Project description:MicroRNAs are small RNA species that regulate gene expression post-transcriptionally and are aberrantly expressed in many cancers including lymphoma. However, the role of microRNAs in the pathogenesis of multiple myeloma (MM) is poorly understood. We therefore elucidated the complete miRNome of purified tumor (CD138+) cells from 33 patients with MM, 5 patients with monoclonal gammopathy of undetermined significance (MGUS) and 9 disease controls. Unsupervised cluster analysis revealed that MM samples have a distinct microRNA expression profile. The majority of microRNAs aberrantly expressed in MM (109/129) were up-regulated. A comparison of these microRNAs with those aberrantly expressed in other B-cell and T-cell lymphomas revealed a surprising degree of similarity (~40%) suggesting the existence of a common lymphoma microRNA signature. We identified 39 microRNAs associated with the pre-malignant condition MGUS. Twenty-three (59%) of these were also aberrantly expressed in MM suggesting common microRNA expression events in MM progression. MM is characterized by multiple chromosomal abnormalities of varying prognostic significance. We identified specific microRNA signatures associated with the most common IgH translocations (t(4;14) and t(11;14)) and del(13q). Expression levels of these microRNAs were distinct between the genetic subtypes (by cluster analysis) and correctly predicted these abnormalities in >85% of cases using the support vector machine algorithm. Additionally, we identified microRNAs associated with light chain only myeloma, as well as IgG and IgA-type MM. Finally, we identified 32 microRNAs associated with event-free survival (EFS) in MM, ten of which were significant by univariate (logrank) survival analysis. In summary, this work has identified aberrantly expressed microRNAs associated with the diagnosis, pathogenesis and prognosis of MM, data which will prove an invaluable resource for understanding the role of microRNAs in this devastating disease. Plasma cells (CD138+) cells were purified from bone marrow samples of 33 patients with MM, 5 patients with monoclonal gammopathy of undetermined significance (MGUS) and 9 disease controls.

Project description:Background: Chronic obstructive pulmonary disease (COPD) is a heterogeneous disease characterized by varying degrees of emphysematous lung destruction and small airway disease, each with distinct effects on clinical outcomes. There is little known about how microRNAs contribute specifically to the emphysema phenotype. We examined how microRNA expression is altered with regional emphysema severity within the lung and how these microRNAs regulate disease-associated gene-expression networks. Results: We profiled microRNAs in different regions in the lung with varying degrees of emphysema from 6 smokers with COPD and 2 controls (8 regions x 8 lungs = 64 samples). 63 microRNAs (p<0.05) were altered with regional emphysema severity as quantified by mean linear intercept (Lm). MicroRNA and gene expression data were then integrated in the same samples. A subset of microRNAs, including miR-638, miR-30c, and miR-181d, correlated with many of their predicted gene targets, suggesting a role in regulating the gene networks that underlie emphysematous lung destruction. Modulating miR-638 expression in primary human lung fibroblasts recapitulated the alterations in its targeted gene-expression network associated with emphysema progression. Pathway analysis revealed that genes involved in oxidative stress and accelerated aging were affected by miR-638 knock-down in fibroblasts. Many miR-638 gene targets in these pathways were amongst those negatively correlated with miR-638 expression in emphysematous lung tissue. Conclusions: Our findings demonstrate that microRNAs are altered with regional emphysema severity and modulate disease-associated gene expression networks. Furthermore, miR-638 may regulate gene expression associated with the oxidative stress response and aging in emphysematous lung tissue and fibroblasts. Paired samples were obtained from 8 regions at regular intervals between the apex and base of each explanted lung from six patients with severe COPD and two donors. The degree of emphysematous destruction was quantified in one sample from each region by mean linear intercept (Lm), while microRNA expression was profiled in the adjacent sample from the same region using the NCode Version 3 microRNA microarrays (Invitrogen, Carlsbad, CA). After quality control 60 samples were used for the analysis.

Project description:Blood consists of different cell populations with distinct functions and correspondingly, distinct gene expression profiles. In this study, global miRNA expression profiling was performed across a panel of nine human immune cell subsets (neutrophils, eosinophils, monocytes, B cells, NK cells, CD4 T cells, CD8 T cells, mDCs and pDCs) to identify cell-type specific miRNAs. mRNA expression profiling was performed on the same samples, to determine if miRNAs specific to certain cell types down-regulated expression levels of their target genes. Six cell-type specific miRNAs (miR-143; neutrophil specific, miR-125; T cells and neutrophil specific, miR-500; monocytes and pDC specific, miR-150; lymphoid cells specific, miR-652 and miR-223; both myeloid cells specific) were negatively correlated with expression of their predicted target genes. These results were further validated using an independent cohort where similar immune cell subsets were isolated and profiled for both miRNA and mRNA expression. miRNAs negatively correlated with target gene expression in both cohorts were identified as candidates for miRNA-mRNA regulatory pairs and were used to construct a cell-type specific regulatory network. miRNA-mRNA pairs formed two distinct clusters in the network corresponding to myeloid (nine miRNAs) and lymphoid lineages (two miRNAs). Several myeloid specific miRNAs targeted common genes including ABL2, EIF4A2, EPC1 and INO80D; these common targets were enriched for genes involved in the regulation of gene expression (p < 9.0E-7). Those miRNA might therefore have significant further effect on gene expression by repressing the expression of genes involved in transcriptional regulation. The miRNA and mRNA expression profiles reported in this study form a comprehensive transcriptome database of various human blood cells and serve as a valuable resource for elucidating the role of miRNA mediated regulation in the establishment of immune cell identity. Nine cell subsets (CD16+CD66b+ Neutrophils, CD16-CD66b+ Eosinophils, CD14+ Monocytes, CD4+ T cells, CD8+ T cells, CD56+ NK cells, CD19+ B cells, CD123+ pDCs and CD11c+ mDCs) were isolated from healthy human blood and assessed for cell type purity by flow cytometry. Cell types were isolated from 5 pools of 5 healthy donors each, with the exception for monocytes, where 10 pools were used. RNA obtained from these purified populations were subsequently used for miRNA and mRNA expression profiling by Affymetrix GeneChip miRNA and HG-U133Plus2.0 microarrays.

Project description:The p53 homologue, p63, is critical for normal epidermal development. While overexpression of deltaNp63alpha has been reported in squamous cell cancers, the contribution of p63 to cancer pathogenesis remains unclear. We previously demonstrated that overexpressed deltaNp63alpha aberrantly maintains proliferation of primary epidermal keratinocytes under conditions that normally induce growth arrest and differentiation. To identify target genes impacted by dysregulated deltaNp63alpha that may contribute to squamous cancer development and progression, microarray analyses were performed. Herein we report that elevated deltaNp63alpha differentially regulates genes in primary mouse keratinocytes involved in a variety of cellular functions, including cell cycle regulation, differentiation, skin barrier formation and function, apoptosis, host defense/inflammation, adhesion, migration and invasion. Of note, multiple protease inhibitor mRNAs were coordinately downregulated under both proliferating and differentiating culture conditions. These downregulated genes include two serine protease inhibitors: maspin (serpinB5) and plasminogen activator inhibitor-2 (PAI-2; serpinB2), as well as a tissue inhibitor of metalloproteinase-3 (TIMP-3). Correspondingly, secreted levels of TIMP-3 and PAI-2 protein declined in the presence of dysregulated deltaNp63alpha, while secreted maspin protein levels remained stable. Intracellular maspin protein expression decreased in response to overexpressed deltaNp63alpha, as did intracellular PAI-2. Unlike PAI-2 and maspin, TIMP-3 protein was not detected intracellularly in control or deltaNp63alpha-overexpressing keratinocytes, supporting a solely extracellular function for TIMP-3. Electrophoretic mobility shift assays using a p53/p63 consensus DNA binding sequence from the maspin promoter revealed binding of an endogenous transcription factor(s) to the consensus sequence in normal keratinocytes that was disrupted by overexpressed deltaNp63alpha. This binding was also interrupted by the addition of a p73 antibody, but not antibodies to p63 or p53, and was absent in samples derived from p73(-/-) keratinocytes, confirming p73 as a constituent of the endogenous transcription factor complex. These data suggest protease inhibitors as novel targets of dysregulated deltaNp63alpha in cancer pathogenesis. Keratinocytes were transduced with adenoviruses encoding deltaNp63alpha. Keratinocytes were either maintained in low calcium conditions (0.05 mM for 24 hours) (n=6) or high calcium conditions (0.12 mM for 24 hours) (n=6). Control samples consisted of keratinocytes transduced with adenoviruses encoding beta-galactosidase also treated with low calcium (n=6) and high calcium (n=6) conditions. Twelve technical repeat microarray experiments were conducted, pairing high-calcium deltaNp63alpha samples with high-calcium beta-galactosidase samples (n=6) and low-calcium deltaNp63alpha samples with low-calcium beta-galactosidase samples (n=6). Six of the technical repeats were conducted as reverse-fluoro experiments.

Project description:BACKGROUND: The molecular mechanisms resulting in the establishment of regionalized gene expression in the human epididymis involve numerous and complex regulatory elements that have not yet been fully elucidated. Interestingly, more than 200 microRNAs (miRNAs) have been identified in the human epididymis that could be involved in the regulation of mRNA stability and post-transcriptionnal expression in this organ. METHODS: Using a global miRNA microarray approach, we investigated the correlation between the miRNA signature and the gene expression profile found in three distinct regions (caput, corpus and cauda) of human epididymides from 3 donors. In silico prediction of transcript miRNA targets was performed in silico using TargetScan and Miranda software’s. To experimentally verify some of these data, FHCE1 immortalized epididymal cell lines were cotransfected with mimics microRNAs and plasmid constructs containing the 3’UTR of target genes downstream of the luciferase gene. RESULTS: We identified 35 miRNAs differentially expressed between the different segments of the epididymis (fold change > 2, P < 0.01). Among these miRNAs, miR-890, miR-892a, miR-892b, miR-891a, miR-891b belonging to the same cluster located on the X chromosome and specifically expressed in epididymal tissues, are significantly more expressed in the corpus and cauda regions compared to the caput. Interestingly, a strong negative correlation (r= -0,89, P <0.001) was found between the pattern of expression of miR-892b and its potential mRNA target Esrrg (Estrogen Related Receptor Gamma), with miR-145 and Cldn10 mRNA (r= -0,92, P<0.001) and with miR-145 and Cftr mRNA (r= -0,69, P<0.05). We confirmed that miR-145 and miR-892b inhibit the expression of the luciferase reporter via Cldn10 and Esrrg 3’ UTRs respectively, whereas miR-145 does not affect the expression of luciferase after its co-transfection with the plasmid containing the Cftr 3’UTR. CONCLUSION: Overall, our study shows that the expression of miRNAs is segmented along the different regions of the human epididymal duct and correlates with the pattern of target gene expression in these regions. Therefore, epididymal miRNAs may be in charge of the maintenance of gene expression profile in the epididymis that dictate segment-specific secretion of proteins and establish physiological compartments that directly or indirectly affect sperm maturation and fertility. Normal human epididymides from three donors of 26–50 years of age, were collected and dissected into 3 anatomical regions (caput, corpus and cauda).A cross-comparison between the miRNA signature found in different segments was performed using GeneChip miRNA Array 1.0 (Affimetrix, Santa Clara, CA).

Dataset Information

MicroRNA expression in Sézary syndrome: Identification, function and diagnostic potential.

Publications

MicroRNA expression in Sezary syndrome: identification, function, and diagnostic potential.

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