Statins and bisphosponates (BPs) are two distinct classes of isoprenoid pathway inhibitors targeting HMG-CoA reductase (upstream enzyme) and Farnesyl-pyrophospate synthase (downstream enzyme) respectively. Here we conducted a comparative study of two representatives of these classes, fluvastatin (Fluva) and Zoledronate (Zol), to assess the differences in their in vivo metastatic potentials and pharmacogenomic profiles. Both drugs, being administered after emergence of detectable metastases, appeared to be potent metastasis inhibitors in MDA-MB-231 breast cancer metastasis model. We observed a reduced number of metastatic sites under Fluva, but not Zol treatment. Combinatorial in vivo treatment by Fluva and Zol showed no synergy for these drugs, as reported earlier on the basis of in vitro studies (Budman DR, Oncology 2006), staying in line with similarity of their transcriptomic profiles. Comparison of Zol and Fluva transcriptomic profiles revealed similar patterns of affected genes (describe involved genes functions) through different kinetics (when treated with IC50 determined for 72h treatment, the majority of changes were observed after 24h incubation with Fluva , and only after 48h incubation with Zol at 72h-IC50 or after 24h treatment with its 3 times higher dose). We demonstrated here that targeting different enzymes of the same pathway neither necessarily leads to distinct changes in gene profiles, nor to synergy for in vivo anti-metastatic potential.
Transcriptome analysis and in vivo activity of fluvastatin versus zoledronic acid in a murine breast cancer metastasis model.
Cell line, Time
View SamplesTo understand the link between invasion behavior and the steps of metastasis formation, we isolated invasive subpopulations from MDA-MB-231 cells in vitro using matrigel coated boyden chambers. Whole genome transcriptional profiling was used to characterize the expression changes uniquely related to invasive abilities of these cells.
Invading basement membrane matrix is sufficient for MDA-MB-231 breast cancer cells to develop a stable in vivo metastatic phenotype.
Cell line
View SamplesWe investigated genome-wide gene alterations in the temporal cortex of a well-characterized cohort of Alzheimers disease (AD) patients using Affymetrix exon arrays.
Genome wide profiling of altered gene expression in the neocortex of Alzheimer's disease.
Sex, Age, Specimen part, Disease
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Combinatorial recruitment of CREB, C/EBPβ and c-Jun determines activation of promoters upon keratinocyte differentiation.
Specimen part, Treatment
View SamplesCombinatorial recruitment of CREB, C/EBPb and Jun determines activation of promoters upon keratinocyte differentiation
Combinatorial recruitment of CREB, C/EBPβ and c-Jun determines activation of promoters upon keratinocyte differentiation.
Specimen part, Treatment
View SamplesABSTRACT: Furin is a proprotein convertase (PC) responsible for proteolytic activation of a wide array of precursor proteins within the secretory pathway. It maps to the PRC1 locus, a type 2 diabetes susceptibility locus, yet its specific role in pancreatic β cells is largely unknown. The aim of this study was to determine the role of furin in glucose homeostasis. We show that furin is highly expressed in human islets, while PCs that potentially could provide redundancy are expressed at considerably lower levels. β cell-specific furin knockout (βfurKO) mice are glucose intolerant, due to smaller islets with lower insulin content and abnormal dense core secretory granule morphology. RNA expression analysis and differential proteomics on βfurKO islets revealed activation of Activating Transcription Factor 4 (ATF4), which was mediated by mammalian target of rapamycin C1 (mTORC1). βfurKO cells show impaired cleavage of the accessory V-ATPase subunit Ac45, and by blocking this pump in β cells the mTORC1 pathway is activated. Furthermore, βfurKO cells show lack of insulin receptor cleavage and impaired response to insulin. Taken together, these results suggest a model of mTORC1-ATF4 hyperactivation in β cells lacking furin, which causes β cell dysfunction.
Loss of <i>Furin</i> in β-Cells Induces an mTORC1-ATF4 Anabolic Pathway That Leads to β-Cell Dysfunction.
Sex, Age, Specimen part
View SamplesGene expression array analysis component. Ligand-dependent transcription by the nuclear receptor glucocorticoid receptor (GR) is mediated by interactions with co-regulators. The role of these interactions in determining selective binding of GR to regulatory elements remains unclear. Recent findings indicate a large fraction of genomic GR binding coincides with chromatin that is accessible prior to hormone treatment, suggesting that receptor binding is dictated by proteins that maintain chromatin in an open state. Combining nucleolytic cleavage and chromatin immunoprecipitation with high-throughput sequencing, we identify the activator protein 1 (AP1) as a major partner for productive GR-chromatin interactions. AP1 is critical for GR-regulated transcription and recruitment to co-occupied regulatory elements, illustrating an extensive AP1-GR interaction network. Importantly, the maintenance of baseline chromatin accessibility facilitates GR recruitment and is dependent on AP1 binding. We propose a model where the basal occupancy of transcription factors act to prime chromatin and direct inducible transcription factors to select regions in the genome.
Transcription factor AP1 potentiates chromatin accessibility and glucocorticoid receptor binding.
Sex, Cell line, Treatment, Time
View SamplesTo investigate maternal whole blood gene expression profiles associated with spontaneous preterm birth (SPTB, <37 weeks) in asymptomatic pregnant women.
Maternal Whole Blood Gene Expression at 18 and 28 Weeks of Gestation Associated with Spontaneous Preterm Birth in Asymptomatic Women.
Specimen part, Subject
View SamplesStudies of the Xenopus organizer have laid the foundation for our understanding of the conserved signaling pathways that pattern vertebrate embryos during gastrulation. Here, we use this wealth of knowledge as leverage in the design and analysis of a genomic visualization of organizer-related gene transcription. Using ectopic expression of the two major activities of the organizer, BMP and Wnt inhibition, as well as endogenous tissues, we generate a focused set of samples that represent different aspects of organizer signaling. The genomic expression values of each sample are then measured with oligonucleotide arrays. From this data, genes regulated by organizer signaling are selected and then clustered by their patterns of regulation. A new GO biological process annotation of the Xenopus genome allows us to rapidly identify clusters that are highly enriched for known gastrula patterning genes. Within these clusters, we can predict the expression patterns of unknown genes with remarkable accuracy, leading to the discovery of new organizer-related gastrula stage expression patterns for 19 genes. Moreover, the patterns of gene response observed within these clusters allow us to parse apart the contributions of BMP and Wnt inhibition in organizer function. We find that the majority of gastrula patterning genes respond transcriptionally to these activities according to only a few stereotyped patterns, allowing us to describe suites of genes that are likely to share similar regulatory mechanisms. These suites of genes demonstrate a mechanism where BMP inhibition initiates the organizer program before gastrulation, and Wnt inhibition maintains and drives the organizer program during gastrulation.
Genomic analysis of Xenopus organizer function.
Specimen part
View SamplesStrains devoid of ppGpp (relA spoT; called ppGpp0), and ppGpp0 dksA- exhibit several amino acid requirements for growth on minimal media. We found that overexpression of DksA can complement some of those requirements. Since DksA is a factor that binds to the RNA polymerase secondary channel, we wondered if other secondary channel proteins might also exert a similar role with respect to growth on minimal media. In our study we found that GreA and partially GreB can in fact complement these requirements under certain conditions. Here, we wished to investigate a broader effect of GreA and GreB on ppGpp0 and ppGpp0 dksA- strains. Since the parent strains are unable to grow in minimal media, we had to supplement the M9 glucose medium with a set of amino acids (DFHILQSTV). We found that both, GreA and GreB can affect a much larger set of genes in the absence of dksA, than in its presence. Also, GreA seems to affect more genes than GreB, under both conditions.
Effects on growth by changes of the balance between GreA, GreB, and DksA suggest mutual competition and functional redundancy in Escherichia coli.
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