Homo sapiens
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PROVIDER: PRJNA233576 | ENA |
REPOSITORIES: ENA
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Project description:Eukaryotic gene regulation implies that transcription factors gain access to genomic information via poorly understood processes involving activation and targeting of kinases, histone-modifying enzymes, and chromatin remodelers to chromatin. Here we report that progestin gene regulation in breast cancer cells requires a rapid and transient increase in poly-(ADP)-ribose (PAR), accompanied by a dramatic decrease of cellular NAD that could have broad implications in cell physiology. This rapid increase in nuclear PARylation is mediated by activation of PAR polymerase PARP-1 as a result of phosphorylation by cyclin-dependent kinase CDK2. Hormone-dependent phosphorylation of PARP-1 by CDK2, within the catalytic domain, enhances its enzymatic capabilities. Activated PARP-1 contributes to the displacement of histone H1 and is essential for regulation of the majority of hormone-responsive genes and for the effect of progestins on cell cycle progression. Both global chromatin immunoprecipitation (ChIP) coupled with deep sequencing (ChIP-seq) and gene expression analysis show a strong overlap between PARP-1 and CDK2. Thus, progestin gene regulation involves a novel signaling pathway that connects CDK2-dependent activation of PARP-1 with histone H1 displacement. Given the multiplicity of PARP targets, this new pathway could be used for the pharmacological management of breast cancer. PARP-1 activation mechanism by CDK2 in response of progestin in breast cancer cells
2014-01-08 | E-GEOD-53855 | biostudies-arrayexpress
Project description:Eukaryotic gene regulation implies that transcription factors gain access to genomic information via poorly understood processes involving activation and targeting of kinases, histone-modifying enzymes, and chromatin remodelers to chromatin. Here we report that progestin gene regulation in breast cancer cells requires a rapid and transient increase in poly-(ADP)-ribose (PAR), accompanied by a dramatic decrease of cellular NAD that could have broad implications in cell physiology. This rapid increase in nuclear PARylation is mediated by activation of PAR polymerase PARP-1 as a result of phosphorylation by cyclin-dependent kinase CDK2. Hormone-dependent phosphorylation of PARP-1 by CDK2, within the catalytic domain, enhances its enzymatic capabilities. Activated PARP-1 contributes to the displacement of histone H1 and is essential for regulation of the majority of hormone-responsive genes and for the effect of progestins on cell cycle progression. Both global chromatin immunoprecipitation (ChIP) coupled with deep sequencing (ChIP-seq) and gene expression analysis show a strong overlap between PARP-1 and CDK2. Thus, progestin gene regulation involves a novel signaling pathway that connects CDK2-dependent activation of PARP-1 with histone H1 displacement. Given the multiplicity of PARP targets, this new pathway could be used for the pharmacological management of breast cancer.
2014-01-08 | GSE53855 | 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:Poly (ADP-ribose) polymerase-1 (PARP-1), a multifunctional chromatin-modulating protein, has gained considerable attention as a target for therapeutic inhibitors in breast cancers. Accumulating evidence suggests a pathological role for PARP-1 in breast cancer through its effects on the transcription of tumor-related genes. Here we report the role of PARP-1 in estrogen-dependent transcription in estrogen receptor alpha (ERα)-positive breast cancers. Global nuclear run-on and sequencing (GRO-seq) analyses suggest that PARP-1 controls the expression of estrogen-regulated genes in ER-positive (ER+) MCF-7 breast cancer cells. Further, ChIP-seq analyses revealed that PARP-1 directly regulates the ligand-dependent binding of ERa and FoxA1 to a subset of its genomic binding sites. Finally, we uncovered that the expression levels of the PARP-1 and estrogen coregulated gene set are enriched in luminal molecular-subtype of breast tumors and high PARP-1 expression in ER+ cases correlates with poor survival. Additionally, treatment with PARP-1 selective inhibitors showed attenuated estrogen-dependent growth of ER+ breast cancer cells. Taken together, the current study suggests that PARP-1 regulates critical molecular pathways that underlie proliferation of ER+ breast cancer cells.
2021-10-13 | GSE166168 | GEO
Project description:Poly (ADP-ribose) polymerase-1 (PARP-1), a multifunctional chromatin-modulating protein, has gained considerable attention as a target for therapeutic inhibitors in breast cancers. Accumulating evidence suggests a pathological role for PARP-1 in breast cancer through its effects on the transcription of tumor-related genes. Here we report the role of PARP-1 in estrogen-dependent transcription in estrogen receptor alpha (ERα)-positive breast cancers. Global nuclear run-on and sequencing (GRO-seq) and RNA-seq analyses suggest that PARP-1 controls the expression of estrogen-regulated genes in ER-positive (ER+) MCF-7 breast cancer cells. Further, ChIP-seq analyses revealed that PARP-1 directly regulates the ligand-dependent binding of ERa and FoxA1 to a subset of its genomic binding sites. Finally, we uncovered that the expression levels of the PARP-1 and estrogen coregulated gene set are enriched in luminal molecular-subtype of breast tumors and high PARP-1 expression in ER+ cases correlates with poor survival. Additionally, treatment with PARP-1 selective inhibitors showed attenuated estrogen-dependent growth of ER+ breast cancer cells. Taken together, the current study suggests that PARP-1 regulates critical molecular pathways that underlie proliferation of ER+ breast cancer cells.
2021-10-13 | GSE173976 | GEO
Project description:Two genes have a synthetic lethal relationship when silencing or inhibition of one gene is only lethal in the context of a mutation or activation of the second gene. This situation offers an attractive therapeutic strategy, as inhibition of such a gene will only trigger cell death in tumor cells with an activated second oncogene but spare normal cells without activation of the second oncogene. Here we present evidence that CDK2 is synthetic lethal to neuroblastoma cells with MYCN amplification and overexpression. Neuroblastomas are childhood tumors with an often lethal outcome. Twenty percent of the tumors have MYCN amplification and these tumors are ultimately refractory to any therapy. Targeted silencing of CDK2 by three RNA interference techniques induced apoptosis in MYCN-amplified neuroblastoma cell lines, but not in MYCN single copy cells. Silencing of MYCN abrogated this apoptotic response in MYCN-amplified cells. Inversely, silencing of CDK2 in MYCN single copy cells did not trigger apoptosis, unless a MYCN transgene was activated. The MYCN induced apoptosis after CDK2 silencing was accompanied by nuclear stabilization of P53 and mRNA profiling showed up-regulation of P53 target genes. Silencing of P53 rescued the cells from MYCN-driven apoptosis. The synthetic lethality of CDK2 silencing in MYCN activated neuroblastoma cells can also be triggered by inhibition of CDK2 with a small molecule drug. Treatment of neuroblastoma cells with Roscovitine, a CDK inhibitor, at clinically achievable concentrations induced MYCN-dependent apoptosis. The synthetic lethal relation between CDK2 and MYCN indicates CDK2 inhibitors as potential MYCN-selective cancer therapeutics. CDK2 shRNA in a tet repressor system was stably transfected in the IMR32 cell line. Time course analysis was performed in triplicate after induction of CDK2 shRNA at 5 time points.
2014-05-19 | E-GEOD-16480 | biostudies-arrayexpress
Project description:Intrinsic or acquired resistance to clinically approved CDK4/6 inhibitors have emerged as a major obstacle that hinders their utility beyond ER+ breast cancer. Palbociclib-sensitive ER+ breast cancer models and pancreatic ductal adenocarcinoma (PDAC) models were employed to identify functional determinants of response. In all models tested the activation of RB and inhibition of CDK2 activity emerged as determinants of sensitivity. While depleting CDK4 and 6 was sufficient to limit proliferation in specific resistance setting, RB loss renders cells completely CDK4/6 independent. The main down-stream target in this context is the activation status of CDK2 which is suppressed with CDK4/6 inhibition in an RB-dependent fashion. The P27KIP1 protein levels are associated with plasticity/rigidity of the cell cycle and correlates with sensitivity to CDK4/6 inhibiion. Exogenous overexpression and pharmacological induction of P27KIP1 by targeting the MEK/ERK pathway enhances the cytostatic effect of palbociclib. Similar to cell-culture data, in vivo experiments revealed that combination treatment of palbociclib and trametinib in mice bearing PDAC PDXs elicited a robust anti-proliferative effect with a corresponding increase in p27 expression. Mice bearing MCF7 xenografts displayed a durable response in the presence of palbociclib; however, over the course of treatment few cells begin to evade the negative cell-cycle regulation. Based on multispectral staining, the MCF7 tumor cells that underwent RB inactivation in the presence of palbociclib harbored low p27 expression. Finally, we demonstrate that the cell-cycle plasticity that enables tumor models to evade the palbociclib mediated RB activation could be potently targeted using a clinically applicable CDK2 inhibitor.
2020-06-30 | GSE146788 | GEO
Project description:Background: Estrogen receptor-positive (ER+) breast cancers represent approximately two-thirds of all breast cancers and have a sustained risk of late disease recurrence. Cyclin-dependent kinase 4 and 6 (CDK4/6) inhibitors have shown significant efficacy in ER+ breast cancer. However, their effects are still limited by drug resistance. In this study, we aim to explore the role of long noncoding RNA TROJAN in ER+ breast cancer. Methods: The expression level of TROJAN in breast cancer tissue and cell lines was determined by quantitative real-time PCR. In vitro and in vivo assays as well as patient derived organoids were preformed to explore the phenotype of TROJAN in ER+ breast cancer. The TROJAN-NKRF-CDK2 axis were screened and validated by RNA pull-down, mass spectrometry, RNA immunoprecipitation, microarray, dual-luciferase reporter and chromatin immunoprecipitation assays. Results: Herein, we showed that TROJAN was highly expressed in ER+ breast cancer. TROJAN promoted cell proliferation and resistance to a CDK4/6 inhibitor and was associated with poor survival in ER+ breast cancer. TROJAN can bind to NKRF and inhibit its interaction with RELA, upregulating the expression of CDK2. The inhibition of TROJAN abolished the activity of CDK2, reversing the resistance to CDK4/6 inhibitor. A TROJAN antisense oligonucleotide sensitized breast cancer cells and organoids to the CDK4/6 inhibitor palbociclib both in vitro and in vivo. Conclusions: TROJAN promotes ER+ breast cancer proliferation and is a potential target for reversing CDK4/6 inhibitor resistance.
2020-04-18 | GSE148858 | GEO
Project description:Two genes have a synthetic lethal relationship when silencing or inhibition of one gene is only lethal in the context of a mutation or activation of the second gene. This situation offers an attractive therapeutic strategy, as inhibition of such a gene will only trigger cell death in tumor cells with an activated second oncogene but spare normal cells without activation of the second oncogene. Here we present evidence that CDK2 is synthetic lethal to neuroblastoma cells with MYCN amplification and overexpression. Neuroblastomas are childhood tumors with an often lethal outcome. Twenty percent of the tumors have MYCN amplification and these tumors are ultimately refractory to any therapy. Targeted silencing of CDK2 by three RNA interference techniques induced apoptosis in MYCN-amplified neuroblastoma cell lines, but not in MYCN single copy cells. Silencing of MYCN abrogated this apoptotic response in MYCN-amplified cells. Inversely, silencing of CDK2 in MYCN single copy cells did not trigger apoptosis, unless a MYCN transgene was activated. The MYCN induced apoptosis after CDK2 silencing was accompanied by nuclear stabilization of P53 and mRNA profiling showed up-regulation of P53 target genes. Silencing of P53 rescued the cells from MYCN-driven apoptosis. The synthetic lethality of CDK2 silencing in MYCN activated neuroblastoma cells can also be triggered by inhibition of CDK2 with a small molecule drug. Treatment of neuroblastoma cells with Roscovitine, a CDK inhibitor, at clinically achievable concentrations induced MYCN-dependent apoptosis. The synthetic lethal relation between CDK2 and MYCN indicates CDK2 inhibitors as potential MYCN-selective cancer therapeutics.
2014-05-19 | GSE16480 | GEO
Project description:Under conditions of hormonal adjuvant treatment the estrogen receptor apoprotein supports breast cancer cell cycling through the retinoic acid receptor α1 apoprotein. Basal proliferation persisted in estrogen-sensitive breast cancer cells grown in hormone depleted conditioned media without or with 4-hydroxytamoxifen (OH-Tam). Downregulating ER using siRNA inhibited basal proliferation by promoting cell cycle arrest. The basal expression of RARα1, the only RARα isoform that was expressed in breast cancer cell lines and in most breast tumors, was supported by apo-ER but was unaffected by OH-Tam. The overlapping tamoxifen-insensitive gene regulation by apo-ER and apo-RARα1 comprised activation of mainly genes promoting cell cycle and mitosis and suppression of genes involved in growth inhibition.
2011-05-13 | GSE26298 | GEO