Missense mutations in the gene for the ubiquitously expressed superoxide dismutase-1 (SOD1) are one of the causes of familial amyotrophic lateral sclerosis (ALS), the most common adult onset motor neuron disease in humans killing selectively large motor neurons. Mice and rats overexpressing mutant SOD1 develop an adult onset neurodegenerative disease with hindlimb-paralysis and subsequent death similar to the human condition. In order to analyze the effects of mutant SOD1 expression onto the most affected cell-type in ALS, a small subpopulation of spinal cord cells, we propose to use laser microdissection to isolate mouse lumbar motor neurons and to assess the changes onto the mRNA expression profile using Affymetrix GeneChips compared to control animals. While two studies applying a genomic approach on the ALS mouse models used the entire spinal cord, contributions of changes to motor neurons were masked by the inflammatory effects of mutant SOD1 and the much larger population of non-motor neuronal cells. What is therefore needed is a cell-type specific expression profile that could reveal dysregulations in the transcriptome of the affected motor neurons.
Toxicity from different SOD1 mutants dysregulates the complement system and the neuronal regenerative response in ALS motor neurons.
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MicroRNA profiling in mucosal biopsies of eosinophilic esophagitis patients pre and post treatment with steroids and relationship with mRNA targets.
Specimen part, Disease
View SamplesEosinophlic esophagitis (EoE) is increasely recognized as an antigen-drived disorder. The goal of this study is to reveal the gene expression changes in EoE before and after a successful glucocorticoid steroid treatment.
MicroRNA profiling in mucosal biopsies of eosinophilic esophagitis patients pre and post treatment with steroids and relationship with mRNA targets.
Specimen part, Disease
View SamplesTristetraprolin (TTP) is an RNA-binding protein that post-transcriptionally suppresses gene expression by delivering mRNA cargo to processing bodies (P-bodies) where the mRNA is degraded. TTP functions as a tumor suppressor in a mouse model of B cell lymphoma, and in some human malignancies low TTP expression correlates with reduced survival. Here we report important prognostic and functional roles for TTP in human prostate cancer. First, gene expression analysis of prostate tumors revealed low TTP expression correlates with patients having high-risk Gleason scores and increased biochemical recurrence. Second, in prostate cancer cells with low levels of endogenous TTP, inducible TTP expression inhibits their growth and proliferation, as well as their clonogenic growth. Third, TTP functions as a tumor suppressor in prostate cancer, as forced TTP expression markedly impairs the tumorigenic potential of prostate cancer cells in a mouse xenograft model. Finally, pathway analysis of gene expression data suggested metabolism is altered by TTP expression in prostate tumor cells, and metabolic analyses revealed that such processes are impaired by TTP, including mitochondrial respiration. Collectively, these findings suggest that TTP is an important prognostic indicator for prostate cancer, and augmenting TTP function would effectively disable the metabolism and proliferation of aggressive prostate tumors. Overall design: PC-3 cells were infected with a pRetroX-Tet-On-Advanced retrovirus and selected for by G418 resistance. Then the G418-resistant cells were secondarily infected with either a pRetroX-Tight-pPGK-tdTomato or a pRetroX-Tight-TTP-pPGK-tdTomato retrovirus and selected for by the expression of tdTomato. G418-resistant, tdTomato-positive cells were used for experiments, in triplicate for each cell type. Cells were treated with 300 ng/ml doxycycline (Dox) for 4h prior to collection. Cells infected with pRetroX-Tight-pPGK-tdTomato were used as controls.
Tristetraprolin disables prostate cancer maintenance by impairing proliferation and metabolic function.
Specimen part, Disease, Disease stage, Cell line, Subject
View SamplesMeiotic recombination is initiated by the Spo11 endonuclease, which directs DNA double strand breaks at discrete regions in the genome coined hotspots. Here we report the profiles and dynamics of histone modifications at the cores of mouse recombination hotspots in early meiotic prophase. To define the spectrum of possible regulators of histone methylation and acetylation at all stages of meiosis I, expression analyses of histone acetylases/deacetylases (HATs/HDACs) and and HMTs/HDMTs genes when comparing those expressed in spermatogonia, pre-leptotene and leptotene/zygotene versus pachytene meiotic stages.
Functional Roles of Acetylated Histone Marks at Mouse Meiotic Recombination Hot Spots.
Sex, Specimen part
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Functional Roles of Acetylated Histone Marks at Mouse Meiotic Recombination Hot Spots.
Sex, Age, Specimen part
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Tristetraprolin impairs myc-induced lymphoma and abolishes the malignant state.
Specimen part
View SamplesPatients with medulloblastoma are typically treated with a narrow range of therapies, but may experience widely divergent outcomes; 80-90% become long-term survivors while 20% develop incurable recurrence. Transcriptomic profiling has identified four subgroups with different recurrence risks, but outcomes remain variable for individual patients within each subgroup. To gain new insight into why patients with similar-appearing tumors have variable outcomes, we examined how the timing of tumor initiation effects medulloblastomas triggered by a single, common driver mutation. We genetically-engineered mice to express an oncogenic Smo allele starting early in development in the broad lineage of neural stem cells, or later, in the more committed lineage of cerebellar granule neuron progenitors. Both groups developed medulloblastomas and no other tumors. We compared medulloblastoma progression, response to therapy, gene expression profile and cellular heterogeneity, determined by single cell transcriptomic analysis (scRNA-seq). The average transcriptomic profiles of the tumors were similar. However, stem cell-triggered medulloblastomas progressed faster, contained more OLIG2-expressing tumor stem cells, and consistently showed radioresistance. In contrast, progenitor-triggered MBs progressed slower, lost stem cell character over time and were radiosensitive. Progenitor-triggered medulloblastomas also contained more diverse stromal populations, including tumor-associated macrophages, indicating that the timing of oncogenesis affected the subsequent interactions between the tumor and microenvironment. Our findings show that developmental events in tumorigenesis may be impossible to infer from transcriptomic profile, but while remaining cryptic can nevertheless influence tumor composition and the outcome of therapy. Precise understanding of medulloblastoma pathogenesis and prognosis requires supplementing transcriptomic data with biomarkers of cellular heterogeneity.
Cryptic developmental events determine medulloblastoma radiosensitivity and cellular heterogeneity without altering transcriptomic profile.
Specimen part, Treatment
View SamplesMyc oncoproteins directly regulate transcription by binding to target genes, yet this only explains a fraction of the genes affected by Myc. mRNA turnover is controlled via AU-binding proteins (AUBPs) that recognize AU-rich elements (AREs) found within many transcripts. Analyses of precancerous and malignant Myc-expressing B cells revealed that Myc regulates hundreds of ARE-containing (ARED) genes and select AUBPs. Notably, Myc directly suppresses transcription of Tristetraprolin (TTP/ZFP36), an mRNA-destabilizing AUBP, and this circuit is also operational during B lymphopoiesis and IL7 signaling. Importantly, TTP suppression is a hallmark of cancers with MYC involvement, and restoring TTP impairs Myc-induced lymphomagenesis and abolishes maintenance of the malignant state. Further, there is a selection for TTP loss in malignancy; thus, TTP functions as a tumor suppressor. Finally, Myc/TTP-directed control of select cancer-associated ARED genes is disabled during lymphomagenesis. Thus, Myc targets AUBPs to regulate ARED genes that control tumorigenesis.
Tristetraprolin impairs myc-induced lymphoma and abolishes the malignant state.
Specimen part
View SamplesMyc oncoproteins directly regulate transcription by binding to target genes, yet this only explains a fraction of the genes affected by Myc. mRNA turnover is controlled via AU-binding proteins (AUBPs) that recognize AU-rich elements (AREs) found within many transcripts. Analyses of precancerous and malignant Myc-expressing B cells revealed that Myc regulates hundreds of ARE-containing (ARED) genes and select AUBPs. Notably, Myc directly suppresses transcription of Tristetraprolin (TTP/ZFP36), an mRNA-destabilizing AUBP, and this circuit is also operational during B lymphopoiesis and IL7 signaling. Importantly, TTP suppression is a hallmark of cancers with MYC involvement, and restoring TTP impairs Myc-induced lymphomagenesis and abolishes maintenance of the malignant state. Further, there is a selection for TTP loss in malignancy; thus, TTP functions as a tumor suppressor. Finally, Myc/TTP-directed control of select cancer-associated ARED genes is disabled during lymphomagenesis. Thus, Myc targets AUBPs to regulate ARED genes that control tumorigenesis.
Tristetraprolin impairs myc-induced lymphoma and abolishes the malignant state.
Specimen part
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