Similar Datasets
Project description:Cancer-related alterations of the p53 Tetramerization Domain (TD) abrogate wild-type (WT) p53 function. They result in a protein that preferentially forms monomers or dimers. These are also normal p53 states under basal cellular conditions. However, their physiological relevance is not well understood. We have established in vivo models for monomeric and dimeric p53 which model Li-Fraumeni Syndrome patients with germline p53 TD alterations. p53 monomers are inactive forms of the protein. Unexpectedly, p53 dimers conferred some tumor suppression that is not mediated by canonical WT p53 activities. p53 dimers upregulate the PPAR pathway. These activities are associated with lower prevalence of thymic lymphomas and inhibition of CD8+ T-cell accumulation. Lymphomas derived from dimeric p53 mice show cooperating alterations in the PPAR pathway, further implicating a role for these activities in tumor suppression. Our data reveal novel functions for p53 dimers and support the exploration of PPAR agonists as therapies.
2023-03-01 | GSE220964 | GEO
Project description:Cancer-related alterations of the p53 Tetramerization Domain (TD) abrogate wild-type (WT) p53 function. They result in a protein that preferentially forms monomers or dimers. These are also normal p53 states under basal cellular conditions. However, their physiological relevance is not well understood. We have established in vivo models for monomeric and dimeric p53 which model Li-Fraumeni Syndrome patients with germline p53 TD alterations. p53 monomers are inactive forms of the protein. Unexpectedly, p53 dimers conferred some tumor suppression that is not mediated by canonical WT p53 activities. p53 dimers upregulate the PPAR pathway. These activities are associated with lower prevalence of thymic lymphomas and inhibition of CD8+ T-cell accumulation. Lymphomas derived from dimeric p53 mice show cooperating alterations in the PPAR pathway, further implicating a role for these activities in tumor suppression. Our data reveal novel functions for p53 dimers and support the exploration of PPAR agonists as therapies.
2023-03-01 | GSE220963 | GEO
Project description:Cancer-related alterations of the p53 Tetramerization Domain (TD) abrogate wild-type (WT) p53 function. They result in a protein that preferentially forms monomers or dimers. These are also normal p53 states under basal cellular conditions. However, their physiological relevance is not well understood. We have established in vivo models for monomeric and dimeric p53 which model Li-Fraumeni Syndrome patients with germline p53 TD alterations. p53 monomers are inactive forms of the protein. Unexpectedly, p53 dimers conferred some tumor suppression that is not mediated by canonical WT p53 activities. p53 dimers upregulate the PPAR pathway. These activities are associated with lower prevalence of thymic lymphomas and inhibition of CD8+ T-cell accumulation. Lymphomas derived from dimeric p53 mice show cooperating alterations in the PPAR pathway, further implicating a role for these activities in tumor suppression. Our data reveal novel functions for p53 dimers and support the exploration of PPAR agonists as therapies.
2023-03-01 | GSE220962 | GEO
Project description:Cancer-related alterations of the p53 Tetramerization Domain (TD) abrogate wild-type (WT) p53 function. They result in a protein that preferentially forms monomers or dimers. These are also normal p53 states under basal cellular conditions. However, their physiological relevance is not well understood. We have established in vivo models for monomeric and dimeric p53 which model Li-Fraumeni Syndrome patients with germline p53 TD alterations. p53 monomers are inactive forms of the protein. Unexpectedly, p53 dimers conferred some tumor suppression that is not mediated by canonical WT p53 activities. p53 dimers upregulate the PPAR pathway. These activities are associated with lower prevalence of thymic lymphomas and inhibition of CD8+ T-cell accumulation. Lymphomas derived from dimeric p53 mice show cooperating alterations in the PPAR pathway, further implicating a role for these activities in tumor suppression. Our data reveal novel functions for p53 dimers and support the exploration of PPAR agonists as therapies.
2023-03-01 | GSE220961 | GEO
Project description:Cancer-related alterations of the p53 Tetramerization Domain (TD) abrogate wild-type (WT) p53 function. They result in a protein that preferentially forms monomers or dimers. These are also normal p53 states under basal cellular conditions. However, their physiological relevance is not well understood. We have established in vivo models for monomeric and dimeric p53 which model Li-Fraumeni Syndrome patients with germline p53 TD alterations. p53 monomers are inactive forms of the protein. Unexpectedly, p53 dimers conferred some tumor suppression that is not mediated by canonical WT p53 activities. p53 dimers upregulate the PPAR pathway. These activities are associated with lower prevalence of thymic lymphomas and inhibition of CD8+ T-cell accumulation. Lymphomas derived from dimeric p53 mice show cooperating alterations in the PPAR pathway, further implicating a role for these activities in tumor suppression. Our data reveal novel functions for p53 dimers and support the exploration of PPAR agonists as therapies.
2023-03-01 | GSE220965 | GEO
Project description:This SuperSeries is composed of the SubSeries listed below.
2017-08-22 | GSE86222 | GEO
Project description:Polynucleotide phosphorylase (PNPase) is an essential mitochondria-localized exoribonuclease implicated in multiple biological processes and human disorders. To reveal role(s) for PNPase in mitochondria, we established PNPase knockout (PKO) systems by first shifting culture conditions to enable cell growth with defective respiration. Interestingly, PKO established in mouse embryonic fibroblasts (MEFs) resulted in the loss of mitochondrial DNA (mtDNA). The transcriptional profile of PKO cells was similar to rho0 mtDNA deleted cells, with perturbations in cholesterol (FDR = 6.35 x 10-13), lipid (FDR = 3.21 x 10-11), and secondary alcohol (FDR = 1.04x10-12) metabolic pathway gene expression compared to wild type parental (TM6) MEFs. Transcriptome analysis indicates processes related to axonogenesis (FDR = 4.49 x 10-3), axon development (FDR = 4.74 x 10-3), and axonal guidance (FDR = 4.74 x 10-3) were overrepresented in PKO cells, consistent with previous studies detailing causative PNPase mutations in delayed myelination, hearing loss, encephalomyopathy, and chorioretinal defects in humans. Overrepresentation analysis revealed alterations in metabolic pathways in both PKO and rho0 cells. Therefore, we assessed the correlation of genes implicated in cell cycle progression and total metabolism and observed a strong positive correlation between PKO cells and rho0 MEFs compared to TM6 MEFs. We quantified the normalized biomass accumulation rate of PKO clones at 1.7% (SD ± 2.0%) and 2.4% (SD ± 1.6%) per hour, which was lower than TM6 cells at 3.3% (SD ± 3.5%) per hour. Furthermore, PKO in mouse inner ear hair cells caused progressive hearing loss that parallels human familial hearing loss previously linked to mutations in PNPase. Combined, our study reports that knockout of a mitochondrial nuclease results in mtDNA loss and suggests that mtDNA maintenance could provide a unifying connection for the large number of biological activities reported for PNPase.
| S-EPMC6053217 | biostudies-literature
Project description:Human cytomegalovirus (HCMV) is a widely prevalent human herpesvirus, which, after primary infection, persists in the host for life. In healthy individuals, the virus is well controlled by the HCMV-specific T cell response. A key feature of this persistence, in the face of a normally robust host immune response, is the establishment of viral latency. In contrast to lytic infection, which is characterised by extensive viral gene expression and virus production, long-term latency in cells of the myeloid lineage is characterised by highly restricted expression of viral genes, including UL138 and LUNA. Here we report that both UL138 and LUNA-specific T cells were detectable directly ex vivo in healthy HCMV seropositive subjects and that this response is principally CD4? T cell mediated. These UL138-specific CD4? T cells are able to mediate MHC class II restricted cytotoxicity and, importantly, show IFN? effector function in the context of both lytic and latent infection. Furthermore, in contrast to CDCD4? T cells specific to antigens expressed solely during lytic infection, both the UL138 and LUNA-specific CD4? T cell responses included CD4? T cells that secreted the immunosuppressive cytokine cIL-10. We also show that cIL-10 expressing CD4? T-cells are directed against latently expressed US28 and UL111A. Taken together, our data show that latency-associated gene products of HCMV generate CD4? T cell responses in vivo, which are able to elicit effector function in response to both lytic and latently infected cells. Importantly and in contrast to CD4? T cell populations, which recognise antigens solely expressed during lytic infection, include a subset of cells that secrete the immunosuppressive cytokine cIL-10. This suggests that HCMV skews the T cell responses to latency-associated antigens to one that is overall suppressive in order to sustain latent carriage in vivo.
| S-EPMC3795018 | biostudies-literature
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:Polynucleotide phosphorylase (PNPase) is an essential mitochondria-localized exoribonuclease implicated in multiple biological processes and several human disorders. To reveal role(s) for PNPase in mitochondria, we established PNPase knockout (PKO) systems by first shifting culture conditions to enable cell growth with defective respiration. PKO resulted in loss of mitochondrial DNA (mtDNA) and a transcriptional profile similar to rho0 mtDNA deleted cells, with perturbations in cholesterol, lipid, and secondary alcohol metabolic pathways. PKO cells also showed growth and cell cycle profiles similar to rho0 cells. PKO in mouse inner ear hair cells cause progressive hearing loss that parallel human familial hearing loss previously linked to mutations in PNPase. Combined, our data suggest that mtDNA maintenance could provide a unifying connection for the large number of biological activities reported for PNPase.
2018-05-01 | GSE111668 | GEO