The mammary gland of the lactating mouse synthesizes and secretes milk lipid equivalent to its entire body weight in a single 20 day lactation cycle, making it one of the most active lipid synthetic organs known. To test the hypothesis that multiple metabolic control points and potential regulatory mechanisms are involved in activating lipid and lactose synthesis at the onset of lactation we compared the mammary transcriptome of 130 genes involved in glucose metabolism between late pregnancy and early lactation and in response to dietary fat. We utilized data obtained from microarray analysis of mammary glands from quadruplicate FVB mice at pregnancy day 17, and lactation day 2. Diets containing 8% or 40% lipid were fed from lactation days 5 to 10 and mammary glands and livers of triplicate FVB mice prepared for microarray analysis. We also compared the metabolome obtained from magnetic resonance spectroscopy of flash frozen glands of the mammary gland at day 17 of pregnancy with that at day 2 of lactation. The results provide a global picture of the multiple metabolic strategies utilized to turn a quiescent organ into an incredibly efficient machine for massive but balanced lipid and lactose synthesis and implicate the transcription factor SREBP-1c in regulation of part of the pathway.
Metabolic regulation in the lactating mammary gland: a lipid synthesizing machine.
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View SamplesCancer incidence increases in the elderly, although the underlying reasons for this association are unknown. We show that B-progenitors in old mice exhibit profound signaling and metabolic defects, and that expression of BCR-ABL, NRASV12 and MYC reverses these fitness defects, leading to selection of oncogenically-initiated cells and leukemogenesis in old hematopoietic backgrounds. Aging is associated with increased inflammation in the BM microenvironment, and inducing inflammation in young mice phenocopies aging B-lymphopoiesis. Importantly, reducing inflammation in aged mice preserves the function of B-progenitors and prevents NRasV12-mediated oncogenesis. We conclude that chronic microenvironments in old age lead to reductions in the fitness of hematopoietic stem and progenitor cell populations. This reduced progenitor pool fitness leads to selection for cells harboring oncogenic mutations in part due to their ability to correct aging-associated functional defects.
Aging-associated inflammation promotes selection for adaptive oncogenic events in B cell progenitors.
Age, Specimen part
View SamplesIn mammals, expansion of adipose tissue mass induces accumulation of adipose tissue macrophages (ATMs). We isolated CD11c- (FB) and CD11c+ (FBC) perigonadal ATMs from SVCs of lean (C57BL/6J Lep +/+) and obese leptin-deficient (C57BL/6J Lep ob/ob) mice.
Obesity activates a program of lysosomal-dependent lipid metabolism in adipose tissue macrophages independently of classic activation.
Specimen part
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Reverse engineering a hierarchical regulatory network downstream of oncogenic KRAS.
Cell line, Treatment
View SamplesRAS mutations are highly relevant for progression and therapy response of human tumours, but the genetic network that ultimately executes the oncogenic effects is poorly understood. Here we used a reverse-engineering approach in an ovarian cancer model to reconstruct KRAS oncogene-dependent cytoplasmic and transcriptional networks from perturbation experiments based on gene silencing and pathway inhibitor treatments. We measured mRNA and protein levels in manipulated cells by microarray, RT-PCR and Western Blot analysis, respectively. The reconstructed model revealed complex interactions among the transcriptional and cytoplasmic components, some of which were confirmed by double pertubation experiments. Interestingly, the transcription factors decomposed into two hierarchically arranged groups. To validate the model predictions we analysed growth parameters and transcriptional deregulation in the KRAS-transformed epithelial cells. As predicted by the model, we found two functional groups among the selected transcription factors. The experiments thus confirmed the predicted hierarchical transcription factor regulation and showed that the hierarchy manifests itself in downstream gene expression patterns and phenotype.
Reverse engineering a hierarchical regulatory network downstream of oncogenic KRAS.
Cell line, Treatment
View SamplesLactoferrin is a highly multifunctional protein. Indeed, it is involved in many physiological functions, including regulation of iron absorption and immune responses.
A nutritional supplement containing lactoferrin stimulates the immune system, extends lifespan, and reduces amyloid <i>β</i> peptide toxicity in <i>Caenorhabditis elegans</i>.
No sample metadata fields
View SamplesRAS mutations are highly relevant for progression and therapy response of human tumours, but the genetic network that ultimately executes the oncogenic effects is poorly understood. Here we used a reverse-engineering approach in an ovarian cancer model to reconstruct KRAS oncogene-dependent cytoplasmic and transcriptional networks from perturbation experiments based on gene silencing and pathway inhibitor treatments. We measured mRNA and protein levels in manipulated cells by microarray, RT-PCR and Western Blot analysis, respectively. The reconstructed model revealed complex interactions among the transcriptional and cytoplasmic components, some of which were confirmed by double pertubation experiments. Interestingly, the transcription factors decomposed into two hierarchically arranged groups. To validate the model predictions we analysed growth parameters and transcriptional deregulation in the KRAS-transformed epithelial cells. As predicted by the model, we found two functional groups among the selected transcription factors. The experiments thus confirmed the predicted hierarchical transcription factor regulation and showed that the hierarchy manifests itself in downstream gene expression patterns and phenotype.
Reverse engineering a hierarchical regulatory network downstream of oncogenic KRAS.
Cell line, Treatment
View SamplesIn osteosarcoma patients, the development of metastases, often to the lungs, is the most frequent cause of death. To improve this situation, a deeper understanding of the molecular mechanisms governing osteosarcoma development and dissemination and the identification of novel drug targets for an improved treatment are needed. Towards this aim, we characterized osteosarcoma tissue samples compared to primary osteoblast cells using Affymetrix HG U133A microarrays.
De novo expression of EphA2 in osteosarcoma modulates activation of the mitogenic signalling pathway.
No sample metadata fields
View SamplesGoals of the study was to compare transcripional and phenotypic response of mouse intestinal organoid cultures to the PIK3CA(H1047R) and CTNNB1(stab) oncogenes. Overall design: Two biological replicates of organoids with transgenic tdTomato-Luciferase, tdTomato-PIK3CAH1047R, tdTomato-CTNNB1stab or td-Tomato-PIK3CAH1047R-CTNNB1stab were analysed by RNA-Seq By comparing 7-10 x 10E7 50bp paired end reads per library we identify transcriptional alterations in the intestinal epithelium following expression of each or both oncogenes,
Oncogenic β-catenin and PIK3CA instruct network states and cancer phenotypes in intestinal organoids.
Specimen part, Cell line, Subject
View SamplesTo investigate potential differences between strong and weak oscillators at the gene expression level we carried out a transcriptome analysis for each cell line. Our results indicate that phenotypic circadian clock differences are reflected by gene expression differences both in genes of the core network, but also in additional genes not directly associated with circadian clock functions.
Ras-mediated deregulation of the circadian clock in cancer.
Specimen part, Cell line, Time
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