novel, clinically relevant biology that identifies FLIPL as a key target for overcoming resistance to p53-activating agents.
2020-04-25 | GSE113682 | GEO
Project description:The transcription factor p73, a member of the p53 tumor-suppressor family, regulates cell death and also supports tumorigenesis, though the mechanistic basis for the dichotomous functions is poorly understood. We report here the identification of an alternate transactivation domain (TAD) located at the extreme carboxyl (C)-terminus of TAp73β, a commonly expressed p73 isoform. Mutational disruption of this TAD significantly reduced TAp73β’s transactivation activity, to a level observed when the amino (N)-TAD that is similar to p53’s TAD is mutated. Mutation of both TADs almost completely abolished TAp73β’s transactivation activity. Expression profiling highlighted a unique set of targets involved in extracellular matrix-receptor interaction and focal adhesion to be regulated by the C-TAD, resulting in FAK phosphorylation, distinct from the N-TAD targets that are common to p53 and involved in growth inhibition. Interestingly, the C-TAD targets are also regulated by the oncogenic, amino-terminal deficient DNp73β isoform. Consistently, mutation of C-TAD reduces cellular migration and proliferation. Mechanistically, selective binding of TAp73β to DNAJA1 is required for the transactivation of C-TAD target genes, and silencing DNAJA1 expression abrogated all C-TAD-mediated effects. Taken together, our results provide a mechanistic basis for the dichotomous functions of TAp73 in the regulation cellular growth through its distinct TADs.
2024-05-07 | GSE262279 | GEO