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ABSTRACT:
PROVIDER: PRJNA1205784 | ENA |
REPOSITORIES: ENA
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Project description:In this study, we investigate the G2 checkpoint activated by chromosome entanglements, the so-called Decatenation Checkpoint (DC), which can be activated by TOP2A catalytic inhibition. Specifically, we focus on the spontaneous ability of cells to bypass or override this checkpoint, referred to as checkpoint adaptation. Some factors involved in adapting to this checkpoint are p53 and MCPH1. Using cellular models depleted of p53 or both p53 and MCPH1 in hTERT-RPE1 cells, we analyzed cell cycle dynamics and adaptation, segregation defects, apoptosis rate, and transcriptional changes related to prolonged exposure to TOP2A inhibitors. Our findings reveal that cell cycle dynamics are altered in MCPH1-depleted cells compared to control cells. We found that MCPH1 depletion can restore the robustness of the DC in a p53-negative background. Furthermore, this research highlights the differential effects of TOP2A poisons and catalytic inhibitors on cellular outcomes and transcriptional profiles. By examining the different mechanisms of TOP2A inhibition and their impact on cellular processes, this study contributes to a deeper understanding of the regulation and physiological implications of the DC and checkpoint adaptation in non-carcinogenic cell lines.
2025-02-01 | GSE286076 | GEO
Project description:Human infants exhibit innate social behaviors at birth, yet little is understood about the embryonic development of sociality. We screened 1120 known drugs and found that embryonic inhibition of topoisomerase IIα (Top2a) resulted in lasting social deficits in zebrafish. In mice, prenatal Top2 inhibition caused behavioral defects related to core symptoms of autism, including impairments in social interaction and communication. Mutation of Top2a in zebrafish caused downregulation of a set of genes highly enriched for genes associated with autism in humans. Both the Top2a-regulated and autism-associated gene sets possess binding sites for polycomb repressive complex 2 (PRC2), a regulatory complex responsible for H3K27 trimethylation. Moreover, both gene sets are highly enriched for H3K27me3. Inhibition of PRC2 component Ezh2 rescued social deficits caused by Top2 inhibition. Therefore, Top2a is a key component of an evolutionarily conserved pathway that promotes the development of social behavior through PRC2 and H3K27me3.
2021-09-20 | GSE181730 | GEO
Project description:Topoisomerases are essential for resolving topological problems in the genome, while their function in gene regulation, especially during cellular differentiation, remains unknown. We reveal that the expression of two Topo II isoforms, Top2a and Top2ß, is characteristic of dividing and postmitotic tissues, respectively. In embryonic stem cells, Top2a preferentially binds to promoters embedded in an active chromatin environment. Inhibition of Top2a activity results in misregulation of target gene expression that accompanies accumulation of double-strand breaks. Common targets of Top2a and Top2ß are housekeeping genes while their unique targets are involved in proliferation/pluripotency and neurogenesis, respectively. Moreover, a subset of Top2a targets exhibit bivalent chromatin state that is resolved upon differentiation concomitant with their activation and occupancy by Top2ß, a feature further observed for long genes. These findings suggest that Top2a not only contributes to stem cell transcriptome regulation but may also prime developmental genes for subsequent activation upon differentiation. mRNA profiles of DMSO and ICRF-193 treated mESCs were generated by deep sequencing in triplicates. ICRF-193 is a well established catalytic inhibitor of Topoisomerase II, hence, we used ICRF-193 to the elucidate role of Top2a catalytic activity on transcription by genome wide transcription profiling.
2013-10-10 | E-GEOD-46066 | biostudies-arrayexpress
Project description:Topoisomerases are essential for resolving topological problems in the genome, while their function in gene regulation, especially during cellular differentiation, remains unknown. We reveal that the expression of two Topo II isoforms, Top2a and Top2ß, is characteristic of dividing and postmitotic tissues, respectively. In embryonic stem cells, Top2a preferentially binds to promoters embedded in an active chromatin environment. Inhibition of Top2a activity results in misregulation of target gene expression that accompanies accumulation of double-strand breaks. Common targets of Top2a and Top2ß are housekeeping genes while their unique targets are involved in proliferation/pluripotency and neurogenesis, respectively. Moreover, a subset of Top2a targets exhibit bivalent chromatin state that is resolved upon differentiation concomitant with their activation and occupancy by Top2ß, a feature further observed for long genes. These findings suggest that Top2a not only contributes to stem cell transcriptome regulation but may also prime developmental genes for subsequent activation upon differentiation. mRNA profiles of DMSO and ICRF-193 treated mESCs were generated by deep sequencing in triplicates. ICRF-193 is a well established catalytic inhibitor of Topoisomerase II, hence, we used ICRF-193 to the elucidate role of Top2a catalytic activity on transcription by genome wide transcription profiling.
2013-10-10 | E-GEOD-49141 | biostudies-arrayexpress
Project description:Background: The intestinal lining renews itself in a programmed fashion that can be affected by adaptation to surgical procedures such as gastric bypass. Results: RNA sequencing suggested significant decreases of gene expression associated with G2/M DNA damage checkpoint regulation of the cell cycle pathway, and significant increases in gene expression associated with CDP-diacylglycerol biosynthesis pathway TCA cycle II pathway, and pyrimidine ribonucleotide salvage pathway after RYGB. Since SLFN12 is reported to influence enterocytic differentiation, we stained mucosa for SLFN12 and observed increased SLFN12 immunoreactivity. We investigated SLFN12 overexpression in HIEC-6 and FHs 74 Int intestinal epithelial cells and observed similar increased expression of the following genes that were also increased after RYGB: HES2, CARD9, SLC19A2, FBXW7, STXBP4, SPARCL1, and UTS. Conclusions: Our data suggests that RYGB promotes SLFN12 protein expression, cellular mechanism and replication pathways, and genes associated with differentiation and restitution (HES2, CARD9, SLC19A2) and obesity-related genes (FBXW7, STXBP4, SPARCL1, UTS).
2022-11-01 | GSE214758 | GEO
Project description:Malignant nerve sheath tumors (MPNST) are rare types of malignant soft tissue sarcomas and characterized by high resistance for current chemotherapeutic strategies, including topoisomerase 2a (TOP2A) inhibitor, etoposide. Although the poor therapeutic or severe side effects of etoposide in MPNST patients are demonstrated, novel molecular targets that promote tumor malignancy have not been identified. Previously, we reported that paired related-homeobox 1 (PRRX1) serves as a malignant factor in human osteosarcoma. Here, we found that expression level of PRRX1 in tumor tissues, especially sarcomas, are higher than in normal tissues using database analysis. PRRX1 was expressed in various human sarcoma tissues, and its level increased during malignant progression from schwannoma or neurofibroma to MPNST. High expression of PRRX1 was also associated with poor prognosis of human MPNST patients, and PRRX1 knockdown suppressed proliferation, invasion and tumorigenic potential of human MPNST cell line, HS-PSS. Immunoprecipitation and mass spectrometry analysis revealed that PRRX1 interacts with TOP2A, and human MPNST patients with high expression of TOP2A showed poor prognosis. Interestingly, database analysis revealed that expression level of TOP2A in tumor tissues were positively correlated with PRRX1. TOP2A knockdown in HS-PSS suppressed proliferation, and inhibited the migration induced by PRRX1A overexpression. Overexpression of PRRX1 and TOP2A cooperatively increased migration and expression of tumor-malignancy associated gene sets, including EMT, mTORC1, KRAS and SRC signaling pathways. Inhibition of PRRX1-TOP2A interaction would be a novel tumor-selective therapeutic strategy that has less severe side effects than current chemotherapies.
2023-05-31 | GSE214899 | GEO
Project description:The G2 DNA damage checkpoint inhibits Cdc2 and mitotic entry through the dual regulation of Wee1 and Cdc25 by the Chk1 effector kinase. Up-regulation of Chk1 by mutation or overexpression bypasses the requirement for up-stream regulators or DNA damage to promote a G2 cell cycle arrest. We screened in fission yeast for mutations that rendered cells resistant to overexpressed Chk1. We identified a mutation in tra1, which encodes one of two homologs of TRRAP, an ATM/R-related pseudokinase that scaffolds several histone acetyltransferase (HAT) complexes. Inhibition of histone deacetylases reverts the resistance to overexpressed Chk1, suggesting this phenotype is due to a HAT activity, though expression of checkpoint and cell cycle genes is not greatly affected. Cells with mutant or deleted tra1 activate Chk1 normally and are checkpoint proficient. However, these cells are semi-wee even when overexpressing Chk1, and accumulate inactive Wee1 protein. The Cdr (changed division response) kinases Cdr1 and Cdr2 are negative regulators of Wee1, and while best characterized in the cellular response to limited nutrition, we show that they are required for the Tra1-dependent alterations to Wee1 function. This identifies Tra1 as another component controlling the timing of entry into mitosis via Cdc2 activation. Two and three independent microaaray experiments were done for wild type and the mutant (tra1-1) respectively.
2010-04-11 | E-GEOD-12674 | biostudies-arrayexpress
Project description:Hypoxia promotes an aggressive tumor phenotype with increased genomic instability, partially due to downregulation of DNA repair pathways. However, in addition to DNA repair, genome stability is also controlled by cell cycle checkpoints. An important issue is therefore whether hypoxia also can alter the DNA damage cell cycle checkpoints. Here, we show that hypoxia (24h 0.2% O2) alters the expression of several G2 checkpoint regulators, as examined by microarray gene expression analysis and immunoblotting of U2OS cells. While some of the changes reflected hypoxia-induced inhibition of cell cycle progression, flow cytometric bar-coding analysis of individual cells showed that the levels of several G2 checkpoint regulators were reduced in G2 phase cells after hypoxic exposure, in particular cyclin B1. These effects were accompanied by decreased Cyclin dependent kinase (CDK) activity in G2 phase cells after hypoxia. Furthermore, cells pre-exposed to hypoxia showed a longer G2 checkpoint arrest upon treatment with ionizing radiation. Similar results were found following other hypoxic conditions (~0.03 % O2 20h and 0.2% O2 72h). These results demonstrate that the DNA damage G2 checkpoint can be altered as a consequence of hypoxia, and we propose that such alterations may influence the genome stability of hypoxic tumors. We measured gene expression changes in U2OS cells after treatment with 0.2% hypoxia for 24 hours. The data were used in the exploration of hyopxia induced alterations in the G2 checkpoint.
2016-01-04 | E-GEOD-70530 | biostudies-arrayexpress
Project description:Topoisomerases are essential for resolving topological problems in the genome, while their function in gene regulation, especially during cellular differentiation, remains unknown. We reveal that the expression of two Topo II isoforms, Top2a and Top2ß, is characteristic of dividing and postmitotic tissues, respectively. In embryonic stem cells, Top2a preferentially binds to promoters embedded in an active chromatin environment. Inhibition of Top2a activity results in misregulation of target gene expression that accompanies accumulation of double-strand breaks. Common targets of Top2a and Top2ß are housekeeping genes while their unique targets are involved in proliferation/pluripotency and neurogenesis, respectively. Moreover, a subset of Top2a targets exhibit bivalent chromatin state that is resolved upon differentiation concomitant with their activation and occupancy by Top2ß, a feature further observed for long genes. These findings suggest that Top2a not only contributes to stem cell transcriptome regulation but may also prime developmental genes for subsequent activation upon differentiation.
2013-10-10 | GSE49141 | GEO
Project description:Topoisomerases are essential for resolving topological problems in the genome, while their function in gene regulation, especially during cellular differentiation, remains unknown. We reveal that the expression of two Topo II isoforms, Top2a and Top2ß, is characteristic of dividing and postmitotic tissues, respectively. In embryonic stem cells, Top2a preferentially binds to promoters embedded in an active chromatin environment. Inhibition of Top2a activity results in misregulation of target gene expression that accompanies accumulation of double-strand breaks. Common targets of Top2a and Top2ß are housekeeping genes while their unique targets are involved in proliferation/pluripotency and neurogenesis, respectively. Moreover, a subset of Top2a targets exhibit bivalent chromatin state that is resolved upon differentiation concomitant with their activation and occupancy by Top2ß, a feature further observed for long genes. These findings suggest that Top2a not only contributes to stem cell transcriptome regulation but may also prime developmental genes for subsequent activation upon differentiation.
2013-10-10 | GSE46066 | GEO