Filtered selection coupled with support vector machines generate functionally relevant prediction model for colorectal cancer. In this study, we built a model that uses Support Vector Machine (SVM) to classify cancer and normal samples using Affymetrix exon microarray data obtained from 90 samples of 48 patients diagnosed with CRC. From the 22,011 genes, we selected the 20, 30, 50, 100, 200, 300 and 500 genes most relevant to CRC using the Minimum-RedundancyMaximum-Relevance (mRMR) technique. With these gene sets, an SVM model was designed using four different kernel types (linear, polynomial, radial basis function and sigmoid).
Filtered selection coupled with support vector machines generate a functionally relevant prediction model for colorectal cancer.
Sex, Age, Specimen part, Disease stage
View SamplesThe molecular mechanisms by which individuals subjected to environmental heat stress either adapt or develop heat-related complications are not well understood. We analysed the changes in blood mononuclear gene expression patterns in human volunteers exposed to an extreme heat in a sauna (temperature of 78 6 C).
A Model of Exposure to Extreme Environmental Heat Uncovers the Human Transcriptome to Heat Stress.
Sex, Age, Specimen part, Treatment, Subject, Time
View SamplesTranscriptome analysis following Bcl6 induction (24h doxycycline) in mouse ES-cell-derived cortical progenitors (differentiation day 12) shows that Bcl6 promotes a neurogenic transcription program and represses selective genes of the main proliferative pathways. Overall design: RNA-seq screen for Bcl6-elicited gene expression changes in in vitro cortical progenitors (n=4)
Cortical Neurogenesis Requires Bcl6-Mediated Transcriptional Repression of Multiple Self-Renewal-Promoting Extrinsic Pathways.
Treatment, Subject
View SamplesRationale: Interstitial fibrosis and tubular atrophy (IFTA) is found in ~25% of 1-year biopsies post-transplant(1, 2). It correlates with decreased graft survival when histological evidence of inflammation is present.(3-5) Identifying the etiology of IFTA is important because longterm graft survival has not changed as expected given improved therapies and a dramatically reduced incidence of acute rejection.(6-8) Methods: Gene expression profiles of 234 samples were obtained with matching clinical and outcome data (7 transplant centers). 81 IFTA samples were divided into subphenotypes by the degree of inflammation on histology: IFTA with acute rejection (AR), IFTA with inflammation and IFTA without inflammation. Samples with AR (n=54) and normally functioning transplants (TX; n=99) were used in comparisons. Conclusions: Gene expression profiling of all IFTA phenotypes were strongly enriched for cAR gene dysregulation pathways, including IFTA samples without histological evidence of inflammation. Thus, by molecular profiling we demonstrate that most IFTA samples have ongoing immune-mediated injury or chronic rejection that is more sensitively detected by gene expression profiling. We also found that the relative expression of AR-affiliated genes correlated with future graft loss in IFTA samples without inflammation. We conclude that undetected and/or undertreated immune rejection is leading to IFTA and graft failure.
Gene Expression in Biopsies of Acute Rejection and Interstitial Fibrosis/Tubular Atrophy Reveals Highly Shared Mechanisms That Correlate With Worse Long-Term Outcomes.
Specimen part, Disease, Disease stage
View SamplesThe ability for cut tissues to join together and form a chimeric organism is a remarkable property of many plants, however, grafting is poorly characterized at the molecular level. To better understand this process we monitored genome-wide temporal and spatial gene expression changes in grafted Arabidopsis thaliana hypocotyls. Tissues above and below the graft rapidly developed an asymmetry such that many genes were more highly expressed on one side than the other. This asymmetry correlated with sugar responsive genes and we observed an accumulation of starch above the graft that decreased along with asymmetry once the sugar-transporting vascular tissues reconnected. Despite the initial starvation response below the graft, many genes associated with vascular formation were rapidly activated in grafted tissues but not in cut and separated tissues indicating that a recognition mechanism activated that was independent of functional vascular connections. Auxin which is transported cell-to-cell, had a rapidly elevated response that was symmetric, suggesting that auxin was perceived by the root within hours of tissue attachment to activate the vascular regeneration process. A subset of genes were expressed only in grafted tissues, indicating that wound healing proceeded via different mechanisms depending on the presence or absence of adjoining tissues. Such a recognition process could have broader relevance for tissue regeneration, inter-tissue communication and tissue fusion events. Overall design: We analyzed the poly-adenylated transcriptomes of Arabidopsis thaliana hypocotyle tissue during grafting. Our dataset contains 82 strand-specific samples, whereas each condition is represented by two biological replicates.
Transcriptome dynamics at <i>Arabidopsis</i> graft junctions reveal an intertissue recognition mechanism that activates vascular regeneration.
Subject
View SamplesMice overexpressing galectin-8 (gal-8 Tg), a secreted mammalian lectin, exhibit enhanced bone turnover and reduced bone mass, similar to cases of post-menopausal osteoporosis. Gal-8 knockout (KO) mice have increased bone mass accrual at young age, but exhibit accelerated bone loss during adulthood. These phenotypes can be attributed to gal-8-mediated increase in RANKL expression that promotes osteoclastogenesis, combined with direct inhibition of osteoblasts differentiation, evident by reduced BMP signaling, SMAD phosphorylation, and reduced expression of osteoblasts differentiation markers OSX, OCN, RUNX2, DMP-1 and ALP. Gal-8 mRNA positively correlates with the mRNA levels of osteoclastogenic markers RANKL, TRAP and CTSK in human femurs. Collectively, these findings identify gal-8 as a new physiological player in the regulation of bone mass.
Ablation of the mammalian lectin galectin-8 induces bone defects in mice.
Specimen part, Cell line, Treatment
View SamplesTo identify the activity-induced gene expression programs in inhibitory and excitatory neurons, we analyzed RNA extracted from cultured E14 mouse MGE- and CTX-derived neurons (DIV 10) after these cultures were membrane-depolarized for 0, 1 and 6 hrs with 55mM extracellular KCl. To identify the gene programs regulated in these cells by the activity-induced early-response transcription factor Npas4, we repeated the same experiment in the MGE- and CTX-cultures lacking Npas4 (Npas4-KO).
Npas4 regulates excitatory-inhibitory balance within neural circuits through cell-type-specific gene programs.
Specimen part, Treatment, Time
View SamplesDespite significant improvements in life expectancy of kidney transplant patients due to advances in surgery and immunosuppression, Chronic Allograft Nephropathy (CAN) remains a daunting problem. A complex network of cellular mechanisms in both graft and peripheral immune compartments complicates the non-invasive diagnosis of CAN, which still requires biopsy histology. This is compounded by non-immunological factors contributing to graft injury. There is a pressing need to identify and validate minimally invasive biomarkers for CAN to serve as early predictors of graft loss and as metrics for managing long-term immunosuppression.
Biomarkers for early and late stage chronic allograft nephropathy by proteogenomic profiling of peripheral blood.
No sample metadata fields
View SamplesSix DD class GABAergic neurons are generated in the embryo to synapse with ventral muscles and receive input from cholinergic neurons in the dorsal nerve cord. After hatching and toward the end of the first larval (L1) stage, DD neurons reverse polarity (i.e., synapse with dorsal muscles, receive ventral cholinergic inputs). Expression profiles were generated from DD neurons in the early L1 stage before the initiation of the remodeling program.
Transcriptional Control of Synaptic Remodeling through Regulated Expression of an Immunoglobulin Superfamily Protein.
Specimen part
View SamplesBrain inflammation, a common feature in neurodegenerative diseases, is a complex series of events, which can be detrimental and even lead to neuronal death. Nonetheless, several studies suggest that inflammatory signals are also positively influencing neural cell proliferation, survival, migration and differentiation. Recently, correlative studies suggested that astrocytes are able to dedifferentiate upon injury, and may thereby re-acquire neural stem cells (NSC) potential. However, the mechanism underlying this dedifferentiation process upon injury remains unclear. In this study, we find that during the early response of reactive gliosis, inflammation induces a conversion of mature astrocytes into neural progenitors. A TNF treatment induces the decrease of specific astrocyte markers, such as GFAP or genes related to glycogen metabolism, while a subset of these cells re-express immaturity markers, such as CD44, Musashi-1 and Oct4. Thus, TNF treatment results in the appearance of cells that exhibit a neural progenitor phenotype and are able to proliferate and differentiate into neurons and/or astrocytes.
Inflammation Promotes a Conversion of Astrocytes into Neural Progenitor Cells via NF-κB Activation.
Specimen part
View Samples