The tumorigenesis capacity of MLL-AF4 alone is insufficient for causing leukemia. Based on the finding that an Flt3 gene mutation in the tyrosine kinase domain (TKD) was observed in approximately 15% of MLL leukemia, we investigated synergistic leukemogenesis effects of the two genes in vitro. In a mouse IL3-dependent cell line, 32Dc, the expression of MLL-AF4 and Flt3 TKD was induced using a lentiviral vector. We performed gene expression profiling in the MLL-AF4 and the Flt3 TKD+MLL-AF4 expressing 32Dc cells. The enhancement of Hox genes expression was not identified. However, instead, the expression of S100A6, which was involved in the control of cell proliferation, was synergistically enhanced in the presence of both MLL-AF4 and Flt3 TKD genes.
Multistep pathogenesis of leukemia via the MLL-AF4 chimeric gene/Flt3 gene tyrosine kinase domain (TKD) mutation-related enhancement of S100A6 expression.
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View SamplesBisphenol A (BPA) is a xenobiotic endocrine disrupting chemical. In vitro and in vivo studies indicated that BPA alters endocrine-metabolic pathways in adipose tissue increasing the risk of developing metabolic disorders. BPA effects on human adipocytes, specifically in children, are poorly investigated. To investigate in childhood the effect of exposure to BPA on metabolic disorders we analyzed in vitro the effects of environmentally relevant doses of BPA on gene expression of mature human adipocytes from pre-pubertal lean patients and on related physiological outcomes. Adipocytes from children were treated in vitro with BPA and gene expression was evaluated by qRT-PCR. Genome wide analyses were performed using GeneChip Human Gene 1.0 ST array. Lipid content in adipocytes was estimated by ORO staining and Triglyceride Quantification Kit. Secreted IL-1, in adipocytes culture medium, and insulin, in PANC-1 culture medium, were performed using ELISA assays. BPA was found to promote up-regulation of ER and ERR, and down-regulation of GPR30 expression modulating estrogen signaling and following a non-linear dose-response. Microarray data analysis demonstrated that BPA increases the gene expression of pro-inflammatory cytokines and lipid metabolism-related FABP4 and CD36 in adipocytes. PCSK1 resulted the most interesting gene being down-regulated by BPA thus impairing insulin production in pancreas. BPA promotes inflammation and lipid metabolism dysregulation in adipocytes from lean children. Moreover, PCSK1 can be a key gene in BPA action modulating insulin production. Exposure to BPA in childhood may be an important risk factor in developing obesity and metabolic disorders.
Bisphenol A effects on gene expression in adipocytes from children: association with metabolic disorders.
Specimen part, Treatment
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 SamplesEstrogen signaling pathway is critical for breast cancer development and has remained the major adjuvant therapeutic target for this disease. Tamoxifen has been used in clinic for many years to treat ER-positive breast cancer. However a great many (30%) suffer relapse due to drug resistance. In this study, the bromodomain inhibitor JQ1 was found to down-regulate ERalpha gene expression and have anti-tumor effect in cultured tamoxifen-resisant breast cancer cells.
An epigenomic approach to therapy for tamoxifen-resistant breast cancer.
Cell line, Treatment
View SamplesEmbryonic stem cells (ESCs) may be able to cure or alleviate the symptoms of various degenerative diseases. However, unresolved issues regarding apoptosis, maintaining function and tumor formation mean a prudent approach should be taken towards advancing ESCs into human clinical trials. The rhesus monkey provides the ideal model organism for developing strategies to prevent immune rejection and test the feasibility, safety and efficacy of ESC-based medical treatments. Transcriptional profiling of rhesus ESCs provides a foundation for future pre-clinical ESC research using non-human primates as the model organism. In this research we use microarray, immunocytochemistry, real-time and standard RT-PCR to characterize and transcriptionally profile rhesus monkey embryonic stem cells. We identify 367 rhesus monkey stemness genes, we demonstrate the high level (>85%) of conservation of rhesus monkey stemness gene expression across five different rhesus monkey embryonic stem cell lines, we demonstrate that rhesus monkey ESC lines maintain a pluripotent undifferentiated state over a wide range of Pou5f1 (Oct-4) expression levels and we compare rhesus monkey, human and murine stemness genes to identify the key mammalian stemness genes.
Transcriptional profiling of rhesus monkey embryonic stem cells.
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View SamplesMitochondria are vital due to their principal role in energy production via oxidative phosphorylation (OXPHOS)1. Mitochondria carry their own genome (mtDNA) encoding critical genes involved in OXPHOS, therefore, mtDNA mutations cause fatal or severely debilitating disorders with limited treatment options. 2. Clinical manifestations of mtDNA disease vary based on mutation type and heteroplasmy levels i.e. presence of mutant and normal mtDNA within each cell. 3,4. We evaluated therapeutic concepts of generating genetically corrected pluripotent stem cells for patients with mtDNA mutations. We initially generated multiple iPS cell lines from a patient with mitochondrial encephalomyopathy and stroke-like episodes (MELAS) caused by a heteroplasmic 3243A>G mutation and a patient with Leigh disease carrying a homoplasmic 8993T>G mutation (Leigh-iPS). Due to spontaneous mtDNA segregation in proliferating fibroblasts, isogenic MELAS iPS cell lines were recovered containing exclusively wild type (wt) mtDNA with normal metabolic function. As expected, all iPS cells from the patient with Leigh disease were affected. Using somatic cell nuclear transfer (SCNT; Leigh-NT1), we then simultaneously replaced mutated mtDNA and generated pluripotent stem cells from the Leigh patient fibroblasts. In addition to reversing to a normal 8993G>T, oocyte derived donor mtDNA (human haplotype D4a) in Leigh-NT1 differed from the original haplotype (F1a) at a additional 47 nucleotide sites. Leigh-NT1 cells displayed normal metabolic function compared to impaired oxygen consumption and ATP production in Leigh-iPS cells or parental fibroblasts (Leigh-fib). We conclude that natural segregation of heteroplasmic mtDNA allows the generation of iPS cells with exclusively wild type mtDNA. Moreover, SCNT offers mitochondrial gene replacement strategy for patients with homoplasmic mtDNA disease. Overall design: Duplicate cDNA libraries of fibroblasts from a Leigh patient and a MELAS patient, two sendai produced iPSC lines from the Leigh patient and three sendai produced iPSC lines from the MELAS patient, three fibroblasts lines produced by differentiating three iPS Leigh patient iPSC lines to fibroblasts, two somatic cell nuclear transfer produced NT-ESC lines from the Leigh patient, two fibroblast lines produced by differentiating two Leigh patient NT-ESC lines, four fibroblasts lines produced by differentiating four MELAS patient iPSC lines with the mutation to fibroblasts, four fibroblast lines produced by differentiating two IVF-ESC lines without mutated mtDNA genomes, four fibroblast lines produced by differentiating two somatic cell nuclear transfer NT-ESC lines without mutated mtDNA genomes, and four fibroblasts lines produced by differentiating two MELAS patient iPSC lines without the mutation to fibroblasts. The sequence reads were mapped to hg19 reference genome and hits that passed quality filters were analyzed for differential expression.
Metabolic rescue in pluripotent cells from patients with mtDNA disease.
No sample metadata fields
View SamplesThe androgen receptor (AR) is a key driver of prostate cancer (PC), even in the state of castration-resistant PC (CRPC), and frequently even after treatment with second-line hormonal therapies such as abiraterone and enzalutamide. The persistence of AR activity via both ligand-dependent and ligand-independent (including constitutively active AR splice variants) mechanisms highlights the unmet need for alternative approaches to block AR signaling in CRPC. We investigated the transcription factor GATA2 as a regulator of AR signaling and a novel therapeutic target in PC. We demonstrate that GATA2 directly promotes AR expression (both full-length and splice variant), resulting in a strong positive correlation between GATA2 and AR expression in PC (cell lines and patient specimens). Conversely, GATA2 expression is repressed by androgen and AR, suggesting a negative feedback regulatory loop that, upon androgen deprivation, derepresses GATA2 to contribute to AR overexpression in CRPC. Simultaneously, GATA2 is necessary for optimal transcriptional activity of AR (both full-length and splice variant). GATA2 co-localizes with AR and FOXA1 on chromatin to enhance recruitment of steroid receptor coactivators (SRCs) and formation of the transcriptional holocomplex. In agreement with these important functions, high GATA2 expression and transcriptional activity predicted for worse clinical outcome in PC patients. A GATA2 small molecule inhibitor suppressed the expression and transcriptional function of AR (both full-length and splice variant) and exerted potent anticancer activity against PC cell lines. We propose pharmacological inhibition of GATA2 as a first-in-field approach to target AR expression and function and improve outcomes in CRPC.
GATA2 facilitates steroid receptor coactivator recruitment to the androgen receptor complex.
Cell line
View SamplesWe previously found a short sleeper mutant, fmn, and identified its mutation in the dopamine transporter gene. In an attempt to discover additional sleep related genes in Drosophila, we carried out a microarray analysis comparing mRNA expression in heads of fmn and control flies and found differentially expressed genes.
The NMDA Receptor Promotes Sleep in the Fruit Fly, Drosophila melanogaster.
Sex, Specimen part
View SamplesThe Arabidopsis thaliana NAC domain transcription factor, VASCULAR-RELATED NAC-DOMAIN7 (VND7), acts as a key regulator of xylem vessel differentiation. In order to identify direct target genes of VND7, we performed global transcriptome analysis using Arabidopsis transgenic lines in which VND7 activity could be induced post-translationally. This analysis identified 63 putative direct target genes of VND7, which encode a broad range of proteins, such as transcription factors, IRREGULAR XYLEM proteins and proteolytic enzymes, known to be closely associated with xylem vessel formation. Recombinant VND7 protein binds to several promoter sequences present in candidate direct target genes: specifically, in the promoter of XYLEM CYSTEINE PEPTIDASE1, two distinct regions were demonstrated to be responsible for VND7 binding. We also found that expression of VND7 restores secondary cell wall formation in the fiber cells of inflorescence stems of nst1nst3 double mutants, as well as expression of NAC SECONDARY WALL THICKENING PROMOTING FACTOR3 (NST3, however, the vessel-type secondary wall deposition was observed only as a result of VND7 expression. These findings indicated that VND7 upregulates, directly and/or indirectly, many genes involved in a wide range of processes in xylem vessel differentiation, and that its target genes are partially different from those of NSTs.
VASCULAR-RELATED NAC-DOMAIN7 directly regulates the expression of a broad range of genes for xylem vessel formation.
Age, Specimen part, Treatment
View SamplesTAZ-deficient mice have the abnormalities in the lung development. We expect the comparison of the gene expression profiles of TAZ-deficient and wild-type lungs would reveal the underlying mechanisms.
Transcriptional coactivator with PDZ-binding motif is essential for normal alveolarization in mice.
No sample metadata fields
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