We are using the ACI rat model of 17beta-estradiol induced mammary cancer to define the mechanisms through which estrogens contribute to breast cancer development; identify and functionally characterize the genetic variants that determine susceptibility; and define the hormone-gene-environment interactions that influence development of mammary cancer in this physiologically relevant rat model. Female ACI rats are uniquely susceptible to development of mammary cancer when treated continuously with physiologic levels of 17beta-estradiol. Induction of mammary cancer in female ACI rats occurs through a mechanism that is largely dependent upon estrogen receptor-alpha. Interval mapping analyses of progeny generated in intercrosses between susceptible ACI rats and resistant Brown Norway (BN) rats revealed seven quantitative trait loci (QTL), designated Emca3 (Estrogen-induced mammary cancer) through Emca9, each of which harbors one or more genetic determinants of mammary cancer susceptibility. Genes that reside within Emca8 on RNO5 and were differentially expressed between 17beta-estradiol treated ACI and ACI.BN-Emca8 congenic rats were identified as Emca8 candidates.
Mapping of three genetic determinants of susceptibility to estrogen-induced mammary cancer within the Emca8 locus on rat chromosome 5.
Sex, Age, Specimen part
View Samplesaffy_popsec_nancy_roots_poplar - This project aims to identify genes of interest for water deficit acclimation and/or adaptation in a tree species: poplar. We look for genes and gene expression networks related to drought stress. We intend to analyse the transcriptome in root apices, in two genotypes, Carpaccio and Soligo, at various stages and intensities of stress. Root apex is the location of root elongation and these analyses intend to identify genes involved in the control of cell expansion and thus of root elongation. Indeed, root growth maintenance in response to water shortage contributes to plant tolerance to water deficit. The comparison between medium and severe stress intensities and between early and long term stresses will power the selection of genes of interest. The co-analysis of two genotypes of contrasted tolerance to water deficit should help to better discriminate genes presenting a potential adaptative character from genes responding passively to the constraint.-Two poplar clones, Soligo (S) and Carpacio (C) were submitted to 4 treatments: control, mild water deficit, moderate water deficit (12-day long for both) and early-drought stress (about 36-h long). Growth and physiology was characterised on a batch of plants and samples collected on another batch of plants. Four to eight root apices (1cm-long) were collected on each individual tree. Total RNAs were extracted from all roots for each tree individually. Two pools of 3 (or 2) individuals were made using equimolar ratio. A pool is considered as one biological replicate and corresponds to one Affymetrix slide. The two biological replicates originate from the same experiment.
Comparative transcriptomics of drought responses in Populus: a meta-analysis of genome-wide expression profiling in mature leaves and root apices across two genotypes.
Specimen part
View Samplesaffy_popsec_nancy_leaves_poplar - affy_popsec_nancy_leaves2007_poplar - This project aims to identify genes of interest for water deficit acclimation and/or adaptation in a tree species: poplar. We look for genes and gene expression networks related to drought stress. We intend to analyse the transcriptome in mature leaves, in two genotypes, Carpaccio and Soligo, at various stages and intensities of stress. During water deficit, leaves underwent many processes aiming to maintain cells integrity such as water status adjustment through osmoregulation or cell detoxication. These analyses intend to identify genes of interest involved in homeostasis maintenance. The comparison between medium and severe stress intensities and between early and long term stresses will power the selection of genes of interest. The co-analysis of two genotypes of contrasted tolerance to water deficit should help to discriminate genes presenting a potential adaptative character from genes responding passively to the constraint-In a first experiment, two poplar clones, Soligo (S) and Carpacio (C) were submitted to 4 treatments: control, mild water deficit, moderate water deficit (12-day long for both) and early-drought stress (about 36-h long). Growth and physiology was characterised on a batch of plants and samples collected on another batch of plants. In a second experiment, two poplar clones, Soligo (S) and Carpacio (C) were submitted to 2 treatments: control and moderate water deficit. Mature leaves were collected and total RNAs were extracted from each tree individually. Two pools of 3 (or 2) individuals were made using equimolar ratio. A pool is considered as one biological replicate and corresponds to one Affimetrix slide.
Comparative transcriptomics of drought responses in Populus: a meta-analysis of genome-wide expression profiling in mature leaves and root apices across two genotypes.
Specimen part
View Samplesaffy_popsec_nancy_leaves_poplar - affy_popsec_nancy_leaves2008_poplar - This project aims to identify genes of interest for water deficit acclimation and/or adaptation in a tree species: poplar. We look for genes and gene expression networks related to drought stress. We intend to analyse the transcriptome in mature leaves, in two genotypes, Carpaccio and Soligo, at various stages and intensities of stress. During water deficit, leaves underwent many processes aiming to maintain cells integrity such as water status adjustment through osmoregulation or cell detoxication. These analyses intend to identify genes of interest involved in homeostasis maintenance. The comparison between medium and severe stress intensities and between early and long term stresses will power the selection of genes of interest. The co-analysis of two genotypes of contrasted tolerance to water deficit should help to discriminate genes presenting a potential adaptative character from genes responding passively to the constraint-In a first experiment, two poplar clones, Soligo (S) and Carpacio (C) were submitted to 4 treatments: control, mild water deficit, moderate water deficit (12-day long for both) and early-drought stress (about 36-h long). Growth and physiology was characterised on a batch of plants and samples collected on another batch of plants. In a second experiment, two poplar clones, Soligo (S) and Carpacio (C) were submitted to 2 treatments: control and moderate water deficit. Mature leaves were collected and total RNAs were extracted from each tree individually. Two pools of 3 (or 2) individuals were made using equimolar ratio. A pool is considered as one biological replicate and corresponds to one Affymetrix slide.
Comparative transcriptomics of drought responses in Populus: a meta-analysis of genome-wide expression profiling in mature leaves and root apices across two genotypes.
Specimen part
View Samplesaffy_genomic_poplar - affy_genomic_poplar - The project aims to identify genes of interest for water deficit acclimation in poplar. We look for genes and gene expression networks related to drought stress in two hybrid cultivars, differing in their drought tolerance in field. Affymetrix poplar genome array was designed on several Populus species. In order to deal with comparative approaches, we checked the convenience of the array by hybridizing genomic DNA of the two hybrid cultivars (Populus deltoides Populus nigra, namely cv Carpaccio and cv Soligo). This point is important as transcript sequence might have diverged in the two genomes (Fossati et al, 2005), which could lead to absence of hybridization without physiological meaning. -Two poplar cultivars, Soligo (S) and Carpacio (C) were grown in controlled conditions. Mature leaves were collected and genomic DNA was extracted from leaves in CTAB buffer. gDNA was fragmented with DNAse1. DNA fragments were labelled with Biotin N6-ddATP and hybridized on Affymetrix poplar genome array. Two technical replicates per genotype were performed.
Comparative transcriptomics of drought responses in Populus: a meta-analysis of genome-wide expression profiling in mature leaves and root apices across two genotypes.
Specimen part
View SamplesThere is increasing evidence that breast and other cancers originate from and are maintained by a small fraction of stem/progenitor cells with self-renewal properties. Whether such cancer stem/progenitor cells originate from normal stem cells based on initiation of a de novo stem cell program, by reprogramming of a more differentiated cell type by oncogenic insults or both remains unresolved. A major hurdle in addressing these issues is lack of immortal human stem/progenitor cells that can be deliberately manipulated in vitro. We present evidence that normal and human telomerase reverse transcriptase (hTERT)-immortalized human mammary epithelial cells (hMECs) isolated and maintained in DFCI-1 medium retain a fraction with progenitor cell properties. These cells co-express basal, luminal and stem/progenitor cell markers. Clonal derivatives of progenitors co-expressing these markers fall into two distinct types: K5+/K19- (Type I) and K5+/K19+ (Type II). We show that both types of progenitor cells have self-renewal and differentiation ability. Through microarray analysis, we want to identify genes and pathways linked to human mammary epithelial stem/progenitor cell self-renewal and differentiation.
Telomerase-immortalized human mammary stem/progenitor cells with ability to self-renew and differentiate.
Sex, Specimen part
View SamplesWhole fetal livers were collected from mouse fetuses at embryonic day 14.5 (E14.5), and single-cell suspensions were prepared by successive passage through 18-, 21 and 23-gauge needles. Fetal liver cells were maintained in Dulbecco modified Eagle medium (DMEM; Invitrogen) supplemented with 10% fetal bovine serum (FBS; Invitrogen), 100 U/ml penicillin, 100g/ml streptomycin, and 50ng/ml recombinant human thrombopoietin (TPO; Peprotech). After 5 days of culture, megakaryocytes were purified using a discontinuous bovine serum albumin gradient (BSA, SigmaAldrich; 3%, 1.5%, and 0%). Total RNA was isolated with TriReagent (MRC) following manufacturers instructions, and its quality was assessed with ND1000 Nanodrop (Peqlab) and on a 1.5% agarose gel.
miR-142 orchestrates a network of actin cytoskeleton regulators during megakaryopoiesis.
Specimen part
View SamplesThe spatial and temporal control of Hox gene transcription is essential for patterning the vertebrate body axis. Although this process involves changes in histone posttranslational modifications, the existence of particular three-dimensional (3D) architectures remained to be assessed in vivo. Using high-resolution chromatin conformation capture methodology, we examined the spatial configuration of Hox clusters in embryonic mouse tissues where different Hox genes are active. When the cluster is transcriptionally inactive, Hox genes associate into a single 3D structure delimited from flanking regions. Once transcription starts, Hox clusters switch to a bimodal 3D organization where newly activated genes progressively cluster into a transcriptionally active compartment. This transition in spatial configurations coincides with the dynamics of chromatin marks, which label the progression of the gene clusters from a negative to a positive transcription status. This spatial compartmentalization may be key to process the collinear activation of these compact gene clusters.
The dynamic architecture of Hox gene clusters.
Specimen part
View SamplesBackground: The Epithelial Cell Adhesion Molecule (EpCAM) has been shown to be strongly expressed in human breast cancer and cancer stem cells and its overexpression has been supposed to support tumor progression and metastasis. However, effects of EpCAM overexpression on normal breast epithelial cells have never been studied before. Therefore, we analyzed effects of transient adenoviral overexpression of EpCAM on proliferation, migration and differentiation of primary human mammary epithelial cells (HMECs).
EpCAM overexpression prolongs proliferative capacity of primary human breast epithelial cells and supports hyperplastic growth.
Specimen part
View SamplesIntroduction: The Epithelial Cell Adhesion Molecule (EpCAM) has been shown to be strongly expressed in human breast cancer and cancer stem cells and its overexpression has been supposed to support tumor progression and metastasis. However, effects of EpCAM overexpression on normal breast epithelial cells have never been studied before. Therefore, we analyzed effects of transient adenoviral overexpression of EpCAM on proliferation, migration and differentiation of primary human mammary epithelial cells (HMECs).
EpCAM overexpression prolongs proliferative capacity of primary human breast epithelial cells and supports hyperplastic growth.
Specimen part, Subject
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