Impact of mutant p53 on TNF-induced gene expression
Ontology highlight
ABSTRACT:
ORGANISM(S): Homo sapiens
SUBMITTER: Piazza Silvano
PROVIDER: S-ECPF-GEOD-53153 | biostudies-other |
REPOSITORIES: biostudies-other
Similar Datasets
Project description:MDA-MB-231 are a metastatic triple-negative breast cancer cell line that bears a missense p53 mutation (R280K). We depleted endogenous mutp53 in MDA-MB-231 cells by siRNA transfection, and treated the cells with Tumor Necrosis Factor (TNF)-alpha. Microarray analysis was performed to evaluate the impact of mutant p53 on the transcriptional response triggered by TNFα in these cells.
2014-10-27 | GSE53153 | GEO
Project description:MDA-MB-231 are a metastatic triple-negative breast cancer cell line that bears a missense p53 mutation (R280K). We depleted endogenous mutp53 in MDA-MB-231 cells by siRNA transfection, and treated the cells with Tumor Necrosis Factor (TNF)-alpha. Microarray analysis was performed to evaluate the impact of mutant p53 on the transcriptional response triggered by TNFα in these cells. MDA-MB-231 cells transfected with control or p53 siRNA were treated with TNFα for 20 hrs or left untreated. The study comprises four experimental points, each in triplicate.
2014-10-27 | E-GEOD-53153 | biostudies-arrayexpress
Project description:Exposure to aristolochic acid (AA) is linked to kidney disease and urothelial cancer in humans. The major carcinogenic component of the AA plant extract is aristolochic acid I (AAI). The tumour suppressor p53 is frequently mutated in AA-induced tumours. We previously showed that p53 protects from AAI-induced renal proximal tubular injury, but the underlying mechanism(s) involved remain to be further explored. In the present study, we investigated the impact of p53 on AAI-induced gene expression by treating Trp53(+/+), Trp53(+/-), and Trp53(-/-) mice with 3.5 mg/kg body weight (bw) AAI daily for six days. The Clariom™ S Assay microarray was used to elucidate gene expression profiles in mouse kidneys after AAI treatment. Analyses in Qlucore Omics Explorer showed that gene expression in AAI-exposed kidneys is treatment-dependent. However, gene expression profiles did not segregate in a clear-cut manner according to Trp53 genotype, hence further investigations were performed by pathway analysis with MetaCore™. Several pathways were significantly altered to varying degrees for AAI-exposed kidneys. Apoptotic pathways were modulated in Trp53(+/+) kidneys; whereas oncogenic and pro-survival pathways were significantly altered for Trp53(+/-) and Trp53(-/-) kidneys, respectively. Alterations of biological processes by AAI in mouse kidneys could explain the mechanisms by which p53 protects from or p53 loss drives AAI-induced renal injury in vivo.
| S-EPMC6940885 | biostudies-literature
Project description:Apoptosis is the major downregulated pathway in cancer. Simultaneous inhibition using specific small interfering RNA (siRNA) of two key player genes, p53 and TNF, is an interesting and feasible strategy when it comes to investigating various molecular pathways and biological processes in triple-negative breast cancer (TNBC), which is one of the most aggressive and therapeutically unresponsive forms of breast cancers. Our present research focuses on evaluating the impact of double p53-siRNA and TNF-siRNA knockdown at a cellular level, and also evaluating cell proliferation, apoptosis, induction of autophagy, and gene expression by using reverse transcription polymerase chain reaction array approaches. Simultaneous inhibition of p53 and TNF in Hs578T TNBC human cell line revealed a panel of up- and downregulated genes involved in apoptosis. Furthermore, the effects of double gene knockdown were validated in a second TNBC cell line, MDA-MB-231, by using reverse transcription polymerase chain reaction TaqMan assay. All our findings help in understanding the functional mechanisms of extrinsic apoptosis, cell signaling pathways, and the mechanisms involved in tumor cell survival, growth, and death in TNBC.
| S-EPMC5113913 | biostudies-literature
Project description:Galectin-7 was initially described as a marker of epithelial differentiation expressed in the stratified epithelium of various tissues. Like other members of the galectin family, its expression level is often significantly altered in cancer cells. In breast cancer, its expression is significantly augmented in aggressive molecular subtypes, most notably in estrogen receptor-negative tumors and in cell lines with a basal-like phenotype. Studies using experimental mouse models have further shown high expression of galectin-7 was sufficient to increase the metastatic behavior of poorly metastatic breast cancer cells, rendering them more resistant to apoptosis. This expression pattern in breast cancer cells is unexpected because galectin-7 was originally identified as a p53-induced gene. To address this paradox, we have examined the molecular mechanisms regulating galectin-7 in breast cancer cells. Our results showed that transfection of breast cancer cells with expression vectors encoding mutant p53 was sufficient to induce galectin-7 at both mRNA and protein levels. Doxorubicin treatment of breast cancer cells harboring a mutant p53 also induced galectin-7. This induction was specific since knockdown of endogenous mutant p53 inhibited doxorubicin-induced galectin-7 expression. The p53-induced galectin-7 expression in breast cancer cells correlated with increased NF-?B activity and was inhibited by NF-?B inhibitors, indicating that the ability of mutant p53 to induce galectin-7 was dependent on NF-?B activity. The implication of NF-?B was further supported by data showing that NF-?B bound to the endogenous galectin-7 promoter and that TNF?-induced galectin-7 expression was abolished by NF-?B inhibitors. Taken together, our data provide an explanation to the observed high galectin-7 expression levels in cancer cells and suggest that galectin-7 could be part of a common pathway used by mutant p53 to promote cancer progression.
| S-EPMC3743813 | biostudies-literature
Project description:TNF? is a pleiotropic cytokine that signals for both survival and apoptotic cell fates. It is still unclear that the dual role of TNF? can be regulated in cancer cells. We previously described an apoptotic pathway involving p53?CDIP?TNF? that was activated in response to genotoxic stress. This pathway operated in the presence of JNK activation; therefore, we postulated that CDIP itself could sensitize cells to a TNF? apoptotic cell fate, survival, or death. We show that CDIP mediates sensitivity to TNF?-induced apoptosis and that cancer cells with endogenous CDIP expression are inherently sensitive to the growth-suppressive effects of TNF? in vitro and in vivo. Thus, CDIP expression correlates with sensitivity of cancer cells with TNF?, and CDIP seems to be a regulator of the p53-mediated death versus survival response of cells to TNF?. This CDIP-mediated sensitivity to TNF?-induced apoptosis favors pro- over antiapoptotic program in cancer cells, and CDIP may serve as a predictive biomarker for such sensitivity.
| S-EPMC3349239 | biostudies-literature
Project description:When cells are induced to express inflammatory genes by treatment with TNF, the mRNAs for the induced genes appear in three distinct waves, defining gene groups I, II, and III, or early, intermediate, and late genes. To examine the basis for these different kinetic classes, we have developed a PCR-based procedure to distinguish pre-mRNAs from mRNAs. It shows that the three groups initiate transcription virtually simultaneously but that delays in splicing characterize groups II and III. We also examined the elongation times, concluding that pre-mRNA synthesis is coordinate but splicing differences directly regulate the timing of mRNA production.
| S-EPMC3718113 | biostudies-literature
Project description:BackgroundThe cytokine tumor necrosis factor (TNF) initiates tissue inflammation, a process mediated by the NF-kappaB transcription factor. In response to TNF, latent cytoplasmic NF-kappaB is activated, enters the nucleus, and induces expression of inflammatory and anti-apoptotic gene expression programs. Recently it has been shown that NF-kappaB displays two distinct activation modes, monophasic and oscillatory, depending on stimulus duration. Characterization of temporal expression patterns for the NF-kappaB network and determination of those genes under monophasic- or oscillatory control has not been experimentally addressed.ResultsTo identify the kinetics of NF-kappaB-dependent gene expression and determine whether these two types of NF-kappaB translocation modes control distinct gene programs, a detailed kinetic analysis of a validated microarray data set was performed on 74 unique NF-kappaB-dependent genes in response to TNF. Hierarchical clustering identified distinct expression profiles termed the "Early", "Middle", "Late" response groups, peaking 1, 3, and 6 h after stimulation, respectively. These expression patterns were validated by Quantitative Real Time PCR (Q-RT-PCR) and NF-kappaB binding was demonstrated by chromatin immunoprecipitation (ChIP) assays. Each response group was mapped to its molecular function; this analysis indicated that the Early group encodes cytokines or negative regulators of the IKK-NF-kappaB pathway, and the Late group encodes cell surface receptors, adhesion molecules and signal adapters. That similar coordinated sequential cascades of gene expression were also seen in response to stimulation by the cytokine IL-1, and expression patterns observed in MRC-5 fibroblasts indicated that the epithelial NF-kappaB program is relatively stimulus- and cell type-independent. Bioinformatic analysis of the Early and Late gene promoters indicates that although both groups contain similar patterns of NF-kappaB-binding sites, only the Early gene promoters contain NF-kappaB-binding sites located in phylogenetically conserved domains. Stimulation protocols designed to produce either monophasic or oscillatory NF-kappaB activation modes showed that the oscillatory mode is required only for expression of the Late genes.ConclusionThis analysis provides important insights into the TNF-regulated genetic response program in epithelial cells, where NF-kappaB controls sequential expression patterns of functionally distinct genes that depend on its oscillatory activation mode.
| S-EPMC1262712 | biostudies-literature
Project description:Chronic ulcerative colitis (CUC) is characterized by increased intestinal epithelial cell (IEC) apoptosis associated with elevated tumor necrosis factor (TNF), inducible nitric oxide synthase (iNOS), and p53. We previously showed that p53 is increased in crypt IECs in human colitis and is needed for IEC apoptosis in chronic dextran sulfate sodium-colitis. Herein, we examined the roles of TNF and iNOS in regulating p53-induced IEC apoptosis in CUC. The IEC TUNEL staining, caspases 3, 8, and 9, and p53 protein levels, induced by anti-CD3 monoclonal antibody (mAb) activation of T cells, were markedly reduced in TNF receptor 1 and 2 gene knockout mice. Induction of IEC apoptosis correlated with increased p53, which was attenuated in iNOS(-/-) mice. IEC p53 levels and apoptosis were reduced in IL-10(-/-) colitic mice treated with neutralizing TNF mAb and the iNOS inhibitor, aminoguanidine, further suggesting that TNF and iNOS are upstream of p53 during colitis-induced IEC apoptosis. IEC apoptosis and p53 levels were assessed in control versus untreated or anti-TNF-treated CUC patients with equivalent levels of inflammation. Data indicated that IEC apoptosis and p53 levels were clearly higher in untreated CUC but markedly reduced in patients treated with anti-TNF mAb. Therefore, TNF-induced iNOS activates a p53-dependent pathway of IEC apoptosis in CUC. The inhibition of IEC apoptosis may be an important mechanism for mucosal healing in anti-TNF-treated CUC patients.
| S-EPMC3463630 | biostudies-other
Project description:The p53 tumor suppressor is a DNA-damage-responsive sequence-specific transcriptional activator. The sustained activation of the p53 response is incompatible with cell growth and viability. To circumvent this issue, a variety of negative feedback loops exist to limit the duration of p53 activation. Despite our understanding of p53 regulation, very little is known about the effect of transient p53 activation on the long-term expression of p53 target genes. Here we used a temperature-sensitive variant of p53 and oligonucleotide microarrays to monitor gene expression during and following reversible p53 activation. The expression of most p53-induced transcripts was rapidly reversible, consistent with active mRNA decay. Representative 3' UTRs derived from short-lived transcripts (i.e., DDB2 and GDF15) conferred instability on a heterologous mRNA, while 3' UTRs derived from more stable transcripts (i.e., CRYAB and TP53I3) did not. The 3' UTRs derived from unstable p53-induced mRNAs were significantly longer than those derived from stable mRNAs. These 3' UTRs had high uridine and low cytosine content, leading to a higher density of U-, AU-, and GU-rich sequences. Remarkably, short-lived p53 targets were induced faster, reaching maximum transcript levels earlier than the stable p53 targets. Taken together, the evidence indicates that the p53 transcriptional response has evolved with primarily short-lived target mRNAs and that post-transcription processes play a prominent role in the p53 response.
| S-EPMC3222134 | biostudies-literature