Homo sapiens
Ontology highlight
ABSTRACT:
PROVIDER: PRJNA311176 | ENA |
REPOSITORIES: ENA
Similar Datasets
Project description:Identification of TRIML2, a Novel p53 Target, that Enhances p53-SUMolylation and Regulates the Transactivation of Pro-apoptotic Genes
| PRJNA260290 | ENA
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:A central challenge in human cancer therapy is the identification of pathways that control tumor cell survival and chemosensitivity in the absence of functional p53. The p53-related transcription factors p63 and p73 exhibit distinct, p53-independent roles in development and cancer: p73 promotes genome stability and mediates chemosensitivity, while p63 largely lacks these p53-like functions and instead promotes proliferation and cell survival. Here, we identify a new and physiologically important mechanism of p63/p73 cross-talk which governs the balance between pro-survival and pro-apoptotic programs in both human and murine squamous cell carcinoma. Through comprehensive profiling of p63-regulated microRNAs (miRs), we identified a subset which target p73 for inhibition, including miR-193a-5p, a direct endogenous transcriptional target repressed by p63 and activated by pro-apoptotic p73 isoforms in both normal cells and tumor cells in vivo. Consequently, chemotherapy treatment causes p63/p73-dependent induction of this miR, thereby limiting chemosensitivity due to miR-mediated feedback control of p73. We demonstrate that interrupting this feedback by inhibiting miR-193a suppresses tumor cell viability and induces dramatic chemosensitivity both in vitro and in vivo. Thus, we have identified a direct, miR-dependent regulatory circuit mediating inducible chemoresistance, whose inhibition provides a new therapeutic opportunity in p53-deficient tumors. Knockdown of endogenous p63 by p63-directed or control lentiviral shRNA in JHU-029 human SCC cells at 48h, in duplicate experiments. Array analysis showing the fold-change and direction of change for all miRs regulated > 1.5-fold in p63-ablated versus control samples
2010-11-23 | E-GEOD-25524 | biostudies-arrayexpress
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:A central challenge in human cancer therapy is the identification of pathways that control tumor cell survival and chemosensitivity in the absence of functional p53. The p53-related transcription factors p63 and p73 exhibit distinct, p53-independent roles in development and cancer: p73 promotes genome stability and mediates chemosensitivity, while p63 largely lacks these p53-like functions and instead promotes proliferation and cell survival. Here, we identify a new and physiologically important mechanism of p63/p73 cross-talk which governs the balance between pro-survival and pro-apoptotic programs in both human and murine squamous cell carcinoma. Through comprehensive profiling of p63-regulated microRNAs (miRs), we identified a subset which target p73 for inhibition, including miR-193a-5p, a direct endogenous transcriptional target repressed by p63 and activated by pro-apoptotic p73 isoforms in both normal cells and tumor cells in vivo. Consequently, chemotherapy treatment causes p63/p73-dependent induction of this miR, thereby limiting chemosensitivity due to miR-mediated feedback control of p73. We demonstrate that interrupting this feedback by inhibiting miR-193a suppresses tumor cell viability and induces dramatic chemosensitivity both in vitro and in vivo. Thus, we have identified a direct, miR-dependent regulatory circuit mediating inducible chemoresistance, whose inhibition provides a new therapeutic opportunity in p53-deficient tumors.
2010-11-23 | GSE25524 | GEO
Project description:The goal of this study was to identify potential Hox5 target genes in cervical motor neurons (C3-C6) using unbiased genomic screens (RNA-seq). We examined expression changes independently of motor neuron cell death by deleting the pro-apoptotic gene Bax in both control and experimental mice.
2020-01-16 | GSE138085 | GEO
Project description:Mutations in genes encoding general transcription factors cause neurological disorders. Despite clinical prominence, the consequences of defects in the basal transcription machinery during brain development are unclear. We found that loss of the TATA-box binding protein associated factor TAF8, a component of the general transcription factor TFIID, in the developing central nervous system affected the expression of many, but notably not all genes. Taf8 deletion caused apoptosis, unexpectedly restricted to forebrain regions. Nuclear levels of the transcription factor p53 were elevated in the absence of TAF8, as were the mRNAs of the pro-apoptotic p53 target genes Noxa, Puma and Bax. The cell death in Taf8–/– forebrain regions was completely rescued by additional loss of p53, but Taf8–/–p53–/– brains failed to initiate a neuronal expression program. Taf8 deletion caused aberrant transcription of promoter regions and splicing anomalies. We propose that TAF8 supports the directionality of transcription and co-transcriptional splicing, and that failure of these processes causes p53- induced apoptosis of neuronal cells in the developing mouse embryo. Taf8 was deleted in the developing mouse central nervous system (CNS) using our Taf8 conditional allele. In the absence of global effects of loss of TAF8 on RNA levels, we determined effects on individual gene loci by RNA sequencing of cortices from Taf8 deleted (E14.5 Taf8lox/–NesCreT/+p53–/–) and control (E14.5 Taf8+/+NesCreT/+p53–/–) cortices. The p53-deficient background was used to avoid complications due to apoptosis, but prevented us from examining changes in p53-induced gene transcription.
2022-03-12 | GSE198505 | GEO
Project description:BAX is a pro-apoptotic BCL-2 protein that resides in the cytosol as a monomer until triggered by cellular stress to transform into an oligomer that permeabilizes the mitochondria and induces apoptosis. We previously reported the generation of a full-length BAX oligomer (BAXO) that recapitulates pro-apoptotic functionality. Here, we find that full-length BCL-w can be induced to form a symmetric dimer (BCL-wD) that dissociates BAXO, inhibits its mitochondrial translocation, induces its retrotranslocation, and thereby blocks its membrane-porating activity. Structure-function analyses revealed discrete conformational changes upon BCL-w dimerization and reciprocal structural impacts upon BCL-wD and BAXO interaction. SAXS analysis demonstrated that BAXO forms pores by inducing negative Gaussian membrane curvature, which is reversed by positive Gaussian curvature exerted by BCL-wD. Our studies reveal an additional mechanism of apoptotic regulation mediated by the protein and membrane interactions of higher-order BCL-2 family multimers, redefining the “point of no return” for BAX-mediated apoptosis.
2025-11-21 | PXD049315 | Pride
Project description:BAX is a pro-apoptotic member of the BCL-2 family, which regulates the balance between cellular life and death. During homeostasis, BAX predominantly resides in the cytosol as a latent monomer but, in response to stress, transforms into an oligomeric protein that permeabilizes the mitochondria, leading to cell death. Because renegade BAX activation poses a grave risk to the cell, the architecture of BAX must ensure monomeric stability yet simultaneously enable conformational change upon stress signaling. The specific structural features that afford both stability and dynamic flexibility remain ill-defined and represent a critical control point of BAX regulation. Here, we identified a nexus of interactions involving four discrete residues of the BAX core α5 helix that are individually essential to maintaining the structure and latency of monomeric BAX and are collectively required for dimeric assembly. We compared the HDX MS profile of full-length recombinant wild-type BAX in solution with that of the BAX L113A, F114A, Y115A, and F116A single point mutants. In each case, we observed striking, regiospecific consequences of replacing the bulky hydrophobic residue with alanine. We also compared HDX in a construct of α2-α5 for the wt protein as well as mutants. The dual yet distinct roles of these residues reveals the intricacy of BAX conformational regulation and opportunities for therapeutic modulation.
2021-08-26 | PXD024479 | Pride
Project description:Intrinsic apoptosis is principally regulated by the BCL-2 family of proteins, but some non-BCL-2 proteins also serve as important regulators. To identify novel apoptosis regulators, we performed a genome-wide CRISPR-Cas9 library screen, and it identified the mitochondrial E3 ubiquitin ligase MARCHF5/MITOL/RNF153 as an important regulator of BAK apoptotic function. Deleting MARCHF5 in multiple BAX-deficient cell lines conferred profound resistance to BH3-mimetic drugs. The loss of MARCHF5 or its E3 ubiquitin ligase activity surprisingly drove BAK to adopt an active conformation, with resistance to BH3-mimetics afforded by the formation of inhibitory complexes with pro-survival proteins MCL-1 and BCL-XL. Importantly, these changes to BAK conformation and pro-survival association occurred independently of BH3-only proteins. This study identifies a mechanism by which MARCHF5 regulates apoptotic cell death and provides new insight into how cancer cells respond to BH3-mimetic drugs. These data also highlight the emerging role of ubiquitin signalling in apoptosis that may be exploited therapeutically.
2022-09-25 | PXD030246 | Pride