The unique metabolic profile of most cancers (aerobic glycolysis) might confer apoptosis-resistance and be therapeutically targeted. Compared to normal cells, several human cancers have high mitochondrial membrane potential and low expression of the K+ channel Kv1.5, both contributing to apoptosis-resistance. Dichloroacetate (DCA), an inhibitor of the mitochondrial pyruvate dehydrogenase kinase (PDK), shifts metabolism from glycolysis to glucose oxidation, decreases mitochondrial membrane potential, increases mitochondrial-H2O2 and activates Kv channels in all cancer, but not normal cells; DCA upregulates Kv1.5 by an NFAT1-dependent mechanism. DCA induces apoptosis, decreases proliferation and tumor growth in vitro and in vivo, without apparent toxicity. Molecular inhibition of PDK2 by siRNA mimics DCA. The mitochondria-NFAT-Kv axis and PDK are important therapeutic targets in cancer; the orally available DCA is a novel selective anticancer agent.
A mitochondria-K+ channel axis is suppressed in cancer and its normalization promotes apoptosis and inhibits cancer growth.
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View SamplesExposure to vanadium pentoxide (V2O5) is a cause of occupational bronchitis. We evaluated gene expression profiles in cultured human lung fibroblasts exposed to V2O5 in vitro in order to identify candidate genes that could play a role in airway remodeling associated with V2O5-induced bronchitis. Gene expression was measured at various time points over a 24 hr period using the Affymetrix Human Genome U133A 2.0 Array. Expression data were preprocessed using RMA with a log2 transformation. Statistical analysis was performed in R using the affylmGUI package using a linear model with contrasts between untreated control and V2O5-exposed fibroblasts. Genes identified as statistically significant were filtered by selecting only those genes that exhibited a > 2-fold change. Quantitative real-time RT-PCR was utilized to confirm expression of selected genes. More than 2000 genes were significantly changed in response to V2O5 over the time course of our experiment. Genes altered by V2O5 were involved in biologic processes related to cell growth and differentiation, oxidative stress responses, immune regulation, and interferon signaling and apoptosis. In particular, V2O5 induced genes that encode growth factors involved in epithelial repair (HB-EGF) or angiogenesis (VEGF), peroxide generating enzymes (SOD2), pro-inflammatory enzymes (PGHS2), while suppressing genes involved in growth arrest (GAS1, STAT-1) and cell cycle inhibition (CDKN1B). Our study also identified a variety of novel genes that could be used as biomarkers of V2O5-induced bronchitis or could serve as candidate genes for disease progression.
Genomic analysis of human lung fibroblasts exposed to vanadium pentoxide to identify candidate genes for occupational bronchitis.
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View SamplesFetal and neonatal beta cells have poor glucose-induced insulin secretion and only gain robust glucose responsiveness several weeks after birth. This unresponsiveness may be due to a generalized immaturity of the metabolic pathways normally found in beta cells.
Rat neonatal beta cells lack the specialised metabolic phenotype of mature beta cells.
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View SamplesThe present research is devoted to the identification of gene(s) severely affected by EMD mutations, leading to striated muscle laminopathies and more specifically the cardiomyopathy. For this purpose, we developped a large-scale gene expression approach on heart and skeletal tissues from Emd KO mouse model.
Activation of MAPK in hearts of EMD null mice: similarities between mouse models of X-linked and autosomal dominant Emery Dreifuss muscular dystrophy.
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View SamplesOvarian follicular granulosa cells surround and nurture oocytes, and produce sex steroid hormones. It is believed that during development the ovarian surface epithelial cells invaginate into the ovary and develop into granulosa cells when associating with oogonia to form follicles. Using bovine fetal ovaries (n = 53) we identified a novel cell type, termed GREL for Gonadal Ridge Epithelial-Like. Using 25 markers for GREL and other cells we conducted immunohistochemistry and electron microscopy and chronologically tracked all somatic cell types during development. Before 70 days of gestation the gonadal ridge/ovarian primordium is formed by proliferation of GREL cells at the surface epithelium of the mesonephros. Primordial germ cells (PGCs) migrate into the ovarian primordium. After 70 days, stroma from the underlying mesonephros begins to penetrate the primordium, partitioning the developing ovary into irregularly-shaped ovigerous cords composed of GREL cells and PGCs/oogonia. Importantly we identified that the cords are separated from the stroma by a basal lamina. Around 130 days of gestation as the stroma expands laterally below the GREL cells on the surface thus establishing a sub-epithelial basal lamina and an epithelial-stromal interface, and it is at this stage that a mature surface epithelium develops from the GREL cells. The stroma continues to partition the ovigerous cords into smaller groups of cells eventually forming follicles containing an oogonium/oocyte surrounded by GREL cells, which become granulosa cells. Thus in contrast to the prevailing theory, the ovarian surface epithelial cells do not invaginate into the ovary to form the granulosa cells of follicles.
A new model of development of the mammalian ovary and follicles.
Specimen part
View SamplesDisruption of peripheral circadian rhyme pathways dominantly leads to metabolic disorders. Studies on circadian rhythm proteins in the heart indicated a role for Clock or Per2 in cardiac metabolism. In fact, Per2-/- mice have larger infarct sizes with a deficient lactate production during myocardial ischemia. To test the hypothesis that cardiac Per2 represents an important regulator of cardiac metabolism during myocardial ischemia, we performed lactate measurements during reperfusion in Per1-/-, Per2-/- or wildtype mice followed by gene array studies using various ischemia-reperfusion protocols comparing wildtype and Per2-/- mice. Lactate measurements in whole blood confirmed a dominant role of Per2 for lactate production during myocardial ischemia. Surprisingly, high-throughput gene array analysis of eight different conditions on one 24-microarray plate revealed dominantly lipid metabolism as differentially regulated pathway in wildtype mice when compared to Per2-/-. In all treatment groups, the enzyme enoyl-CoA hydratase, which is essential in fatty acid beta-oxidation, was regulated in wildtype animals only. Studies using nuclear magnet resonance imaging (NMRI) confirmed altered fatty acid populations with higher mono-unsaturated fatty acid levels in hearts from Per2-/- mice. Unexpectedly, studies on gene regulation during reperfusion revealed solely pro inflammatory genes as differentially regulated 'Per2-genes'. Subsequent studies on inflammatory markers showed increasing IL6 or TNFa levels during reperfusion in Per2-/- mice. In summary, these studies reveal a novel role of cardiac Per2 for fatty acid metabolism or inflammation during myocardial ischemia and reperfusion.
Cardiac Per2 functions as novel link between fatty acid metabolism and myocardial inflammation during ischemia and reperfusion injury of the heart.
Sex, Specimen part
View SamplesThe androgen receptor (AR) is a mediator of both androgen-dependent and castration- resistant prostate cancers. Identification of cellular factors affecting AR transcriptional activity could in principle yield new targets that reduce AR activity and combat prostate cancer, yet a comprehensive analysis of the genes required for AR-dependent transcriptional activity has not been determined. Using an unbiased genetic approach that takes advantage of the evolutionary conservation of AR signaling, we have conducted a genome-wide RNAi screen in Drosophila cells for genes required for AR transcriptional activity and applied the results to human prostate cancer cells. We identified 45 AR-regulators, which include known pathway components and genes with functions not previously linked to AR regulation, such as HIPK2 (a protein kinase) and MED19 (a subunit of the Mediator complex). Depletion of HIPK2 and MED19 in human prostate cancer cells decreased AR target gene expression and, importantly, reduced the proliferation of androgen-dependent and castration-resistant prostate cancer cells. We also systematically analyzed additional Mediator subunits and uncovered a small subset of Mediator subunits that interpret AR signaling and affect AR-dependent transcription and prostate cancer cell proliferation. Importantly, targeting of HIPK2 by an FDA approved kinase inhibitor phenocopied the effect of depletion by RNAi and reduced the growth of AR-positive, but not AR negative, treatment-resistant prostate cancer cells. Thus, our screen has yielded new AR regulators including drugable targets that reduce the proliferation of castration-resistant prostate cancer cells.
A genome-wide RNA interference screen identifies new regulators of androgen receptor function in prostate cancer cells.
Cell line
View SamplesTo determine the effects of depleting TIP60, CDK8, or HIF1A on the transcriptional response to hypoxia, we performed RNAseq analysis of four HCT116 colorectal carcinoma cell lines (shNT, HIF1A-/-, shTIP60 and shCDK8) in normoxic and hypoxic (24hrs, 1% O2) conditions. Overall design: PolyA RNA for two independent biological replicates was purified from HCT116 cells stably expressing an shRNA against a non-targeting control (shNT), TIP60 (shTIP60) or CDK8 (shCDK8), or genetically deleted HIF1A (HIF1A-/-) subjected to 24hrs 1% O2 (hypoxia) or maintained under ambient oxygen (21%; normoxia) was sequenced on the Ion Torrent platform. Reads were aligned to the human genome and gene-level counts were used for differential expression analysis.
The TIP60 Complex Is a Conserved Coactivator of HIF1A.
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View SamplesThis SuperSeries is composed of the SubSeries listed below.
Activation of MAPK pathways links LMNA mutations to cardiomyopathy in Emery-Dreifuss muscular dystrophy.
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View SamplesThe present research is devoted to the identification of gene(s) severely affected by LMNA mutations, leading to striated muscle laminopathies and more specifically the cardiomyopathy. For this purpose, we developped a large-scale gene expression approach on heart and skeletal tissues from Lmna H222P heterozygous Knock-In mouse model.
Activation of MAPK pathways links LMNA mutations to cardiomyopathy in Emery-Dreifuss muscular dystrophy.
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