This SuperSeries is composed of the SubSeries listed below.
Mulcom: a multiple comparison statistical test for microarray data in Bioconductor.
Specimen part, Cell line, Treatment
View SamplesBackground
Mulcom: a multiple comparison statistical test for microarray data in Bioconductor.
Specimen part, Cell line, Treatment
View SamplesMitochondria are centers of metabolism and signaling whose content and function must adapt to changing cellular environments. The biological signals that initiate mitochondrial restructuring and the cellular processes that drive this adaptive response are largely obscure. To better define these systems, we performed matched quantitative genomic and proteomic analyses of mouse muscle cells as they performed mitochondrial biogenesis. We find that proteins involved in cellular iron homeostasis are highly coordinated with this process, and that depletion of cellular iron results in a rapid, dose-dependent decrease of select mitochondrial protein levels and oxidative capacity. We further show that this process is universal across a broad range of cell types and fully reversed when iron is reintroduced. Collectively, our work reveals that cellular iron is a key regulator of mitochondrial biogenesis, and provides quantitative datasets that can be leveraged to explore post-transcriptional and post-translational processes that are essential for mitochondrial adaptation.
Complementary RNA and protein profiling identifies iron as a key regulator of mitochondrial biogenesis.
Cell line, Treatment
View SamplesThe therapeutic potential of pro-resolution factors in determining the outcome of inflammatory events has gained ground over the past decade. However, the attention has been focused on the non-genomic effects of these endogenous, anti-inflammatory substances. In this study, we have focused our attention on identifying specific annexin 1 (AnxA1) protein/ALX receptor mediated gene activation, in an effort to identify down-stream genomic targets of this well-known, glucocorticoid induced, pro-resolution factor.
Downstream gene activation of the receptor ALX by the agonist annexin A1.
No sample metadata fields
View SamplesAdvanced ovarian cancers are initially responsive to chemotherapy with platinum drugs but develop drug resistance in most cases. We showed recently that hepatocyte growth factor (HGF) enhances death of human ovarian cancer cell lines treated with cisplatin (CDDP) and that this effect is mediated by the p38 mitogen-activated protein kinase. In this work, we integrated genome-wide expression profiling, in silico data survey, and functional assays to identify transcripts regulated in SK-OV-3 ovarian cancer cells made more responsive to CDDP by HGF. Using oligonucleotide microarrays, we found that HGF pretreatment changes the transcriptional response to CDDP. Quantitative reverse transcription-PCR not only validated all the 15 most differentially expressed genes but also confirmed that they were primarily modulated by the combined treatment with HGF and CDDP and reversed by suppressing p38 mitogen-activated protein kinase activity. Among the differentially expressed genes, we focused functional analysis on two regulatory subunits of the protein phosphatase 2A, which were down-modulated by HGF plus CDDP. Decrease of each subunit by RNA interference made ovarian cancer cells more responsive to CDDP, mimicking the effect of HGF. In conclusion, we show that HGF and CDDP modulate transcription in ovarian cancer cells and that this transcriptional response is involved in apoptosis regulation. We also provide the proof-of-concept that the identified genes might be targeted to either increase the efficacy of chemotherapeutics or revert chemotherapy resistance.
Genes regulated by hepatocyte growth factor as targets to sensitize ovarian cancer cells to cisplatin.
Cell line
View SamplesMalignant melanoma is a complex genetic disease and the most aggressive form of skin cancer. Melanoma progression and metastatic dissemination fundamentally relies on the process of angiogenesis. Melanomas produce an array of angiogenic modulators that mediate pathological angiogenesis. Such tumor-associated modulators arbitrate the enhanced proliferative, survival and migratory responses exhibited by endothelial cells, in the hypoxic tumor environment. The current study focuses on melanoma-induced survival of endothelial cells under hypoxic conditions. Melanoma conditioned media were capable of enabling prolonged endothelial cell survival under hypoxia, in contrast with the conditioned media derived from melanocytes, breast and pancreatic tumors. To identify the global changes in gene expression and further characterize the pro-survival pathway induced in endothelial cells, we performed microarray analysis on endothelial cells treated with melanoma conditioned medium under normoxic and hypoxic conditions.
Melanomas prevent endothelial cell death under restrictive culture conditions by signaling through AKT and p38 MAPK/ ERK-1/2 cascades.
Specimen part
View SamplesComplement inhibitor C4b-binding protein (C4BP) is synthesized in liver and pancreas and composed of 7 identical alpha chains and one unique beta chain. We showed previously that C4BP binds islet amyloid polypeptide (IAPP) and affects fibril formation in vitro. Now we found that polymeric C4BP inhibited lysis of human erythrocytes incubated with monomeric IAPP while no erythrocyte lysis was observed after incubation with preformed IAPP fibrils. In contrast, monomeric alpha chain of C4BP had significantly reduced activity. Further, addition of monomeric IAPP to a rat insulinoma cell line (INS-1) resulted in decreased cell viability, which was restored in the presence of physiological concentrations of C4BP. Accordingly, addition of C4BP rescued the ability of INS-1 cells and isolated rat islets to respond to glucose stimulation with insulin secretion, which was impaired in the presence of IAPP alone. C4BP was internalized together with IAPP into INS-1 cells and therefore we aimed to study its effect on gene expression. Pathway analyses of mRNA expression microarray data indicated that cells exposed to C4BP and IAPP in comparison to IAPP alone increased expression of genes involved in cholesterol synthesis. Depletion of cholesterol through methyl--cyclodextrin or cholesterol oxidase abolished the protective effect of C4BP on IAPP cytotoxicity of INS-1 cells. Also, inhibition of phosphoinositide 3-kinase but not NF-B had a similar effect. Taken together, one of the mechanisms by which C4BP protects beta-cells from IAPP cytotoxicity is by enhancing cholesterol synthesis.
C4b-binding Protein Protects β-Cells from Islet Amyloid Polypeptide-induced Cytotoxicity.
Specimen part, Cell line
View SamplesIn the present investigation, we have exploited the opportunity provided by neoadjuvant treatment of a group of postmenopausal women with large operable or locally advanced breast cancer (in which therapy is given with the primary tumour remaining within the breast) to take sequential biopsies of the same cancers before and after 10-14 days treatment with letrozole. RNA extracted from the biopsies has been subjected to Affymetrix microarray analysis and the data from paired biopsies interrogated to discover genes whose expression is most influenced by oestrogen deprivation.
Changes in breast cancer transcriptional profiles after treatment with the aromatase inhibitor, letrozole.
No sample metadata fields
View SamplesThis SuperSeries is composed of the SubSeries listed below.
A systems immunology approach identifies the collective impact of 5 miRs in Th2 inflammation.
No sample metadata fields
View SamplesAllergic asthma is a chronic inflammatory disease dominated by a CD4+ T helper 2 (Th2) cell signature. The immune response amplifies in self-enforcing loops, promoting Th2-driven cellular immunity and leaving the host unable to terminate inflammation. Posttranscriptional mechanisms, including miRNAs, are pivotal in maintaining immune-homeostasis. Since an altered expression of various miRNAs has been associated with T cell-driven diseases, including asthma, we hypothesized that miRNAs control mechanisms ensuring Th2 stability and maintenance in the lung. We isolated murine CD4+ Th2 cells from allergic inflamed lungs and profiled gene and microRNA expression.
A systems immunology approach identifies the collective impact of 5 miRs in Th2 inflammation.
No sample metadata fields
View Samples