Goal of experiment: Identification of differentially expressed immune genes from male and female BWF1 lupus-prone mice. (Female incidence is higher than male--attempting to find sex hormone regulated genes that may contribute to this difference). Whole spleen was taken from pre-lupus (4 months old) BWF1 (females are lupus-prone) male and female mice. Preparation of cDNA. Double-stranded cDNA was synthesized from purified RNA. The first strand was synthesized by incubating 5 g of RNA with 100 pg/ml T7-(dT)24 primer (HPLC purified DNA primer sequence: 5-GGCCAGTGAATTGTAATACG ACTCACTATAGGGAGGCGG-(dT)24 -3 Genset Corp, San Diego, CA) at 70C for 10 minutes. Samples were incubated for 1 hour at 42C with the following mix: 1X first strand buffer, 10 mM dithiothreitol, 500 M each dNTP, 200 U SuperScript II in diethylpyrocarbonate (DEPC)-treated water up to 20 l. Second strand synthesis was performed by incubating the first strand with the following mix for 2 hours at 16C: 1X second strand reaction buffer, 200 M dntps, 10 U E. coli DNA ligase, 40 U E coli DNA Polymerase I, 2 U of E. coli RNase H up to 150 l with DEPC-treated water (all reagents were contained in SuperScript Choice System for cDNA Synthesis, Invitrogen). A phenol/chloroform extraction was performed on the ds-cDNA preparation before biotin-labeled cRNA was generated. Synthesis and fragmentation of biotin-labeled cRNA (in vitro transcription). The ENZO BioArrayTM HighYieldTM RNA Transcript Labeling Kit (T7) (Enzo diagnostics, Inc., Farmingdale, NY) was used to produce large amounts of hybridizable biotin-labeled RNA targets by in vitro transcription from the ds-cDNA. The following mix was incubated at 37C for 5 hours: 1 g of ds-cDNA, 1X HY reaction buffer, 1X biotin labeled ribonucleotides, 1X dithiothreitol, 1X T7 RNA Polymerase. Biotin-labeled cRNA was run over RNeasy spin columns (Qiagen), quantified, and run on an agarose gel to visualize the size distribution of labeled transcripts. Twenty micrograms of cRNA was incubated with 1X fragmentation buffer for 35 minutes at 94C. (5X fragmentation buffer: 200 mM Tris-acetate, pH 8.1, 500 mM KOAc, 150 mM MgOAc). After fragmentation, the samples were stored at -20C until the hybridization was performed. Sample hybridization. Oligonucleotide microarrays (MGU74v2 A, B, and C GeneChip probe arrays; Affymetrix) were hybridized with labeled cRNA derived from spleens from individual mice. For each array,15 g of fragmented cRNA was mixed with a hybridization cocktail consisting of 1X hybridization buffer (2X hybridization buffer: 100 mM MES, 1 M [Na+], 20 mM EDTA, 0.01% Tween), 0.5 mg/ml acetylated BSA (Invitrogen), 0.1 mg/ml herring sperm DNA (Promega), and water (BioWhittaker) up to 300 l). Biotin labeled cRNA transcripts of the E. coli and P1 bacteriophage genes, BioB, bioC, bioD, and cre (GeneChip Eukaryotic Hybridization control kit, Affymetrix) were spiked into each hybridization mix at 1.5, 5, 25, and 100 pM to evaluate sample hybridization efficiency for each array. The hybridization cocktail was heated to 99C and then 45C for 5 minutes each before it was centrifuged to remove any insoluble material. The array was equilibrated to room temperature, moistened with 1X hybridization buffer, and incubated for 10 minutes at 45C with rotation. After incubation, the buffer solution was removed from the array. The array was filled with 300 l of the hybridization cocktail, placed in a rotisserie box in a 45C oven, and incubated for 16 hours while rotating at 60 rpm. Washing and staining of array. The hybridization cocktail was removed and the GeneChip Fluidics Station 400 (Affymetrix) with Microarray Suite software (Affymetrix) was used to wash and stain the probe arrays with the following protocol: 10 cycles of 2 mixes/cycle with wash buffer A at 25C, 4 cycles of 15 mixes/cycle with wash buffer B at 50C, 30 minute incubation with staining solution at 25C, 10 cycles of 4 mixes/cycle with wash buffer A at 25C. Wash buffer A -- non-stringent wash buffer (6X sodium chloride sodium phosphate + ethylenediaminetetraacetic acid (SSPE), 0.01% Tween-20). (20X SSPE: 3 M NaCl, 0.2 M NaH2PO4, 0.02 EDTA) (BioWhittaker). Wash buffer B stringent wash buffer (100mM MES, 0.1 M [Na+], 0.1% Tween 20). Staining solution (1X 2-(N-Morpholino)ethanesulfonic Acid (MES) stain buffer, 2 mg/ml acetylated BSA, 10 g/ml Streptavidin Phycoerythrin (SAPE), and water up to 600 l). (12X MES stain buffer: 1.22 M MES, 0.89 M [Na+]). Analysis. After staining, the probe arrays were scanned using the GeneChip 3000 Scanner (Affymetrix) with Microarray Suite software (Affymetrix). Technical and assay variation between arrays was corrected for by multiplying or dividing the overall intensity of each array by a scaling factor so that the overall intensity of each array was equivalent to facilitate comparison analysis.
Identification of candidate genes that influence sex hormone-dependent disease phenotypes in mouse lupus.
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View SamplesComparative analysis can provide important insights into complex biological systems. As demonstrated in the accompanying paper, Translating Ribosome Affinity Purification (TRAP), permits comprehensive studies of translated mRNAs in genetically defined cell populations following physiological perturbations.
Application of a translational profiling approach for the comparative analysis of CNS cell types.
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View SamplesNdn is a candidate metastasis suppressor gene that has been reported to regulate transcription.
Necdin is a breast cancer metastasis suppressor that regulates the transcription of c-Myc.
Cell line
View SamplesWe have developed mouse models for serous epithelial ovarian cancer (SEOC) based on conditional inactivation of p53 and Rb tumor suppression (RB-TS) in combination with or without Brca1/2 following injection of adenovirus expressing Cre recombinase into the ovarian bursa. These models develop metastatic (Stage IV) disease with key histopathological features resembling human SEOC.To determine whether these mouse tumors resemble human SEOC at the molecular level, we conducted global gene expression analysis on 27 ovarian carcinomas and 3 pooled normal ovarian surface epithelium samples (single epithelial layer isolated from ovarian surface by laser capture).
Perturbation of Rb, p53, and Brca1 or Brca2 cooperate in inducing metastatic serous epithelial ovarian cancer.
Specimen part
View SamplesWe previously generated genetically engineered mouse (GEM) models based on perturbation of Tp53, Rb with or without Brca1 or Brca2 that develop serous epithelial ovarian cancer (SEOC) closely resembling the human disease on histologic and molecular levels. We have adapted these GEM models to orthotopic allografts that uniformly develop tumors with short latency in immunocompetent recipients and are ideally suited for routine preclinical studies. To monitor passaged tumors at the molecular level, we analyzed transcriptional profiles of a set of primary SEOC and matching derived passaged tumors. We have merged this dataset with previously published ( doi: 10.1158/0008-5472.CAN-11-3834; PMID 22617326) dataset of murine primary ovarian tumors from our GEM models (GSE46169) and merged and compared them to expression profiles of human dataset published previously (doi: 10.1038/nature10166).
Pathway-specific engineered mouse allograft models functionally recapitulate human serous epithelial ovarian cancer.
Specimen part
View SamplesBackground: Identifying individuals at heightened cardiovascular risk is a priority for reducing the global burden of cardiovascular disease. Aspirin is widely used to prevent cardiovascular events, though with variable results. Therefore, we hypothesized that aspirin exposure would reveal novel biological pathways relevant to the development of cardiovascular events. Methods: We administered aspirin, followed by peripheral blood RNA microarray profiling, in a discovery cohort of healthy volunteers (n = 50, HV1), followed by two validation cohorts of healthy volunteers (n = 53, HV2) or outpatient cardiology (OPC, n = 25) patients, in conjunction with platelet function testing with the platelet functions score (PFS, HV1 and HV2) or the VerifyNow Asprin (VN, OPC) test. Sets of coexpressed genes, or Factors were identified via Bayesian sparse factor analysis and associated with platelet function in HV1 and validated in HV2 and OPC. Validated factors were associated with death/MI in observational (n = 191) and case:control (n = 447) patient cohorts with available RNA data collected at the time of cardiac catheterization. Results: Factor analysis yielded 20 Factors, of which one, Factor 14, contained 60 genes and was associated with PFS in HV1 (r = -0.31, p-value = 0.03). Factor 14 was associated with platelet function with the same strength and direction in HV2 (r = -0.34, p-value = 0.02) and OPC (one-sided p-value for aspirin resistant vs. aspirin sensitive = 0.046), thus validating the association. Factor 14 was associated with death/MI in the two patient cohorts, odds ratio (OR) = 1.2, 95% CI [1.02-1.4], p-value = 0.01 and hazard ratio = 1.5, [1.2-1.9], p = 0.001, respectively, independent of known cardiovascular risk factors (combined OR = 1.2, CI = [1.02, 1.4], p = 0.03). Factor 14 and the expression of the Factor 14 transcript most highly correlative of PFS, ITGA2B, improved reclassification compared to traditional risk factors (category-free net reclassification index = 31% and 37%, p 0.0002 for both). Conclusions: By challenging humans subjects with aspirin, a medication used for cardiovascular risk reduction, we elucidated genes and pathways that may underlie platelet function and mechanisms responsible for cardiovascular death/MI.
Aspirin insensitive thrombophilia: transcript profiling of blood identifies platelet abnormalities and HLA restriction.
Specimen part
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