Kaposi's sarcoma-associated herpesvirus (KSHV) is the etiologic agent of Kaposi's sarcoma (KS). In sub-Saharan Africa, the high prevalence of both HIV-1 and KSHV has made KS a leading cancer in the region, associated with poor prognosis and high mortality due to late medical presentation and advanced disease stages. A better understanding of the cellular and viral transcriptome profiles during neoplastic growth will aid in the definition of biomarkers and cellular functions associated with KS tumorigenesis and progression. Our approach is to examine the transcriptome profile in actual KS lesions versus non-cancer tissues from the same individual for a total of four male African epidemic KS patients. These patients have undetectable HIV-1 plasma viral load after successful anti-retroviral therapy. Our results capture the cellular complexity of in vivo lesion environment and provide a marked contrast to those derived from in vitro monoculture models. The findings demonstrate that latency and immune modulation related functions dominate the viral gene expression pattern. Moreover, KSHV significantly affected the cellular transcriptome profile with genes involved in lipid and glucose metabolism disorder pathways being the most substantially dysregulated. Despite the implied infiltration of immune cells into the lesions as predicted by CIBERSORT, KS tumor continued to progress, suggesting immunological dysfunction in these KS patients despite control of HIV-1 viremia. Lastly, there is limited overlap of our in vivo dataset with in vitro studies, suggesting a limitation of in vitro KS models. Overall design: RNA-seq of Kaposi's sarcoma lesions and control tissues
RNA-Seq of Kaposi's sarcoma reveals alterations in glucose and lipid metabolism.
Specimen part, Subject
View SamplesPI3K/AKT pathway plays one of pivotal roles in breast cancer development and maintenance. PIK3CA, coding PIK3 catalytic subunit, is the oncogene which shows the high frequency of gain-of-function mutations leading to the PI3K/AKT pathway activation in breast cancer. In particular in the ER-positive breast tumors PIK3CA mutations have been observed in 30% to 40%. However, genes expressed in connection to the pathway activation in breast tumorigenesis remain largely unknown.
Gene expression profiling reveals new aspects of PIK3CA mutation in ERalpha-positive breast cancer: major implication of the Wnt signaling pathway.
Sex, Age, Specimen part
View SamplesAlternative promoters (APs) occur in >30% protein-coding genes and contribute to proteome diversity. However, large-scale analyses of AP regulation are lacking, and little is known about their potential physiopathologic significance. To better understand the transcriptomic impact of estrogens, which play a major role in breast cancer, we analyzed gene and AP regulation by estradiol in MCF7 cells using pan-genomic exon arrays. We thereby identified novel estrogen-regulated genes, and determined the regulation of AP-encoded transcripts in 150 regulated genes. In <30% cases, APs were regulated in a similar manner by estradiol, while in >70% cases, they were regulated differentially. The patterns of AP regulation correlated with the patterns of estrogen receptor (ER) and CCCTC-binding factor (CTCF) binding sites at regulated gene loci. Interestingly, among genes with differentially regulated APs, we identified cases where estradiol regulated APs in an opposite manner, sometimes without affecting global gene expression levels. This promoter switch was mediated by the DDX5/DDX17 family of ER coregulators. Finally, genes with differentially regulated promoters were preferentially involved in specific processes (e.g., cell structure and motility, and cell cycle). We show in particular that isoforms encoded by the NET1 gene APs, which are inversely regulated by estradiol, play distinct roles in cell adhesion and cell cycle regulation, and that their expression is differentially associated with prognosis in ER+ breast cancer. Altogether, this study identifies the patterns of AP regulation in estrogen-regulated genes, demonstrates the contribution of AP-encoded isoforms to the estradiol-regulated transcriptome, as well as their physiopathologic significance in breast cancer.
Estrogen regulation and physiopathologic significance of alternative promoters in breast cancer.
Disease, Disease stage, Cell line, Time
View SamplesExpression data from NIH-3T3 cells left uninfected or infected with MCMV for 2, 4 or 6h on total RNA as well as newly transcribed RNA labeled for 1-2, 3-4, and 5-6hpi. For newly transcribed RNA, the isolated RNA was labeled for 1h and separated from total cellular RNA following Trizol RNA preparation and thiol-specific biotinylation. We used microarrays to analyze the effects of MCMV infection in total and newly transcribed RNA.
Real-time transcriptional profiling of cellular and viral gene expression during lytic cytomegalovirus infection.
Disease, Cell line, Time
View SamplesThe lungs are a frequent target of metastatic breast cancer cells, but the underlying molecular mechanisms are unclear. All existing data were obtained either using statistical association between gene expression measurements found in primary tumors and clinical outcome, or using experimentally derived signatures from mouse tumor models. Here, we describe a distinct approach that consists to utilize tissue surgically resected from lung metastatic lesions and compare their gene expression profiles with those from non-pulmonary sites, all coming from breast cancer patients.
A six-gene signature predicting breast cancer lung metastasis.
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View SamplesBackground: Recently a 76-gene prognostic signature able to predict distant metastases in lymph node-negative (N-) breast cancer patients was reported. The aims of this study conducted by TRANSBIG were to independently validate these results and to compare the outcome with clinical risk assessment. Materials and Methods: Gene expression profiling of frozen samples from 198 N- systemically untreated patients was performed at the Bordet Institute, blinded to clinical data and independent of Veridex. Genomic risk was defined by Veridex, blinded to clinical data. Survival analyses, done by an independent statistician, were performed with the genomic risk and adjusted for the clinical risk, defined by Adjuvant!Online. Results: The actual 5- and 10-year time to distant metastasis (TDM) were 98% (88%-100%) and 94% (83%-98%) respectively for the good profile group and 76% (68%- 82%) and 73% (65%-79%) for the poor profile group. The actual 5- and 10-year overall survival (OS) were 98% (88%-100%) and 87% (73%-94%) respectively for the good profile group and 84% (77%-89%) and 72% (63%-78%) for the poor profile group. We observed a strong time-dependency of this signature, leading to an adjusted HR of 13.58 (1.85-99.63) and 8.20 (1.10-60.90) at 5 years, and 5.11 (1.57-16.67) and 2.55 (1.07-6.10) at 10 years for TDM and OS respectively. Conclusion: This independent validation confirmed the performance of the 76-gene signature and adds to the growing evidence that gene expression signatures are of clinical relevance, especially for identifying patients at high risk of early distant metastases.
Strong time dependence of the 76-gene prognostic signature for node-negative breast cancer patients in the TRANSBIG multicenter independent validation series.
Age, Disease stage
View SamplesCells producing adrenalin are largely derived from nerve-associated Schwann cell precursors via an intermediate progenitor “bridge” cell. We demonstrate that large numbers of chromaffin cells arise from peripheral glial stem cells, termed Schwann cell precursors (SCPs) Overall design: SCPs migrate along the visceral motor nerve to the vicinity of the forming adrenal gland where they detach from the nerve and form post-synaptic neuroendocrine chromaffin cells. An intricate molecular logic drives two sequential phases of gene expression, one unique for a distinct transient cellular state and another for cell-type specification. Subsequently, these programs downregulate SCP- and upregulate chromaffin-cell-gene networks. The adrenal medulla forms through limited cell expansion and requires the recruitment of numerous SCPs. Thus, peripheral nerves serve as a stem cell niche for neuroendocrine system development.
RNA velocity of single cells.
Specimen part, Subject
View SamplesHek293 cells were metabolically labelled using 4-thiouracil as described in (Schwalb et al, Science. 2016 Jun 3;352(6290):1225-8) but without fragmentation, and then bulk RNA was prepared for sequencing using the STRT method (Islam et al, Genome Res. 2011 Jul;21(7):1160-7). Samples were incubated in duplicate for 5, 15 and 30 minutes and included an unlabeled control representing the steady-state expression state. Overall design: 2 samples each of 4 incubation times, 2 cDNA preparations, 2 tagmentation replicates, and 2 biological replicates
RNA velocity of single cells.
Cell line, Subject
View SamplesCholecystokinin (CCK) is a satiety hormone produced by discrete enteroendocrine cells scattered among absorptive cells of the small intestine. CCK is released into blood following a meal; however, the mechanisms inducing hormone secretion are largely unknown. Ingested fat is the major stimulant of CCK secretion. We recently identified a novel member of the lipoprotein remnant receptor family known as immunoglobulin-like domain containing receptor 1 (ILDR1) in intestinal CCK cells and postulated that this receptor conveyed the signal for fat-stimulated CCK secretion. In the intestine, ILDR1 is expressed exclusively in CCK cells. Orogastric administration of fatty acids elevated blood levels of CCK in wild type but not ILDR1-deficient mice, although the CCK secretory response to trypsin inhibitor was retained. The uptake of fluorescently labeled lipoproteins in ILDR1-transfected CHO cells and release of CCK from isolated intestinal cells required a unique combination of fatty acid plus HDL. CCK secretion secondary to ILDR1 activation is associated with increased [Ca2+]i consistent with regulated hormone release. These findings demonstrate that ILDR1 regulates CCK release through a mechanism dependent on fatty acids and lipoproteins and that absorbed fatty acids regulate gastrointestinal hormone secretion.
Immunoglobulin-like domain containing receptor 1 mediates fat-stimulated cholecystokinin secretion.
Specimen part
View SamplesChoroid plexuses (CP) develop early during development. They form a barrier between the blood and the cerebrospinal fluid, and fulfill important protective and nutritive functions. We used Affymetrix microarrays to assess whether CP of the lateral ventricles (LVCP) have similar functions in developing and adult brain. We identified distinct families of protective and transport genes and found that most of these genes were already well expressed during development.
Developmental changes in the transcriptome of the rat choroid plexus in relation to neuroprotection.
Specimen part
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