MCF-7 Luciferase, PARP-1, PARG, SIRT1, and macroH2A Knockdown
Ontology highlight
ABSTRACT:
ORGANISM(S): Homo sapiens
SUBMITTER: Lee Kraus
PROVIDER: E-GEOD-12971 | biostudies-arrayexpress |
REPOSITORIES: biostudies-arrayexpress
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Project description:Poly(ADP-ribose) polymerase-1 (PARP-1) and poly(ADP-ribose) glycohydrolase (PARG) are enzymes that modify target proteins in the nucleus by the addition and removal, respectively, of ADP-ribose polymers. Although a role for PARP-1 in gene regulation has been well established, the role of PARG is less clear. To investigate how PARP-1 and PARG coordinately regulate global patterns of gene expression, we used short hairpin RNAs (shRNAs) to stably knockdown PARP-1 or PARG in MCF-7 cells, followed by expression microarray analyses. Experiment Overall Design: Two shRNAs targeting Luciferase (Luc, control), PARP-1, or PARG were cloned into the pSUPER.retro vector (puro or neo resistant) and sequentially introduced into parental MCF-7 cells using a standard retroviral infection technique. Luc, PARP-1, and PARG control-matched cell lines were generated three independent times. Experiment Overall Design: Total RNA was isolated from stable Luc, PARP-1, and PARG knockdown cells was analyzed for global patterns of gene expression. Briefly, 7 μg of total RNA was labeled using Affymetrix's standard one-cycle amplification and labeling protocol. The labeled cRNA was then hybridized to Affymetrix Human U133A 2.0 GeneChips, which were scanned using a GeneChip Scanner 3000. Each biological replicate (1, 2 or 3) represents a single RNA isolation from each set of cell lines. Experiment Overall Design: These 9 samples were samples were part of a 15-sample microarray analysis (GSE12971) examining expression regulation by SIRT1, PARP-1, PARG and macroH2A. All 15 samples were included for the data normalization steps. Experiment Overall Design: The raw array data was processed by Affymetrix GeneChip Operating Software (GCOS) to obtain detection calls (ABS_CALL) and signal values (VALUE_2). The signals were then normalized by scaling to a target value of 500 using GCOS. To adjust for batch effects due to day-to-day differences in RNA isolations, the empirical Bayes method was applied to the data set. After adjusting any values less than 0.01 to 0.01, the data was log2 transformed, median centered for each array, and median centered for each individual probe set (VALUE). Filters were then applied to obtain final gene lists. Experiment Overall Design: Specifically, the criteria for a gene to be considered regulated by PARP-1 or PARG was: (1) detection call flagged as present or marginal in 2 out of 3 array replicates for both control and factor knockdown cell lines and (2) significance of values between control and knockdown cell lines for any given gene had a two-tailed Studentâ??s t-test with a p-value < 0.05. To determine the genes most robustly regulated by PARP-1 or PARG, a fold change criteria was applied, namely log2 fold change > 0.5 or < -0.5 when compared to the Luc control knockdown cells.
2009-10-30 | E-GEOD-12952 | biostudies-arrayexpress
Project description:SIRT1 is a nuclear NAD+-dependent protein deacetylase. Expression microarray analysis was used to study the effect of SIRT1 knockdown on gene expression in MCF-7 breast cancer cells. Experiment Overall Design: SIRT1 stable knockdown was achieved using two retroviral shRNA constructs. An shRNA directed against Luciferase was used to generate the Luc control cells. Three independent biological replicates with matching Luc controls were analyzed using Affymetrix U133A 2.0 microarrays. Experiment Overall Design: These 6 samples were part of a 15-sample microarray analysis (GSE12971) examining expression regulation by SIRT1, PARP-1, PARG and macroH2A. All 15 samples were included for the following data normalization steps: data sets obtained using the GCOS software were grouped based on date of experiment and adjusted for batch effect using the parametric empirical Bayes method (Combat R); all values < 0.01 were adjusted to 0.01; the data were log2 transformed, median centered for each array, and median centered for each gene.
2009-06-08 | E-GEOD-13459 | biostudies-arrayexpress
Project description:Affymetrix expression arrays were used to compare expression patterns upon knockdown of PARP-1, PARG, SIRT1, or macroH2A in comparison to Luciferase control.
2010-01-31 | GSE12971 | GEO
Project description:MCF-7 Luciferase, PARP-1, PARG, SIRT1, and macroH2A Knockdown
| PRJNA112579 | ENA
Project description:Poly(ADP-ribose) polymerase-1 (PARP-1) and poly(ADP-ribose) glycohydrolase (PARG) are enzymes that modify target proteins in the nucleus by the addition and removal, respectively, of ADP-ribose polymers. Although a role for PARP-1 in gene regulation has been well established, the role of PARG is less clear. To investigate how PARP-1 and PARG coordinately regulate global patterns of gene expression, we used short hairpin RNAs (shRNAs) to stably knockdown PARP-1 or PARG in MCF-7 cells, followed by expression microarray analyses.
2009-10-23 | GSE12952 | GEO
Project description:ARH3/ADPRHL2 and PARG are the major enzymes reversing ADP-ribosylation in vertebrates, yet their functions in vivo remain unclear. ARH3 is the only hydrolase able to removes serine-linked mono(ADP-ribose) (MAR), but is much less efficient than PARG against poly(ADP-ribose) (PAR) chains in vitro. Here, by utilizing ARH3-deficient cells, we demonstrate that endogenous MARylation persists on chromatin throughout the cell cycle including mitosis, and is, surprisingly, well tolerated. Conversely, persistent PARylation is highly toxic and has distinct physiological effects, in particular on active transcription histone marks such as H3K9ac and H3K27ac. Furthermore, we reveal a synthetic lethal interaction between ARH3 and PARG, and identify loss of ARH3 as a mechanism of PARP inhibitor resistance, both of which can be exploited in cancer therapy. Finally, we extend our findings to neurodegeneration, suggesting that patients with inherited ARH3 deficiency suffer from stress-induced pathogenic increase in PARylation that can be mitigated by PARP inhibition.
2021-05-20 | GSE167060 | GEO
Project description:Poly (ADP-ribose) glycohydrolase (PARG) is a dePARylating enzyme which promotes DNA repair by removal of poly (ADP-ribose) (PAR) from PARP1-parylated proteins. Loss or inhibition of PARG results in replication stress and sensitizes cancer cells to DNA damaging agents, suggesting that PARG inhibitors may provide a therapeutic option for cancer therapy. Indeed, PARG inhibitors (PARGi) are now undergoing clinical development for patients having tumors with homologous recombination deficiency (HRD), such as ovarian and breast cancer patients with germline or somatic BRCA1/2-mutations. Biomarkers of PARGi response will be required for the optimal development of these important new drugs. PARP inhibitors kill BRCA-deficient cancer cells by increasing ssDNA gaps during replication. Here, we report that, similar to PARP inhibitors, PARGi treatment can also cause an accumulation of ssGAPs in sensitive cells. PARGi exposure increased accumulation of S-Phase specific PAR, a marker for Okazaki fragment processing (OFP) defects on lagging strands, in sensitive cells but not in resistant cells. PARGi also caused accumulation of PAR at the replication fork and increased pRPA, a marker for replication stress, at the replication fork in sensitive cells. Additionally, PARGi exhibited monotherapy activity in some HR-deficient, as well as HR-proficient, patient-derived organoids of ovarian cancer, and drug sensitivity directly correlated with the accumulation of ssDNA gaps. Taken together, PARGi treatment results in toxic accumulation of PAR at replication forks resulting in ssDNA gaps due to OFP defects during replication. Regardless of the BRCA-status, the induction of ssDNA gaps in preclinical models of ovarian cancer cells correlates with PARGi sensitivity. Patient-derived organoids will be a useful model system for testing PARGi sensitivity and functional biomarkers
2024-10-31 | GSE270384 | GEO
Project description:Cockayne syndrome (CS) is an accelerated aging disorder characterized by progressive neurodegeneration caused by mutations in the genes encoding the DNA repair proteins CSA or CSB. Csbm/m mice were given a high-fat, caloric-restricted or resveratrol-supplemented diet. The high-fat diet rescued the phenotype of Csbm/m mice at the metabolic, transcriptomic and behavioral levels. Additional analysis suggests that the premature aging seen in CS mice, nematodes and human cells results from aberrant PARP activation due to deficient DNA repair leading to decreased SIRT1 activity and mitochondrial dysfunction. Notably, β-hydroxybutyrate levels are increased by the high-fat diet; and β-hydroxybutyrate, PARP inhibition, or NAD+ supplementation can activate SIRT1 and rescue CS-associated phenotypes. Mechanistically, CSB is able to displace activated PARP1 from damaged DNA to limit its activity. This study connects two emerging longevity metabolites, β-hydroxybutyrate and NAD+, through the deacetylase SIRT1 and suggests possible interventions for CS. 4-month-old mice, WT and Csbm/m on a C57BL/6 background, were fed a standard AIN-93G diet (SD; carbohydrate:protein:fat ratio of 64:19:17 percent of kcal) ad libitum or at 40% CR, a SD supplemented with 100 mg/kgchow resveratrol ad libitum, or a high-fat diet ad libitum consisting of AIN-93G with 60% of calories from fat, primarily hydrogenated coconut oil (HFD; carbohydrate:protein:fat ratio of 16:23:61). Each group was on the specified diet for 8 months, after which the mice were sacrificed and the cerebellum was removed. For nicotinamide treatments, 4- or 18-month-old WT and Csbm/m mice were given daily injections of nicotinamide riboside (NR) (500 mg/kg/d, ip) or saline for one week, after which the mice were sacrificed and the cerebellum was removed. RNA was extracted from the cerebellums of all mice using Trizol, and RNA quality and quantity were tested using an Agilent 2100 BioAnalyzer with RNA 6000 nano chips. RNA was labeled using the standard Illumina protocol for Illumina TotalPrep RNA Amplification Kit. Labeled RNA was hybridized to Illumina's Sentrix MouseRef-8 v2 Expression BeadChips (Illumina, San Diego, CA) overnight and washed, stained and scanned the next day.
2014-12-22 | E-GEOD-62194 | biostudies-arrayexpress
Project description:NMNAT1 is a nuclear enzyme in the mammalian NAD+ salvage pathway. Expression microarray analysis was used to study the effect of NMNAT1 knockdown on gene expression in MCF-7 breast cancer cells. Experiment Overall Design: NMNAT1 stable knockdown was achieved using a retroviral shRNA construct. An shRNA directed against Luciferase was used to generate the Luc control cells. Three independent cell populations with matching Luc controls were prepared for the expression analysis. Each cell population was treated with either vehicle control (ethanol) or estradiol (E2) for 3 hours before harvest of RNA samples. Four samples in one replicate (LUC2 CON, LUC2 E2, NMNAT2 CON and NMNAT2 E2) were hybridized to Affymetrix U133 Plus 2.0 arrays, while the other two replicates of eight samples were hybridized to Affymetrix U133A 2.0 arrays. Experiment Overall Design: All 12 samples were included for the following data normalization steps: common probe sets on both U133A 2.0 and U133 Plus 2.0 platforms were selected; within each sample group hybridized to the same microarray platform, the signal values were log2 transformed, median centered for each array, and median centered for each gene; the data sets were further adjusted using the parametric empirical Bayes method (Combat R) to eliminate batch effect caused by the different array platforms.
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Project description:The histone variant macroH2A generally associates with transcriptionally inert chromatin, however the factors that regulate its chromatin incorporation remain elusive. Here, we identify the SWI/SNF helicase, ATRX, as a novel macroH2A interacting protein. Unlike its role in assisting H3.3 chromatin deposition, ATRX acts as a negative regulator of macroH2A’s chromatin association. In human erythroleukemic cells deficient for ATRX, ChIP-sequencing studies reveal that macroH2A accumulates at the HBA gene cluster on the subtelomere of chromosome 16, coinciding with the loss of α globin expression. Collectively, our results implicate deregulation of macroH2A’s distribution as a contributing factor to the α thalassemia phenotype of ATRX syndrome. Mononucleosomes from K562 cells bearing integrated lentiviral shRNA constructs targeting either luciferase (shluc) or ATRX (sh92) were isolated and ChIP'd with mH2A1 antibody. DNA from shluc Input and the two mH2A1 ChIPs were isolated and sequenced on Illumina's Hiseq.
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