The naturally occurring polyamines putrescine, spermidine or spermine are ubiquitous in all cells. Although polyamines have prominent regulatory roles in cell division and growth, precise molecular and cellular functions are not well established in vivo. In this work we have performed a microarray experiment in a polyamine mutant (delta-spe3 delta-fms1) strain to investigate the responsiveness of yeast genes to supplementation with spermidine and spermine. Expression analysis identified genes responsive to the addition of either excess spermidine (10-5 M) or spermine (10-5 M) compared to a control culture containing 10-8 M spermidine. 247 genes were up-regulated >2-fold, and 11 genes were up-regulated more than 10-fold after spermidine addition. Functional categorization of the genes showed induction of transport related genes, and genes involved in methionine, arginine, lysine, NAD and biotin biosynthesis. 268 genes were down-regulated more than 2-fold, and 6 genes were down-regulated more than 8-fold after spermidine addition. A majority of the down-regulated genes are involved in nucleic acid metabolism and various stress responses. In contrast, only few genes (18) were significantly responsive to spermine. Thus, results from global gene expression profiling demonstrate a more major role for spermidine in modulating gene expression in yeast than spermine.
Microarray studies on the genes responsive to the addition of spermidine or spermine to a Saccharomyces cerevisiae spermidine synthase mutant.
Treatment
View SamplesBackground: Epithelial-to-Mesenchymal Transition (EMT) is predicted to play a critical role in tumor progression and metastasis in Hepatocellular Carcinoma. Our goal was to elucidate a mechanism of tumor proliferation and metastasis using a novel murine model of EMT.
Epithelial-to-mesenchymal transition of murine liver tumor cells promotes invasion.
Specimen part
View SamplesPheochromocytomas, catecholamine-secreting tumors of neural crest origin, are frequently hereditary. However, the molecular basis of the majority of these tumors is unknown. We identified the transmembrane-encoding gene TMEM127 on chromosome 2q11 as a new pheochromocytoma susceptibility gene. In a cohort of 103 samples, we detected truncating germline TMEM127 mutations in approximately 30% of familial tumors and about 3% of sporadic-appearing pheochromocytomas without a known genetic cause. The wild-type allele was consistently deleted in tumor DNA, suggesting a classic mechanism of tumor suppressor gene inactivation. Pheochromocytomas with mutations in TMEM127 are transcriptionally related to tumors bearing NF1 mutations and, similarly, show hyperphosphorylation of mammalian target of rapamycin (mTOR) effector proteins. Accordingly, in vitro gain-of-function and loss-of-function analyses indicate that TMEM127 is a negative regulator of mTOR. TMEM127 dynamically associates with the endomembrane system and colocalizes with perinuclear (activated) mTOR, suggesting a subcompartmental-specific effect. Our studies identify TMEM127 as a tumor suppressor gene and validate the power of hereditary tumors to elucidate cancer pathogenesis.
Germline mutations in TMEM127 confer susceptibility to pheochromocytoma.
No sample metadata fields
View SamplesLung cancer is the leading cause of cancer related mortality worldwide, with non-small cell lung cancer (NSCLC) as the most prevalent form. Despite advances in treatment options including minimally invasive surgery, CT-guided radiation, novel chemotherapeutic regimens, and targeted therapeutics, prognosis remains dismal. Therefore, further molecular analysis of NSCLC is necessary to identify novel molecular targets that impact prognosis and the design of new-targeted therapies. In recent years, tumor “activated/reprogrammed” stromal cells that promote carcinogenesis have emerged as potential therapeutic targets. However, the contribution of stromal cells to NSCLC is poorly understood. Here, we show increased numbers of bone marrow (BM)-derived hematopoietic cells in the tumor parenchyma of NSCLC patients compared with matched adjacent non-neoplastic lung tissue. By sorting specific cellular fractions from lung cancer patients, we compared the transcriptomes of intratumoral myeloid compartments within the tumor bed with their counterparts within adjacent non-neoplastic tissue from NSCLC patients. The RNA sequencing of specific myeloid compartments (immature monocytic myeloid cells and polymorphonuclear neutrophils) identified differentially regulated genes and mRNA isoforms, which were inconspicuous in whole tumor analysis. Genes encoding secreted factors, including osteopontin (OPN), chemokine (C-C motif) ligand 7 (CCL7) and thrombospondin 1 (TSP1) were identified, which enhanced tumorigenic properties of lung cancer cells indicative of their potential as targets for therapy. This study demonstrates that analysis of homogeneous stromal populations isolated directly from fresh clinical specimens can detect important stromal genes of therapeutic value. Overall design: We sorted pure populations of the immature monocytic myeloid cells (IMMCs), neutrophils (Neu), and epithelial cells (Epi) from tumors and adjacent lung tissues of stage I-III lung adenocarcinoma patients. RNA samples (totally 17 samples) were sequenced: from tumor IMMC (n=3), Neu (n=2), Epi (n=2); from adjacent lung IMMC (n=3), Neu (n=4), Epi (n=3).
Identification of Reprogrammed Myeloid Cell Transcriptomes in NSCLC.
No sample metadata fields
View SamplesGene expression profiles of human cell (THP-1) lines exposed to a novel Daboiatoxin (DbTx) isolated from Daboia russelli russelli, and specific cytokines and inflammatory pathways involved in acute infection caused by Burkholderia pseudomallei.
Gene Microarray Analyses of Daboia russelli russelli Daboiatoxin Treatment of THP-1 Human Macrophages Infected with Burkholderia pseudomallei.
No sample metadata fields
View SamplesBreast cancer cell lines containing stable dox inducible shRNAs targeting SF3B1 were profiled by RNA sequencing. We determined the effect of gene expression and splicing changes before and after knocking down SF3B1 in cell lines with normal copy number (SF3B1neutral) or partial copy loss (SF3B1loss) cell lines Overall design: RNA profiles for SF3B1 suppression were generated from 8 breast cancer cell line pairs (-/+ dox) with no techincal replicates.
Copy-number and gene dependency analysis reveals partial copy loss of wild-type SF3B1 as a novel cancer vulnerability.
Subject
View SamplesPheochromocytomas are neural crest-derived tumors that arise from inherited or sporadic mutations in at least six independent genes: RET, VHL, NF1, and subunits B, C and D of succinate dehydrogenase (SDH). The proteins encoded by these multiple genes regulate distinct functions. To identify molecular interactions between the distinct pathways we performed expression profiling of a large cohort of pheochromocytomas. We show here a functional link between tumors with VHL mutations and those with disruption of the genes encoding for succinate dehydrogenase (SDH) subunits B (SDHB) and D (SDHD). A transcription profile of reduced oxidoreductase is detected in all three of these tumor types, together with an angiogenesis/hypoxia profile typical of VHL dysfunction. The oxidoreductase defect, not previously detected in VHL-null tumors, is explained by suppression of the SDHB protein, a component of mitochondrial complex II. The decrease in SDHB is also noted in tumors with SDHD mutations. Gain-of-function and loss-of-function analyses show that the link between hypoxia signals (via VHL) and mitochondrial signals (via SDH) is mediated by HIF1?. These findings explain the shared features of pheochromocytomas with VHL and SDH mutations and suggest an additional mechanism for increased HIF1? activity in tumors.
A HIF1alpha regulatory loop links hypoxia and mitochondrial signals in pheochromocytomas.
Specimen part
View SamplesMembers of the CUG-BP, Elav-like family (CELF) regulate alternative splicing in the heart. In MHC-CELFdelta transgenic mice, CELF splicing activity is inhibited postnatally in heart muscle via expression of a nuclear dominant negative CELF protein under an a-myosin heavy chain promoter. MHC-CELFdelta mice develop dilated cardiomyopathy characterized by alternative splicing defects, enlarged hearts, and severe contractile dysfunction. In this study, gene expression profiles in the hearts of wild type, high- and low-expressing lines of MHC-CELFdelta mice were compared using microarrays. Gene ontology and pathway analyses identified contraction and calcium signaling as the most affected processes. Network analysis revealed that the serum response factor (SRF) network is highly affected. Downstream targets of SRF were up-regulated in MHC-CELFdelta mice compared to the wild type, suggesting an increase in SRF activity. Although SRF levels remained unchanged, known inhibitors of SRF activity were down-regulated. These results suggest a role for CELF-mediated alternative splicing in the regulation of contractile gene expression, achieved in part through modulating the activity of SRF, a key cardiac transcription factor.
Gene expression analyses implicate an alternative splicing program in regulating contractile gene expression and serum response factor activity in mice.
Sex, Age, Specimen part
View SamplesDiabetes and obesity are widespread diseases with signifciant socioeconomic implications. We used three different types of human adipose tissue (epigastric, visceral, and subcutaneous) in order to determine differences in global gene expression between these adipose depots in severely obese patients.
Gene expression profiling in subcutaneous, visceral and epigastric adipose tissues of patients with extreme obesity.
Specimen part, Race
View SamplesThe mutation in the budding yeast gene PCNA, pol30-8, as well as deletion of DOT1 (dot1), encoding the only histone H3 K79 methyltransferase in budding yeast, have been implicated in telomeric silencing. To further analyze these mutants, we used microarrays to study whether either pol30-8, dot1 or the double mutant leads to changes in gene expression levels when compared to isogenic wild-type strains.
A common telomeric gene silencing assay is affected by nucleotide metabolism.
No sample metadata fields
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