Homo sapiens
Ontology highlight
ABSTRACT:
PROVIDER: PRJNA253690 | ENA |
REPOSITORIES: ENA
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Project description:Non-small cell lung cancer (NSCLC) is often treated with cisplatin (CDDP). Here, we report that two distinct poly(ADP-ribose) polymerase (PARP) inhibitors exhibited a hyperadditive combination effect with CDDP to kill NSCLC cells. A majority of CDDP-resistant cell lines and clones exhibited constitutively increased PARP expression and enzymatic activity. Cells with hyperactivated PARP initiated a DNA damage response and the intrinsic pathway of apoptosis in response to pharmacological PARP inhibition or PARP1-targeting siRNAs. Transcriptome analysis depicted an unsupervised hierarchical clustering of NSCLC cells and CDDP resistant counterparts regarding to their response to PARP inhibitors. PARP-overexpressing tumors displayed elevated levels of intracellular poly(ADP-ribose) (PAR), which predicted the response to PARP inhibitors in vitro and in vivo more accurately than PARP expression itself. Thus, CDDP-resistant cancer cells develop a dependency to PARP, becoming susceptible to PARP inhibitor-induced apoptosis.
2013-10-31 | E-MTAB-1353 | biostudies-arrayexpress
Project description:PARP inhibitors have exhibited efficacy in BRCA-proficient patients, further highlighting the necessity for a deeper understanding of PARP1 function and its inhibition in cancer therapy. Here, we unveil PIN2/TRF1-interacting telomerase inhibitor 1 (PINX1) as an uncharacterized PARP1-interacting protein that synergizes with PARP inhibitors upon its depletion across various cancer cell lines. Loss of PINX1 compromises DNA damage repair capacity upon etoposide treatment. The vulnerability of PINX1-deficient cells to etoposide and PARP inhibitors could be effectively restored by introducing either a full-length or a mutant form of PINX1 lacking telomerase inhibitory activity. Mechanistically, PINX1 is recruited to DNA lesions via PARP1, facilitating the downstream recruitment of the DNA repair factor XRCC1. In the absence of DNA damage, PINX1 constitutively binds to PARP1, promoting PARP1-chromatin association and transcription of specific DNA damage repair proteins, including XRCC1, and transcriptional regulators, including GLIS3. Collectively, our findings identify PINX1 as a multifaceted partner of PARP1, crucial for safeguarding cells against genotoxic stress and emerging as a potential candidate for targeted tumor therapy.
2024-08-21 | GSE256388 | GEO
Project description:Post-translational modifications, such as poly(ADP-ribosyl)ation (PARylation), regulate chromatin-modifying enzymes, ultimately affecting gene expression. This study explores the role of poly(ADP-ribose) polymerase (PARP) on global gene expression in a lymphoblastoid B cell line. We found that inhibition of PARP catalytic activity with olaparib resulted in global gene deregulation, affecting approximately 11% of genes expressed. Gene ontology analysis revealed that PARP could exert these effects through transcription factors and chromatin-remodeling enzymes, including the Polycomb Repressive Complex 2 (PRC2) member EZH2. EZH2 mediates the trimethylation of histone H3 at lysine 27 (H3K27me3), a modification associated with chromatin compaction and gene silencing. Both pharmacological inhibition of PARP and knockdown of PARP1 induced the expression of EZH2 that resulted in increased global H3K27me3. Chromatin immunoprecipitation confirmed that PARP1 inhibition led to H3K27me3 deposition at EZH2-target genes, which resulted in gene silencing. Moreover, increased EZH2 expression is attributed to occupancy loss of the transcription repressor E2F4 at the EZH2 promoter following PARP inhibition. Together, these data show that PARP plays an important role in global gene regulation and identifies for the first time a direct role of PARP1 in regulating the expression and function of EZH2.
2015-11-13 | GSE74974 | GEO
Project description:Breast tumors are characterized into different subtypes based on their surface marker expression, which affects their prognosis and treatment. For example, triple negative breast cancer cells (ER-/PR-/Her2-) show reduced susceptibility towards radiotherapy and chemotherapeutic agents. Poly (ADP-ribose) polymerase (PARP) inhibitors have shown promising results in clinical trials, both as single agents and in combination with other chemotherapeutics, in several subtypes of breast cancer patients. PARP1 is involved in DNA repair, apoptosis, and transcriptional regulation and an understanding of the effects of PARP inhibitors, specifically on metabolism, is currently lacking. Here, we have used NMR-based metabolomics to probe the cell line-specific effects of PARP inhibitor and radiation on metabolism in three distinct breast cancer cell lines. Our data reveal several cell line independent metabolic changes upon PARP inhibition, including an increase in taurine. Pathway enrichment and topology analysis identified that nitrogen metabolism, glycine, serine and threonine metabolism, aminoacyl-tRNA biosynthesis and taurine and hypotaurine metabolism were enriched after PARP inhibition in the three breast cancer cell lines. We observed that the majority of metabolic changes due to radiation as well as PARP inhibition were cell line dependent, highlighting the need to understand how these treatments affect cancer cell response via changes in metabolism. Finally, we observed that both PARP inhibition and radiation induced a similar metabolic response in the HCC1937 (BRCA mutant cell line), but not in MCF-7 and MDAMB231 cells, suggesting that radiation and PARP inhibition share similar interactions with metabolic pathways in BRCA mutant cells. Our study emphasizes the importance of differences in metabolic responses to cancer treatments in different subtypes of cancers.
2016-11-07 | MTBLS337 | MetaboLights
Project description:Epstein-Barr virus (EBV) establishes life-long latency in human B-cells by maintaining its chromatinized episomes within the nucleus. These circularized mini-chromosomes do not integrate into the host genome. Therefore, it is essential for EBV to organize its chromatin in a manner suitable for genomic stability, DNA replication, and efficient gene expression. Poly [ADP-ribose] polymerase 1 (PARP1) activity is significantly higher in B-cells infected with EBV than those without, and considerably higher in the transcriptionally active type III latency compared to the immunoevasive type I. In addition to its role in DNA damage response, PARP1 has been implicated in transcriptional regulation and structural maintenance of both the human and EBV genome at specific regions. To better understand PARP1's role in the regulation of the EBV episome, we have functionally characterized the effect of PARP enzymatic inhibition on total episomal structure through in situ Hi-C mapping, generating the first complete 3D structure of the EBV genome. We have also mapped intragenomic contact changes after PARP inhibition to global binding of the chromatin looping factors CTCF and cohesin across the EBV genome. Additionally, PARP inhibition was shown to alter gene expression at the regions where chromatin looping was most effected. Finally, we have identified a novel function of PARP, which regulates cohesin complex chromatin binding. In conclusion, PARP1 inhibition does not alter the location of cohesin binding but does increase its frequency of binding at these regions. Despite this, there are fewer overall unique intragenomic interactions after PARP inhibition, while some areas have new chromatin loops not seen in the untreated EBV episome, leading us to conclude that PARP does have an essential role in the regulation of global EBV chromatin structure. The altered expression profile after the structural rearrangement induced by PARP inhibition also supports the idea that PARP1 helps maintain EBV latency programs.
2021-11-05 | GSE160973 | GEO
Project description:PARP does have an essential role in the regulation of global EBV episome chromatin structure. We have functionally characterized the effect of PARP enzymatic inhibition on total episomal structure and we mapped intragenomic contact changes after PARP inhibition to global binding of the chromatin looping factors CTCF and cohesin across the EBV genome. The altered expression profile after the structural rearrangement induced by PARP inhibition supports the model where PARP1 helps maintain EBV latency programs.
2021-11-16 | GSE159836 | GEO
Project description:PARP does have an essential role in the regulation of global EBV episome chromatin structure. We have functionally characterized the effect of PARP enzymatic inhibition on total episomal structure and we mapped intragenomic contact changes after PARP inhibition to global binding of the chromatin looping factors CTCF and cohesin across the EBV genome. The altered expression profile after the structural rearrangement induced by PARP inhibition supports the model where PARP1 helps maintain EBV latency programs.
2021-11-16 | GSE159834 | GEO
Project description:Transcriptionally active and inactive chromatin domains tend to segregate into separate sub-nuclear compartments to maintain stable expression patterns. However, we have uncovered here an inter-chromosomal network connecting active loci enriched in circadian genes to repressed lamina-associated domains (LADs). The interactome is regulated by PARP1 and its co-factor, CTCF, which not only mediate chromatin fiber interactions, but also promote the recruitment of circadian genes to the lamina. Synchronization of circadian rhythm by serum shock induces oscillations in PARP1-CTCF interactions, which is accompanied by oscillating recruitment of circadian loci to the lamina, followed by the acquisition of repressive H3K9me2 marks and transcriptional attenuation. Furthermore, depletion of H3K9me2/3, inhibition of PARP activity by Olaparib or down-regulation of PARP1 or CTCF expression counteracts both recruitment to the envelope and circadian transcription. PARP1- and CTCF-regulated contacts between circadian loci and the repressive chromatin environment at the lamina thus mediate circadian transcriptional plasticity. ChIP-Seq for H3k9me2 in HCT116 colon cancer cells (2 replicates)
2015-08-27 | E-GEOD-58534 | biostudies-arrayexpress
Project description:The synthetic lethal association between BRCA deficiency and poly (ADP-ribose) polymerase (PARP) inhibition supports PARP inhibitor (PARPi) clinical efficacy in BRCA-mutated tumors. PARPis also demonstrate activity in non-BRCA mutated tumors presumably through induction of PARP1-DNA trapping. Despite pronounced clinical response, therapeutic resistance to PARPis inevitably develops. An abundance of knowledge has been built around resistance mechanisms in BRCA-mutated tumors, however, parallel understanding in non-BRCA mutated settings remains insufficient. In this study, we find a strong correlation between the epithelial-mesenchymal transition (EMT) signature and resistance to a clinical PARPi, Talazoparib, in non-BRCA mutated tumor cells. Genetic profiling demonstrates that SNAI2, a master EMT transcription factor, is transcriptionally induced by Talazoparib treatment or PARP1 depletion and this induction is partially responsible for the emerging resistance. Mechanistically, we find that the PARP1 protein directly binds to SNAI2 gene promoter and suppresses its transcription. Talazoparib treatment or PARP1 depletion lifts PARP1-mediated suppression and increases chromatin accessibility around SNAI2 promoters, thus driving SNAI2 transcription and drug resistance. We also find that depletion of the chromatin remodeler CHD1L suppresses SNAI2 expression and reverts acquired resistance to Talazoparib. The PARP1/CHD1L/SNAI2 transcription axis might be therapeutically targeted to re-sensitize Talazoparib in non-BRCA mutated tumors.
2022-07-07 | GSE202437 | GEO
Project description:The synthetic lethal association between BRCA deficiency and poly (ADP-ribose) polymerase (PARP) inhibition supports PARP inhibitor (PARPi) clinical efficacy in BRCA-mutated tumors. PARPis also demonstrate activity in non-BRCA mutated tumors presumably through induction of PARP1-DNA trapping. Despite pronounced clinical response, therapeutic resistance to PARPis inevitably develops. An abundance of knowledge has been built around resistance mechanisms in BRCA-mutated tumors, however, parallel understanding in non-BRCA mutated settings remains insufficient. In this study, we find a strong correlation between the epithelial-mesenchymal transition (EMT) signature and resistance to a clinical PARPi, Talazoparib, in non-BRCA mutated tumor cells. Genetic profiling demonstrates that SNAI2, a master EMT transcription factor, is transcriptionally induced by Talazoparib treatment or PARP1 depletion and this induction is partially responsible for the emerging resistance. Mechanistically, we find that the PARP1 protein directly binds to SNAI2 gene promoter and suppresses its transcription. Talazoparib treatment or PARP1 depletion lifts PARP1-mediated suppression and increases chromatin accessibility around SNAI2 promoters, thus driving SNAI2 transcription and drug resistance. We also find that depletion of the chromatin remodeler CHD1L suppresses SNAI2 expression and reverts acquired resistance to Talazoparib. The PARP1/CHD1L/SNAI2 transcription axis might be therapeutically targeted to re-sensitize Talazoparib in non-BRCA mutated tumors.
2022-07-07 | GSE202435 | GEO