The functions of key oncogenic transcription factors independent of context have not been fully delineated despite our richer understanding of the genetic alterations in human cancers. The MYC ...oncogene, which produces the Myc transcription factor, is frequently altered in human cancer and is a major regulatory hub for many cancers. In this regard, we sought to unravel the primordial signature of Myc function by using high-throughput genomic approaches to identify the cell-type independent core Myc target gene signature. Using a model of human B lymphoma cells bearing inducible MYC, we identified a stringent set of direct Myc target genes via chromatin immunoprecipitation (ChIP), global nuclear run-on assay, and changes in mRNA levels. We also identified direct Myc targets in human embryonic stem cells (ESCs). We further document that a Myc core signature (MCS) set of target genes is shared in mouse and human ESCs as well as in four other human cancer cell types. Remarkably, the expression of the MCS correlates with MYC expression in a cell-type independent manner across 8,129 microarray samples, which include 312 cell and tissue types. Furthermore, the expression of the MCS is elevated in vivo in Eμ-Myc transgenic murine lymphoma cells as compared with premalignant or normal B lymphocytes. Expression of the MCS in human B cell lymphomas, acute leukemia, lung cancers or Ewing sarcomas has the highest correlation with MYC expression. Annotation of this gene signature reveals Myc's primordial function in RNA processing, ribosome biogenesis and biomass accumulation as its key roles in cancer and stem cells.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Chronic obstructive pulmonary disease (COPD) is a prevalent smoking-related disease for which no disease-altering therapies currently exist. As dysregulated TGF-β signaling associates with lung ...pathology in patients with COPD and in animal models of lung injury induced by chronic exposure to cigarette smoke (CS), we postulated that inhibiting TGF-β signaling would protect against CS-induced lung injury. We first confirmed that TGF-β signaling was induced in the lungs of mice chronically exposed to CS as well as in COPD patient samples. Importantly, key pathological features of smoking-associated lung disease in patients, e.g., alveolar injury with overt emphysema and airway epithelial hyperplasia with fibrosis, accompanied CS-induced alveolar cell apoptosis caused by enhanced TGF-β signaling in CS-exposed mice. Systemic administration of a TGF-β-specific neutralizing antibody normalized TGF-β signaling and alveolar cell death, conferring improved lung architecture and lung mechanics in CS-exposed mice. Use of losartan, an angiotensin receptor type 1 blocker used widely in the clinic and known to antagonize TGF-β signaling, also improved oxidative stress, inflammation, metalloprotease activation and elastin remodeling. These data support our hypothesis that inhibition of TGF-β signaling through angiotensin receptor blockade can attenuate CS-induced lung injury in an established murine model. More importantly, our findings provide a preclinical platform for the development of other TGF-β-targeted therapies for patients with COPD.
Objective To evaluate the impact of two different luteal phase support protocols on gene expression of extracellular matrix (ECM) proteins and adhesion molecules in the human endometrium. Design ...Eighty-four ECM protein and adhesion molecule genes were analyzed using array-based reverse-transcription polymerase chain reaction. Setting Academic hospital. Patient(s) Nine oocyte donors. Intervention(s) Endometrial biopsies were obtained on the day of oocyte retrieval (group I) and 3–5 days later (group II) after randomization into 3 groups. Group IIa had no luteal phase support, group IIb had luteal support with micronized progesterone, and group IIc had luteal support with progesterone plus 17β-estradiol. Main Outcome Measure(s) Gene expression profiles in relation to different types of luteal phase support protocols. Result(s) Compared with the day of retrieval (group I), 24 genes were significantly up-regulated (4 in group IIa, 14 in group IIb, 22 in group IIc) and 14 genes were down-regulated (5 in group IIa, 2 in group IIb, 10 in group IIc) on day 3–5 ( P <.05). In the luteal support group, up- regulation occurred predominantly in genes encoding for matrix metallopeptidases (MMP10, MMP3, MMP9), integrins (ITGA3, ITGA5, ITGB3, ITGB4), and laminin (LAMB3). In contrast, the most significant suppression was documented in genes encoding for catenin-D2, collagen-11A1, and the laminins (LAMA1 and LAMA3). Significant changes between groups IIb and IIc were also observed in 9 genes. Conclusion(s) Luteal phase support following controlled ovarian stimulation has a profound impact on the ECM pathway targeted genes.
A population of stromal cells that retains osteogenic capacity in adult bone (adult bone stromal cells or aBSCs) exists and is under intense investigation. Mice heterozygous for a null allele of ...prkar1a (Prkar1a⁺/⁻), the primary receptor for cyclic adenosine monophosphate (cAMP) and regulator of protein kinase A (PKA) activity, developed bone lesions that were derived from cAMP-responsive osteogenic cells and resembled fibrous dysplasia (FD). Prkar1a⁺/⁻ mice were crossed with mice that were heterozygous for catalytic subunit Cα (Prkaca⁺/⁻), the main PKA activity-mediating molecule, to generate a mouse model with double heterozygosity for prkar1a and prkaca (Prkar1a⁺/⁻Prkaca⁺/⁻). Unexpectedly, Prkar1a⁺/⁻Prkaca⁺/⁻ mice developed a greater number of osseous lesions starting at 3 months of age that varied from the rare chondromas in the long bones and the ubiquitous osteochondrodysplasia of vertebral bodies to the occasional sarcoma in older animals. Cells from these lesions originated from an area proximal to the growth plate, expressed osteogenic cell markers, and showed higher PKA activity that was mostly type II (PKA-II) mediated by an alternate pattern of catalytic subunit expression. Gene expression profiling confirmed a preosteoblastic nature for these cells but also showed a signature that was indicative of mesenchymal-to-epithelial transition and increased Wnt signaling. These studies show that a specific subpopulation of aBSCs can be stimulated in adult bone by alternate PKA and catalytic subunit activity; abnormal proliferation of these cells leads to skeletal lesions that have similarities to human FD and bone tumors.
Respiratory dysfunction is a major contributor to morbidity and mortality in aged populations. The susceptibility to pulmonary insults is attributed to "low pulmonary reserve", ostensibly reflecting ...a combination of age-related musculoskeletal, immunologic and intrinsic pulmonary dysfunction.
Using a murine model of the aging lung, senescent DBA/2 mice, we correlated a longitudinal survey of airspace size and injury measures with a transcriptome from the aging lung at 2, 4, 8, 12, 16 and 20 months of age. Morphometric analysis demonstrated a nonlinear pattern of airspace caliber enlargement with a critical transition occurring between 8 and 12 months of age marked by an initial increase in oxidative stress, cell death and elastase activation which is soon followed by inflammatory cell infiltration, immune complex deposition and the onset of airspace enlargement. The temporally correlative transcriptome showed exuberant induction of immunoglobulin genes coincident with airspace enlargement. Immunohistochemistry, ELISA analysis and flow cytometry demonstrated increased immunoglobulin deposition in the lung associated with a contemporaneous increase in activated B-cells expressing high levels of TLR4 (toll receptor 4) and CD86 and macrophages during midlife. These midlife changes culminate in progressive airspace enlargement during late life stages.
Our findings establish that a tissue-specific aging program is evident during a presenescent interval which involves early oxidative stress, cell death and elastase activation, followed by B lymphocyte and macrophage expansion/activation. This sequence heralds the progression to overt airspace enlargement in the aged lung. These signature events, during middle age, indicate that early stages of the aging immune system may have important correlates in the maintenance of tissue morphology. We further show that time-course analyses of aging models, when informed by structural surveys, can reveal nonintuitive signatures of organ-specific aging pathology.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Using cDNA microarrays we have investigated gene expression patterns in brain regions of patients with schizophrenia. A cDNA neuroarray, comprised of genes related to brain function, was used to ...screen pools of samples from the cerebellum and prefrontal cortex from a matched set of subjects, and middle temporal gyrus, from a separate subject cohort. Samples of cerebellum and prefrontal cortex from neuroleptic naive patients were also included. Genes that passed a 3% reproducibility criterion for differential expression in independent experiments included 21 genes for drug-treated patients and 5 genes for drug-naive patients. Of these 26 genes, 10 genes were increased and 16 were decreased. Many of the differentially expressed genes were related to synaptic signaling and proteolytic functions. A smaller number of these genes were also differentially expressed in the middle temporal gyrus. The five genes that were differentially expressed in two brain regions from separate cohorts are: tyrosine 3-monooxygenase/tryptophan 5-monooxygenase activation protein, eta polypeptide; sialyltransferase; proteasome subunit, alpha type 1; ubiquitin carboxyl-terminal esterase L1; and solute carrier family 10, member 1. Identification of patterns of changes in gene expression may lead to a better understanding of the pathophysiology of schizophrenia disorders.
We hypothesize that pulmonary arterial hypertension (PAH)-associated genes identified by expression profiling of peripheral blood mononuclear cells (PBMCs) from patients with idiopathic pulmonary ...arterial hypertension (IPAH) can also be identified in PBMCs from scleroderma patients with PAH (PAH-SSc). Gene expression profiles of PBMCs collected from IPAH (n = 9), PAH-SSc (n = 10) patients, and healthy controls (n = 5) were generated using HG_U133A_2.0 GeneChips and were processed by the RMA/GCOS_1.4/SAM_1.21 data analysis pipeline. Disease severity in consecutive patients was assessed by functional status and hemodynamic measurements. The expression profiles were analyzed using PAH severity-stratification, and identified candidate genes were validated with real-time polymerase chain reaction (PCR). Transcriptomics of PBMCs from IPAH patients was highly comparable with that of PMBCs from PAH-SSc patients. The PBMC gene expression patterns significantly correlate with right atrium pressure (RA) and cardiac index (CI), which are known predictors of survival in PAH. Array stratification by RA and CI identified 364 PAH-associated candidate genes. Gene ontology (GO) analysis revealed significant (Zscore > 1.96) alterations in angiogenesis genes according to PAH severity: matrix metalloproteinase 9 (MMP9) and vascular endothelial growth factor (VEGF) were significantly upregulated in mild as compared with severe PAH and healthy controls, as confirmed by real-time PCR. These data demonstrate that PBMCs from patients with PAH-SSc carry distinct transcriptional expression. Furthermore, our findings suggest an association between angiogenesis-related gene expression and severity of PAH in PAH-SSc patients. Deciphering the role of genes involved in vascular remodeling and PAH development may reveal new treatment targets for this devastating disorder.
1 Division of Pulmonary and Critical Care Medicine, Department of Medicine, Case Western Reserve University School of Medicine, Cleveland, Ohio; 2 Johns Hopkins University School of Medicine, 3 ...Division of Physiology, Department of Environmental Health Sciences, Johns Hopkins University Bloomberg School of Public Health, and 4 Division of Allergy and Clinical Immunology, Johns Hopkins University School of Medicine, Baltimore, Maryland; 5 Howard Hughes Medical Institute, Oklahoma Medical Research Foundation, Departments of Biochemistry and Molecular Biology and Pathology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma; and 6 Department of Medicine, University of Chicago Pritzker School of Medicine, Chicago, Illinois
Submitted 12 November 2008
; accepted in final form 6 April 2009
The coagulation system is central to the pathophysiology of acute lung injury. We have previously demonstrated that the anticoagulant activated protein C (APC) prevents increased endothelial permeability in response to edemagenic agonists in endothelial cells and that this protection is dependent on the endothelial protein C receptor (EPCR). We currently investigate the effect of APC in a mouse model of ventilator-induced lung injury (VILI). C57BL/6J mice received spontaneous ventilation (control) or mechanical ventilation (MV) with high (HV T ; 20 ml/kg) or low (LV T ; 7 ml/kg) tidal volumes for 2 h and were pretreated with APC or vehicle via jugular vein 1 h before MV. In separate experiments, mice were ventilated for 4 h and received APC 30 and 150 min after starting MV. Indices of capillary leakage included bronchoalveolar lavage (BAL) total protein and Evans blue dye (EBD) assay. Changes in pulmonary EPCR protein and Rho-associated kinase (ROCK) were assessed using SDS-PAGE. Thrombin generation was measured via plasma thrombin-antithrombin complexes. HV T induced pulmonary capillary leakage, as evidenced by significant increases in BAL protein and EBD extravasation, without significantly increasing thrombin production. HV T also caused significant decreases in pulmonary, membrane-bound EPCR protein levels and increases in pulmonary ROCK-1. APC treatment significantly decreased pulmonary leakage induced by MV when given either before or after initiation of MV. Protection from capillary leakage was associated with restoration of EPCR protein expression and attenuation of ROCK-1 expression. In addition, mice overexpressing EPCR on the pulmonary endothelium were protected from HV T -mediated injury. Finally, gene microarray analysis demonstrated that APC significantly altered the expression of genes relevant to vascular permeability at the ontology (e.g., blood vessel development) and specific gene (e.g., MAPK-associated kinase 2 and integrin-β 6 ) levels. These findings indicate that APC is barrier-protective in VILI and that EPCR is a critical participant in APC-mediated protection.
endothelial protein C receptor; mechanical stress; vascular barrier function; ventilator-induced lung injury
Address for reprint requests and other correspondence: P. M. Hassoun, Division of Pulmonary and Critical Care Medicine, 5501 Hopkins Bayview Circle, Baltimore, MD 21224 (e-mail: phassoun{at}jhmi.edu )
In cancer cells, cyclic AMP-dependent protein kinase (PKA) is secreted into the conditioned medium. This PKA, designated as extracellular protein kinase A (ECPKA), is markedly up-regulated in the ...sera of patients with cancer. The currently available tumor markers are based on the antigen determination method and lack specificity and sensitivity. Here, we present an ECPKA autoantibody detection method for a universal biomarker that detects cancer of various cell types. We tested sera from 295 patients with cancers of various cell types, 155 normal controls, and 55 patients without cancer. The specificity and sensitivity of this autoantibody enzyme immunoassay method were compared with the conventional antigen determination method by receiver-operating characteristic plots. In the sera, the presence of autoantibody directed against ECPKA was highly correlated with cancer. High anti-ECPKA autoantibody titers (frequency, 90%; mean titer, 3.0) were found in the sera of patients with various cancers, whereas low or negative titers (frequency, 12%; mean titer, 1.0) were found in the control group. The receiver-operating characteristic plot showed that autoantibody enzyme immunoassay exhibited 90% sensitivity and 88% specificity, whereas the enzymatic assay exhibited 83% sensitivity and 80% specificity. These results show that the autoantibody method distinguished between patients with cancer and controls better than the antigen method could. Our results show that autoantibody ECPKA is a universal serum biomarker for cancers of various cell types.
Background Myosin light chain kinase (MYLK) is a multifunctional protein involved in regulation of airway hyperreactivity and other activities relevant to asthma. Objective To determine the role of ...MYLK gene variants in asthma among African Caribbean and African American populations. Methods We performed association tests between single nucleotide polymorphisms (SNPs) in the MYLK gene and asthma susceptibility and total serum IgE concentrations in 2 independent, family-based populations of African descent. Previously we identified variants/haplotypes in MYLK that confer risk for sepsis and acute lung injury; we compared findings from our asthma populations to findings in the African American sepsis and acute lung injury groups. Results Significant associations between MYLK SNPs and asthma and total serum IgE concentrations were observed in the African Caribbean families: a promoter SNP (rs936170) in the smooth muscle form gave the strongest association ( P = .009). A haplotype including rs936170 corresponding to the actin-binding activity of the nonmuscle and smooth muscle forms was negatively associated with asthma (eg, decreased risk) in both the American ( P = .005) and Caribbean families ( P = .004), and was the same haplotype that conferred risk for severe sepsis ( P = .002). RNA expression studies on PBMCs and rs936170 suggested a significant decrease in MYLK expression among patients with asthma with this variant ( P = .025). Conclusion MYLK polymorphisms may function as a common genetic factor in clinically distinct diseases involving bronchial smooth muscle contraction and inflammation. Clinical implications Genetic variants in MYLK are significantly associated with both asthma and sepsis in populations of African ancestry.
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