Histone deacetylase 3 (HDAC3) is an epigenome-modifying enzyme that is required for normal mouse development and tissue-specific functions. In vitro, HDAC3 protein itself has minimal enzyme activity, but gains its histone deacetylation function from stable association with the conserved deacetylase activation domain (DAD) contained in nuclear receptor corepressors NCOR1 and SMRT. Here we show that HDAC3 enzyme activity is undetectable in mice bearing point mutations in the DAD of both NCOR1 and SMRT (NS-DADm), despite normal levels of HDAC3 protein. Local histone acetylation is increased, and genomic HDAC3 recruitment is reduced though not abrogated. Remarkably, the NS-DADm mice are born and live to adulthood, whereas genetic deletion of HDAC3 is embryonic lethal. These findings demonstrate that nuclear receptor corepressors are required for HDAC3 enzyme activity in vivo, and suggest that a deacetylase-independent function of HDAC3 may be required for life.
Nuclear receptor co-repressors are required for the histone-deacetylase activity of HDAC3 in vivo.
Specimen part, Time
View SamplesWe report the hepatic gene expression changes in NCOR and SMRT DADm-mutated mice.
Nuclear receptor co-repressors are required for the histone-deacetylase activity of HDAC3 in vivo.
Specimen part, Time
View SamplesMouse trophoblast stem cells were treated for 48 hours with two different stealth ds-siRNA against Elts2 and expression compared to samples treated with Invitrogen's mediumGC control and to no treatment samples.
Elf5 and Ets2 maintain the mouse extraembryonic ectoderm in a dosage dependent synergistic manner.
Specimen part
View SamplesAnalysis of estrogen receptor (ER)-positive MCF7 cell total RNA expression and polysome-assiciated RNA expression following treatment with estradiol (E2) and vehicle (etoh).
Estrogen coordinates translation and transcription, revealing a role for NRSF in human breast cancer cells.
Cell line
View SamplesUterine leiomyomata, or fibroids, are benign tumors of the uterine myometrium that significantly affect up to 30% of reproductive-age women. Despite being the primary cause of hysterectomy in the United States, accounting for up to 200,000 procedures annually, the etiology of leiomyoma remains largely unknown. Due to the lack of an effective medicinal therapy for these tumors, this disease continues to have a tremendous negative impact on womens health. As a basis for understanding leiomyoma pathogenesis and identifying targets for pharmacotherapy, we conducted transcriptional profiling of leiomyoma and unaffected myometrium from humans and Eker rats, the best characterized preclinical model of leiomyoma. A global comparison of mRNA from leiomyoma versus myometrium in human and rat identified a highly significant overlap of dysregulated gene expression in leiomyoma. An unbiased pathway analysis using a method of gene set enrichment based on the Sigpathway algorithm detected the mammalian target of rapamycin (mTOR) pathway as one of the most highly upregulated pathways in both human and rat tumors. Activation of this pathway was confirmed in both human and rat leiomyomata at the protein level via Western. Inhibition of mTOR in female Eker rats with the rapamycin analog WAY-129327 for 2 weeks decreased mTOR signaling and cell proliferation in tumors, and treatment for 4 months significantly decreased tumor incidence, multiplicity and size. These results identify dysregulated mTOR signaling as a component of leiomyoma etiology across species and directly demonstrate the dependence of these tumors on mTOR signaling for growth in the Eker rat. Modulation of this pathway warrants additional investigation as a potential therapy for uterine leiomyoma.
Comparison of human and rat uterine leiomyomata: identification of a dysregulated mammalian target of rapamycin pathway.
No sample metadata fields
View SamplesPurpose: The ability to rationally manipulate the transcriptional states of cells would be of great use in medicine and bioengineering. We have developed a novel algorithm, NetSurgeon, which utilizes genome-wide gene regulatory networks to identify interventions that force a cell toward a desired expression state. Results: We used NetSurgeon to select transcription factor deletions aimed at improving ethanol production in S. cerevisiae cultures that are catabolizing xylose. We reasoned that interventions that move the transcriptional states of cells utilizing xylose toward the fermentative state typical of cells that are producing ethanol rapidly (while utilizing glucose) might improve xylose fermentation. Some of the interventions selected by NetSurgeon successfully promoted a fermentative transcriptional state in the absence of glucose, resulting in strains with a 2.7-fold increase in xylose import rates, a 4-fold improvement in xylose integration into central carbon metabolism, or a 1.3-fold increase in ethanol production rate. Conclusions: We conclude by presenting an integrated model of transcriptional regulation and metabolic flux that will enable future metabolic engineering efforts aimed at improving xylose fermentation to prioritize functional regulators of central carbon metabolism. Overall design: Mutant and wildtype S. cerevisiae cells were put into 48 hour aerobic batch fermentations of synthetic complete medium supplmented with 2% glucose and 5% xylose and culture samples were taken at 4 hours and 24 hours for transcriptional profiling performed by RNA-Seq analysis. In addition, wildtype S. cerevisiae cells were grown in various single carbon sources for 12 hours and culture samples were taken for transcriptional profiling performed by RNA-Seq analysis.
Model-based transcriptome engineering promotes a fermentative transcriptional state in yeast.
Subject
View SamplesFew studies have investigated heterogeneity of selection response in replicate lines subjected to equivalent selection. We developed 4 replicate lines of mice based on high levels of voluntary wheel running (high runner or HR lines) while also maintaining 4 non-selected control lines. This led to the unexpected discovery of the HR mini-muscle (HRmini) phenotype, recognized by a 50% reduction in hindlimb muscle mass, which became fixed in 1 of the 4 HR selected lines.
Gene expression profiling of gastrocnemius of "minimuscle" mice.
Sex, Specimen part
View SamplesTight regulation of hematopoietic stem cell (HSC) homeostasis is essential for life-long hematopoiesis, for preventing blood cancers and for averting bone marrow failure. The underlying mechanisms are incompletely understood. Here, we identify production of inositol-tetrakisphosphate (IP4) by inositoltrisphosphate 3-kinase B (ItpkB) as essential for HSC quiescence and function. Young ItpkB-/- mice accumulated phenotypic HSC and showed extramedullary hematopoiesis. ItpkB-/- HSC were less quiescent and proliferated more than wildtype controls. They downregulated quiescence and stemness associated mRNAs, but upregulated activation, oxidative metabolism, protein synthesis and lineage associated transcripts. Although they showed no significant homing defects, ItpkB-/- HSC had a severely reduced competitive long-term repopulating potential. Aging ItpkB-/- mice lost hematopoietic stem and progenitor cells and died with severe anemia. Wildtype HSC normally repopulated ItpkB-/- hosts, incidating a HSC-intrinsic ItpkB requirement. ItpkB-/- HSC had reduced cobblestone-area forming cell activity in vitro and showed increased stem-cell-factor activation of the phosphoinositide 3-kinase (PI3K) effector Akt, reversed by exogenous provision of the known PI3K/Akt antagonist IP4. They also showed transcriptome changes consistent with hyperactive Akt/mTOR signaling. Thus, we propose that ItpkB ensures HSC quiescence by limiting cytokine-induced PI3K signaling in HSC. Overall design: For each of 3 replicate ItpkB-/- or wt samples, we enriched Lin- cells from BM of 4 pooled age-matched mice with Rapidspheres (Stemcell Technologies), FACS-sorted =10,000 LSK CD34-CD150+CD48-Flk2- LT-HSC into lysis buffer and prepared RNA with RNeasy Micro kits (Quiagen). RNA sequencing was done using an Illumina HISeq Analyzer 2000, Casava v1.8.2 genome analyzer pipeline, TopHat v1.4.1/Bowtie2 genome alignment and Partek v6.6 mRNA annotation software. Statistical analyses were done with edgeR (Bioconductor package), excluding genes with false discovery rates >0.15, fold-change magnitudes =1.4 and log2(counts per million) =4 to avoid undefined values and the poorly defined log fold-changes for low counts close to 0. Unsupervised clustering of 441 significantly changed genes was done with dChip using rank correlation and a centroid linkage method. Scatter plots were generated in Spotfire. GSEA was performed with gene set permutation, using gene sets from MSigDB (www.broadinstitute.org/gsea/msigdb/index.jsp) or manually curated from, excluding genes without HUGO approved symbols
IP3 3-kinase B controls hematopoietic stem cell homeostasis and prevents lethal hematopoietic failure in mice.
No sample metadata fields
View SamplesA phase I trial of a SRC kinase Inhibitor, dasatinib, in combination with paclitaxel and carboplatin in patients with advanced or recurrent ovarian cancer. Background: We conducted a phase I study of dasatinib, an oral SRC tyrosine kinase inhibitor, in combination with paclitaxel and carboplatin in advanced and recurrent epithelial ovarian cancer (EOC). Methods: The primary objective was to determine the maximum tolerated dose (MTD). Secondary objectives included toxicity, response rate (RR), pharmacokinetics and pharmacodynamics. Based on the 3+3 design, cohorts of 3-6 pts received paclitaxel 175 mg/m2 and carboplatin AUC 6 every three weeks with escalating doses of dasatinib (100, 120, 150 mg daily), followed by an 8 patient expansion cohort. Results: Twenty patients were enrolled between 06/07 and 12/09. The median age was 61 yrs (42-82) with a median of 2 prior regimens (0-6), and 71% had platinum-sensitive disease. There were 3-6 pts in each cohort, and 8 in the expansion cohort. Pharmacokinetics were observed over the first 2 cycles of therapy. One DLT was observed in the 100 mg dasatinib cohort (grade 3 myalgia. Other toxicities in all cycles included neutropenia (95% grade 3-4), thrombocytopenia (35% grade 3-4), and fatigue (10% grade 3). The RR was 45% (complete responses, 3/18(17%); partial responses, 5/18(28%)) and 56% (10/18) had stable disease. The PFS6-month actuarial estimate was 86%. The median PFS and OS were 7.8 and 16.2 months, respectively. Conclusions: Due to the high incidence of myelosuppression with subsequent cycles the recommended phase II dose is 150 mg daily of dasatinib in combination with paclitaxel and carboplatin. The combination was safe with evidence of clinical activity in advanced EOC.
A phase I trial of dasatinib, an SRC-family kinase inhibitor, in combination with paclitaxel and carboplatin in patients with advanced or recurrent ovarian cancer.
Subject
View SamplesInduced sputum is used to sample inflammatory cells, predominantly neutrophils and macrophages, from the airways of COPD patients. Our aim was to identify candidate genes associated with the degree of airflow obstruction and the extent of emphysema by expression profiling, and then to confirm these findings for selected candidates using specific PCR and protein analysis.
Induced sputum genes associated with spirometric and radiological disease severity in COPD ex-smokers.
Sex, Age
View Samples