Transcriptome and translatome profiling of MCF7 vector cells after p53 activation
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ABSTRACT:
ORGANISM(S): Homo sapiens
SUBMITTER: Toma Tebaldi
PROVIDER: E-GEOD-50650 | biostudies-arrayexpress |
REPOSITORIES: biostudies-arrayexpress
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Project description:We subjected MCF7 cells to starvation with 0.5% charcoal treated serum for 48h and then we added 17-beta estradiol (E2) at final concentration of 10 nM, profiling before and after 60 minutes of treatment the transcriptome and the translatome, coming from the polysomal pool of mRNAs after sucrose gradient separation. Comparison of translatome profile changes with corresponding transcriptome profile changes represents a way of studying translational control networks and the degree of concordance between cellular controls affecting mRNA abundance and cellular controls affecting mRNA availability to translation. It is well known that E2 is a strong transcriptional regulator, while its translational control activity is less characterized. To provide a direct experimental evaluation of E2 induced translational regulation, we compared translatome and transcriptome profiles of E2 treated cells. Keywords: polysomal profiling, translatome profiling, polysomal RNA, translational control, translational profiling, polysome profiling, post-transcriptional regulation, estradiol stimulation, estrogen receptor. The comparison between transcriptional and polysomal profiling was used for the discovery of general and mRNA-specific changes in the translation state of the serum starved MCF7 cells transcriptome in response to E2 stimulus. To identify translationally regulated mRNA molecules, gene expression signals derived from the polysomal populations were compared by microarrays analysis to those obtained from unfractionated total RNAs. Polysomal RNA and total RNA were isolated from MCF7 cells serum starved and treated with E2. Cells lysates were collected before (t = 0 min) and after (t = 60 min) E2 treatment. All experiments were run in quadruplicates.
2010-12-31 | E-GEOD-22012 | biostudies-arrayexpress
Project description:Neuroblastoma (NB) is the most frequent extracranial solid tumour of childhood. Clinical courses are highly variable, ranging from spontaneous regression/maturation to rapid progression despite intensive multimodal therapy. The estimation of 5-year event free survival in high-risk patients of only about 40 % stresses an importance of novel therapeutic strategies. A number of iron chelators have demonstrated marked in vitro and in vivo anti-tumor activity and are currently being developed as novel anti-cancer agents. Therefore, the potential antitumor effect of iron chelators in NB cancer was investigated. Among the compounds tested, ciclopirox olamine (CPX) was shown to be one of the most effective intracellular iron chelators in NB cells. To unveil the molecular mechanisms underlying the effects of CPX on viability of NB cells, microarray analysis was performed in CHP134 control cells and cells treated with 5 M-BM-5M CPX for 90 minutes. Inclusion of both total RNA (reflecting transcriptional status of the cells) and polysomal RNA (approximating the proteomic representation of the cells) provided us with a deeper understanding of changes in the cells upon CPX treatment. Keywords: ciclopirox olamine, iron chelator, neuroblastoma, translatome profiling, transcriptome profiling. Keywords: ciclopirox olamine, iron chelator, neuroblastoma, translatome profiling, transcriptome profiling, polysomal profiling, polysomal RNA, translational control, translational profiling, polysome profiling Microarray analysis was performed to enable a comprehensive view of the changes in the transcriptional and translational status of the cells in response to the treatment with an iron chelator CPX. Polysomal RNA and total RNA were isolated from vehicle-treated CHP134 cells and CHP134 cells treated with 5 M-BM-5M CPX for 90 minutes. Each condition is represented by three biological replicates, i.e. the experiment was repeated starting each time from cells seeding yielding an independent RNA sample. In total, 12 samples corresponding to 4 conditions were subjected to microarray analysis.
2015-02-04 | E-GEOD-60675 | biostudies-arrayexpress
Project description:We applied in parallel RNA-Seq and Ribosome-profiling analyses to immortalized human primary BJ fibroblast cells in which p53 was induced by Nutlin-3a RNA-seq, using Illumina HiSeq 2000, was applied to BJ cells treated with Nutlin-3a, at 5 timepoints: 0, 2, 4, 6, 19 hrs Ribosome profiling was applied to BJ cells treated with Nutlin-3a, at 5 timepoints: 0, 2, 4, 6, 19 hrs
2013-06-01 | E-GEOD-45785 | biostudies-arrayexpress
Project description:We applied in parallel RNA-Seq and Ribosome-profiling analyses to immortalized human primary BJ fibroblast cells under the following conditions: normal proliferation, quiescence (induced by serum depletion), senescence (induced by activation of the oncogenic RASG12V gene, and examined at early (5 days; pre-senescent state) and late (14 days; fully senescent state) time points), and neoplastic transformation (induced by RASG12V in the background of stable p53 and p16INK4A knockdowns and SV40 small-T expression. RNA-seq, using Illumina HiSeq 2000, was applied to BJ cells under 5 conditions: proliferation, quiescence, pre-senescence, full-senescence, and transfomed. Ribosome profiling, using Illumina HiSeq 2000, was applied to BJ cells under 5 conditions: proliferation, quiescence, pre-senescence, full-senescence, and transfomed.
2013-03-24 | E-GEOD-42509 | biostudies-arrayexpress
Project description:Loss of function of the tumor suppressor BRCA1 (Breast Cancer 1) protein is responsible for numerous familial and sporadic breast cancers. We previously identified PABP1 as a novel BRCA1 partner and showed that BRCA1 modulates translation through its interaction with PABP1. We showed that the global translation was diminished in BRCA1-depleted cells and increased in BRCA1-overexpressing cells. Our findings raised the question whether BRCA1 affects translation of all cytoplasmic cellular mRNAs or whether it specifically targets a subset of mRNAs. In the present study, we investigated which mRNAs are regulated by BRCA1 using a microarray analysis of polysome-associated RNAs from BRCA1-depleted MCF7 cells, a human breast cancer cell line. We isolated mRNAs from the high-molecular-weight polysomes (fractions 12 to 18) and total cellular cytoplasmic mRNAs from the cytoplasmic fraction of MCF7 cells transiently expressing either siRNA directed against BRCA1 or control siRNA. Since we were interested in identifying the mRNAs that were translationally regulated by BRCA1, we determined the relative translatability of each mRNA. The relative translatability of an mRNA was determined by normalizing the change in abundance in polysomal mRNA to the change in abundance in total cytoplasmic mRNA for each mRNA.
2013-12-31 | E-GEOD-40730 | biostudies-arrayexpress
Project description:We explored the combinatorial interactions between p53, estrogen receptors and NFkB using the breast adenocarcinoma-derived MCF7 cells. Recently, we have established that p53 can modulate transcription also through non-canonical response elements (REs), consisting of half-sites and ¾ sites. In particular, we identified a half-site p53 response element in the promoter of FLT1/VEGFR-I gene that was required but not sufficient for the p53 responsiveness of the promoter. The transcriptional control required also estrogen receptor (ER) half-sites (EREs) located in close proximity to the p53 RE. Further studies led us to establish that p53-mediated transcription from the FLT1 half site RE is dependent on ER binding at the EREs and strongly influenced by the level of ER proteins, and the specific nature of the p53-inducing stress as well as ER ligand. In another study we found an enrichment of NFkB REs nearby p53 REs in p53 target genes, suggesting an additional mode of functional interactions between these two transcription factors. To identify at a genome scale the transcriptional network that selectively responds to the concomitant activation of p53, ER and/or NFkB, we measured gene expression upon treatment with specific chemotherapeutic agents combined with 17-β estradiol (E2) and/or the inflammatory cytokine TNFα. Firstly we measured using MCF7 cells growing in estrogen-depleted media the transcriptome changes induced by doxorubicin (doxo) and 5-fluorouracil (5FU), two different drugs both able to stabilize and activate the p53 protein. We next obtained the expression profiles in the presence of E2 with or without doxo or 5FU. We also measured transcriptome changes in response to TNFαalone or in combination with doxo and/or E2. All these analyses were conducted using the same batch of MCF7 cells (wild type for p53, ERα, ERβ -weakly-, and NFkB positive) that we had previously used to characterize the cis-mediated transcriptional cooperation between p53 and ER at the FLT1 gene. Keywords: transcription factor, transcriptional networks, p53, ER, NFkB, p53-ER-NFkB crosstalk, doxorubicin, 5-fluorouracil, 17-β estradiol, TNFα, combined genotoxic, estrogenic and inflammatory responses, composite DNA binding site signatures, MCF7. The cooperation at the transcriptional level among p53, ERs and NFkB was analyzed by transcriptome analysis in response to different stimuli (doxo or 5FU, E2, TNFα). To identify mRNA molecules that would be modulated by the coordinated activity of the three TFs, gene expression signals derived from the combinatorial treatment were compared by microarrays analyses to those obtained from each drug when individually administered. Total RNA was isolated from MCF7 cells grown in estrogen-depleted medium and treated so as to stimulate the activity of the three different transcription factors (p53, ERs and NFkB). Cells lysates were collected after 10 hours from the treatments. All experiments were run from triplicate to septuples.
2011-06-01 | E-GEOD-24065 | biostudies-arrayexpress
Project description:Small RNAs play essential regulatory roles in genome stability, development and stress responses in most eukaryotes. Plants encode DICER-LIKE (DCL) RNaseIII enzymes, including DCL1, which produces miRNAs, and DCL2, DCL3 and DCL4, which produce diverse size classes of siRNA. Plants also encode RNASE THREE-LIKE (RTL) enzymes that lack DCL-specific domains and whose function is largely unknown. Small RNA sequencing in plants over-expressing RTL1 or RTL2 or lacking RTL2 revealed that RTL1 over-expression inhibits the accumulation of all types of small RNAs produced by DCL2, DCL3 and DCL4, indicating that RTL1 is a general suppressor of plant siRNA pathways. By contrast, RTL2 plays minor, if any, role in the small RNA repertoire. In vivo and in vitro assays revealed that RTL1 prevents siRNA production by degrading dsRNA before they are processed by DCL2, DCL3 and DCL4. The substrate of RTL1 cleavage is likely long perfect (or near-perfect) dsRNA, consistent with the RTL1-insensitivity of miRNAs, which derive from short imperfect dsRNA. RTL1 is naturally expressed only weakly in roots, but virus infection strongly induces its expression in leaves, suggesting that RTL1 induction is a general strategy used by viruses to counteract the siRNA-based plant antiviral defense. Accordingly, transgenic plants over-expressing RTL1 are more sensitive to TYMV infection than wild-type plants, likely because RTL1 prevents the production of antiviral siRNAs. However, TCV, TVCV and CMV, which encode stronger suppressors of RNA silencing (VSR) than TYMV, are insensitive to RTL1 over-expression. Indeed, TCV VSR inhibits RTL1 activity, suggesting that inducing RTL1 expression and dampening RTL1 activity is a dual strategy used by viruses to establish a successful infection. These results reveal another level of complexity in the evolutionary battle between viruses and plant defenses. Flower sRNA profiles in diverse conditions involving RTL1 and RTL2
2013-09-10 | E-GEOD-49866 | biostudies-arrayexpress
Project description:During differentiation of embryonic stem cells, chromatin reorganizes to establish cell type specific expression programs. Here, we have dissected the linkages between DNA methylation (5mC), hydroxymethylation (5hmC), nucleosome repositioning and binding of the transcription factor CTCF during this process. By integrating MNase-seq and ChIP-seq experiments in mouse embryonic stem cells (ESC) and their differentiated counterparts with biophysical modeling, we find that the interplay between these factors depends on their large-scale genomic context. The mostly unmethylated CpG islands have a reduced nucleosome occupancy and are enriched in cell type-independent binding sites for CTCF. The few remaining methylated CpG dinucleotides are preferentially associated with nucleosomes. In contrast, outside of CpG islands most CpGs are methylated and their average density oscillates so that it is highest in the linker region between nucleosomes. Outside CpG islands binding of TET1, an enzyme that converts 5mC to 5hmC, is associated with labile, MNase-sensitive nucleosomes. Such nucleosomes are poised for eviction in ESCs and become stably bound in differentiated cells where the level of TET1 and 5hmCs goes down. In particular, this has a dramatic effect at variable CTCF sites enriched outside CpG islands, that are occupied by CTCF in ESCs but loose CTCF during differentiation. To rationalize this cell type dependent targeting of CTCF binding in competition with the histone octamer, we have developed a quantitative biophysical model, which allowed predicting differences in CTCF binding due to TET1/5hmC/5mC-dependent nucleosome repositioning. MNase-seq experiments for analysis of mononucleosomes were conducted as described previously (Teif et al. Nature Struct. Mol. Biol., 2012). In addition, a dinucleosome fraction also was gel purified and sequenced. Briefly, embryonic stem cells from 129P2/Ola mice were cultured in ESGRO complete medium (Millipore), harvested and resuspended in low salt buffer (10 mM Hepes, pH 8, 10 mM KCl, 0.5 mM DTT) at 4 M-BM-0C. After disruption of the cells with a douncer the nuclei were collected by centrifugation and washed once with the MNase Buffer (10 mM TrisM-bM-^@M-^SHCl, pH 7.5, 10 mM CaCl2), resuspended in the MNase Buffer and digested with 0.5 units MNase per microliter (Fermentas) and incubation for 6M-bM-^@M-^S11 minutes at 37 M-BM-0C. The MNase digestion was stopped by putting the samples on ice and adding EDTA to a concentration of 10 mM. After digestion with 0.1 M-BM-5g M-BM-5lM-bM-^@M-^S1 RNase A (Fermentas) and removal of protein by phenol and chloroform extraction, the DNA was ethanol precipitated and the resulting DNA pellet was dissolved in H2O. DNA fragments corresponding to mononucleosomes or dinucleosomes were separated on a 2 % agarose gel using an E-Gel electrophoresis system (Life Technologies). The libraries for sequencing were prepared according to the standard Illumina protocol. High-throughput paired-end sequencing of at least 50 bp read length was performed on the Illumina HiSeq 2000 platform at the DKFZ sequencing core facility in Heidelberg, Germany. We obtained about 150 million nucleosome positions per sequencing reaction. ChIP-seq experiments were conducted as described previously (Teif et al. 2012). For each sample, 1 x 106 cells were cross-linked with 1% PFA and cell nuclei were prepared using a swelling buffer (25 mM Hepes, pH 7.8, 1 mM MgCl2, 10 mM KCl, 0.1% NP-40, 1 mM DTT). Chromatin was sheared to mononucleosomal fragments. After IgG preclearance the sheared chromatin was incubated with 4 M-BM-5g of either H3K9me3 (Abcam ab8898) or H3K4me3 (Abcam ab8580) antibody over night. After washes with sonication (10 mM TrisM-bM-^@M-^SHCl, pH 8.0, 200 mM NaCl, 1 mM EDTA, 0.5% N-lauroylsarcosine, 0.1% NaM-bM-^@M-^Sdeoxycholate), high-salt-buffer (50 mM Hepes pH 7.9, 500 mM NaCl, 1mM EDTA, 1% Triton X-100, 0.1% NaM-bM-^@M-^Sdeoxycholate, 0.1% SDS), lithium buffer (20 mM TrisM-bM-^@M-^SHCl pH 8.0, 1 mM EDTA, 250 mM LiCl, 0.5% NP-40, 0.5% NaM-bM-^@M-^Sdeoxycholate) and 10 mM TrisM-bM-^@M-^SHCl, chromatin was eluted from the protein G magnetic beads and the crosslink was reversed over night. After RNase A and proteinase K digestion, DNA was purified and cloned in a barcoded sequencing library for the Illumina HiSeq 2000 sequencing platform (single reads of 50 bp length).
2014-05-07 | E-GEOD-56938 | biostudies-arrayexpress
Project description:Tumor characteristics are decisive in the determination of treatment strategy for breast cancer patients. Patients with estrogen receptor a(ERa)-positive breast cancer can benefit from long-term hormonal treatment. Nonetheless, the majority of patients will develop resistance to these therapies. Here, we investigated the role of the nuclear receptor liver receptor homolog-1 (LRH-1, NR5A2) in anti-estrogen (AE) sensitive and resistant breast cancer cells. We identified genome-wide LRH-1 binding sites using ChIP-seq, uncovering preferential binding to regions distal to transcriptional start sites (TSS). We further characterized these LRH-1 binding sites by integrating overlapping layers of specific chromatin marks, revealing that many LRH-1 binding sites are active and could be involved in long-range enhancer-promoter looping. Combined with transcriptome analysis of LRH-1 depleted cells, these results show that LRH-1 regulates specific subsets of genes involved in cell proliferation in AE-sensitive and AE-resistant breast cancer cells. Furthermore, the LRH-1 transcriptional program is highly associated with a signature of poor outcome and high-grade breast cancer tumors in vivo. Herein we report the genome-wide location and molecular function of LRH-1 in breast cancer cells and reveal its therapeutic potential for the treatment of breast cancers, notably for tumors resistant to treatments currently used in therapies. ChIP-seq examination of LRH-1 binding sites with specific chromatin marks in MCF7 breast cancer cells.
2014-02-27 | E-GEOD-47027 | biostudies-arrayexpress
Project description:The traditional method for studying cancer in vitro is to grow immortalized cancer cells in two-dimensional (2D) monolayers on plastic. However, many cellular features are impaired in these unnatural conditions and big alterations in gene expression in comparison to tumors have been reported. Three-dimensional (3D) cell culture models have become increasingly popular and are suggested to be better models than 2D monolayers due to improved cell-to-cell contacts and structures that resemble in vivo architecture. The aim of this study was to compare gene expression patterns of MCF7 breast cancer cells when grown as xenografts, in 2D, in polyHEMA coated anchorage independent 3D models and in Matrigel on-top 3D cell culture models. Surprisingly small variations in gene expression patterns were observed between the models indicating that 3D and xenograft are not always that different from 2D cell cultures. Gene expression analysis of MCF7 breast cancer cells cultured as xenografts for 43 days, in two dimensional cultures for seven days (2D7d), in polyHEMA three dimensional cell culture models for four and seven days (PH7d and PH7d), and in Matrigel three dimensional cultures for four and seven days (MG4d and MG7d). Two biological replicates was included for each sample.
2013-10-30 | E-GEOD-47583 | biostudies-arrayexpress