Adenovirus E1A oncogene induces re-replication of cellular DNA and alters DNA replication dynamics
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ABSTRACT:
ORGANISM(S): Homo sapiens
PROVIDER: GSE47140 | GEO | 2013/05/22
SECONDARY ACCESSION(S): PRJNA204400
REPOSITORIES: GEO
Similar Datasets
Project description:Human adenovirus type 5 oncogene E1A was shown to induce massive re-replication of cellular DNA in late S phase. Using DNA combing analysis, it was shown that DNA replication dynamics including replicon length, fork velocity and inter-origin distance were dramatically altered in E1A expressing cells as compared to that of normal serum stimulated cells. It was also shown that c-Myc that is induced in E1A expressing cells is essential for the efficient entry of E1A expressing cells into S phase. Serum starved cells were infected with an adenovirus expressing only the transforming E1A protein, and with Adbeta-galactosidase (control) were analyzed by flow cytomery. DNA prepared from such cells were analyzed by DNA combing analysis and data obtained were examined statistically. Requirement of Myc in E1A induced S phase entry was also examined by using antisense Myc vector.
2013-05-22 | E-GEOD-47140 | biostudies-arrayexpress
Project description:Replication timing in Saccharomyces cerevisiae in various replication stress conditions using CGH microarrays of S vs G1 cells. Replication of the eukaryotic genomes follows a characteristic temporal program, with different regions replicating at different times in S phase. We describe a stochastic model of DNA replication that naturally explains the replication profiles of a dozen of S. cerevisiae mutants. Each profile is described by a single parameter that differ between the mutants: the ratio between the fork velocity and the typical initiation rate (the “replicon length”), while all other origin-specific parameters remain unchanged. We devise an analytical method to infer the replicon lengths from the available data, and predicted its value in different mutant backgrounds. Further experiments verified model’s predictions. Our study supports a stochastic model of DNA replication in S. cerevisiae and explains the apparent robustness of this profile to perturbations that extend S phase.
2011-09-09 | GSE32002 | GEO
Project description:Replication timing in Saccharomyces cerevisiae in various replication stress conditions using CGH microarrays of S vs G1 cells. Replication of the eukaryotic genomes follows a characteristic temporal program, with different regions replicating at different times in S phase. We describe a stochastic model of DNA replication that naturally explains the replication profiles of a dozen of S. cerevisiae mutants. Each profile is described by a single parameter that differ between the mutants: the ratio between the fork velocity and the typical initiation rate (the “replicon length”), while all other origin-specific parameters remain unchanged. We devise an analytical method to infer the replicon lengths from the available data, and predicted its value in different mutant backgrounds. Further experiments verified model’s predictions. Our study supports a stochastic model of DNA replication in S. cerevisiae and explains the apparent robustness of this profile to perturbations that extend S phase. DNA from FACS-sorted cells was extracted, labeled with Cy dyes, hybridized to the CGH microarray and scanned. 18 strains were used, with variable biological repeats number.
2011-09-08 | E-GEOD-32002 | biostudies-arrayexpress
Project description:DNA molecular combing-based replication fork directionality profiling
| PRJNA689720 | ENA
Project description:Adenoviruses force quiescent cells to re-enter the cell cycle to replicate their DNA, and for the most part, this is accomplished after they express the E1A protein immediately after infection. In this context, E1A is believed to inactivate cellular proteins (e.g., p130) that are known to be involved in the silencing of E2F-dependent genes that are required for cell cycle entry. However, the potential perturbation of these types of genes by E1A relative to their functions in regulatory networks and canonical pathways remains poorly understood. We have used DNA microarrays analyzed with Bayesian ANOVA for microarray (BAM) to assess changes in gene expression after E1A alone was introduced into quiescent cells from a regulated promoter. Approximately 2,401 genes were significantly modulated by E1A, and of these, 385 and 1033 met the criteria for generating networks and functional and canonical pathway analysis respectively, as determined by using Ingenuity Pathway Analysis software. After focusing on the highest-ranking cellular processes and regulatory networks that were responsive to E1A in quiescent cells, we observed that many of the up-regulated genes were associated with DNA replication, the cell cycle and cellular compromise. We also identified a cadre of up regulated genes with no previous connection to E1A; including genes that encode components of global DNA repair systems and DNA damage checkpoints. Among the down-regulated genes, we found that many were involved in cell signalling, cell movement, and cellular proliferation. Remarkably, a subset of these was also associated with p53-independent apoptosis, and the putative suppression of this pathway may be necessary in the viral life cycle until sufficient progeny have been produced. These studies have identified for the first time a large number of genes that are relevant to E1A’s activities in promoting quiescent cells to re-enter the cell cycle in order to create an optimum environment for adenoviral replication.
2011-05-01 | GSE28420 | GEO
Project description:Dicer, RNase III endonuclease, is an essential enzyme in miRNA biogenesis that regulates target gene expression, and it has been reported that aberrant expressions of Dicer associate with the clinical outcomes of patients in various cancers. To explore the miRNA differencial expression regulated by Dicer in MDA-MB-231/E1A cells, the microarray profiling analysis was employed to conduct differentially expressed miRNAs in stable MDA-MB-231/vector, MDA-MB-231/E1A, and MDA-MB-231/E1A/shDicer cells. The four groups including vector control, E1A-expressing and Dicer knockdown in E1A-expressing MDA-MB-231 cells were harvested and RNA were isolated. Two independent experiments were performed for each group.
2016-01-16 | E-GEOD-76924 | biostudies-arrayexpress
Project description:Proliferating C2C12 myoblasts were induced to differentiate into myotubes and then infected with adenovirus expressing E1A (Ad-E1A), which induces cell cycle re-entry and dedifferentiation. We analyzed the transcriptional profile of E1A infected C2C12-myotubes through the Affymetrix Mouse Genome 430 2.0 Array, searching for genes that were significantly regulated between two independent biological replicates at two different time points (24h and 36h after infection with Ad-E1A). In addition, we took advantage of the E1A mutant known as YH47/dl928 (hereafter referred as YH47), which bears two mutations in the pocket-binding region of E1A (Y48H, C124G) able to disrupt the interaction with Rb and its cognate proteins and to impair cell-cycle re-entry phenotype. YH47 mutant was used to identify the Rb independent transcriptional reprogramming of C2C12.
2012-05-31 | GSE28457 | GEO
Project description:Proliferating C2C12 myoblasts were induced to differentiate into myotubes and then infected with adenovirus expressing E1A (Ad-E1A), which induces cell cycle re-entry and dedifferentiation. We analyzed the transcriptional profile of E1A infected C2C12-myotubes through the Affymetrix Mouse Genome 430 2.0 Array, searching for genes that were significantly regulated between two independent biological replicates at two different time points (24h and 36h after infection with Ad-E1A). In addition, we took advantage of the E1A mutant known as YH47/dl928 (hereafter referred as YH47), which bears two mutations in the pocket-binding region of E1A (Y48H, C124G) able to disrupt the interaction with Rb and its cognate proteins and to impair cell-cycle re-entry phenotype. YH47 mutant was used to identify the Rb independent transcriptional reprogramming of C2C12. C2C12 cells were differentiated in vitro to myotubes as previously described. Myotubes were, then, infected with an adenovirus carrying the 12S form of E1A (dl520), with the YH47 E1A mutant (dl928) or with a control adenovirus (CTR) expressing a deletion of essentially the entire E1A gene (dl312). Two different time points after infection were considered (24 hours and 36 hours) to evaluate changes in C2C12 cells expression profile. Technical (A or B) and biological replicates (EXP1 or EXP2) were done for each condition.
2012-05-30 | E-GEOD-28457 | biostudies-arrayexpress
Project description:Adenoviruses force quiescent cells to re-enter the cell cycle to replicate their DNA, and for the most part, this is accomplished after they express the E1A protein immediately after infection. In this context, E1A is believed to inactivate cellular proteins (e.g., p130) that are known to be involved in the silencing of E2F-dependent genes that are required for cell cycle entry. However, the potential perturbation of these types of genes by E1A relative to their functions in regulatory networks and canonical pathways remains poorly understood. We have used DNA microarrays analyzed with Bayesian ANOVA for microarray (BAM) to assess changes in gene expression after E1A alone was introduced into quiescent cells from a regulated promoter. Approximately 2,401 genes were significantly modulated by E1A, and of these, 385 and 1033 met the criteria for generating networks and functional and canonical pathway analysis respectively, as determined by using Ingenuity Pathway Analysis software. After focusing on the highest-ranking cellular processes and regulatory networks that were responsive to E1A in quiescent cells, we observed that many of the up-regulated genes were associated with DNA replication, the cell cycle and cellular compromise. We also identified a cadre of up regulated genes with no previous connection to E1A; including genes that encode components of global DNA repair systems and DNA damage checkpoints. Among the down-regulated genes, we found that many were involved in cell signalling, cell movement, and cellular proliferation. Remarkably, a subset of these was also associated with p53-independent apoptosis, and the putative suppression of this pathway may be necessary in the viral life cycle until sufficient progeny have been produced. These studies have identified for the first time a large number of genes that are relevant to E1A’s activities in promoting quiescent cells to re-enter the cell cycle in order to create an optimum environment for adenoviral replication. Six independent cell cultures (n = 6) were randomly assigned to two treatment groups with three independent biological replicates per group. The control group, denoted ‘Q’, are quiescent cells without Doxycycline, i.e. no E1A expression (untreated for 8 hr, total RNA harvested 1 hour after). The stimulated group, denoted ‘S’, are stimulated cells with Doxycycline, i.e. with E1A expression (treated with Doxycycline for 8 hr, total RNA harvested 1 hour after treatment).
2011-05-01 | E-GEOD-28420 | biostudies-arrayexpress
Project description:During genome replication, the leading strand DNA polymerase conducts continuous synthesis over long stretches of DNA within each replicon. Processive DNA synthesis supports symmetric progression of sister replication forks and efficient genome duplication. To address the mechanisms underlying leading strand polymerase-mediated synthesis, we examine one of its conserved domains, referred to as POPS, in the budding yeast Pol2 enzyme. We provide evidence that POPS supports replication fork symmetry and efficient genome replication via balancing the function of the Pol2 exonuclease domain. We found that the defective growth, slow S phase progression, and impaired genome synthesis associated with a POPS mutation were rescued by abolishing the Pol2 exonuclease activity. The suppressive effects further extended to the increased DNA re-arrangements in the POPS mutant and its negative genetic interactions with mutants of other genome maintenance factors. Significantly, our single molecule replicon-seq data demonstrate that the POPS mutant exhibited genome-wide replication fork asymmetry, and this defect was improved by eliminating the Pol2 exonuclease activity, thus providing a basis for its rescuing of a range of POPS mutant phenotypes. Collectively, these data suggest a model in which balanced activity between a unique Pol2 catalytic domain, and its exonuclease domain facilitates replication fork symmetry and genome maintenance.
2022-09-02 | GSE212101 | GEO