The goal of this experiment was to compare the genes expressed in malignant peripheral nerve sheath tumors (MPNSTs) that arise in zebrafish as a result of homozygous mutation of the p53 gene or heterozygous mutation of several different ribosomal protein (rp) mutations. Since MPNSTs arise very rarely in wild type zebrafish, it seemed a possibility that p53 and rps may in fact be functioning in similar pathways. The tumors arising from the different mutations had been previously classified as similar by histology, thus the goal of the array experiments was to establish if any molecular signatures could be found that could delineate the p53 from the rp MPNSTs.
Loss of p53 synthesis in zebrafish tumors with ribosomal protein gene mutations.
No sample metadata fields
View SamplesSIRT1 deacetylase functions in a variety of cells and tissues to mitigate age- and disease-induced damages. However, it remains unknown if SIRT1 also acts to prevent pathological changes that accrue in motor units, and specifically alpha-motor neurons, with advancing age and during the progression of amyotrophic lateral sclerosis (ALS). Here, we show that SIRT1 expression decreases in the spinal cord of wild type mice with advancing age. Using mouse models that overexpress or inactivate SIRT1 in motor neurons, we discovered that SIRT1 prevents age-related degeneration of motor neurons' presynaptic sites at neuromuscular junctions (NMJs). We also found that increasing SIRT1 in motor neurons delays degeneration of presynaptic sites at NMJs and extends the lifespan of SOD1G93A mice. Thus, SIRT1 has a similar effect on aging and ALS-affected motor neurons, two conditions in which a remarkable number of transcripts are similarly altered in the spinal cord. These include genes involved in inflammatory and immune responses and genes with known function at synapses. These findings show that SIRT1 functions to mitigate pathological changes induced by aging and ALS, two conditions with a surprising degree of overlap in the spinal cord. Overall design: Eight replicates spinal cords from mice aged 18-24 months, eight replicates of spinal cords from mice aged 3-4 months, 3 replicates of spinal cords from ALS symptomatic mice aged 5-6 months and 3 replicates of spinal cords from wt controls aged 5-6 months.
SIRT1 deacetylase in aging-induced neuromuscular degeneration and amyotrophic lateral sclerosis.
Cell line, Subject
View SamplesAneuploidy, an incorrect chromosome number, is the leading cause of miscarriages and mental retardation in humans and is a hallmark of cancer. We examined the effects of aneuploidy on primary mouse cells by generating a series of cell lines that carry an extra copy of one of four mouse chromosomes. In all four trisomic lines proliferation was impaired and metabolic properties were altered. Immortalization, the acquisition of the ability to proliferate indefinitely, was also affected by the presence of an additional chromosome, with some chromosomes inhibiting immortalization while others accelerating the process. Our data indicate that aneuploidy decreases not only organismal but also cellular fitness and elicits traits that are shared between different aneuploid cells.
Aneuploidy affects proliferation and spontaneous immortalization in mammalian cells.
No sample metadata fields
View SamplesWe have investigated whether gene expression signatures can be used to predict inter-individual responses to DNA damaging agents
Genomic predictors of interindividual differences in response to DNA damaging agents.
No sample metadata fields
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Let-7 represses Nr6a1 and a mid-gestation developmental program in adult fibroblasts.
Specimen part
View SamplesMicroRNAs (miRNAs) are critical to proliferation, differentiation, and development. Here, we characterize gene expression in murine Dicer-null adult mesenchymal stem cell lines, a fibroblast cell type. Loss of Dicer leads to de-repression of let-7 targets at levels that exceed 10-100 fold with increases in transcription. Direct and indirect targets of this miRNA belong to a mid-gestation embryonic program that encompasses known oncofetal genes as well as oncogenes not previously associated with an embryonic state. Surprisingly, this mid-gestation program represents a distinct period that occurs between the pluripotent state of the inner cell mass at embryonic day 3.5 and the induction of let-7, upon differentiation, at embryonic day 10.5. Within this mid-gestation program, we characterize the let-7 target Nr6a1, an embryonic transcriptional repressor that regulates gene expression in adult fibroblasts following miRNA loss. In total, let-7 is required for the continual suppression of embryonic gene expression in adult cells, a mechanism that may underlie its tumor suppressive function. Overall design: mRNAs from adult mesenchymal stem cells (immortalized monoclonal lines of murine MSCs) with and without Dicer (WT: Dicer f/f, KO: Dicer -/-), were analyzed. WT and KO cells were transfected with a nontargeting control siRNA. KO cells were separately transfected with a synthetic let-7g siRNA duplex, or an siRNA targeting Nr6a1.
Let-7 represses Nr6a1 and a mid-gestation developmental program in adult fibroblasts.
Specimen part, Cell line, Subject
View SamplesMicroRNAs (miRNAs) are critical to proliferation, differentiation, and development. Here, we characterize gene expression in murine Dicer-null adult mesenchymal stem cell lines, a fibroblast cell type. Loss of Dicer leads to de-repression of let-7 targets at levels that exceed 10-100 fold with increases in transcription. Direct and indirect targets of this miRNA belong to a mid-gestation embryonic program that encompasses known oncofetal genes as well as oncogenes not previously associated with an embryonic state. Surprisingly, this mid-gestation program represents a distinct period that occurs between the pluripotent state of the inner cell mass at embryonic day 3.5 and the induction of let-7, upon differentiation, at embryonic day 10.5. Within this mid-gestation program, we characterize the let-7 target Nr6a1, an embryonic transcriptional repressor that regulates gene expression in adult fibroblasts following miRNA loss. In total, let-7 is required for the continual suppression of embryonic gene expression in adult cells, a mechanism that may underlie its tumor suppressive function.
Let-7 represses Nr6a1 and a mid-gestation developmental program in adult fibroblasts.
Specimen part
View SamplesProtein 4.1B is a 4.1/ezrin/radixin/moesin (FERM) domain-containing protein whose expression is frequently lost in a variety of human tumors, including meningiomas, non-small-cell lung cancers and breast carcinomas. However, its potential tumor suppressive function under in vivo conditions remains to be validated. In a screen for genes involved with prostate cancer metastasis, we found that 4.1B expression is reduced in highly metastatic tumors. Downregulation of 4.1B increased the metastatic propensity of poorly metastatic cells in an orthotopic model of prostate cancer. Furthermore, 4.1B-deficient mice displayed increased susceptibility for developing aggressive, spontaneous prostate carcinomas. In both cases, enhanced tumor malignancy was associated with reduced apoptosis. As expression of Protein 4.1B is frequently downregulated in human clinical prostate cancer, as well as in a spectrum of other tumor types, these results suggest a more general role for Protein 4.1B as a negative regulator of cancer progression to metastatic disease.
Protein 4.1B suppresses prostate cancer progression and metastasis.
No sample metadata fields
View SamplesMicroRNAs (miRNAs) are critical to proliferation, differentiation, and development. Here, we characterize gene expression in murine Dicer-null adult mesenchymal stem cell lines, a fibroblast cell type. Loss of Dicer leads to de-repression of let-7 targets at levels that exceed 10-100 fold with increases in transcription. Direct and indirect targets of this miRNA belong to a mid-gestation embryonic program that encompasses known oncofetal genes as well as oncogenes not previously associated with an embryonic state. Surprisingly, this mid-gestation program represents a distinct period that occurs between the pluripotent state of the inner cell mass at embryonic day 3.5 and the induction of let-7, upon differentiation, at embryonic day 10.5. Within this mid-gestation program, we characterize the let-7 target Nr6a1, an embryonic transcriptional repressor that regulates gene expression in adult fibroblasts following miRNA loss. In total, let-7 is required for the continual suppression of embryonic gene expression in adult cells, a mechanism that may underlie its tumor suppressive function. Overall design: mRNAs from Flag-HA-NR6A1-overexpressing Dicer wild-type adult mesenchymal stem cells (immortalized monoclonal lines of murine MSCs) and vector-only Dicer WT MSCs were analyzed.
Let-7 represses Nr6a1 and a mid-gestation developmental program in adult fibroblasts.
Specimen part, Cell line, Subject
View SamplesMicroRNAs (miRNAs) are critical to proliferation, differentiation, and development. Here, we characterize gene expression in murine Dicer-null adult mesenchymal stem cell lines, a fibroblast cell type. Loss of Dicer leads to de-repression of let-7 targets at levels that exceed 10-100 fold with increases in transcription. Direct and indirect targets of this miRNA belong to a mid-gestation embryonic program that encompasses known oncofetal genes as well as oncogenes not previously associated with an embryonic state. Surprisingly, this mid-gestation program represents a distinct period that occurs between the pluripotent state of the inner cell mass at embryonic day 3.5 and the induction of let-7, upon differentiation, at embryonic day 10.5. Within this mid-gestation program, we characterize the let-7 target Nr6a1, an embryonic transcriptional repressor that regulates gene expression in adult fibroblasts following miRNA loss. In total, let-7 is required for the continual suppression of embryonic gene expression in adult cells, a mechanism that may underlie its tumor suppressive function. Overall design: Small RNAs from adult mesenchymal stem cells (immortalized clonal lines of murine MSCs) with and without Dicer (Dicer f/f, Dicer -/-) were analyzed.
Let-7 represses Nr6a1 and a mid-gestation developmental program in adult fibroblasts.
Specimen part, Cell line
View Samples