Cyclin D1 is an important cell cycle regulator but in cancer its overexpression also increases cellular migration mediated by p27KIP1 stabilization and RhoA inhibition. Recently, a common polymorphism at the exon 4-intron 4 boundary of the human cyclin D1 gene within a splice donor region was associated with an altered risk of developing cancer. Altered RNA splicing caused by this polymorphism gives rise to a variant cyclin D1 isoform termed cyclin D1b, which has the same N-terminus as the canonical cyclin D1a isoform but a distinct C-terminus. Analysis was performed of mouse cyclin D1 knockout 3T3 cells infected with splice variants of cyclin D1. 3T3 cells transduced with retroviral vectors expressing each cyclin D1 isoform were processed for expression analysis.
Alternate cyclin D1 mRNA splicing modulates p27KIP1 binding and cell migration.
No sample metadata fields
View SamplesSmall molecule curaxin CBL0137 has broad anti-cancer activity in different preclinical models. It interferes with histone-DNA interactions via binding to DNA without causing DNA damage. It resposents first in class "chromatin damaging" agent without genotoxic properties. Its effect on the transcription in human tumor cells was evaluated. DNA-targeting small molecules are widely used for anticancer therapy based on their ability to induce cell death, presumably via DNA damage. DNA in the eukaryotic cell is packed into chromatin, a highly-ordered complex of DNA, histones, and non-histone proteins. These agents perturb chromatin organization. However, the mechanisms, consequences, and impact of the alterations of chromatin structure in relation to their anti-cancer activity is unclear because it is difficult to separate DNA damage and chromatin damage in cells. We recently demonstrated that curaxins, small molecules with broad anticancer activity, bind DNA without causing detectable DNA damage by interfering with histone/DNA interactions and destabilizing the nucleosome. Chromatin unfolding caused by curaxins is sensed by histone chaperone FACT. FACT binds unfolded nucleosomes, which leads to chromatin trapping or c-trapping. In this study, we investigated whether other DNA-targeting small molecules disturb chromatin and cause c-trapping. We found that only compounds directly binding DNA induce chromatin damage and c-trapping. Chromatin damage may occur in the absence of DNA damage and is dependent on the mechanism of compound binding to DNA and its ability to bind chromatinized DNA in cells. We show that FACT is sensitive to a plethora of nucleosomes perturbations induced by DNA-binding small molecules, including displacement of the linker histone, eviction of core histones, and accumulation of negative supercoiling. Most importantly, the cytotoxicity of DNA-binding small molecules correlates with their ability to cause chromatin damage , but not DNA damage. Overall design: HT1080 cells were treated with CBL0137 for 1 hour at 1uM. EU was added for the last 15 minutes. Newly synthesized RNA was isolated using Click-iTâ„¢ Nascent RNA Capture Kit (Invitrogen, cat#C10365) according to manufacturer instruction.
Prevention of Chromatin Destabilization by FACT Is Crucial for Malignant Transformation.
Cell line, Subject
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Redistribution of H3K27me3 upon DNA hypomethylation results in de-repression of Polycomb target genes.
Specimen part
View SamplesDNA methylation and the Polycomb Repression System are epigenetic mechanisms that play important roles in maintaining transcriptional repression. Recent evidence suggests that DNA methylation can attenuate the binding of Polycomb protein components to chromatin and thus plays a role in determining their genomic targeting. However, whether this role of DNA methylation is important in the context of transcriptional regulation is unclear. By genome-wide mapping of the Polycomb Repressive Complex 2 (PRC2)-signature histone mark, H3K27me3, in severely DNA hypomethylated mouse somatic cells, we show that hypomethylation leads to widespread H3K27me3 redistribution, in a manner that reflects the local DNA methylation status in wild-type cells. Unexpectedly, we observe striking loss of H3K27me3 and PRC2 from Polycomb-target gene promoters in DNA hypomethylated cells, including Hox gene clusters. Importantly, we show that many of these genes become ectopically expressed in DNA hypomethylated cells, consistent with loss of Polycomb-mediated repression. An intact DNA methylome is required for appropriate Polycomb-mediated gene repression by constraining PRC2 targeting. These observations identify a previously unappreciated role for DNA methylation in gene regulation and therefore influence our understanding of how this epigenetic mechanism contributes to normal development and disease.
Redistribution of H3K27me3 upon DNA hypomethylation results in de-repression of Polycomb target genes.
Specimen part
View SamplesRhoB null mice show decreases in pathological angiogenesis in the ischemic retina and reduces angiogenesis in response to cutaneous wounding, but enhances lymphangiogenesis following both dermal wounding and inflammatory challenge.
RhoB controls coordination of adult angiogenesis and lymphangiogenesis following injury by regulating VEZF1-mediated transcription.
Sex, Specimen part
View SamplesThis dataset is part of a study that investigated how the hematopoietic system coordinates the rapid and efficient regeneration of the megakaryocytic lineage during stress scenarios. We found that the phenotypic hematopoietic stem cell (HSC) compartment contains stem-like megakaryocyte-committed progenitors (SL-MkPs), a cell population that shares many features with multipotent HSCs and serves as a lineage-restricted emergency pool for inflammatory insults. This dataset contains single-cell RNA sequencing data of 30 hematopoietic stem and progenitor cells which, in the context of our study, confirmed that MK-specfic transcripts are of highly variable expression in HSCs. The dataset further showed that variations in MK transcript expression in HSCs is not correlated with global transcriptomic rearrangements. Overall design: Murine bone marrow cells were sorted by Lin-cKit+CD150+CD48- (referred to as cd150+ in the following) and Lin-cKit+CD150- (referred to as cd150- in the following). Transcriptomes of 11 cd150- and 9 cd150+ HSCs were determined using QUARTZ, a single-cell RNASeq protocol
Inflammation-Induced Emergency Megakaryopoiesis Driven by Hematopoietic Stem Cell-like Megakaryocyte Progenitors.
No sample metadata fields
View SamplesDiet-induced obesity (DIO) is rapidly becoming a global health problem, particularly as Westernization of emerging nations continues. Currently, one third of adult Americans are considered obese and, if current trends continue, >90% of US citizens are predicted to be affected by 2050. However, efforts to fight this epidemic have not yet produced sound solutions for prevention or treatment. Our studies reveal a balanced and chronobiological relationship between food consumption, daily variation in gut microbial evenness and function, basomedial hypothalamic circadian clock (CC) gene expression, and key hepatic metabolic regulatory networks , including CC and nuclear receptors (NR), that is are essential for metabolic homeostasis. Western diets high in saturated fats dramatically alter diurnal variation in microbial composition and function, which in turn lead to uncoupling of the hepatic CC and NR networks from central CC control in ways that offset the timing and types of regulatory factors directing metabolic function. These signals include microbial metabolites such as short chain fatty acids (SCFAs) and hydrogen sulfide (H2S) that can directly regulate or disrupt metabolic networks of the hepatocyte. Our study therefore provides insights into the complex and dynamic relationships between diet, gut microbes, and the host that are critical for maintenance of health. Perturbations of this constellation of processes, in this case by diet-induced dysbiosis and its metabolomic signaling, can potentially promote metabolic imbalances and disease. This knowledge opens up many possibilities for novel therapeutic and interventional strategies to treat and prevent DIO, ranging from the manipulation of gut microbial function to pharmacological targeting of host pathways to restore metabolic balance.
Effects of diurnal variation of gut microbes and high-fat feeding on host circadian clock function and metabolism.
Specimen part
View SamplesMicroarray expression analysis of mouse ESCs treated with the MYCi 10058-F4.
Myc Depletion Induces a Pluripotent Dormant State Mimicking Diapause.
Specimen part
View SamplesWe here show that the niche regulates the quality of the hematopoietic stem cells (HSCs) that are regenerated after transplantation. We find that a reduced level of Wnt5a in the niche regenerates dysfunctional HSCs, which do not successfully engraft secondary recipients. In particular, RNA sequencing shows a dysregulated Zeb1-associated gene expression of multiple genes involved in the small GTPase-dependent actin polymerization pathway. Misexpression of these genes results in reduced ability to direct polarized F-actin localization, leading to defects in adhesion, migratory behavior and homing to the bone marrow of secondary recipients. Our study further shows that the Wnt5a-haploinsufficient environment similarly affects BCR-ABLp185+ cells, which, in 42% of the studied recipients, fail to generate leukemia and, in the remaining cases, fail to transfer leukemia to secondary hosts. Thus, we show that Wnt5a in the niche is required to regenerate HSCs and leukemic cells with functional ability to rearrange the actin cytoskeleton which is required for successful engraftment. Overall design: Hematopoietic stem cells are regenerated in WT or Wnt5a-haploinsufficient niches. We profile LSK hematopoiteic stem cells after transplantation and three cell populations from the niche environment: endothelial cells (EC), osteoblastic cells (OBC), and mesenchymal cells (MSC)
Niche WNT5A regulates the actin cytoskeleton during regeneration of hematopoietic stem cells.
Cell line, Subject
View SamplesIn order to identify transcript changes in response to DEF , we used human macrophages with or without DEF treatment. In order to study the effect of iron chelation on LPS-polarized macrophage transcriptome, we exposed DEF-treated or control macrophages to short time exposure to LPS. We then performed whole-genome transcriptome sequencing by RNA-sequencing (RNA-seq). Overall design: Macrophages from 3 healthy donors were either treated with DEF (500 µM - designated as DEF) or left unstimulated (CONTROL). LPS treatment (100 ng/ml, 3 hours) was performed in cells with DEF (designated as LPS+DEF) or without (LPS). RNA-seq was performed on Illumina Hiseq 2500
Acute Iron Deprivation Reprograms Human Macrophage Metabolism and Reduces Inflammation In Vivo.
Specimen part, Treatment, Subject
View Samples