Androgen Receptor (AR) is essential for the growth and progression of prostate cancer in both hormone-sensitive and hormone-refractory disease. We have designed a sequence-specific DNA binding polyamide (1) that targets the consensus androgen response element (ARE). This polyamide binds the PSA promoter ARE, inhibits androgen-induced expression of PSA and several other AR-regulated genes in cultured prostate cancer cells, and reduces AR occupancy at the PSA promoter and enhancer. Down-regulation of PSA by this polyamide was comparable to that produced by the synthetic anti-androgen bicalutamide (Casodex) at the same concentration. Genome-wide expression analysis reveals that a similar number of transcripts are affected by treatment with the polyamide and with bicalutamide. Direct inhibition of AR-DNA binding by sequence-specific DNA binding small molecules could offer an alternative approach to antagonizing AR activity. A polyamide (2) that targets a different DNA sequence is included as a control.
Suppression of androgen receptor-mediated gene expression by a sequence-specific DNA-binding polyamide.
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View SamplesAnalysis of dexamethasone-stimulated A549 lung adenocarcinoma epithelial cells treated with a glucocorticoid response (GR) element (GRE) specific DNA binding polyamide. Polyamide designed to target the sequence 5'-WGWWCW-3' and disrupt GR-mediated gene expression. Effects of the GR antagonist mifepristone also examined.
Repression of DNA-binding dependent glucocorticoid receptor-mediated gene expression.
Cell line
View SamplesTranscription mediated by hypoxia inducible factor (HIF-1) contributes to tumor angiogenesis and metastasis but is also involved in the activation of cell-death pathways and normal physiological processes. Given the complexity of HIF-1 signaling it could be advantageous to target a subset of HIF-1 effectors rather than the entire pathway. We compared the genome-wide effects of three molecules that each interfere with the HIF-1-DNA interaction: a polyamide targeted to the hypoxia response element (HRE), siRNA targeted to HIF-1, and echinomycin, a DNA binding natural product with a similar but less specific sequence preference to the polyamide. The polyamide affects a subset of hypoxia-induced genes that are consistent with the binding site preferences of the polyamide. For comparison, siRNA targeted to HIF-1 and echinomycin each affect the expression of nearly every gene induced by hypoxia. Remarkably, the total number of genes affected by either polyamide or HIF-1 siRNA over a range of thresholds is comparable. The data shows how polyamides can be used to affect a subset of a pathway regulated by a transcription factor. In addition, this study offers a unique comparison of three complementary approaches towards exogenous control of endogenous gene expression.
Modulating hypoxia-inducible transcription by disrupting the HIF-1-DNA interface.
No sample metadata fields
View SamplesTo determine whether the polyamide-Chl conjugate 1R-Chl would cause similar changes in global gene expression in K562 cells, affymetrix gene chip analysis was performed using 1R-Chl. Through class comparison analysis, 1R-Chl affected the levels of transcription and genes of interest were determined.
Small molecules targeting histone H4 as potential therapeutics for chronic myelogenous leukemia.
Sex, Age, Disease
View SamplesLymphoblast cells from a patient with Freidriech's Ataxia were incubated with pyrrole-imidazole polyamides targeted to the GAA triplet repeat in the intron 1. The polyamides were shown in cell culture to increase levels of endogenous frataxin mRNA. A normal sibling derived lymphoblast cell line was used as a control.
DNA sequence-specific polyamides alleviate transcription inhibition associated with long GAA.TTC repeats in Friedreich's ataxia.
No sample metadata fields
View SamplesWe recently reported the scalable in vitro production of functional stem cell-derived cells. Here we extend this approach to generate SC- cells from Type 1 diabetic patients (T1D), a cell type that is destroyed during disease progression and has not been possible to extensively study. These cells express cell markers, respond to glucose both in vitro and in vivo, prevent alloxan-induced diabetes in mice, and respond to anti-diabetic drugs. Furthermore, we use an in vitro disease model to demonstrate the cells respond to different forms of cell stress. Using these assays, we find no major differences in T1D SC- cells compared to SC- cells derived from non-diabetic patients (ND). These results show that T1D SC- cells can be used for the treatment of diabetes, drug screening, and the study of cell biology.
Generation of stem cell-derived β-cells from patients with type 1 diabetes.
Specimen part
View SamplesPersons with Down syndrome (DS) exhibit low muscle strength that significantly impairs their physical functioning. The Ts65Dn mouse model of DS also exhibits muscle weakness in vivo and may serve as a useful model to examine potential factors responsible for DS-associated muscle dysfunction. Therefore, the purpose of this experiment was to directly assess skeletal muscle function in the Ts65Dn mouse and to reveal potential mechanisms of DS-associated muscle weakness. Soleus muscles were harvested from anesthetized male Ts65Dn and wild-type (WT) colony controls. In vitro muscle contractile experiments revealed normal force generation of unfatigued Ts65Dn soleus, but a 12% reduction in force was observed in Ts65Dn muscle during recovery following fatiguing contractions compared to WT muscle (p<0.05). Oxidative stress may contribute to DS-related pathologies, including muscle weakness, which may be the result of overexpression of chromosome 21 genes (e.g., copper-zinc superoxide dismutase (SOD1)). SOD1 expression was 25% higher (p<0.05) in Ts65Dn soleus compared to WT muscle but levels of other antioxidant proteins were unchanged. Lipid peroxidation (4-hydroxynoneal) was unaltered in Ts65Dn muscle although protein carbonyls were 20% greater compared to muscle of WT animals (p<0.05). Cytochrome c oxidase expression was reduced 22% in Ts65Dn muscle, suggesting a limitation in mitochondrial function may contribute to post-fatigue muscle weakness. Microarray analysis of Ts65Dn soleus revealed alteration of numerous cellular pathways including: proteolysis, glucose and fat metabolism, neuromuscular transmission, and ATP biosynthesis. In summary, the Ts65Dn mouse displays evidence of muscle dysfunction, and the potential role of mitochondria and oxidative stress warrants further investigation.
Functional and biochemical characterization of soleus muscle in Down syndrome mice: insight into the muscle dysfunction seen in the human condition.
Sex, Age, Specimen part
View SamplesFeeding animals with either concentrates supplemented with vitamin E or alfalfa grazing has been proven to reduce the oxidative process that occurs in meat products. Indoor-kept lambs were fed a standard concentrate (n=7, C) or concentrate supplemented with vitamin E (n=7, VE) for 30 days before slaughtering all animals at 2224 kg of live weight. Simultaneously, 7 unweaned lambs grazed in alfalfa paddocks (ALF) with their dams. Global transcriptomic data of longissimus thoracis (LT) muscle and subcutaneous fat (SF) with the Affymetrix Ovine Gene 1.1 microarray was used. In LT muscle when ALF group was compared with C group, were identified 41 genes differentially expressed. Among these genes 32 were down- regulated and 9 were up- regulated. Meanwhile when VE treatment was compared with C group were identified a total of 29 genes, 26 were down- regulated and 3 genes were up- regulated. In SF when ALF treatment was compared with C, were identified only 4 genes differentially expressed, all of them up-regulated in ALF group. Meanwhile when VE treatment was compared with C group, were identified a total of 330 genes. Among them, 295 genes were up- regulated and 35 were down- regulated. In LT muscle the clusters corresponding to gene expression profiles from treatments ALF, C and VE were clearly separated from each other. In SF, ALF group, overlap with VE and C treatments, however, VE and C clearly were separate in different clusters. These differentially expressed genes were selected for a functional analysis by using DAVID. In LT muscle some of the identified significant biological processes were catabolic and lipid process (down-regulated, except CPT1B) (CPT1B, PLA2G16, SPSB1, LRTOMT, PLCD4, FBXO9, CNBP and CYP27A1) and muscle organ differentiation (down-regulated) (CPT1B, MYOD1, MYLK2 and MSTN) in ALF; whereas intracellular signaling cascade (IGF1R, DEF8, AKAP7 and CISH) was down-regulated. In SF, vitamin E supplementation had an important effect; most of the genes were up-regulated. DAVID analysis showed that biosynthesis lipid pathway was the most represented with 20 genes, such as EBP, MVD, CYP51A1, DHCR7, HMGCS1, LSS and FDFT1 implicated in cholesterol synthesis. Further exploration of the links between these genes and vitamin E will lead to a better understanding of how vitamin E affects the oxidative process that occurs in meat products.
Genome-wide expression profiling in muscle and subcutaneous fat of lambs in response to the intake of concentrate supplemented with vitamin E.
Sex, Treatment
View SamplesThe generation of insulin-producing pancreatic cells from stem cells in vitro would provide an unprecedented cell source for drug discovery and cell transplantation therapy in diabetes. However, insulin-producing cells previously generated from human pluripotent stem cells (hPSC) lack many functional characteristics of bona fide cells. Here we report a scalable differentiation protocol that can generate hundreds of millions of glucose-responsive cells from hPSC in vitro. These stem cell derived cells (SC) express markers found in mature cells, flux Ca2+ in response to glucose, package insulin into secretory granules and secrete quantities of insulin comparable to adult cells in response to multiple sequential glucose challenges in vitro. Furthermore, these cells secrete human insulin into the serum of mice shortly after transplantation in a glucose-regulated manner, and transplantation of these cells ameliorates hyperglycemia in diabetic mice.
Generation of functional human pancreatic β cells in vitro.
Specimen part, Cell line
View SamplesRationale: Lipopolysaccharide (LPS) is ubiquitous in the environment. Inhalation of LPS has been implicated in the pathogenesis and/or severity of several lung diseases, including pneumonia, chronic obstructive pulmonary disease and asthma. Alveolar macrophages are the main resident leukocytes exposed to inhaled antigens. Objectives: To obtain insight into which innate immune pathways become activated within human alveolar macrophages upon exposure to LPS in vivo.
Gene expression profiles in alveolar macrophages induced by lipopolysaccharide in humans.
Sex, Specimen part, Treatment, Subject
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