Analysis of transcriptional changes upon persistent heat stress with emphasis on epigenetically regulated genes
Epigenetic regulation of repetitive elements is attenuated by prolonged heat stress in Arabidopsis.
Specimen part
View SamplesA case of transcriptional gene silencing, originally observed in tetraploid Arabidopsis plants, created an epiallele resistant to many mutations or inhibitor treatments that activate other suppressed genes. This raised the question about the molecular basis of this extreme stability.
Cooperation of multiple chromatin modifications can generate unanticipated stability of epigenetic States in Arabidopsis.
Specimen part
View SamplesMedulloblastoma (MB) is the most common malignant brain tumor in children, among whom overexpression or amplification of MYC oncogenes has been associated with poor clinical outcome. Although the MYC functions during normal development and oncogenesis in various systems have been extensively investigated, the transcriptional targets mediating MYC effects in MB are still elusive. Their identification and roles during MB onset and progression are important and will ultimately suggest novel potential therapeutic targets. cDNA microarray analysis was used to compare the effects of overexpressing and silencing MYC on the transcriptome of a MB-derived cell line. We identified 209 genes with potential relevance to MYC-dependent cellular responses in MB. Among the MYC-responsive genes, we found members of the bone morphogenetic protein (BMP) signaling pathway, which plays a crucial role during the development of the cerebellum. In particular, the cytokine gene BMP7 was identified as a direct target of MYC in MB cells. Similar to the effect induced by BMP7 silencing by siRNA, the use of a small-molecule inhibitor of the BMP/SMAD signaling pathway reduced cell viability in a panel of MB cells. Altogether, our findings indicate that high MYC levels drive BMP7 expression in MB to induce pro-survival and pro-proliferative cellular pathways. This observation suggests that targeting the BMP/SMAD pathway may be a new therapeutic concept for the treatment of childhood MB.
Bone morphogenetic protein-7 is a MYC target with prosurvival functions in childhood medulloblastoma.
Specimen part, Cell line
View SamplesATP6AP2 is an essential accessory component of the vacuolar H+ ATPase (V-ATPase) and has been associated with intellectual disabilities (ID) and Parkinsonism. ATP6AP2 has been implicated in several signaling pathways, but little is known about its role in the nervous system. To decipher its function in behaviour and cognition, we generated and characterized conditional ATP6AP2 Drosophila and mouse models in the nervous system. In Drosophila, knockdown of ATP6AP2 induced defective phototaxis and vacuolisation of photoreceptor neurons and pigment cells when deleted in eyes and alteration of short- and long-term memory when deleted in the mushroom body. In mouse, conditional Atp6ap2 deletion in glutamatergic neurons (Atp6ap2Camk2aCre/0 mice) caused increased spontaneous locomotor activity and altered memory for fear. Both Drosophila ATP6AP2 knockdown and Atp6ap2Camk2aCre/0 mice presented with presynaptic transmission defect, abnormal number and morphology of synapses, and alteration of axonal transport in fly. In addition, Atp6ap2Camk2aCre/0 mice showed autophagy defect leading to axonal and neuronal degeneration in the cortex and the hippocampus. Surprisingly, myelinisation of axons was affected in our mutant mice. In accordance with the identified phenotypes across species, genome-wide transcriptome profiling of Atp6ap2Camk2aCre/0 mouse hippocampi revealed dysregulated genes involved in myelination, action potential, membrane bound vesicles and adult behaviour. In summary, disruption of ATP6AP2 in mouse and fly leads to cognitive impairment and neurodegeneration, mimicking aspects of the neuropathology associated with ATP6AP2 mutations in humans. Our results identify ATP6AP2 as an essential gene for the nervous system. Overall design: 4 samples, 2 wt and 2 Atp6ap2Camk2aCre/0
Conditional depletion of intellectual disability and Parkinsonism candidate gene ATP6AP2 in fly and mouse induces cognitive impairment and neurodegeneration.
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View SamplesSystemic transcriptional responses in Arabidopsis thaliana distal leaves to wounding
The plant NADPH oxidase RBOHD mediates rapid systemic signaling in response to diverse stimuli.
Age, Specimen part
View SamplesThe bifunctional enzyme 6-phosphofructo-2-kinase/fructose-2,6-biphosphatase-4 (PFKFB4) controls metabolic flux through allosteric regulation of glycolysis. Here we show that p53 regulates the expression of PFKFB4 and that p53-deficient cancer cells are highly dependent on the function of this enzyme. We found that p53 down-regulates PFKFB4 expression by binding to its promoter and mediating transcriptional repression via histone deacetylases. Depletion of PFKFB4 from p53 deficient cancer cells increased levels of the allosteric regulator fructose 2,6-bisphophate, leading to increased glycolytic activity but decreased routing of metabolites through the oxidative arm of the pentose phosphate pathway. PFKFB4 was also required to support the synthesis and regeneration of nicotinamide adenine dinucleotide phosphate (NADPH) in p53 deficient cancer cells. Moreover, depletion of PFKFB4 attenuated cellular biosynthetic activity and resulted in the accumulation of reactive oxygen species and cell death in the absence of p53. Finally, silencing of PFKFB4 induced apoptosis in p53 deficient cancer cells in vivo and interfered with tumour growth. These results demonstrate that PFKFB4 is essential to support anabolic metabolism in p53-deficient cancer cells and suggest that inhibition of PFKFB4 could be an effective strategy for cancer treatment. Overall design: Gene expression changes in HCT116 p53+/+ and p53-/- xenograft tumours after PFKFB4 silencing
6-Phosphofructo-2-kinase/fructose-2,6-biphosphatase 4 is essential for p53-null cancer cells.
Specimen part, Cell line, Subject
View SamplesConventional anti-cancer drug screening is typically performed in the absence of accessory cells (e.g. stromal cells) of the tumor microenvironment, which can profoundly alter anti-tumor drug activity. To address this major limitation, we have developed assays (e.g. the tumor cell-specific in vitro bioluminescence imaging (CS-BLI) assay) to selectively quantify tumor cell viability, in presence vs. absence of non-malignant stromal cells or drug treatment. These assays have allowed us to identify that neoplastic cells from diverse malignancies exhibit stroma-induced resistance to different anti-tumor agents. In this analysis, we evaluated the molecular changes triggered in myeloma cells by their in vitro interaction with stromal cells. The transcriptional profile of 3 human multiple myeloma (MM) cell lines (MM.1S, MM.1R, INA-6) co-cultured with stromal cells vs. when cultured alone was characterized by oligonucleotide microarray analysis, using the human U133 plus 2.0 Affymetrix GeneChip.
Tumor cell-specific bioluminescence platform to identify stroma-induced changes to anticancer drug activity.
Cell line
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Human but not mouse adipogenesis is critically dependent on LMO3.
Specimen part, Treatment
View SamplesIn this study we aimed to gain further insight on the role of GCs in adipocyte differentiation. For the future drugability of candidate targets it is of utmost importance to find factors relevant to human biology. Thus, we analyzed the transcriptome of GC induced primary human adipose stem cells (hASC) to identify novel factors downstream of GC action
Human but not mouse adipogenesis is critically dependent on LMO3.
Specimen part
View SamplesIn this study, we aimed to gain further insight on the role of glucocorticoids (GCs) in adipocyte differentiation. For the future drugability of candidate targets, it is of utmost importance to find factors relevant to human biology. Thus, we analyzed the transcriptome of GC-induced primary human adipose stem cells (hASCs) isolated from paired subcutaneous adipose tissue (SAT) and visceral adipose tissue (VAT) to identify novel factors downstream of GC action.
Human but not mouse adipogenesis is critically dependent on LMO3.
Specimen part, Treatment
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