The highly conserved Epidermal Growth Factor-receptor (Egfr) pathway is required in all animals for normal development and homeostasis; consequently, aberrant Egfr signaling is implicated in a number of diseases. Genetic analysis of Drosophila melanogaster Egfr has contributed significantly to understanding this conserved pathway and has led to the discovery of new components and targets. Here we used microarray analysis of Drosophila third instar wing discs, in which Egfr signaling was perturbed, to identify new Egfr-responsive genes. Upregulated transcripts included five known targets suggesting the approach was valid. We investigated the function of 29 previously uncharacterized genes, which had pronounced responses. The Egfr pathway is important for wing-vein patterning and using reverse genetic analysis we identified five genes that showed venation defects. Three of these genes are expressed in vein primordia and all showed transcriptional changes in response to altered Egfr activity consistent with being targets of the pathway. Genetic interactions with Egfr further linked two of the genes, Sulfated (Sulf1), an endosulfatase gene, and CG4096, an ADAMTS (A Disintegrin And Metalloproteinase with ThromboSpondin motifs) gene, to the pathway. Sulf1 showed a strong genetic interaction with the neuregulin-like ligand vein (vn) and may influence binding of Vn to heparan-sulfated proteoglycans (HSPGs). Genetic evidence also shows that CG4096 functions by modulating activity of the Egfr ligands. The substrate(s) and how ligand activity is affected are unknown, but interestingly vertebrate EGF ligands are regulated by a related ADAMTS protein. We conclude Sulf1 and CG4096 are negative feedback regulators of Egfr signaling that function in the extracellular space to influence ligand activity.
New negative feedback regulators of Egfr signaling in Drosophila.
Specimen part
View SamplesMYC is a pleiotropic transcription factor that regulates numerous pathways and whose deregulation promotes cancer. Myc+/- mice have extended lifespan relative to their wild type littermates. To better understand the effects of the Myc+/- genotype on cellular processes, microarrays were performed on young (5 month) and old (24 month) Myc+/- and WT males in liver, skeletal muscle, and adipose tissues.
Reduced expression of MYC increases longevity and enhances healthspan.
Sex, Age, Specimen part
View Samplesp63 mutations have been associated with several human hereditary disorders characterized by ectodermal dysplasia such as EEC syndrome, ADULT syndrome and AEC syndrome . The location and functional effects of the mutations that underlie these syndromes reveal a striking genotype-phenotype correlation. Unlike EEC and ADULT that result from missense mutations in the DNA-binding domain of p63, AEC is solely caused by missense mutations in the SAM domain of p63. We report a study on the TAp63a isoform, the first to be expressed during development of the embryonic epithelia, and on its naturally occurring Q540L mutant derived from an AEC patient. To assess the effects of the Q540L mutation, we generated stable cell lines expressing TAp63a wt, DeltaNp63 alpha or the TAp63 alpha-Q540L mutant protein and used them to systematically compare the cell growth regulatory activity of the mutant and wt p63 proteins and to generate, by microarray analysis, a comprehensive profile of differential gene expression. We found that the Q540L substitution impairs the transcriptional activity of TAp63a and causes misregulation of genes involved in the control of cell growth and epidermal differentiation.
The Hay Wells syndrome-derived TAp63alphaQ540L mutant has impaired transcriptional and cell growth regulatory activity.
No sample metadata fields
View SamplesLearn about the transcriptome profiling of zona glomerulosa (ZG), zona fasciculata (ZF) and aldosterone-producing adenomas (APA) in human adrenals
DACH1, a zona glomerulosa selective gene in the human adrenal, activates transforming growth factor-β signaling and suppresses aldosterone secretion.
Specimen part, Disease
View SamplesOchratoxin A gene expression profiling in liver and kidney, with time points of exposure from 7 days to 12 motnhs
A toxicogenomics approach to identify new plausible epigenetic mechanisms of ochratoxin a carcinogenicity in rat.
No sample metadata fields
View SamplesPhotoreceptor disorders are collectively known as retinal degeneration (RD), and include retinitis pigmentosa (RP), cone-rod dystrophy and age related macular degeneration (AMD). These disorders are largely genetic in origin; individual mutations in any one of >200 genes cause RD, making mutation specific therapies prohibitively expensive. A better treatment plan, particularly for late stage disease, may involve stem cell transplants into the photoreceptor or ganglion cell layers of the retina. Stem cells from young mouse retinas can be transplanted, and can form photoreceptors in adult retinas. These cells can be grown in tissue culture, but can no longer form photoreceptors. We have used microarrays to investigate differences in gene expression between cultured retinal progenitor cells (RPCs) that have lost photoreceptor potential, postnatal day 1 (pn1) retinas and the postnatal day 5 (pn5) retinas that contain transplantable photoreceptors. We have also compared FACS sorted Rho-eGFP expressing rod photoreceptors from pn5 retinas with Rho-eGFP negative cells from the same retinas. We have identified over 300 genes upregulated in rod photoreceptor development in multiple comparisons, 37 of which have been previously identified as causative of retinal disease when mutated. It is anticipated that this research should bring us closer to growing photoreceptors in culture and therefore better treatments for RD. This dataset is also a resource for those seeking to identify novel retinopathy genes in RD patients.
Gene expression changes during retinal development and rod specification.
No sample metadata fields
View SamplesProgestins have long been used clinically for the treatment of endometrial cancers, however, the response rates to progestin therapy vary and the molecular mechanisms behind progestin insensitivity are poorly understood. We hypothesized that in PTEN mutated endometrial cancers, hyperactive Akt signaling downregulates Progesterone Receptor B (PRB) transcriptional activity, leading to overall impaired progestin responses. We report that knockdown of Akt is sufficient to upregulate a subset of PRB target genes.
Akt regulates progesterone receptor B-dependent transcription and angiogenesis in endometrial cancer cells.
Specimen part, Cell line
View SamplesBoth microRNAs and alternative pre-mRNA splicing have been implicated in the development of the nervous system (NS), but functional interactions between these two pathways are poorly understood. We demonstrate that the neuron-specific microRNA miR-124a directly targets PTBP1/PTB/hnRNPI mRNA, which encodes a global repressor of alternative pre-mRNA splicing in non-neuronal cells. Among the targets of PTBP1 is a critical cassette exon in the pre-mRNA of PTBP2/nPTB/brPTB, an NS-enriched PTBP1 homolog. When this exon is skipped, PTBP2 mRNA is subject to nonsense-mediated decay. During neuronal differentiation, miR-124a reduces PTBP1 levels leading to the accumulation of correctly spliced PTBP2 mRNA and a dramatic increase in PTBP2 protein. These events culminate in the transition from non-NS to NS-specific alternative splicing patterns. We also present evidence that miR-124a plays a key role in the differentiation of progenitor cells to mature neurons. Thus, miR-124a promotes NS development at least in part by regulating an intricate network of NS-specific alternative splicing.
The MicroRNA miR-124 promotes neuronal differentiation by triggering brain-specific alternative pre-mRNA splicing.
No sample metadata fields
View SamplesHeirarchical development of B-cells involves the induction and supression of large sets of genes that provide the basis for differentiation and, ultimately, antibody production.
Signatures of murine B-cell development implicate Yy1 as a regulator of the germinal center-specific program.
Specimen part
View SamplesMYC is a major oncogenic driver of Multiple Myeloma (MM) and yet almost no therapeutic agents exist that target MYC in MM. Here we report that the let-7 biogenesis inhibitor LIN28B correlates with MYC expression in MM and is associated with adverse outcome. We also demonstrate that the LIN28B/let-7 axis modulates the expression of MYC, itself a let-7 target. Further, perturbation of the axis regulates the proliferation of MM cells in vivo in a xenograft tumor model. RNA sequencing and gene set enrichment analyses of CRISPR-engineered cells further suggest that the LIN28/let-7 axis regulates MYC and cell cycle pathways in MM. We provide proof-of-principle for therapeutic regulation of MYC through let-7 with an LNA-GapmeR containing a let-7b mimic in vivo, demonstrating that high levels of let-7 expression repress tumor growth by regulating MYC expression. These findings reveal a novel mechanism of therapeutic targeting of MYC through the LIN28B/let-7 axis in MM that may impact other MYC dependent cancers as well. Overall design: RNA sequencing of MOLP-8 cells transduced with lentiCRISPRv2 scrambled control or containing a sgRNA against LIN28B. Both control and LIN28B KO cells were sequenced in triplicate.
The LIN28B/let-7 axis is a novel therapeutic pathway in multiple myeloma.
No sample metadata fields
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